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

Abstract

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, NO_x, 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, NO_x 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 NO_x respectively compared with diesel which gave corresponding emissions of 0.8, 35 and 200 g/kwh for CO, HC and NO_x respectively.