A Detailed Simulation of a DME/Hydrogen RCCI Engine Performance and Emissions

The current simulation study seeks to completely eliminate dependence on fossil fuels consumption in a diesel fuel/natural gas RCCI engine. Instead, the engine uses two final products resulting from the natural gas steam reforming process, hydrogen and DME. By changing the engine fuels to nonfossil fuels, the results reveal that along with a 100% reduction in fossil fuel consumption, the total fuel cost per hour of the engine operation will increase by 300%. Compared to diesel fuel/natural gas RCCI engine, the duration of combustion was increased beyond 50 degree crank angle along with the reduction in peak pressure by up to 57 bar. However, a maximum increase of 2.57 bar in indicated mean effective pressure with a gross indicated efficiency of over 55% can be achieved without any concerns about diesel knock. In the hydrogen/DME RCCI engine, carbon dioxide emission can be reduced by up to 157 tons per year in each cylinder. The 2007 EPA and EURO VI levels for formaldehyde and unburned methane are achievable, respectively. Lower than Euro II level for carbon monoxide is unattainable. Moreover, the level of soot and NOx emission lead to the relevant Euro II range due to the chemical properties of DME.