Heat to Hydrogen by RED—Reviewing Membranes and Salts for the RED Heat Engine Concept

Membranes

Önder Tekinalp¹  Liyuan Deng¹  Øivind Wilhelmsen²  Simon Birger Byremo Solberg³  Odne Stokke Burheim³  Pauline Zimmermann³  Jacob Joseph Lamb³ 

[1] Department of Chemical Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway;Department of Chemistry, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway;Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway;

关键词: hydrogen production;    reverse electrodialysis;    waste heat utilization;    ion-exchange membranes;    closed loop;    heat engine;   

DOI  :  10.3390/membranes12010048

来源: DOAJ

【 摘 要 】

The Reverse electrodialysis heat engine (REDHE) combines a reverse electrodialysis stack for power generation with a thermal regeneration unit to restore the concentration difference of the salt solutions. Current approaches for converting low-temperature waste heat to electricity with REDHE have not yielded conversion efficiencies and profits that would allow for the industrialization of the technology. This review explores the concept of Heat-to-Hydrogen with REDHEs and maps crucial developments toward industrialization. We discuss current advances in membrane development that are vital for the breakthrough of the RED Heat Engine. In addition, the choice of salt is a crucial factor that has not received enough attention in the field. Based on ion properties relevant for both the transport through IEMs and the feasibility for regeneration, we pinpoint the most promising salts for use in REDHE, which we find to be KNO₃, LiNO₃, LiBr and LiCl. To further validate these results and compare the system performance with different salts, there is a demand for a comprehensive thermodynamic model of the REDHE that considers all its units. Guided by such a model, experimental studies can be designed to utilize the most favorable process conditions (e.g., salt solutions).

【 授权许可】

Unknown