Effects of hydrogen enrichment on diesel engine fueled with Afzelia Africana biodiesel – TiO2 blends

Owing to strict emission-policies, vehicle manufacturers are mandated to control hazardous emissions from diesel engines. One novel step adopted in this work, is the use of hydrogen enrichment with nanofuel, where TiO2 nanoparticles- Afzelia Africana biodiesel-mix was blended with hydrogen for use in a diesel engine. 25 ppm TiO2 nanoparticles were admixed with biodiesel and ultrasonicated. Thereafter, H2 was introduced through the air inlet at the lowest possible flow rate (3–4 LPM) to avoid reaching H2/air explosion limit. The ratio of H2 to the blended fuels (BNH) is (15: 85 vol/vol %). The effects of the nanofuels blended with pure H2 were investigated by evaluating the brake thermal efficiency (BTE), wall temperature of the combustion chamber, NOx, CO, and HC emissions. Via a simplified model, the associated uncertainties in the parametric variations were determined while a Supervisory Computer Aided Data Acquisition (SCADA) system with an in-built program, was configured in the engine set-up for data generation. The results showed that higher BTE of the blends + 25 ppm TiO2 alongside hydrogen flowrates of 3 LPM and 4 LPM helped to improve the engine performance with lesser emissions of CO, NOx and HC respectively. Sample BNH@-3-LPM gave the best performance/BTE of 39.5 % compared to BNH@-4-LPM (32.4 %), BN (29 %) and diesel (29.4 %), whereas, BNH@-3-LPM gave the lowest emissions of 0.4, 5 and 81 g/kwh for CO, HC and NOx respectively compared with diesel which gave corresponding emissions of 0.8, 35 and 200 g/kwh for CO, HC and NOx respectively.