CN102796765A

CN102796765A - Method for treating easily-degradable organic waste in two-phase hydrogen-production methane-production coupling reaction

Info

Publication number: CN102796765A
Application number: CN2012102770562A
Authority: CN
Inventors: 刘广青; 冯璐; 何艳峰; 刘晓英; 郑毅
Original assignee: Changzhou Institute for Advanced Materials Beijing University of Chemical Technology
Current assignee: Changzhou Institute for Advanced Materials Beijing University of Chemical Technology
Priority date: 2012-08-06
Filing date: 2012-08-06
Publication date: 2012-11-28

Abstract

The invention discloses a method for treating easily-degradable organic waste in a two-phase hydrogen-production methane-production coupling reaction, and belongs to the field of efficient resource utilization of organic solid wastes. In the existing two-phase technology, the end product is only methane, and hydrogen is directly discharged; and the partial hydrogen-methane coproducing technology is difficult to apply because the yield of hydrogen is low. According to the invention, the easily-degradable organic waste is stirred and then added into an acidifying reactor; solid and liquid phases in reaction products directly enter into a rear end to produce a methane phase; a gas phase is subjected to pressure swing adsorption to decarburize; and a product gas the main component of which is H2 is introduced into the methane phase to react with CO2 which is produced by methanation reaction to generate CH4. By using the method, on one hand, the yield of CH4 is improved, and on the other hand, the purity of CH4 in the product gas is improved. The method disclosed by the invention has the advantages of high treatment efficiency, high gas producing rate, short period, no discharged waste water and the like, and can be used for continuously and stably producing the gas.

Description

A kind of two produce the producing hydrogen and methane coupling reaction mutually handles the method that is prone to the degraded organic waste

Technical field

The invention belongs to organic solid castoff high-efficiency resource recycling field, relate to and a kind ofly utilize two to produce the method that the producing hydrogen and methane coupling technique handle to be prone to the degraded organic waste mutually.

Background technology

Be prone to the degraded organic waste and be meant the easy corruption that produces in life and the production process and the waste of readily biodegradable, mainly comprise fruits and vegetables rubbish, changing food waste etc.Along with the generally raising of China's living standards of the people, this type organic absolute yield and in total rubbish output shared ratio significantly improve.China's changing food waste YO in 2007 surpasses 8,000 ten thousand tons, and fruits and vegetables class waste output is also above 5,000 ten thousand tons.The maximum characteristics that are prone to the degraded organic waste are that water ratio and organic content are high; Perishable, acidifying; Therefore domestic refuse disposal technology commonly used difficulty is handled such waste preferably;, in the process of landfill disposal, can produce a large amount of percolates and get into underground water, and bigger water ratio makes it be difficult to direct burning disposal because organic content is higher like such waste.

Because it is high to be prone in the degraded organic waste organic content, thereby can handle it through anaerobic digestion techniques, not only can decontamination through this technology, can the organic constituent in the waste be converted into clean energy biogas simultaneously.All concentrate on traditional single phase and TPAD about the research that is prone to degraded organic waste anaerobic methane production gas at present; Characteristics such as water ratio height, complicated component, volume are big because such waste has, heterogeneous body, mobile poor, content of cellulose height; Traditional single-phase mixing anaerobic digestion process efficient is low; Two-phase anaerobic digestion system has realized that under certain condition two are separated, and has greatly improved the processing efficiency of organic waste simultaneously, can realize the coproduction of hydrogen, methane.But because the first middle mutually amounts of hydrogen that produces is less, and calorific value own is lower, is difficult to really be able to use; As the acidifying phase reaction is strengthened, improve hydrogen output in the acidification reaction and can cause biomass again first the consuming excessively in mutually, influence the output of follow-up methane, be difficult to reach the production capacity balance.Also do not see at present two produce the producing hydrogen and methane coupling reaction mutually patent report.

Summary of the invention

In order to solve the problem of above-mentioned existence; A kind of efficient methane production method that is different from the coproduction of traditional TPAD hydrogen methane is provided in this patent; After stirring, the organic waste that at first will be prone to degrade adds acidification reaction in the acidifying phase reactor; Reaction back mushy stage acidizing product directly gets into efficient anaerobic digestion methane-producing reactor, and gaseous product (mainly is H ₂And CO ₂Mixture) through C0 ₂Get in the efficient anaerobic digestion methane-producing reactor C0 that in methanation, produces after removing device ₂The reduction reaction takes place under the effect of methanobacteria generate methane.This technology has added the pressure swing adsorption decarbonization device behind acidification reactor on the basis of common TPAD, through the H after will purifying ₂Feed back segment produce methane mutually in once more with the acidizing product methanation in the CO that produces ₂The gas generation methane that reacts makes the H in the acidifying mutually on the one hand ₂Obtain effective utilization, avoided the waste of biomass energy; Also increased simultaneously the output of methane in the whole technology; In addition, because H ₂With the CO in the methanator ₂Reduction reaction takes place consumed the portion C 0 in the methane phase gaseous product ₂, also improved CH in the product gas ₄The content of gas.

Technical scheme of the present invention is achieved in that a kind of two produce the acidifying that method (1) that the producing hydrogen and methane coupling reaction handle to be prone to the degraded organic waste is prone to the degraded organic waste mutually: organic waste is stirred, and to add concentration be that the sludge of sewage treatment plant of 25000mg/L is as microbe inoculation in the back; And through control aeration gas flow reach the little aerobic acidication environment that dissolved oxygen concentration is 0.2-0.5mg/L; Carry out little aerobic enhanced hydrolysis acidification reaction; Thereby the compositions such as Mierocrystalline cellulose in the solid materials are obtained degraded; Make solid matter be converted into solvability COD and a part is converted into low carbon chain lipid acid; (2) solidliquid mixture that produces in the acidization is regulated pH to 7 ~ 8 backs and feed methanator, (3) are with the gas process CO that produces in the acidification reactor ₂Filtration unit makes the hydrogen content in the gas increase to more than 80% by original 20% ~ 30%, and the gas after (4) will purify feeds in the methanator, with the CO in the gas ₂The reduction reaction takes place under the effect of methanobacteria, produces CH ₄Gas, (5) percolate return-flow system: the Digestive system in the methanator pumps in the reactor for hydrolysis and acidification, further promotes the acidication process of solid residue.

Compared with prior art, innovation of the present invention is:

1, little aerobic acidication technology is used for acidifying phase process, has improved indissoluble is separated material in the organic waste degradability and anaerobic digestion potentiality,

2, acidifying phase internal reaction is produced gas after transformation absorption, with the H in the product gas ₂Concentration has been brought up to about 80% by 20%, the gas after purifying feed methane mutually in, under the effect of methanobacteria and CO ₂The generation methane that reacts has improved the CH of entire system ₄Output,

3, methane mutually in because H ₂With CO ₂Reduction reaction has taken place, and has reduced the CO in the product gas ₂Content, improved the ratio of combustibleconstituents in the whole prod gas,

4, the supernatant behind the methanator product methane does not discharge, and is back in the reactor for hydrolysis and acidification to recycle, and promotes acidication efficient also to reduce the system water amount.

Description of drawings

Fig. 1 the present invention produces the schema of biogas.

Embodiment

Below in conjunction with specific embodiment the present invention is described in further detail.

System comprises 1 raw material stirring system, the reactor for hydrolysis and acidification of 1 5L, 1 2L methanator, a pressure swing adsorption decarbonization device.Add concentration and be the seed sludge of 25000mg/L and feed certain oxygen that to keep dissolved oxygen concentration be that 0.3mg/L carries out little aerobic pretreatment acidifying; Liquid-solid phase product after the acidifying is added NaOH regulate pH value to 7.0; Get into efficient product methane process through the continuously feeding mode; Simultaneously the acidifying aerogenesis is fed in the decarbonization device and purify the H after purifying ₂Get into back and CO in the methanator ₂Reduction reaction takes place generate methane.Utilize the constant current peristaltic pump to realize water outlet reflux cycle use in acidification reactor of methanator simultaneously; Realized carrying out continuously of entire reaction system; System reaches stable aerogenesis; Factor of created gase reaches more than the 680ml/gVS, and methane content reaches more than 70%, and does not occur the inhibition of organic acid accumulation and ammonia nitrogen in the reactive system.

Claims

1. a two-phase is produced the producing hydrogen and methane coupled reaction and is handled the method that is prone to the degraded organic waste, it is characterized in that may further comprise the steps:

1) is prone to mixing of degraded organic waste: organic waste through after evenly mixing, is converted into the soup compound of homogeneous with heterogeneous organic waste, effectively improves its degradability, reduce the difficulty of subsequent technique.

2) the little aerobic acidifying of easily biodegradable organics: adopt little aerobic technology that organism is carried out acidification reaction, whole acidication process is strengthened, improved processing power, solid matter efficiently is converted into solvability COD to the part of the difficult degradation in the waste.

3) acidifying phase gas purification: acidifying phase gaseous product (is mainly H ₂And CO ₂Mixed gas) through the pressure swing adsorption decarbonization device, the gas after will purifying again feeds in the methane phase reactor.

4) hydrogen methanation: the gas after the purification feeds in the high efficiency reactor drum, the reduction reaction takes place under the effect of methanobacteria generate methane, improves system's methane production.

5) Digestive system recycle: the discharging of methane reactor is back to promotes in the acidification reactor that acidifying is pretreated and carry out.

2. method according to claim 1 is characterized in that 2) with the gaseous product in the acidifying mutually behind pressure swing adsorption decarbonization, H in the gaseous product ₂Content increases to more than 80% by about 20%.

3. method according to claim 1 is characterized in that 3) reduction reaction takes place in hydrogen in the acidifying mutually in methane reactor, can improve CH ₄About 20% of output has also consumed portion C O simultaneously ₂, make the CH in the product gas ₄Content is improved.

4. method according to claim 1; It is characterized in that; Imitate the high efficiency reactor that methane-producing reactor can adopt all water treatments in the step 4), like CSTR (complete), UASB (upflow anaerobic sludge blanket reactor), ASBR (anaerobic sequencing batch reactor drum), AF (anaerobism fixed-film reactor), PFR (anaerobism is moved back flow reactor), IC (internal-circulation anaerobic reactor) or EGSB (CGSB).