Performance and emission characteristics of an indirect diesel injection engine fueled with Mahua methyl ester and methanol as an additive

Abstract

Biodiesel is as an attractive alternat ive fuel for replacement of conventional diesel with small or no changes made to the original design of the engine. 100% replacement entails some problems such as excess Nitrogen Oxide (NO_x) generation in the exhaust gases and crankcase oil dilution. Biodiesel made from non-edible oils is a safer choice. Mahua methyl ester (MME) biodiesel is one of the many fuels receiving attention as an alternative fuel for diesel engines, and carries religious significance for being used in temples. Much work and research have been carried out on a Direct Injection (DI) diesel engine with biodiesel and additives. Research in biodiesel acknowledges its advantages and it is envisaged that the emissions can be substantially reduced. Biodiesel is an oxygenated fuel containing approximately 11% of O₂ in its molecular structure. This may lead to the release of more NO_x in the exhaust gas. In this study, an effort has been made to reduce crank case oil dilution and NO_x emission by adopting an Indirect Diesel Injection (IDI) engine. Combustion phenomena were studied and emissions were compared using biodiesel with methyl alcohol as an additive. The aim of the current work is to investigate the emission characteristics of an IDI engine fuelled with Mahua methyl ester (MME) along with Methanol (M) additive blends with an attempt to reduce NO_x, HC, CO and smoke emissions employing the concept of low temperature combustion because of methanol's higher latent heat. A four-stroke single-cylinder, forced air and oil cooled IDI diesel engine was used for the investigation. Smoke, NO_x, carbon monoxide (CO) and carbon dioxide (CO₂) emissions were recorded and various engine performance parameters were measured. A comparative study was conducted using Petro diesel, biodiesel and additive blends of biodiesel on an IDI diesel engine. Mahua methyl ester (MME) was used with additive methanol in different proportions such as 1%, 2%, 3%, 4% and 5% and was tested at different loads in an IDI diesel engine. The performance and emissions of the engine using biodiesel with the additive was compared with an engine with neat diesel operation: 57% HC, 20% CO, 14% NO_x, 27% smoke reductions were observed at 3% methanol additive at maximum opted load (2.70 kW and 1500 rpm) operation of the engine.

Keywords:

• additives
• biodiesel
• IDI engine
• exhaust gas emissions
• methanol