NOVEL PREPARATION METHOD MACROPOROUS LIME FROM LIMESTONE FOR HIGH-TEMPERATURE DESULFURIZATION

In order to develop a highly active calcium oxide high-temperature des ulfurization sorbent, macroporous calcium oxides were directly prepare d from limestone. This method is composed of two steps: swelling of th e limestone in the gas phase followed by drying and calcination of the swelled samples. The swelling was found when limestone was exposed to a vapor of aqueous acetic acid. The swelling of the sample resulted f rom an increase of calcium acetate formation in the sample. It was the n converted to macroporous calcium oxides by heating the sample to 850 degrees C. The reactivity of the macroporous calcium oxide for the re moval of SO2 or H2S under coexisting H2O vapor was higher than that of the calcined raw limestone. In particular, its SO2 removal capacity a nd oxidative character of CaS to CaSO4 and CaO were greatly improved b y the swelling method.