| 摘要 |
A process for separating 3,5-diethyltoluene (3,5-DET) and/or 2,6-diethyltoluene (2,6-DET) from a feed mixture comprising at least one isomer from the group 3,5- and 2,6-diethyltoluene and at least one other isomer thereof, which process comprises contacting the mixture at adsorption conditions with an adsorbent comprising an X zeolite, cation exchanged with a mixture of barium and potassium or sodium, lithium, barium or copper cations or mixtures thereof or a Y zeolite cation exchanged with barium, calcium, sodium, potassium or copper cations or mixtures thereof, thereby selectively adsorbing one or more of said isomers and removing one or more relatively non-adsorbed isomer(s) from contact with the adsorbent. 2,6-diethyltoluene is the most strongly adsorbed isomer with certain adsorbents and is recovered by desorption at desorption conditions with a desorbent material comprising a monocyclic alkyl-substituted aromatic hydrocarbon, e.g., p-diethylbenzene, m-diethylbenzene, p-xylene or p-toluene and optionally, a diluent, e.g., a straight chain or branched paraffin, e.g., n-heptane or iso-octane, an ether or a halogenated hydrocarbon. With certain adsorbents 3,5-DET is the least strongly adsorbed isomer and can be recovered in the raffinate. Certain of the adsorbent-cation combinations perform the dual function of strongly adsorbing 2,6-DET and least strongly adsorbing 3,5-DET.
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