Abstract
A novel design for packed bed membrane fermenters is investigated. The system is composed of a counter current configuration with partial blinding of a part of the membrane at the fermenter entrance. It is shown that this configuration can achieve the objective of increasing both the ethanol productivity and the ethanol concentration. A detailed parametric investigation is carried out in order to determine the optimum design and operating parameters that maximize the benefits of this configuration. The superiority of this novel configuration over other configurations (i.e. no membrane, co-current, and unblinded counter current configurations) is demonstrated quantitatively and is shown to be quite appreciable with regard to both ethanol productivity and concentration.