Session: 01-02-01: General

Paper Number: 73478

Start Time: Tuesday, 10:05 AM

73478 - Performance Analysis of the Direct Contact Membrane Distillation Using Sonication Effect 

Membrane distillation is an emerging option among various desalination technologies. The full-scale applications of membrane-based distillation systems are still in process of development. Membrane-based distillation systems include direct contact, air gap, vacuum and permeate gap desalination systems. Direct contact membrane distillation has been widely utilized in laboratory studies due to its benefits such as simple design, high salt rejection and less environmental footprints. Also, it has the potential to utilize renewable energy resources such as solar energy to heat the feed water. However, the disadvantages associated with direct contact membrane distillation continue to hamper its commercial applications. These membranes often suffer membrane fouling, scaling, low permeate water flux and pore wetting. Hence, research is in progress to find out ways to solve these issues. In a similar attempt, this study focuses on the integration of sonication with direct contact membrane distillation to mitigate these problems particularly the fouling and scaling. For this purpose, a computational fluid dynamic model has been developed for the attenuation of concentration and temperature polarization through sonication enhanced direct contact membrane distillation. Although the concept of sonication is novel in the area of membrane-based desalination systems, it has the potential to help in solving some major challenges associated with the membrane-based desalination system. The application of the sonication effect will also alter the flow physics of various components such as feed, brine and permeate. Therefore, the current work is aimed at evaluating the performance of membrane distillation considering various parameters particularly the sonication effect. The computational domain consists of two channels, i.e., feed and permeate channels. It has a length of 20 mm, with a height of 1 mm for each channel, and a membrane thickness of 130 µm. Laminar flow at a low Reynolds number is considered, with feed and permeate flowing in a counter-flow configuration at the same inlet velocity but at different temperatures. The employed numerical model is non-isothermal and is governed by unsteady Navier–Stokes equations which are coupled thermally with the membrane. The model is subjected to different sonication frequencies with varying amplitudes. It employs dynamic mesh in conjunction with transient conditions. Moreover, a very small-time step is used to solve the governing equations associated with the sonication effect. A sensitivity study based on the effect of different parameters on the performance of the direct contact membrane distillation is conducted. The parameters studied include the effect of sonication amplitude, frequency, feed flow rate and feed temperature on temperature polarization coefficient, heat transfer coefficient, and thermal efficiency of the system.

Keywords: membrane distillation, desalination, CFD, sonication

Presenting Author: Isam Janajreh Khalifa University of Scienece and Technology

Authors:

Ussama Ali Khalifa University of Science and Technology
Muhammad Sajjad Khalifa University of Science and Technology
Isam Janajreh Khalifa University of Science and Technology