Sludge and kitchen waste collaborative promotion green methanol production system

Abstract

The utility model discloses a sludge and kitchen garbage collaborative promotion green methanol production system, including the existing treatment facility that passes through pipeline is connected in proper order, marsh gas reforming module, catalytic synthesis module and methanol separation module, the existing treatment facility is including fermentation container, and the marsh gas treatment facility is connected with the fermentation container, the marsh gas treatment facility includes desulfurization module and denitrification module, and the desulfurization module is connected with the marsh gas reforming module, the pipeline between the marsh gas reforming module with the catalytic synthesis module is set with first condensing separator, synthesis gas compressor and preheater in proper order, the pipeline between the catalytic synthesis module with the methanol separation module is equipped with second condensing separator, the utility model discloses through the collaborative processing sewage sludge and kitchen garbage, realizes the efficient reduction of two kinds of pollutants, improves the utilization efficiency of existing facilities, and through the optimization marsh gas utilization path, promotes the large -scale production of green methanol.

Description

Technical Field

[0001] This utility model relates to sewage sludge and kitchen waste treatment technology, and more specifically, to a system for synergistic promotion of green methanol production by sludge and kitchen waste. Background Technology

[0002] With the continuous increase in urbanization rate, the production of sewage sludge and kitchen waste continues to rise. Both sewage sludge and kitchen waste contain a large amount of organic matter, and if they are not properly treated, they will not only waste resources but also cause serious environmental pollution.

[0003] Currently, one common method for the resource utilization of sewage sludge is to convert the organic matter in the sludge into biogas. However, due to the low organic matter content of sewage sludge, the organic loading rate of existing anaerobic digestion facilities is typically only about 1.14 kgVS / m³. 3 The OLR is around 50 kgVS / m³, far below the theoretical maximum. Under ideal conditions, the OLR of an anaerobic digestion system can reach 50 kgVS / m³. 3 / d (assuming SRT = 20d, VS / TS = 100%). Considering the limitations of solid-phase mass transfer, under high solids content sludge conditions (TS = 20%), its maximum can reach 10kgVS / m³. 3 / d. Therefore, current sewage sludge treatment projects still face two major problems that urgently need to be addressed: (1) low organic matter sludge limits the treatment capacity of existing facilities; (2) biogas utilization pathways have low value and high-value conversion methods are urgently needed. Utility Model Content

[0004] In view of the deficiencies in the existing technology, the purpose of this utility model is to provide a green methanol production system that synergistically promotes the production of sludge and kitchen waste. By synergistically treating sewage sludge and kitchen waste, the system achieves efficient reduction of both types of pollutants, improves the utilization efficiency of existing facilities, and promotes large-scale production of green methanol by optimizing the biogas utilization pathway.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A system for synergistic promotion of green methanol production through sludge and kitchen waste includes an existing treatment facility, a biogas reforming module, a catalytic synthesis module, and a methanol separation module connected sequentially by pipelines.

[0007] The existing treatment facility includes a fermentation vessel, on which a biogas treatment facility is connected. The biogas treatment facility includes a desulfurization module and a denitrification module, and the desulfurization module is connected to the biogas reforming module.

[0008] A first condenser separator, a syngas compressor, and a preheater are sequentially installed on the pipeline between the biogas reforming module and the catalytic synthesis module.

[0009] A second condenser separator is provided on the pipeline between the catalytic synthesis module and the methanol separation module.

[0010] Preferably, the fermentation container is equipped with a stirring mechanism and a heating element.

[0011] Preferably, the desulfurization module includes an activated carbon bed;

[0012] A biogas compressor and a preheater are sequentially installed on the pipeline between the activated carbon bed and the biogas reforming module;

[0013] An evaporator is installed on the pipeline between the biogas compressor and the preheater.

[0014] Preferably, the hydrogen generated by electrolyzing water in an electrolyzer is delivered to the syngas compressor, or delivered to a hydrogen storage tank via a hydrogen compressor for storage.

[0015] The outlet pipe of the hydrogen storage tank is connected to the pipeline between the syngas compressor and the preheater.

[0016] Preferably, the methanol separation module includes a top distillation column and a methanol distillation column connected in sequence;

[0017] The outlet of the top distillation column is connected to the pipeline between the first condenser and the syngas compressor via a pipeline.

[0018] Preferably, the gas outlet of the top distillation column is connected to the gas outlet of the second condenser connected to the catalytic synthesis module by a pipeline, and a circulating compressor is provided on the pipeline. The outlet of the circulating compressor is connected to the pipeline between the synthesis gas compressor and the preheater through a pipeline.

[0019] This invention provides a system for the synergistic promotion of green methanol production using sludge and kitchen waste. By co-treating kitchen waste and sewage sludge, it not only replenishes the organic matter content within the system, increasing the anaerobic digestion rate and biogas production, but also enhances the overall utilization efficiency of the treatment facilities, achieving synergistic pollution reduction and resource utilization, resulting in a synergistic effect of "1+1>2". Simultaneously, with the same sludge treatment volume, the co-introduction of kitchen waste significantly increases biogas production, providing sufficient quantity for subsequent energy utilization. Since biogas is mainly composed of methane and carbon dioxide, these two components can be co-converted into methanol under specific conditions, enabling the large-scale production of green methanol. This approach not only improves the utilization level of biogas quality but also achieves the resource conversion of carbon dioxide. The produced methanol can also serve as a green alternative fuel, showing broad application prospects in high-carbon emission industries such as international shipping. Moreover, the entire system has a simple structure, is easy to operate, and can produce green methanol on a large scale. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structural framework of the sludge and kitchen waste synergistic green methanol production system of this utility model;

[0021] Figure 2 This is a schematic diagram illustrating the working principle of the green methanol production system that synergistically promotes the production of sludge and kitchen waste. Detailed Implementation

[0022] To better understand the above-mentioned technical solution of this utility model, the technical solution of this utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0023] Combination Figure 1 and Figure 2 As shown, the present invention provides a green methanol production system that synergistically promotes the production of sludge and kitchen waste, comprising an existing treatment facility 1, a biogas reforming module 2, a catalytic synthesis module 3, and a methanol separation module 4, which are connected in sequence by pipelines.

[0024] The existing treatment facility 1 includes a fermentation vessel for anaerobic fermentation reaction; a stirring mechanism is installed inside the fermentation vessel to maintain uniform mixing of materials; and a heating element is installed inside the fermentation vessel to maintain a suitable fermentation temperature to promote the degradation of organic matter by microorganisms.

[0025] The fermentation vessel is connected to a biogas treatment facility, which includes a desulfurization module 101 and a denitrification module. The desulfurization module 101 is used to remove hydrogen sulfide from the biogas to prevent it from poisoning the subsequent catalyst; the denitrification module is used to remove nitrogen and other irrelevant gases from the biogas to improve the purity of the subsequent reaction gases.

[0026] The desulfurization module 101 is connected to the biogas reforming module 2, which converts methane and carbon dioxide into syngas of carbon monoxide and hydrogen under the action of a catalyst. The biogas reforming module 2 is connected to a catalytic synthesis module, which converts the syngas into a mixture of methanol and water under the action of a catalyst.

[0027] The desulfurization module 101 includes an activated carbon bed, and a biogas compressor 5 and a preheater 6 are sequentially installed on the pipeline between the activated carbon bed and the biogas reforming module 2.

[0028] An evaporator 7 is installed on the pipeline between the biogas compressor 5 and the preheater 6.

[0029] The pipeline between the biogas reforming module 2 and the catalytic synthesis module 3 is sequentially equipped with a first condenser separator 8, a synthesis gas compressor 9, and a preheater 10.

[0030] The catalytic synthesis module 3 is connected to the methanol separation module 4, which uses the difference in boiling points of the components in the mixture to obtain high-purity methanol through separation.

[0031] A second condenser 11 is installed on the pipeline between the catalytic synthesis module 3 and the methanol separation module 4 to keep the methanol in a liquid state.

[0032] The hydrogen produced by electrolyzing water in the electrolyzer 12 is transported to the syngas compressor 9, or transported to the hydrogen storage tank 14 via the hydrogen compressor 13 for storage.

[0033] The outlet pipe of the hydrogen storage tank 14 is connected to the pipeline between the syngas compressor 9 and the preheater 10.

[0034] The methanol separation module 4 includes a top distillation column 401 and a methanol distillation column 402 connected in sequence.

[0035] The outlet of the top distillation column 401 is connected to the pipeline between the first condenser separator 8 and the synthesis gas compressor 9 via a pipeline.

[0036] The outlet of the top distillation column 401 is connected to the outlet of the second condenser 11 connected to the catalytic synthesis module 3 by a pipeline, and a circulating compressor 15 is installed on the pipeline. The outlet of the circulating compressor 15 is connected to the pipeline between the synthesis gas compressor 9 and the preheater 10 through a pipeline.

[0037] Under low-pressure conditions, the top distillation column 401 releases some unreacted syngas. Part of the released syngas is compressed by the circulating compressor 15 and directly enters the pipeline between the syngas compressor 9 and the preheater 10, then enters the preheater and then the catalytic synthesis module 3; the other part is directly mixed with the syngas produced by the biogas reforming module 2, compressed by the syngas compressor 9, and then enters the subsequent steps. At the same time, the second condenser separator 11 and the top distillation column 401 discharge excess gas that cannot be circulated and compressed to the furnace 16 for combustion. The discharged tail gas is mainly carbon dioxide and water vapor.

[0038] The workflow of this utility model's system for co-promoting green methanol production using sludge and kitchen waste is as follows:

[0039] (1) A wastewater treatment plant obtained wastewater sludge (solids content 5.19%, VS / TS ratio 52.66%, pH 6.72, ammonia nitrogen concentration 73.59 mg / L) and inoculation sludge (solids content 4.38%, VS / TS ratio 49.05%, pH 7.02, ammonia nitrogen concentration 192.51 mg / L); and kitchen waste (solids content 25.07%, VS / TS ratio 88.62%, pH 3.96, ammonia nitrogen concentration 314.83 mg / L). The wastewater sludge was stored at 4℃, and the inoculation sludge was placed in a 37℃ constant temperature incubator for cultivation until gas production ceased.

[0040] (2) When using, mix 46.52g of sewage sludge, 5.72g of kitchen waste and 117.46g of inoculation sludge at an inoculation ratio of 1:1, and add 30.3g of tap water to dilute, so as to keep the VS ratio of sludge to kitchen waste at 1:1.

[0041] (3) Place the mixture in a 250mL fermentation container and place it in a 37℃ constant temperature air bath shaker with a shaking speed of 120rpm for anaerobic fermentation.

[0042] (4) The system stopped producing gas on day 19 of fermentation, with a cumulative methane yield of 285.91 mL / gVS. 降解 (Sludge treated alone: ​​66.18 mL / g VS) 降解 The synergy effect index (SEI) is 76%.

[0043] Specifically, the expression for the synergy effect index is:

[0044]

[0045] In the formula, M co This indicates cumulative methane production, in mL / g. VS 降解 ;X e and X f These represent the percentage of VS (surcharge) for wastewater sludge and food waste within the system, in %; M e and M f These represent the cumulative methane production from treating wastewater sludge separately and from treating food waste separately, respectively, in mL / g. 降解 .

[0046] (5) Based on methane production and SEI calculations, co-processing can increase the methane production per unit of VS degradation by approximately 332%. Considering the proportion of methane in biogas in actual engineering projects, with a ratio of 60% methane and 40% carbon dioxide, biogas can be converted into syngas through a dual reforming process. Specifically, pure water is evaporated to form steam, and the biogas passes through a desulfurization module and a denitrification module for desulfurization and denitrification. After being heated to 700°C by the steam in a preheater, it enters the biogas reforming module, where it is converted into a mixed gas of carbon monoxide and hydrogen (or syngas) at 5 bar and 70°C. The mixed gas then passes through a condenser separator, where the steam is condensed and discharged at 40°C. Then, the syngas is compressed by a syngas compressor and passed through an electrolyzer with pure water at 50 bar and 70°C to produce hydrogen. This hydrogen is then preheated to 230°C in a preheater and then fed into a catalytic synthesis module to produce a mixture of methanol and water (using commercially available Cu, ZnO, or Al2O3 as the catalyst). The methanol-water mixture is then condensed in a condenser at 65 bar and 35°C and fed to a top distillation column. At 8 bar, some unreacted syngas is released. Part of this released syngas is compressed by a circulating compressor and directly enters the pipeline between the syngas compressor and the preheater, then enters the preheater and then the catalytic synthesis module. The other part is directly mixed with the syngas produced in the biogas reforming module, compressed by the syngas compressor, and then fed into subsequent steps. The gas removed from light components in the top distillation column is then fed to a methanol distillation column to obtain methanol.

[0047] The results showed that every 0.78m 3 Biogas can be converted into 1 kg of green methanol with a purity of up to 99.85 wt%.

[0048] Specifically, the main reaction formula utilized in the dual-process can be expressed as:

[0049] 3CH4 + CO2 + 2H2O → 4CO + 8H2

[0050] (6) Based on the city’s annual sludge production, the sludge and kitchen waste co-promoting green methanol production system of this utility model has the potential to produce about 170,000 tons of green methanol per year.

[0051] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present utility model and are not intended to limit the present utility model. Any changes or modifications to the above embodiments within the scope of the essential spirit of the present utility model will fall within the scope of the claims of the present utility model.

Claims

1. A system for synergistically promoting green methanol production using sludge and kitchen waste, characterized in that: This includes existing treatment facilities, a biogas reforming module, a catalytic synthesis module, and a methanol separation module, which are connected sequentially via pipelines. The existing treatment facility includes a fermentation vessel, on which a biogas treatment facility is connected. The biogas treatment facility includes a desulfurization module and a denitrification module, and the desulfurization module is connected to the biogas reforming module. A first condenser separator, a syngas compressor, and a preheater are sequentially installed on the pipeline between the biogas reforming module and the catalytic synthesis module. A second condenser separator is provided on the pipeline between the catalytic synthesis module and the methanol separation module.

2. The sludge and kitchen waste co-promoting green methanol production system according to claim 1, characterized in that: The fermentation container is equipped with a stirring mechanism and a heating element. 3.The sludge and kitchen waste synergistically promoted green methanol production system according to claim 1, characterized in that: The desulfurization module includes an activated carbon bed; A biogas compressor and a preheater are sequentially installed on the pipeline between the activated carbon bed and the biogas reforming module; An evaporator is installed on the pipeline between the biogas compressor and the preheater.

4. The sludge and kitchen waste synergistically promoted green methanol production system according to claim 1, characterized in that: Hydrogen generated by electrolyzing water in an electrolyzer is transported to the syngas compressor, or transported to a hydrogen storage tank via a hydrogen compressor for storage. The outlet pipe of the hydrogen storage tank is connected to the pipeline between the syngas compressor and the preheater.

5. The sludge and kitchen waste synergistically promoted green methanol production system according to claim 1, characterized in that: The methanol separation module includes a top distillation column and a methanol distillation column connected in sequence. The outlet of the top distillation column is connected to the pipeline between the first condenser and the syngas compressor via a pipeline. 6.The sludge and kitchen waste synergistically promoted green methanol production system according to claim 5, characterized in that: The gas outlet of the top distillation column is connected to the gas outlet of the second condenser separator connected to the catalytic synthesis module by a pipeline, and a circulating compressor is installed on the pipeline. The outlet of the circulating compressor is connected to the pipeline between the synthesis gas compressor and the preheater through a pipeline.

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