High-pressure process for the preparation of melamine from urea
Номер патента: EP1140869A1
Опубликовано: 10-10-2001
Автор(ы): Hans Vrijenhoef
Принадлежит: Kemira Agro Oy
Опубликовано: 10-10-2001
Автор(ы): Hans Vrijenhoef
Принадлежит: Kemira Agro Oy
Реферат: The invention relates to a process for the preparation of melamine from urea comprising the steps of: (a) introducing urea melt and hot ammonia gas into a melamine reactor having a pressure within the range 50-150 bar and a temperature within the range 360-470 °C, to obtain a melamine melt and off-gases; (b) separating said off-gases from said melamine melt; (c) introducing said melamine melt and ammonia gas into an evaporator having a pressure within the range 1-15 bar and a temperature within the range 290-520 °C, to obtain a melamine-containing gas mixture; and (d) introducing said melamine-containing gas mixture into a cooler having a pressure within the range 1-15 bar and a temperature within the range 0-250 °C, to convert the gaseous melamine to solid high purity melamine.
High-pressure process for the preparation of melamine from urea
Номер патента: WO2000040567A1. Автор: Hans Vrijenhoef. Владелец: Kemira Agro Oy. Дата публикации: 2000-07-13.