Modeling Tray Separation Columns with Parallel Streams

Abstract

Linear tray models based on liquid phase plug flow, are developed for absorption and desorption using conventional-, para-, and meta separation columns. The models are explicit in the local (point) efficiency rather than tray efficiency, leading to direct integration of the Lewis enhancement effects, i.e. of point-to-plate efficiency enhancement. The models lead to mathematical systems, also encountered in modeling and analysis of periodic separations. With similar analysis, the models can evaluate stationary profiles and tray efficiencies of systems with arbitrary numbers of trays and parallel streams. The models are used to simulate stripping/desorption of ammonia from water with air and absorption of SO2 with seawater. The presented framework of modeling and analysis makes it possible to develop a basis for comparing different separation forms on a common basis. Periodic separation and conventional tray-based separation are special cases of para separation and meta separation without stream partitioning. Similarly, para separation and meta separation can be seen as extensions of periodic and conventional separation to higher numbers of parallel streams.