PROPERTIES OF COPPER ALUMINA SORBENTS USED FOR THE REMOVAL OF SULFUR-DIOXIDE

An attempt has been made to determine the structure of Cu/alumina sorbents used for the removal of SO2 from flue gas. Fresh, used, and regenerated Grace η-alumina 1/16-in. spheres containing 7.2% Cu were studied by various techniques. X-ray and electron diffraction showed that the copper compounds are not crystalline. The magnetic susceptibilities were much higher than those of any of the copper compounds that might be expected in these sorbents. Extended X-ray absorption fine-structure analysis indicated that the copper is surrounded by an average of 2.4-2.7 oxygens and that the CuO units are very small or amorphous. The low coordination number may be related to the material being a good sorbent for SO2.