(513bw) Comparison of Autothermal and Cooled Tubular Reactor Designs for Odh of Ethane over Movtenbo Mixed Metal Oxide Catalyst

Ethylene is a platform chemical used in the production of polyethylene, ethylene dichloride and ethylene oxide. Oxidative dehydrogenation of ethane (ODHE) represents a potential alternative that is less capital and energy-intensive compared to steam cracking processes currently used to produce ethylene. Most current research is focused on developing new catalysts and interpreting catalytic function over heterogeneous catalysts that demonstrate high performance, an example of which are Mo-V-Te-Nb based bulk mixed metal oxides. Despite extensive catalysis-focused research, to date, there hasn’t been a single reactor design proposed that can be plausibly implemented on an industrial scale. In this work, we show that ODHE can be operated autothermally with ambient temperature feeds and no external heat input.

An ODHE kinetic model developed using lab-scale kinetic data was used to compare autothermal and multitubular reactor designs. The results show that the autothermal reactor configuration is more favorable than the multi-tubular one for this highly exothermic reaction, and becomes even more so with increasing catalyst activity. The autothermal reactor designed as part of our study, unlike multitubular ones, takes advantage of multiple steady-states and falls close to the extinction point on the ignited branch. We also discuss, for the first time, a bifurcation analysis of an ODHE system based on ignition and extinction behavior discussed as a function of adiabatic temperature rise, catalyst activity, and oxygen reaction orders, thereby providing additional insights into strategies for successfully operating these processes on an industrial scale.