Comparative performance of an adiabatic and a nonadiabatic PSA process for bulk gas separation—a numerical simulation

Abstract

A detailed numerical model of a Skarstrom‐like PSA process is used to investigate the separation performance of an adiabatic and a nonadiabatic process for removal of bulk CO2 impurity from inert He. The complexity of the gas phase adsorbate composition, adsorbate loading, and the adsorbent temperature profiles as functions of positions inside an adsorber at the start and end of each step of the PSA process are discussed. The separation performance of a nonadiabatic PSA process is generally inferior to that of the corresponding adiabatic process. Smaller adsorbent column diameter accentuates nonadiabatic operation and hence lower separation efficiency. Furthermore, the separation efficiency decreases more rapidly at short cycle times and smaller column diameters. Insulation of PSA columns of a process development unit operated under these conditions is recommended for reliable data analysis. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4066–4078, 2017

Zeolites for CO2–CO–O2 Separation to Obtain CO2-Neutral Fuels

“…It is also assumed that the adsorbent crystals are agglomerated in pellets and that mass transfer between the gas and the adsorbent is controlled by macropore diffusion, neglecting intracrystalline resistance. 25…”

Potential of CO2 capture from flue gases by physicochemical and biological methods: A comparative study

“…40,41 It is also assumed that the adsorbent crystals are agglomerated in pellets, and that mass transfer between gas and adsorbent is controlled by macropore diffusion, neglecting intracrystalline resistance. 42 The multicomponent adsorption isotherms for the PSA simulations were obtained by applying the Ideal Adsorption Solution Theory (IAST) 43 , previously obtained by GCMC simulations. Isotherms were fitted with the Langmuir equation.…”

“…To compare the performance of each of the studied zeolites in a PSA industrial cycle, we have employed the so-called "Bed Capacity Factor" (BCF) to compare the PSA performance of each structure when using the Skarstrom cycle. 42 This parameter is defined as the adsorption capacity of the column utilized at the end of adsorption step (ADS in Fig. S3, incipient breakthrough of the adsorbate) under cyclic steady state operation relative to the maximum capacity of the column under feed gas conditions.…”

Efficiency of Thermal Management Using Phase-Change Material for Nonisothermal Adsorption Process

“…3 Rapid PSA technology, in which the total cycle time of the PSA process is reduced to decrease the bed size factor (the amount of adsorbent required to produce a unit quantity of the product in unit time), is a successful example of these attempts. 4,5 However, this type of strategy for achieving high-throughput separation through the PSA process, including simply enlarging the system size, 6 tends to make the system near adiabatic. Therefore, the heat of adsorption plays an important role in such processes because the adsorbed amount decreases as the temperature increases.…”

“…Many studies to improve its productivity have been conducted in a wide range of fields, including CO 2 separation and volatile organic compound separation . Rapid PSA technology, in which the total cycle time of the PSA process is reduced to decrease the bed size factor (the amount of adsorbent required to produce a unit quantity of the product in unit time), is a successful example of these attempts. , However, this type of strategy for achieving high-throughput separation through the PSA process, including simply enlarging the system size, tends to make the system near adiabatic. Therefore, the heat of adsorption plays an important role in such processes because the adsorbed amount decreases as the temperature increases. , Yang and Cen compared a PSA process for CH 4 /H 2 separation using activated carbon under adiabatic conditions to that under isothermal conditions .…”