CN116063176A

CN116063176A - Device and method for producing succinic acid by taking butane and/or benzene as raw materials through oxidative hydrogenation hydrolysis

Info

Publication number: CN116063176A
Application number: CN202111272553.9A
Authority: CN
Inventors: 吴长江; 王国清; 李琰; 彭晖; 李东风; 张利军; 过良; 罗淑娟; 田峻; 师慧敏
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2021-10-29
Filing date: 2021-10-29
Publication date: 2023-05-05

Abstract

The invention provides a device and a method for producing succinic acid by taking butane and/or benzene as raw materials through oxidative hydrogenation hydrolysis, wherein the device comprises the following steps: along the material flow direction, an oxidation separation system, a maleic anhydride hydrogenation separation system and a succinic anhydride hydrolysis system are connected in series; wherein butane and/or benzene and oxygen-containing gas are subjected to oxidation reaction in an oxidation separation system and separated to obtain maleic anhydride materials; the maleic anhydride material enters a maleic anhydride hydrogenation separation system to carry out hydrogenation reaction and is separated to obtain succinic anhydride; and (3) enabling the succinic anhydride to enter a succinic anhydride hydrolysis system for hydrolysis and crystallization to obtain a succinic acid product. The invention provides a process for producing succinic acid from butane/benzene for enterprises with butane or benzene resources, which is characterized in that a two-stage hydrogenation reactor is preferably adopted, and the material at the outlet part of the two-stage reactor is extracted and circulated to a first-stage reactor, and the maleic anhydride content in the first-stage reaction feed can be effectively diluted as the material does not contain maleic anhydride, so that the reaction heat generated by the first-stage reaction is taken away.

Description

Device and method for producing succinic acid by taking butane and/or benzene as raw materials through oxidative hydrogenation hydrolysis

Technical Field

The invention relates to a device and a method for producing succinic acid by taking butane and/or benzene as raw materials through oxidative hydrogenation hydrolysis.

Background

Succinic acid, also known as succinic acid, is widely present in succinic acid tissues of various plants and humans and animals, in addition to succinic acid, as a colorless or white, odorless solid with sour taste. Succinic acid is an important organic chemical raw material and intermediate, and is mainly applied to pharmacy, pesticides, foods, synthetic plastics, rubber, protective coating, dye and other industries. In addition, succinic acid can be derived from a number of downstream products such as 1, 4-Butanediol (BDO), tetrahydrofuran (THF), gamma-butyrolactone (GBL), N-methylpyrrolidone (NMP), and the like. With the rise of the degradable plastic PBS resin in the global scope, the largest consumer market field of succinic acid products is the synthesis of the degradable plastic PBS resin in the future. At present, international large-scale succinic acid production enterprises are fewer, the productivity is about 5 ten thousand t/a, the production scale of the existing succinic acid production enterprises in China is not large, and the single-line productivity is only 1000t at maximum.

The production method of succinic acid is numerous, and the main industrialization at present is as follows: electrolytic reduction, maleic anhydride catalytic hydrogenation, biological fermentation, etc. Because the electrochemical production process has a plurality of problems to be solved, such as high power consumption, easy breakage of an ionic membrane, serious electrode corrosion, difficult maintenance of an electrolytic cell, large sewage discharge amount, large occupied area, unfavorable mass production and the like, the requirement of rapid increase of succinic acid requirements at the present stage is difficult to meet. The biological fermentation method has more foreign reports, and the domestic biological fermentation method for preparing succinic acid starts later and is not applied to actual production.

The maleic anhydride catalytic hydrogenation method for producing the succinic acid has the advantages of high conversion rate, high product purity, no obvious side reaction, environmental friendliness and the like, and is the most widely applied succinic acid synthesis method in the industry at present. The common process for producing succinic acid by maleic anhydride catalytic hydrogenation is a two-step method, namely, maleic anhydride is firstly subjected to catalytic hydrogenation to produce succinic anhydride, and succinic anhydride is then hydrolyzed to produce succinic acid.

For raw maleic anhydride, domestic production methods can be divided into benzene oxidation method and n-butane oxidation method according to raw material routes, and for maleic anhydride catalytic hydrogenation process, succinic anhydride is produced by hydrogenation of maleic anhydride and is a strong exothermic reaction (delta H= -128 kJ/mol), the adiabatic temperature rise of the reaction is large, organic matters are easily initiated to polymerize and coke on the surface of the catalyst, the activity of the catalyst is reduced, and meanwhile, the temperature of a catalyst bed layer is easily caused to be rapidly increased, so that the phenomenon of temperature runaway occurs. Therefore, how to take effective means to reduce the exothermic reaction is an important and difficult point of the maleic anhydride hydrogenation process.

CN103570650a discloses a process for continuously producing succinic anhydride and co-producing succinic acid by maleic anhydride hydrogenation, which adopts a two-stage hydrogenation reactor, and after heat exchange of materials at the outlet of a first-stage hydrogenation reactor, part of reaction liquid enters a second-stage hydrogenation reactor, and after the rest of reaction liquid is mixed with raw maleic anhydride solution, the mixture enters a first-stage hydrogenation reactor device again. In the method, the material at the outlet of the primary reactor still contains a certain amount of maleic anhydride, and the material is recycled to the inlet of the primary reactor, so that the amount of maleic anhydride entering the primary reactor is not obviously reduced, and therefore, the heat removal effect of the reactor is limited.

CN105801536a discloses a method for preparing succinic anhydride by selective hydrogenation of maleic anhydride liquid phase, which adopts two-stage reactors in series, adopts hydrogen to remove heat, and introduces hydrogen into the first-stage reactor and the second-stage reactor, and after reducing the reaction heat, the hydrogen is separated by a gas-liquid separator and recycled, wherein the molar ratio of the recycled hydrogen to maleic anhydride is 30-200: 1. the method can achieve a certain heat removal effect, but the energy consumption of the circulating hydrogen compressor is larger because the circulating hydrogen amount is larger, and meanwhile, the hydrogen amount entering the reactor is larger, the corresponding reactor volume needs to be increased, so that the investment is increased, and the energy consumption is increased.

Therefore, development of a succinic acid production process is needed, which can effectively remove heat released by maleic anhydride hydrogenation reaction, and simultaneously reduce the problems of large investment, high energy consumption and the like of the whole process.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a device and a method for producing succinic acid by using butane/benzene as a raw material.

The invention provides a device for producing succinic acid by taking butane and/or benzene as raw materials through oxidative hydrogenation hydrolysis, which comprises: along the material flow direction, an oxidation separation system, a maleic anhydride hydrogenation separation system and a succinic anhydride hydrolysis system are connected in series; wherein butane and/or benzene and oxygen-containing gas are subjected to oxidation reaction in an oxidation separation system and separated to obtain maleic anhydride materials; the maleic anhydride material enters a maleic anhydride hydrogenation separation system to carry out hydrogenation reaction and is separated to obtain succinic anhydride; and (3) enabling the succinic anhydride to enter a succinic anhydride hydrolysis system for hydrolysis and crystallization to obtain a succinic acid product.

Preferably, the maleic anhydride hydrogenation separation system comprises: a maleic anhydride hydrogenation system and a hydrogenation product separation system.

Preferably, the maleic anhydride hydrogenation system comprises:

a first-stage hydrogenation reactor, which comprises a lower gas phase inlet and/or a bottom gas phase inlet, a lower liquid phase feed inlet and/or a bottom liquid phase feed inlet, a top discharge outlet and/or an upper discharge outlet; and a first-stage reaction product cooler and a first-stage gas-liquid separator which are sequentially connected in series at the discharge port end of the first-stage hydrogenation reactor;

the second-stage hydrogenation reactor is communicated with the first-stage gas-liquid separator in series and comprises a lower gas-phase inlet and/or a bottom gas-phase inlet, a lower liquid-phase feed inlet and/or a bottom liquid-phase feed inlet, a top discharge outlet and/or an upper discharge outlet;

the second-stage gas-liquid separator is communicated with the discharge port of the second-stage hydrogenation reactor in series;

the liquid phase raw material supply pipeline is communicated with the liquid phase feed inlet of the first-stage hydrogenation reactor and the liquid phase feed inlet of the second-stage hydrogenation reactor.

Preferably, the hydrogenation product separation system comprises:

the light component removing tower and the heavy component removing tower are connected in series;

The feeding port of the light component removing tower is communicated with the liquid phase discharging port of the two-stage gas-liquid separator, and the light component removing tower is provided with a top outlet and a tower kettle discharging port;

the feed inlet of the heavy-removal tower is communicated with the discharge outlet of the tower kettle of the light-removal tower, and the heavy-removal tower is provided with a top outlet, a bottom outlet and a side line extraction outlet.

Preferably, in the maleic anhydride hydrogenation system,

the top gas phase outlet of the first-stage gas-liquid separator is communicated with the lower gas phase inlet and/or the bottom gas phase inlet of the second-stage hydrogenation reactor through pipelines; and/or

The bottom liquid phase outlet of the first-stage gas-liquid separator is communicated with the lower liquid phase feed inlet and/or the bottom liquid phase feed inlet of the second-stage hydrogenation reactor through pipelines; and/or

The top gas phase outlet of the two-stage gas-liquid separator is communicated with the lower gas phase inlet and/or the bottom gas phase inlet of the first-stage hydrogenation reactor through pipelines; and/or

The bottom liquid phase outlet of the two-stage gas-liquid separator is communicated with the lower liquid phase feed inlet and/or the bottom liquid phase feed inlet of the one-stage hydrogenation reactor through pipelines.

Preferably, in the maleic anhydride hydrogenation system,

a circulating material cooler is arranged on a communicating pipe between a bottom liquid phase outlet of the two-stage gas-liquid separator and a lower liquid phase feed inlet and/or a bottom liquid phase feed inlet of the one-stage hydrogenation reactor;

Preferably, a second-stage cooler is arranged at the top gas phase outlet end of the second-stage gas-liquid separator or the second-stage cooler and a third gas-liquid separator are sequentially connected in series, and the gas phase outlet of the third gas-liquid separator is communicated with the lower gas phase inlet and/or the bottom gas phase inlet of the first-stage hydrogenation reactor through pipelines; the bottom liquid phase outlet of the third gas-liquid separator is communicated with the liquid phase feed inlet of the second-stage gas-liquid separator;

the maleic anhydride hydrogenation system further comprises: and the distributor is used for distributing the liquid-phase raw material into two paths for supplying the first-stage hydrogenation reactor and the second-stage hydrogenation reactor according to the requirement.

Preferably, the oxidative separation system comprises: the maleic anhydride separation system comprises an absorption tower and a rectifying tower which are communicated in series, and maleic anhydride solution obtained by separation of the absorption tower and the rectifying tower is directly used as a raw material of a maleic anhydride hydrogenation separation system, so that the maleic anhydride hydrogenation can be carried out without introducing a solvent additionally.

The invention provides a method for producing succinic acid by taking butane and/or benzene as raw materials through oxidative hydrogenation hydrolysis, which is carried out in the device provided by the invention and comprises the following steps: butane and/or benzene and oxygen-containing gas are subjected to oxidation reaction in an oxidation separation system and separated to obtain maleic anhydride materials; the maleic anhydride material enters a maleic anhydride hydrogenation separation system to carry out hydrogenation reaction and is separated to obtain succinic anhydride; and (3) enabling the succinic anhydride to enter a succinic anhydride hydrolysis system for hydrolysis and crystallization to obtain a succinic acid product.

Preferably, the maleic anhydride hydrogenation separation system is internally provided with two-stage hydrogenation, and the maleic anhydride hydrogenation method comprises the following steps:

(1) The maleic anhydride solution from the oxidation separation system is divided into two materials, wherein one material is mixed with the liquid phase material of the second-stage hydrogenation reaction after being cooled or uncooled, and then enters the first-stage hydrogenation reactor from the liquid phase feed inlet at the bottom of the first-stage hydrogenation reactor and/or the liquid phase feed inlet at the lower part to contact with hydrogen for hydrogenation, and hydrogen enters the first-stage hydrogenation reactor from the gas phase inlet at the bottom and/or the gas phase inlet at the lower part of the first-stage hydrogenation reactor;

(2) Cooling the first-stage hydrogenation product in sequence, separating gas from liquid, allowing all gas phases separated from gas phase inlets at the bottom of the second-stage hydrogenation reactor and/or gas phase inlets at the lower part to enter the second-stage hydrogenation reactor, mixing liquid phases separated from gas and liquid with another maleic anhydride solution, and allowing the liquid phases to enter the second-stage hydrogenation reactor from liquid phase feed inlets at the bottom of the second-stage reactor and/or liquid phase feed inlets at the lower part;

(3) And carrying out gas-liquid separation on the second-stage hydrogenation product to obtain a gas phase and a liquid phase material of the second-stage hydrogenation reaction, and optionally using part or all of the gas phase as circulating hydrogen.

Preferably, the hydrogen raw material in the step (1) is a mixed hydrogen raw material of circulating hydrogen and supplementary hydrogen; and/or

The liquid phase material of the two-stage hydrogenation reaction in the step (1) is a cooled material.

More preferably, the liquid phase material of the two-stage hydrogenation reaction in the step (1) is cooled to 30-80 ℃, preferably cooled to 40-60 ℃.

Preferably, the maleic anhydride hydrogenation process further comprises:

cooling a gas phase obtained by gas-liquid separation of the second-stage hydrogenation product, and then performing third gas-liquid separation, wherein part or all of the obtained gas phase is used as the circulating hydrogen and the supplementary hydrogen to be mixed to be used as a hydrogen raw material of the first-stage hydrogenation reactor; optionally, returning the obtained liquid phase to a two-stage gas-liquid separator for gas-liquid separation;

preferably, the gas phase obtained by gas-liquid separation of the two-stage hydrogenation product is cooled to a temperature of 30-80 ℃.

Preferably, in the step (1),

the maleic anhydride solution is a mixture of maleic anhydride and a solvent, wherein the solvent is one or more of acetic anhydride, gamma-butyrolactone, dioxane, tetrahydrofuran, aromatic hydrocarbon, ethyl acetate, four-carbon dibasic acid ester, ethanol, isopropanol, hexane, cyclohexane, propylene oxide, ketone and ether; and/or

The maleic anhydride concentration of the maleic anhydride solution is 1 to 90% by weight, preferably 10 to 40% by weight; and/or

The ratio of one strand to the other strand is 5 to 95 wt% respectively; preferably, the proportion of one strand is 20 to 50% by weight and the proportion of the other strand is 50 to 80% by weight; and/or

The molar ratio of the total hydrogen amount to the total maleic anhydride in the maleic anhydride solution is 5-100, preferably 10-40; and/or

The operating conditions of the stage hydrogenation reactor include: the temperature is 30-100deg.C, preferably 40-80deg.C, such as 40deg.C, 41 deg.C, 42 deg.C, 43 deg.C, 44 deg.C, 45 deg.C, 46 deg.C, 47 deg.C, 48 deg.C, 49 deg.C, 50 deg.C, etc., and so on, and each reaction temperature is applicable to the present invention; and/or a reaction pressure of 0.1 to 10MPa, preferably 0.5 to 5MPa, preferably 1 to 2MPa; and/or space velocity of 0.5-5h ^-1 ；

In step (2), the operating conditions of the two-stage hydrogenation reactor include:

the temperature is 30-120deg.C, preferably 40-100deg.C, such as 40deg.C, 41 deg.C, 42 deg.C, 43 deg.C, 44 deg.C, 45 deg.C, 46 deg.C, 47 deg.C, 48 deg.C, 49 deg.C, 50 deg.C, etc., and so on, and each reaction temperature is applicable to the present invention; and/or a pressure of 0.1 to 10MPa, preferably 0.5 to 5MPa, preferably 1.2 to 1.5MPa; and/or space velocity of 0.5-5h ^-1 。

Preferably, wherein, within the maleic anhydride separation system:

the absorber operating conditions include: the pressure is 0.0-1.0 MPag, the temperature is 40-120 ℃, and the theoretical plate number is 5-50;

the absorbent is selected from one or more mixed solvents of gamma-butyrolactone, dibutyl phthalate, diisobutyl hexahydrophthalate, tetrahydrofuran, aromatic hydrocarbon, ethyl acetate, four-carbon dibasic acid ester, ethanol, isopropanol, hexane, cyclohexane, propylene oxide, benzene, xylene, chlorobenzene, dichlorobenzene, ketone and ether, more preferably gamma-butyrolactone and/or tetrahydrofuran;

the rectifying column operating conditions include: the pressure is 0.0-1.0 MPag, the temperature is 40-150 ℃, and the theoretical plate number is 5-100;

cooling part of the material at the tower bottom of the absorption tower to 30-80 ℃ and returning the material to the absorption tower; and/or

The material at the top of the absorption tower is cooled to 20-50 ℃ by a heat exchanger, then is sent to the outside of the boundary region by a gas-liquid separator, and the liquid phase is sent to a rectifying tower.

Preferably, within the hydrogenation product separation system:

the light ends column operating conditions include: the pressure is 0.5-20 KPa, the temperature is 30-150 ℃, and the theoretical plate number is 10-80; and/or the de-duplication column operating conditions include: the pressure is 0.5-20 KPa, the temperature is 30-150 ℃, and the theoretical plate number is 10-80.

The method of the invention has the following characteristics:

(1) The invention provides a process for producing succinic acid from butane/benzene for enterprises with butane or benzene resources, which is characterized in that a two-stage hydrogenation reactor is preferably adopted, and the material at the outlet part of the two-stage reactor is extracted and circulated to a first-stage reactor, and the maleic anhydride content in the first-stage reaction feed can be effectively diluted as the material does not contain maleic anhydride, so that the reaction heat generated by the first-stage reaction is taken away.

(2) The invention preferably comprises the steps of cooling, gas-liquid separation, gas phase entering the second-stage reactor, effectively removing the reaction heat generated by the second-stage reaction, gas-liquid separation, gas phase entering the reactor and liquid phase entering the reactor respectively, and gas-liquid distributor, so that the materials entering the reactor are contacted more fully, the gas-liquid is contacted well, the effective utilization rate of the catalyst is high, and the investment is saved.

(3) By adopting the method, the succinic anhydride is obtained through the light component removing tower and the heavy component removing tower, the succinic anhydride product has high purity, and meanwhile, the succinic acid product obtained by hydrolysis has good purity, and the whole process operation is easy to control.

(4) The device and the method have the characteristics of simple flow, investment saving, strong applicability, easy control and the like.

Drawings

Fig. 1 is a schematic diagram of a method of a preferred embodiment of the present invention.

Fig. 2 is a schematic diagram of a method of a preferred embodiment of the present invention.

FIG. 3 is a schematic diagram of a maleic anhydride hydrogenation process according to the present invention.

FIG. 4 is a schematic diagram of a maleic anhydride hydrogenation process according to the present invention.

Description of the reference numerals

1 a dispenser; 2 a first-stage hydrogenation reactor; 3 a first stage reaction product cooler; 4, a first-stage gas-liquid separator; a 5-stage hydrogenation reactor; a second-stage gas-liquid separator; 7, circulating a material cooler; 8 two-stage cooler; 9 a third gas-liquid separator; 11 maleic anhydride solution; 12 reaction products; 13 supplement hydrogen

Detailed Description

The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.

The present invention is described in detail below with reference to the specific drawings and examples, and it is necessary to point out that the following examples are given for further illustration of the present invention only and are not to be construed as limiting the scope of the present invention, since numerous insubstantial modifications and adaptations of the invention to those skilled in the art will still fall within the scope of the present invention.

As shown in fig. 1, the present invention provides an apparatus for producing succinic acid by oxidative hydrogenation hydrolysis of butane and/or benzene as raw materials, the apparatus comprising: along the material flow direction, an oxidation separation system, a maleic anhydride hydrogenation separation system and a succinic anhydride hydrolysis system are connected in series; wherein butane and/or benzene and oxygen-containing gas are subjected to oxidation reaction in an oxidation separation system and separated to obtain maleic anhydride materials; the maleic anhydride material enters a maleic anhydride hydrogenation separation system to carry out hydrogenation reaction and is separated to obtain succinic anhydride; and (3) enabling the succinic anhydride to enter a succinic anhydride hydrolysis system for hydrolysis and crystallization to obtain a succinic acid product.

According to a preferred embodiment of the present invention, as shown in fig. 1, 2, 3 and 4, the maleic anhydride hydrogenation separation system comprises: a maleic anhydride hydrogenation system and a hydrogenation product separation system; the maleic anhydride hydrogenation separation system comprises a two-stage hydrogenation reactor, and according to a preferred embodiment of the present invention, as shown in fig. 3 and 4, the maleic anhydride hydrogenation system comprises:

The present invention has no special requirements on the setting and operating conditions of the hydrogenation product separation system, and can be specifically adjusted according to the needs, as shown in fig. 1 and 2, and according to a preferred embodiment of the present invention, the hydrogenation product separation system comprises:

the light component removing tower and the heavy component removing tower are connected in series; the feeding port of the light component removing tower is communicated with the liquid phase discharging port of the two-stage gas-liquid separator, and the light component removing tower is provided with a top outlet and a tower kettle discharging port; the feed inlet of the heavy-removal tower is communicated with the discharge outlet of the tower kettle of the light-removal tower, and the heavy-removal tower is provided with a top outlet, a bottom outlet and a side line extraction outlet.

According to the invention, the hydrogenation product separation system mainly comprises a light component removing tower and a heavy component removing tower. Materials from the maleic anhydride hydrogenation reaction system enter a light component removal tower, materials at the tower bottom of the light component removal tower enter a heavy component removal tower, a solvent is extracted from the top of the heavy component removal tower, succinic anhydride is extracted from the side line of the tower, and heavy components are extracted from the tower bottom.

In the present invention, the light component means dissolved hydrogen, and a small amount of solvent such as gamma-butyrolactone, tetrahydrofuran, etc.

In the present invention, the purpose of the light ends column is to remove hydrogen, a small amount of solvents such as gamma-butyrolactone, tetrahydrofuran, etc. There is no particular requirement on the setting and operating conditions thereof, as long as the object of the present invention can be achieved.

In the invention, the purpose of the heavy removal tower is to remove the solvent from the tower top, remove the heavy components generated by polymerization from the tower bottom, and obtain succinic anhydride meeting the requirements from the side line, and the arrangement and the operation conditions of the succinic anhydride are not particularly required, so long as the purpose of the invention can be realized.

According to a preferred embodiment of the present invention, preferably, the top gas phase outlet of the one-stage gas-liquid separator is in communication with the lower gas phase inlet and/or the bottom gas phase inlet of the two-stage hydrogenation reactor via a pipeline.

According to a preferred embodiment of the present invention, preferably, the bottom liquid phase outlet of the one-stage gas-liquid separator is in communication with the lower liquid phase feed inlet and/or the bottom liquid phase feed inlet of the two-stage hydrogenation reactor via a pipeline.

According to a preferred embodiment of the present invention, preferably, the top gas phase outlet of the two-stage gas-liquid separator is in communication with the lower gas phase inlet and/or the bottom gas phase inlet of the one-stage hydrogenation reactor via a pipeline.

According to a preferred embodiment of the present invention, preferably, the bottom liquid phase outlet of the two-stage gas-liquid separator is in communication with the lower liquid phase feed inlet and/or the bottom liquid phase feed inlet of the one-stage hydrogenation reactor via a pipeline.

According to a preferred embodiment of the present invention, preferably, a circulating material cooler is disposed on a communicating pipe between the bottom liquid phase outlet of the two-stage gas-liquid separator and the lower liquid phase feed port and/or the bottom liquid phase feed port of the one-stage hydrogenation reactor.

According to the preferred embodiment of the present invention, preferably, as shown in fig. 4, a second-stage cooler is disposed at the top gas phase outlet end of the second-stage gas-liquid separator or a second-stage cooler and a third gas-liquid separator are sequentially disposed in series, and the gas phase outlet of the third gas-liquid separator is communicated with the lower gas phase inlet and/or the bottom gas phase inlet of the first-stage hydrogenation reactor through a pipeline; and a bottom liquid phase outlet of the third gas-liquid separator is communicated with a liquid phase feed inlet of the second gas-liquid separator.

According to a preferred embodiment of the present invention, preferably, the maleic anhydride hydrogenation system further comprises: and the distributor is used for distributing the liquid-phase raw material into two paths for supplying the first-stage hydrogenation reactor and the second-stage hydrogenation reactor according to the requirement.

According to the present invention, butane/benzene and an oxygen-containing gas such as air are introduced into an oxidation separation system, the design and operation conditions of which are not particularly limited as long as an oxidation reaction and separation operation can be achieved, and those skilled in the art are determined according to the professional knowledge and the prior art. As shown in fig. 2, the oxidation separation system includes, for example, an oxidation reaction system (including an oxidation reactor) and a maleic anhydride separation system including, for example, an absorption column, a stripping column, a light component column, and a product finishing column, and according to a preferred embodiment of the present invention, the oxidation separation system includes: the maleic anhydride separation system comprises an absorption tower and a rectifying tower which are communicated in series, and maleic anhydride solution obtained by separation of the absorption tower and the rectifying tower is directly used as a raw material of a maleic anhydride hydrogenation separation system, so that the maleic anhydride hydrogenation can be carried out without introducing a solvent additionally.

The maleic anhydride separation system according to the present invention mainly comprises an absorption column, a rectification column, other equipment such as heat exchangers, pumps, tanks, pipelines, etc., without specific requirements, as determined by the person skilled in the art according to the situation and the prior art. And the oxidation reaction product after heat exchange and cooling enters the absorption tower from the bottom of the absorption tower, the solvent enters the absorption tower from the top of the tower, the material at the top of the absorption tower is sent out of the boundary region, the rich solvent obtained at the bottom of the absorption tower enters the rectifying tower, the material at the top of the rectifying tower is extracted and sent out of the boundary region, and the material at the bottom of the rectifying tower is sent to the maleic anhydride hydrogenation separation system.

In the invention, the oxidation reaction system and the succinic anhydride hydrolysis system are not particularly required, and the technical staff can determine the reaction according to common knowledge and professional knowledge.

According to the invention, the rectifying tower can also be used for extracting the materials at the top of the tower and sending the materials to the outside of the boundary region, extracting maleic anhydride solvent mixture at the side line of the tower and sending the mixture to a maleic anhydride hydrogenation reaction system, and carrying out the next crystallization on the materials at the bottom of the tower.

As shown in fig. 1, the present invention provides a method for producing succinic acid by using butane and/or benzene as raw materials through oxidative hydrogenation hydrolysis, wherein the method is performed in the device of the present invention, and the method comprises: butane and/or benzene and oxygen-containing gas are subjected to oxidation reaction in an oxidation separation system and separated to obtain maleic anhydride materials; the maleic anhydride material enters a maleic anhydride hydrogenation separation system to carry out hydrogenation reaction and is separated to obtain succinic anhydride; and (3) enabling the succinic anhydride to enter a succinic anhydride hydrolysis system for hydrolysis and crystallization to obtain a succinic acid product.

The present invention is not particularly limited to the oxygen-containing gas, and common oxygen-containing gases may be used in the present invention, for example, air and/or oxygen.

According to the invention, the operating pressure of the absorber is preferably from 0.0 to 1.0MPag, the operating temperature is from 40 to 120℃and the theoretical plate number is from 5 to 50.

According to the invention, the operating pressure of the rectification column is preferably 0.0 to 1.0MPag, the operating temperature is 40 to 150 ℃, and the theoretical plate number is 5 to 100.

According to the invention, the absorber column is preferably supplemented with a fresh absorbent, which is introduced into the top of the absorber column.

According to the present invention, the absorbent is preferably a solvent required for the hydrogenation of maleic anhydride, for example, one or more mixed solvents selected from the group consisting of gamma-butyrolactone, dibutyl phthalate, diisobutyl hexahydrophthalate, tetrahydrofuran, aromatic hydrocarbons, ethyl acetate, tetra-carbon dibasic acid esters, ethanol, isopropyl alcohol, hexane, cyclohexane, propylene oxide, benzene, xylene, chlorobenzene, dichlorobenzene, and a part of ketone, ether solvents, etc., more preferably gamma-butyrolactone, tetrahydrofuran.

The solvent ratio of the absorbent to maleic anhydride is not particularly limited according to the present invention, and may be determined by one skilled in the art based on the expert knowledge and the prior art.

According to the invention, optionally, a part of the material at the bottom of the absorption tower is separated and is returned to the absorption tower after being cooled to 30-80 ℃.

According to the invention, optionally, the material at the top of the absorption tower is cooled to 20-50 ℃ by a heat exchanger, and then is sent to the outside of the boundary region by a gas-liquid separator, and the liquid phase is sent to a rectifying tower.

In the invention, the maleic anhydride solution required by the invention can be separated by the cooperation of the absorption tower and the rectifying tower, so that the whole process flow of the method is flexible and controllable.

The invention has no special requirement on the operating conditions of the light component removal tower, and the common operating conditions of the light component removal tower are suitable for the invention, and aiming at the invention, the operating pressure of the light component removal tower in the step (4) is preferably 0.5-20 KPa, preferably 6-15 KPa; the operating temperature is 30-150 ℃, preferably 80-130 ℃; the theoretical plate number is 10-80.

The invention has no special requirement on the operating condition of the heavy-removal tower, and the common operating condition of the light-removal tower is suitable for the invention, and for the invention, the operating pressure of the heavy-removal tower in the step (4) is preferably 0.5-20 KPa, preferably 3-15 KPa; the operating temperature is 30-150 ℃, preferably 80-130 ℃; the theoretical plate number is 10-80.

According to the invention, the solvent obtained by separation preferably needs to exchange heat to the absorption temperature, and is recycled to the absorption tower in the step (2) for recycling.

According to the present invention, the operating conditions of the hydrolysis system are not particularly limited, and are determined by those skilled in the art based on the expert knowledge and the prior art.

According to a preferred embodiment of the present invention, the absorber operating conditions include: the pressure is 0.0-1.0 MPag, the temperature is 40-120 ℃, and the theoretical plate number is 5-50; the absorbent is selected from one or more mixed solvents of gamma-butyrolactone, dibutyl phthalate, diisobutyl hexahydrophthalate, tetrahydrofuran, aromatic hydrocarbon, ethyl acetate, four-carbon dibasic acid ester, ethanol, isopropanol, hexane, cyclohexane, propylene oxide, benzene, xylene, chlorobenzene, dichlorobenzene, ketone and ether, and more preferably gamma-butyrolactone and/or tetrahydrofuran. The rectifying column operating conditions include: the pressure is 0.0-1.0 MPag, the temperature is 40-150 ℃, and the theoretical plate number is 5-100.

According to a preferred embodiment of the invention, after the part of the material at the bottom of the absorption tower is cooled to 30-80 ℃, the material is returned to the absorption tower, the material at the top of the absorption tower is cooled to 20-50 ℃ by a heat exchanger, and then the material is sent to the outside of the boundary region by a gas-liquid separator, and the liquid phase is sent to a rectifying tower.

According to a preferred embodiment of the invention, the invention comprises in particular the following steps: butane/benzene and air enter an oxidation reaction system to obtain maleic anhydride; maleic anhydride enters a maleic anhydride hydrogenation reaction system to obtain succinic anhydride; and (5) enabling the succinic anhydride to enter a hydrolysis system to obtain a succinic acid product.

According to the invention, butane/benzene and air enter an oxidation reaction system, and maleic anhydride products are obtained after separation through oxidation reaction and are sent to a maleic anhydride hydrogenation reaction system. The oxidation reaction system is not particularly limited in the present invention, and is determined by those skilled in the art based on expert knowledge and prior art.

According to the present invention, the maleic anhydride hydrogenation reaction system mainly comprises: a first-stage hydrogenation reactor, a second-stage hydrogenation reactor, a light component removal tower, a heavy component removal tower and the like. Other equipment, such as heat exchangers, pumps, tanks, compressors, etc., are not specifically required and will be determined by those skilled in the art based on the circumstances and prior art.

According to the present invention, maleic anhydride or a maleic anhydride solution may be separated from the oxidation separation system, if maleic anhydride is separated, the separated maleic anhydride is mixed with a solvent from the outside (the solvent mixed with maleic anhydride may be acetic anhydride, gamma-butyrolactone, dioxane, tetrahydrofuran, aromatic hydrocarbon, ethyl acetate, tetracarbon dibasic acid ester, ethanol, isopropanol, hexane, cyclohexane, propylene oxide, and a part of ketone, ether solvent, etc., the concentration of the maleic anhydride solution is 1% to 90%), and a maleic anhydride solution is prepared, after the maleic anhydride solution is mixed with a part of the second-stage hydrogenation reaction, fresh hydrogen is fed from the first-stage hydrogenation reactor into the reactor, after the fresh hydrogen is mixed with the circulating gas phase material, the mixture is fed from the first-stage hydrogenation reactor into the reactor, and after the mixture is contacted with a catalyst, a hydrogenation reaction is performed, the maleic anhydride is completely/partially converted into succinic anhydride. The reaction temperature of the primary hydrogenation reactor is 30-100 ℃, preferably 40-80 ℃. The reaction pressure is 0.1 to 10MPa, preferably 0.5 to 5MPa. The molar ratio of recycled hydrogen and make-up fresh hydrogen to maleic anhydride fed is from 5 to 100, preferably from 10 to 40.

According to the present invention, it is preferable that the oxidation separation system comprises an absorption column and a rectifying column, and is capable of separating to obtain the maleic anhydride solution required for the maleic anhydride hydrogenation reaction of the present invention.

According to the preferred embodiment of the invention, the first-stage hydrogenation product is cooled by a heat exchanger and then separated by a gas-liquid separator, the gas phase is completely fed into the reactor from the top of the second-stage reactor, the liquid phase is completely fed into the second-stage reactor from the upper part of the second-stage hydrogenation reactor, contacts with the catalyst, and undergoes hydrogenation reaction, and the maleic anhydride is completely converted into succinic anhydride. The reaction temperature of the two-stage hydrogenation reactor is 30-120 ℃, preferably 50-100 ℃. The reaction pressure is 0.1 to 10MPa, preferably 0.5 to 5MPa.

According to the preferred embodiment of the invention, after gas-liquid separation, the gas phase is mixed with the supplementary fresh hydrogen after heat exchange to the reaction temperature, and then enters the first-stage hydrogenation reactor for recycling, the liquid phase part is sent to the light component removal tower, and the liquid phase part is recycled to the first-stage hydrogenation reactor after heat exchange and is mixed with maleic anhydride solution to enter the first-stage hydrogenation reactor. Preferably, 10 to 80 percent of liquid phase reaction products are sent to a light component removal tower, and the rest liquid phase is returned to a first-stage reactor for recycling.

According to a preferred embodiment of the invention, the light components are extracted from the top of the light component removing tower, and the materials in the tower bottom are sent to the heavy component removing tower. And extracting solvent from the top of the de-weight tower, partially serving as dissolved maleic anhydride, partially serving as a byproduct, extracting succinic anhydride from the side line of the de-weight tower, conveying the succinic anhydride to a subsequent hydrolysis system, and extracting heavy components from the tower kettle. The operating pressure of the light component removing tower is 0.5-20 KPa, the operating temperature is 30-150 ℃, and the theoretical plate number is 10-80. The operating pressure of the heavy-removal tower is 0.5-20 KPa, the operating temperature is 30-150 ℃, and the theoretical plate number is 10-80. Succinic anhydride is extracted from the side line of the heavy-removal tower, preferably from the stripping section.

According to a preferred embodiment of the invention, the bottom material of the light component removal tower is firstly sent to a solvent recovery tower. The solvent is extracted from the top of the solvent recovery tower, part of the solvent is used as dissolved maleic anhydride, the other part of the solvent is extracted as a byproduct, and the materials in the tower bottom are sent to the de-weight tower. Succinic anhydride is extracted from the top of the de-weight tower, and heavy components are extracted from the tower bottom. The operation pressure of the solvent recovery tower is 0.5-20 KPa, the operation temperature is 30-150 ℃, and the theoretical plate number is 10-80.

According to a preferred embodiment of the present invention, the first-stage hydrogenation reactor and the second-stage hydrogenation reactor are not limited, and any maleic anhydride hydrogenation catalyst may be used, such as the catalysts described in chinese patents CN 20201118431. X, CN 202011120495.3.

According to a preferred embodiment of the invention, after gas-liquid separation of the two-stage hydrogenation reaction product, the gas phase material is cooled by a heat exchanger, the cooling temperature is preferably 30-80 ℃, the cooled material is subjected to gas-liquid separation, the gas phase is recycled to the first-stage reactor for use, and the liquid phase is returned to the previous gas-liquid separator.

According to a preferred embodiment of the invention, after gas-liquid separation of the second-stage hydrogenation product, preferably the gas phase yields about 0.5% to 2% of the material to be fuelled, the remaining gas phase is recycled to the first-stage hydrogenation reactor, mixed with additional fresh hydrogen and fed into the first-stage hydrogenation reactor.

According to a preferred embodiment of the present invention, succinic anhydride is subjected to hydrolysis-crystallization and the like to obtain succinic acid product. The present invention is not limited to a specific hydrolysis-crystallization method, and those skilled in the art will recognize from the expertise and prior art.

According to a preferred embodiment of the present invention, the maleic anhydride hydrogenation process comprises performing a two-stage hydrogenation reaction,

(1) The maleic anhydride solution is divided into two materials, wherein one material is mixed with the liquid phase material of the second-stage hydrogenation reaction after cooling or uncooled part, and then enters the first-stage hydrogenation reactor from the liquid phase feed inlet at the bottom of the first-stage hydrogenation reactor and/or the liquid phase feed inlet at the lower part to contact hydrogen for hydrogenation, and hydrogen enters the first-stage hydrogenation reactor from the gas phase inlet at the bottom and/or the gas phase inlet at the lower part of the first-stage hydrogenation reactor;

The maleic anhydride hydrogenation method can effectively withdraw the heat released by the reaction, is flexible to operate and is easy to control; the maleic anhydride concentration in the incoming maleic anhydride solution can be not too low, so that the use amount of the solvent is reduced, and the energy consumption for recycling the subsequent solvent is reduced; the gas-liquid solid is well contacted, the effective utilization rate of the catalyst is high, and the investment is saved; the invention has mild reaction operation condition and low temperature rise of the reaction bed layer, can carry out maleic anhydride hydrogenation reaction at about 40 ℃, and is favorable for improving the selectivity of the catalyst and prolonging the service life of the catalyst.

According to a preferred embodiment of the present invention, the hydrogen feed to step (1) is a mixed hydrogen feed of recycled hydrogen and make-up hydrogen.

According to a preferred embodiment of the present invention, the liquid phase material of the two-stage hydrogenation reaction described in step (1) is preferably a cooled material. Therefore, the heat can be effectively removed, the effective utilization rate of the catalyst can be improved, and the service life of the catalyst can be prolonged.

According to a preferred embodiment of the present invention, the liquid phase material of the two-stage hydrogenation reaction of step (1) is preferably cooled to 30-80 ℃, preferably to 40-60 ℃. Therefore, the heat can be effectively removed, the effective utilization rate of the catalyst can be improved, and the service life of the catalyst can be prolonged.

According to a preferred embodiment of the present invention, preferably, the method further comprises:

cooling a gas phase obtained by gas-liquid separation of the second-stage hydrogenation product, and then performing third gas-liquid separation, wherein part or all of the obtained gas phase is used as the circulating hydrogen and the supplementary hydrogen to be mixed to be used as a hydrogen raw material of the first-stage hydrogenation reactor; optionally, the obtained liquid phase is returned to the two-stage gas-liquid separator for gas-liquid separation. Therefore, the heat can be effectively removed, the effective utilization rate of the catalyst can be improved, and the service life of the catalyst can be prolonged.

According to a preferred embodiment of the present invention, the gas phase obtained by gas-liquid separation of the two-stage hydrogenation product is preferably cooled to a temperature of 30 to 80 ℃. Therefore, the heat can be effectively removed, the effective utilization rate of the catalyst can be improved, and the service life of the catalyst can be prolonged.

According to a preferred embodiment of the present invention, preferably, the maleic anhydride solution is not particularly required, and may be a common maleic anhydride raw material, and for the present invention, preferably, a mixture of maleic anhydride and a solvent, the kind of which is not particularly required, and for the present invention, preferably, the solvent is one or more of acetic anhydride, γ -butyrolactone, dioxane, tetrahydrofuran, aromatic hydrocarbon, ethyl acetate, four-carbon dibasic acid ester, ethanol, isopropanol, hexane, cyclohexane, propylene oxide, ketone, and ether.

By adopting the method provided by the invention, the maleic anhydride concentration in the incoming maleic anhydride solution can be not too low, the solvent consumption is reduced, and the energy consumption for subsequent solvent recovery is reduced. According to a preferred embodiment of the invention, the maleic anhydride concentration of the maleic anhydride solution is preferably from 1 to 90% by weight, preferably from 10 to 40% by weight.

According to a preferred embodiment of the invention, it is preferred that the ratio of one strand to the other strand is each 5 to 95 weight; preferably, one strand is present in an amount of 20 to 50% by weight and the other strand is present in an amount of 50 to 80% by weight. Therefore, the heat can be effectively removed, the effective utilization rate of the catalyst can be improved, and the service life of the catalyst can be prolonged.

According to a preferred embodiment of the present invention, the molar ratio of the total hydrogen amount to the total maleic anhydride in the maleic anhydride solution is preferably 5 to 100, preferably 10 to 40.

According to a preferred embodiment of the present invention, preferably, the operating conditions of the one-stage hydrogenation reactor comprise: the temperature is 30-100deg.C, preferably 40-80deg.C, such as 40deg.C, 41 deg.C, 42 deg.C, 43 deg.C, 44 deg.C, 45 deg.C, 46 deg.C, 47 deg.C, 48 deg.C, 49 deg.C, 50 deg.C, etc., and so on, and each reaction temperature is applicable to the present invention; and/or the reaction pressure is 0.1 to 10MPa, preferably 0.5 to 5MPa; and/or space velocity of 0.5-5h ^-1 . Therefore, the heat can be effectively removed, the effective utilization rate of the catalyst can be improved, and the service life of the catalyst can be prolonged.

According to a preferred embodiment of the present invention, preferably, the operating conditions of the two-stage hydrogenation reactor comprise: the temperature is 30-100deg.C, preferably 40-80deg.C, such as 40deg.C, 41 deg.C, 42 deg.C, 43 deg.C, 44 deg.C, 45 deg.C, 46 deg.C, 47 deg.C, 48 deg.C, 49 deg.C, 50 deg.C, etc., and so on, and each reaction temperature is applicable to the present invention; and/or a pressure of 0.1 to 10MPa, preferably 0.5 to 5 MPa; and/or space velocity of 0.5-5h ^-1 . Therefore, the heat can be effectively removed, the effective utilization rate of the catalyst can be improved, and the service life of the catalyst can be prolonged.

According to a preferred embodiment of the invention, preferably from 20 to 90% by weight of the liquid phase material of the two-stage hydrogenation is returned to step (1) for use as feed and the remainder is sent as liquid phase product to a subsequent separation system. Therefore, the heat can be effectively removed, the effective utilization rate of the catalyst can be improved, and the service life of the catalyst can be prolonged.

According to a preferred embodiment of the invention, preferably, 0.5 to 2% by volume of the gas phase material of the two-stage hydrogenation is taken as fuel gas and the remainder is used as the recycle hydrogen. Therefore, the heat can be effectively removed, the effective utilization rate of the catalyst can be improved, and the service life of the catalyst can be prolonged.

According to the present invention, as shown in fig. 3, the maleic anhydride hydrogenation of the present invention specifically comprises:

(1) The maleic anhydride solution is divided into two materials, wherein one of the two materials is mixed with the liquid phase material of the two-stage reaction, then enters the first-stage hydrogenation reactor from the bottom/lower part of the reactor, and the other one of the two materials is mixed with the liquid phase material of the first-stage reaction, and then enters the second-stage hydrogenation reactor from the bottom/lower part of the reactor;

(2) After the circulating hydrogen is mixed with the fresh hydrogen which is supplemented, the mixture enters a first-stage hydrogenation reactor from the bottom of the reactor to react with maleic anhydride, and the maleic anhydride is completely/partially reacted to be converted into succinic anhydride;

(3) Cooling the first-stage hydrogenation product by a cooler, separating the first-stage hydrogenation product into gas-liquid two phases by a gas-liquid separator, enabling the gas phase to fully enter a second-stage hydrogenation reactor from the bottom of the reactor, mixing the liquid phase with part of maleic anhydride solution, enabling the liquid phase to enter the second-stage hydrogenation reactor from the bottom/lower part of the reactor, reacting with hydrogen, and enabling all maleic anhydride to react into succinic anhydride;

(4) And (3) after gas-liquid separation, gas phase cooling is carried out on the second-stage hydrogenation reaction product to the reaction temperature, the gas phase is recycled to the step (2), a liquid phase part is adopted out of a subsequent system, and a part of the gas phase part is cooled and then mixed with maleic anhydride solution, and enters a first-stage hydrogenation reactor.

According to the invention, in the step (3), after the gas-liquid separation of the first-stage hydrogenation product, the gas phase is completely fed into the second-stage hydrogenation reactor from the bottom of the reactor, the liquid phase is mixed with a part of maleic anhydride solution, and then fed into the second-stage hydrogenation reactor from the bottom/lower part of the reactor, and after the two-stage hydrogenation reaction, the maleic anhydride is completely converted into succinic anhydride.

According to the invention, optionally, in the step (4), after the gas-liquid separation of the product of the second-stage hydrogenation reaction, the gas-phase material may be cooled by a heat exchanger, the cooling temperature is preferably 30-80 ℃, the cooled material is further subjected to gas-liquid separation, the gas phase is recycled to the step (2), and the liquid phase is returned to the previous gas-liquid separator.

According to the invention, in the step (4), after gas-liquid separation, preferably gas phase extraction, about 0.5% -2% of the material is removed from fuel gas, and the rest is recycled to the first-stage hydrogenation reactor, and is mixed with the supplementary fresh hydrogen and then enters the first-stage hydrogenation reactor.

According to the invention, in the step (4), after the two-stage hydrogenation product is subjected to gas-liquid separation, the liquid phase preferably 10% -80% of the liquid phase reaction product is sent to a subsequent separation system, and the rest liquid phase reaction product is cooled to 40-80 ℃ by a cooler and then mixed with maleic anhydride solution, and then enters the first-stage hydrogenation reactor from the bottom/lower part of the reactor.

In the present invention, the first-stage hydrogenation reactor and the second-stage hydrogenation reactor are not limited, and any maleic anhydride hydrogenation catalyst, such as the catalyst described in chinese patent No. CN 20201118431. X, chinese patent No. CN202011120495.3, may be used.

In the present invention, optionally, in the steps (1) to (3), the gas phase and the liquid phase are contacted with the catalyst after passing through the distributor when entering the first-stage reactor and the second-stage reactor.

The maleic anhydride hydrogenation reaction method has the following characteristics:

(1) The maleic anhydride solution is divided into two streams, and the two streams are respectively mixed with different materials and then enter the two hydrogenation reactors, so that the maleic anhydride content entering the reactors is reduced, the heat released by the reaction can be effectively withdrawn, the operation is flexible, and the control is easy.

(2) By adopting the method provided by the invention, the maleic anhydride concentration in the incoming maleic anhydride solution can be not too low, the solvent consumption is reduced, and the energy consumption for subsequent solvent recovery is reduced.

(3) After the first-stage reaction, the gas phase is completely fed into the second-stage reactor after the gas-liquid separation by cooling, so that the reaction heat generated by the second-stage reaction can be effectively removed.

(4) The reaction materials enter from the bottom of the reactor, and after the first section of the reactor, gas-liquid separation is arranged, and gas phase and liquid phase enter the reactor respectively, so that the materials entering the reactor are more fully contacted, the gas-liquid solid contact is good, the effective utilization rate of the catalyst is high, and the investment is saved.

(5) The invention has mild reaction operation condition, the reaction temperature is 40-50 ℃, the reaction temperature is greatly reduced, the temperature of a reaction bed layer is low, and the invention is favorable for improving the selectivity of the catalyst and prolonging the service life of the catalyst.

According to a preferred embodiment of the present invention, the following example maleic anhydride hydrogenation process is carried out using the flow scheme shown in fig. 3 or fig. 4, 1 distributor; 2 a first-stage hydrogenation reactor; 3 a first stage reaction product cooler; 4, a first-stage gas-liquid separator; a 5-stage hydrogenation reactor; a second-stage gas-liquid separator; 7, circulating a material cooler; 8 two-stage cooler; 9 a third gas-liquid separator; 11 maleic anhydride solution; 12 reaction products; 13, the maleic anhydride process of the present invention comprises:

(1) The maleic anhydride solution 11 is divided into two materials through a raw material distributor 1, wherein one material is mixed with a liquid phase material (cooling is carried out in a circulating material cooler 7) of a cooled or uncooled part of two-stage hydrogenation reaction, and then enters the one-stage hydrogenation reactor 2 from a liquid phase feed inlet at the bottom of the one-stage hydrogenation reactor 2 and/or a liquid phase feed inlet at the lower part of the one-stage hydrogenation reactor to contact hydrogen (containing make-up hydrogen 13 and circulating hydrogen) for hydrogenation, and the hydrogen enters the one-stage hydrogenation reactor from a gas phase inlet at the bottom of the one-stage hydrogenation reactor and/or a gas phase inlet at the lower part of the one-stage hydrogenation reactor;

(2) The first-stage hydrogenation product sequentially enters a first-stage reaction product cooler 3 for cooling, a first-stage gas-liquid separator 4 performs gas-liquid separation, gas phases subjected to gas-liquid separation all enter the second-stage hydrogenation reactor 5 from a gas phase inlet at the bottom of the second-stage hydrogenation reactor 5 and/or a gas phase inlet at the lower part of the second-stage hydrogenation reactor, and liquid phases subjected to gas-liquid separation enter the second-stage hydrogenation reactor 5 from a liquid phase feed inlet at the bottom of the second-stage reactor and/or a liquid phase feed inlet at the lower part of the second-stage hydrogenation reactor after being mixed with another maleic anhydride solution;

(3) And (3) feeding the second-stage hydrogenation product into a second-stage gas-liquid separator 6 for gas-liquid separation to obtain a gas phase and a liquid phase material (the other part is used as a reaction product 12) of the second-stage hydrogenation reaction in the step (1), and optionally using part or all of the gas phase as circulating hydrogen.

Or as shown in fig. 4, the second-stage hydrogenation product enters a second-stage cooler 8 for cooling and then enters a third gas-liquid separator 9 for gas-liquid separation, and part or all of the obtained gas phase is used as the hydrogen raw material of the first-stage hydrogenation reactor by mixing the circulating hydrogen and the supplementary hydrogen 13; optionally, returning the obtained liquid phase to the two-stage gas-liquid separator 6 for gas-liquid separation; the gas phase obtained by gas-liquid separation of the two-stage hydrogenation product is preferably cooled in the two-stage cooler 8 at a temperature of 30 to 80 ℃. Thereby effectively removing heat and improving catalytic efficiency.

The following examples employed the following catalysts:

chinese patent application cn20201118431. X-example 1

(1) 50.00g of basic nickel carbonate (nickel content: 45% by weight) and 9.16g of Cu (NO) were weighed out ₃ ) ₂ ·3H ₂ Mixing 49.91g of ethylenediamine tetraacetic acid, 500g of deionized water and 100g of 25 wt% ammonia water, introducing ammonia gas, regulating the pH value of the solution to 10.5, and stirring at 45 ℃ until all solids are dissolved to obtain a nickel-copper ammonia complex solution;

(2) Weighing 458.31g of silica sol and mixing the silica sol with the nickel-copper ammonia complex solution obtained in the step (1) to obtain a mixed solution;

(3) Aging the mixed solution for 14 hours at the temperature of 60 ℃ under stirring, and drying for 12 hours at the temperature of 120 ℃ to obtain a catalyst precursor;

(4) Will contain 11.41g of Ce (NO) ₃ ) ₃ ·6H ₂ Saturated impregnating the catalyst precursor with cerium nitrate solution of O to obtain a matrix catalyst;

(5) Drying the matrix catalyst at 115 ℃ for 12 hours, then roasting at 400 ℃ for 4 hours, and forming to obtain the catalyst S1.

The catalyst S1 comprises, based on the total weight of the catalyst S1: 19 wt% NiO, 2 wt% CuO, 3 wt% CeO ₂ And 76% by weight of SiO ₂ 。

Chinese patent application CN 202011120495.3-example 1

(1) 10.90g of Ni (NO 3) 3.6H was weighed out ₂ O and 5.04g of Ce (NO) ₃ ) ₃ ·6H ₂ Cerium oxide, dissolved in water and fixed to a volume of 50.0ml, and then 50g of SiO as a carrier ₂ Immersing (specific surface area 300m2/g, water absorption 1.0 mL/g) in nickel nitrate-cerium nitrate mixed solution, stirring uniformly, standing and aging for 4 hours, then drying at 120 ℃ for 12 hours, and finally roasting at 450 ℃ in air for 4 hours to obtain a composite oxide carrier E;

(2) The composite oxide carrier E is added into 100ml of ruthenium metal solution with exothermic Ru content of 0.02g/L, ammonia water with mass concentration of 25% is added dropwise under stirring, the pH value of the solution is regulated and maintained at 9 and 55 ℃ for reaction for 6 hours, then the solution is filtered, then dried at 110 ℃ for 12 hours, and finally baked in air at 500 ℃ for 4 hours, thus obtaining the finished catalyst S1.

The catalyst S1 contains: siO with the catalyst carrier ₂ Wherein the mass fraction of Ni in the catalyst is 7% of the mass of the carrier, ceO ₂ The mass fraction of (2) is 4% of the mass of the carrier, and the mass fraction of Ru is 0.4% of the mass of the carrier.

Example 1

A method for producing succinic acid by using butane as a raw material is shown in figure 2.

Butane and air are mixed and enter an oxidation separation system. The catalyst used in the oxidation reaction is described in Chinese patent CN 201710053664.8-example 1. The reaction product enters an absorption tower after heat exchange and temperature reduction, dibutyl phthalate is adopted as a solvent, the solvent enters the absorption tower from the tower top, 20 theoretical plates are added in the absorption tower, the operating temperature is 90 ℃, the operating pressure is 0.05MPag, tail gas is extracted from the top of the absorption tower, the tail gas is sent to the outside of a boundary region, and the rich solvent in the tower bottom enters a stripping tower. The stripping column has 25 theoretical plates and has an operating temperature of 142 ℃ and an operating pressure of 12KPa. The top material of the stripping tower is sent to the light component tower, and the bottom material of the stripping tower is sent to the absorption tower for recycling. The light component tower has 20 theoretical plates and has an operating temperature of 40 ℃ and an operating pressure of 8KPa. The materials at the top of the light component tower are sent to the outside of the boundary region, and the materials at the bottom of the tower are sent to a product refining tower. The product refining tower has 25 tower plates and has an operating temperature of 132 ℃ and an operating pressure of 10KPa. And (3) the maleic anhydride product is extracted from the lateral line at the upper part of the product refining tower and is sent to a maleic anhydride hydrogenation separation system, and materials at the tower bottom are returned to the absorption tower for recycling after heat exchange to 50 ℃.

The maleic anhydride hydrogenation separation system adopts a two-stage hydrogenation reactor. Introducing a gamma-butyrolactone as a solvent from the outside, mixing with a circulating solvent and maleic anhydride to prepare a 10 wt% maleic anhydride solution, transferring the solution to the upper part of a first-stage hydrogenation reactor after heat exchange to 40 ℃, and introducing the mixture of the fresh hydrogen and the circulating hydrogen which are supplemented from the top of the first-stage hydrogenation reactor, wherein the molar ratio of the hydrogen to the maleic anhydride is 12. Space velocity of one-stage hydrogenation reactor for 2.5h ^-1 The reaction temperature is 40 DEG CThe pressure is 1.5MPa. Cooling the first-stage hydrogenation reaction product to 40 ℃, separating gas from liquid, respectively introducing gas phase and liquid phase from the top of the reactor into a second-stage hydrogenation reactor, and the space velocity of the second-stage hydrogenation reactor is 1h ^-1 The reaction temperature is 45 ℃ and the reaction pressure is 1.3MPa. The gas phase of the second-stage hydrogenation reaction product is discharged by 1% after passing through a gas-liquid separator, the residual gas phase and the supplementary fresh hydrogen gas are sent into a first-stage hydrogenation reactor together, the liquid phase after gas-liquid separation is sent into a light component removal tower by adopting 65% by weight of liquid phase, and the 35% by weight of liquid phase is mixed with maleic anhydride solution after heat exchange to 40 ℃ and enters the first-stage hydrogenation reactor together. The catalysts filled in the first-stage and second-stage reactors are Ni active component catalysts, and the specific composition is shown in the Chinese patent CN20201118431. X-example 1.

After two-stage hydrogenation reaction, the total conversion rate of maleic anhydride is 99.91%, and the total selectivity of succinic anhydride is 99.80%.

Materials from the maleic anhydride hydrogenation reaction system enter a succinic anhydride separation system, light components in the materials are separated out through a light component removal tower, and tower bottom materials are sent to a heavy component removal tower. And (3) extracting gamma-butyrolactone from the top of the heavy-duty removal tower, and recycling the gamma-butyrolactone as a maleic anhydride dissolving solvent. Heavy components are extracted from the tower bottom of the de-heavy tower, and succinic anhydride is extracted from the side line and is sent to a succinic anhydride hydrolysis system.

The theoretical plates of the light component removal column are 26 pieces of tower plates, the pressure at the top of the tower is 10KPa, the operating temperature is 100 ℃, the theoretical plates of the heavy component removal column are 25 pieces of tower plates, the pressure at the top of the tower is 3KPa, and the operating temperature is 105 ℃. The purity of the obtained succinic anhydride is 99.9 percent.

The operating pressure of the hydrolysis kettle of the hydrolysis system is 0.12MPa, the operating temperature is 80 ℃, and the succinic acid product is obtained after centrifugal separation and drying. The purity of the succinic acid product is 99.9 percent.

Example 2

The procedure of example 1 was followed except that the maleic anhydride solution was obtained in the separation stage of the oxidative separation system by separation using an absorber-rectifying column.

Butane and air are mixed to perform oxidation reaction. The reaction product enters an absorption tower, gamma-butyrolactone is adopted as solvent, the reaction product enters the absorption tower from the tower top, tail gas is extracted from the tower top of the absorption tower, and the tower bottom rich solvent enters a rectifying tower. Light components are extracted from the top of the rectifying tower, and the materials in the tower bottom are maleic anhydride solution.

in the above operation conditions, adjusting the operation conditions and the type of the absorbent to obtain maleic anhydride solution with the solvent of gamma-butyrolactone and maleic anhydride content of 10 weight percent;

the maleic anhydride solution was split into two streams according to the proportions of 50 wt% and 50 wt% by using the maleic anhydride hydrogenation reaction method shown in fig. 3, one of which was mixed with the recycled two-stage hydrogenation reaction product, and then fed into the one-stage hydrogenation reactor from the lower part of the reactor. The other strand is mixed with the first-stage hydrogenation reaction product and then enters the second-stage hydrogenation reactor from the lower part of the reactor. The molar ratio of the total hydrogen of the recycled hydrogen to the fresh hydrogen supplemented to the total maleic anhydride in the incoming maleic anhydride solution was 10.

In the first-stage hydrogenation reactor, the space velocity of the first-stage hydrogenation reactor is 2.5h ^-1 The reaction temperature is 40 ℃ and the reaction pressure is 1.5MPa. Cooling the first-stage hydrogenation reaction product to 40 ℃, separating gas from liquid, allowing the gas phase to enter the second-stage hydrogenation reactor from the bottom of the reactor, mixing the liquid phase with part of maleic anhydride solution, and allowing the mixture to enter the second-stage hydrogenation reactor from the lower part of the reactor. Space velocity of two-stage hydrogenation reactor 1h ^-1 The reaction temperature is 42 ℃ and the reaction pressure is 1.3MPa. And (3) after the second-stage hydrogenation reaction product passes through a gas-liquid separator, 1% by volume of gas phase is discharged, the rest gas phase is cooled to 40 ℃, and the rest gas phase and the additional fresh hydrogen enter the first-stage hydrogenation reactor from the bottom of the reactor. After gas-liquid separation, the liquid phase of the second-stage hydrogenation reaction product is sent to a subsequent separation system, 35 wt% of the liquid phase is mixed with maleic anhydride solution, and the mixture is subjected to heat exchange to 40 ℃ and enters a first-stage hydrogenation reactor.

The catalysts filled in the first-stage hydrogenation reactor and the second-stage hydrogenation reactor are Ni active component catalysts, and the specific composition is shown in the Chinese patent CN20201118431. X-example 1.

After two-stage reaction, the total conversion rate of maleic anhydride is 99.92%, and the total selectivity of succinic anhydride is 99.83%.

The succinic acid was isolated and hydrolyzed by the method of example 1 to obtain a succinic acid product having a purity of 99.9% or higher.

Example 3

Butane and air were separated by oxidation according to the method of example 2, except that the operation conditions and the kind of the absorbent were adjusted to obtain a maleic anhydride solution having a maleic anhydride content of 25% by weight using hexane as a solvent;

the maleic anhydride solution is divided into two parts according to the proportion of 40 weight percent and 60 weight percent by adopting the maleic anhydride hydrogenation reaction method shown in fig. 4, wherein 40 percent of maleic anhydride solution is mixed with the second-stage hydrogenation reaction product and then enters the first-stage hydrogenation reactor from the bottom of the reactor, and 60 percent of maleic anhydride solution is mixed with the first-stage hydrogenation reaction product and then enters the second-stage hydrogenation reactor from the bottom of the reactor. The molar ratio of total hydrogen of the recycled hydrogen to the fresh hydrogen make-up to total maleic anhydride in the incoming maleic anhydride solution was 40.

In the first-stage hydrogenation reactor, the space velocity of the first-stage hydrogenation reactor is 3h ^-1 The reaction temperature is 40 ℃ and the reaction pressure is 1.7MPa. Cooling the first-stage hydrogenation reaction product to 42 ℃, separating gas from liquid, introducing gas phase into the second-stage hydrogenation reactor from the bottom of the reactor, mixing liquid phase with another part of maleic anhydride solution, and introducing the mixture into the second-stage hydrogenation reactor from the bottom of the reactor. Space velocity of the two-stage hydrogenation reactor is 0.8h ^-1 The reaction temperature is 45 ℃ and the reaction pressure is 1.5MPa. The second-stage hydrogenation reaction product is cooled to 40 ℃ again after passing through a gas-liquid separator, and then the gas phase and the supplementary fresh hydrogen are sent into a first-stage hydrogenation reactor together after passing through the gas-liquid separator, 50 weight percent of the liquid phase of the gas-liquid separator B is taken and sent to a light component removal tower, 50 weight percent of the liquid phase is taken and returned to the first-stage hydrogenation reactor, and after being mixed with partial maleic anhydride solution, the mixture is subjected to heat exchange to 40 ℃ and then enters the first-stage hydrogenation reactor.

The catalysts filled in the first-stage hydrogenation reactor and the second-stage hydrogenation reactor are Ni active component catalysts, and the specific composition is shown in Chinese patent CN 202011120495.3-example 1.

After two-stage reaction, the total conversion rate of maleic anhydride is 99.80%, and the total selectivity of succinic anhydride is 99.71%.

Example 4

Butane and air were separated by oxidation according to the method of example 2, except that the operating conditions and the type of absorbent were adjusted to obtain maleic anhydride solution having 18% by weight maleic anhydride content in the solvent using dioxane;

the maleic anhydride solution is divided into two parts according to the proportion of 20 weight percent and 80 weight percent by adopting the maleic anhydride hydrogenation reaction method shown in fig. 3, wherein the maleic anhydride solution with the proportion of 20 weight percent is mixed with the second-stage hydrogenation reaction product and then enters the first-stage hydrogenation reactor from the bottom of the reactor, and the maleic anhydride solution with the proportion of 80 weight percent is mixed with the first-stage hydrogenation reaction product and then enters the second-stage hydrogenation reactor from the bottom of the reactor. The molar ratio of the total hydrogen of the recycled hydrogen and the additional fresh hydrogen to the total maleic anhydride in the incoming maleic anhydride solution was 30.

In the first-stage hydrogenation reactor, the space velocity of the first-stage hydrogenation reactor is 1.8h ^-1 The reaction temperature is 40 ℃ and the reaction pressure is 1.2MPa. Cooling the first-stage hydrogenation reaction product to 45 ℃, separating gas from liquid, allowing the gas phase to enter the second-stage hydrogenation reactor from the bottom of the reactor, mixing the liquid phase with another part of maleic anhydride solution, and allowing the mixture to enter the second-stage hydrogenation reactor from the bottom of the reactor. Space velocity of the two-stage hydrogenation reactor is 1.2h ^-1 The reaction temperature is 48 ℃ and the reaction pressure is 1.2MPa. The gas phase is extracted to be 1% by volume and is exhausted after the second-stage hydrogenation reaction product passes through a gas-liquid separator, the rest gas phase and the supplementary fresh hydrogen are sent into a first-stage hydrogenation reactor together, 60% by weight of liquid phase is taken and sent to a subsequent separation system, 40% by weight of liquid phase is taken and returned to the first-stage hydrogenation reactor, and the mixture is mixed with maleic anhydride solution, and then heat exchange is carried out to the reaction temperature, and the mixture enters the first-stage hydrogenation reactor.

After two-stage reaction, the total conversion rate of maleic anhydride is 99.86%, and the total selectivity of succinic anhydride is 99.81%.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.

Claims

1. An apparatus for producing succinic acid by using butane and/or benzene as raw materials and performing oxidative hydrogenation hydrolysis, which is characterized in that the apparatus comprises: along the material flow direction, an oxidation separation system, a maleic anhydride hydrogenation separation system and a succinic anhydride hydrolysis system are connected in series; wherein butane and/or benzene and oxygen-containing gas are subjected to oxidation reaction in an oxidation separation system and separated to obtain maleic anhydride materials; the maleic anhydride material enters a maleic anhydride hydrogenation separation system to carry out hydrogenation reaction and is separated to obtain succinic anhydride; and (3) enabling the succinic anhydride to enter a succinic anhydride hydrolysis system for hydrolysis and crystallization to obtain a succinic acid product.

2. The apparatus of claim 1, wherein,

the maleic anhydride hydrogenation separation system comprises: a maleic anhydride hydrogenation system and a hydrogenation product separation system;

the maleic anhydride hydrogenation system comprises:

the liquid phase raw material supply pipeline is communicated with the liquid phase feed inlet of the first-stage hydrogenation reactor and the liquid phase feed inlet of the second-stage hydrogenation reactor;

and/or

The hydrogenation product separation system comprises:

3. The apparatus according to claim 2, wherein in the maleic anhydride hydrogenation system,

4. The apparatus according to claim 3, wherein in the maleic anhydride hydrogenation system,

5. The apparatus of any of claims 1-4, wherein the oxidative separation system comprises: the maleic anhydride separation system comprises an absorption tower and a rectifying tower which are communicated in series, and maleic anhydride solution obtained by separation of the absorption tower and the rectifying tower is directly used as a raw material of a maleic anhydride hydrogenation separation system, so that the maleic anhydride hydrogenation can be carried out without introducing a solvent additionally.

6. A process for the production of succinic acid by oxidative hydrogenation of butane and/or benzene as starting materials, characterized in that it is carried out in a device according to any one of claims 1 to 5, which comprises: butane and/or benzene and oxygen-containing gas are subjected to oxidation reaction in an oxidation separation system and separated to obtain maleic anhydride materials; the maleic anhydride material enters a maleic anhydride hydrogenation separation system to carry out hydrogenation reaction and is separated to obtain succinic anhydride; and (3) enabling the succinic anhydride to enter a succinic anhydride hydrolysis system for hydrolysis and crystallization to obtain a succinic acid product.

7. The process of claim 6, wherein the maleic anhydride hydrogenation separation system comprises a two-stage hydrogenation process comprising:

8. The process according to claim 7, wherein in the maleic anhydride hydrogenation process,

the hydrogen raw material in the step (1) is a mixed hydrogen raw material of circulating hydrogen and supplementary hydrogen; and/or

The liquid phase material of the two-stage hydrogenation reaction in the step (1) is a cooled material;

more preferably, the method further comprises the steps of,

the liquid phase material of the two-stage hydrogenation reaction in the step (1) is cooled to 30-80 ℃, preferably cooled to 40-60 ℃.

9. The process of claim 7 or 8, wherein the maleic anhydride hydrogenation process further comprises:

10. The method according to any one of claims 7 to 9, wherein in step (1),

The operating conditions of the stage hydrogenation reactor include: the temperature is 30-100deg.C, preferably 40-80deg.C; and/or the reaction pressure is 0.1 to 10MPa, preferably 0.5 to 5MPa; and/or space velocity of 0.5-5h ^-1 ；

the temperature is 30-120deg.C, preferably 40-100deg.C; and/or the pressure is 0.1-10 MPa; and/or space velocity of 0.5-5h ^-1 。

11. The method of any of claims 7-10, wherein the oxidative separation system comprises: the maleic anhydride separation system comprises an absorption tower and a rectifying tower which are communicated in series, and maleic anhydride solution obtained by separation of the absorption tower and the rectifying tower is directly used as a raw material of a maleic anhydride hydrogenation separation system, so that a solvent can not be additionally introduced in maleic anhydride hydrogenation;

Wherein, in maleic anhydride separation system:

12. The method of any of claims 7-11, wherein, within the hydrogenation product separation system:

the light ends column operating conditions include: the pressure is 0.5-20 KPa, the temperature is 30-150 ℃, and the theoretical plate number is 10-80; and/or

The operating conditions of the heavy-duty removal tower comprise: the pressure is 0.5-20 KPa, the temperature is 30-150 ℃, and the theoretical plate number is 10-80.