The kinetics of propane (I) ammoxidn. to acrylonitrile (II) on a V-Sb-Al-based mixed oxide catalyst are described by a Langmuir-Hinshelwood approach, 6 parallel reactions of formation of II, propylene (III), C oxides, acetonitrile (IV), HCN, and C2 hydrocarbons, 3 reactions of consecutive transformation of the intermediate III to II, IV and HCN, 5 decompn. reactions of intermediate products to C oxides, and 1 reaction of decompn. of ammonia (V). The kinetics were studied in a quartz tubular flow reactor operating both in differential and integral conditions, using I, O, and V concns. in the 0-20% range and reaction temps. of 680-810 K. II forms principally from the intermediate III, and the limiting factor in the formation of II is the relative slowness of this step compared to the others and the higher rate of III oxidn. to C oxides as compared to that of II to COx. The max. yields and selectivities to II obtained were in the 35-40 and 50-60% ranges, resp., for I conversions in the 60-80 and 40-50% ranges, resp. The relevance of the kinetic information in detg. the best reaction conditions and performance using different possible feedstocks is also discussed. [on SciFinder(R)]
Kinetics and reaction network in propane ammoxidation to acrylonitrile on vanadium-antimony-aluminum based mixed oxides
CENTI, Gabriele;
1992-01-01
Abstract
The kinetics of propane (I) ammoxidn. to acrylonitrile (II) on a V-Sb-Al-based mixed oxide catalyst are described by a Langmuir-Hinshelwood approach, 6 parallel reactions of formation of II, propylene (III), C oxides, acetonitrile (IV), HCN, and C2 hydrocarbons, 3 reactions of consecutive transformation of the intermediate III to II, IV and HCN, 5 decompn. reactions of intermediate products to C oxides, and 1 reaction of decompn. of ammonia (V). The kinetics were studied in a quartz tubular flow reactor operating both in differential and integral conditions, using I, O, and V concns. in the 0-20% range and reaction temps. of 680-810 K. II forms principally from the intermediate III, and the limiting factor in the formation of II is the relative slowness of this step compared to the others and the higher rate of III oxidn. to C oxides as compared to that of II to COx. The max. yields and selectivities to II obtained were in the 35-40 and 50-60% ranges, resp., for I conversions in the 60-80 and 40-50% ranges, resp. The relevance of the kinetic information in detg. the best reaction conditions and performance using different possible feedstocks is also discussed. [on SciFinder(R)]Pubblicazioni consigliate
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