Fatty acid methyl esters (FAME) are synthesized via the single step esterification of non-edible feedstock, crude karanj oil (CKO), of high level of free fatty acids (FFAs about 20%) with methanol over series of solid acid catalysts prepared by anchoring molybdophosphoric acid (MP, 5 to 25 wt.%) onto SBA-16 support. The prepared catalysts were intensively characterized for their intrinsic physicochemical and textural properties using BET surface area, NH3-TPD, XRD, SAXS, FT-IR, SEM and EDX Characterization results revealed that the intact MP Keggin structure was preserved in the final catalyst after the thermal treatment at 220 degrees C. The catalyst with 15 wt.% MP (MP-S-16(15)) exhibited a peerless catalytic activity achieving 82% of FAME yield using a molar ratio of methanol to CKO of 1:8 at 140 C and after 5 h. The effect of different operational parameters such as MP concentration in the final catalysts, reaction temperature, molar ratio of methanol to CKO, catalyst wt.% and reaction time were investigated over the MP-S-16(15) catalyst toward the maximum FAME yield. The stability of the catalytic activity was examined through leaching and reusability tests. As such, the MP-S-16(15) catalyst was recycled through four consecutive batch runs to understand its stability. (c) 2013 Elsevier B.V. All rights reserved.