Oil gas recovery system and oil gas recovery process for reducing hydrocarbon concentration

Abstract

The invention relates to an oil gas recovery system and an oil gas recovery process capable of reducing hydrocarbon concentration, and the oil gas recovery system capable of reducing hydrocarbon concentration comprises a first-stage pressure swing adsorption oil gas recovery system, a second-stage pressure swing adsorption oil gas recovery system, a third-stage pressure swing adsorption oil gas recovery system and a fourth-stage pressure swing adsorption oil gas recovery system, the second-stage activated carbon adsorption system is connected with the exhaust end of the first-stage pressure swing adsorption oil gas recovery system, and the second-stage activated carbon adsorption system comprises a first activated carbon bed layer V-A and a second activated carbon bed layer V-B which alternately work; the regeneration system is used for providing a vacuum environment required by regeneration for the first activated carbon bed layer V-A and the second activated carbon bed layer V-B; and the automatic valve system is used for controlling the adsorption and regeneration processes of the first activated carbon bed layer V-A and the second activated carbon bed layer V-B. The system has the advantages that the overall performance of the system can be improved, efficient resource utilization is achieved, and continuous work can be 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 system and an oil and gas recovery process for reducing the concentration of hydrocarbons. Background Art

[0002] With the acceleration of industrialization and urbanization, the application of petroleum and its derivatives has become increasingly widespread, which has also led to the emission of a large amount of waste gas containing hydrocarbons. Hydrocarbons not only pose a serious threat to environmental air quality, but may also have adverse effects on human health.

[0003] In the prior art, the filling of liquid HC products is carried out by pumping the product into empty containers (filled with air) in trucks, trains or ships. Once the liquid enters the tank or other container, it will evaporate and saturate the gas phase space according to its true vapor pressure and temperature. As the liquid gradually fills the container, the pressure in the container will increase, causing the safety valve to open; therefore, the oil and gas need to be taken away from the top of the tank through a dedicated pipeline. The oil and gas pipelines in each loading station must be connected to the oil and gas recovery unit (VRU) to recover the oil and gas, which mainly includes hydrocarbon gas, and discharge clean air at the same time. After VRU treatment, a certain amount of hydrocarbons may still remain in the exhaust gas, so further treatment is required to further reduce the emission concentration of hydrocarbons. Summary of the invention

[0004] The object of the present invention is to provide an oil and gas recovery system and an oil and gas recovery process for reducing hydrocarbon concentration, which can improve the overall performance of the system, realize efficient resource utilization and can work continuously.

[0005] An oil and gas recovery system for reducing hydrocarbon concentration includes a first-stage pressure swing adsorption oil and gas recovery system for preliminarily treating hydrocarbon-containing gas to reduce hydrocarbon concentration; A second-stage activated carbon adsorption system is connected to the exhaust end of the first-stage pressure swing adsorption oil and gas recovery system. The second-stage activated carbon adsorption device includes two alternately working first activated carbon beds VA and second activated carbon beds VB, which are used to further reduce the concentration of hydrocarbons in the gas after being treated by the first-stage pressure swing adsorption oil and gas recovery system; A regeneration system, used for providing a vacuum environment required for regeneration of the first activated carbon bed layer VA and the second activated carbon bed layer VB; The automatic valve system is used to control the adsorption and regeneration process of the first activated carbon bed VA and the second activated carbon bed VB.

[0006] In the above scheme, the system first uses the first-stage pressure swing adsorption oil and gas recovery system to preliminarily treat the gas containing hydrocarbons, effectively reducing its concentration. This step uses the pressure swing adsorption technology and the adsorption and desorption characteristics of the adsorbent under different pressures to achieve efficient oil and gas separation. Subsequently, the preliminarily treated gas enters the second-stage activated carbon adsorption system. The alternating first activated carbon bed VA and the second activated carbon bed VB can further capture and adsorb the residual low-concentration hydrocarbons. The calculation of the activated carbon amount of the first activated carbon bed VA and the second activated carbon bed VB is based on continuous adsorption for 10-12 hours. The two beds of the second-stage activated carbon adsorption system work alternately, ensuring the continuous processing capacity of the system. When one bed is performing adsorption operation, the other bed is in a regeneration state, realizing efficient resource utilization. The vacuum environment provided by the regeneration system is conducive to the rapid and thorough regeneration of activated carbon, extending the service life of activated carbon and improving the overall stability of the system. The automatic valve system enables the adsorption and regeneration process of the first activated carbon bed VA and the second activated carbon bed VB to be automatically switched and controlled.

[0007] Furthermore, it also includes an HC concentration monitoring device, which is connected to the automatic valve system and includes a first HC analyzer and a second HC analyzer. The first HC analyzer is installed at the exhaust end of the first-stage pressure swing adsorption oil and gas recovery system, and the second HC analyzer is installed at the exhaust end of the second-stage activated carbon adsorption system.

[0008] In the above scheme, the first HC analyzer is used to monitor the concentration of hydrocarbons in the oil and gas discharged from the first-stage pressure swing adsorption oil and gas recovery system. This data is crucial for evaluating the treatment effect of the first-stage system, adjusting operating parameters, and ensuring the smooth progress of subsequent treatment steps. The second HC analyzer is used to monitor the concentration of hydrocarbons in the oil and gas discharged from the second-stage activated carbon adsorption system. This data directly reflects the treatment effect of the entire oil and gas recovery system and is an important basis for judging whether the system meets emission standards.

[0009] Furthermore, the regeneration system includes a vacuum pump of the first-stage pressure swing adsorption oil and gas recovery system.

[0010] In the above scheme, by using the vacuum pump of the first-stage pressure swing adsorption oil and gas recovery system as the power source of the regeneration system, the need for additional vacuum pumps is avoided, thereby saving equipment investment costs. Integrating the vacuum pump into the first-stage system and using it for the regeneration of the second-stage activated carbon adsorption system reduces the number and complexity of system components, making the entire oil and gas recovery system more compact and integrated.

[0011] Furthermore, the first-stage pressure swing adsorption oil and gas recovery system includes a first carbon bed V-1 and a second carbon bed V-2, and the first carbon bed V-1 and the second carbon bed V-2 are connected to the first activated carbon bed VA.

[0012] In the above scheme, the first carbon bed V-1 in the first-stage pressure swing adsorption oil and gas recovery system adsorbs oil and gas for a certain period of time and then is regenerated, and then adsorbed by the second carbon bed V-2. Since the first activated carbon bed VA is connected with the first carbon bed V-1 and the second carbon bed V-2, no matter whether the first carbon bed V-1 or the second carbon bed V-2 is adsorbed, the adsorbed gas can be received by the first activated carbon bed VA and further adsorbed, which can improve the efficiency and purity of oil and gas recovery.

[0013] An oil and gas recovery process, implemented by using the oil and gas recovery system for reducing hydrocarbon concentration described in the above scheme, comprises the following steps: When the second activated carbon adsorption system receives gas from the first pressure swing adsorption oil and gas recovery system, the first activated carbon bed VA performs adsorption; After the first activated carbon bed VA has been adsorbed for 10-12 hours, the first activated carbon bed VA is regenerated through the automatic valve system, and the second activated carbon bed VB replaces the first activated carbon bed VA for adsorption; After the second activated carbon bed VB has been adsorbed for 10-12 hours, the second activated carbon bed VB is regenerated through the automatic valve system, and the first activated carbon bed VA replaces the second activated carbon bed VB for adsorption, thereby realizing the circulation work in the second activated carbon adsorption system.

[0014] In the above scheme, the process effectively reduces the concentration of hydrocarbons in the gas through preliminary treatment in the first pressure swing adsorption oil and gas recovery system, and then the second activated carbon adsorption system further deeply adsorbs to ensure efficient recovery of oil and gas. This multi-stage treatment method significantly improves the recovery efficiency of oil and gas and reduces the concentration of hydrocarbons in the discharged oil and gas. The first activated carbon bed VA and the second activated carbon bed VB alternately perform adsorption and regeneration operations. This design not only ensures the continuous operation of the system, but also realizes the recycling of activated carbon. Through the regular regeneration process, the adsorption performance of activated carbon is restored, which prolongs its service life and reduces the replacement cost.

[0015] Furthermore, the regeneration process of the first activated carbon bed VA and the second activated carbon bed VB comprises the following steps: The first activated carbon bed VA or the second activated carbon bed VB is evacuated by a vacuum pump of the first-stage pressure swing adsorption oil and gas recovery system; Under high vacuum conditions, a small amount of gas is introduced to purge the first activated carbon bed VA or the second activated carbon bed VB; Air is introduced into the first activated carbon bed VA or the second activated carbon bed VB from the outside to balance the vacuum of the first activated carbon bed VA or the second activated carbon bed VB.

[0016] In the above scheme, the use of a vacuum pump can quickly and effectively reduce the pressure in the activated carbon bed, thereby prompting the oil and gas molecules adsorbed on the activated carbon to quickly desorb. This process not only improves the efficiency of regeneration, but also helps to restore the adsorption performance of the activated carbon, so that it can continue to adsorb oil and gas efficiently. The introduction of a small amount of gas for purge helps to completely remove the oil and gas molecules remaining in the activated carbon bed, avoiding the impact on the subsequent adsorption process. Through the efficient regeneration process, the activated carbon bed can continue to maintain a high adsorption performance, thereby reducing oil and gas emissions.

[0017] The oil and gas recovery system and oil and gas recovery process for reducing the concentration of hydrocarbons of the present invention have the beneficial effects of improving the overall performance of the system, achieving efficient resource utilization and being able to work continuously. The system first uses the first-stage pressure swing adsorption oil and gas recovery system to preliminarily treat the gas containing hydrocarbons, effectively reducing its concentration. This step uses the pressure swing adsorption technology and the adsorption and desorption characteristics of the adsorbent under different pressures to achieve efficient oil and gas separation. Subsequently, the preliminarily treated gas enters the second-stage activated carbon adsorption system. The alternating first activated carbon bed VA and second activated carbon bed VB can further capture and adsorb residual low-concentration hydrocarbons. The calculation of the amount of activated carbon in the first activated carbon bed VA and the second activated carbon bed VB is based on continuous adsorption for 10-12 hours. The concentration of hydrocarbon hydroxide (HC) can be reduced to 5g / Nm3, or even to 1g / Nm3. The two beds of the second-stage activated carbon adsorption system work alternately, ensuring the continuous processing capacity of the system. When one bed is performing adsorption operation, the other bed is in a regeneration state, realizing efficient resource utilization. The vacuum environment provided by the regeneration system is conducive to the rapid and thorough regeneration of activated carbon, extending the service life of activated carbon and improving the overall stability of the system. The automatic valve system enables the adsorption and regeneration process of the first activated carbon bed VA and the second activated carbon bed VB to be automatically switched and controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a simple schematic diagram of an embodiment in which the first activated carbon bed VA performs adsorption and the second activated carbon bed VB performs regeneration.

[0019] Figure 2 1 is a diagram of the oil and gas recovery process steps of an embodiment. DETAILED DESCRIPTION

[0020] The oil and gas recovery system and oil and gas recovery process for reducing hydrocarbon concentration of the present invention will be further described in detail below in conjunction with specific embodiments and drawings.

[0021] like Figure 1 As shown, in a preferred embodiment, an oil and gas recovery system for reducing the concentration of hydrocarbons of the present invention includes a first-stage pressure swing adsorption oil and gas recovery system for preliminarily treating the gas containing hydrocarbons to reduce the concentration of hydrocarbons; a second-stage activated carbon adsorption system connected to the exhaust end of the first-stage pressure swing adsorption oil and gas recovery system, the second-stage activated carbon adsorption device including two alternately working first activated carbon beds VA and second activated carbon beds VB, for further reducing the concentration of hydrocarbons in the gas after being treated by the first-stage pressure swing adsorption oil and gas recovery system; a regeneration system for providing the first activated carbon bed VA and the second activated carbon bed VB with the vacuum environment required for regeneration; and an automatic valve system for controlling the adsorption and regeneration process of the first activated carbon bed VA and the second activated carbon bed VB.

[0022] The system first uses the first-stage pressure swing adsorption oil and gas recovery system to preliminarily treat the gas containing hydrocarbons, effectively reducing its concentration. This step uses pressure swing adsorption technology and the adsorption and desorption characteristics of the adsorbent under different pressures to achieve efficient oil and gas separation. Subsequently, the preliminarily treated gas enters the second-stage activated carbon adsorption system. The alternating first activated carbon bed VA and second activated carbon bed VB can further capture and adsorb residual low-concentration hydrocarbons. The calculation of the activated carbon content of the first activated carbon bed VA and the second activated carbon bed VB is based on continuous adsorption for 10-12 hours. The concentration of hydrocarbon hydroxide (HC) can be reduced to 5g / Nm3, or even to 1g / Nm3. The two beds of the second-stage activated carbon adsorption system work alternately, ensuring the continuous processing capacity of the system. When one bed is performing adsorption operation, the other bed is in a regeneration state, realizing efficient resource utilization. The vacuum environment provided by the regeneration system is conducive to the rapid and thorough regeneration of activated carbon, extending the service life of activated carbon and improving the overall stability of the system. The automatic valve system enables the adsorption and regeneration process of the first activated carbon bed VA and the second activated carbon bed VB to be automatically switched and controlled.

[0023] In some embodiments, it also includes an HC concentration monitoring device, which is connected to the automatic valve system and includes a first HC analyzer and a second HC analyzer. The first HC analyzer is installed at the exhaust end of the first-stage pressure swing adsorption oil and gas recovery system, and the second HC analyzer is installed at the exhaust end of the second-stage activated carbon adsorption system. The first HC analyzer is used to monitor the concentration of hydrocarbons in the oil and gas discharged from the first-stage pressure swing adsorption oil and gas recovery system. This data is crucial for evaluating the treatment effect of the first-stage system, adjusting operating parameters, and ensuring the smooth progress of subsequent treatment steps. The second HC analyzer is used to monitor the concentration of hydrocarbons in the oil and gas discharged from the second-stage activated carbon adsorption system. This data directly reflects the treatment effect of the entire oil and gas recovery system and is an important basis for judging whether the system meets the emission standards.

[0024] By monitoring the concentration of hydrocarbons in real time, the system can automatically adjust the parameters such as time, pressure and temperature of the adsorption and regeneration process to optimize the treatment effect. For example, when the exhaust concentration of the first-stage pressure swing adsorption oil and gas recovery system is higher than the preset value, the system can extend the adsorption time or increase the amount of adsorbent used; when the exhaust concentration of the second-stage system approaches or reaches the emission standard, the system can stop the adsorption operation in time and turn to regeneration of activated carbon.

[0025] like Figure 1 As shown, in some embodiments, the regeneration system includes a vacuum pump of the first-stage pressure swing adsorption oil and gas recovery system. By using the vacuum pump of the first-stage pressure swing adsorption oil and gas recovery system as the power source of the regeneration system, the need to purchase an additional vacuum pump is avoided, thereby saving equipment investment costs. Integrating the vacuum pump into the first-stage system and using it for the regeneration of the second-stage activated carbon adsorption system reduces the number and complexity of system components, making the entire oil and gas recovery system more compact and integrated.

[0026] like Figure 1 As shown, in some embodiments, the first-stage pressure swing adsorption oil and gas recovery system includes a first carbon bed V-1 and a second carbon bed V-2, and the first carbon bed V-1 and the second carbon bed V-2 are connected to the first activated carbon bed VA. The first carbon bed V-1 in the first-stage pressure swing adsorption oil and gas recovery system adsorbs oil and gas for a certain period of time and then regenerates, and the second carbon bed V-2 performs adsorption. Since the first activated carbon bed VA is connected to the first carbon bed V-1 and the second carbon bed V-2, no matter whether the first carbon bed V-1 or the second carbon bed V-2 performs adsorption, the adsorbed gas can be received by the first activated carbon bed VA and further adsorbed, which can improve the efficiency and purity of oil and gas recovery.

[0027] like Figure 2 As shown, in a preferred embodiment, an oil and gas recovery process is implemented using the oil and gas recovery system for reducing hydrocarbon concentration in the above embodiment, comprising the following steps: S100, when the second activated carbon adsorption system receives the gas from the first pressure swing adsorption oil and gas recovery system, the first activated carbon bed VA performs adsorption; S200, after the first activated carbon bed VA has been adsorbed for 10-12 hours, the first activated carbon bed VA is regenerated by controlling the automatic valve system, and the second activated carbon bed VB replaces the first activated carbon bed VA for adsorption; S300, after the second activated carbon bed VB has been adsorbed for 10-12 hours, the second activated carbon bed VB is regenerated by controlling the automatic valve system, and the first activated carbon bed VA replaces the second activated carbon bed VB for adsorption, thereby realizing the circulation work in the second activated carbon adsorption system.

[0028] The process effectively reduces the concentration of hydrocarbons in the gas through preliminary treatment in the first pressure swing adsorption oil and gas recovery system. Subsequently, the second activated carbon adsorption system further deeply adsorbs to ensure efficient recovery of oil and gas. This multi-stage treatment method significantly improves the recovery efficiency of oil and gas and reduces the concentration of hydrocarbons in the discharged oil and gas. The first activated carbon bed VA and the second activated carbon bed VB alternately perform adsorption and regeneration operations. This design not only ensures the continuous operation of the system, but also realizes the recycling of activated carbon. Through the regular regeneration process, the adsorption performance of activated carbon is restored, which prolongs its service life and reduces the replacement cost.

[0029] In some embodiments, the regeneration process of the first activated carbon bed VA and the second activated carbon bed VB comprises the following steps: a. The first activated carbon bed VA or the second activated carbon bed VB is evacuated by the vacuum pump of the first-stage pressure swing adsorption oil and gas recovery system; b. Under high vacuum conditions, a small amount of gas is introduced to purge the first activated carbon bed VA or the second activated carbon bed VB; C, introducing air into the first activated carbon bed layer VA or the second activated carbon bed layer VB from the outside to balance the vacuum of the first activated carbon bed layer VA or the second activated carbon bed layer VB.

[0030] The use of a vacuum pump can quickly and effectively reduce the pressure in the activated carbon bed, thereby prompting the oil and gas molecules adsorbed on the activated carbon to desorb quickly. This process not only improves the efficiency of regeneration, but also helps to restore the adsorption performance of the activated carbon, enabling it to continue to efficiently adsorb oil and gas. Introducing a small amount of gas for purge helps to completely remove the oil and gas molecules remaining in the activated carbon bed, avoiding the impact on subsequent adsorption processes. Through an efficient regeneration process, the activated carbon bed can continue to maintain a high adsorption performance, thereby reducing oil and gas emissions.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] Although the present invention is described in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications and changes according to the above content. Therefore, all such substitutions, improvements and changes are included in the spirit and scope of the appended claims.

Claims

1. A gas recovery system for reducing hydrocarbon concentration, characterized in that: include The first-stage pressure swing adsorption oil and gas recovery system is used to initially treat the hydrocarbon-containing gas and reduce the concentration of hydrocarbons; A second-stage activated carbon adsorption system is connected to the exhaust end of the first-stage pressure swing adsorption oil and gas recovery system. The second-stage activated carbon adsorption device includes two alternately working first activated carbon beds VA and second activated carbon beds VB, which are used to further reduce the concentration of hydrocarbons in the gas after being treated by the first-stage pressure swing adsorption oil and gas recovery system; A regeneration system, used for providing a vacuum environment required for regeneration of the first activated carbon bed layer VA and the second activated carbon bed layer VB; The automatic valve system is used to control the adsorption and regeneration process of the first activated carbon bed VA and the second activated carbon bed VB.

2. The oil vapor recovery system for reducing hydrocarbon concentration according to claim 1, characterized in that: It also includes an HC concentration monitoring device, which is connected to the automatic valve system and includes a first HC analyzer and a second HC analyzer. The first HC analyzer is installed at the exhaust end of the first-stage pressure swing adsorption oil and gas recovery system, and the second HC analyzer is installed at the exhaust end of the second-stage activated carbon adsorption system.

3. The oil vapor recovery system for reducing hydrocarbon concentration according to claim 1, characterized in that: The regeneration system includes a vacuum pump of the first-stage pressure swing adsorption oil vapor recovery system.

4. The oil vapor recovery system for reducing hydrocarbon concentration according to claim 1, characterized in that: The first-stage pressure swing adsorption oil and gas recovery system includes a first carbon bed V-1 and a second carbon bed V-2, and the first carbon bed V-1 and the second carbon bed V-2 are connected to the first activated carbon bed layer VA.

5. An oil and gas recovery process, characterized in that: The oil and gas recovery system for reducing hydrocarbon concentration according to any one of claims 1 to 4 is implemented, comprising the following steps: When the second activated carbon adsorption system receives gas from the first pressure swing adsorption oil and gas recovery system, the first activated carbon bed VA performs adsorption; After the first activated carbon bed VA has been adsorbed for 10-12 hours, the first activated carbon bed VA is regenerated through the automatic valve system, and the second activated carbon bed VB replaces the first activated carbon bed VA for adsorption; After the second activated carbon bed VB has been adsorbed for 10-12 hours, the second activated carbon bed VB is regenerated through the automatic valve system, and the first activated carbon bed VA replaces the second activated carbon bed VB for adsorption, thereby realizing the circulation work in the second activated carbon adsorption system.

6. The oil and gas recovery process according to claim 5, characterized in that: The regeneration process of the first activated carbon bed VA and the second activated carbon bed VB comprises the following steps: The first activated carbon bed VA or the second activated carbon bed VB is evacuated by a vacuum pump of the first-stage pressure swing adsorption oil and gas recovery system; Under high vacuum conditions, a small amount of gas is introduced to purge the first activated carbon bed VA or the second activated carbon bed VB; Air is introduced into the first activated carbon bed VA or the second activated carbon bed VB from the outside to balance the vacuum of the first activated carbon bed VA or the second activated carbon bed VB.

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