Thermal cycling absorption process: A simple, efficient and safe strategy for hydrogen isotope separation

The hydrogen isotopes are vital due to their significant applications in scientific research, biomedicine and potential application in fusion energy. D-T fusion, in particular, holds the promise solving human fossil energy reliance and the resulting environmental pollution. Methods including cryogenic distillation and Girdler Sulfide process etc. have been developed to satisfy the demand towards pure D2 and T2 but generally suffer high energy consumption and low separation efficiency. Furthermore, emerging methods such as laser catalysis and quantum sieving have been demonstrated but suffers harsh separation conditions, low separation volumes and material life etc. Thermal cycling absorption process (TCAP) delivers seductive aspects regarding hydrogen isotope separation for efficiency and throughput, small footprint and high automation level. Herein, firstly, the advantages and disadvantages of various separation methods are briefly elucidated and provides the necessities for developing new separation methods. Then the preferred TCAP strategy is outlined in detail, containing working mechanisms and optimization process. Finally, the history and outlook of TCAP are listed. We hope this paper would spark some inspirations for further TCAP development towards hydrogen isotope separation.