Equilibrium‐limited periodic separating reactors

Abstract

A new unit operation is presented that utilizes a rapid feed pressure swing cycle in a bed packed with catalyst and adsorbent to effect both reaction and separation. This hybrid device combines features of a cyclic-steady-state pressure swing adsorber with those of a flowforced catalytic reactor. Feed sequences for the periodic separating reactor (PSR) are those of rapid, single-bed pressure swing adsorbers (PSA). Only the case of extremely fast reactions is considered here. A perturbed reaction-sorption equilibrium model is formulated and solved for isothermal operation for different equilibrium constants and reaction stoichiometries. The capacity and separation performance for an equilibrium-limited PSR (EPSR) can be of the same order of magnitude as PSA alone. For reactions involving a single reactant or single product, the principal component in a particular exit stream depends upon both the reaction stoichiometry and feed fraction of the process cycle. The pressure dependency of the reaction equilibrium expression is the cause of separation reversals as parameters are varied.

Pressure swing adsorption reactors: Simulation of three‐step one‐bed process

“…The model developed by Vaporciyan and Kadlec (1987) considers linear adsorption equilibrium isotherms and Darcy's law for flow in the bed.…”

Chromatographic Reactors

“…This technology was originally proposed by Vaporciyan and Kadlec [45,46]. These authors present simulation [45] and experimental results [46] of a unit operating with a rapid pressure swing adsorption cycle and using a bed packed with a mixture of catalyst and adsorbent. The proposed cycle combines the following three steps: feed, delay, and exhaust.…”

“…During the exhaust, both ends of the bed are opened and the column is let to depressurize quickly. At the end of this step, the greater part of the reaction products retained in the adsorbed phase is expected to have been desorbed, and the bed is ready to start a new cycle [45]. The experimental results presented were for CO oxidation in a bed packed with platinum catalyst beads and with a 5-Å molecular sieve.…”

Selectivity effects on series reactions by reactant storage and PSA operation

“…is essential for design LaCava et al, 1998 . Ž . Vaporciyan and Kadlec 1987 were the first to extend PSA to chemical reactors, thereby employing in-situ separation of productsrreactants during chemical conversion. They proposed to use a mixture of a catalyst and a sorbent in the Correspondence concerning this article should be addressed to A. Bliek or A. J.…”