Investigating the emissions and performance of hydrogen enriched-biogas-Parinari polyandra biodiesel in a direct injection (DI) engine

Owing to strict emission-policies, vehicle manufacturers are mandated to control emis-sions from diesel engines. To comply with such policies, one of the novel steps adopted in this study, is the use of hydrogen enriched biogas (HE-B) from chicken droppings and pig manure admixed biodiesel. Different fuel-samples were made available. The ratio of bio-diesel to hydrogen enriched biogas B(HE-B) in the blends is 85:15 %vol/vol respectively. Biodiesel/diesel and the inducted HE-B were metered at 0.5, 0.75 and 1.0 kg/h with air at the intake manifold of the DI engine and the combustion characteristics of the fuels were compared. The fuel-sample, metered at 0.75 kg/h, gave the best BTE (36.5%) compared to those of the blended fuels whose values are 31.0, 32.4 and 29.4% for the B(HE-B)0.5 kg/h, B(HE-B)1.0 kg/h and diesel respectively, whereas, the CO emissions increased in the following order: B(HE-B)0.75 (0.4 g/kWh) < B(HE-B)1.0 (0.53 g/kWh) < B(HE-B)0.5 (0.54 g/ kWh) < diesel (0.72 g/kWh), while for HC emissions, the order is B(HE-B)0.75 (5.0 g/kWh) < B(HE-B)1.0 (11.0 g/kWh) < B(HE-B)0.5 (12.0 g/kWh) < diesel (21 g/kWh). For the NOx emissions, the established trend is B(HE-B)0.75 (81 g/kWh) < B(HE-B)1.0 (107 g/kWh) < B(HE-B)0.5 (111 g/kWh) < diesel (149 g/kWh).(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.