Heat and Mass Transfer Study to Understand Thermal-Cycling Absorption Process (TCAP) Scale-Up Issues

Abstract

The first-year goal of this study was to better understand the underlying physics affecting the separation capability of TCAP in order to provide a strong technical basis for design of a scaled up mega-TCAP, of interest for fusion and other potential applications. Assessing mass transfer factors, researchers performed an extensive review and evaluation of prior theoretical work, mathematical models, and experiments on chromatographic separation. This effort resulted in the discovery of a previously unidentified factor impacting TCAP column scale-up. A model derived by J. Calvin Giddings indicates that the combination of coiling a packed column and increasing the column tube radius will decrease column separative performance. FY2019 Objectives Understand the fundamental physics of the efficiency losses previously noted during the 2004 HT-TCAP scale up and devise means to overcome them through the following: • Determine the factors affecting and affected by TCAP gas mass transfer • Determine the factors affecting and affected by TCAP heat transfer.

Gas Chromatography and Thermal Cycling Absorption Techniques for Hydrogen Isotopes Separation in Water Detritiation Systems

“…Furthermore, as previously discussed, the other main advantages introduced by the new TCAP configuration consist of the reduction in the tritium inventory (to 1/2) and in the heat load (25%). The characteristics of the new TCAP configuration (Figure 7) considered in this analysis are: With a feed flow rate of about 8 STP L/h (assessment based on a cycle duration of about 0.5 h), a raffinate and product purity of about 99% were obtained during an inherently safe, robust, and fault-proof operation [46].…”

“…The Savannah River National Laboratory has continually improved the TCAP's ability to enrich tritium gas in a more cost-effective process that uses one-pass liquid nitrogen cooling and reduces the heat load and tritium risk. Miniature versions of TCAP systems that fit into a small glovebox extend the use of this process to several tritium applications [46].…”