Sustainability assessment of sugarcane biorefinery and molasses ethanol production in Thailand using eco-efficiency indicator

The study aims to evaluate the sugarcane biorefinery and molasses ethanol production in Thailand using the combined environmental and economic sustainability indicator, so called “Eco-efficiency”. Four sugarcane biorefinery scenarios in Thailand are evaluated. The total output values (US$) and the life cycle greenhouse gas (GHG) emissions (kg CO2eq) are selected as the indicators for characterizing economic and environmental performance, respectively. The results show that the biorefinery system of mechanized farming along with cane trash utilization for power generation yields the highest eco-efficiency. The benefits come from the increased value added of the biorefinery together with the decreased GHG emissions of the biorefinery system. As compared to the base case scenario, the new systems proposed result in the eco-efficiency improvement by around 20-70%. The biorefinery concept induces reduction of GHG emissions attributed to molasses ethanol. Green cane production and harvesting results in further lowering of the GHG emissions. Integration of sugarcane biomass utilization across the entire sugarcane complex would enhance the sustainability of the sugarcane production system.