Wahyuningsih, Slamet2015-04-132015-04-132015-04-13Dodyhttp://repository.unri.ac.id/xmlui/handle/123456789/7017Indonesia is tropical country having various plants that can be developed as alternative energy resources. Biodiesel is one of alternative energies. Biodiesel can be made from coconut oil and is referred to as cocodiesel. This research studies the optimum condition of cocodiesel production by methanolysis reaction between coconut oil and methanol using heterogen catalyst of calcium carbonate (CaCOs) is calcined for 1.5 hours at 90(fC. In order to get optimum condition, several experimental parameters are applied such as reaction time 1-3 hours, temperature 40-8(fC, catalyst concentration 1-3 %-wt and molar ratio of methanol/coconut oil 4:1-12:1. The optimum condition obtained from this experimental as follow: methanolysis reaction time was 1.5 hours, catalyst concentration was 2%, molar ratio of methanol/coconut oil was 8:1 at 6(fC, produced the higgest conversion of cocodiesel 75.02%. The cocodiesel meet the requirement of Standar Nasional Indonesia (SNI) specifications, where the density was 860 kg/m , kinematic viscosity was 2.44 mm^/s, flash point was ll(fC, water content was 0,039%-v, setana number was 65.94, acid number was 0.049 mg KOH/g and iod number was 6.35 gr Iod/100 gr. Based on data analysis, the product has a qualification as diesel fuelcocodieselmethanolysisheterogen catalystcalcinedUR e-Research