The Research Of Key Technology On Biological Strengthen Fermentation In Cold Regions

Methane fermentation is process by a variety of microbial joint, the complex biochemicalprocess alternative action, fermentation temperature, water, raw materials, pH and airtight is theguarantee the biochemical process for the necessary condition. The temperature is an importantfactor of influence to biogas-fermentation, especially in our country the north, the winters are longcold, long-term temperature conditions lead to methane fermentation bacterium groupphysiological activity reduced, the trace biogas generated can’t application and even keepfermentation system itself operation, leading to disable methane. Therefore, improve thephysiological activity of fermentation bacterial flora in low temperature, what the most effectiveway to solution the problems with development of obstacle factors in cold regions. Among them,the methanogens group of the most sensitive to temperature, and also the anaerobic digestion ofchain speed limit bacterial flora. It’s the reaction system activity decided the final efficiency. So toexplore the new development model of biogas in alpine region, improving the Methane gasproduction rate and utilization of raw materials, is the top priority in our province.At lower temperature (20℃), fifty-six microbe flora, which collected from different habitatsin Heilongjiang province, were enriched and screened. Three psychroactive consortiums wereobtained. Then, the different digesters fed with manure were intensified by psychroactiveconsortiums at low temperature (20℃). In this project, biogas accelerantsand the optimization offermentation process were also investigated. The results are as follows:(1) With the enrichment generation, the flora amounts, biogas production and the content ofbiogas were increasing quickly. by contrast, Produce this kind of the reasons for the differencesmay be in two aspects: the first, the methane bacteria relatively small number in original mudsample; the second, choose the appropriate substrate and strictly anaerobic environment ensure theactivity of methanogens group in each generation process of enrichment. Reach to fifth generation,the gas production in enrichment process reached significant level. In addition, the change rule ofpH value is consistent, and stability in6.5to7.5, the system normal.(2)The experiment indicated that iron (Fe), nickel (Ni), cobalt (Co) and activated carbon werethe main factors that influenced biogas production. The optimal formula was1.8%Fe,0.05%Co,0.09%Ni,0.01%Mn,0.01%Zn,1.8%activated carbon and0.9%cellulose. Additionally, theeffect of biogas accelerant was changing with different consortiums. So the best combination is theflora of Gannanxingwu combination with biogas accelerant and the flora of Baiquan combinationwith biogas accelerant.(3)The substrate in which the proportion of cattle dung and straw was3:1can effectivelyimprove the biogas efficiency. With the increasing of the straw proportion, the biogas productionwas reducing. The optimal proportion of cow dung and straw was3:1.(4)Use the fermentation tank of1m3for biogas fermentation, through the water cycle to control the temperature into20±2℃. The temperature difference between internal and externalrelative add great, the water cycle through the longer time and frequency to achieve the purpose ofaccurate temperature control, the relationship with outdoor temperature change and thetemperature of fermentation tank, suggested that through the data analysis to establish a datamodel and temperature control equipment for the realization of automatic temperature control.Two feeding, can maximum guarantee flora inherent behavior was not damaged and Increase thealready propagation as well as the adaptability of the flora. So flora effect right away and the gasproduction is higher, the total gas production is9.258m~3in30d, the average gas production rate fordigester capacity is0.44090.2m~3/d·m~3.So this test the selection of methanogens group of activity is higher in low temperature,Cooperate with culture of low temperature biogas accelerant and biological strengthenfermentation of fermentation technology, Indeed can improving the efficiency of biogasfermentation in alpine region.