13-15: Evaluation of alkaline hydrogen peroxide pretreatment of sugarcane bagasse at high solids concentrations

Monday, April 29, 2013
Exhibit Hall
Luiza H. S. Martins, Dpq, Unicamp, Campinas, Brazil and Aline C. Costa, Laboratory of Fermentative and Enzymatic Process Engineering (LEPFE), Department of Process and Product Design (DDPP), School of Chemical Engineering, State University of Campinas, Campinas, Brazil
Several studies were conducted using alkaline hydrogen peroxide – a reagent of high cost. However, despite this drawback, hydrogen peroxide can be considered efficient for the pretreatment, since it leaves no residue, doesn’t cause significant loss of cellulose and leads to high yields of sugars after hydrolysis. Thus, based on previous studies that concluded that the peroxide concentration required for efficient pretreatment of biomass was approximately 7% (v/v) the present study aimed to maintain this concentration and increase the solids loading (bagasse) to minimize reagent consumption and hence reduce the cost in production. The replacement of the base used to increase the pH of the hydrogen peroxide solution was also evaluated by testing the substitution of NaOH or KOH and Mg(OH)2. Sodium hypochlorite, although it is not a base, was also evaluated in substitution of NaOH. Moreover, we also quantified the concentration of each studied base and hypochlorite to assess the viability of the process. The conditions studied in this work were: 7% (v/v) of alkaline hydrogen peroxide for 1 h, solids concentration of 20 to 30% and a temperature of 50 to 90 °C for the pretreatment carried out with experimental design 3² with 3 repetitions at the center point. The pretreated material was subjected to enzymatic hydrolysis at 10% solids, with a load of 15 FPU/g of cellulase and 25CBU /g of ß-glucosidase. Analyses of the chemical composition of the raw material and pre-treated were carried out to evaluate the changes after each pretreatment step.