Intensified Catalytic Transfer Hydrogenation of Sunflower Oil Using Ultrasound

Abstract

The present work deals with the catalytic transfer hydrogenation (CTH) of sunflower oil focusing on establishing the best conditions of ultrasonic operating and reaction parameters to maximize the extent of hydrogenation of sunflower oil. The processing is based on the use of 5% Pd/C as the catalyst, ammonium formate as the hydrogen donor, and water as solvent. The effect of ultrasonic power, ultrasonic frequency, temperature, speed of agitation, catalyst loading, and water quantity on the extent of CTH has been investigated. Under the best operating conditions of ultrasonic power as 150 W, 22 kHz as frequency, 30 °C as the reaction temperature, 800 rpm as the agitation speed, 2% w/ w as the catalyst loading, and 50 mL of water, a maximum reduction in iodine value was obtained from 141.65 to 87.24 g/100 g of oil. It was also demonstrated that use of ultrasound resulted in significant intensification (final acid value of 87.24 g/100 g of oil) as compared to the conventional approach based on only stirring (final acid value of 105.85 g/ 100g of oil). Overall the work has clearly demonstrated that ultrasound-assisted CTH is a useful approach for the conversion of sunflower oil into value added products with demonstrated intensification benefits.

Preparation of Conjugated Linoleic Acid by Ultrasound-assisted Nanonickel Catalyst Isomerization of Sunflower Oil

“…Sound waves with a frequency higher than 20 kHz are called ultrasonic waves. When ultrasonic waves propagate in the medium, they will produce a series of effects such as mechanical effects, thermal effects, and cavitation 18 . They have a good emulsification effect and can promote a reaction 19 , so ultrasonic assistance can greatly increase a reaction rate.…”

“…The use of ultrasonic technology instead of the activation of conventional hydroprocessing catalysts also ensures the safety of the conjugate conversion process 20 . Studies have shown that ultrasound can cause rapid pres-sure changes 21 , and a synergistic effect between the catalyst and ultrasound 18 , paving the way for reactions that are usually not feasible under quiet conditions. This synergy between ultrasound and catalysis is mainly observed in the presence of solid catalysts.…”