High-Shear Mixing-Assisted Esterification of Lauric Acid to Produce Value-Added Products and Intermediaries: Effect of the Alcohol Structure

This paper describes the benefits of incorporating the high-shear mixing (HSM) technology to intensify the homogeneous acid-catalyzed esterification of lauric acid (LA) with a set of alcohols having different chain lengths and branching degrees to produce lauric acid alkyl esters, as a sustainable alternative for producing diverse products (cosmetics, diesel fuel, cetane improvers, and chemical intermediaries). To elucidate the effect of the alcohol structure, the esterification reaction is conducted in the liquid phase at 60 °C, with an alcohol-to-LA molar ratio of 13:1 and 500 rpm for 12 min, using sulfuric acid as the catalyst. The HSM-assisted esterification requires only 12 min to suffice to convert from 88.2 to 93.6% fed LA and from 16.3 to 90.7% fed LA when reacting with linear and branched alcohols, respectively. LA conversion is generally low when using relatively simple and branched alcohols (tert-butanol and isopropanol) due to thermodynamic restrictions, which are ascribed to a steric hindrance effect. Notably, it is also demonstrated that the incorporation of HSM not only reduces the required time for LA conversion but also makes the reaction more efficient, thus compensating for the inherent negative dilution effect of the produced water on the liquid acid catalyst compared with the nonintensified esterification process.