Low-carbon coupled waste treatment system and treatment method

Abstract

The present invention relates to the technical field of waste treatment, and more specifically to a low-carbon coupled waste treatment system and treatment method. The method comprises the following steps: separating food waste into large wet fractions and organic residues, drying the large wet fractions and feeding same into a waste incinerator for combustion to release heat; fermenting the organic residues to obtain biogas used for combustion to heat methanol liquid to generate methanol vapor, mixing the methanol vapor and water vapor and then carrying out catalytic hydrogen production to obtain a mixed gas; drying sludge, feeding part of the dried sludge into a biomass gasifier for coupled gasification with biomass waste to generate biomass gas, and feeding the remaining dried sludge into the waste incinerator for co-combustion; and separating the mixed gas obtained by the catalytic hydrogen production to obtain hydrogen and other combustible gases, and feeding the biomass gas and the other combustible gases into the waste incinerator for co-combustion. The present solution enables coupled treatment of food waste, sludge and biomass waste, and achieves hydrogen production.

Description

A low-carbon coupled waste treatment system and method Technical Field

[0001] This invention relates to the field of waste treatment technology, and more specifically, to a low-carbon coupled waste treatment system and method. Background Technology

[0002] With economic development, the amount of food waste, sewage sludge, and biomass waste generated is constantly increasing, and incineration can be used to reduce their volume. Because food waste and sewage sludge have a high water content, they also need to be dried before incineration.

[0003] In existing waste disposal methods, food waste, sewage sludge, and biomass waste are typically incinerated separately. However, because these types of waste have low calorific value or are difficult to burn, additional high-calorific-value auxiliary fuels are usually required to promote combustion. This results in poor treatment efficiency, resource waste, and increased carbon emissions. Summary of the Invention

[0004] To overcome the problems of poor treatment effect, resource waste and increased carbon emissions caused by direct incineration of kitchen waste, sewage sludge and biomass waste in the prior art, this invention provides a low-carbon coupled waste treatment system and method that can coupled the treatment of kitchen waste, sewage sludge and biomass waste and use waste resources to produce hydrogen.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] This invention provides a low-carbon coupled waste treatment method, comprising the following steps:

[0007] The kitchen waste is sorted to separate large pieces of wet material and organic waste residue. The large pieces of wet material are dried and then fed into the waste incinerator for combustion. The heat from the flue gas generated by the waste incinerator is used to heat the waste heat boiler to obtain high-temperature and high-pressure steam. The high-temperature and high-pressure steam can be used by users.

[0008] Organic waste residue is fermented to obtain biogas, and the biogas is used to heat methanol liquid to produce methanol vapor. The methanol vapor is mixed with a portion of high-temperature and high-pressure water vapor generated by the waste heat boiler and then catalytically produced to produce hydrogen to obtain a mixed gas.

[0009] The sludge is dried, and a portion of the dried sludge is fed into a biomass gasification furnace to couple with biomass waste to produce biomass fuel gas. The remaining dried sludge is fed into a waste incinerator for co-combustion.

[0010] The mixed gas obtained from catalytic hydrogen production is separated to obtain hydrogen and other combustible gases. The hydrogen is sent out, while the biomass gas and other combustible gases are sent to the waste incinerator for co-combustion.

[0011] In the technical solution of this invention, biogas is generated by fermenting organic waste residue separated from kitchen waste and then used to heat a methanol solution. The methanol solution is mixed with a portion of high-temperature, high-pressure steam generated by a waste heat boiler and then catalytically used to produce hydrogen, thus realizing the reuse of waste resources. Other combustible gases produced by catalytic hydrogen production are separated from the hydrogen and then fed back into the waste incinerator for combustion, releasing heat. Simultaneously, a mixture of biomass waste and dried sludge is used as raw material for coupled gasification to obtain biomass gas, which can promote the combustion of dried kitchen waste, sludge, and municipal solid waste, improving the waste incineration treatment efficiency without the need for additional high-calorific-value auxiliary fuel.

[0012] Preferably, the catalytic hydrogen production uses porous Ni / Al2O3 as a catalyst, and the reaction temperature is 700℃.

[0013] Preferably, the mixed gas obtained from the catalytic hydrogen production is separated from other combustible gases using an adsorption-desorption bed.

[0014] Preferably, the method further includes the following steps: obtaining preheated air, i.e. high-temperature hot air, through an air preheater connected to the waste incinerator; sending a portion of the high-temperature hot air into the waste incinerator to assist combustion; and inputting another portion of the high-temperature hot air, high-temperature and high-pressure water vapor, and a portion of the hot flue gas generated by the waste incinerator into a biomass gasification furnace for coupled gasification.

[0015] In this scheme, a mixture of agricultural and forestry waste with high volatile content and dried sludge is used as raw material. A mixture of high-temperature flue gas, water vapor, and high-temperature air generated by the waste incinerator is used as the gasifying agent. Through a high-temperature oxidation-reduction reaction, biomass gas can be produced with high gasification efficiency. Biomass gas promotes the combustion of waste in the incinerator, ensuring stable combustion of waste in the incinerator without adding other high-calorific-value auxiliary fuels, and increasing the proportion of sludge and kitchen waste in the combustion process. Simultaneously, it reduces coking in the furnace and the emission of harmful gases, saving manpower and resources.

[0016] Preferably, 10% to 20% of the dried sludge is fed into the biomass gasification furnace 20, and the remaining sludge is fed into the waste incinerator.

[0017] Preferably, both the bulk wet material and the sludge are dried using a vacuum drying method.

[0018] This invention also provides a low-carbon coupled waste treatment system, comprising: a food waste sorting device, a biogas fermentation tank, a methanol heating device, a mixer, a catalytic hydrogen production device, an adsorption-desorption bed, a food waste drying device, a sludge drying device, a waste incinerator, a waste heat boiler, and a biomass gasification furnace. The food waste sorting device has a large wet material outlet and an organic waste residue outlet; the biogas fermentation tank has an organic waste residue inlet and a biogas outlet; the methanol heating device has a combustion chamber and a heating chamber, the heating chamber having a methanol liquid inlet and a methanol vapor outlet; the mixer has a water vapor inlet, a methanol vapor inlet, and a mixed raw material outlet; the catalytic hydrogen production device has a raw material inlet and a mixed gas outlet; the adsorption-desorption bed has a reaction product inlet, a hydrogen outlet, and a mixed combustible gas outlet; the food waste drying device has a large wet material inlet and a dry food waste outlet; the sludge drying device has a wet sludge inlet and a dry sludge outlet; and the waste incinerator has a mixed combustible gas inlet and a dry food waste outlet. The waste heat boiler includes a feed inlet, a biomass gas inlet, a dry sludge combustion inlet, and a municipal solid waste inlet. The waste heat boiler has a boiler body, a low-temperature steam outlet, and a high-temperature steam outlet. The biomass gasification furnace has a biomass waste inlet, a biomass gas outlet, and a dry sludge gasification inlet. A bulk wet material outlet is connected to the bulk wet material inlet. An organic waste residue outlet is connected to the organic waste residue inlet. A biogas outlet is connected to the combustion chamber. A dry kitchen waste outlet is connected to the dry kitchen waste inlet. The boiler body is connected to the waste incinerator. A high-temperature steam outlet is connected to the steam inlet. A methanol steam outlet is connected to the methanol steam inlet. A mixed raw material outlet is connected to the raw material inlet. A mixed gas outlet is connected to the reaction product inlet. A mixed combustible gas outlet is connected to the mixed combustible gas inlet. A biomass gas outlet is connected to the biomass gas inlet. A dry sludge outlet is connected to both the dry sludge gasification inlet and the dry sludge combustion inlet.

[0019] Furthermore, the waste-coupled treatment system also includes a low-temperature air preheater and a high-temperature air preheater. The low-temperature air preheater has an external air inlet, a low-temperature preheated air outlet, a low-temperature preheated steam inlet, and a low-temperature preheated steam outlet. The high-temperature air preheater has a high-temperature preheated air inlet, a high-temperature preheated air outlet, a high-temperature preheated steam inlet, and a high-temperature preheated steam outlet. The waste incinerator has a combustion hot air inlet, a first flue gas outlet, and a second flue gas outlet. The biomass gasification furnace has a gasification hot air inlet, a gasification steam inlet, and a gasification flue gas inlet. The low-temperature steam outlet is connected to the low-temperature preheated steam inlet, the high-temperature steam outlet is connected to the high-temperature preheated steam inlet, the high-temperature preheated air outlet is connected to both the combustion hot air inlet and the gasification hot air inlet, the gasification steam inlet is connected to the low-temperature preheated steam outlet, the steam inlet is connected to the high-temperature preheated steam outlet, the gasification flue gas inlet is connected to the first flue gas outlet, and the second flue gas outlet is connected to a chimney.

[0020] Furthermore, the food waste drying device includes a first ejector, a first vacuum dryer, a first heating water jacket, and a hot water tank. The first ejector has a first high-pressure ejector inlet, a first low-pressure ejector inlet, and a first ejector outlet. The large wet material inlet and the dry food waste outlet are located in the first vacuum dryer. The first vacuum dryer also has a first drying outlet. The first heating water jacket has a first ejector heat inlet, a first hot water inlet, and a first hot water outlet. The first high-pressure ejector inlet is connected to the high-temperature preheating steam outlet. The first low-pressure ejector inlet is connected to the first drying outlet. The first ejector outlet is connected to the first ejector heat inlet. The outlet of the hot water tank is connected to the first hot water inlet.

[0021] Furthermore, the sludge drying device includes a second ejector, a second vacuum dryer, and a second heating water jacket. The second ejector has a second high-pressure ejector inlet, a second low-pressure ejector inlet, and a second ejector outlet. The wet sludge inlet and the dry sludge outlet are located in the second vacuum dryer, which also has a second drying outlet. The second heating water jacket has a second ejector hot inlet, a second hot water inlet, and a second hot water outlet. The second high-pressure ejector inlet is connected to the high-temperature preheating steam outlet, the second low-pressure ejector inlet is connected to the second drying outlet, and the second ejector outlet is connected to the second ejector hot inlet. The outlet of the hot water tank is connected to the second hot water inlet, and the first hot water outlet and the second hot water outlet are also connected to a sewage tank.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] I. The waste-to-energy low-carbon coupled treatment system and method of this invention utilizes the fermentation of organic waste residue separated from kitchen waste to generate biogas, which is then burned to heat a methanol solution. The methanol vapor generated after heating the methanol solution is mixed with high-temperature, high-pressure steam generated by a waste heat boiler and then catalytically used to produce hydrogen, thus realizing the reuse of waste resources. Other combustible gases produced by catalytic hydrogen production are separated from the hydrogen and then fed back into the waste incinerator for combustion, releasing heat. Simultaneously, a mixture of biomass waste and dried sludge is used as raw material for coupled gasification to obtain biomass gas, which can promote the combustion of dried kitchen waste, sludge, and municipal solid waste, improving the waste incineration treatment efficiency, and eliminating the need for additional high-calorific-value auxiliary fuels.

[0024] II. By using a mixture of agricultural and forestry waste with high volatile content and dried sludge as raw materials, and a mixture of high-temperature flue gas, water vapor, and high-temperature air generated by the waste incinerator as a gasifying agent, a high-calorific-value biomass fuel gas can be produced through a high-temperature oxidation-reduction reaction with high gasification efficiency. This biomass fuel gas promotes waste combustion in the incinerator, ensuring stable combustion of waste without the need for additional high-calorific-value auxiliary fuels, and increasing the co-combustion ratio of sludge and kitchen waste. Simultaneously, it reduces furnace coking and harmful gas emissions, saving manpower and resources. Attached Figure Description

[0025] Figure 1 is a schematic diagram of the overall structure of the waste low-carbon coupled treatment system of the present invention;

[0026] Figure 2 is an enlarged view of the kitchen waste drying device and sludge drying device shown in Figure 1.

[0027] In the attached diagram: 1. Food waste sorting device; 11. Large wet material outlet; 12. Organic waste residue outlet; 2. Biogas fermentation tank; 21. Organic waste residue inlet; 22. Biogas outlet; 3. Methanol heating device; 31. Combustion chamber; 32. Heating chamber; 321. Methanol liquid inlet; 322. Methanol vapor outlet; 4. Mixer; 41. Water vapor inlet; 42. Methanol vapor inlet; 43. Mixed raw material outlet; 5. Catalytic hydrogen production device; 51. Raw material inlet; 52. Mixed gas outlet; 6. Adsorption-desorption bed; 61. Reaction product inlet; 62. Hydrogen outlet; 63. Mixed combustible gas outlet; 7. Food waste drying device; 7 1. First ejector; 711. First high-pressure ejector inlet; 712. First low-pressure ejector inlet; 713. First ejector outlet; 72. First vacuum dryer; 721. Large wet material inlet; 722. Kitchen waste dry material outlet; 723. First drying outlet; 73. First heating water jacket; 731. First ejector hot inlet; 732. First hot water inlet; 733. First hot water outlet; 74. Hot water tank; 8. Sludge drying device; 81. Second ejector; 811. Second high-pressure ejector inlet; 812. Second low-pressure ejector inlet; 813. Second ejector outlet; 82. Second vacuum dryer; 821. Wet sludge inlet; 822. Dry sludge outlet; 823. Second drying outlet; 83. Second heating water jacket; 831. Second ejector heat inlet; 832. Second hot water inlet; 833. Second hot water outlet; 9. Waste incinerator; 91. Mixed combustible gas inlet; 92. Kitchen waste dry material inlet; 93. Biomass gas inlet; 94. Dry sludge combustion inlet; 95. Incineration hot air inlet; 96. First flue gas outlet; 97. Municipal solid waste inlet; 98. Second flue gas outlet; 10. Waste heat boiler; 101. Boiler body; 102. Low-temperature steam outlet; 103. High-temperature steam outlet; 104. User steam outlet; 20. Biological Biomass gasification furnace; 201, biomass waste inlet; 202, biomass gas outlet; 203, sludge gasification inlet; 204, gasification hot air inlet; 205, gasification steam inlet; 206, gasification flue gas inlet; 30, low-temperature air preheater; 301, external air inlet; 302, low-temperature preheated air outlet; 303, low-temperature preheated steam inlet; 304, low-temperature preheated steam outlet; 40, high-temperature air preheater; 401, high-temperature preheated air inlet; 402, high-temperature preheated air outlet; 403, high-temperature preheated steam inlet; 404, high-temperature preheated steam outlet; 50, deaerator; 60, chimney; 70, wastewater tank. Detailed Implementation

[0028] The accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0029] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "long," and "short" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0030] The technical solution of the present invention will be further described in detail below through specific embodiments and with reference to the accompanying drawings:

[0031] Example 1

[0032] Referring to the systems in Figures 1 and 2, this embodiment discloses a low-carbon coupled waste treatment method, including the following steps:

[0033] S1: The kitchen waste is sorted to separate large wet materials and organic waste residue. The large wet materials are dried and then put into the waste incinerator 9 for combustion.

[0034] S2: Organic waste residue is fermented to obtain biogas. The biogas is used to heat methanol liquid to produce methanol vapor. High-temperature and high-pressure water vapor is obtained through the waste heat boiler 10 connected to the waste incinerator 9. The methanol vapor and a portion of the high-temperature and high-pressure water vapor are mixed and then catalytically produced to produce hydrogen to obtain a mixed gas.

[0035] S3: The sludge is dried, and a portion of the dried sludge is fed into the biomass gasification furnace 20 to couple with the biomass waste to produce biomass fuel gas. The remaining dried sludge is fed into the waste incinerator 9 for co-combustion.

[0036] S4: Separate the mixed gas obtained from catalytic hydrogen production to obtain hydrogen and other combustible gases. Send the hydrogen out and send the biomass gas and other combustible gases into the waste incinerator 9 for co-combustion.

[0037] In this embodiment, biogas produced by fermenting organic waste residue separated from kitchen waste is burned to heat a methanol solution. The methanol solution is then mixed with high-temperature, high-pressure steam generated by a waste heat boiler 10 and catalytically used to produce hydrogen, thus realizing the reuse of waste resources. Other combustible gases produced by catalytic hydrogen production are separated from the hydrogen and reintroduced into the waste incinerator 9 to promote combustion. Simultaneously, a mixture of biomass waste and dried sludge is used as raw material for coupled gasification to obtain biomass gas, which promotes the mixed combustion of dried kitchen waste and sludge, improving the waste combustion treatment efficiency without requiring additional high-calorific-value auxiliary fuel. In some embodiments, municipal solid waste can be fed into the waste incinerator 9, allowing the dried kitchen waste, sludge, and municipal solid waste to be co-burned.

[0038] Specifically, the sorting method for kitchen waste can be as follows: Dedicated kitchen waste collection vehicles enter the site after being weighed by a weighbridge. They then unload the kitchen waste into the main plant's receiving hopper at a designated location in the unloading hall. After processes such as sorting, impurity removal, sand removal, and pressing, large inorganic impurities (metals, sand, bones, plastic bags, etc.) are removed, forming large wet materials, leaving a homogeneous granular slurry containing some organic matter. This slurry is then heated a second time and passed through an oil-water three-phase separation system to extract the oil, yielding organic waste residue. The oil can be used for other purposes, while the remaining organic waste residue can be fermented to produce biogas. The sorting process for kitchen waste can be carried out using existing kitchen waste sorting equipment 1.

[0039] In the method of this embodiment, porous Ni / Al2O3 is used as a catalyst for catalytic hydrogen production, and the mixed gas obtained from catalytic hydrogen production is separated from other combustible gases by an adsorption-desorption bed.

[0040] Specifically, the adsorption-desorption bed is an existing device that uses the principle of pressure swing adsorption (PSA) to separate hydrogen. The PSA process utilizes solid adsorbents such as silica gel, activated carbon, and molecular sieves housed in a vertical pressure vessel to selectively adsorb impurities such as CO2 in a mixed gas. Because the components in the mixed gas have different boiling points, when the feed gas passes through the adsorbent bed, the components other than hydrogen are selectively adsorbed as impurities, while hydrogen, with its low boiling point and highest volatility, is largely unadsorbed, leaving the adsorption bed with a purity greater than 98% v%, thus achieving separation from other impurities. The hydrogen production reaction equation, based on the feed ratio, is: 9CH3OH(g) + 8H2O(g) → 26H2(g) + 7.5CO2(g) + 1.5CO(g). A small amount of CH4 is also produced during the reaction.

[0041] In this embodiment, 10% to 20% of the total amount of dried sludge is fed into the biomass gasification furnace 20, and the remaining sludge is fed into the waste incinerator 9. Optionally, 15% of the dried sludge is fed into the biomass gasification furnace 20 for coupled gasification with biomass waste, and 85% of the dried sludge is fed into the waste incinerator 9 for co-combustion with dried kitchen waste and household waste.

[0042] In this embodiment, both large pieces of wet material and sludge are dried using vacuum drying. Heating and drying large pieces of wet material and sludge in a vacuum environment can achieve drying at a lower temperature, reducing the drying heating temperature. The heat energy of low-temperature hot water can be used for drying without the need for steam, greatly reducing drying costs.

[0043] Example 2

[0044] Based on the systems in Figures 1 and 2, this embodiment discloses a low-carbon coupled waste treatment method, similar to Embodiment 1, except that in this embodiment, the method further includes the steps of: obtaining preheated air through an air preheater connected to the waste incinerator 9, sending a portion of the preheated air into the waste incinerator 9 to assist combustion, and inputting another portion of the preheated air (high-temperature hot air), high-temperature and high-pressure water vapor, and a portion of the hot flue gas generated by the waste incinerator 9 into the biomass gasifier 20 as a gasifying agent for coupled gasification.

[0045] The high-temperature steam generated by the waste heat boiler 10 is primarily supplied to users, with a portion used to preheat outside air in an air preheater to obtain hot air that promotes waste combustion in the waste incinerator 9. In some embodiments, the air preheater may include a high-temperature air preheater 40 and a low-temperature air preheater 30. Outside air undergoes a first preheating process in the low-temperature air preheater 30, followed by a second preheating process in the high-temperature air preheater 40. The waste steam obtained after passing through the low-temperature air preheater 30 has a slightly lower temperature and pressure, making it more suitable for use in the biomass gasification furnace 20. The waste steam obtained after passing through the high-temperature air preheater 40 has a higher temperature, making it more suitable for catalytic hydrogen production by mixing with methanol steam.

[0046] In this embodiment, a mixture of agricultural and forestry waste with high volatile content and dried sludge is used as raw material, and a mixture of high-temperature flue gas, water vapor, and high-temperature air generated by the waste incinerator 9 is used as a gasifying agent. Through a high-temperature oxidation-reduction reaction, biomass fuel gas is produced with high gasification efficiency. The biomass fuel gas promotes the combustion of waste in the waste incinerator 9, ensuring stable combustion of waste in the incinerator 9 without adding other high-calorific-value auxiliary fuels, and increasing the proportion of sludge and kitchen waste in combustion. Simultaneously, it reduces furnace coking and harmful gas emissions, saving manpower and resources.

[0047] In some embodiments, the flue gas temperature generated by the waste incinerator 9 is approximately 180°C, the hot air temperature obtained by the external air passing through the high-temperature air preheater is approximately 220°C, the steam with a pressure of approximately 30 kg generated by the waste heat boiler 10 passes through the high-temperature air preheater 40 to obtain steam with a pressure of approximately 20 kg and a temperature of approximately 200°C, and the steam with a pressure of approximately 13 kg generated by the waste heat boiler 10 passes through the low-temperature air preheater 30 to obtain steam with a pressure of approximately 8 kg. Methanol liquid is heated to obtain methanol vapor at approximately 700°C, and the methanol vapor is mixed with the steam with a pressure of approximately 20 kg and a temperature of approximately 200°C in the mixer 4, where a catalytic hydrogen production reaction is carried out at a temperature of approximately 400°C-500°C.

[0048] Example 3

[0049] Referring to Figures 1 and 2, this embodiment discloses a low-carbon coupled waste treatment system, including a food waste sorting device 1, a biogas fermentation tank 2, a methanol heating device 3, a mixer 4, a catalytic hydrogen production device 5, an adsorption-desorption bed 6, a food waste drying device 7, a sludge drying device 8, a waste incinerator 9, a waste heat boiler 10, and a biomass gasification furnace 20. The food waste sorting device 1 has a large wet material outlet 11 and an organic waste residue outlet 12. The biogas fermentation tank 2 has an organic waste residue inlet 21 and a biogas outlet 22. The methanol heating device 3 has a combustion chamber 31 and a heating chamber 32. The heating chamber 32 has a methanol liquid inlet 321 and a methanol vapor outlet 322; the mixer 4 has a water vapor inlet 41, a methanol vapor inlet 42, and a mixed raw material outlet 43; the catalytic hydrogen production unit 5 has a raw material inlet 51 and a mixed gas outlet 52; the adsorption-desorption bed 6 has a reaction product inlet 61, a hydrogen outlet 62, and a mixed combustible gas outlet 63; the food waste drying unit 7 has a large wet material inlet 721 and a dry food waste outlet 722; the sludge drying unit 8 has a wet sludge inlet 821 and a dry sludge outlet 822; and the waste incinerator 9 has a mixed... The combined combustible gas inlet 91, dry kitchen waste inlet 92, biomass gas inlet 93, dry sludge combustion inlet 94, and municipal solid waste inlet 97; the waste heat boiler 10 has a boiler body 101, a low-temperature steam outlet 102, and a high-temperature steam outlet 103; the biomass gasification furnace 20 has a biomass waste inlet 201, a biomass gas outlet 202, and a sludge gasification inlet 203; a bulk wet material outlet 11 is connected to a bulk wet material inlet 721; an organic waste residue outlet 12 is connected to an organic waste residue inlet 21; a biogas outlet 22 is connected to a combustion chamber 31; and the dry kitchen waste inlet 97... Outlet 722 connects to the dry food waste inlet 92; boiler body 101 connects to the waste incinerator 9; high-temperature steam outlet 103 connects to steam inlet 41; methanol steam outlet 322 connects to methanol steam inlet 42; mixed raw material outlet 43 connects to raw material inlet 51; mixed gas outlet 52 connects to reaction product inlet 61; mixed combustible gas outlet 63 connects to mixed combustible gas inlet 91; biomass gas outlet 202 connects to biomass gas inlet 93; and dry sludge outlet 822 connects to sludge gasification inlet 203 and dry sludge combustion inlet 94, respectively. Domestic waste can be fed into the waste inlet 97, where dried food waste, dry sludge, and domestic waste are co-burned in the waste incinerator 9.

[0050] The waste heat boiler 10 has a user steam outlet 104, which is connected to external user equipment. The high-temperature steam generated by the waste heat boiler 10 is mainly supplied to users through the steam outlet 104, and a portion of it is used to preheat external air in an air preheater.

[0051] In this embodiment, the waste low-carbon coupled treatment system further includes a low-temperature air preheater 30 and a high-temperature air preheater 40. The low-temperature air preheater 30 has an external air inlet 301, a low-temperature preheated air outlet 302, a low-temperature preheated steam inlet 303, and a low-temperature preheated steam outlet 304. The high-temperature air preheater 40 has a high-temperature preheated air inlet 401, a high-temperature preheated air outlet 402, a high-temperature preheated steam inlet 403, and a high-temperature preheated steam outlet 404. The waste incinerator 9 has a combustion hot air inlet 95, a first flue gas outlet 96, and a second flue gas outlet 98. The biomass gasification furnace 20 has... Gasification hot air inlet 204, gasification steam inlet 205, and gasification flue gas inlet 206 are connected. Low-temperature steam outlet 102 is connected to low-temperature preheating steam inlet 303, high-temperature steam outlet 103 is connected to high-temperature preheating steam inlet 403, high-temperature preheating air outlet 402 is connected to incineration hot air inlet 95 and gasification hot air inlet 204, gasification steam inlet 205 is connected to low-temperature preheating steam outlet 304, steam inlet 41 is connected to high-temperature preheating steam outlet 404, gasification flue gas inlet 206 is connected to the first flue gas outlet 96, and the second flue gas outlet (98) is connected to a chimney (60). A small portion of the flue gas generated by the waste incinerator 9 enters the biomass gasifier 20 from the first flue gas outlet 96, and most of the flue gas enters the chimney 60 from the second flue gas outlet 98 and is discharged.

[0052] In some embodiments, both the low-temperature preheating steam outlet 304 and the high-temperature preheating steam outlet 404 are connected to a deaerator 50 to remove oxygen from the boiler feedwater and prevent corrosion of the equipment.

[0053] In this embodiment, the waste incinerator is connected to a chimney 60 to discharge most of the excess flue gas generated in the waste incinerator.

[0054] In this embodiment, the food waste drying device 7 includes a first ejector 71, a first vacuum dryer 72, a first heating water jacket 73, and a hot water tank 74. The first ejector 71 has a first high-pressure ejector inlet 711, a first low-pressure ejector inlet 712, and a first ejector outlet 713. A large wet material inlet 721 and a dry food waste outlet 722 are opened in the first vacuum dryer 72. The first vacuum dryer 72 also has a first drying outlet 723. The first heating water jacket 73 has a first ejector heat inlet 731, a first hot water inlet 732, and a first hot water outlet 733. The first high-pressure ejector inlet 711 is connected to the high-temperature preheating steam outlet 404, the first low-pressure ejector inlet 712 is connected to the first drying outlet 723, the first ejector outlet 713 is connected to the first ejector heat inlet 731, and the outlet of the hot water tank 74 is connected to the first hot water inlet 732.

[0055] In this embodiment, the sludge drying device 8 includes a second ejector 81, a second vacuum dryer 82, and a second heating water jacket 83. The second ejector 81 has a second high-pressure ejector inlet 811, a second low-pressure ejector inlet 812, and a second ejector outlet 813. A wet sludge inlet 821 and a dry sludge outlet 822 are opened in the second dryer. The second dryer also has a second drying outlet 823. The second heating water jacket 83 has a second ejector heat inlet 831, a second hot water inlet 832, and a second hot water outlet 833. The second high-pressure ejector inlet 811 is connected to the high-temperature preheating steam outlet 404, the second low-pressure ejector inlet 812 is connected to the second drying outlet 823, the second ejector outlet 813 is connected to the second ejector heat inlet 831, and the outlet of the hot water tank 74 is connected to the second hot water inlet 832.

[0056] In some embodiments, the first hot water outlet 733 and the second hot water outlet 833 are also connected to a wastewater tank 70. The wastewater tank 70 is used to collect the polluted wastewater generated by the first heating water jacket 73 and the second heating water jacket 83.

[0057] The system in this embodiment, when used in conjunction with the methods of Embodiment 1 or Embodiment 2, can couple the processing of kitchen waste, sewage sludge, and biomass waste, and utilize waste resources to produce hydrogen.

[0058] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A low-carbon coupled waste treatment method, characterized in that: Includes the following steps: Kitchen waste is sorted to separate large wet materials and organic waste residue. The large wet materials are dried and then put into the waste incinerator (9) for combustion. The heat of the flue gas generated by the waste incinerator (9) is used to heat the waste heat boiler (10) to obtain high temperature and high pressure steam. Organic waste residue is fermented to obtain biogas, and the biogas is used to heat methanol liquid to produce methanol vapor. The methanol vapor is mixed with high-temperature and high-pressure water vapor and then catalytically produced to obtain a mixed gas. The sludge is dried, and a portion of the dried sludge is fed into a biomass gasifier (20) to couple with biomass waste to produce biomass fuel gas. The remaining dried sludge is fed into a waste incinerator (9) for co-combustion. The mixed gas obtained from catalytic hydrogen production is separated to obtain hydrogen and other combustible gases. The hydrogen is sent out, and the biomass gas and other combustible gases are sent into the waste incinerator (9) for co-combustion.

2. The waste low-carbon coupled treatment method according to claim 1, characterized in that: The catalytic hydrogen production uses porous Ni / Al2O3 as a catalyst.

3. The waste low-carbon coupled treatment method according to claim 1, characterized in that: The mixed gas obtained from the catalytic hydrogen production is separated from other combustible gases by an adsorption-desorption bed (6).

4. The waste low-carbon coupled treatment method according to claim 1, characterized in that: The method further includes the steps of: obtaining preheated air through an air preheater connected to the waste incinerator (9), sending a portion of the preheated air into the waste incinerator (9) to assist combustion, and feeding another portion of the preheated air, high-temperature and high-pressure water vapor, and a portion of the flue gas generated by the waste incinerator (9) into the biomass gasifier (20) for coupled gasification.

5. The waste low-carbon coupling treatment method according to claim 1, characterized in that: 10% to 20% of the dried sludge is fed into the biomass gasification furnace (20), and the remaining sludge is fed into the waste incinerator (9).

6. The waste low-carbon coupled treatment method according to claim 1, characterized in that: Both the bulk wet material and the sludge are dried using a vacuum drying method.

7. A low-carbon coupled waste treatment system, comprising: The kitchen waste sorting device (1), biogas fermentation tank (2), methanol heating device (3), mixer (4), catalytic hydrogen production device (5), adsorption-desorption bed (6), kitchen waste drying device (7), sludge drying device (8), waste incinerator (9), waste heat boiler (10), and biomass gasification furnace (20) are provided. The kitchen waste sorting device (1) has a large wet material outlet (11) and an organic waste residue outlet (12). The biogas fermentation tank (2) has an organic waste residue inlet (21) and a biogas outlet (22). The methanol heating device (3) has a combustion chamber (31) and a heating chamber (32). The heating chamber (32) has a methanol liquid inlet (321) and a methanol vapor outlet (322). The mixer (4) has a steam inlet (41), a methanol steam inlet (42), and a mixed raw material outlet (43); the catalytic hydrogen production device (5) has a raw material inlet (51) and a mixed gas outlet (52); the adsorption-desorption bed (6) has a reaction product inlet (61), a hydrogen outlet (62), and a mixed combustible gas outlet (63); the kitchen waste drying device (7) has a large wet material inlet (721) and a dry kitchen waste outlet (722); the sludge drying device (8) has a wet sludge inlet (821) and a dry sludge outlet (822); and the waste incinerator (9) has a mixed combustible gas inlet (91), a dry kitchen waste inlet (92), and a biomass gas inlet (93). The waste heat boiler (10) has a boiler body (101), a low-temperature steam outlet (102), and a high-temperature steam outlet (103). The biomass gasification furnace (20) has a biomass waste inlet (201), a biomass gas outlet (202), and a sludge gasification inlet (203). The bulk wet material outlet (11) is connected to the bulk wet material inlet (721). The organic waste residue outlet (12) is connected to the organic waste residue inlet (21). The biogas outlet (22) is connected to the combustion chamber (31). The kitchen waste dry material outlet (722) is connected to the kitchen waste dry material inlet (92). The boiler body (101) has a dry sludge combustion inlet (94) and a domestic waste inlet (97). 1) Connect the waste incinerator (9), the high-temperature steam outlet (103) is connected to the steam inlet (41) through the high-temperature air preheater (40), the methanol steam outlet (322) is connected to the methanol steam inlet (42), the mixed raw material outlet (43) is connected to the raw material inlet (51), the mixed gas outlet (52) is connected to the reaction product inlet (61), the mixed combustible gas outlet (63) is connected to the mixed combustible gas inlet (91), the biomass gas outlet (202) is connected to the biomass gas inlet (93), and the dry sludge outlet (822) is connected to the sludge gasification inlet (203) and the dry sludge combustion inlet (94) respectively.

8. The waste low-carbon coupled treatment system according to claim 7, characterized in that: The waste low-carbon coupled treatment system also includes a low-temperature air preheater (30) and a high-temperature air preheater (40). The low-temperature air preheater (30) has an external air inlet (301), a low-temperature preheated air outlet (302), a low-temperature preheated steam inlet (303), and a low-temperature preheated steam outlet (304). The high-temperature air preheater (40) has a high-temperature preheated air inlet (401), a high-temperature preheated air outlet (402), a high-temperature preheated steam inlet (403), and a high-temperature preheated steam outlet (404). The waste incinerator (9) has a combustion hot air inlet (95), a first flue gas outlet (96), and a second flue gas outlet (98). The biomass gasification furnace (20) has a gasification hot air inlet (204). The gasification steam inlet (205) and the gasification flue gas inlet (206) are connected. The low-temperature steam outlet (102) is connected to the low-temperature preheating steam inlet (303). The high-temperature steam outlet (103) is connected to the high-temperature preheating steam inlet (403). The high-temperature preheating air outlet (402) is connected to the combustion hot air inlet (95) and the gasification hot air inlet (204). The gasification steam inlet (205) is connected to the low-temperature preheating steam outlet (304). The steam inlet (41) is connected to the high-temperature preheating steam outlet (404). The gasification flue gas inlet (206) is connected to the first flue gas outlet (96). The second flue gas outlet (98) is connected to a chimney (60).

9. The waste low-carbon coupled treatment system method according to claim 8, characterized in that: The kitchen waste drying device (7) includes a first ejector (71), a first vacuum dryer (72), a first heating water jacket (73), and a hot water tank (74). The first ejector (71) has a first high-pressure ejector inlet (711), a first low-pressure ejector inlet (712), and a first ejector outlet (713). The large wet material inlet (721) and the kitchen waste dry material outlet (722) are located in the first vacuum dryer (72). The first vacuum dryer (72) also has a first drying outlet (713). 23) The first heating water jacket (73) has a first ejector heat inlet (731), a first hot water inlet (732) and a first hot water outlet (733). The first high-pressure ejector inlet (711) is connected to the high-temperature preheating steam outlet (404). The first low-pressure ejector inlet (712) is connected to the first drying outlet (723). The first ejector outlet (713) is connected to the first ejector heat inlet (731). The outlet of the hot water tank (74) is connected to the first hot water inlet (732).

10. The waste low-carbon coupled treatment system according to claim 9, characterized in that: The sludge drying device (8) includes a second ejector (81), a second vacuum dryer (82), and a second heating water jacket (83). The second ejector (81) has a second high-pressure ejection inlet (811), a second low-pressure ejection inlet (812), and a second ejection outlet (813). The wet sludge inlet (821) and the dry sludge outlet (822) are located in the second vacuum dryer (82). The second vacuum dryer (82) also has a second drying outlet (823). The second heating water jacket (83) has a second ejection heat inlet (811). 31) A second hot water inlet (832) and a second hot water outlet (833), the second high-pressure ejector inlet (811) is connected to the high-temperature preheating steam outlet (404), the second low-pressure ejector inlet (812) is connected to the second drying outlet (823), the second ejector outlet (813) is connected to the second ejector heat inlet (831), the outlet of the hot water tank (74) is connected to the second hot water inlet (832), and the first hot water outlet (733) and the second hot water outlet (833) are also connected to a sewage tank (70).

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