Design of an Extractive Distillation Column for the Environmentally Benign Separation of Zirconium and Hafnium Tetrachloride for Nuclear Power Reactor Applications

Abstract

Nuclear power with strengthened safety regulations continues to be used as an important resource in the world for managing atmospheric greenhouse gases and associated climate change. This study examined the environmentally benign separation of zirconium tetrachloride (ZrCl4) and hafnium tetrachloride (HfCl4) for nuclear power reactor applications through extractive distillation using a NaCl-KCl molten salt mixture. The vapor-liquid equilibrium behavior of ZrCl4 and HfCl4 over the molten salt system was correlated with Raoult's law. The molten salt-based extractive distillation column was designed optimally using a rigorous commercial simulator for the feasible separation of ZrCl4 and HfCl4. The molten salt-based extractive distillation approach has many potential advantages for the commercial separation of ZrCl4 and HfCl4 compared to the conventional distillation because of its milder temperatures and pressure conditions, smaller number of required separation trays in the column, and lower energy requirement for separation, while still taking the advantage of environmentally benign feature by distillation. A heat-pump-assisted configuration was also explored to improve the energy efficiency of the extractive distillation process. The proposed enhanced configuration reduced the energy requirement drastically. Extractive distillation can be a promising option competing OPEN ACCESSEnergies 2015, 8 10355 with the existing extraction-based separation process for zirconium purification for nuclear power reactor applications.

Electron beam melting efficiency at multiple hafnium e-beam processing

“…Obtaining pure hafnium poses an additional challenge due to its inseparable association with zirconium, a companion element found in the natural raw material. Various techniques have been • τ = 30 min employed to address these challenges, including solvent extraction, carbochlorination, Kroll reduction, vacuum distillation, and electron beam melting [2][3][4][5].…”

Enhancement of a R-410A Reclamation Process Using Various Heat-Pump-Assisted Distillation Configurations

“…One of the most attractive solutions is using cleaner electricity generated from sustainable energy sources, such as wind power and solar cells. Heat pump (HP) technology, which allows for the use of the waste heat released at the condenser for supplying energy to the reboiler, is a cost-effective approach to reducing the energy requirement of the distillation column [8][9][10][11]. This technology can be beneficial in the case of the small temperature difference between the overhead and bottom of the column and the high heat load.…”

Evaluation of a novel configuration of bottom flashing on dual distillation columns for saving energy

“…This is probably its main draw back. Various technologies such as heat pump assisted distillation [3][4][5], distillation with vapor recompression [6][7][8][9], distillation with bottom flashing [10,11] and internally heat integrated distillation columns (i-HIDiC) [12][13][14][15][16][17] have been developed previously for reducing energy requirements of distillation systems. Simplified process flow diagrams of bottom flashing heat pump is shown in Fig.…”