SCI和EI收录∣中国化工学会会刊

Chin.J.Chem.Eng. ›› 2018, Vol. 26 ›› Issue (10): 2077-2083.DOI: 10.1016/j.cjche.2018.04.019

• Catalysis, Kinetics and Reaction Engineering • Previous Articles     Next Articles

Catalytic reduction of NOx by biomass-derived activated carbon supported metals

Yun Shu, Fan Zhang, Fan Wang, Hongmei Wang   

  1. Research Center of Air Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
  • Received:2017-09-13 Revised:2018-04-12 Online:2018-11-14 Published:2018-10-28
  • Contact: Yun Shu,E-mail addresses:shuyun@craes.org.cn;Hongmei Wang,E-mail addresses:wanghm5188@sina.com
  • Supported by:

    Supported by the National Natural Science Foundation of China (21507119), the Key Technology Research and Development Program of Qinghai Province (2012-J-144) and the National High Technology Research and Development Program of China (2012AA06A11303).

Catalytic reduction of NOx by biomass-derived activated carbon supported metals

Yun Shu, Fan Zhang, Fan Wang, Hongmei Wang   

  1. Research Center of Air Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
  • 通讯作者: Yun Shu,E-mail addresses:shuyun@craes.org.cn;Hongmei Wang,E-mail addresses:wanghm5188@sina.com
  • 基金资助:

    Supported by the National Natural Science Foundation of China (21507119), the Key Technology Research and Development Program of Qinghai Province (2012-J-144) and the National High Technology Research and Development Program of China (2012AA06A11303).

Abstract: In this study, to prepare a series of activated carbon-supported metals for the catalytic reduction of NOx to N2 in excess O2, activated carbons derived from lignocellulosic and herbaceous biomasses were selected as the reducing agents, and alkali and transition metals were used as the catalytic active phases. The effects of the type of biomass, carbonization temperature and catalyst composition on NOx reduction efficiency were analyzed in a fixed-bed flow reactor. The results showed that two temperature regimes are present for the NOx-carbon reaction:at temperatures below 250℃, the NOx adsorption process on the carbon surface was predominant, whereas true NOx reduction by carbon occurred at temperatures above 250℃, producing N2, CO2 and CO. The influence of the carbonization temperature on carbon reactivity depended on the effect of the carbonization temperature on the carbon surface area and the reduction of the metal species on carbon. All studied metals catalyzed both NOx and O2 reduction by carbon, and potassium could strongly enhance the C-NOx reaction without substantial carbon consumption by O2. Moreover, the potassium supported by sawdust-derived activated carbon exhibited higher selectivity and capacity towards NOx reduction than did its previously reported coal-derived counterparts. These properties were ascribed to the high dispersion of the active potassium species on the carbon surface, as observed through the comparison of X-ray photoelectron spectroscopy and powder X-ray diffraction results for the carbons made from biomass and coal-based precursors.

Key words: Biomass, NOx reduction, Activated carbon, Selectivity

摘要: In this study, to prepare a series of activated carbon-supported metals for the catalytic reduction of NOx to N2 in excess O2, activated carbons derived from lignocellulosic and herbaceous biomasses were selected as the reducing agents, and alkali and transition metals were used as the catalytic active phases. The effects of the type of biomass, carbonization temperature and catalyst composition on NOx reduction efficiency were analyzed in a fixed-bed flow reactor. The results showed that two temperature regimes are present for the NOx-carbon reaction:at temperatures below 250℃, the NOx adsorption process on the carbon surface was predominant, whereas true NOx reduction by carbon occurred at temperatures above 250℃, producing N2, CO2 and CO. The influence of the carbonization temperature on carbon reactivity depended on the effect of the carbonization temperature on the carbon surface area and the reduction of the metal species on carbon. All studied metals catalyzed both NOx and O2 reduction by carbon, and potassium could strongly enhance the C-NOx reaction without substantial carbon consumption by O2. Moreover, the potassium supported by sawdust-derived activated carbon exhibited higher selectivity and capacity towards NOx reduction than did its previously reported coal-derived counterparts. These properties were ascribed to the high dispersion of the active potassium species on the carbon surface, as observed through the comparison of X-ray photoelectron spectroscopy and powder X-ray diffraction results for the carbons made from biomass and coal-based precursors.

关键词: Biomass, NOx reduction, Activated carbon, Selectivity