Feeding strategies of methanol and lipase on eversa® transform‐mediated hydroesterification for FAME production

Abstract

This work reports the influence of different feeding strategies of methanol and catalysts on fatty acid methyl esters (FAME) yield in a beef tallow hydroesterification reaction for biodiesel production catalyzed by liquid lipase. Soluble lipase from the Thermomyces lanuginosus microorganism, named Eversa® Transform, was selected for the reactions in this work. The feeding of methanol and lipase into the system was evaluated varying the methanol to fat molar ratio of 4.0:1 and 4.5:1 and the lipase load of 1.0 wt% and 1.45 wt% in relation to the mass of beef tallow utilized in each assay. The highest yield (85.08 %) of FAME was reached at 35 °C, methanol to fat molar ratio of 4.5:1, 1.0 wt% of lipase, 6.0 wt% of water in only 8 h of reaction, with a one‐step addition of lipase and methanol fed to the process at a constant flow of 3.0 g · h−1. Moreover, the reutilization process of the liquid lipase after four cycles was evaluated, which is a point rarely addressed in similar works available in the open literature. The findings of this paper demonstrate that the adoption of an appropriate strategy to feed inputs to the system is fundamental in order to take advantage of the maximum catalytic capacity of the lipase and consequently to obtain high yields in the process.