| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing methylamines, suppressing degradation of catalyst activity and capable of continuously using the catalyst for a long term. SOLUTION: The production of methylamines comprises combining operations of: [1] a disproportionation step in which a mixture of ammonia, methanol and methylamine is committed to a gas phase catalytic reaction in the presence of a solid acid catalyst so as to decrease trimethylamine content; [2] a main reaction step in which the whole or a part of the methylamine-containing mixture obtained in the disproportionation step is committed with ammonia and methanol to gas phase catalytic reaction in the presence of a solid acid catalyst to produce methylamines; and [3] a distillation step in which the methylamine-containing mixture obtained in the main reaction step or a mixture of that mixture with a part of the methylamine-containing mixture obtained in the disproportionation step is distilled under a pressurized conditions to distil trimethylamine in the mixture from the overhead as a mixture with ammonia, wherein the temperature difference between the lowest temperature and the highest temperature in a catalyst layer is made≤20°C by heat exchange between a reaction fluid and a heat transfer medium. COPYRIGHT: (C)2007,JPO&INPIT
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