Evaluation of pretreatments and enzymatic hydrolysis of sugarcane bagasse for ethanol production

• Grant number: 07/05309-9
• Support type: Regular Research Grants
• Duration: June 01, 2008 - July 31, 2010
• Field of knowledge: Engineering - Chemical Engineering
• Principal Investigator: Aline Carvalho da Costa
• Grantee: Aline Carvalho da Costa
• Home Institution: Faculdade de Engenharia Química (FEQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Nowadays the raw material used for ethanol production is sugar cane sacarose. In Brazil, the availability of bagasse with low costs makes the development of technologies to hydrolyse this material and use it for the production of ethanol attractive, due to the possibility of integration with sugar plants and distilleries, using the existing infrastructure. If bagasse is used, a significant increase in ethanol production can be obtained without increasing the planted area, besides being possible to diminish the production costs. During decades the efficient hydrolysis of lignocellulosic material and the posterior fermentation of the resulting sugars have been a great challenge. The most known routes are the acid and enzymatic hydrolysis. Although the acid hydrolysis is efficient and relatively cheap, it generates pollutant residues and products that inhibit the posterior fermentation. Besides, they tend to degrade glucose and generate toxic side products. Therefore, the enzymatic saccharification has been object of most of the studies, although this process is still economically impracticable, what strengthens the necessity of researches on the subject. The objective of this project is to study the production of ethanol by enzymatic hydrolysis of sugar cane bagasse. Experiments will be carried out to compare two pretreatments that occur in mild conditions of temperature and pressure and in the absence of acids (alkaline hydrogen peroxide and calcium hydroxide). The optimum values of the variables temperature, pretreatment time and reactant concentration will be determined for both pretreatments and the influence of these variables on glucose yield will be evaluated for the studied range. Experiments will also be performed to determine the minimum enzymatic load that provides high hydrolysis yield. The viability of using bagasse without sieving, as available in the plants, will also be assessed. The hydrolysate obtained with the two pretreatments will be fermented and ethanol yields will be compared. Also, a kinetic model for enzymatic hydrolysis will be determined. (AU)