CN102766010A - Process for production of propylene - Google Patents

Abstract

The present invention provides a method for producing propylene by reacting at least one of methanol and dimethyl ether with an olefin raw material having 4 or more carbon atoms in the presence of a catalyst. The method can produce propylene with a high yield using a small amount of raw material and Deterioration of the catalyst is suppressed.

Description

The preparation method of propylene

This application is a divisional application of the application with the filing date of September 20, 2007, the application number of 200780035328.5, and the title of the invention of "Preparation Method of Propylene".

technical field

The present invention relates to a method for producing propylene from a raw material mixture containing at least one of methanol and dimethyl ether and an olefin having 4 or more carbon atoms.

Background technique

As the preparation method of propylene, the steam cracking method of naphtha and ethane and the fluidized catalytic cracking method of vacuum diesel oil are usually used in the past. In recent years, the method of metathesis reaction using ethylene and 2-butene as raw materials has 4 The catalytic cracking method of olefins with more than 3 carbon atoms, and the MTO process using at least one of methanol and dimethyl ether as raw materials have also attracted much attention. On the other hand, there is also known a method for producing lower olefins from olefins having 4 or more carbon atoms and oxygen-containing compounds such as methanol (Patent Document 1).

Patent Document 1: US Patent No. 6888038

Contents of the invention

The problem to be solved by the invention

So far, a large number of methods for preparing propylene have been proposed, most of which are about reaction and purification methods, and about the method for preparing propylene with olefins with more than 4 carbon atoms and oxygen-containing compounds such as methanol as raw materials, although its The reaction itself is disclosed, but the process flow including the purification system on the downstream side of the reactor is not suggested.

Therefore, the first object of the present invention is to provide a novel and economical process for producing propylene by reacting at least one of methanol and dimethyl ether with an olefin having 4 or more carbon atoms.

On the other hand, as far as the steam cracking process flow of the mainstream preparation method of ethylene and propylene is concerned, the ratio of prepared ethylene and propylene does not change greatly, and by combining the process flow of the present invention with the steam cracking process flow, The ratio of ethylene and propylene can be varied considerably. Furthermore, since the fluids discarded in each other's processes can be effectively utilized by combining the two processes, it is expected to construct a more efficient process through its synergistic effect.

Therefore, the second object of the present invention is to provide a novel and economical process flow combining the present process flow and the steam cracking process flow.

way of solving the problem

The inventors of the present invention obtained the following findings when they studied the reaction of producing propylene by reacting at least one of methanol and dimethyl ether with an olefin having 4 or more carbon atoms.

If the amount of olefins consumed by the reaction is too much, the amount of undesirable compounds such as aromatic compounds or paraffins produced by side reactions will increase significantly, and if the amount of olefins consumed by the reaction is too small, the yield of propylene will be too low. Propylene can be obtained with high selectivity and high yield by appropriately setting reaction conditions such as temperature, pressure, partial pressure, and space velocity, and controlling the amount of olefin consumed within a specific range. When the reaction is carried out under such conditions, since a large amount of olefins having 4 or more carbon atoms which can be used as reaction raw materials is contained in the outlet fluid of the reactor, it is preferable to recycle these compounds into the reactor.

On the other hand, in the reaction of at least one of methanol and dimethyl ether with an olefin having 4 or more carbon atoms, a trace amount of aromatic compounds and paraffins are also produced and contained in the reactor outlet fluid. In particular, when a paraffin-containing raw material is used as the olefin raw material having 4 or more carbon atoms, the paraffin concentration in the reactor outlet fluid increases. Since paraffins hardly react in the reactor, when they are recycled to the reactor together with olefins having 4 or more carbon atoms, the paraffins are concentrated and accumulated in the system. Therefore, it is preferable to take out part of the fluid containing paraffins from the system. At this time, it is preferable to make the extracted fluid have a composition that can be effectively used.

In addition, when there are aromatic compounds at a specific concentration or more in the recycled olefin fluid with 4 or more carbon atoms, the reaction of these aromatic compounds with olefins with 4 or more carbon atoms, and the reaction of methanol and dimethyl ether At least one reaction with the aromatic compound becomes remarkable, and the consumption of at least one of methanol and dimethyl ether and an olefin having 4 or more carbon atoms to be supplied exceeds the necessary consumption, which is not preferable.

In addition, when the aromatic compound is supplied to the reactor, the compound formed by the reaction of the aromatic compound and the above-mentioned olefin having 4 or more carbon atoms clogs the pores of the catalyst and accelerates the deterioration of the catalyst. Aromatic compounds present in the fluid are removed from the system as much as possible to reduce the concentration of aromatic compounds in the fluid recycled to the reactor. At this time, it is still preferable that the extracted fluid has a composition that can be effectively used.

In this way, in the method for producing propylene using at least one of methanol and dimethyl ether, and olefins with 4 or more carbon atoms as raw materials, the present inventors have discovered various problems, and by constructing a process flow that can solve these problems , it is possible to suppress catalyst deterioration and produce propylene with a high yield using a small amount of raw material.

In addition, it was found that by supplying the fluid taken out from the present process to the steam cracking process and supplying the fluid from the steam cracking process to the present process, it is possible to effectively utilize cheap fluids and realize an efficient process.

Based on the above findings, the present invention has been accomplished, and the present invention includes the following points.

[1] A method for producing propylene, which is produced by contacting a raw material containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether with a catalyst in a reactor in the presence of a catalyst Propylene method, wherein,

At least a part of the aromatic compound contained in the reactor outlet effluent gas (reactor outlet gas) is taken out, and the olefin having 4 or more carbon atoms contained in the reactor outlet effluent gas (reactor outlet gas) At least a portion of is again contacted with the catalyst in the reactor.

[2] The method for producing propylene according to [1], wherein the olefin raw material having 4 or more carbon atoms contains paraffins having 4 or more carbon atoms.

[3] The method for producing propylene according to [2], wherein the paraffins include at least one of n-butane and isobutane.

[4] The method for producing propylene according to any one of [1] to [3], wherein the raw material supplied to the reactor contains butadiene.

[5] The method for producing propylene according to any one of [1] to [4], wherein the total amount of aromatic compounds contained in all raw materials supplied to the reactor is equal to the total amount of aromatic compounds contained in all raw materials The molar ratio of the total amount of olefins containing 4 or more carbon atoms is less than 0.05.

[6] The method for producing propylene according to any one of [1] to [5], wherein the above-mentioned The amount of the olefin having 4 or more carbon atoms supplied to the reactor is 0.2 to 10 in molar ratio.

[7] The method for producing propylene according to any one of [1] to [6], wherein the olefins having 4 or more carbon atoms, methanol, and dimethyl The total concentration (matrix concentration) of base ether is controlled at 20 volume % or more and 80 volume % or less.

[8] A method for producing propylene, which comprises contacting a raw material containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether with a catalyst in a reactor in the presence of a catalyst. A process for propylene consisting of a process flow comprising the following steps (1), (2) and (3A),

Step (1): At least one of methanol and dimethyl ether, the olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (D) recycled from step (3A) are supplied to the reactor, relative to the reaction The molar flow rate of olefins with 4 or more carbon atoms at the reactor inlet, and the molar flow rate of olefins with 4 or more carbon atoms at the outlet of the reactor are more than 20% and less than 90%. Under the reaction conditions, make it contact with the above catalyst, Obtain gas containing propylene, other olefins, paraffins, aromatic compounds and water from the outlet of the reactor (reactor outlet gas);

Step (2): Separating the reactor outlet gas from the above step (1) into a fluid rich in hydrocarbons with 3 or less carbon atoms, a fluid (A) rich in hydrocarbons with 4 or more carbon atoms, and a fluid rich in water the fluid;

Step (3A): separating at least a part of fluid (C) from fluid (A) in the above step (2) into fluid (D) and fluid (E), and the above fluid (D) is recycled to the reactor, the above Fluid (E) is taken out from the process flow, wherein the concentration of aromatic compounds in the fluid (D) is lower than that in the fluid (C), and the concentration of hydrocarbons with 4 carbon atoms in the fluid (E) is lower than that in the fluid (C) )mid Lo.

[9] A method for producing propylene, which comprises contacting a raw material containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether with a catalyst in a reactor in the presence of a catalyst. A process for propylene consisting of a process flow comprising the following steps (1), (2) and (3A),

Step (1): At least one of methanol and dimethyl ether, the olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (D) recycled from step (3A) are supplied to the reactor, relative to the reaction The molar flow rate of olefins with 4 or more carbon atoms at the inlet of the reactor, and the molar flow rate of olefins with 4 or more carbon atoms at the outlet of the reactor are 20% or more and less than 90%. Under these reaction conditions, the above-mentioned The material contacts with above-mentioned catalyzer, obtains the gas (reactor outlet gas) that contains propylene, other olefins, paraffin, aromatic compound and water by reactor outlet;

Step (2): Separating the reactor outlet gas from the above step (1) into a fluid rich in hydrocarbons with 3 or less carbon atoms, a fluid (A) rich in hydrocarbons with 4 or more carbon atoms, and a fluid rich in water the fluid;

Step (3A): A part (B) of the fluid (A) in the above step (2) is taken out from the process flow, and the remaining fluid (C) is separated into fluid (D) and fluid (E), and the above Stream (D) is recycled to the reactor and said stream (E) is withdrawn from the process, wherein said stream (D) has a lower concentration of aromatic compounds than stream (C), said stream (E) The concentration of hydrocarbons with a carbon number of 4 is lower than in fluid (C).

[10] The method for producing propylene according to [8] or [9], wherein the reactor includes two or more reaction sections connected in series, and the olefin having 4 or more carbon atoms supplied to the reactor is The raw material, at least one of methanol and dimethyl ether, and at least one of the recycled hydrocarbon-containing fluid (D) are dividedly supplied to the first-stage reaction section and the second-stage or subsequent reaction section.

[11] The method for producing propylene according to any one of [8] to [10], wherein the fluid (B) is supplied to a steam cracking process flow and used as a cracking raw material.

[12] The method for producing propylene according to [11], wherein at least a part of the fluid (B) is brought into contact with a hydrogenation catalyst and then supplied to a steam cracking process flow.

[13] The method for producing propylene according to any one of [8] to [12], wherein the total concentration of aromatic compounds contained in the fluid (B) is less than 5.0% by volume.

[14] The method for producing propylene according to any one of [8] to [13], wherein the fluid (E) is mixed with the cracked gasoline fraction of the steam cracking process.

[15] The method for producing propylene according to any one of [8] to [14], wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (E) is less than 5% by weight.

[16] The method for producing propylene according to any one of [8] to [15], wherein all the raw materials supplied to the reactor The total concentration (matrix concentration) of olefins with 4 or more carbon atoms, methanol, and dimethyl ether contained in the mixture is controlled at 20% by volume or more and 80% by volume or less.

[17] A method for producing propylene, which is produced by contacting a mixture containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether with a catalyst in a reactor in the presence of a catalyst The method for propylene, it comprises following steps (1), (2) and (3B),

Step (1): At least one of methanol and dimethyl ether, an olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (I) recycled from step (3B) are supplied to the reactor, relative to the reaction The molar flow rate of olefins with 4 or more carbon atoms at the inlet of the reactor, and the molar flow rate of olefins with 4 or more carbon atoms at the outlet of the reactor are 20% or more and less than 90%. Under these reaction conditions, the above-mentioned The material is contacted with the catalyst, and the gas containing propylene, other olefins, paraffins, aromatic compounds and water is obtained from the reactor outlet (reactor outlet gas);

Step (2): Separating the reactor outlet gas from the above step (1) into a fluid rich in hydrocarbons with 3 or less carbon atoms, a fluid (A) rich in hydrocarbons with 4 or more carbon atoms, and a fluid rich in water the fluid;

Step (3B): The fluid (A) in the above step (2) is separated into fluid (G) and fluid (F), and at least a part (I) of the above fluid (G) is recycled to the reactor, and the remaining Fluid (H) is taken out from the process flow, wherein the concentration of aromatic compounds in the fluid (G) is lower than that in the fluid (A), and the concentration of hydrocarbons with 4 carbon atoms in the fluid (F) is lower than that in the fluid (A) )mid Lo.

[18] A method for producing propylene, which comprises contacting a mixture containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether with a catalyst in a reactor in the presence of a catalyst. A process for propylene, which consists of a process flow comprising the following steps (1), (2) and (3B),

Step (1): At least one of methanol and dimethyl ether, the olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (I) recycled from step (3B) are supplied to the reactor, relative to the reaction The molar flow rate of olefins with 4 or more carbon atoms at the inlet of the reactor, and the molar flow rate of olefins with 4 or more carbon atoms at the outlet of the reactor are 20% or more and less than 90%. Under these reaction conditions, the above-mentioned The material is contacted with the catalyst, and the gas containing propylene, other olefins, paraffins, aromatic compounds and water is obtained from the reactor outlet (reactor outlet gas);

Step (2): Separating the reactor outlet gas from the above step (1) into a fluid rich in hydrocarbons with 3 or less carbon atoms, a fluid (A) rich in hydrocarbons with 4 or more carbon atoms, and a fluid rich in water the fluid;

Step (3B): separating the fluid (A) in the above-mentioned step (2) into a fluid (G) and a fluid (F), taking the above-mentioned fluid (F) from the process flow, and taking the above-mentioned fluid (G) A portion (I) is recycled to the reactor and the remaining stream (H) is withdrawn from the process, wherein said stream (G) has a lower concentration of aromatics than stream (A), said stream (F) The concentration of hydrocarbons having a carbon number of 4 is lower than in fluid (A).

[19] The method for producing propylene according to [17] or [18], wherein the reactor includes two or more reaction sections connected in series, and the olefin having 4 or more carbon atoms supplied to the reactor is The raw material, at least one of methanol and dimethyl ether, and at least one of the recycled hydrocarbon-containing fluid (I) are dividedly supplied to the first-stage reaction section and the second-stage or subsequent reaction section.

[20] The method for producing propylene according to any one of [17] to [19], wherein the fluid (H) is supplied to a steam cracking process flow and used as a cracking raw material.

[21] The method for producing propylene according to [20], wherein at least a part of the fluid (H) is brought into contact with a hydrogenation catalyst and then supplied to a steam cracking process flow.

[22] The method for producing propylene according to any one of [17] to [21], wherein the total concentration of aromatic compounds contained in the fluid (H) is less than 5.0% by volume.

[23] The method for producing propylene according to any one of [17] to [22], wherein the fluid (F) is mixed with a cracked gasoline fraction of a steam cracking process flow.

[24] The method for producing propylene according to any one of [17] to [23], wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (F) is less than 5% by weight.

[25] The method for producing propylene according to any one of [17] to [24], wherein, by controlling the flow rates of the fluid (F) and the fluid (H), the above-mentioned The total concentration (substrate concentration) of olefins having 4 or more carbon atoms, methanol, and dimethyl ether contained in all raw materials is controlled to be 20% by volume or more and 80% by volume or less.

[26] The method for producing propylene according to any one of [8] to [25], wherein the step (2) includes the step of: condensing and removing water, and then separated by distillation into a fluid rich in hydrocarbons with 2 or less carbon atoms and a fluid rich in hydrocarbons with 3 or more carbon atoms, and then separating the fluid rich in hydrocarbons with 3 or more carbon atoms Separated into a fluid rich in hydrocarbons with 3 carbon atoms and a fluid rich in hydrocarbons with 4 or more carbon atoms.

[27] The method for producing propylene according to any one of [8] to [25], wherein the step (2) includes the step of: condensing and removing water, and then separated by distillation into a fluid rich in hydrocarbons with 3 or less carbon atoms and a fluid rich in hydrocarbons with 4 or more carbon atoms, and then the fluid rich in hydrocarbons with 3 or less carbon atoms was separated by distillation Separation into a fluid rich in hydrocarbons with 2 or less carbon atoms and a fluid rich in hydrocarbons with 3 carbon atoms.

[28] The method for producing propylene according to any one of [8] to [25], wherein the step (2) includes the step of: condensing and removing Moisture, and then separated by distillation into a fluid containing hydrocarbons with 2 or less carbon atoms and hydrocarbons with 3 carbon atoms, and a fluid rich in hydrocarbons with more than 3 carbon atoms, and then the carbon-rich fluid is separated by distillation The fluid containing hydrocarbons having 3 or more atoms is separated into a fluid rich in hydrocarbons having 3 carbon atoms and a fluid rich in hydrocarbons having 4 or more carbon atoms.

[29] The method for producing propylene according to any one of [8] to [25], wherein the step (2) includes the step of: condensing and removing water, and then separated by distillation into a fluid rich in hydrocarbons with 3 or less carbon atoms and a fluid rich in hydrocarbons with 4 or more carbon atoms, and then the fluid rich in hydrocarbons with 3 or less carbon atoms was separated by distillation Separation into a fluid containing hydrocarbons with 2 or less carbon atoms and hydrocarbons with 3 carbon atoms, and a fluid rich in hydrocarbons with 3 carbon atoms.

[30] The method for producing propylene according to any one of [8] to [29], wherein the olefin raw material having 4 or more carbon atoms contains paraffins having 4 or more carbon atoms.

[31] The method for producing propylene according to [30], wherein the paraffins contain at least one of n-butane and isobutane.

[32] The method for producing propylene according to any one of [8] to [31], wherein the raw material supplied to the reactor contains butadiene.

[33] The method for producing propylene according to any one of [8] to [32], wherein the total amount of aromatic compounds contained in all raw materials supplied to the reactor is equal to the total amount of aromatic compounds contained in all raw materials The molar ratio of the total amount of olefins having 4 or more carbon atoms contained is less than 0.05.

[34] The method for producing propylene according to any one of [8] to [33], wherein the amount of the olefin having 4 or more carbon atoms supplied to the reactor is the same as the amount of olefins supplied to the reactor The molar ratio of twice the number of moles of dimethyl ether to the total amount of the number of moles of methanol is 0.2 to 10.

[35] The method for producing propylene according to any one of [8] to [34], wherein the olefin raw material with 4 or more carbon atoms supplied to the reactor contains carbon atoms obtained from the steam cracking process Hydrocarbon fluids numbered 4.

[36] A process for producing propylene, which is produced by contacting a mixture containing at least one of methanol and dimethyl ether and containing an olefin having 4 or more carbon atoms with a catalyst in the presence of a catalyst A process for propylene consisting of a process flow comprising the following steps (1C), (2C), (3C) and (4C),

Step (1C): At least one of methanol and dimethyl ether, an olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (Q) recycled from step (4C) are supplied to the reactor, and the relative reaction The molar flow rate of olefins with 4 or more carbon atoms at the inlet of the reactor, and the molar flow rate of olefins with 4 or more carbon atoms at the outlet of the reactor are 20% or more and less than 90%. Under these reaction conditions, the above-mentioned The material is contacted with the catalyst, and the gas containing propylene, other olefins, paraffins, aromatic compounds and water is obtained from the reactor outlet (reactor outlet gas);

Step (2C): cooling the reactor outlet gas from the above step (1C), and separating it into a gaseous fluid (L), a liquid fluid (M) rich in hydrocarbons with 4 or more carbon atoms and containing aromatic compounds, and a liquid fluid (M) rich in Aqueous fluids;

Step (3C): separating the gaseous fluid (L) in the above step (2C) into a fluid rich in hydrocarbons with 3 or less carbon atoms and a fluid (N) rich in hydrocarbons with 4 or more carbon atoms;

Step (4C): recycling at least a portion of the fluid (Q) of the aforementioned fluid (N) to the reactor.

[37]. A method for producing propylene, comprising contacting a mixture containing at least one of methanol and dimethyl ether and an olefin having 4 or more carbon atoms with the catalyst in a reactor in the presence of a catalyst. A process for the preparation of propylene consisting of a process flow comprising the following steps (1C), (2C), (3C) and (4C),

Step (1C): At least one of methanol and dimethyl ether, an olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (Q) recycled from step (4C) are supplied to the reactor, and the relative reaction The molar flow rate of olefins with 4 or more carbon atoms at the inlet of the reactor, and the molar flow rate of olefins with 4 or more carbon atoms at the outlet of the reactor are 20% or more and less than 90%. Under these reaction conditions, the above-mentioned The material is contacted with the catalyst, and the gas containing propylene, other olefins, paraffins, aromatic compounds and water is obtained from the reactor outlet (reactor outlet gas);

Step (2C): cooling the reactor outlet gas from the above step (1C), and separating the cooled gaseous fluid (K) into gaseous fluid (L), rich in hydrocarbons with 4 or more carbon atoms and containing Liquid fluids (M) of aromatic compounds, and fluids enriched with water;

Step (3C): separating the gaseous fluid (L) in the above step (2C) into a fluid rich in hydrocarbons with 3 or less carbon atoms and a fluid (N) rich in hydrocarbons with 4 or more carbon atoms;

Step (4C): A part (P) of the above-mentioned stream (N) is withdrawn from the process flow and the remaining stream (Q) is recycled to the reactor.

[38] The method for producing propylene according to [36] or [37], wherein the liquid fluid (M) is separated into fluid (R) and fluid (S) by distillation, wherein the fluid (R) The concentration of aromatic compounds is lower than in the liquid fluid (M), and the concentration of hydrocarbons with 4 carbon atoms in the fluid (S) is lower than that in the liquid fluid (M).

[39] The method for producing propylene according to [38], wherein the fluid (R) is returned to the fluid (K), (L), (M), (P) and (Q) selected from the above Any one or more than two kinds of fluid flow parts.

[40] The method for producing propylene according to any one of [36] to [39], wherein the step (3C) includes the step of: separating the gaseous fluid (L) into carbon-rich A fluid rich in hydrocarbons with 2 or less atoms and a fluid rich in hydrocarbons with more than 3 carbon atoms, and then the fluid rich in hydrocarbons with 3 or more carbon atoms is separated into a fluid rich in hydrocarbons with 3 carbon atoms and a fluid rich in hydrocarbons with 3 or more carbon atoms A fluid (N) rich in hydrocarbons having 4 or more carbon atoms.

[41] The method for producing propylene according to any one of [36] to [39], wherein the step (3C) includes the step of: separating the gaseous fluid (L) into carbon-rich A fluid containing hydrocarbons with 3 or less atoms and a fluid rich in hydrocarbons with 4 or more carbon atoms (N), and then separating the fluid rich in hydrocarbons with 3 or less carbon atoms into hydrocarbons with 2 or less carbon atoms by distillation fluids and fluids rich in hydrocarbons with 3 carbon atoms.

[42] The method for producing propylene according to any one of [36] to [39], wherein the step (3C) includes the step of: separating the gaseous fluid (L) by distillation into Hydrocarbons with a number of 2 or less and hydrocarbons with a carbon number of 3, and fluids rich in hydrocarbons with a carbon number of 3 or more, and the fluids rich in hydrocarbons with a carbon number of 3 or more are separated into carbon-rich fluids by distillation A fluid containing 3 hydrocarbons and a fluid rich in hydrocarbons having 4 or more carbon atoms (N).

[43] The method for producing propylene according to any one of [36] to [39], wherein the step (3C) includes the step of: separating the gaseous fluid (L) into carbon-rich A fluid containing hydrocarbons with 3 or less atoms and a fluid (N) rich in hydrocarbons with 4 or more carbon atoms, and then separating the fluid rich in hydrocarbons with 3 or less carbon atoms into hydrocarbons with 2 or less carbon atoms and A fluid containing hydrocarbons with 3 carbon atoms, and a fluid rich in hydrocarbons with 3 carbon atoms.

[44] The method for producing propylene according to any one of [36] to [43], wherein the reactor includes two or more reaction sections connected in series, and the carbon atoms supplied to the reactor The olefin feedstock of number 4 or more, at least one of methanol and dimethyl ether, and at least one of the recycled hydrocarbon-containing fluid are divided and supplied to the first-stage reaction section and the second-stage or subsequent reaction section.

[45] The method for producing propylene according to any one of [36] to [44], wherein the olefin raw material having 4 or more carbon atoms contains paraffins having 4 or more carbon atoms.

[46] The method for producing propylene according to [45], wherein the paraffins contain at least one of n-butane and isobutane.

[47] The method for producing propylene according to any one of [36] to [46], wherein the raw material supplied to the reactor contains butadiene.

[48] The method for producing propylene according to any one of [36] to [47], wherein the total amount of aromatic compounds contained in all raw materials supplied to the reactor is equal to the total amount of aromatic compounds contained in all raw materials. The molar ratio of the total amount of olefins containing 4 or more carbon atoms is less than 0.05.

[49] The method for producing propylene according to any one of [36] to [48], wherein at least one of the fluid (M) and the fluid (P) is supplied to the steam cracking process In, it is used as cracking raw material.

[50] The method for producing propylene according to [49], wherein at least a part of at least one of the fluid (M) and the fluid (P) is contacted with a hydrogenation catalyst, and then supplied to a steam cracking process in process.

[51] The method for producing propylene according to any one of [36] to [50], wherein the aromatic compound contained in at least one of the fluid (M) and the fluid (P) The total concentration is less than 5.0% by volume.

[52] The method for producing propylene according to any one of [36] to [51], wherein the fluid (M) is mixed with the cracked gasoline fraction of the steam cracking process flow.

[53] The method for producing propylene according to any one of [36] to [52], wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (M) is less than 5% by weight.

[54] The method for producing propylene according to any one of [36] to [53], wherein, by controlling the flow rates of the fluid (M) and the fluid (P), the above-mentioned The total concentration (substrate concentration) of olefins having 4 or more carbon atoms, methanol, and dimethyl ether contained in all raw materials is controlled to be 20% by volume or more and 80% by volume or less.

[55] The method for producing propylene according to any one of [38] to [54], wherein the fluid (R) is supplied to a steam cracking process flow and used as a cracking raw material.

[56] The method for producing propylene according to [55], wherein at least a part of the fluid (R) is brought into contact with a hydrogenation catalyst and then supplied to a steam cracking process flow.

[57] The method for producing propylene according to any one of [38] to [56], wherein the total concentration of aromatic compounds contained in the fluid (R) is less than 5.0% by volume.

[58] The method for producing propylene according to any one of [38] to [57], wherein the fluid (S) is mixed with the cracked gasoline fraction of the steam cracking process flow.

[59] The method for producing propylene according to any one of [38] to [58], wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (S) is less than 5% by weight.

[60] The method for producing propylene according to any one of [38] to [59], wherein, by controlling the flow rates of the fluid (P), the fluid (R) and the fluid (S), the above-mentioned supply to The total concentration (substrate concentration) of olefins having 4 or more carbon atoms, methanol, and dimethyl ether contained in all raw materials of the reactor is controlled to be 20% by volume or more and 80% by volume or less.

[61] The method for producing propylene according to any one of [38] to [60], wherein, after returning the fluid (R) to the fluid (K), (L), (N ), (P) and (Q) when any one or two or more fluids are located, by controlling the position where the fluid (R) returns and its flow rate, all the above-mentioned materials supplied to the reactor The total concentration (substrate concentration) of olefins containing 4 or more carbon atoms, methanol, and dimethyl ether is controlled to be 20% by volume or more and 80% by volume or less.

[62] The method for producing propylene according to any one of [36] to [61], wherein the amount of the olefin having 4 or more carbon atoms supplied to the reactor is equal to the amount of the diolefin supplied to the reactor. The molar ratio of twice the number of moles of methyl ether to the total number of moles of methanol is 0.2 to 10.

[63] The method for producing propylene according to any one of [38] to [62], wherein the olefin raw material with 4 or more carbon atoms supplied to the reactor contains carbon atoms obtained from the steam cracking process. 4 or more hydrocarbon fluids.

The effect of the invention

According to the present invention, the method for producing propylene by reacting at least one of methanol and dimethyl ether with an olefin having 4 or more carbon atoms in the presence of a catalyst can make full use of raw materials, suppress degradation of the catalyst, and achieve high yields. Propylene is produced.

Furthermore, the method of the present invention can be combined with a steam cracking process flow to provide a low cost process flow.

Description of drawings

[ Fig. 1 ] is a system diagram showing an example of an embodiment of the method for producing propylene of the present invention.

[ Fig. 2 ] is a system diagram showing another example of the embodiment of the propylene production method of the present invention.

[ Fig. 3 ] is a system diagram showing still another example of the embodiment of the propylene production method of the present invention.

Symbol Description

10 reactors

20 The first separation and purification system

30A, 30B The second separation and purification system

13 reactors

23 compressors

33 separation tank

43 oil-water separator

53 The first separation and purification system

63 The second separation and purification system

Detailed ways

Hereinafter, representative embodiments for carrying out the present invention will be specifically described, but the present invention is not limited to the following embodiments unless the gist of the present invention is exceeded.

The method for producing propylene of the present invention is a method for producing propylene by contacting a raw material containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether in a reactor with a catalyst in the presence of a catalyst, wherein, At least a part of the aromatic compound contained in the effluent gas from the reactor is taken out, and at least a part of the olefins having 4 or more carbon atoms contained in the effluent gas from the reactor is brought into contact with the catalyst again in the reactor.

As more specific first and second embodiments, including the above three steps (1), (2), (3A) or (1), (2), (3B), in addition, the third embodiment Including the above-mentioned 4 steps (1C), (2C), (3C) and (4C), but as long as the purpose of solving the problem of the present invention can be realized, it does not exclude the existence of other steps, which can be performed before and after the 4 steps. There are other steps and there may be other steps in between.

It should be noted that "rich" in the present invention means that the purity of the target substance is 50 mol% or more, preferably 70 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol% or more. For example, the "fluid (N) rich in hydrocarbons with 4 or more carbon atoms" means "containing 50 mol% or more, preferably 70 mol% or more, more preferably 90 mol% or more, and more preferably 95 mol% Fluids of the above "hydrocarbons having 4 or more carbon atoms".

[catalyst]

First, the catalyst used in the present invention will be described.

As the catalyst used in the reaction of the present invention, as long as it is a solid substance with Brönsted acidity, there are no particular restrictions, conventionally known catalysts can be used, for example, the following catalysts can be listed: clay minerals such as kaolin; Substances impregnated/loaded with acids such as sulfuric acid and phosphoric acid; acidic ion exchange resins; zeolites; aluminum phosphates; solid acid catalysts such as mesoporous aluminum silicate such as Al-MCM41.

Among the above-mentioned solid acid catalysts, catalysts having a molecular sieve effect are preferable, and catalysts whose acid strength is not too high are preferable.

Among the above-mentioned solid acid catalysts, the structure of a zeolite-based or aluminum phosphate-based catalyst having a molecular sieve effect can be represented by a code specified by the International Zeolite Association (IZA), such as AEI, AET, AEL, AFI, AFO , AFS, AST, ATN, BEA, CAN, CHA, EMT, ERI, EUO, FAU, FER, LEV, LTL, MAZ, MEL, MFI, MOR, MTT, MTW, MWW, OFF, PAU, RHO, STT, TON wait. Wherein, the skeleton density of preferred catalyst is the catalyst below 18.0T/nm3, as this kind of catalyst, preferred MFI, MEL, MOR, MWW, FAU, BEA, CHA, more preferred MFI, MEL, MOR, MWW, CHA, particularly preferred The most popular are MFI, MEL, MWW, CHA.

Wherein, the framework density (unit: T/nm ³ ) refers to the number of T atoms (atoms other than oxygen among the atoms constituting the zeolite framework) present in the zeolite per unit volume (1nm ³ ), and this value is determined by determined by the zeolite structure.

In addition, as the solid acid catalyst, crystalline aluminum silicates having micropores with a pore diameter of 0.3 to 0.9 nm, a BET specific surface area of 200 to 700 m ² /g, and a pore volume of 0.1 to 0.5 g/ml are more preferable. Metal silicates or crystalline aluminum phosphates, etc. In addition, the pore diameter herein means the crystallographic freediameter of the channels stipulated by the International Zeolite Association (IZA), and when the shape of the pore (channel) is a perfect circle, the pore diameter refers to Its diameter, when the pore shape is ellipse, the pore diameter refers to its short diameter.

In addition, it is preferable that the molar ratio of SiO ₂ /Al ₂ O ₃ in the aluminum silicate is 10 or more. If the molar ratio of SiO ₂ /Al ₂ O ₃ is too low, the durability of the catalyst will decrease, which is not preferable. The upper limit of the SiO ₂ /Al ₂ O ₃ molar ratio is usually 10,000 or less. If the molar ratio of SiO ₂ /Al ₂ O ₃ exceeds 10,000, it is not preferable since the catalytic activity will decrease. The above-mentioned molar ratio can be obtained by common methods such as fluorescent X-rays and chemical analysis.

The aluminum content in the catalyst can be controlled by adjusting the feed amount of raw materials when preparing the catalyst. In addition, the Al content can also be reduced by steam processing after preparation. In addition, part of Al may be replaced by other elements such as boron or potassium, and boron is particularly preferred.

The above catalysts may be used alone or in combination of two or more.

In the present invention, the above catalyst active component can be directly used as a catalyst for the reaction, and can also be used in the reaction by granulating, molding, or mixing them with inactive substances or binders. Alumina, alumina sol, silica, silica gel, quartz, mixtures thereof, and the like are exemplified as the inactive substance or binder.

In addition, the composition of the above-mentioned catalyst is only the composition of the catalyst active component, and it does not include the above-mentioned inactive substances, binders, and the like. However, when the catalyst of the present invention contains the above-mentioned inactive substances or binders, the above-mentioned catalyst active components and these inactive substances or binders are collectively referred to as catalysts. ; When the above-mentioned inactive substances or binders are not contained, only the catalyst active component is called a catalyst.

The particle size of the catalytically active component used in the present invention varies depending on the conditions at the time of synthesis, but usually the average particle size is 0.01 μm to 500 μm. If the particle size of the catalyst is too large, the surface area showing catalytic activity will be reduced, and if the particle size is too small, the handleability will be deteriorated, and neither too large nor too small is preferable. This average particle diameter can be obtained by SEM observation etc.

There are no particular limitations on the preparation method of the catalyst used in the present invention, and it can usually be prepared by a known method called hydrothermal synthesis. In addition, the composition of the catalyst can be changed by modification such as ion exchange, dealumination, impregnation or loading after hydrothermal synthesis.

The catalyst used in the present invention may be prepared by any method as long as it has the above physical properties or composition when participating in the reaction.

<Reaction material>

Next, the olefin having 4 or more carbon atoms, methanol, and dimethyl ether used as the reaction raw materials in the present invention will be described.

〈Olefin raw material〉

The olefin having 4 or more carbon atoms used as a reaction raw material is not particularly limited. For example, olefins having 4 or more carbon atoms, especially olefins having 4 to 10 carbon atoms obtained by various known methods can be used arbitrarily, for example, olefins having 4 or more carbon atoms produced from petroleum feedstocks by catalytic cracking or steam cracking, etc. The above olefins (BB fraction, C4 raffinate-1, C4 raffinate-2, etc.) and the hydrogen/CO mixture gas obtained from coal gasification are used as raw materials for FT (Fischer-Tropsch) synthesis. Olefins with 4 or more carbon atoms, olefins with 4 or more carbon atoms obtained by oligomerization of ethylene including dimerization, and paraffins with 4 or more carbon atoms by dehydrogenation or oxidative dehydrogenation Olefins with 4 or more carbon atoms produced by the hydrogen method, olefins with 4 or more carbon atoms produced by the MTO reaction, olefins with 4 or more carbon atoms produced by the dehydration reaction of alcohols, Olefins having 4 or more carbon atoms produced by the hydrogenation reaction of diene compounds having 4 or more carbon atoms, etc., in this case, the state in which these compounds other than olefins having 4 or more carbon atoms arbitrarily mixed by the production method can be used as it is The following olefins having 4 or more carbon atoms may be purified olefins.

Among them, when an olefin raw material containing paraffins having 4 or more carbon atoms is used, since the paraffin acts as a diluent gas, it is easy to control the reaction temperature, and the raw material containing paraffin can be obtained at low cost, so it is preferable. More preferred are olefin feedstocks containing at least one of n-butane and isobutane.

Examples of these preferable raw materials include the above-mentioned BB fraction, C4 raffinate-1, and C4 raffinate-2. These feedstocks usually contain butadiene. Since butadiene is easily converted into aromatic compounds by reaction, it is very important to take out at least a part of the produced aromatic compounds instead of recycling them to the reactor as in the present invention. In addition, since the BB fraction contains a large amount of butadiene, it is preferable to bring it into contact with a hydrogenation catalyst to reduce the butadiene concentration, and use this reduced butadiene concentration fluid as a raw material.

<Methanol, Dimethyl ether>

As at least one of methanol and dimethyl ether used as a reaction raw material, its production source is not particularly limited. For example, products obtained by hydrogenating a mixed gas of hydrogen/CO, which is a by-product derived from coal, natural gas, and iron manufacturing, and products obtained by modifying alcohols derived from plants Products; products obtained by fermentation; products obtained from organic matter such as recycled plastics, municipal waste, etc. At this time, when compounds other than methanol and dimethyl ether are produced in each of the above-mentioned production methods, the products in the state where these compounds are arbitrarily mixed with methanol and dimethyl ether can be used as they are, or purified methanol and dimethyl ether can be used. At least one of dimethyl ether.

[Reaction operation, conditions: Steps (1) (1C) in the first to third embodiments]

Hereinafter, the operation and conditions of the propylene production reaction of the present invention using the above-mentioned catalyst and reaction raw materials will be described.

<reactor>

In the present invention, the reaction of at least one of methanol and dimethyl ether with an olefin having 4 or more carbon atoms is a gas phase reaction. The form of the gas-phase reactor is not particularly limited, and it can usually be selected from a continuous fixed-bed reactor or a fluidized-bed reactor. Fixed bed reactors are preferred.

In addition, when the above-mentioned catalyst is filled in the fixed-bed reactor, in order to control the temperature distribution of the catalyst layer in a small range, it can also be filled with inactive granular materials such as quartz sand, alumina, silica, aluminum silicate, etc. Mixtures of substances and catalysts, etc. At this time, there is no particular limitation on the usage amount of inactive granular materials such as quartz sand. In addition, in order to have a uniform mixing property with the catalyst, it is preferable that the particle diameter of the granular material is about the same as that of the catalyst.

It should be noted that the reactor may include two or more reaction parts connected in series. In this case, one reactor may be divided into a plurality of reaction chambers, or two or more reactors may be connected in series.

When two or more reactors are connected in series, a heat exchanger may be provided between the reactors to remove the heat released during the reaction.

In addition, in order to disperse the heat generation, the reaction substrate (reaction raw material) may be divided and supplied. It is preferable to divide and supply at least one of methanol and dimethyl ether to the reaction part (reactor or reaction chamber) of the first stage and the reaction part (reactor or reaction chamber) of the second stage or later.

Under the reaction conditions used in the present invention, the catalyst is seldom coked, and the catalyst deterioration rate is slow. When continuous operation is carried out for more than one year, it is necessary to regenerate the catalyst during operation.

For example, when selecting a fixed-bed reactor, it is desirable to arrange at least two or more reactors in parallel, and switch between reactions and regenerations while operating. As the form of the fixed bed reactor, a multitubular reactor or an adiabatic reactor can be selected.

On the other hand, when a fluidized bed reactor is selected, it is preferable to continuously feed the catalyst into the regeneration tank, and to carry out the reaction while continuously returning the catalyst regenerated in the regeneration tank to the reactor.

Here, as the regeneration operation of the catalyst, there may be mentioned a method of regenerating the catalyst deteriorated by coking by treating it with oxygen-containing nitrogen or water vapor, or the like. As a regeneration operation in a fixed-bed reactor, it is preferable to use nitrogen to remove volatile organic compounds attached to the catalyst, then use nitrogen containing a low concentration of oxygen to remove coke components, and then remove the molecular state contained in the catalyst layer by treating with nitrogen. oxygen method.

<Concentration ratio of olefin to at least one of methanol and dimethyl ether supplied to the reactor>

In the present invention, the molar ratio of the amount of olefins having 4 or more carbon atoms supplied to the reactor to the total of twice the moles of dimethyl ether and the moles of methanol supplied to the reactor is 0.2 or more, preferably 0.5 or more, and 10 or less, preferably 5 or less.

That is, when the supplied molar amount of olefins having 4 or more carbon atoms is represented by Mc4, the supplied molar amount of methanol is represented by Mm, and the supplied molar amount of dimethyl ether is represented by Mdm, Mc4 is (Mm+2Mdm) 0.2~10 times, preferably 0.5~5 times.

If the supply concentration ratio is too low or too high, the reaction will be slowed down, which is not preferable. In particular, when the supply concentration ratio is too low, the consumption of raw material olefins will be reduced, which is not preferable.

Here, the supply concentration ratio can be known by quantifying the composition of each fluid supplied to the reactor or the mixed fluid using a common analysis method such as gas chromatography.

Also, when feeding at least one of methanol and dimethyl ether and an olefin having 4 or more carbon atoms into the reactor, they may be fed separately, or a part or all of them may be mixed in advance before feeding.

<Concentration of substrate supplied to the reactor>

In the present invention, the total concentration (substrate concentration) of olefins having 4 or more carbon atoms, methanol, and dimethyl ether in all feed materials supplied to the reactor is preferably 20% by volume or more and 80% by volume or less, more preferably 30% by volume or less. Volume % to 70 volume %.

Here, the substrate concentration can be known by quantifying the composition of each fluid supplied to the reactor or the mixed fluid using a common analysis method such as gas chromatography.

If the substrate concentration is too high, the formation of aromatic compounds or paraffins becomes more significant, and the selectivity of propylene tends to decrease. On the contrary, if the concentration of the substrate is too low, the reaction rate will be slowed down, a large amount of catalyst will be required, and the purification cost of the product and the construction cost of the reaction equipment will be increased, which is uneconomical.

In the present invention, the reaction substrate is diluted with a diluent gas to be described later so that the concentration of the substrate falls within the above range. In this case, as a method of controlling the substrate concentration, a method of controlling the flow rate of the fluid taken out of the process flow can be mentioned. That is, by varying the flow rate of the fluid withdrawn from the process flow, the flow rate of the diluent gas that is recycled to the reactor can be varied, thereby varying the substrate concentration.

<Concentration of impurities in the gas supplied to the reactor>

In the present invention, although butadiene may be contained in olefins having 4 or more carbon atoms and/or recycled hydrocarbon-containing fluids described later, as butadiene in all raw materials supplied to the reactor The concentration of alkene is preferably 2.0% by volume or less. If the concentration of butadiene in the raw material is high, the amount of aromatic compound produced will increase, and the degradation due to coking of the catalyst will be accelerated, which is not preferable.

Here, the concentration of butadiene can be known by quantifying the composition of each of the fluids supplied to the reactor or the mixed fluid using a common analytical method such as gas chromatography.

As a method of reducing the concentration of butadiene in the raw material, there may be mentioned a partial hydrogenation method in which the fluid is brought into contact with a hydrogenation catalyst to convert butadiene into olefins.

In addition, aromatic compounds may be contained in the hydrocarbon-containing fluid described later that is recycled to the reactor, but it is preferable that the total amount of aromatic compounds contained in all raw materials supplied to the reactor be equal to the total amount of aromatic compounds contained in all raw materials supplied to the reactor. The molar ratio of the total amount of olefins with 4 or more carbon atoms contained in is less than 0.05. If the concentration of aromatic compounds in the raw material is high, the reaction of aromatic compounds with olefins with more than 4 carbon atoms in the reactor, and the reaction of aromatic compounds with at least one of methanol and dimethyl ether become more significant, resulting in consumption of necessary At least one of methanol and dimethyl ether and olefins having 4 or more carbon atoms are not preferable.

Moreover, when an aromatic compound is supplied to the reactor, the aromatic compound reacts with the above-mentioned olefin having 4 or more carbon atoms, and the resulting compound clogs the pores of the catalyst, thereby accelerating deterioration of the catalyst. Aromatic compounds present in the fluid are withdrawn from the system, thereby reducing the concentration of aromatic compounds in the fluid recycled to the reactor.

Here, the ratio of the total amount of the above-mentioned aromatic compounds to the total amount of olefins having 4 or more carbon atoms can be determined by analyzing the composition of each fluid supplied to the reactor or the mixed fluid by using a common analysis method such as gas chromatography. known quantitatively.

As a method of reducing the concentration of the aromatic compound in the raw material, a method of separating by distillation is mentioned.

<diluent gas>

In the reactor, in addition to at least one of methanol and dimethyl ether and olefins with more than 4 carbon atoms, there may also be other reactive gases, including paraffins , aromatics, water vapor, carbon dioxide, carbon monoxide, nitrogen, argon, helium, and mixtures of the above components. In addition, in the above-mentioned diluent gas, depending on the reaction conditions, some of the paraffins and aromatics may sometimes react, but because the amount of reaction is small, it can still be defined as a diluent gas.

As the diluent gas, impurities contained in the reaction raw material may be used as they are, or a diluent gas prepared in another manner may be mixed with the reaction raw material and used.

In addition, the diluent gas may be mixed with the reaction raw material before being charged into the reactor, or the diluent gas and the reaction raw material may be separately supplied to the reactor.

Preferable diluent gases are paraffins having 4 or more carbon atoms. At least one of n-butane and isobutane is more preferred. As for these paraffins, paraffins contained in the olefin raw material can be utilized, and since they are compounds with a large heat capacity, the reaction temperature can be easily controlled.

<space velocity>

The space velocity mentioned here refers to the flow rate of the reaction raw material corresponding to the catalyst (catalyst active component) per unit weight, that is, the olefin with 4 or more carbon atoms. The weight of the pellets, the shaped inactive ingredients and the catalyst active ingredients of the binder. In addition, the said flow rate means the flow rate (weight/hour) of the olefin with 4 or more carbon atoms.

The space velocity is preferably between 0.1 Hr ⁻¹ and 500 Hr ⁻¹ , more preferably between 1.0 Hr ⁻¹ and 100 Hr ⁻¹ . If the space velocity is too high, the conversion rate of at least one of raw materials methanol and dimethyl ether to olefins will be low, and sufficient propylene selectivity will not be obtained. In addition, if the space velocity is too low, the amount of catalyst necessary to obtain a certain output increases, which not only makes the reactor too large, but also generates non-preferred by-products such as aromatic compounds or paraffins, and the propylene selectivity decreases. Therefore, Not preferred.

<reaction temperature>

The lower limit of the reaction temperature is usually about 300°C or higher, preferably 400°C or higher, and the upper limit of the reaction temperature is usually 700°C or lower, preferably 600°C or lower. If the reaction temperature is too low, the reaction rate will be low, a large amount of unreacted raw materials may remain, and the propylene yield will further decrease. On the other hand, if the reaction temperature is too high, the yield of propylene will drop significantly.

<reaction pressure>

The upper limit of the reaction pressure is usually at most 2 MPa (absolute pressure, the same applies hereinafter), preferably at most 1 MPa, and more preferably at most 0.7 MPa. In addition, the lower limit of the reaction pressure is not particularly limited, but is usually 1 kPa or more, preferably 50 kPa or more. If the reaction pressure is too high, the production amount of unpreferred by-products such as paraffins and aromatic compounds increases, and the yield of propylene tends to decrease. If the reaction pressure is too low, the reaction rate tends to slow down.

<Consumption of raw materials due to reaction>

The sum of the molar flow of methanol and twice the molar flow of dimethyl ether at the reactor outlet is preferably less than 1 relative to the sum of the molar flow of methanol supplied to the reactor and twice the molar flow of dimethyl ether %. More preferably less than 0.1%.

If the consumption of methanol and dimethyl ether in the reactor is small, but the amount of methanol or dimethyl ether at the outlet of the reactor increases excessively, it will make it difficult to purify the product olefins.

As a method of increasing the consumption of methanol and dimethyl ether, a method of raising the reaction temperature or lowering the space velocity is mentioned.

In addition, in the present invention, the molar flow rate of olefins having 4 or more carbon atoms at the outlet of the reactor is 20% or more and less than 90% with respect to the molar flow rate of olefins having 4 or more carbon atoms supplied to the reactor. The molar flow ratio is preferably 20% or more and less than 70%, more preferably 25% or more and less than 60%. If the consumption of olefins having 4 or more carbon atoms in the reactor is too small, unreacted olefins will increase and the flow rate of the fluid recycled to the reactor will increase excessively, which is not preferable. Conversely, if the consumption is too large, undesired compounds such as paraffins and aromatic compounds will be produced by-produced, and the yield of propylene will decrease, which is not preferable.

As a method of adjusting the consumption of olefins having 4 or more carbon atoms, a method of appropriately setting the reaction temperature, the space velocity, and the like can be mentioned.

Among them, the flow rate of methanol, dimethyl ether, and olefins with more than 4 carbon atoms supplied to the reactor can be analyzed by analyzing the various fluids or mixed fluids supplied to the reactor by using common analysis methods such as gas chromatography. Composition is quantified, so as to measure the flow rate of various fluids, and the flow rate of methanol, dimethyl ether and olefins with more than 4 carbon atoms at the reactor outlet can be measured by gas chromatography and other commonly used methods. The composition of the fluid at the reactor can be quantified, so as to measure or calculate the flow rate of the fluid at the outlet of the reactor.

<reaction product>

A mixed gas containing propylene which is a reaction product, unreacted raw materials, by-products, and a diluent can be obtained as a reactor outlet gas (reactor effluent). The propylene concentration in the mixed gas is usually 5 to 95% by weight.

The unreacted raw material is usually an olefin having 4 or more carbon atoms. Depending on the reaction conditions, at least one of methanol and dimethyl ether is contained, but the reaction is preferably carried out under reaction conditions in which at least one of methanol and dimethyl ether does not remain. In this way, separation of reaction products and unreacted raw materials is easily performed.

Examples of by-products include ethylene, olefins having 4 or more carbon atoms, paraffins, aromatic compounds, and water.

[Separation step]

Separation steps in the first and second embodiments

<Separation of hydrocarbons with 3 or less carbon atoms and water: Step (2)>

The reactor outlet gas can be separated into a fluid rich in hydrocarbons with 3 or less carbon atoms, a fluid (A) rich in hydrocarbons with 4 or more carbon atoms, and a water-rich fluid through cooling, compression, and distillation. .

As a first embodiment of the above-mentioned general separation step, a method including the step of removing moisture by condensation in the cooling and compression steps, and separating by distillation into hydrocarbons rich in 2 or less carbon atoms can be used. Fluids and fluids rich in hydrocarbons with 3 or more carbon atoms, and the fluids rich in hydrocarbons with 3 or more carbon atoms are separated into fluids rich in hydrocarbons with 3 or more carbon atoms and fluids rich in hydrocarbons with 4 or more carbon atoms The hydrocarbon fluid (A).

As a second embodiment of the usual separation step, there can be used a method comprising the steps of: separating into a fluid rich in hydrocarbons having 3 or less carbon atoms by distillation after removing water by condensation in the cooling and compression steps and a fluid (A) rich in hydrocarbons with more than 4 carbon atoms, and then the fluid (A) rich in hydrocarbons with 3 or less carbon atoms is separated into a fluid rich in hydrocarbons with 2 or less carbon atoms and a fluid with rich carbon atoms 3 hydrocarbon fluids.

As a third embodiment of the usual separation step, there can be used a method comprising the steps of: separating by distillation into hydrocarbons containing 2 or less carbon atoms and carbon atoms after removing water by condensation in the cooling and compression steps. A fluid containing hydrocarbons with 3 or more carbon atoms and a fluid rich in hydrocarbons with 3 or more carbon atoms, and then by distillation, the fluid with hydrocarbons with 3 or more carbon atoms is separated into a fluid rich in hydrocarbons with 3 or more carbon atoms and A fluid (A) rich in hydrocarbons having 4 or more carbon atoms.

As a fourth embodiment of the usual separation step, there can be used a method comprising the steps of: separating into a fluid rich in hydrocarbons having 3 or less carbon atoms by distillation after removing water by condensation in the cooling and compression steps and a fluid (A) rich in hydrocarbons with more than 4 carbon atoms, and then the fluid (A) rich in hydrocarbons with 3 or less carbon atoms is separated into hydrocarbons with 2 or less carbon atoms and hydrocarbons with 3 carbon atoms by distillation Fluids, and fluids rich in hydrocarbons with 3 carbon atoms.

In the first to fourth embodiments of the above-mentioned usual separation steps, it is preferable to perform treatments such as quenching, alkali washing, and dehydration as necessary. When the oxygen-containing compound is contained in the outlet gas of the reactor, at least a part of the oxygen-containing compound is removed by terminating the reaction step. When acid gas such as carbon dioxide is contained in the outlet gas of the reactor, at least part of the acid gas is removed by alkali washing.

Water can mainly be separated by condensation by compression and cooling. It is preferable to remove residual moisture with an adsorbent such as molecular sieve. Water removed by condensation and/or adsorption can be used in wastewater treatment steps such as activated sludge, and can also be used in process water and the like.

When the process flow of the present invention (hereinafter sometimes referred to as "this process flow") is close to the steam cracking process flow, the water recovered from the reactor outlet gas is preferably used as the cracking steam source. In addition, it can also be recycled to the reactor of this process as a dilution gas.

In addition, it is preferable that the hydrocarbons having 2 or less carbon atoms and the hydrocarbons having 3 carbon atoms obtained from the outlet gas of the reactor are further subjected to purification steps such as distillation to obtain high-purity ethylene and propylene, respectively. The purity of ethylene is 95% or more, preferably 99% or more, more preferably 99.9% or more. The purity of propylene is 95% or more, preferably 99% or more, more preferably 99.9% or more.

The ethylene and propylene obtained in this way can also be used as raw materials for ethylene and propylene derivatives that are usually produced from the viewpoint of quality such as the amount of impurities. Ethylene can be used for the following production: Glycols, ethanolamines, glycol ethers, etc.; preparation of vinyl chloride monomer, 1,1,1-trichloroethane, vinyl chloride resin, vinylidene chloride by chlorination; or preparation of α-olefins, low Density or high-density polyethylene; preparation of ethylbenzene by ethylation of benzene, etc.

Polyethylene terephthalate can be further prepared from ethylene glycol prepared from ethylene, and higher alcohols can be prepared from α-olefins through carbonylation reaction and subsequent hydrogenation reaction, and ethylbenzene can also be used It is used as raw material to prepare styrene monomer, ABS resin, etc. In addition, vinyl acetate is produced by reaction with acetic acid, acetaldehyde and ethyl acetate as a derivative thereof are produced by wacker reaction, and the like.

In addition, propylene is suitable for the production of, for example, acrylonitrile by ammoxidation; acrolein, acrylic acid and acrylates by selective oxidation; n-butanol, 2-ethylhexanol by oxo reactions Other oxo alcohols; Polypropylene is produced by the polymerization of propylene; Propylene oxide and propylene glycol are produced by the selective oxidation of propylene. In addition, the Wacker reaction can be used to prepare acetone, and acetone can be used to prepare methyl isobutyl ketone. Also, acetone cyanohydrin can be produced from acetone, which can finally be converted into methyl methacrylate. In addition, isopropanol can also be prepared by hydration of propylene. In addition, cumene can be obtained by alkylating benzene, which can be used as a raw material to prepare phenol, bisphenol A, and polycarbonate resins.

In addition, it is preferable to supply the fluid containing hydrocarbons having 2 or less carbon atoms and hydrocarbons having 3 carbon atoms obtained in the third embodiment and the fourth embodiment of the above-mentioned general separation step to a production process other than this process flow. Purification is carried out in the process flow of ethylene and propylene. Examples of processes for producing ethylene and propylene other than this process include steam cracking processes for naphtha, ethane, and the like. Therefore, the equipment investment in the process flow can be significantly reduced.

On the other hand, when the ethylene-containing fluid produced in this process cannot be supplied to processes for producing ethylene and propylene other than this process, since it is necessary to perform purification of ethylene in this process, in this case Next, it is preferable to adopt the above-mentioned first embodiment or second embodiment.

Separation step in the third embodiment

[Separation step]

<Separation of gas components, liquid components and water: steps (2C), (3C)>

In the present invention, the outlet gas of the reactor is cooled, and the cooled gaseous fluid (K) is separated into a gaseous fluid (L), a fluid rich in hydrocarbons with 4 or more carbon atoms, and a liquid fluid containing aromatic compounds by compression. (M) and a fluid rich in water (step (2C)), and subsequently, the gaseous fluid (L) is separated into a fluid rich in hydrocarbons with 3 or less carbon atoms and a fluid rich in carbon atoms Fluid (N) of 4 or more hydrocarbons (step (3C)).

In step (2C), the temperature of the reactor outlet gas is usually about 300-600°C, and the reactor outlet gas is cooled to about 20-200°C. This cooling can usually be done by means of a heat exchanger, or it can be done directly by mixing with a fluid which is cooler than the gas. The cooled fluid (K) is separated into a gaseous fluid (L) rich in hydrocarbons with 6 or less carbon atoms, a gaseous fluid (L) rich in hydrocarbons with 4 or more carbon atoms, and Aromatic-containing liquid fluids (M) and water-rich fluids. In addition, in the above-mentioned heat exchanger, the fluid that exchanges heat with the reactor outlet gas is not particularly limited, but one or more fluids supplied to the reactor are preferred.

The gaseous fluid (L) rich in hydrocarbons having 6 or less carbon atoms separated by the reaction step (2C) is a hydrocarbon-containing fluid, and in the step (3C), it is separated into a gaseous fluid rich in A fluid containing hydrocarbons having 3 or less carbon atoms and a fluid rich in hydrocarbons having 4 or more carbon atoms (N).

As a first embodiment of the above-mentioned general separation step, a method including the step of separating by distillation into a fluid rich in hydrocarbons having 2 or less carbon atoms and a fluid rich in hydrocarbons having 3 carbon atoms can be employed. The above hydrocarbon fluid is separated into a fluid rich in hydrocarbons with 3 or more carbon atoms and a fluid rich in hydrocarbons with 4 or more carbon atoms by distillation (N).

As a second embodiment of the separation step, a method including a step of separating by distillation into a fluid rich in hydrocarbons having 3 or less carbon atoms and a fluid rich in hydrocarbons having 4 or more carbon atoms can be employed. The fluid (N) is separated by distillation from the fluid rich in hydrocarbons with 3 or less carbon atoms into a fluid rich in hydrocarbons with 2 or less carbon atoms and a fluid rich in hydrocarbons with 3 carbon atoms.

As a third embodiment of the usual separation step, a method including the steps of: separating by distillation into a fluid containing hydrocarbons having 2 or less carbon atoms and hydrocarbons having 3 carbon atoms, and a fluid rich in hydrocarbons with 3 or more carbon atoms, and then the fluid rich in hydrocarbons with 3 or more carbon atoms is separated into a fluid rich in hydrocarbons with 3 or more carbon atoms and a fluid rich in hydrocarbons with 4 or more carbon atoms Hydrocarbon fluid (N).

As a fourth embodiment of the usual separation step, a method including the step of separating by distillation into a fluid rich in hydrocarbons having 3 or less carbon atoms and a fluid rich in hydrocarbons having 4 or more carbon atoms can be used. The fluid (N) of hydrocarbons, and then by distillation, the fluid rich in hydrocarbons with a carbon number of 3 or less is separated into a fluid containing hydrocarbons with a carbon number of 2 or less and a hydrocarbon with a carbon number of 3, and a fluid rich in carbon atoms 3 hydrocarbon fluids.

In the above process flow, it is preferred to perform termination reaction, alkali washing, dehydration and other treatments if necessary. When the oxygen-containing compound is contained in the outlet gas of the reactor, at least a part of the oxygen-containing compound is removed by terminating the reaction step. When acid gas such as carbon dioxide is contained in the outlet gas of the reactor, at least part of the acid gas is removed by alkali washing.

Water can mainly be separated by condensation by compression and cooling. It is preferable to remove residual moisture with an adsorbent such as molecular sieve. Water removed by condensation and/or adsorption can be used in wastewater treatment steps such as activated sludge, and can also be used in process water and the like.

When the process flow of the present invention (hereinafter sometimes referred to as "this process flow") is close to the steam cracking process flow, the water recovered from the reactor outlet gas is preferably used as the cracking steam source. In addition, it can also be recycled to the reactor of this process as a dilution gas.

In addition, it is preferable that the hydrocarbons having 2 or less carbon atoms and the hydrocarbons having 3 carbon atoms obtained from the outlet gas of the reactor are further subjected to purification steps such as distillation to obtain high-purity ethylene and propylene, respectively. The purity of ethylene is 95% or more, preferably 99% or more, more preferably 99.9% or more. The purity of propylene is 95% or more, preferably 99% or more, more preferably 99.9% or more.

The ethylene and propylene obtained in this way can be used as commonly prepared ethylene and propylene derivatives, and ethylene can be used for the following preparations: for example, preparing ethylene oxide, ethylene glycol, ethanolamine, glycol ether, etc. by oxidation; Chlorination to prepare vinyl chloride monomer, 1,1,1-trichloroethane, vinyl chloride resin, vinylidene chloride; or prepare α-olefins, low-density or high-density polyethylene through the polymerization of ethylene; through the ethyl of benzene Chemical to prepare ethylbenzene and so on.

Polyethylene terephthalate can be further prepared from ethylene glycol prepared from ethylene, and higher alcohols can be prepared from α-olefins through carbonylation reaction and subsequent hydrogenation reaction, and ethylbenzene can also be used It is used as raw material to prepare styrene monomer, ABS resin, etc. In addition, vinyl acetate is produced by reaction with acetic acid, acetaldehyde and ethyl acetate as a derivative thereof are produced by Wacker reaction, and the like.

In addition, propylene is suitable for the production of, for example, acrylonitrile by ammoxidation; acrolein, acrylic acid and acrylates by selective oxidation; n-butanol, 2-ethylhexanol by oxo reactions Other oxo alcohols; Polypropylene is produced by the polymerization of propylene; Propylene oxide and propylene glycol are produced by the selective oxidation of propylene. In addition, the Wacker reaction can be used to prepare acetone, and acetone can be used to prepare methyl isobutyl ketone. Also, acetone cyanohydrin can be produced from acetone, which can finally be converted into methyl methacrylate. In addition, isopropanol can also be prepared by hydration of propylene. In addition, cumene can be obtained by alkylating benzene, which can be used as a raw material to prepare phenol, bisphenol A, and polycarbonate resins.

In addition, it is preferable to supply the fluid containing hydrocarbons having 2 or less carbon atoms and hydrocarbons having 3 carbon atoms obtained in the third embodiment and the fourth embodiment of the separation step to the ethylene production and Purification is carried out in the process flow of propylene. Examples of processes for producing ethylene and propylene other than this process include steam cracking processes for naphtha, ethane, and the like. Therefore, the equipment investment in the process flow can be significantly reduced.

On the other hand, when the ethylene-containing fluid produced in this process cannot be supplied to processes for producing ethylene and propylene other than this process, since it is necessary to perform purification of ethylene in this process, in this case Next, it is preferable to adopt the above-mentioned first embodiment or second embodiment.

1st and 2nd embodiment

<Separation and recycling of hydrocarbons having 4 or more carbon atoms: steps (3A), (3B)>

At least a part of the fluid (A) rich in hydrocarbons with 4 or more carbon atoms separated from the reactor outlet gas (hereinafter referred to as the hydrocarbon fluid (A) with 4 or more carbon atoms) is recycled to the reactor, and the remaining fluid Removed from this process flow.

The term "taken out from the process" here means that it is not recycled to the reactor of the process, and can be directly supplied to other processes through piping, or temporarily stored in a container through piping before being recycled. supplied to other processes. In addition, it can also be used as a fuel without being supplied to other processes.

As a first embodiment of the method for recycling the hydrocarbon fluid (A) having 4 or more carbon atoms to the reactor, a method including the step of: recycling the hydrocarbon fluid (A) having 4 or more carbon atoms Part (B) of (A) is taken out from the process flow, and the remaining fluid (C) is separated into fluid (D) and fluid (E) by usual separation methods such as distillation, and fluid (D) is recycled to In the reactor, the fluid (E) is taken out from the process flow, wherein the aromatic compound concentration (weight %) in the fluid (D) is lower than that in the fluid (C), and the number of carbon atoms in the fluid (E) is The hydrocarbon concentration of 4 is lower than in fluid (C).

As a second embodiment, a method including the step of separating the hydrocarbon fluid (A) having 4 or more carbon atoms into fluid (G) and fluid (F) by a common separation method such as distillation can be employed. , and at least a portion of the fluid (F) is withdrawn from the process, at least a portion of the fluid (I) of the stream (G) is recycled to the reactor, and the remaining fluid (H) is withdrawn from the process , wherein the concentration (% by weight) of aromatic compounds in the fluid (G) is lower than that in the fluid (A), and the concentration of hydrocarbons with 4 carbon atoms in the fluid (F) is lower than that in the fluid (A).

When using a raw material containing paraffins with 4 or more carbon atoms as the olefin raw material with 4 or more carbon atoms, since the fluid (B) in the first embodiment or the fluid (H) in the second embodiment contains a large amount of chain The composition of alkanes is fluid, so it is difficult to separate and purify effective components such as butene. Therefore, when the process flow is close to the steam cracking process flow, it is preferably supplied to the steam cracking process flow and effectively utilized as a cracking raw material.

Therefore, these fluids (B), (H) can be used as raw materials for the production of ethylene or propylene in the steam cracking process flow. At this time, it is preferable to contact at least a part of the fluid (B) or the fluid (H) with a hydrogenation catalyst, and to supply the fluid having a higher paraffin concentration than the fluid (B) or the fluid (H) to the steam cracking process flow. When a fluid with a high olefin concentration is supplied to a cracker in a steam cracking process, carbon precipitation is likely to occur in the cracker, and therefore it is not preferable.

In addition, at this time, the total concentration of the aromatic compounds contained in the fluid (B) or the fluid (H) is preferably less than 5.0% by volume, more preferably less than 3.0% by volume. When the concentration of aromatic compounds is high, not only is there a large amount of carbon precipitated but also the ethylene yield tends to decrease when it is supplied to a cracker, which is not preferable.

In addition, it is preferable to mix the fluid (E) in the above-mentioned first embodiment or the fluid (F) in the second embodiment with a cracked gasoline fraction such as a steam cracking process. In this way, the fluid (E) or the fluid (F) can be effectively used.

The cracked gasoline mentioned here refers to a fluid mainly containing paraffins, olefins, dienes, and aromatic compounds with a carbon number of 5 to 10, and the effective components can be recovered from the cracked gasoline as required. Examples of active ingredients include hydrocarbons having 5 carbon atoms, or aromatic compounds such as benzene, toluene, and xylene.

When the cracked gasoline contains hydrocarbons having 4 carbon atoms, it is not preferable because the hydrocarbon fluid having 5 carbon atoms recovered from the cracked gasoline contains hydrocarbons having 4 carbon atoms. Therefore, it is preferable that the hydrocarbons having 4 carbon atoms in the fluid (E) or the fluid (F) mixed with the cracked gasoline fraction is less than 5% by weight, more preferably less than 2% by weight.

As a feature of the first embodiment, since the burden of separation steps such as distillation can be reduced by taking out the fluid (B), it is more advantageous than the second embodiment in terms of auxiliary material costs and equipment investment costs. However, the fluid (B) has the same composition as the fluid (A), and has a higher concentration of aromatic compounds than the fluid (H) obtained in the second embodiment. Therefore, the process flow is selected according to the use of the fluid being taken out.

third embodiment

<Recycling of hydrocarbons having 4 or more carbon atoms: Step (4C)>

A part (P) of the fluid (N) rich in hydrocarbons with 4 or more carbon atoms (hereinafter referred to as "hydrocarbon fluid (N) with 4 or more carbon atoms") separated through step (3C) from the process flow The residual fluid (Q) is recycled to the reactor. In addition, at least a part of the liquid fluid (M) rich in hydrocarbons having 4 or more carbon atoms and containing aromatic compounds condensed in the compression step is taken out from the process flow.

The term "taken out from the process" here means that it is not recycled to the reactor of the process, and can be directly supplied to other processes through piping, or temporarily stored in a container through piping before being recycled. supplied to other processes. In addition, it can also be used as a fuel without being supplied to other processes.

The liquid fluid (M) can be separated by distillation into a fluid (R) and a fluid (S), wherein the aromatic compound concentration (weight %) in the fluid (R) is lower than in the liquid fluid (M), and the fluid ( The concentration of hydrocarbons having a carbon number of 4 in S) is lower than in the liquid fluid (M). At this time, it is preferable to return the fluid (R) to the circulation site of any one or two or more fluids selected from the aforementioned fluids (K), (L), (M), (P) and (Q). This distillation operation is particularly preferably performed when the liquid fluid (M) contains a large amount of hydrocarbons having 4 or less carbon atoms.

When using a raw material containing paraffins with 4 or more carbon atoms as an olefin raw material with 4 or more carbon atoms, since the above-mentioned fluids (M), (P), and (R) are compositional fluids containing a large amount of paraffins, it is difficult to separate and purify them. Active ingredients such as butene. Therefore, when the process flow is close to the steam cracking process flow, preferably one or more of these fluids (M), (P), (R) are supplied to the steam cracking process flow for effective utilization as cracking raw materials.

These streams can thus be used as feedstock for the production of ethylene or propylene in steam cracking. At this time, it is preferable to bring at least a part of the fluids (M), (P), (R) into contact with a hydrogenation catalyst, and to supply a fluid having a higher paraffin concentration than the fluids (M), (P), (R) to the steam in the cracking process. When a fluid with a high olefin concentration is supplied to a cracker in a steam cracking process, carbon precipitation is likely to occur in the cracker, and therefore it is not preferable.

In addition, at this time, the total concentration of the aromatic compounds contained in the fluids (M), (P), and (R) is preferably less than 5.0% by volume, more preferably less than 3.0% by volume. When the concentration of aromatic compounds is high, not only is there a large amount of carbon precipitated but also the ethylene yield tends to decrease when it is supplied to a cracker, which is not preferable.

In addition, it is preferable that the above-mentioned fluid (S) is mixed with a cracked gasoline fraction of a steam cracking process flow or the like. In this way, the fluid (S) can be effectively used. In addition, when the concentration of hydrocarbons having 4 or less carbon atoms in the fluid (S) is low, the fluid (M) may be directly mixed with the cracked gasoline fraction.

The cracked gasoline mentioned here refers to a fluid mainly containing paraffins, olefins, dienes, and aromatic compounds with a carbon number of 5 to 10, and the effective components can be recovered from the cracked gasoline as required. Examples of active ingredients include hydrocarbons having 5 carbon atoms, or aromatic compounds such as benzene, toluene, and xylene.

When the cracked gasoline contains hydrocarbons having 4 carbon atoms, it is not preferable because the hydrocarbon fluid having 5 carbon atoms recovered from the cracked gasoline contains hydrocarbons having 4 carbon atoms. Therefore, it is preferred that the hydrocarbons having 4 carbon atoms in the fluid (M) or the fluid (S) mixed with the cracked gasoline fraction be less than 5% by weight, more preferably less than 2% by weight.

<Control of Substrate Concentration at Reactor Inlet>

In the above-mentioned first embodiment, by controlling the flow rates of the fluid (B) and the fluid (E), the flow rate of diluent gas such as paraffin contained in the fluid (D) recycled to the reactor can be controlled.

Furthermore, in the second embodiment, by controlling the flow rates of the fluid (F) and the fluid (H), it is possible to control the flow rate of diluent gases such as paraffins contained in the fluid (I) recycled to the reactor.

In the above third embodiment, the flow rate of fluid (R) is further controlled by controlling the flow rates of fluid (M) and fluid (P) or by controlling the flow rates of fluid (P), fluid (R) and fluid (S) Or its return position, it is possible to control the diluent gas flow rate such as paraffin contained in the fluid (Q) which is recycled to the reactor, wherein the fluid (R) is returned to the fluid (K), (L), ( The fluid in the circulation site of any one or two or more fluids of M), (P) and (Q).

In this way, it is preferable to control the total concentration (substrate concentration) of olefins having 4 or more carbon atoms, methanol, and dimethyl ether in all feed materials supplied to the reactor to 20% by volume or more and 80% by volume or less.

[Combination with steam cracking process]

In the steam cracking process, most of the necessary components are removed from the obtained hydrocarbon fluid (BB fraction) with 4 carbon atoms, and the obtained low-value fluid (mainly C4 raffinate-2) is hydrogenated , and return it to the cracker.

In this process flow, the fluid with low value can be used as raw material, and then the fluid not needed in this process flow can be used in the steam cracking process flow. From this point of view, this process flow can combine low Extremely efficient process flow for efficient utilization of value fluids.

[Implementation of the process flow]

Hereinafter, embodiments of the process flow of the present invention will be described with reference to the drawings.

FIG. 1 shows the first embodiment of the process flow of the present invention, and FIG. 2 shows the second embodiment.

In Figs. 1 and 2, 10 is a reactor, 20 is a first separation and purification system, and 30A and 30B are a second separation and purification system. 101 to 114 represent piping, respectively.

<Explanation of the first embodiment (FIG. 1)>

At least one of the raw material having 4 or more carbon atoms, the hydrocarbon fluid (D) having 4 or more carbon atoms from the second separation and purification system 30A, methanol, and dimethyl ether is passed through pipes 101, 102, 103 and pipe 104, respectively. into the reactor 10. The olefin raw material having 4 or more carbon atoms supplied to the reactor 10 may contain paraffins having 4 or more carbon atoms such as n-butane or isobutane. In addition, the raw material fluid supplied to the reactor 10 via the pipe 104 may contain butadiene or an aromatic compound. As described above, the butadiene concentration in the raw material fluid is usually 2.0% by volume or less, and the molar ratio of the total amount of aromatic compounds to the total amount of olefins with 4 or more carbon atoms contained in the raw material fluid in piping 104 is usually less than 0.05. It should be noted that the raw material fluids refer to the total amount of fluids supplied through the pipes 101 , 102 , and 103 , and these fluids do not necessarily have to be combined before entering the reactor 10 , and may be separately supplied to the reactor 10 . The raw material gas supplied to the reactor 10 contacts and reacts with a catalyst in the reactor 10 to obtain a reactor outlet gas containing propylene, other olefins, paraffins, aromatic compounds, and water.

The gas at the outlet of the reactor is sent to a common separation and purification system 20 such as cooling, compression, and distillation through a pipe 105. In the separation and purification system 20, it is separated into a fluid rich in hydrocarbons with a carbon number of 3 or less, a carbon atom-rich The fluid (A) of hydrocarbons of the number 4 or more and the fluid rich in water are taken out via pipes 106 , 108 , and 107 , respectively. Here, the fluid rich in hydrocarbons having 3 or less carbon atoms refers to one or more fluids. For example, it may be a fluid containing hydrocarbons with 3 or less carbon atoms, or a fluid rich in hydrocarbons with 2 or less carbon atoms and a fluid rich in hydrocarbons with 3 carbon atoms, or a fluid containing 2 or less carbon atoms. Two types of fluids are the following hydrocarbons and a fluid containing hydrocarbons with 3 carbon atoms and a fluid rich in hydrocarbons with 3 carbon atoms. Three or more fluids are also possible.

A part of the fluid (A) rich in hydrocarbons having 4 or more carbon atoms is taken out of the process through a pipe 109 , and the remaining fluid (C) is supplied to a general separation and purification system 30A such as distillation through a pipe 110 . A portion of stream (B) of stream (A) can be taken out of the process flow. At this time, the fluid (B) taken out can be used as the cracking raw material of the steam cracking process flow. In this case, it is preferable to bring the withdrawn fluid (B) into contact with a hydrogenation catalyst to obtain a fluid with an increased paraffin concentration and to supply it to the steam cracking process flow. The total concentration of aromatic compounds in the withdrawn fluid (B) at this time is less than 5.0% by volume.

In the separation and purification system 30A, fluid (C) is separated into fluid (D) and fluid (E), and at least a part of fluid (D) is recycled to reactor 10 via piping 102, while fluid (E) is recycled via piping 102 111 is taken out from the process flow, wherein the concentration of aromatic compounds in the fluid (D) is lower than that in the fluid (C), and the concentration of hydrocarbons with more than 4 carbon atoms in the fluid (E) is lower than that in the fluid (C) . The withdrawn fluid (E) can be mixed with the cracked gasoline fraction of the steam cracking process flow and the like. In this case, the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (E) is preferably less than 5% by weight.

A part of the fluid (D) (hereinafter referred to as "fluid (X)") can be taken out of the process flow. At this point, the extracted fluid (X) can be used as cracking raw material for the steam cracking process flow. In this case, it is preferable to bring the withdrawn fluid (X) into contact with a hydrogenation catalyst, and to supply the fluid with an increased paraffin concentration to the steam cracking process flow. The total concentration of aromatic compounds in the withdrawn fluid (X) at this time is less than 5.0% by volume.

The above-mentioned fluid (D) and fluid (X) are not necessarily taken out from the process flow, but in order to prevent the accumulation of paraffins, it is preferable to take at least any one of the fluids out of the process flow.

<Explanation of the second embodiment (FIG. 2)>

At least one of the raw material having 4 or more carbon atoms, the hydrocarbon fluid (I) having 4 or more carbon atoms from the second separation and purification system 30B, methanol, and dimethyl ether is passed through pipes 101, 102, 103 and pipe 104, respectively. into the reactor 10. Then, in the first separation and purification system 20, since the gas from the outlet of the reactor 10 is separated into a fluid rich in hydrocarbons with 3 or less carbon atoms, a hydrocarbon fluid (A) with 4 or more carbon atoms, and a fluid rich in water The steps up to the fluid are the same as those in Fig. 1, so the description will be omitted.

The hydrocarbon fluid (A) having 4 or more carbon atoms is supplied to a general separation and purification system 30B such as distillation through a pipe 108 . In the separation and purification system 30B, it is separated into a fluid (G) having an aromatic compound concentration lower than that of the fluid (A) and a fluid (F) having a hydrocarbon concentration of 4 or more carbon atoms lower than that of the fluid (A), and the fluid (F) is passed through Piping 112 is taken out of the process flow. The withdrawn fluid (F) can be mixed with the cracked gasoline fraction of the steam cracking process flow or the like. In this case, the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (F) is preferably less than 5% by weight.

Fluid (G) is taken out via pipe 113 , part of it (H) is taken out of the process flow via pipe 114 , and the remaining fluid (I) is recycled to reactor 10 via pipe 102 . The extracted fluid (H) can be used as the cracking raw material of the steam cracking process flow. In this case, it is preferable to bring the fluid (H) into contact with a hydrogenation catalyst, and to supply the fluid with an increased paraffin concentration to the steam cracking process flow. The total concentration of aromatic compounds in the fluid (H) at this time is less than 5.0% by volume.

It is not essential to take the above-mentioned fluid (H) out of the process flow, but it is preferable to take at least part of any one of the fluids out of the process flow in order to prevent the accumulation of paraffins.

[Implementation of the process flow]

<Third Embodiment (FIG. 3)>

Hereinafter, embodiments of the process flow of the present invention will be described with reference to the drawings.

Figure 3 shows an embodiment of the process flow of the present invention.

In Fig. 3, 13 is a reactor, 23 is a compressor, 33 is a separation tank, 43 is an oil-water separator, 53 is a first separation and purification system, and 63 is a second separation and purification system. 301 to 315 represent piping, respectively.

At least one of the olefin raw material having 4 or more carbon atoms, the hydrocarbon fluid (Q) having 4 or more carbon atoms from the first separation and purification system 53, methanol, and dimethyl ether is passed through pipes 301, 302, 303 and pipes 301, 302, 303, respectively. 304 is fed into the reactor 13. The olefin raw material having 4 or more carbon atoms supplied to the reactor 13 may contain paraffins having 4 or more carbon atoms, such as n-butane, isobutane, and the like. In addition, the raw material fluid supplied to the reactor 13 via the pipe 304 may contain butadiene or an aromatic compound. As described above, the butadiene concentration in the raw material fluid is usually 2.0% by volume or less, and the molar ratio of the total amount of aromatic compounds to the total amount of olefins with 4 or more carbon atoms contained in the raw material fluid in piping 304 is usually less than 0.05. It should be noted that the raw material fluid refers to the total amount of fluids supplied through the pipes 301 , 302 , and 303 , and these fluids do not necessarily have to be combined before entering the reactor 13 , and may be separately supplied to the reactor 13 . The raw material gas supplied to the reactor 13 contacts and reacts with a catalyst in the reactor 10 to obtain a reactor outlet gas containing propylene, other olefins, paraffins, aromatic compounds, and water.

The gas at the outlet of the reactor is cooled by, for example, a heat exchanger, and the cooled gaseous fluid (K) passes through the pipe 305 to be pressurized by the compressor 23 . One compressor 23 may be used, but a plurality of compressors is preferable. A heat exchanger and a separation tank 33 are provided after each compressor 23, and the compressed gas is cooled and then separated into a gaseous fluid (L) and a condensed component. The condensed component is sent to the oil-water separator 43 through the pipeline 308, and is separated into a fluid (M) rich in hydrocarbons with more than 4 carbon atoms and a fluid rich in water; the fluid rich in water is taken out through the pipeline 310, and the fluid rich in water The fluid (M) containing hydrocarbons having 4 or more carbon atoms is sent to the second separation and purification system 63 through the pipe 309 .

The gaseous fluid (L) separated by the separation tank 33 is sent to a common first separation and purification system 53 such as distillation through a pipe 307, and is separated into a fluid rich in hydrocarbons having 3 or less carbon atoms and a fluid containing 4 or more carbon atoms. Fluids (N) of hydrocarbons are taken out through pipes 313 and 314 , respectively. Here, the fluid rich in hydrocarbons having 3 or less carbon atoms refers to one or more fluids. For example, it may be a fluid containing hydrocarbons with 3 or less carbon atoms, or a fluid rich in hydrocarbons with 2 or less carbon atoms and a fluid rich in hydrocarbons with 3 carbon atoms, or a fluid containing 2 or less carbon atoms. Two types of fluids are the following hydrocarbons and a fluid containing hydrocarbons with 3 carbon atoms and a fluid rich in hydrocarbons with 3 carbon atoms. Three or more fluids are also possible.

A part (P) of the fluid (N) rich in hydrocarbons having 4 or more carbon atoms is taken out of the process through the pipe 315 , and the remaining fluid (Q) is recycled to the reactor 13 through the pipe 302 . The fluid (P) can be used as the cracking raw material of the steam cracking process flow. In this case, it is preferable to bring the fluid (P) into contact with a hydrogenation catalyst, and to supply the fluid with an increased paraffin concentration to the steam cracking process flow. At this time, it is preferred that the total concentration of aromatic compounds in the fluid (P) is less than 5.0% by volume.

On the other hand, the liquid fluid (M) separated by the oil-water separator 43 is a liquid component rich in hydrocarbons with more than 4 carbon atoms and containing aromatic compounds, and the liquid fluid (M) can be directly taken out from the process flow , at this time, the liquid fluid (M) can be used as the cracking raw material of the steam cracking process flow. In this case, it is preferable to bring the fluid (M) into contact with a hydrogenation catalyst, and to supply the fluid with an increased paraffin concentration to the steam cracking process flow. At this time, it is preferred that the total concentration of aromatic compounds in the fluid (M) is less than 5.0% by volume.

In addition, when the concentration of hydrocarbons with 4 carbon atoms in the liquid fluid (M) is low, the fluid (M) can also be directly mixed with the cracked gasoline fraction of the steam cracking process or the like. In this case, it is preferable that the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (M) is less than 5% by weight.

In addition, it is preferable to separate at least a part of the liquid fluid (M) into a fluid (R) and a fluid (S) through a usual separation step such as distillation, that is, the second separation and purification system 60, and the concentration of aromatic compounds in the fluid (R) is lower than in fluid (M) in which the concentration of hydrocarbons having 4 carbon atoms is lower than in fluid (M). Among them, the separated fluid (R) is taken out through the pipe 111, but it is preferable that the fluid (R) returns to the pipe through which the fluid (K), the fluid (L), the fluid (N), the fluid (P), and the fluid (Q) flow. One or more of 305, 307, 314, 315, 302.

On the other hand, a fluid (S) is taken out from the pipe 312, and this fluid (S) can be mixed with a cracked gasoline fraction of a steam cracking process or the like. In this case, it is preferable that the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (S) is less than 5% by weight.

The above-mentioned operation of taking out the fluid (P) out of the process flow is not essential, but in order to prevent the accumulation of paraffins, it is preferable to take out at least part of any one of the fluids from the process flow.

Example

Hereinafter, although an Example is given and the present invention is demonstrated more concretely, this invention is not limited to the following Example at all.

[Preparation of Catalyst]

Catalysts used in the following examples and comparative examples were prepared by the following methods.

<Preparation example of catalyst>

Dissolve 26.6g of tetra-n-propylammonium bromide (TPABr) and 4.8g of sodium hydroxide in 280g of water successively, then slowly add 75g of colloidal silicon dioxide (SiO ₂ =40% by weight, Al<0.1% by weight) and 35g of water The mixed solution was fully stirred to obtain an aqueous gel. Then, this gel was placed in a 1000 ml autoclave, and hydrothermal synthesis was performed at 170° C. for 72 hours while stirring at 300 rpm under self-pressure. The solid content was separated from the product by pressure filtration, washed with water sufficiently, and then dried at 100° C. for 24 hours. The dried catalyst was fired at 550° C. for 6 hours under air circulation to obtain Na-type aluminosilicate.

2.0 g of the Na-type aluminosilicate was suspended in 40 ml of a 1 M ammonium nitrate aqueous solution, and stirred at 80° C. for 2 hours. The solid content was separated from the treated solution by suction filtration, washed with water sufficiently, suspended again in 40 ml of 1 M ammonium nitrate aqueous solution, and stirred at 80° C. for 2 hours. The solid content was separated from the treated solution by suction filtration, washed with water sufficiently, and then dried at 100° C. for 24 hours. The dried catalyst was calcined at 500° C. for 4 hours under air circulation to obtain H-type aluminosilicate.

By performing XRD (X-ray diffraction) on the above catalyst, it was confirmed that the zeolite structure was MFI type. The composition of the catalyst was quantified by chemical analysis, and SiO ₂ /Al ₂ O ₃ =1100 (molar ratio).

[Preparation of Propylene]

The following are examples and comparative examples of producing propylene using the above-mentioned catalysts.

<Example 1>

The production of propylene is carried out using the catalyst described above.

A normal-pressure fixed-bed circulation reactor was used for the reaction, and a reaction tube made of quartz with an inner diameter of 6 mm was filled with a mixture of 0.10 g of the catalyst and 1.0 g of quartz sand. The reactor is fed by evaporator with isobutene (40 vol %), methanol (20 vol %), benzene (0.8 vol %), butadiene (0.1 vol %) and isobutane (39.1 vol %) The gas was used as a simulated gas having a composition corresponding to the inlet gas (pipe 104 in FIG. 1 or FIG. 2 ) of the reactor of the present invention. The reaction temperature (gas temperature at the reactor inlet) was 550°C. 70 minutes after the start of the reaction, the product was analyzed by gas chromatography. The reaction conditions and reaction results at this time are shown in Table 1.

The selectivity of propylene was 54.8%, which was a very high level.

The reaction was continued, and the time until the conversion of methanol fell below 99% was evaluated as the catalyst life. As a result, the catalyst life was 312 hours.

<Example 2>

The reaction was performed in the same manner as in Example 1, except that the concentration of benzene supplied to the reactor was 1.6% by volume and the concentration of isobutane was 38.3% by volume. 70 minutes after the start of the reaction, the product was analyzed by gas chromatography. The reaction conditions and reaction results at this time are shown in Table 1.

The selectivity of propylene was 54.4%, which was a very high level.

The reaction was continued, and the time until the conversion of methanol fell below 99% was evaluated as the catalyst life. As a result, the catalyst life was 305 hours.

<Comparative example 1>

The reaction was performed in the same manner as in Example 1, except that the concentration of benzene supplied to the reactor was 3.2% by volume and the concentration of isobutane was 36.7% by volume. 70 minutes after the start of the reaction, the product was analyzed by gas chromatography. The reaction conditions and reaction results at this time are shown in Table 1.

The selectivity of propylene was 51.4%, which was a very low level compared with Examples 1 and 2.

This is because the raw material butene and/or methanol react with benzene to generate alkylated benzene, so that the butene and/or methanol that should be used to generate propylene are uselessly consumed.

The reaction was continued, and the time until the conversion of methanol fell below 99% was evaluated as the catalyst life. As a result, the catalyst life was 221 hours, which was a very short result compared with Examples 1 and 2. This is presumably because the aforementioned alkylated benzene clogs the fine pores of the catalyst and promotes coking.

Thus, according to the method of the present invention, by taking at least a part of the aromatic compound out instead of recycling it to the reactor, the concentration of the aromatic compound at the inlet of the reactor is reduced, which is very important for achieving a high propylene yield and suppressing the coking degradation of the catalyst. Effective.

[Table 1]

^* 1: Selectivity of olefins with 5 or more carbon atoms

^* 2: Total selectivity of aromatics and paraffins

Although the present invention has been described in detail with reference to specific embodiments, it is clear to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

This application is based on the Japanese Patent Application (Japanese Patent Application No. 2006-255503) filed on September 21, 2006, and the Japanese Patent Application (Japanese Patent Application No. 2006-255504) filed on September 21, 2006. The content of the application is incorporated into the present application by reference.

Industrial Applicability

The present invention provides a novel and inexpensive process flow for the production of propylene by making methanol and dimethyl A process flow for producing propylene by reacting at least one of ethers with olefins having 4 or more carbon atoms.

Claims (56)

1. A method for preparing propylene, the method is that in the presence of a catalyst, a raw material containing olefins with more than 4 carbon atoms and at least one of methanol and dimethyl ether is contacted with a catalyst in a reactor to prepare propylene The method, it is made up of the technological process comprising following steps (1), (2) and (3A), Step (1): At least one of methanol and dimethyl ether, an olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (D) recycled from step (3A) are supplied to the reactor, relative to the reaction The molar flow rate of olefins with 4 or more carbon atoms at the inlet of the reactor, and the molar flow rate of olefins with 4 or more carbon atoms at the outlet of the reactor are 20% or more and less than 90%. Under these reaction conditions, the above-mentioned The material contacts with above-mentioned catalyzer, obtains the gas (reactor outlet gas) that contains propylene, other olefins, paraffin, aromatic compound and water by reactor outlet; Step (2): Separating the reactor outlet gas from the above step (1) into a fluid rich in hydrocarbons with 3 or less carbon atoms, a fluid (A) rich in hydrocarbons with 4 or more carbon atoms, and a fluid rich in water the fluid; Step (3A): separating at least a part of fluid (C) from fluid (A) in the above-mentioned step (2) into fluid (D) and fluid (E), and the above-mentioned fluid (D) is recycled to the reactor, and the above-mentioned fluid (E) is taken out from the process flow, wherein the concentration of aromatic compounds in the fluid (D) is lower than that in the fluid (C), and the concentration of hydrocarbons with 4 carbon atoms in the fluid (E) is lower than that in the fluid (C) mid Lo. 2. A method for preparing propylene, the method is that in the presence of a catalyst, a raw material containing an olefin having more than 4 carbon atoms and at least one of methanol and dimethyl ether is contacted with a catalyst in a reactor to prepare propylene The method, it is made up of the technological process comprising following steps (1), (2) and (3A), Step (1): At least one of methanol and dimethyl ether, an olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (D) recycled from step (3A) are supplied to the reactor, relative to the reaction The molar flow rate of olefins with 4 or more carbon atoms at the inlet of the reactor, and the molar flow rate of olefins with 4 or more carbon atoms at the outlet of the reactor are 20% or more and less than 70%. Under these reaction conditions, the above-mentioned The material contacts with above-mentioned catalyzer, obtains the gas (reactor outlet gas) that contains propylene, other olefins, paraffin, aromatic compound and water by reactor outlet; Step (2): Separating the reactor outlet gas from the above step (1) into a fluid rich in hydrocarbons with 3 or less carbon atoms, a fluid (A) rich in hydrocarbons with 4 or more carbon atoms, and a fluid rich in water the fluid; Step (3A): A part (B) of fluid (A) in the above step (2) is taken out from the process flow, and the remaining fluid (C) is separated into fluid (D) and fluid (E), and the above fluid (D) recycle to the reactor from which the above-mentioned stream (E) is withdrawn, wherein said stream (D) has a lower concentration of aromatic compounds than stream (C), said stream (E) contains carbon The concentration of hydrocarbons having an atomic number of 4 is lower than in fluid (C). 3. The method for producing propylene according to claim 1 or 2, wherein the reactor comprises two or more reaction sections connected in series, and at least one of methanol and dimethyl ether supplied to the reactor, At least one of the olefin raw material having 4 or more carbon atoms and the recycled hydrocarbon-containing fluid (D) is dividedly supplied to the first-stage reaction section and the second-stage or subsequent reaction section. 4. The method for preparing propylene according to any one of claims 1 to 3, wherein the above-mentioned fluid (B) is supplied to the steam cracking process flow and used as a cracking raw material. 5. The method for producing propylene according to claim 4, wherein at least a part of the fluid (B) is brought into contact with a hydrogenation catalyst, and then supplied to a steam cracking process flow. 6. The method for producing propylene according to any one of claims 1 to 5, wherein the total concentration of the aromatic compounds contained in the fluid (B) is less than 5.0% by volume. 7. The method for preparing propylene according to any one of claims 1 to 6, wherein the above-mentioned fluid (E) is mixed with the cracked gasoline fraction of the steam cracking process flow. 8. The method for producing propylene according to any one of claims 1 to 7, wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (E) is less than 5% by weight. 9. The method for producing propylene according to any one of claims 1 to 8, wherein, by controlling the flow rates of the above-mentioned fluid (B) and the above-mentioned fluid (E), the The total concentration of olefins with 4 or more carbon atoms, methanol and dimethyl ether is controlled to be 20% by volume or more and 80% by volume or less. 10. A method for preparing propylene, the method is in the presence of a catalyst, making a mixture containing olefins with more than 4 carbon atoms and at least one of methanol and dimethyl ether contact with the catalyst in a reactor to prepare propylene The method, it is made up of the technological process comprising following steps (1), (2) and (3B), Step (1): At least one of methanol and dimethyl ether, an olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (I) recycled from step (3B) are supplied to the reactor, relative to the reaction The molar flow rate of olefins with 4 or more carbon atoms at the inlet of the reactor, and the molar flow rate of olefins with 4 or more carbon atoms at the outlet of the reactor are 20% or more and less than 90%. Under these reaction conditions, the above-mentioned The material is contacted with the catalyst, and the gas containing propylene, other olefins, paraffins, aromatic compounds and water is obtained from the reactor outlet (reactor outlet gas); Step (2): Separating the reactor outlet gas from the above step (1) into a fluid rich in hydrocarbons with 3 or less carbon atoms, a fluid (A) rich in hydrocarbons with 4 or more carbon atoms, and a fluid rich in water the fluid; Step (3B): The fluid (A) in the above step (2) is separated into fluid (G) and fluid (F), and at least a part (I) of the above fluid (G) is recycled to the reactor, wherein the The concentration of aromatic compounds in the fluid (G) is lower than that in the fluid (A), and the concentration of hydrocarbons with 4 carbon atoms in the fluid (F) is lower than that in the fluid (A). 11. A method for preparing propylene, the method is in the presence of a catalyst, making a mixture containing olefins with more than 4 carbon atoms and at least one of methanol and dimethyl ether contact with the catalyst in a reactor to prepare propylene The method, it is made up of the technological process comprising following steps (1), (2) and (3B), Step (1): At least one of methanol and dimethyl ether, an olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (I) recycled from step (3B) are supplied to the reactor, relative to the reaction The molar flow rate of olefins with more than 4 carbon atoms at the reactor inlet, and the molar flow rate of olefins with more than 4 carbon atoms at the reactor outlet are more than 20% and less than 70%. Under the reaction conditions, make it contact with the catalyst, by The reactor outlet obtains gas containing propylene, other olefins, paraffins, aromatic compounds and water (reactor outlet gas); Step (2): Separating the reactor outlet gas from the above step (1) into a fluid rich in hydrocarbons with 3 or less carbon atoms, a fluid (A) rich in hydrocarbons with 4 or more carbon atoms, and a fluid rich in water the fluid; Step (3B): The fluid (A) in the above-mentioned step (2) is separated into a fluid (G) and a fluid (F), the above-mentioned fluid (F) is taken out from the process flow, and a part of the above-mentioned fluid (G) is (I) recirculation to the reactor, the remaining stream (H) is withdrawn from the process, wherein said stream (G) has a lower concentration of aromatics than stream (A), said stream (F) The concentration of hydrocarbons having a carbon number of 4 is lower than in fluid (A). 12. The method for producing propylene according to claim 10 or 11, wherein the reactor comprises two or more reaction sections connected in series, and the above-mentioned olefin raw material having 4 or more carbon atoms supplied to the reactor, At least one of methanol and dimethyl ether, and the recycled hydrocarbon-containing fluid (I) are dividedly supplied to the first-stage reaction section and the second-stage or subsequent reaction section. 13. The method for preparing propylene according to any one of claims 10 to 12, wherein the fluid (H) is supplied to the steam cracking process flow and used as cracking raw material. 14. The process for the production of propylene according to claim 13, wherein at least a part of the fluid (H) is brought into contact with a hydrogenation catalyst and then fed into a steam cracking process flow. 15. The method for producing propylene according to any one of claims 10 to 14, wherein the total concentration of aromatic compounds contained in the fluid (H) is less than 5.0% by volume. 16. The method for preparing propylene according to any one of claims 10 to 15, wherein the fluid (F) is mixed with the cracked gasoline fraction of the steam cracking process flow. 17. The method for producing propylene according to any one of claims 10 to 16, wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (F) is less than 5% by weight. 18. The method for producing propylene according to any one of claims 10 to 17, wherein, by controlling the flow rates of the fluid (F) and the fluid (H), all the raw materials supplied to the reactor The total concentration of olefins with more than 4 carbon atoms, methanol and dimethyl ether is controlled to be more than 20% by volume and less than 80% by volume. 19. The method for preparing propylene according to any one of claims 1 to 18, wherein the step (2) comprises the steps of: removing moisture by condensation from the reactor outlet gas through cooling and compression steps, and then passing Separate by distillation into a fluid rich in hydrocarbons with 2 or less carbon atoms and a fluid rich in hydrocarbons with 3 or more carbon atoms, and then separate the fluid rich in hydrocarbons with 3 or more carbon atoms into a fluid rich in carbon atoms by distillation Fluids with 3 hydrocarbons and fluids rich in hydrocarbons with 4 or more carbon atoms. 20. The method for preparing propylene according to any one of claims 1 to 18, wherein the step (2) comprises the steps of: removing moisture by condensation from the reactor outlet gas through cooling and compression steps, and then passing Separate by distillation into a fluid rich in hydrocarbons with 3 or less carbon atoms and a fluid rich in hydrocarbons with 4 or more carbon atoms, and then separate the fluid rich in hydrocarbons with 3 or less carbon atoms into a fluid rich in carbon atoms by distillation Fluids containing hydrocarbons with a number of 2 or less and fluids rich in hydrocarbons with a number of carbon atoms of 3. 21. The method for preparing propylene according to any one of claims 1 to 18, wherein the step (2) comprises the steps of: removing moisture by condensation from the reactor outlet gas through cooling and compression steps, and then passing Distillation and separation into a fluid containing hydrocarbons with 2 or less carbon atoms and hydrocarbons with 3 carbon atoms, and a fluid rich in hydrocarbons with 3 or more carbon atoms, and then distilling the hydrocarbons with 3 or more carbon atoms The fluid is separated into a fluid rich in hydrocarbons with 3 carbon atoms and a fluid rich in hydrocarbons with 4 or more carbon atoms. 22. The method for preparing propylene according to any one of claims 1 to 18, wherein the step (2) comprises the steps of: removing moisture by condensation from the reactor outlet gas through cooling and compression steps, and then passing Distillation is separated into a fluid rich in hydrocarbons with 3 or less carbon atoms and a fluid rich in hydrocarbons with 4 or more carbon atoms, and then the fluid rich in hydrocarbons with 3 or less carbon atoms is separated by distillation into a fluid containing Fluids of hydrocarbons with 2 or less hydrocarbons and hydrocarbons with 3 carbon atoms, and fluids rich in hydrocarbons with 3 carbon atoms. 23. The method for producing propylene according to any one of claims 1 to 22, wherein the olefin raw material having 4 or more carbon atoms contains paraffins having 4 or more carbon atoms. 24. The method for producing propylene according to claim 23, wherein the paraffins contain at least one of n-butane and isobutane. 25. The method for producing propylene according to any one of claims 1 to 24, wherein butadiene is contained in the raw material supplied to the reactor. 26. The method for producing propylene according to any one of claims 1 to 25, wherein the total amount of aromatic compounds contained in all raw materials supplied to the reactor is equal to the carbon content contained in all raw materials The molar ratio of the total amount of olefins having 4 or more atoms is less than 0.05. 27. The method for producing propylene according to any one of claims 1 to 26, wherein the amount of the olefin having 4 or more carbon atoms supplied to the reactor is equal to the mole of dimethyl ether supplied to the reactor The molar ratio of twice the number of methanol to the total number of moles of methanol is not less than 0.2 and not more than 10. 28. The method for preparing propylene according to any one of claims 1 to 27, wherein the olefin raw material with more than 4 carbon atoms supplied to the reactor contains olefins with 4 carbon atoms obtained from the steam cracking process flow hydrocarbon fluid. 29. A method for producing propylene, which comprises contacting a mixture containing an olefin having at least 4 carbon atoms and at least one of methanol and dimethyl ether in a reactor with the catalyst in the presence of a catalyst to produce propylene A method comprising the following steps (1C), (2C), (3C) and (4C) process flow, Step (1C): At least one of methanol and dimethyl ether, an olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (Q) recycled from step (4C) are supplied to the reactor, relative to the reaction The molar flow rate of olefins with 4 or more carbon atoms at the inlet of the reactor, and the molar flow rate of olefins with 4 or more carbon atoms at the outlet of the reactor are 20% or more and less than 90%. Under these reaction conditions, the above-mentioned The material is contacted with the catalyst, and the gas containing propylene, other olefins, paraffins, aromatic compounds and water is obtained from the reactor outlet (reactor outlet gas); Step (2C): cooling the reactor outlet gas from the above step (1C), and separating it into a gaseous fluid (L), a liquid fluid (M) rich in hydrocarbons with 4 or more carbon atoms and containing aromatic compounds, and a liquid fluid (M) rich in Aqueous fluids; Step (3C): separating the gaseous fluid (L) in the above step (2C) into a fluid rich in hydrocarbons with 3 or less carbon atoms and a fluid (N) rich in hydrocarbons with 4 or more carbon atoms; Step (4C): recycling at least a portion of the fluid (Q) of the aforementioned fluid (N) to the reactor. 30. A method for producing propylene, the method comprising: in the presence of a catalyst, a mixture containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether is contacted with the catalyst in a reactor to produce propylene A method comprising the following steps (1C), (2C), (3C) and (4C) process flow, Step (1C): At least one of methanol and dimethyl ether, an olefin raw material having 4 or more carbon atoms, and the hydrocarbon fluid (Q) recycled from step (4C) are supplied to the reactor, relative to the reaction The molar flow rate of olefins with 4 or more carbon atoms at the inlet of the reactor, and the molar flow rate of olefins with 4 or more carbon atoms at the outlet of the reactor are 20% or more and less than 70%. Under these reaction conditions, the above-mentioned The material is contacted with the catalyst, and the gas containing propylene, other olefins, paraffins, aromatic compounds and water is obtained from the reactor outlet (reactor outlet gas); Step (2C): cooling the reactor outlet gas from the above step (1C), and separating the cooled gaseous fluid (K) into gaseous fluid (L), hydrocarbons rich in 4 or more carbon atoms, and Liquid fluids (M) containing aromatic compounds, and fluids enriched with water; Step (3C): separating the gaseous fluid (L) in the above step (2C) into a fluid rich in hydrocarbons with 3 or less carbon atoms and a fluid (N) rich in hydrocarbons with 4 or more carbon atoms; Step (4C): At least a part (P) of the above-mentioned stream (N) is withdrawn from the process flow, and the remaining stream (Q) is recycled to the reactor. 31. The method for preparing propylene according to claim 29 or 30, wherein, the above-mentioned liquid fluid (M) is separated into fluid (R) and fluid (S) by distillation, wherein the aromatic compound in the fluid (R) The concentration is lower than in the liquid fluid (M) in which the concentration of hydrocarbons having 4 carbon atoms is lower than in the liquid fluid (M). 32. The production method of propylene according to claim 31, wherein, the fluid (R) is returned to any one selected from the above fluids (K), (L), (M), (P) and (Q) The circulation part of one or two or more fluids. 33. The method for preparing propylene according to any one of claims 29 to 32, wherein the above-mentioned step (3C) comprises the step of: separating the gaseous fluid (L) into carbon atoms rich in 2 or less by distillation The fluid containing hydrocarbons and the fluid rich in hydrocarbons with more than 3 carbon atoms, and then the fluid rich in hydrocarbons with more than 3 carbon atoms is separated into the fluid rich in hydrocarbons with 3 carbon atoms and the fluid rich in carbon atoms Fluid (N) of hydrocarbons with number 4 or more. 34. The method for preparing propylene according to any one of claims 29 to 32, wherein the above-mentioned step (3C) comprises the step of: separating the gaseous fluid (L) into carbon atoms rich in 3 or less carbon atoms by distillation The fluid containing hydrocarbons and the fluid (N) rich in hydrocarbons with more than 4 carbon atoms, and then the fluid rich in hydrocarbons with 3 or less carbon atoms is separated by distillation into the fluid rich in hydrocarbons with 2 or less carbon atoms and the fluid rich in hydrocarbons with 2 or less carbon atoms Fluids containing hydrocarbons with 3 carbon atoms. 35. The method for producing propylene according to any one of claims 29 to 32, wherein the above-mentioned step (3C) comprises the step of: separating the gaseous fluid (L) into carbon atoms containing 2 or less carbon atoms by distillation Hydrocarbons and hydrocarbons with 3 carbon atoms, and fluids rich in hydrocarbons with 3 or more carbon atoms, and then the fluid rich in hydrocarbons with 3 or more carbon atoms is separated into fluids rich in hydrocarbons with 3 or more carbon atoms A hydrocarbon fluid and a fluid rich in hydrocarbons having 4 or more carbon atoms (N). 36. The method for preparing propylene according to any one of claims 29 to 32, wherein the above-mentioned step (3C) comprises the step of: separating the gaseous fluid (L) into carbon atoms rich in 3 or less carbon atoms by distillation The fluid containing hydrocarbons with 4 or more carbon atoms and the fluid (N) rich in hydrocarbons with 4 or more carbon atoms, and then the fluid with hydrocarbons with 3 or less carbon atoms is separated by distillation into hydrocarbons with 2 or less carbon atoms and hydrocarbons with 2 or less carbon atoms. 3 hydrocarbon fluids, and fluids rich in hydrocarbons with 3 carbon atoms. 37. The method for producing propylene according to any one of claims 29 to 36, wherein the reactor comprises two or more reaction sections connected in series, and the methanol and dimethyl ether supplied to the reactor are At least one of the above, at least one of the olefin raw material having 4 or more carbon atoms, and at least one of the recycled hydrocarbon-containing fluid are divided and supplied to the first-stage reaction part and the second-stage or subsequent reaction part. 38. The method for producing propylene according to any one of claims 29 to 37, wherein the olefin raw material having 4 or more carbon atoms contains paraffins having 4 or more carbon atoms. 39. The method for producing propylene according to claim 38, wherein the paraffins contain at least one of n-butane and isobutane. 40. The method for producing propylene according to any one of claims 29 to 39, wherein the raw material supplied to the reactor contains butadiene. 41. The method for producing propylene according to any one of claims 29 to 40, wherein the total amount of aromatic compounds contained in all the raw materials supplied to the reactor is equal to the carbon atoms contained in the entire raw materials The molar ratio of the total amount of olefins having the number 4 or more is less than 0.05. 42. The method for preparing propylene according to any one of claims 29 to 41, wherein at least one of the fluid (M) and the fluid (P) is supplied to the steam cracking process flow as a cracking process Raw materials used. 43. The process for the production of propylene according to claim 42, wherein at least a part of at least one of the fluid (M) and the fluid (P) is contacted with a hydrogenation catalyst and then supplied to the steam cracking process flow . 44. The method for producing propylene according to any one of claims 29 to 43, wherein the total concentration of aromatic compounds contained in at least one of the fluid (M) and the fluid (P) is less than 5.0 volume%. 45. The method for preparing propylene according to any one of claims 29 to 44, wherein the fluid (M) is mixed with the cracked gasoline fraction of the steam cracking process flow. 46. The method for producing propylene according to any one of claims 29 to 45, wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (M) is less than 5% by weight. 47. The method for producing propylene according to any one of claims 29 to 46, wherein, by controlling the flow rates of the fluid (M) and the fluid (P), all the raw materials supplied to the reactor The total concentration of olefins with more than 4 carbon atoms, methanol and dimethyl ether is controlled to be more than 20% by volume and less than 80% by volume. 48. The method for preparing propylene according to any one of claims 29 to 47, wherein the fluid (R) is supplied to the steam cracking process flow and used as a cracking raw material. 49. The process for the production of propylene as claimed in claim 48, wherein at least a part of said stream (R) is brought into contact with a hydrogenation catalyst before being fed into a steam cracking process flow. 50. The method for producing propylene according to any one of claims 31 to 49, wherein the total concentration of aromatic compounds contained in the fluid (R) is less than 5.0% by volume. 51. The method for preparing propylene according to any one of claims 31 to 50, wherein the fluid (S) is mixed with the cracked gasoline fraction of the steam cracking process flow. 52. The method for producing propylene according to any one of claims 31 to 51, wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (S) is less than 5% by weight. 53. The method for producing propylene according to any one of claims 31 to 52, wherein, by controlling the flow rates of the fluid (P), the fluid (R) and the fluid (S), all of the above-mentioned supplies to the reactor The total concentration of olefins having 4 or more carbon atoms, methanol, and dimethyl ether contained in the raw material is controlled to be 20% by volume or more and 80% by volume or less. 54. The method for preparing propylene according to any one of claims 31 to 53, wherein, after the fluid (R) is returned to the fluid (K), (L), (N), (P ) and (Q) where any one or two or more fluids are located, by controlling the position where the fluid (R) returns and its flow rate, the carbon atoms contained in all the raw materials supplied to the reactor mentioned above The total concentration of olefins, methanol and dimethyl ether with a number above 4 is controlled to be above 20% by volume and below 80% by volume. 55. The method for producing propylene according to any one of claims 29 to 54, wherein the amount of the olefin having 4 or more carbon atoms supplied to the reactor and the mole of dimethyl ether supplied to the reactor are The molar ratio of twice the number of methanol to the total number of moles of methanol is not less than 0.2 and not more than 10. 56. The method for producing propylene according to any one of claims 29 to 55, wherein the olefin raw material with 4 or more carbon atoms supplied to the reactor contains hydrocarbons with 4 or more carbon atoms obtained in the steam cracking process fluid.

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