Characteristics and Composition of Soyabean Oil Seed from India by Alkali-Catalyzed Transesterification and its Potential as Biodiesel Feedstock

Biodiesel is a mixture of monoalkyl esters of long chain fatty acids, which are mainly produced from vegetable oils, seeds of fatty acids and animal fats. Biodiesel is produced by the acid or by base catalyzed transesterification reactions of vegetable oils, seeds of fatty acids and animal fats with ethanol or methanol [1]. Without any modification of the engine biodiesel can be used in diesel engines. The remarkable endeavour have been formulate for procure biodiesel by acid-base catalyzed transesterification of oil obtained from jatropha, soyabean, sunflower, food waste, grease, cotton seed, rapeseed, sorghum and palm etc. During the acid-base catalyzed transesterification reaction the presence of glycerine increases the viscosity of biodiesel which may leads other problems like higher viscosity. Transesterification of oil and fats using short chain alcohols, results in monoesters having viscosity that is closer to petroleum based diesel fuel. The physico-chemical properties such as viscosity, density, flash point, fire point, cloud point, pour point, iodine value and acid value etc. affect the biodiesel engine performance and emission. There are many advantages of biodiesel e.g., it is ecofriendly, non-flammable and nontoxic, its renewable, safe for traditional diesel engines, good performance of engine, reduces the discharge of exhaust system, perceptible gas, toxic fumes and odour’s. The emerge of biodiesel has during the last few Characteristics and Composition of Soyabean Oil Seed from India by Alkali-Catalyzed Transesterification and its Potential as Biodiesel Feedstock

years. Generally the production of biodiesel directly dependence upon feedstock and the large per cent of the direct biodiesel production costs, including capital cost and return cost dependence upon the feedstock costs [2]. Soyabean constitute of phytic acid, dietary minerals and B vitamins. Soyabean seed oil comprises of saturated and unsaturated fatty acids. The major unsaturated fatty acids in soyabean seed oil triglycerides are the poly unsaturated α-linolenic acid, linoleic acid and the mono unsaturated oleic acid. Soyabean seed oil also contains the saturated fatty acids i.e., stearic acid and palmitic acid [3]. Oil extraction from soybeans and biodiesel production was performed using conventional and ultrasonication methods [4]. Soyabean oil seed biodiesel can also be prepared by the hydrotalcite was synthesized using the co-precipitation method with Mg/Al molar ratio of 3.0 and calcined at 450 °C (723 K), under Ar flow, for 6 h. The obtained solid was characterized by X-ray powder diffraction and temperature-programmed desorption of CO2 (CO2-TPD) [5] but there is no characterization of methyl ester of soyabean seed oil were found. The main objectives of this study are the enhancing the production of methyl ester and their characterization.

Extraction of oil from soyabean seeds:
For the preparation of oil, the seeds should be dried in the presence of sunlight for several hours. During this process cell of the seeds oil containing break down and improve the extraction process. The seeds were finally grinded to the extraction process. In the present study the oil can be extracted from the seeds by two methods i.e., cold percolation method and Soxhlet method.
In cold percolation method [6], 10 g of fine grained powder of seed mixed with 6.6 g of glass power and sodium sulphate into the 500 mL vial. Add the 300 mL of carbon tetrachloride into vial. The solution was kept into rotatory shaker for 24 h. Now filter the solution and the filtrate containing the oil with carbon tetrachloride. Evaporate the carbon tetrachloride at 60°C. After the evaporation the oil containing vial kept into the desiccator for cooling and weigh the oil.
In other method mix the 25 g of fine grained powder and 250 mL of n-hexane in Soxhlet apparatus. Filter the extract and also extracted the lipid from solvent. Now evaporate the n-hexane at 40 °C from the filtrate and store the extracted oil at -2 °C for the degradation.
Conversion of extracted seed oil into methyl ester by transesterification reactions: Pour the known amount of oil into round bottom flask and add the known amount of potassium methoxide (KOH + excess amount of methanol) into the round bottom flask, while continuous stirring of the flask. Maintain the temperature of the reaction mixture at 55 °C for 1 h. After the complete addition of potassium methoxide, some of the sample drawn from the flask to confirm the formation of methyl ester (by titration method and TLC method). After the formation of methyl ester the reaction mixture allow to separate into the phase by standing for overnight in a separating funnel and add 5 mL CH3COOH to this reaction mixture to neutralize the KOH present in the ester. Glycerol and biodiesel are two phase observed in separating funnel so as to remove the glycerol from the biodiesel. Now wash the biodiesel with water and allow standing for overnight in separating funnel. The dense mixture was carefully removed from the bottom of the funnel. Removed the moisture content from the biodiesel by placing in oven for 1 h.
Characterization of methyl ester: Standard test methods were used for determining the physical and chemical properties of the soyabean seed oil biodiesel such as kinematic viscosity, flash point, fire point pours point, cloudpoint, saponification value, iodine value and acid value. These standard values were compared with ASTM D-6751 [7] are compared with jatropha oil biodiesel [8][9][10][11][12].
Oil content: Oil content is represented in terms of percentage of oil in the dry soyabean seeds powder [13]. 2 [14].

RESULTS AND DISCUSSION
Physico-chemical analysis: The physico-chemical results of biodiesel sample are given in Table-1.
The oil content of the soyabean is 15.85 % which is less than the jetropha oil non-edible seed. The oil content indicated that the soyabean seeds are suitable as an edible vegetable oil feedstock in oleochemical industries (biodiesel, fatty acids, etc.). The density of the soyabean biodiesel is 0.8534 is less than the jetropha biodiesel 0.930 g/mL. Density of oil is decreases with increases molecular weight, increases with unsaturation. Specific gravity of the soyabean biodiesel is 0.8497 which is likely to be similar as jetropha biodiesel 0.94.
Kinematic viscosity of the soyabean biodiesel is much more than the other biodiesel. High viscosity of the oil seed are not fit for the directly use as an engine fuel. Iodine value of soyabean biodiesel is 48.7296 which is less than ASTM D6751 and jetropha. Lower iodine value indicates that the less unsaturation of fats and oil. Saponification value of the studied soyabean biodiesel were 3.6 which is less than the jetropha oil, indicated that normal triglycerides are not useful in production of oil industries (likely shampoo, soap). The acid value of soyabean biodiesel is 1.3621 which is higher than the ASTM D6751, indicates the quality of the fatty acid present in biodiesel. The higher value of the fatty acid present in oil affected the esterification process and to reduces the values. Flash point and Pour point of the biodiesel is likely similar to ASTM D6751. GC-MS analysis of the methyl ester: On the analysis of biodiesel by GC-MS around 90 % of methyl ester formed and the analysis of spectra different constituents of methyl ester and their derivatives are produced (Fig. 1)  Characteristics and Composition of Soyabean Oil Seed and its Potential as Biodiesel Feedstock 527 fication process ethyl ester was comparatively less than that of formation of methyl ester (Table-2).

Conclusion
This study shows that the biodiesel could be produced successfully from the soyabean seeds by alkali-catalyzed transesterification process. The soyabean seeds are the good source and potential of renewable biodiesel. GC-MS study confirms the formation of methyl ester. But the production cost is affected on the formation of soyabean biodiesel. The physical and chemical properties of the biodiesel produced confirm to available standards. In this viscosity, acid number of the biodiesel is comparatively higher than the standards. Furthermore work may be carried out to characterize the soyabean biodiesel to reduce the viscosity, acid number and also create a gentle relationship between ester formation and the other important parameters such as viscosity, lubricity and stability for the future fuels.