Prilezhaev epoxidation of oleic acid in the presence and absence of ultrasound irradiation

Abstract

BACKGROUND: Epoxidation of double bonds in vegetable oils provide valuable green intermediates for the chemical industry. The epoxidation of oleic acid with hydrogen peroxide according to the Prilezhaev principle was studied experimentally in a multiphase laboratory-scale batch reactor operated isothermally at 50°C and atmospheric pressure. A solid cation exchanger (Amberlite IR-120) was used as the solid catalyst to enhance the slow step in the Prilezhaev process: the in situ formation of the epoxidation agent, peracetic acid, from hydrogen peroxide and acetic acid. A rotating basket stirrer was used to suppress the external mass transfer limitations and to guarantee a turbulent random flow in the vicinity of the catalyst particles. Kinetic experiments demonstrated the catalytic effect of the cation exchanger. Several experiments were performed in the presence and absence of ultrasound irradiation at different amplitudes. RESULTS:The exposure of ultrasound irradiation on the multiphase reaction mixture impaired the conversion of the double bonds and the yield of the epoxide, compared to a reference experiment conducted under silent conditions. Catalyst characterization by scanning electron microscopy and the determination of the acid sites in recycled catalyst samples confirmed that the main reason for deactivation was leaching and/or neutralization of the sulfonic acid groups from the solid catalyst matrix. CONCLUSIONS:The application of ultrasound at different input powers resulted in lower reaction yields compared to the silent reference experiment. This observation was attributed to deactivation of the catalyst caused by leaching and/or neutralization of the sulfonic groups promoted by ultrasound exposure.

A Novel Approach for Sunflower Oil Based Polyol Production by Ring Opening of Epoxidized Linoleic Acid

“…Most researchers have considered about employing environmentally friendly materials, natural zeolites were offered as a catalyst in this study because they have several benefits over synthetic zeolites, such as lower cost, availability, renewability, and greater adsorption capabilities, making them a more acceptable alternative for a wide range of uses. 19 Synthetic zeolites are often more costly to produce and may also be less eco-friendly than natural zeolites due to the chemicals employed in its manufacture. 20 Additionally, natural, and synthetic zeolites have similar Brunauer-Emmett-Teller (BET) surface area which are 32.25 m 2 /g and 34.90 m 2 /g.…”

The Lord of the Chemical Rings: Catalytic Synthesis of Important Industrial Epoxide Compounds

“…However when using Amberlite 120H, the benefit was overshadowed by the fast kinetics obtained by the solid catalyst. In another attempt to enhance the mass transfer in the epoxidation of oleic acid with Amberlite IR-120, Aguilera et al [105] have applied ultrasound irradiation to the three-phase system. However, the ultrasound irradiation produced deactivation of the catalyst, and the experiments under silent conditions resulted in higher yields of epoxide.…”

Theoretical and experimental mechanistic study of water molecule involvement in the Prilezhaev reaction

“…The Prilezhaev reaction entails the oxidation of olefins using peroxy acids to form epoxides. [1][2][3][4] The reaction usually proceeds in inert solvents such as toluene, dichloromethane, etc. In this way, styrene can be used to produce valuable intermediates for the synthesis of various high-value-added chemicals, such as plasticizers, fragrances, and pharmaceuticals.…”