INVESTIGATIONS ON POLLUTANTS OF BIODIESEL RUN INSULATED DIESEL ENGINE WITH EXHAUST GAS RECIRCULATIONG. Sainna, M.V.S. Murali Krishna and P. Usha Sri
In the context of fast depletion of fossil fuels, ever increase of pollution levels with fossil fuels and increase of economic burden on Government of India due to import of crude petroleum, the search for alternative fuels has become pertinent. Alcohols and vegetable oils are important substitutes of diesel fuel. However, alcohols have low cetane number, while vegetable oils have high viscosity and low volatility to use them in diesel engines. Hence biodiesel which has oxygen in its molecular composition and high cetane number is good substitute for diesel fuels. Biodiesel is prepared form vegetable oils by the process known as esterification. The concept of the insulated engine or low heat rejection (LHR) engine is to minimize the heat loss to the coolant by providing thermal insulation in the path of heat flow to the coolant, thereby increase heat flow rate and provide faster rate of combustion and hence these engine are suitable for burning low calorific value fuels. Exhaust emissions from diesel engine are particulate matter (PM) and nitrogen oxide (NOx) levels and breathing of which cause many health hazards and also cause environmental disorders like acid rain and Greenhouse effect. Hence control of these emissions is an immediate step. Investigations on carried out on LHR four-stroke, single-cylinder, 3.68 kW at the rated speed of 1500 rpm, water cooled diesel engine with air gap insulated piston and air gap insulated liner with tamarind biodiesel with exhaust gas recirculation (EGR). Exhaust emissions of PM and NOx levels were reduced by 50% when compared without EGR.