Process for the preparation of melamine from urea
AssigneeDsm N.V.
InventorsCornelis G. M. van de Moesdijk, Hendrik J. Janssen, Josephus C. Schroijen
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Abstract
The invention relates to a selective removal of impurities from the gas stream leaving a melamine synthesis reactor in the preparation of melamine from urea by means of a treatment with steam at elevated temperature in the presence of a catalyst which is shape-selective. For instance a molecular sieve is chosen.
Claims11
A process for treating a product gas stream having by-products therein from the preparation of melamine from urea in a reactor or from the thermal decomposition products of urea in a reactor, wherein said gas stream is the product stream leaving the reactor, comprising treating said gas stream with steam at a temperature of 100.degree. C. to 500.degree. C. in the presence of a shape-selected hydrolysis catalyst having micropores with an effective diameter between 0.3 and 2.0 nm and having at least 50% of active sites of the catalyst located within the micropores, whereby bi-products in said gas stream are converted into carbon dioxide and ammonia.
Dependencies are inferred from the claim text.