Continuous supercritical water gasification-oxidation coupling reactor applied to combined heat and power generation

Abstract

The invention discloses a continuous supercritical water gasification-oxidation coupling reactor applied to combined heat and power generation. The continuous supercritical water gasification-oxidation coupling reactor comprises a water cooling wall, an inner sleeve and an external annular reaction zone, the membrane water-cooled wall is arranged on the outer wall of the reactor; the inner sleeve is fixed at the top of the reactor main body; the external annular space is a supercritical water gasification reaction zone. An upper outlet product of the membrane water wall is a preheating water source; an annular space outside the reactor is provided with a material inlet and an annular preheated water inlet; a slag outlet is formed in the lower part of the reactor main body; a heat exchange sleeve is arranged in the reaction cavity; introducing an oxidant into the heat exchange sleeve from the upper part of the reactor; a system product outlet is formed in the bottom of the inner sleeve. Energy is supplied to the gasification reaction process through the reaction of an oxidizing agent and a gasification product, so that the self-heating of the reactor is realized, and higher equipment investment and operation cost caused by electric heating equipment are reduced; a high-temperature product after the oxidation reaction is used for a combined heat and power generation process.

Description

Technical Field

[0001] The present invention belongs to the field of clean and efficient utilization of energy, and particularly relates to a continuous supercritical water gasification-oxidation coupling reactor applied to cogeneration, and the reaction is based on supercritical water gasification technology. Background Art

[0002] The traditional combustion methods of organic waste and fossil energy are highly polluting and inefficient. In order to improve the utilization efficiency of fuels and avoid the generation of polluting gases, it is necessary to achieve the efficient and clean utilization of traditional fuels, which is an important direction for energy development.

[0003] Supercritical water refers to water whose temperature and pressure both exceed the critical point (critical temperature 374 °C, critical pressure 22.1 MPa), and it has good transport properties and dissolution characteristics, and can dissolve most organic substances and gases. Under supercritical conditions, water has a low dielectric constant, a high diffusion coefficient, and a density that changes with pressure.

[0004] Supercritical water gasification technology refers to the process of mixing and fluidizing water with coal or biomass under supercritical conditions to react to generate non-toxic and harmless methane, hydrogen, carbon monoxide, carbon dioxide, etc., while producing high-quality combustible gases during the degradation of organic substances and avoiding the generation of NOx and SOx. This process is an endothermic process and can be heated by means such as electricity, solar energy, and waste heat utilization.

[0005] Cogeneration refers to a production method in which a power plant can produce electrical energy and at the same time use the steam that has done work in a steam turbine for heating, which can make full use of fuel to save resources.

[0006] Therefore, using supercritical water gasification technology for cogeneration is an effective and promising treatment method. Summary of the Invention

[0007] The purpose of the present invention is to combine advantages to provide a continuous supercritical water gasification-oxidation coupling reactor applied to cogeneration, which can reduce the investment and operating costs of electric heating equipment and provide a way to achieve the efficient and clean utilization of coal and cogeneration.

[0008] The inner sleeve in the reactor divides the reaction into an oxidation reaction exothermic zone and a supercritical water gasification endothermic zone, and the high-temperature products of the oxidation reaction are used in the power generation process. The oxidation exothermic reaction takes place in the inner sleeve of the reactor, and the gasification endothermic reaction takes place in the external annular space. The heat from the oxidation exothermic process can be supplied to the gasification endothermic process, so that the temperature of the oxidation zone can be easily controlled, while reducing the heating cost of the gasification endothermic process and improving the economy of the system.

[0009] The present invention provides a device for gasifying organic substances in a supercritical water gasification-oxidation coupling reactor, comprising: a reactor shell, an inner sleeve, a material inlet, an oxidant inlet, a membrane water wall, a preheated water inlet, a system product outlet, and a slag discharge port. The inner sleeve is fixed at the bottom of the reactor and has an upper opening; the membrane water wall is arranged on the outer wall of the reactor; an annular preheated water inlet and a slag discharge port are provided at the bottom of the outer annular space, and a material inlet is provided at the lower part; the oxidant inlet is arranged at the upper part of the reactor and leads into the inner sleeve; a product outlet is provided at the lower part of the inner sleeve. The reaction fluid is heated by the outer wall of the inner sleeve and the inner wall of the reactor during the upward process.

[0010] In the above-mentioned supercritical water gasification-oxidation coupling reactor, multiple thermocouples can be installed and arranged to monitor the temperature distribution in the reaction area.

[0011] After passing through the membrane water wall, the water heated to a certain temperature flows in from the preheated water inlet, and the un-preheated pulverized coal is sprayed in from the material inlet. After the material is mixed with the water, under the action of electric heating, it quickly rises to the supercritical state and fluidizes in the outer annular space to carry out the supercritical water gasification reaction, generating gases such as H 2 、CH 4 、CO 2 、N 2 etc. The gas products flow into the inner sleeve from the upper part. After the reaction in the outer annular space is stable for a period of time, oxygen or compressed air is introduced from the upper oxidant inlet. The oxidant is fully mixed with the gas products, and a supercritical water thermal combustion reaction occurs. A large amount of heat is released by the reaction and transferred to the outer annular space through the outer wall of the inner sleeve to supply the supercritical water gasification reaction, so as to achieve the purpose of supercritical water gasification-oxidation energy coupling. As the reaction progresses, the power of the electric heating is gradually reduced until the electric heating is completely stopped, realizing the self-heating of the reactor and enabling continuous and stable operation. The solid products and inorganic salts of the supercritical water gasification reaction in the outer annular space are regularly discharged through the slag discharge port provided at the lower part of the reactor. The oxidation reaction products generated in the inner sleeve are discharged through the product outlet at the lower part for further power generation and heat supply processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic structural diagram of the present invention, wherein, A is the material inlet, B is the preheated water inlet (annular), C is the membrane water wall, D is the oxidant inlet, E is the system product outlet, and F is the slag discharge port. The inner sleeve in the middle and the outer annular reaction zone; Figure 2 is a schematic structural diagram of the membrane water wall; wherein, A is the cooling water pipe, B is the steel plate, and C is the outer wall of the reactor. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be further described in detail below with reference to the accompanying drawings: ReferenceFigure 2 , which is the membrane water wall structure used in this patent. To ensure the smoothness of the inner wall of the reactor, the existing membrane water wall is vertically arranged on the outer wall of the reactor; Reference Figure 1 , a schematic diagram of a continuous supercritical water gasification-oxidation coupling reaction device according to the present invention. It consists of a material inlet A, a preheated water inlet B (ring-shaped inlet), a water wall C, an oxidant inlet D, a system product outlet F, an inner sleeve, and an external annular reaction zone. The inner sleeve is fixed at the bottom of the reactor body and is the oxidation exothermic reaction zone, with a system product outlet E provided at the lower part; the oxidant inlet D is fixed at the top of the reactor body; the membrane water wall C is vertically distributed on the outer wall; the preheated water inlet B is annularly distributed at the bottom of the reactor; the material is sprayed into the reactor from the lower inlet A of the reactor body, and the slag discharge port F is arranged at the lower part of the reactor body; the external annular zone is the supercritical water gasification reaction zone;

[0014] After passing through the membrane water wall C, the water heated to a certain temperature flows in from the preheated water inlet B, and the un-preheated pulverized coal is sprayed into the reactor from the material inlet A. After the material is mixed with water, under the action of electric heating, it quickly heats up to the supercritical state, fluidizes in the external annular space, and undergoes a supercritical water gasification reaction to generate H 2 , CH 4 , CO 2 , N 2 and other gas products; the gas products flow into the inner sleeve from the upper part. After the reaction in the annular space has been stable for a period of time, oxygen or compressed air is introduced from the upper oxidant inlet D. The oxidant is fully mixed with the gas products, and a supercritical water thermal combustion reaction occurs. A large amount of heat is released by the reaction and is transferred to the external annular space through the outer wall of the inner sleeve to supply the supercritical water gasification reaction, thereby achieving the purpose of supercritical water gasification-oxidation energy coupling. As the reaction progresses, the power of the electric heating is gradually reduced until the electric heating is completely stopped, realizing the self-heating of the reactor and enabling continuous and stable operation. The solid products and inorganic salts of the supercritical water gasification reaction in the external annular space are regularly discharged through the slag discharge port F provided at the lower part of the reactor. The oxidation reaction products generated in the inner sleeve are discharged through the product outlet E at the lower part for further power generation and heat supply processes.

[0015] Multiple thermocouples can be installed and arranged in the above-mentioned supercritical water gasification-oxidation coupling reactor to monitor the temperature distribution in the reaction area.

[0016] By coupling the supercritical water gasification reaction and the oxidation exothermic reaction in the present invention, the heat generated during the oxidation exothermic process can be supplied to the gasification endothermic process, so that the temperature in the oxidation zone is easy to control. At the same time, the cost of supplying heat for the gasification endothermic process is reduced, and the economy of the system is improved.

Claims

1. In a continuous supercritical water gasification-oxidation coupled reactor for cogeneration of heat and power, characterized in that: It consists of an inner sleeve and an outer annular reaction zone; including material inlet A, preheated water inlet B (annular inlet), membrane water-cooled wall C, oxidant inlet D, and system product outlet F. The inner sleeve is fixed at the bottom of the reactor body and is the oxidation exothermic reaction zone, with a system product outlet E at the bottom; the oxidant inlet D is fixed at the top of the reactor body; the membrane water-cooled wall C is vertically distributed on the outer wall; the preheated water inlet B is annularly distributed at the bottom of the reactor; the material is sprayed from the inlet A at the bottom of the reactor body, and the slag discharge port F is set at the bottom of the reactor body; the outer annular zone is the supercritical water gasification reaction zone.

2. A continuous supercritical water gasification-oxidation coupled reactor for cogeneration of heat and power according to claim 1, characterized in that: The inner sleeve is fixed at the bottom of the reactor body, oxygen or compressed air is introduced from the upper oxidant inlet, and a system product outlet E is provided at the lower part.

3. The continuous supercritical water gasification-oxidation coupled reactor for cogeneration of heat and power according to claim 1, characterized in that: The membrane water-cooled wall of the outer wall is arranged vertically.

4. The continuous supercritical water gasification-oxidation coupled reactor for cogeneration of heat and power according to claim 1, characterized in that: The preheated water inlet B is distributed in an annular shape at the bottom of the reactor, and the material inlet is arranged on the lower side wall of the external annular space.

5. The continuous supercritical water gasification-oxidation coupled reactor for cogeneration of heat and power according to claim 1, characterized in that: A slag discharge port F is provided on the lower side wall of the outer annular space.

6. A continuous supercritical water gasification-oxidation coupled reactor for cogeneration of heat and power according to claim 1.

7. A continuous supercritical water gasification-oxidation coupled reactor for cogeneration of heat and power, characterized in that: After passing through the water-cooled wall C, water heated to a certain temperature flows in from the preheated water inlet B, and unpreheated pulverized coal is sprayed in from the material inlet A. After the material and water are mixed, they are rapidly heated to a supercritical state under the action of electric heating, and fluidized in the external annular space to undergo supercritical water gasification reaction to generate gas products such as H2, CH4, CO2, and N2; the gas products flow into the inner sleeve from the top, and after the reaction in the annular space is stable for a period of time, oxygen or compressed air is introduced from the upper oxidant inlet D, and the oxidant and gas products are fully mixed to undergo a supercritical water thermal combustion reaction. The reaction releases a large amount of heat, which is transferred to the external annular space through the outer wall of the inner sleeve and supplied to the supercritical water gasification reaction, thereby achieving the purpose of supercritical water gasification-oxidation energy coupling. As the reaction proceeds, the power of the electric heating is gradually reduced until the electric heating is completely stopped, so that the reactor is self-heated and can operate continuously and stably. The solid products and inorganic salts of the supercritical water gasification reaction in the external annular space are regularly discharged through the slag discharge port F set at the bottom of the reactor. The oxidation reaction products occurring in the inner sleeve are discharged through the product outlet E at the bottom for further power generation and heat supply processes.

8. The continuous supercritical water gasification-oxidation coupled reactor for cogeneration of heat and power according to claim 6, characterized in that: Multiple thermocouples can be installed and arranged to monitor the temperature distribution in the reaction area.

9. The continuous supercritical water gasification-oxidation coupled reactor for cogeneration of heat and power according to claim 6, characterized in that: The heat released by the oxidation exothermic process is used to supply the gasification endothermic process, so that the temperature of the oxidation zone can be easily controlled, while the cost of heating the gasification endothermic process is reduced, thereby improving the economy of the system.

10. The continuous supercritical water gasification-oxidation coupled reactor for cogeneration of heat and power according to claim 6, characterized in that: The system product discharged from outlet E is supplied to the cogeneration process.

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