Selective catalytic reduction of sulfur dioxide to elemental sulfur. Quarterly technical progress report No. 10, October 1994--December 1994

摘要

Elemental sulfur recovery from SO(sub 2)-containing gas stream is highly attractive as it produces a salable product and no waste. However, commercially available schemes are complex and involve multi-stage reactors, such as, most notably in the Resox (reduction of SO(sub 2) with coke) and Claus plant (reaction of SO(sub 2) with H(sub 2)S over catalyst). This project will investigate a cerium oxide catalyst for the single stage selective reduction of SO(sub 2) to elemental sulfur by a reductant, such as carbon monoxide. Cerium oxide has been identified in recent work at MIT as a superior catalyst for SO(sub 2) reduction by CO to elemental sulfur because its high activity and high selectivity to sulfur over COS over a wide temperature range (400-650(degrees)C). The detailed kinetic and parametric studies of SO(sub 2) reduction planned in this work over various CeO(sub 2)-formulations will provide the necessary basis for development of a very simplified process, namely that of a single-stage elemental sulfur recovery scheme from variable concentration gas streams. The potential cost- and energy-efficiency benefits from this approach cannot be overstated. A first apparent application is treatment of a regenerator off-gases in power plants using regenerative flue gas desulfurization. Such a simple catalytic converter may offer the long-sought (open quotes)Claus-alternative(close quotes) for coal-fired power plant applications.