Effect of operating conditions on the reduction of nitrous oxide by propane over a Fe-zeolite monolith

• Published in: Applied catalysis. B, Environmental Environmental, 2005-11, Vol.61 (3-4), p.306-315
• Main Authors: Ruiz-Martínez, E., Sánchez-Hervás, J.M., Otero-Ruiz, J.
• Format: Article
• Language: English
• Subjects: Fe-ZSM-5; Fluidised bed combustion; Nitric oxide; Nitrous oxide; Propane; Selective catalytic reduction; Space velocity; Sulphur dioxide; Water
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2005.06.005

Fluidised bed combustion is an important source of nitrous oxide emissions. The influence of different operating parameters, such as catalyst volume, temperature, gas hourly space velocity, and hydrocarbon addition, on the activity, selectivity, and poisoning tolerance of a Fe-ZSM-5 monolith for the nitrous oxide selective catalytic reduction, has been investigated under realistic conditions, at bench scale. Both in the absence or in the presence of poisons, such as H2O, NO, and SO2, the optimisation of operating conditions gives rise to a broadening of the temperature window for N2O reduction, making it more compatible with real application conditions, with a simultaneous reduction in hydrocarbon fugitive emission, resulting in an environmental friendly process. Excessively high reaction temperatures seem to be needed to obtain an acceptable level of N2O decomposition. On the contrary, high N2O reduction conversions are obtained, even in the presence of poisons and at relatively low temperatures, which is the preferred situation in the processes of pollutants removal from stationary combustion sources. The optimum value of C3H8/N2O ratio to be used for reducing N2O over the catalyst system seems to be about the unity, since higher N2O and C3H8 conversions and lower hydrocarbon unwanted emissions are attained, with a low consume of propane as selective reductant.