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Thermal Control of Microstructured Reactors through Staged Oxidant Addition

Anna Lee Tonkovich1, Ravi Arora1, Steve Perry1, Bin Yang1, Terry Mazanec1, and Dave Hesse2. (1) Technology Development, Velocys, Inc., 7950 Corporate Boulevard, Plain City, OH 43064, (2) Battelle Memorial Institute, Columbus, OH 43016

Microstructured reactors have shown great promise for reducing the size and cost of reactor systems while simultaneously enhancing conversion and or selectivity through temperature control. The present work shows both experimental and theoretical results of how temperature control is achieved using staged addition for oxidation reactions. Staged oxidant addition has been extensively described in the literature using membranes or porous walls (1-4). These approaches were successful at reaction times in the range of seconds, where the heat generation load is fairly modest (< 0.1 W/cm3). The present work extends this concept to the range of millisecond kinetics in commercially-scaleable microstructured reactors where higher rates of volumetric heat generation (> 10 W/cm3) must be managed. An oxidant, air in this work, is staged along the reactor length using a small number of openings or jets of various geometries. Air flows through a jet opening and impinges into a hydrocarbon stream flowing in an adjacent microchannel before reacting on a catalyst coated microchannel wall. The corresponding wall temperatures must be moderated to avoid catalyst sintering. Detailed theoretical and experimental work has mapped the thermal profile in both the gas and wall, and shown excellent thermal control near the target temperature. Commercialization of microstructured reactors requires the careful integration of multiple unit operations. Staged addition of an oxidant is one tool to tailor the performance of a large commercial reactor.

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