Influence of Exhaust Gas Recirculation on Emission Metrics in a Diesel Engine Operated with Hydrogen Induction and <italic>Cassia fistula</italic> Biodiesel

<div class="section abstract"><div class="htmlview paragraph">The current study investigates the influence of exhaust gas recirculation technique on the hydrogen (10lpm) inducted diesel engine using <i>Cassia fistula</i> derived biodiesel fuel. The focus is on evaluating the emission characteristics of the engine, with a particular emphasis on reducing NOx emissions. The study also examines the impact of varying the Exhaust Gas Recirculation (EGR) flow rate 10 and 20% on the aforementioned parameters. The novelty of this investigation lies in the comprehensive evaluation of emission metrics, particularly when combining Cassia fistula biodiesel with hydrogen induction. The experiment carried in Kirloskar TV1-V4A engine with blends consists 10%, 20%, 30% and 40% by volume of CFME blends with diesel. The inducted hydrogen at 10 lpm caused increased NOx which were discussed to suppress by EGR applications. Among the tested fuels, a blend containing 40% <i>cassia fistula</i> methyl ester (CFME) and 60% diesel (CFME40D60) showed the lowest hydrocarbon (HC) emissions, achieving 20 ppm, 18 ppm, and 23 ppm under non-EGR, 10% EGR, and 20% EGR conditions, respectively. Additionally, the CFME40D60 blend exhibited the lowest carbon monoxide (CO) emissions, with values of 0.0141%, 0.0156%, and 0.0159% by volume under the same conditions. The blend also demonstrated superior performance in reducing smoke opacity, achieving 32%, 32%, and 31% opacity, compared with diesel. Notably, the NOx emissions were significantly low with CFME10D90 blend, showing values of 1910 ppm, 1801 ppm, and 1598 ppm, with a 312 ppm reduction at the 20% EGR rate compared to non-EGR conditions. These findings provide insights into optimizing the fuel mixture and EGR settings to achieve improved engine performance and reduced emissions, making it a viable option for sustainable transportation.</div></div>