摘要 |
A process to separate multimethyl-branched alkanes from a mixture of multimethyl-branched alkanes, monomethyl-branched alkanes, and normal alkanes has been developed. The mixture is introduced to a simulated moving bed of solid adsorbent particles having the selectivity normal alkanes>monomethyl-branched alkanes>multimethyl-branched alkanes. The adsorbent may be silicalite, ferrierite, zeolite Beta, MAPO-31, SAPO-31, SAPO-11, zeolite X ion exchanged with alkaline cations, alkaline earth cations, or a mixture thereof, and zeolite Y ion exchanged with alkaline cations, alkaline earth cations, or a mixture thereof. A raffinate stream enriched in multimethyl-branched alkanes is removed from the simulated moving bed. The monomethyl-branched alkanes are desorbed from the solid adsorbent particles using a first desorbent capable of desorbing the monomethyl-branched alkanes but incapable of desorbing the normal alkanes and first extract stream enriched in the desorbed monomethyl-branched alkanes is removed from the simulated moving bed. The normal alkanes are desorbed from the solid adsorbent particles using a second desorbent, and a second extract stream enriched in the desorbed normal alkanes is removed from the simulated moving bed. The process may be incorporated into an isomerization flowscheme.
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