Branched Fatty Acids: The Potential of Zeolite Catalysis

Abstract

Isostearic acid, a C18 saturated branched chain fatty acid containing one or more methyl or ethyl groups on the carbon chain, is of great interest for the oleochemical industry due to its interesting physicochemical properties. Its current industrial production, as a side product of the acid clay catalyzed dimerization of unsaturated fatty acids, lacks efficiency. Therefore, research focuses strongly on new catalytic systems based on zeolites. Significantly higher yields of branched fatty acids can be obtained using zeolites, demonstrating their superiority compared to acid clay catalysts. Despite previous efforts, there is insufficient insight in the product itself and the catalytic system to use it optimally. With this knowledge, it would, however, be possible to tune zeolite catalysts to meet predetermined product compositions and thus application characteristics. This perspective aims to provide the knowledge required to get a profound insight in the current state-of-the-art while pointing at remaining questions and challenges. Focus is on the reaction mechanisms taking place during reaction, the analysis of the reaction product and the zeolite catalysts themselves.