Techno-economic assessment of ethanol production from rice straw based on the biochemical biorefinery

Abstract

The present project aims to perform a techno-economic evaluation of the second-generation ethanol production from rice straw, within the biorefinery concept. These studies will be performed taking into account the conditions already defined in the current PhD project, which consists in applying a mild alkaline pretreatment before the dilute acid pretreatment step, followed by enzymatic hydrolysis. The developed strategy of two-steps pretreatment is able to significantly remove acetyl groups and phenolics compounds from the lignocellulosic matrix, without promoting sugar loss. As a consequence, the hemicellulose hydrolysate produced during dilute acid pretreatment has lower toxicity, and the remaining cellulose-rich solid has higher enzymatic digestibility. Besides the techno-economic evaluation, the research internship will also comprise a study on the thermochemical properties of the residual lignin recovered after the simultaneous saccharification and fermentation process, which will generate a better understanding to a possible formulation of an integrated process. The mass and energy balances of the whole process will be determined from all the experimental data and the results will be used in a simulation procedure for a techno-economic analysis to draw recommendations on the technological, economic and environmental feasibility for implementation of this type of biorefinery using rice straw as feedstock.