Water resources disturbance risk assessment base on whole life cycle of biomass energy——a case study of biodiesel from rapeseed

Bermuda grass,rich in cellulose content,is an annual vegetation of gramineous grass family.After the processing of dilute acid,cellulose and xylanase,cellulose can be decomposed,which can be fermented by pachysolen tannophilus,then bioethanol is obtained.Taking ethanol yield as objective,the experiment studies the effects of single factors on ethanol yield,glucose content,yeast extract content,peptone content,inoculation quantity,temperature,time and pH value are all included.Then by the orthogonal experiment,the optimal experiment combination is chosen.Finally,replace glucose with saccharification liquid of bermuda grass for fermentation.The results showed that the optimum production conditions of using glucose as the raw material is as followed.In 100 mL culture medium,glucose 20 g,yeast extract 1.5 g,peptone 0.5 g,inoculation quantity 13 mL,temperature of 30 ℃,time 60 h,pH5.5,ammonium sulfate 1g,potassium dihydrogen phosphate 0.2 g,magnesium sulfate 0.1 g,the ethanol yield is 43.35%,that of bermuda grass saccharification liquid is 7.04%.