Epoxidation of fatty acids and vegetable oils assisted by microwaves catalyzed by a cation exchange resin

“Epoxidation of oleic acid and cottonseed oil was conducted in a semibatch reactor with in-situ-formed percarboxylic acid (peracetic acid or perpropionic acid), using hydrogen peroxide as an oxidizing agent and carboxylic acid (acetic acid or propionic acid) as oxygen carriers. Amberlite IR-120 was implemented as the catalyst. The system was comprised of a loop reactor, where the mixture was pumped through a single-mode cavity in which microwave irradiation was introduced. A heat exchanger was integrated into the system to replace microwave heating, to compare the results obtained via microwave heating versus conventional heating. The catalyst loading effect was studied, as well as the influence of microwave irradiation and the implementation of the SpinChem rotating bed reactor (RBR), in hopes of decreasing the influence of the internal mass transfer. The application of microwave irradiation results in an improvement of the reaction yield in the absence of a catalyst.”

Highlights:

• “Moreover, to approach the development of cleaner, safer, smaller, and more-energy-efficient processes with products of higher quality, i.e., process intensification, microwave (MW) technology was used and combined with a special mixing device: a SpinChem Rotating Bed Reactor (RBR). The objective of the new mixing technology is to immobilize the catalyst and to minimize the mass-transfer limitations by forced, centrifugal flow through the catalyst bed.”
• “The design of SpinChem RBR maximizes both axial mixing and convective heat transport.”
• “In addition, the use of the Spinchem RBR streamlines the experimental procedure, because no filtrations are needed at the end of the reaction to separate the solid catalyst from the liquid medium.”
• “The use of a special mixing device, SpinChem RBR, was beneficial, in terms of eliminating the mass-transfer limitations, it enabled a simpler collection and recycling of the catalyst and minimized the mechanical wear of the solid catalyst, thus possibly prolonging the catalyst lifetime.”