Operational parameters optimization of sugarcane straw pretreatment

Abstract

The commitment to meeting the needs of the present without compromising the ability to meet the needs of future generations makes the diversification of the Brazilian and the global energy matrix a compulsory factor. Thus, the use of lignocellulosic biomass to obtain cleaner fuels from an environmental point of view is widely discussed today. Fuel ethanol has been obtained from alternative energy sources, as lignocellulosic biomass. This type of biomass has high content of fermentable sugars. However, these sugars were not directly available, which need to include additional steps in the process to achieve this goal. This study aims to carry out an operational parameters optimization in the sugarcane straw pretreatment through a 2² experimental design with three replications at the central point. The study variables were: straw-water ratio (m/v) in the hydrothermal pretreatment and the temperature reaction in the alkaline pretreatment, sequential to hydrothermal. The study reveals that the delignification did not promote significant improvements in glucose conversion during the enzymatic hydrolysis. Thus, this addition step was not justified, under the evaluated conditions. Furthermore, the hydrothermal pretreatment showed good results reaching conversions higher than 85% in the hydrolysis step, in particular for the straw-water ratios 1:6.7 and 1:20 (m/v).