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

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.

Biography:

Aliyeva Aygun Zabit, the head researcher of the Institute of Petrochemical Processes in Azerbaijan, DSc in chemistry. She is engaged in the oxidation of hydrocarbons in the liquid phase, the synthesis of catalysts by CVD and study the structures of the catalysts on X-Ray.
In 2008 defended her PhD thesis in chemistry entitled “Liquid-phase oxidation of saturated hydrocarbons C10, C11, C16, petroleum fraction in the presence of C60/C70 fullerene and combination with transition metal naphthenates” in 2018 her habilitation dissertation "Study of metal-containing and carbon nanostructuredcatalytic systems in the processes of producing synthetic petroleum acids and their esters"