The policy recommendations on cassava ethanol in China: Analyzed from the perspective of life cycle “2E&W”

The Chinese government has been implementing the policy of encouraging to use ethanol-blended gasoline as fuels. However, the actual application is still facing lots of challenges. In this study, a well-operated cassava ethanol system in China was chosen as the case study to investigate energy consumption, GHGs emission, and water footprints (“2E&W”) from the life cycle perspective. The status quo and the evolution of China's policies on bioethanol were also reviewed. Positive net energy value of 13.64 MJ/L ethanol and net GHGs emission of 1473 gCO2-eq/L ethanol were found for cassava ethanol, which indicates that it could be an excellent substitute for gasoline. Compared with gasoline, using E10 and E85 could have the potential reduce fossil energy usage and GHG emissions. During its life cycle, ethanol conversion is the most energy-intensive and GHGs-intensive stage. The water footprint of cassava ethanol is 2998 m3/tonne. Unlike energy consumption and GHGs, the cassava planting stage is the most water-footprint-intensive stage due to the grey water caused by the fertilizer. The life cycle results of cassava ethanol are sensitive to many factors, such as cassava yield, energy input. Finally, some policy recommendations are provided.