Adsorption modeling for off-gas treatment

Off-gas generated from the reprocessing of used nuclear fuel contains a mixture of several radioactive gases including ¹²⁹I₂, ⁸⁵Kr, HTO, and ¹⁴CO₂. Over the past few decades, various separation and recovery processes have been studied for capturing these gases. Adsorption data for gaseous mixtures of species can be difficult to determine experimentally. Therefore, procedures capable of predicting the adsorption behavior of mixtures need to be developed from the individual isotherms of each of the pure species. A particular isotherm model of interest for the pure species is the Generalized Statistical Thermodynamic Adsorption isotherm. This model contains an adjustable number of parameters and will therefore describe a wide range of adsorption isotherms for a variety of components. A code has been developed in C++ to perform the non-linear regression analysis necessary for determination of the isotherm parameters, as well as the least number of parameters needed to describe an entire set of data.