A Comparative Study Concerned with the Effect of Different Pretreatments on Ethanol Production from Lemon Peel (Citrus latifolia)

ABSTRACT: In this study the effects of autoclave, microwave and ultrasonic pretreatments with or without acid addition were investigated on the amount of glucose, soluble and insoluble lignin, furfural, yeast viability and bioethanol. The findings showed that autoclave-acid impregnated sample, has the highest glucose release from lignocellulose materials (14.61 and 14.95 g/l for solvent exposed and untreated sample, respectively) whereas for the control sample glucose content was at its minimal level. Pretreatments caused decrease in soluble and insoluble lignin and the highest decrease was caused by autoclave followed by microwave and ultrasonic pretreatments (p30.05). Moderate increase on furfural was observed for pretreated samples than the control. The most yeast viability and bioethanol content belonged to the autoclave samples especially the acidimpregnated ones (40.33%). Comparison between solvent treated and untreated samples indicated that significant differences were observed between the two tested groups (p30.01) in terms of lignin, cell viability and ethanol content but glucose and furfural didn’t show a significant difference.