Post-treatment system for increasing content of CO and H2 in coal gasification gas
By introducing high-temperature pure oxygen non-catalytic partial oxidation reaction and heat recovery equipment into the underground coal gasification system, more CO and H2 are generated, simplifying the coal gas purification process, solving the problems of complexity and high cost in existing technologies, and achieving efficient coal gas purification and energy recovery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2026-03-17
AI Technical Summary
The existing coal gasification process for underground coal gasification has problems such as complex technology routes, poor recovery and removal effects, and high investment costs, especially in the separation and recovery of valuable substances, sulfur removal, and water treatment of process condensate.
The system employs non-catalytic partial oxidation reaction equipment and heat recovery equipment, including a high-temperature pure oxygen non-catalytic partial oxidation reaction module, a vertical coil waste heat boiler module, a boiler feedwater preheater module, and a gas-liquid separation module. Through high-temperature reaction, more CO and H2 are generated, heat is recovered, and condensate is separated, simplifying the process flow.
This method increases the CO and H2 content in coal gas, simplifies the purification process, reduces costs, improves energy efficiency, and ensures the purity of the product gas, thus facilitating subsequent syngas chemical plants.
Smart Images
Figure CN224002707U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of a processing system for the contents of CO and H2 in coal gasification coal gas, and in particular to a post-treatment system for increasing the contents of CO and H2 in coal gasification coal gas. Background Technique
[0002] Underground coal gasification is a process of directly converting coal into product gas through the controlled combustion and gasification reaction of underground coal seams in the presence of an oxidant. The product gas is usually called product coal gas or raw synthesis gas, and this product coal gas can subsequently be used as a raw material for various applications, including fuel production, chemical production, power generation, etc. This underground coal gasification technology is applicable to most coal deposits. Given the increasingly strict environmental protection and safety requirements in the mining industry and considering the relevant labor costs and infrastructure costs, the underground coal gasification technology is undoubtedly very attractive.
[0003] Surface drilling penetrates directly into the coal seam, providing an effective channel for oxidant injection and product gas production. A pair of drillings are connected underground or horizontally extended to form a substantially horizontal drilling channel, which helps oxidant injection, growth of the burned-out area, and product gas transportation. A drilling for oxidant injection is called an "injection well", and another drilling for producing product gas is called a "product well". Directional horizontal drilling and vertical drilling can both be used as injection wells or product wells. One or more vertical wells may also be required between the injection well and the product well for underground coal gasification.
[0004] When the existing product coal gas generated by underground coal gasification is used, whether it is the separation and recovery of valuable substances such as coal tar, phenol, and hydrocarbon steam, or the removal of sulfur and the water treatment of the generated process condensate, it all faces problems such as complex process technical routes, poor recovery and removal effects, and high investment costs.
[0005] Aiming at the problems that the existing product coal gas generated by underground coal gasification, as well as the removal of sulfur and the water treatment of the generated process condensate, all face complex process technical routes, poor recovery and removal effects, and high investment costs, this post-treatment system greatly simplifies the process flow of product gas purification in underground coal gasification by setting up a non-catalytic partial oxidation reaction device and a heat recovery device. It can conduct preliminary purification and heat recovery of the product gas, making the process of the product gas purification treatment device supporting the underground coal gasification device more economical and reasonable, and giving full play to the advantages of reliable underground coal gasification technology and low cost. Content of the Utility Model
[0006] To overcome the challenges of complex technological routes, poor recovery and removal effects, and high investment costs in the use of existing coal gasification products, whether it is the separation and recovery of valuable substances such as coal tar, phenols, and hydrocarbon vapors, the removal of sulfur, or the water treatment of the generated process condensate.
[0007] The technical solution of this utility model is: a post-treatment system for increasing the CO and H2 content in coal gasification gas, comprising the following modules:
[0008] Coal underground gasification product gas input module: used to safely and efficiently introduce the high-temperature product gas produced in the coal underground gasification well into the system;
[0009] High-temperature pure oxygen non-catalytic partial oxidation reaction module: used to partially oxidize product gas using a high-temperature pure oxygen non-catalytic partial oxidation reactor.
[0010] High-temperature vertical coil waste heat boiler module: used to recover heat from high-temperature gas and convert it into usable steam energy;
[0011] Boiler feedwater preheater module: used to recover heat from the product gas and preheat the boiler feedwater that enters the waste heat boiler.
[0012] Gas-liquid separation module: used to separate the condensed liquid from the product gas through a gas-liquid separation tank;
[0013] Syngas output module: Used to stably deliver purified, heat-recovered and composition-adjusted product gas to downstream units via pipelines.
[0014] As a preferred option, the coal underground gasification product input module is used as the inlet of the post-processing system to safely and efficiently introduce the high-temperature product gas produced in the coal underground gasification well into the system, providing sufficient raw material supply for subsequent reactions. The product gas contains a variety of components, including CO, CO2, H2, CH4, coal tar, benzene, toluene, phenolic organic matter, as well as trace amounts of H2S, NH3 and organic sulfur impurities.
[0015] As a preferred embodiment, the high-temperature pure oxygen non-catalytic partial oxidation reaction module is used to partially oxidize the product gas using a high-temperature pure oxygen non-catalytic partial oxidation reactor. The product gas is mixed with high-purity oxygen from an oxygen generator at the burner end of the reactor and burned rapidly, generating a high-temperature environment of over 1300°C. The high temperature promotes the CH4 cracking reaction in the product gas, generating more CO and H2, thus increasing the content of effective components in the gas. At the same time, organic matter such as coal tar, benzene, toluene, and phenol are also cracked at high temperature, transforming into high-temperature gases containing CO and H2, while organic sulfur impurities are transformed into easily removable H2S.
[0016] Preferably, the high-temperature vertical coil waste heat boiler module is used to recover the heat in high-temperature gases and convert it into available steam energy. The high-temperature gases after the reaction enter the high-temperature vertical coil waste heat boiler and exchange heat with the boiler feed water through the vertical spiral coils. During the heat exchange process, the heat of the high-temperature gases is transferred to the boiler feed water, causing it to boil and generate saturated steam, providing additional energy for the system by reducing the temperature of the gases and improving the energy utilization efficiency of the entire system.
[0017] Preferably, the boiler feed water preheater module is used to recover the heat in the product gas. The boiler feed water preheater module preheats the boiler feed water entering the waste heat boiler. The low-temperature boiler feed water exchanges heat with the product gas that has come out of the waste heat boiler and whose temperature has decreased. This step increases the temperature of the boiler feed water, enabling it to reach the boiling point faster when entering the waste heat boiler, thus improving the steam generation efficiency. At the same time, it also further reduces the temperature of the product gas, facilitating subsequent gas-liquid separation.
[0018] Preferably, the gas-liquid separation module is used to separate the condensed liquid in the product gas through a gas-liquid separation tank after the gas temperature drops to 200°C. The condensed liquid mainly includes water, uncompletely cracked organic substances, and other impurities. Through gas-liquid separation, it ensures that the gas received by the subsequent syngas chemical production device is pure and free of condensed liquid or impurities.
[0019] Preferably, the syngas output module is used to send the product gas to the downstream syngas chemical production device for synthesizing chemical products. The syngas output module stably transports the product gas that has been purified, had its heat recovered, and had its composition adjusted to the downstream device through a pipeline.
[0020] Advantages of the present utility model:
[0021] A post-treatment system that increases the CO and H2 contents in the product gas of underground coal gasification while converting the organic impurities therein. By setting up a non-catalytic partial oxidation reaction device and a heat recovery device, the process flow of gas purification for the product gas of underground coal gasification is greatly simplified. It can preliminarily purify and recover the heat of the product gas, making the process of the product gas purification and treatment device配套 with the underground coal gasification device more economical and reasonable, giving full play to the advantages of reliable and low-cost underground coal gasification technology to solve the problems existing in the current underground coal gasification process. At the same time, through this device, the CH4 in the coal gas also undergoes cracking to generate CO and H2, increasing the content of effective components in the coal gas and facilitating the operation of the subsequent syngas chemical production device. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 Shown is a schematic diagram of a post-treatment system for increasing the CO and H2 contents in coal gasified gas of the present utility model;
[0023] Explanation of reference numerals in the attached diagram: 1. Coal underground gasification injection well; 2. Coal underground gasification product well; 3. Oxygen generator; 4. Coal underground gasification product gas; 5. Refractory material; 6. High-temperature pure oxygen non-catalytic partial oxidation reactor; 7. Reactor burner; 8. Reactor oxygen flow regulation system; 9. High-temperature vertical coil waste heat boiler; 10. Medium-pressure saturated steam pipeline network; 11. Boiler feedwater preheater; 12. Boiler feedwater system; 13. Gas-liquid separator; 14. Downstream syngas chemical production unit; 15. Water treatment unit; 16. Raw water; 17. Coal underground gasifier; 18. Oxygen; 19. Waste heat boiler three-stroke regulation system; 20. Gas-liquid separator level regulation system; 21. Boiler feedwater; 22. Raw water; 23. Syngas; 24. Medium-pressure saturated steam. Detailed Implementation
[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0025] Please see Figure 1 This utility model provides an embodiment: a post-treatment system for increasing the CO and H2 content in coal gasification gas, comprising the following modules:
[0026] Coal underground gasification product gas input module: used to safely and efficiently introduce the high-temperature product gas produced in the coal underground gasification well into the system;
[0027] High-temperature pure oxygen non-catalytic partial oxidation reaction module: used to partially oxidize product gas using a high-temperature pure oxygen non-catalytic partial oxidation reactor.
[0028] High-temperature vertical coil waste heat boiler module: used to recover heat from high-temperature gas and convert it into usable steam energy;
[0029] Boiler feedwater preheater module: used to recover heat from the product gas and preheat the boiler feedwater that enters the waste heat boiler.
[0030] Gas-liquid separation module: used to separate the condensed liquid from the product gas through a gas-liquid separation tank;
[0031] Syngas output module: Used to stably deliver purified, heat-recovered and composition-adjusted product gas to downstream units via pipelines.
[0032] As a preferred option, the coal underground gasification product input module is used as the inlet of the post-processing system to safely and efficiently introduce the high-temperature product gas produced in the coal underground gasification well into the system, providing sufficient raw material supply for subsequent reactions. The product gas contains a variety of components, including CO, CO2, H2, CH4, coal tar, benzene, toluene, phenolic organic matter, as well as trace amounts of H2S, NH3 and organic sulfur impurities.
[0033] As a preferred embodiment, the high-temperature pure oxygen non-catalytic partial oxidation reaction module is used to partially oxidize the product gas using a high-temperature pure oxygen non-catalytic partial oxidation reactor. The product gas is mixed with high-purity oxygen from an oxygen generator at the burner end of the reactor and burned rapidly, generating a high-temperature environment of over 1300°C. The high temperature promotes the CH4 cracking reaction in the product gas, generating more CO and H2, thus increasing the content of effective components in the gas. At the same time, organic matter such as coal tar, benzene, toluene, and phenol are also cracked at high temperature, transforming into high-temperature gases containing CO and H2, while organic sulfur impurities are transformed into easily removable H2S.
[0034] As a preferred option, the high-temperature vertical coil waste heat boiler module is used to recover heat from high-temperature gas and convert it into usable steam energy. The high-temperature gas after the reaction enters the high-temperature vertical coil waste heat boiler and exchanges heat with the boiler feedwater through the vertical spiral coil. During the heat exchange process, the heat of the high-temperature gas is transferred to the boiler feedwater, causing it to boil and generate saturated steam. The reduced gas temperature provides additional energy to the system, improving the energy utilization efficiency of the entire system.
[0035] Preferably, the boiler feedwater preheater module is used to recover heat from the product gas. The boiler feedwater preheater module preheats the boiler feedwater entering the waste heat boiler. The low-temperature boiler feedwater exchanges heat with the product gas, which has already cooled down from the waste heat boiler. This step increases the temperature of the boiler feedwater, allowing it to reach the boiling point more quickly when entering the waste heat boiler, thereby improving the efficiency of steam generation. At the same time, this also further reduces the temperature of the product gas, facilitating subsequent gas-liquid separation.
[0036] Preferably, the gas-liquid separation module is used to separate the condensate from the product gas through a gas-liquid separation tank after the gas temperature drops to 200°C. The condensate mainly includes water, incompletely decomposed organic matter, and other impurities. Through gas-liquid separation, it is ensured that the gas received by the subsequent syngas chemical production unit is pure and free of condensate or impurities.
[0037] Preferably, the syngas output module is used to deliver product gas to downstream syngas chemical production units for the synthesis of chemical products. The syngas output module stably delivers the purified, heat-recovered and composition-adjusted product gas to the downstream units through pipelines.
[0038] A post-treatment system for increasing the CO and H2 content in coal gasification gas includes the following steps during operation:
[0039] S101: The product gas from the outlet of the underground coal gasification product well, with a temperature of about 325°C, is introduced to the neck of the high-temperature pure oxygen non-catalytic partial oxidation reactor through the process pipeline and enters the reactor from the side of the neck.
[0040] S102: Pure oxygen from the oxygen generator is delivered to the burner at the top of the reactor through the oxygen pipeline and injected into the furnace through the burner end to mix with the product gas and form a combustion flame. By monitoring the temperature of the gas at the reactor outlet, the oxygen flow rate is adjusted to ensure that the combustion and reaction process reaches the required high temperature.
[0041] S103: The coal underground gasification product gas fed in is mixed and burned with pure oxygen in a pure oxygen non-catalytic partial oxidation reactor, generating a high temperature of over 1300℃. In the furnace chamber of the reactor, CH4 in the product gas undergoes a cracking reaction to generate CO and H2. At the same time, a large amount of coal tar, benzene, toluene and phenol and other organic matter in the product gas also cracks at high temperature and is converted into high temperature gas containing CO and H2. In addition, organic impurities in the product gas, such as organic sulfur (COS, sulfides and thiophene, etc.), are also converted into H2S that is easy to remove.
[0042] S104: The high-temperature gas after the reaction (approximately 1300°C) enters a high-temperature vertical coil waste heat boiler that is directly connected to the high-temperature pure oxygen non-catalytic partial oxidation reactor. In the waste heat boiler, the high-temperature gas is conducted to the boiler feedwater outside the tubes through the tube walls of the vertical coil heat exchange tubes, causing the water to continuously boil and evaporate, generating saturated steam and exporting it. This process reduces the temperature of the product gas to approximately 400°C.
[0043] S105: After passing through the waste heat boiler, the product gas is sent to the downstream boiler feedwater preheater to heat the boiler feedwater entering the waste heat boiler and further recover the heat in the product gas. After that, the temperature of the product gas is reduced to about 200°C and contains a large amount of condensate. The condensate in the product gas is separated out by the gas-liquid separator.
[0044] S106: The product gas after gas-liquid separation is sent to the downstream syngas processing unit for the synthesis of chemical products. Since it has undergone a high-temperature pure oxygen non-catalytic partial oxidation combustion reaction, most of the organic matter and organic sulfur in the product gas have been converted, so the subsequent treatment is simpler and more efficient.
[0045] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.
Claims
1. A post-treatment system for increasing the content of CO and H2 in coal gasification coal gas, comprising the following modules: a coal underground gasification product gas input module for safely and efficiently introducing high-temperature product coal gas produced in a coal underground gasification product well into the system; a high-temperature pure oxygen non-catalytic partial oxidation reaction module for using a high-temperature pure oxygen non-catalytic partial oxidation reaction furnace to perform a partial oxidation reaction on the product coal gas; a high-temperature vertical coil waste heat boiler module for recovering heat in the high-temperature gas and converting it into usable steam energy; a boiler feed water preheater module for recovering heat in the product coal gas and preheating boiler feed water entering the waste heat boiler; a gas-liquid separation module for separating condensed liquid in the product gas through a gas-liquid separation tank; a synthesis gas output module for stably transporting the product gas after purification, heat recovery and composition adjustment to downstream devices through a pipeline.
2. The system for increasing the content of CO and H2 in coal gas according to claim 1, characterized in that: The coal underground gasification product input module is used as an entrance of the post-treatment system, safely and efficiently introduces high-temperature product coal gas produced in a coal underground gasification product well into the system, and provides sufficient raw material supply for subsequent reactions. The product coal gas contains various components, including CO, CO2, H2, CH4, coal tar, benzene, toluene, phenolic organic matter, and trace amounts of H2S, NH3 and organic sulfur impurities.
3. The system for increasing the content of CO and H2 in coal gas according to claim 1, characterized in that: The high-temperature pure oxygen non-catalytic partial oxidation reaction module is used for using a high-temperature pure oxygen non-catalytic partial oxidation reaction furnace to perform a partial oxidation reaction on the product coal gas. The product coal gas is mixed with high-purity oxygen gas from an oxygen generation device at the end of the burner of the reaction furnace and burns quickly to generate a high-temperature environment of up to 1300°C or above. The high temperature promotes the CH4 cracking reaction in the product gas to generate more CO and H2, increasing the content of effective components in the coal gas. At the same time, organic matter such as coal tar, benzene, toluene and phenol is also cracked at high temperature and converted into high-temperature gas containing CO and H2. Organic sulfur impurities are converted into H2S which is easy to remove.
4. The system for increasing the content of CO and H2 in coal gas according to claim 1, characterized in that: The high-temperature vertical coil waste heat boiler module is used for recovering heat in the high-temperature gas and converting it into usable steam energy. The high-temperature gas after the reaction enters the high-temperature vertical coil waste heat boiler, and heat exchange is performed between the vertical spiral coil and the boiler feed water. In the heat exchange process, the heat of the high-temperature gas is transferred to the boiler feed water, causing it to boil and generate saturated steam. The reduced gas temperature provides additional energy for the system, improving the energy utilization efficiency of the entire system.
5. The system for increasing the content of CO and H2 in coal gas according to claim 1, characterized in that: The boiler feed water preheater module is used for recovering heat in the product coal gas. The boiler feed water preheater module preheats the boiler feed water entering the waste heat boiler. The low-temperature boiler feed water is heat-exchanged with the product coal gas which has been reduced in temperature after coming out of the waste heat boiler. This step increases the temperature of the boiler feed water, enabling it to reach the boiling point more quickly when it enters the waste heat boiler, thereby improving the efficiency of steam generation. At the same time, this further reduces the temperature of the product coal gas, providing convenience for subsequent gas-liquid separation.
6. The system for increasing the content of CO and H2 in coal gas according to claim 1, characterized in that: The gas-liquid separation module is used to separate the condensed liquid in the product gas through the gas-liquid separation tank after the temperature of the gas is reduced to 200 DEG C, and the condensed liquid mainly includes water, incomplete cracking of organic matter and other impurities. Through gas-liquid separation, it is ensured that the gas received by the subsequent synthetic gas chemical production device is pure and does not contain condensed liquid or impurities.
7. The system for increasing the content of CO and H2 in coal gas according to claim 1, characterized in that: The synthetic gas output module is used to send the product gas to the downstream synthetic gas chemical production device for synthesizing chemical products. The synthetic gas output module stably transports the product gas after purification, heat recovery and composition adjustment to the downstream device through a pipeline.