The effects of reaction temperature, SO_2 and CO_2 concentration in an air gas stream, particle sizes of limestone on the reactivity and capacity of SO_2 removal have been determined in a thermogravimetric analyser(TGA). The apparent reaction order of sulfation reaction of pre-calcined lime(CaO) with respect to SO_2 is found to be close to unity. The apparent activation energies are found to be 17,000 ㎉/kmol for sulfation of pre-calcined lime and 19,500 ㎉/kmol for direct sulfation of limestone(CaCO_3). The initial sulfation reaction rate of pre-calcined lime increases with increasing temperature, whereas the sulfur capture capacity exhibits a maximum value at 900℃. In direct sulfation of limestone, sulfation reactivity and sulfur capature capacity of sorbent increase with increasing temperature and decreasing CO_2 concentration in a gas bulk stream. The main pore of pre-calcined lime is shifted to the larger pore sizes and pore volume decreases with increasing sulfation time and temperature. The surface area of lime decreases with increasing calcination temperature under an air atmosphere, whereas is rearly constant under a CO_2(5, 10%) atmosphere in a gas stream.

• 강순국 | Soon Kook Kang
• 정명규 | Myung Giu Chung