The combined effect of EGR and hydrogen addition on a Syzygium cumini (jamun) liquid biofuel engine.

Rapid depletion of fossil fuels required the development of alternate and sustainable fuel sources that could replace conventional fuel while having no negative environmental impact. Combining hydrogen induction with biodiesel ensures strict emission standards and lowers energy consumption compared to conventional fuels. In this study, the performance, emissions, and combustion of a CI engine for Syzygium cumini (B20) were assessed and compared to diesel fuel while using a fixed amount of hydrogen flow rate (6L/m). Throughout the experiment, an exhaust gas recirculation (EGR) technology of 10% and 20% and a constant engine speed of 1500 rpm at varying engine load circumstances were used. When hydrogen is added to B20, it decrease the emissions of carbon monoxide (CO), unburned hydrocarbons (UHC), brake thermal efficiency (BTE), and brake specific energy consumption (BSEC). At maximum load, the use of the EGR system decreased the exhaust gas temperature (EGT) by 13.4% and nitrogen oxide (NO) emission by 25%, but it had a negative impact on BTE, BSEC, as well as other emission parameters including CO and UHC. Therefore, using hydrogen in dual fuel mode in a CI engine enhances performance and lowers exhaust emissions, while using the EGR approach reduces NO emissions.