Back to Search
Start Over
Effect of CaO on the selective non-catalytic reduction deNO process: Experimental and kinetic study
- Source :
- Chemical Engineering Journal. 249:252-259
- Publication Year :
- 2014
- Publisher :
- Elsevier BV, 2014.
-
Abstract
- The selective non-catalytic reduction (SNCR) deNOx process was influenced by high-concentration CaO particles in the pre-calciners when applied to cement industry. The influence of CaO on the SNCR deNOx process was investigated using a fixed bed reactor at temperature that ranges from 873 K to 1373 K and the mechanism of the process was analyzed. The experimental results demonstrated that CaO has catalytic effects on NH3 decomposition, NO reduction by NH3, and NH3 oxidation. It inhibits the SNCR deNOx process mainly via catalyzing NH3 oxidation to NO. The catalytic effect of CaO can be ignored at temperatures higher than 1273 K. NH3 was found that first adsorbed onto the CaO surface and then dissociated to NH2 by Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The mechanism analysis of CaO catalysis during the SNCR deNOx process showed that NH3 dissociation on the CaO surface is the rate-controlling step, and the intermediate substance, NH2, reacts with O2 or NO to produce NO or N2. The competition of the two reactions determines the product selectivity. A kinetic model including CaO-catalyzed NH3 conversion and gas phase SNCR deNOx reaction was developed, which well predicted the CaO-involved SNCR deNOx process.
- Subjects :
- Diffuse reflectance infrared fourier transform
Kinetic model
Chemistry
General Chemical Engineering
Inorganic chemistry
General Chemistry
Kinetic energy
Industrial and Manufacturing Engineering
Dissociation (chemistry)
Catalysis
Adsorption
Selective non-catalytic reduction
Environmental Chemistry
Selectivity
Subjects
Details
- ISSN :
- 13858947
- Volume :
- 249
- Database :
- OpenAIRE
- Journal :
- Chemical Engineering Journal
- Accession number :
- edsair.doi...........c86c09be5dad5aea1443751723bd6ba8