Kitchen waste high-solid-content two-phase anaerobic digestion methane production system

Abstract

The utility model relates to a high-solid-content two-phase anaerobic digestion methane production system for kitchen waste. The system comprises a hydrolytic acidification phase and a methane production phase, the hydrolytic acidification phase is provided with a kitchen waste accumulation chamber and a leachate collection chamber, and the leachate collection chamber is used for collecting leachate generated in the kitchen waste accumulation chamber; anaerobic digestion sludge is arranged in the methanogenesis phase; a first pipeline and a second pipeline which are used for outputting leachate are respectively arranged at the bottom of the leachate collecting chamber, and the first pipeline is connected to the methanogenesis phase and is used for introducing the leachate output by the first pipeline into the methanogenesis phase and carrying out contact reaction on the leachate and anaerobic digestion sludge in the methanogenesis phase; the methanogenesis phase is connected to the second pipeline and is used for enabling part of anaerobic digestion sludge in the methanogenesis phase to flow out, mixing the anaerobic digestion sludge with leachate output by the second pipeline and returning the mixture to the kitchen waste accumulation chamber; and air distribution holes are formed in the bottom of the methanogenesis phase and are used for introducing headspace gas generated by the hydrolytic acidification phase. The system enhances the stability of the reaction system and improves the methane conversion efficiency.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of kitchen waste energy technology, concretely to a kitchen waste high solid content two-phase anaerobic digestion methane production system. BACKGROUND

[0002] Kitchen waste is an important part of urban organic solid waste, and the annual output of kitchen waste exceeds 120 million tons, with a solid content rate of generally 20%-40%. Kitchen waste has characteristics such as high grease and high organic matter, and traditional treatment methods such as landfill and incineration can easily cause secondary pollution and resource waste. Anaerobic digestion technology has become one of the mainstream treatment methods due to its energy recovery and carbon emission reduction potential. However, anaerobic digestion of high solid content kitchen waste still faces many technical bottlenecks, and system optimization and process innovation are urgently needed.

[0003] The solid content rate of kitchen waste is usually 20%-40%, and its high viscosity and low flowability make it difficult to transport and mix, and it is easy to form a local acidification zone, which inhibits microbial activity. In addition, the carbon-nitrogen ratio (C / N) of kitchen waste is high (about 15-30:1), and volatile fatty acids (VFAs) are easy to accumulate during rapid degradation, which causes a sharp drop in system pH, triggers acid inhibition effect, and significantly reduces methane production efficiency. At the same time, the presence of high salt and grease further exacerbates microbial metabolic inhibition, affecting long-term operation stability. The existing single-phase anaerobic digestion system couples hydrolysis and acidification with methane production in the same reactor, but the hydrolysis rate of complex organic matter in high solid content material and the metabolic rate of methanogenic bacteria are not matched, which easily leads to accumulation of intermediate products (such as VFAs), disrupting the acid-base balance of the system. With the advancement of "waste-free city" construction and "double carbon" target, the efficient energy conversion and carbon fixation of kitchen waste are in urgent need. The existing process needs to consider high solid content treatment efficiency, low operating cost and carbon emission reduction benefit.

[0004] The existing high solid content kitchen waste anaerobic digestion system has significant shortcomings in phase separation efficiency, inhibition resistance and resource recycling. This patent aims to solve the problems of poor flowability of high solid content material, acidification inhibition and low methane production efficiency by optimizing the structure of two-phase reactor, coupling acidification gas and biogas reflux control strategy. UTILITY MODEL CONTENTS

[0005] In view of the problems existing in the prior art, the utility model aims to provide a kitchen waste high solid content two-phase anaerobic digestion methane production system, which can enhance the stability of the reaction system and improve the organic matter degradation rate.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0007] A kitchen waste high solid content two-phase anaerobic digestion methane production system, comprising a hydrolysis acidification phase and a methane production phase.

[0008] The hydrolysis acidification phase is provided with a kitchen waste accumulation chamber and a leachate collection chamber for collecting leachate generated in the kitchen waste accumulation chamber; and the methanogenesis phase is provided with anaerobic digestion sludge;

[0009] The bottom of the leachate collection chamber is respectively provided with a first pipeline and a second pipeline for outputting leachate,

[0010] The first pipeline is connected to the methanogenesis phase, and is used for passing the leachate output by the first pipeline into the methanogenesis phase and reacting with the anaerobic digestion sludge in the methanogenesis phase;

[0011] The methanogenesis phase is connected to the second pipeline, and is used for flowing part of the anaerobic digestion sludge in the methanogenesis phase out, mixing the leachate output by the second pipeline, and returning to the kitchen waste accumulation chamber;

[0012] The bottom of the methanogenesis phase is provided with a gas distribution hole for passing the headspace gas generated in the hydrolysis acidification phase.

[0013] Further, the hydrolysis acidification phase is a percolation bed reactor and is integrated with a leachate circulation sprinkling system; the percolation bed reactor includes the kitchen waste accumulation chamber and a leachate collection chamber below the kitchen waste accumulation chamber, the leachate circulation sprinkling system is arranged above the kitchen waste accumulation chamber and is connected to the second pipeline; and the methanogenesis phase is an upflow anaerobic sludge bed reactor.

[0014] Further, a safety valve is installed on the percolation bed reactor.

[0015] Further, the first pipeline and the second pipeline respectively output 50% of the leachate in the leachate collection chamber, and the anaerobic digestion sludge flowing out of the methanogenesis phase is mixed with the leachate output by the second pipeline at a volume ratio of 1:1.

[0016] Further, a methanogenesis phase feeding pump is arranged on the first pipeline, and is used for conveying the leachate output by the first pipeline to the methanogenesis phase.

[0017] Further, a temperature control module is further included, and the temperature control module is used for controlling the hydrolysis acidification phase and the methanogenesis phase to be kept at 55±1℃ and 35±1℃.

[0018] Further, the temperature control module includes a first circulating water inlet valve and a first circulating water outlet valve connected to the hydrolysis acidification phase, and a second circulating water inlet valve and a second circulating water outlet valve connected to the methanogenesis phase.

[0019] Further, a sampling port is installed on the methanogenesis phase, and a sampling valve is arranged on the sampling port.

[0020] Further, the gas pressure control system is further included, the top of the hydrolysis acidification phase is provided with an acidification gas outlet valve, the methane production phase is provided with a methane production phase gas inlet valve, the acidification gas outlet valve, the gas pressure control system, the methane production phase gas inlet valve and the gas distribution hole are sequentially connected.

[0021] Further, the top of the methane production phase is provided with a three-phase separator and a methane collection bag, and the methane produced by the methane production phase is collected in the methane collection bag through the three-phase separator.

[0022] Overall, the utility model has the following advantages:

[0023] The system separates the hydrolysis acid production phase and the methane production phase, controls the two phases to be in the optimal reaction condition respectively, and enhances the stability of the reaction system; the reflux of the methane production phase biogas liquid neutralizes the pH of the leachate, the hydrolysis acidification of the high solid content organic matter of the kitchen waste is promoted through the reflux of the circulating spray system; the pressure control of the headspace gas of the hydrolysis acidification phase eliminates the inhibition of the hydrogen partial pressure on the substrate hydrolysis acidification; the utilization of the hydrolysis acidification gas improves the methane production, and thus the methane conversion efficiency of the whole high solid content anaerobic digestion system of the kitchen waste is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structural schematic view of the utility model.

[0025] In the drawing:

[0026] 1, hydrolysis acidification phase; 2, kitchen waste accumulation chamber; 3, leachate collection chamber; 4, leachate outlet valve; 5, first circulating water inlet valve; 6, first circulating water outlet valve; 7, leachate reflux pump; 8, leachate inlet valve; 9, circulating spray system; 10, acidification gas outlet valve; 11, safety valve; 12, gas pressure control system; 13, methane production phase feeding pump; 14, methane production phase feeding valve; 15, methane production phase gas inlet valve; 16, second circulating water inlet valve; 17, second circulating water outlet valve; 18, sampling valve; 19, biogas liquid reflux valve; 20, gas distribution hole; 21, methane production phase; 22, three-phase separator; 23, methane outlet valve; 24, methane collection bag. DETAILED DESCRIPTION

[0027] The utility model will be further explained in detail as follows.

[0028] As shown in the drawing, Figure 1 A kitchen waste high solid two-phase anaerobic digestion methane production system, which comprises a hydrolysis acidification phase 1, a methane production phase 21, a gas pressure control system 12 and a biogas liquid reflux valve 19.

[0029] Preferably, the hydrolysis acidification phase 1 is a pressure-resistant percolation bed reactor integrated with a leachate circulation leaching system 9; the methane production phase 21 adopts an upflow anaerobic sludge bed reactor; the hydrolysis acidification phase 1 and the methane production phase 21 are connected through a gas pressure control system 12 and a biogas slurry reflux valve 19.

[0030] Further, the percolation bed reactor is provided with a kitchen waste accumulation chamber 2 and a leachate collection chamber 3, and the leachate generated in the kitchen waste accumulation chamber 2 can be discharged into the leachate collection chamber 3 below in time, avoiding the acid inhibition effect caused by high solid content materials.

[0031] Further, the upflow anaerobic sludge bed reactor contains anaerobic digestion sludge, and the methane generated at the top is collected by a methane collection bag 24 with a methane outlet valve 23 after passing through a three-phase separator 22.

[0032] Further, the bottom of the leachate collection chamber 3 is provided with a leachate outlet valve 4 for outputting leachate, and the leachate outlet valve 4 is connected to a first pipeline and a second pipeline respectively, 50% of the leachate in the leachate collection chamber 3 flows into the methane production phase 21 through the first pipeline and a methane production phase feeding pump 13, and the leachate is pumped into the methane production phase 21 from a methane production phase feeding valve 14 at the bottom of the upflow anaerobic sludge bed reactor, and the contact time with the anaerobic digestion sludge is increased during the rising process, so that the methane production reaction is more sufficient.

[0033] The anaerobic digestion sludge in the methane production phase 21 is mixed with 50% of the leachate output by the second pipeline in a volume ratio of 1:1 through a biogas slurry reflux valve 19, and then connected to a circulation leaching system 9 through a leachate inlet valve 8, and finally returned to the hydrolysis acidification phase 1, the pH of the anaerobic digestion sludge is neutralized, and the mixed liquid is uniformly sprayed into the kitchen waste accumulation chamber 2, promoting the hydrolysis acidification of the high solid content organic matter in the kitchen waste.

[0034] Further, the headspace gas generated in the hydrolysis acidification phase 1 passes through an acidification gas outlet valve 10 and enters a gas pressure control system 12 and is introduced into a gas distribution hole 20 at the bottom of the methane production phase 21, and the gas rises from the bottom of the reactor, increasing the contact time with the anaerobic digestion sludge, so that the methane production reaction is more sufficient.

[0035] Further, a safety valve 11 is installed on the percolation bed reactor.

[0036] Further, a sampling port is installed on the upflow anaerobic sludge bed reactor, and a sampling valve 18 is arranged on the sampling port.

[0037] Further, the system further comprises a temperature control module, which is used to control the hydrolysis acidification phase 1 and the methane production phase 21 to be kept at 55±1℃ and 35±1℃ respectively.

[0038] Preferably, the temperature control module comprises a first circulating water inlet valve 5 and a first circulating water outlet valve 6 connected to the hydrolytic acidification phase 1, a second circulating water inlet valve 16 and a second circulating water outlet valve 17 connected to the methanogenic phase 21, which maintain the temperature of the two phases respectively through external heat exchangers.

[0039] The working principle of the utility model is: the kitchen waste first enters the kitchen waste accumulation chamber 2 of the hydrolytic acidification phase 1, the leachate produced after hydrolytic acidification flows into the leachate collection chamber 3, then 50% of the leachate flows into the upflow anaerobic sludge blanket reactor from the bottom through the methanogenic phase feeding pump 13 and the methanogenic phase feeding valve 14, the remaining 50% of the leachate is mixed with the biogas slurry backflow liquid of the methanogenic phase 21, then returns to the hydrolytic acidification phase 1 through the leachate backflow pump 7, the hydrolytic acid-producing phase inlet valve and the circulating spray system 9, the gas produced by the hydrolytic acid-producing phase enters the gas pressure control system 12 through the acidification gas outlet valve 10, controls the headspace air pressure and makes the gas enter the methanogenic phase 21 through the methanogenic phase air inlet valve 15 and the air distribution hole 20.

[0040] The above embodiment is the preferred implementation of the utility model, but the implementation of the utility model is not limited by the above embodiment, any change, modification, replacement, combination, simplification made without departing from the spirit and principle of the utility model should be an equivalent replacement method, which is included in the protection scope of the utility model.

Claims

1. A two-phase anaerobic digestion system for producing methanogens from high-solids-content food waste, characterized in that: Includes the hydrolysis-acidification phase and the methanogenic phase; The hydrolysis-acidification phase includes a food waste accumulation chamber and a leachate collection chamber. The leachate collection chamber is used to collect the leachate generated in the food waste accumulation chamber. The methanogenic phase contains anaerobic digested sludge. The bottom of the leachate collection chamber is equipped with a first pipeline and a second pipeline for discharging leachate. The first pipeline is connected to the methanogenic phase and is used to pass the leachate output from the first pipeline into the methanogenic phase and react with the anaerobic digested sludge in the methanogenic phase. The methanogenic phase is connected to the second pipeline, which is used to allow part of the anaerobic digested sludge in the methanogenic phase to flow out and mix with the leachate output from the second pipeline before returning it to the food waste accumulation chamber. The bottom of the methanogenic phase is provided with a gas distribution hole, which is used to introduce headspace gas generated by the hydrolysis acidification phase.

2. The high-solids-content two-phase anaerobic digestion and methanogenic system for food waste according to claim 1, characterized in that: The hydrolysis acidification phase is a percolation bed reactor and is integrated with a leachate circulation spray system; the percolation bed reactor includes a food waste accumulation chamber and a leachate collection chamber below it, and the leachate circulation spray system is located above the food waste accumulation chamber and connected to the second pipeline; The methanogenic phase is an upflow anaerobic sludge bed reactor.

3. The high-solids-content two-phase anaerobic digestion and methanogenic system for food waste according to claim 1, characterized in that: Safety valves are installed on the percolation bed reactor.

4. The high-solids-content two-phase anaerobic digestion and methanogenic system for food waste according to claim 2, characterized in that: The first and second pipelines each output 50% of the leachate from the leachate collection chamber. The anaerobic digested sludge flowing out of the methanogenic phase is mixed with the leachate output from the second pipeline at a 1:1 volume ratio.

5. The high-solids-content two-phase anaerobic digestion and methanogenic system for food waste according to claim 1, characterized in that: The first pipeline is equipped with a methanogenic phase feed pump, which is used to transport the leachate output from the first pipeline to the methanogenic phase.

6. The high-solids-content two-phase anaerobic digestion and methanogenic system for food waste according to claim 1, characterized in that: It also includes a temperature control module, which is used to control the hydrolysis acidification phase and the methanogenic phase to be maintained at 55±1℃ and 35±1℃, respectively.

7. A two-phase anaerobic digestion system for producing methanates from high-solids-content food waste according to claim 6, characterized in that: The temperature control module includes a first circulating water inlet valve and a first circulating water outlet valve connected to the hydrolysis acidification phase, and a second circulating water inlet valve and a second circulating water outlet valve connected to the methanogenic phase.

8. A two-phase anaerobic digestion system for producing methanates from high-solids-content food waste according to claim 1, characterized in that: A sampling port is installed on the methanogenic phase, and a sampling valve is installed on the sampling port.

9. A two-phase anaerobic digestion system for producing methanates from high-solids-content food waste according to claim 1, characterized in that: It also includes a gas pressure control system, an acidification gas outlet valve at the top of the hydrolysis acidification phase, and a methanogenic phase inlet valve. The acidification gas outlet valve, the gas pressure control system, the methanogenic phase inlet valve, and the gas distribution hole are connected in sequence.

10. A two-phase anaerobic digestion system for producing methanates from high-solids-content food waste according to claim 1, characterized in that: The top of the methanogenic phase is equipped with a three-phase separator and a methane collection bag. The methane produced by the methanogenic phase is collected in the methane collection bag after passing through the three-phase separator.

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