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

In this study the effects of autoclave, microwave and ultrasonic pretreatments with or withoutacid addition were investigated on the amount of glucose, soluble and insoluble lignin, furfural, yeast viabilityand bioethanol. The findings showed that autoclave-acid impregnated sample, has the highest glucose releasefrom 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 insoluble and insoluble lignin and the highest decrease was caused by autoclave followed by microwave andultrasonic pretreatments (p30.05). Moderate increase on furfural was observed for pretreated samples than thecontrol. The most yeast viability and bioethanol content belonged to the autoclave samples especially the acidimpregnatedones (40.33%). Comparison between solvent treated and untreated samples indicated thatsignificant differences were observed between the two tested groups (p30.01) in terms of lignin, cell viabilityand ethanol content but glucose and furfural didn’t show a significant difference.