Continuous methyl ester production process from waste cooking oil (WCO) was studied by using a transesterification process at room temperature. The aim of this research was to investigate the optimized production conditions and specific energy consumption (SEW*h/kg of neat biodiesel) of the bumpy surface rotor reactor. There are 6.9%, 13.8%, and 27.6% of area fractions (AF) respectively. The reaction was under the condition being theoretical methanol to oil molar ratio and the reactor volume was 0.5L. At 2,000-4,000rpm of rotor speed, 1.0-1.5%w/w of KOH and 1.132-5.110L/min of precursor flow rate are used. It was found that the highest FAME content (fatty acid methyl ester in neat biodiesel, %) being 98.6%. It was achieved by using AF 27.6% rotor reactor under experimental conditions including 3,000rpm, 1.50%w/w of KOH and 2.027L/min of precursor flow rate. In addition, this condition gave SEC of 12.5W*h/kg. It was lower than that of orifice hydrodynamic cavitation reactor, power ultrasonic reactor, and mechanical stirring reactor around 93.2%, 95.0%, and 97.5% respectively. The properties of produced FAME met both EN 14214 and ASTM D 6751 standards.

jjocs oil (WCO) has been used to produce biodiesel by transesterification process 8) . Reducing material costs is the primary method of reducing total costs, and when used in combination with an efficient production method that increases productivity, it affects the reduction of energy consumption per unit thereby reducing total costs 9) . Chuah et al. 10) reviewed the previous intensification technologies in biodiesel production that guided energy recovery in terms of yield efficiency (g/J) . Their relationships were compared with hydrodynamic cavitation (HC) , microwave (MW) , ultrasonic cavitation (UC) and mechanical stirring (MS) methods in the following order: HC＞MW＞UC＞MS. Ji et