| 摘要 |
A process for dehydrating an essentially one-phase wet solvent stream obtained in a solvent dewaxing-solvent deoiling process, which solvent stream contains at least 60% toluene with the balance being water and methyl ethyl ketone (hereinafter MEK), is dehydrated by (a) fractionally distilling to produce a bottom fraction of anhydrous MEK-toluene solvent and an overhead fraction containing all the water originally present in the wet solvent stream; (b) condensing and separating said overhead fraction into a toluene-containing, water-lean phase, which is used as reflux in step (a), and a toluene-free, MEK-containing, water-rich phase; (c) extracting into a hydrocarbon stream some MEK from said water-rich phase and from the condensed azeotropic mixture recycled from step (g) hereinafter; (d) recovering from step (c) a second water-rich stream, which water-rich stream contains the MEK not extracted into said hydrocarbon stream; (e) azeotropically distilling said second water-rich stream so as to obtain water as a bottom product and a vaporous, overhead fraction consisting of an azeotropic mixture of water and MEK; (f) condensing said vaporous azeotropic mixture; (g) recycling a portion of said condensed azeotropic mixture to step (e) as reflux and the remaining portion to step (c); and (h) recovering an essentially anhydrous solvent from step (a), a hydrocarbon stream containing anhydrous MEK from step (c), and a water stream from step (e).
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