Research On Two-phase Anaerobic Thermophilic Digestion Of Kitchen Waste With High Solid Content

Kitchen waste is a kind of organic waste in the resident's life expends,accounting for about half of the urban domestic garbage.As the continuous development of society and economy,the problem that kitchen waste caused is increasingly serious.Due to characteristics of high moisture content,rich organic matter content and high solid content,it can be converted into renewable energy like methane and hydrogen by anaerobic digestion process.Base on the former study,a kind of dry anaerobic digestion reactor for kitchen waste is designed.The main conclusions are as follows:(1)Through the thermophilic digestion of kitchen waste,we find the preliminary determination of inoculation of anaerobic fermentation of kitchen waste and relatively reasonable acidification cycle.The fermentation liquid can improve the performance of kitchen waste hydrolysis,fermentation liquid after inoculating 10%,material pH was decreased and the final stable between 3.72~3.80;(2)The test shows that,when feedstock to inoculum rate is 10%,the kitchen waste reaches a maximum VFA concentration,while the content of propionic acid is relatively low,and the greatest degree of fermentation is obtained.Finally,considering the production practice,though it can greatly reduce the organic loading of the kitchen waste,the efficiency in the mixed fermentation doesn't improve obviously.Therefore,we don't take the mixed fermentation of stalk and kitchen waste into consideration.(3)Adding test with small load,increasing load way to observe the effects of different processing load on kitchen waste treatment,test the acidizing fluid as inoculation material,fermentation liquid as the start of the feasibility of dry sludge,thermophilic anaerobic fermentation experiments showed that food waste;dry anaerobic thermophilic fermentation test run the optimum feed load 60 kg-TS-M-3-D-1,the volume of gas production is the highest of 1.18L-L-1-D-1,the methane content is 55.19%;in the methanogenic phase of anaerobic microorganisms on the new 3~4 D load need time to adapt,and ultimately achieve stable operation.