Experimental investigations into engine characteristics fuelled with hibiscus coconut biodiesel and its blends

The world's fossil fuel sources are decreasing rapidly. Rising population growth needs alternative fuels. Biodiesel is an alternate and sustainable fuel obtained from different feedstocks. In this work, biodiesel was made from hibiscus-coconut oil by the transesterification technique. The aim of the present research is to investigate the emissions, combustion and performance characteristics of a single-cylinder variable compression ratio diesel engine fuelled with hibiscus-coconut biodiesel blends. The blends of B05 (5% biodiesel and 95% diesel), B10 (10% biodiesel and 90% diesel), and B15 (15% biodiesel and 85% diesel) were prepared with hibiscus-coconut biodiesel and diesel. The engine is running at a speed of 1500 rpm and a compression ratio of 17.5:1 at various loads. The experimental findings are compared with those of diesel fuel. The brake thermal efficiency (BTE) and brake power (BP) were improved by 2.48% and 1.78% for blend B15 at peak load. The brake specific fuel consumption is the same as that of diesel. The maximum cylinder pressure is 63.82 bar. Carbon monoxide, hydrocarbon emissions and smoke have decreased by 18.03%, 13.79% and 52.71%, respectively. There is a marginal increment in nitrogen oxides of 14.37%. The blend B15 is acceptable for diesel engines as a renewable fuel. Thus, the findings show that, without any modification to the engine, the blend B15 can be utilized as an alternate fuel for diesel engines.