Evaluation of electricity generation from lignin residue and biogas in cellulosic ethanol production

Abstract

This study takes the first insight on the rigorous evaluation of electricity generation based on the experimentally measured higher heating value (HHV) of lignin residue, as well as the chemical oxygen demand (COD) and biological oxygen demand (BOD5) of wastewater. For producing one metric ton of ethanol fuel from five typical lignocellulose substrates, including corn stover, wheat straw, rice straw, sugarcane bagasse and poplar sawdust, 1.26–1.85tons of dry lignin residue is generated from biorefining process and 0.19–0.27tons of biogas is generated from anaerobic digestion of wastewater, equivalent to 4335–5981kWh and 1946–2795kWh of electricity by combustion of the generated lignin residue and biogas, respectively. The electricity generation not only sufficiently meets the electricity needs of process requirement, but also generates more than half of electricity surplus selling to the grid.