Life Cycle Assessment Of Fuel Ethanol Based On Simapro

The excessive utilization of traditional fossil energy has caused energy shortages and environmental pollution problems.The development and use of clean energy and the acceleration of the transformation of the energy consumption structure to cleanness have become the focus of energy strategies of all countries.As a clean and sustainable energy,fuel ethanol is showing rapid development under the guidance of national industrial policies.China's fuel ethanol production now ranks fourth in the world.Fuel ethanol shows many advantages in energy supply supplement,and it is a good alternative energy source for fossil fuels.However,it needs to go through production,transportation and use from production to combustion.This process involves multiple energy input and consumption.Assessing the environmental impact of fuel ethanol from a life-cycle perspective has become an important task for the sustainable development of the industry.Based on the current development level of China's fuel ethanol industry,this thesis used the life cycle assessment(LCA)theory as a guide and selects corn-based ethanol,cassava-based ethanol and corncob-based ethanol as the research objects.SimaPro software was used to evaluate the life-cycle environmental impact of three types of fuel ethanol.The main contents and conclusions of this thesis are as follows.(1)The process flow and related parameters of fuel ethanol production were collected to construct the life-cycle inventory of fuel ethanol in accordance with the actual production level in China.The life cycle of fuel ethanol was divided into five stages: raw material production stage,raw material transportation stage,fuel ethanol production stage,fuel ethanol transportation stage and fuel ethanol combustion stage.A systematic LCA model was established.(2)By characterizing,standardizing and weighting the life cycle inventory of 10 types of environmental impact in CML method,the life-cycle environmental impact and the potential contribution of environmental impact at each stage of three types offuel ethanol were obtained.The results showed that the corncob-based ethanol has the largest comprehensive environmental impact index,followed by corn-based ethanol,and cassava-based ethanol.The three types of fuel ethanol have the greatest impact on terrestrial ecotoxicity potential(TETP)and freshwater ecotoxicity potential(FAETP).Among the stages of life cycle,the biggest contribution to the environment is the fuel ethanol combustion stage.(3)Cumulative Energy Demand(CED)method was used to calculate the life-cycle energy demand of fuel ethanol,and IPCC 2013GWP20 a and IPCC2013GWP100 a methods were used to calculate the Greenhouse Gas(GHG)emissions with the time range of 20 years and 100 years respectively.Compared with conventional gasoline,the energy demand saving of corn-based ethanol,cassava-based ethanol and corncob-based ethanol was lower than that of conventional gasoline by13.00%,24.12% and 4.96% respectively.The greenhouse gas emissions reduction rates of the three fuels ethanol were 10.79%,26.29% and 3.15% respectively,under the condition that crop photosynthesis was not included in the agricultural production stage.(4)Single factors such as biomass distribution ratio,the use of nitrogen fertilizer and steam were selected to analyze the sensitivity of life cycle of the three types of fuel ethanol.The results showed that the change of nitrogen fertilizer consumption has the greatest impact on the life cycle environment of fuel ethanol.Among the 10 types of environmental impact categories in CML,the TETP is most sensitive to changes in the amount of nitrogen fertilizer,with a sensitivity range of 0.738-0.793.According to life cycle analysis of environmental impact,CED and GHG emissions,combined with China's current fuel ethanol industry planning and overall development level,providing optimization suggestions for continuing to promote China's fuel ethanol industry to the development of environmentally friendly industries,for example,scientific advance green agricultural production,optimizing the structure of fuel supply and production process,formulating the relevant policy or fuel ethanol solution,etc.