摘要 |
An integrated process for the preparation of urea and melamine is described wherein heat requirements for the decomposition of ammonium carbamate contained in the urea product solution, which is cycled as feed to the melamine synthesis stage, is supplied, at least in part, from the heat released by the desublimation of the melamine vapors obtained in the melamine synthesis gas product stream, by bringing this gas stream into direct contact, either in counter-current or co-current flow, with the ammonium carbamate-containing urea product solution. |