Chemical Engineering Science, Vol.49, No.24, 3981-3994, 1994
Catalytic Partial Oxidation Reactions and Reactors
Catalytic partial oxidation processes involving alkanes have great promise for the fast, highly selective production of chemicals from readily available feedstocks. However, oxidation processes are so complex that they are always poorly understood, and because of safety concerns they are inevitably operated far from optimally. This paper describes the experimental characterization of two partial oxidation reactions, the partial oxidation of methane to synthesis gas (>90% selectivities at >90% conversion) and the oxidative dehydrogenation of higher alkanes to olefins (70% selectivity at >80% conversion). It also describes experiments with two novel reactor geometries, ceramic coated monoliths and fluidized beds, which can achieve high conversions and selectivities in these processes at residence times between 10(-4) and 10(-1) s. Then the characteristics of these reactor types for these processes will be discussed and how reactors should be adapted to optimize selectivity and conversion in partial oxidation processes will be considered. These include high mass and heat transfer rates, narrow residence time distributions, and elimination of homogeneous processes which lead to multiple products, flames and explosions.
Keywords:SYNTHESIS GAS-FORMATION;METHANE;DEHYDROGENATION;SELECTIVITY;MONOLITHS;ETHANE;EXTINCTION;NI/AL2O3;SURFACES;IGNITION