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 S c 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.