Suryandari, Aprilia HapsariNurhayatiAmri, T. Ariful2016-05-102016-05-102016-05-10wahyu sari yenihttp://repository.unri.ac.id/xmlui/handle/123456789/8357CaO can be used as a catalyst in the synthesis of biodiesel. Biodiesel synthesis was strongly influenced by the activity and selectivity of the catalyst. This study find out activity data from CaO catalyst regeneration (derived from blood cockle shells) in the synthesis of biodiesel. Biodiesel synthesis was done on the reaction conditions: catalyst loading 4 g wt, reaction temperature of 60 °C, reaction time of 3 hours, and methanol to oil mole ratio of 6:1 by using CaO catalyst from blood cockle shells calcined at temperature of 800 oC. Catalyst regeneration carried out by washing the catalyst with methanol three times and dried at 105 oC for 12 hours, then the catalyst recalcined at the same temperature as previous treatment for 3 hours. The yield of biodiesel produces in the first reaction cycle using fresh catalyst reaches 84.72%. The second until fourth reaction cycle using used catalyst decreased the yield from 80,12; 75,38; to 69,38%, respectively. This catalyst employed in this work can be recycled very easily during four reaction cycles with high biodiesel yield, so it can reduce the production cost of biodiesel.enCaOblood cockle shellbiodieselcatalyst regenerationstudent Paper Post Degree