Production of biodiesel from the transesterification between soybean oil and methanol was conducted in this study by a membrane reactor, in which ceramic membrane was packed with MCM-41 supported p-toluenesulfonic acid (PTSA). Box-Behnken design and response surface methodology (RSM) were used to investigate the effects of reaction temperature, catalyst amount and circulation velocity on the yield of biodiesel. A reduced cubic model was developed to navigate the design space. Reaction temperature was found to have most significant effect on the biodiesel yield while the interaction of catalyst amount and circulation velocity have minor effect on it. 80 degrees C of reaction temperature, 0.27 g/cm(3) of catalyst amount and 4.15 mL/min of circulation velocity were proved to be the optimum conditions to achieve the highest biodiesel yield. (C) 2014 Elsevier Ltd. All rights reserved.