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• An S-shaped adsorption isotherm model for gate-opening and breathing adsorbents. • Spreading pressure derivation to address mixture adsorption behaviors. • Fitting method for the S-shaped isotherm model with varying temperatures. • Practical example by applying the isotherm model to a process simulation. Recently S-shaped (sigmoidal-shaped) adsorption isotherms have attracted much attention as having potential for reduced energy use in pressure or temperature swing based separations. Despite a wide variety of such isotherm data reported in the literature, convenient mathematical representations of S-shaped isotherms are not yet available. The absence of such models relating pressure and uptake values hinders the evaluation of many potentially promising adsorbents in separation and storage. Herein, a new mathematical model is proposed that parameterizes S-shaped isotherm data. The model provides a basis for deriving analytical expressions for the spreading pressures, to achieve a dramatic computational cost reduction in the ideal adsorption solution theory (IAST) calculation for multi-component isotherms. Then, the proposed model is generalized for its broader application. To consider the temperature effect based on isotherm data distributed at varying temperatures, a method is suggested to use such distributed data in fitting a single isotherm model. Each of the models and methods is illustrated with their application examples to facilitate the understanding and clarifying the advantages of the proposed model. Among them, a practical example with simulations of breakthrough experiments is provided. [ABSTRACT FROM AUTHOR]

We developed a computer-aided evaluation software system for CO 2 capture adsorbents, named General Adsorbent Library and Evaluation (GALE). This software, freely available for downloads, provides two practical functions: an extensive sorbent library with isotherm parameters for more than 2000 sorbents and a computationally efficient function to evaluation their performance for user in a pressure swing adsorption (PSA) process. The new sorbent library provides isotherm parameters, which were calculated through molecular simulations using the previously available structure libraries. Based on these parameters in the software, performances of user-selected adsorbents can be evaluated and ranked in terms of the CO 2 capture efficiency in an ideal PSA process. The evaluation function is designed to address diverse situations such as varying feed conditions and target purities. Some innovative strategies regarding the use of purity upper bound and candidate pool reduction concepts are suggested to lower the computational load. [ABSTRACT FROM AUTHOR]