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Abstract:
Developments efforts to find renewable energy sources that are more environmentally friendly is to create alternative energy sources such as biodiesel. Biodiesel can be extracted from the esterification of free fatty acid with alcohol through using acid catalyst or transesterification from triglyceride and alcohol using a basic catalyst. catalyst CaO is a more active catalyst and has long been researched for transesterification reaction because it is inexpensive and has high strong of base. In this study, the authors have synthesized calcium oxide (CaO) from limestone which used as a catalyst in the esterification of palm oil which converted into biodiesel. The synthesis was carried out by limestone calcination at temperature variations 700, 800, 900 and 1000 C. Calcination of limestone at 900 C showed the highest amount of CaO used as a catalyst in biodiesel production.
Key words: limestone; biodiesel; catalyst; palm oil
Introduction
The evolution of the industry in the world has made an increase in energy needs. Most of today's energy needs are still being supplied from non-renewable natural resources such as petroleum, natural gas, and coal which will soon run out. One of the developments efforts to find renewable energy sources that are more environmentally friendly is to create alternative energy sources such as biodiesel[1]. Vegetable oil can be used as a precursor for biodiesel production because it is a renewable energy source, can be mass-produced and environmentally friendly[2].
Biodiesel can be extracted from the esterification of free fatty acid with alcohol through using acid catalyst or transesterification from triglyceride and alcohol using a basic catalyst[3]. Examples of the commonly used catalyst are NaOH and KOH. These homogeneous catalysts have disadvantages such as highly corrosive that can impact on the machine causing damage and less eco-friendly[4]. One of the efforts to handle these disadvantages is by using a heterogeneous catalyst..
Heterogeneous catalyst is a catalyst that has different phases with reactants and products, The usage of heterogeneous catalyst in biodiesel production has been done like the usage of MgO/SiO2 catalyst in biodiesel production[5], CaO-ZnO catalysts in biodiesel production[6], biodiesel production using metal oxide[7] and the application of calcium oxide and magnesium oxide from natural dolomitic rock for biodiesel[8]. The result of the researches suggests that heterogeneous catalyst has an impact...