A Comparative Performance and Emission Analysis of Blended Groundnut Oil and Mineral Oil Based Lubricants Using a Spark Ignition Engine

Abstract

This paper presents the performance and emission behaviour of a spark ignition engine run on groundnut oil blended lubricants. However, for the purpose of comparism, benchmark tests were carried out on multigrade and monograde motor oils. A 5.0 h.p engine test-bed incorporated with an A.C dynamometer and flue gas analyzer was used to conduct the tests. At maximum engine speed, the groundnut oil blended lubricants generated an exhaust temperature of 6.02% higher than multigrade oil, and 6.26% higher than monograde oil. The brake power was 12.70% and 10.94% higher than the monograde and multigrade oils. In terms of fuel economy, the monograde and groundnut oil blended lubricants are 7.50% and 2.18% higher than multigrade oil respectively. It is shown that as the proportion of viscosity modifier in the oil sample increases, exhaust temperature, brake power, brake mean effective pressure (b.m.e.p) also increases, while the specific fuel consumption diminishes. At various speeds, CO2 level emitted by the use of groundnut oil blended lubricants was observed to be higher than it was the case for multigrade and monograde oils. In the light of the fast depleting fossil fuel reserve in Nigeria, this work has demonstrated the feasibility of using groundnut oil blends as lubricant substitutes in spark ignition engines.