Pore Distribution Changes of Calcium-Based Sorbents Reacting with Sulfur Dioxide

摘要

The paper gives results of a determination of changes in the pore structure of calcium oxide sorbents derived from calcium carbonate (termed c-CaO) and calcium hydroxide (termed h-CaO) reacting with sulfur dioxide (SO2). Results show that the pore shape of c-CaO approximates a cylinder, while that of h-CaO appears to be slit or plate-like. The pore volume of c-CaO is located in much smaller pores than that of h-CaO when compared on the basis of an equivalent geometric model. The effect of sintering was to reduce surface area through coalescence of smaller pores, while only minor effects were observed upon pore volume and conversion from CaO to calcium sulfate (CaSO4). Both sorbents expand to allow greater reaction than is possible given the initial porosity and formation of a larger-volume product.