A gas station oil and gas recovery system based on a three-stage composite process

Abstract

This invention belongs to the field of oil and gas recovery technology, and particularly relates to an oil and gas recovery system for gas stations based on a three-stage composite process, comprising: an oil storage tank; a condensation mechanism, with its inlet connected to the outlet of the oil storage tank and its outlet connected to the return outlet of the oil storage tank; a gas-liquid separation mechanism, with its inlet connected to the outlet of the condensation mechanism and its outlet connected to the return outlet of the oil storage tank; and a membrane separation mechanism, with its inlet connected to the outlet of the gas-liquid separation mechanism and its outlet connected to the return outlet of the oil storage tank. This invention can reduce the energy consumption and operating costs of oil and gas recovery, and improve the adaptability of the oil and gas recovery system.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas recovery technology, and particularly relates to an oil and gas recovery system for gas stations based on a three-stage composite process. Background Technology

[0002] Gas station vapor recovery primarily addresses volatile organic compounds (VOCs) emitted during tanker unloading and vehicle refueling. Condensation combined with adsorption is a classic process. The vapors are first liquefied and condensed to recover most of the vapors, then adsorbed to treat the remaining low-concentration vapors. The key lies in the seamless integration and coordination between these two units. The equipment structure includes the condenser unit, adsorption tank, piping, and instrumentation. The methodology emphasizes the operational procedures and key parameters, such as condensation temperature control and adsorbent regeneration cycle. The drawbacks of the condensation + adsorption combined process include high energy consumption, high operating costs, system complexity, and poor adaptability to low-temperature environments.

[0003] Therefore, it is necessary to design a gas station oil and gas recovery system based on a three-stage composite process to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a gas station oil and gas recovery system based on a three-stage composite process to solve the above-mentioned problems and achieve the goals of reducing energy consumption, reducing operating costs, and improving adaptability.

[0005] To achieve the above objectives, the present invention provides the following solution: a gas station oil and gas recovery system based on a three-stage composite process, comprising: Oil storage tanks; The condensing mechanism has an inlet connected to the outlet of the oil storage tank, and the outlet of the condensing mechanism is connected to the return outlet of the oil storage tank. The gas-liquid separation mechanism has an air inlet connected to the air outlet of the condensation mechanism, and a liquid outlet connected to the liquid return port of the oil storage tank. The membrane separation mechanism has an air inlet connected to the air outlet of the gas-liquid separation mechanism, and a liquid outlet connected to the liquid return port of the oil storage tank.

[0006] The present invention discloses a gas station oil and gas recovery system based on a three-stage composite process. The condensation mechanism includes a refrigeration unit. The liquid inlet of the refrigeration unit is connected to the liquid outlet of the oil storage tank, the liquid outlet of the refrigeration unit is connected to the liquid return outlet of the oil storage tank, and the air outlet of the refrigeration unit is connected to the air inlet of the gas-liquid separation mechanism.

[0007] The present invention discloses a gas station oil and gas recovery system based on a three-stage composite process, wherein a flame arrester, a flow meter, and a one-way valve are provided between the liquid inlet of the refrigeration unit and the liquid outlet of the oil storage tank, and the one-way valve is provided between the liquid outlet of the refrigeration unit and the liquid return port of the oil storage tank.

[0008] The present invention discloses a gas station oil and gas recovery system based on a three-stage composite process. The gas-liquid separation mechanism includes an air compressor. The air inlet of the air compressor is connected to the air outlet of the refrigeration unit. The air outlet of the air compressor is connected to the air inlet of a gas-liquid separator. The liquid outlet of the gas-liquid separator is connected to the liquid return port of the oil storage tank. The air outlet of the gas-liquid separator is connected to the air inlet of the membrane separation mechanism.

[0009] The present invention discloses a gas station oil and gas recovery system based on a three-stage composite process, wherein a pressure transmitter and an angle valve are provided between the liquid outlet of the gas-liquid separator and the liquid return port of the oil storage tank.

[0010] The present invention discloses a gas station oil and gas recovery system based on a three-stage composite process. The membrane separation mechanism includes a membrane module. The air inlet of the membrane module is connected to the air outlet of the gas-liquid separator, and the liquid outlet of the membrane module is connected to the liquid return outlet of the oil storage tank. The air outlet of the membrane module is provided with an exhaust section.

[0011] The present invention discloses a gas station oil and gas recovery system based on a three-stage composite process. The exhaust section includes an exhaust pipe, one end of which is connected to the outlet of the membrane module, and the other end of which is provided with a flame arrestor and vent cap. The exhaust pipe is provided with a flame arrester, an angle valve, a tee, and a solenoid valve. The third port of the tee is provided with another solenoid valve.

[0012] The present invention discloses a gas station oil and gas recovery system based on a three-stage composite process, wherein a temperature sensor is provided between the gas outlet of the gas-liquid separator and the gas inlet of the membrane module, and a desorption pump and an angle valve are provided between the liquid outlet of the membrane module and the liquid return port of the oil storage tank.

[0013] The present invention discloses a gas station oil and gas recovery system based on a three-stage composite process, wherein the return port of the oil storage tank is provided with a four-way valve, the second interface of the four-way valve is connected to the liquid outlet of the refrigeration unit, the third interface of the four-way valve is connected to the liquid outlet of the gas-liquid separator, and the fourth interface of the four-way valve is connected to the liquid outlet of the membrane module.

[0014] The present invention discloses a gas station oil and gas recovery system based on a three-stage composite process, wherein the outlet of the oil storage tank is equipped with a flame-retardant and ventilated cap.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects: This invention achieves more efficient oil and gas recovery and lower exhaust emissions through a three-stage treatment process. First, a condensation unit liquefies and recovers most of the oil and gas. Then, a gas-liquid separation unit pressurizes and separates the uncondensed oil and gas, further recovering liquid hydrocarbons. Finally, a membrane separation unit selectively separates the remaining low-concentration oil and gas, returning the permeate to the storage tank, and purifying the exhaust gas to meet emission standards. This technical solution, through multi-stage coordination and integrated control of precision components, significantly improves overall recovery efficiency and operational stability, while avoiding the energy consumption and maintenance problems associated with adsorbent regeneration. The system is more adaptable, effectively reducing operating costs and achieving an optimized upgrade of the oil and gas recovery process. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall invention.

[0018] The components include: 1. Oil storage tank; 2. Flame arrestor vent cap; 3. Flame arrester; 4. Flow meter; 5. Check valve; 6. Refrigeration unit; 7. Air compressor; 8. Pressure transmitter; 9. Four-way valve; 10. Desorption pump; 11. Angle valve; 12. Gas-liquid separator; 13. Temperature sensor; 14. Membrane module; 15. T-junction; 16. Solenoid valve; and 17. Exhaust pipeline. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Reference Figure 1 As shown, this invention provides a gas station oil and gas recovery system based on a three-stage composite process, comprising: Oil storage tank 1; The condensing mechanism has its inlet connected to the outlet of the oil storage tank 1, and its outlet connected to the return port of the oil storage tank 1. The gas-liquid separation mechanism has an air inlet connected to the air outlet of the condensation mechanism, and a liquid outlet connected to the liquid return port of the oil storage tank 1. The membrane separation mechanism has its air inlet connected to the air outlet of the gas-liquid separation mechanism, and its liquid outlet connected to the liquid return port of the oil storage tank 1.

[0022] Furthermore, the condensation mechanism includes a refrigeration unit 6, the liquid inlet of the refrigeration unit 6 is connected to the liquid outlet of the oil storage tank 1, the liquid outlet of the refrigeration unit 6 is connected to the liquid return outlet of the oil storage tank 1, and the air outlet of the refrigeration unit 6 is connected to the air inlet of the gas-liquid separation mechanism.

[0023] Furthermore, a flame arrester 3, a flow meter 4, and a one-way valve 5 are installed between the liquid inlet of the refrigeration unit 6 and the liquid outlet of the oil storage tank 1, and a one-way valve 5 is installed between the liquid outlet of the refrigeration unit 6 and the liquid return port of the oil storage tank 1.

[0024] Furthermore, the gas-liquid separation mechanism includes an air compressor 7, the air inlet of the air compressor 7 is connected to the air outlet of the refrigeration unit 6, the air outlet of the air compressor 7 is connected to the air inlet of the gas-liquid separation tank 12, the liquid outlet of the gas-liquid separation tank 12 is connected to the liquid return port of the oil storage tank 1, and the air outlet of the gas-liquid separation tank 12 is connected to the air inlet of the membrane separation mechanism.

[0025] Furthermore, a pressure transmitter 8 and an angle valve 11 are installed between the liquid outlet of the gas-liquid separator 12 and the liquid return port of the oil storage tank 1.

[0026] Furthermore, the membrane separation mechanism includes a membrane module 14, the air inlet of the membrane module 14 is connected to the air outlet of the gas-liquid separator 12, the liquid outlet of the membrane module 14 is connected to the liquid return outlet of the oil storage tank 1, and the air outlet of the membrane module 14 is provided with an exhaust section.

[0027] Furthermore, the exhaust section includes an exhaust pipe 17, one end of which is connected to the air outlet of the membrane module 14, and the other end of the exhaust pipe 17 is provided with a flame arrestor and vent cap 2. The exhaust pipe 17 is provided with a flame arrester 3, an angle valve 11, a three-way valve 15, and a solenoid valve 16. The third interface of the three-way valve 15 is provided with another solenoid valve 16.

[0028] Furthermore, a temperature sensor 13 is installed between the gas outlet of the gas-liquid separator 12 and the gas inlet of the membrane module 14, and a desorption pump 10 and an angle valve 11 are installed between the liquid outlet of the membrane module 14 and the liquid return port of the oil storage tank 1.

[0029] Furthermore, the return port of the oil storage tank 1 is equipped with a four-way valve 9. The second interface of the four-way valve 9 is connected to the liquid outlet of the refrigeration unit 6, the third interface of the four-way valve 9 is connected to the liquid outlet of the gas-liquid separator 12, and the fourth interface of the four-way valve 9 is connected to the liquid outlet of the membrane module 14.

[0030] Furthermore, the outlet of the oil storage tank 1 is equipped with a flame-arresting and ventilated cap 2.

[0031] The working process of this invention is as follows: The oil and gas first exit from the outlet of the storage tank, passing through the first flame arrestor and vent cap to ensure initial safety. Subsequently, the oil and gas flow sequentially through the flame arrestor, flow meter, and check valve. The flow meter monitors the amount of oil and gas processed, and the check valve prevents backflow. The oil and gas then enter the core heat exchange unit of the condensation mechanism. Here, the refrigeration system cools the oil and gas to a lower temperature, causing most of the high-hydrogen compounds to condense and liquefy. The liquefied oil then flows through pipelines, passes through the check valve, and merges into the return main pipe connected to the return port of the storage tank, ultimately returning to the storage tank, completing the first stage of primary recovery.

[0032] After condensation, the unliquefied, low-concentration, low-temperature oil and gas enters the gas-liquid separation unit from the outlet of the refrigeration unit. The core of this unit is the air compressor, which pressurizes the incoming gas. This pressurization process serves a dual purpose: first, it increases the partial pressure of the oil and gas, causing some of the oil and gas that is difficult to condense at normal pressure to undergo further condensation based on the dew point characteristics of hydrocarbons; second, it provides the necessary operating pressure differential for the subsequent membrane separation unit. The pressurized gas-liquid mixture enters the gas-liquid separator. Inside the separator, due to the reduced flow rate and gravity, the condensed droplets are separated. The separated liquid flows through the bottom outlet of the separator, controlled by a pressure transmitter and angle valve, and is also returned to the storage tank via the return main. At this point, the hydrocarbon concentration in the gas has been significantly reduced.

[0033] The oil and gas exiting from the top of the gas-liquid separator, having undergone the first two stages of treatment, are monitored by temperature sensors before entering the membrane separation unit to ensure their temperature remains within the optimal operating range of the membrane module. The oil and gas then enter the membrane module. Membrane separation technology leverages the differences in dissolution-diffusion rates of different gas components within the membrane material to achieve highly selective permeation of hydrocarbon VOCs. Driven by pressure differential, hydrocarbon molecules in the oil and gas preferentially permeate through the membrane wall, becoming hydrocarbon-rich permeate gas. This permeate gas is collected on the other side of the membrane module and transported via a desorption pump and angle valve, ultimately flowing into the return manifold and back to the oil storage tank, maximizing hydrocarbon recovery.

[0034] The remaining gas that fails to permeate the membrane is mainly purified air, with hydrocarbon concentrations far below national emission standards. This compliant exhaust gas enters the exhaust section from the membrane module's outlet. The exhaust section piping is sequentially equipped with a flame arrester, angle valve, tee, and solenoid valve, ultimately being safely discharged into the atmosphere through a flame arrestor vent cap. The solenoid valve in the piping can automatically control the exhaust process based on system pressure or concentration monitoring signals. The tee and another solenoid valve configuration may be used for auxiliary functions such as system purging, backflushing, or safety pressure relief to ensure long-term stable system operation.

[0035] The entire system's liquid recovery pipelines converge through a four-way connector, clearly separating the recovered liquid flows from three different process units and returning them uniformly to the storage tank, resulting in a compact structure. A flame-retardant vent cap at the storage tank outlet maintains the tank's breathing balance when the system is not operating. By integrating flow, pressure, and temperature monitoring instruments and automatic valves, the system achieves continuous monitoring and automatic adjustment of key parameters such as condensation temperature, compressor start / stop and pressure, membrane inlet temperature, and regeneration / discharge cycle, forming a closed, efficient, and automated three-stage oil and gas recovery treatment cycle. Ultimately, this improves the recovery rate while ensuring stable and compliant emissions of exhaust gases.

[0036] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0037] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope of the present invention.

Claims

1. A gas station oil and gas recovery system based on a three-stage composite process, characterized in that, include: Oil storage tank (1); The condensing mechanism has an inlet connected to the outlet of the oil storage tank (1) and an outlet connected to the return port of the oil storage tank (1). The gas-liquid separation mechanism has an air inlet connected to the air outlet of the condensation mechanism, and a liquid outlet connected to the liquid return port of the oil storage tank (1). The membrane separation mechanism has an air inlet connected to the air outlet of the gas-liquid separation mechanism, and a liquid outlet connected to the liquid return port of the oil storage tank (1).

2. The vapor recovery system for gas stations based on a three-stage composite process according to claim 1, characterized in that, The condensation mechanism includes a refrigeration unit (6), the liquid inlet of the refrigeration unit (6) is connected to the liquid outlet of the oil storage tank (1), the liquid outlet of the refrigeration unit (6) is connected to the liquid return port of the oil storage tank (1), and the air outlet of the refrigeration unit (6) is connected to the air inlet of the gas-liquid separation mechanism.

3. The gas station oil and gas recovery system based on a three-stage composite process according to claim 2, characterized in that, A flame arrester (3), a flow meter (4), and a check valve (5) are provided between the liquid inlet of the refrigeration unit (6) and the liquid outlet of the oil storage tank (1). The check valve (5) is provided between the liquid outlet of the refrigeration unit (6) and the liquid return port of the oil storage tank (1).

4. A gas station oil and gas recovery system based on a three-stage composite process according to claim 2, characterized in that, The gas-liquid separation mechanism includes an air compressor (7), the air inlet of the air compressor (7) is connected to the air outlet of the refrigeration unit (6), the air outlet of the air compressor (7) is connected to the air inlet of the gas-liquid separation tank (12), the liquid outlet of the gas-liquid separation tank (12) is connected to the liquid return port of the oil storage tank (1), and the air outlet of the gas-liquid separation tank (12) is connected to the air inlet of the membrane separation mechanism.

5. A gas station oil and gas recovery system based on a three-stage composite process according to claim 4, characterized in that, A pressure transmitter (8) and an angle valve (11) are provided between the outlet of the gas-liquid separator (12) and the return port of the oil storage tank (1).

6. A gas station oil and gas recovery system based on a three-stage composite process according to claim 4, characterized in that, The membrane separation mechanism includes a membrane module (14), the air inlet of the membrane module (14) is connected to the air outlet of the gas-liquid separator (12), the liquid outlet of the membrane module (14) is connected to the liquid return port of the oil storage tank (1), and the air outlet of the membrane module (14) is provided with an exhaust section.

7. A gas station oil and gas recovery system based on a three-stage composite process according to claim 6, characterized in that, The exhaust section includes an exhaust pipe (17), one end of which is connected to the outlet of the membrane assembly (14), and the other end of the exhaust pipe (17) is provided with a flame arrestor and vent cap (2). The exhaust pipe (17) is provided with a flame arrestor (3), an angle valve (11), a three-way valve (15), and a solenoid valve (16). The third port of the three-way valve (15) is provided with another solenoid valve (16).

8. A gas station oil and gas recovery system based on a three-stage composite process according to claim 6, characterized in that, A temperature sensor (13) is provided between the gas outlet of the gas-liquid separator (12) and the gas inlet of the membrane module (14), and a desorption pump (10) and an angle valve (11) are provided between the liquid outlet of the membrane module (14) and the liquid return port of the oil storage tank (1).

9. A gas station oil and gas recovery system based on a three-stage composite process according to claim 6, characterized in that, The return port of the oil storage tank (1) is provided with a four-way valve (9). The second interface of the four-way valve (9) is connected to the outlet of the refrigeration unit (6), the third interface of the four-way valve (9) is connected to the outlet of the gas-liquid separator (12), and the fourth interface of the four-way valve (9) is connected to the outlet of the membrane module (14).

10. A gas station oil and gas recovery system based on a three-stage composite process according to claim 1, characterized in that, The oil storage tank (1) is equipped with a flame-retardant and ventilated cap (2) at its outlet.

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