UREA PRODUCTION WITH CONTROLLED BIURET
    22.
    发明申请

    公开(公告)号:US20190210963A1

    公开(公告)日:2019-07-11

    申请号:US15735153

    申请日:2017-04-28

    Inventor: Eelco MOSTERT

    CPC classification number: C07C273/04 B01B1/005 C07C273/16 Y02P20/582

    Abstract: Disclosed is a novel method of controlling the formation of biuret in urea production. This is accomplished by reducing or preventing the formation of biuret in a concentration section, particularly in one or more concentrators or evaporators. The method comprises controlling the residence time of a urea aqueous stream treated in such concentration section in a manner independently of the volume flow per time interval of said stream into said concentration section. The residence time can be controlled, e.g., by providing the concentration section with an adjustable volume or by adding a gas to the urea stream to be treated. A combination of such measures can also be applied.

    Method for revamping a urea production complex

    公开(公告)号:US10196348B2

    公开(公告)日:2019-02-05

    申请号:US15325050

    申请日:2015-04-21

    Abstract: The present invention provides a method for increasing the capacity of a urea production complex, the method comprising a step of adding to an existing urea production complex a CO2 production unit, which unit employs a CO2 production method comprising: i) subjecting a hydrocarbon feed to short contact time catalytic partial oxidation (SCT-CPO) to produce a first gas mixture comprising H2, CO and CO2, ii) subjecting said first gas mixture to a water gas shift reaction yielding a second gas mixture, iii) separating CO2 from said second gas mixture yielding a purified CO2 stream and a hydrogen containing stream and subsequently iv) reacting said purified CO2 stream with ammonia from the ammonia production unit to produce urea. The invention also provides a urea production complex realized by the application of this method and a urea production method.

    INTEGRATED PRODUCTION OF UREA AND MELAMINE

    公开(公告)号:US20170362188A1

    公开(公告)日:2017-12-21

    申请号:US15692715

    申请日:2017-08-31

    Abstract: Disclosed is a process for the integrated production of urea and melamine. A urea production zone produces a urea synthesis stream comprising urea, water and ammonium carbamate. This stream is subjected to processing, preferably involving stripping, so as to separate an aqueous urea stream from residual dissociated carbamate vapor comprising ammonia, carbon dioxide, and water. The urea is fed to a melamine synthesis zone and subjected to melamine forming conditions so as to form melamine and off-gas comprising carbon dioxide and ammonia. The dissociated carbamate vapor and the melamine off-gas are subjected to combined condensation so as to form a dilute melamine off-gas condensate.

    ZERO EMISSION UREA PROCESS AND PLANT
    27.
    发明申请

    公开(公告)号:US20170349542A1

    公开(公告)日:2017-12-07

    申请号:US15685308

    申请日:2017-08-24

    CPC classification number: C07C273/04 B01J19/24

    Abstract: Disclosed is a method for the production of urea allowing a substantial reduction, even down to zero, of the continuous emission of ammonia conventionally resulting from such a process. According to a preferred embodiment of the invention, the urea-forming reaction from carbon dioxide and ammonia is conducted in a synthesis section that does not require passivation by oxygen. As a result of the absence of oxygen, a hydrogen-rich gas stream results from the synthesis section, that can be used as a fuel in an incinerator. In the incinerator, ammonia-comprising gas streams from the urea production process are combusted.

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