Simulation of an Enriching Reflux PSA Process with Parallel Equalization for Concentrating a Trace Component in Air

Abstract

The utility of a simple numerical model, based on the LDF approximation and the frozen solid phase assumption, was developed to predict the performance of an enriching reflux (ER) pressure swing adsorption (PSA) cycle with parallel equalization (PEQ) for concentrating a trace component. The utility of this model was successfully demonstrated with the enrichment of Xe from air using 13X zeolite and a two-bed, 6-step, ER PSA cycle with PEQ. With the LDF mass transfer coefficient (Ka) ranging from 2.0 to 3.0 kg m-3 s-1, the model predictions of the enrichment factor (YHP/YF) compared well with the experimental results over a wide range of conditions. Both the modeling and experimental results showed that ambient Xe in air could be enriched up to 80 times by the ER PSA cycle with PEQ. The enrichment factor that could be obtained from the more conventional stripping reflux PSA cycle was theoretically limited to 12.5, i.e., the high to low pressure ratio, with the actual value usually being much less than half ...