SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2020, Vol. 28 ›› Issue (1): 299-306.DOI: 10.1016/j.cjche.2019.07.023

• Energy, Resources and Environmental Technology • Previous Articles     Next Articles

Activation mechanisms on potassium hydroxide enhanced microstructures development of coke powder

Xiaojing Chen1, Huirong Zhang1, Yanxia Guo1, Yan Cao2, Fangqin Cheng1   

  1. 1 State Environmental Protection Key Laboratory on Efficient Resource-utilization Techniques of Coal Waste, Institute of Resources and Environmental Engineering, Shanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related Wastes, Shanxi University, Taiyuan 030006, China;
    2 Institute for Combustion Science and Environmental Technology(ICSET), Western Kentucky University(WKU), Bowling Green, KY 42101, United States
  • Received:2018-10-14 Revised:2019-07-15 Online:2020-03-31 Published:2020-01-28
  • Contact: Huirong Zhang, Yanxia Guo, Yan Cao, Fangqin Cheng
  • Supported by:
    Supported by the National Key R&D Plan (2016YFE0131100, 2017YFB0603101) and the Program for Sanjin Scholars of Shanxi Province and the Talent Training Program of Shanxi Joint Postgraduate Training Base (2016JD07).

Activation mechanisms on potassium hydroxide enhanced microstructures development of coke powder

Xiaojing Chen1, Huirong Zhang1, Yanxia Guo1, Yan Cao2, Fangqin Cheng1   

  1. 1 State Environmental Protection Key Laboratory on Efficient Resource-utilization Techniques of Coal Waste, Institute of Resources and Environmental Engineering, Shanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related Wastes, Shanxi University, Taiyuan 030006, China;
    2 Institute for Combustion Science and Environmental Technology(ICSET), Western Kentucky University(WKU), Bowling Green, KY 42101, United States
  • 通讯作者: Huirong Zhang, Yanxia Guo, Yan Cao, Fangqin Cheng
  • 基金资助:
    Supported by the National Key R&D Plan (2016YFE0131100, 2017YFB0603101) and the Program for Sanjin Scholars of Shanxi Province and the Talent Training Program of Shanxi Joint Postgraduate Training Base (2016JD07).

Abstract: Coke powder is expected to be an excellent raw material to produce activated carbon because of its high carbon content. Potassium hydroxide (KOH), as an effective activation agent, was reported to be effective in activating coke powder. However, the microstructures development in the coke powder and its mechanisms when KOH was applied were still unclear. In this study, effects of KOH on the microstructure activation of coke powder were investigated using the surface area and pore structure analyzer, scanning electron microscope (SEM) and thermogravimetry-differential scanning calorimetry-mass spectrometry (TG-DSC-MS), etc. Results revealed that the addition KOH at its lower ratio (mass ratios of KOH and coke powder in a range of 0.5 and 1) decreased the specific surface area and average lateral sizes, but sharply increased of the specific surface area to 132 m2·g-1 and 355 m2·g-1 and decreased of the space size of aromatic crystallites upon the further increase of the KOH addition amounts (ratios of KOH and coke powder in a range of 3 and 7), generating a number of new micropores and mesopores. The mechanisms study implied surface reactions between KOH and aliphatic hydrocarbon side chain and other carbon functional groups of the coke powder to destruct aromatic crystallites in one dimension and broaden pores at lower KOH addition. In the activation process, KOH was decomposed to be more active components, which can be rapidly destruct the aromatic layers in spatial scope to form developed porous carbon structures within coke powder at higher KOH addition.

Key words: Activated carbon, Coke powder, Activation, Structure, Potassium hydroxide

摘要: Coke powder is expected to be an excellent raw material to produce activated carbon because of its high carbon content. Potassium hydroxide (KOH), as an effective activation agent, was reported to be effective in activating coke powder. However, the microstructures development in the coke powder and its mechanisms when KOH was applied were still unclear. In this study, effects of KOH on the microstructure activation of coke powder were investigated using the surface area and pore structure analyzer, scanning electron microscope (SEM) and thermogravimetry-differential scanning calorimetry-mass spectrometry (TG-DSC-MS), etc. Results revealed that the addition KOH at its lower ratio (mass ratios of KOH and coke powder in a range of 0.5 and 1) decreased the specific surface area and average lateral sizes, but sharply increased of the specific surface area to 132 m2·g-1 and 355 m2·g-1 and decreased of the space size of aromatic crystallites upon the further increase of the KOH addition amounts (ratios of KOH and coke powder in a range of 3 and 7), generating a number of new micropores and mesopores. The mechanisms study implied surface reactions between KOH and aliphatic hydrocarbon side chain and other carbon functional groups of the coke powder to destruct aromatic crystallites in one dimension and broaden pores at lower KOH addition. In the activation process, KOH was decomposed to be more active components, which can be rapidly destruct the aromatic layers in spatial scope to form developed porous carbon structures within coke powder at higher KOH addition.

关键词: Activated carbon, Coke powder, Activation, Structure, Potassium hydroxide