Kitchen waste anaerobic treatment method
Through three-phase separation and multi-stage hydrolysis and acidification technology, combined with UBF anaerobic anaerobic device, the problems of high investment in equipment and high dehydration costs in anaerobic fermentation are solved, and the anaerobic tank volume and investment are significantly reduced, as well as the operating cost are reduced. .
Patent Information
- Application Number
- CN202411534936.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-01-07
AI Technical Summary
In the existing anaerobic fermentation technology, the equipment investment is high during the treatment of kitchen waste, the moisture content of the slag after dehydration is high, the dehydration agent costs high, and the operational power consumption is large, and the full mixing mixing requires high equipment, resulting in relatively high costs. high.
Three-phase separation technology is used to separate the slurry into oil phase, liquid phase and solid phase, and hydrolyze and acidify and dehydrate respectively. Fermentation is performed using an anaerobic reactor to reduce the hydraulic residence time. UBF anaerobic device is used to replace the fully mixed anaerobic reaction. reduces the mixing requirement.
Anaerobic tank volume was reduced by 60%, investment was reduced by 38%, dehydration agent cost was reduced by 32%, sludge discharge was reduced by 34%, operating power consumption was reduced by 39%, and the final moisture content of the solid phase was 60%, which reduced treatment. Cost and equipment burden.
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Figure CN119265245A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of anaerobic treatment of kitchen waste, and in particular to a method for anaerobic treatment of kitchen waste. Background Art
[0002] Anaerobic fermentation is one of the main methods of food waste disposal at present. The production of biogas can realize the resource utilization of organic matter in food waste.
[0003] The food waste treatment generally starts with pulping, and then the slurry containing organic matter is transported to the hydrolysis acidification tank for hydrolysis, and then enters the fully mixed anaerobic reactor for anaerobic fermentation.
[0004] However, the full amount of slurry entering the anaerobic reactor results in a large volume and a long material residence time. The high solid content requires full mixing, which places very high requirements on tank installation, agitator design and materials, making anaerobic equipment the process equipment with the highest investment in the treatment of food waste. In addition, the water content of the biogas residue produced by anaerobic fermentation is generally still above 80% after dehydration. A large amount of reagents are added during the dehydration process, which has a significant impact on the reduction effect and the cost-effectiveness of the treatment.
[0005] Based on this, the present invention designs a method for anaerobic treatment of kitchen waste to solve the above problems. Summary of the invention
[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a method for anaerobic treatment of kitchen waste.
[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions:
[0008] A method for anaerobic treatment of kitchen waste comprises the following steps:
[0009] Pulping: Make the kitchen waste into slurry, in which the particles are controlled below 2mm;
[0010] Three-phase separation: Heat the slurry to 55-90°C and use a centrifugal three-phase separator to separate the slurry into oil phase, liquid phase and solid phase by using density difference;
[0011] The liquid phase is filtered through a filter to remove suspended matter, and a liquid phase A and a solid phase A are obtained. The liquid phase A enters the 1# hydrolysis and acidification tank for hydrolysis and acidification for 1-3 days to produce a hydrolyzate. The 1# hydrolysis and acidification tank transmits the hydrolyzate to the anaerobic reactor.
[0012] The solid phase and solid phase A are both transferred to the 2# hydrolysis acidification tank for hydrolysis acidification for 2-6 days. After dehydration by the dehydrator B, liquid phase C and solid phase C are generated. 50% of the solid phase C is refluxed to the 2# hydrolysis acidification tank, and the rest is discharged; the liquid phase C enters the anaerobic reactor;
[0013] The anaerobic reactor ferments for 6-20 days, and the generated biogas is recovered. The remaining material is dehydrated by the dehydrator A to produce liquid phase B and solid phase B. The liquid phase B enters the sewage treatment system for treatment, and the solid phase B enters the pyrolyzer; the pyrolyzer heats the solid phase B to above 80°C, and the residence time is more than 15 minutes; the pyrolyzer discharge enters the 2# hydrolysis acidification tank for hydrolysis and acidification.
[0014] Furthermore, pulping can be done by mechanical pulping or hydraulic pulping.
[0015] Furthermore, the filter is a plate and frame filter.
[0016] Furthermore, the anaerobic reactor is a UASB, UBF, IC or CSTR anaerobic reactor.
[0017] Furthermore, the mesophilic anaerobic temperature is controlled at 35-40°C, or the thermophilic anaerobic temperature is controlled at 45-60°C.
[0018] Furthermore, steam is introduced into the pyrolysis tank to raise the temperature to above 95°C.
[0019] Furthermore, both the dehydrator A and the dehydrator B are centrifugal or plate-frame dehydrators, and the solid content of the liquid phase after dehydration is less than 2%.
[0020] Furthermore, the pyrolyzer discharge enters the 2# hydrolysis acidification tank for hydrolysis and acidification.
[0021] Furthermore, 50% of the solid phase C is refluxed to the 2# hydrolysis acidification tank.
[0022] In order to better achieve the purpose of the present invention, the present invention also provides
[0023] Compared with the prior art, the present invention has the following beneficial effects: 1. A method for anaerobic treatment of kitchen waste provided in an embodiment of the present invention adopts a UBF anaerobic device, which reduces the volume of the anaerobic tank by 60% and the investment by 38% compared with the traditional fully mixed anaerobic device.
[0024] 2. The method for anaerobic treatment of kitchen waste provided in an embodiment of the present invention can reduce the cost of dehydration agents by 32% and the amount of sludge discharged by more than 34% compared with the traditional full-mix anaerobic reactor. It does not require intermediate or side wall stirring and reduces power consumption during operation by 39%.
[0025] 3. The method for anaerobic treatment of kitchen waste provided in the embodiment of the present invention produces biogas slurry with low solid content, which is beneficial to the subsequent biogas slurry treatment, and the final water content of the discharged solid phase is 60%. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0027] Figure 1 The present invention is a flow chart of a method for anaerobic treatment of kitchen waste. DETAILED DESCRIPTION
[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0029] Embodiment 1: In some embodiments, please refer to the drawings of the specification Figure 1 , a method for anaerobic treatment of kitchen waste, comprising the following steps:
[0030] Pulping: Mechanical pulping, hydraulic pulping and other methods can be used to make the food waste into slurry, in which the particle size is controlled at 1.8mm.
[0031] Three-phase separation: Heat the slurry to 55°C and use a centrifugal three-phase separator to separate the slurry into oil phase, liquid phase and solid phase using density difference. The oil phase can be sold externally.
[0032] The liquid phase is filtered through a plate and frame filter to remove suspended matter, and a liquid phase A and a solid phase A are obtained. The liquid phase A enters the 1# hydrolysis and acidification tank, which is a closed tank with stirring or other homogenization functions. The material stays in it for 1 day, and hydrolysis and acidification are carried out to produce a hydrolyzate. The 1# hydrolysis and acidification tank transmits the hydrolyzate to the anaerobic reactor;
[0033] The solid phase and solid phase A are both transferred to the 2# hydrolysis acidification tank. The 2# hydrolysis acidification tank is a closed tank with stirring or other homogenizing functions. The material stays in it for 2 days for hydrolysis acidification. After dehydration by the dehydrator B, liquid phase C (hydrolyzate) and solid phase C are generated. 50% of the solid phase C is refluxed to the 2# hydrolysis acidification tank, and the rest is discharged; the liquid phase C enters the anaerobic reactor;
[0034] Anaerobic reactor fermentation: the material is fermented in the anaerobic reactor to produce biogas, and the remaining material is dehydrated by the dehydrator A to produce liquid phase B and solid phase B. The liquid phase B enters the sewage treatment system for treatment, and the solid phase B enters the pyrolyzer. The pyrolyzer heats the solid phase B to 95°C for 30 minutes. The pyrolyzer discharge enters the 2# hydrolysis acidification tank for hydrolysis and acidification;
[0035] The anaerobic reactor may be UASB (upflow anaerobic sludge bed), UBF (upflow sludge bed filter), IC (internal circulation anaerobic reactor), CSTR (totally mixed reactor) and similar anaerobic reactors, with the mesophilic anaerobic temperature controlled at 35°C and the residence time of 6 days;
[0036] Among them, both dehydrator A and dehydrator B can adopt centrifugal, plate and frame or dehydrators with equivalent functions, and the solid content of the liquid phase after dehydration is 1.8%.
[0037] Embodiment 2: In some embodiments, Figure 1 As shown, as a preferred embodiment of the present invention, a method for anaerobic treatment of food waste comprises the following steps:
[0038] Pulping: Mechanical pulping, hydraulic pulping and other methods can be used to make the food waste into slurry, in which the particle size is controlled at 1.5mm.
[0039] Three-phase separation: Heat the slurry to 90°C and use a centrifugal three-phase separator to separate the slurry into oil phase, liquid phase and solid phase using density difference. The oil phase can be sold externally.
[0040] The liquid phase is filtered through a plate and frame filter to remove suspended matter, and a liquid phase A and a solid phase A are obtained. The liquid phase A enters the 1# hydrolysis acidification tank, which is a closed tank with stirring or other homogenization functions. The material stays in it for 3 days for hydrolysis and acidification to produce a hydrolyzate. The 1# hydrolysis acidification tank transmits the hydrolyzate to the anaerobic reactor;
[0041] The solid phase and solid phase A are both transferred to the 2# hydrolysis acidification tank. The 2# hydrolysis acidification tank is a closed tank with stirring or other homogenizing functions. The material stays in it for 6 days for hydrolysis acidification. After dehydration by the dehydrator B, liquid phase C (hydrolyzate) and solid phase C are generated. 50% of the solid phase C is refluxed to the 2# hydrolysis acidification tank, and the rest is discharged; the liquid phase C enters the anaerobic reactor;
[0042] Anaerobic reactor fermentation: the material is fermented in the anaerobic reactor to produce biogas, and the remaining material is dehydrated by the dehydrator A to produce liquid phase B and solid phase B. The liquid phase B enters the sewage treatment system for treatment, and the solid phase B enters the pyrolyzer. The pyrolyzer heats the solid phase B to 125°C for 40 minutes. The pyrolyzer discharge enters the 2# hydrolysis acidification tank for hydrolysis and acidification;
[0043] Among them, the anaerobic reactor can adopt UASB, UBF, IC, CSTR and similar anaerobic reactors, and the mesophilic anaerobic temperature is controlled at 40℃ and the residence time is 20 days;
[0044] Wherein, both dehydrator A and dehydrator B can adopt centrifugal, plate-and-frame or dehydrators with equivalent functions, and the solid content of the liquid phase after dehydration is 1.5%.
[0045] Embodiment 3: In some embodiments, Figure 1 As shown, as a preferred embodiment of the present invention, a method for anaerobic treatment of food waste comprises the following steps:
[0046] Pulping: Mechanical pulping, hydraulic pulping and other methods can be used to make the food waste into slurry, in which the particle size is controlled at 1.5mm.
[0047] Three-phase separation: Heat the slurry to 60°C and use a centrifugal three-phase separator to separate the slurry into oil phase, liquid phase and solid phase using density difference. The oil phase can be sold externally.
[0048] The liquid phase is filtered through a plate and frame filter to remove suspended matter, and a liquid phase A and a solid phase A are obtained. The liquid phase A enters the 1# hydrolysis and acidification tank, which is a closed tank with stirring or other homogenization functions. The material stays in it for 2 days for hydrolysis and acidification to produce a hydrolyzate. The 1# hydrolysis and acidification tank transmits the hydrolyzate to the anaerobic reactor;
[0049] The solid phase and solid phase A are both transferred to the 2# hydrolysis acidification tank. The 2# hydrolysis acidification tank is a closed tank with stirring or other homogenizing functions. The material stays in it for 4 days for hydrolysis and acidification. After dehydration by the dehydrator B, liquid phase C (hydrolyzate) and solid phase C are generated. 50% of the solid phase C is refluxed to the 2# hydrolysis acidification tank, and the rest is discharged; the liquid phase C enters the anaerobic reactor;
[0050] Anaerobic reactor fermentation: The material is fermented in the anaerobic reactor to produce biogas, and the remaining material is dehydrated by the dehydrator A to produce liquid phase B and solid phase B. The liquid phase B enters the sewage treatment system for treatment, and the solid phase B enters the pyrolyzer. The pyrolyzer heats the solid phase B to 110°C with a residence time of 45 minutes. The pyrolyzer discharge enters the 2# hydrolysis acidification tank for hydrolysis and acidification;
[0051] Among them, the anaerobic reactor can adopt UASB, UBF, IC, CSTR and similar anaerobic reactors, and the mesophilic anaerobic temperature is controlled at 38°C and the residence time is 10 days;
[0052] Among them, both dehydrator A and dehydrator B can adopt centrifugal, plate and frame or dehydrators with equivalent functions, and the solid content of the liquid phase after dehydration is 1.6%.
[0053] Embodiment 4: In some embodiments, Figure 1 As shown, as a preferred embodiment of the present invention, a method for anaerobic treatment of food waste comprises the following steps:
[0054] Pulping: Mechanical pulping, hydraulic pulping and other methods can be used to make the food waste into slurry, in which the particle size is controlled at 1.6mm.
[0055] Three-phase separation: Heat the slurry to 80°C and use a centrifugal three-phase separator to separate the slurry into oil phase, liquid phase and solid phase using density difference. The oil phase can be sold externally.
[0056] The liquid phase is filtered through a plate and frame filter to remove suspended matter, and a liquid phase A and a solid phase A are obtained. The liquid phase A enters the 1# hydrolysis and acidification tank, which is a closed tank with stirring or other homogenization functions. The material stays in it for 2 days for hydrolysis and acidification to produce a hydrolyzate. The 1# hydrolysis and acidification tank transmits the hydrolyzate to the anaerobic reactor;
[0057] The solid phase and solid phase A are both transferred to the 2# hydrolysis acidification tank. The 2# hydrolysis acidification tank is a closed tank with stirring or other homogenizing functions. The material stays in it for 5 days for hydrolysis and acidification. After dehydration by the dehydrator B, liquid phase C (hydrolyzate) and solid phase C are generated. 50% of the solid phase C is refluxed to the 2# hydrolysis acidification tank, and the rest is discharged; the liquid phase C enters the anaerobic reactor;
[0058] Anaerobic reactor fermentation: the material is fermented in the anaerobic reactor to produce biogas, and the remaining material is dehydrated by the dehydrator A to produce liquid phase B and solid phase B. The liquid phase B enters the sewage treatment system for treatment, and the solid phase B enters the pyrolyzer. The pyrolyzer heats the solid phase B to 105°C for 20 minutes. The pyrolyzer discharge enters the 2# hydrolysis acidification tank for hydrolysis and acidification;
[0059] Among them, the anaerobic reactor can adopt UASB, UBF, IC, CSTR and similar anaerobic reactors, and the high temperature anaerobic temperature is controlled at 60℃ and the residence time is 8 days;
[0060] Among them, both dehydrator A and dehydrator B can adopt centrifugal, plate and frame or dehydrators with equivalent functions, and the solid content of the liquid phase after dehydration is 1.9%.
[0061] Embodiment 5: In some embodiments, Figure 1 As shown, as a preferred embodiment of the present invention, a method for anaerobic treatment of food waste comprises the following steps:
[0062] Pulping: Mechanical pulping, hydraulic pulping and other methods can be used to make the food waste into slurry, in which the particle size is controlled at 1.7mm.
[0063] Three-phase separation: Heat the slurry to 88°C and use a centrifugal three-phase separator to separate the slurry into oil phase, liquid phase and solid phase using density difference. The oil phase can be sold externally.
[0064] The liquid phase is filtered through a plate and frame filter to remove suspended matter, and a liquid phase A and a solid phase A are obtained. The liquid phase A enters the 1# hydrolysis and acidification tank, which is a closed tank with stirring or other homogenization functions. The material stays in it for 1.5 days, and hydrolysis and acidification are carried out to produce a hydrolyzate. The 1# hydrolysis and acidification tank transmits the hydrolyzate to the anaerobic reactor;
[0065] The solid phase and solid phase A are both transferred to the 2# hydrolysis acidification tank. The 2# hydrolysis acidification tank is a closed tank with stirring or other homogenizing functions. The material stays in it for 4.5 days for hydrolysis and acidification. After dehydration by the dehydrator B, liquid phase C (hydrolyzate) and solid phase C are generated. 50% of the solid phase C is refluxed to the 2# hydrolysis acidification tank, and the rest is discharged; the liquid phase C enters the anaerobic reactor;
[0066] Anaerobic reactor fermentation: The material is fermented in the anaerobic reactor to produce biogas, and the remaining material is dehydrated by the dehydrator A to produce liquid phase B and solid phase B. The liquid phase B enters the sewage treatment system for treatment, and the solid phase B enters the pyrolyzer. The pyrolyzer heats the solid phase B to 115°C for 25 minutes. The pyrolyzer discharge enters the 2# hydrolysis acidification tank for hydrolysis and acidification;
[0067] Among them, the anaerobic reactor can adopt UASB, UBF, IC, CSTR and similar anaerobic reactors, and the high temperature anaerobic temperature is controlled at 45℃ and the residence time is 6 days;
[0068] Among them, both dehydrator A and dehydrator B can adopt centrifugal, plate and frame or dehydrators with equivalent functions, and the solid content of the liquid phase after dehydration is 1.6%.
[0069] Embodiment 6: In some embodiments, Figure 1 As shown, as a preferred embodiment of the present invention, a method for anaerobic treatment of food waste comprises the following steps:
[0070] Pulping: Mechanical pulping, hydraulic pulping and other methods can be used to make the food waste into slurry, in which the particle size is controlled at 1.7mm.
[0071] Three-phase separation: Heat the slurry to 89°C and use a centrifugal three-phase separator to separate the slurry into oil phase, liquid phase and solid phase using density difference. The oil phase can be sold externally.
[0072] The liquid phase is filtered through a plate and frame filter to remove suspended matter, and a liquid phase A and a solid phase A are obtained. The liquid phase A enters the 1# hydrolysis and acidification tank, which is a closed tank with stirring or other homogenization functions. The material stays in it for 2.5 days, and hydrolysis and acidification are carried out to produce a hydrolyzate. The 1# hydrolysis and acidification tank transmits the hydrolyzate to the anaerobic reactor;
[0073] The solid phase and solid phase A are both transferred to the 2# hydrolysis acidification tank. The 2# hydrolysis acidification tank is a closed tank with stirring or other homogenizing functions. The material stays in it for 5.5 days for hydrolysis acidification. After dehydration by the dehydrator B, liquid phase C (hydrolyzate) and solid phase C are generated. 50% of the solid phase C is refluxed to the 2# hydrolysis acidification tank, and the rest is discharged; the liquid phase C enters the anaerobic reactor;
[0074] Anaerobic reactor fermentation: the material is fermented in the anaerobic reactor to produce biogas, and the remaining material is dehydrated by the dehydrator A to produce liquid phase B and solid phase B. The liquid phase B enters the sewage treatment system for treatment, and the solid phase B enters the pyrolyzer. The pyrolyzer heats the solid phase B to 122°C with a residence time of 45 minutes; the pyrolyzer discharge enters the 2# hydrolysis acidification tank for hydrolysis and acidification;
[0075] Among them, the anaerobic reactor can adopt UASB, UBF, IC, CSTR and similar anaerobic reactors, and the mesophilic anaerobic temperature is controlled at 36°C and the residence time is 11 days;
[0076] Among them, both dehydrator A and dehydrator B can adopt centrifugal, plate and frame or dehydrators with equivalent functions, and the solid content of the liquid phase after dehydration is 1.7%.
[0077] Embodiment 7: In some embodiments, Figure 1 As shown, as a preferred embodiment of the present invention, a method for anaerobic treatment of food waste comprises the following steps:
[0078] Pulping: Mechanical pulping, hydraulic pulping and other methods can be used to make the food waste into slurry, in which the particle size is controlled at 1.8mm.
[0079] Three-phase separation: Heat the slurry to 77°C and use a centrifugal three-phase separator to separate the slurry into oil phase, liquid phase and solid phase using density difference. The oil phase can be sold externally.
[0080] The liquid phase is filtered through a plate and frame filter to remove suspended matter, and a liquid phase A and a solid phase A are obtained. The liquid phase A enters the 1# hydrolysis and acidification tank, which is a closed tank with stirring or other homogenization functions. The material stays in it for 1 day, and hydrolysis and acidification are carried out to produce a hydrolyzate. The 1# hydrolysis and acidification tank transmits the hydrolyzate to the anaerobic reactor;
[0081] The solid phase and solid phase A are both transferred to the 2# hydrolysis acidification tank. The 2# hydrolysis acidification tank is a closed tank with stirring or other homogenizing functions. The material stays in it for 6 days for hydrolysis acidification. After dehydration by the dehydrator B, liquid phase C (hydrolyzate) and solid phase C are generated. 50% of the solid phase C is refluxed to the 2# hydrolysis acidification tank, and the rest is discharged; the liquid phase C enters the anaerobic reactor;
[0082] Anaerobic reactor fermentation: the material is fermented in the anaerobic reactor to produce biogas, and the remaining material is dehydrated by the dehydrator A to produce liquid phase B and solid phase B. The liquid phase B enters the sewage treatment system for treatment, and the solid phase B enters the pyrolyzer. The pyrolyzer heats the solid phase B to 88°C, and the residence time is 22 minutes; the pyrolyzer discharge enters the 2# hydrolysis acidification tank for hydrolysis and acidification;
[0083] Among them, the anaerobic reactor can adopt UASB, UBF, IC, CSTR and similar anaerobic reactors, and the mesophilic anaerobic temperature is controlled at 39°C and the residence time is 10 days;
[0084] Among them, both dehydrator A and dehydrator B can adopt centrifugal, plate and frame or dehydrators with equivalent functions, and the solid content of the liquid phase after dehydration is 1.3%.
[0085] Experimental example
[0086] Example 1 Compared with the traditional fully mixed anaerobic device, the reduction rate of the anaerobic tank volume, investment, dehydration agent cost, external sludge volume, power consumption during operation and other parameters was calculated. At the same time, the final external solid phase moisture content was detected. The results are shown in Table 1.
[0087] Table 1 Parameter comparison calculation results
[0088] project Results (unit %) Anaerobic tank volume reduction rate 60 Investment reduction rate 38 Dehydration agent cost reduction rate 32 External sludge reduction rate 34.5 Power consumption reduction rate during operation 39 Final discharged solid phase moisture content 60
[0089] The present invention can effectively dispose of restaurant kitchen waste and obtain valuable products such as grease and biogas. Compared with the current mainstream anaerobic fermentation treatment process, the volume of the anaerobic reactor can be reduced, and a low-investment anaerobic reactor can be used to reduce the project operation cost. The specific technical effects are as follows:
[0090] 1. The embodiment of the present invention provides a method for anaerobic treatment of kitchen waste, which uses a UBF anaerobic device. Compared with the traditional fully mixed anaerobic device, the volume of the anaerobic tank is reduced by 60% and the investment is reduced by 38%.
[0091] 2. The method for anaerobic treatment of kitchen waste provided in an embodiment of the present invention can reduce the cost of dehydration agents by 32% and the amount of sludge discharged by more than 34% compared with the traditional full-mix anaerobic reactor. It does not require intermediate or side wall stirring and reduces power consumption during operation by 39%.
[0092] 3. The method for anaerobic treatment of kitchen waste provided in the embodiment of the present invention produces biogas slurry with low solid content, which is beneficial to the subsequent biogas slurry treatment, and the final water content of the discharged solid phase is 60%.
[0093] In summary, the present invention achieves solid-liquid separation of the front-end slurry, hydrolysis and acidification before anaerobic fermentation, separate anaerobic treatment of the liquid phase and the solid phase, and multi-stage hydrolysis and acidification of the solid phase. A general wastewater treatment reactor is used instead of a fully mixed anaerobic reactor, which greatly reduces the hydraulic retention time, increases the load of the anaerobic reactor, reduces the reactor volume, and does not require an agitator in the middle or on the side wall, thereby greatly reducing the investment cost and the operation cost.
[0094] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for anaerobic treatment of kitchen waste, characterized in that: The following steps are involved: Pulping: Make the kitchen waste into slurry, in which the particles are controlled below 2mm; Three-phase separation: Heat the slurry to 55-90°C and use a centrifugal three-phase separator to separate the slurry into oil phase, liquid phase and solid phase by using density difference; The liquid phase is filtered through a filter to remove suspended matter, and a liquid phase A and a solid phase A are obtained. The liquid phase A enters the 1# hydrolysis and acidification tank for hydrolysis and acidification for 1-3 days to produce a hydrolyzate. The 1# hydrolysis and acidification tank transmits the hydrolyzate to the anaerobic reactor. The solid phase and solid phase A are both transferred to the 2# hydrolysis acidification tank for hydrolysis acidification for 2-6 days. After dehydration by the dehydrator B, liquid phase C and solid phase C are generated. A part of the solid phase C is returned to the 2# hydrolysis acidification tank, and the rest is discharged; the liquid phase C enters the anaerobic reactor; The anaerobic reactor ferments for 6-20 days, and the generated biogas is recovered. The remaining material is dehydrated by the dehydrator A to produce liquid phase B and solid phase B. The liquid phase B enters the sewage treatment system for treatment, and the solid phase B enters the pyrolyzer; the pyrolyzer heats the solid phase B to above 80°C, and the residence time is more than 15 minutes; the pyrolyzer discharge enters the 2# hydrolysis acidification tank for hydrolysis and acidification.
2. The method for anaerobic treatment of kitchen waste according to claim 1, characterized in that: Pulping can be done by mechanical pulping or hydraulic pulping.
3. The method for anaerobic treatment of kitchen waste according to claim 2, characterized in that: in, The filter adopts plate and frame filter.
4. The method for anaerobic treatment of kitchen waste according to claim 3, characterized in that: in, The anaerobic reactor adopts UASB, UBF, IC or CSTR anaerobic reactor.
5. The method for anaerobic treatment of food waste according to claim 4, characterized in that: The temperature of mesophilic anaerobic culture is controlled at 35-40℃, or the temperature of thermophilic anaerobic culture is controlled at 45-60℃.
6. The method for anaerobic treatment of food waste according to claim 5, characterized in that: Steam is introduced into the pyrolysis tank to raise the temperature to above 95°C.
7. The method for anaerobic treatment of food waste according to claim 6, characterized in that: Dehydrator A and dehydrator B are both centrifugal or plate-frame dehydrators, and the solid content of the liquid phase after dehydration is less than 2%.
8. The method for anaerobic treatment of food waste according to claim 7, characterized in that: The pyrolyzer discharge enters the 2# hydrolysis acidification tank for hydrolysis and acidification.
9. The method for anaerobic treatment of kitchen waste according to claim 8, characterized in that: 50% of the solid phase C is refluxed to the 2# hydrolysis acidification tank.