The addition of limestone for sulfur retention in fluidized bed combustion (FBC) has in many cases been observed to influence the emission of N2O. The catalytic activity of N2O over calcined Stevns Chalk for decomposition of N2O in a laboratory fixed bed quartz reactor was measured. It was found that calcined Stevns Chalk is an active catalyst for N2O decomposition in an inert atmosphere at FBC temperatures, and the presence of 3 vol% CO increased the rate of N2O destruction by a factor of 5 due to the catalytic reduction of N2O by CO. The activity decreased with increasing CO2 concentration, and uncalcined or recarbonated limestone had negligible activity. Sulfation of the calcined limestone under oxidizing conditions lowered the activity, however sulfidation under reducing conditions showed that CaS is an active catalyst for the reduction of N2O by CO. Without CO present a gas solid reaction between N2O and CaS takes place and SO2 is released.
|Title of host publication||Proceedings of the 7th International Workshop on Nitrous Oxide Emissions|
|Publication status||Published - 1997|
|Event||7th International Workshop on Nitrous Oxide Emissions - Cologne|
Duration: 1 Jan 1997 → …
|Conference||7th International Workshop on Nitrous Oxide Emissions|
|Period||01/01/1997 → …|
Johnsson, J. E., Jensen, A., Vaaben, R., & Dam-Johansen, K. (1997). Decomposition and Reduction of N2O over Limestone under FBC Conditions. In Proceedings of the 7th International Workshop on Nitrous Oxide Emissions (pp. 19-29)