| 1. |
- Leckner, Bo G, 1936, et al.
(author)
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Influence of additives on selective noncatalytic reduction of nitric oxide with ammonia in circulating fluidized bed boilers
- 1991
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In: Industrial & Engineering Chemistry Research. - 1520-5045 .- 0888-5885. ; 30:11, s. 2396-2404
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Journal article (peer-reviewed)abstract
- The application of selective noncatalytic reduction of nitric oxide with ammonia in circulating fluidized bed boilers is investigated. Special attention is directed to the use of additives to the ammonia so that the efficiency of the NO reduction at lower temperatures can be increased. Tests under realistic conditions in a research boiler and reaction kinetic calculations show that the type of additives used did not improve the process. On the other hand, it is shown that ammonia injection as such, when employed before the cyclone of the boiler, effectively reduces the NO emission to a level of 20-60 ppm, without significant negative effects such as ammonia bypass and an increased CO emission.
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| 2. |
- Sanati, Mehri, et al.
(author)
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Kinetics and Mechanisms in the Ammoxidation of Toluene over a Titania TiO2(B)-Supported Vanadium Oxide Monolayer Catalyst. 1. Selective Reactions
- 1991
-
In: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 0888-5885 .- 1520-5045. ; 30:2, s. 312-320
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Journal article (peer-reviewed)abstract
- A kinetic investigation of the ammoxidation of toluene was carried out over a TiO,(B)-supported vanadium oxide catalyst with a loading corresponding to a theoretical monolayer. The partial pressures of reactants toluene, oxygen, and ammonia were varied, and rates were measured for the formations of benzaldehyde and benzonitrile. By analysis of the rate dependencies on partial pressures of reactants, rate expressions completely describing the data were derived. These show that benzaldehyde is formed from two routes in which the. active ensemble accommodates one and two toluene molecules, respectively. The latter route is most facile. For the formation of benzonitrile, there are also two routes. In the route that is major at low partial pressures of ammonia, one ammonia molecule is adsorbed. With increase in the partial pressure of ammonia, a second route involving adsorption of two ammonia molecules at the active ensemble becomes increasingly important.
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| 3. |
- Sanati, Mehri, et al.
(author)
-
Kinetics and Mechanisms in the Ammoxidation of Toluene over a Titania TiO2(B)-Supported Vanadium Oxide Monolayer Catalyst. 2.Combustion Reactions
- 1991
-
In: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 0888-5885 .- 1520-5045. ; 30:2, s. 320-326
-
Journal article (peer-reviewed)abstract
- To obtain knowledge about combustion mechanisms operating in the ammoxidation of toluene, the formation of carbon oxides was studied over a Ti02(B)-supported vanadium oxide catalyst with monolayer loading. The partial pressures of reactants were varied and kinetic rate expressions, completely describing experimental data, were derived. A comparison of the expressions obtained with those for the formation of nitrile and aldehyde shows that carbon oxides are formed at sites that are not involved in the mechanism of partial oxidation. Furthermore, C02 and CO are formed in routes having a common type of active ensemble. All of the adsorption steps are fast and in equilibrium. For the formation of C02 and CO, the rate-limiting step in both cases comprises a chemical transformation of which the details are unknown. The introduction of ammonia leads to a strong decrease of the rates for formation of carbon oxides.
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