Study Of Life Cycle Sustainability Assessment Of Fuel Bioethanol

Due to the rapid growth of gasoline consumption,China is facing huge challenges in energy security and environmental issues.The use of renewable energy is an inevitable requirement for the sustainable development of China’s economy and society.Ethanol is a clean,renewable energy source that can be blended in gasoline to form ethanol gasoline,reducing emissions of nitrogen oxides,particulate matter,carbon monoxide and hydrocarbons.Ethanol gasoline could ease energy shortages and reduce greenhouse gas emissions.In 2017,China issued a document calling for nationwide promotion of the use of ethanol gasoline by 2020,and initially established a market-oriented mechanism.However,the practical application of fuel ethanol still faces many problems,such as whether it produces net energy,whether it is really environmentally friendly.The production and use of fuel bioethanol is likely to have many socio-economic and environmental impacts,with the greatest concern on the impact on food prices and food security.Other impacts include greenhouse gas emissions,air pollution,water consumption/pollution,deforestation,and biodiversity loss.Therefore,the study on the sustainability of biomass fuel ethanol has become a very important subject.At present,domestic studies on fuel bioethanol mainly focuson its technical feasibility,environmental impact and energy efficiency analysis,but lack of systematic studies on the comprehensive sustainability analysis of fuel ethanol.Conducting the life cycle sustainability assessment of fuel ethanol,from the raw material plant to ethanol conversion and ultimately burn,not only helps the fuel ethanol production reducing environmental pollution from the whole life cycle,but also helps to improve the quality of product function and provide the reference of developing fuel ethanol industry in China.Therefore,it is necessary to evaluate the sustainability of the fuel ethanol produced in China.According to the characteristics of fuel ethanol,energy efficiency and resource utilization are added into the life cycle sustainability assessment framework as two dimensions,so five sustainability dimensions of environmental impact,energy efficiency,economic benefit,resource consumption and social impact are selected to establish an assessment model.In China,the main raw materials for the production of biofuel ethanol are corn and cassava.At present,the fuel ethanol project using an advanced solid fermentation technology of sweet sorghum stalks has been put into production in Inner Mongolia,Shandong and other places.This technology is expected to solve the constraints of farmland and food security on the development of fuel ethanol.So in this research fuel ethanol used corn,cassava and sorghum stalks as feedstock was selected to conduct fuel ethanol life cycle sustainability assessment.After defined the system boundary of fuel ethanol,the parameter value of environmental impact,net surplus energy,land utilization,water footprint,life cycle costing and direct full-time work was calculated.Their impact on the environment,energy,resource consumption,economic benefits and social influence are studied.Based on the analytic hierarchy process(AHP),according to the assumptions of stakeholders with different values(egalitarianism,hierarchy and individualism),the weight of the sustainability dimension is integrated,and finally the comprehensive sustainability of fuel ethanol based on different values is obtained.Results show that the sweet sorghum stalks fuel ethanol has the highest sustainable index value,in the aspect of economy,energy efficiency is the best,the sustainable development index were calculated based on different values after also has a good performance,its disadvantage is that the water consumption is greater than the other two kinds of fuel ethanol.As a result,the government can develop the sweet sorghum stalks based fuel ethanol in where water is abundant.The sustainability of corn fuel ethanol under the mainstream values in China is also good.The results of this research can provide reference for China to select fuel ethanol raw materials rationally and adjust industrial layout.