Title : Use of ultrasonic pretreatment in the reaction of liquid-phase aerobic oxidation of C10-C20 paraffin hydrocarbons in the presence of nickel salt of natural petroleum acids
Abstract:
The paper presents the results of studies on the reaction of liquid-phase aerobic oxidation of a mixture of C10-C20 hydrocarbons in the catalytic presence of nickel salts of natural petroleum acids (NPA) isolated from oil by leaching. The catalyst was preliminarily subjected to ultrasonic treatment for 1 minute in order to activate the particles. It is assumed that ultrasound contributes to the dispersion of particles and their uniform distribution in a mixture of hydrocarbons. It has been determined that the proposed scheme helps to accelerate the process of liquid-phase aerobic oxidation of hydrocarbons in a short time and increase the yield of target reaction products, namely synthetic fatty acids. It has been established that ultrasound used in autocatalysis of the oxidation of a mixture of hydrocarbons does not affect the process of accelerated conversion of hydrocarbons into oxygen-containing compounds and the acid number (A.n.), which is an indicator of the process of hydrocarbon oxidation, is equal to 7.5 mgKOH/g, with a reaction duration of 4 hours, and using a catalyst treated with ultrasound, this the number equates to 49.5 mgKOH/g for 5 hours. As a result, of the research, it was noticed that the catalytic efficiency of micro-sized catalytic systems is increased through the use of irritating agents, that is, ultrasound. It is assumed that a synergistic effect is created between heterogeneous catalyst particles and ultrasound. Briefly, ultrasonication of catalyst particles causes them to disperse effectively, resulting in a wide active surface area of the catalyst.
Liquid-phase oxidation of paraffin hydrocarbons with molecular oxygen was carried out in a bubble-type oxidation unit in a glass reactor [1]. The nickel salt of natural petroleum acid (RCOO)2Ni, used in the oxidation reaction of hydrocarbons as a catalyst, was synthesized in laboratory conditions, according to the method given in [2]. Ultrasonic treatment of the catalyst in a mixture of hydrocarbons C10-C20 was carried out on a cavitation installation of the Hielscher brand ((Ultrasound Technology, made in Germany) UP200St. In the cavitation process, titanium santrode of the s26d7 brand (Hielscher) was used, with a diameter of 7 mm and an amplitude of 190 µm.
The research results on liquid-phase aerobic oxidation of paraffin hydrocarbons with molecular oxygen in the presence of nickel salt of PNA treated with ultrasound are (? = 135-1400?, amount of air – 100-120l/h) (SFA - synthetic fatty acids; SOFA - synthetic oxyfatty acids):
As a result, of the research, it was noticed that the catalytic efficiency of micro-sized catalytic systems is increased through the use of irritating agents, that is, ultrasound. It is assumed that a synergistic effect is created between heterogeneous catalyst particles and ultrasound. Briefly, ultrasonication of catalyst particles causes them to disperse effectively, resulting in a wide active surface area.
