Exergetic, exergoeconomic and exergoenvironmental analyses of a hybrid combined locomotive powering system for rail transportation

Abstract Alternative and clean powering options are recognized as a crucial step in making rail transportation environmentally-benign, efficient and sustainable. This paper presents the exergetic, exergoeconomic and exergoenvironmental analyses of a new hybrid locomotive powering system, consisting of an internal combustion engine, molten carbonate fuel cell, gas turbine, and absorption refrigeration system. Five alternative fuels are selected and considered with different concentrations, such as natural gas, methanol, ethanol, dimethyl ether, and hydrogen. The entire system achieves a high exergetic efficiency of 83% with a total exergy destruction of 17 MW. The system components have a total levelized capital cost of 32.15 $/h and component-related environmental impact of 86 mPt/h. The entire system has a specific exergy cost and specific environmental impact of 0.10$/GJ and 69.4 mPt/MJ, respectively. It has the total exergoeconomic and environmental impact factors of 3.7% and 0.015%, and the relative cost and environmental impact differences of 21.9% and 19.4%, respectively. The fuel blend of 75% pure natural gas and 25% hydrogen is found to be the most cost effective option with the least environmental impact, compared to other alternative fuel blends.