Practical considerations for a simple ethanol concentration from a fermentation broth via a single adsorptive process using molecular-sieving carbon

A simple ethanol concentration process composed of a simple adsorptive apparatus using a single adsorbent, i.e., molecular-sieving carbon (MSC), is proposed for small-scale bioethanol production. The process designed to comprise pre-concentration of ethanol through gaseous-phase adsorption onto MSC and selective dehydration driven by molecular-sieving during desorption was tested under various conditions. Among the candidate adsorbents, MSC 5A showed the highest maximum ethanol adsorption capacity (0.163 g g−1). It was confirmed that the adsorption temperature and the initial ethanol concentration in the broth are crucial factors for the adsorption stage. For the desorption stage, the water recovery temperature significantly affected the final ethanol concentration and the ethanol recovery. As a practical option for the application of the proposed system, sequential batch fermentation and ethanol recovery was successfully demonstrated.