Life cycle economic and environmental impact assessment of alternative transport fuels and power-train technologies

In this study, we assessed the economic and environmental life cycle impacts of alternative transport fuels via a life cycle approach. The selected fuels include diesel, petrol, LPG, biodiesel, ethanol, hydrogen and electricity. The life cycle analysis is confined to the fuel cycle analysis and it has been divided into 2 major components – (1) Well-to-Tank (WTT) and Tank-to-Wheel (TTW). The system boundary consists of the following three phases: (i) material extraction, (ii) processing and production phase, and (iii) the use phase. The functional unit is defined as “One MJ of fuel input” and “One kilometre distance driven”. The modelling is performed using SimaPro 8.05 life cycle assessment software using Recipe mid-point hierarchist methodology for calculating characterisation results and Recipe end-point hierarchist methodology for calculating single score results. The fuel life cycle emissions reported in this study are: air emissions (including greenhouse gas emissions and criteria air contaminants); emissions to water and emissions to soil in μg/MJ. The techno-economic analysis include capital and operating costs. Finally, we combined the environmental life cycle assessment results with economic impact assessment results after normalizing the results with respect to diesel as a reference fuel. Overall, the combined results of environmental and economic impact assessment suggest that the impacts are the highest for CNG followed by LPG, biodiesel and minimum for hydrogen fuel cell vehicles.