PROCESS FOR PRODUCING MIDDLE DISTILLATES BY HYDROISOMERIZATION AND HYDROCRACKING OF A HEAVY FRACTION DERIVED FROM A FISCHER-TROPSCH EFFLUENT EMPLOYING A RESIN

摘要

The present invention describes a process for producing middle distillates from a paraffinic feed produced by Fischer-Tropsch synthesis and divided into two fractions, a light fraction, termed the cold condensate, and a heavy fraction, termed the waxes, comprising a) fractionating said cold condensate fraction into a gaseous C4− fraction and an intermediate fraction with an initial boiling point in the range 15° C. to 40° C. and an end point in the range 300° C. to 450° C.; b) passing the intermediate fraction over at least one ion exchange resin; eliminating at least a portion of the water from the effluent derived from step b); decontaminating said heavy fraction termed the waxes by passage over a guard bed; recombining the purified intermediate fraction and the effluent derived from step d) to obtain a purified C5+ fraction; f) hydrogenating the unsaturated compounds of the purified C5+ fraction; g) hydroisomerization/hydrocracking of the effluent derived from step f); h) separating and recycling unreacted hydrogen and light gases to the hydroisomerization/hydrocracking step; and distilling the effluent derived from step h).