Experimental Investigation of the Potential of Hydrogen as an Alternative to Brazilian Commercial Diesel Fuel in Current Heavy-Duty Fleet

<div class="section abstract"><div class="htmlview paragraph">Mobility in Brazil, dominated by road transportation, is responsible for consuming around a third of the energy matrix and for emitting approximately half of the energy-related emissions in the country. Among the alternatives to reduce its greenhouse gas emissions, the use of low-carbon hydrogen has a strong potential for decarbonization and improvement of engine efficiency. Thus, this study experimentally investigated the partial replacement of commercial diesel (with 12% of fatty acids methyl esters (FAME) biodiesel) by hydrogen in a commercial vehicle equipped with a compression-ignition internal combustion engine. To investigate the effects of this substitution on performance and emission profile, the vehicles was adapted for dual-fuel operation and hydrogen was injected together with air into the MB OM 924 LA engine of a Mercedes-Benz Accelo 1016 vehicle. Tests were carried out on a chassis dynamometer with 0%, 2% and 4% slope and at speeds equal to 50, 60 and 70 km/h to simulate various loads. For each of these combinations, commercial diesel was replaced by hydrogen with hydrogen energy share of 0%, 2%, 4%, 6%, 8% and 10%, respectively. The results showed that replacing commercial diesel with hydrogen resulted in a relative reduction of up to 17.6% in CO<sub>2</sub> emissions, 13.7% in CO and 25.5% in THC. However, the results of the performance parameters showed no improvement in efficiency under the tested conditions, with a reduction of up to 20.8% in thermal efficiency and an increase of up to 26.3% in specific fuel consumption. In conclusion, with minimal alterations, the results obtained with a commercial vehicle demonstrated the feasibility of hydrogen as a promising alternative fuel for use in compression ignition engines in the current fleet to reduce emissions.</div></div>