公开(公告)号：DE69902864T2

公开(公告)日：2003-05-08

申请号：DE69902864

申请日：1999-12-22

Applicant: PRAXAIR TECHNOLOGY INC

Inventor： ECHEGARAY DIEGO FERNANDEZ ,  VELLOSO ANTONIO AUGUSTO M ,  WAGNER MATTHEW LINCOLN

IPC: C07D201/06 ,  C07D201/10

Abstract: An improvement in the conventional process for the production of caprolactam. The process involves: (a) reacting air with ammonia gas in an ammonia conversion zone to produce nitric oxide; (b) oxidizing a portion of the nitric oxide to nitrogen dioxide to produce an NOx-rich process gas stream; (c) reacting the NOx-rich stream with ammonium carbonate in a nitriting zone to produce ammonium nitrite; (d) reducing the ammonium nitrite to hydroxylamine diammonium sulfate; (e) hydrolyzing the hydroxylamine diammonium sulfate to hydroxylamine sulfate; (f) oximating the hydroxylamine sulfate with cyclohexanone to produce cyclohexanone oxime; and (g) converting the cyclohexanone oxime to caprolactam. The process is improved by adding supplemental oxygen downstream of the ammonia conversion zone to increase the quantity and rate of formation of nitrogen dioxide in the NOx-rich process gas stream.

公开(公告)号：PT1013643E

公开(公告)日：2002-12-31

申请号：PT99125632

申请日：1999-12-22

Applicant: PRAXAIR TECHNOLOGY INC

Inventor： ECHEGARAY DIEGO FERNANDEZ ,  VELLOSO ANTONIO AUGUSTO M ,  WAGNER MATTHEW LINCOLN

IPC: C07D201/06 ,  C07D201/10

Abstract: An improvement in the conventional process for the production of caprolactam. The process involves: (a) reacting air with ammonia gas in an ammonia conversion zone to produce nitric oxide; (b) oxidizing a portion of the nitric oxide to nitrogen dioxide to produce an NOx-rich process gas stream; (c) reacting the NOx-rich stream with ammonium carbonate in a nitriting zone to produce ammonium nitrite; (d) reducing the ammonium nitrite to hydroxylamine diammonium sulfate; (e) hydrolyzing the hydroxylamine diammonium sulfate to hydroxylamine sulfate; (f) oximating the hydroxylamine sulfate with cyclohexanone to produce cyclohexanone oxime; and (g) converting the cyclohexanone oxime to caprolactam. The process is improved by adding supplemental oxygen downstream of the ammonia conversion zone to increase the quantity and rate of formation of nitrogen dioxide in the NOx-rich process gas stream.

公开(公告)号：AT223892T

公开(公告)日：2002-09-15

申请号：AT99125632

申请日：1999-12-22

Applicant: PRAXAIR TECHNOLOGY INC

Inventor： ECHEGARAY DIEGO FERNANDEZ ,  VELLOSO ANTONIO AUGUSTO M ,  WAGNER MATTHEW LINCOLN

IPC: C07D201/06 ,  C07D201/10

Abstract: An improvement in the conventional process for the production of caprolactam. The process involves: (a) reacting air with ammonia gas in an ammonia conversion zone to produce nitric oxide; (b) oxidizing a portion of the nitric oxide to nitrogen dioxide to produce an NOx-rich process gas stream; (c) reacting the NOx-rich stream with ammonium carbonate in a nitriting zone to produce ammonium nitrite; (d) reducing the ammonium nitrite to hydroxylamine diammonium sulfate; (e) hydrolyzing the hydroxylamine diammonium sulfate to hydroxylamine sulfate; (f) oximating the hydroxylamine sulfate with cyclohexanone to produce cyclohexanone oxime; and (g) converting the cyclohexanone oxime to caprolactam. The process is improved by adding supplemental oxygen downstream of the ammonia conversion zone to increase the quantity and rate of formation of nitrogen dioxide in the NOx-rich process gas stream.

公开(公告)号：ID24018A

公开(公告)日：2000-06-29

申请号：ID991022

申请日：1999-11-01

Applicant: PRAXAIR TECHNOLOGY INC

Inventor： FERNANDEZ DIEGO ,  VELLOSO ANTONIO AUGUSTO M ,  WAGNER MATTHEW LINCOLN

IPC: C01B21/38 ,  C01B21/26 ,  C01B21/40

Abstract: A process is described for producing nitric acid involving oxidizing ammonia gas to form dinitrogen tetroxide gas, reacting the dinitrogen tetroxide with water in an absorption zone to form aqueous nitric acid and nitric oxide gas, removing a nitric acid/nitric oxide stream from the absorption zone and feeding the stream into a nitric acid bleaching zone, removing impurities from the nitric acid in the bleaching zone to form nitric acid product and adding supplemental oxygen gas to one or more of the reaction streams to increase nitric acid production and or strength. The improvement involves injecting the supplemental oxygen into a nitric acid-containing process stream to form a gas bubble/liquid mixture in the stream, the mixture forming a fine dispersion of gas bubbles having diameters of less than about 0.1 mm. According to the invention, increased interfacial surface is created between the gas bubbles and the liquid mixture to facilitate removal of impurities from the liquid phase and shifting of the reaction.

公开(公告)号：CA2293004A1

公开(公告)日：2000-06-24

申请号：CA2293004

申请日：1999-12-21

Applicant: PRAXAIR TECHNOLOGY INC

Inventor： ECHEGARAY DIEGO FERNANDEZ ,  WAGNER MATTHEW LINCOLN ,  VELLOSO ANTONIO AUGUSTO M

IPC: C01B21/38 ,  C01B21/26 ,  C01B21/40

Abstract: A process is described for producing nitric acid involving oxidizing ammonia gas to form dinitrogen tetroxide gas, reacting the dinitrogen tetroxide with water in an absorption zone to form aqueous nitric acid and nitric oxide gas, removing a nitric acid/nitric oxide stream from the absorption zone and feeding the stream into a nitric acid bleaching zone, removing impurities from the nitric acid in the bleaching zone to form nitric acid product and adding supplemental oxygen gas to one or more of the reaction streams to increase nitric acid production and or strength. The improvement involves injecting the supplemental oxygen into a nitric acid-containing process stream to form a gas bubble/liquid mixture in the stream, the mixture forming a fine dispersion of gas bubbles having diameters of less than about 0.1 mm. According to the invention, increased interfacial surface is created between the gas bubbles and the liquid mixture to facilitate removal of impurities from the liquid phase and shifting of the reaction.