| abstract |
Method for optimising the production of middle distillate in a refinery, comprising at least one catalytic cracking unit ( 3 ) and at least one vacuum distillation unit ( 2, 4 ), the optimising operation consisting in:n a) recycling ( 14 ) at least part of the cut obtained by fractionation of the effluents from catalytic cracking of an atmospheric and/or vacuum residue, distilling at at least 320° C. also called 320° C.+ cut in the feed of the said vacuum distillation unit ( 4 ), b) distilling the said cut under vacuum into at least two fractions, a fraction distilling between 320° C. and 550° C. called the HCOSV fraction, and a fraction distilling at at least 550° C. called the SSV fraction, c) sending the HCOSV fraction ( 18 ) thereby obtained to at least one of the distillate treatment units, d) and sending the SSV fraction ( 13 ) to the feed of the catalytic cracking unit ( 3 ), as such or after intermediate upgrading treatment. |