Separation of VOC Gaseous Mixtures Using an Adsorption-Desorption Device

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.