Mechanism of Separation of Contaminants from Activated Carbon by Closed Cycle Temperature Swing Desorption

Abstract

In this paper, the mechanism of separation of volatile organic compounds (VOCs) from activated carbon adsorption beds during closed cycle temperature swing desorption was studied. Toluene gas at different concentrations was used as the gas for closed cycle temperature swing desorption to regenerate activated carbon beds saturated with toluene. This research advances our understanding of the separation of contaminants from activated carbon and the mechanism of the process by which waste gas with a background concentration desorbs activated carbon in hot gas with a background concentration, establishing a technological foundation for the closed cycle temperature swing desorption process of activated carbon. When the background concentration was 2 g/m3, the average desorption rates of unit activated carbon at 10 cm in 40 min and 60 min were the largest, at 0.0099 and 0.0067 g/ (g•min), respectively. The fit of the Bangham desorption rate equation was the best. When the background concentration of toluene was 2 g/m3 and the filling length of the activated carbon layer was 10 cm, the desorption rate constant was the highest, at 0.0152 min−1.

Keywords

• activated carbon
• desorption mechanism
• diffusion
• kinetics
• separation of contaminants
• volatile organic compounds