A high-concentration oil and gas absorption pretreatment device absorbent recycling system

Abstract

This utility model relates to the field of oil and gas purification technology, and particularly to a high-concentration oil and gas absorption pretreatment device absorbent recycling system. The high-concentration oil and gas absorption pretreatment device absorbent recycling system includes: a gas-liquid separator, an oil and gas transport compressor, an oil and gas absorption tower, a rich absorbent oil pump, an absorbent storage tank, a lean absorbent oil pump, a nitrogen stripping pipeline, an absorbent storage tank exhaust pipeline, and a rich absorbent oil external discharge pipeline. The gas-liquid separator has two inlets and one outlet. The first inlet is connected to the outlet of the oil and gas collection pipeline in the tank area or loading operation via a pipeline. The second inlet is connected to the outlet end of the absorbent storage tank exhaust pipeline via a pipeline. The outlet is connected to the inlet of the oil and gas transport compressor via a pipeline. This utility model regenerates the rich absorbent oil in the absorbent storage tank by stripping with nitrogen during the intermittent exhaust phase of production, achieving long-term recycling of the absorbent.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas purification technology, and in particular to an absorbent recycling system for a high-concentration oil and gas absorption pretreatment device. Background Technology

[0002] Petrochemical enterprises release large amounts of high-concentration organic oil and gas during tank farms (such as oil tanks and chemical tanks) and loading operations. The main pollutants are hydrocarbon components, and these oil and gas are characterized by large concentration fluctuations and intermittent emissions (such as the tank farm's constant circadian rhythm and the start-up and shutdown of loading operations). Currently, the industry mostly uses solvent absorption processes to pretreat these high-concentration oil and gas to recover hydrocarbon components and reduce the load and safety risks of subsequent deep purification units (such as catalytic oxidation and RTO units).

[0003] However, existing absorption pretreatment technologies have many problems that urgently need to be solved: First, traditional absorbents (such as semi-finished diesel) have limited absorption capacity, especially for volatile light hydrocarbon components such as C2, C3, and C4. Moreover, many tank farms and loading points are far from refineries and lack pipelines for transporting semi-finished diesel, making it difficult to obtain and recover absorbents conveniently. Second, absorbents are difficult to regenerate after absorption saturation. Direct replacement would increase operating costs, and failure to treat them in a timely manner would lead to a sharp decline in absorption efficiency, failing to meet the safety requirement in the "Technical Specification for Waste Gas Treatment Engineering in Petroleum Refining Industry" that "the concentration of organic matter entering the incineration unit must be less than 25% LEL". Third, existing systems lack stable pressure and flow control mechanisms. Pressure fluctuations during oil and gas transportation can easily lead to unstable compressor operation, making it difficult to accurately control the concentration of oil and gas after absorption, which in turn affects the operational safety and stability of subsequent deep purification units.

[0004] Based on the problems of "difficulty in obtaining absorbent, difficulty in regeneration, and unstable system control" in the existing technology, this utility model provides a brand-new high-concentration oil and gas absorption pretreatment device absorbent recycling and regeneration system. It aims to improve absorbent utilization through recycling and regeneration mechanism and ensure system stability through precise control, so as to meet the oil and gas pretreatment needs of petrochemical enterprises' tank farms and loading operations. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a high-concentration oil and gas absorption pretreatment device absorbent recycling system.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A high-concentration oil and gas absorption pretreatment device absorbent circulation and regeneration system includes: a gas-liquid separator, an oil and gas conveying compressor, an oil and gas absorption tower, a rich absorbent oil pump, an absorbent storage tank, a lean absorbent oil pump, a nitrogen stripping pipeline, an absorbent storage tank exhaust pipeline, and a rich absorbent oil external discharge pipeline.

[0008] The gas-liquid separator has two inlets and one outlet. The first inlet is connected to the outlet of the oil and gas collection pipeline of the tank area or loading operation through a pipeline. The second inlet is connected to the outlet end of the exhaust pipeline of the absorbent storage tank through a pipeline. The outlet is connected to the inlet of the oil and gas transmission compressor through a pipeline.

[0009] The outlet of the oil and gas transmission compressor is connected to the oil and gas inlet of the oil and gas absorption tower through a pipeline; the top of the oil and gas absorption tower is equipped with an exhaust port, and the bottom of the tower is equipped with a bottom absorbent outlet. The exhaust port is connected to the subsequent deep purification treatment device through a pipeline, and the bottom absorbent outlet is connected to the inlet of the rich absorption oil pump through a pipeline.

[0010] The outlet of the rich absorption oil pump is connected to the inlet of the absorbent storage tank via a pipeline; the outlet of the absorbent storage tank is connected to the inlet of the lean absorption oil pump via a pipeline; and the outlet of the lean absorption oil pump is connected to the inlet of the spray device at the top of the oil and gas absorption tower via a pipeline.

[0011] The inlet of the rich absorption oil external discharge pipeline is fixedly located on the outlet pipeline of the rich absorption oil pump;

[0012] The outlet end of the nitrogen stripping pipeline extends to the bottom of the absorbent storage tank; the inlet end of the absorbent storage tank exhaust pipeline is connected to the top outlet of the absorbent storage tank via a pipeline.

[0013] Furthermore, a first pressure detection element is fixedly installed inside the gas-liquid separator, and the first pressure detection element is electrically connected to the control unit of the oil-gas delivery compressor via a wire.

[0014] Furthermore, the oil and gas transmission compressor is a liquid ring compressor; an oil and gas return pipeline is connected in parallel between the inlet and outlet of the oil and gas transmission compressor, and a compressor return regulating valve is fixedly installed on the oil and gas return pipeline.

[0015] Furthermore, a first flow meter is fixedly installed on the connecting pipeline between the outlet of the oil and gas transmission compressor and the oil and gas inlet of the oil and gas absorption tower. The first flow meter is electrically connected to the control unit of the compressor reflux regulating valve through a wire.

[0016] Furthermore, the oil and gas absorption tower has a fixed packing layer inside the tower body, which is either bulk packing or structured packing made of 304 stainless steel.

[0017] Furthermore, a VOCs concentration detector is fixedly installed at the exhaust port of the oil and gas absorption tower. The VOCs concentration detector is electrically connected to the control unit of the oil and gas conveying compressor via a wire.

[0018] Furthermore, a nitrogen flow regulating valve is fixedly installed on the nitrogen stripping pipeline; an absorbent storage tank exhaust flow regulating valve is fixedly installed on the absorbent storage tank exhaust pipeline.

[0019] Furthermore, a second pressure detection element is fixedly installed on the exhaust pipeline of the absorbent storage tank. The second pressure detection element is electrically connected to the control unit of the exhaust flow regulating valve of the absorbent storage tank via a wire.

[0020] Furthermore, a second flow meter is also fixedly installed on the nitrogen stripping pipeline. The second flow meter is electrically connected to the control unit of the nitrogen flow regulating valve via a wire.

[0021] Furthermore, the absorbent storage tank contains absorbent with a flash point of not less than 165°C.

[0022] The present invention adopts the above technical solution and has the following technical effects compared with the prior art:

[0023] This invention achieves absorbent recycling and regeneration through the cooperation of an absorbent storage tank and a nitrogen stripping pipeline, eliminating the need to rely on refinery semi-finished diesel pipelines and solving the problems of absorbent acquisition and regeneration. The linkage between the first pressure detection element and the oil-gas delivery compressor, and the linkage between the first flow meter and the compressor reflux regulating valve, ensures stable oil-gas delivery pressure and flow. The linkage between the second pressure detection element and the second flow meter, respectively, and their corresponding regulating valves, ensures stable nitrogen stripping and oil-gas reflux during absorbent regeneration. Simultaneously, a VOCs concentration detector can monitor the concentration of oil and gas after absorption in real time, meeting the safe feeding requirements of subsequent deep purification devices. The overall system balances economy, stability, and safety. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the process flow structure of this utility model;

[0025] The reference numerals in the attached figures are:

[0026] 1. Gas-liquid separator; 2. Oil-gas transfer compressor; 21. Compressor reflux regulating valve; 3. Oil-gas absorption tower; 31. Oil-gas inlet; 32. Exhaust port; 4. Rich absorbent oil pump; 5. Absorbent storage tank; 6. Lean absorbent oil pump; 55. Nitrogen stripping pipeline; 53. Absorbent storage tank exhaust pipeline; 7. Rich absorbent oil external discharge pipeline; PC-02. First pressure sensing element; FC-01. First flow meter; 52. Nitrogen flow regulating valve; 51. Absorbent storage tank exhaust flow regulating valve; PC-03. Second pressure sensing element; FC-04. Second flow meter. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments of the present invention can be combined with each other.

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0030] Example

[0031] like Figure 1 As shown, this embodiment provides a high-concentration oil and gas absorption pretreatment device absorbent circulation and regeneration system, including: gas-liquid separator 1, oil and gas conveying compressor 2, oil and gas absorption tower 3, rich absorbent oil pump 4, absorbent storage tank 5, lean absorbent oil pump 6, nitrogen stripping pipeline 55, absorbent storage tank exhaust pipeline 53, and rich absorbent oil external discharge pipeline 7.

[0032] The gas-liquid separator 1 has two inlets that serve the functions of "oil and gas collection" and "regenerated oil and gas reflux": the first inlet is connected to the outlet of the oil and gas collection pipeline of the tank area or loading operation through a pipeline to receive high-concentration oil and gas to be treated; the second inlet is connected to the outlet end of the exhaust pipeline 53 of the absorbent storage tank through a pipeline to receive the regenerated oil and gas generated during the absorbent regeneration process; the outlet of the gas-liquid separator 1 is connected to the inlet of the oil and gas conveying compressor 2 through a pipeline to realize the conveying of oil and gas after gas-liquid separation.

[0033] A first pressure detection element PC-02 is fixedly installed inside the gas-liquid separator 1. The first pressure detection element PC-02 is electrically connected to the control unit of the oil-gas delivery compressor 2 through a wire. When the pressure inside the gas-liquid separator 1 is too high, the control unit increases the compressor operating parameters to speed up the exhaust; when the pressure is too low, the control unit decreases the compressor operating parameters to ensure that the pressure inside the tank is stable.

[0034] The oil and gas transfer compressor 2 is a liquid ring compressor. An oil and gas return pipeline is connected in parallel between the inlet and outlet of the oil and gas transfer compressor 2. A compressor return regulating valve 21 is fixedly installed on the oil and gas return pipeline. At the same time, a first flow meter FC-01 is fixedly installed on the connecting pipeline between the outlet of the oil and gas transfer compressor 2 and the oil and gas inlet 31 of the oil and gas absorption tower 3. The first flow meter FC-01 is electrically connected to the control unit of the compressor return regulating valve 21 through a wire. When the first flow meter FC-01 detects that the oil and gas flow exceeds the set range, the control unit adjusts the opening of the compressor return regulating valve 21 so that some oil and gas returns to the compressor inlet through the return pipeline, ensuring that the oil and gas flow entering the oil and gas absorption tower 3 is relatively stable.

[0035] The oil and gas absorption tower 3 has an oil and gas inlet 31 at its lower part, which is connected to the outlet of the oil and gas delivery compressor 2 via a pipeline. The top of the oil and gas absorption tower 3 has an exhaust port 32, which is connected to the subsequent deep purification treatment device via a pipeline. The bottom of the oil and gas absorption tower 3 has a bottom absorbent outlet, which is connected to the inlet of the rich absorption oil pump 4 via a pipeline. A top spray device is installed at the top of the oil and gas absorption tower 3 below the exhaust port 32. Inside the oil and gas absorption tower 3, between the oil and gas inlet 31 and the top spray device, a packing layer is fixedly installed. The packing layer is made of 304 stainless steel bulk packing (or structured packing), ensuring that hydrocarbon components are fully absorbed. Furthermore, a VOCs concentration detector is fixedly installed at the exhaust port 32 of the oil and gas absorption tower 3. The VOCs concentration detector is electrically connected to the control unit of the oil and gas delivery compressor 2 via a wire to monitor the VOCs concentration of the absorbed oil and gas in real time, ensuring that the concentration is below 25% LEL to meet the safety requirements of subsequent devices.

[0036] The inlet of the rich absorption oil pump 4 is connected to the bottom absorbent outlet of the oil and gas absorption tower 3 via a pipeline, and the outlet of the rich absorption oil pump 4 is connected to the liquid inlet of the absorbent storage tank 5 via a pipeline. This is used to transport the "rich absorption oil" (saturated absorbent) after absorbing hydrocarbon components to the absorbent storage tank 5 for storage. The outlet of the absorbent storage tank 5 is connected to the inlet of the lean absorption oil pump 6 via a pipeline, and the outlet of the lean absorption oil pump 6 is connected to the inlet of the top spray device of the oil and gas absorption tower 3 via a pipeline. This is used to transport the "lean absorption oil" (unsaturated absorbent) to be used in the storage tank to the top spray device to realize absorbent circulation.

[0037] The absorbent storage tank 5 contains absorbent with a flash point of not less than 165℃ (such as diesel oil, C9 solvent, etc.) to meet safety and absorption performance requirements. A rich absorbent oil discharge pipeline 7 is installed on the outlet pipeline of the lean absorbent oil pump 6. When the rich absorbent oil level in the absorbent storage tank 5 is too high, or when the absorbent adsorption performance drops to the set threshold, the rich absorbent oil is periodically discharged through the rich absorbent oil discharge pipeline 7. After discharge, new absorbent can be added to the storage tank.

[0038] The outlet end of the nitrogen stripping pipeline 55 extends to the bottom of the absorbent storage tank 5. The nitrogen stripping pipeline 55 is fixedly equipped with a second flow meter FC-04 and a nitrogen flow regulating valve 52. The second flow meter FC-04 is electrically connected to the control unit of the nitrogen flow regulating valve 52 through a wire. During the interval between tank area exhaust or loading operations, the nitrogen supply is turned on. The second flow meter FC-04 detects the nitrogen flow and feeds it back to the control unit. The control unit adjusts the opening of the nitrogen flow regulating valve 52 to ensure that the nitrogen enters the absorbent storage tank 5 evenly and strips the light hydrocarbons absorbed in the absorbent.

[0039] The inlet end of the absorbent storage tank exhaust pipeline 53 is connected to the top outlet of the absorbent storage tank 5 via a pipeline. A second pressure detection element PC-03 and an absorbent storage tank exhaust flow regulating valve 51 are fixedly installed on the absorbent storage tank exhaust pipeline 53. The second pressure detection element PC-03 is electrically connected to the control unit of the absorbent storage tank exhaust flow regulating valve 51 via a wire. When the nitrogen and hydrocarbon mixed oil and gas generated by the stripping is transported through the absorbent storage tank exhaust pipeline 53, the second pressure detection element PC-03 detects the pressure in the pipeline, and the control unit adjusts the opening of the exhaust flow regulating valve 51 to ensure that the mixed oil and gas stably returns to the second inlet of the gas-liquid separator 1 to participate in the next round of absorption process.

[0040] In use: Oil and gas absorption: High-concentration oil and gas emitted from tank farms or loading operations enter the gas-liquid separator 1, where it undergoes gas-liquid separation together with the mixed oil and gas returned from absorbent regeneration. After gas-liquid separation, the oil and gas are pressurized and flow-regulated by the oil and gas conveying compressor 2 before entering the oil and gas absorption tower 3. The waste gas generated inside the oil and gas absorption tower 3 passes through the packing layer from bottom to top. At the same time, the lean absorption oil pump 6 transports the lean absorption oil in the absorbent storage tank 5 to the top spray device. The "lean absorption oil" (unsaturated absorbent) is sprayed from top to bottom, making full contact with the high-concentration oil and gas in the packing layer and absorbing the hydrocarbon components in the oil and gas. The absorbed oil and gas is discharged through the exhaust port 32 (monitored by the VOCs concentration detector), while the "rich absorption oil" (saturated absorbent) is transported to the absorbent storage tank 5 through the bottom absorbent outlet and the rich absorption oil pump 4.

[0041] Absorbent regeneration: During the intervals between tank venting or loading operations, nitrogen supply is turned on. Nitrogen enters the bottom of absorbent storage tank 5 through nitrogen stripping pipeline 55 to strip light hydrocarbons from the "rich absorbent oil" (saturated absorbent). The stripped mixed oil and gas return to gas-liquid separator 1 through absorbent storage tank venting pipeline 53, completing absorbent regeneration. The rich absorbent oil is also periodically stripped through rich absorbent oil external discharge pipeline 7 to maintain a stable liquid level in absorbent storage tank.

[0042] In summary, this invention solves the problems of difficult acquisition and high replacement cost of traditional absorbents through an absorbent recycling mechanism. It also ensures stable system pressure and flow through the linkage of multiple sets of "detection elements, control units and regulating valves" and meets safety requirements through VOCs concentration monitoring. Overall, it improves the economy and reliability of high-concentration oil and gas pretreatment and is suitable for oil and gas treatment scenarios in tank farms and loading operations of petrochemical enterprises.

[0043] The above description of this utility model is merely a preferred embodiment of this utility model and does not limit the implementation method and protection scope of this utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of this utility model should be included within the protection scope of this utility model.

Claims

1. A high concentration oil and gas absorption pre-treatment unit absorbent circulation regeneration system characterized by, include: Gas-liquid separator (1), oil-gas transfer compressor (2), oil-gas absorption tower (3), rich absorption oil pump (4), absorbent storage tank (5), lean absorption oil pump (6), nitrogen stripping pipeline (55), absorbent storage tank exhaust pipeline (53), and rich absorption oil external discharge pipeline (7); The first inlet of the gas-liquid separator (1) is connected to the outlet of the oil and gas pipeline discharged from the tank area or loading operation, the second inlet of the gas-liquid separator (1) is connected to the outlet end of the exhaust pipeline (53) of the absorbent storage tank, and the outlet of the gas-liquid separator (1) is connected to the inlet pipeline of the oil and gas conveying compressor (2). The outlet of the oil and gas transport compressor (2) is connected to the oil and gas inlet (31) of the oil and gas absorption tower (3); The top of the oil and gas absorption tower (3) is provided with an exhaust port (32), and the bottom of the oil and gas absorption tower (3) is provided with a bottom absorbent outlet; the exhaust port (32) is connected to the pipeline of the subsequent deep purification treatment device, and the bottom absorbent outlet is connected to the inlet pipeline of the rich absorption oil pump (4). The outlet of the rich absorption oil pump (4) is connected to the inlet pipe of the absorbent storage tank (5); the outlet of the absorbent storage tank (5) is connected to the inlet pipe of the lean absorption oil pump (6); and the outlet of the lean absorption oil pump (6) is connected to the inlet pipe of the top spray device of the oil and gas absorption tower (3). The inlet of the rich absorption oil external discharge pipeline (7) is fixedly located on the outlet pipeline of the lean absorption oil pump (6); The outlet end of the stripping nitrogen pipeline (55) is located at the bottom of the absorbent storage tank (5), and the inlet end of the absorbent storage tank exhaust pipeline (53) is connected to the top outlet of the absorbent storage tank (5).

2. The system of claim 1, wherein, A first pressure detection element (PC-02) is fixedly installed in the gas-liquid separator (1), and the first pressure detection element (PC-02) is electrically connected to the control unit of the oil-gas transfer compressor (2).

3. The system of claim 1 or 2, wherein, The oil and gas delivery compressor (2) is a liquid ring compressor. An oil and gas return pipeline is provided between the inlet and outlet of the oil and gas delivery compressor (2). A compressor return regulating valve (21) is fixedly installed on the oil and gas return pipeline.

4. The system of claim 3, wherein, A first flow meter (FC-01) is fixedly installed on the pipeline connecting the outlet of the oil and gas transmission compressor (2) and the oil and gas inlet (31). The first flow meter (FC-01) is electrically connected to the control unit of the compressor return regulating valve (21).

5. The system of claim 1 or 2, wherein, The oil and gas absorption tower (3) has a packing layer inside its tower body. The packing layer is either bulk packing or structured packing made of 304 stainless steel.

6. The system of claim 1 or 2, wherein, A VOCs concentration detector is fixedly installed at the exhaust port (32) of the oil and gas absorption tower (3).

7. The system of claim 1 or 2, wherein, A nitrogen flow regulating valve (52) is fixedly installed on the nitrogen stripping pipeline (55); an absorbent storage tank exhaust flow regulating valve (51) is fixedly installed on the absorbent storage tank exhaust pipeline (53).

8. The system of claim 7, wherein, A second pressure detecting element (PC-03) is fixedly arranged on the absorbent storage tank exhaust pipeline (53) and electrically connected with the control unit of the absorbent storage tank exhaust flow regulating valve (51).

9. The system of claim 7, wherein, A second flow meter (FC-04) is fixedly arranged on the stripping nitrogen pipeline (55) and electrically connected with the control unit of the nitrogen flow regulating valve (52).

10. The system of claim 1, wherein, The absorbent storage tank (5) contains absorbent with a flash point not lower than 165℃.

Images