Simultaneous Calcination and Sulfidation of Limestone at High Pressure

Based on the fact that both calcination and sulfidation of limestone in high-pressure gasifiers may occur simultaneously,simultaneous calcination and sulfidation experiments were carried out in a pressurized thermogra-vimetric analyzer under reducing atmosphere,and the effects of temperature(800—900,℃)and CO2 partial pres-sure(0—0.03,MPa)on the reaction were investigated according to the sample mass loss curves.The experimental re-sults show that the simultaneous calcination and sulfidation processes are influenced by temperature in the absence of CO2 in mixture gases,which is more obvious at 800,℃.In the presence of CO2 in mixture gases,calcination reac-tion rate becomes slower significantly and hence hinders subsequent sulfidation reaction.In addition,the CaS product layer also greatly slows down the calcination process.It is concluded that for the simultaneous calcination and sulfida-tion of limestone at high partial pressure of CO2,calcination and sulfidation processes have a great influence on each other.