FUELLING A SMALL CAPACITY AGRICULTURAL UNMODIFIED DIESEL ENGINE WITH MACRO-EMULSIFIED ETHANOL, DIESEL AND JATROPHA DERIVED BIODIESEL :PERFORMANCE AND EMMISSION STUDIES

Abstract

Due to rapid depletion of fossil fuels and environmental concerns, vegetable oils and alcohols are believed to be the potential replacements of petrodiesel. But reactivity of unsaturated hydrocarbon chains and undesirable combustion features of vegetable oils and material compatibility, dissolution of lubricant, and poor ignition of alcohols are some which prevented these two fuels to go long. Transesterification for vegetable oils (this brings modification in its molecular structure), thus converting it to biodiesel, was appropriate measure. Even with this, emission of excess NOx becomes a major problem. Therefore instead of using pure biodiesel or alcohol as substitution, blending of these fuels with diesel was taken an alternative solution at present days. An unmodified single cylinder, four stroke, direct injection, and water-cooled natural aspirated vertical compression ignition, typical to engines used in the agricultural sector (pumps, tractors) was fueled with macro-emulsified ethanol, diesel and jatropha biodiesel at different ratios in the current performance and emission studies. Fuel characteristics (density, calorific value, viscosity and flash point), engine performance and emission characteristics have been investigated and significant improvements were observed. 5.86% (25.90% from 20.04%) in maximum thermal efficiency, 22.64% (13899.71 KJ/Kw-hr from17968.13 KJ/Kw-hr) in minimum brake specific energy consumption, and considerable improvement in smoke opacity was observed with sample fuel D75JB15E10 (75% diesel, 15%jatropha biodiesel and 10%ethanol) compared to that of D100 (100% diesel)