ISSN 2395-1621 The Effect of Exhaust Gas Recirculation (EGR) on Performance of Diesel Engine Fuelled by Cotton Seed Oil & its Blend #1 AnandMarkad, #2 NitinMorkane 1 anandmarkad@gmail.com, 2 ntn7@rediffmail.com #1 DepartmentofMechanicalEngineering,G.S.MozeCollegeofengineering Pune, India. #2 WalchandInstituteofTechnology, Solapur, India. ABSTRACT ARTICLEINFO Literature survey on the topic of dissertation is presented.in the previous chapter of present study have been mentioned.avariety of experimental,analytical and computational research works has been carried. A methylester of cottonseed oil was prepared and blended with diesel in four different compositions varying from 5% to 20% insteps of 5%.Tests were conducted in a single cylinder variable compression ratio diesel engine at a constant speed of 1500 rpm.highest brake thermal efficiency and lowest specific fuel consumption were observed for 5%biodiesel blend for compression ratio of 15 and 17 and 20% biodiesel blend for compression ratio of 19.The 20% biodiesel blend at a compression ratio of 17 had maximumn it ricoxide emission as 205 ppm,while it was 155 ppm for diesel.substantial reduction in Carbonmonoxide emissions and smoke in the full range of compression ratio and loads was observed.improved heat release characteristics were observed for the prepared biodiesels.the results reveal that the biodiesels can be used safely without any modification to the engine. Article History : Received:2 nd November 2015 Received in revised form: 4 th November 2015 Accepted : 5 th November 2015 Keywords:cottonseed oil,egr,biodiesel,compression ratio,blending and trans esterification.. I. INTRODUCTION India is the second largest producer of cotton seed in the world next to china with the potential of 4.6 million tons of oil seeds per annum. With the rapid development of rural agricultural production and rapid growth of local industry in India, the discrepancy between Demand and supply of energy has become an increasingly acute problem. Due to seasonality of farm work, a temporary shortage of fuel will bring about unexpected and irreparable loss to peasants. The limited (and fast diminishing) resources of fossil fuels, increasing prices of Crude oil, and environmental concerns have been the diverse reasons for exploring the use of vegetable oils as alternative to diesel oil [1-4]. Vegetable oils offer almost the same output with slightly lower thermal efficiency when used in diesel engines [5-7]. Reduction of engine Emissions is a major research aspect in engine development with the increasing concern over Environmental protection and the stringent exhaust gas regulation [8-13]. The use of neat vegetable oils poses some problems when subjected to prolonged usage in CI engines. These problems are attributed to high viscosity, low volatility and polyunsaturated character of vegetable oils [14-17]. Some of the common problems posed by using vegetable oils in diesel engines are coking and trumpet formation on the injectors, carbon deposits, oil ring sticking and thickening and gelling of lubricating oil as a result of contamination by the vegetable oils [18-20]. Different methods such as preheating, blending and transesterification [21-25] are being used to reduce the viscosity and to produce biodiesel, suitable for engine applications. In the present investigation, bio-diesel is prepared from cotton seed oil. The fuel properties 2015, IERJ All Rights Reserved Page 164
of the synthesized bio-diesel were determined and their performance, emission and combustion characteristics were studied on a four-stroke, single cylinder, and variable compression ratio direct injection diesel engine to ensure their suitability as CI engine fuel. The effect of EGR on NOx reduction can be attributed to three theories 1) increased ignition delay, 2) increased heat capacity and 3) dilution of the intake charge with inert gases. The ignition delay theory asserts that because EGR causes an increase in ignition delay, it has the same effect as retarding the injection timing. The heat capacity theory states that the addition of the inert exhaust gas into the intake increases the heat capacity (specific heat) of the non-reacting matter present during the combustion. The increased heat capacity has the effect of lowering the peak combustion temperature. According to the dilution theory, the effect of EGR on NOx is caused by increasing amounts of inert gases in the mixture, which reduces the adiabatic flame temperature. With the use of EGR, there is a trade-off between reduction in NOx and increase in soot, CO (carbon monoxide) and unburnt HC (hydrocarbons). The change in oxygen concentration causes change in the structure of the flame and hence changes the duration of combustion. It is suggested that flame temperature reduction is the most important factor influencing NOx formation. This indirectly shows the potential for reduction of NOx emission. This can be concluded from the fact that the most important reason for the formation of NOx in the combustion chamber is the high temperature of about 20000 K at the site of combustion. Thermal efficiency and brake specific fuel consumption are not affected significantly by EGR. However particulate matter emission in the exhaust increases, as evident from smoke opacity observations. Diesel engines score higher than that of other engines in most aspects like fuel consumption and low CO emissions, but lose in NOx emissions. EGR is proved to be one of the most efficient methods of NOx reduction in diesel engines.[1] II METHODOLOGY 2.1. The raw cotton seed oil was extracted by mechanical expeller in which small traces of organic matter, water and other impurities were present. Transesterification is a most common and well established chemical reaction in which alcohol reacts with triglycerides of fatty acids (vegetable Oil) in presence of catalyst to form glycerol and esters [13, 10, 17, 22-23].The reaction is shown in Figure-1.Experiments were conducted in a laboratory setup consisting Of heating mantle, reaction flask (made of glass), separating funnel and mechanical stirrer. A round bottom flask of 2 litres was used as laboratory scale reactor for the present analysis. It consisted of three necks. One for stirrer, the others for condenser and inlet of reactants, as Well as for placing the thermocouple to observe the reaction temperature. The flask has astopcock at the bottom for collection of the final product. The progress of the reaction was observed by measuring the acid value. In the course of the test, it was observed that the appropriate quality of biodiesel could be produced from cotton seed oil in both acid catalyst esterification and alkaline catalyst esterification. 2.2 Esterification procedure The cotton seed oil in the flask was heated on a heating mantle with a mechanical stirrer arrangement. The mixture (methanol and cotton seed oil) was continuously stirred in the air closed reaction flask for 2 h at 650C with a stirring speed of 450 rpm. The temperature in the Apparatus should be maintained just above the boiling point of alcohol i.e, 650C to accomplish the reaction. Alcohol in vegetable oils affects the conversing on efficiency of the process. For the stochiometric transesterification, 3 mols of alcohol are required for each mole of the oil. However, in practice, the molar ratio should be higher than this theoretical ratio in order to derive the reaction towards early completion [25-27]. Sulphuric acid is used as catalyst in the acid-catalyst pretreatment. Experimentally it is optimized that 1% by volume of the sulphuric acid and a molar ratio of 6:1 gives the maximum conversion efficiency. The products of the first stage are used as input for alkaline process. A molar ratio of 9:1 and 1.5% by weight of NaOH is found to give the maximum ester yield. With the completion of the reaction, the products were allowed to separate in to two layers. The lower layers contained impurities and glycerol. The top ester layer is separated and purified by using distilled water (10% by volume). Hot distilled water is sprayed over the ester, stirred gently and allowed to settle in the separating funnel. After washing, the final product was heated up to 70C0 for 15 min under vacuum condition resulting in a clear amberlight yellow liquid with a viscosity comparable to diesel and then stored for further use The summary of esterification process, settling and washing is illustrated in Figure-2. 2.3Characterization of cotton seed oil The source of cottonseed oil is cottonseed, which is a crop byproduct. It is basically a triglyceride ester with a number of branched chains of 8-18 carbon atoms. It contains 85.3% fatty acids. Fatty acid composition of the oil is essential to determine the quantity of reactants and the catalyst. FFA (Free Fatty Acids) can be determined from the acid value. It has been stated that the acid value of the vegetable oil should be less than one for a base catalyzed transesterification process [15, 22] from earlier studies. The significant properties of cotton seed oil are found during the present investigation. The result indicates that, transesterification has improved the important fuel properties like specific gravity; viscosity; flash point; and acid value. The viscosity substantially got reduced. The result indicates that, transesterification has improved the important fuel properties like specific gravity; viscosity; flash point; and acid value. The viscosity substantially got reduced from a value of 50 to4.2 mm 2/s (approximately one 11th of initial value). The calorific value of methyl ester is lower than that of diesel because of its oxygen content. The flash point temperature of CSO and COME is higher than the pure diesel fuel. The high flash point temperature of COME is a beneficial safety feature, as the fuel can be safely stored and transported at the room temperature. The cetane number (CN) of COME prohibits its direct use as the alternative fuel in diesel engines, but it could be used in blends with the pure diesel fuel, because most of the determined properties of the a COME-diesel blended fuels were very close to the diesel fuel. The final structure along with chemical formula, exact mass, molecular weight and elemental analysis is given by CHEMOFFICE software as shown in Figure-2 2015, IERJ All Rights Reserved Page 165
Figure-2 Schematic diagram showing molecular structure raw cotton seed oil. III. EXPERIMENTAL SET- UP Diesel Engine with EGR Figure-3 Layout of EGR System Table I: Engine Specifications Specification Item Make Brand New - Kirloskar Model TV1, Water cooled Power 8HP at 1500 R.P.M Stroke 110 mm Bore 87.5 mm Volume 661 c.c. Compression Ratio 1:17:5 2015, IERJ All Rights Reserved Page 166
Graphs 6-MECHANICAL EFFICIENCY (%) Vs. LOAD (Kg) EGR Graphs 10-NOx (ppm % Vol.)Vs. LOAD (Kg) EGR Graphs 8-BRAKE POWER (KW) VS LOAD (KG) EGR Graphs 11-HC (ppm % Vol) Vs. LOAD (Kg) Graphs 9-NOx (ppm % Vol.)Vs. LOAD (Kg) Graphs 11-HC (ppm % Vol) Vs. LOAD (Kg) V. CONCLUSION The experimental conclusions of this investigation can be summarized as follows: 1) It is observed that the brake thermal efficiency for various biodiesel blends has increased up to 3% as compare to diesel as fuel. 2) With implementation of EGR technique and valve opening of 20%, it has increase up to 3-4%. 3) We have also found the blend B2 as a optimal fuel for diesel engine which has higher break 2015, IERJ All Rights Reserved Page 167
4) Thermal efficiency so we suggest using B2 as an alternative fuel in the future for engine. 5) The break specific fuel consumption for blend B2 is less than diesel and other bio- diesel blend. 6) The mechanical efficiency is not much affected by the implementation of EGR technique. 7) There is drastically reduction of NOx with the implementation of EGR technique. REFERANCES 1. Biodiesel as an alternate fuel in a diesel engine with the cooled exhaust gas recirculation ameasure to reduce harmful emissions,s.adinarayana1,ymcsekhar2,bvarao3&m.anil prakash; international journal of applied research in mechanical engineering (ijarme),issn:2231 5950, volume- 1,issue-2;2011 2. Performance, Combustion and Emission of a PKME Fuelled DI- Diesel Engine with Exhaust Gas Recirculation, YMC Sekhar, S. Adinarayana, M. Anil Prakash, K. Praveen, K. Ajay ;International Journal of Engineering and Technology Volume 2 No; 7 July, 2012 3. Experimental Studies on Emission and Performance Characteristics in Diesel Engine Using Bio-Diesel Blends And EGR(Exhaust Gas Recirculation), a. Pooja Ghodasara, Mayur Ghodasara ; International Journal of Emerging Technology and Advanced Engineering (ISSN 2250-2459, Volume 2); 2, February 2012. 4. Trade-off between NOX, Soot and EGR rates for an IDI diesel engine fuelled with JB5, M. Gomaa, A.J. Alimin and K.A. Kamarudin ; World Academy of Science, Engineering and Technology ; 3 8 2010. 5. The Effect of Biodiesel and Bioethanol Blended Diesel Fuel on the Performance and Emission Characteristics of a Direct Injection Diesel Engine, G. Venkata Subbaiah, K. Raja Gopal and Syed Altaf Hussain ; Iranica Journal of Energy & Environment 1 (3): 211-221 ; 2010. 6. The Status of Biodiesel as an Alternative Fuel for Diesel Engine An Overview, S. Jaichandar, and K. Annamalai; Journal of Sustainable Energy & Environment 2 ; 2011. 7. Combining Biodiesel and Exhaust Gas Recirculation for Reduction in NOx and Particulate Emissions, Rachel L. Muncrief, Charles W. Rooks, Miguel Cruz, and Michael P. Harold ; Department of Chemical and Biomolecular Engineering, UniVersity of Houston, 4800 Calhoun, a. S222 Engineering Building 1, Houston, Texas 77204-4004 b. ReceiVed August 3, 2007. ReVised Manuscript ReceiVed; NoVember 21, 2007. 8. Performance Characterization Of Single Cylinder DI Diesel Engine Fueled With Castor Biodiesel, M. M. Kulkarni V.S.Dhumal; International Journal of Engineering Research & Technology (IJERT) Vol. 1 Issue 10 ; December- 2012. 9. Impact of Biodiesel and its Blends with Diesel and Methanol on Engine Performance, Gaurav Dwivedi, Siddharth Jain, M.P. Sharma ; International Journal of Energy Science ; 2009. 10. Addition of Ester (Biodiesel) to Ethanol-Diesel Blend to Improve the Engine Performance and to Control the Emissions of Nitrous Oxides, a. Donepudi Jagadish*, Ravi Kumar Puli, K. Madhu Murthy; Energy and Power; 201 2015, IERJ All Rights Reserved Page 168