Effect of ultrasound on the colloidal-disperse properties of petroleum systems

Abstract

The effect of ultrasound on crude oils of different chemical natures and distillation residues with a different degree of takeoff of the cuts was investigated. Its effect on the degree of dispersity of petroleum systems was determined. The effectiveness of ultrasound as a method of regulating the degree of dispersity of crude oil feedstock in all refining processes was demonstrated.Crude oil and its cuts and residues are not molecular solutions but colloidal-disperse systems in ordinary conditions. Feedstock is ever more widely being prepared in refining practice by deliberately altering the balance of intermolecular interaction forces to regulate the degree of dispersity of the petroleum system.The methods of preparation based on this principle include: blending of feedstock streams in a certain ratio; addition of activating additives and surfactants (SF); use of electric and magnetic fields, ultrasound; mechanical effects, etc.Intensification of industrial dehydration and desalinization of crudes and dewaxing of oils with electric fields and SF are widely known. The changes that take place in the petroleum system here are reflected in its electrophysical properties. The characteristics of macroscopic structural phase transitions, in particular, the transition from the bound-disperse (gel) state to the free-disperse (sol) state have been successfully studied with the experimental temperature curves of the dielectric constant of petroleum disperse systems. This allowed developing new methods of determining the solid point of crude oils [2]. Anomalies in the viscosity and electrophysical and other properties in the same temperature ranges are characteristic of liquids containing high-molecular-weight compounds, primarily resins and asphaltenes (RA). The existing methods of analyzing disperse systems allow recording the structural transformations on the level of individual particles of the disperse phase [3].We investigated the effect of ultrasound on crude oils of different chemical natures and residues from distillation of these crudes with a different degree of cut takeoff. It was previously shown [4, 5] that ultrasound 44 Table 1 treatment of petroleum and other systems can not only induce dispersion but also chemical reactions (sonochemistry) [5].The physicochemical properties of the investigated crudes are reported in Table 1. These crudes differ in both chemical composition and in distillation. Usa crude contains significantly more paraffins and naphthenes but less asphaltenes and sulfur than heavy West Siberian crudes.The samples were treated with ultrasound on a UZDN-2T standard instrument at a temperature of 20°C (±2°). Thermostating was conducted with an ice-water bath. These conditions were selected by increasing the temperature in the system during treatment, which decreased the rate of the sonochemical reactions and consequently the effectiveness of the ultrasound.Release of energy in local microscopic regions of the system under the effect of ultrasound and, as noted in [5], subsequent rapid cooling ...

Supramolecular Structures of Oil Systems as the Key to Regulation of Oil Behavior

“…One of such technologies is the ultrasonic action [39][40][41][42][43]. The regularities of the influence of ultrasonic treatment on the structure of heavy oil with high content of resins were identified.…”

Structural and Mechanical Properties of Highly Paraffinic Crude Oil Processed in High-Frequency Acoustic Field

“…Studies show that changes in the structural and mechanical properties of crude oil after sonication are largely determined by their group composition [8][9][10][11][12]. However there are no many studies which examined the effect of sonication on the structural-group composition of oil and its components.…”