Nitric ammonia, catalytic oxidation kinetic

Reduction of Nitric Oxide with Ammonia. - Control of the emission of NO from stationary sources is possible by selective catalytic reduction, for which up to now NH3 is the only effective reductant in the presence of excess 02. Beside noble metal catalysts Bauerle etal.101 109 and Wu and Nobe108 studied Al2 03-supported vanadium oxide and found this to be highly effective in NO removal which is considerably enhanced by the presence of 02. Alkali metal compounds which are usually added as promoters for S02 oxidation completely inactivate the catalysts for NO reduction. Adsorption kinetic studies indicated first-order dependence on NH3 adsorption. Similar results were obtained for NO on reduced vanadium oxide, but its adsorption on... 

In Section IV.B the five mathematical BSR models will be discussed. This includes a discussion of the general assumptions or restrictions made in the development of the models and a discussion of the additional assumptions that lead to each of the separate models. The relations that were used to describe momentum and mass transfer have already been discussed in the previous two sections, and will therefore not be repeated here. Furthermore the kinetic model to be implemented in a BSR model is considered to be known. In Section IV.C the adequacy of the models will be illustrated based on the results of validation experiments. For those experiments, the selective catalytic reduction (SCR) of nitric oxide with excess ammonia served as the test reaction, using a BSR filled with strings of a commercial deNO catalyst shaped as hollow extrudates. The kinetics of this reaction had been studied separately in a recycle reactor. 

In 1909, Ostwald was awarded the Nobel Prize in chemistry for his work in catalysis. My suspicion is that the committee decided to award him the prize - he was the "Mr. Physical Chemistry" of his day -and they chose his work in catalysis as providing as good a basis as any other. In fact, not much of his career had been devoted to catalysis. In 1884, he reported a study of the acid-catalyzed hydrolysis of methyl acetate which introduced kinetics, in the modern sense, into catalysis. He also tied the concept of catalytic activity to rate. Both of these items were important. Then in 1901-1904 he and his former student, Brauer, developed the Ostwald process for the oxidation on platinum of ammonia to nitric oxide. The first plant went on stream in Bochum in 1906 at a level of 300 kg of nitric acid per day. In 1908, the production was 3000 kg per day. The process actually goes back to Kuhlmann in 1838, but there had been no industrial interest in such a process, because Chili saltpeter was cheaper source of nitric acid than ammonia. However, at the beginning of the twentieth century, the ease with which the British fleet could sever the sea lane between Chili and Germany had become a stimulus to the development of the Ostwald process. 

Amiridis M D, Puglisi F, Dumesic J A, Millman W.S, Topsoe N.Y (1993) Kinetic and infrared spectroscopic studies of Fe-Y zeolites for the selective catalytic reduction of nitric-oxide by ammonia. J. Catal. 142 (2) 572-584. 

Dumesic JA, Tops0e N-Y, Tops0e H, Chen Y, Slabiak T (1996) Kinetics of Selective Catalytic Reduction of Nitric Oxide by Ammonia over Vanadia/Titania. J Catal 163... 

Dumesic, J.A., Topspe, H., Chen, Y., and Slabiak, T. Kinetics of selective catalytic reduction of nitric oxide by ammonia over vanadia/titania. J. Catal 1996, 163, 409-417. 

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