Separation of VOC Gaseous Mixtures Using an Adsorption–Desorption Device

Abstract

The aim of this work was to separate ethanol in an experimental adsorption–desorption device. We focused on concentrating ethanol by adsorption onto granulated activated carbon in its gaseous phase, which was produced by stripping a matrix with different ethanol concentrations (2, 5, 10, and 15% v/v). For adsorption, three kinds of granulated activated carbon (GAC) were used, marked as GAC1, GAC2, and GAC3. The separation product had a higher ethanol concentration than the initial ethanol concentration before the adsorption–desorption process. The enrichment factor was, in the case of the initial ethanol concentration, 2% v/v at the level of 10. With our new adsorption–desorption device, it is possible to achieve a product with an ethanol concentration of 59.0% v/v with stripping, adsorption, desorption, and condensation. To verify the separation efficiency, a real matrix (fermentation broth) was used. The ethanol concentration in the real matrix was, at the beginning of the separation process, 0.65% v/v; after using our separation device, it was 11.35% v/v. Using a real matrix, the enrichment factor was at the level of 18. The main advantage is the use of our new adsorption–desorption device for the continuous separation of ethanol from fermentation broth. A mathematical model was created, based on which it is possible to calculate the ethanol concentration in the product of the separation process with high accuracy.