Details

Autor(en) / Beteiligte

• Yan, Jingchun
• Ge, Huijun
• Jiang, Shouxi
• Gu, Haiming
• Song, Tao
• Guo, Qingjie
• Shen, Laihong

Titel

Effect of Sodium Removal on Chemical Looping Combustion of High-Sodium Coal with Hematite as an Oxygen Carrier

Ist Teil von

• Energy & fuels, 2019-03, Vol.33 (3), p.2153-2165

Ort / Verlag

American Chemical Society

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Chemical looping combustion (CLC) technology has been proved to be an effective method to cope with severe ash-related problems occurring during utilization of high-sodium Zhundong coal (ZD). Although alkali metals in coal have significant impacts on the coal conversion process, it is still unclear how different occurrence modes of alkali metals influence thermal conversion of ZD during a CLC process. Here, a method using sequential extraction to remove different occurrence modes of sodium from ZD is presented. Besides, the effects of cycle numbers, gasification agents, and different occurrence modes of sodium on the CLC performance of ZD were investigated in a laboratory-scale fluidized bed reactor. The data indicate that water–soluble sodium is the predominant occurrence form in ZD. The H2O–soluble sodium plays a prohibitive role in a typical CLC reduction process, whereas the CH3COONH4–soluble sodium and HCl–soluble sodium have a distinct catalytic effect on promoting combustion performance during CLC of ZD. The Brunauer–Emmett–Teller and scanning electron microscopy analyses show that the surface structure of ZD with different extraction levels changed slightly. It indicates that removal of different modes of sodium plays a dominant role in the combustion performance of ZD during a CLC process. The main reduced phase of an oxygen carrier after use was Fe3O4, and a certain amount of Na2O·Al2O3·SiO2 with high melting point was also detected. The results implied that the CLC with hematite as an oxygen carrier was a suitable approach for ZD conversion without severe ash-related problems.