SCI和EI收录∣中国化工学会会刊

Chin.J.Chem.Eng. ›› 2015, Vol. 23 ›› Issue (1): 241-246.DOI: 10.1016/j.cjche.2014.10.007

• ENERGY, RESOURCES AND ENVIRONMENTAL TECHNOLOGY • Previous Articles     Next Articles

Experimental study on SO2 recovery using a sodium-zinc sorbent based flue gas desulfurization technology

Yang Zhang1, Tao Wang2, Hairui Yang1, Hai Zhang1, Xuyi Zhang1   

  1. 1 Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084, China;
    2 National Engineering Laboratory of Coal-Fired Pollution Reduction, School of Energy and Power Engineering, Shandong University, Jinan 250061, China
  • Received:2013-04-09 Revised:2013-09-09 Online:2015-01-24 Published:2015-01-28
  • Contact: Hai Zhang
  • Supported by:

    Supported by the National High Technology Research and Development Program of China (2009AA05Z302).

Experimental study on SO2 recovery using a sodium-zinc sorbent based flue gas desulfurization technology

Yang Zhang1, Tao Wang2, Hairui Yang1, Hai Zhang1, Xuyi Zhang1   

  1. 1 Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, Beijing 100084, China;
    2 National Engineering Laboratory of Coal-Fired Pollution Reduction, School of Energy and Power Engineering, Shandong University, Jinan 250061, China
  • 通讯作者: Hai Zhang
  • 基金资助:

    Supported by the National High Technology Research and Development Program of China (2009AA05Z302).

Abstract: A sodium-zinc sorbent based flue gas desulfurization technology (Na-Zn-FGD) was proposed based on the experiments and analyses of the thermal decomposition characteristics of CaSO3 and ZnSO3·2.5H2O, the waste products of calcium-based semi-dry and zinc-based flue gas desulfurization (Ca-SD-FGD and Zn-SD-FGD) technologies, respectively. Itwas found that ZnSO3·2.5H2O first lost crystal H2O at 100 ℃ and then decomposed into SO2 and solid ZnO at 260 ℃ in the air, while CaSO3 is oxidized at 450 ℃ before it decomposed in the air. The experimental results confirm that Zn-SD-FGD technology is good for SO2 removal and recycling, but with problem in clogging and high operational cost. The proposed Na-Zn-FGD is clogging proof, and more cost-effective. In the newprocess, Na2CO3 is used to generate Na2CO3 for SO2 absorption, and the intermediate product NaHSO3 reacts with ZnO powders, producing ZnSO3·2.5H2O precipitate and Na2CO3 solution. The Na2CO3 solution is clogging proof, which is re-used for SO2 absorption. By thermal decomposition of ZnSO3·2.5H2O, ZnO is re-generated and SO2 with high purity is co-produced as well. The cycle consumes some amount of raw material Na2CO3 and a small amount of ZnO only. The newly proposed FGD technology could be a substitute of the traditional semi-dry FGD technologies.

Key words: Flue gas desulfurization, Waste treatment, ZnSO3·, 2.5H2O pyrolysis, Sodium-zinc sorbent based, SO2 co-production

摘要: A sodium-zinc sorbent based flue gas desulfurization technology (Na-Zn-FGD) was proposed based on the experiments and analyses of the thermal decomposition characteristics of CaSO3 and ZnSO3·2.5H2O, the waste products of calcium-based semi-dry and zinc-based flue gas desulfurization (Ca-SD-FGD and Zn-SD-FGD) technologies, respectively. Itwas found that ZnSO3·2.5H2O first lost crystal H2O at 100 ℃ and then decomposed into SO2 and solid ZnO at 260 ℃ in the air, while CaSO3 is oxidized at 450 ℃ before it decomposed in the air. The experimental results confirm that Zn-SD-FGD technology is good for SO2 removal and recycling, but with problem in clogging and high operational cost. The proposed Na-Zn-FGD is clogging proof, and more cost-effective. In the newprocess, Na2CO3 is used to generate Na2CO3 for SO2 absorption, and the intermediate product NaHSO3 reacts with ZnO powders, producing ZnSO3·2.5H2O precipitate and Na2CO3 solution. The Na2CO3 solution is clogging proof, which is re-used for SO2 absorption. By thermal decomposition of ZnSO3·2.5H2O, ZnO is re-generated and SO2 with high purity is co-produced as well. The cycle consumes some amount of raw material Na2CO3 and a small amount of ZnO only. The newly proposed FGD technology could be a substitute of the traditional semi-dry FGD technologies.

关键词: Flue gas desulfurization, Waste treatment, ZnSO3·, 2.5H2O pyrolysis, Sodium-zinc sorbent based, SO2 co-production