Separation of $H_2/CO_2$, $H_2/CO$ gas mixtures by pressure swing adsorption process, and fixed-bed dynamics

Abstract

The separation of $H_2/CO_2$ and $H_2/CO$ mixtures by pressure swing adsorption process was performed to obtain high purity $H_2$ with high recovery rate. To study the PSA processes systematically, three steps of experiments were carried out ; the adsorption equilibrium experiment, the fixed-bed experiment and the PSA experiment. Also, to understand the characteristics of PSA performance and fixed bed dynamics, various mathematical models are developed and solved by a numerical technique. 1. Adsorption equilibrium: In the adsorption equilibrium experiment, equilibrium data for the adsorption of hydrogen, carbon dioxide and carbon monoxide on activated carbon were experimentally determined along with pressures up to 15 atm at 298 K, 313 K, 333 K and 348 K. The experimental data were fitted to the Langmuir isotherm, and the Langmuir isotherm parameters were represented as a function of temperature for the mathematical modeling. 2. Fixed-bed system: In the fixed-bed experiment, two different fixed-bed systems are considered such as trace component system and bulk component system. 2-1. Trace component fixed-bed system: In the trace component system, the adsorption and desorption breakthrough behaviors of carbon monoxide and carbon dioxide on activated carbon at the wide ranges of pressure were studied theoretically and experimentally for single component as well as multicomponent systems. The effects of total pressure, inlet composition and flow rate on adsorption and desorption curves also were determined. The experimental adsorption and desorption curves could be predicted fairly well by the linear driving force(LDF) model, and the LDF mass transfer coefficients at various operating conditions were determined by matching the theoretical model with the experimental breakthrough curves for the single component system. A linear driving force mass transfer relationship with pressure-dependent mass transfer coefficients calculated from the single component system pro...