The use of biodiesel derived from oils and fats is making an increased contribution as a renewable energy
source. The synthesis of biodiesel involves transesterification of triglycerides to the monoalkyl esters,
a process often made challenging by the presence of free fatty acids (FFA). Herein an integratedflow
system for the synthesis of biodiesel, employing a solid supported acid catalyst for esterification of FFAs,
followed by transesterification using polymer supported N-heterocycle carbene (NHC) catalyst is
reported. This system delivers biodiesel in high yields from a variety of fat and oils, using robust and
recyclable catalysts