Computational Fluid Dynamics Simulation of Three-Dimensional Liquid Flow and Mass Transfer on Distillation Column Trays

This paper presents a three-dimensional computational fluid dynamics (CFD) model for describing the liquid-phase flow and concentration distribution on a distillation column tray. Both volume fractions of gas and liquid as well as the interfacial forces and the interphase mass-transfer item Sc are considered in modeling. Simulations of three-dimensional liquid flow and the concentration distribution were carried out on both a single tray and all trays of a distillation column with 10 sieve trays under total reflux. The simulations were performed by using software Star-CD. The prediction by the present model for liquid flow on a single tray was confirmed by the experimental measurement reported by Solari and Bell (AIChE J. 1986, 32, 640) and the simulation by Gesit et al. (AIChE J. 2003, 49, 910) on a 1.22-m-diameter sieve tray. The predicted overall column efficiency resulting from the concentration distribution on each tray for the cyclohexane−heptane separation in a 10-tray distillation column under total reflux was roughly in agreement with the experimental work by Yanagi and Sakata (Inst. Chem. Eng. Symp. Ser. 1979, 56, 21). The present study demonstrates that the application of CFD as a tool for the theory-based distillation design and performance analysis is feasible and dependable.