Production development of ethyl ester biodiesel from palm oil using continuous deglycerolisation (CD) process with atmospheric gravity separator of immiscible liquid was investigated. For reversible transesterification, removal of glycerol during reaction can drive the equilibrium to the product side in order to obtain high conversion. In this work, KOCH3 was selected as the catalyst in transesterification and the reaction temperature was maintained at 60 degrees C. The effects of the key variables involved in the process: molar ratio of oil to ethanol, KOCH3 concentration and retention time, were investigated. Results showed that ethyl ester production using CD process could obtain good purity and yield in a single step transesterification. The suitable conditions found in this study were: molar ratio of oil to ethanol of 1:5.5, KOCH3 concentration of 1.2 wt.% and retention time of 30 min. Under these conditions, ester content and yield were 98.0 wt.% and 93.1 wt.%, respectively. (C) 2013 Elsevier Ltd. All rights reserved.