Calcium oxide-loaded porous materials have shown promise as catalysts in transesterification. However,
the slow diffusion of bulky triglycerides through the pores limited the activity of calcium oxide (CaO). In
this work, bimodal meso-macroporous silica was used as a support to enhance the accessibility of the
CaO dispersed inside the pores. Unimodal porous silica having the identical mesopore diameter was
employed for the purpose of comparison. Effects of CaO content and catalyst pellet size on the yield of
fatty acid methyl esters (FAME) were investigated. The basic strength was found to increase with increasing
the CaO content. The CaO-loaded bimodal porous silica catalyst with the pellet size of 325 lm
achieved a high %FAME of 94.15 in the first cycle, and retained an excellent %FAME of 88.87 after five consecutive
cycles.