Tuesday, May 3, 2011
Liberation of fermentable sugars from lignocellulosic biomass is one of the key challenges in production of cellulosic ethanol. Aqueous ammonia cleaves ether and ester bonds in lignin carbohydrate complexes. It is an effective swelling reagent for lignocellulosic biomass. The aqueous ammonia pretreatment selectively reduces the lignin content of biomass. However, at high temperatures, this process solubilizes more than 50% of the hemicellulose in the biomass. Pretreatment is an essential element in the bioconversion of lignocellulosic substrates. The pretreatment of lignoccellulosic is primarily employed to increase the accessible surface area of cellulose to enhance the conversion of cellulose to glucose. The advantage of acid pretreatment is the solubilization of hemicellulose and by this, making the cellulose more easily accessible for the enzymes. The cellulose, hemicellulose and lignin of the selective separation are a necessary step in order for high yield production of fermentable sugars. In this study, we conducted a Soaking in Aqueous Ammonia(SAA) process by moderate reaction temperatures at atmospheric pressure using lignocellulosic biomass. Pretreatment of lignocellulosic biomass using the percolation process was usually determined to be 150°C. Soaking process was carried out mild conditions at atmospheric pressure of 60°C. In this research, we had performed two pretreatment processes by various alkaline solutions and found the characteristics of Eucalyptus pretreatment by alkaline solutions.