CN112795400B - Catalytic cracking device and method based on double settlers - Google Patents

Abstract

The invention discloses a catalytic cracking device and a catalytic cracking method based on double settlers, which are characterized in that gas, liquefied gas, naphtha or gasoline fraction, kerosene fraction and diesel fraction are sequentially input into a first riser from low to high in sections, wax oil, atmospheric residuum and residuum are sequentially input into a second riser from low to high in sections after being pretreated, a high-temperature catalyst settled by the first settler is input into the second riser, and the high-temperature catalyst settled by the first settler is directly used as a reaction catalyst of the second reactor by adopting the double settlers connected in series, so that the coking rate and coking amount of the catalyst are flexibly controlled by a sequential combined feeding mode, the activity of the catalyst is utilized to the maximum extent, the proportion of basic chemical raw materials such as various low-carbon olefins, aromatic hydrocarbons and the like are obtained from crude oil is improved to the maximum extent, the thorough conversion from the production of the fuel oil to the production of chemical products is realized, and the crude oil is selectively and maximally converted into various basic chemical raw materials.

Description

Catalytic cracking device and method based on double settlers

Technical Field

The invention relates to the field of catalytic cracking or catalytic cracking devices and processes, in particular to a catalytic cracking device and a catalytic cracking method based on double settlers.

Background

At present, catalytic cracking or catalytic cracking is one of the main methods of petroleum secondary processing, namely, the process of cracking and cracking heavy distillate oil under the action of high temperature and catalyst and converting the heavy distillate oil into gasoline, diesel oil and cracked gas, and the process mainly comprises four parts of reaction regeneration, fractionation, absorption stabilization and flue gas energy recycling, wherein the reaction regeneration is used as a chemical reaction part, and the reaction regeneration is the most influencing factor on the selectivity of raw materials and products.

However, the catalytic cracking or catalytic cracking process adopted in the prior art has the problems of complex structure of the device, poor selectivity of raw materials or products, unreasonable energy utilization, high unit investment and the like, and particularly has difficulty in increasing the proportion of basic chemical raw materials such as low-carbon olefins such as ethylene, propylene, butylene and the like and monocyclic aromatic hydrocarbons such as benzene, toluene, xylene and the like obtained from crude oil to a greater extent.

Accordingly, there is a need for improvement and development in the art.

Disclosure of Invention

In order to solve the technical problems, the invention provides the catalytic cracking device based on the double settlers, which can obviously improve the proportion of basic chemical raw materials obtained from crude oil, and has the advantages of less number of used devices and lower cost.

Meanwhile, the invention also provides a catalytic cracking method based on the double settlers, which can obviously improve the proportion of basic chemical raw materials obtained from crude oil, and has simple overall process and lower cost.

The technical scheme of the invention is as follows, a catalytic cracking method based on double settlers comprises the following steps:

The gas, liquefied gas, naphtha or gasoline fraction, kerosene fraction and diesel fraction distilled by the constant vacuum distillation device are sequentially input into the first riser from low to high in sections;

after pretreatment, wax oil, atmospheric residuum and residuum distilled from a constant vacuum distillation device are sequentially and sectionally input into a second riser from low to high;

The high-temperature catalyst settled by the first settling vessel is used as a reaction catalyst of the second reactor and is input into a second riser; the high-temperature catalyst settled by the second settler is input into a catalyst regenerator for burning regeneration;

the regenerated catalyst is fed into the first riser as reaction catalyst for the first reactor.

The catalytic cracking method based on the double-settler comprises the steps of pressurizing less than one fourth of gas and liquefied gas to a pressure of more than 0.8Mpa, gasifying and overheating to a temperature of more than 150 ℃, respectively taking the gasified and overheated gas and the gasified and overheated liquefied gas as catalyst lifting gas of a first lifting pipe and a second lifting pipe, and controlling the oil ratio of the gas to the liquefied gas to be more than 100:1.

The catalytic cracking method based on the double settlers comprises the following steps:

feeding liquefied gas from the lowest section of the first lifting pipe, wherein the agent-oil ratio is controlled to be 50:1-90:1;

the gasoline fraction or naphtha is mixed and then is subjected to system separation to return light oil, the temperature is raised to be more than 150 ℃, the mixture is mixed and atomized with superheated steam with the pressure of more than 0.8Mpa and the temperature of more than 200 ℃ according to the proportion of more than 1:0.1, and then the mixture is fed from the upper part of a liquefied gas feeding section of a first lifting pipe, wherein the ratio of the catalyst to the oil is controlled between 20:1 and 90:1;

heating the kerosene fraction to a temperature of >150 ℃, mixing and atomizing the kerosene fraction with superheated steam with a pressure of >0.8Mpa and a temperature of >200 ℃ according to a proportion of >1:0.15, and feeding the kerosene fraction from the upper part of a naphtha or gasoline feeding section of the first riser, wherein the catalyst-oil ratio is controlled between 20:1 and 90:1;

The diesel oil fraction is heated to the temperature of >150 ℃, mixed and atomized with superheated steam with the pressure of >0.8Mpa and the temperature of >200 ℃ according to the proportion of >1:0.2, and then fed from the upper part of a kerosene feeding section of the first riser, wherein the catalyst-oil ratio is controlled between 20:1 and 90:1.

The catalytic cracking method based on the double settlers comprises the following steps:

The agent-to-oil ratio of the liquefied gas feeding section of the first riser is more than 36:1;

the catalyst to oil ratio of the naphtha or gasoline feeding section of the first riser is more than 36:1, and the gas flow rate is controlled to be more than 1m/s;

the agent-oil ratio of the kerosene feeding section of the first riser is more than 36:1, and the gas flow rate is controlled to be more than 1m/s;

the diesel oil feeding section of the first riser has a catalyst to oil ratio of >20:1, and the control gas flow rate is greater than 1m/s.

The catalytic cracking method based on the double settlers comprises the following steps:

Cutting catalytic diesel oil after catalytic reaction in a second reactor, taking light components with the normal pressure distillation range of 230-280 ℃, heating to the temperature of >150 ℃, mixing and atomizing the light components with superheated steam with the pressure of >0.8Mpa and the temperature of >200 ℃ according to the proportion of >1:0.1, and feeding from the lowest section of a second riser, wherein the catalyst-oil ratio is controlled between 20:1 and 90:1;

Heating wax oil to a temperature of >150 ℃, mixing and atomizing the wax oil with superheated steam with a pressure of >0.8Mpa and a temperature of >200 ℃ according to a proportion of >1:0.1, and feeding the mixture from the upper part of a light catalytic diesel feeding section of a second riser, wherein the ratio of the catalyst to the oil is controlled between 20:1 and 90:1;

Heating the residual oil to a temperature of >150 ℃, mixing and atomizing the residual oil with superheated steam with a pressure of >0.8Mpa and a temperature of >200 ℃ according to a proportion of >1:0.1, and feeding the residual oil from the upper part of a wax oil feeding section of the second lifting pipe, wherein the ratio of the agent to the oil is controlled between 20:1 and 90:1;

And (3) heating part of catalytic slurry oil after catalytic reaction to a temperature of >150 ℃, mixing and atomizing the heated slurry oil with superheated steam with a pressure of >0.8Mpa and a temperature of >200 ℃ according to a proportion of >1:0.1, and feeding the slurry oil from the upper part of a residual oil feeding section of the second riser, wherein the catalyst-oil ratio is controlled between 20:1 and 90:1.

The catalytic cracking method based on the double settlers comprises the following steps:

The catalyst-to-oil ratio of the light catalytic diesel feeding section of the second riser is more than 30:1;

The agent-oil ratio of the wax oil feeding section of the second riser is more than 20:1, and the gas flow rate is controlled to be more than 1m/s;

The agent-oil ratio of the residual oil feeding section of the second riser is more than 20:1, and the gas flow rate is controlled to be more than 1m/s;

the catalyst to oil ratio of the second riser catalytic slurry feed section is >20:1, and the control gas flow rate is greater than 1m/s.

The catalytic cracking method based on the double settlers comprises the steps of pretreating crude oil by an electric desalting device, then entering an atmospheric and vacuum distillation device, and separating gas, liquefied gas, naphtha or gasoline fraction, kerosene fraction, diesel fraction, wax oil, atmospheric residuum and residuum according to the molecular weight and the distillation range from low to high, wherein the distillation range of the naphtha fraction is 20-160 ℃, the distillation range of the gasoline fraction is 10-235 ℃, the distillation range of the kerosene fraction is 145-280 ℃, and the distillation range of the diesel fraction is 230-390 ℃.

A catalytic cracking device based on double settlers comprises a first settler, a second settler, a first riser, a second riser and a catalyst regenerator, wherein,

The first settler is connected in series at the top end of the first riser to form a first reactor, the first riser consists of a plurality of sections from low to high, and each section is provided with a feed inlet for sequentially inputting gas, liquefied gas, naphtha or gasoline fraction, kerosene fraction and diesel fraction which are distilled by the constant reduced pressure distillation device from low to high respectively;

The second settler is connected in series at the top end of the second riser to form a second reactor, the second riser consists of a plurality of sections from low to high, and each section is provided with a feed inlet for sequentially inputting the wax oil, the atmospheric residue and the residue which are fractionated by the constant vacuum distillation device and pretreated from low to high respectively;

The first reactor, the second reactor and the catalyst regenerator are arranged in series; a first inclined tube is connected between the first settler and the bottom of the second riser and used for inputting the high-temperature catalyst settled by the first settler into the second riser as a reaction catalyst of the second reactor;

The regenerated catalyst is used as a reaction catalyst of the first reactor and is input into the first riser through a corresponding pipeline.

The catalytic cracking device based on the double settlers comprises:

the first and second settlers are provided with respective cyclone separating devices;

after the reaction catalyst in the first reactor is settled by the first settling vessel, the reaction catalyst passes through the dipleg of the cyclone separation device and enters the second riser through the first inclined tube;

After settling in the second reactor, the reaction catalyst passes through the dipleg of the cyclone and enters the catalyst regenerator through the second inclined tube.

The catalytic cracking device based on the double settlers comprises:

a hydrogenation or light oil refining device is arranged between the atmospheric and vacuum distillation device and the first reactor and is used for selectively preprocessing the distilled light oil component of the atmospheric and vacuum distillation device according to the sulfur content, the saturated hydrocarbon content and the corresponding environmental protection index requirements;

And/or a wax oil hydrogenation device, a residual oil hydrogenation device and/or a solvent deasphalting device are/is arranged between the atmospheric and vacuum distillation device and the second reactor, and are used for selectively preprocessing wax oil, atmospheric residual oil and residual oil which are distilled out by the atmospheric and vacuum distillation device according to the sulfur content, the saturated hydrocarbon content, the metal content and the requirements of corresponding environmental protection indexes.

The catalytic cracking device and the method based on the double settlers adopt the double settlers in a serial connection mode, the two settlers are connected with the ascending riser through the descending agent pipe, all or the main part of the high-temperature catalyst settled by the first settler is directly used as the reaction catalyst of the second reactor, the coking rate and the coking quantity of the catalyst are flexibly controlled through an orderly combined feeding mode, the activity and the temperature grade of the catalyst are utilized to the greatest extent, the conversion selectivity of various basic chemical raw materials is greatly improved, the proportion of various low-carbon olefin, aromatic hydrocarbon and other basic chemical raw materials obtained from crude oil is greatly improved, the thorough conversion of the crude oil from the production of fuel oil to the production of chemicals is realized, the crude oil is selectively and maximally converted into various basic chemical raw materials, and the catalytic cracking device has outstanding substantial characteristics and remarkable progress.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way, the shapes and scale dimensions of the various components in the drawings are merely illustrative, to aid in understanding the present disclosure, and are not intended to specifically limit the shapes and scale dimensions of the various components of the present disclosure, and one skilled in the art may select various possible shapes and scale dimensions to practice the present disclosure as the case may be given the teachings of the present disclosure.

FIG. 1 is a schematic structural diagram of an embodiment of a dual settler-based catalytic cracking unit in accordance with the present invention;

The figures summarize the references to atmospheric and vacuum distillation unit 100, wax residue hydrogenation unit 110, pressurization unit 120, first settler 210, first inclined tube 211, second settler 220, second inclined tube 221, first riser 230, first reactor catalyst feed end 231, second riser 240, catalyst regenerator 250, regenerated catalyst discharge end 251.

Detailed Description

The following detailed description and examples of the present invention will be presented in conjunction with the accompanying drawings, wherein the detailed description is provided for the purpose of illustrating the invention only and not for the purpose of limiting the same, for example, crude oil is fractionated by an atmospheric and vacuum distillation apparatus, the fractionation products thereof are classified according to distillation ranges, the names of the classifications are called in a colloquial manner, and the renaming or renaming of the fractions does not affect the claims of the present patent.

As shown in fig. 1, fig. 1 is a schematic structural diagram of an embodiment of a catalytic cracker based on double-settler according to the present invention, which comprises a first settler 210, a second settler 220, a first riser 230, a second riser 240 and a catalyst regenerator 250, wherein the first settler 210 is connected in series with the top of the first riser 230 to form a first reactor integrally, the first riser 230 is divided into 2-15 sections from low to high, each section is provided with a feed inlet for sequentially and separately inputting gas, liquefied gas, naphtha or gasoline fraction, kerosene fraction and diesel fraction distilled from low to high by the atmospheric distillation device 100, one or more components may be omitted, the second settler 220 is connected in series with the top of the second riser 240 to form a second reactor integrally, the second riser 240 is divided into 2-15 sections from low to high, each section is also provided with a feed inlet for sequentially and separately inputting wax oil from low to high by the atmospheric distillation device 100 and pre-treated, the first catalyst is also connected to the second riser 210 as a second catalyst regenerator 250, the second catalyst is connected in series with the first catalyst regenerator 250 and the second settler 210 as a second catalyst is regenerated by the second catalyst, the first catalyst is connected in series with the second settler 220 and the second catalyst regenerator 250, and the second catalyst is regenerated by the second catalyst is connected in series with the first catalyst 240 and the second settler 210 and the first catalyst is regenerated by the second catalyst 250, i.e., a corresponding conduit (not shown) is used to communicate the regenerated catalyst discharge end 251 of the catalyst regenerator 250 with the first reactor catalyst feed end 231 at the lower end of the first riser 230.

Further, each of the first and second settlers 210 and 220 is provided with respective cyclone means, and the reaction catalyst in the first reactor after settling in the first settler 210 passes through the legs of the cyclone means thereof and enters the second riser 240 through the first inclined tube 211, while the reaction catalyst in the second reactor after settling in the second settler 220 passes through the legs of the cyclone means thereof and enters the catalyst regenerator 250 through the second inclined tube 221.

Further, a component separation device, a hydrogenation saturated device or a light oil refining device can be further arranged between the atmospheric and vacuum distillation device 100 and the first reactor, and the atmospheric and vacuum distillation device is used for selectively preprocessing the light oil component fractionated by the atmospheric and vacuum distillation device 100 according to the sulfur content, the saturated hydrocarbon content and the corresponding environmental protection index requirements, and of course, the gas, the liquefied gas, the gasoline fraction, the kerosene fraction and the diesel fraction can also be directly used as the feed of the first reactor.

Further, a wax oil hydrogenation device, a residual oil hydrogenation device and/or a solvent deasphalting device, such as the wax residual oil hydrogenation device 110 in fig. 1, may be further disposed between the atmospheric and vacuum distillation device 100 and the second reactor, for selectively preprocessing the wax oil, the atmospheric residual oil and the residual oil distilled from the atmospheric and vacuum distillation device 100 according to the sulfur content, the saturated hydrocarbon content, the metal content and the corresponding environmental protection index requirements, for example, when the carbon residue of the atmospheric residual oil or the residual oil exceeds 10% of the feeding index value of the fixed bed residual oil hydrogenation, the atmospheric residual oil or the residual oil is first subjected to decarburization preprocessing by the solvent deasphalting device and then is used as the feeding material of the second reactor.

The catalytic cracker based on double settlers is an improvement with remarkable innovation on the basis of the existing atmospheric and vacuum distillation unit 100, hydrogenation unit and/or catalytic cracking/cracking unit, and is characterized in that the double settlers in a serial connection mode are adopted, the two settlers are connected with an uplink riser through a downlink falling agent pipe, all or a main part of the high-temperature catalyst settled by the first settling device 210 is directly used as the reaction catalyst of the second reactor, and is not mainly returned to the catalyst regenerator 250 for burning, so that the problems of excessive reaction oil gas, difficult control of the catalyst and the reaction time and flow rate of the reaction oil gas are solved, and various low-carbon hydrocarbons and aromatic hydrocarbons are obtained from crude oil to the maximum degree by virtue of a simplified device.

As shown in FIG. 1, the double-settler-based catalytic cracking process or method of the present invention generally comprises the steps of, on one hand, dividing the atmospheric gas, liquefied gas, naphtha or gasoline fraction, kerosene fraction and diesel fraction of the atmospheric distillation unit 100 into a first riser 230 in order from low to high stages, on the other hand, dividing the wax oil, atmospheric residue and residuum of the atmospheric distillation unit 100 into a second riser 240 in order from low to high stages after pretreatment, simultaneously, inputting the high-temperature catalyst settled in the first settler 210 into the second riser 240 as the reaction catalyst of the second reactor, inputting the high-temperature catalyst settled in the second settler 220 into a catalyst regenerator 250 for coke burning regeneration, and inputting the regenerated catalyst into the first riser 230 as the reaction catalyst of the first reactor.

Specifically, the pressurizing device 120 in fig. 1 may be used to pressurize a small portion, for example, less than one fourth, of the gas and the liquefied gas to a pressure of >0.8Mpa, for example >1.0Mpa, and then gasify and overheat the gas and liquefied gas to a temperature of >150 ℃, for example >300 ℃, through a gasifier and a superheater (not shown), as the catalyst lifting gas of the first lifting pipe 230 and the second lifting pipe 240, respectively, and the oil ratio of the control agent is >75:1, for example >100:1, and further, for example >150:1, and saturated liquefied gas, liquefied gas containing olefins, C4-C5 olefin components, C5-C6 gasoline components may be optionally combined as the catalyst lifting gas of the second lifting pipe 240, so that products such as lower olefins and monocyclic aromatics with higher yields may be selectively obtained.

In the first reactor, specifically, liquefied gas (mainly refers to C2-C4 alkane components) is fed from the lowest section of the first riser 230, steam, gas, the liquefied gas and a high-temperature catalyst are firstly contacted, and the catalyst-to-oil ratio is controlled to be 50:1-90:1;

After the gasoline fraction or naphtha is mixed and atomized according to the proportion of >1:0.1, the mixture is fed from the upper part of the liquefied gas feeding section of the first riser 230, the ratio of the catalyst to the oil is controlled between 20:1 and 90:1, and various components in the light oil separated and returned by the gasoline fraction or naphtha after mixing and the system are subjected to catalytic cracking/cracking reaction mainly in the first riser 230, wherein the pressure of the components is >0.8Mpa, for example >1.0Mpa, and the temperature of the components is >200 ℃, for example >300 ℃, and the cracking conversion rate of the components can reach more than 40%;

Heating the kerosene fraction to a temperature of >150 ℃, such as >300 ℃, and mixing and atomizing the kerosene fraction with superheated steam with a pressure of >0.8Mpa, such as >1.0Mpa and a temperature of >200 ℃, such as >300 ℃ and another temperature of >400 ℃ according to a proportion of >1:0.15, and feeding the mixture from the upper part of a naphtha or gasoline feeding section of the first riser 230, wherein the catalyst-to-oil ratio is controlled to be 20:1-90:1;

The diesel fraction is heated to a temperature of >150 ℃, such as >300 ℃, and mixed and atomized with superheated steam with a pressure of >0.8Mpa, such as >1.0Mpa, and a temperature of >200 ℃, such as >300 ℃, and another such as >400 ℃ according to a proportion of >1:0.2, the diesel fraction is fed from above a kerosene feeding section of the first riser 230, the catalyst-to-oil ratio is controlled between 20:1 and 90:1, various components in the diesel fraction undergo catalytic cracking/cracking reactions mainly in the first riser 230, and the cracking conversion rate of the part can reach more than 40%.

For example, the ratio of agent to oil of the liquefied gas feed section of the first riser 230 is >36:1, e.g., >72:1, the ratio of agent to oil of the naphtha or gasoline feed section of the first riser 230 is >36:1, e.g., >72:1, and the gas flow rate is controlled to be >1m/s, e.g., 2m/s, and another example is 3m/s, the ratio of agent to oil of the kerosene feed section of the first riser 230 is >36:1, e.g., >72:1, and the gas flow rate is controlled to be >1m/s, e.g., 2m/s, and another example is 3m/s, the ratio of agent to oil of the diesel feed section of the first riser 230 is >20:1, e.g., >40:1, and the gas flow rate is controlled to be >1m/s, e.g., 2m/s, and another example is 3m/s.

The injection amount of the gasoline fraction, the kerosene fraction and the diesel fraction and the oil ratio of the regulator are gradually injected into the first riser 230 and controlled, wherein the injection amount comprises recycled components equivalent to the gasoline fraction, the kerosene fraction and the diesel fraction, and dilution steam with the raw material ratio of 0-1:1 is matched according to the severity of reaction coking; while feeding gradually, various gases and micron-sized powdery catalyst flow upwards to form a first fluidized bed, the temperature of the catalyst and the volume ratio of the catalyst in the first riser 230 gradually rises, the catalyst and the catalyst gradually decrease, the catalyst coking particle ratio also gradually increases, when the catalyst temperature in the first reactor decreases to 550-620 ℃, the reaction oil gas and the catalyst in the first riser 230 enter a first settler 210, the reaction oil gas is output from the top end of the first settler 210 by utilizing a cyclone separation device in the first settler 210, enters a subsequent quenching and fractionation system through a corresponding pipeline or enters a downstream separation device for separation, components equivalent to a gasoline fraction, a kerosene fraction and a diesel fraction after olefin and aromatic hydrocarbon are separated through the downstream fractionation system can be used as the feed of the first riser 230 until all raw materials entering the first reactor react to generate (methane, hydrogen or ethane and the like) saturated alkanes, (ethylene, propylene, butylene, pentene and the like) low-carbon olefins, (benzene, toluene, xylene, heavy aromatics and the like) hydrocarbon and the like, and the catalyst of the cyclone separation device is still high in the relatively settling device because the coking phenomenon is that the catalyst in the cyclone separation device is high, the catalyst is still contacted with the catalyst in the first settler 210, as reaction catalyst for the second reactor, enters the bottom of the second riser 240 via the first inclined tube 211.

In the second reactor, specifically, catalytic diesel oil (with an atmospheric distillation range of 230-360 ℃) after catalytic reaction by a first reactor is cut, light components with an atmospheric distillation range of 230-280 ℃ are taken, the temperature is raised to be more than 150 ℃, for example, more than 300 ℃, the temperature is more than 0.8Mpa, for example, more than 1.0Mpa and the temperature is more than 200 ℃, for example, more than 300 ℃, superheated steam with the temperature of more than 400 ℃ is mixed and atomized according to the proportion of more than 1:0.1, for example, more than 1:0.2, for example, more than 1:0.3, and then the mixture is fed from the lowest section of the second riser 240, the catalyst-oil ratio is controlled to be between 20:1 and 90:1, and various components in the light catalytic diesel oil are subjected to catalytic cracking/cracking reactions mainly in the second riser 240, wherein the cracking conversion rate of the parts can reach more than 40%;

Heating wax oil or hydrogenated wax oil to a temperature of >150 ℃, such as >300 ℃, and mixing and atomizing the wax oil or hydrogenated wax oil with superheated steam with a pressure of >0.8Mpa, such as >1.0Mpa, and a temperature of >200 ℃, such as >300 ℃, and another temperature of >400 ℃ according to a proportion of >1:0.1, such as >1:0.2, and feeding the mixture from the upper part of a light catalytic diesel feeding section of the second riser 240, wherein the ratio of the catalyst to the oil is controlled between 20:1 and 90:1, and the catalytic cracking/cracking reaction of various components in the wax oil is mainly carried out in the second riser 240, wherein the cracking conversion rate of the part can reach more than 40 percent;

heating the residual oil or hydrogenated residual oil to a temperature of >150 ℃, such as >300 ℃, and mixing and atomizing the residual oil or hydrogenated residual oil with superheated steam with a pressure of >0.8Mpa, such as >1.0Mpa and a temperature of >200 ℃, such as >300 ℃, such as >400 ℃ according to a proportion of >1:0.1, such as >1:0.2, and such as >1:0.3, and feeding the residual oil or hydrogenated residual oil from the upper part of a wax oil feeding section of the second riser 240, wherein the ratio of the catalyst to the oil is controlled to be 20:1-90:1;

The catalyst slurry is fed from above the residual oil feeding section of the second riser 240 after being heated to a temperature of >150 ℃, for example >300 ℃, and mixed and atomized with superheated steam having a pressure of >0.8Mpa, for example >1.0Mpa, and a temperature of >200 ℃, for example >300 ℃, for example >400 ℃ according to a ratio of >1:0.1, for example >1:0.2, for example >1:0.3, for example >1:0.4, and the catalyst-to-oil ratio is controlled between 20:1 and 90:1, and various components in the catalyst slurry undergo catalytic cracking/cracking reactions in the second riser 240. The conversion rate of the part can reach more than 40 percent;

For example, the second riser 240 light catalytic diesel feed section has a ratio of agent to oil of >15:1, e.g., 20:1, another example 30:1 or 40:1, another example 50:1 or >60:1, the second riser 240 wax oil feed section has a ratio of agent to oil of >15:1, e.g., 20:1, another example 30:1, another example >40:1, and a control gas flow rate of >1m/s, e.g., 2m/s, another example 3m/s, the second riser 240 residuum feed section has a ratio of agent to oil of >20:1, e.g., 30:1, another example >40:1, and a control gas flow rate of >1m/s, e.g., 2m/s, another example 3m/s, the second riser 240 catalyzes the slurry feed section to agent to oil of >20:1, e.g., 30:1, another example >40:1, and a control gas flow rate of >1m/s, e.g., 2m/s, another example 3m/s.

The injection amount of the catalytic diesel oil, wax oil, residual oil and catalytic slurry oil and the oil ratio of the regulator are gradually injected into the second riser 240, the components which are equivalent to the distillation range of the catalytic diesel oil and the catalytic slurry oil are recycled, and dilution steam with the raw material proportion of 0-0.7:1 is matched according to the severity of the reaction coking; while feeding gradually, various gases and powdery catalyst flow upwards to form a second fluidized bed, the temperature of the catalyst and the catalyst gradually decreases along with the gradual increase of the volume ratio of the gases and the catalyst in the second riser 240, the coking particle ratio of the catalyst also obviously increases, when the temperature of the catalyst in the second reactor decreases to 480-550 ℃, the reaction oil gas and the catalyst in the second riser 240 enter the second settler 220, the reaction oil gas is output from the top end of the second settler 220 by utilizing a cyclone separation device in the second settler 220, enters a subsequent quenching and fractionation system through a corresponding pipeline or enters a downstream separation device for separation, components which are recycled after olefin and aromatic hydrocarbon are separated through the downstream fractionation system and are equivalent to the distillation range of the catalytic diesel oil and the catalytic slurry can be used as the feed of the second riser 240 until all raw materials entering the second reactor react to generate saturated alkanes (methane, hydrogen, ethane and the like), low-carbon olefins, (ethylene, propylene, butylene, pentene and the like), heavy aromatics and the like, and the catalyst (benzene, toluene, xylene and the hydrocarbon and the like) are coked in the second riser 240, and the catalyst has serious coking phenomenon because of the coking phenomenon is that the coking phenomenon is relatively low when the coking phenomenon is relatively heavy, the catalyst is more serious, the coking phenomenon is achieved when the catalyst is more serious, the coking phenomenon is more than the catalyst is more than the coking phenomenon of the catalyst is selected, after passing through the dipleg of the cyclone in the second settler 220, it enters the catalyst regenerator 250 via a second inclined tube 221 for coke burn regeneration.

The catalyst regenerator 250 can raise the temperature of the catalyst to 680-780 ℃ for burning regeneration, and the catalyst is input into the bottom of the first riser 230 through a corresponding pipeline to be recycled as the reaction catalyst of the first reactor, and meanwhile, a small amount of catalyst is not excluded from being recycled in the first riser 230, the first settler 210, the second riser 240, the second settler 220 or the catalyst regenerator 250.

In the atmospheric and vacuum distillation apparatus 100, specifically, crude oil is pretreated by an electric desalting apparatus (not shown), then enters the atmospheric and vacuum distillation apparatus 100, and gas, liquefied gas, naphtha or gasoline fraction, kerosene fraction, diesel fraction, wax oil, atmospheric residue and residue are separated according to the molecular weight and the distillation range from low to high, wherein the distillation range of the naphtha fraction is 20-160 ℃, the distillation range of the gasoline fraction is 10-235 ℃ (preferably 20-145 ℃), the distillation range of the kerosene fraction is 145-280 ℃ (preferably 145-230 ℃), the distillation range of the diesel fraction is 230-390 ℃ (preferably 230-360 ℃), and the pretreatment optimization is carried out on the wax oil, the atmospheric residue and residue according to the sulfur content, metal content, saturated hydrocarbon, asphaltene, colloid and other component content before the wax oil, the atmospheric residue and residue enter the second reactor, taking into consideration hydrogenation or solvent deasphalting and other means to obtain more olefin and less coke or char yield.

The source of the liquefied gas component can comprise the liquefied gas component which is processed by the atmospheric and vacuum distillation device 100 or the oil refining secondary processing device, can also comprise the component which is obtained by catalyzing the liquefied gas to be subjected to dealkenation and is mainly composed of saturated alkane and accords with the definition of the liquefied gas, and can even further comprise the liquefied gas component which is mainly composed of propylene and butylene.

The source of the gasoline fraction can comprise the gasoline fraction which is processed by the atmospheric and vacuum distillation device 100 or the oil refining secondary processing device and can also comprise the gasoline fraction which is mainly saturated alkane and is obtained by catalyzing gasoline to be subjected to hydrodearomatics.

The kerosene fraction may be obtained by processing in atmospheric and vacuum distillation unit 100 or a secondary processing unit for oil refining, or may be obtained by processing in hydrocarbon-based compounds having similar distillation ranges.

The diesel oil fraction may be obtained through processing in atmospheric and vacuum distillation unit 100 or secondary oil refining unit, or may be hydrocarbon compound with similar distillation range.

The catalytic cracking process or method based on the double settlers is also an improvement with remarkable innovation on the basis of the existing atmospheric and vacuum distillation process, hydrogenation process and/or catalytic cracking/cracking process, and is characterized in that an orderly combined feeding mode is utilized, the coking rate and coking amount of the catalyst can be flexibly controlled, the activity of the catalyst can be utilized to the maximum extent, the conversion rate of various basic chemical raw materials can be selectively and greatly improved, and various low-carbon hydrocarbons and aromatic hydrocarbons are maximally obtained from crude oil on the basis of a simplified flow.

The catalytic cracking device and the method based on the double-settler have wide raw material range, basically cover all fractions of various crude oils, ensure that the catalytic cracking/cracking production of olefin is not limited to a small amount of paraffin-based wax residual oil or deep hydrogenated wax oil, greatly reduce the production cost, provide an optimization scheme with lower cost and larger effect for converting oil refining enterprises into chemical enterprises, and show that the total yield of various low-carbon olefin and aromatic hydrocarbon can be more than 60 percent of the crude oil through experimental data of various crude oils.

Taking paraffin-based crude oil with a total sulfur content of less than 0.5% as an example, the paraffin-based crude oil enters an atmospheric and vacuum distillation device 100 after electric desalting treatment, and can be separated into yields of 2% of gas, 5% of liquefied gas, 15% of naphtha (with a distillation range of 20-160 ℃), 12% of kerosene (with a distillation range of 145-230 ℃), 25% of diesel (with a distillation range of 230-360 ℃), 25% of wax oil (with a distillation range of 360-540 ℃) and 16% of residual oil (with a distillation range of >540 ℃);

Pressurizing less than one fifth of the gas and liquefied gas to a pressure of >1.0Mpa and gasifying and superheating to a temperature of >180 ℃ as a catalyst lift gas for the first riser 230, controlling the oil ratio of >150:1;

Spraying steam, gas and liquefied gas mainly containing C2-C4 alkane molecules from the lowest section of a first riser 230 of a first reactor, contacting with a high-temperature catalyst first, wherein the oil ratio of a control agent is more than 72:1;

The naphtha is mixed, the system is separated, the returned light oil is heated to the temperature of >250 ℃, mixed and atomized with superheated steam with the pressure of >1.0Mpa and the temperature of >250 ℃ according to the proportion of >1:0.1, and then sprayed from the upper part of a liquefied gas feeding section of a first lifting pipe 230, the oil ratio of a control agent is >72:1, and the gas flow rate is controlled to be about 3m/s;

Heating the kerosene fraction to a temperature of >250 ℃, mixing and atomizing the kerosene fraction with superheated steam with a pressure of >1.0Mpa and a temperature of >250 ℃ according to a ratio of >1:0.15, spraying materials from the upper part of a naphtha or gasoline feeding section of the first riser 230, controlling the oil ratio to be >40:1, and controlling the gas flow rate to be about 3m/s;

Heating the diesel fraction to a temperature of >300 ℃, mixing and atomizing the diesel fraction with superheated steam with a pressure of >1.0Mpa and a temperature of >400 ℃ according to a ratio of >1:0.2, spraying materials from the upper part of a naphtha or gasoline feeding section of the first riser 230, controlling the oil ratio to be >40:1, and controlling the gas flow rate to be about 3m/s;

The reaction oil gas and the catalyst in the first riser 230 enter the first settler 210, and the reaction oil gas after catalytic cracking/cracking is output from the top end of the first settler 210 by using a cyclone separation device in the first settler 210 and enters a downstream separation device for separation through a corresponding pipeline;

pressurizing less than one fifth of the gas and the liquefied gas to a pressure of >1.0Mpa and gasifying and superheating to a temperature of >200 ℃, as a catalyst lift gas for the second riser 240, controlling the oil ratio of >150:1;

Cutting the catalytic diesel after catalytic reaction, taking light components with the distillation range of 230-280 ℃, heating to the temperature of >200 ℃, mixing and atomizing the light components with superheated steam with the pressure of >1.0Mpa and the temperature of >250 ℃ according to the proportion of >1:0.3, and spraying the light components from the lowest section of the second riser 240, wherein the oil ratio of the control agent is >40:1;

Heating wax oil to a temperature of >200 ℃, mixing and atomizing the wax oil with superheated steam with a pressure of >1.0Mpa and a temperature of >250 ℃ according to a ratio of >1:0.2, spraying the mixture from above a light catalytic diesel feeding section of the second riser 240, controlling the oil ratio of the control agent to be >40:1, and controlling the gas flow rate to be about 3m/s;

Heating the residual oil to a temperature of more than 300 ℃, mixing and atomizing the residual oil with superheated steam with a pressure of more than 1.0Mpa and a temperature of more than 400 ℃ according to a proportion of more than 1:0.3, spraying the superheated steam from the upper part of a light catalytic diesel feeding section of the second riser 240, controlling the oil ratio of more than 40:1, and controlling the gas flow rate to be about 3m/s;

Heating the catalytic slurry oil after partial catalytic reaction to a temperature of >300 ℃, mixing and atomizing the catalytic slurry oil with superheated steam with a pressure of >1.0Mpa and a temperature of >400 ℃ according to a ratio of >1:0.4, spraying the superheated steam from the upper part of a residual oil feeding section of the second riser 240, controlling the oil ratio to be >40:1, and controlling the gas flow rate to be about 3m/s;

after processing in the above manner, 1 ton of paraffinic crude oil may be obtained as a reaction product as shown in the following table (in% yield wt):

Hydrogen gas	Methane	Ethane (ethane)	Ethylene	Propylene	Butene (B)	Benzene	Toluene (toluene)	Xylene (P)	Catalytic diesel	Scorch of
											1	9	4	15	25	8	3	7	12	7	9

As can be seen from the data in the table, the equipment system used by the catalytic cracking device and the catalytic cracking method based on the double-settler has the advantages of simple structure, remarkable yield increasing effect of olefin and aromatic hydrocarbon, lower raw material cost, lower processing cost, low energy consumption and environmental friendliness, and is the catalytic cracking device and the catalytic cracking method with the lowest energy consumption and material consumption in the existing known process for producing olefin and aromatic hydrocarbon.

It should be understood that the foregoing description is only a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention, and it is possible for those skilled in the art to add, remove, replace or modify the technical solution of the present invention according to the above description, for example, the present invention describes only one working solution for crude oil to illustrate the basic principle and main characteristics of the innovative points of the present invention, but it should be understood by those skilled in the art that the innovative points of the present invention are not limited by the above embodiment, the description of the above embodiment is only for illustrating the principle of the innovative points of the present invention, and various changes and modifications can be made therein without departing from the scope of the invention claimed in the present invention, and the scope of the protection claimed in the present invention should be defined by the corresponding claims and equivalents, and all such added, removed, replaced, modified or modified technical solution is intended to fall within the scope of the protection of the appended claims.

Claims (6)

1. A catalytic cracking process based on double settler, characterized by the following steps:

The gas, liquefied gas, naphtha or gasoline fraction, kerosene fraction and diesel fraction distilled by the constant vacuum distillation device are sequentially input into the first riser from low to high in sections;

after pretreatment, wax oil, atmospheric residuum and residuum distilled from a constant vacuum distillation device are sequentially and sectionally input into a second riser from low to high;

The high-temperature catalyst settled by the first settling vessel is used as a reaction catalyst of the second reactor and is input into a second riser; the high-temperature catalyst settled by the second settler is input into a catalyst regenerator for burning regeneration;

The regenerated catalyst is used as a reaction catalyst of the first reactor and is input into a first riser;

Pressurizing less than one fourth of the gas and the liquefied gas to a pressure of >0.8Mpa and gasifying and superheating to a temperature of >150 ℃, respectively taking the gasified and superheated gas and the liquefied gas as catalyst lifting gas of the first lifting pipe and the second lifting pipe, wherein the oil ratio of the control agent is >100:1;

feeding liquefied gas from the lowest section of the first lifting pipe, wherein the agent-oil ratio is controlled to be 50:1-90:1;

the gasoline fraction or naphtha is mixed and then is subjected to system separation to return light oil, the temperature is raised to be more than 150 ℃, the mixture is mixed and atomized with superheated steam with the pressure of more than 0.8Mpa and the temperature of more than 200 ℃ according to the proportion of more than 1:0.1, and then the mixture is fed from the upper part of a liquefied gas feeding section of a first lifting pipe, wherein the ratio of the catalyst to the oil is controlled between 20:1 and 90:1;

heating the kerosene fraction to a temperature of >150 ℃, mixing and atomizing the kerosene fraction with superheated steam with a pressure of >0.8Mpa and a temperature of >200 ℃ according to a proportion of >1:0.15, and feeding the kerosene fraction from the upper part of a naphtha or gasoline feeding section of the first riser, wherein the catalyst-oil ratio is controlled between 20:1 and 90:1;

Heating the diesel fraction to a temperature of >150 ℃, mixing and atomizing the diesel fraction with superheated steam with a pressure of >0.8Mpa and a temperature of >200 ℃ according to a proportion of >1:0.2, and feeding the diesel fraction from the upper part of a kerosene feeding section of a first riser, wherein the catalyst-oil ratio is controlled between 20:1 and 90:1;

Cutting catalytic diesel oil after catalytic reaction in a second reactor, taking light components with the normal pressure distillation range of 230-280 ℃, heating to the temperature of >150 ℃, mixing and atomizing the light components with superheated steam with the pressure of >0.8Mpa and the temperature of >200 ℃ according to the proportion of >1:0.1, and feeding from the lowest section of a second riser, wherein the catalyst-oil ratio is controlled between 20:1 and 90:1;

Heating wax oil to a temperature of >150 ℃, mixing and atomizing the wax oil with superheated steam with a pressure of >0.8Mpa and a temperature of >200 ℃ according to a proportion of >1:0.1, and feeding the mixture from the upper part of a light catalytic diesel feeding section of a second riser, wherein the ratio of the catalyst to the oil is controlled between 20:1 and 90:1;

Heating the residual oil to a temperature of >150 ℃, mixing and atomizing the residual oil with superheated steam with a pressure of >0.8Mpa and a temperature of >200 ℃ according to a proportion of >1:0.1, and feeding the residual oil from the upper part of a wax oil feeding section of the second lifting pipe, wherein the ratio of the agent to the oil is controlled between 20:1 and 90:1;

And (3) heating part of catalytic slurry oil after catalytic reaction to a temperature of >150 ℃, mixing and atomizing the heated slurry oil with superheated steam with a pressure of >0.8Mpa and a temperature of >200 ℃ according to a proportion of >1:0.1, and feeding the slurry oil from the upper part of a residual oil feeding section of the second riser, wherein the catalyst-oil ratio is controlled between 20:1 and 90:1.

2. The double settler-based catalytic cracking process as claimed in claim 1, characterized in that:

The agent-to-oil ratio of the liquefied gas feeding section of the first riser is more than 36:1;

the catalyst to oil ratio of the naphtha or gasoline feeding section of the first riser is more than 36:1, and the gas flow rate is controlled to be more than 1m/s;

the agent-oil ratio of the kerosene feeding section of the first riser is more than 36:1, and the gas flow rate is controlled to be more than 1m/s;

the diesel oil feeding section of the first riser has a catalyst to oil ratio of >20:1, and the control gas flow rate is greater than 1m/s.

3. The double settler-based catalytic cracking process as claimed in claim 1, characterized in that:

The catalyst-to-oil ratio of the light catalytic diesel feeding section of the second riser is more than 30:1;

The agent-oil ratio of the wax oil feeding section of the second riser is more than 20:1, and the gas flow rate is controlled to be more than 1m/s;

The agent-oil ratio of the residual oil feeding section of the second riser is more than 20:1, and the gas flow rate is controlled to be more than 1m/s;

the catalyst to oil ratio of the second riser catalytic slurry feed section is >20:1, and the control gas flow rate is greater than 1m/s.

4. A catalytic cracking method based on double settlers according to any one of claims 1 to 3, wherein the crude oil is pretreated by an electric desalting device, and then enters an atmospheric and vacuum distillation device, and gas, liquefied gas, naphtha or gasoline fraction, kerosene fraction, diesel fraction, wax oil, atmospheric residue and residual oil are separated according to the molecular weight and the distillation range from low to high, wherein the distillation range of the naphtha fraction is 20-160 ℃, the distillation range of the gasoline fraction is 10-235 ℃, the distillation range of the kerosene fraction is 145-280 ℃ and the distillation range of the diesel fraction is 230-390 ℃.

5. A catalytic cracking device based on double settlers is characterized by comprising a first settler, a second settler, a first riser, a second riser and a catalyst regenerator, wherein,

The first settler is connected in series at the top end of the first riser to form a first reactor, the first riser consists of a plurality of sections from low to high, and each section is provided with a feed inlet for sequentially inputting gas, liquefied gas, naphtha or gasoline fraction, kerosene fraction and diesel fraction which are distilled by the constant reduced pressure distillation device from low to high respectively;

The second settler is connected in series at the top end of the second riser to form a second reactor, the second riser consists of a plurality of sections from low to high, and each section is provided with a feed inlet for sequentially inputting the wax oil, the atmospheric residue and the residue which are fractionated by the constant vacuum distillation device and pretreated from low to high respectively;

The first reactor, the second reactor and the catalyst regenerator are arranged in series; a first inclined tube is connected between the first settler and the bottom of the second riser and used for inputting the high-temperature catalyst settled by the first settler into the second riser as a reaction catalyst of the second reactor;

the regenerated catalyst is used as a reaction catalyst of the first reactor and is input into a first riser through a corresponding pipeline;

the first and second settlers are provided with respective cyclone separating devices;

after the reaction catalyst in the first reactor is settled by the first settling vessel, the reaction catalyst passes through the dipleg of the cyclone separation device and enters the second riser through the first inclined tube;

After settling in the second reactor, the reaction catalyst passes through the dipleg of the cyclone and enters the catalyst regenerator through the second inclined tube.

6. The catalytic cracking unit based on double settler according to claim 5, characterized in that:

a hydrogenation or light oil refining device is arranged between the atmospheric and vacuum distillation device and the first reactor and is used for selectively preprocessing the distilled light oil component of the atmospheric and vacuum distillation device according to the sulfur content, the saturated hydrocarbon content and the corresponding environmental protection index requirements;

And/or a wax oil hydrogenation device, a residual oil hydrogenation device and/or a solvent deasphalting device are/is arranged between the atmospheric and vacuum distillation device and the second reactor, and are used for selectively preprocessing wax oil, atmospheric residual oil and residual oil which are distilled out by the atmospheric and vacuum distillation device according to the sulfur content, the saturated hydrocarbon content, the metal content and the requirements of corresponding environmental protection indexes.