1. INTRODUCTION
Catalytic distillation (CD) is a process where chemical reactions and distillation occur simultaneously in a distillation column. For the purposes of this paper, the term catalytic distillation will be restricted to the process with a heterogeneous (solid) catalyst and the term reactive distillation will be used to describe the process with a homogeneous catalyst. CD is most commonly used to react methanol with isobutylene to form methyl t-butyl ether (MTBE), which is an octane enhancing oxygenate added to gasoline. One of the major benefits that CD offers MTBE producers is its ability to increase conversion beyond its equilibrium limit. For this reason the CD-based process boasts higher isobutylene conversions than are possible with conventional fixed-bed processes (Hutchings et al., 1992).