Numerical comparative analysis on performance and emission characteristics of methanol/hydrogen, ethanol/hydrogen and butanol/hydrogen blends fuels under lean burn conditions in SI engine

Hydrogen is currently recognized as a clean and renewable energy source, and it has broad prospects for being used in engines. Based on the author's previous research experience on alcohol-gasoline, and previous researchers' individual research basis on methanol-H-2, ethanol-H-2, or n-butanol-H-2. An alcohol-H-2 engine model is established through the GT-Power simulation platform, and the combustion and emission performance of methanol, ethanol and n-butanol under different hydrogen ratios are compared and analyzed. The results show that adding 10% hydrogen to methanol, ethanol or n-butanol can increase brake torque (BT) to 3.49%, 5.02% and 6.48% at 1500 r/min, respectively. At 2000 r/min, BT increased by 3.14%, 4.74%, and 6.62% respectively. At the same time, brake specific fuel consumption (BSFC) is reduced by 31.51%, 24.6% and 21.16% at 1500 r/min, respectively. At 2000 r/min, the BSFC is reduced by 31.37%, 24.4% and 21.23% respectively. HC, CO and CO2 emissions are reduced, but NOx emissions increase. At 10% hydrogen ratio, compared with ethanol-H-2 and n-butanol-H-2 blends, methanol-H-2 blends can reduce CO by 48.28% and 65.91%, and CO2 by 14.9% and 24.61% at 2000r/min, respectively. When using a high proportion of hydrogen, it can better increase BT and reduce BSFC and carbon emissions.