Verbal modeling of microprocesses of continuous oil and grease adsorption

Abstract

The use of oils and greases in various fields of activity leads to their contamination by hazardous substances. Regeneration of properties is performed by various technologies, in particular, by continuous adsorption purification. For the automatic control of multicomponent purification it is necessary to know the mechanisms of substances interaction in the adsorber. A mathematical model that is adequate to the actual adsorption course, will ensure high control efficiency by meeting the quality requirements for the materials and reducing production emissions into the environment.It is important to create a mathematical model of the processes in adsorber, which would give an adequate reflection of substances behavior in it when changing properties of raw materials and adsorbent, that are continuously flow into this apparatus. Main modern modeling methods use generalized properties of input material flows and are based on the approximation of empirical adsorption data. We have chosen a method for describing behavior of substances in adsorber, which is supposed to determine the driving forces that occur between molecules of contaminated oils or greases (OG) on the one hand and adsorbent on the other. Existing studies on the properties of contaminated materials as nanosystems provide grounds for this.It is suggested to consider adsorbent and contaminated OG that enter the adsorber as separate objects with features of nanosystems. The environment in adsorber has been investigated as a collection of these systems and the new one – "adsorbent – contaminated OG" – whose properties are formed not additively but dynamically by the action of intermolecular forces.The properties of each of the nanosystems and the forces that are proposed to consider as driving forces in these systems are determined. Purification of contaminated OG is performed on polar adsorbents. In the adsorbent there are important the size of entrance windows, the structure of granules (elementary cells) and the elemental composition, which affects its polarity, and in the adsorbent – the size of molecules and their component composition. The most influential forces that act during the process are electrostatic ones – orientation and induction forces.It is shown under what scenarios the adsorbent granules can be filled in the presence of several contaminants. It was determined that the adsorption of resin molecules, followed by sulfur and aromatic hydrocarbons, takes place first. The paraffins that underlie the greases are not adsorbed by the adsorbent granules due to the adsorption selectivity, which is characterized by the attraction forces between molecule and adsorbent surface. The adsorption rate of such components will be low compared to pollutants due to the adsorption heat effect, which is the lowest in case of paraffins.Authors suggest to consider multicomponent adsorption as a phenomenon that implies the presence of innumerable random microprocesses. Such a verbal model made it possible to identify mathematical modeling techniques that would be appropriate to use when creating model for a control system.The developed model gives an idea of the relationship between the adsorbent particles and contaminated OG at the molecular level and allows us to consider multi-component adsorption purification of oils and greases as random processes. It is shown that the creation of control systems for this process will require such mathematical support, which should use methods of probability theory, adaptation and artificial intelligence.