Performance and emission characteristics of biogas fuelled dual fuel engine with waste plastic oil as secondary fuel

This study investigates the performance, emission and combustion characteristics of a stationary engine under diverse operating conditions. The research focuses on the impact of waste plastic oil (WPO) blends with and without biogas addition. WPO added in diesel at various proportions such as 20%, 35% and 50% by volume. Biogas is inducted through inlet manifold. Biogas flow rate was varied. This study introduces a pioneering approach by investigating the superior performance of WPO blends coupled with the unique exploration of biogas addition, revealing intricate relationships between fuel blends and combustion characteristics for enhanced stationary engine efficiency and reduced emissions. Notably, WPO with 80% diesel (WPO20) demonstrates superior Brake Thermal Efficiency (BTE), showcasing a significant increase compared to WPO35 and WPO50 across varying load conditions. The addition of biogas to WPO20 results in a measurable reduction in BTE due to incomplete combustion, insufficient excess air, and increased emissions. Hydrocarbon (HC) emissions increase with load for WPO blends, with WPO20 exhibiting the lowest HC emissions. Carbon monoxide (CO) emissions are influenced by WPO concentration, with WPO20–B12 and WPO20–B16dual fuel mode showing varying trends. Nitrogen oxides (NOx) emissions decrease with the addition of biogas, indicating a 10% reduction for WPO20–B16 compared to WPO20–B12. Smoke emissions increase with higher WPO concentrations but decrease with the introduction of biogas, exhibiting a 20% reduction in smoke for WPO20–B16 compared to WPO20–B12.