Adsorption Isotherms from Temperature-Programmed Physiosorption -Equilibrium & Kinetics-

The separation of gas mixtures is a major operation in the process industry for hydrocarbon separation, removal of pollutant from effluent streams, and purification of process streams. The work in this thesis is related to gas separation by pressure swing adsorption (PSA); a well-known example is the separation of methane-carbon dioxide mixtures from landfill gases. Generally the separation process is based on the equilibrium and kinetic characteristics of the gases and the adsorbents. A lot of commercial adsorptive separation processes are based on the difference in equilibrium. In the design and development of the process the adsorption isotherms of all components in the mixture must be considered in the concentration and temperature range of the process. In other processes the kinetic data are essential in the design, these processes are based on the difference in diffusion rates of the various gases in the pores; an example is the production of nitrogen from air with carbon molecular sieves. In both types of processes heat effects due to ad- and desorption are important. The temperature range of the process can be broad and the influence of temperature on both equilibrium and kinetics must be taken into account. Thus, in the design and development of gas separation processes a detailed description of both equilibrium and kinetics in a broad concentration and temperature range is necessary.