Advanced byproduct recovery: Direct catalytic reduction of SO{sub 2} to elemental sulfur. First quarterly technical progress report, [October--December 1995]

The team of Arthur D. Little, Tufts University and Engelhard Corporation will be conducting Phase I of a four and a half year, two-phase effort to develop and scale-up an advanced byproduct recovery technology that is a direct, single-stage, catalytic process for converting sulfur dioxide to elemental sulfur. this catalytic process reduces SO{sub 2} over a fluorite-type oxide (such as ceria or zirconia). The catalytic activity can be significantly promoted by active transition metals, such as copper. More than 95% elemental sulfur yield, corresponding to almost complete sulfur dioxide conversion, was obtained over a Cu-Ce-O oxide catalyst as part of an ongoing DOE-sponsored University Coal Research Program. This type of mixed metal oxide catalyst has stable activity, high selectivity for sulfur production, and is resistant to water and carbon dioxide poisoning. Tests with CO and CH{sub 4} reducing gases indicates that the catalyst has the potential for flexibility with regard to the composition of the reducing gas, making it attractive for utility use. the performance of the catalyst is consistently good over a range of SO{sub 2} inlet concentration (0.1 to 10%) indicating its flexibility in treating SO{sub 2} tail gases as well as high concentration streams