CN-121988125-A - Oil gas recovery method of continuous absorption-condensation-multistage adsorption, oil gas recovery integrated system and application

Abstract

The invention discloses a continuous absorption-condensation-multistage adsorption oil gas recovery method, an oil gas recovery integrated system and application. The oil gas recovery method comprises the following steps of (1) sending oil gas mixture to an absorption tower for absorption treatment by an absorbent to obtain absorption liquid and unabsorbed oil gas, (2) condensing the unabsorbed oil gas, recovering liquid after gas-liquid separation, obtaining tail gas after the first-stage absorption treatment and the second-stage absorption treatment of the separated unagglomerated oil gas, and (3) resolving the absorbent for the first-stage absorption treatment and/or the second-stage absorption treatment, and recycling the resolved oil gas to the absorption tower for reuse. According to the invention, through optimizing the tower plate arrangement of the absorption tower, the absorption effect of the absorbent in the absorption tower on oil gas is greatly improved. In addition, the invention combines the advantages and disadvantages of the prior art, couples a plurality of technologies, adopts an oil gas recovery integrated system of a continuous absorption-condensation-multistage adsorption integrated system, not only achieves the purposes of oil gas recovery and oil gas treatment standard emission, but also can improve the single regeneration period and the service life of the adsorbent and reduce the energy consumption of vacuum desorption and the operation cost of oil gas recovery.

Inventors

• WANG DEJU
• SHANG CHENGCHENG
• REN JIE
• QI SHENGDONG
• CONG WENJIE

Assignees

• 中石化（上海）石油化工研究院有限公司
• 中国石油化工股份有限公司

Dates

Publication Date

20260508

Application Date

20241108

Claims (11)

1. 1. An oil gas recovery method of continuous absorption-condensation-multistage adsorption, comprising the following steps: (1) The mixed gas of the oil and the gas is sent to an absorber for absorption treatment to obtain absorption liquid and unabsorbed oil and gas, and the absorption liquid is optionally reused as the absorber in the absorber after being cooled; (2) Condensing the unabsorbed oil gas, recovering the liquid after gas-liquid separation to obtain recovered oil, and carrying out primary adsorption treatment and secondary adsorption treatment on the unabsorbed oil gas after gas-liquid separation to obtain tail gas; (3) Optionally resolving the adsorbent for primary adsorption treatment and/or secondary adsorption treatment, and recycling the resolved oil gas as oil gas mixture gas to an absorption tower for recycling.
2. 2. The oil and gas recovery method according to claim 1, characterized in that: Step (1), The absorption tower is internally provided with T i layers of porous tower plates, wherein i in T i is more than or equal to 2 and is an integer, the T 1 layers are first layer of tower plates at the bottom, the T i layers are T i layer of tower plates at the upper part of the T 1 layers, the oil-gas mixture rises step by step from bottom to top through the holes on the tower plates and is in step countercurrent contact with cooled absorption liquid, and preferably i is an integer between 2 and 31; further preferably, each layer of trays is arranged along the centerline of the vertical absorption column; Still further preferably the method comprises the steps of, The pore diameters of the pores gradually decrease from the T 1 layer tray to the T i layer tray of the absorption tower, and/or, From the T 1 layers of trays to the T i layers of trays of the absorption tower, the vertical distance between the adjacent trays is gradually reduced.
3. 3. The oil and gas recovery method according to claim 2, characterized in that: In the absorption tower, the liquid crystal material is absorbed by the liquid crystal material, The aperture ratio of the holes on the T i layer tower plate to the T 1 layer tower plate is 1 (1+i/m), wherein m is a certain value in an integer of 1-6.
4. 4. The oil and gas recovery method according to claim 2, characterized in that: In the absorption tower, the liquid crystal material is absorbed by the liquid crystal material, The vertical distance between the T i layer tower plate/the T i-1 layer tower plate is 1 (1+i/n) of the vertical distance between the T 2 layer tower plate/the T 1 layer tower plate, wherein n is a certain value in an integer of 3-10.
5. 5. The oil and gas recovery method according to claim 1, characterized in that: Step (1), The absorbent comprises C 4 -C 12 alkanes, optional alkenes, aromatic hydrocarbons, optional ethers and alcohols, wherein the mass ratio of the alkanes is 40-60%, the mass ratio of the alkenes is 0-20%, the mass ratio of the aromatic hydrocarbons is 20-30%, the mass ratio of the alcohols and ethers is 0-10%, and/or, The temperature of the absorbent in the absorption tower is-20 ℃ to 10 ℃, preferably 0 ℃ to 10 ℃, and/or, The liquid level of the absorbent in the absorption tower is 10% -100% of the full range, and is preferably 20% -80% of the full range.
6. 6. The oil and gas recovery method according to claim 1, characterized in that: Step (2), The temperature of the condensation treatment is-20 ℃ to 10 ℃, preferably-10 ℃ to 0 ℃, and/or, Step (3), The primary adsorption treated adsorbent is selected from activated carbon adsorbents, preferably the activated carbon adsorbents have a toluene to water static adsorption capacity ratio of greater than 4, and/or, The adsorbent of the secondary adsorption treatment is selected from molecular sieve adsorbent or resin adsorbent, and/or, The volume ratio of the adsorbent in the primary adsorption module to the adsorbent in the secondary adsorption module is 20-1:1, preferably 20-10:1, and/or, The analysis process adopts vacuum analysis process.
7. 7. The oil and gas recovery method according to claim 1, characterized in that: The concentration of the oil gas before the oil gas mixture is absorbed by the absorption tower is 25mg/m 3 ～1600000mg/m 3 , the concentration of the oil gas after the oil gas mixture is absorbed by the absorption tower is 25mg/m 3 ～120000mg/m 3 , the concentration of the uncondensed oil gas after condensation is 25mg/m 3 ～15000mg/m 3 , the concentration of the oil gas after the oil gas mixture is absorbed by the primary absorption module is 25mg/m 3 ～1000mg/m 3 , and the concentration of the oil gas after the oil gas mixture is absorbed by the secondary absorption module is 0-25 mg/m 3 .
8. 8. An integrated continuous absorption-condensation-multistage adsorption oil gas recovery system, which is characterized in that: the system comprises an absorption tower (2), a condenser (4), a gas-liquid separation device (5), a primary adsorption module (6), a secondary adsorption module (7) and an optional vacuum pump (9); The gas-oil mixture discharging port of the absorption tower (2) is sequentially connected with the feeding port of the condenser (4) and the feeding port of the gas-liquid separation device (5), the gas discharging port of the gas-liquid separation device (5) is sequentially connected with the feeding port of the primary adsorption module (6) and the feeding port of the secondary adsorption module (7), the adsorbent resolving port of the primary adsorption module (6) and the adsorbent resolving port of the secondary adsorption module (7) are sequentially connected with the feeding port of the optional vacuum pump (9), and the discharging port of the optional vacuum pump (9) is connected with the gas-oil mixture feeding port of the absorption tower (2).
9. 9. The oil and gas recovery integrated system of claim 8, wherein: The system also comprises a fan (1), wherein a discharge port of the fan (1) is connected with an oil-gas mixture inlet of the absorption tower (2), and/or, The system also comprises an oil return pump (8) and a refrigerating unit (3), wherein the discharge port of the absorption liquid of the absorption tower (2) is connected with the feed port of the oil return pump (8), the discharge port of the oil return pump (8) is connected with the feed port of the absorption liquid of the absorption tower (2), the two connected pipelines pass through the refrigerating unit (3), and/or, The condensing medium for the condenser (4) also enters the refrigerating unit (3) through a pipeline for cooling.
10. 10. The oil and gas recovery integrated system of claim 8, wherein: the refrigerating mode of the refrigerating unit is at least one of compressor refrigeration, water cooling or liquid nitrogen cooling, and/or, The vacuum pump is a variable-frequency speed-regulating vacuum pump and/or, The gas-liquid separation device (5) is a coalescer and/or, The primary adsorption module (6) and the secondary adsorption module (7) are respectively and independently formed by connecting one or more groups of adsorption tanks in parallel, and the adsorption tanks are preferably selected from fixed bed adsorption tanks.
11. 11. Use of a hydrocarbon recovery method according to any one of claims 1 to 7 or a hydrocarbon recovery method integration system according to any one of claims 8 to 10 in hydrocarbon recovery.

Description

Oil gas recovery method of continuous absorption-condensation-multistage adsorption, oil gas recovery integrated system and application Technical Field The invention relates to the technical field of oil gas recovery and treatment, in particular to an oil gas recovery method of continuous absorption-condensation-multistage adsorption, an oil gas recovery integrated system and application. Background In recent years, environmental problems have also begun to become more prominent with the continued development of industrial processes. The petroleum refining and chemical products are widely applied in various fields, and volatile organic compounds VOCs generated in the processes of production, loading, unloading, storage and transportation, use and the like of the products pollute the atmosphere and can seriously influence the health of human bodies. The oil gas recovery can prevent atmospheric pollution caused by oil gas volatilization, eliminates potential safety hazards, improves the resource utilization rate and reduces the waste of resources. Oil gas recovery is a technical direction of energy conservation and environmental protection. The oil gas recovery technology is used for preventing atmospheric pollution caused by oil gas volatilization, eliminating potential safety hazards, reducing economic loss by improving the utilization rate of energy sources, and having good economic and social benefits. Currently, there are common methods such as adsorption, absorption, condensation, membrane separation, and the like. However, from the practical application effect, the methods have the problems of limited recovery effect, treatment indexes exceeding the specified indexes, high running cost and the like in the single use process. The absorption method has large occupied space of equipment, strict requirement on the performance of the absorbent and low process recovery rate. The adsorption method generally adopts activated carbon as an adsorbent, and the activated carbon has higher adsorption heat, and has lower adsorption selectivity on organic pollutants due to competing adsorption of water. The condensation method can obtain better recovery efficiency under the condition of very low temperature, and the problem that organic pollutants are crystallized to form particles which run away along with tail gas is caused by the too low temperature, so that the condensation method has higher requirements on temperature control and a cold source. Multi-stage refrigeration is typically required, making it relatively costly to invest and operate. The membrane separation method has the problems of higher investment cost and lower efficiency. CN115141648a discloses a system and a method for recovering oil gas, which utilize recovery systems including a supergravity desulfurization device, a compression condensing device, a membrane separation device, an adsorption analysis device, a recovery device and the like, and then adopt methods of desulfurization treatment, overlapping treatment, storage, emission treatment and the like to realize low concentration emission and high recovery rate of non-methane total hydrocarbons. The method mainly removes sulfur in advance so as to avoid adverse effects of sulfur on membrane separation, and the core of the method is membrane separation technology. CN102527073a describes an adsorption-condensation combined type oil gas recovery device for recovering oil gas, and mainly relates to the theory that after the oil gas is adsorbed by an adsorption tank, the oil gas is connected with a condenser by a pipeline and a vacuum pump, so that the recovery purpose of mainly adsorbing and secondarily condensing is achieved. CN104096452a provides a cooling oil pre-absorption adsorption process for recovering oil gas, which mainly uses the principle that the oil gas after hydrocarbon absorption by an absorption tower is transported to an absorption tower containing active carbon for re-absorption to recover the oil gas. The existing treatment method mainly takes oil gas absorption and recovery or adsorbent absorption as main materials, the oil gas absorption and recovery or adsorbent absorption are not effectively coupled, and the oil gas absorption effect can be further improved by adopting the adsorbent in the existing absorption tower. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a continuous absorption-condensation-multistage adsorption oil gas recovery method, an oil gas recovery integrated system and application. According to the invention, through optimizing the tower plate arrangement of the absorption tower, the absorption effect of the absorbent in the absorption tower on oil gas is greatly improved. In addition, the invention combines the advantages and disadvantages of the prior art, couples a plurality of technologies, adopts an oil gas recovery integrated system of a continuous absorption-condensation-multistage absorption integrate