The effects of oxygen and metal oxide catalysts on the reduction reaction of NO with lignite char during combustion flue gas cleaning

Ning Yang, Jiang-long Yu, Jin-xiao Dou, Arash Tahmasebi, Hui Song, Behdad Moghtaderi, John Lucas, Terry Wall

Research output: Contribution to journalArticleResearchpeer-review

21 Citations (Scopus)

Abstract

The development of lignite-char-supported metal oxide catalyst for reduction of nitric oxide (NO) is investigated in this paper. The characteristics of NO reduction by copper and iron oxide catalysts supported on activated lignite chars (ALC) was studied using a fixed-bed reactor at 300 °C. The results showed that the impregnation of Cu on ALC resulted in higher catalytic reactivity during NO reduction compared with that of Fe. Chemisorption of O2 and NO on Cu/ALC catalyst was found to play an important role in denitrification. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses showed that chemically adsorbed oxygen facilitates the formation of C(O) complex and oxidation of Cu0 to Cu+ for Cu/ALC catalyst. The C(O) intermediates and C∗production formed due to the fact that C/O2 reaction promoted the reduction of NO. It is suggested that the catalytic reaction of NO in this case comprised of C/O2 reaction, C(O)/NO reaction and formation of N2 and CO2. Cu seemed to have significantly promoted the C(O) formation and CO oxidation compared with Fe. The catalytic reactivity of Cu species for C(O) formation and CO oxidation followed the order of Cu0 > Cu+ > Cu2 +. Fe3O4 was believed to be the active phase in Fe catalyst. The oxygen and char-supported metal catalysts significantly promoted C/NO reaction, and therefore may lead to a lower operation temperature of NOx removal.

Original languageEnglish
Pages (from-to)102-107
Number of pages6
JournalFuel Processing Technology
Volume152
DOIs
Publication statusPublished - Nov 2016
Externally publishedYes

Keywords

  • Activated-char
  • Catalytic NO reduction
  • Flue gas cleaning
  • NO emission

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