Effectiveness of gases in desulphurization of coal

✍ Scribed by Seymour S. Block; Jim B. Sharp; Larry J. Darlage

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 779 KB
• Volume: 54
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(75)90066-6

✦ Synopsis

The effect of air, steam and hydrogen on the desulphurization of 10 U.S. high-volatile bituminous coals was investigated. Air treatment was most effective at 450°C where an average of 38% total sulphur, comprising 51% of the inorganic sulphur and 20% of the organic sulphur, was removed. With steam at 6OO"C, 61% of the total sulphur, 87% of inorganic and 25% of organic was lost. Hydrogen was not effective below 850°C. but at 900°C 86% of the total sulphur was dispelled, i.e. 94% of the inorganic and 76% of the organic sulphur. Without oxidative pretreatment the sulphur was much more difficult to remove; after oxidative pretreatment at 3OO*C for 10 min followed by treatment with hydrogen at 9OO"C, as much sulphur was removed in 4 min as in 60 min without the pretreatment. With raw coal, heating under nitrogen 'cooked-in' or fixed some of the sulphur making it more difficult to remove with hydrogen; whereas following oxidative pretreatment, heating for up to 1 h did not lessen the reduction of sulphur with hydrogen. For temperature-swelling coals with large quantities of organic sulphur, heating at 300°C in air followed by reduction with hydrogen at 9OO'C appears to permit rapid discharge (3-10 min) of the organic as well as the inorganic sulphur, to produce a smokeless product with a CV (per unit of product) similar to the fuel value of the untreated coal.

* See ASTM standard, van Krevelen (196 1) etc.