Experimental investigation of VCR engine by using fuel waste cooking oil/diesel blends and development model to predicating emission using semi-empirical approach #1 Swati V. Patil, #2 Dr Abhay A. Pawar #1 PG Student, Rajarshi Shahu College of Engineering, Tathawade,SP Pune University, Mumbai, India #2 Professor, Rajarshi Shahu College of Engineering, Tathawade,SP Pune University, Mumbai, India ABSTRACT The purpose of the study is to prepare biodiesel from waste cooking oil using transesterification reaction. Since the world is facing crisis due to fast depletion of fossil fuel it is very important to replace this fuel by some alternate fuel. Waste cooking oil is an efficient and effective alternate to prepare biodiesel since its initial cost is low as compared to other raw materials, and also it result in better usage of problematic waste into environment friendly fuel. Worldwide increase of for diesel fuel and environmental emission control has led to considerable research for better fuel formulations and thus reduction in smoke and particle levels with the help of Semi Empirical Approach Keywords Transesterification reaction, Waste cooking oil, Titration, Biodiesel, Semi-Empirical Model I. INTRODUCTION The demand oh high energy in the industrial and different commercial sectors has led to fast depletion of fossil fuel which further leads to imbalance in the ecology, also the rising prices of this fossil fuel has inspire a mankind to think of preparing of different types of alternate fuel. Biodiesel is a biodegradable, renewable and environment friendly alternate fuel, since it can be produced from renewable sources such as vegetable oil, animal fats, waste cooking oil etc. Moreover the method used to produce biodiesel is simple, easy and safe to store due to its higher property of flash point. As waste cooking oil is a cheaper feedstock, and oil which is otherwise wasted after its use can be utilize as a better option to produce most economical biodiesel. In India some of the hotels and restaurants are having good practice of disposing off the used oil after reaching the degradation level of oil. Also the glycerol which the bi-product after successful reaction can be used to make soap, grease etc by proper treatment and processes. Waste cooking oil is an efficient and effective alternate to prepare biodiesel since its initial cost is low as compared to other raw matetial. 2. Methodology 2.1 Materials and Equipment Used Waste cooking oil (WCO), Magnetic stirrer, Magnetic pin, Round bottom flask with condenser, Electric heater, Beaker, Funnel, Electrical supply, Water supply, Stand, Conical separating funnel, Pan, Methanol, Sodium hydroxide (NaOH), Sodium sulphate, Isopropyl alcohol, Weighing machine, Measuring flask. Experimental Procedure 2015, IERJ All Rights Reserved Page 1
Waste cooking oil Pre-Treatment (straining and heating) Determination of free fatty acid Transesterification reaction Glycerine separation Water washing of crude biodiesel. Pure biodiesel 2.2 Collection And Pre-Treatment Of Waste Cooking Oil Waste cooking oil is collected from different hotels, mess, catering services and dhabas for the present study, therefore the cost of the raw material used is negligible. However in some cases it may carry charges. This waste cooking oil has suspended solid particles which can be removed by proper straining in the strainer, further the oil is heated to remove any moisture content and thus making a moisture free waste cooking oil. 2.3 Determination Of Free Fatty Acid Content For determining the free fatty acid content present in the waste cooking oil, Titration process is carried out, In which 0.1N NaOH(0.4gms in 100 ml distilled water) solution is titrated against a mixture of 10ml isopropyl alcohol and 1ml oil sample with 2-3 drops of phenolphthalein indicator. The end point of titration is reached when the solution turns pink and stays pink for 10sec.The amount of 0.1N NaOH solution needed is equal to the extra gms of pure sodium hydroxide needed to allow proper reaction to take place to prepare biodiesel, thus the amount of NaOH needed for the reaction is taken (3.5+x) gm. per liter of oil, where x is the titration reading in ml, this extra amount of NaOH is needed to neutralize the free fatty acid content in the oil. 2.4 Esterification Process The waste cooking oil is mixed with sodium methoxide solution which is prepared by mixing NaOH pallets (3.5+X)gm per liter of oil into analytical grade methanol(for 1000ml of oil 200ml of methanol), Generally methanol used is 20% of waste cooking oil. This solution is poured in the round bottom flask and it is placed on the magnetic stirrer with condenser fitted at the mouth of the flask. The constant temperature of 65 0-70 0 was maintained using electric heater (since boiling point of methanol is 65 0 ) and the mixture was vigorously stirred using magnetic stirrer for about 2hrs. The care should be taken that he flow to the condenser should be adequate so that there should not be any evaporation of methanol to the atmosphere, thus 100% methanol takes part in the reaction. The setup is shown in fig 1.After 2hrs of reaction time the condenser is removed from the mouth of round bottom flask and the mixture is heated openly with constant stirring for further one and half hour. This allows the excess methanol to evaporate which does not take part in the reaction. The reagent (mixture) is poured in the conical separating funnel and the solution is left overnight for about 20-24hrs for the separation in two layers after settlement. Basically successful reaction produces two layer vise i.e. ester and crude glycerol as shown in fig 2. The bottom layer is a glycerol which can be drained off and the crude biodiesel is taken for further process. 2.5 Water Washing Process Since there are number of water soluble impurities left in the crude biodiesel after reaction and initial settling is complete. These contaminants include a small amount of left over methanol, catalyst and free glycerin. Water washing process can be adopted to treat this impurities and further pure biodiesel can be obtained. This method involves three steps, first crude biodiesel sample is poured in conical separating flask and water is added gently by an amount one-third to that of crude biodiesel, the water separates immediately due to density difference, it can be noticed that the pure water which is added is not clear then the funnel is shacked vigorously for separating the contaminants, the unclear funnel which is settling down is drained off. This process is repeated till the pure water is drained from the crude biodiesel. Generally this process is repeated for about 10-12 times. Water washing also has two additional advantages i.e. it stops the very slow remaining reaction that occur sometimes. Secondly if the fuel is not washed then the glycerin settle over a period of weeks or months due to left over methanol and catalyst. 2015, IERJ All Rights Reserved Page 2
After repeated process till water is clear in order to remove the water traces in the biodiesel 10% by weight of biodiesel heated dry sodium sulphate is added and decant it after sometime. Dry sodium sulphate absorbs the moisture and gives moisture free biodiesel. During the process utmost care should be taken not to drain of any biodiesel traces which may affect final biodiesel yielding. Various stages in biodiesel production are shown in fig below. The specification of VCR engine Table 1: Specifications of the variable compression ratio engine 3.Results And Discussion 3.1 Performance Analysis Various engine performance characteristics such as BTHE, BP, Mech eff etc and engine emissions such as CO, NO, HC and were analysed for all blends of biodiesel along with fuel with petroleum diesel at different loads and various compression ratio. 3.1.1Brake Thermal Efficiency:- Brake thermal efficiency is the ratio of brake power to the energy released during the combustion process. Fig shows variations in brake thermal efficiency at different loads with different compression ratio, it can be observed that at BTHE for all biodiesel blends are higher than that of diesel fuel this may be due to higher cetane number, which can reduce knocking tendency by, decreasing delay period.. 2015, IERJ All Rights Reserved Page 3
fig 5 variation of brake thermal efficiency at different loads and different blends 3.1.2Mechanical Efficiency-: Graph is show that as load increases conveniently mechanical efficiency increases as compared with different CR fig 6 variation in mechanical efficiency at different loads and different blends 3.1.3Brake Power-:Graph is show that as load increases subsequently brake power increases. As diesel is having the higher heating value as compared to B20, B20DIE5 and B20DIE10 the brake power obtained is maximum to diesel as compared to biodiesel blends. 2015, IERJ All Rights Reserved Page 4
fig 7 variation in brake power at different loads and different blend 3.2 Emission Analysis 3.2.1 Oxides Of Nitrogen -:Graph show variation in oxides of nitrogen with different loads and different blends it can be seen that NOx produced for B20DIE5 and B20DIE10 are higher at lower compression ratio. Fig 8 Variation In Oxides Of Nitrogen At Different Loads With Different Blends 2015, IERJ All Rights Reserved Page 5
3.2.2Carbon Monoxide Emission:-Graph show variation in carbon monoxide at different loads with different blends with different CR. fig 9 variation in carbon monoxide emission with different loads and different blends. 3.2.3 Hydro Carbon Emissions Graph show the plots of hydrocarbon variation with respect to different loads and different fuel blends. As can be seen at lower compression ratio for B20DIE5 and B20DIE10 hydro carbon emissions are quite large as compared to diesel fuel. 2015, IERJ All Rights Reserved Page 6
Fig 10 Variation In Hydro Carbon Emissions At Different Loads And Different Blends 4. Semi-Empirical Approach A semi-empirical model has been proposed for the determination of Hydrocarbon of diesel-biodiesel blends. The wastage cooking oil was used as biodiesel in the experimentation. The basic model was developed using dimensional analysis, coefficients and power indices were evaluated from experimental results using multiple regression analysis. The engine performance and emission characteristics of diesel, wastage cooking oil and their blends like D100, B20, B20+5%, B20+10% were evaluated. Semi- Eperical Model-: Dimensionless Analysis s Speed = [M 0 L 0 T -1 ] TORQUE= [M 1 L 2 T -2 ] LOAD = [M 1 L 0 T 0 ] IMEP = [M 1 L -1 T -2 ] HC = [M¹L T ¹] N=No. of parameters =5 M= No. of fundamental dimensions = 3 Parameters in terms = M + 1 =3+1 = 4 Let [M 0 L 0 T 0 ] [M 0 L 0 T -1 ] (a 1 ) [M 1 L 2 T -2 ] (b 1 ) [M 1 L 0 T 0 ] (c 1 ) [HC] Equating power of M, L,T we get For M: 0 = b 1 +c 1 +1........ (1) For L: 0 = 2b 1 +0....... (2) For T: 0 =-a 1-2b 1-1......... (3) Solving we get a 1 = -1,b 1 = 0, c 1 = -1. 2015, IERJ All Rights Reserved Page 7
Now [M 0 L 0 T 0 ] = [M 0 L 0 T -1 ] (a 2 ) [M 1 L 2 T -2 ] (b 2 ) [M 1 L 0 T 0 ] (c 2 ) [IMHP] Equating power of M, L,T we get For M: 0 = b 2 +c 2-1........ (1) For L: 0 = 2b 2-1....... (2) For T: 0 =-a 2-2b 2-2......... (3) Solving we get a 2 = -3,b = 1/2, c1 = -3/2 = HC = K X ^A X [(SPEED)(LOAD) ]^B HC = K. (X)^A. (Y)^B Taking Log both side Log (HC) = Log (K) + A Log (X) + B Log(Y) Then putting all observation value in above eq and then getting all constant value by using MINITAP.. K = 1.0030, A = 0.000052 B = 0.000061 HC =K X[ ]^A X [(SPEED)(LOAD) ]^B HC = 1.0030 X[ ]^0.000052 X [(SPEED)(LOAD) ]^0.000061 Then getting the valve of HC by putting all value in above eq HC= 0.000586 And then compared original HC value to Numerical HC value HC = 0.000586 2015, IERJ All Rights Reserved Page 8
II CONCLUSION In the present investigation, the performance and emission characteristics of a single cylinder four variable compression ratio (VCR) engine fuelled with stroke waste cooking oil biodiesel and its blends have been studied and compared with the diesel fuel, all the results have been summarized below 1. Biodiesel can be prepared from waste cooking oil by transesterification process and all the properties meets ASTMD6751 standards of biodiesel. 2. Diesel engine can work satisfactorily on biodiesel and its blends with the diesel fuel and additives without any engine modification. 3. Performance characteristics such as BTHE, BP, MECHEFF are higher for blends B20DIE5 and B20DIE10 due to higher cetane number, whereas SFC for B20 blend is lower to that of diesel at different load conditions. 4. It is also observed that the significant reduction in CO, HC and smoke emission for biodiesel and its blends compared to diesel fuel. NOx emission were decreased with B20 blend as compared to diesel fuel. 5..The value of HC is calculated with the help the semi empirical model is similar to the actual HC value. III.ACKNOWLEDGMENT The authors would like to present their sincere gratitude towards the Faculty of Mechanical Engineering in Rajarshi Shahu College of Engineering, Pune. REFERENCES K. Muralidharan, D. Vasudevan (2011) Performance, emission and combustion characteristics of a variable compression ratio engine using methyl esters of waste cooking oil and diesel blends, Applied Energy, Volume 88, pages 3959 3968. Hiba Abdalla Mahagoub, Nimir ali salih (2015) Suitable condition of biodiesel production from waste cooking oil-al-baha city- KSA,Multidisciplinary and current research, volume 3, pages 447-450. Y. Zhang, M. A. Dube, D. D. McLean (2003) Biodiesel production from waste cooking oil: 1. Process design and technological assessment Bioresource Technology volume 89,pages 1-16. Noor Hindryawati, Gaanty Pragas Maniam, Md. Rezaul Karim (2014) Transesterification of used cooking oil over alkali metal (Li, Na, K) supported rice husk silica as potential solid base catalyst Engineering science and technology, an international journal, volume 17, pages 95-103. Abile Teshita, Alemayehu Gashaw (2014) Production of biodiesel from waste cooking oil and factors affecting its formation: A review International Journal of Renewable and Sustainable Energy, volume 5, pages 92-98. Mohammed EL-Kassaby, Medhat A. Nemit-allah(2013) Studying the effect of compression ratio on an engine fueled with oil produced biodiesel/diesel fuel Alexandria Engineering Journal, volume 52,pages 1-11. 2015, IERJ All Rights Reserved Page 9