Green hydrogen production and purification system based on organic garbage gasification

Abstract

The invention particularly relates to a green hydrogen production and purification system based on organic garbage gasification. The green hydrogen production and purification system comprises a circulating fluidized bed gasification module; a purification reforming module; and a hydrogen separation and purification module. In the invention, the purification reforming module comprehensively applies various dust removal, desulfurization and dechlorination technologies, effectively removes impurities in synthesis gas, protects a water-gas shift reaction catalyst, and provides sufficient raw materials for subsequent purification by combining with accurate control of reaction parameters and improvement of hydrogen yield; the hydrogen separation and purification module combines pressure swing adsorption and membrane separation technologies, exerts the advantages of the pressure swing adsorption and membrane separation technologies, realizes efficient separation and purification of hydrogen, produces high-purity hydrogen, meets the requirements of various application scenarios, and significantly improves the green hydrogen production benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of green hydrogen production, and particularly to a green hydrogen production and purification system based on organic waste gasification. Background Art

[0002] With the continuous growth of the global demand for clean energy, green hydrogen, as a zero-carbon clean energy carrier, has received extensive attention. At present, the main methods for producing green hydrogen include electrolysis of water to produce hydrogen, biomass gasification to produce hydrogen, etc. Using solid waste, such as domestic waste, to gasify and produce hydrogen can not only realize the resource utilization of waste, but also reduce the production cost of green hydrogen, and has broad application prospects.

[0003] Therefore, a green hydrogen production and purification system based on organic waste gasification is needed to address the above-mentioned problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a green hydrogen production and purification system based on organic waste gasification to solve the above problems.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A green hydrogen production and purification system based on organic waste gasification, comprising: A pretreatment module; performing pretreatment on domestic waste, including sorting, crushing, and drying and forming; A circulating fluidized bed gasification module: Domestic waste undergoes a gasification reaction with high-purity oxygen produced by an air separation unit in a circulating fluidized bed gasifier to generate syngas; A purification and reforming module: After the syngas is purified, it undergoes a steam reforming reaction to convert and into and ; A hydrogen separation and purification module: Performing pressure swing adsorption and membrane separation on hydrogen to obtain high-purity hydrogen.

[0006] Preferably, the pretreatment module specifically includes: Sorting: Fine screening of the collected mixed domestic waste is carried out by magnetic separation, gravity separation, and flotation physical separation techniques; Crushing: Using jaw crushers and hammer crushers to perform multi-stage crushing on the sorted domestic waste; Drying and forming: Using hot air drying and vacuum drying methods to reduce the moisture content of the crushed domestic waste to a preset content.

[0007] Preferably, the circulating fluidized bed gasification module specifically includes: The pretreated RDF enters the circulating fluidized bed gasifier, where a high-temperature and oxygen-deficient environment is maintained; high-purity oxygen produced by the air separation unit is introduced from the bottom of the gasifier and undergoes a gasification reaction with the RDF; under the action of high temperature, the organic substances in the RDF undergo pyrolysis and redox reactions to generate syngas mainly composed of , , , and

[0008] Preferably, the purification and reforming module specifically includes syngas purification and water-gas shift reaction; Syngas purification: Dust removal: Cyclone dust collectors and bag filters work together; Desulfurization: Wet desulfurization and dry desulfurization technologies are adopted; wet desulfurization usually uses an alkaline solution as an absorbent to chemically react with sulfides in the syngas to form soluble salts, thereby removing sulfides; Dechlorination: Chlorides in the syngas are removed by adsorption, chemical absorption or water washing; Water-gas shift reaction: The purified syngas enters the reforming reactor and undergoes a reforming reaction with steam under the action of iron-based and copper-based catalysts.

[0009] Preferably, the hydrogen separation and purification module specifically includes: Pressure swing adsorption: Hydrogen separation is achieved by utilizing the difference in the adsorption capacity of adsorbents for different gases at different pressures; Membrane separation: Hydrogen separation is carried out according to the difference in the permeation rate of different gases in the membrane material.

[0010] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows: 1. By comprehensively applying various dust removal, desulfurization, and dechlorination technologies in the purification and reforming module of the present invention, impurities in the syngas are effectively removed, protecting the catalysts for the water-gas shift reaction. By precisely controlling the reaction parameters, the hydrogen production rate is increased, providing sufficient raw materials for subsequent purification; the hydrogen separation and purification module combines pressure swing adsorption and membrane separation technologies, giving full play to their respective advantages, achieving efficient hydrogen separation and purification, producing high-purity hydrogen, meeting the requirements of various application scenarios, and significantly improving the production efficiency of green hydrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In the following description of the exemplary embodiments with reference to the drawings, more details, features, and advantages of the present application are disclosed. In the drawings: Figure 1 is a flowchart of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Several embodiments of the present application will be described in more detail below with reference to the accompanying drawings so that those skilled in the art can implement the present application. The present application can be embodied in many different forms and for many different purposes and should not be limited to the embodiments set forth herein. These embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the application to those skilled in the art. The embodiments do not limit the present application.

[0013] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and / or this specification, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0014] Please refer to Figure 1 as shown, the present invention provides a technical solution: A green hydrogen production and purification system based on organic waste gasification, comprising: A pretreatment module; performing pretreatment on domestic waste including sorting, crushing, and drying and forming; The pretreatment module specifically includes: Sorting: Through various physical sorting technologies such as magnetic separation, gravity separation, and flotation, the collected mixed domestic waste is finely screened; ferromagnetic substances such as waste metal products are separated by magnetic separation equipment; relying on gravity separation, according to the density differences of different substances, bricks, stones, glass, etc. with larger densities are preliminarily separated from the high-calorie organic matter components; flotation can be used to separate some organic domestic waste with specific surface properties. Finally, high-calorie organic matter components such as waste paper, plastics, and wood materials are accurately screened out to provide high-quality raw materials for subsequent gasification reactions; Crushing: Using equipment such as jaw crushers and hammer crushers, the sorted domestic waste is crushed in multiple stages; first, it is coarsely crushed by a jaw crusher to break the larger lumps of domestic waste into smaller pieces, initially reducing the particle size of the domestic waste; then, it is further finely crushed by a hammer crusher so that the particle size of the domestic waste is less than 50 millimeters. Such a particle size can ensure that the domestic waste can be evenly distributed in the fluidized bed gasification furnace and fully contact with oxygen, greatly improving the gasification reaction efficiency; Drying and forming: By means of hot air drying, vacuum drying, etc., the moisture content of the crushed domestic waste is reduced to a preset level; in hot air drying, hot air is brought into full contact with the domestic waste to evaporate the moisture by heating; in vacuum drying, the boiling point of water is reduced under a low-pressure environment to achieve rapid drying. The dried domestic waste is processed into RDF (Refuse Derived Fuel) by a forming machine. Common forming methods include extrusion forming, molding, etc., to produce RDF with specific shapes and specifications, which is convenient for subsequent transportation, storage and efficient utilization; Circulating fluidized bed gasification module: The domestic waste undergoes a gasification reaction with high-purity oxygen produced by an air separation unit in a circulating fluidized bed gasifier; Specifically include: The pretreated RDF enters the circulating fluidized bed gasifier, where a high temperature (generally 800 - 1000 °C) and an anoxic environment are maintained; the high-purity oxygen produced by the air separation unit is introduced from the bottom of the gasifier and undergoes a gasification reaction with the RDF; under the action of high temperature, the organic substances in the RDF undergo complex reactions such as pyrolysis and redox reactions to generate syngas mainly composed of , , , ; Due to the special structure and gas flow design in the gasifier, the domestic waste is in a state of violent turbulence, greatly increasing the gas-solid contact area and effectively improving the gasification efficiency. The syngas at the outlet of the gasifier carries a large number of semi-coke particles that have not reacted completely. The semi-coke particles are separated by a cyclone separator using centrifugal force and returned to the gasifier through a return device for continuous reaction, realizing the recycling of domestic waste and improving the raw material utilization rate; at the same time, maintaining the temperature in the gasification section above 1200 °C enables the tar in the syngas to undergo a secondary gasification reaction and decompose into small molecule gases, avoiding the condensation and accumulation of tar in subsequent equipment and affecting the normal operation of the equipment; Purification and reforming module: After the syngas is purified, it undergoes a steam reforming reaction; Specifically include syngas purification and water-gas shift reaction; Syngas purification: Dust removal: Use equipment such as a cyclone dust collector and a bag filter to work together; the cyclone dust collector first removes larger-sized dust particles in the syngas using centrifugal force, allowing the dusty gas to enter the dust collector along the tangential direction. Under the action of centrifugal force, the dust particles are thrown towards the wall of the device and fall; the bag filter further filters the remaining fine dust. When the dusty gas passes through the filter bag, the dust is intercepted on the surface of the filter bag, and the purified gas is discharged from the inside of the filter bag to ensure that the dust content in the syngas meets the operating requirements of subsequent equipment and protects the equipment from wear; Desulfurization: Wet desulfurization and dry desulfurization technologies are adopted. In wet desulfurization, an alkaline solution (such as sodium hydroxide solution, ammonia water, etc.) is usually used as the absorbent to chemically react with sulfides in the syngas to form soluble salts, thereby removing sulfides. In dry desulfurization, solid desulfurizers (such as zinc oxide, iron oxide, etc.) are used, and the sulfides chemically react with the desulfurizer and are fixed on the surface of the desulfurizer. The combination of the two methods can effectively remove sulfides in the syngas and prevent them from poisoning and deactivating the catalyst in the subsequent water-gas shift reaction; Dechlorination: Chlorides in the syngas are removed by adsorption method, chemical absorption method or water washing method. In the adsorption method, a special dechlorination adsorbent (such as metal oxide supported on activated alumina) is used, and the chlorides are adsorbed on the surface of the adsorbent. In the chemical absorption method, an alkaline absorbent solution reacts with the chlorides to remove them from the syngas, preventing the chlorides from corroding the equipment. Based on the solubility of chlorides in water, in the water washing method, the syngas is passed through a water washing tower, and the chlorides are dissolved in water, thus achieving separation from the syngas; Water-gas shift reaction: The purified syngas enters the reforming reactor and undergoes a reforming reaction with steam under the action of catalysts such as iron-based and copper-based catalysts. During the reaction, reacts with steam to generate and , also reacts with steam and is converted into and ; By precisely controlling the reaction temperature (generally 300 - 500 °C), pressure (1 - 3 MPa) and the ratio of steam to syngas, the hydrogen production rate is increased, providing a more abundant hydrogen source for subsequent hydrogen separation and purification; Hydrogen separation and purification module: Hydrogen is separated and purified. Specifically including: Pressure swing adsorption: Hydrogen separation is achieved by utilizing the difference in the adsorption capacity of adsorbents (such as activated carbon, molecular sieve, etc.) for different gases under different pressures. The syngas enters the adsorption tower under high pressure (generally 3 - 5 MPa). The adsorbent has a strong adsorption capacity for impurity gases such as , , in the syngas, while having a weak adsorption for hydrogen. Hydrogen quickly passes through the adsorption tower to achieve preliminary separation. When the adsorbent is saturated with adsorption, the pressure of the adsorption tower is reduced (close to atmospheric pressure), and the adsorbed impurity gases are desorbed and discharged. The adsorbent is regenerated and can be recycled. High-purity hydrogen is continuously produced through the alternating adsorption and desorption operations of multiple adsorption towers; Membrane separation: Hydrogen is separated according to the difference in the permeation rates of different gases in the membrane material (such as organic polymer membranes, inorganic ceramic membranes, etc.); The syngas contacts the membrane material under pressure driving. Due to its smaller molecular size and higher permeation ability, hydrogen molecules preferentially and rapidly permeate through the membrane, while other gas molecules permeate more slowly or cannot permeate. The permeated gas is collected on the other side of the membrane to obtain high-purity hydrogen. There is no phase change in the membrane separation process, and the equipment is simple, the operation is convenient, and the energy consumption is low.

[0015] The above formulas are all obtained through software simulation by collecting a large amount of data and selecting a formula close to the true value. The influence weight factors and specific coefficient values in the formula are set by those skilled in the art according to the actual situation and can be adjusted and modified subsequently.

[0016] The above description of the embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A green hydrogen production and purification system based on the gasification of organic waste, characterized in that, Comprising: A pretreatment module; Performing pretreatment on domestic waste, including sorting, crushing, and drying and forming; A circulating fluidized bed gasification module: Domestic waste undergoes a gasification reaction with high-purity oxygen produced by an air separation unit in a circulating fluidized bed gasifier to generate syngas; Purification and reforming module: After the syngas is purified, it undergoes steam reforming reaction to convert and into and ; A hydrogen separation and purification module: Performing pressure swing adsorption and membrane separation on hydrogen to obtain high-purity hydrogen.

2. The green hydrogen production and purification system based on organic waste gasification according to claim 1, characterized in that, The pretreatment module specifically includes: Sorting: Fine screening of the collected mixed domestic waste is carried out through physical sorting technologies such as magnetic separation, gravity separation, and flotation; Crushing: Using jaw crushers and hammer crushers, the sorted domestic waste is crushed in multiple stages; Drying and forming: By means of hot air drying and vacuum drying methods, the moisture content of the crushed domestic waste is reduced to a preset content.

3. The green hydrogen production and purification system based on organic waste gasification according to claim 1, characterized in that, The circulating fluidized bed gasification module specifically includes: The pretreated RDF enters the circulating fluidized bed gasifier, and a high-temperature and oxygen-deficient environment is maintained in the furnace; The high-purity oxygen produced by the air separation unit is introduced from the bottom of the gasifier and undergoes a gasification reaction with the RDF; Under the action of high temperature, the organic substances in the RDF undergo pyrolysis and redox reactions to generate syngas.

4. The green hydrogen production and purification system based on organic waste gasification according to claim 1, characterized in that, The purification and reforming module specifically includes syngas purification and water gas shift reaction; Syngas purification: Dust removal: Using a cyclone dust collector and a bag filter to work together; Desulfurization: Adopting wet desulfurization and dry desulfurization technologies; Wet desulfurization usually uses an alkaline solution as an absorbent to chemically react with sulfides in the syngas to form soluble salts, thereby removing sulfides; Dechlorination: Removing chlorides in the syngas through adsorption, chemical absorption, or water washing methods; Water gas shift reaction: The purified syngas enters the reforming reactor and undergoes a reforming reaction with steam under the action of iron-based and copper-based catalysts.

5. The green hydrogen production and purification system based on organic waste gasification according to claim 1, wherein The hydrogen separation and purification module specifically includes: Pressure swing adsorption: Realizing hydrogen separation by utilizing the difference in the adsorption capacity of adsorbents for different gases at different pressures; Membrane separation: Separating hydrogen according to the difference in the permeation rate of different gases in the membrane material.

Images