| 초록 |
Pressure swing adsorption (PSA) is used in many industrial applications ranging from the separation of a gaseous mixture into its components to the purification of an inert carrier gas by the elimination of impurities. A PSA process usually involves a series of adsorption beds, each executing the same sequence of operations but shifted in phase. The basic operations that are performed on each bed include pressurization, high pressure adsorption, blowdown, and purge. In addition to the basic operations, pressure equalization step is often involved in the multi-bed PSA process. In the large commercial PSA process, two or more pressure equalization steps are often employed to enhance the recovery of the light component. All these steps can be simulated with single column five step PSA process (Yang, 1987) which consists of I) pressurization with product (backfill step) II) high pressure adsorption III) cocurrent depressurization IV) blowdown V) purge. The cocurrent depressurization step can simulate such as the pressure equalization step and the step providing purge gas in the multi-bed H2 purification process (Yang, 1987). After one decides the cocurrent depressurization pressure, one can make a decision how many pressure equalization steps can be involved and how large quantity of purge gas is available from the cocurrent depressurization step. For the PSA process based on the different equilibrium selectivities of the components in the gas mixture, the solution predicted by the local equilibrium model can predicted the PSA performance relatively easily. In this study, the performance characteristics of 5 steps PSA cycles were investigated with respect to the cocurrent depressurization pressure and the extent of purge with eqilibrium model. The contour maps of the light component recovery and throughput are made according to the cocurrent depressurization pressure and the extent of purge. The maximum throughput at fixed recovery or the maximum recovery at fixed throughput is analyzed.
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