Prenos mase na rotirajući disk adsorpcionom i elektrohemijskom metodom

Abstract

One of the ways to intensify the process is the use of rotating elements, which increase the mass transfer coefficients many times over. In this study, the mass transfer coefficient was determined by adsorption and electrochemical methods, using a rotating disk (RD) to study the effect of rotation on the mass transfer intensity. For adsorption method, a dilute solution of methylene blue was used, and silica gel foils on rotation disk were used as adsorbents. The measurements were performed under diffusion-controlled conditions, and the color intensity of the surface was determined using SIGMA Scan Pro. The study of mass transfer by electrochemical method was performed in batch systems with a volume of 20 dm3 and 0.8 dm3 , using a solution of sulfuric acid and copper sulfate, and potassium ferricyanide (III), potassium ferricyanide (II), and potassium chloride. Disks with diameters of 0.8 cm, 1 cm, 2 cm, 5.6 cm, and 20 cm were used in the rotation range up to 800 rpm. After determining the operating voltage, the current intensity was measured at different rpm and the mass transfer coefficients were calculated. It was found that the mass transfer coefficient increases as the rotation speed of the RD increases, and that is does not depend on the diameter of RD. It is shown that the current density increases with the increase of the RD speed, while the diffusion layer thickness decreases. A comparative analysis of the results obtained by the adsorption and electrochemical methods was made and the results were compared with literature correlations.