Removal of Sulfur Dioxide from Waste Gases

1 Removal of Sulfur Dioxide from Waste Gases 

The main sources of sulfur dioxide emission to the atmosphere are coal-fired production units and industrial facilities using sulfide ores such as power plants, ferrous and non-ferrous metallurgical industries, and several chemical and petrochemical industries. 

Another part of the sulfur formed by the reaction between the carbon surface and SO2 gets bonded to the carbon surface in the form of stable carbon-sulfur surface compounds that can be neither desorbed by extraction with a solvent nor by heat treatment. These surface compounds can only be desorbed as H2S on heat treatment in hydrogen gas, as mentioned earlier. The formation of these carbon-sulfur surface compounds reduces the availability of the carbon surface for any further adsorption, making the regeneration of the sulfurized activated carbon difficult. The proportion of these three forms in which SO2 is adsorbed on the carbon surface depends upon the temperature and composition of the exhaust gases and the nature of the carbon surface. It, therefore, indicates that the experimental conditions for using activated carbon adsorption technique for the recovery of SO2 should be such that there is 

Uptake of Sulfur Dioxide by Activated Carbon in tbe Presence of Oxygen and Water Vapor 

Erom Derbyshire, F., Jagtoyen, M., Andrews, R., Rao, A., Martin-Gullon, I., and Grulke, E.A., in Chemistry and Physics of Carbon, L.R. Radovic, Ed., Marcel Dekker, New York, 2001, Vol. 27. Reproduced with permission from Marcel Dekker. 

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Stauffer JE (1994) Bipolar process for removal of sulfur dioxide from waste gases. US Patent 5344529... 

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