Biodiesel Production Using Ultralow Catalyst Concentrations

Biodiesel is a nontoxic, biodegradable, renewable diesel fuel obtained from lipid feedstocks. The most common production process for biodiesel is through the batch transesterification of vegetable oils with methanol. In the batch process, excess catalyst which is used to drive the reaction to completion can result in high material and processing costs and the degradation of components found in lipid feedstocks which impart color to the resulting biodiesel. Much work on heterogeneous catalysts has been done in the past decade; however, most of the work was done at temperatures and pressures well above those used in atmospheric batch processes. Under these conditions, the reaction rates of homogeneously catalyzed reactions would be enhanced. However, equilibrium limitations do require substantial amounts of catalyst to be present to drive the reactions to completion. Reducing the amount of homogeneous catalysts required for the transesterification would reduce the need for washing of the fatty acid methyl e...