Evaluation of NOx-Reduction Measures for Iron-Ore Rotary Kilns
Artikel i vetenskaplig tidskrift, 2020

The grate-kiln process is employed for sintering and oxidation of iron-ore pellets. In this process, a fuel (typically coal) is combusted with a large amount of excess air in a rotary kiln, and the high air-to-fuel ratio leads to significant NOx formation. The current Article is an assessment of NOx reduction measures that have been tested in pilot-scale and in full-scale by the Swedish iron-ore company Luossavaara-Kiirunavaara Aktiebolag (LKAB). The results show that the scaling between the full-scale kiln and the pilot-scale kiln is crucial, and several primary measures that reduce NOx significantly in pilot-scale achieve negligible reduction in full-scale. In the investigated full-scale kiln, thermal NOx formation is efficiently suppressed and low compared with the NO formation from the fuel-bound nitrogen (especially char-bound nitrogen). Suppressing the NO formation from the char-bound nitrogen is difficult due to the high amounts of excess air, and all measures tested to alter mixing patterns have shown limited effect. Switching to a fuel with a lower nitrogen content is efficient and probably necessary to achieve low NOx emissions without secondary measures. Simulations show that replacing the reference coal with a biomass that contains 0.1% nitrogen can reduce NOx emissions by 90%.


Rikard Edland

Chalmers, Rymd-, geo- och miljövetenskap, Energiteknik

Neil Smith

University of Adelaide

Thomas Allgurén

Chalmers, Rymd-, geo- och miljövetenskap, Energiteknik

Christian Fredriksson


Fredrik Normann

Chalmers, Rymd-, geo- och miljövetenskap, Energiteknik

Denver Haycock

Brigham Young University

Colson Johnson

Texas A&M University

Jacob Frandsen

Brigham Young University

Tom Fletcher

Brigham Young University

Klas Andersson

Chalmers, Rymd-, geo- och miljövetenskap, Energiteknik

Energy & Fuels

0887-0624 (ISSN) 1520-5029 (eISSN)

Vol. 34 4 4934-4948

Reduktion av CO2-utsläpp från LKABs roterugnsprocess - en studie av effekten av alternativa bränslen

Energimyndigheten (2012-009098), 2013-05-01 -- 2016-04-30.

LKAB (Roteringsugnsprocess), 2013-05-01 -- 2016-04-30.


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