Research On Optimization Of Co-fermentation Process Of Agricultural Waste And Food Waste

With the rapid development of rural economy,rural garbage has become an unavoidable problem in the construction of new countryside.Using kitchen waste and agricultural waste to develop biomass energy by anaerobic fermentation is an effective way to solve the problems of energy shortage and environmental pollution in rural areas of China.Based on the national key research and development project of the 13th Five-Year Plan:rural water supply and drainage integration technology and support of application demonstration in typical water shortage areas in western China,on the basis of studying the characteristics of single factor anaerobic fermentation gas production of agricultural waste and kitchen waste,a multi-factor experiment with 3 factors and 5levels was designed by using the center combination,and the pretreatment temperature of agricultural waste was investigated emphatically.The effects of three factors of initial organic loading?OLR?and raw material mass ratio?kitchen waste:agricultural waste?on the gas production performance of mixed anaerobic fermentation of agricultural waste and kitchen waste at medium temperature of 35?.The response surface method is used to optimize the process parameters in order to realize the harmless utilization and reduction of garbage disposal and to explore a new and efficient technical way for the energy utilization of agricultural waste and the rural environmental treatment at the same time.The results of single-factor and multi-factor experiments showed that proper pretreatment of agricultural waste could significantly improve the gas production efficiency and organic load of co-fermentation.The optimum conditions for co-fermentation of agricultural waste and kitchen residue were obtained by response surface optimization analysis.The pretreatment temperature was170?.The initial organic load is 0.02gVS m L-1,the mass ratio of kitchen waste to waste is 2:1,and the maximum predicted value of methane production rate is 521.05m L·g^-1VS.The relative deviation from the experimental average of 511.35 m L·g^-1VS is only 1.86%.At the same time,the influence of different factors on methane production rate was analyzed in the order of initial organic load>cooking straw mass ratio>pretreatment temperature.The organic matter before and after pretreatment was qualitatively analyzed by infrared spectroscopy and scanning electron microscope,and the changes of cellulose content before and after pretreatment were detected.It was found that the pretreatment of agricultural waste by hot water hydrolysis,cellulose,hemicellulose,Lignin and its functional groups were destroyed to a certain extent,and the biodegradability was improved,which was the main reason for the higher efficiency of gas production.