Sustainable methane-hydrogen fuel in heavy duty drive cycle

COP26 aims to reduce GHG emissions by 45% (2010-2030), requiring a shift away from carbon-intensive fuels in heavy-duty (HD) transport. Replacing diesel with natural gas can reduce tailpipe CO 2 , with further gains possible through partial substitution with H 2 . The novelty of the current work lies in showing how H 2 influences a Euro 6 HD methane engine, using a combined experimental-simulation approach that explicitly converges on cycle-weighted outcomes. This is achieved by integrating experimental testing and validated Chemkin-Pro spark-ignition modelling to evaluate CH 4 -H 2 blends across 60% of a typical drive cycle to provide system-level insights. H 2 substitution levels of 20% and 28% by volume were assessed. Experimentally, H 2 (20%) reduced engine-out HC and NO x emissions by 15%, alongside up to 10% decreases in CO 2 emissions and gravimetric fuel consumption. The Chemkin-Pro multizone simulation was applied to extend the analysis across a wider range of engine speeds/loads, provide a mechanistic interpretation of NO x pathways, and reveal efficiency and emissions trends. The key contribution lies in showing not only whether H 2 substitution reduces emissions, but where and under what duty-cycle conditions benefits are maximised or trade-offs emerge. This cycle-anchored, experimentally validated assessment offers valuable guidance for low-carbon powertrain development. Integrated over the drive cycle, the combined results demonstrate that H 2 (20%) can simultaneously reduce engine-out emissions (lowered NO x and HC emissions by 15%) and deliver 4% reductions in gravimetric fuel consumption. When combined with a renewable CH 4 and H 2 supply, this establishes a promising pathway to decarbonise existing engine platforms. • Tested optimised Euro 6 SI CH4-H2 engine at 900-1100 rpm, 100-180 Nm • Quantified ignition delay, combustion duration, peak pressure, NOx, HC, CO2 & BTE; • Identified CH4-H2 ratios & spark timing for HD drive cycle performance & emissions • Validated Chemkin-Pro simulations for mechanistic NOx analysis & extended results • Lower drive cycle NOx 15%, HC 15%, CO 2 29 kg/day, for 20% hydrogen vs methane