Production of Methyl Ester from Mixed Oil (Dairy Waste Scum & Karanja Oil)

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1 Production of Methyl Ester from Mixed Oil (Dairy Waste Scum & Karanja Oil) Omkaresh B R 1, Yatish K. V. 2, R. Suresh 3 1 Assistant Professor, Department Mechanical Engineering, SIT, Tumakuru, Karnataka, India 2 Scientific Assistant, Bioenergy Research Information & Demonstration Centre, SIT, Tumakuru, Karnataka, India 3 Professor, Department Mechanical Engineering, SIT, Tumakuru, Karnataka, India. omkara313@gmail.com Abstract Conventional energy resources or fossil fuels are depleting day by day due to increase in population, industrialization and transportation all over the world. Hence there is increasing worldwide concern about developing renewable resources to replace conventional resources. Globally renewable ecofriendly resources are available in the form of agricultural biomass residues, which can be used as a source for biodiesel production, but the process of conversion or chemical transformation will become more expensive. This work involves biodiesel production from Karanja oil (Pongamia Pinata), Scum oil and Mixed oil (Karanja and Scum) through transesterification process using base catalysts. The percentage yield of biodiesel obtained from each oil by using homogeneous catalyst (KOH) and heterogeneous catalyst (Na3PO4) are compared. The biodiesel obtained are blended with conventional diesel in different proportions and fuel properties like kinematic viscosity, flash point and density are determined for each blend. Key words Fossil fuel, Biodiesel, Transesterification, Fuel properties, KOH and Na 3 PO 4. I. INTRODUCTION Rapid development in technology and increasing automation in industries, increased civil constructions and diminution of liquid fossil fuels creates increase in requirement of fuel and energy. Biodiesel (Fatty acid Methyl ester) derived from any vegetable oil is renewable, nontoxic fuel which can be obtained by transesterification process in presence of suitable catalyst. Generally Homogeneous and Heterogeneous catalyst were used. The homogeneous are preferred due to availability and cheap compared to heterogeneous catalysts [1]. Transesterification rate is very rapid with homogeneous alkaline catalysts. Large quantity of water used to wash the biodiesel leading to reduce ph value of biodiesel to normal, but this will generate large amount of wastewater containing high acidity or basicity [2-4]. Use of heterogeneous catalysts is currently preferred because of advantages of easily separation and purification [5-9]. However, different heterogeneous catalyst developed are quite expensive and complicated to prepare. [1]. Heterogeneous catalyst process is noncorrosive, reusable, easy separation of final biodiesel from catalyst and glycerine [11, 12]. Different types of heterogeneous solid catalysts, BaO, SrO CaO MgO, Na3PO4 have been used for the transesterification of vegetable oils [13, 14]. Three hundred different species of trees in India produces oil seeds [15]. India has the potential to be a leading world producer of biodiesel by using Non-edible oil seeds as source [16]. Pongamia pinata is a Nonedible oil seeds bearing tree grows to about meters in height [17]. Pongamia seeds contain around 35% oil [18]. Dairy scum is a less dense floating solid mass usually formed by a mixture of fat, lipids, proteins, packing materials etc. A huge dairy, which processes large quantity of milk per day, will produce effluent dairy scum every day. Hence, dairy scum can also be used as raw material for production of biodiesel [19]. Biodiesel has many advantages compared to diesel fuel. It has higher cetane number than diesel and contains no aromatics, almost no sulphur and 1-12% oxygen by weight. Biodiesel-fuelled engines produce less emissions than diesel fuel [2, 21]. Biodiesel improves the lubricity, which results in the longer engine component life [22-24]. However, the drawback of biodiesel is tendency to oxidize with air especially at high temperatures [25]. When diesel engines are fuelled with biodiesel, NOx emissions increases compared to diesel [26]. Physical and chemical properties of biodiesel have direct impact on performance and emission of the engine [27]. Fuel properties like fire point, flash point, viscosity, density cloud point, pour point, ash content and copper corrosion were determined. These properties will affect the performance and emission characteristics of diesel engine [28]. Higher viscosity causes poor fuel atomization during spray, increases the carbon deposition on fuel filter, demands more energy from the fuel pump [29]. JoRSTEM, Malla Reddy Engineering College (Autonomous). 22

2 In addition, the higher viscosity of biodiesel fuel affects the start of injection(soi) and fuel spray characteristics [3-32]. The density of the diesel fuel is also important parameter, since other parameter like cetane number have been correlated against it [33]. In addition, the density values have also been used to measure the amount fuel in fuel system by volumetric method [28]. The flash point does not directly affect the combustion, it makes the biodiesel safer regarding the storage and transport [34, 35]. This work is based on biodiesel production from Karanja oil, Dairy Scum oil and Mixed oil (both Karanja and Dairy Scum oil) by using KOH as homogeneous catalyst and Na3PO4 as heterogeneous catalyst and comparing the percentage yield of biodiesel. This work also involves determining the fuel properties (kinematic viscosity, flash point and density) of biodiesel and comparing it with diesel. II. EXPERIMENTAL METHODS AND MATERIALS A. Materials The Karanja oil is collected from Biofuel I&D centre, SIT, Tumakuru, Karnataka, India. The Scum oil is collected from KMF, Tumakuru, Karnataka, India. The Potassium hydroxide, Sodium phosphate and methanol is purchased from Veeresh Scientifics, Tumakuru, Karnataka, India. B. Characterization of mixed oil. The karanja oil and the dairy scum oil are mixed in 5:5 proportions to get the mixed oil. The fatty acid composition of the mixed oil was analysed using gas chromatography (GC). The data is given in table1. TABLE I: CHEMICAL COMPOSITION OF MIXED OIL. C. Biodiesel Transesterification Reactions Initially FFA content of mixed oil is found out by using.1n NaOH and Phenolphthalein to determine whether the oil should undergo esterification before transesterification. i.e. If the oil contains free fatty acids content > 4%, then 2 step transesterification is required to convert oil to its mono esters [24]. The first step, the acid catalysed esterification and the second step, alkaline transesterification process converts the products of the first step to its mono esters and glycerol. Transesterification process consists of a sequence of three consecutive reversible reactions i.e. conversion of triglycerides to diglycerides followed by diglycerides to monoglycerides. The glycerides were converted into glycerol and one ester molecule at each step. The mechanism was represented in equations as follows [36]. ROH B RO BH H 2 COCR 3 O OR OR H 2 C O C R 3 O OR H 2 C O C R 3 O BH ROOCR 3 H 2 C OH JoRSTEM, Malla Reddy Engineering College (Autonomous). 23 H 2 C O Scheme 2. Mechanism of transesterification reaction D. Transesterification setup Take 1ltr of mixed oil in a three neck flask with reflux condenser, heat the oil up to 6-65 C. After heating the oil add methanol and catalyst. The methanol to oil molar ratio is 6:1 and 1% of potassium hydroxide is to be added to oil in case of homogeneous catalyst. The methanol to oil molar ratio is 6:1 and 2% of Trisodium phosphate is to be added to oil in case of heterogeneous catalyst. Run the process for about 9 minutes. Transfer that oil into separating funnel and allow it to settle into different layers for about 8-16 hours. Then two layers will be formed in case of

3 Percentage yield Kinematic viscosity (Cst) Journal of Research in Science, Technology, Engineering and Management (JoRSTEM) homogeneous catalyst as shown in figure-2 below, upper layer is biodiesel and lower layer is glycerin. Separate the glycerin from biodiesel. Three layers will be formed in case of heterogeneous catalyst as shown in figure-3 below. Biodiesel Glycerin Catalyst Fig. 2 Settling in separating funnel using KOH catalyst E. Washing and Drying This is done only in homogeneous catalyst biodiesel production method. Washing is a process of removing the excess basicity or acidity, soaps, entrained glycerol and excess methanol. The biodiesel obtained after transesterification is washed until the biodiesel layer had a ph of similar to the ph of distilled water. After washing, the biodiesel is heated above 1oC for about 3min to remove water content in it. This process is called Drying. F. Decalcification This is done only in heterogeneous catalyst biodiesel production method. It is the process of removal of calcium content from the biodiesel. It is carried out by the complexing agent such as Citric acid or EDTA (Ethylene Diamine tetra-acetic acid). This complexing agent can absorb the catalyst content from the biodiesel. It can also use to absorb the impurities from the biodiesel. Obtained biodiesel from transesterification process contains methanol and some amount of catalyst. The methanol from the biodiesel can be recovered from distillation setup. After that we can add 8 ml of Citric acid for 1litre of biodiesel during decalcification process. The complexing agent with catalyst powder is collected at the bottom by giving pure biodiesel. III. RESULTS AND DISCUSSION Fig. 3 Settling in separating funnel using Na3PO4 catalyst A. Percentage yield of biodiesel The percentage yield of biodiesels by using homogeneous catalyst (KOH) and heterogeneous catalyst (Na3PO4) are shown in graph-1. 1 using KOH using Na 3 PO 4 6 Karanja Biodiesel Scum Biodiesel Mixed oil Biodiesel Karanja Scum Mixed oil Homogeneous catalyst Heterogeneous catalyst Type of oil Type of catalyst Graph 1 Percentage yield of biodiesel obtained using different catalyst Graph 2 Kinematic viscosity of biodiesels The percentage yield of Karanja biodiesel, Scum biodiesel and Mixed oil biodiesel is found to be 95%, 93% and 94% respectively by using homogeneous catalyst (KOH) and 97%, 96% and 98% respectively by using heterogeneous catalyst (Na3PO4). Hence the above graph shows that the maximum yield of biodiesel can be obtained by using Na3PO4 than KOH. B. Kinematic viscosity Higher viscosity causes poor fuel atomization during spray and affects the start of injection, injection pressure and the fuel spray characteristics, which are the main parameters that affect engine performance and exhaust emissions. The kinematic viscosity of various biodiesels produced using homogeneous catalyst (KOH) and JoRSTEM, Malla Reddy Engineering College (Autonomous). 24

4 Flash Point ( O C) Density (Kg m -3 ) Journal of Research in Science, Technology, Engineering and Management (JoRSTEM) heterogeneous catalyst (Na3PO4) are shown in graph-2. The viscosity of biodiesels produced using heterogeneous catalyst is more than biodiesels produced from homogeneous catalyst. The kinematic viscosity of Karanja biodiesel produced from both catalyst is more than scum biodiesel. But the kinematic viscosity of karanja biodiesel can be reduced by mixing karanja oil with scum oil. The kinematic viscosity of various biodiesels are in the range of ASTM standards (1.9-6.) but more than that of diesel which is 2.54Cst. Hence the biodiesels can be used as blends with diesel with suitable proportions. C. Flash point The flash point of the biodiesel is also important parameter to be considered because it makes the biodiesel safer regarding the storage and transport. The flash point of various biodiesels produced using homogeneous catalyst (KOH) and heterogeneous catalyst (Na3PO4) are shown in graph-3. The flash point of biodiesels produced using heterogeneous catalyst is more than that of biodiesels produced from homogeneous catalyst. The flash point of Karanja and mixed oil biodiesels are in the range of ASTM standards (>13 OC) but flash point of Scum biodiesel is less than ASTM standard range. Hence the flash point of Scum biodiesel can be increased to required range by mixing Scum oil with Karanja oil. The flash point of diesel is 54 C. It shows the flash point of biodiesels that are produced from both catalyst is more than diesel hence safer for transport. D. Density The density of the diesel fuel is also a very important parameter, since other crucial performance parameters of engine such as cetane number and heating value have been correlated against it. The variation of density affects the power and the fuel spray characteristics during fuel injection and combustion in cylinder. The value of density depends on the triglyceride molecules present and higher molecular weights. The density of various biodiesels produced using homogeneous catalyst (KOH) and heterogeneous catalyst (Na3PO4) are shown in graph Karanaja Biodiesel Scum Biodiesel Mixed oil Biodiesel Karanja Biodiesel Scum Biodiesel Mixed oil Biodiesel Homogeneous catalyst Type of catalyst Na3PO4 catalyst Homogeneous catalyst Type of catalyst Heterogeneous catalyst Graph 3 Flash point of biodiesels Graph 4 Density of biodiesels The density of biodiesels produced using heterogeneous catalyst is more than that of biodiesels produced from homogeneous catalyst. The density of obtained biodiesels are in the range of ASTM standards (86-9 Kg/m3). The density of diesel is 816 Kg/m3. Since the density of biodiesels obtained is more than diesel, the biodiesels are blended in suitable proportions with diesel. IV. CONCLUSION The present work shows that both Potassium hydroxide and Trisodium phosphate are suitable catalysts for production of biodiesel. Trisodium phosphate can be recovered and it can be reused. The percentage yield of biodiesels obtained by using Trisodium phosphate is more than Potassium hydroxide. The fuel properties (kinematic viscosity, flash point and density) of Karanja biodiesel is more compared to Scum biodiesel and Mixed oil biodiesel. The flash point of each biodiesel is higher, hence it is safer for fuel transportation. The fuel properties (kinematic viscosity, flash point and density) of each biodiesel that are produced is very high compared to diesel. Hence these biodiesels can be used as blends with diesel with suitable proportions to achieve CI engine specification range. JoRSTEM, Malla Reddy Engineering College (Autonomous). 25

5 V. ACKNOWLEDGEMENT We thank the Bioenergy research Information & Demonstration Centre, SIT, Tumakuru-3 Karnataka, India for providing necessary experimental setup to perform this research. We also thank Bangalore Test House, KSSIDC Industrial Estate, Rajajinagar, Bangalore , India. REFERENCES [ 1 ] Z.J. Predojevic et al. The production of biodiesel from waste frying oils: a comparison of different purification steps, Fuel, Vol. 87, No , pp , 28. [ 2 ] G. Guan et al. Tri-potassium phosphate as a solid catalyst for biodiesel production from waste cooking oil, Fuel Processing Technology, Vol. 9, No. 4, pp , 29. [ 3 ] M. Zabeti et al. Optimization of the activity of CaO/Al2O3 catalyst for biodiesel production using response surface methodology, Applied Catalysis A: General, Vol. 366, No. 1, pp , 29. [ 4 ] M. Kouzu et al. Calcium oxide as a solid base catalyst for transesterification of soybean oil and its application to biodiesel production, Fuel, Vol. 87, No. 12, pp , 28. [ 5 ] J. Kansedo et al. Biodiesel production from palm oil via heterogeneous transesterification, Biomass and Bioenergy, Vol. 33, No. 2, pp , 29. [ 6 ] M. Zabeti et al. Optimization of the activity of CaO/Al2O3 catalyst for biodiesel production using response surface methodology, Applied Catalysis A: General, Vol. 366, No. 1, pp , 29. [ 7 ] M. Kouzu et al. Calcium oxide as a solid base catalyst for transesterification of soybean oil and its application to biodiesel production, Fuel, Vol. 87, No. 12, pp , 28. [ 8 ] K.G. Georgogianni et al. Transesterification of soybean frying oil to biodiesel using heterogeneous catalysts, Fuel Processing Technology, Vol. 9, No. 5, pp , 29. [ 9 ] G. Arzamendi et al. Synthesis of biodiesel with heterogeneous NaOH/alumina catalysts: Comparison with homogeneous NaOH, Chemical Engineering Journal, Vol. 134, No. 1 3, pp , 27. [ 1 ] M.C.G. Albuquerque et al. CaO supported on mesoporous silicas as basic catalysts for transesterification reactions, Applied Catalysis A: General, 334 (1 2), pp , 28. [ 11 ] Shimada Y Et al. Enzymatic alcoholysis for biodiesel fuel production and application of the reaction to oil processing. J Mol Catal B: Enzym., Vol. 17, pp , 22. [ 12 ] Liu X Et al. Transesterification of soybean oil to biodiesel using CaO as a solid base catalyst. Fuel, Vol. 87, pp , 28. [ 13 ] S. Gryglewicz et al. Rapeseed oil methyl esters preparation using heterogeneous catalysts, Bioresour. Technol. Vol. 7, pp , [ 14 ] S. Gryglewicz et al. Alkaline-earth metal compounds as alcoholysis catalysts for ester oils synthesis, Appl. Catal. A: Gen. 192, pp , 2. [ 15 ] Kalam MA et al. PAH and other emissions from coconut oil blended fuels. IND Res. Vol. 67, No. 11, pp , 28. [ 16 ] Orko L. N et al. Synthesis, Calorimetric and Viscometri study of Groundnut oil Biodiesel and Blends, RJCS, Vol. 1, No. 3, pp , 211. [ 17 ] Sanjib Kumar Karmee et al. Preparation of Biodiesel from Crude oil of pongamia pinnata, Bioresourse Technology, pp , 25. [ 18 ] Freedom B et al.variables affecting the yields of fatty esters from transesterified vegetable oils. J Am oil Chem Soc., Vol. 61, No. 1, pp , [ 19 ] P.Sukumar et al. Biodiesel production by alkali catalyzed transesterification of dairy waste scum. Fuel 9, pp , 211. [ 2 ] Graboski MS and McCormik RL, Combustion of fat and vegetable oil derived fuels in diesel engines. Prog Energy Combust Sci., Vol. 24, pp , [ 21 ] Tomasevic AV, Marinkovic SS. Methanolysis of used frying oil.f.process Technol, Vol. 81, pp. 1-6, 23. [ 22 ] Boehman LA. et al. Biodiesel production and processing. Fuel Process Technol, Vol. 86, 157-8, 25. [ 23 ] Kinast JA. et al. Production of biodiesels from multiple feedstocks and properties of biodiesels and biodieseldiesel blends. National renewable energy laboratory report, Des Plains, 21. [ 24 ] Gerpen JV. Biodiesel processing and production. Fuel Process Technol, Vol. 86, , 25. [ 25 ] Monyem A, Canakci M, Gerpen JV. Investigation of biodiesel thermal stability under simulated in-use conditions. Appl Eng Agric, Vol. 16, No. 4, pp , 2. [ 26 ] Canakci M, Gerpen JV. Comparision of engine performance and emissions for petroleum diesel fuel, yellow grease biodiesel and soybean oil biodiesel. Trans ASAE, Vol. 46(4), pp , 23. [ 27 ] Tate R et al. The density of three biodiesel fuels at temperatures up to 3oC. Fuel, 85, (7-8):14-9, 26. JoRSTEM, Malla Reddy Engineering College (Autonomous). 26

6 [ 28 ] Alptekin E, Canakci M. Determination of the viscosity and the density of biodiesel-diesel fuel blend. Renewable Energy, Vol. 33, No. 12, pp , 28. [ 29 ] Tate R et al. The viscosities of three biodiesel fuels at temperatures up to 3oC. Fuel, Vol. 85, No. 7-8, 11-5, 26. [ 3 ] Heywood JB. Internal combustion engine fundamentals. New York: McGrawHill.;1988. [ 31 ] Coulson JF, Richardson JH. Particle technology and separation process. London: Butterworth Heinemann; 22. [ 32 ] Holland, Chapman. Pumping of liquids. New York: Reinhold Publishing Corporation; [ 33 ] Tate M, Garpen J. The specific gravity of biodiesel and its blends with diesel fuels. JAOCS, Vol. 77, No. 2, pp , 2. [ 34 ] Encinar JM, Gonzalez-Reinares A. Biodiesel from used frying oil variable affecting the yields and characteristics of biodiesel. Ind Eng Chem Res, 44:5491-9, 25. [ 35 ] Owen K, Coley T. Automotive fuels reference book. Society of Automobile Engineers. 2 nd Ed., Warrandale; [ 36 ] Ma F. and Hanma M.A Biodiesel production: A review Bioresource technol, 7, pp. 1-15, JoRSTEM, Malla Reddy Engineering College (Autonomous). 27