公开(公告)号：US20210332017A1

公开(公告)日：2021-10-28

申请号：US17368430

申请日：2021-07-06

申请人： Casale SA

发明人： Andrea Scotto ,  Simone Gamba

IPC分类号： C07D251/62 ,  C07D251/60

摘要： A process for the purification of a melamine melt (5) containing melamine and by-products, comprising the steps of: (a1) In quenching of said melamine melt; (a2) decomposition of by-products with alkali, providing an alkaline aqueous solution of melamine (26); (b) stripping of said alkaline aqueous solution of melamine (26); (c) crystallization of melamine with a first alkali-containing solution (6b) and separation of solid melamine (7) from a mother liquor (8); (d) treatment of said mother liquor, providing a waste water stream (11) containing carbonates; (e) decomposition of at least part of the carbonates contained in said waste water stream (11) into carbon dioxide and alkali, providing a second alkali-containing aqueous solution (30); (f) recycle of at least part of said alkali-containing aqueous solution (30) to at least one of said steps (a1), (a2) and (c).

公开(公告)号：US20230014395A1

公开(公告)日：2023-01-19

申请号：US17787810

申请日：2020-12-17

申请人： Casale SA

发明人： Simone Gamba ,  Gbrile Di Carlo ,  Erico Rizzi

IPC分类号： C07D251/60 ,  C07D251/62 ,  B01J10/00 ,  B01J3/04 ,  B01J19/00

摘要： Reactor for the high-pressure non-catalytic synthesis of melamine from urea, comprising coaxial inner reaction zone (6) and outer reaction zone (7) wherein a crude melamine is formed in the inner reaction zone and contacted with gaseous ammonia for stripping in the outer reaction zone, wherein a gaseous phase liberated in the outer zone is collected in a gas collection chamber (12) above the reaction zones, wherein the crude melamine melt is transferred from the inner zone into the outer zone via a submerged liquid passage below the liquid level to provide a liquid seal between the chambers.

公开(公告)号：US11834422B2

公开(公告)日：2023-12-05

申请号：US17368540

申请日：2021-07-06

申请人： Casale SA

发明人： Andrea Scotto ,  Simone Gamba

IPC分类号： C07D251/60 ,  C07D251/62

CPC分类号： C07D251/62 ,  C07D251/60

摘要： A process for the purification of a melamine melt (5) containing melamine and by-products, comprising the steps of: (a1) In quenching of said melamine melt; (a2) decomposition of by-products with alkali, providing an alkaline aqueous solution of melamine (26); (b) stripping of said alkaline aqueous solution of melamine (26); (c) crystallization of melamine with a first alkali-containing solution (6b) and separation of solid melamine (7) from a mother liquor (8); (d) treatment of said mother liquor, providing a waste water stream (11) containing carbonates; (e) decomposition of at least part of the carbonates contained in said waste water stream (11) into carbon dioxide and alkali, providing a second alkali-containing aqueous solution (30); (f) recycle of at least part of said alkali-containing aqueous solution (30) to at least one of said steps (a1), (a2) and (c).

公开(公告)号：US20230125818A1

公开(公告)日：2023-04-27

申请号：US17912445

申请日：2021-03-02

申请人： Casale SA

发明人： Simone Gamba

IPC分类号： C07D251/60

摘要： A process for the synthesis of melamine from urea, preferably of the high-pressure type, wherein offgas quenching is performed in a quenching vessel wherein in the upper part of the vessel, a rising flow of offgas is contacted in counter-current with liquid ammonia to obtain precipitation of melamine contained in the offgas and melamine-free anhydrous washed offgas; in the lower part of the vessel, the solid melamine is contacted with a liquid solvent to form a solution of melamine or a melamine slurry.

公开(公告)号：US11840520B2

公开(公告)日：2023-12-12

申请号：US17368430

申请日：2021-07-06

申请人： Casale SA

发明人： Andrea Scotto ,  Simone Gamba

IPC分类号： C07D251/60 ,  C07D251/62

CPC分类号： C07D251/62 ,  C07D251/60

摘要： A process for the purification of a melamine melt (5) containing melamine and by-products, comprising the steps of: (a1) In quenching of said melamine melt; (a2) decomposition of by-products with alkali, providing an alkaline aqueous solution of melamine (26); (b) stripping of said alkaline aqueous solution of melamine (26); (c) crystallization of melamine with a first alkali-containing solution (6b) and separation of solid melamine (7) from a mother liquor (8); (d) treatment of said mother liquor, providing a waste water stream (11) containing carbonates; (e) decomposition of at least part of the carbonates contained in said waste water stream (11) into carbon dioxide and alkali, providing a second alkali-containing aqueous solution (30); (f) recycle of at least part of said alkali-containing aqueous solution (30) to at least one of said steps (a1), (a2) and (c).

公开(公告)号：US20190152928A1

公开(公告)日：2019-05-23

申请号：US16318736

申请日：2017-06-21

申请人： Casale SA

发明人： Andrea Scotto ,  Simone Gamba

IPC分类号： C07D251/62 ,  C07D251/60

摘要： A process for the purification of a melamine melt (5) containing melamine and by-products, comprising the steps of: (a1) quenching of said melamine melt; (a2) decomposition of by-products with alkali, providing an alkaline aqueous solution of melamine (26); (b) stripping of said alkaline aqueous solution of melamine (26); (c) crystallization of melamine with a first alkali-containing solution (6b) and separation of solid melamine (7) from a mother liquor (8); (d) treatment of said mother liquor, providing a waste water stream (11) containing carbonates; (e) decomposition of at least part of the carbonates contained in said waste water stream (11) into carbon dioxide and alkali, providing a second alkali-containing aqueous solution (30); (f) recycle of at least part of said alkali-containing aqueous solution (30) to at least one of said steps (a1), (a2) and (c).

公开(公告)号：US11858903B2

公开(公告)日：2024-01-02

申请号：US17912445

申请日：2021-03-02

申请人： Casale SA

发明人： Simone Gamba

IPC分类号： C07D251/60

CPC分类号： C07D251/60

摘要： A process for the synthesis of melamine from urea, preferably of the high-pressure type, wherein offgas quenching is performed in a quenching vessel wherein in the upper part of the vessel, a rising flow of offgas is contacted in counter-current with liquid ammonia to obtain precipitation of melamine contained in the offgas and melamine-free anhydrous washed offgas; in the lower part of the vessel, the solid melamine is contacted with a liquid solvent to form a solution of melamine or a melamine slurry.

公开(公告)号：US20210332018A1

公开(公告)日：2021-10-28

申请号：US17368540

申请日：2021-07-06

申请人： Casale SA

发明人： Andrea Scotto ,  Simone Gamba

IPC分类号： C07D251/62 ,  C07D251/60

摘要： A process for the purification of a melamine melt (5) containing melamine and by-products, comprising the steps of: (a1) In quenching of said melamine melt; (a2) decomposition of by-products with alkali, providing an alkaline aqueous solution of melamine (26); (b) stripping of said alkaline aqueous solution of melamine (26); (c) crystallization of melamine with a first alkali-containing solution (6b) and separation of solid melamine (7) from a mother liquor (8); (d) treatment of said mother liquor, providing a waste water stream (11) containing carbonates; (e) decomposition of at least part of the carbonates contained in said waste water stream (11) into carbon dioxide and alkali, providing a second alkali-containing aqueous solution (30); (f) recycle of at least part of said alkali-containing aqueous solution (30) to at least one of said steps (a1), (a2) and (c).

公开(公告)号：US11059793B2

公开(公告)日：2021-07-13

申请号：US16318736

申请日：2017-06-21

申请人： Casale SA

发明人： Andrea Scotto ,  Simone Gamba

IPC分类号： C07D251/62 ,  C07D251/60

摘要： A process for the purification of a melamine melt (5) containing melamine and by-products, comprising the steps of: (a1) quenching of said melamine melt; (a2) decomposition of by-products with alkali, providing an alkaline aqueous solution of melamine (26); (b) stripping of said alkaline aqueous solution of melamine (26); (c) crystallization of melamine with a first alkali-containing solution (6b) and separation of solid melamine (7) from a mother liquor (8); (d) treatment of said mother liquor, providing a waste water stream (11) containing carbonates; (e) decomposition of at least part of the carbonates contained in said waste water stream (11) into carbon dioxide and alkali, providing a second alkali-containing aqueous solution (30); (f) recycle of at least part of said alkali-containing aqueous solution (30) to at least one of said steps (a1), (a2) and (c).

公开(公告)号：US20200156952A1

公开(公告)日：2020-05-21

申请号：US16621360

申请日：2018-06-05

申请人： CASALE SA

发明人： Marco Carlucci Mazzamuto ,  Sergio Panza ,  Simone Gamba

IPC分类号： C01C1/04 ,  C01B3/02 ,  F25B15/06 ,  F25B29/00

摘要： A chemical plant comprising a refrigeration system including an absorption refrigeration unit, and a steam system including one or more steam producers, steam users, and at least one steam condenser, wherein a heat exchanger is arranged to intercept at least part of a steam flow directed to said steam condenser, and said heat exchanger transfers heat to a working fluid of said absorption refrigeration unit to provide at least part of a heat input required for operation of said refrigeration system.