The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 04, 1980
Filed:
Sep. 22, 1978
Ivor E Campbell, New Albany, OH (US);
James M Henderson, New Brunswick, NJ (US);
Walter Johnson, El Paso, TX (US);
William H Wetherill, Staten Island, NY (US);
Smelter Control Research Association, Inc., New York, NY (US);
Abstract
An ammonia-based double-alkali process for removing sulfur oxides from stack gases. In this process, usually continuous, stack gases are contacted with an aqueous wash liquid containing ammonium sulfite as a sulfur oxide reactive compound to form a spent absorbent liquor containing bisulfite, sulfite and sulfate salts of ammonia. A portion of the reactive compound is regenerated by reacting the spent scrubbing liquor with a source of calcium ions, usually limestone. During the regeneration, calcium sulfite solids are precipitated as a by-product, any gypsum solids precipitation during the process being tolerated for a time insufficient to degrade substantially process performance. The resultant calcium solids are separated from the regenerated liquor which is returned for further contact with the stack gases, a portion of these solids being recycled to the regeneration stage. The process is preferably regulated by monitoring and controlling of the calcium concentration of the regenerated liquor, upset conditions being corrected by the addition of make-up ammonia during regeneration of the liquor.