| 摘要 |
Process for the conversion of heavy feedstocks comprising the following steps: .cndot. mixing the heavy feedstock with a suitable hydrogenation cata- lyst and sending the mixture obtained to a first hydrotreatment area (HT1) to which hydrogen or a mixture of hydrogen and H2S are introduced; .cndot. sending the effluent stream from the first hydrotreatment area (HT1), containing the hydrotreatment reaction product and the catalyst in dispersed phase, to a first distillation area (D1) having one or more flash steps and/or atmospheric distillation and/or vacuum distillation whereby the various fractions coming from the hydrotreatment reaction are separated; .cndot. sending at least part of the distillation residue (tar) or liquid leaving the flash unit of the first distillation area (D1), containing the catalyst in dispersed phase, rich in metal- lic sulfides produced by demetallation of the feedstock and op- tionally minimum quantities of coke, to a deasphalting area (SDA) in the presence of solvents or to a physical separation area, obtaining, in the case of the deasphalting area, two streams, one consisting of deasphalted oil (DAO), the other con- taining asphaltenes at least partially recycled to the first hy- drotreatment area, in the case of the physical separation area, the solids separated and a liquid stream; .cndot. sending the stream consisting of deasphalted oil (DAO) or the liquid stream separated in the physical separation area to a second hydrotreatment area (HT2), to which hydrogen or a mixture of hydrogen and H2S and a suitable hydrogenation catalyst are introduced; .cndot. sending the effluent stream from the second hydrotreatment area (HT2), containing the hydrotreatment reaction product and the catalyst in dispersed phase, to a second distillation area (D2) having one or more flash and/or distillation steps whereby the various fractions coming from the second hydrotreatment area are separated; .cndot. recycling at least part of the distillation residue or liquid leaving the flash unit of the second distillation area (D2), containing the catalyst in dispersed phase to the second hy- drotreatment area (HT2).
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