(45g) Styrene Production Via a Highly Selective Partial Oxidation Route Enabled by Novel Catalyst Substrates in Microchannel Reactors

Commercial styrene production requires large capital investment and results in high operating costs to supply heat for the endothermic dehydrogenation reaction with superheated steam. An alternative chemistry has long been suggested in the literature for an exothermic partial oxidation route from ethylbenzene to styrene, but high selectivity at commercially-attractive conversion rates has not been realized. The challenge for this reaction is obtaining the desired selectivity, resulting from more than 30x difference in heat of reaction for styrene production versus deep oxidation.

Recently, the performance barrier for oxidative styrene production has been overcome by merging a new class of catalysts with a novel thermally-effective and low-tortuosity catalyst substrate. In a single stage microchannel reactor, selectivity to styrene over 95% has been demonstrated with an ethylbenzene conversion exceeding 70%. Comparative experiments were conducted for the same catalyst without the novel substrate; the catalyst as packed in a narrow channel reactor demonstrated thermal runaway above 40% conversion. An evaluation of commercial economics based on this improved oxidative synthesis route illustrates the substantial improvement in economic return for this process.