Bioprocess Systems Engineering (BSE) applied to the production of bioethanol from sugarcane bagasse

Resumo

The industrial production of biofuels, understood as fuels produced from biological feedstock, is presently at what can be called a technological crossroad, and a hard competition among different technologies is in course. The winners will be defined by a combination of economical criteria, process robustness and compliance to environmental and sustainability restrictions. In this scenario the optimization of this complex, interconnected process ideally must be pursued ever since its early stages of development, aiming at costs reduction, negative overall CO2 balance, cutback of water usage and of effluent emissions and so forth. Fine-tuned processes, operating at (near-) optimum conditions will have a significant competitive advantage. This project focuses on the rational application of (Bio-)Process Systems Engineering (BSE) techniques to the process for production of bioethanol from an important lignocellulosic material in the Brazilian scenario, sugarcane bagasse. In other words, the same approach that allowed oil refineries to achieve a high productivity is herein applied to biorefineries. The validation of BSE tools for assessing different routes for bioethanol, however, must be based on real data. With this purpose, this project joins efforts of a group of researchers from the Chemical Engineering Department of UFSCar and from Brazilian Agricultural Research Corporation (EMBRAPA Agriculture Instrumentation). A biochemical route for production of ethanol from sugarcane bagasse is our selected case study, encompassing different technologies, some of them still exploratory: in situ production of cellulases in triphasic reactors; feedstock pre-treatment; enzymatic production of pentoses (and their transformation) and of hexoses via a non-conventional process using immobilized enzymes, combined with simultaneous (SSF) or consecutive fermentation (CSF), using S. cerevisiae in conventional and non-conventional bioreactors. A global view is necessary to integrate these processes from the early stage of development. Therefore, this project aims simultaneously at providing the necessary software and at researching new feasible routes for bioethanol which, in addition to their intrinsic value, will be employed for validation of the methodology. (AU)