Using a hybrid fermentative/microbial electrolysis cell system to enhance hydrogen production from sugarcane vinasse

• Grant number: 14/25366-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2016
• End date: February 15, 2022
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Marcelo Zaiat
• Grantee: Melida Del Pilar Anzola Rojas
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 15/06246-7 - Biorefinery concept applied to biological wastewater treatment plants: environmental pollution control coupled with material and energy recovery, AP.TEM
• Associated scholarship(s): 16/14377-7 - Microbial electrolysis cell: assembly, operation and performance evaluation, BE.EP.PD

Abstract

Economic growth of Brazil is largely supported by bioethanol production, which is a biofuel obtained from a renewable material, and its combustion is less aggressive to the environment, as compared to fossil fuels. Nevertheless, each liter of bioethanol generates approximately between 10 and 15 L of vinasse, which contains high amount of organic matter, as well as antibacterial and recalcitrant compounds. Currently, vinasse is used as a fertilizer in sugarcane cultivation, causing negative impacts on microorganisms, plants and groundwater. Thus, facing to the need of improving the sustainability of the biorefinery, research about the treatment of its wastes has been increased. Anaerobic digestion has been considered as an attractive method to stabilize the organic matter from vinasse, since it recovers sustainable energy, such as H2 and other products of chemical interest. Notwithstanding, the energy recovery is low and the yield is thermodynamically limited to 4 mol H2 per mol of glucose, although the theoretical stoichiometric potential is 12 mol H2 mol-1. In this sense, a microbial electrolysis cell (MEC), an emerging type of bioelectrochemical system (BES), in where the redox metabolism is driven by a small input energy, has been used to overcome such that thermodynamic limit. Therefore, this postdoc research project proposes the application of a hybrid fermentative/MEC system. In a first step, in an acidogenic anaerobic reactor the carbohydrates will be consumed, which leads the formation of organic acids. As a second step, the effluent rich in organic acids will be used as substrate in a MEC. Thus, such sequential system allows improving the energy recovery, in the form of H2 and/or other valuable products, compared with a classical fermentative process.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ROJAS, MELIDA DEL PILAR ANZOLA; ZAIAT, MARCELO; GONZALEZ, ERNESTO RAFAEL; DE WEVER, HELEEN; PANT, DEEPAK. Enhancing the gas-liquid mass transfer during microbial electrosynthesis by the variation of CO2 flow rate. Process Biochemistry, v. 101, p. 50-58, FEB 2021. (14/25366-0, 16/14377-7)