| 摘要 |
A method for preparing xylenediamine is provided to reduce the content of solvent containing liquid ammonia with maintaining a high yield, thereby decreasing the energy necessary for removing the solvent. A method for preparing xylenediamine comprises the steps of supplying 1-20 wt% of a phthalonitrile solution of a solvent containing liquid ammonia to the inlet of a first reaction region, and hydrogenating it in the presence of a hetero-catalyst at the first reaction region to convert 60-98 % of the nitrile group into an aminomethyl group, thereby obtaining a first hydrogenated product; hydrogenating the first hydrogenated product in the presence of a hetero-catalyst at a second reaction region to obtain a second hydrogenated product whose cyanobenzyl amine content is 0.2 wt% or less of xylenediamine; and distilling the second hydrogenated product to remove a solvent and purifying it, wherein 30-90 % of the first hydrogenated product discharged from the first reaction region is circulated into the inlet of the first reaction region and the rest is introduced into the second reaction region.
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