The role of nonfood bioethanol production in neutralizing China's transport carbon emissions: An integrated life cycle environmental-economic assessment

Abstract

Lignocellulosic bioethanol may contribute significantly to neutralizing global greenhouse gases emissions as an alternative fuel, but controversies have increasingly arisen in relevant researches as to whether the ethanol production pathway is environmental- and cost-competitive or not and which hotspots may impede its commercial-scale deployment. Here we explore a cost-effective biorefinery pathway of sugarcane bagasse, molasses and Dioscorea composite hemls, from an integrated environmental and economic assessment model to evaluate the performance of bioethanol, as an alternative to gasoline, characterized by gCO2eq and MSP, in terms of its emission mitigation potential and cost, as well as its other environmental impacts with the CML method of assessment. Specifically, this study examines the production of 1 ton bioethanol with the considered environmental and economic indicators by three defensible allocation approaches affecting the total mitigation potential with anywhere between 20% and 82.5%, where the electricity consumed in the process of the bioethanol conversion is produced with more sustainable means, increasing the emission savings by up to 48.5%. The economic competitivity have also been examined to promote dialogues across environmental and economic fields, exemplified by the emission mitigation cost with the calculation of minimum selling price at 49.1/ton CO2eq, comparable with the EU-ETS carbon permit price. Signs of advantages abound in the current emission trading scheme, where the decrease in carbon tax levels can cut down the price of bioethanol production, especially with regard to the supply chain collaboration with electricity, and thus enhance the overall revenue of neutralizing transport emissions.