Title:
Integration of Biogas in Brazilian Bioethanol Plants to Increase the Production of 2G Ethanol
Author(s):
Joppert, C.L., Santos, M.M., Coelho, S.T.
Document(s):
Paper
Abstract:
The ethanol and sugar sector in Brazil stand out in the productions of biofuel (1G ethanol) and bioelectricity. Residues of ethanol production can be used to produce more biofuels, such as biogas from biodigestion of vinasse and filter cake and lignocellulosic ethanol (2G ethanol) from sugarcane bagasse hydrolysis. However, using bagasse for producing 2G ethanol would impact the energy matrix of the ethanol plant, since this biomass is currently used for steam and power generation (CHP). A possible solution for minimizing these imbalances is using biogas produced from residues of ethanol to replace the energy input of bagasse to the mill, therefore increasing its availability for 2G ethanol production. This work aims to perform a technical and economic analysis of using biogas produced from vinasse and filter cake biodigestion as a substitute to sugarcane bagasse, shifting it towards the production of 2G ethanol without altering the ethanol and sugar mill energy balance. Different configurations of thermodynamic cycles for power generation were studied in scenarios with only vinasse digestion and with vinasse and filter cake co-digestion. Each of these scenarios were submitted to an economic analysis, aiming to obtain the minimum ethanol selling price (MESP) considering the absence and the contributions of biofuel credits from RenovaBio. The results show that the technology that can displace more bagasse is the combined Rankine-Brayton Cycle. However, the economic results show that the Rankine cycle-based scenarios present greater feasibility than other technologies. Furthermore, the use of co-digestion of vinasse and filter cake improved the results both technically and economically. Nevertheless, none of the scenarios reached the selling price of 1G ethanol, showing that 2G ethanol production still has to be improved in economic and technical terms, even when revenues from RenovaBio are considered.
Keywords:
biogas, ethanol, sugar cane bagasse, second generation, integration
Topic:
Biomass Conversion Technologies for Heating, Cooling and Electricity
Subtopic:
Anaerobic digestion for biogas and biomethane production
Event:
27th European Biomass Conference and Exhibition
Session:
2DO.4.3
Pages:
595 - 604
ISBN:
978-88-89407-19-6
Paper DOI:
10.5071/27thEUBCE2019-2DO.4.3
Price:
FREE
