Greenhouse Gas Emissions of Ethanol Production from Lignocellulosic Biomass in Biorefinery System

Greenhouse gas (GHG) emissions reduction is one of the main drivers for bioenergy development to replace petroleum-based fuels and chemicals.  Biorefinery concept has recently attracted the attention from governments and private sectors since this implies the effective and sustainable use of biomass resources for ensuring food and energy security, mitigating climate change, and meeting the demand for renewable based chemicals and materials.  This objective of this work is to estimate the GHG emission of a biorefinery system to produce ethanol as a base case study.  The different generations (first, second, third generation) and types (hardwood and corn stover) of feedstocks were compared.  In addition, the amount of harvesting residue left on the field was examined considering fertilizer requirement.  Two conversion processes such as biochemical and gasification process were simulated and compared with gasification option to produce electricity.  The experimental lab results together with existing literature data were used for the GREET modeling work.