Numerical simulation and theoretical study on simultaneous effects of operating parameters in vacuum membrane distillation

The Persian Gulf and its coastal areas are the world's largest single source of crude oil, and related industries dominate the region. Also the waste heat from refineries and petrochemical industries, which are located close to the Persian Gulf, can be used according to the simple feed inlet condition in vacuum membrane distillation (VMD). Hence, in order to enhance the performance of VMD in desalination of Persian Gulf water and to get more flux, a simultaneous heat and mass transfer model in VMD system has been developed and validated with experimental data. The model has been solved numerically using MATLAB. The influence of some operating conditions such as feed temperature, vacuum on permeate side, feed concentration, heat transfer coefficient, feed velocity and some membrane characteristics such as thickness, porosity, pore size distribution and tortuosity on permeate flux has been considered. The effects of feed temperature, feed velocity and membrane thickness on temperature polarization have also been taken into account. The results showed that the permeate flux improved with increase of feed temperature, velocity, heat transfer coefficient, porosity and pore size distribution, and decreased with enhancement of vacuum pressure, feed concentration, thickness and tortuosity of membrane. (C) 2013 Elsevier B.V. All rights reserved.