Greening of the Automotive Diesel Engine by Hydrogen Use

Nowadays, the utilization of alternative fuels to improve engine performance and reduce pollution is more attractive than ever. Among the various alternative fuels used for internal combustion engines, H2 is a suitable energy source for engines because offers the possibility of a sharp reduction in pollutant emissions and an improvement in energy performance. In the European Union and Asian countries, vehicles equipped with internal combustion engines fueled with hydrogen and used for urban mobility can be considered zero-emission vehicles because of their exhaust gas emission diminution. The current study provides experimental results obtained from a 1.5-L automotive diesel engine supplied with diesel fuel and H2. Hydrogen energy proportions of up to 40% were used in the running mode, with a 50% load and 2000 rev/min engine speed. With hydrogen use, a reduction in CO2 of 37%, a reduction in HC of 22%, a reduction in the smoke number of 48% and a reduction in NO of 16% were obtained. With hydrogen fueling, the specific energy consumption and the cyclic dispersion decreased due to a better combustion process compared with diesel fuel fueling. The optimal adjustment between the engine operating parameters established for the reduction in the exhaust emission levels may represent a novel aspect. Hydrogen use even for diesel engines represents an attractive method that may provide the possibility of maintaining the operation of vehicles equipped with diesel engines.