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    251.
    发明专利
    未知

    公开(公告)号：DE69902864D1

    公开(公告)日：2002-10-17

    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.

    252.
    发明专利
    未知

    公开(公告)号：BR9905965A

    公开(公告)日：2001-01-23

    申请号：BR9905965

    申请日：1999-12-22

    Applicant: PRAXAIR TECHNOLOGY INC

    Inventor： ECHEGARAY DIEGO FERNANDEZ ,  VELOSO ANTONIO AUGUSTO M ,  WAGNER MATHEW LINCLN

    IPC: C07D201/06 ,  C07D201/10 ,  C07D201/16

    Abstract: A method for production of caprolactam. The method involves: (a) reacting air with ammonia gas in an ammonia conversion zone to produce nitric oxide; (b) oxidizing at least a portion of the nitric oxide to nitrogen dioxide to produce an NOx-rich process gas stream; (c) reactively absorbing the NOx-rich gas stream with phosphoric acid containing solution in an absorption zone to form nitrate ions; (d) contacting the nitrate ions with air in a degassing zone to produce a nitrate-rich aqueous process stream; (e) reducing the nitrate-rich aqueous stream with hydrogen in the presence of phosphoric acid to produce hydroxylammonium phosphate; (f) oximating the hydroxylammonium phosphate with cyclohexanone to produce cyclohexanone oxime; and (g) converting the cyclohexanone oxime to caprolactam. According to the invention, supplemental oxygen is added downstream of the ammonia conversion zone to increase the quantity and rate of formation of nitrogen dioxide in the NOx-rich process gas stream.

    253.
    发明专利
    未知

    公开(公告)号：ID25716A

    公开(公告)日：2000-11-02

    申请号：ID991023

    申请日：1999-11-04

    Applicant: PRAXAIR TECHNOLOGY INC

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

    IPC: C07D201/06 ,  C07D201/10 ,  C07D201/00

    Abstract: A method for production of caprolactam. The method involves: (a) reacting air with ammonia gas in an ammonia conversion zone to produce nitric oxide; (b) oxidizing at least a portion of the nitric oxide to nitrogen dioxide to produce an NOx-rich process gas stream; (c) reactively absorbing the NOx-rich gas stream with phosphoric acid containing solution in an absorption zone to form nitrate ions; (d) contacting the nitrate ions with air in a degassing zone to produce a nitrate-rich aqueous process stream; (e) reducing the nitrate-rich aqueous stream with hydrogen in the presence of phosphoric acid to produce hydroxylammonium phosphate; (f) oximating the hydroxylammonium phosphate with cyclohexanone to produce cyclohexanone oxime; and (g) converting the cyclohexanone oxime to caprolactam. According to the invention, supplemental oxygen is added downstream of the ammonia conversion zone to increase the quantity and rate of formation of nitrogen dioxide in the NOx-rich process gas stream.

    METHOD FOR PRODUCTION OF HYDROXYLAMINE SULFATE IN THE CONVENTIONAL PROCESS FOR THE SYNTHESIS OF CAPROLACTAM
    254.
    发明专利
    METHOD FOR PRODUCTION OF HYDROXYLAMINE SULFATE IN THE CONVENTIONAL PROCESS FOR THE SYNTHESIS OF CAPROLACTAM 未知

    公开(公告)号：CA2292904A1

    公开(公告)日：2000-06-24

    申请号：CA2292904

    申请日：1999-12-22

    Applicant: PRAXAIR TECHNOLOGY INC

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

    IPC: C07D201/06 ,  C07D201/10 ,  C07D223/10

    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 NO x-rich process gas stream; (c) reacting the NO x-rich stream with ammonium carbonate in a nitrating 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 NO x-rich process gas stream.

    259.
    发明专利
    未知

    公开(公告)号：ES553304A0

    公开(公告)日：1987-05-16

    申请号：ES553304

    申请日：1986-03-24

    Applicant: FRIULI CHIM SPA

    IPC: C07D201/16 ,  C07D201/08 ,  C07D201/10

    Abstract: A method of preparing ω -lactams, in particular caprolactam, comprising: a step of premixing cycloaliphatic acids having the formulawhere n = 3 - 13, with a dehydrating agent; the first step of reaction with a nitrosating agent; the second step of reaction with the addition of a very small amount of water corresponding to a molar ratio U = H 2 O/SO 3 within the 0.1 to 0.9 range; and the step of reclaiming the unreacted cycloaliphatic acid. The method affords improved output from the lactamization reaction and reduced byproducts.

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