Extended replacement cycle of perfluorinated compounds (PFCS) gas decomposition catalysts using Ca(OH)₂ adsorbent in multi-bed reactor

Al₂O₃ catalysts, used for the hydrolysis of perfluorinated compounds (PFCs), have a limitation in that their lifetime is abruptly lowered by the generation of hydrogen fluoride (HF) during the reaction. In the PFCs hydrolysis plants, increasing replacement cycles is one of the major challenges in reducing maintenance costs. In this study, the Ca(OH)₂ layer, which decomposes the HF, was inserted between the Co-Zr/Al₂O₃ catalyst layers to increase the catalyst replacement cycle during the CF4 gas decomposition at 750oC. As a result, the decomposition rate was rapidly recovered through the replacement of the adsorbent, and the time to maintain a decomposition rate more than 90% improved by more than eight times compared to the bare catalyst layer without adsorbent.