Method of removing SO.sub.2 and/or other acid components from waste gases

US4039304A · kind A · utility

Assignee

• Walther & Cie AG · DE

Inventors

• Horst Bechthold · Lechenich, DE
• Paul E. K. Bottger · Heusenstamm, DE

Key dates

• Filing date: Jun 30, 1975
• Grant date: Aug 2, 1977
• Expiry date: Jun 30, 1995

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D53/50
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Waste gas is contacted with a solution of a salt from a pollutant of the gas. This solution is obtained from another stage of the process used for cleansing or purifying the gas. The resulting mixture of gas and solution is subjected to vaporization so as to obtain a dry gaseous substance constituted by the waste gas and the evaporated solvent for the salt. The gaseous substance thus formed contains crystals of the salt as well as the pollutant present in the original waste gas. The salt crystals and other solid particles are removed from the gaseous substance in the form of a dry solids mixture. The gaseous substance is subsequently mixed with an absorption fluid such as an ammonia solution in order to wash out and redissolve any salt crystals which may remain in the gaseous substance and in order to remove the pollutant present in the original waste gas from the gaseous substance. The pollutant and the redissolved salt crystals form a salt solution together with the absorption fluid and it is this salt solution which is brought into contact with the waste gas. The gaseous substace is exhausted to the atmosphere after being mixed with the absorption fluid.