Method for waste gas treatment

US5096680A · kind A · utility

Assignee

• Waagner-Biro Aktiengesellschaft · AT

Inventors

• Ralf Lindbauer · Graz, AT
• Franz Mair · Augsburg, DE

Key dates

• Filing date: Jul 29, 1988
• Grant date: Mar 17, 1992
• Expiry date: Jul 29, 2008

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02A50/20
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

In a sorption bed which is formed as a fluidized bed reactor possibly with circulating fluid, or as a fixed-bed reactor, for dry waste gas or waste air, purification sorbents introduced in the dry state are contacted at a temperature range between about 30 and 130.degree. C. by the waste gas with an at least 2% oxygen content and the acidic and/or oxidizable noxious gaseous components of the waste gas are found by the sorbent. Noxious gaseous components potentially include SO.sub.x, HCl, HF, NO.sub.x, Co and also hydrocarbons. The average dwelling time of the sorbents is at least about 20 minutes, in general several hours or days, and the average grain size of sorbent is at most 125 microns. The sorbent is introduced fresh and in stoichiometric ratio, with spent sorbent being correspondingly removed. Sorbents which may be considered are primarily baking soda (sodium bicarbonate), Ca(OH).sub.2 and Mg(OH).sub.2. Chlorides, fluorides, sulfate/sulfite mixtures, and nitrate/nitrite mixtures or mixtures of all of these compounds, occur in spent or used up sorbents. In particular, the reaction product that is carbonized in a low-temperature sorption stage, is reactivated through decarboni…