An integrated oil-hydrogen co-production system and method for underground coal gasification and pyrolysis

Abstract

A system and method for the integrated underground coal gasification and pyrolysis of oil and hydrogen co-production, the system comprising: a horizontal gasification channel of a lower coal seam for receiving a gasifying agent from an injection well and performing gasification, wherein the raw coal gas obtained after gasification is transmitted to the horizontal pyrolysis channel of an upper coal seam via the connecting channel; the horizontal pyrolysis channel of the upper coal seam is used for in-situ heating and pyrolysis of the raw coal gas to obtain an oil and gas mixture which is discharged from the production well; the oil and gas processing unit is used for separating and processing the oil and gas mixture to obtain a mixture of hydrogen and carbon dioxide; the carbon dioxide capture unit is used for separating and processing the hydrogen and carbon dioxide mixture obtained by the oil and gas processing unit to obtain separated hydrogen and carbon dioxide, and circulating part of the separated carbon dioxide into the injection well.

Description

Technical Field

[0001] This article relates to the field of underground coal pyrolysis technology, and in particular to an integrated oil-hydrogen co-production system and method of underground coal gasification and pyrolysis. Background Art

[0002] With the rapid development of my country's economy, the demand for oil and gas resources is increasing. However, the characteristics of my country's energy structure, "lack of oil, little gas, and rich in coal", are constraining my country's energy security. In addition, the utilization of conventional shallow coal resources is becoming increasingly exhausted, and coal mining and utilization are gradually moving towards deeper coal seams. According to statistics, nearly 70% of my country's coal resources are distributed below medium and deep layers, and the amount of coal resources at a depth of 1000-3000m is nearly 3.77×10 12 Therefore, it is very necessary to study how to efficiently and pollution-free convert these deep coal resources into coal-based oil and gas resources, which can increase the supply channels and supply of oil and gas resources and ensure my country's energy security.

[0003] Underground in-situ chemical mining technology for coal is the future development direction of green and low-carbon coal resource mining in my country. It mainly includes underground coal seam in-situ pyrolysis and in-situ gasification technology. Underground coal in-situ pyrolysis technology refers to the pyrolysis reaction of coal seams in a high-temperature, oxygen-free environment to produce oil and gas resources. Underground coal in-situ gasification technology is the controlled combustion of coal seams under high temperature and high pressure to produce synthesis gas resources. Compared with traditional ground treatment processes, underground coal in-situ treatment technology can not only save a lot of transportation and labor costs, but also retain some pollutants directly underground, thereby reducing pollutant emissions. At the same time, the ground coal-to-oil process has not been widely used due to the limitations of oil dust clogging and separation difficulties. Underground coal in-situ pyrolysis technology is expected to avoid this problem and ultimately achieve stable production of coal-to-oil processes.

[0004] Some deep coal seam in-situ methods often focus on single-use gasification or pyrolysis technologies, without integrating these two technologies. There is an urgent need for an integrated underground coal gasification and pyrolysis system and method for oil-hydrogen cogeneration that can organically combine these two technologies. Summary of the Invention

[0005] The present application provides an integrated oil-hydrogen co-production system and method for underground coal gasification and pyrolysis. The system uses the heat of underground coalbed methane gas to directly pyrolyze the upper coal seam to achieve integrated in-situ gasification and pyrolysis co-production of deep coal seams, while achieving clean and efficient utilization of deep coal seams and obtaining high-value oil-phase products and hydrogen energy.

[0006] The present application provides an integrated underground coal gasification and pyrolysis oil and hydrogen co-production system, the system comprising: an injection well, a deep coal seam gasification and pyrolysis unit, an oil and gas processing unit, and a carbon dioxide capture unit; wherein the deep coal seam gasification and pyrolysis unit comprises a lower coal seam horizontal gasification channel, a connecting channel, an upper coal seam horizontal pyrolysis channel, and a production well;

[0007] The lower coal seam horizontal gasification channel is used to receive the gasification agent from the injection well and perform gasification, and the raw coal gas obtained after gasification is transmitted to the upper coal seam horizontal pyrolysis channel through the connecting channel;

[0008] The upper coal seam horizontal pyrolysis channel is used for in-situ heating and pyrolysis of the raw coal gas to obtain an oil and gas mixture which is discharged from the production well;

[0009] The oil and gas processing unit is used to separate the oil and gas mixture to obtain an oil phase product, hydrogen and carbon dioxide mixed gas;

[0010] The carbon dioxide capture unit is used to separate and process the hydrogen and carbon dioxide mixed gas obtained by the oil and gas processing unit to obtain separated hydrogen and carbon dioxide, and to circulate part of the separated carbon dioxide into the injection well.

[0011] In an exemplary embodiment, the oil and gas processing unit includes a condenser and a separator;

[0012] The condenser is used to cool the oil and gas mixture discharged from the production well by heat exchange and transmit it to the separator;

[0013] The separator is used to separate the oil-gas mixture cooled by the condenser into an oil phase product and a gas phase product.

[0014] In an exemplary embodiment, the oil and gas processing unit further comprises a desulfurization tower, a steam reforming and a water-gas shift module;

[0015] The desulfurization tower is used to desulfurize the gaseous product separated by the separator and transmit part of the desulfurized synthesis gas to the steam reforming and water-gas shift module;

[0016] The steam reforming and water-gas shift module is used to convert methane and carbon monoxide in the received synthesis gas into hydrogen and carbon dioxide.

[0017] In an exemplary embodiment, the steam reforming and water-gas shift module includes: a steam reforming reactor, a water-gas shift reactor;

[0018] The steam reforming reactor is used to perform a reforming reaction on the received synthesis gas using a predetermined catalyst to obtain carbon monoxide and hydrogen;

[0019] The water-gas shift reactor is used to convert the carbon monoxide and steam into a mixed gas of hydrogen and carbon dioxide.

[0020] In an exemplary embodiment, the carbon dioxide capture unit is further used to separate carbon dioxide from a mixture of hydrogen and carbon dioxide using a polyethylene glycol dimethyl ether solution to obtain hydrogen; and to input part of the separated carbon dioxide into the injection well, and to geologically seal the remaining CO2.

[0021] In an exemplary embodiment, the oil and gas processing unit further includes a burner;

[0022] The burner is used to burn the remaining part of the desulfurized synthesis gas to produce steam for use in the steam reforming reactor and the water-gas shift reactor.

[0023] In an exemplary embodiment, the oil and gas processing unit further includes a first heat exchanger and a second heat exchanger;

[0024] The first heat exchanger is used to connect the hot end to the burner and the cold end to water;

[0025] The second heat exchanger is used to connect the hot end to the water-gas shift reactor and the cold end to the CO2 capture unit.

[0026] The present application also provides an underground coal gasification and pyrolysis integrated oil and hydrogen co-production method, which uses the underground coal gasification and pyrolysis integrated oil and hydrogen co-production system described in any one of the above embodiments, and the method includes:

[0027] The gasifying agent is injected into the horizontal gasification channel of the lower coal seam from the injection well for gasification;

[0028] The raw coal gas obtained by gasification is input into the horizontal pyrolysis channel of the upper coal seam, and the upper coal seam is heated and pyrolyzed in situ to obtain an oil-gas mixture;

[0029] The oil and gas mixture is discharged through a production well to obtain hydrogen.

[0030] In an exemplary embodiment, discharging the oil-gas mixture through a production well to obtain hydrogen includes:

[0031] Separating the oil-gas mixture into oil and gas using a condenser and a separator to obtain an oil phase product and a gas phase product;

[0032] The gaseous product is transported to a desulfurization tower for desulfurization to obtain synthesis gas;

[0033] A portion of the synthesis gas is transferred to a steam reforming and water-gas shift module to produce hydrogen.

[0034] In an exemplary embodiment, after the gaseous product is transported to a desulfurization tower for desulfurization to obtain synthesis gas, the method further comprises:

[0035] The remaining portion of the synthesis gas is fed to a combustor to produce steam, which is used by a steam reforming reactor and a water-gas shift reactor.

[0036] Compared with the related art, the present application provides an integrated oil-hydrogen co-production system and method for underground coal gasification and pyrolysis, the system comprising: an injection well, a deep coal seam gasification and pyrolysis unit, an oil and gas processing unit, and a carbon dioxide capture unit; wherein the deep coal seam gasification and pyrolysis unit comprises a lower coal seam horizontal gasification channel, a connecting channel, an upper coal seam horizontal pyrolysis channel, and a production well; the lower coal seam horizontal gasification channel is used to receive the gasification agent from the injection well and perform gasification, and the raw coal gas obtained after gasification is transmitted to the upper coal seam horizontal pyrolysis channel through the connecting channel; the upper coal seam horizontal pyrolysis channel is used to be in-situ heated and pyrolyzed by the raw coal gas to obtain an oil and gas mixture and discharged from the production well; the oil and gas processing unit is used to separate and process the oil and gas mixture to obtain an oil phase product, hydrogen, and a carbon dioxide mixed gas; the carbon dioxide capture unit is used to separate and process the hydrogen and carbon dioxide mixed gas obtained by the oil and gas processing unit to obtain separated hydrogen and carbon dioxide, and circulate part of the separated carbon dioxide to the injection well. Through the technical solution of the present invention, the system uses the heat of underground coalbed methane gas to directly pyrolyze the upper coal seam, realizing the integrated co-production of in-situ gasification and pyrolysis of deep coal seams; at the same time, it can cleanly and efficiently utilize deep coal seams to obtain high-value oil-phase products and hydrogen energy; the system can also realize carbon dioxide capture and storage, realizing the demand for carbon emission reduction.

[0037] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. Other advantages of the present application can be realized and obtained by the solutions described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0039] Figure 1 Schematic diagram of an integrated oil-hydrogen co-production system of underground coal gasification and pyrolysis according to an embodiment of the present application;

[0040] Figure 2This is a flow chart of the integrated oil and hydrogen co-production method of underground coal gasification and pyrolysis according to an embodiment of the present application;

[0041] Figure 3 Schematic diagram of an integrated oil-hydrogen co-production system of underground coal gasification and pyrolysis in some exemplary embodiments. DETAILED DESCRIPTION

[0042] This application describes multiple embodiments, but this description is exemplary rather than restrictive, and it will be apparent to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described herein. Although many possible feature combinations are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0043] This application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features, and elements disclosed in this application may also be combined with any conventional features or elements to form a unique inventive solution defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other inventive solutions to form another unique inventive solution defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the appended claims and their equivalents, the embodiments are not subject to other limitations. In addition, various modifications and changes may be made within the scope of protection of the appended claims.

[0044] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps in the specific order described. As will be understood by those skilled in the art, other orders of steps are also possible. Therefore, the specific order of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to performing their steps in the order written, and those skilled in the art can readily understand that these orders can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0045] In some technologies, deep coal seams and in-situ methods are mostly single gasification or pyrolysis technology research, without organically combining the two technologies. Single coal seam gasification or pyrolysis will cause a large amount of heat energy to be unable to be effectively utilized, which will then be lost to the formation rocks and even threaten the stability of the formation, making it impossible to achieve the cascade utilization of deep coal seams. Therefore, the technology of using the heat from the in-situ gasification of deep coal seams to pyrolyze coal seams can effectively improve the utilization rate of thermal energy and resources, and promote efficient and clean mining of deep coal seams. In addition, the supplementation of pyrolysis gas can further increase the effective gas components of the gasification gas, which can provide more raw materials for the subsequent hydrogen production process.

[0046] The embodiment of the present disclosure provides an integrated oil and hydrogen co-production system of underground coal gasification and pyrolysis, such as Figure 1 As shown, the system includes: an injection well 100, a deep coal seam gasification and pyrolysis unit 110, an oil and gas processing unit 120, and a carbon dioxide capture unit 130; wherein the deep coal seam gasification and pyrolysis unit 110 includes a lower coal seam horizontal gasification channel 1101, a connecting channel 1102, an upper coal seam horizontal pyrolysis channel 1103, and a production well 1104;

[0047] The lower coal seam horizontal gasification channel is used to receive the gasification agent from the injection well and perform gasification, and the raw coal gas obtained after gasification is transmitted to the upper coal seam horizontal pyrolysis channel through the connecting channel;

[0048] The upper coal seam horizontal pyrolysis channel is used to perform in-situ heating and pyrolysis on the raw coal gas to obtain an oil and gas mixture and discharge it from the production well;

[0049] The oil and gas processing unit is used to separate the oil and gas mixture to obtain a mixture of hydrogen and carbon dioxide;

[0050] The carbon dioxide capture unit is used to separate and process the hydrogen and carbon dioxide mixed gas obtained by the oil and gas processing unit to obtain separated hydrogen and carbon dioxide, and to circulate part of the separated carbon dioxide into the injection well.

[0051] In this embodiment, the gasification agent (oxygen, water) heated by heat exchange is introduced into the horizontal gasification channel of the lower coal seam through the injection well, and the lower coal seam is ignited for in-situ gasification. The high-temperature and high-pressure crude synthesis gas generated is transmitted to the horizontal pyrolysis channel of the upper coal seam through the connecting channel for in-situ heating and pyrolysis.

[0052] In an exemplary embodiment, the oil and gas processing unit includes a condenser and a separator; the condenser is used to perform heat exchange cooling on the oil and gas mixture discharged from the production well and transmit it to the separator; the separator is used to separate the oil and gas mixture after cooling by the condenser into oil phase products and gas phase products.

[0053] In an exemplary embodiment, the oil and gas processing unit also includes a desulfurization tower, a steam reforming and water-gas shift module; the desulfurization tower is used to desulfurize the gaseous product separated by the separator, and transmit most of the desulfurized synthesis gas to the steam reforming and water-gas shift module; for example: 70% of the desulfurized synthesis gas can be transmitted to the steam reforming and water-gas shift module; the steam reforming and water-gas shift module is used to convert methane and carbon monoxide in the received synthesis gas into hydrogen.

[0054] In an exemplary embodiment, the steam reforming and water-gas shift module includes: a steam reforming reactor and a water-gas shift reactor; wherein the water-gas shift reactor includes a first WGS reactor and a second WGS reactor; the steam reforming reactor is used to perform a reforming reaction on the received synthesis gas using a predetermined catalyst to obtain carbon monoxide and hydrogen; the water-gas shift reactor is used to convert the carbon monoxide and steam into a mixture of hydrogen and carbon dioxide, that is, the two-stage reaction treatment of the first WGS reactor and the second WGS reactor in sequence can make the carbon monoxide and steam more fully converted to obtain purer hydrogen.

[0055] In an exemplary embodiment, the carbon dioxide capture unit is also used to separate carbon dioxide from a mixture of hydrogen and carbon dioxide using a polyethylene glycol dimethyl ether solution to obtain high-purity hydrogen, for example: a hydrogen product with a purity greater than 98% is high-purity; and partially separate the carbon dioxide is input into the injection well, and the remaining CO2 is geologically sealed.

[0056] In an exemplary embodiment, the oil and gas processing unit further includes a burner; the burner is used to burn the remaining portion of the desulfurized synthesis gas to produce steam for use in the steam reforming reactor and the water-gas shift reactor.

[0057] In an exemplary embodiment, the oil and gas processing unit further includes a first heat exchanger and a second heat exchanger; the first heat exchanger is used to connect the hot end to the burner and the cold end to water; the second heat exchanger is used to connect the hot end to the second WGS reactor and the cold end to the carbon dioxide capture unit.

[0058] In this embodiment, the system connects the lower coal seam gasification channel and the upper coal seam pyrolysis channel in series, using the high-temperature heat energy of the gasified gas to pyrolyze the upper coal seam, ultimately achieving integrated in-situ gasification and pyrolysis co-production of deep coal seams. This process not only enables in-situ clean cascade utilization of deep coal seams, but also reduces CO2 emissions, achieving carbon neutrality, and producing high-quality oil-phase products and hydrogen energy, reducing energy waste.

[0059] This application also provides an integrated oil and hydrogen co-production method of underground coal gasification and pyrolysis, such as Figure 2 As shown, the method applies the underground coal gasification and pyrolysis integrated oil and hydrogen co-production system described in any one of the above embodiments, and the method includes steps S200-S220:

[0060] S200. The gasification agent is injected into the lower coal seam horizontal gasification channel for gasification;

[0061] S210. The raw coal gas obtained by gasification is input into the horizontal pyrolysis channel of the upper coal seam, and the upper coal seam is heated and pyrolyzed in situ to obtain an oil-gas mixture;

[0062] S220. Discharge the oil and gas mixture through a production well to obtain hydrogen.

[0063] In an exemplary embodiment, the process of discharging the oil-gas mixture through a production well to obtain hydrogen includes: using a condenser and a separator to separate the oil-gas mixture into oil and gas to obtain an oil phase product and a gas phase product; transporting the gas phase product to a desulfurization tower for desulfurization to obtain synthesis gas; and transmitting a portion of the synthesis gas to a steam reforming and water-gas shift module to obtain H2 gas.

[0064] In an exemplary embodiment, after the gaseous product is transported to a desulfurization tower for desulfurization to obtain synthesis gas, the method further includes: transporting the remaining portion of the synthesis gas to a burner to produce steam, which is used for a steam reforming reactor and a water-gas shift reactor.

[0065] Example 1

[0066] like Figure 3 The figure shows a schematic diagram of a high-temperature and high-pressure underground coal gasification and pyrolysis integrated oil and hydrogen co-production system. The system includes: an injection well 300, a deep coal seam gasification and pyrolysis unit 310, an oil and gas processing unit 320, and a carbon dioxide capture unit 330.

[0067] The deep coal seam gasification and pyrolysis unit includes a lower coal seam horizontal gasification channel 3101, a connecting channel 3102, an upper coal seam horizontal pyrolysis channel 3103, and a production well 3104;

[0068] The oil and gas processing unit 320 includes a condenser 3201, a separator 3202, a desulfurization tower 3203, a steam reforming and water-gas shift module 3204, a burner 3205, a first heat exchanger 3206, and a second heat exchanger 3207;

[0069] The steam reforming and water-gas shift module 3204 includes: a steam reforming reactor 32041 and a water-gas shift reactor 32042;

[0070] The water-gas shift reactor 32042 includes a first WGS reactor heat exchanger and a second WGS reactor.

[0071] The process of implementing the underground coal gasification and pyrolysis integrated oil and hydrogen co-generation method based on the above-mentioned high-temperature and high-pressure underground coal gasification and pyrolysis integrated oil and hydrogen co-generation system is as follows:

[0072] In the first step, the gasifying agent (O2 and water) is introduced into the horizontal gasification channel 3101 of the lower coal seam through the injection well 300 after heat exchange with the gasification / pyrolysis product, and the lower coal seam is ignited and gasified at high temperature and high pressure using the injection point backward process. The raw coal gas obtained after gasification is transmitted to the horizontal pyrolysis channel 3103 of the upper coal seam through the connecting channel 3102; the horizontal pyrolysis channel of the upper coal seam heats and pyrolyzes the raw coal gas in situ to obtain an oil and gas mixture, which is discharged from the production well 3104.

[0073] In this step, the gasifying agent O2 and water are heated to 200°C-300°C and then injected into the horizontal gasification channel of the lower coal seam, i.e., the gasification cavity of the lower deep coal seam, through the injection well. The deep coal seam (referring to a coal seam with a depth greater than 800m) is subjected to high-temperature and high-pressure controllable combustion to carry out a gasification reaction using the CRIP process. The coal seam pressure is about 8MPa, the molar ratio of O2 to water in the gasifying agent can be between 1:2-1:4, the circulating amount of CO2 (CO2:O2 ratio) can be between 0.2-0.4, and the coal seam gasification combustion temperature in the gasification cavity can be within 1200°C.

[0074] The raw coal gas obtained after gasification is transmitted to the horizontal pyrolysis channel of the upper coal seam through the connecting channel; under the action of high-temperature gasification gas, the upper coal seam is slowly and steadily pyrolyzed at an average temperature of about 500°C, and the oil and gas produced by pyrolysis enter the negative pressure pyrolysis channel through the cracks and pores of the coal seam, mix with the gasification gas, and then be discharged from the production well.

[0075] In the second step, the oil and gas products discharged from the production well 3104 are processed through the oil and gas processing unit 320 and the carbon dioxide capture unit 330 to obtain a high-concentration H2 product.

[0076] In this step, the oil and gas products discharged from production well 3104 are heat exchanged in a condenser to room temperature and then transported to a separator for separation into an oil phase product and a gas phase product. The oil phase product can be processed for industrial use, while the gas phase product requires further processing. The sulfur component H2S in the gas phase product is removed in a desulfurization unit, resulting in clean net syngas. A portion of the resulting net syngas can be fed into a burner, while the remaining portion undergoes a reforming reaction in a steam methane reformer after heat exchange and temperature increase. For example, approximately 30% of the net syngas can be fed into a burner for combustion. The high-temperature flue gas from the combustion heats water to produce 400°C and 300°C steam, respectively, for use in the steam reformer and the water-gas shift reactor (WGS). The remaining portion, approximately 70%, undergoes a reforming reaction in the steam methane reformer after heat exchange and temperature increase. The remaining portion then undergoes a two-stage WGS water-gas shift reactor to convert CO and steam into high-concentration H2 and CO2. Among them, Ni / TiO2 catalyst can be used in the steam reforming reactor, the reaction temperature is 700℃, and the two-stage WGS reaction temperatures are 250℃ and 225℃ respectively.

[0077] After being processed by the oil and gas processing unit, a synthesis gas with high concentrations of H2 and CO2 is obtained. When it enters the CO2 capture device, Selexol solution can be used to physically absorb and separate CO2, and finally a high-concentration H2 product is obtained.

[0078] The separated CO2 is then mixed with the flue gas from the burner outlet and passed into the abandoned gasification chamber for geological storage, ultimately achieving zero CO2 emissions and carbon neutrality. Furthermore, some of the CO2 is reheated and then reinjected into the underground coal seam to enhance the gasification reaction of the char, thereby promoting the efficient and stable expansion of the gasification chamber.

[0079] The technical effects of this embodiment include:

[0080] 1) By connecting the lower coal seam gasification channel and the upper coal seam pyrolysis channel, a series of in-situ high-temperature and high-pressure gasification and pyrolysis systems are formed. The lower coal seam is gasified in-situ, and the heat energy generated by gasification is fully utilized to carry out in-situ pyrolysis of the upper coal seam. This realizes the integration of gasification and pyrolysis of deep coal seams, increases the effective components of gas phase products, and avoids the waste of heat energy.

[0081] 2) This embodiment utilizes in-situ pyrolysis of the upper coal seam, which not only minimizes the waste of oil and gas resources but also effectively avoids the difficulty of oil-dust separation in the above-ground coal pyrolysis process, and is expected to produce a cleaner oil-phase product.

[0082] 3) The integrated underground coal gasification and pyrolysis oil-hydrogen cogeneration system in this embodiment uses the Selexol physical absorption method to capture CO2 from hydrogen-rich gas. This not only produces high-quality clean energy H2, but also reduces CO2 emissions, ultimately achieving carbon capture.

[0083] 4) In this embodiment, the integrated underground coal gasification and pyrolysis oil-hydrogen cogeneration system adopts a partial CO2 reinjection scheme, which not only recovers the heat energy in the system, but also facilitates the reduction reaction of coal char under high temperature and high pressure, thereby enhancing the efficient expansion of the gasification chamber.

[0084] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As is well known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable, and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those skilled in the art that communication media generally embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. An integrated underground coal gasification and pyrolysis oil and hydrogen co-production system, characterized in that: The system includes: an injection well, a deep coal seam gasification and pyrolysis unit, an oil and gas processing unit, and a carbon dioxide capture unit; wherein the deep coal seam gasification and pyrolysis unit includes a lower coal seam horizontal gasification channel, a connecting channel, an upper coal seam horizontal pyrolysis channel, and a production well; The injection well, the lower coal seam horizontal gasification channel, the connecting channel, the upper coal seam horizontal pyrolysis channel and the production well are connected in series, the upper coal seam horizontal pyrolysis channel is located in the upper coal seam, the lower coal seam horizontal gasification channel is located in the lower coal seam, and the connecting channel is located in the upper coal seam, the middle coal seam and the lower coal seam; The lower coal seam horizontal gasification channel is used to receive the gasification agent from the injection well and perform gasification, and the raw coal gas obtained after gasification is transmitted to the upper coal seam horizontal pyrolysis channel through the connecting channel; The upper coal seam horizontal pyrolysis channel is used to be heated and pyrolyzed in situ by the crude coal gas to produce an oil-gas mixture, which is then discharged from the production well. The crude coal gas is transmitted to the upper coal seam horizontal pyrolysis channel through the connecting channel. Under the action of the crude coal gas, the upper coal seam is slowly and steadily pyrolyzed. The oil and gas produced by the pyrolysis enter the negative pressure upper coal seam horizontal pyrolysis channel through the cracks and pores of the coal seam, mix with the crude coal gas to produce an oil-gas mixture, which is then discharged from the production well. The oil and gas processing unit is used to separate the oil and gas mixture to obtain oil phase products, hydrogen and carbon dioxide mixed gases respectively; The carbon dioxide capture unit is used to separate and process the hydrogen and carbon dioxide mixture obtained by the oil and gas processing unit to obtain separated hydrogen and carbon dioxide, and to circulate part of the separated carbon dioxide into the injection well and to geologically seal the remaining carbon dioxide; The oil and gas processing unit also includes a separator, a burner, a desulfurization tower, a steam reforming and a water-gas shift module; The desulfurization tower is used to desulfurize the gaseous product separated by the separator and transmit part of the desulfurized synthesis gas to the steam reforming and water-gas shift module; The steam reforming and water gas shift module is used to convert methane and carbon monoxide in the received synthesis gas into hydrogen and carbon dioxide; The steam reforming and water-gas shift module includes: a steam reforming reactor and a water-gas shift reactor; The steam reforming reactor is used to perform a reforming reaction on the received synthesis gas using a predetermined catalyst to obtain carbon monoxide and hydrogen; The water-gas shift reactor is used to convert the carbon monoxide and steam into a mixed gas of hydrogen and carbon dioxide; The burner is used to burn the remaining part of the desulfurized synthesis gas to produce steam for use in the steam reforming reactor and the water-gas shift reactor.

2. The underground coal gasification and pyrolysis integrated oil and hydrogen co-production system according to claim 1 is characterized in that: The oil and gas processing unit includes a condenser; The condenser is used to cool the oil and gas mixture discharged from the production well by heat exchange and transmit it to the separator; The separator is used to separate the oil-gas mixture cooled by the condenser into an oil phase product and a gas phase product.

3. The underground coal gasification and pyrolysis integrated oil and hydrogen co-production system according to claim 2, characterized in that: The carbon dioxide capture unit is further used to separate carbon dioxide from the mixture of hydrogen and carbon dioxide using polyethylene glycol dimethyl ether solution to obtain hydrogen product; and to circulate part of the separated carbon dioxide into the injection well.

4. The underground coal gasification and pyrolysis integrated oil and hydrogen co-production system according to claim 3 is characterized in that: The oil and gas processing unit further includes a first heat exchanger and a second heat exchanger; The first heat exchanger is used to connect the hot end to the burner and the cold end to water; The second heat exchanger is used to connect the hot end to the water-gas shift reactor and the cold end to the carbon dioxide capture unit.

5. A method for the integrated oil and hydrogen co-production of underground coal gasification and pyrolysis, using the underground coal gasification and pyrolysis integrated oil and hydrogen co-production system according to any one of claims 1 to 4, characterized in that: The method comprises: The gasifying agent is injected into the horizontal gasification channel of the lower coal seam from the injection well for gasification; The raw coal gas obtained by gasification is input into the horizontal pyrolysis channel of the upper coal seam, and the upper coal seam is heated and pyrolyzed in situ to obtain an oil-gas mixture; The oil and gas mixture is discharged through a production well to obtain hydrogen.

6. The method for integrated oil and hydrogen co-production of underground coal gasification and pyrolysis according to claim 5, characterized in that: The step of discharging the oil and gas mixture through a production well to obtain hydrogen comprises: Separating the oil-gas mixture into oil and gas using a condenser and a separator to obtain an oil phase product and a gas phase product; The gaseous product is transported to a desulfurization tower for desulfurization to obtain synthesis gas; A portion of the synthesis gas is transferred to a steam reforming and water-gas shift module to produce hydrogen.

7. The method for integrated oil and hydrogen co-production of underground coal gasification and pyrolysis according to claim 6, characterized in that: After the gaseous product is transported to a desulfurization tower for desulfurization to obtain synthesis gas, the method further comprises: The remaining portion of the synthesis gas is fed to a combustor to produce steam, which is used by a steam reforming reactor and a water-gas shift reactor.

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