| Energy supply security is a key link in the national strategic security.With the depletion of fossil energy and the rapid development of economy and society,the threat of energy security is becoming more and more serious.The development and utilization of new energy represented by biomass energy has been paid more and more attention by governments and researchers.At the same time,kitchen waste as the main component of urban waste,the annual growth rate showed a rapid upward trend.kitchen waste,high energy density,high biomass content(16%~22%),but the kitchen waste with high salinity and high water content(70%~90%),high fat,perishable,low heat of combustion(less than 5000 k J/kg)and easy to breed pathogenic properties,determine the only suitable for anaerobic fermentation compared with consumption the kitchen waste in the greatest degree of clean energy biogas production at the same time.Because the kitchen waste C/N is relatively low,the vetiver added C source.Vetiver is a kind of perennial energy plants,mainly used for fixing soil,prevent soil erosion and improve soil ecology,has a certain value.In order to obtain the optimal fermentation process of biogas production by anaerobic co fermentation of kitchen waste and vetiver,first through the orthogonal experiment combined anaerobic methane fermentation of kitchen waste and vetiver preliminary to find the optimal fermentation process was as follows:the activity of sediment content is 15%,the percentage of the total solid kitchen waste is 40%,total solid content of 12% and canning rate 90%.After roughly determine the scope of the fermentation process of the orthogonal test,and then control the diameter of the single factor experiment of vetiver.The experimental results show that the S2 group set size 5~15 mm for anaerobic fermentation to produce biogas,kitchen waste and the best size.Size control experimental basis in the orthogonal test and particles of vetiver,vetiveria zizanioides pretreatment experiment.The experimental results show that the method of vetiver pretreatment P3 experimental group used the method for the gas explosion,both Guangliangyouxiang grass roots pretreatment method.In the orthogonal test,the particle size control experiment and vetiver zizanioides Pretreatment Based on comparative tests,the response surface experiment.Plackett-Burman design was used to evaluate the effects of five factors on CH4 production.The results showed that the kitchen waste percentage of total solid,particle size of vetiver,and total solids content have significant effects on CH4 yield.A steepest ascent procedure and response surface methodology based on a Box-Behnken experimental design were employed to optimize the three main influencing factors.The optimal fermentation conditions were a bacterium content of 10%,kitchen waste percentage of total solid of 40.13%,particle size of vetiver of 8.71 mm,total solids content of 12.45% and fermentation tank rate of 85%.Three parallel experiments were carried out under the optimal conditions,which reached a CH4 yield of 19,016 m L and increased CH4 yield by 46.03% compared to non-optimized conditions.Error was only 1.27% between the theoretical value of the model and actual value.Finally,the optimum process of the anaerobic fermentation to produce biogas kitchen waste and vetiver proved that the 100 L.Verify the optimum anaerobic fermentation to produce biogas kitchen waste and vetiver as active sediment inoculum 10%,total solid kitchen waste percentage of 40.13%,Vetiver size of 8.71 mm,total solid content was 12.45%,total solids canning rate of 85%,gas explosion pretreatment and vetiver daily mechanical stirring for 8 h. |
PDF Full Text Request