| 摘要 |
PURPOSE: A method of making phosphate-based catalysts which are useful for the production of triethylenediamine (TEDA) is provided. CONSTITUTION: The catalysts are prepared by mixing phosphoric acid with a substantially water insoluble alkaline earth metal salt such that the phosphorus to alkaline earth metal molar ratio is less than 1. An aqueous slurry of the salt, such as strontium carbonate, calcium carbonate, or barium carbonate, is mixed with an aqueous solution of phosphoric acid to form an alkaline earth hydrogen phosphate. Since less than stoichiometric amounts of alkaline earth metal salt and acid are used, some of the alkaline earth metal salt remains unreacted and is present in the precipitated product. The product, containing alkaline earth metal hydrogen phosphate and the starting alkaline earth metal salt, is filtered and dried. The mixture can be used as a catalyst in the production of TEDA from, for example, mono-and di-substituted piperazines, such as hydroxyethylpiperazine and aminoethylpiperazine, ethanolamines and substituted ethanolamines, and crude hydroxyethylpiperazine containing piperazine, hydroxyethylpiperazine, bis-hydroxyethylpiperazine, and water.
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