Energy & Fuels, Vol.33, No.2, 1489-1500, 2019
Study on the Migration Characteristics of Sodium and Chlorine in Chemical Looping Process of ZhunDong Coal with Hematite Oxygen Carrier
ZhunDong coal is the largest coal resource in China but is characterized by high sodium and chlorine content. Chemical looping combustion with hematite as oxygen carrier is an attractive alternative technology for ZhunDong coal conversion without severe slagging and fouling problems. However, the influence of the chemical looping process for the migration characteristics of sodium and chlorine is not clear. Especially with the presence of hematite, it is bound to have a great influence on the migration of sodium and chlorine. For better controlling slagging and fouling problems caused by sodium and chlorine migration, it is necessary to study the migration paths of sodium and chlorine in the chemical looping process. Experimental results and analysis show that the migration characteristics and path of sodium and chlorine in the chemical looping process are different at different temperature ranges. However, some common grounds could be found. The releasing form of chlorine in the chemical looping process is similar, which is released mainly in the form of HCl gas phase as well as a little of NaCl gas phase. On the aspect of sodium migration, sodium is mainly reserved as solid phase, i.e., Na2O center dot 3SiO(2) and Na2O center dot nAl(2)O(3)center dot mSiO(2).