CN114479935B

CN114479935B - Hydrogenation device and hydrogenation method for mixed C4 material flow

Info

Publication number: CN114479935B
Application number: CN202011149785.0A
Authority: CN
Inventors: 刘俊杰; 杨士芳; 李晓锋; 杨沙沙
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: 2020-10-23
Filing date: 2020-10-23
Publication date: 2023-02-28
Anticipated expiration: 2040-10-23
Also published as: CN114479935A

Abstract

The invention relates to the field of petrochemical industry, in particular to a hydrogenation device and a hydrogenation method for a mixed C4 material flow. The hydrogenation device for the mixed C4 material flow provided by the invention adopts a dividing wall tower which is provided with an external condensation zone and is divided into a selective hydrogenation zone and a butadiene extraction zone, and simultaneously completes the selective hydrogenation and butadiene extraction of the mixed C4 material flow, so that the yield of butadiene is improved, and the full hydrogenation unit is combined to make unsaturated hydrocarbon in the unsaturated hydrocarbon-rich material flow perform full hydrogenation reaction, so that the content of the unsaturated hydrocarbon is reduced, namely, the obtained C4 alkane material flow with the content of the unsaturated hydrocarbon less than 10wt% can be used as a high-quality cracking raw material to return to a cracking furnace again, and the utilization rate of the material is improved. In addition, the device saves equipment investment, simplifies operation and is convenient for industrial production design.

Description

Hydrogenation device and hydrogenation method for mixed C4 material flow

Technical Field

The invention relates to the field of petrochemical industry, in particular to a hydrogenation device and a hydrogenation method for a mixed C4 material flow.

Background

The petroleum hydrocarbon cracking ethylene preparing device produces a large amount of mixed carbon four as a byproduct, wherein the cracking mixed carbon four contains about 40-60wt% of 1, 3-butadiene, 0.5-2wt% of Vinyl Acetylene (VA) and Ethyl Acetylene (EA), and the balance of butane, butylene and a small amount of 1, 2-butadiene, carbon three and carbon five. Usually, this portion of 1, 3-butadiene is separated from C4 by extractive distillation or the like.

The cracking mixed C4 is industrially refined by two-stage solvent extractive distillation and direct distillation to obtain butadiene material flow, and the yield of the butadiene is usually 97-98.5%. The alkyne separated from the industrial production contains 20-40wt% of VA and EA and 10-40wt% of 1, 3-butadiene, and the material is the so-called high alkyne tail gas, and is in consideration of safety factors in industrial production, and the alkyne is usually diluted by a carbon four-fraction and then subjected to torch treatment, so that resource waste and environmental pollution are caused.

CN101172929A discloses an NMP method one-stage extraction technology adopting a pre-hydrogenation technology, which is characterized in that alkyne is removed before extraction and rectification by adopting the pre-hydrogenation technology, and materials at the top of an analytical tower can be condensed into a liquid phase, so that the materials can be pumped to a refining tower without using a compressor, and the method has the characteristics of investment saving, energy consumption reduction, simplified operation, high safety and the like.

CN101665399A discloses a new process for producing butadiene, which adopts a process flow combining selective hydrogenation and extractive distillation, and arranges a degassing tower at the extraction position of the extraction tower top, and separates out the residual hydrogen and light components with less than four carbon atoms after hydrogenation reaction.

The three modes cancel the second-stage extractive distillation part, so that alkyne in the C4 material flow needs to be removed to below 15ppm in the selective hydrogenation process, the loss of butadiene in the hydrogenation process is inevitably caused, and the yield of the butadiene is not improved. In addition, the existing hydrogenation reaction and the separation of butadiene are realized by adopting a plurality of reactors, the operation flow is complex, and the equipment investment is large.

Accordingly, there is a need for a hybrid C4 stream hydrogenation apparatus and hydrogenation process.

Disclosure of Invention

The invention aims to overcome the technical problems and provides a hydrogenation device and a hydrogenation method for a mixed C4 material flow, wherein the device simultaneously completes selective hydrogenation and butadiene extraction of the mixed C4 material flow by utilizing a dividing wall tower, so that the equipment investment is saved and the operation is simplified; meanwhile, the method reduces the alkyne content in the material flow entering the butadiene extraction zone and improves the butadiene content and the yield.

In order to achieve the above object, a first aspect of the present invention provides a hydrogenation apparatus for a mixed C4 stream, the apparatus comprising: the device comprises a dividing wall tower and a full-hydrogenation unit, wherein the dividing wall tower comprises a shell and a condenser, a partition plate parallel to the central axis of the shell is arranged in the shell, the partition plate is connected with the top of the dividing wall tower and the tower wall and is not connected with the bottom of the dividing wall tower, and the partition plate divides the interior of the shell into a selective hydrogenation zone and a butadiene extraction zone;

the selective hydrogenation zone is provided with a selective hydrogenation catalyst bed layer and is used for carrying out a selective hydrogenation reaction by carrying out countercurrent contact on a mixed C4 material flow containing alkyne and an extraction liquid with hydrogen so as to saturate the alkyne into olefin and obtain a selective hydrogenation product, and simultaneously, under the stripping action of the hydrogen, separating a light component and a heavy component from the selective hydrogenation product;

the condenser is arranged outside the shell and above the selective hydrogenation zone and is used for mixing the light components with unreacted hydrogen and condensing to obtain condensate;

the condenser is provided with a condensate outlet which is communicated with a mixed C4 material flow inlet arranged in the selective hydrogenation zone and is used for returning the condensate to be mixed into the mixed C4 material flow;

the butadiene extraction area is used for extracting a mixed solution containing heavy components, an extraction liquid and unsaturated hydrocarbon to obtain a butadiene material flow and an unsaturated hydrocarbon-rich material flow;

an unsaturated hydrocarbon-rich material flow outlet arranged on the dividing wall tower is communicated with an inlet arranged on the full hydrogenation unit and is used for carrying out full hydrogenation reaction on the unsaturated hydrocarbon-rich material flow and hydrogen to obtain a C4 alkane material flow with the unsaturated hydrocarbon content of less than 10wt%.

In a second aspect, the invention provides a process for hydrogenating a mixed C4 stream, the process comprising the steps of:

(1) In the presence of a selective hydrogenation catalyst, carrying out a selective hydrogenation reaction by countercurrent contact of a mixed C4 material flow containing alkyne and an extraction liquid with hydrogen to saturate alkyne into olefin to obtain a selective hydrogenation product, and simultaneously separating a light component and a heavy component from the selective hydrogenation product under the stripping action of the hydrogen;

(2) Mixing the light components with unreacted hydrogen and condensing to obtain condensate, returning the condensate to the mixed C4 material flow and mixing the condensate into the mixed C4 material flow;

(3) Extracting a mixed solution containing heavy components, an extraction liquid and unsaturated hydrocarbon to obtain a butadiene material flow and an unsaturated hydrocarbon-rich material flow;

(4) In the presence of a full hydrogenation catalyst, performing full hydrogenation reaction on the unsaturated hydrocarbon-rich material flow and hydrogen to obtain a C4 alkane material flow with the unsaturated hydrocarbon content of less than 10wt%;

wherein the method is carried out in the apparatus provided in the first aspect.

According to the technical scheme, the hydrogenation device for the mixed C4 material flow provided by the invention adopts the divided wall tower which is provided with the external condensation and is divided into the selective hydrogenation area and the butadiene extraction area, simultaneously completes the selective hydrogenation and butadiene extraction of the mixed C4 material flow, improves the yield of butadiene, and combines the full hydrogenation unit to perform the full hydrogenation reaction on unsaturated hydrocarbon in the unsaturated hydrocarbon-rich material flow, so that the content of the unsaturated hydrocarbon is reduced, namely, the obtained C4 alkane material flow with the content of the unsaturated hydrocarbon less than 10wt% can be used as a high-quality cracking raw material to return to the cracking furnace again, and the utilization rate of the material is improved. In addition, the device saves equipment investment, simplifies operation and is convenient for industrial production design.

Drawings

FIG. 1 is a schematic diagram of a hydrogenation unit for a mixed C4 stream provided by the present invention.

Description of the reference numerals

1. Hydrogen 2, mixed C4 stream 3, extract

4. Gas phase tail gas 5, condensate 6, butadiene stream

7. Unsaturated hydrocarbon-rich stream 8, C4 alkane stream with unsaturated hydrocarbon content more than or equal to 10wt percent

9. C4 alkane stream 10 having an unsaturated hydrocarbon content of less than 10wt%, separator

I. A selective hydrogenation zone II, a butadiene extraction zone III and a condenser

A. A first-stage full hydrogenation zone B and a second-stage full hydrogenation zone

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and these ranges or values should be understood to encompass values close to these ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In the present invention, the "top" of the container referred to in the specification means a position of 0 to 10% of the container from the top to the bottom, without special cases; the "upper" portion of the vessel refers to the 0-30% position of the vessel from top to bottom; the "lower part" of the container means 70-100% of the position of the container from top to bottom; the "bottom" of the container refers to 90-100% of the container from top to bottom.

In a first aspect, the present invention provides a hydrogenation apparatus for a mixed C4 stream, the apparatus comprising: the device comprises a dividing wall tower and a full-hydrogenation unit, wherein the dividing wall tower comprises a shell and a condenser, a partition plate parallel to the central axis of the shell is arranged in the shell, the partition plate is connected with the top of the dividing wall tower and the tower wall and is not connected with the bottom of the dividing wall tower, and the partition plate divides the interior of the shell into a selective hydrogenation zone and a butadiene extraction zone;

the selective hydrogenation zone is provided with a selective hydrogenation catalyst bed layer and is used for carrying out a selective hydrogenation reaction by carrying out countercurrent contact on a mixed C4 material flow containing alkyne and an extraction liquid with hydrogen so as to saturate alkyne into olefin and obtain a selective hydrogenation product, and meanwhile, under the stripping action of the hydrogen, a light component and a heavy component are separated from the selective hydrogenation product;

the butadiene extraction zone is used for extracting a mixed solution containing heavy components, an extraction liquid and unsaturated hydrocarbon to obtain a butadiene material flow and an unsaturated hydrocarbon-rich material flow;

and an unsaturated hydrocarbon-rich material flow outlet arranged on the dividing wall tower is communicated with an inlet arranged on the full hydrogenation unit and is used for carrying out full hydrogenation reaction on the unsaturated hydrocarbon-rich material flow and hydrogen to obtain a C4 alkane material flow with the unsaturated hydrocarbon content of less than 10wt%.

The inventor of the invention researches and finds that: the method adopts a dividing wall tower with external condensation and separated into a selective hydrogenation zone and a butadiene extraction zone, and combines the stripping action of hydrogen to simultaneously complete the selective hydrogenation and butadiene extraction of mixed C4 material flow, thereby reducing the retention time of materials, reducing the alkyne content in the materials entering the butadiene extraction zone while simplifying the process flow, simultaneously improving the butadiene content and further being beneficial to improving the yield of the extracted butadiene; in addition, two sections of full hydrogenation zones are adopted to saturate the unsaturated hydrocarbon-rich material flow, so that the conversion rate of C4 alkane is improved, the obtained C4 alkane material flow with the unsaturated hydrocarbon content of less than 10wt% can be used as a high-quality cracking raw material, and the C4 resource is fully utilized.

In the present invention, the selective hydrogenation products are butadiene and butene, preferably, the butadiene is 1, 3-butadiene and/or 1, 2-butadiene, and the butene is 1-butene and/or 2-butene, unless otherwise specified; the light component is butylene, and the heavy component is butadiene.

In the present invention, the unsaturated hydrocarbon refers to an olefin and an unreacted alkyne in a mixed C4 stream without special cases.

In the present invention, there is no particular case where one end of the partition is connected to the top of the divided wall column and the other end of the partition is not connected to the bottom of the divided wall column.

According to the present invention, preferably, the selective hydrogenation zone is further provided with an extract inlet, a mixed C4 stream inlet and a hydrogen inlet.

In order to fully embody the countercurrent contact of the mixed C4 stream and the extract with hydrogen and to increase the saturation ratio of acetylenes in the mixed C4 stream. Preferably, the extract inlet and the mixed C4 stream inlet are each independently disposed above the hydrogen inlet.

According to the invention, preferably, the height ratio of the bed of selective hydrogenation catalyst to the selective hydrogenation zone is between 0.4 and 0.9:1, preferably 0.6 to 0.8:1. in the present invention, the height of the selective hydrogenation zone corresponds to the height of the partition, unless otherwise specified. And the optimized conditions are adopted, so that the alkyne in the mixed C4 material flow is more favorably converted into the butadiene and the butene, and the conversion rate of the alkyne is improved.

Preferably, the bed of selective hydrogenation catalyst is disposed below the mixed C4 stream inlet and the extract inlet and above the hydrogen inlet.

In the present invention, the mixed C4 stream inlet and the extract liquid inlet are not limited, and preferably, the extract liquid inlet is disposed above the mixed C4 stream inlet.

According to a preferred device of the present invention, the selective hydrogenation zone is provided with an extract inlet, a mixed C4 stream inlet, a selective hydrogenation catalyst bed and a hydrogen inlet, wherein the mixed C4 stream inlet is arranged above the extract inlet, and the selective hydrogenation catalyst bed is arranged below the extract inlet and above the hydrogen inlet.

According to the present invention, preferably, the ratio of the radius of the selective hydrogenation zone to the radius of the butadiene extraction zone is from 0.5 to 1.5:1, preferably 0.8 to 1.2:1. the optimized conditions are adopted, so that the sufficiency of the selective hydrogenation reaction and the extraction and separation of the butadiene is ensured.

Preferably, the ratio of the height of the partition to the height of the divided wall column is from 0.5 to 0.9:1, preferably 0.7 to 0.9:1. preferred conditions are used to better facilitate the simultaneous selective hydrogenation of the mixed C4 feed and stripping of the upper hydrogen on the left side of the dividing wall column.

In the present invention, the partition has a wide range of options as long as the partition wall column is partitioned into a selective hydrogenation zone and a butadiene extraction zone.

According to the invention, preferably, the total hydrogenation unit comprises at least one total hydrogenation zone in series; further preferably, the total hydrogenation unit comprises a primary total hydrogenation zone and a secondary total hydrogenation zone.

In the present invention, the primary full hydrogenation zone and the secondary full hydrogenation zone are each independently a full hydrogenation reactor without specific description. In the present invention, the kind or type of the full hydrogenation reactor is not limited at all.

According to the present invention, preferably, the first-stage total hydrogenation zone is used for carrying out a first-stage total hydrogenation reaction on the unsaturated hydrocarbon-rich stream and hydrogen to obtain a first-stage total hydrogenation product.

Preferably, the second-stage total hydrogenation zone is used for carrying out a second-stage total hydrogenation reaction on the first-stage total hydrogenation product and hydrogen to obtain a C4 alkane stream.

According to the invention, preferably, the outlet of the second-stage full hydrogenation zone is communicated with the inlet of the first-stage full hydrogenation zone, and the C4 alkane material flow with the unsaturated hydrocarbon content of more than or equal to 10wt% is returned to the first-stage full hydrogenation zone.

The invention provides a schematic diagram of a hydrogenation device for a mixed C4 material flow, as shown in figure 1, the device comprises: the device comprises a dividing wall tower and a full hydrogenation unit, wherein the dividing wall tower comprises a shell and a condenser III, a partition plate 10 parallel to the central axis of the shell is arranged in the shell, the partition plate 10 is connected with the top of the dividing wall tower and the tower wall and is not connected with the bottom of the dividing wall tower, and the partition plate 10 divides the interior of the shell into a selective hydrogenation zone I and a butadiene extraction zone II; the selective hydrogenation zone I is provided with a selective hydrogenation catalyst bed layer and is used for carrying out a selective hydrogenation reaction by carrying out countercurrent contact on a mixed C4 material flow 2 containing alkyne and an extraction liquid 3 with hydrogen 1 to saturate the alkyne into olefin to obtain a selective hydrogenation product, and simultaneously, under the steam stripping action of the hydrogen 1, separating a light component and a heavy component from the selective hydrogenation product; the condenser III is arranged outside the shell and above the selective hydrogenation zone I, and is used for mixing the light components with unreacted hydrogen and condensing to obtain a condensate 5 and a gas-phase tail gas 4; the condenser III is provided with a condensate outlet which is communicated with a mixed C4 material flow inlet arranged in the selective hydrogenation zone I and is used for returning and mixing the condensate into the mixed C4 material flow; the butadiene extraction area II is used for extracting a mixed solution containing heavy components, an extraction liquid and unsaturated hydrocarbon to obtain a butadiene material flow 6 and an unsaturated hydrocarbon-rich material flow 7; an unsaturated hydrocarbon-rich material flow outlet arranged on the dividing wall tower is communicated with an inlet arranged on the full hydrogenation unit and is used for carrying out full hydrogenation reaction on the unsaturated hydrocarbon-rich material flow 7 and hydrogen to obtain a C4 alkane material flow 9 with the unsaturated hydrocarbon content of less than 10wt%; the full hydrogenation unit comprises a first-stage full hydrogenation area A and a second-stage full hydrogenation area B, wherein the first-stage full hydrogenation area A is used for carrying out first-stage full hydrogenation reaction on the unsaturated hydrocarbon-rich material flow and hydrogen to obtain a first-stage full hydrogenation product, and the second-stage full hydrogenation area B is used for carrying out second-stage full hydrogenation reaction on the first-stage full hydrogenation product and the hydrogen to obtain a C4 alkane material flow 9 with the unsaturated hydrocarbon content of less than 10wt%.

Preferably, the outlet of the second-stage full hydrogenation zone is communicated with the inlet of the first-stage full hydrogenation zone, and is used for returning the C4 alkane material flow 8 with the unsaturated hydrocarbon content of more than or equal to 10wt% to the first-stage full hydrogenation zone.

In a second aspect, the present invention provides a process for hydrogenating a mixed C4 stream, the process comprising the steps of:

(2) Mixing the light components with unreacted hydrogen and condensing to obtain a condensate, returning the condensate to the mixed C4 material flow and mixing the condensate into the mixed C4 material flow;

(4) In the presence of a full hydrogenation catalyst, carrying out full hydrogenation reaction on the unsaturated hydrocarbon-rich material flow and hydrogen to obtain a C4 alkane material flow with the unsaturated hydrocarbon content of less than 10wt%;

In some embodiments of the present invention, preferably, the alkyne is present in an amount of from 0.5 to 10wt%, preferably from 0.6 to 3wt%, based on the weight of the mixed C4 stream.

In the present invention, the alkyne refers to a C4 alkyne unless otherwise specified. Preferably, the alkyne is selected from at least one of methylacetylene, ethylacetylene and vinylacetylene.

According to the present invention, preferably, said mixed C4 stream also contains butadiene, preferably selected from 1, 3-butadiene and/or 1, 2-butadiene; further preferably, the butadiene content is from 5 to 80wt%, preferably from 40 to 60wt%, based on the weight of the mixed C4 stream.

In the present invention, there is a wide range of choices for the source of the mixed C4 stream. Preferably, the mixed C4 stream is from at least one of a stripping section acetylenic scrubber and a hydrocarbon steam cracker that exits a butadiene extraction unit. Among them, the hydrocarbon steam cracking device may be an ethylene cracking device.

According to the present invention, preferably, in step (1), the selective hydrogenation reaction refers to that alkynes in the mixed C4 stream are saturated into olefins, so as to obtain selective hydrogenation products, namely butadiene and butylene; further preferably, the butadiene is selected from 1, 3-butadiene and/or 1, 2-butadiene, preferably 1, 3-butadiene; the butene is selected from 1-butene and/or 2-butene, preferably 1-butene.

Preferably, the molar ratio of the mixed C4 stream to hydrogen is 1:0.5-5.5, preferably 1:0.5-1.5; wherein the moles of the mixed C4 stream are based on the moles of acetylenes in the mixed C4 stream.

According to the invention, preferably, the weight ratio of the extraction liquid to the mixed C4 stream is from 0.3 to 5:1, preferably 0.5 to 1.5:1.

in the present invention, the extract is intended to separate butadiene to increase the yield of butadiene, and preferably, the extract is an aqueous solution containing an extractant.

In some embodiments of the invention, the water content of the extract is preferably 1-20wt%, e.g., 1wt%, 5wt%, 7wt%, 9wt%, 11wt%, 13wt%, 15wt%, 17wt%, 20wt%, and any two of the numerical ranges, preferably 5-15wt%.

In the present invention, there is a wide choice of the extractant, as long as the butadiene and the unsaturated hydrocarbon-rich stream are separated, i.e., the butadiene is insoluble in the extractant. Preferably, the extractant is selected from at least one of N-methylpyrrolidone, acetonitrile, furfural, formylmorpholine, dimethylacetamide and dimethylformamide.

In the present invention, there is a wide range of selection of the conditions for the selective hydrogenation reaction. Preferably, the conditions of the selective hydrogenation reaction include: the temperature is 20-80 ℃, preferably 30-80 ℃; the pressure is 0.6-5MPa, preferably 1-4MPa; the volume space velocity is 5-200h ^-1 Preferably 10-200h ^-1 . Wherein the volume space velocity is the volume space velocity of the mixed C4 stream. Preferred conditions are employed to further facilitate saturation of acetylenes in a mixed C4 stream to olefins.

In the present invention, there is a wide selection range for the selective hydrogenation catalyst, and preferably, the selective hydrogenation catalyst contains a first active component and a first carrier; further preferably, the first active component comprises a first main active component and optionally a first co-active component.

According to the present invention, preferably, the content of the first main active component is 0.01 to 5wt%, preferably 0.1 to 1.5wt%, based on the weight of the selective hydrogenation catalyst; the content of the first co-active component is 0-25wt%, preferably 0-12wt%.

In some embodiments of the present invention, preferably, the first main active component is selected from at least one of palladium, rhodium, platinum and nickel, and the first auxiliary active component is selected from at least one of potassium, sodium, lithium, calcium, magnesium, barium, fluorine, copper, silver, gold, lead, tin, zinc, manganese, bismuth, molybdenum, zirconium and rare earth elements, preferably lead.

Preferably, the first support is selected from at least one of alumina, silica, spinel, diatomaceous earth, titania, zinc oxide, tin oxide and molecular sieves, preferably alumina.

In the present invention, there is a wide range of choices for the shape of the selective hydrogenation catalyst. Preferably, the shape of the selective hydrogenation catalyst is selected from at least one of a granular shape, a spherical shape, a gear shape, a blade shape and a bar shape.

According to a preferred embodiment of the invention, the specific surface area of the first support is between 1 and 250m ² A/g, preferably from 100 to 200m ² (ii)/g; the average pore diameter is 5-300nm, preferably 80-180nm; the pore volume is 0.2-1mL/g, preferably 0.3-0.7mL/g.

In the present invention, the selective hydrogenation catalyst can be obtained commercially or prepared; wherein, the preparation method of the selective hydrogenation catalyst is a method well known to those skilled in the art.

According to the invention, in the step (2), the condensation is to separate the mixed liquid containing light components and unreacted hydrogen to obtain a condensed liquid and a gas-phase tail gas; preferably, the condensate is selected from butenes and C4 alkynes; the gas phase tail gas is at least one of unreacted hydrogen, methane, ethane and propane, wherein the methane, the ethane and the propane are all gas phase light components in the mixed C4 material flow.

According to the invention, preferably, in the step (2), the condensate is returned and mixed into the mild C4 stream, which is beneficial to reducing the bed temperature shock caused by the heat release of the selective hydrogenation reaction by reducing the content of alkyne in the mixed C4 stream, effectively inhibiting the generation of polymer and the deposition on the surface of the selective hydrogenation catalyst, and prolonging the service life of the selective hydrogenation catalyst.

According to the invention, in the step (3), the extraction is to separate the mixed solution containing the heavy component, the extraction liquid and the unsaturated hydrocarbon to obtain the butadiene material flow and the unsaturated hydrocarbon-rich material flow. In the present invention, the extraction is performed in a butadiene extraction apparatus, which is not limited in the present invention.

According to a preferred embodiment of the present invention, the butadiene extraction device is an extractive distillation column; preferably, the extraction conditions include: the theoretical plate number is 50-95, preferably 60-85; the pressure is 0.1-1MPa, preferably 0.5-0.6MPa; the temperature of the top of the tower is 25-60 ℃, and the preferable temperature is 35-50 ℃; the temperature of the tower bottom is 120-150 ℃, preferably 125-145 ℃. The preferred conditions are used to further facilitate the separation of the butadiene and unsaturated hydrocarbon-rich stream.

According to the invention, preferably, the butadiene stream has a content of 1, 3-butadiene of from 80 to 99.9% by weight, preferably from 99 to 99.9% by weight; further preferably, the yield of butadiene in the butadiene stream is not less than 99%, preferably 99.01-99.2%.

Preferably, the molar ratio of the unsaturated hydrocarbon-rich stream to hydrogen is 1:0.2 to 4.5, preferably: 0.2-1.5; wherein the molar amount of the unsaturated hydrocarbon-rich stream is based on the molar amount of unsaturated bonds in the unsaturated hydrocarbon-rich stream.

Preferably, the unsaturated hydrocarbon-rich stream has an unsaturated hydrocarbon content of from 10 to 40wt%, preferably from 15 to 25wt%.

In the present invention, there is a wide range of selection of the conditions for the total hydrogenation reaction, as long as the unsaturated hydrocarbons in the unsaturated hydrocarbon-rich stream are converted to saturated hydrocarbons. Preferably, the conditions of the total hydrogenation reaction include: the temperature is 10-90 ℃, preferably 20-80 ℃; the pressure is 1-10MPa, preferably 1-4MPa; the volume space velocity is 5-300h ^-1 Preferably 10-200h ^-1 . Wherein the volume space velocity refers to the volume space velocity of the unsaturated hydrocarbon-rich stream.

According to the present invention, preferably, the total hydrogenation catalyst contains a second active component and a second carrier; further preferably, the second active component comprises a second main active component and optionally a second co-active component.

Preferably, the second main active component is present in an amount of 0.01 to 5wt%, preferably 0.1 to 2wt%, based on the weight of the perhydrogenation catalyst; the content of the second auxiliary active component is 0-15wt%, preferably 0.05-10wt%.

In some embodiments of the present invention, preferably, the second main active component is selected from at least one of palladium, rhodium, platinum and nickel, and the second auxiliary active component is selected from at least one of potassium, sodium, lithium, calcium, magnesium, barium, fluorine, copper, silver, gold, lead, tin, zinc, manganese, bismuth, molybdenum, zirconium and rare earth elements, preferably silver.

Preferably, the second support is selected from at least one of alumina, silica, spinel, diatomaceous earth, titania, zinc oxide, tin oxide and molecular sieves, preferably alumina.

In the present invention, there is a wide range of choices for the shape of the total hydrogenation catalyst. Preferably, the shape of the total hydrogenation catalyst is at least one selected from the group consisting of a pellet, a sphere, a gear, a blade, and a bar.

According to a preferred embodiment of the invention, the specific surface area of the second support is between 1 and 300m ² A/g, preferably of from 100 to 250m ² (ii)/g; the average pore diameter is 5-250nm, preferably 50-200nm; the pore volume is 0.3-1.5mL/g, preferably 0.5-1mL/g.

In the present invention, the perhydrogenation catalyst may be obtained commercially or may be prepared; wherein, the preparation method of the total hydrogenation catalyst is a method well known by the technical personnel in the field.

According to the invention, preferably, the C4 alkane stream has a content of unsaturated hydrocarbons of < 10 wt.%, preferably 0.02 to 0.5 wt.%.

Preferably, the yield of said C4 alkanes in said C4 alkane stream is from 60 to 95%, preferably from 82 to 95%.

According to a preferred embodiment of the present invention, the total hydrogenation reaction includes a one-stage total hydrogenation reaction and a two-stage total hydrogenation reaction. Preferred conditions are used to further increase the yield of C4 alkanes from the C4 alkane stream.

According to the present invention, preferably, the one-stage total hydrogenation reaction comprises contacting the unsaturated hydrocarbon-rich stream with hydrogen to obtain a one-stage total hydrogenation product.

Preferably, the second-stage total hydrogenation reaction comprises contacting the first-stage total hydrogenation product with hydrogen to obtain a C4 alkane stream with unsaturated hydrocarbon content of less than 10wt%.

Further preferably, the method further comprises: a stream of C4 paraffins having an unsaturated hydrocarbon content of 10 wt.% or more is returned and mixed into the unsaturated hydrocarbon-rich stream.

In the present invention, the conditions of the first-stage total hydrogenation reaction and the conditions of the second-stage total hydrogenation reaction are each independently the same as the conditions of the total hydrogenation reaction, unless otherwise specified.

According to a preferred embodiment of the present invention, the conditions of the first-stage total hydrogenation reaction and the conditions of the second-stage total hydrogenation reaction each independently comprise: the temperature is 10-90 ℃, preferably 20-80 ℃; the pressure is 1-10MPa, preferably 1-4MPa; the volume space velocity is 5-300h ^-1 Preferably 10-200h ^-1 。

According to the present invention, preferably, the method further comprises: the unsaturated hydrocarbon-rich stream is pretreated prior to the full hydrogenation reaction.

Further preferably, the pre-treatment comprises compressing, condensing and boosting the unsaturated hydrocarbon-rich stream in sequence. Wherein, the compression, condensation and pressure increase are all conventional technical means in the field, and the invention is not described herein.

In some embodiments of the present invention, preferably, the compression conditions are: the pressure is 0.01-0.1MPa, preferably 0.05-0.08MPa.

In some embodiments of the present invention, preferably, the compression conditions are: the temperature is 1 to 10 ℃ and preferably 2 to 8 ℃.

In some embodiments of the present invention, preferably, the boosting condition is: the pressure is 1 to 4MPa, preferably 2 to 3MPa.

The present invention will be described in detail below by way of examples.

Example 1

(1) A hybrid C4 stream hydrogenation unit is shown in FIG. 1, i.e., the unit includes: the device comprises a dividing wall tower and a full hydrogenation unit, wherein the dividing wall tower comprises a shell and a condenser III, a partition plate 10 parallel to the central axis of the shell is arranged in the shell, the partition plate 10 is connected with the top of the dividing wall tower and the tower wall and is not connected with the bottom of the dividing wall tower, the partition plate 10 partitions the interior of the shell into a selective hydrogenation zone I and a butadiene extraction zone II, the condenser III is arranged outside the shell and above the selective hydrogenation zone I, and the condenser III is provided with a condensate outlet and communicated with a mixed C4 material flow inlet arranged in the selective hydrogenation zone I;

the selective hydrogenation zone I is provided with an extraction liquid inlet, a mixed C4 material flow inlet, a selective hydrogenation catalyst bed layer and a hydrogen inlet, wherein the mixed C4 material flow inlet is arranged below the extraction liquid, the selective hydrogenation catalyst bed layer is arranged below the mixed C4 material flow inlet and is arranged above the hydrogen inlet, and the height ratio of the selective hydrogenation catalyst bed layer to the selective hydrogenation zone is 0.6;

the radius ratio of the selective hydrogenation zone I to the butadiene extraction zone II is 1; the height of the partition 10 from the divided wall column is 0.8;

the total hydrogenation unit comprises a first-stage total hydrogenation zone A and a second-stage total hydrogenation zone B.

(2) A process for hydrogenating a mixed C4 stream, the process comprising：

a. In the selective hydrogenation catalyst (active components are palladium and silver, carrier is alumina, and by using the weight of the selective hydrogenation catalyst as reference, the content of the palladium is 0.2wt%, the content of the silver is 10wt%, and the specific surface area of the alumina is 150m ² Per g, average pore diameter of 200nm, pore volume of 0.8 mL/g) a mixed C4 stream with an alkyne content of 1 wt.% (ethylene cracker) and an N-methylpyrrolidone solution with a water content of 9 wt.% were subjected to a selective hydrogenation reaction with hydrogen, wherein the weight ratio of N-methylpyrrolidone solution to mixed C4 stream was 1The molar ratio of the synthesized C4 material flow to the hydrogen is 1.2, and the conditions of the selective hydrogenation reaction comprise: the temperature is 45 ℃, the pressure is 2MPa, and the volume space velocity is 100h ^-1 Obtaining a selective hydrogenation product, wherein the alkyne content in the selective hydrogenation product is 0.34wt%, and simultaneously, under the stripping action of hydrogen, a light component containing butene and a heavy component containing butadiene are separated from the selective hydrogenation product;

b. mixing the light component containing the butene, the light component in the mixed C4 material flow and unreacted hydrogen and condensing to obtain a condensate containing the butene and C4 alkyne, returning the condensate to the mixed C4 material flow and mixing the condensate into the mixed C4 material flow;

c. extracting a mixed solution of heavy components containing butadiene, olefin in a mixed C4 material flow, unreacted alkyne and an extraction liquid, wherein the extraction conditions comprise: the theoretical plate number is 80, the pressure is 0.6MPa, the temperature at the top of the tower is 35 ℃, and the temperature at the bottom of the tower is 125 ℃, so that a butadiene material flow and an unsaturated hydrocarbon-rich material flow are obtained; wherein the butadiene stream had a 1, 3-butadiene content of 99.8wt% and a butadiene yield of 99.05%; the unsaturated hydrocarbon content in the unsaturated hydrocarbon-rich stream is 18wt%;

d. in the full hydrogenation catalyst (active components are palladium and silver, a carrier is alumina, based on the weight of the selective hydrogenation catalyst, the content of the palladium is 0.5wt%, the content of the silver is 1.5wt%, and the specific surface area of the alumina is 250m ² Per g, the average pore diameter is 200nm, and the pore volume is 0.5 mL/g), the unsaturated hydrocarbon-rich material flow is sequentially compressed to 0.06MPa, condensed to 2 ℃, and is processed by increasing the pressure to 2.5MPa, and then is subjected to a first-stage full hydrogenation reaction with hydrogen, wherein the conditions of the first-stage full hydrogenation reaction comprise: the molar ratio of the unsaturated hydrocarbon-rich material flow to the hydrogen is 1.9, the temperature is 50 ℃, the pressure is 3MPa, and the volume space velocity is 150h ^-1 And carrying out a second-stage total hydrogenation reaction on the obtained first-stage total hydrogenation product and hydrogen, wherein the conditions of the second-stage total hydrogenation reaction comprise: the mol ratio of the first-stage full hydrogenation product to the hydrogen is 1.5, the temperature is 50 ℃, the pressure is 2.8MPa, and the volume space velocity is 150h ^-1 To obtain C4 alkane material flow;

wherein the C4 alkane stream has an unsaturated hydrocarbon content of 4.67wt% and a C4 alkane content of 85wt%.

Example 2

(1) A hybrid C4 stream hydrogenation unit is shown in FIG. 1, i.e., the unit comprises: the device comprises a dividing wall tower and a full hydrogenation unit, wherein the dividing wall tower comprises a shell and a condenser III, a partition plate 10 parallel to the central axis of the shell is arranged in the shell, the partition plate 10 is connected with the top of the dividing wall tower and the tower wall and is not connected with the bottom of the dividing wall tower, the partition plate 10 partitions the interior of the shell into a selective hydrogenation zone I and a butadiene extraction zone II, the condenser III is arranged outside the shell and above the selective hydrogenation zone I, and the condenser III is provided with a condensate outlet and communicated with a mixed C4 material flow inlet arranged in the selective hydrogenation zone I;

the selective hydrogenation zone I is provided with an extraction liquid inlet, a mixed C4 material flow inlet, a selective hydrogenation catalyst bed layer and a hydrogen inlet, wherein the mixed C4 material flow inlet is arranged below the extraction liquid, the selective hydrogenation catalyst bed layer is arranged below the mixed C4 material flow inlet and is arranged above the hydrogen inlet, and the height ratio of the selective hydrogenation catalyst bed layer to the selective hydrogenation zone is 0.7;

the radius ratio of the selective hydrogenation zone I to the butadiene extraction zone II is 1; the height of the partition 10 from the divided wall column is 0.9;

(2) A process for hydrogenating a mixed C4 stream, the process comprising:

a. in a selective hydrogenation catalyst (active components are palladium and silver, a carrier is alumina, the weight of the selective hydrogenation catalyst is taken as a reference, the content of the palladium is 0.8 weight percent, the content of the silver is 13 weight percent, and the specific surface area of the alumina is 200m ² Per g, mean pore diameter of 180nm, pore volume of 0.7 mL/g) with hydrogen, a mixed C4 stream having an alkyne content of 3% by weight (butadiene extraction unit) and a solution of N-methylpyrrolidone having a water content of 12% by weight (N-methylpyrrolidone) were selectively addedHydrogen reaction, wherein the weight ratio of the N-methyl pyrrolidone solution to the mixed C4 stream is 1: the temperature is 70 ℃, the pressure is 3MPa, and the volume space velocity is 150h ^-1 Obtaining a selective hydrogenation product, wherein the alkyne content in the selective hydrogenation product is 0.4wt%, and simultaneously, under the stripping action of hydrogen, a light component containing butene and a heavy component containing butadiene are separated from the selective hydrogenation product;

b. mixing the light component containing the butylene and the light component in the mixed C4 material flow with unreacted hydrogen and condensing to obtain a condensate containing the butylene and the C4 alkyne, returning the condensate and mixing the condensate into the mixed C4 material flow;

c. extracting a mixed solution of a heavy component containing butadiene, unreacted alkyne and an extraction liquid, wherein the extraction conditions comprise: the theoretical plate number is 70, the pressure is 0.5MPa, the temperature at the top of the tower is 45 ℃, and the temperature at the bottom of the tower is 130 ℃; obtaining a butadiene stream and an unsaturated hydrocarbon-rich stream; wherein the butadiene stream had a 1, 3-butadiene content of 99.7wt% and a butadiene yield of 99.15%; the unsaturated hydrocarbon content in the unsaturated hydrocarbon-rich stream was 22wt%;

d. in the full hydrogenation catalyst (active components are palladium and silver, a carrier is alumina, based on the weight of the selective hydrogenation catalyst, the content of the palladium is 0.3wt%, the content of the silver is 1.5wt%, and the specific surface area of the alumina is 220m ² The average pore diameter is 200nm, the pore volume is 0.7 mL/g), the unsaturated hydrocarbon-rich material flow is sequentially compressed to 0.07MPa, condensed to 7 ℃, and subjected to pressure boosting to 3MPa, and then is subjected to a first-stage full hydrogenation reaction with hydrogen, wherein the conditions of the first-stage full hydrogenation reaction comprise: the molar ratio of the unsaturated hydrocarbon-rich material flow to the hydrogen is 1, the temperature is 75 ℃, the pressure is 2MPa, and the volume space velocity is 120h ^-1 And carrying out a second-stage total hydrogenation reaction on the obtained first-stage total hydrogenation product and hydrogen, wherein the conditions of the second-stage total hydrogenation reaction comprise: the mol ratio of the first-stage full hydrogenation product to hydrogen is 1.5, the temperature is 70 ℃, the pressure is 2.2MPa, and the volume space velocity is 120h ^-1 To obtain C4 alkane material flow;

wherein the C4 alkane stream has an unsaturated hydrocarbon content of 3.8wt% and a C4 alkane content of 88wt%.

Example 3

The process of example 1 is followed except that step d is different, namely:

d. in the full hydrogenation catalyst (active components are palladium and silver, carrier is alumina, and based on the weight of the selective hydrogenation catalyst, the content of the palladium is 0.5wt%, the content of the silver is 1.5wt%, and the specific surface area of the alumina is 250m ² Per g, the average pore diameter is 200nm, and the pore volume is 0.5 mL/g), the unsaturated hydrocarbon-rich material flow is compressed to 0.06MPa, condensed to 2 ℃, and is processed by increasing the pressure to 2.5MPa, and then is subjected to full hydrogenation reaction with hydrogen, wherein the conditions of the full hydrogenation reaction comprise: the molar ratio of the unsaturated hydrocarbon-rich stream to hydrogen is 1.9, the temperature is 50 ℃, the pressure is 3MPa, and the volume space velocity is 150h ^-1 To obtain C4 alkane material flow;

wherein, the content of unsaturated hydrocarbon in the C4 alkane material flow is 5.8wt percent, and the content of C4 alkane is 80wt percent.

Example 4

The process of example 1 is followed except that in step d, the unsaturated hydrocarbon-rich stream is not pretreated, i.e., the mixture comprising the unsaturated hydrocarbon-rich stream and the recycle stream is directly subjected to a first-stage total hydrogenation reaction and a second-stage total hydrogenation reaction with hydrogen to obtain a C4 alkane stream.

Wherein, the content of unsaturated hydrocarbon in the C4 alkane material flow is 8.5wt percent, and the content of C4 alkane is 70wt percent.

Comparative example 1

The hydrogenation unit for the mixed C4 stream differs from example 1.

(1) In a selective hydrogenation catalyst (active components are palladium and silver, a carrier is alumina, the weight of the selective hydrogenation catalyst is taken as a reference, the content of the palladium is 0.2 weight percent, the content of the silver is 10 weight percent, and the specific surface area of the alumina is 150m ² Per g, average pore diameter of 200nm, pore volume of 0.8 mL/g) of a mixed C4 stream having an alkyne content of 1 wt.% (ethylene cracker) with hydrogenCarrying out selective hydrogenation reaction in a fixed bed reactor, wherein the molar ratio of the mixed C4 material flow to the hydrogen is 1: the temperature is 38 ℃, the pressure is 1.2MPa, and the volume space velocity is 100h ^-1 To obtain selective hydrogenation products;

(2) The selective hydrogenation product is used as an extraction raw material and enters a gas-liquid separation device, gas-liquid separation is carried out by adopting a rectification method, a small amount of gas phase tail gas such as hydrogen, methane and the like is obtained at the tower top, the number of theoretical plates is 30, the temperature at the tower top is 13.7 ℃, the pressure is 0.6MPa, the temperature at the tower bottom is 73 ℃, the mass reflux ratio is 30, and the four carbon fractions discharged from the tower bottom enter the extraction device;

(3) Taking N-methyl pyrrolidone solution as an extracting agent to obtain butadiene material flow, wherein the yield of butadiene is 98.5%, and feeding the obtained unsaturated hydrocarbon-rich material flow into a full hydrogenation unit for full hydrogenation reaction;

(4) In the full hydrogenation catalyst (active components are palladium and silver, a carrier is alumina, based on the weight of the selective hydrogenation catalyst, the content of the palladium is 0.5wt%, the content of the silver is 1.5wt%, and the specific surface area of the alumina is 250m ² Per g, average pore diameter of 200nm and pore volume of 0.5 mL/g) with hydrogen, wherein the conditions of the first-stage full hydrogenation reaction comprise: the molar ratio of the unsaturated hydrocarbon-rich stream to hydrogen is 1.68, the temperature is 40 ℃, the pressure is 2.4MPa, and the volume space velocity is 150h ^-1 And carrying out a second-stage total hydrogenation reaction on the obtained first-stage total hydrogenation product and hydrogen, wherein the conditions of the second-stage total hydrogenation reaction comprise: the mol ratio of the first-stage full hydrogenation product to hydrogen is 1.22, the temperature is 40 ℃, the pressure is 2.2MPa, and the volume space velocity is 150h ^-1 To obtain C4 alkane material flow;

wherein the C4 alkane stream has an unsaturated hydrocarbon content of 6.2wt% and a C4 alkane content of 76wt%.

Comparative example 2

The process of example 1 is followed except that the condensate containing butene and C4 acetylenes obtained in step b is not returned and mixed into the mixed C4 stream.

Wherein the butadiene stream has a 1, 3-butadiene content of 95wt% and a butadiene yield of 96%; the unsaturated hydrocarbon content of the unsaturated hydrocarbon-rich stream is 25wt%;

the C4 alkane stream had an unsaturated hydrocarbon content of 4.8wt% and a C4 alkane content of 88wt%.

Comparative example 3

The process of example 1 is followed except that the hydrogenation unit without step b, i.e., the mixed C4 stream, comprises a dividing wall column having a partition into a selective hydrogenation zone and a butadiene extraction zone and a total hydrogenation unit, that is, the dividing wall column is free of an external condenser for condensation.

Wherein the butadiene stream has a 1, 3-butadiene content of 93wt% and a butadiene yield of 94%; the unsaturated hydrocarbon content in the unsaturated hydrocarbon-rich stream was 28wt%;

the C4 alkane stream had an unsaturated hydrocarbon content of 5.1wt% and a C4 alkane content of 86wt%.

Comparing the examples with the comparative examples, it can be seen that the hydrogenation device for the mixed C4 material flow provided by the invention adopts a dividing wall tower which is externally condensed and is divided into a selective hydrogenation area and a butadiene extraction area, and simultaneously realizes the selective hydrogenation and butadiene extraction of the mixed C4 material flow, thereby reducing the process flow and improving the yield of butadiene; and the total hydrogenation unit is combined, so that the yield of the C4 alkane in the C4 alkane material flow is improved.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including various technical features being combined in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A hydrogenation unit for a mixed C4 stream, the unit comprising: the device comprises a dividing wall tower and a full-hydrogenation unit, wherein the dividing wall tower comprises a shell and a condenser, a partition plate parallel to the central axis of the shell is arranged in the shell, the partition plate is connected with the top of the dividing wall tower and the tower wall and is not connected with the bottom of the dividing wall tower, and the partition plate divides the interior of the shell into a selective hydrogenation zone and a butadiene extraction zone;

2. The apparatus of claim 1, wherein the selective hydrogenation zone is further provided with an extract inlet, a mixed C4 stream inlet, and a hydrogen inlet.

3. The apparatus of claim 2, wherein the extract inlet and the mixed C4 stream inlet are each independently disposed above the hydrogen inlet.

4. The apparatus of claim 2, wherein the height ratio of the bed of selective hydrogenation catalyst to the selective hydrogenation zone is from 0.4 to 0.9:1.

5. the apparatus of claim 2, wherein the height ratio of the bed of selective hydrogenation catalyst to the selective hydrogenation zone is from 0.6 to 0.8:1.

6. the apparatus of claim 2, wherein the bed of selective hydrogenation catalyst is disposed below the mixed C4 stream inlet and the extract inlet and above the hydrogen inlet.

7. The apparatus of any of claims 1-6, wherein the ratio of the radii of the selective hydrogenation zone to the butadiene extraction zone is from 0.5 to 1.5:1.

8. the apparatus of claim 7, wherein the ratio of the radii of the selective hydrogenation zone to the butadiene extraction zone is from 0.8 to 1.2:1.

9. the apparatus of claim 7, wherein the ratio of the height of the partition to the divided wall column is from 0.5 to 0.9:1.

10. the apparatus of claim 7, wherein the ratio of the height of the partition to the divided wall column is from 0.7 to 0.9:1.

11. the apparatus of any of claims 1-6, wherein the perhydrogenation unit comprises at least one perhydrogenation zone in series.

12. The apparatus of claim 11, wherein the total hydrogenation unit comprises a primary total hydrogenation zone and a secondary total hydrogenation zone; the first-stage full hydrogenation zone is used for carrying out first-stage full hydrogenation reaction on the unsaturated hydrocarbon-rich material flow and hydrogen to obtain a first-stage full hydrogenation product; and the second-stage full hydrogenation zone is used for carrying out second-stage full hydrogenation reaction on the first-stage full hydrogenation product and hydrogen to obtain a C4 alkane material flow with the unsaturated hydrocarbon content of less than 10wt%.

13. The apparatus of claim 12, wherein the outlet of the second-stage total hydrogenation zone is connected to the inlet of the first-stage total hydrogenation zone for returning a C4 alkane stream having an unsaturated hydrocarbon content of 10wt% or more to the first-stage total hydrogenation zone.

14. A process for the hydrogenation of a mixed C4 stream, characterized in that the process comprises the steps of:

wherein the method is carried out in an apparatus according to any one of claims 1 to 13.

15. The process of claim 14, wherein the alkyne is present in an amount of from 0.5 to 10wt% based on the weight of the mixed C4 stream.

16. The process of claim 15, wherein the alkyne is present in an amount of from 0.6 to 3wt% based on the weight of the mixed C4 stream.

17. The method of claim 15, wherein the mixed C4 stream is from at least one of a butadiene extraction unit and a hydrocarbon steam cracking unit.

18. The method of any of claims 14-17, wherein the molar ratio of the mixed C4 stream to hydrogen is 1:0.5-5.5.

19. The method of claim 18, wherein the molar ratio of the mixed C4 stream to hydrogen is from 1:0.5-1.5.

20. The method of claim 18, wherein the extraction fluid is an aqueous solution containing an extractant; the water content in the extract is 1-20wt%.

21. The method as claimed in claim 20, wherein the water content of the extract is 5-15wt%.

22. The process of claim 20, wherein the extractant is selected from at least one of N-methylpyrrolidone, acetonitrile, furfural, formylmorpholine, dimethylacetamide, and dimethylformamide.

23. The method of claim 18, wherein the conditions of the selective hydrogenation reaction comprise: the temperature is 20-80 ℃; the pressure is 0.6-5MPa; the volume space velocity is 5-200h ^-1 。

24. The method of claim 18, wherein the conditions of the selective hydrogenation reaction comprise: the temperature is 30-80 ℃; the pressure is 1-4MPa; the volume space velocity is 10-200h ^-1 。

25. The method of claim 18, wherein the conditions of the extraction comprise: the number of theoretical plates is 50-95; the pressure is 0.1-1MPa; the temperature of the tower top is 25-60 ℃; the temperature of the tower kettle is 120-150 ℃.

26. The method of claim 18, wherein the conditions of the extraction comprise: the theoretical plate number is 60-85; the pressure is 0.5-0.6MPa; the temperature of the tower top is 35-50 ℃; the temperature of the tower kettle is 125-145 ℃.

27. The process of any of claims 14-17, wherein the selective hydrogenation catalyst comprises a first active component and a first support; the first active component contains a first main active component and optionally a first co-active component.

28. The process of claim 27, wherein the first primary active component is present in an amount of from 0.01 to 5wt%, based on the weight of the selective hydrogenation catalyst; the content of the first auxiliary active component is 0-25wt%.

29. The process of claim 27, wherein the first major active component is present in an amount of from 0.1 to 1.5wt%, based on the weight of the selective hydrogenation catalyst; the content of the first auxiliary active component is 0-12wt%.

30. The process of claim 27, wherein the butadiene stream has a 1, 3-butadiene content of from 80 to 99.9wt%.

31. The process of claim 27, wherein the butadiene stream has a 1, 3-butadiene content of from 99 to 99.9wt%.

32. The process of claim 27, wherein the butadiene stream has a butadiene yield of 99% or more.

33. The process of claim 27, wherein the butadiene yield in the butadiene stream is from 99.01 to 99.2%.

34. The process according to claim 27, wherein the unsaturated hydrocarbon-rich stream has an unsaturated hydrocarbon content of from 10 to 40wt%.

35. The process according to claim 27, wherein the unsaturated hydrocarbon-rich stream has an unsaturated hydrocarbon content of from 15 to 25wt%.

36. The process according to any one of claims 14 to 17, wherein the molar ratio of the unsaturated hydrocarbon-rich stream to hydrogen is from 1:0.2-4.5.

37. The method of claim 36, wherein the molar ratio of the unsaturated hydrocarbon-rich stream to hydrogen is from 1:0.2-1.5.

38. The process of claim 36, wherein the conditions of the total hydrogenation reaction comprise: the temperature is 10-90 ℃; the pressure is 1-10MPa; the volume space velocity is 5-300h ^-1 。

39. The process of claim 36, wherein the conditions of the total hydrogenation reaction comprise: the temperature is 20-80 ℃; the pressure is 1-4MPa; the volume space velocity is 10-200h ^-1 。

40. The process of claim 36, wherein the total hydrogenation catalyst comprises a second active component and a second support; the second active component comprises a second main active component and optionally a second co-active component.

41. The process of claim 40, wherein the second primary active component is present in an amount of from 0.01 to 5wt%, based on the weight of the total hydrogenation catalyst; the content of the second auxiliary active component is 0-15wt%.

42. The process of claim 40, wherein the second major active component is present in an amount of 0.1 to 2wt% based on the weight of the total hydrogenation catalyst; the content of the second auxiliary active component is 0.05-10wt%.

43. The method of claim 36, wherein the C4 alkane stream has an unsaturated hydrocarbon content of from 0.02 wt% to 0.5wt%.

44. The method of claim 36, wherein the yield of C4 alkanes in the C4 alkane stream is 60-95%.

45. The method of claim 36, wherein the yield of C4 alkanes in the C4 alkane stream is from 82 to 95%.

46. The process of any one of claims 14-17, wherein the total hydrogenation reaction comprises a one-stage total hydrogenation reaction and a two-stage total hydrogenation reaction; the first-stage full hydrogenation reaction comprises contacting the unsaturated hydrocarbon-rich stream with hydrogen to obtain a first-stage full hydrogenation product; the second-stage full hydrogenation reaction comprises the step of contacting the first-stage full hydrogenation product with hydrogen to obtain a C4 alkane material flow with the unsaturated hydrocarbon content of less than 10wt%.

47. The method of claim 46, further comprising: a stream of C4 paraffins having an unsaturated hydrocarbon content of 10 wt.% or more is returned and mixed into the unsaturated hydrocarbon-rich stream.