Esterification of free fatty acids in a rotor-stator spinning disc reactor

Fatty acid methyl esters (FAMEs) were produced by the esterification of free fatty acids (FFA) with methanol, and sulfuric acid as the catalyst in a rotor-stator spinning disc reactor (RSSDR). The RSSDR, which shows excellent mixing efficiency and fast phase separation, was used as a novel continuous-flow esterification reactor. The influence of the variables (e.g., rotational speed, volume flow rate, rotor-stator distance, methanol-FFA molar ratio, catalyst dosage, and temperature) on esterification conversion (eta) and productivity of FAMEs (P-FAME) were investigated. It was found that the experimental parameters have a great impact on the eta and P-FAME in the RSSDR system, due to the effect of micromixing intensity and residence time distribution. Furthermore, to compare with other traditional esterification reactors, the values of eta, P-FAME, and P-FAME per unit reactor volume (P-FAME/V-R) in the RSSDR were also employed to assess the performance for the production of FAMEs. It shows that the maximum values of P-FAME, and P-FAME/V-R attained were 0.14 mol/min and 3.06x10(-2) mol/(mL min), respectively. Therefore, the RSSDR is proven to be an effective esterification reactor with high esterification conversion in comparison to conventional esterification reactors.