Background
Recovery of sulfur dioxide air emissions and reuse as industrial or agricultural materials has been demonstrated in both North America and Europe. Numerous commercial, demonstration and pilot installations have proven their technical and economic viability. The Peoples Republic of China (PRC) has expressed interest in these recovery/reuse technologies but has few such systems installed. At present, the majority of such recovery/reuse systems in the PRC are for sulfur dioxide emissions from non-ferrous smelters. In this application hundreds of thousands of metric tons/year sulfur dioxide emissions have been eliminated and sulfuric acid has been produced for use in the smelter.
Several power and steam boilers in the PRC have installed technologies to recover/reuse sulfur dioxide emissions by converting them to ammonium sulfate fertilizer or gypsum useful in producing cement, sulfuric acid or wallboard. Some information on the degree of success of these installations has been forthcoming.
A new and emerging sulfur dioxide recovery/reuse application is that from cement kiln exhaust gas. Gypsum (hydrated calcium sulfate) is produced that can be blended into the raw materials for making cement to improve the quality. No installations in the PRC have yet been reported.
Sulfur Dioxide Air Emission Recovery and Reuse in China | 
