Pretreatment of sugarcane bagasse to acid or enzymatic hydrolysis applying the advanced oxidation process by ionizing radiation to ethanol biofuel production

• Grant number: 08/56066-1
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants
• Start date: February 01, 2009
• End date: January 31, 2011
• Field of knowledge: Engineering - Nuclear Engineering - Applications of Radioisotopes
• Principal Investigator: Celina Lopes Duarte
• Grantee: Celina Lopes Duarte
• Host Institution: Instituto de Pesquisas Energéticas e Nucleares (IPEN). Secretaria de Desenvolvimento Econômico (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

The main objective of the project is to study the cleavage of lignocellulosic material from sugarcane bagasse using ionizing radiation from an industrial electron beam accelerator, in order to make easier the cellulose hydrolysis and the fermentation of their sugars to ethanol biofuel production. Sugarcane bagasse generally contain up to 45% glucose polymer cellulose, much of which is in a crystalline structure, 40% hemicelluloses, an amorphous polymer usually composed of xylose, arabinose, galactose, glucose, and mannose and 20% lignin, which cannot be easily separated into readily usable components due to their recalcitrant nature. The main difficulty to produce ethanol biofuel from this biomass is to break cellulose down into starches and sugars suitable for fermentation. The reactive species generated by the interaction of ionizing radiation with water (oxidant OH radical and redutants e-aq, and H radical) reveal as a very efficient way for the organic compounds oxidation in simple molecules and to enhance the processes of lignocellulosic enzymatic or chemical attack as well as the direct fermentation. The radiation effects on cellulose properties have been studied extensively, and the results have shown a decreasing of the polymerization degree and an increasing of the carbonyl content. Although this subject has been studied before, the sugarcane bagasse usually used were dehydrated or very old, and, in most cases, the cellulose was separated from bagasse before the radiation processing. In the present study it was used bagasse samples collect directly from the sugarcane mill. These samples have about 50% of humidity and the ionizing radiation does not change this parameter, which is a positive point for combination with enzymatic or chemical hydrolysis. The main challenge is to obtain the desirable effects applying doses as low as necessary to get some break in the polysaccharides, and at the same time to avoid the glucose loosing due to uncontrolled degradation of cellulose and hemicelluloses. (AU)