Oil gas recovery device and method for oil product loading and unloading vehicle and tank field

Abstract

The invention relates to the technical field of oil gas recovery, and discloses an oil gas recovery device and method for an oil product loading and unloading vehicle and a tank field, and the oil gas recovery device comprises a compression and condensation unit which is used for compressing oil gas generated in the loading process and condensing and recovering part of organic matters; the adsorption and desorption unit comprises a plurality of adsorption tanks and is used for adsorbing organic matters in the oil gas through activated carbon and recovering high-concentration organic matters through vacuum desorption; the low-temperature absorption unit is used for removing organic matter components in the desorption gas; and the control system is used for controlling the operation of each unit and acquiring the operation data of the device in real time for analysis and processing. By adopting the technical scheme of combining compression condensation and gas-liquid separation, the oil gas is subjected to effective primary treatment through the compressor and the condenser, the liquid-phase component in the oil gas is separated and recycled, and the technical effect of reducing the treatment load of a subsequent adsorption and desorption unit is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas recovery, and in particular to an oil and gas recovery device and method for oil loading and unloading vehicles and tank areas. Background Art

[0002] Organic chemical products, especially petrochemical products, volatilize oil and gas (VOCs) during loading, unloading and storage. Conventional absorption, adsorption, membrane separation and condensation methods and their combined treatment processes are difficult to achieve continuous and stable emission standards. Biological methods, photocatalytic oxidation methods and low-temperature plasma methods are still very immature in technology. Destruction methods, such as catalytic combustion and high-temperature combustion, generally have problems such as large equipment investment, high operating costs and poor overall performance. The condensation method is mainly based on the characteristics of organic gases. Through the decrease of gas temperature, organic vapor becomes supersaturated, and then liquefied and recovered. Oil and gas can basically be effectively treated by the condensation method, but the condensation method has high energy consumption, high equipment failure rate, and cannot be used for the treatment of low-concentration or light-component waste gas. The absorption method is to select a certain liquid absorbent and use its affinity for organic matter in VOCs organic waste gas to absorb organic matter from the waste gas. It is widely used in the production, storage and transportation of petrochemical products. The absorption efficiency mainly depends on the performance of the absorbent and the level of the absorbent treatment equipment.

[0003] Traditional adsorption methods mostly use activated carbon to adsorb organic components in oil and gas, and regenerate the adsorbent by high-temperature desorption or nitrogen purging. Although the adsorption efficiency is high, high-temperature desorption will cause irreversible damage to the activated carbon pores, significantly shortening the life of the adsorbent. Frequent replacement of the adsorbent not only increases operating costs, but also reduces the economic efficiency of the equipment.

[0004] The condensation method recovers the oil and gas by condensing it through lowering its temperature. However, the condensation method alone has limited effect on the treatment of oil and gas with low gas component concentrations. There are still a lot of unrecovered organic matter in the exhaust gas, which cannot meet strict emission requirements. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides an oil and gas recovery device and method for oil loading and unloading vehicles and tank farms, which solves the problem that the traditional adsorption method mostly uses activated carbon to adsorb organic components in oil and gas, and regenerates the adsorbent by high-temperature desorption or nitrogen purge. Although the adsorption efficiency is high, high-temperature desorption will cause irreversible damage to the activated carbon pores and significantly shorten the life of the adsorbent, and the common absorption method has a large amount of absorbent and low absorption efficiency.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: an oil and gas recovery device for oil loading and unloading vehicles and tank areas, comprising:

[0007] The compression and condensation unit is used to compress the oil and gas generated during the loading process and condense and recover some organic matter;

[0008] Adsorption and desorption unit, including multiple adsorption tanks, is used to adsorb organic matter in oil and gas through activated carbon and recover high-concentration organic matter through vacuum desorption;

[0009] Low temperature absorption unit, used to remove organic components in the desorbed gas;

[0010] The control system is used to control the operation of the above-mentioned units and collect the operation data of the device in real time for analysis and processing.

[0011] Preferably, the compression condensing unit includes a compressor, a condenser and a gas-liquid separator, the inlet of the compressor is connected to the gas storage tank, the outlet is connected to the inlet of the condenser, the outlet of the condenser is connected to the gas-liquid separator through a pipeline, and the gas-liquid separator is used to separate the condensed oil and gas mixture, wherein the liquid part is transported to the tank area through a production pump, and the gas part enters the adsorption and desorption unit.

[0012] Preferably, the adsorption and desorption unit comprises a plurality of adsorption tanks and a vacuum pump, the bottom gas phase inlet of the adsorption tank is connected to the top gas phase outlet of the gas-liquid separator, the top gas phase outlet of the adsorption tank is connected to the chimney, the top nitrogen inlet is connected to the nitrogen pipeline for replenishing nitrogen during desorption, the bottom desorption outlet is connected to the vacuum pump inlet, and the vacuum pump outlet is connected to the subsequent low-temperature absorption unit.

[0013] Preferably, the low-temperature absorption unit includes an absorption tower, a heat exchanger, a refrigerator, and an oil-rich production pump. The gas phase inlet at the bottom of the absorption tower is connected to the vacuum pump outlet, the gas phase outlet at the top is connected to the compressor inlet, the liquid phase inlet at the top of the absorption tower is connected to the heat exchanger outlet, the heat exchanger inlet is connected to the gasoline tank area, the liquid phase outlet of the absorption tower kettle is connected to the oil-rich production pump inlet, and the oil-rich production pump outlet is connected to the tank area.

[0014] A method for recovering oil and gas in oil loading and unloading vehicles and tank farms, comprising the following steps:

[0015] S1. Oil and gas compression and condensation: The oil and gas generated by loading are pressurized by the compressor and then enter the condenser to recover some organic matter;

[0016] S2. Oil and gas adsorption: non-condensable gas is passed into the adsorption unit, and activated carbon is used to adsorb organic matter in the oil and gas;

[0017] S3. Vacuum desorption: vacuum desorption of the saturated adsorption tank to recover high-concentration organic matter;

[0018] S4. Low temperature absorption: The desorbed gas is passed into the low temperature absorption unit to absorb the organic components therein.

[0019] Preferably, the vacuum desorption includes three steps of vacuuming, vacuum cleaning and breaking the vacuum, and the desorbed gas is returned to the system inlet after being processed by the low-temperature absorption unit.

[0020] Preferably, during the adsorption process, the adsorption tanks are operated in series to ensure that the non-methane total hydrocarbon content in the tail gas is less than 50 mg / m 3 In the low-temperature absorption step, the absorbent in the absorption tower is set to gasoline, and its temperature is controlled by a heat exchanger to improve the absorption efficiency.

[0021] Preferably, when the device is running, the control system monitors the compressor pressure, the adsorption tank pressure, the desorption gas concentration, and the operating status of each valve in real time, and generates an operation report.

[0022] Preferably, during the vacuum desorption process, the inert components of the desorbed gas are significantly reduced, the organic matter concentration is greatly increased, and the gas volume is greatly reduced, thereby reducing the amount of absorbent and equipment investment. All steps of the method can be operated at room temperature, reducing the energy consumption of the device operation.

[0023] The present invention provides an oil and gas recovery device and method for oil loading and unloading vehicles and tank areas. It has the following beneficial effects:

[0024] 1. The present invention adopts a technical solution combining compression condensation with gas-liquid separation, performs effective preliminary treatment on oil and gas through a compressor and a condenser, separates and recovers the liquid components in the oil and gas, and achieves the technical effect of reducing the processing load of the subsequent adsorption and desorption unit. Compared with the technical solution of directly treating the entire oil and gas flow through the adsorption unit in the prior art, it solves the problems of low adsorption efficiency and high activated carbon usage, and significantly improves the operating reliability and service life of the device.

[0025] 2. The present invention adopts a technical solution combining multiple adsorption tanks in series with vacuum desorption technology. Through three adsorption tanks alternately performing adsorption and desorption operations, the system is ensured to operate continuously and efficiently, achieving the technical effect of efficiently recovering organic components in oil and gas. Compared with the technical solutions of single-stage adsorption and hot nitrogen desorption in the prior art, which cause large adsorbent loss, the present invention solves the problems of high energy consumption, poor adsorption effect, and frequent replacement of adsorbents, effectively reduces operating costs and prolongs the service life of adsorbents.

[0026] 3. The present invention adopts a technical solution of further treating the desorbed tail gas by using a low-temperature absorption unit. The organic components in the tail gas are absorbed from top to bottom by the cooled absorbent, achieving the technical effect of efficient purification of tail gas and resource utilization. Compared with the technical solution of directly recycling the desorbed tail gas back to the inlet of the device in the prior art, the hidden danger of light components circulating and accumulating in the system is effectively avoided, and the safety and economic benefits of the system are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a complete system architecture diagram of the present invention;

[0028] Figure 2 It is a system flow chart of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings of the present invention specification to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Please see attached Figure 1 - Attachment Figure 2 The embodiment of the present invention provides an oil and gas recovery method for oil loading and unloading vehicles and tank farms, comprising the following steps:

[0031] S1. Oil and gas compression and condensation: The oil and gas generated by loading are pressurized by the compressor and then enter the condenser to recover some organic matter;

[0032] S2. Pressurized adsorption: non-condensable gas is passed into the adsorption unit, and activated carbon is used to adsorb organic matter in the oil and gas;

[0033] S3. Vacuum desorption: vacuum desorption of the saturated adsorption tank to recover high-concentration organic matter;

[0034] S4. Low temperature absorption: passing the desorbed gas into the low temperature absorption unit to absorb the organic components therein;

[0035] The above method adopts an oil and gas recovery device for oil loading and unloading vehicles and tank farms, comprising:

[0036] The compression and condensation unit is used to compress the oil and gas generated during the loading process and condense and recover some organic matter;

[0037] Adsorption and desorption unit, including multiple adsorption tanks, is used to adsorb organic matter in oil and gas through activated carbon and recover high-concentration organic matter through vacuum desorption;

[0038] Low temperature absorption unit, used to remove organic components in the desorbed gas;

[0039] The control system is used to control the operation of the above-mentioned units and collect the operation data of the device in real time for analysis and processing.

[0040] The compression condensing unit includes a compressor, a condenser and a gas-liquid separator. The inlet of the compressor is connected to the buffer tank, and the outlet is connected to the inlet of the condenser. The outlet of the condenser is connected to the gas-liquid separator through a pipeline. The gas-liquid separator is used to separate the condensed oil and gas mixture, wherein the liquid part is transported to the tank area through a production pump, and the gas part enters the adsorption and desorption unit.

[0041] The adsorption and desorption unit includes multiple adsorption tanks and vacuum pumps. The gas phase inlet at the bottom of the adsorption tank is connected to the gas phase outlet at the top of the gas-liquid separator, the gas phase outlet at the top of the adsorption tank is connected to the chimney, the nitrogen inlet at the top is connected to the nitrogen pipeline for replenishing nitrogen during desorption, the desorption outlet at the bottom is connected to the inlet of the vacuum pump, and the vacuum pump outlet is connected to the subsequent low-temperature absorption unit.

[0042] The low-temperature absorption unit includes an absorption tower, a heat exchanger, a refrigerator, and an oil-rich production pump. The gas phase inlet at the bottom of the absorption tower is connected to the vacuum pump outlet, the gas phase outlet at the top is connected to the compressor inlet, the liquid phase inlet at the top of the absorption tower is connected to the heat exchanger outlet, the heat exchanger inlet is connected to the gasoline tank area, the liquid phase outlet of the absorption tower kettle is connected to the oil-rich production pump inlet, and the oil-rich production pump outlet is connected to the tank area.

[0043] Specifically, S1. Oil and gas compression and condensation: The oil and gas generated by loading are pressurized to about 0.3MPa by a compressor, and the intermolecular interaction force is enhanced by pressurization, thereby improving the subsequent condensation and adsorption effects, effectively recovering the liquid organic components while reducing the subsequent processing load. After pressurization, the high-temperature oil and gas are passed into the condenser, condensed to about 0-10°C, and then passed into the gas-liquid separator. The separated liquid phase is produced to the tank area through a production pump, and the separated gas phase is passed into the subsequent adsorption and desorption unit; S2. Pressurized adsorption: The non-condensable gas is passed into the adsorption unit. The adsorption tank adopts pressurized operation, and the high-efficiency adsorption characteristics of activated carbon are used to capture and process the organic matter in the oil and gas. Through the design of multiple adsorption tanks in series, the concentration of non-methane total hydrocarbons in the exhaust gas is kept <60mg / m 3, in line with national emission standards, the series operation of the adsorption units not only improves the adsorption efficiency and ensures the adsorption effect, but also avoids over-saturation of the adsorbent by optimizing the switching operation; S3. Vacuum desorption, vacuum desorption of the adsorption tank saturated with adsorption, and recovery of high-concentration organic matter. Vacuum desorption includes three steps: vacuum pumping, vacuum cleaning and vacuum breaking. Vacuum pumping reduces the pressure in the adsorption tank by a vacuum pump. After it drops to about 5kPa(a), the organic matter in the adsorbent is gradually desorbed. Vacuum cleaning uses a small amount of nitrogen to further reduce the oil and gas partial pressure to completely regenerate the adsorbent. Vacuum breaking gradually restores the system to normal pressure by controlling the air pressure. , this process not only improves the desorption efficiency, but also significantly extends the service life of the adsorbent; S4. Low-temperature absorption, the desorbed gas is passed into the low-temperature absorption unit to absorb the organic components therein, and the absorbent is reduced to about -10 to 0°C through the heat exchanger, and then passed into the liquid phase inlet at the top of the absorption tower, and the organic matter in the desorbed tail gas is efficiently absorbed by the cooled absorbent, so as to avoid the accumulation of organic matter in the system and cause the exhaust gas at the outlet of the device to exceed the standard. The small amount of non-condensable steam remaining at the top of the absorption tower is returned to the compressor inlet for treatment. At the same time, by setting the absorbent to an efficient absorption solvent such as gasoline, resource recovery is achieved, and the amount of absorbent and equipment investment are reduced. Under the real-time monitoring of the control system, the entire method can dynamically adjust the operating parameters, such as compressor pressure, adsorption tank pressure and desorbed gas concentration, to ensure that the system can realize the automation and intelligent management of the entire process while operating efficiently, and generate an operation report to guide equipment maintenance and optimize operations. Compared with the prior art, the method of the present invention avoids the problems of low oil and gas recovery efficiency, high equipment energy consumption and incomplete resource utilization by precisely controlling the operating conditions of each unit, and achieves the significant technical effects of low energy consumption, high recovery rate and resource utilization. All steps of the method can be operated under normal temperature conditions, which not only reduces the complexity of the equipment and the operating cost, but also effectively reduces the energy consumption of the system, thereby further improving the economy and environmental friendliness of the method.

[0044] Working principle: It adopts the process of compression condensation plus pressurized adsorption plus vacuum desorption plus low-temperature absorption. First, the oil and gas generated by loading are pressurized by the compressor and then passed into the condenser. Condensation can eliminate the heat generated by gas compression, and can recover some organic matter, reduce the load of subsequent adsorption units, improve adsorption efficiency, and prevent overheating caused by adsorption heat release. The condensate generated by condensation is produced by the production pump to the tank area, and the non-condensable steam after condensation is passed into the subsequent adsorption and desorption unit.

[0045] The adsorption unit is equipped with three adsorption tanks, which are operated in series, two for adsorption and one for desorption. After the desorption, the adsorption tank switches back to the adsorption state, thus completing a cycle. After the tail gas enters the adsorption tank, the C2, C3, C4 and above organic matter are adsorbed by the activated carbon, and the separated gas reaches the required pressure reduction and is discharged through the chimney.

[0046] The adsorption bed regeneration operation includes three steps: vacuuming step, vacuum cleaning step and vacuum breaking step.

[0047] Vacuuming step: Use the vacuum pump to evacuate the adsorption bed. As the vacuum pressure decreases, the organic matter adsorbed on the adsorbent gradually begins to be desorbed. The desorbed gas with a high concentration of organic matter discharged from the vacuum pump outlet is passed into the subsequent low-temperature absorption unit.

[0048] Vacuum cleaning step - while the vacuum pump continues to evacuate the adsorption bed, open the cleaning gas valve on the outlet side of the adsorption bed to introduce a small amount of nitrogen, which further desorbs the organic matter adsorbed on the adsorbent by reducing the oil and gas partial pressure. The desorbed gas obtained in the vacuum cleaning step undergoes the same process as the desorbed gas obtained in the second extraction step. After the vacuum cleaning step, the adsorption bed is completely regenerated.

[0049] Vacuum breaking step: open the cleaning vacuum breaking valve on the outlet side of the adsorption bed, and gradually break the vacuum of the adsorption bed evenly to atmospheric pressure with air or nitrogen under the control of the vacuum breaking regulating valve.

[0050] At this point, an adsorption bed completes one adsorption cycle and enters the cycle of the next adsorption cycle.

[0051] The purpose of the low-temperature absorption unit is to remove organic components from the desorbed gas, pass the high-concentration tail gas desorbed from the adsorption tank into the bottom inlet of the absorption tower, set a heat exchanger in the gasoline feed pipeline to cool the absorbent to improve the absorption efficiency, and transport the low-temperature absorbent to the top of the absorption tower to absorb hydrocarbon components and other chemically active substances in the oil and gas from top to bottom. The absorbed oil is returned to the storage tank through the rich oil pump, and the gas phase at the top of the tower returns to the inlet of the device.

[0052] Through the above design, the present invention realizes the efficient separation and recovery of organic matter in oil and gas, which not only reduces the energy consumption of the system, optimizes the working efficiency of the device, but also significantly improves the operating efficiency and economy of the entire device. Compared with the prior art, the present invention effectively makes up for the limitations of single condensation or adsorption treatment technology, and the pressurized conditions greatly improve the treatment efficiency of the condensation and adsorption units, and absorbs the desorbed gas at low temperature, avoiding the circulation and accumulation of light components in the system, solving the problems of high energy consumption and low resource utilization in the oil and gas recovery process, and significantly improving the overall performance and service life of the device.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An oil and gas recovery device for oil loading and unloading vehicles and tank farms, characterized in that: include: The compression and condensation unit is used to compress the oil and gas generated during the loading process and condense and recover some organic matter; Adsorption and desorption unit, including multiple adsorption tanks, is used to adsorb organic matter in oil and gas through activated carbon and recover high-concentration organic matter through vacuum desorption; Low temperature absorption unit, used to remove organic components in the desorbed gas; The control system is used to control the operation of the above-mentioned units and collect the operation data of the device in real time for analysis and processing.

2. The oil and gas recovery device for oil loading and unloading vehicles and tank farms according to claim 1 is characterized in that: The compression condensation unit comprises a compressor, a condenser and a gas-liquid separator, wherein the inlet of the compressor is connected to the buffer tank, the outlet is connected to the inlet of the condenser, the outlet of the condenser is connected to the gas-liquid separator through a pipeline, and the gas-liquid separator is used to separate the condensed oil-gas mixture, wherein the liquid part is transported to the tank area through the production pump, and the gas part enters the adsorption and desorption unit; The adsorption and desorption unit comprises a plurality of adsorption tanks and a vacuum pump, wherein the gas phase inlet at the bottom of the adsorption tank is connected to the gas phase outlet at the top of the gas-liquid separator, the gas phase outlet at the top of the adsorption tank is connected to the chimney, the nitrogen inlet at the top is connected to the nitrogen pipeline for supplementing nitrogen during desorption, the desorption outlet at the bottom is connected to the inlet of the vacuum pump, and the outlet of the vacuum pump is connected to the subsequent low-temperature absorption unit; The low-temperature absorption unit includes an absorption tower, a heat exchanger, a refrigerator, and an oil-rich production pump. The gas phase inlet at the bottom of the absorption tower is connected to the vacuum pump outlet, the gas phase outlet at the top is connected to the compressor inlet, the liquid phase inlet at the top of the absorption tower is connected to the heat exchanger outlet, the heat exchanger inlet is connected to the gasoline tank area, the liquid phase outlet of the absorption tower kettle is connected to the oil-rich production pump inlet, and the oil-rich production pump outlet is connected to the tank area.

3. An oil and gas recovery method for oil loading and unloading vehicles and tank farms, according to the oil and gas recovery device for oil loading and unloading vehicles and tank farms described in claim 1-2, characterized in that: The following steps are involved: S1. Oil and gas compression and condensation: The oil and gas generated by loading are pressurized by the compressor and then enter the condenser to recover some organic matter; S2. Oil and gas adsorption: non-condensable gas is passed into the adsorption unit, and activated carbon is used to adsorb organic matter in the oil and gas; S3. Vacuum desorption: vacuum desorption of the saturated adsorption tank to recover high-concentration organic matter; S4. Low temperature absorption: The desorbed gas is passed into the low temperature absorption unit to absorb the organic components therein.

4. The oil and gas recovery method for oil loading and unloading vehicles and tank farms according to claim 3 is characterized in that: The vacuum desorption includes three steps of vacuuming, vacuum cleaning and breaking the vacuum. The desorbed gas is processed by the low-temperature absorption unit and then returns to the system inlet.

5. The oil and gas recovery method for oil loading and unloading vehicles and tank farms according to claim 3 is characterized in that: During the adsorption process, multiple adsorption tanks are set up in series to ensure that the total non-methane hydrocarbon content in the tail gas is less than 50 mg / m 3 In the low-temperature absorption step, the absorbent in the absorption tower is set to gasoline, and its temperature is controlled by a heat exchanger to improve the absorption efficiency.

6. The oil and gas recovery method for oil loading and unloading vehicles and tank farms according to claim 3 is characterized in that: When the device is running, the control system monitors the compressor pressure, the adsorption tank pressure, the desorption gas concentration and the operating status of each valve in real time, and generates an operating report.

7. The oil and gas recovery method for oil loading and unloading vehicles and tank farms according to claim 3 is characterized in that: During the vacuum desorption process, the inert components of the desorbed gas are significantly reduced, the organic matter concentration is greatly increased, and the gas volume is greatly reduced, thereby reducing the amount of absorbent and equipment investment. All steps of the method can be operated at room temperature, reducing the energy consumption of the device operation.

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