IJISET - International Journal of Innovative Science, Engineering & Technology, Vol.5 Issue 4, April 2018 ISSN (Online) 2348 – 7968 www.ijiset.com 127 Determination of Optimal Yield of Biodiesel from Coconut (Cocos Nucifera) Seed Oil. Hadiza Garba Abubakar 1 and Ismail Muhammad 2 1, 2 Ibrahim Shehu Shema Centre for Renewable Energy Research, Umaru Musa Yar’adua University, Katsina, +234, Nigeria. Abstract Coconut seeds were investigated for its use as biodiesel feedstock.67.2% oil was extracted using soxhlet extraction. Biodiesel synthesis was developed and optimized using Box-Behnken design in Response Surface Methodology to study the effect of experimental variables such as methanol to oil ratio, catalyst concentration, reaction temperature and reaction time on the extracted oil from coconut seeds. The model shows optimum conditions of biodiesel yield of 79% were found at 6:1 alcohol/oil ratio, 1% catalyst concentration (KOH), reaction temperature of 65 0 C and reaction time of 40 min. respectively. At the end of experimental design it was found that the catalyst concentration and reaction time significantly affect the biodiesel yield than molar ratio among others under the range of values studied. The produced biodiesel was analyzed for its physicochemical and fuel properties all of which are within ASTM specification except for cetane number and sulphur content indicating suitability as an alternative source of fuel. Keywords: Biodiesel, Response Surface Methodology, Optimization, ASTM Specification. 1. Introduction The replacement of mineral fuel by biodiesel is one of the effective ways of solving the problem of saving and effective usage of energetic resources. Biodiesel is becoming an increasingly acceptable alternative to fossil diesel because of narrowing gap between worldwide oil production and consumption. Also Nigeria’s vegetation and rainfall regime support agrarian activities that can produce feedstock for Biofuel production. Sustainable biofuel production will create more jobs and stimulate related industries thus improving the socio-economic industries of the country (Itodo et al., 2010). The surge of interest in biodiesel has highlighted a number of positive environmental effects associated with its use. These potentialities include reduction in greenhouse gas emission, deforestation, pollution and the rate of biodegradation (US department of energy, 2003). Biodiesel is a non-petroleum based fuel made from virgin or used vegetable oil (both edible and non-edible) and animal fat. The main sources or biodiesel can be non- edible oils obtained from plants species available in different countries. Direct application of vegetable oils as fuel for diesel engine is not possible due to its higher viscosity; hence reduction of vegetable oil viscosity is an urgent need. Transesterification is the process of biodiesel Production which involves the reaction of fat/oil with alcohol in the presence of acidic, basic or enzymatic catalyst to form esters and glycerol (Agarwal, 2007).This study tends to investigate the impact of reaction variables (Molar Ratio/Oil, Catalyst Concentration, Reaction time and Temperature) on Biodiesel production from Cocos nucifera seed oil and also analyzed fuel properties of the produced Biodiesel produced for use as an alternative to fossil fuels. 2 Experimental 2.1 Sampling and Sample Treatment. The Coconut seeds were obtained from vendors at kasuwar K Daji in Sokoto metropolis, Sokoto State, Nigeria. The shell of the seed was removed after which the seeds were sun dried then cut into smaller pieces and put into a blender in order to reduce its size and hardness. The smashed sample was then powdered in the blender and later taken for oil extraction. Oil was extracted from the powdered samples using n-hexane as extraction solvent using soxhlet extractor. 2.2 Physicochemical Analysis of Extracted Oil. Acid value , Moisture content, Saponication values, Ester value and Iodine Value of the extracted oil were determined according methods by Verma, 2001. 2.3 Optimization Of Transesterification Process Using Response Methodology Surface (RSM). The seed oil was pre-heated up to 65 0 C in the reaction flask, the oil was allowed to cool at room temperature, A 6:1 molar ratio of methanol to coconut oil methylation process was carried out by dissolving KOH (2.25g) in methanol (198cm 3 ) then mixed with the extracted oil (375g) in a round bottom flask (500cm 3 ) fitted with a cork, the content was stirred on magnetic stirrer for 5min., then heated on a water bath at 65ºC for 40min. The mixture was poured into separating funnel and allowed to settle under gravity for 12 hours. Two distinct layers were observed a dark yellow layer (glycerol) at the bottom and a light yellow layer (biodiesel) at the upper layer. The glycerol was separated from the biodiesel which was then measured and recorded (Dalai, 2004).