Method for highly recovering C3 + light hydrocarbon optimized gas components

Through the collection, collection and transportation and centralized processing systems, the problem of unrecovered C3+ light hydrocarbons in fuel gas is solved, and efficient recovery of C3+ light hydrocarbons is achieved, reducing safety risks, improving economic benefits and hydrogen production.

CN120272241APending Publication Date: 2025-07-08PETROCHINA CO LTD
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Patent Information

Application Number
CN202311845999.5
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2023-12-28
Publication Date
2025-07-08

AI Technical Summary

Technical Problem

After the processing process is adjusted in a short process, the fuel gas contains a large amount of light hydrocarbons but is not equipped with special facilities for recycling, resulting in loss of benefits.

Method used

Through the collection, collection and transportation and centralized processing system, the fuel gas is collected using coking, gasoline hydrogenation, diesel purification and diesel modification devices, and the C3+ light hydrocarbon components are separated and recovered in turn through equipment such as liquid ring pumps, air presses, heat exchangers and absorption towers.

Benefits of technology

The content of C3+ light hydrocarbon components in fuel gas is reduced from about 40% to 12%-15%, reducing loss, improving economic benefits, reducing safety risks, and increasing hydrogen production, with low cost and high returns.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention belongs to the technical field of light hydrocarbon recovery, and particularly relates to a method for optimizing gas components by highly recovering C3 + light hydrocarbons, which comprises the following steps of: S1, intensively collecting high C3 + fuel gas by using a coking device, atmospheric and vacuum distillation, gasoline hydrogenation, diesel oil refining and a diesel oil modification device; s2, the fuel is fed into an inlet liquid separation tank through a liquid ring pump, liquid phase components in the fuel are removed, gas phase components are gathered and conveyed into a coking absorption tower through an aerostatic press, the gas phase components sequentially pass through a heat exchanger, an outlet liquid separation tank and an absorption tower, the tower top gas phase components enter a coking rerecovery tower, and C3 and above C3 components in gas are absorbed; s3, tower top dry gas is discharged into a gas system or enters a desulfurization device. According to the invention, the loss of efficient components is reduced, and the economic benefit is improved; the phenomenon that the fuel gas carries liquid is avoided, so that the fuel gas does not need liquid cutting operation any more, and the safety risk is reduced; the dry gas feeding proportion of the gas recovery device is increased, and the hydrogen yield is increased.
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Description

Technical Field

[0001] The present invention belongs to the technical field of light hydrocarbon recovery, and particularly relates to a method for optimizing the gas composition by highly recovering C3+ light hydrocarbons. Background Art

[0002] The efficient and refined utilization of petroleum has become a development trend. After the short-process adjustment of the processing flow in some factories, there is an excess of fuel gas. The fuel gas contains a large amount of light hydrocarbons and there is no dedicated facility to recover them in time. Instead, it is used for self-use or sold as fuel gas, resulting in a huge loss of benefits.

[0003] Therefore, we propose a method for optimizing the gas composition by highly recovering C3+ light hydrocarbons to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for optimizing the gas composition by highly recovering C3+ light hydrocarbons in view of the deficiencies of the prior art, which solves the problem that after the short-process adjustment of the processing flow in the factory building, there is an excess of fuel gas, the fuel gas contains a large amount of light hydrocarbons, there is no dedicated facility to recover them in time, and instead, it is used for self-use or sold as fuel gas, resulting in a huge loss of benefits.

[0005] The present invention provides the following technical solution: A method for optimizing the gas composition by highly recovering C3+ light hydrocarbons, comprising the following steps:

[0006] S1. Using the coking unit, the high C3+ fuel gas from the atmospheric and vacuum distillation unit, gasoline hydrogenation unit, diesel refining unit, and diesel upgrading unit is centrally collected;

[0007] S2. Using a liquid ring pump to send the fuel into the inlet liquid separation tank to remove the liquid-phase components therein. The gas-phase components are collected and transported by a gas compressor and enter the coking absorption tower, and successively pass through a heat exchanger, an outlet liquid separation tank, and an absorption tower. The gas-phase components at the top of the tower enter the coking re-absorption tower to absorb the C3 and above components in the gas;

[0008] S3. The dry gas at the top of the tower is discharged into the gas system or enters the desulfurization device;

[0009] S4. The liquid-phase components in the outlet liquid separation tank are sent to the stripping tower by a pump. The bottom components enter the stabilizing tower, and the dry gas at the top of the tower enters the desulfurization device;

[0010] S5. Using the catalytic unit, the high C3+ fuel gas from the reforming unit and isomerization unit is centrally collected;

[0011] S6. Sending the fuel into the inlet liquid separation tank to remove the liquid-phase components therein. The gas-phase components are collected and transported by a gas compressor and enter the catalytic absorption tower, and successively pass through a water cooler, a gas compressor outlet liquid separation tank, and an absorption tower. The gas-phase components at the top of the tower enter the re-absorption tower to absorb the C3 components in the gas phase;

[0012] S7. The liquid components enter the stripping column and pass through the condensate oil pump, heat exchanger, and stripping column in sequence. The bottom liquid of the column enters the stabilizing column through the dehexanizer pump and heat exchanger, and the liquefied gas separated from the top of the column is sent out of the unit.

[0013] Preferably, the output end of the liquid ring pump is connected to the gas phases of the reflux drums at the tops of the diesel hydrotreating stripper, diesel upgrading stripper, gasoline hydrofining fractionator, gasoline hydrotreating stabilizer, and the post-cooler of the coker fractionator through pipelines, and the gas components are collected centrally through pipelines and enter the gathering and transportation system.

[0014] Preferably, the gathering and transportation system includes a coker gas compressor. The pipeline at the input end of the compressor is connected to the inlet knockout drum, the pipeline at the output end of the compressor is connected to the air cooler, the pipeline of the air cooler is connected to a heat exchanger, and a knockout drum is provided at the output end of the heat exchanger, and it enters the centralized treatment system through gathering and transportation.

[0015] Preferably, the outer wall of the inlet knockout drum is sprayed with zinc-rich epoxy primer.

[0016] Preferably, a pressure gauge is fixedly connected inside the inlet knockout drum.

[0017] Preferably, an external pipeline is connected to the wall of the inlet knockout drum, and a protective sleeve is sleeved on the outer wall of the external pipeline.

[0018] Preferably, a jacket is sleeved on the inlet knockout drum.

[0019] Preferably, a water inlet pipe and a water outlet pipe are fixedly connected to the side wall of the jacket, and the height of the water inlet pipe is lower than that of the water outlet pipe.

[0020] Compared with the existing technology, the advantages of a method for optimizing the gas composition of high-recovery C3+ light hydrocarbons are as follows:

[0021] 1. By means of the collection, gathering and transportation, and centralized treatment systems provided in the present invention, the problem of high C3+ light hydrocarbon components in the fuel gas is solved. The content of C3+ light hydrocarbon components in the fuel gas is reduced from about 40% to 12%-15%, reducing the loss of high-efficiency components and improving economic benefits. After the present invention is put into use, about 447 t of liquid hydrocarbon components are recovered monthly, and it is estimated that about 5364 t of liquid hydrocarbons can be recovered more annually (the amount of recovered liquid hydrocarbons is related to the ambient temperature and will be further tracked), and the externally transported fuel gas is basically zero.

[0022] 2. The present invention solves the problem of liquid entrainment in the fuel gas, eliminating the need for liquid drainage operation of the fuel gas and reducing the safety risk.

[0023] 3. The present invention increases the dry gas feed ratio of the gas recovery device and increases the hydrogen production.

[0024] 4. The present invention relies on existing devices and only modifies part of the processes. The cost of this project is approximately 2.25 million yuan, with an efficiency increase of approximately 19 million yuan. It has a small investment and large returns. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic structural diagram of a method for optimizing the gas composition with high recovery of C3+ light hydrocarbons provided by the present invention;

[0026] Figure 2 is a schematic diagram of the optimization structure of a small amount of fuel gas in a method for optimizing the gas composition with high recovery of C3+ light hydrocarbons provided by the present invention.

[0027] In the figure: 1, inlet liquid separation tank; 2, gas compressor; 3, coking absorption tower; 4, heat exchanger; 5, outlet liquid separation tank; 6, absorption tower; 7, coking reabsorption tower; 8, pump; 9, stripping tower; 10, stabilizer tower. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] As Figure 1-2 shown, a method for optimizing the gas composition with high recovery of C3+ light hydrocarbons includes the following steps:

[0030] S1. Utilize the coking unit to centrally collect the high C3+ fuel gas from the atmospheric and vacuum distillation unit, gasoline hydrogenation unit, diesel refining unit, and diesel upgrading unit;

[0031] S2. Use the liquid ring pump 8 to send the fuel into the inlet liquid separation tank 1 to remove the liquid phase components therein. The gas phase components are collected and transported through the gas compressor 2 into the coking absorption tower 3, and successively pass through the heat exchanger 4, the outlet liquid separation tank 5, and the absorption tower 6. The gas phase components at the top of the tower enter the coking reabsorption tower 7 to absorb the C3 and components above C3 in the gas;

[0032] S3. The dry gas at the top of the tower is discharged into the gas system or enters the desulfurization device;

[0033] S4. The liquid phase components in the outlet liquid separation tank 5 are sent by the pump 8 into the stripping tower 9. The components at the bottom of the tower enter the stabilizer tower 10, and the dry gas at the top of the tower enters the desulfurization device;

[0034] S5. Utilize the catalytic unit to centrally collect the high C3+ fuel gas from the reforming unit and isomerization unit;

[0035] S6. Feed the fuel into the inlet liquid separation tank 1 to remove the liquid-phase components therein. The gas-phase components are collected and transported by the gas compressor 2 and enter the catalytic absorption tower 6, passing through the water cooler, the outlet liquid separation tank 5 of the gas compressor 2, and the absorption tower 6 in sequence. The gas-phase components at the top of the tower enter the reabsorption tower 6 to absorb the C3 components in the gas phase.

[0036] S7. The liquid-phase components enter the stripping tower 9, passing through the condensate oil pump 8, the heat exchanger 4, and the stripping tower 9 in sequence. The liquid at the bottom of the tower passes through the dehexane pump 8 and the heat exchanger 4 and enters the stabilizer tower 10. The liquefied gas separated at the top of the tower exits the unit.

[0037] The output end of the liquid ring pump 8 is connected to the gas phase of the reflux drum at the top of the diesel hydrotreating stripper, the gas phase of the reflux drum at the top of the diesel upgrading stripper, the gas phase of the reflux drum at the top of the gasoline hydrogenation fractionator, the gas phase of the reflux drum at the top of the gasoline hydrogenation stabilizer tower 10, and the gas-phase components of the after-cooler at the top of the coking fractionator through pipelines and are centrally collected and enter the gathering and transportation system.

[0038] The gathering and transportation system includes a coking gas compressor 2. The pipeline at the input end of the gas compressor 2 is connected to the inlet liquid separation tank in front of the machine, and the pipeline at the output end of the gas compressor 2 is connected to the air cooler. The pipeline of the air cooler is connected to a heat exchanger 4, and a liquid separation tank is provided at the output end of the heat exchanger 4, and it enters the centralized treatment system through gathering and transportation.

[0039] The outer wall of the inlet liquid separation tank 1 is sprayed with an epoxy zinc-rich primer, which improves the rust prevention ability of the inlet liquid separation tank 1.

[0040] A pressure gauge is fixedly connected inside the inlet liquid separation tank 1, which can detect the internal pressure of the inlet liquid separation tank 1.

[0041] The tank wall of the inlet liquid separation tank 1 is connected to an external pipeline, and a protective sleeve is sleeved on the outer wall of the external pipeline, which can transport gas to the inlet liquid separation tank 1.

[0042] The inlet liquid separation tank 1 is sleeved with a jacket, which can insulate the inlet liquid separation tank 1.

[0043] The side wall of the jacket is fixedly connected with a water inlet pipe and a water outlet pipe. The height of the water inlet pipe is lower than that of the water outlet pipe, ensuring the heating efficiency of the inlet liquid separation tank 1.

[0044] Now, the operating principle of the present invention is described as follows:

[0045] Example 1:

[0046] Using a coking unit, the high C3+ fuel gas from atmospheric and vacuum distillation units, gasoline hydrogenation units, diesel refining units, and diesel upgrading units is collected centrally. The fuel is sent into the inlet liquid separation tank 1 by the liquid ring pump 8 to remove the liquid-phase components therein. The gas-phase components are collected and transported into the coking absorption tower 3 through the gas compressor 2, and then sequentially pass through the heat exchanger 4, the outlet liquid separation tank 5, and the absorption tower 6. The gas-phase components at the top of the tower enter the coking re-absorption tower 7 to absorb the C3 and components above C3 in the gas. The dry gas at the top of the tower is discharged into the gas system or enters the desulfurization unit. The liquid-phase components in the outlet liquid separation tank 5 are sent into the stripping tower 9 by the pump 8, the bottom components enter the stabilizing tower 10, and the dry gas at the top of the tower enters the desulfurization unit.

[0047] Example 2:

[0048] Using a catalytic unit, the high C3+ fuel gas from reforming units and isomerization units is collected centrally. The fuel is sent into the inlet liquid separation tank 1 to remove the liquid-phase components therein. The gas-phase components are collected and transported into the catalytic absorption tower 6 through the gas compressor 2, and then sequentially pass through the water cooler, the outlet liquid separation tank 5 of the gas compressor 2, and the absorption tower 6. The gas-phase components at the top of the tower enter the re-absorption tower 6 to absorb the C3 components in the gas phase. The liquid-phase components enter the stripping tower 9 and sequentially pass through the condensate oil pump 8, the heat exchanger 4, and the stripping tower 9. The bottom liquid phase passes through the dehexanizer pump 8 and the heat exchanger 4 and enters the stabilizing tower 10, and the liquefied gas precipitated at the top of the tower leaves the unit.

[0049] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for optimizing the gas composition by highly recycling C3+ light hydrocarbons, characterized in that, Comprising the following steps: S1. Use the coking unit to centrally collect the high C3+ fuel gas from the atmospheric and vacuum distillation unit, gasoline hydrogenation unit, diesel refining unit, and diesel upgrading unit; S2. Use the liquid ring pump (8) to send the fuel into the inlet liquid separation tank (1) to remove the liquid phase components therein. The gas phase components are collected and transported through the air compressor (2) and enter the coking absorption tower (3), and successively pass through the heat exchanger (4), outlet liquid separation tank (5), and absorption tower (6). The gas phase components at the top of the tower enter the coking re-absorption tower (7) to absorb the C3 and above components in the gas; S3. The dry gas at the top of the tower is discharged into the gas system or enters the desulfurization unit; S4. The liquid phase components of the outlet liquid separation tank (5) are sent by the pump (8) into the stripping tower (9). The bottom components enter the stabilizer tower (10), and the dry gas at the top of the tower enters the desulfurization unit; S5. Use the catalytic unit to centrally collect the high C3+ fuel gas from the reforming unit and isomerization unit; S6. Send the fuel into the inlet liquid separation tank (1) to remove the liquid phase components therein. The gas phase components are collected and transported through the air compressor (2) and enter the catalytic absorption tower (6), and successively pass through the water cooler, outlet liquid separation tank (5) of the air compressor (2), and absorption tower (6). The gas phase components at the top of the tower enter the re-absorption tower (6) to absorb the C3 components in the gas phase; S7. The liquid phase components enter the stripping tower (9), and successively pass through the condensate oil pump (8), heat exchanger (4), and stripping tower (9). The bottom liquid phase passes through the dehexanizer pump (8) and heat exchanger (4) and enters the stabilizer tower (10). The liquefied gas separated at the top of the tower exits the unit.

2. The method for optimizing the gas composition with high-recovery C3+ light hydrocarbons according to claim 1, characterized in that The output end of the liquid ring pump (8) is connected to the gas phase of the reflux tank at the top of the diesel refining stripper, the gas phase of the reflux tank at the top of the diesel upgrading stripper, the gas phase of the reflux tank at the top of the gasoline hydrogenation fractionator, the gas phase of the reflux tank at the top of the gasoline hydrogenation stabilizer tower (10), and the gas phase components of the after-cooler at the top of the coking fractionator through pipelines and are centrally collected into the gathering and transportation system.

3. A method for optimizing the gas composition with high-recovery C3+ light hydrocarbons according to claim 1, characterized in that, The gathering and transportation system includes a coking air compressor (2). The pipeline at the input end of the air compressor (2) is connected to the liquid separation tank in front of the machine, the pipeline at the output end of the air compressor (2) is connected to the air cooler, the pipeline of the air cooler is connected to a heat exchanger (4), and a liquid separation tank is provided at the output end of the heat exchanger (4) and is gathered and transported into the centralized treatment system.

4. A method for optimizing the gas composition by highly recovering C3+ light hydrocarbons according to claim 1, characterized in that, The outer wall of the inlet liquid separation tank (1) is sprayed with an epoxy zinc-rich primer.

5. A method for optimizing the gas composition with high-recovery C3+ light hydrocarbons according to claim 1, characterized in that, A pressure gauge is fixedly connected inside the inlet liquid separation tank (1).

6. The method for optimizing the gas composition with high-recovery C3+ light hydrocarbons according to claim 1, characterized in that, An external pipeline is communicated with the tank wall of the inlet liquid separation tank (1), and a protective sleeve is sleeved on the outer wall of the external pipeline.

7. A method for optimizing the gas composition with high-recovery C3+ light hydrocarbons according to claim 1, characterized in that, The inlet liquid separation tank (1) is sleeved with a jacket.

8. A method for optimizing the gas composition with high-recovery C3+ light hydrocarbons according to claim 7, characterized in that, The side wall of the jacket is fixedly communicated with a water inlet pipe and a water outlet pipe, and the height of the water inlet pipe is lower than the height of the water outlet pipe.