The main drawback of Orimulsion is the relatively high sulfur content of its bitumen base - 3.8 percent, almost in the middle coal's range of 1 to 8 percent sulfur content. (nytimes.com)
Generally these erupt near the Equator and eject material with high sulfur content into the Stratosphere. (drtimball.com)
The coal produced in this region is bituminous coal with relatively high sulfur content. (eia.gov)