Composite hydrogen production method for organic solid waste and composite hydrogen production device for organic solid waste

Abstract

The present application relates to a composite hydrogen production method for organic solid waste and belongs to the technical field of organic solid waste treatment. Said method comprises the following steps: (1) pretreatment; (2) low-temperature oxygen-free carbonization treatment; (3) carbon sorting; and (4) high-temperature gasification hydrogen production. The present application carbonizes organic solid waste by means of low-temperature oxygen-free carbonization technology, carbonization products being combustible oil gas having high heat value and biochar powder; and then by means of composite high-temperature gasification hydrogen production technology, fully converts the combustible oil gas and the biochar powder together with water and organic solid waste leachate into clean energy hydrogen and liquid-state or solid-state carbon dioxide for reuse, thereby lowering the emission of greenhouse gases such as carbon dioxide by 90% or above. The present application uses the composited technology of "carbonization + hydrogen production" to achieve a whole industry chain mode for the organic solid waste industry, thereby achieving safe disposal, reduction and fully-recycling treatment for municipal organic waste during environmental protection and obtaining high-grade environment-friendly and green hydrogen energy without secondary pollution to the environment.

Description

Organic solid waste composite hydrogen production method and organic solid waste composite hydrogen production device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 25, 2023, with application number CN202310752962.1 and application name “A Composite Hydrogen Production Process from Organic Solid Waste”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the technical field of organic solid waste treatment, and specifically relates to a method for producing hydrogen from organic solid waste composites. Background Art

[0003] my country generates a massive amount of organic solid waste annually (360 million tons of household waste; 65 million tons of urban sewage sludge; 52.87 million tons of restaurant waste; 20 million tons of separately collected kitchen waste; 858 million tons of crop straw; and 3.8 billion tons of livestock and poultry manure). For example, waste-to-energy incineration, the most market-oriented sector, currently has a harmless resource recovery rate of only approximately 35%. This is particularly true in less populated counties, towns, and rural areas, where the harmless disposal of various types of organic solid waste faces enormous pressure.

[0004] Currently, the main methods for treating domestic waste in my country are composting, sanitary landfill, and incineration for power generation. Composting has been phased out of the market. Sanitary landfill cannot achieve harmlessness or reduce waste volume, and it occupies a large amount of land, pollutes groundwater, and pollutes the air. Many developed countries have explicitly banned landfills, and my country will gradually ban and phase out this method. Waste-to-energy incineration is associated with heavy metal fly ash and dioxin emissions, requiring significant investment, with limited economic benefits, low power generation efficiency, and uncompetitive pricing, making it heavily dependent on government subsidies.

[0005] Summary of the Invention

[0006] In response to the deficiencies in the above-mentioned existing technologies, this application provides a method for composite hydrogen production from organic solid waste. By using the composite technology of "carbonization and hydrogen production", the whole industrial chain model of the organic solid waste industry is solved, the front-end harmless disposal of organic solid waste is solved, and the back-end energy hydrogen production is carried out on the products after disposal, thus realizing a full resource utilization model.

[0007] The specific technical solutions are as follows:

[0008] A method for producing hydrogen from organic solid waste composites, comprising the following steps:

[0009] (1) Pretreatment: Using the waste heat of the system to dry the organic solid waste through preheating and drying;

[0010] (2) Low-temperature oxygen-free carbonization treatment: The dried material is subjected to a thermochemical reduction reaction at a treatment temperature of 350-500°C in an oxygen-free working environment, and is thermally decomposed into solid and gaseous two-phase products;

[0011] (3) Carbon separation: The solid product produced by low-temperature oxygen-free carbonization treatment is cooled and mechanically separated into biochar powder, copper, aluminum, iron, glass, and sand and gravel, and each product is recycled;

[0012] (4) High-temperature gasification to produce hydrogen: The solid product biochar powder after carbon separation in step (3) and the gaseous product flammable gas obtained in step (2) are input into a high-temperature gasification device for thermochemical reaction, thereby realizing efficient and synergistic thermochemical conversion of the two-phase carbonization products into synthesis gas. The synthesis gas is purified in the first stage and separated in the second stage to extract pure hydrogen.

[0013] By adopting the above technical solution, organic solid waste is carbonized by low-temperature oxygen-free carbonization technology. The products after carbonization are high calorific value combustible oil and gas and biochar powder. The combustible oil and gas are combined with biochar powder and compounded with high-temperature gasification hydrogen production technology to convert them all into clean energy - hydrogen and liquid or solid carbon dioxide for reuse, thereby reducing the emission of greenhouse gases such as carbon dioxide by more than 90%. The waste residue passes through a mechanical automatic sorting system to form a recyclable and renewable resource product. The organic solid waste composite production process of this application is suitable for the harmless, reduced, and fully resource-based treatment of urban organic solid waste, and obtains high-grade, environmentally friendly green hydrogen energy without secondary pollution to the environment.

[0014] Furthermore, in the step (4), the temperature of the thermochemical reaction is 1200-1400°C.

[0015] Furthermore, in the step (4), CO and H2 in the synthesis gas are subjected to deep purification processes such as conversion and pressure swing adsorption to extract pure hydrogen.

[0016] Furthermore, the organic solid waste leachate generated by the organic solid waste is subjected to high-temperature gasification treatment in conjunction with the carbonization product.

[0017] By adopting the above technical solution, there is no need to use an additional leachate treatment system and no need to supplement external water sources; the wastewater (leachate) returns to the high-temperature chemical reaction section of hydrogen production, there is no wastewater discharge, and the water consumption required for the hydrogen production process is reduced.

[0018] Furthermore, in the step (1), there is no need to sort or classify the organic solid waste. The material particle size range requirement of the low-temperature oxygen-free carbonization treatment in step (2) is only required, and the material with a particle size of less than 500 mm is dried by preheating and drying.

[0019] Furthermore, in the step (1), the preheating and drying utilizes the residual heat of the low-temperature oxygen-free carbonization treatment in the step (2), and no external heating is required.

[0020] Furthermore, in the step (4), high-temperature gasification to produce hydrogen generates high-temperature waste heat, and CO is recycled to the low-temperature oxygen-free carbonization treatment in step (2) as a heating energy source. The high-temperature waste heat is utilized in a gradient manner, effectively improving the waste heat utilization efficiency. By controlling the intelligent system, efficient conversion of thermal energy and chemical energy is achieved, thereby improving the economic benefits of hydrogen production.

[0021] By adopting the above technical solution, high-temperature gasification hydrogen production generates high-temperature waste heat, and CO is recycled to the low-temperature anaerobic pyrolysis system as heating energy. The high-temperature waste heat is utilized in a gradient manner, effectively improving the waste heat utilization efficiency. By controlling the intelligent system, efficient conversion of thermal energy and chemical energy is achieved, thereby improving the economic benefits of hydrogen production.

[0022] Furthermore, the material after the drying treatment in step (1) is transported to step (2) through an air-locking and oxygen-isolating feeding device for low-temperature oxygen-free carbonization treatment.

[0023] Furthermore, the S and N polluting elements contained in the organic solid waste generate H2S and NH3 under the reducing atmosphere of high-temperature gasification hydrogen production, and the sulfur and ammonia nitrogen are recovered and utilized as resources through tannin extract desulfurization and water washing ammonia evaporation process.

[0024] Furthermore, the organic solid waste includes municipal solid waste, biomass, waste tire rubber, medical waste, petrochemical oil sludge, and coal-based solid waste.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] (1) This application carbonizes organic solid waste using a low-temperature, oxygen-free carbonization technology. The carbonization products are high-calorific value combustible gas and biochar powder. The combustible gas and biochar powder are combined with water and organic solid waste leachate using a high-temperature gasification hydrogen production technology to convert them all into clean energy - hydrogen and liquid or solid carbon dioxide for reuse, thereby reducing greenhouse gas emissions such as carbon dioxide by more than 90%;

[0027] (2) This application solves the whole industrial chain model of the organic solid waste industry through the composite technology of "carbonization and hydrogen production", solves the harmless disposal of organic solid waste at the front end, and uses the post-disposal products for high-quality energy at the back end to extract high-purity green hydrogen, with higher economic benefits, more advanced technology, and a short investment return cycle, thus realizing a full resource model;

[0028] (3) The technology of this application enables urban organic waste in environmental protection to be harmless, reduced in volume, and fully resource-based, obtaining high-grade, environmentally friendly green hydrogen energy without secondary pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a flow chart of a method for producing hydrogen from organic solid waste in accordance with an embodiment of the present application.

[0030] In the figure: A, material pretreatment system; B, drying system; C, oxygen-free carbonization system; D, carbon separation system; E, hydrogen production system; F, tail gas treatment system. DETAILED DESCRIPTION

[0031] The principles and features of the present application are described below with reference to examples and FIG1 . The examples are only used to explain the present application and are not used to limit the scope of the present application.

[0032] Example 1

[0033] A method for producing hydrogen from organic solid waste composites, referring to FIG1 , comprises the following steps:

[0034] (1) Pretreatment: Organic solid waste (including municipal solid waste, biomass, waste tires, medical waste, coal-based solid waste, etc.) is dried in a dryer by preheating and drying using the system's waste heat;

[0035] (2) Low-temperature oxygen-free carbonization treatment: The dried material is transported to the carbonization chamber of the oxygen-free carbonization furnace through an air-locked oxygen-free feeding device for thermochemical reduction reaction. The carbonization chamber is a relatively low-temperature (350-500°C) oxygen-free working environment. The material is decomposed into solid and gaseous products by heat in the carbonization chamber.

[0036] (3) Carbon separation: The solid product produced by low-temperature oxygen-free carbonization treatment is passed through a cooling device, and the biochar powder, copper, aluminum, iron, glass, sand and gravel, and other products are automatically separated for resource utilization;

[0037] (4) High-temperature gasification hydrogen production: The solid product biochar powder after carbon sorting in step (3) and the gaseous product flammable gas obtained in step (2) are respectively sent to a high-temperature gasification device for thermochemical reaction, and the temperature is raised twice to 1200-1400°C to achieve efficient synergistic thermochemical conversion of the two-phase carbonization products into synthesis gas. The synthesis gas is subjected to a primary purification and a secondary separation to extract pure hydrogen, that is, CO and H2 in the synthesis gas are subjected to deep purification processes such as conversion and pressure swing adsorption to extract pure hydrogen. The purified high-purity hydrogen is stored / produced through mature organic liquid normal temperature and pressure storage and transportation technology to achieve efficient and safe storage and transportation; further, the organic solid waste leachate produced by the organic solid waste is synergistically carbonized and enters the high-temperature gasification device according to a certain proportion for high-temperature gasification treatment, which not only achieves harmless treatment but also saves the water consumption required for hydrogen production;

[0038] In step (1), the organic solid waste does not need to be sorted or classified during the front-end pretreatment process. It only needs to be dried by preheating and drying according to the material particle size range requirements of the low-temperature oxygen-free carbonization treatment in step (2);

[0039] In step (1), the preheat drying utilizes the waste heat (medium-temperature flue gas) from the low-temperature oxygen-free carbonization treatment in step (2), without the need for external heating;

[0040] In step (4), high-temperature gasification hydrogen production generates high-temperature waste heat (heat exchange of high-temperature flue gas 850°C to 1000°C), and CO is reused in low-temperature oxygen-free carbonization treatment as heating energy. The high-temperature waste heat is utilized in a gradient manner, effectively improving the waste heat utilization efficiency. By controlling the intelligent system, efficient conversion of thermal energy and chemical energy is achieved, thereby improving the economic benefits of hydrogen production.

[0041] The S and N polluting elements contained in organic solid waste generate H2S and NH3 under the reducing atmosphere of high-temperature gasification hydrogen production. Through tannin extract desulfurization and water washing ammonia evaporation process, sulfur and ammonia nitrogen are recovered and utilized as resources.

[0042] The overall gasification efficiency of the present invention is greater than 70%.

[0043] Example 2

[0044] A method for producing hydrogen from organic solid waste is similar to Example 1, except that:

[0045] When the reaction temperature in the carbonization chamber is 500℃ and the steam residual time is 5 minutes, the carbonization produces about 20% semi-coke. The volume fractions of the main components of the volatile combustible gas produced by carbonization are: CO: 10.77%, CH4: 20.06%, H2: 6.36%, CO2: 17.85%, hydrocarbon compounds other than CH4: 9.6%, O2: 0.28%; the calorific value of carbon powder is 2600kcal / kg, and the calorific value of combustible gas is 4295kcal / m 3 ;

[0046] When the thermochemical reaction temperature in the high-temperature gasification device is 1200°C, the volume fractions of the gas components are: CO: 50%, H2: 27.29%, N2+CO2: 21.43%, H2S: 1.18%, and others: 0.1%.

[0047] Example 3

[0048] A method for producing hydrogen from organic solid waste is similar to Example 1, except that:

[0049] When the reaction temperature in the carbonization chamber is 440℃ and the steam retention time is 8 minutes, the carbonization produces about 23% semi-coke. The volume fractions of the main components of the volatile combustible gas produced by carbonization are: CO: 15.89%, CH4: 24.21%, H2: 11.23%, CO2: 21.56%, hydrocarbon compounds other than CH4: 4.45%, O2: 0.27%; the calorific value of carbon powder is 2800kcal / kg, and the calorific value of combustible gas is 3808kcal / m 3 ;

[0050] When the thermochemical reaction temperature in the high-temperature gasification device is 1280°C, the volume fractions of the gas components are: CO: 48.2%, H2: 29.09%, N2+CO2: 21.53%, H2S: 1.08%, and others: 0.1%.

[0051] Example 4

[0052] A method for producing hydrogen from organic solid waste is similar to Example 1, except that:

[0053] When the reaction temperature in the carbonization chamber is 360℃ and the steam residual time is 15 minutes, the carbonization produces about 27% semi-coke. The volume fractions of the main components of the volatile combustible gas produced by carbonization are: CO: 15.87%, CH4: 22.59%, H2: 16.88%, CO2: 14.57%, hydrocarbon compounds other than CH4: 1.46%, O2: 0.54%; the calorific value of carbon powder is 3200kcal / kg, and the calorific value of combustible gas is 3163kcal / m 3 ;

[0054] When the thermochemical reaction temperature in the high-temperature gasification device is 1360°C, the volume fractions of the gas components are: CO: 46.4%, H2: 29.99%, N2+CO2: 21.93%, H2S: 1.58%, and others: 0.1%.

[0055] Low-temperature oxygen-free carbonization process test

[0056] Organic solid waste undergoes decomposition reaction under external temperature surface heating conditions. The reaction process mainly produces products such as water evaporation (water vapor), volatile gas (flammable), and semi-coke (carbon powder).

[0057] When organic solid waste enters the anaerobic carbonization system, the main reaction process is: organic solid waste preheating (predrying), initial carbonization on the surface, deep carbonization of organic solid waste, and volatilization of organic component gas.

[0058] The changes in the anaerobic carbonization temperature data are as follows:

[0059] 1. When the temperature of the organic solid waste in the carbonization chamber rises to 80-120°C, a small amount of volatile gas is generated on the surface of the organic solid waste. The color is mainly white and the gas component is water vapor;

[0060] When the temperature of organic solid waste rises to 120-160°C, a large amount of volatile gas is generated, and most of the water contained in the organic solid waste is volatilized and precipitated due to heat, turning the organic solid waste into dry matter.

[0061] 2. When the temperature of the organic solid waste in the carbonization chamber rises to 160-260°C, the surface of the dried organic solid waste is heated, forming an initial carbonized layer. Due to the complex and unstable composition of organic solid waste, materials containing plastics and rubber begin to "soften" on the surface due to heat, with a small amount of volatile gases being released. Materials containing fiber or hemicellulose also undergo an initial surface carbonization layer, which decomposes and releases a small amount of volatiles. This porous organic carbon protective layer forms on the surface, hindering heat penetration and conduction, preventing deep carbonization.

[0062] 3. When the temperature of the organic solid waste in the carbonization chamber rises to 260-350°C, the softened organic solid waste, fibers, and hemicellulose undergo a violent carbonization-reduction reaction, producing a large amount of volatile gases and releasing a large amount of reaction heat. The particle size of the material determines the thickness of the carbonization layer. At 260-350°C, the remaining solid product is the organic solid waste wrapped in the carbonization layer. Further carbonization requires increasing the temperature or extending the carbonization time to achieve complete carbonization.

[0063] 4. After being "softened" at 350-500℃, the organic solid waste, fiber and hemicellulose undergo a violent thermal carbonization and reduction reaction as in the outbreak period, and the carbon protective layer formed in this cycle is quickly stripped off, so that new fracture layers are formed between the carbon and the carbon-wrapped organic solid waste. Each interface of the new fracture layer of the organic solid waste is fully heated, and the heat energy is fully and effectively utilized. Due to the relatively low temperature and oxygen-free environment, heavy metals will not undergo phase changes, and the conditions for the production of dioxins are also eliminated, so as to achieve the purpose of energy conservation and emission reduction.

[0064] Table 1 Different materials react with heat at different temperatures

[0065] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for producing hydrogen from organic solid waste, characterized in that: The steps include: (1) Pretreatment: Using the waste heat of the system to dry the organic solid waste through preheating and drying; (2) Low-temperature anaerobic carbonization treatment: The dried material is subjected to a thermochemical reduction reaction at a treatment temperature of 350-500°C in an anaerobic working environment, and is thermally decomposed into solid and gaseous two-phase products; (3) Carbon sorting: The solid products produced by low-temperature anaerobic carbonization treatment are cooled and automatically sorted into biochar powder, copper, aluminum, iron, glass, and sand and gravel, and each product is recycled; (4) High-temperature gasification to produce hydrogen: The solid product biochar powder after carbon sorting in step (3) and the gaseous product flammable gas obtained in step (2) are input into a high-temperature gasification device for thermochemical reaction to achieve efficient synergistic thermochemical conversion of the two-phase carbonization products into synthesis gas, and the synthesis gas is subjected to primary purification and secondary separation to extract pure hydrogen.

2. The method for producing hydrogen from organic solid waste according to claim 1, characterized in that: In the step (4), the temperature of the thermochemical reaction is 1200-1400°C.

3. The method for producing hydrogen from organic solid waste according to claim 2, characterized in that: In the step (4), CO and H2 in the synthesis gas are subjected to transformation, pressure swing adsorption and other deep purification processes to extract pure hydrogen.

4. The method for producing hydrogen from organic solid waste according to claim 1, characterized in that: The organic solid waste leachate produced by the organic solid waste is treated by high-temperature gasification together with the carbonization products.

5. The method for producing hydrogen from organic solid waste according to claim 1, characterized in that: In the step (1), the material that meets the material particle size range requirements of the low-temperature oxygen-free carbonization treatment in step (2) is dried, and the material particle size range is below 500 mm.

6. The method for producing hydrogen from organic solid waste according to claim 1, characterized in that: In the step (1), the preheating and drying utilizes the residual heat of the low-temperature oxygen-free carbonization treatment in step (2).

7. The method for producing hydrogen from organic solid waste according to claim 1, characterized in that: In the step (4), high-temperature gasification to produce hydrogen generates high-temperature waste heat, and CO is recycled to the low-temperature oxygen-free carbonization treatment in step (2) as a heating energy source, thereby performing gradient utilization of the high-temperature waste heat.

8. The method for producing hydrogen from organic solid waste according to claim 1, characterized in that: The material after the drying treatment in step (1) is transported to step (2) through an air-locking and oxygen-isolating feeding device for low-temperature oxygen-free carbonization treatment.

9. The method for producing hydrogen from organic solid waste according to claim 1, characterized in that: The S and N polluting elements contained in the organic solid waste generate H2S and NH3 under the reducing atmosphere of high-temperature gasification hydrogen production. The sulfur and ammonia nitrogen are recovered and utilized as resources through tannin extract desulfurization and water washing and ammonia evaporation processes.

10. The method for producing hydrogen from organic solid waste according to claim 1, characterized in that: The organic solid waste includes urban domestic waste, biomass, waste tire rubber, medical waste, petrochemical oil sludge, and coal-based solid waste.

11. The organic solid waste composite hydrogen production device used in the organic solid waste composite hydrogen production method according to any one of claims 1 to 10 comprises a drying system, an anaerobic carbonization system, a carbon separation system and a hydrogen production system connected in sequence; The drying system comprises a dryer inner cavity and a dryer outer annular gap cavity covering the outer wall of the dryer inner cavity; The anaerobic carbonization system comprises an anaerobic carbonization furnace and an annular gap heating chamber covered on the outer wall of the anaerobic carbonization furnace; the solid material outlet of the inner cavity of the dryer is connected to the feed port of the anaerobic carbonization furnace; The solid material outlet of the anaerobic carbonization system is connected to the feed inlet of the carbon separation system; The carbon sorting system is used to cool the solid product produced by low-temperature anaerobic carbonization treatment and mechanically and automatically sort out biochar powder, copper, aluminum, iron, glass, and sand and gravel; The hydrogen production system includes a high-temperature gasification device; The combustible oil and gas outlet of the anaerobic carbonization furnace is connected to the oil and gas inlet of the high-temperature gasification device; the biochar powder outlet of the carbon sorting system is connected to the carbon powder inlet of the high-temperature gasification device.

12. The organic solid waste composite hydrogen production device according to claim 11, characterized in that: It also includes an air-locking and oxygen-isolating feeding device, which is used to transport the dried material obtained by the drying system into the carbonization chamber of the oxygen-free carbonization furnace.

13. The organic solid waste composite hydrogen production device according to claim 11, characterized in that: It also includes a material pre-processing system; The solid material outlet of the material pretreatment system is connected to the feed inlet of the inner cavity of the dryer; The odor outlet of the material pretreatment system is connected to the odor inlet of the high-temperature gasification device; the leachate outlet of the material pretreatment system is connected to the leachate inlet of the high-temperature gasification device. Connectivity.

14. The organic solid waste composite hydrogen production device according to claim 11, characterized in that: The inner cylinder smoke outlet of the inner cavity of the dryer is communicated with the smoke inlet of the high-temperature gasification device.

15. The organic solid waste composite hydrogen production device according to claim 11, characterized in that: The medium-temperature flue gas outlet of the oxygen-free carbonization furnace is connected to the drying system.

16. The organic solid waste composite hydrogen production device according to claim 11, characterized in that: The high-temperature flue gas outlet of the high-temperature gasification device is connected to the anaerobic carbonization system.

17. The organic solid waste composite hydrogen production device according to claim 11 or 12, characterized in that: It also includes an exhaust gas treatment system; The low-temperature flue gas outlet of the inner cavity of the dryer is communicated with the air inlet of the tail gas treatment system.

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