Sustainable Desalination by Permeate Gap Membrane Distillation Technology
Abstract
Membrane distillation (MD) as a thermally driven process with moderate operating temperatures is a known effective technology for salt-water desalination. In this research, the permeate gap membrane distillation configuration (PGMD), as a novel sustainable MD design having internal heat recovery characteristics, is introduced, designed and the system performance investigated in terms of permeate water flux rate and specific thermal energy consumption (STEC). The experimental results show that, increasing the feed flow rate from 0.1 to 1.1 L/min for the feed salinity in a range of (0−30) ppt, led to increasing the fresh water flux from 2 to 12 kg/m2h, however STEC of the system also showed an increase and varied in a range of 1000 and 2500 kWh/m3. Furthermore, a single node theoretical model is developed and the modeling results validated with experimental values. It is concluded, optimization of the MD module performance to improve internal heat recovery and produce higher fresh water rate would be achievable by adjusting the effective membrane surface area and feed flow rate.