Process for the purification and reheating of exhaust gases

US4931269A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Gunter Lailach · Krefeld, DE
• Rudolf Gerken · Krefeld, DE

Key dates

• Filing date: Oct 21, 1988
• Grant date: Jun 5, 1990
• Expiry date: Oct 21, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01B17/74
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for the removal of dust and sulphur dioxide from hot exhaust gases which have a low hydrogen halide content and the reheating of the purified exhaust gases, wherein PA0 (a) the hot exhaust gases are cooled to temperatures below 135.degree. C. by scrubbing with sulphuric acid, PA0 (b) sulphuric acid containing solids and dissolved metal sulphates is then separated from the exhaust gases from (a), PA0 (c) the exhaust gases from (b) are cooled to temperatures of 50.degree. to 70.degree. C. by scrubbing with 15 to 50% sulphuric acid, PA0 (d) and desulphurized with the formation of sulphuric acid, PA0 (e) and reheated to temperatures of 70.degree. to 90.degree. C. by scrubbing with 50 to 65% sulphuric acid while the sulphuric acid discharged from (c) is concentrated and PA0 (f) the sulphuric acid from stage (a) together with the solid particles contained therein is cooled with the pure sulphuric acid from (e) in heat exchangers. The process according to the invention is particularly suitable for the purification of hot exhaust gases which are at a temperature of 170.degree. to 500.degree. C.