Intensification of epoxidation of vegetable oils using a continuous mesoscale oscillatory baffled reactor

Epoxidized vegetable oils (EVOs) are widely used in the polymer industry as plasticizers, stabilizers, polyols synthesis and elsewhere as precursors for lubricants. Currently, the epoxidation uses peracids (peracetic or performic acid) and is carried out in a semi-batch or batch reactor. The reaction is highly exothermic, necessitating the gradual addition (typically over 2 hours) of the hydrogen peroxide (HOOH) at a moderate temperature (~60°C), to prevent thermal runaway. In practice, this leads to reaction times of 8 hours or more. In this study, rapeseed oil was epoxidized in a mesoscale oscillatory baffled reactor (“meso-OBR”), operating in continuous mode, to investigate the feasibility of using this reactor design to convert this batch reaction to continuous. It was found that the continuous meso-OBR could exceed the product specification of the commercial batch operation. Yields over 75% were achieved, at 10 minutes residence times because a higher molar ratio of acetic acid and HOOH to oil could be used due to the enhanced heat transfer characteristics of the reactor. Based on these findings, an OBR operating at the same production rate as the commercial batch reactor would be approximately 144 times smaller, due to the reduction in residence time, and removal of the various inherent inefficiencies of the batch cycle. © 2020 American Institute of Chemical Engineers