Effect of Methanol Fumigation on Performance and Emission Characteristics in a Waste Cooking Oil Fuelled Single Cylinder CI Engine

Abstract

Use of bio oils in diesel engines results in increased NOx, smoke and reduced brake thermal efficiency. Dual fuel engines can use a wide range of fuels mainly alcohols and yet operate with high thermal efficiency and simultaneous reduction of NO and smoke emissions. The present study aims to explore the effect of methanol-waste cooking oil (WCO) dual fuel mode on performance and emission characteristics in a single cylinder CI engine producing 3.7 kW at 1500 rpm. WCO was injected in the conventional injection system-replacing diesel as pilot fuel. Methanol was fumigated along with intake air using a variable jet carburetor, which was installed in the inlet manifold. The methanol was fumigated and the energy share was varied for each load till the knock limit. Performance parameters like brake thermal efficiency (BTE) and emission parameters like HC, CO, NO and smoke emissions were tested for various energy share of methanol with WCO as pilot fuel. The results show that increase in methanol fumigation reduced brake thermal efficiency (BTE) at lower loads. At 75 % and 100 % load conditions, BTE was higher with methanol addition. The maximum BTE was observed for 38 % methanol share, which is about 11 % higher, compared to WCO at 100 % load condition. Methanol fumigation aided in simultaneous reduction of NO and smoke emission and the maximum reduction was occurred with 51 % methanol share at 100 % load condition. HC and CO emissions were higher at all load conditions with methanol fumigation.