Word: sulfured
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...ecological disaster known as global warming has been put off five years at least, thanks to last year's eruption of Mount Pinatubo. When the Philippine volcano blew its top, it lofted some 20 million tons of sulfur dioxide into the upper atmosphere. Since then, the stuff has circled the globe, forming a layer of droplets floating in the stratosphere, between 19 and 23 km (12 and 14 miles) above the surface. Scientists predicted that the droplets would act as a worldwide sun shield. Satellite measurements are proving they were right: the planet has cooled off about 0.5 degreesC...
...class in materials science, the student was trying out various chemicals to see if there was some agent that would allow drills to penetrate coal more easily. When he applied ammonia, explained Keller, the raw coal broke down into fine particles, separating the purer hydrocarbons from rock and pyritic sulfur and significantly reducing its ash content...
There was real promise here, Keller said. Ash and sulfur are the principal pollutants in coal. Without them, the remaining fuel would burn clean, unlike the dirty coal used by many big utility plants in the U.S. If the process Keller was describing could be duplicated on a mass scale, it would provide an attractive alternative...
...mechanics and science behind Otisca are clear and simple. Its advantages in terms of transportation and use in various engines, including diesels and turbines, put it in direct competition with oil and gas. Coal's chief disadvantages are that it is bulky and dirty. Sulfur oxides (SOx) and nitrogen oxides (NOx) have been indicted as principal villains in the formation of acid rain. More than half the nation's electricity is produced by power plants that burn coal. By running finely ground coal through a chemical bath (currently pentane, a hydrocarbon similar to butane), the Otisca process separates...
...Clean Air Act of 1990 tries to change the old way of doing things; it allows companies to meet pollution goals by whatever means they can. With regard to emissions of noxious sulfur dioxide, the new law sets up a clever system in which companies and utilities will be issued permits to produce certain amounts of the gas. If a company finds ways to produce less SO2 than it is allowed to, it can make money by selling unused pollution permits to other firms. "This is the frontier of environmental policy," says Robert Stavins, an economist at Harvard's Kennedy...