Carbon-based energy supercritical water gasification hydrogen production and CO2 energy utilization system and method

Abstract

A system and method for hydrogen production by supercritical water gasification of carbon-based energy and energy utilization of CO2, comprising: a main reaction process, in which the heat of the reaction products of supercritical water gasification for hydrogen production is used to preheat the materials, and then CO2 and liquid-phase products are separated. After the temperature and pressure of the liquid-phase products are adjusted, supercritical water oxidation reaction is carried out. The heat of the reaction products of supercritical water oxidation is used to preheat the liquid-phase products after temperature and pressure adjustment, and then the pressure is reduced for three-phase separation to obtain CO2 and liquid-phase products, and the liquid-phase products are replenished for coal slurry preparation; an energy-based carbon fixation process, in which the CO2 obtained from the main reaction process is used for microalgae carbon fixation reaction to produce bio-crude oil; an oxidant supply process, which supplies oxygen for the supercritical water gasification reaction and the supercritical water oxidation reaction; and material supply, which carries out coal slurry preparation and supplies materials to the main reaction process. The present invention combines supercritical water combustion technology, supercritical water gasification technology, and supercritical water oxidation technology, realizing the high-value and clean conversion and utilization of the whole process of coal.

Description

Technical Field

[0001] The present invention belongs to the technical field of clean and efficient conversion and utilization of energy and carbon fixation, and in particular relates to a carbon-based energy supercritical water gasification hydrogen production and CO2 energy utilization system and method. Background Art

[0002] As the most promising new energy source, hydrogen has the advantages of abundant sources, light weight, high calorific value, no carbon emissions, water as a combustion product, and can be directly used in hydrogen fuel cells. With the increasing attention paid to environmental quality by society, and the fact that hydrogen can be widely used in industrial fields such as petroleum, chemical industry, metallurgy, medicine, and aerospace, it has become a research hotspot in various countries in recent years. In 2018, China's coal accounted for nearly 60% of primary energy consumption. The clean utilization of coal is of great significance for energy conservation and emission reduction, and building an ecological power. Coal is used as a raw material to produce hydrogen on a large scale. However, the traditional coal gasification process has the following technical problems: low hydrogen yield; poor adaptability of coal types and high coal quality requirements; short service life of burners and refractory bricks, and easy damage; syngas is easy to carry ash and water, and syngas coolers are prone to ash accumulation; gasification equipment is difficult to discharge slag and easy to clog.

[0003] Supercritical water gasification technology (SCWG) utilizes the special properties of supercritical water (SCW) to add reactants into the SCWG reactor for pyrolysis and gasification without adding oxidants, and produce high calorific value gases such as hydrogen and methane, and organic matter will not generate byproducts such as coke during the reaction. SCWG hydrogen production technology is one of the most promising hydrogen production technologies. Compared with conventional coal gasification processes, it has high reaction efficiency and high hydrogen selectivity. However, due to the temperature resistance limit of high-pressure reactors and preheater materials, the current large-scale SCWG process reaction temperature is mostly 400-600℃. The low gasification temperature leads to low hydrogen yield and low carbon gasification rate. The residual carbon content after gasification is high, and the residual slurry after gas separation needs to be harmlessly treated and has a high energy utilization value. In addition, a large amount of CO2 will be generated during the SCWG hydrogen production process of coal, and its direct emission will bring many problems such as the "greenhouse effect". How to improve hydrogen production efficiency, realize the reuse of residual slurry with high energy utilization value, and low-cost recovery and utilization of CO2 have become the main obstacles restricting the development of SCWG process. Summary of the invention

[0004] In order to overcome the shortcomings of the conventional SCWG hydrogen production process in the above-mentioned prior art, the purpose of the present invention is to provide a carbon-based energy supercritical water gasification hydrogen production and CO2 energy utilization system and method, which couples supercritical water thermal combustion technology, supercritical water gasification technology, and supercritical water oxidation technology in one, realizing high-value clean conversion and utilization of coal in the entire process.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A carbon-based energy supercritical water gasification hydrogen production and CO2 energy utilization system, comprising:

[0007] The main reaction module comprises a supercritical water gasification reactor 1, the bottom outlet of the supercritical water gasification reactor 1 is connected to a separator via a material regenerator 2 hot fluid side, the liquid phase outlet of the separator is connected to an inlet of a supercritical water oxidation reactor 10 via a component recovery unit 7, a booster slurry pump 8 and a slurry regenerator 9 cold fluid side in sequence, the outlet of the supercritical water oxidation reactor 10 is connected to an inlet of a three-phase separator 13 via a slurry regenerator 9 hot fluid side, an economizer 11 and a pressure reducer 12 in sequence, and the liquid phase outlet of the three-phase separator 13 is connected to a coal slurry preparation unit 21;

[0008] The energy-based carbon fixation module includes a high-carbon gas collection and supply unit 14, the input port of the high-carbon gas collection and supply unit 14 is connected to the CO2 gas of the separator and the three-phase separator 13, the outlet of the high-carbon gas collection and supply unit 14 is connected to the first inlet of the microalgae carbon fixation reactor 15, the outlet of the microalgae carbon fixation reactor 15 is connected to the centrifugal separator 16, the bottom outlet of the centrifugal separator 16 is connected to the hydrothermal liquefaction reactor 17, and the top outlet of the centrifugal separator 16 is connected to the second inlet of the microalgae carbon fixation reactor 15;

[0009] The oxidant supply module includes an air separation device 19, the oxygen-rich gas outlet of the air separation device 19 is connected to the inlet of the oxygen compressor 20, and the outlet of the oxygen compressor 20 is divided into two paths, one of which is connected to the top inlet of the supercritical water gasification reactor 1, and the other is connected to the inlet of the supercritical water oxidation reactor 10;

[0010] The material supply module includes a coal slurry preparation unit 21. The outlet of the coal slurry preparation unit 21 is connected to the cold fluid side inlet of the material regenerator 2 through a high-pressure material pump 22. The cold fluid side outlet of the material regenerator 2 is divided into two paths, one is connected to the top inlet of the supercritical water gasification reactor 1, and the other is connected to the upper side inlet of the supercritical water gasification reactor 1.

[0011] Furthermore, in the main reaction module, the separator includes a high-pressure separator 3 and a low-pressure separator 6, the hot fluid side outlet of the material reheater 2 is connected to the high-pressure separator 3, the bottom outlet of the high-pressure separator 3 is connected to the low-pressure separator 6 via the thermostat 4 and the pressure regulator 5, the liquid phase outlet of the low-pressure separator 6 is connected to the recovery unit 7, and the gas phase outlet of the high-pressure separator 3 is connected to the inlet of the gas separation unit 18.

[0012] Furthermore, the gas separation unit 18 is provided with three outlets, the first outlet outputs hydrogen, and the third outlet outputs CO2, which are connected to the high-carbon gas collection and supply unit 14.

[0013] Furthermore, the high-carbon gas collection and supply unit 14 is provided with three input ports, which are respectively connected to the CO2 outlet of the gas separation unit 18, the top gas phase outlet of the three-phase separator 13, and the top gas phase outlet of the low-pressure separator 6.

[0014] Furthermore, the upper side inlet of the supercritical water gasification reactor 1 is an annular channel structure, and a plurality of incident nozzles are arranged inside the annular channel; there is a hydrothermal flame zone at the top of the supercritical water gasification reactor 1, and the supercritical water gasification reactor 1 is surrounded by a high-efficiency cooling jacket.

[0015] Furthermore, the hydrothermal flame zone is spherical or ellipsoidal, the top inlet of the supercritical water gasification reactor 1 is located at the top of the center of the hydrothermal flame zone, and the upper side inlet of the supercritical water gasification reactor 1 is located at the lower outlet of the hydrothermal flame zone.

[0016] Furthermore, the component recovery unit 7 is used to recover sulfur, ammonia water, and ammonium sulfate, and the discharge from the bottom outlet of the three-phase separator 13 is completely mineralized and stabilized ash.

[0017] Furthermore, the materials include coal, sludge and oil sludge.

[0018] Furthermore, the present invention also provides a method for producing hydrogen by supercritical water gasification of carbon-based energy and a CO2 energy utilization system, comprising:

[0019] The main reaction process is to carry out a supercritical water gasification hydrogen production reaction in a supercritical water gasification reactor 1, and the heat of the supercritical water gasification hydrogen production reaction product is used to preheat the material, and then hydrogen, CO2 and liquid products are separated, and the liquid products are sent to a supercritical water oxidation reactor 10 after temperature and pressure adjustment for supercritical water oxidation reaction, and the heat of the supercritical water oxidation reaction product is used to preheat the liquid products after temperature and pressure adjustment, and then the pressure is reduced and sent to a three-phase separator for three-phase separation, and the separated liquid phase is replenished for coal slurry preparation;

[0020] The energy-based carbon fixation process uses the CO2 obtained in the main reaction process as the main raw material, performs a microalgae carbon fixation reaction in the microalgae carbon fixation reactor 15, and produces bio-crude oil;

[0021] Oxidant supply process, using air separation unit 19 and oxygen compressor 20 to supply oxygen to supercritical water gasification reactor and supercritical water oxidation reaction;

[0022] In the material supply process, carbon-based energy and water are used to prepare coal slurry in the coal slurry preparation unit 21 to supply materials to the main reaction process.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Innovatively coupling supercritical hydrothermal combustion technology and supercritical water gasification technology, coal slurry enters the supercritical water gasification reactor in two ways. The fuel material is mixed with oxygen at the top and quickly burns and heats to a high temperature of more than 1000°C. The gasified material is directly preheated to a higher reaction temperature through intermolecular mixing, which solves the problem of low hydrogen production caused by the low gasification temperature of conventional supercritical water gasification process.

[0025] 2. The residual slurry from coal gasification is treated with supercritical water oxidation. Its own calorific value can meet the heat required by the supercritical water oxidation device. No external energy is required, and the harmless and energy-based utilization of the residual slurry can be achieved in one step.

[0026] 3. By setting up an energy-based carbon fixation process, the CO2 produced by the supercritical hydrothermal combustion and hydrothermal gasification of coal is captured and utilized through a microalgae carbon fixation reactor to produce renewable biomass energy - microalgae, and further produce bio-crude oil through hydrothermal liquefaction, truly realizing the "zero carbon emission" of coal conversion and utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the system structure of the present invention.

[0028] Among them: 1. Supercritical water gasification reactor; 2. Material regenerator; 3. High-pressure separator; 4. Temperature regulator; 5. Pressure regulator; 6. Low-pressure separator; 7. Component recovery unit; 8. Booster slurry pump; 9. Slurry regenerator; 10. Supercritical water oxidation reactor; 11. Economizer; 12. Pressure reducer; 13. Three-phase separator; 14. High-carbon gas collection and supply unit; 15. Microalgae carbon fixation reactor; 16. Centrifugal separator; 17. Hydrothermal liquefaction reactor; 18. Gas separation unit; 19. Air separation unit; 20. Oxygen compressor; 21. Coal slurry preparation unit; 22. High-pressure material pump. DETAILED DESCRIPTION

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "one side", "one end", "one side" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] like Figure 1 As shown, in this embodiment, a carbon-based energy supercritical water gasification hydrogen production and carbon dioxide energy utilization system is provided, including a main reaction module, an energy carbon fixation module, an oxidant supply module and a material supply module. The main reaction process includes a supercritical water gasification reactor 1, the bottom outlet of the supercritical water gasification reactor 1 is connected to the high-pressure separator 3 through the hot fluid side of the material regenerator 2, the bottom outlet of the high-pressure separator 3 is connected to the low-pressure separator 6 through the thermostat 4 and the pressure regulator 5, the bottom outlet of the low-pressure separator 6 is connected to the supercritical water oxidation reactor 10 through the component recovery unit 7, the booster slurry pump 8, and the cold fluid side of the slurry regenerator 9 in sequence, the outlet of the supercritical water oxidation reactor 10 is connected to the hot fluid side of the slurry regenerator 9, the economizer 11, the pressure reducer 12, and the three-phase separator 13 in sequence, and the liquid phase outlet of the three-phase separator 13 is connected to the coal slurry preparation unit 21.

[0032] The energy-based carbon fixation module mainly includes a high-carbon gas collection and supply unit 14, which is provided with three input ports, which are respectively connected to the third outlet of the gas separation unit 18, the top outlet of the three-phase separator 13, and the top outlet of the low-pressure separator 6; the outlet of the high-carbon gas collection and supply unit 14 is connected to the first inlet of the microalgae carbon fixation reactor 15, the outlet of the microalgae carbon fixation reactor 15 is connected to the centrifugal separator 16, the bottom outlet of the centrifugal separator 16 is connected to the hydrothermal liquefaction reactor 17, and the top outlet of the centrifugal separator 16 is connected to the second inlet of the microalgae carbon fixation reactor 15.

[0033] The oxidant supply module includes an air separation device 19, the oxygen-rich gas outlet of the air separation device 19 is connected to the inlet of the oxygen compressor 20, and the outlet of the oxygen compressor 20 is divided into two paths, one is connected to the top inlet of the supercritical water gasification reactor 1, and the other is connected to the inlet of the supercritical water oxidation reactor 10 to complete the supercritical water oxidation reaction with the coal gasification residual slurry.

[0034] The CO2 and other gases generated by the third outlet of the gas separation unit 18, the top outlet of the three-phase separator 13, and the top outlet of the low-pressure separator 6 in the system enter the high-carbon gas collection and supply unit 14 through the three input ports set by the high-carbon gas collection and supply unit 14 to complete the energy carbon fixation process. The high-carbon gas flowing out of the high-carbon gas collection and supply unit 14 enters the microalgae carbon fixation reactor 15 for microalgae cultivation. The outlet of the microalgae carbon fixation reactor 15 is connected to the centrifugal separator 16. The cultivated microalgae liquid is separated in the centrifugal separator 16. The concentrated algae slurry enters the hydrothermal liquefaction reactor 17 through the bottom outlet of the centrifugal separator 16, and the dilute algae liquid enters the second inlet of the microalgae carbon fixation reactor 15 through the top outlet of the centrifugal separator 16.

[0035] The upper side entrance of the supercritical water gasification reactor 1 is an annular channel structure, and a plurality of injection nozzles are arranged inside the annular channel, and the gasified material enters through the injection nozzles. There is a hydrothermal flame zone at the top of the supercritical water gasification reactor 1, and the fuel material burns and releases heat rapidly in the hydrothermal flame zone, and then flows downward to mix with the gasified material for heat exchange. The supercritical water gasification reactor 1 is surrounded by a high-efficiency cooling jacket to prevent the wall from overheating.

[0036] The inlet of the gas separation unit 18 is connected to the top outlet of the high-pressure separator 3. The gas separation unit 18 is provided with three outlets. The first outlet outputs hydrogen, and the third outlet is connected to the high-carbon gas collection and supply unit 14. The gas separation method includes but is not limited to pressure swing adsorption, molecular sieve adsorption, etc., which is determined according to the specific gas composition and processing scale. The separated hydrogen enters the hydrogen storage unit or is directly utilized by the hydrogen energy utilization device. The component recovery unit 7 is used to recover sulfur, ammonia water, ammonium sulfate, etc. The discharge from the bottom outlet of the three-phase separator 13 is completely mineralized and stabilized ash. In addition, the carbon-based energy supercritical water gasification hydrogen production and carbon dioxide energy utilization system, its applicable materials are not limited to coal, sludge, oil sludge, etc.

[0037] In summary, the present invention discloses a carbon-based energy supercritical water gasification hydrogen production and carbon dioxide energy utilization system, which includes supercritical hydrothermal combustion coupled gasification technology, supercritical water oxidation technology and CO2 capture microalgae cultivation technology, realizing the "zero carbon emission" of coal conversion and utilization. The coal slurry enters the supercritical water gasification reactor in two ways. The fuel material is mixed with oxygen at the top and burns and heats up rapidly, and the gasified material is heated by direct heat transfer between molecules, which not only solves the problem of low hydrogen production caused by low temperature in conventional supercritical water gasification, but also greatly saves the energy consumption of the system. The residual slurry of coal gasification can be completely harmless and energy-utilized after being treated with supercritical water oxidation. The CO2 generated during the supercritical hydrothermal combustion, gasification and oxidation of coal is separated and collected and used for microalgae cultivation, effectively completing the carbon energy collection and utilization. This system can not only realize the high-value clean conversion and utilization of coal and near-zero carbon emissions, but also can be applied to the resource recycling of sludge, oil sludge, etc., so as to prepare hydrogen with low consumption and high efficiency.

[0038] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A carbon-based energy supercritical water gasification hydrogen production and CO2 energy utilization system, characterized in that: include: The main reaction module comprises a supercritical water gasification reactor (1), the bottom outlet of the supercritical water gasification reactor (1) is connected to a separator via a hot fluid side of a material regenerator (2), the liquid phase outlet of the separator is connected to an inlet of a supercritical water oxidation reactor (10) via a component recovery unit (7), a booster slurry pump (8) and a cold fluid side of a slurry regenerator (9), the outlet of the supercritical water oxidation reactor (10) is connected to an inlet of a three-phase separator (13) via a hot fluid side of a slurry regenerator (9), an economizer (11) and a pressure reducer (12), and the liquid phase outlet of the three-phase separator (13) is connected to a coal slurry preparation unit (21); The energy-based carbon fixation module comprises a high-carbon gas collection and supply unit (14), the input port of the high-carbon gas collection and supply unit (14) is connected to the CO2 gas of the separator and the three-phase separator (13), the outlet of the high-carbon gas collection and supply unit (14) is connected to the first inlet of the microalgae carbon fixation reactor (15), the outlet of the microalgae carbon fixation reactor (15) is connected to the centrifugal separator (16), the bottom outlet of the centrifugal separator (16) is connected to the hydrothermal liquefaction reactor (17), and the top outlet of the centrifugal separator (16) is connected to the second inlet of the microalgae carbon fixation reactor (15); The oxidant supply module comprises an air separation device (19), wherein the oxygen-rich gas outlet of the air separation device (19) is connected to the inlet of an oxygen compressor (20), and the outlet of the oxygen compressor (20) is divided into two paths, one of which is connected to the top inlet of a supercritical water gasification reactor (1), and the other is connected to the inlet of a supercritical water oxidation reactor (10); The material supply module comprises a coal slurry preparation unit (21), the outlet of the coal slurry preparation unit (21) is connected to the cold fluid side inlet of the material regenerator (2) via a high-pressure material pump (22), the cold fluid side outlet of the material regenerator (2) is divided into two paths, one path is connected to the top inlet of the supercritical water gasification reactor (1), and the other path is connected to the upper side inlet of the supercritical water gasification reactor (1); In the main reaction module, the separator includes a high-pressure separator (3) and a low-pressure separator (6); the hot fluid side outlet of the material reheater (2) is connected to the high-pressure separator (3); the bottom outlet of the high-pressure separator (3) is connected to the low-pressure separator (6) via a thermostat (4) and a pressure regulator (5); the liquid phase outlet of the low-pressure separator (6) is connected to a recovery unit (7); the gas phase outlet of the high-pressure separator (3) is connected to the inlet of a gas separation unit (18); the gas separation unit (18) is provided with three outlets, the first outlet outputs hydrogen, the third outlet outputs CO2, and is connected to a high-carbon gas collection and supply unit (14); the high-carbon gas collection and supply unit (14) is provided with three input ports, which are respectively connected to the CO2 outlet of the gas separation unit (18), the top gas phase outlet of the three-phase separator (13), and the top gas phase outlet of the low-pressure separator (6).

2. According to claim 1, the carbon-based energy supercritical water gasification hydrogen production and CO2 energy utilization system is characterized in that: The upper side inlet of the supercritical water gasification reactor (1) is an annular channel structure, and a plurality of injection nozzles are arranged inside the annular channel; a hydrothermal flame zone exists at the top of the supercritical water gasification reactor (1), and the supercritical water gasification reactor (1) is surrounded by a high-efficiency cooling jacket.

3. The carbon-based energy supercritical water gasification hydrogen production and CO2 energy utilization system according to claim 2 is characterized in that: The hydrothermal flame zone is spherical or ellipsoidal, the top inlet of the supercritical water gasification reactor (1) is located at the top of the center of the hydrothermal flame zone, and the upper side inlet of the supercritical water gasification reactor (1) is located at the lower outlet of the hydrothermal flame zone.

4. According to claim 1, the carbon-based energy supercritical water gasification hydrogen production and CO2 energy utilization system is characterized in that: The component recovery unit (7) is used to recover elemental sulfur, ammonia water, and ammonium sulfate, and the discharge from the bottom outlet of the three-phase separator (13) is completely mineralized and stabilized ash.

5. According to claim 1, the carbon-based energy supercritical water gasification hydrogen production and CO2 energy utilization system is characterized in that: The materials include coal, sewage sludge and oil sludge.

6. The method for producing hydrogen from supercritical water gasification of carbon-based energy and CO2 energy utilization system according to claim 1 is characterized in that: include: The main reaction process is to carry out a supercritical water gasification hydrogen production reaction in a supercritical water gasification reactor (1), the heat of the supercritical water gasification hydrogen production reaction product is used to preheat the material, and then hydrogen and CO2 and liquid products are separated, and the liquid products are sent to a supercritical water oxidation reactor (10) after temperature and pressure adjustment to carry out a supercritical water oxidation reaction, the heat of the supercritical water oxidation reaction product is used to preheat the liquid products after temperature and pressure adjustment, and then the pressure is reduced and sent to a three-phase separator for three-phase separation, and the separated liquid phase is replenished to prepare coal slurry; The energy-based carbon fixation process uses the CO2 obtained in the main reaction process as the main raw material, performs a microalgae carbon fixation reaction in a microalgae carbon fixation reactor (15), and produces bio-crude oil; An oxidant supply process, using an air separation unit (19) and an oxygen compressor (20) to supply oxygen to a supercritical water gasification reactor and a supercritical water oxidation reaction; In the material supply process, carbon-based energy and water are used to prepare coal slurry in the coal slurry preparation unit (21) to supply materials to the main reaction process.

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