Method of purifying flue gases from sulphur dioxide

US4454102A · kind A · utility

Assignee

• Flakt, Inc. · SE

Inventors

• Leif V. Lindau · Växjö, SE
• Stefan Ahman · Växjö, SE

Key dates

• Filing date: Sep 18, 1981
• Grant date: Jun 12, 1984
• Expiry date: Sep 18, 2001

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D53/501
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Purification of gases from acid gas components according to the dry method means that the gas is contacted with an absorbent in a solid phase, which yields a relatively low reaction rate. In order to increase the reaction rate according to the invention, the gas is contacted with a mixture consisting partially of a solid absorbent phase and partially a liquid phase on the surface of the solid phase. At the purification of flue gases from sulphur dioxide hot gas is contacted with an absorption liquid in a drying apparatus, where evaporation of the water supplied and a reaction between sulphur dioxide and the absorption substance take place simultaneously, whereafter the solid product phase is separated from the gas in a dust separator and a slower, secondary absorption reaction is operative. In order to achieve a higher reaction rate in the dust separator, a substance is added to the flue gas which, together with other chemical species derived from the gas or the solid absorbent forms a liquid phase distributed over the surface of the solid phases. The liquid phase usually contains water and has a good solubility for reactants and reaction products.