| 摘要 |
<PICT:0992835/C4-C5/1> In the isomerization of C4-C7 hydrocarbons in the presence of hydrogen halide and a liquid Friedel-Crafts catalyst, the reaction effluent, containing isomerized and unreacted light hydrocarbons, at least one lower boiling constituent and dissolved and possibly entrained catalyst, is subjected to partial degasification to reduce the content of lower boiling components and then distilled to recover a vaporous phase comprising light hydrocarbons and lower boiling constituents and liquid phase containing catalyst and at least a major part of the light hydrocarbons are condensed. Feed is line 14 is dried if necessary at 16 and contacted counter-currently with catalyst from reactor 22 in the extractor 20 whereby catalyst is dissolved in the feed and sludge is removed by line 26. The feed is mixed with recycled hydrogen and hydrogen chloride in line 30 and contacted in reactor 22 with a body of liquid catalyst, preferably a mixture of antimony trichloride and aluminium chloride containing 2-16% by wt. of the latter. In degasifier 34 the contents of lower boiling components, viz. hydrogen, hydrogen chloride and methane, is reduced to 0.7-9% mol. The gases are preferably contacted with liquid product from line 46 to reduce loss. The pressure in the degasifier is preferably below that in the reactor and above that in the distillation column 38 where light hydrocarbons are removed overhead and may be condensed by cooling with refinery water at 38 DEG C. The maximum temperature in column 38 should not be above 160 DEG C. Catalyst in line 60 is recycled. Hydrogen chloride is removed in stripper 50 and traces removed by caustic and water washing at 56. |
