Biogas production integrated to the concept of lignocellulosic biomass: operational aspects and use of nanoparticles

Abstract

In the challenging context of the Paris discussion (COP21-2015), biogas production returns to global highlight, and consequently, government and industrial initiatives. Production is performed through Anaerobic Digestion (AD), which allows the recovery of the energy source through the use of methane (CH4), in addition to the possible generation of by-products with value to the agro-industry. In a life-expectancy scenario, substrates derived from sugar-alcohol activity are are considered potential facilitators of the development of biorefineries, making the system more resilient and versatile. It is notorious how intense the interest has been in the use of lignocellulosic byproducts for the production of methane. However, there are gaps in the literature regarding AD of waste from the production of lignocellulosic (or second generation, 2G) ethanol, but it is known that its recalcitrance may be an obstacle to the biological process. In this scenario, the co-digestion with substrates more easily biodegradable appears as an interesting alternative, being able to soften the inhibitory effects of those residues to AD. Alongside this, there are crucial parameters and conditions to be investigated that could provide better understanding and optimization of anaerobic co-digestion, such as redox potential, the identification of the proteome and of the microbial consortium and the use of nanoparticles in the production of biogas. Such information is scarce in the literature, and even non existent with respect to the use of by-products of the production of 2G ethanol for the production of biogas. In this context, the present project aims to explore biogas production in an innovative biorefinery concept for the lignocellulosic ethanol integrated into the traditional production of ethanol from sugarcane from the co-digestion of its residues (e.g., vinasse, filter cake and pretreatment and hydrolysis residues), in which the potential for production of CH4 is assessed. The project includes the monitoring of redox potential and proteome analyzes and identification of the microbial consortium through Molecular Biology techniques along the co-digestion, as well as the investigation of the continuous production of methane with the use of nanoparticles, opening up alternative possibilities for process optimization in sugarcane biorefineries. The development of this project should become one of the first sources of knowledge for the Brazilian production of 2G ethanol coupled with environmental responsibility. This project is linked to thematic project FAPESP-BBSRC n° 15/50612-8. (AU)