fulltext.study @t Gmail

Evaluation of catalysts for N2O abatement in fluidized-bed combustion

Paper ID Volume ID Publish Year Pages File Format Full-Text
47940 46486 2009 6 PDF Available
Title
Evaluation of catalysts for N2O abatement in fluidized-bed combustion
Abstract

Several catalysts, including FeZSM-5, Co2AlO4, LaCoO3, and BaFeAl11O19, were evaluated for N2O decomposition under representative flue-gas conditions in fluidized-bed combustion (FBC). Closely related formulations proved active and stable catalysts for process-gas or tail-gas de-N2O in nitric acid plants. With this as starting point, their potential suitability for N2O abatement in stationary combustion was assessed. Tests were carried out in a fixed-bed reactor at ambient pressure and in the temperature range of 473–1123 K using mixtures of N2O, O2, NO, CO, SO2, and H2O. The mixed oxide catalysts were strongly inhibited by water and sulfur dioxide and experienced fast deactivation in the simulated mixture containing all the gases. Bulk sulfate phases were detected by X-ray diffraction in the used perovskite and hexaaluminate, revealing insufficient chemical stability in the presence of sulfur and discouraging installation in the freeboard of the combustor. In great contrast, the activity of steam-activated FeZSM-5 in the model and simulated mixtures was comparable, rendering very stable performance during 30 h on stream. The unique tolerance of this iron zeolite to the complex combination of feed components makes it prone to implementation after the cyclone of FBCs, where temperatures are typically 800–1100 K.

Keywords
N2O abatement; Fluidized-bed combustion; Iron zeolite; Spinel; Perovskite; Hexaaluminate; Sulfur tolerance
First Page Preview
Evaluation of catalysts for N2O abatement in fluidized-bed combustion
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis B: Environmental - Volume 90, Issues 1–2, 25 July 2009, Pages 83–88
Authors
, , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis