Skid-mounted CO2 floodback exhaust gas desulfurization, dehydration and CO2 recovery system

Abstract

The present invention provides a skid-mounted carbon dioxide drive return exhaust gas desulfurization, dehydration and carbon dioxide recovery system, which includes a return exhaust gas pretreatment and desulfurization skid, a cold drying skid, a compressor membrane inlet skid, a membrane separation skid, and a carbon dioxide pressurization reinjection skid; the cold drying skid is connected to the return exhaust gas pretreatment and desulfurization skid; the compressor membrane inlet skid is connected to the cold drying skid; the membrane separation skid is connected to the compressor membrane inlet skid; the carbon dioxide pressurization reinjection skid is connected to the membrane separation skid; wherein the return exhaust gas enters the return exhaust gas pretreatment and desulfurization skid for pretreatment and desulfurization, and then enters the cold drying skid for dehydration treatment, the return exhaust gas after dehydration enters the compressor membrane inlet skid for pressurization treatment, and the pressurized return exhaust gas enters the membrane separation skid for gas separation. The skid-mounted design of the skid-mounted carbon dioxide drive return exhaust gas desulfurization, dehydration and carbon dioxide recovery system of the present invention is convenient to install and operate, and is convenient for processing return exhaust gas with a small gas volume.

Description

Technical Field

[0001] The present invention relates to the field of carbon dioxide recovery, and in particular to a skid-mounted carbon dioxide drive-back exhaust gas desulfurization and dehydration and carbon dioxide recovery system. Background Art

[0002] With the large-scale promotion of CO2-driven tertiary oil recovery technology, the surface process of CO2-driven produced liquid faces some difficulties: after CO2 is injected into the ground, about 50% to 60% is permanently sealed underground, and the remaining 40% to 50% overflows with the return gas of the oilfield produced liquid. Since the return gas of CO2-driven produced liquid contains more CO2, the return gas of CO2-driven produced liquid cannot enter the gathering and transportation pipeline network or be ignited without necessary treatment, and can only be discharged directly, which not only pollutes the environment, but also wastes natural gas and CO2 resources, and reduces the effect of CO2 flooding and storage. The recovery and utilization of CO2 in the return gas of CO2-driven produced liquid in the oil field can not only protect the environment, but also utilize resources and improve economic benefits. Reasonable recovery and utilization of the return gas resources of CO2-driven produced liquid will be a trend in my country's future development.

[0003] For single-well CO2 flooding projects, the amount of gas returned in the produced fluid is small, and the traditional amine method of desulfurization and decarbonization requires large investment, high operating costs, and is not economical. Summary of the invention

[0004] In view of the problems existing in the background technology, the purpose of the present invention is to provide a skid-mounted carbon dioxide drive return exhaust gas desulfurization, dehydration and carbon dioxide recovery system, which can process the return exhaust gas and separate carbon dioxide from natural gas, thereby effectively utilizing natural gas and recovering carbon dioxide. The skid-mounted design is convenient for processing return exhaust gas with a small gas volume, thereby reducing the processing cost of the return exhaust gas.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a skid-mounted carbon dioxide drive return exhaust gas desulfurization, dehydration and carbon dioxide recovery system, which includes a return exhaust gas pretreatment and desulfurization skid, a cold drying skid, a compressor membrane inlet skid, a membrane separation skid, and a carbon dioxide pressurization reinjection skid. The cold drying skid is connected to the return exhaust gas pretreatment and desulfurization skid through a pipeline; the compressor membrane inlet skid is connected to the cold drying skid through a pipeline; the membrane separation skid is connected to the compressor membrane inlet skid through a pipeline; the carbon dioxide pressurization reinjection skid is connected to the membrane separation skid through a pipeline. Among them, the return exhaust gas first enters the return exhaust gas pretreatment and desulfurization skid for pretreatment and desulfurization, and the return exhaust gas after pretreatment and desulfurization enters the cold drying skid to be dehydrated in the cold drying skid. The return exhaust gas after dehydration enters the compressor membrane inlet skid to be pressurized, and the pressurized return exhaust gas enters the membrane separation skid for gas separation to separate carbon dioxide and hydrocarbon gas. The separated carbon dioxide enters the carbon dioxide pressurization reinjection skid for pressurization reinjection, and the hydrocarbon gas is used as natural gas.

[0006] In one embodiment, the return exhaust gas pretreatment and desulfurization skid includes a first gas-liquid separator, a first particle filter, an activated carbon tower, and at least one stage of desulfurization tower.

[0007] The first gas-liquid separator includes: a first gas-liquid separator inlet; a first gas-liquid separator first outlet; and a first gas-liquid separator second outlet, which is used to communicate with an external sewage tank.

[0008] The first particle filter comprises: a first particle filter inlet, connected to the first outlet of the first gas-liquid separator; a first particle filter first outlet; and a first particle filter second outlet, used to be connected to an external sewage tank.

[0009] The activated carbon tower comprises: an activated carbon tower inlet connected to a first outlet of a first particle filter; a first outlet of the activated carbon tower; and a second outlet of the activated carbon tower connected to an external sewage tank.

[0010] The primary desulfurization tower includes: a primary desulfurization tower inlet, connected to the first outlet of the activated carbon tower; the first outlet of the primary desulfurization tower, connected to the cold-drying skid; and the second outlet of the primary desulfurization tower, used to connect to an external sewage tank.

[0011] Among them, the return exhaust gas enters the first gas-liquid separator through the first gas-liquid separator inlet for gas-liquid separation and forms separated gas and liquid, and the liquid enters the sewage tank through the second outlet of the first gas-liquid separator; the separated gas enters the first particle filter through the first outlet of the first gas-liquid separator and the first particle filter inlet for filtration, so as to perform initial filtration on the solid impurity particles mixed in the separated gas, and the filtered solid impurity particles are discharged into the sewage tank through the second outlet of the first particle filter, and the filtered separated gas enters the activated carbon tower through the first outlet of the first particle filter and the inlet of the activated carbon tower for heavy hydrocarbon removal, and the removed heavy hydrocarbons are discharged into the sewage tank through the second outlet of the activated carbon tower, and the separated gas with heavy hydrocarbon removal at least partially enters the primary desulfurization tower through the first outlet of the activated carbon tower and the inlet of the primary desulfurization tower for desulfurization, and the removed sulfur-containing wastewater flows into the sewage tank through the second outlet of the primary desulfurization tower, and the desulfurized separated gas flows into the cold drying skid through the first outlet of the desulfurization tower to carry out the next operation.

[0012] In one embodiment, the return gas pretreatment and desulfurization skid further includes a secondary desulfurization tower, and the secondary desulfurization tower includes: a secondary desulfurization tower inlet, connected to the first outlet of the activated carbon tower and the first outlet of the primary desulfurization tower; the first outlet of the secondary desulfurization tower, connected to the cold-drying skid; and the second outlet of the secondary desulfurization tower, used to connect to an external sewage pool. Among them, at least part of the separated gas discharged through the first outlet of the activated carbon tower enters the secondary desulfurization tower through the secondary desulfurization tower inlet for desulfurization treatment, and the separated gas discharged through the first outlet of the primary desulfurization tower enters the secondary desulfurization tower again through the secondary desulfurization tower inlet for secondary desulfurization, and the separated gas after desulfurization flows into the cold-drying skid through the first outlet of the secondary desulfurization tower, and the sulfur-containing wastewater removed by the secondary desulfurization tower flows into the sewage pool through the second outlet of the secondary desulfurization tower.

[0013] In one embodiment, the return exhaust gas pretreatment and desulfurization skid further includes: a shut-off valve, which is arranged on the upstream pipeline of the first gas-liquid separator inlet and is used to control the opening and closing of the upstream pipeline of the first gas-liquid separator inlet.

[0014] In one embodiment, the cold-drying skid comprises a cold dryer, a second gas-liquid separator and a second particle filter.

[0015] The cold dryer includes: a cold dryer inlet, connected to the first outlet of the primary desulfurization tower and the first outlet of the secondary desulfurization tower; a cold dryer first outlet; and a cold dryer second outlet, used to connect to an external sewage tank.

[0016] The second gas-liquid separator includes: a second gas-liquid separator inlet connected to the first outlet of the cold dryer; a second gas-liquid separator first outlet; and a second gas-liquid separator second outlet connected to an external sewage tank.

[0017] The second particle filter comprises: a second particle filter inlet connected to the first outlet of the second gas-liquid separator; a second particle filter first outlet connected to the compressor membrane inlet skid; and a second particle filter second outlet connected to an external sewage tank.

[0018] Among them, the desulfurized separation gas discharged from the primary desulfurization tower and the secondary desulfurization tower enters the cold dryer through the cold dryer inlet for dehydration treatment, the dehydrated separation gas enters the second gas-liquid separator through the first outlet of the cold dryer and the second gas-liquid separator inlet for gas-liquid separation, the separated gas enters the second particle filter through the first outlet of the second gas-liquid separator and the second particle filter inlet to further remove solid impurity particles in the gas, the removed solid impurity particles are discharged into the sewage pool, and the gas filtered by the second particle filter flows into the compressor membrane inlet skid through the first outlet of the second particle filter for further operation.

[0019] In one embodiment, the compressor membrane inlet skid includes a first compressor. The first compressor includes: a first compressor inlet, connected to the first outlet of the second particle filter; a first compressor first outlet; a first compressor second outlet, used to connect to an external sewage tank. The gas discharged through the first outlet of the second particle filter enters the first compressor through the first compressor inlet, the gas is compressed and pressurized by the first compressor, and then enters the membrane separation skid through the first outlet of the first compressor for further operation.

[0020] In one embodiment, the membrane separation skid comprises a filter assembly, an electric heater, a primary membrane tube, and a secondary membrane tube.

[0021] The filter assembly includes a third particle filter and a fourth particle filter, which are sequentially arranged downstream of the first outlet of the first compressor. The third particle filter includes: a third particle filter inlet, connected to the first outlet of the first compressor; a third particle filter first outlet; a third particle filter second outlet, used to connect to an external sewage tank. The fourth particle filter includes: a fourth particle filter inlet, connected to the first outlet of the third particle filter; a fourth particle filter first outlet; a fourth particle filter second outlet, used to connect to an external sewage tank.

[0022] The electric heater comprises: an electric heater inlet connected to the fourth particle filter outlet; and an electric heater outlet.

[0023] The primary membrane tube comprises: a primary membrane tube inlet connected to the electric heater outlet; a primary membrane tube low-pressure outlet connected to the first compressor inlet; and a primary membrane tube high-pressure outlet.

[0024] The secondary membrane tube includes: a secondary membrane tube inlet, connected to the primary membrane tube high-pressure outlet; a secondary membrane tube low-pressure outlet, connected to the carbon dioxide pressurization reinjection skid; and a secondary membrane tube high-pressure outlet, used to connect to an external natural gas pipeline.

[0025] The pressurized gas discharged through the first outlet of the first compressor enters the third particulate filter and the fourth particulate filter in sequence for filtration, the filtered gas enters the electric heater through the inlet of the electric heater for gasification treatment, and then is discharged through the outlet of the electric heater, the discharged gas first undergoes primary separation treatment in the primary membrane tube, and then enters the secondary membrane tube for secondary separation to separate the carbon dioxide from the hydrocarbon gas in the gas, the separated carbon dioxide enters the carbon dioxide pressurization reinjection skid through the low-pressure outlet of the secondary membrane tube; the separated hydrocarbon gas directly enters the external natural gas pipeline.

[0026] In one embodiment, the membrane separation skid further comprises a second gas analyzer, wherein the first membrane tube low pressure outlet, the first membrane tube high pressure outlet, the second membrane tube low pressure outlet, and the second membrane tube high pressure outlet are respectively connected to the second gas analyzer.

[0027] In one embodiment, two compressor membrane inlet skids are provided; correspondingly, two membrane separation skids are provided, each membrane separation skid is communicated with two compressor membrane inlet skids respectively, and each membrane separation skid is communicated with a carbon dioxide pressurization reinjection skid.

[0028] In one embodiment, the carbon dioxide pressurization and reinjection skid includes a second compressor, and the second compressor includes: a second compressor inlet; a second compressor first outlet for discharging carbon dioxide; and a second compressor second outlet for connecting to an external sewage tank. The gas separated by the secondary membrane tube low-pressure outlet of each membrane separation skid enters the second compressor from the second compressor inlet for compression, and the compressed carbon dioxide is discharged through the second compressor first outlet for further processing.

[0029] The beneficial effects of the present invention are as follows:

[0030] In the skid-mounted carbon dioxide drive return exhaust gas desulfurization and dehydration and carbon dioxide recovery system according to the present invention, the carbon dioxide drive return exhaust gas is processed through return exhaust gas pretreatment and desulfurization skid, cold drying skid, compressor membrane skid, membrane separation skid, and carbon dioxide pressurization and reinjection skid, forming the steps of pretreatment, desulfurization, cold drying and dehydration, pressurization, and membrane decarbonization of the return exhaust gas, effectively separating and extracting carbon dioxide and hydrocarbon gas (natural gas) in the return exhaust gas, so that the carbon dioxide in the return exhaust gas is recovered and effectively utilized, avoiding direct discharge into the atmosphere to pollute the environment, and the extracted natural gas is used for fuel combustion, preventing energy waste; in addition, the skid-mounted and modular design of the skid-mounted carbon dioxide drive return exhaust gas desulfurization and dehydration and carbon dioxide recovery system of the present invention makes the system simple and easy to install and operate, and is convenient for processing return exhaust gas with a small gas volume, thereby reducing the processing cost of the return exhaust gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The invention relates to a skid-mounted carbon dioxide drive-back exhaust gas desulfurization, dehydration and carbon dioxide recovery system.

[0032] The reference numerals are described as follows:

[0033] A Return exhaust gas pretreatment and desulfurization skid 20A First compressor inlet

[0034] 11 First gas-liquid separator 20B1 First compressor first outlet

[0035] 11A First gas-liquid separator inlet 20B2 First compressor second outlet

[0036] 11B1 First gas-liquid separator first outlet D membrane separation skid

[0037] 21 filter components

[0038] 11B2 First gas-liquid separator second outlet 211 Third particle filter 211A Third particle filter inlet 12 First particle filter

[0039] 12A First particle filter inlet 211B1 Third particle filter first outlet 12B1 First particle filter first outlet

[0040] 211B2 Third particle filter second outlet 12B2 First particle filter Second outlet 212 Fourth particle filter

[0041] 13First-stage desulfurization tower 212A fourth particle filter inlet 13A primary desulfurization tower entrance

[0042] 13B1 First outlet of primary desulfurization tower 212B1 First outlet of fourth particle filter 13B2 Second outlet of primary desulfurization tower

[0043] 14 Secondary desulfurization tower 212B2 Fourth particle filter second outlet 14A Secondary desulfurization tower entrance

[0044] 14B1 Secondary desulfurization tower first outlet 22 electric heater

[0045] 14B2 Secondary desulfurization tower second outlet 22A electric heater inlet

[0046] 15 Flow meter 22B electric heater outlet B cold dry skid 23 first level membrane tube

[0047] 16 Cold dryer 23A primary membrane tube inlet

[0048] 16A cold dryer inlet 23B1 first-level membrane tube low-pressure outlet

[0049] 16B1 cold dryer first outlet 23B2 first-level membrane tube high pressure outlet

[0050] 16B2 cold dryer second outlet 24 secondary membrane tube

[0051] 17 Second gas-liquid separator 24A secondary membrane tube inlet

[0052] 17A Second gas-liquid separator inlet 24B1 Secondary membrane tube low pressure outlet

[0053] 17B1 The first outlet of the second gas-liquid separator 24B2 The high-pressure outlet of the secondary membrane tube 25 Second Gas Analyzer

[0054] 17B2 Second gas-liquid separator second outlet E CO2 booster re-injection skid 26 Second compressor

[0055] 18 Second particulate filter 26A Second compressor inlet

[0056] 18A Second particulate filter inlet 26B1 Second compressor first outlet

[0057] 18B1 Second particle filter first outlet 26B2 Second compressor second outlet 27 Activated carbon tower

[0058] 18B2 Second particle filter second outlet 27A Activated carbon tower inlet 27B1 Activated Carbon Tower First Exit

[0059] 19 First gas analyzer 27B2 active tower second outlet C Compressor membrane inlet skid 28 cut-off valve

[0060] 20First compressor DETAILED DESCRIPTION

[0061] Reference Figure 1 The skid-mounted carbon dioxide drive return exhaust gas desulfurization, dehydration and carbon dioxide recovery system according to the present invention includes a return exhaust gas pretreatment and desulfurization skid A, a cold drying skid B, a compressor membrane feed skid C, a membrane separation skid D, and a carbon dioxide pressurization reinjection skid E. The cold drying skid B is connected to the return gas pretreatment and desulfurization skid A through a pipeline; the compressor membrane inlet skid C is connected to the cold drying skid B through a pipeline; the membrane separation skid D is connected to the compressor membrane inlet skid C through a pipeline; the carbon dioxide boosting and reinjection skid E is connected to the membrane separation skid D through a pipeline; wherein the return gas first enters the return gas pretreatment and desulfurization skid A for pretreatment and desulfurization, and the return gas after pretreatment and desulfurization enters the cold drying skid B to be dehydrated in the cold drying skid B, the return gas after dehydration enters the compressor membrane inlet skid C to be pressurized, and the pressurized return gas enters the membrane separation skid D for gas separation to separate carbon dioxide and hydrocarbon gas, and the separated carbon dioxide enters the carbon dioxide boosting and reinjection skid E for boosting and reinjection, and the hydrocarbon gas is used as natural gas. In one embodiment, the return gas comes from the top outlet of the three-phase separator (not shown) at the wellhead of the carbon dioxide flooding oil production well.

[0062] It should be noted that skids are skid-mounted equipment, which is to assemble equipment (gas-liquid separators, particle separators, compressors, desulfurization towers, etc. described below), pipelines, valves, instruments, etc. on a steel structure base to form an integrated device that can independently, completely and accurately achieve a certain function. The manufacturing and assembly of skids can be carried out in the factory, and after prefabrication, they are transported to the site for installation.

[0063] In the skid-mounted carbon dioxide drive return exhaust gas desulfurization, dehydration and carbon dioxide recovery system according to the present invention, the carbon dioxide drive return exhaust gas is treated by return exhaust gas pretreatment and desulfurization skid A, cold drying skid B, compressor membrane skid C, membrane separation skid D, and carbon dioxide pressurization reinjection skid E, forming the steps of pretreatment, desulfurization, cold drying and dehydration, pressurization, and membrane decarbonization of the return exhaust gas, effectively separating and extracting carbon dioxide and hydrocarbon gas (natural gas) in the return exhaust gas, so that the carbon dioxide in the return exhaust gas is recovered and effectively utilized, avoiding direct discharge into the atmosphere to pollute the environment, and the extracted natural gas is used for fuel combustion, preventing energy waste; in addition, compared with traditional on-site installation equipment that requires equipment procurement, on-site installation and commissioning, the skid-mounted carbon dioxide drive return exhaust gas desulfurization and dehydration system according to the present invention is simple and convenient to use. The skid-mounted and modular design of the water and carbon dioxide recovery system makes the system simple and easy to install and operate. It only needs to be installed and debugged between the skid blocks, which reduces the on-site construction costs and greatly reduces the amount of engineering on-site construction work involved in the return gas treatment process. In addition, when problems occur in the system, the skid-mounted design only requires maintenance and debugging of the corresponding skid blocks, without the need to inspect and repair the entire system, thereby improving the stability and reliability of the system movement, facilitating system maintenance and management, and reducing the operating cost of the equipment. Furthermore, when the return gas comes from a single-well CO2 flooding project, the amount of the return gas is small. If traditional amine-based desulfurization and decarbonization are used, the investment is large, the operating cost is high, and it is not economical. The skid-mounted system of the present invention is convenient for processing the return gas with a small amount of gas, thereby reducing the processing cost of the return gas.

[0064] It should be noted that the return gas from the top outlet of the three-phase separator at the wellhead of the carbon dioxide-driven oil well is mainly composed of hydrocarbons such as methane, and often contains acidic substances such as hydrogen sulfide. Sulfide is corrosive and can easily cause corrosion and blockage of the pipeline during the subsequent return gas transportation process. In addition, if sulfide is mixed in the return gas, when the membrane method is used to separate carbon dioxide from the return gas, the presence of sulfide will cause the membrane tube to be unable to separate carbon dioxide. Furthermore, hydrogen sulfide is toxic and harmful. The hydrogen sulfide content in the natural gas standard stipulated by the state should be less than a certain value (20 mg / Nm3). Therefore, due to the above reasons, the return gas needs to be desulfurized; in addition, the return gas also contains many liquid and solid impurities such as oilfield chemicals and particulate matter. These liquid or solid impurities will have a serious adverse effect on the performance of the membrane (primary membrane tube and secondary membrane tube) when the membrane method is used for subsequent decarbonization. Therefore, before using the membrane method for decarbonization, the return gas needs to be pretreated, dehydrated, and solid impurities removed.

[0065] The return exhaust gas pretreatment and desulfurization skid A comprises a first gas-liquid separator 11, a first particle filter 12, an activated carbon tower 27, and at least one stage of desulfurization tower.

[0066] The first gas-liquid separator 11 comprises: a first gas-liquid separator inlet 11A; a first gas-liquid separator first outlet 11B1; and a first gas-liquid separator second outlet 11B2, which are used to communicate with an external sewage tank.

[0067] The first particle filter 12 comprises a first particle filter inlet 12A, connected to the first gas-liquid separator first outlet 11B1; a first particle filter first outlet 12B1; and a first particle filter second outlet 12B2, for connecting to an external sewage tank.

[0068] The activated carbon tower 27 includes: an activated carbon tower inlet 27A, connected to the first outlet 12B1 of the first particle filter; an activated carbon tower first outlet 27B1; and an activated carbon tower second outlet 27B2, which is used to connect to an external sewage tank.

[0069] The primary desulfurization tower 13 includes: a primary desulfurization tower inlet 13A, connected to the first outlet 27B1 of the activated carbon tower; a primary desulfurization tower first outlet 13B1, connected to the cold-drying skid B; and a primary desulfurization tower second outlet 13B2, used to connect to an external sewage tank.

[0070] The return exhaust gas enters the first gas-liquid separator 11 through the first gas-liquid separator inlet 11A for gas-liquid separation and forms separated gas and liquid (sewage and oil), and the liquid flows into the sewage tank through the first gas-liquid separator second outlet 11B2; the separated gas enters the first particle filter 12 through the first gas-liquid separator first outlet 11B1 and the first particle filter inlet 12A for filtration, so as to filter the solid impurity particles mixed in the separated gas for the first time, and the filtered solid impurity particles are discharged into the sewage tank through the first particle filter second outlet 12B2, and the filtered solid impurity particles are discharged into the sewage tank. The separated gas enters the activated carbon tower 27 through the first outlet 12B1 of the first particulate filter and the inlet 27A of the activated carbon tower to remove heavy hydrocarbons, and the removed heavy hydrocarbons are discharged into the sewage pool through the second outlet 27B2 of the activated carbon tower. The separated gas from which heavy hydrocarbons are removed at least partially enters the primary desulfurization tower 13 through the first outlet 27B1 of the activated carbon tower and the inlet 13A of the primary desulfurization tower for desulfurization, and the removed sulfur-containing wastewater flows into the sewage pool through the second outlet 13B2 of the primary desulfurization tower. The desulfurized separated gas flows into the cold drying skid B through the first outlet 13B1 of the desulfurization tower for the next operation.

[0071] The first gas-liquid separator 11 is set to effectively perform preliminary separation of liquids such as chemical agents and at least part of heavy hydrocarbons in the return gas, while the first particle filter 12 effectively performs the first filtering of solid impurity particles mixed in the return gas; the primary desulfurization tower 13 can remove sulfides such as hydrogen sulfide in the return gas. The first gas-liquid separator 11, the first particle filter 12, the activated carbon tower 27 and the primary desulfurization tower 13 realize the pretreatment of the return gas, which is convenient for the subsequent removal of carbon dioxide from the return gas by membrane separation.

[0072] Preferably, in one embodiment, the return exhaust gas pretreatment and desulfurization skid A also includes a secondary desulfurization tower 14, and the secondary desulfurization tower 14 includes: a secondary desulfurization tower inlet 14A, connected to the first outlet 27B1 of the activated carbon tower and the first outlet 13B1 of the primary desulfurization tower; the first outlet 14B1 of the secondary desulfurization tower, connected to the cold-drying skid B; and the second outlet 14B2 of the secondary desulfurization tower, used to connect to an external sewage tank.

[0073] Among them, at least part of the separated gas discharged through the first outlet 27B1 of the activated carbon tower enters the secondary desulfurization tower 14 through the secondary desulfurization tower inlet 14A for desulfurization treatment, and the separated gas discharged through the first outlet 13B1 of the primary desulfurization tower enters the secondary desulfurization tower 14 again through the secondary desulfurization tower inlet 14A for secondary desulfurization, and the desulfurized separated gas flows into the cold drying skid B through the first outlet 14B1 of the secondary desulfurization tower, and the sulfur-containing wastewater removed by the secondary desulfurization tower 14 flows into the sewage pool through the second outlet 14B2 of the secondary desulfurization tower. In one embodiment, the primary desulfurization tower 13 and the secondary desulfurization tower 14 are respectively equipped with a large sulfur capacity ferric hydroxide desulfurizer. The setting of the secondary desulfurization tower 14 can ensure that the sulfide and other acidic gases are fully removed from the return exhaust gas, and the secondary desulfurization tower inlet 14A of the secondary desulfurization tower 14 is connected to the first outlet 27B1 of the activated carbon tower, and is in parallel with the primary desulfurization tower 13, thereby improving the desulfurization efficiency; in addition, the secondary desulfurization tower inlet 14A of the secondary desulfurization tower 14 is also connected to the first outlet 13B1 of the primary desulfurization tower, so that the separated gas discharged through the first outlet 27B1 of the activated carbon tower is desulfurized twice in sequence, so that the separated gas is fully and thoroughly desulfurized.

[0074] The return gas pretreatment and desulfurization skid A also includes a shut-off valve 28, which is arranged on the upstream pipeline of the first gas-liquid separator inlet 11A, and is used to control the opening and closing of the upstream pipeline of the first gas-liquid separator inlet 11A. When there is an excessive return gas flow from the top outlet of the three-phase separator or other emergency situations, the shut-off valve 28 can close the upstream pipeline of the first gas-liquid separator inlet 11A in time to protect the safety of the system.

[0075] The return gas pretreatment and desulfurization skid A also includes a flow meter 15, which is arranged on the pipeline between the first particle filter 12 and the activated carbon tower 27, and is used to monitor the flow of the separated gas flowing out through the first outlet 12B1 of the first particle filter. The flow meter 15 is used to measure the flow of the separated gas entering the primary desulfurization tower 13 and the secondary desulfurization tower 14 to prevent the separated gas from being desulfurized incompletely due to excessive flow.

[0076] The first gas-liquid separator 11, the first particle filter 12, the activated carbon tower 27, the primary desulfurization tower 13, the secondary desulfurization tower 14, the flow meter 15, and the shut-off valve 28 are skid-mounted to form a return exhaust gas pretreatment and desulfurization skid A. This skid-mounted design only requires the various parts (the first gas-liquid separator 11, the first particle filter 12, the activated carbon 27, the primary desulfurization tower 13, the secondary desulfurization tower 14, the flow meter 15, the shut-off valve 28, and pipelines) to be assembled in the factory to form an integrated device, which is then transported to the production site for use, thereby simplifying the structural complexity of the equipment required for separating carbon dioxide and natural gas in the return exhaust gas and reducing the installation cost. In addition, the return exhaust gas pretreatment and desulfurization skid A is easy to maintain and manage.

[0077] The cold-drying skid B comprises a cold dryer 16 , a second gas-liquid separator 17 and a second particle filter 18 .

[0078] The cold dryer 16 comprises: a cold dryer inlet 16A, connected to the first outlet 13B1 of the primary desulfurization tower and the first outlet 14B1 of the secondary desulfurization tower; a cold dryer first outlet 16B1; and a cold dryer second outlet 16B2, for connecting to an external sewage tank.

[0079] The second gas-liquid separator 17 comprises: a second gas-liquid separator inlet 17A connected to the first outlet 16B1 of the cold dryer; a second gas-liquid separator first outlet 17B1; and a second gas-liquid separator second outlet 17B2 connected to an external sewage tank.

[0080] The second particle filter 18 comprises: a second particle filter inlet 18A connected to the second gas-liquid separator first outlet 17B1; a second particle filter first outlet 18B1 connected to the compressor membrane inlet skid C; and a second particle filter second outlet 18B2 connected to an external sewage tank.

[0081] Among them, the desulfurized separation gas discharged through the primary desulfurization tower 13 and the secondary desulfurization tower 14 enters the cold dryer 16 through the cold dryer inlet 16A for cold drying and dehydration treatment, and the dehydrated separation gas (the dehydrated separation gas will still carry some small droplets) enters the second gas-liquid separator 17 through the first outlet 16B1 of the cold dryer and the second gas-liquid separator inlet 17A for gas-liquid separation, and the separated gas enters the second particle filter 18 through the first outlet 17B1 of the second gas-liquid separator and the second particle filter inlet 18A to further remove solid impurity particles in the gas, and the removed solid impurity particles are discharged into the sewage pool, and the gas filtered by the second particle filter 18 flows into the compressor membrane inlet skid C through the first outlet 18B1 of the second particle filter for further operation.

[0082] It should be noted that the water content in the return gas will seriously increase the load of the membrane in the primary membrane tube 23 and the secondary membrane tube 24 described below, seriously affecting the selectivity and permeability of the membrane. The cold dryer 16 is used to further dehydrate the separated gas after desulfurization. Under the action of the cold dryer 16, the water vapor carried in the separated gas will condense and convert into small droplets. The small droplets enter the external sewage tank. The setting of the cold dryer 16 further removes the water contained in the separated gas, improves the separation efficiency of the membrane tube described below, and reduces the dew point of the separated gas, which can ensure that the separated gas does not produce condensed liquid when entering the membrane separation skid D; in addition, the setting of the second particle filter 18 can play a role in removing solid particle impurities from the gas entering the membrane separation skid D, and prevent the gas entering the membrane tube from carrying solid particles and affecting the separation performance of the membrane tube.

[0083] The cold drying skid B also includes a first gas analyzer 19, which is disposed between the second outlet 14B2 of the secondary desulfurization tower and the cold dryer 16, and is used to detect the content of sulfide in the gas discharged from the first outlet 14B1 of the secondary desulfurization tower and the first outlet 13B1 of the primary desulfurization tower. The first gas analyzer 19 can effectively monitor the content of hydrogen sulfide contained in the separated gas discharged through the first outlet 13B1 of the primary desulfurization tower and the first outlet 14B1 of the secondary desulfurization tower, thereby ensuring that the sulfide such as hydrogen sulfide is reduced to the required requirements.

[0084] The cold dryer 16, the second gas-liquid separator 17, the second particulate filter 18, and the first gas analyzer 19 are skid-mounted to form a cold dry skid B. This skid-mounted design only requires the various parts (cold dryer 16, the second gas-liquid separator 17, the second particulate filter 18, the first gas analyzer 19, pipelines, etc.) to be assembled in the factory to form an integrated device, which can then be transported to the production site for use. This simplifies the structural complexity of the equipment required to separate carbon dioxide and natural gas from the return exhaust gas and reduces installation costs. In addition, the cold dry skid B is easy to maintain and manage, reducing the cost of subsequent maintenance and management.

[0085] The compressor film feed skid C includes a first compressor 20 .

[0086] The first compressor 20 comprises: a first compressor inlet 20A, connected to the first outlet 18B1 of the second particulate filter; a first compressor first outlet 20B1; and a first compressor second outlet 20B2, used for connecting to an external sewage tank.

[0087] The gas discharged through the first outlet 18B1 of the second particulate filter enters the first compressor 20 through the first compressor inlet 20A, is compressed and pressurized by the first compressor 20, and then enters the membrane separation skid D through the first compressor first outlet 20B1 for further operation.

[0088] It should be noted that the gas before entering the membrane (the primary membrane tube 23 and the secondary membrane tube 24 described below) needs to have a certain pressure, and the first compressor 20 is set to pressurize the gas discharged through the first outlet 18B1 of the second particle filter, ensuring that the gas has the required pressure before entering the membrane, and ensuring that the membrane separation skid D separates the natural gas that meets the standards. Similarly, the design of the compressor membrane skid C simplifies the structural complexity of the equipment required for separating carbon dioxide and natural gas from the return exhaust gas, reduces the installation cost, and reduces the cost of subsequent maintenance and management.

[0089] The membrane separation skid D includes a filter assembly 21 , an electric heater 22 , a primary membrane tube 23 , and a secondary membrane tube 24 .

[0090] The filter assembly 21 includes a third particulate filter 211 and a fourth particulate filter 212 , which are sequentially disposed downstream of the first outlet 20B1 of the first compressor.

[0091] The third particle filter 211 includes: a third particle filter inlet 211A connected to the first compressor first outlet 20B1; a third particle filter first outlet 211B1; and a third particle filter second outlet 211B2 connected to an external sewage tank.

[0092] The fourth particle filter 212 includes: a fourth particle filter inlet 212A, connected to the third particle filter first outlet 211B1; a fourth particle filter first outlet 212B1; and a fourth particle filter second outlet 212B2, which is used to connect to an external sewage tank. As mentioned above, if the gas carries solid particle impurities, it will have an adverse effect on the performance of the membrane separation skid D, seriously affecting the membrane separation effect. The dual filtering effect of the third particle filter 211 and the fourth particle filter 212 can effectively remove the solid particle impurities mixed in the gas, prevent the gas before entering the membrane from carrying solid impurity particles, and ensure the separation effect and efficiency of the primary membrane tube 23 and the secondary membrane tube 24 described below.

[0093] The electric heater 22 includes: an electric heater inlet 22A, connected to the first outlet 212B1 of the fourth particle filter; and an electric heater outlet 22B. Similarly, if the gas before entering the membrane contains liquid such as water vapor, it will also affect the separation performance of the membrane in the membrane tube. The setting of the heater 22 heats the gas before entering the membrane to convert the droplets carried in the gas into a gaseous state, while keeping the gas at a sufficiently high temperature to prevent the gas from generating condensed liquid after entering the membrane tube, thereby ensuring the separation effect of the membrane tube.

[0094] The primary membrane tube 23 includes: a primary membrane tube inlet 23A connected to the electric heater outlet 22B; a primary membrane tube low-pressure outlet 23B1 connected to the first compressor inlet 20A; and a primary membrane tube high-pressure outlet 23B2.

[0095] The secondary membrane tube 24 includes: a secondary membrane tube inlet 24A connected to the primary membrane tube high pressure outlet 23B2; a secondary membrane tube low pressure outlet 24B1 connected to the carbon dioxide pressurization reinjection skid E; and a secondary membrane tube high pressure outlet 24B2 for connecting to an external natural gas pipeline.

[0096] The pressurized gas discharged through the first outlet 20B1 of the first compressor enters the third particulate filter 211 and the fourth particulate filter 212 in sequence for filtration, the filtered gas enters the electric heater 22 through the electric heater inlet 22A for vaporization treatment, and then is discharged through the electric heater outlet 22B, the discharged gas first undergoes primary separation treatment in the primary membrane tube 23, and then enters the secondary membrane tube 24 for secondary separation and separates the carbon dioxide from the hydrocarbon gas in the mixed gas, the separated carbon dioxide enters the carbon dioxide pressurization reinjection skid E through the secondary membrane tube low-pressure outlet 24B1; the separated hydrocarbon gas directly enters the external natural gas pipeline.

[0097] The primary membrane tube 23 performs the initial separation and filtration on the mixed gas. The carbon dioxide discharged from the low-pressure outlet 23B1 of the primary membrane tube is mixed with a part of hydrocarbon gases such as methane. Therefore, the low-pressure outlet 23B1 of the primary membrane tube is connected to the first compressor inlet 20A, so that the carbon dioxide containing hydrocarbon gases is recompressed and pressurized to enter the membrane separation skid D again for filtration, which reduces the waste of natural gas and increases the extraction amount of natural gas. The natural gas discharged from the high-pressure outlet 23B2 of the primary membrane tube is mixed with a part of carbon dioxide. The purity of the natural gas fails to meet the natural gas use standard. Therefore, further separation and filtration are required. Therefore, the natural gas containing carbon dioxide The gas flows into the secondary membrane tube 24 through the high-pressure outlet 23B2 of the primary membrane tube for further separation. Through the action of the secondary membrane tube 24, the natural gas containing carbon dioxide is separated into carbon dioxide and natural gas of use standard. The carbon dioxide flows into the carbon dioxide reinjection skid E through the low-pressure outlet 24B1 of the secondary membrane tube for reinjection. The natural gas that meets the use standard discharged from the high-pressure outlet 24B2 of the secondary membrane tube flows into the external natural gas pipeline. The dual filtering action of the primary membrane tube 23 and the secondary membrane tube 24 fully filters and extracts the natural gas, thereby preventing the waste of natural gas, and effectively recovering carbon dioxide, thereby reducing environmental pollution.

[0098] The membrane separation skid D further comprises a second gas analyzer 25 , wherein the first membrane tube low pressure outlet 23B1 , the first membrane tube high pressure outlet 23B2 , the second membrane tube low pressure outlet 24B1 , and the second membrane tube high pressure outlet 24B2 are respectively connected to the second gas analyzer 25 .

[0099] Similarly, the filter assembly 21, the electric heater 22, the primary membrane tube 23, the secondary membrane tube 24, and the second gas analyzer 25 are skid-mounted to form a membrane separation skid D. This skid-mounted design only requires the various parts (filter assembly 21, electric heater 22, primary membrane tube 23, secondary membrane tube 24, second gas analyzer 25, pipelines, etc.) to be assembled in the factory to form an integrated device, which is then transported to the production site and connected to other skids for use. This simplifies the structural complexity of the equipment required for separating carbon dioxide and natural gas from the return exhaust gas and reduces the installation cost. In addition, when a problem occurs with the membrane separation skid D, only this skid needs to be maintained and managed separately, reducing the cost of system maintenance and management.

[0100] In one embodiment, two compressor membrane inlet skids C are provided; correspondingly, two membrane separation skids D are provided, each membrane separation skid D is communicated with two compressor membrane inlet skids C respectively, and each membrane separation skid D is communicated with the carbon dioxide pressurization reinjection skid E. This design allows the gas discharged through the first outlet 18B1 of the second particulate filter to enter the two compressor membrane inlet skids C, and then enter the two membrane separation skids D to separate carbon dioxide from natural gas, thereby improving the separation efficiency of carbon dioxide and natural gas in the return exhaust gas.

[0101] The carbon dioxide pressurizing and reinjecting skid E includes a second compressor 26, which includes: a second compressor inlet 26A; a second compressor first outlet 26B1 for discharging carbon dioxide; and a second compressor second outlet 26B2 for connecting to an external sewage tank. The gas separated through the secondary membrane tube low-pressure outlet 24B1 of the secondary membrane tube 24 of each membrane separation skid D enters the second compressor 26 from the second compressor inlet 26A for compression, and the compressed carbon dioxide is discharged through the second compressor first outlet 26B1 and then reinjected into the ground. This process effectively recovers carbon dioxide, allowing it to be used again, reducing the amount of additional carbon dioxide consumed by the produced fluid of the carbon dioxide flooding oil field, reducing costs, and preventing carbon dioxide from being discharged into the atmosphere and polluting the environment.

Claims

1. A skid-mounted carbon dioxide driveback exhaust gas desulfurization, dehydration and carbon dioxide recovery system, characterized in that: It includes return exhaust gas pretreatment and desulfurization skid (A), cold drying skid (B), compressor membrane skid (C), membrane separation skid (D), and carbon dioxide booster reinjection skid (E); The cold drying skid (B) is connected to the return exhaust gas pretreatment and desulfurization skid (A) through pipelines; The compressor film inlet skid (C) is connected to the cold drying skid (B) through a pipeline; The membrane separation skid (D) is connected to the compressor membrane inlet skid (C) through a pipeline; The carbon dioxide pressurizing and reinjecting skid (E) is connected to the membrane separation skid (D) through a pipeline; The return gas first enters the return gas pretreatment and desulfurization skid (A) for pretreatment and desulfurization. After pretreatment and desulfurization, the return gas enters the cold drying skid (B) for dehydration treatment. After dehydration treatment, the return gas enters the compressor membrane skid (C) for pressurization treatment. The pressurized return gas enters the membrane separation skid (D) for gas separation to separate carbon dioxide and hydrocarbon gas. The separated carbon dioxide enters the carbon dioxide pressurization reinjection skid (E) for pressurization reinjection treatment, and the hydrocarbon gas is used as natural gas. The return exhaust gas pretreatment and desulfurization skid (A) comprises a first gas-liquid separator (11), a first particle filter (12), an activated carbon tower (27), and at least one stage of desulfurization tower; The first gas-liquid separator (11) comprises: First gas-liquid separator inlet (11A); The first outlet (11B1) of the first gas-liquid separator; The second outlet (11B2) of the first gas-liquid separator is used to connect to an external sewage tank; The first particle filter (12) comprises: A first particle filter inlet (12A) connected to a first outlet (11B1) of a first gas-liquid separator; A first particle filter first outlet (12B1); The second outlet (12B2) of the first particle filter is used to communicate with an external sewage tank; The activated carbon tower (27) comprises: The activated carbon tower inlet (27A) is connected to the first outlet (12B1) of the first particle filter; Activated carbon tower first outlet (27B1); The second outlet of the active tower (27B2) is used to connect to the external sewage tank; The primary desulfurization tower (13) includes: The inlet of the primary desulfurization tower (13A) is connected to the first outlet of the activated carbon tower (27B1); The first outlet (13B1) of the primary desulfurization tower is connected to the cold-drying skid (B); The second outlet (13B2) of the primary desulfurization tower is used to connect to the external sewage tank; The return exhaust gas enters the first gas-liquid separator (11) through the first gas-liquid separator inlet (11A) to undergo gas-liquid separation and form separated gas and liquid, and the liquid flows into the sewage tank through the first gas-liquid separator second outlet (11B2); the separated gas enters the first particle filter (12) through the first gas-liquid separator first outlet (11B1) and the first particle filter inlet (12A) to undergo filtration, so as to initially filter the solid impurity particles mixed in the separated gas, and the filtered solid impurity particles are discharged into the sewage tank through the first particle filter second outlet (12B2), and the filtered separated gas is discharged through the first particle filter inlet (12A). The first outlet (12B1) of a particle filter and the inlet (27A) of an activated carbon tower enter the activated carbon tower (27) to remove heavy hydrocarbons, and the removed heavy hydrocarbons are discharged into a sewage pool through the second outlet (27B2) of the activated carbon tower. At least part of the separated gas from which the heavy hydrocarbons have been removed enters the primary desulfurization tower (13) through the first outlet (27B1) of the activated carbon tower and the inlet (13A) of the primary desulfurization tower to be desulfurized, and the removed sulfur-containing wastewater flows into the sewage pool through the second outlet (13B2) of the primary desulfurization tower. The separated gas after desulfurization flows into the cold drying skid (B) through the first outlet (13B1) of the desulfurization tower to carry out the next operation; The return exhaust gas pretreatment and desulfurization skid (A) also includes a secondary desulfurization tower (14). The secondary desulfurization tower (14) includes: The inlet of the secondary desulfurization tower (14A) is connected to the first outlet of the activated carbon tower (27B1) and the first outlet of the primary desulfurization tower (13B1); The first outlet (14B1) of the secondary desulfurization tower is connected to the cold-drying skid (B); The second outlet (14B2) of the secondary desulfurization tower is used to connect to the external sewage tank; wherein at least part of the separated gas discharged through the first outlet (27B1) of the activated carbon tower enters the secondary desulfurization tower (14) through the secondary desulfurization tower inlet (14A) for desulfurization treatment, and the separated gas discharged through the first outlet (13B1) of the primary desulfurization tower enters the secondary desulfurization tower (14) again through the secondary desulfurization tower inlet (14A) for secondary desulfurization, the separated gas after desulfurization flows into the cold drying skid (B) through the first outlet (14B1) of the secondary desulfurization tower, and the sulfur-containing wastewater removed by the secondary desulfurization tower (14) flows into the sewage pool through the second outlet (14B2) of the secondary desulfurization tower; The cold-drying skid (B) comprises a cold-drying machine (16), a second gas-liquid separator (17) and a second particle filter (18). The cold dryer (16) comprises: The cold dryer inlet (16A) is connected to the first outlet of the primary desulfurization tower (13B1) and the first outlet of the secondary desulfurization tower (14B1); First outlet of cold dryer (16B1); The second outlet of the cold dryer (16B2) is used to connect to the external sewage tank; The second gas-liquid separator (17) comprises: The second gas-liquid separator inlet (17A) is connected to the first outlet (16B1) of the cold dryer; The first outlet (17B1) of the second gas-liquid separator; The second outlet (17B2) of the second gas-liquid separator is used to communicate with an external sewage tank; The second particulate filter (18) comprises: A second particle filter inlet (18A) connected to a first outlet (17B1) of a second gas-liquid separator; The first outlet (18B1) of the second particle filter is connected to the compressor membrane inlet skid (C); The second outlet (18B2) of the second particle filter is used to communicate with an external sewage tank; The desulfurized separation gas discharged from the primary desulfurization tower (13) and the secondary desulfurization tower (14) enters the cold dryer (16) through the cold dryer inlet (16A) for cold drying and dehydration treatment, the dehydrated separation gas enters the second gas-liquid separator (17) through the first outlet (16B1) of the cold dryer and the second gas-liquid separator inlet (17A) for gas-liquid separation, the separated gas enters the second particle filter (18) through the first outlet (17B1) of the second gas-liquid separator and the second particle filter inlet (18A) to further remove solid impurity particles in the gas, the removed solid impurity particles are discharged into the sewage tank, and the gas filtered by the second particle filter (18) flows into the compressor membrane inlet skid (C) through the first outlet (18B1) of the second particle filter for further operation; The compressor film feed skid (C) comprises a first compressor (20), The first compressor (20) comprises: A first compressor inlet (20A) connected to a first outlet (18B1) of a second particulate filter; First compressor first outlet (20B1); The second outlet (20B2) of the first compressor is used to connect to an external sewage tank; The gas discharged through the first outlet (18B1) of the second particle filter enters the first compressor (20) through the first compressor inlet (20A), the gas is compressed and pressurized by the first compressor (20), and then enters the membrane separation skid (D) through the first outlet (20B1) of the first compressor for further operation; The membrane separation skid (D) comprises a filter assembly (21), an electric heater (22), a primary membrane tube (23), and a secondary membrane tube (24); The filter assembly (21) comprises a third particle filter (211) and a fourth particle filter (212), wherein the third particle filter (211) and the fourth particle filter (212) are sequentially arranged downstream of the first outlet (20B1) of the first compressor. The third particle filter (211) comprises: A third particle filter inlet (211A) connected to a first outlet (20B1) of the first compressor; A third particulate filter first outlet (211B1); The second outlet (211B2) of the third particle filter is used to communicate with an external sewage tank; The fourth particulate filter (212) comprises: A fourth particle filter inlet (212A) connected to a first outlet (211B1) of the third particle filter; a fourth particulate filter first outlet (212B1); The second outlet (212B2) of the fourth particle filter is used to communicate with an external sewage tank; The electric heater (22) comprises: An electric heater inlet (22A) connected to a first outlet (212B1) of a fourth particle filter; Electric heater outlet (22B); The primary membrane tube (23) comprises: The first-stage membrane tube inlet (23A) is connected to the electric heater outlet (22B); The first-stage membrane tube low-pressure outlet (23B1) is connected to the first compressor inlet (20A); High-pressure outlet of the first-stage membrane tube (23B2); The secondary membrane tube (24) comprises: The secondary membrane tube inlet (24A) is connected to the primary membrane tube high-pressure outlet (23B2); The low-pressure outlet of the secondary membrane tube (24B1) is connected to the carbon dioxide pressurization and reinjection skid (E); The secondary membrane tube high-pressure outlet (24B2) is used to connect to an external natural gas pipeline; The pressurized gas discharged through the first outlet (20B1) of the first compressor enters the third particulate filter (211) and the fourth particulate filter (212) in sequence for filtration; the filtered gas enters the electric heater (22) through the electric heater inlet (22A) for gasification treatment, and then is discharged through the electric heater outlet (22B); the discharged gas first undergoes primary separation treatment in the primary membrane tube (23), and then enters the secondary membrane tube (24) for secondary separation to separate carbon dioxide from hydrocarbon gas in the gas; the separated carbon dioxide enters the carbon dioxide pressurization reinjection skid (E) through the secondary membrane tube low-pressure outlet (24B1); the separated hydrocarbon gas directly enters the external natural gas pipeline.

2. The skid-mounted carbon dioxide driveback exhaust gas desulfurization, dehydration and carbon dioxide recovery system according to claim 1 is characterized in that: The membrane separation skid (D) also includes a second gas analyzer (25), The first membrane tube low-pressure outlet (23B1), the first membrane tube high-pressure outlet (23B2), the second membrane tube low-pressure outlet (24B1), and the second membrane tube high-pressure outlet (24B2) are respectively connected to the second gas analyzer (25).

3. The skid-mounted carbon dioxide driveback exhaust gas desulfurization, dehydration and carbon dioxide recovery system according to claim 2 is characterized in that: The number of compressor membrane inlet skids (C) is two; correspondingly, the number of membrane separation skids (D) is two, each membrane separation skid (D) is connected to two compressor membrane inlet skids (C) respectively, and each membrane separation skid (D) is connected to a carbon dioxide pressurization reinjection skid (E).

4. The skid-mounted carbon dioxide driveback exhaust gas desulfurization, dehydration and carbon dioxide recovery system according to claim 3 is characterized in that: The carbon dioxide pressurizing and reinjecting skid (E) comprises a second compressor (26), and the second compressor (26) comprises: Second compressor inlet (26A); The first outlet (26B1) of the second compressor is used to discharge carbon dioxide; The second outlet (26B2) of the second compressor is used to communicate with an external sewage tank; The gas separated through the secondary membrane tube low-pressure outlet (24B1) of the secondary membrane tube (24) of each membrane separation skid (D) enters the second compressor (26) from the second compressor inlet (26A) for compression, and the compressed carbon dioxide is discharged through the second compressor first outlet (26B1) for further processing.

5. The skid-mounted carbon dioxide driveback exhaust gas desulfurization, dehydration and carbon dioxide recovery system according to claim 1 is characterized in that: The return exhaust gas pretreatment and desulfurization skid (A) also includes: a shut-off valve (28) arranged on the upstream pipeline of the first gas-liquid separator inlet (11A) and used to control the opening and closing of the upstream pipeline of the first gas-liquid separator inlet (11A).

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