International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 1 (2018) pp. 14-20 © Research India Publications. http://www.ripublication.com 14 A Comparative Analysis of Diesel Engine Fuelled with Diesel Fuel and Methyl Ester of Waste Cooking Oil Dr. Mohamed F. Al-dawody* 1 and Dr. Khaled A. Al-Farhany 2 1,2 Department of Mechanical Engineering, University of Al-Qadisiyah, Ad Diwaniyah, Iraq. *Orcid: 0000-0002-2730-1036, 1 Orcid: 0000-0002-5806-3800 Abstract An experimental work has been investigated on a constant speed diesel engine using methyl ester waste cooking oil (MEWCO) and diesel. The biodiesel was prepared by transesterification process and mixed with original diesel with 10%, 20%, and 100% of MEWCO on volume basis. The impact of the blending ratio on performance, pollutant emissions as well as combustion parameters, were examined at variable load conditions. The results reported significant reduction in nitrogen oxides (NOx) and raising carbon emissions as well in all tested blend of MEWCO. 20% MEWCO is the recommended mixing percentage and above this ratio, noticeable reduction in the outcome of the performance has been observed. Keywords: Waste cooked oil, transesterification, Diesel engine, Performance, Emissions. Nomenclature Symbol Definition and unit 10% MEWCO Blend ratio of 90 % diesel and 10 % MEWCO 20% MEWCO Blend ratio of 80 % diesel and 20 % MEWCO 100% MEWCO Blend ratio of 100 % MEWCO BTE Brake Thermal Efficiency (%) BSEC Brake specific energy consumption (MJ/kW.hr) BSFC Specific Consumption of Fuel (Brake) (g/kW.h) EGT Exhaust gas temperature (C) CA o Crank shaft angle (deg.) NOx Oxides of nitrogen (%) P Cylinder pressure (pa) HC Hydrocarbon emission (%) TDC Top Dead Centre INTRODUCTION Renewable sources, especially vegetable oils stand for more attention all over the globe. The main driving criteria that divert the researchers' attention, is the limited fossil fuel sources, environmental pollution concerns, energy self sufficiency as well as the development of rural economy [1]. Edible and non edible vegetable oils can be employed as replacements for original petroleum fuel [2]. However, edible oils can’t be spared for utilization of energy and the remaining choice is to induce the usage of non-edible or waste frying oils for energy uses. The production of biodiesel from vegetable oils is different from country to country due to different soil and climate conditions, hence; each country is looking for definte types of vegetable oils to compensate diesel fuel [3]. The present day scenario says: there is a not that much attempt makable to utilize biodiesel from non-edible sources commercially to substitute petroleum fuel. Several investigations have reported the results of the test engine with waste frying oil without transesterification process and the emission findings are different some researchers reporting reduces of a certain pollutants and other reporting increases [4]. As the new diesel engine has direct injection systems that is too sensible to quality of fuel, hence properties which are nearer to diesel fuel are required [5]. Therefore the recent research work is considering the transesterification of waste cooking oils before feeding the engine. The utilization of wasted cooked oils as biodiesel feedstocks reduce the price of production [6] as the feedstocks spend roughly 70-95% of the gross monetary value of production of biodiesel [7]. However, using wastage frying oil and oils based on inedible sources would be afford superior precedency above the sources of etable one as feedstock of biodiesel. A massive number of investigations are made with vegetable oils as a substitution for the fuel of internal combustion engine by different researchers. A part of these experimental findings are summarized below: Isigigur et al. [8] tested diesel fuel blended with 10% and 20% MEWCO and reported that even the energy content and cetane number are less than for ordinary diesel, most properties of blended fuels are nearer to those for pure diesel. Mittelbach et al. [9] investigated the influence of used wastage oil methyl ester on exhaust pollutant emission of a diesel engine. The observations are reduction in carbon emissions and increasing nitrogen oxides on the other hand. Regarding performance parameters, it is recorded lower fuel economy for the biodiesel comparatively to diesel. Reed et al. [10] converting wasting frying oil to its methyl ester and examined biodiesel and a 30% proportion of biodiesel with 70% diesel in a diesel bus by using a chassis dynamometer.