Performance and emission characteristics of tylosema esculentum biodiesel in a diesel engine: an experimental investigation

Abstract

Biodiesel derived from indigenous feed stocks such as Tylosema esculentum kernel oil is deemed a feasible alternative to petroleum diesel for the diesel engine. This paper presents results of investigation of performance and emissions characteristics of diesel engine using Tylosema biodiesel. In this investigation, Tylosema biodiesel was prepared, analyzed and compared with the performance of petroleum diesel fuel using a single cylinder compression ignition diesel engine. The specific fuel consumption, engine torque, engine brake power, hydrocarbons, carbon monoxide and carbon dioxide were analyzed. The tests showed a decrease in engine brake power and torque with increase in engine load, while specific fuel consumption showed an increasing trend with maximum variation of 33% between the two fuels at engine load of 90%. Emission levels of hydrocarbons, carbon monoxide and carbon dioxide showed an increasing trend with increase in load for both fuels. Tylosema biodiesel produced significantly lower concentrations of hydrocarbons than petroleum diesel, while levels of carbon dioxide and carbon monoxide were largely comparable to those of petroleum diesel. Soot production from combustion of Tylosema biodiesel was found to be approximately 98% lower than that from combustion of petroleum biodiesel, demonstrating insignificant contribution to environmental pollution.