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:
Sep. 15, 1998
Filed:
Aug. 04, 1995
Reinhard Langer, Krefeld, DE;
Hans-Josef Buysch, Krefeld, DE;
Paul Wagner, Dusseldorf, DE;
Ursula Pentling, Kempen, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
Aromatic amines are produced by hydrogenation of the associated aromatic nitro compounds in the gas phase over fixed catalysts. The catalysts contain active hydrogenation metals on supports. The reaction is conducted at a pressure of 2-50 bar and at a temperature in the range 250.degree.-500.degree. C. under adiabatic conditions. A circulating gas is passed over the catalyst, which circulating gas contains 3-150 moles of hydrogen, 2-100 moles of the amino groups to be formed per mole of nitro groups, and 2 to 6 moles of water per amino group equivalent. The amine and water formed, as well as a purification stream, are separated from the circulating gas. Thereafter the circulating gas is enriched with volatilised aromatic nitro compound and fresh hydrogen and recycled.