Thermoelectric heating and cooling for efficient membrane distillation

Abstract

This study introduces the concept of thermoelectric desalination which involves deploying an electrically-powered self-contained direct contact membrane distillation (EPSCD) system for efficient desalination. The EPSCD system integrates thermoelectric devices and effectively combines multistage membrane distillation and heat recovery in a single, compact unit to efficiently manage the energy requirement for the desalination process. Inside the EPSCD system, thermoelectric coolers, arranged in parallel electrically, provide the driving force for the process by pumping the heats of condensation (associated with vapor transport) and conduction (through the membrane) from the cold side back to the hot side for vaporization. The proposed system is simple in design and can achieve instant water desalination with excellent salt rejection and relatively low power consumption. Preliminary results indicate that an energy efficiency up to 86% and a corresponding specific energy consumption of 780 kWh/m3 can be achieved with this system.