Separation of ethanol solvent from aqueous solutions

Separation of ethanol solvent from aqueous solutions via membrane distillation

Fawzi Banat, Fahmi Abu Al-Rub, Mohammad Al-Shannag

The effect of membrane distillation process parameters on ethanol–water separation has been investigated using a comprehensive mathematical model[1]. Three mass transfer solutions are considered in the model, namely: the exact solution of the Stefan–Maxwell equations developed by Krishna and Standart; the approximate solution of the Stefan–Maxwell equations suggested by Krishna and Wesselingh; and the binary Fickian solution. As in our other studies [2-9], temperature and concentration variation along the flow and diffusion paths are accounted for in the model. Though the exact and approximate solutions of the Stefan–Maxwell equations are coincident with each other, some differences are noticed between them and the Fickian-based solution. The difference between the three mass transfer-based solutions, as well as the process performance under several process parameters, are discussed.

References 1. Banat, F.A., Al-Rub, F.A., Shannag, M. (1999). Modeling of dilute ethanol–water mixture separation by membrane distillation, Separation and Purification Technology, 16, 119-131. 2. AL-RUB, F.A., BANAT, F.A., SHANNAG, M. (1999). Theoretical assessment of dilute acetone removal from aqueous streams by membrane distillation, Separation Science and Technology, 34, 2817-2836. 3. Banat, F., Al-Rub, F., Shannag, M. (1999). Simultaneous removal of acetone and ethanol from aqueous solutions by membrane distillation: prediction using the Fick's and the exact and approximate Stefan-Maxwell relations, Heat and mass transfer, 35, 423-431. 4. Banat, F., Al-Shannag, M. (2000). Recovery of dilute acetone–butanol–ethanol (ABE) solvents from aqueous solutions via membrane distillation, Bioprocess Engineering, 23, 643-649. 5. Banat, F.A., Al-Rub, F.A., Jumah, R., Al-Shannag, M. (1999). Application of Stefan–Maxwell approach to azeotropic separation by membrane distillation, Chemical Engineering Journal, 73, 7175. 6. Banat, F.A., Al-Rub, F.A., Jumah, R., Shannag, M. (1999). Theoretical investigation of membrane distillation role in breaking the formic acid-water azeotropic point: comparison between Fickian and Stefan-Maxwell-based models, International communications in heat and mass transfer, 26, 879-888. 7. Banat, F.A., Al-Rub, F.A., Jumah, R., Shannag, M. (1999). On the effect of inert gases in breaking the formic acid–water azeotrope by gas-gap membrane distillation, Chemical Engineering Journal, 73, 37-42. 8. BANAT, F.A., AL-RUB, F.A.A., JUMAH, R., AL-SHANNAG, M. (1999). Modeling of desalination using tubular direct contact membrane distillation modules, Separation Science and Technology, 34, 2191-2206. 9. Al-Shannag, M., Theoretical Investigation of Multicomponent Separation Problems by Membrane Distillation, Chemical Engineering Department, Jordan University of Science and Technology, Jordan, 1998.