Pengaruh Waktu Reaksi Dan Konsentrasi Katalis Terhadap Proses Transesterifikasi Dalam Pembuatan Biodiesel Dari Minyak Jelantah Dengan Katalis Abu Layang Batubara

Fuel oil (BBM) is a major requirement for all Indonesian people. Now the use of fuel oil is increasing, to overcome this, the fuel derived from fossils must be reduced in use and then need to develop renewable alternative energy, one of which is vegetable fuel such as biodiesel. Waste cooking oil has the potential to be used as a source of energy so that it can reduce the potential for pollution in the environment. The transesterification method was chosen because the process is quite simple, namely by reacting triglycerides with alcohol to form fatty acid methyl esters (FAME) and glycerol as a by-product. In the transesterification process, it is generally carried out by adding a catalyst. Coal fly ash (fly ash) has the potential to be used as a catalyst in making biodiesel because it is composed of several porous oxides, SiO2, Al2O3, Fe2O3, MgO and CaO. This study aims to examine the effect of reaction time (60, 90 and 120 minutes) and the weight of the catalyst (3,4 and 5% b/b oil) on the biodiesel produced. The application of the transesterification method with dependent variables of temperature of 60oC, stirring speed of 400 rpm, and a molar ratio of oil: methanol 1: 9. Produced biodiesel with a density of 0.845-0.875 g/cm3 (Indonesia National Standard SNI in the range of 0.85-0.90 g/cm3) and a yield 24.21% for the reaction time of 120 minutes and catalyst weight of 5%. Then the components and composition of biodiesel were analyzed using GC-MS and the characteristics of fly ash using XRD (X-ray diffraction) and SAA BET (Brunaur, Emmett and Teller Surface Area Analyzer) methods. In the GC-MS test results, the dominant composition of methyl ester was methyl oleate 48.86%, and the XRD test results of coal fly ash catalysts had Al2Na2O8Si2 component 61.1%; 20.5% AlO4P and 18.4% SiO2, while SAA BET test results of coal fly ash catalyst had surface area of 104.106m2/g. Key word: Coal fly ash, biodiesel, waste cooking oil, trasesterificatio