A method comprising contacting an alcohol, a feed comprising one or more glycerides and equal to or greater than 2 wt % of one or more free fatty acids, and a solid acid catalyst, a nanostructured polymer catalyst, or a sulfated zirconia catalyst in one or more reactors, and recovering from the one or more reactors an effluent comprising equal to or greater than about 75 wt % alkyl ester and equal to or less than about 5 wt % glyceride.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
The embodiments described in this disclosure were made, at least in part, with funding from the Department of Energy Contract No. DE-FG02-04ER86169, U.S. Department of Agriculture Contract No. 2006-33610-16838, and Environmental Protection Agency Contract No. EP-D-07-058. Accordingly, the U.S. government may have certain rights in the subject matter disclosed herein.