Renewable synthetic fuels such as methanol and diethylene glycol dimethyl ether (DGM), produced via atmospheric CO₂ capture, represent a promising strategy to reduce fossil fuel consumption in compression ignition (CI) engines. However, their effects on engine performance and exhaust emissions under conventional operating conditions remain insufficiently understood and require further investigation, particularly in small diesel engines operating with ternary methanol/DGM/diesel blends. In this context, this study systematically investigates the effects of blending synthetic fuels with diesel fuel on CI engine performance and emissions. Experimental tests were conducted using four fuel blends: M10D90 (10% methanol and 90% diesel), M20D80 (20% methanol and 80% diesel), DG15M5D80 (15% DGM, 5% methanol, and 80% diesel), and DG5M10D85 (5% DGM, 10% methanol, and 85% diesel), all tested at a constant load and engine speed of 2600 rpm. Pure diesel was also evaluated as a baseline. Engine performance parameters and exhaust emissions were assessed under steady-state conditions without engine modifications, using the standard fuel injection system. The results indicate reductions in pollutant emissions, with CO decreasing by up to 10% and NOX by 2.3% for the M10D90 blend compared to the baseline, without significant changes in fuel conversion efficiency and with a slight increase in specific fuel consumption. Additionally, a slight reduction in CO₂ emissions was observed. Thus, this work contributes to improving the understanding of the use of synthetic fuels blended with conventional diesel and their potential to reduce fossil fuel consumption in CI engines.
Marchioro et al. (Mon,) studied this question.