Specific energy requirement of direct contact membrane distillation

The study aims to provide a clear picture of the thermal energy requirements of Direct Contact Membrane Distillation (DCMD) system as function of different variables influencing the specific energy consumption. This includes membrane properties, operating conditions, recovery factor and the option of heat recovery from the permeate and retentate streams. We simultaneously analyze the variation in specific energy demand and membrane surface area needed as a function of the membrane characteristics, operating conditions and recovery rate, taken as a design parameter. We observe that the specific energy demand of DCMD shows a relatively weak dependence on temperature polarization and membrane properties considered in the current study and a strong dependence on the recovery rate. The advantages of using a heat exchanger very much depends on the recovery rate of the process.