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:
Oct. 18, 1988
Filed:
Feb. 18, 1987
Robert R Grinstead, Walnut Creek, CA (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
The present invention relates to a cyclic continuous process and composition for the removal of NO and SO.sub.2 from a variety of fluid streams. A fluid stream containing NO and SO.sub.2 is contacted with an aqueous solution of water-soluble organic polymeric chelate containing a polyvalent metal, e.g., Fe (II). The NO is catalytically absorbed and in the presence of SO.sub.2, the imidodisulfonate is formed. Optionally, a reducing agent, such as sodium hydrogen sulfide, is added to maintain the polyvalent metal in the reduced state. The process next includes removal of the imidodisulfonate formed. The separation of water and low molecular weight materials and products, e.g. molecular weight below 500, usually occurs by ultrafiltration or dialysis, with recycle and re-use of the polyvalent metal chelate.