Copyright © 2015 IJEIR, All right reserved 816 International Journal of Engineering Innovation & Research Volume 4, Issue 6, ISSN: 2277 – 5668 Comparative Study of Homogenous and Heterogeneous Catalytic Transesterification of High Free Fatty Acid Jatropha curcas Oil: Effects on Products Quality *Haruna Ibrahim, Kenneth O. Nwanya, Susannah I. Ayilara, Deborah C. Nwakuba, Olubukola B. Adegbola, Umar I., Hassan and Yunusa Tukur *Corresponding Author's Email: ibrahimhauna@gmail.com Abstract – The effects of high free fatty acids in feedstocks on biodiesel qualities was investigated in this study by carrying out homogenous and heterogeneous catalytic transesterification of 3.36 FFA Jatropha curcas seed oil with methanol. The catalysts used were NaOH and MgO, same methanol to oil molar ratio catalyst loading and reaction conditions. The reactions were carried out at 60oC for 60 minutes and 3:1 moles of methanol to oil. Methyl esters contents for homogenous products were satisfactory; 95.5%, 98.4%, 97.4% and 85.7% but poor viscosities 0.5 mm2/s, while heterogeneous products had low methyl esters contents;77.9%, 73.7%, 71.1% and 76.2% but had satisfactory viscosities of 3.5 mm2/s. The acid values in the products of the two processes were too high 0 to 12% for homogenous and 7.3% to 9.5% for heterogeneous. The products of two processes did not satisfactorily meet the EN 14214 and ASTM D6751 standards due to effect of the free fatty acids in the feedstock. Keywords – Comparative Study, Effect of Free Fatty Acid Feedstock, Transesterification. I. INTRODUCTION Biodiesel is continuing gaining acceptance internationally due to its environmental benign nature. Its degradability, no toxicity, low emission of carbon monoxide, particulate matter and unburned hydrocarbons and also renewability [1] have made it to be accepted for use in compression ignition engines. It is free of sulphur and aromatic compounds, has higher energy content and lubricating machines parts better than fossil diesel. Especially biodiesel from plant oils do not have sulphur except that produced from animal fats [2]. Biodiesel has higher cetane number (ranging from 45-70) than fossil diesel (40-52) [3]. Biodiesel is compatible with conventional diesel fuel and already comprises a commercial fuel in Europe and U.S. [4] in the percentage of 10 and 20 called B10 and B20 respectively. According to Guo and Fang [5] homogeneous alkali catalysts can convert triglycerides to fatty acid alkyl esters (FAAEs) with high yield, less time and low cost, but separating the catalyst from the product mixture is technically difficult. The use of homogeneous catalysts requires neutralization and separation from the reaction mixture, leading to a series of environmental problems related to the use of large amounts of solvents and energy [6]. According to Singh et al,.[7] the most commonly used alkaline catalysts in the biodiesel industry are potassium hydroxide (KOH) and sodium hydroxide (NaOH) flakes which are inexpensive, easy to handle in transportation and storage, and are preferred by small producers. The homogenous acids catalysts, apart from catalyzed transesterification very slow are corrosive to the equipment [5]. This study was carried out to determine the effects of high free fatty acid in feedstocks on the transesterification reactions and products. A Jatropha curcas oil of 3.36 free fatty acid was used to produce biodiesel with methanol in 1:3 molar ratio (oil/methanol) using NaOH and MgO as catalysts. The catalyst loading were the same for both and also same reaction conditions were maintained. II. MATERIALS AND METHODS The materials used in this investigation include; NaOH, MgO as catalyst, 0.1M KOH, methanol, concentrated sulphuric acid, phenolphthalein, propan-2-ol, Jatropha curcas seed oil, conical flasks, burette, magnetic stirrer, thermometer, viscometer and GC-MS machine. 2.1 Transesterification FFA of raw Jatropha curcas L oil was determined by dissolving 1.0 g of it in 25 mL of propan-2-ol. The resulting solution with two drops of phenolphthalein was titrated with 0.1 M KOH to pink colour. The raw oil was divided into two. 100 g of one part was transesterified with methanol and 1.2 g of NaOH and same mass of the second part was transesterified with methanol and 1.2 g magnesium oxide (MgO). In both reactions 3 moles of methanol was used with one mole of oil. The catalyst loading in the two cases was 1.2% of the mass of oil. The transesterifications were carried out in conical flasks on magnetic stirrers simultaneously for 60 minutes. The transesterified products were transferred into separating funnels for separation after filtration. The one catalyzed by MgO remained uniform. The one catalyzed by NaOH was separated into biodiesel, glycerol and soap. The biodiesel was collected washed and dried. This process was repeated until it stopped foaming. This experiment was repeated with 4.5, 6 and 7.5 moles of methanol to one mole of oil. 2.2 GC-MS Analysis 2 ml of each sample was diluted with n-hexane. The resulting mixture was filled into a sample bottle and inserted into the GC-MS machine. The machine was run and the chemical components of the sample were analyzed. The methyl esters content was calculated from area% of the GC-MS analysis. This analysis was