JP2008156248A - Method for producing hydroxy compound - Google Patents

Abstract

The present invention relates to a method for producing a hydroxy compound, which converts a hydrocarbon compound into a hydroxy compound, which basically does not generate by-products, and therefore does not require treatment of by-products or wastewater, and only the target hydroxy compound. It is possible to provide a method for producing a hydroxy compound having an excellent feature that can be produced very efficiently and economically.
A chlorination step, a hydrolysis step, a hydrochloric acid separation step, a hydrogen chloride separation step, a water separation step, an oxidation step, and a chlorine separation step are included. Hydrocarbons include saturated and unsaturated hydrocarbons such as methane, ethane, and propylene, aromatic hydrocarbons such as benzene, toluene, and xylene, and aromatic rings of these compounds are nitro, amino, and alkyl groups. It may be substituted with a substituent such as (excluding a methyl group). Further, in addition to the monocyclic aromatic compound, a polycyclic aromatic compound such as a naphthalene ring or an anthracene ring may be used.
[Selection] Figure 1

Description

  The present invention relates to a method for producing a hydroxy compound. More specifically, the present invention relates to a method for producing a hydroxy compound for converting a hydrocarbon compound into a hydroxy compound, which basically does not generate by-products, and therefore does not require treatment of by-products or waste water, and is a target product. It is related with the manufacturing method of the hydroxy compound which has the outstanding characteristic that only the hydroxy compound which is can be manufactured very efficiently and economically.

  For example, a method for producing a hydroxy compound such as phenol indirectly from a hydrocarbon such as benzene, hydrogen chloride, and oxygen via monochlorobenzene, which is a chlorinated hydrocarbon compound, is known as Raschig process. In this process, monochlorobenzene is produced from benzene, hydrogen chloride and oxygen by the oxychlorination method, monochlorobenzene is hydrolyzed to produce phenol, and by-produced hydrogen chloride is recovered to produce monochlorobenzene. It is a process of using for the oxychlorination method (for example, refer patent document 1).

  Also, without using the oxychlorination method, monochlorobenzene is produced by chlorination reaction using chlorine, hydrogen chloride produced as a by-product by chlorination and hydrolysis is recovered, and chlorine is produced and reused by oxidation reaction. A process has also been proposed (Patent Document 2).

  Here, hydrogen chloride produced by hydrolysis is obtained as a mixture with unreacted chlorinated hydrocarbon, water and hydroxy compound, but hydrogen chloride and water are separated and recovered from chlorinated hydrocarbon compound and hydroxy compound as hydrochloric acid. be able to. On the other hand, when hydrogen chloride is extracted from hydrochloric acid and oxidized to produce chlorine, hydrogen chloride and water form an azeotrope, making it difficult to completely separate hydrogen chloride and water by simple distillation. was there. Specifically, when the concentration of hydrogen chloride in the recovered hydrochloric acid is higher than the azeotropic composition of hydrogen chloride and water under the distillation pressure, high-purity hydrogen chloride can be recovered from the top of the column, but at the bottom, The hydrogen chloride concentration can only be reduced to the boiling composition. In addition, when the concentration of hydrogen chloride in the recovered hydrochloric acid is smaller than the azeotropic composition of hydrogen chloride and water under the distillation pressure, water can be separated at the top of the column. The hydrogen concentration cannot be increased. As a method of effectively using this azeotrope, there is a method of using the azeotrope as a raw material for oxidation or hydrolysis (for example, Patent Document 3).

  This method has the advantage that it does not require complete separation of hydrogen chloride and water when water produced by oxidation is used for hydrolysis or hydrogen chloride produced by hydrolysis is used for oxidation. Since the reaction product is mixed in the raw material for hydrolysis or oxidation, there is a problem that the reaction is difficult to proceed.

U.S. Pat. No. 3,322,063 JP 2006-131617 A JP 2006-306833 A

  In such a situation, the problem to be solved by the present invention is a method for producing a hydroxy compound for converting a hydrocarbon compound into a hydroxy compound, which basically does not generate a by-product, and therefore treats the by-product and waste water. Therefore, the present invention provides a method for producing a hydroxy compound having an excellent characteristic that only the target hydroxy compound can be produced very efficiently and economically.

That is, the present invention relates to a method for producing a hydroxy compound including the following steps.
Chlorination step: a step in which a hydrocarbon compound and chlorine are reacted to obtain a chlorinated hydrocarbon compound and hydrogen chloride Hydrolysis step: a reaction between the chlorinated hydrocarbon compound obtained in the chlorination step and water to produce a hydroxy compound A step of producing hydrogen chloride to obtain a mixture comprising a chlorinated hydrocarbon compound, water, a hydroxy compound, and hydrogen chloride Hydrochloric acid separation step: The mixture obtained in the hydrolysis step is divided into a portion mainly composed of hydrogen chloride and water; A process of separating a chlorinated hydrocarbon compound and a hydroxy compound into main parts and supplying a main part of hydrogen chloride and water to the following water separation process or hydrogen chloride separation process. Hydrogen chloride separation process: Under a pressure higher than the pressure, a mixture of hydrogen chloride and water having a composition richer in hydrogen chloride than the azeotropic composition of hydrogen chloride and water at the pressure is subjected to distillation, and hydrogen chloride is removed from the top of the column. Supplying the mixture to the following oxidation step, obtaining a mixture of hydrogen chloride and water from the bottom of the column and supplying at least a part thereof to the water separation step. Water separation step: Under a pressure lower than that of the hydrogen chloride separation step, Subjecting a mixture of hydrogen chloride and water having a composition richer in water than the azeotropic composition of water and hydrogen chloride at a pressure to distillation, obtaining water from the top of the tower, and supplying at least a portion thereof to the hydrolysis step; A step of obtaining a mixture of hydrogen chloride and water from the bottom of the column and supplying at least a part thereof to the hydrogen chloride separation step. Oxidation step: reacting hydrogen chloride obtained in the hydrogen chloride separation step with oxygen to produce chlorine and water. A process of obtaining a mixture of hydrogen chloride, oxygen, chlorine and water Chlorine separation process: The mixture obtained in the above oxidation process is composed mainly of chlorine, oxygen mainly, hydrogen chloride and water. Separated into parts, mainly oxygen At least a portion of the minute is supplied to the oxidation step, a portion composed mainly of chlorine fed to the chlorination step, supplying a portion mainly containing hydrogen chloride and water in the hydrogen chloride separation step or water separation step

  According to the present invention, a hydroxy compound is produced by converting a hydrocarbon compound into a hydroxy compound, which basically generates no by-products, and therefore does not require treatment of by-products or waste water, and is a target hydroxy compound. Thus, it is possible to provide a method for producing a hydroxy compound having an excellent feature that it can be produced very efficiently and economically.

  The chlorination step of the present invention is a step of reacting hydrocarbon and chlorine to obtain chlorinated hydrocarbon and hydrogen chloride.

  Hydrocarbons include saturated and unsaturated hydrocarbons such as methane, ethane, and propylene, aromatic hydrocarbons such as benzene, toluene, and xylene, and aromatic rings of these compounds are nitro, amino, and alkyl groups. It may be substituted with a substituent such as (excluding a methyl group). Further, in addition to the monocyclic aromatic compound, a polycyclic aromatic compound such as a naphthalene ring or an anthracene ring may be used.

  As chlorinated hydrocarbon compounds, chlorinated hydrocarbon compounds in which one chlorine atom is substituted on a chain hydrocarbon such as methyl chloride, ethyl chloride, and allyl chloride, and multiple chlorine atoms such as carbon tetrachloride are substituted. Monochlorobenzene, 1,2-, 1,3- or 1,4-dichlorobenzene, 1,2,3-, 1,2,4- or 1,3,5-trichlorobenzene, tetrachlorobenzene In addition, aromatic compounds such as pentachlorobenzene or hexachlorobenzene, mono- or polychlorotoluene, mono- or polychloroxylene, and the like can be exemplified by compounds in which one or more chlorine atoms are substituted. Moreover, the aromatic ring of those compounds may be substituted with a substituent such as a nitro group, an amino group, or an alkyl group (excluding a methyl group). Further, in addition to the monocyclic aromatic compound, a polycyclic aromatic compound such as a naphthalene ring or an anthracene ring may be used. Further, not only compounds in which the aromatic ring is directly substituted with chlorine, but also those in which the aromatic ring substituents are chlorinated, such as benzyl chloride and cumyl chloride.

  A method of obtaining monochlorobenzene or dichlorobenzene, which is a chlorinated hydrocarbon compound, using benzene as the hydrocarbon compound is particularly important from an industrial viewpoint.

  The chlorine to be used is not particularly limited, and may be any of chlorine generated by electrolysis of sodium chloride, chlorine generated by oxidation of hydrogen chloride, chlorine generated by electrolysis of hydrochloric acid and / or hydrogen chloride, etc. As at least a part thereof, chlorine obtained by chlorination of a hydrocarbon compound and oxidation of hydrogen chloride produced by hydrolysis of the chlorinated hydrocarbon is used.

  In the hydrolysis step of the present invention, the chlorinated hydrocarbon compound obtained in the chlorination step is reacted with water to produce a hydroxy compound and hydrogen chloride, and consists of a chlorinated hydrocarbon compound, water, a hydroxy compound, and hydrogen chloride. This is a step of obtaining a mixture.

  Examples of the hydroxy compound include alcohols having a single hydroxy group in a chain hydrocarbon such as methanol, ethanol, and allyl alcohol, those substituted with a plurality of hydroxy groups such as pentaerythritol, phenol, cresol, catechol, An aromatic compound such as resorcin, hydroquinone or the like can be exemplified by a compound in which one or more hydroxy groups are substituted. Moreover, the aromatic ring of those compounds may be substituted with a substituent such as a nitro group, an amino group, or an alkyl group (excluding a methyl group). In the case of an aromatic compound, in addition to the above monocyclic aromatic compound, a polycyclic aromatic compound such as naphthol or anthracene ring which is a naphthalene ring may be used. Further, not only compounds in which an aromatic ring is directly substituted with a hydroxy group, but also those in which an aromatic ring substituent is hydroxylated, such as benzyl alcohol and cumyl alcohol.

  The raw materials supplied to the hydrolysis process are chlorinated hydrocarbon compounds and water, but unreacted water from the hydrolysis process is recovered as hydrochloric acid together with hydrogen chloride produced by the reaction, and these are combined with distillation under different pressure conditions. It is a feature of the present invention that water obtained by separation is reused as a raw material. Thereby, even if unreacted water remains in the hydrolysis step, it can be reused and the amount of drainage is reduced.

  From an industrial point of view, when the chlorinated hydrocarbon compound is a chlorinated aromatic compound and the hydroxy compound is a hydroxy aromatic compound, especially when the chlorinated hydrocarbon compound is monochlorobenzene and the hydroxy compound is phenol. Of particular importance.

  The method for reacting the chlorinated hydrocarbon compound with water is not particularly limited, and a known method can be used. An example of a specific method is as follows. The reaction is carried out either in the liquid phase or in the gas phase. In the case of a gas phase reaction, the reaction form may be a fixed bed, a fluidized bed, or a moving bed. The molar ratio of water to chlorinated hydrocarbon (water / chlorinated hydrocarbon) is usually 0.5 to 10, the reaction temperature is 160 to 600 ° C., and the reaction pressure may be any of reduced pressure, normal pressure, and pressurized pressure. However, it is usually normal pressure or pressurization. In the case of a chlorinated aromatic compound such as monochlorobenzene, a supported phosphoric acid catalyst or a supported copper catalyst can be used as the catalyst.

  The hydrolysis reaction is preferably carried out manually using a crystalline metallosilicate catalyst and / or a metal-supported crystalline metallosilicate catalyst from the viewpoint of improving the activity and selectivity of the hydrolysis reaction.

  The crystalline metallosilicate catalyst contains Si as an essential component, and includes Al, Cu, Ga, Fe, B, Zn, Cr, Be, Co, La, Ge, Ti, Zr, Hf, V, Ni, Sb, and Bi. 1 or 2 or more metal elements selected from Nb, etc., Si and other metal atomic ratio, Si / Me atomic ratio (where Me is Al, Cu, Ga, Fe, B, Zn, Cr 1 or 2 or more metal elements selected from Be, Co, La, Ge, Ti, Zr, Hf, V, Ni, Sb, Bi, Nb, etc.), a crystalline metallosilicate having 5 or more Is more preferable, but it may be a crystalline silicate composed of silicon dioxide substantially free of the Me component.

  Further, a catalyst in which the above Me component is further supported on the crystalline metallosilicate may be used as a catalyst.

  The hydrochloric acid separation step of the present invention is a step of separating the mixture obtained in the hydrolysis step into a portion mainly composed of hydrogen chloride and water and a portion mainly composed of a chlorinated hydrocarbon compound and a hydroxy compound.

  In the liquefied state, the mixture obtained in the hydrolysis step is separated into an oil layer mainly composed of organic substances such as hydroxy compounds and unreacted chlorinated hydrocarbon compounds, and an unreacted water and a hydrochloric acid layer mainly composed of produced hydrogen chloride. The hydrochloric acid layer can be separated by a known oil-water separation operation. Hydroxy compounds are usually soluble in water due to the hydrophilicity of the hydroxyl group, but are easily distributed to the oil layer side because hydrogen chloride is dissolved in water to form hydrochloric acid. When the separation of the oil layer and the hydrochloric acid layer is insufficient, the oil layer and the hydrochloric acid layer may be separated by an extraction operation using an organic solvent having lower mutual solubility with hydrochloric acid. In addition, organic substances such as hydroxy compounds, chlorinated hydrocarbons, and organic solvents contained in trace amounts in the recovered hydrochloric acid layer can be further removed by operations such as extraction and distillation. The hydrochloric acid obtained by the above operation is supplied to the following water separation step or hydrogen chloride separation step.

  The hydrogen chloride separation step of the present invention is a distillation of a mixture of hydrogen chloride and water having a composition richer in hydrogen chloride than the azeotropic composition of hydrogen chloride and water at a pressure higher than the pressure of the water separation step described below. In this step, hydrogen chloride is obtained from the top of the column and supplied to the oxidation step, and a mixture of hydrogen chloride and water is obtained from the bottom of the column and at least a part thereof is supplied to the water separation step.

  As the raw material for the hydrogen chloride separation step, a portion mainly composed of hydrogen chloride and water obtained in the hydrochloric acid separation step, the following water separation step, and the chlorine recovery step can be used, but the average of all the raw materials supplied to the distillation column The composition should be richer in hydrogen chloride than the azeotropic composition of hydrogen chloride and water under the operating pressure of the distillation column. The operation pressure of the distillation tower is desirably 0.1 to 1.0 MPa, and more preferably 0.1 to 0.7 MPa. The hydrogen chloride concentration in the column bottom liquid at that time can be reduced to an azeotropic composition under the column bottom pressure. The hydrogen chloride concentration in the azeotropic composition is 21% by weight at 0.1 MPa and 13% by weight at 1.0 MPa. If the operating pressure is too low, vacuum equipment is required and the equipment costs are high, and the concentration of hydrogen chloride in the residual hydrochloric acid increases, resulting in a decrease in the hydrogen chloride recovery rate. On the other hand, if the operating pressure is too high, the concentration of hydrogen chloride in the residual hydrochloric acid decreases and the hydrogen chloride recovery rate increases, but the column bottom temperature increases, so the materials that can be used in the apparatus are limited to high-grade materials such as tantalum. In addition, a high-temperature heating source is required. Hydrogen chloride obtained from the top of the distillation column can be used for various purposes, but at least a part of the hydrogen chloride is supplied to the following oxidation step and used for the production of chlorine. The produced chlorine can be used as a raw material for producing a chlorinated hydrocarbon compound that is a raw material for the hydrolysis step.

  In the water separation step of the present invention, under a pressure lower than that of the hydrogen chloride separation step, a mixture of hydrogen chloride and water having a composition richer in water than the azeotropic composition of hydrogen chloride and water at the pressure is subjected to distillation. In this step, water is obtained from the top of the column and supplied to the hydrolysis step, and a mixture of hydrogen chloride and water is obtained from the bottom of the column and at least a part thereof is supplied to the hydrogen chloride separation step.

  As the raw material for the water separation step, a portion mainly composed of hydrogen chloride and water obtained in the hydrochloric acid separation step, the hydrogen chloride separation step, and the following chlorine recovery step can be used, but the average of all the raw materials supplied to the distillation column The composition should be richer in water than the azeotropic composition of hydrogen chloride and water under the operating pressure of the distillation column. The operation pressure of the distillation tower is desirably 0.001 to 0.1 MPa, and more preferably 0.003 to 0.05 MPa. The hydrogen chloride concentration in the column bottom liquid at that time can be increased to an azeotropic composition under the column bottom pressure. Since the azeotropic mixture of hydrogen chloride and water has a composition richer in hydrogen chloride as the pressure is lower, the operation pressure in this step is preferably lower in concentrating the hydrogen chloride. On the other hand, in order to recover the water obtained from the top of the tower and supply it to the hydrolysis process, it is effective to condense and pressurize with a pump as a liquid, but if the operating pressure is less than 0.001 MPa, it can be condensed with ordinary cooling water. It becomes difficult.

  The oxidation step in the present invention is a step in which hydrogen chloride obtained in the hydrogen chloride separation step is reacted with oxygen to produce chlorine and water to obtain a mixture composed of hydrogen chloride, oxygen, chlorine and water.

  There is no restriction | limiting in particular about the method of making hydrogen chloride and oxygen react, A well-known method can be used. An example of a specific method is as follows. The molar ratio of hydrogen chloride to oxygen (hydrogen chloride / oxygen) is 0.5 to 2.0, the reaction temperature is 200 to 500 ° C., preferably 200 to 380 ° C., and the reaction pressure is 0.1 to 5 MPa. Yes, the superficial velocity is 0.7-10 m / s. As the reactor, a fixed bed reactor, a fluidized bed reactor, or a moving bed reactor can be used. In the reaction, a chromium oxide catalyst or a ruthenium oxide catalyst can be used as a catalyst.

  In the chlorine separation step of the present invention, the reaction mixture of the oxidation step is separated into a portion mainly composed of chlorine, a portion mainly composed of unreacted oxygen, and a portion mainly composed of unreacted hydrogen chloride and water. At least a part of the main part is supplied to the oxidation process, the main part of chlorine is supplied to the chlorination process, and the main part of hydrogen chloride and water is supplied to the hydrogen chloride separation process or water separation process. It is the process of supplying to.

  The reaction mixture of the oxidation step contains chlorine, hydrogen chloride, water and oxygen. These components are separated and recovered in this step into hydrochloric acid and oxygen consisting of chlorine, hydrogen chloride and water.

  In order to carry out the chlorine separation step, for example, absorption, condensation and distillation may be used. About hydrogen chloride and water, it is condensed or absorbed in a solvent and separated and recovered as hydrochloric acid. If the reaction rate of hydrogen chloride in the oxidation step is low and the entire amount of unreacted hydrogen chloride does not dissolve in the reaction product water, use hydrochloric acid obtained from the bottom of the distillation column in the hydrogen chloride separation step or water separation step as the absorbent. May completely dissolve the hydrogen chloride. The recovered hydrochloric acid is supplied to either the hydrogen chloride separation step or the water separation step, separated into hydrogen chloride and water in these steps, and used as a raw material for the oxidation step and the hydrolysis step, respectively. Here, when the concentration of hydrogen chloride in the recovered hydrochloric acid is larger than the azeotropic composition of hydrogen chloride and water at the distillation column operating pressure in the water separation step, it is desirable to supply the recovered hydrochloric acid to the hydrogen chloride separation step. Moreover, the chlorine obtained here can be used for production of chlorinated hydrocarbons by chlorination of hydrocarbon compounds in the chlorination step.

In the present invention, from the viewpoint of effective utilization of unreacted hydrocarbon compounds and stabilization of the downstream hydrolysis process, it is preferable to use the following chlorinated hydrocarbon purification process.
Chlorinated hydrocarbon refining process: A process for purifying the chlorinated hydrocarbon obtained in the chlorination process The chlorinated hydrocarbon obtained in the chlorination process is composed of hydrocarbons and a small amount of by-products. Contains organisms. Chlorinated hydrocarbons purified from such a mixture can be separated and recovered. On the other hand, the hydrocarbons used in this step are separated and recovered, and at least a part thereof is recycled to the chlorination step.

  In order to carry out the chlorinated hydrocarbon purification step, for example, distillation, extractive distillation, adsorption separation or the like may be used. In particular, distillation is used for unreacted hydrocarbons and chlorinated hydrocarbons having different boiling points, and extractive distillation, adsorptive separation, or the like is used for separation between isomers having similar boiling points even for chlorinated hydrocarbons.

In the present invention, from the viewpoint of effective utilization of unreacted chlorinated hydrocarbons and high purification of hydroxy compounds, it is desirable to use the following hydroxy compound purification step.
Hydroxy compound purification step: A portion mainly composed of chlorinated hydrocarbon compound and hydroxy compound obtained in the hydrochloric acid separation step, a portion mainly composed of chlorinated hydrocarbon compound, a portion mainly composed of hydroxy compound and impurities. Supplying the above hydrolysis step with at least a part of a portion mainly composed of a chlorinated hydrocarbon compound.

  The oil layer obtained in the hydrochloric acid separation step contains a small amount of impurities such as a hydroxy compound, an unreacted chlorinated hydrocarbon compound, and a hydrocarbon compound by-produced by hydrolysis. In this step, these are separated into a part mainly composed of chlorinated hydrocarbon compounds, a part mainly composed of hydroxy compounds, and a part mainly composed of impurities to obtain a purified hydroxy compound, and the chlorinated hydrocarbon compound is hydrolyzed. It is recycled as a raw material for decomposition.

  For example, distillation may be used to carry out the hydroxy compound purification step. At that time, the portion mainly containing impurities may be separated and recovered as two or more fractions according to the boiling point of the impurity component contained.

In the present invention, it is desirable to use the following hydrogen chloride purification step from the viewpoint of stabilizing the downstream oxidation step.
Hydrogen chloride refining step: After separating and recovering the main part of hydrocarbon compound, chlorinated hydrocarbon compound and hydroxy compound from the main part of hydrogen chloride obtained in the above chlorination step and hydrogen chloride separation step, Supplying the remaining hydrogen chloride to the oxidation process

  Examples of the purification method in this step include a method of cooling and gas-liquid separation to obtain purified hydrogen chloride as a gas, and a method of removing impurities by adsorption. Both of these methods can be used in combination.

Example 1
Next, an example of the case of using benzene as the hydrocarbon compound, monochlorobenzene as the chlorinated hydrocarbon compound, and obtaining phenol as the hydroxy compound will be specifically described using the flow of FIG. 1 and the material balance of Tables 1 to 3. I will explain it.
Benzene (fluid number 2) and chlorine (fluid number 3) are supplied to a reactor equipped with a condenser and a condenser for removing the heat of reaction in the chlorination step (A), and reacted in the liquid phase to monochloro. Generates benzene and hydrogen chloride. In this embodiment, monochlorobenzene is the target product of the chlorination process, and benzene is supplied excessively with respect to chlorine in order to suppress the production of polychlorinated products such as dichlorobenzene. Gas that is accompanied by benzene and monochlorobenzene with hydrogen chloride generated in the reaction is cooled in a condenser, and the condensate rich in benzene and monochlorobenzene is returned to the reactor. A gas mainly composed of hydrogen chloride (fluid number 4) is returned to the reactor. It takes out and supplies to a hydrogen chloride production | generation process (J). A liquid mainly composed of unreacted benzene and monochlorobenzene (fluid number 5) obtained from the reactor is supplied to the chlorinated hydrocarbon purification step (H), and a portion mainly composed of benzene (fluid number 7) by distillation, monochloro. It separates into a part mainly composed of benzene (fluid number 8) and a part mainly composed of impurities (fluid numbers 6 and 9). The separated main portion of benzene is recycled as a raw material for the chlorination step, and the main portion of monochlorobenzene is supplied to the hydrolysis step (B).

In the hydrolysis step, monochlorobenzene (fluid number 10) and water (fluid number 11) are heated and vaporized, and then subjected to a hydrolysis reaction in a reactor filled with a copper-supported zeolite catalyst to produce phenol and hydrogen chloride. At this time, benzene is produced by a side reaction. Here, the molar ratio of water supplied to the reactor to monochlorobenzene (water / monochlorobenzene) is 1.5, and 30% of the supplied monochlorobenzene is converted into phenol and benzene by the reaction.
The produced reaction mixture containing phenol, hydrogen chloride, benzene, unreacted monochlorobenzene and water (fluid number 12) is supplied to the hydrochloric acid separation step (C), and is mainly composed of vent gas (fluid number 13), mainly Separation into an oil layer (fluid number 14) composed of phenol, monochlorobenzene and benzene and a hydrochloric acid layer (fluid number 15) mainly composed of hydrogen chloride and water. The concentration of hydrogen chloride in the resulting hydrochloric acid layer is 27% by weight. This hydrochloric acid layer is divided into hydrochloric acid (fluid No. 24) having a hydrogen chloride concentration of 23% by weight supplied from the water separation step and hydrogen chloride supplied from the chlorine separation step. Gas (mainly hydrogen chloride) from the top (fluid) is supplied to the hydrogen chloride separation step (D) together with hydrochloric acid (fluid number 35) having a concentration of 30% by weight, and hydrogen chloride gas is diffused using a pressurized distillation column. No. 17) is obtained from the bottom of the column with hydrochloric acid (18) having a hydrogen chloride concentration reduced to 17% by weight from the raw material. At this time, fresh hydrochloric acid (fluid number 38) having a hydrogen chloride concentration of 30% by weight from the outside is used to compensate for the chlorine content that is lost to the fluid purged outside the system (fluid numbers 6, 9, 13, 21, 22, and 28). To the feed.

Part of the hydrochloric acid obtained from the bottom of the column is supplied to the water separation step (E) and separated using a vacuum distillation column. Water (fluid No. 19) is separated from the top, and the hydrogen chloride concentration from the bottom is 23% by weight. Hydrochloric acid (fluid no. 20) is obtained. A part of the water obtained from the top is purged outside the system to avoid accumulation of impurities (fluid number 21), and the rest (fluid number 11) is recycled as a raw material for the hydrolysis process. Hydrochloric acid obtained from the bottom of the column is partially purged (fluid number 22) outside the system in order to avoid impurity accumulation, and further part (fluid number 23) is supplied to the chlorine separation process to remove unreacted hydrogen chloride in the oxidation process. The remaining part (fluid number 24) is recycled to the hydrogen chloride separation step as an absorbent.
The oil layer obtained in the hydrochloric acid separation step is supplied to the hydroxy compound purification step (I), and by distillation, a fraction mainly containing benzene (fluid number 25), a fraction mainly containing monochlorobenzene (fluid number 26), and phenol. The main fraction (fluid number 27) and other impurities are separated into main fractions (fluid number 28). The benzene-based fraction is recycled to the chlorination process and used as a reaction raw material. A fraction mainly composed of monochlorobenzene is recycled to the hydrolysis process and used as a reaction raw material.

The gas mainly composed of hydrogen chloride obtained in the chlorination step and the hydrogen chloride separation step contains trace amounts of impurities such as benzene, monochlorobenzene, and water. After cooling this in the hydrogen chloride purification step (J), the activated carbon Impurities are separated by passing through a packed tower. Purified hydrogen chloride gas (fluid number 29) is supplied to the oxidation step (F), and the separated and recovered impurities (fluid number 30) are recycled to the hydrochloric acid separation step.
In the oxidation step, purified hydrogen chloride gas is reacted in the gas phase using oxygen (fluid number 32) and a ruthenium-supported catalyst to generate chlorine and water. The reaction gas (fluid number 33) containing the generated chlorine, water, unreacted hydrogen chloride, and oxygen is supplied to the chlorine separation step (G), and the gas mainly containing oxygen (fluid number 34) is obtained by condensation liquefaction and distillation. ), Hydrochloric acid (fluid number 35) composed mainly of chlorine (3), hydrogen chloride and water. Here, as an absorption liquid for liquefying hydrogen chloride together with water and sufficiently separating it from oxygen and chlorine and recovering it as hydrochloric acid, one of hydrochloric acid having a hydrogen chloride concentration of 23% by weight obtained from the bottom of the distillation column in the water separation step. Part. Part of the gas mainly composed of oxygen (fluid number 36) is purged to prevent accumulation of impurities, and the remaining part (fluid number 37) is recycled to the oxidation process, and new oxygen (fluid number 31) supplied from the outside is recycled. ) And as an oxidation reaction raw material.
By the above method, 1 mol of phenol is obtained from 1.03 mol of benzene and 0.62 mol of oxygen.

It is an example of the flow which implements this invention.

Explanation of symbols

A: Chlorination step B: Hydrolysis step C: Hydrochloric acid separation step D: Hydrogen chloride separation step E: Water separation step F: Oxidation step G: Chlorine separation step H: Chlorinated hydrocarbon purification step I: Hydroxy compound purification step J : Hydrogen chloride purification process

Claims (5)

The manufacturing method of the hydroxy compound including the following process.
Chlorination step: a step in which a hydrocarbon compound and chlorine are reacted to obtain a chlorinated hydrocarbon compound and hydrogen chloride Hydrolysis step: a reaction between the chlorinated hydrocarbon compound obtained in the chlorination step and water to produce a hydroxy compound A step of producing hydrogen chloride to obtain a mixture comprising a chlorinated hydrocarbon compound, water, a hydroxy compound, and hydrogen chloride Hydrochloric acid separation step: The mixture obtained in the hydrolysis step is divided into a portion mainly composed of hydrogen chloride and water; A process of separating a chlorinated hydrocarbon compound and a hydroxy compound into main parts and supplying a main part of hydrogen chloride and water to the following water separation process or hydrogen chloride separation process. Hydrogen chloride separation process: Under a pressure higher than the pressure, a mixture of hydrogen chloride and water having a composition richer in hydrogen chloride than the azeotropic composition of hydrogen chloride and water at the pressure is subjected to distillation, and hydrogen chloride is removed from the top of the column. Supplying the mixture to the following oxidation step, obtaining a mixture of hydrogen chloride and water from the bottom of the column and supplying at least a part thereof to the water separation step. Water separation step: Under a pressure lower than that of the hydrogen chloride separation step, Subjecting a mixture of hydrogen chloride and water having a composition richer in water than the azeotropic composition of water and hydrogen chloride at a pressure to distillation, obtaining water from the top of the tower, and supplying at least a portion thereof to the hydrolysis step; A step of obtaining a mixture of hydrogen chloride and water from the bottom of the tower and supplying at least a part thereof to the hydrogen chloride separation step. Oxidation step: The hydrogen chloride obtained in the chlorination step and the hydrogen chloride separation step is reacted with oxygen to react with chlorine. Process for producing water and obtaining a mixture comprising hydrogen chloride, oxygen, chlorine and water Chlorine separation process: The mixture obtained in the above oxidation process is composed of a part mainly composed of chlorine, a part mainly composed of oxygen, hydrogen chloride and water. Is divided into the main parts, Supply at least a part of the main part of oxygen to the oxidation process, supply a main part of chlorine to the chlorination process, and separate the main part of hydrogen chloride and water into the hydrogen chloride separation process or water separation. Supplying process The manufacturing method of Claim 1 including the following chlorinated hydrocarbon refinement | purification processes.
Chlorinated hydrocarbon purification process: A process for purifying the chlorinated hydrocarbon obtained in the above chlorination process. The manufacturing method of Claim 1 including the following hydroxy compound refinement | purification process.
Hydroxy compound purification step: A portion mainly composed of chlorinated hydrocarbon compound and hydroxy compound obtained in the hydrochloric acid separation step, a portion mainly composed of chlorinated hydrocarbon compound, a portion mainly composed of hydroxy compound and impurities. Supplying the above hydrolysis step with at least a part of a portion mainly composed of a chlorinated hydrocarbon compound. The manufacturing method of Claim 1 including the following hydrogen chloride refinement | purification processes.
Hydrogen chloride refining step: After separating and recovering the main part of hydrocarbon compound, chlorinated hydrocarbon compound and hydroxy compound from the main part of hydrogen chloride obtained in the above chlorination step and hydrogen chloride separation step, Supplying the remaining hydrogen chloride to the oxidation process The production method according to claim 1, wherein the hydrocarbon compound is benzene, the chlorinated hydrocarbon compound is monochlorobenzene, and the hydroxy compound is phenol.

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