A comprehensive review on the applicability of hydrogen and natural gas as gaseous fuel for dual fuel engine operation

Hydrogen and natural gas are promising alternatives to fossil fuels in combustion engines for sustainable environment. Consumption of fossil fuels is a matter of growing concern that needs to be dealt with seriously for a sustainable, better tomorrow as fossil fuels have dreadful implications on the environment. Therefore, there is an urgent need across the globe to quest for environment-friendly alternative fuels, which can power internal combustion engines. Moreover, regulated and unregulated emissions from engines have been affecting human health and the environment. In this review article, hydrogen in combination with natural gas along with diesel as a pilot fuel is investigated. The impactsof exhaust gas recirculation with hydrogen and natural gas are also discussed. It is observed from the review that an H2 proportion of up to 5-30% is beneficial in combination with natural gas as well with other alternative fuels. The further increase in the hydrogen proportion create the problem of backfiring, knocking as well as increasing the NOx emissions. The transportation and storage are the biggest problems with the hydrogen fuel. Among the alternatives, gaseous fuels have great importance, and they need proper attention for inclusion in the CI engine as a fuel used in dual-fuel mode.