Alternative fuel vehicle-routing problem: A life cycle analysis of transportation fuels

Abstract

Given the current and ever-growing trend of environmental concerns, transport enterprises, as other large energy consumer sectors, face constant internal and external pressures to meet rigorous regulatory requirements. This study aims to evaluate the economic and environmental performance of alternative fuels in Vehicle Routing Problem (VRP), through measurement and quantification of potential adverse effects of the emitted pollutants on human health and ecosystem quality. Accounting for fuel emissions, especially pollutants of concern (i.e., NOx, HC and CO) and GHG emissions (i.e., CO2, N2O) during production, distribution, and combustion phases, several mixed-integer programming models have been developed based on Well-to-Wheel and Tank-to-Wheel analysis. Aside from factors such as distance, load and speed, the proposed models incorporate the transmission gear ratio as a major factor affecting vehicle mileage and emissions. Several numerical tests were conducted to examine the effects on fuel type and gear selection on fuel consumption and pollutant intensity. The results show that though pure biodiesel combustion emissions have the same negative impact on environmental quality, further analysis, taking into account the whole fuel chain activities leading to produce and consuming the product, demonstrate 37% reduction in GHG emissions compared to conventional diesel based on equivalent carbon dioxide measure.