Dilute Acid Hydrolysis of Ailanthus excelsa (Mahaneem) its Detoxification and Fermentation for Lignocellulosic Ethanol Production

Ethanol is now a days an important product in the fuel market. Its market grew from less than a billion liters in 1975 to more than 39 billion liters in 2006 and is expected to reach 100 billion liters in 2015. However, the amounts of sugar substances and grains are limited in the world. They are relatively expensive feed stocks for ethanol production, and ethanol competes with human food for these raw materials. This competition may push the price of grains and sugar to higher levels in the future. Therefore, production of ethanol from other lingocellulosic wastes (e.g. wood residue, sugarcane bagasse, corn fiber, rice straw, cassava waste etc.) has received widespread interest due to their availability, abundance and relatively low cost. Therefore twenty one different hydrolysis-conditions of wood of Ailanthus excelsa were tested. Single step acid hydrolysis applying microwave or autoclave as heating methods gave parallel results. The single stage autoclave mediated dilute acid hydrolysis was chosen as “optimal” because of higher yields of pentoses (280 mg/g) and total sugars (285 mg/g). Heating of wood hydrolysate for 15 minutes in its acidic conditions increases the rate of hydrolysis of oligomers into their monomers and pentoses and total sugars increases from (110 mg/g) and (116 mg/g) to (292 mg/g) and (300 mg/g) respectively. Overliming up to pH 11 along with adding Alum, Whey water, Milk however, significantly improved ethanol production from hemicellulose in parallel combination with Lime as lignin content (0.192–0.114) decreases and other inhibitors were removed and fermentability also increased. Fermentation of (HAP) in 50% and 70% treated with adding lime, Alum, Whey water, Milk gives better ethanol production. Treatment of hydrolysate with milk and whey water gives maximum ethanol production.