PROCESS FOR THE CONVERSION OF HEAVY FEEDSTOCKS SUCH AS HEAVY CRUDE OILS AND DISTILLATION RESIDUES

摘要

Process for the conversion of heavy feestocks such as heavy crude oils, tars from oil sands and distillation residues, by the combined use of the following three process units: hydroconversion with catalysts in slurry phase (HT), distillation or flash (D), deasphalting (SDA), characterized in that the three units operate on mixed streams consisting of fresh charge and recycled streams, by the use of the following steps: sending at least one fraction of the heavy feedstock to a deasphalting section (SDA) in the presence of hydrocarbon solvents obtaining two streams, one consisting of deasphalted oil (DAO), the other of asphalts; mixing the asphalt with a suitable hydrogenation catalyst and optionally with the remaining fraction of heavy charge not sent to the deasphalting section and sending the mixture obtained to a hydro-treatment reactor (HT) into which hydrogen or a mixture of hydrogen and H2S is charged; sending the stream containing the hydro-treatment reaction product and the catalyst in dispersed phase to one or more distillation or flash steps (D) whereby the most volatile fractions are separated, among which the gases produced in the hydro-treatment reaction; recycling at least 60% by weight, preferably at least 80%, more preferably at least 95%, of the distillation residue (tar) or liquid leaving the flash unit, containing the catalyst in dispersed phase, rich in metallic sulfides produced by demetallation of the charge and possibly coke, to the deasphalting zone