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:
Jul. 24, 1984
Filed:
May. 19, 1983
Susumu Tahara, Ube, JP;
Kozo Fujii, Ube, JP;
Keigo Nishihira, Ube, JP;
Masaoki Matsuda, Ube, JP;
Katsuhiko Mizutare, Ube, JP;
Ube Industries, Ltd., Ube, JP;
Abstract
There is provided a process for the continuous preparation of a diester of oxalic acid which comprises a first step of reacting carbon monoxide with an ester of nitrous acid in the gaseous phase; a second step of condensing the gaseous reaction mixture to separate a non-condensed gas from a condensed liquid containing the diester of oxalic acid; a third step of introducing the non-condensed gas of the second step to a regeneration column and thereby contacting it with a gas containing molecular oxygen and an alcohol to regenerate nitrogen monoxide in the non-condensed gas into an ester of nitrous acid so as to bring the concentration of nitrogen monoxide in the gas at the outlet of the column to a level of from 2 to 7% by volume; and a fourth step of recycling the gas of the third step containing the ester of nitrous acid and from 2 to 7% by volume of nitrogen monoxide to the reactor of the first step.