LPG mass separation by vortex tube cascade and its economics

Highlights: • Cascaded arrangements of VTs for LPG mass separation are studied. • Effects of operational parameters on mass separation are experimentally investigated. • A simple purity index for the hot outlet stream is proposed. • Economic comparison between VT cascade and conventional methods is made. • VT cascade potential for pre-purification processes is suggested. -- Abstract: In the present experimental study, the effect of operating parameters such as inlet and outlet pressure as well as inlet temperature on the mass separation capability of vortex tubes (VTs) for a gas mixture is investigated. Specifically, concentrating heavier components of a gas mixture in the hot outlet stream is considered. Proposing a semi-empirical index from the experimental study, the simulation of different arrangements of VTs, and the effect of recycling a portion of the hot outlet stream on its mass separation performance are investigated. Moreover, the proposed separation method by VTs is economically compared with commonly used methods by distillation columns and two-phase separators. The comparison shows the proposed VT cascade is more advantageous, and finally, its potential use in industrial applications is suggested.