Reactive distillation (RD), an unconventional and attractive technique, has
been applied in fuel ether production. A typical application of RD is the
synthesis of the widely used methyl tert-butyl ether (MTBE). RD has also be
en found to have potential to produce high quality ethyl tert-butyl ether (
ETBE), a potential alternative to MTBE. A RD process integrates conventiona
l reaction and separation into a single unit, resulting in extra complexity
and dual process objectives, i.e. maximization of reactant conversion and
purity of products. The conversion and the purity are thus important variab
les to be controlled in RD of ETBE. Unfortunately, both of them are not eco
nomically and reliably available for closed-loop control. This study aims t
o develop an effective method to infer the conversion and the purity from m
ultiple temperature measurements that are easily available on-line and in r
eal time. Nonlinear inferential models are recommended for ETBE synthesis w
ith a ten-stage pilot scale RD column. The models are two-variable third-or
der regressive models, in which the temperature measurements of the reboile
r and the bottom reactive section are employed. Experimental design, model
identification, and model testing are also investigated.