Impact of Intake Charge Preheating on a Biogas Run Dual Fuel Diesel Engine Using Ternary Blends of Diesel-Biodiesel-Ethanol

Abstract

In the pursuit of minimizing a considerable amount of imported fossil diesel and greenhouse gas (GHG) emissions, green fuels like biodiesel, ethanol, and biogas can be used efficiently under dual fuel mode (DFM) of a diesel engine. The present study aims to investigate the performance, combustion, and emissions (designated as overall performance) of a DFM engine run on various ternary blends of diesel-biodiesel-ethanol (D-B-E) as the pilot (but primary) fuel and biogas as the secondary fuel. The blends chosen were D7-B2-E1, D75-B2-E5, D72-B2-E8, D77-B15-E8, D67-B25-E8, and D1-B-E, for which the numerical values represent the volume percentage of the individual component in the blends. The blends are designated as TB-1, TB-2, TB-3, TB-4, TB-5, and TB-, respectively. All experiments were conducted with these blends at the intake charge preheating temperature of 55°C (±2°C) and at the optimized total fuel-air equivalence ratio (ϕtotal). In order to have a direct comparison, experiments were also conducted without preheating the intake charge (WPI), and this is designated as TB--WPI. On the basis of the engine’s overall performance, the TB-3 blend is found to be optimum among the tested blends with preheating. The maximum brake thermal efficiency (BTE) of 26.73% is achieved with the TB-3 blend, which is 5.4% higher in contrast to TB-1. The highest drop of carbon monoxide (CO) and hydrocarbon (HC) were 86.23 and 83.97%, respectively, in contrast to TB--WPI, whereas the maximum reduction as compared to pure diesel of 63.4% of oxides of nitrogen (NOx) is achieved with TB--WPI.