先端化学工学ジャーナル

概要

Control Volume Approach for Modeling the Interphase Mass Transfer in a Packed Column Distillation

Goro Nishimura, Kunio Kataoka, Hideo Noda and Naoto Ohmura

A simplified mass transfer model for a ternary ideal solution was constructed by a control volume method proposed for a packed distillation column. The concept of modeling was in how to bridge between the distillation experiment of a real column and the computer-aided process simulation of an ideal column. The control volume approach using local values of HETPs determined by experiment was contrived to determine step-by-step local values of the vapor-phase and liquid-phase mass transfer coefficients. A commercial-scaled 5.5 m high packed column equipped with three beds of wire-mesh corrugated-structured packing was used as a test column. The experiment was conducted at normal pressure under the total-reflux condition for a ternary system of methanol, ethanol, and iso-propanol. The process simulation analysis for an ideal equilibrium-staged column was made to compare with the distillation experiment made by a real column. The volumetric film coefficients of mass transfer in the vapor phase and liquid phase, respectively, were evaluated step-by-step by the control volume method taking into account the experimentally obtained HETPs. Local variation of the experimental mass transfer correlations were generalized in a dimensionless form separating into the effect of local behavior and the Reynolds number dependency.