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:
Aug. 19, 1980
Filed:
May. 16, 1978
Logan C Bostian, Virginia Beach, VA (US);
Charles E Winslow, Jr, Norfolk, VA (US);
Virginia Chemicals Inc., Portsmouth, VA (US);
Abstract
A batch process, in which a sodium bisulfite compound is the alkaline agent, is described for producing anhydrous sodium dithionite at high productivity by reduction of sulfur dioxide with the formate radical in concentrated aqueous methanolic solution. Minimum amounts of water, in which sodium formate is dissolved, and of methanol, in which sulfur dioxide is dissolved, are used. The process provides the optimum productivity of U.S. Pat. No. 3,887,695 while obviating the hazards and freeze-up difficulties that are inherent in forming and transferring a sodium hydroxide solution at 160.degree. C. and also minimizes the amount of methyl formate formed at equilibrium after a large number of methanol recyclings.