Patent ID: 8802878

Claim:
A process for producing fatty acid methyl esters, comprising: mixing an alcohol with a feedstock oil to prepare an alcohol/oil mixture; reacting the alcohol/oil mixture in an acid esterification process catalyzed by a first heterogeneous catalyst, thereby producing a glycerin-containing product free of homogenous catalyst; separating glycerin from the glycerin-containing product by a coalescer, thereby producing a biodiesel-containing feedstock and glycerin; separating biodiesel from the biodiesel-containing feedstock by a coalescer, thereby producing unreacted feedstock and biodiesel; reacting the unreacted feedstock using a second heterogeneous catalyst in a trans-esterification process catalyzed by a second heterogeneous catalyst, thereby producing a glycerin-biodiesel-methanol mixture free of homogenous catalyst; separating biodiesel and glycerin in separate streams from the glycerin-biodiesel-methanol mixture by a coalescer, thereby producing additional glycerin and additional biodiesel; and wherein all process steps are free of any homogeneous catalyst.