Modelling reactive distillation

In this paper we discuss design guidelines for solid-catalyzed reactive distillation systems. The guidelines are used to generate initial estimates for column pressure, reactive zone location, catalyst mass, reactant feed location, reactant ratio, reflux ratio, column diameter, number of equilibrium stages, and packed height. They form a part of a methodical design procedure that makes extensive use of both nonequilibrium (rate-based) and equilibrium-stage simulation models. Important choices prior to design include selection of reliable thermodynamic and reaction kinetic models. We tested the guidelines for two etherification systems and validated them experimentally for a hydration reaction. The results from a case study, the manufacture of tert-amyl methyl ether, are shown here. Superimposing reaction on separation leads to unique design trade-offs. Thus, column diameter depends both on maximum vapor velocity and on packing catalyst density, reactant ratios are a function of conversion and azeotrope fo...

Design Guidelines for Solid-Catalyzed Reactive Distillation Systems

Fluid dynamics in reactive distillation packing Katapak®-S

Reactive separations: more ways to skin a cat

Hydrodynamic and mass transfer efficiency of ceramic foam packing applied to distillation

The geometry of catalyst-containing bale packing is characterized in this paper. The calculated packing parameters (specific surface area and void fraction) are employed in conjunction with a model to predict two-phase pressure drop, maximum capacity, and height equivalent to a theoretical plate (HETP). Experimental data obtained in a 5.3-cm (2.1-in.) column, operated at total reflux, are presented for two systems (cyclohexane/n-heptane and acetone/methyl ethyl ketone) at pressures of 138 and 241 kPa (20 and 35 psia). Model predictions for pressure drop and HETP are validated with experimental data obtained under nonreactive conditions. An appropriate procedure for scaleup of HETP and pressure drop, with associated limitations, is also discussed.

J.C. Gonzalez

Papers

Capacity and efficiency of reactive distillation bale packing : Modeling and experimental validation