Novel coiled hollow fiber module for high-performance membrane distillation

Membrane distillation (MD) scale-up is challenged by ineffective heat recovery and the temperature polarization effect. Direct contact membrane distillation (DCMD) modules suffer high thermal conduction losses due to feed flow direction along the length of the membrane, resulting in low thermal efficiency. We propose a novel module design named coiled hollow fiber (CHF) to decouple the flow direction from the membrane surface in hollow fiber (HF) DCMD. Experimental and computational analyses were employed to compare the performance of CHF and the conventional design. The CHF module design successfully mitigates the TP effect in HF DCMD, increasing the flux by 148 % and 163 % in cross-flow and localized heating (LH) modes, respectively. Moreover, CHF operated in LH mode exhibits the lowest energy consumption of all configurations (81 % decrease) compared to the conventional design. This novel module design represents a new pathway for efficient and highly performing DCMD module.