An acetonitrile process for hydrorefining butadiene extraction apparatus and method

Abstract

The application belongs to the field of acetonitrile method butadiene extraction device, and relates to a butadiene extraction device and method of acetonitrile method hydrogenation rectification. The device comprises a first extraction tower system, a first stripping tower system, an alkyne selective hydrogenation reaction rectification system, a second extraction tower system, a water washing tower system and a butadiene refining system; a first extraction tower system bottom discharge pipeline is connected with the first stripping tower system, a first stripping tower system side line production pipeline is connected with the alkyne selective hydrogenation reaction rectification system, and a first stripping tower system bottom discharge pipeline is connected with the second extraction tower system; a second extraction tower system top discharge pipeline is sequentially connected with the water washing tower system and the butadiene refining system, and a second extraction tower system bottom discharge pipeline is connected with the first stripping tower system. The selective hydrogenation reaction rectification system is coupled with the traditional acetonitrile method butadiene extraction device through alkyne, the stability of the extraction extraction device operation is ensured, and the purpose of canceling the second stripping system is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of acetonitrile method butadiene extraction device, and particularly relates to an acetonitrile method hydrogenation rectification butadiene extraction device and method. BACKGROUND

[0002] The butadiene extraction device carries out butadiene extraction through two-stage extraction and carbon four refining process. Taking the acetonitrile method as an example, a typical process is shown in the figure, the first-stage extraction is to separate mono-olefins, alkanes and di-olefins, acetylenes, the second-stage extraction is to further separate di-olefins and acetylenes to remove acetylenes, the water washing system is to remove the solvent, and the refining system is to remove light and heavy components. The traditional butadiene extraction device is a two-stage extraction process, the process flow is long, and the energy consumption and investment are relatively high. In addition, the traditional acetylene tail gas treatment method is to add a fixed bed hydrogenation system, which requires a certain equipment investment. Figure 1 With the development and mature application of selective hydrogenation catalysts, if the catalyst is applied in the butadiene extraction device process, a separate hydrogenation system is not needed, and the second stripping tower can be cancelled, saving about 10% to 15% of the energy consumption of the entire device. Therefore, by coupling the reaction rectification tower with the traditional butadiene extraction device while controlling the acetylene removal rate and butadiene loss rate within a reasonable range, the economic and environmental performance of the device can be greatly improved, the comprehensive energy consumption of the device can be reduced, and the comprehensive utilization value of carbon four can be increased.

[0003] There are three key problems in the acetylene selective hydrogenation technology: ensuring the selectivity and conversion rate of acetylenes while reducing the loss of butadiene through catalysts and operating conditions; the problem of heavy components and purge gas emissions generated by hydrogenation reaction; and the problem of reducing the number of devices in the butadiene extraction process and reducing the increase in the number of devices caused by hydrogenation. Solving the three problems at the same time can realize industrialization, reduce investment, and ensure the economic performance of the project.

[0004] Currently, there are three main methods for butadiene extraction device acetylene selective hydrogenation to produce rich butadiene products, the first method is to take out the acetylene-containing material from the side line of the de-butane tower of the ethylene device for hydrogenation and then return it to the de-butane tower, the second method is to subject the cracked carbon four raw material of the butadiene extraction device to selective hydrogenation and then enter the extraction extraction device, and the third method is to take out the acetylene-containing material at the high acetylene position of the butadiene extraction device for selective hydrogenation.

[0005]

[0006] ​CN102381920 through the debutanizer side line of ethylene device production containing acetylenic material for hydrogenation treatment, CN101172929 by the front hydrogenation treatment of cracking C4 raw material to achieve the conversion of acetylenic hydrocarbon to rich butadiene material, but these two ways need to set up fixed bed hydrogenation system separately, increase the equipment investment; At the same time, whether the side line material or cracking C4 raw material contains high concentration of butadiene, butadiene loss is difficult to avoid in hydrogenation process. And the boiling point of vinyl acetylene is very close to that of butadiene, the former is difficult to separate and hydrogenate from the side line of acetylenic hydrocarbon, and acetylenic hydrocarbon will still enter the butadiene extraction device at the top of the debutanizer, which is difficult to ensure the product qualification.

[0007] US2003181772 to NMP method butadiene extraction process through the wall column and coupled rectification column to realize the selective hydrogenation of acetylenic material, the method realizes the removal of acetylenic hydrocarbon through reactive distillation while increasing the production of butadiene, the process flow is simple, a single wall column can realize the extraction distillation, the separation of acetylenic hydrocarbon and the selective hydrogenation of acetylenic hydrocarbon, but the process equipment wall column is more complex, the increase of internal member leads to the polymerization of diene and acetylenic hydrocarbon, which causes coking and material loss, at the same time, the industrialization is difficult, and the process flow is only for NMP solvent.

[0008] The present application aims at the above problems, and develops a hydrogenation reactive distillation system for acetonitrile method butadiene extraction process, which can realize the increase of fixed bed hydrogenation system, simplify the process equipment structure, save energy and reduce consumption, and facilitate the industrial application. SUMMARY

[0009] The purpose of the present application is to solve the problems of long process flow, high energy consumption and low raw material utilization rate of the existing butadiene device, and to provide an acetonitrile method hydrogenation rectification butadiene extraction device and method, which realizes the purpose of canceling the second stripping system by coupling the acetylenic hydrocarbon selective hydrogenation reactive distillation column with the traditional acetonitrile method butadiene extraction device, solves the drawbacks of traditional butadiene device, and increases the economic benefit of the device.

[0010] In order to achieve the above purpose, the first aspect of the present application provides an acetonitrile method hydrogenation rectification butadiene extraction device, which comprises a first extraction tower system, a first stripping tower system, an acetylenic hydrocarbon selective hydrogenation reactive distillation system, a second extraction tower system, a water washing tower system and a butadiene refining system.

[0011] The first extraction column system is provided with a raw material feeding pipeline, a first extraction column system top discharge pipeline and a first extraction column system bottom discharge pipeline, the first extraction column system bottom discharge pipeline is connected with the first stripping column system, the first stripping column system is provided with a first stripping column system top discharge pipeline, a first stripping column system bottom discharge pipeline and a first stripping column system side line discharge pipeline, the first stripping column system top discharge pipeline is connected with the lower part of the second extraction column system, and the first stripping column system side line discharge pipeline is connected with the alkyn selective hydrogenation reaction rectification system;

[0012] The alkyn selective hydrogenation reaction rectification system is provided with a hydrogen feeding pipeline, an alkyn selective hydrogenation reaction rectification system top discharge pipeline, an alkyn selective hydrogenation reaction rectification system bottom discharge pipeline and an alkyn selective hydrogenation reaction rectification system side line discharge pipeline, the alkyn selective hydrogenation reaction rectification system side line discharge pipeline is connected with the upper part of the first stripping column system, and the alkyn selective hydrogenation reaction rectification system bottom discharge pipeline is connected with the lower part of the first stripping column system;

[0013] The first stripping column system bottom discharge pipeline is divided into two branches, one branch is connected with the upper part of the first extraction column system, and the other branch is connected with the upper part of the second extraction column system;

[0014] The second extraction column system is provided with a second extraction column system top discharge pipeline and a second extraction column system bottom discharge pipeline, the second extraction column system top discharge pipeline is sequentially connected with the water washing column system and the butadiene refining system, and the second extraction column system bottom discharge pipeline is connected with the upper part of the first stripping column system.

[0015] The second aspect of the present application provides an acetonitrile method hydrogenation rectification butadiene extraction method, which is carried out by using the acetonitrile method hydrogenation rectification butadiene extraction device, and comprises the following steps:

[0016] The alkyn-containing cracking carbon four raw material enters the first extraction column system, the overhead is extracted to extract the liquid containing monoolefin and alkane, the column is extracted to extract the solvent rich in diene and alkyn, and the solvent and carbon four are separated in the first stripping column system, the top material of the first stripping column system is sent to the lower part of the second extraction system, and the material with a higher ethynyl acetylene concentration extracted from the side line of the first stripping column system is sent to the alkyn selective hydrogenation reaction rectification system to perform alkyn selective hydrogenation and rectification reaction with hydrogen;

[0017] The carbon four material with a higher butadiene concentration extracted from the side line of the alkyn selective hydrogenation reaction rectification system is returned to the upper part of the first stripping column system, the overhead gas of the alkyn selective hydrogenation reaction rectification system is sent out, and the material at the bottom of the alkyn selective hydrogenation reaction rectification system is sent to the lower part of the first stripping column;

[0018] The first stripping tower system bottom material is divided into two parts, one part is sent to the upper part of the first extraction tower system, and the other part is sent to the upper part of the second extraction tower system, the second extraction tower system top material is sent to the water washing tower system and the butadiene refining system in turn, and the second extraction tower system bottom material returns to the first stripping tower system.

[0019] The beneficial effects of the present application are:

[0020] 1) The carbon four comprehensive utilization efficiency is increased by setting the selective hydrogenation reaction rectification system;

[0021] 2) The butadiene yield is increased, and the device economy is improved by setting the alkyne selective hydrogenation reaction rectification system to convert the ethynyl acetylene into butadiene;

[0022] 3) The second stripping tower system is omitted by setting the alkyne selective hydrogenation reaction rectification system, and the fixed bed hydrogenation system is not increased, thereby reducing the comprehensive energy consumption and saving investment;

[0023] 4) The non-condensable gas and heavy components such as carbon five and polymer generated in the reaction process can be removed by setting the alkyne selective hydrogenation reaction rectification system, so as to ensure the stability of the extraction device operation and reduce the polymerization risk;

[0024] 5) The concentration of ethynyl acetylene can be reduced by setting the alkyne selective hydrogenation reaction rectification system, so as to ensure the safety of the device operation;

[0025] 6) The present application preferably uses a nickel-based catalyst, and the economic benefit is outstanding;

[0026] 7) The alkyne selective hydrogenation reaction rectification system and the second extraction tower can realize that the alkyne does not enter the refining system, so as to ensure that the butadiene product is qualified.

[0027] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0028] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the several views, in which exemplary embodiments of the present application are shown.

[0029] Figure 1 It is a traditional acetonitrile method butadiene extraction device flow chart.

[0030] Figure 2 It is an acetonitrile method hydrogenation rectification butadiene extraction device flow chart of the present application.

[0031] Figure 3 It is an alkyne selective hydrogenation reaction rectification system detail drawing of the present application.

[0032] Explanation of reference numerals in the attached figures:

[0033] First extraction tower system 1, first stripping tower system 2, second extraction tower system 3, second stripping tower system 4, water washing tower system 5, butadiene refining system light removal tower 6, butadiene refining system heavy removal tower 7, alkyne selective hydrogenation reactive distillation tower 8, tower top condenser 9, tower top reflux tank 10, tail gas cooler 11, reflux pump 12. Detailed Implementation

[0034] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0035] To achieve the above objectives, a first aspect of the present invention provides an acetonitrile hydrodistillation butadiene extraction apparatus, comprising a first extraction tower system, a first stripping tower system, an alkyne selective hydrogenation reactive distillation system, a second extraction tower system, a water washing tower system, and a butadiene refining system.

[0036] The first extraction tower system is equipped with a raw material feed pipeline, a top discharge pipeline, and a bottom discharge pipeline. The bottom discharge pipeline of the first extraction tower system is connected to the first stripping tower system. The first stripping tower system is equipped with a top discharge pipeline, a bottom discharge pipeline, and a side discharge pipeline. The top discharge pipeline of the first stripping tower system is connected to the lower part of the second extraction tower system. The side discharge pipeline of the first stripping tower system is connected to the alkyne selective hydrogenation reactive distillation system.

[0037] The selective hydrogenation reactive distillation system for alkynes is equipped with a hydrogen feed line, a top discharge line, a bottom discharge line, and a side discharge line. The side discharge line is connected to the upper part of the first stripping tower, and the bottom discharge line is connected to the lower part of the first stripping tower system.

[0038] The bottom discharge pipeline of the first stripping tower system is divided into two branches, one of which is connected to the upper part of the first extraction tower system, and the other is connected to the upper part of the second extraction tower system.

[0039] The second extraction column system is provided with a second extraction column system top discharge pipeline and a second extraction column system bottom discharge pipeline, the second extraction column system top discharge pipeline is sequentially connected with the water washing column system and the butadiene refining system, and the second extraction column system bottom discharge pipeline is connected with the upper part of the first stripping column system.

[0040] In the present application, the first extraction column system, the first stripping column system, the second extraction column system, the water washing column system and the butadiene refining system of the butadiene extraction device are all typical settings of conventional butadiene extraction devices.

[0041] According to the present application, preferably, the acetylene selective hydrogenation reaction rectification system comprises an acetylene selective hydrogenation reaction rectification column, a column top condenser, a column top reflux tank, a tail gas cooler and a reflux pump;

[0042] The first stripping column system side line extraction pipeline is connected with the acetylene selective hydrogenation reaction rectification column, the acetylene selective hydrogenation reaction rectification column is provided with an acetylene selective hydrogenation reaction rectification column top discharge pipeline, an acetylene selective hydrogenation reaction rectification column side line discharge pipeline and an acetylene selective hydrogenation reaction rectification column bottom discharge pipeline; the acetylene selective hydrogenation reaction rectification column top discharge pipeline is sequentially connected with the column top condenser and the column top reflux tank, the column top reflux tank is provided with a column top reflux tank top discharge pipeline and a column top reflux tank bottom discharge pipeline, the column top reflux tank top discharge pipeline is connected with the tail gas cooler; the tail gas cooler is provided with a tail gas cooler top discharge pipeline and a tail gas cooler bottom discharge pipeline, the tail gas cooler bottom discharge pipeline is connected with the column top reflux tank, and the column top reflux tank bottom discharge pipeline is sequentially connected with the reflux pump and the lower part of the acetylene selective hydrogenation reaction rectification column; the acetylene selective hydrogenation reaction rectification column bottom discharge pipeline is connected with the lower part of the first stripping column system; and the acetylene selective hydrogenation reaction rectification column side line discharge pipeline is connected with the upper part of the first stripping column system.

[0043] According to the present application, preferably, the butadiene refining system comprises a butadiene refining system light component removal column and a butadiene refining system heavy component removal column;

[0044] The butadiene refining system light component removal column is provided with a butadiene refining system light component removal column top discharge pipeline and a butadiene refining system light component removal column bottom discharge pipeline, and the butadiene refining system light component removal column bottom discharge pipeline is connected with the butadiene refining system heavy component removal column;

[0045] The butadiene refining system heavy component removal column is provided with a butadiene refining system heavy component removal column top discharge pipeline and a butadiene refining system heavy component removal column bottom discharge pipeline.

[0046] The second aspect of the present application provides a butadiene extraction method by acetonitrile hydrogenation rectification, which is carried out by using the butadiene extraction device by acetonitrile hydrogenation rectification, and comprises the following steps:

[0047] The acetylene-containing cracking C4 raw material enters a first extraction column system, the overhead of which extracts a raffinate containing mono-olefins and alkanes, and the bottom of which extracts solvent rich in di-olefins and acetylenes, which is sent to a first stripping column system to separate the solvent and C4, the top material of the first stripping column system is sent to the lower part of a second extraction system, the side line of the first stripping column system extracts material with a higher concentration of vinyl acetylene, which is sent to an acetylene selective hydrogenation reaction distillation system to perform acetylene selective hydrogenation and distillation reaction with hydrogen.

[0048] The side line of the acetylene selective hydrogenation reaction distillation system extracts C4 material with a higher concentration of butadiene, which is returned to the upper part of the first stripping column system, the overhead gas of the acetylene selective hydrogenation reaction distillation system is discharged, and the bottom material of the acetylene selective hydrogenation reaction distillation system is sent to the lower part of the first stripping column.

[0049] The bottom material of the first stripping column system is divided into two parts, one part is sent to the upper part of the first extraction column system, and the other part is sent to the upper part of the second extraction column system, the top material of the second extraction column system is sent to a water washing column system and a butadiene refining system in turn, and the bottom material of the second extraction column system is returned to the first stripping column system.

[0050] In the present application, the top material of the first stripping column system is returned to the second extraction column system, and the solvent extracts the acetylene-containing material that does not enter the hydrogenation reaction distillation system and returns to the first stripping column system, thereby ensuring that the subsequent butadiene product does not contain acetylenes.

[0051] According to the present application, preferably, the side line of the first stripping column system extracts material with a higher concentration of vinyl acetylene, which is sent to an acetylene selective hydrogenation reaction distillation column with hydrogen, the top material of the acetylene selective hydrogenation reaction distillation column enters a top condenser and a top reflux tank in turn, the top material of the top reflux tank enters a tail gas cooler for cooling, the uncondensed gas phase material is discharged from the top, and the bottom material of the tail gas cooler returns to the top reflux tank; the bottom material of the top reflux tank is connected to a reflux pump and the acetylene selective hydrogenation reaction distillation column in turn; the side line of the acetylene selective hydrogenation reaction distillation column extracts C4 material with a higher concentration of butadiene, which is returned to the upper part of the first stripping column; and the bottom material of the acetylene selective hydrogenation reaction distillation column is sent to the lower part of the first stripping column.

[0052] According to the present application, preferably, the top material of the water washing column system is sent to a butadiene refining system light removal column, the light components are separated from the top and discharged, the bottom material of the butadiene refining system light removal column is sent to a butadiene refining system heavy removal column, the heavy components are separated from the bottom, and the butadiene product is obtained from the top.

[0053] According to the present application, preferably, the acetylene-containing cracking C4 raw material contains acetylenes, di-olefins, and mono-olefins and / or alkanes; wherein the butadiene content is 20wt%-70wt%, and the vinyl acetylene content is 0.1wt%-10wt%.

[0054] According to the present application, preferably, the butadiene content is 40wt%-55wt%, and the vinyl acetylene content is 0.5wt%-5wt%.

[0055] According to the present application, preferably, the catalyst of the acetylene selective hydrogenation reaction rectification column is located in the rectification section, and a catalyst cloth bag is filled in the column tray or a supported catalyst is used; the catalyst is a nickel-based catalyst and / or a palladium-based catalyst, preferably a nickel-based catalyst.

[0056] According to the present application, preferably, the selective hydrogenation operation conditions include: the operation temperature is 35-90℃, the operation pressure is 0-1.0MPaG, the reaction temperature rise is 5-25℃, the hydrogen-acetylene molar ratio is 0.5-5, the number of column plates is 20-100, and the reflux ratio is 5-50.

[0057] Example 1

[0058] This example is carried out by using a butadiene extraction device for acetonitrile method hydrogenation rectification as shown in Figure 2 and Figure 3 which includes a first extraction column system, a first stripping column system, an acetylene selective hydrogenation reaction rectification system, a second extraction column system, a water washing column system, and a butadiene refining system;

[0059] The first extraction column system is provided with a raw material feeding pipeline, a first extraction column system top discharge pipeline and a first extraction column system bottom discharge pipeline, the first extraction column system bottom discharge pipeline is connected with a first stripping column system, the first stripping column system is provided with a first stripping column system top discharge pipeline, a first stripping column system bottom discharge pipeline and a first stripping column system side line extraction pipeline, the first stripping column system top discharge pipeline is connected with a second extraction column system lower part, the first stripping column system side line extraction pipeline is connected with an alkyne selective hydrogenation reaction rectification column, the alkyne selective hydrogenation reaction rectification column is provided with an alkyne selective hydrogenation reaction rectification column top discharge pipeline, an alkyne selective hydrogenation reaction rectification column side line discharge pipeline and an alkyne selective hydrogenation reaction rectification column bottom discharge pipeline; the alkyne selective hydrogenation reaction rectification column top discharge pipeline is connected with a tower top condenser and a tower top reflux tank in sequence, the tower top reflux tank is provided with a tower top reflux tank top discharge pipeline and a tower top reflux tank bottom discharge pipeline, the tower top reflux tank top discharge pipeline is connected with a tail gas cooler; the tail gas cooler is provided with a tail gas cooler top discharge pipeline and a tail gas cooler bottom discharge pipeline, the tail gas cooler bottom discharge pipeline is connected with the tower top reflux tank, the tower top reflux tank bottom discharge pipeline is connected with a reflux pump and an alkyne selective hydrogenation reaction rectification column lower part in sequence; the alkyne selective hydrogenation reaction rectification column bottom discharge pipeline is connected with the first stripping column system lower part; the alkyne selective hydrogenation reaction rectification column side line discharge pipeline is connected with the first stripping column system upper part;

[0060] The first stripping column system bottom discharge pipeline is divided into two branches, one branch is connected with the first extraction column system upper part, and the other branch is connected with the second extraction column system upper part;

[0061] The second extraction column system is provided with a second extraction column system top discharge pipeline and a second extraction column system bottom discharge pipeline, the second extraction column system bottom discharge pipeline is connected with the first stripping column system upper part, the second extraction column system top discharge pipeline is connected with a water washing column system and a butadiene refining system light-removing column in sequence, the butadiene refining system light-removing column is provided with a butadiene refining system light-removing column top discharge pipeline and a butadiene refining system light-removing column bottom discharge pipeline, the butadiene refining system light-removing column bottom discharge pipeline is connected with a butadiene refining system heavy-removing column; the butadiene refining system heavy-removing column is provided with a butadiene refining system heavy-removing column top discharge pipeline and a butadiene refining system heavy-removing column bottom discharge pipeline.

[0062] The butadiene extraction method by acetonitrile hydrogenation rectification includes the following steps:

[0063] The acetylene-containing cracking C4 raw material enters a first extraction column system, the overhead of which extracts a raffinate containing mono-olefins and alkanes, and the bottom of which extracts a solvent rich in di-olefins and acetylenes, which is sent to a first stripping column system to separate the solvent and the C4, the top material of the first stripping column system is sent to the lower part of a second extraction system, the side line of the first stripping column system extracts material with a higher concentration of vinyl acetylene, which is sent to an acetylene selective hydrogenation reactive distillation column together with hydrogen, the top material of the acetylene selective hydrogenation reactive distillation column is sequentially sent to a top condenser and a top reflux tank, the top material of the top reflux tank is sent to a tail gas cooler for cooling, the non-condensed gas phase material is discharged from the top, and the bottom material of the tail gas cooler is returned to the top reflux tank; the bottom material of the top reflux tank is sequentially connected to a reflux pump and the acetylene selective hydrogenation reactive distillation column; the side line of the acetylene selective hydrogenation reactive distillation column extracts C4 material with a higher concentration of butadiene, which is returned to the upper part of the first stripping column; the bottom material of the acetylene selective hydrogenation reactive distillation column is sent to the lower part of the first stripping column;

[0064] The bottom material of the first stripping column system is divided into two parts, one part is sent to the upper part of the first extraction column system, and the other part is sent to the upper part of the second extraction column system, the bottom material of the second extraction column system containing acetylenes is extracted and returned to the first stripping column system, and the top material of the second extraction column system is sequentially sent to a water washing column system, the top material of the water washing column system is sent to a butadiene refining system light removal column, the light components are separated and discharged from the top, the butadiene refining system light removal column bottom material is sent to a butadiene refining system heavy removal column, the heavy components are separated from the bottom, and the butadiene product is obtained from the top.

[0065] The composition of the cracking C4 raw material is shown in Table 1 below (taking a 200,000 tons / year butadiene device as an example)

[0066] Table 1

[0067]

[0068]

[0069] The catalyst is a nickel-based catalyst, the selective hydrogenation operating conditions are a temperature of 80°C, an operating pressure of 0.07 MPaG, a reaction temperature rise of 5-25°C, and a hydrogen to acetylene (the sum of acetylenes and di-olefins) molar ratio of 1; the top operating temperature is 70°C, the number of trays is 40, and the reflux ratio is 10.

[0070] Because the second extraction column can ensure a high concentration of C4 acetylenes in the middle position of the first stripping column, the selective hydrogenation reactive distillation system does not have a high requirement for the single-pass conversion rate (the single-pass conversion rate reaches 80%, and the final conversion rate is close to 100%), the selectivity can reach more than 40%, and the economic benefits are considerable.

[0071] Having described various embodiments of the application, it is to be understood that the above description is meant to be illustrative only, and that many modifications and variations of the embodiments are possible without departing from the scope and spirit of the described embodiments. Many modifications and variations of the described embodiments are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims and their equivalents, the described embodiments can be practiced otherwise than as specifically described.

Claims

1. An acetonitrile process hydro-rectification butadiene extraction apparatus characterized by, The first extraction column system, the first stripping column system, the alkyne selective hydrogenation reaction rectification system, the second extraction column system, the water washing column system and the butadiene refining system; The first extraction column system is provided with a raw material feeding pipeline, a first extraction column system top discharge pipeline and a first extraction column system bottom discharge pipeline, the first extraction column system bottom discharge pipeline is connected with the first stripping column system, the first stripping column system is provided with a first stripping column system top discharge pipeline, a first stripping column system bottom discharge pipeline and a first stripping column system side line discharge pipeline, the first stripping column system top discharge pipeline is connected with the lower part of the second extraction column system, and the first stripping column system side line discharge pipeline is connected with the alkyne selective hydrogenation reaction rectification system. The alkyne selective hydrogenation reaction rectification system is provided with a hydrogen feeding pipeline, an alkyne selective hydrogenation reaction rectification system top discharge pipeline, an alkyne selective hydrogenation reaction rectification system bottom discharge pipeline and an alkyne selective hydrogenation reaction rectification system side line discharge pipeline, the alkyne selective hydrogenation reaction rectification system side line discharge pipeline is connected with the upper part of the first stripping column, and the alkyne selective hydrogenation reaction rectification system bottom discharge pipeline is connected with the lower part of the first stripping column system. The alkyne selective hydrogenation reaction rectification system comprises an alkyne selective hydrogenation reaction rectification column, a column top condenser, a column top reflux tank, a tail gas cooler and a reflux pump. The first stripping column system bottom discharge pipeline is divided into two branches, one of which is connected with the upper part of the first extraction column system, and the other of which is connected with the upper part of the second extraction column system. The second extraction column system is provided with a second extraction column system top discharge pipeline and a second extraction column system bottom discharge pipeline, the second extraction column system top discharge pipeline is sequentially connected with the water washing column system and the butadiene refining system, and the second extraction column system bottom discharge pipeline is connected with the upper part of the first stripping column system.

2. The acetonitrile method hydrogenation rectification butadiene extraction device according to claim 1, wherein The first stripping column system side line discharge pipeline is connected with the alkyne selective hydrogenation reaction rectification column, the alkyne selective hydrogenation reaction rectification column is provided with an alkyne selective hydrogenation reaction rectification column top discharge pipeline, an alkyne selective hydrogenation reaction rectification column side line discharge pipeline and an alkyne selective hydrogenation reaction rectification column bottom discharge pipeline, the alkyne selective hydrogenation reaction rectification column top discharge pipeline is sequentially connected with the column top condenser and the column top reflux tank, the column top reflux tank is provided with a column top reflux tank top discharge pipeline and a column top reflux tank bottom discharge pipeline, the column top reflux tank top discharge pipeline is connected with the tail gas cooler, the tail gas cooler is provided with a tail gas cooler top discharge pipeline and a tail gas cooler bottom discharge pipeline, the tail gas cooler bottom discharge pipeline is connected with the column top reflux tank, the column top reflux tank bottom discharge pipeline is sequentially connected with the reflux pump and the lower part of the alkyne selective hydrogenation reaction rectification column, the alkyne selective hydrogenation reaction rectification column bottom discharge pipeline is connected with the lower part of the first stripping column system, and the alkyne selective hydrogenation reaction rectification column side line discharge pipeline is connected with the upper part of the first stripping column system.

3. The acetonitrile process hydro-rectification butadiene extraction apparatus of claim 1, wherein, The butadiene refining system comprises a butadiene refining system light-removing column and a butadiene refining system heavy-removing column. The butadiene refining system light-removing column is provided with a butadiene refining system light-removing column top discharge pipeline and a butadiene refining system light-removing column bottom discharge pipeline. The butadiene refining system heavy-removing column is provided with a butadiene refining system heavy-removing column top discharge pipeline and a butadiene refining system heavy-removing column bottom discharge pipeline.

4. A butadiene extractive hydrocracking process by acetonitrile method, characterized by, The method is performed by using the acetonitrile method extraction device for butadiene hydrodehydrogenation rectification in any one of claims 1-3, comprising the following steps: The acetylene-containing cracking C4 raw material enters the first extraction column system, the overhead of which extracts a raffinate containing mono-olefins and alkanes, and the bottom of which extracts a solvent rich in di-olefins and acetylenes and sends it to the first stripping column system to separate the solvent and C4, the top material of the first stripping column system is sent to the lower part of the second extraction system, the material with a higher concentration of vinyl acetylene extracted from the side line of the first stripping column system is sent to the acetylene selective hydrogenation reaction rectification system to perform acetylene selective hydrogenation and rectification reaction with hydrogen; The material with a higher concentration of butadiene extracted from the side line of the acetylene selective hydrogenation reaction rectification system is returned to the upper part of the first stripping column system, the overhead gas of the acetylene selective hydrogenation reaction rectification system is discharged, and the bottom material of the acetylene selective hydrogenation reaction rectification system is sent to the lower part of the first stripping column; The bottom material of the first stripping column system is divided into two parts, one part is sent to the upper part of the first extraction column system, and the other part is sent to the upper part of the second extraction column system, the top material of the second extraction column system is sent to the water washing column system and the butadiene refining system in turn, and the bottom material of the second extraction column system is returned to the first stripping column system.

5. The acetonitrile process hydro-rectification of butadiene extraction process of claim 4 wherein, The material with a higher concentration of vinyl acetylene extracted from the side line of the first stripping column system is sent to the acetylene selective hydrogenation reaction rectification column with hydrogen, the top material of the acetylene selective hydrogenation reaction rectification column enters the overhead condenser and the overhead reflux tank in turn, the top material of the overhead reflux tank enters the tail gas cooler for cooling, the uncondensed gas phase material is discharged from the top, and the bottom material of the tail gas cooler returns to the overhead reflux tank; the bottom material of the overhead reflux tank is connected to the reflux pump and the acetylene selective hydrogenation reaction rectification column in turn; the material with a higher concentration of butadiene extracted from the side line of the acetylene selective hydrogenation reaction rectification column is returned to the upper part of the first stripping column; and the bottom material of the acetylene selective hydrogenation reaction rectification column is sent to the lower part of the first stripping column.

6. The acetonitrile process hydro-rectification of butadiene extraction process of claim 4 wherein, The top material of the water washing column system is sent to the butadiene refining system light-removing column, the light components are separated and discharged from the top, the butadiene refining system light-removing column bottom material is separated from the bottom and sent to the butadiene refining system heavy-removing column, the heavy components are separated from the bottom, and the butadiene product is obtained from the top.

7. The acetonitrile process hydro-rectification of butadiene extraction process of claim 4 wherein, The acetylene-containing cracking C4 raw material contains acetylenes, di-olefins, mono-olefins and / or alkanes; wherein the butadiene content is 20wt%-70wt%, and the vinyl acetylene content is 0.1wt%-10wt%.

8. The acetonitrile process hydro-rectification of butadiene extraction process of claim 7 wherein, The butadiene content is 40wt%-55wt%, and the vinyl acetylene content is 0.5wt%-5wt%.

9. The acetonitrile process hydro-rectification of butadiene extraction process of claim 4 wherein, The catalyst of the acetylene selective hydrogenation reaction rectifying tower is located in the rectifying section, and a catalyst cloth bag is filled in the tray or a supported catalyst is used; the catalyst is a nickel-based catalyst and / or a palladium-based catalyst.

10. The acetonitrile process hydro-rectification of butadiene extraction process of claim 9 wherein, The catalyst is a nickel-based catalyst.

11. The acetonitrile process hydro-rectification of butadiene extraction process of claim 4 wherein, The selective hydrogenation operation conditions include: an operation temperature of 35-90 DEG C, an operation pressure of 0-1.0 MPaG, a reaction temperature rise of 5-25 DEG C, a hydrogen-acetylene molar ratio of 0.5-5, a tray number of 20-100, and a reflux ratio of 5-50.

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