| 摘要 |
A process for the separation of one or more hydroxy paraffinic dicarboxylic acids from a feed mixture comprising said acid(s), and one or more olefinic dicarboxylic acids which process employs an adsorbent comprising a non-zeolitic, hydrophobic, crystalline silica molecular sieve material, to selectively reject the hydroxy paraffinic dicarboxylic acid(s) to a raffinate stream for the ultimate recovery of a purified quantity of such acid(s). The olefinic dicarboxylic acid(s) are thereafter removed from the adsorbent by contacting the adsorbent with a desorbent material and said acid(s) is (are) recovered to an extract stream. In a preferred embodiment the process uses a silicalite adsorbent, aqueous acetone desorbent and a simulated moving-bed countercurrent flow system utilizing therein a pre-pulse technique.
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