Styrene from Ethylbenzene Using Membrane Reactors

In this review we examine the production of styrene from ethylbenzene by dehydrogenation in membrane reactors. First, we review the literature on this and related subjects to ascertain the type of membrane and reactor as well as the configurations and operating conditions that are most favorable. Next, we design a plant to produce 1 billion lb/yr (454,000 t/yr) of styrene. We discuss variations of the design features and we then estimate the capital investment and production costs, comparing them with two established processes.

Although the membrane process using presently available membrane technology may not have an advantage over the conventional nonmembrane dehydrogenation process, if membranes now in the research stage were to be successfully introduced, the improved membrane process could be competitive. On the other hand, the advantage of any further improvement would be only marginal because the conventional process has already attained a fairly good conversion and selectivity.

Actually, making styrene from ethylbenzene by the membrane process is only in an early stage of research. The present evaluation, based on many assumptions (though we consider all these assumptions to be reasonable), must be considered as speculative. However, future prospects are positive and this study should serve as a useful guideline to researchers and developers.