Multi-objective optimization and analysis of chemical kinetics properties: Exploring the impact of different hydrogen blending ratios on LPG and methane-air mixtures

The use of hydrogen with hydrocarbon fuels like methane and LPG is crucial for carbon neutrality and environmental goals. United Nations Environment Programme (UNEP) and the International Energy Agency (IEA) emphasise reducing LPG and methane emissions to prevent temperature increases. Utilising H2-LPG and H2-CH4 blends enhances free radical formation, mitigates emissions, and combats global warming. Using the CHEMKIN tool, this research compares the combustion characteristics of H2-CH4-air and H2-LPG-air mixtures under atmospheric conditions and different operating conditions. Blending 50 % hydrogen with LPG and methane yields notable variations, including a 20.97 % higher flame speed in H2-CH4, 42.89 % more H free radical formation in H2-LPG, 50.24 % reduction in O free radical formation in H2-LPG, and a 24.01 % increase in OH free radical formation in H2-LPG. The study investigates the energy and environmental impacts of incorporating hydrogen into CH4-air and LPG-air combustion, focusing on 50 % H2 blending with LPG. The benefits of hydrogen blending encompass heightened flame speed and augmented free radical formation, ultimately contributing to emission reduction in hydrogen-blended fuels. These findings highlight H2-LPG and H2-CH4 blends as environmentally friendly alternatives with improved combustion.