Production of hydrocarbon fractions from crude oil e.g. diesel, petrol

摘要

Production of specific hydrocarbons from a mixture, by (1) hydroconversion, (2) hydrotreatment, (3) distillation and (4) catalytic cracking of the heavier fractions, before they are recycled to (a) or (b). The output from this process contains 50 to 100% the desired fractions. The process also removes sulphur contamination. Process for converting a hydrocarbon fraction with a sulphur content of at least 0.3%, an initial boiling point of at least 300 deg. C and a final boiling point of at least 400 deg. C, with the following stages: (1) the hydrocarbon charge is treated in the presence of hydrogen, in a triphase reactor containing at least a hydroconversion catalyst in which the mineral support of at least partly amorphous. The boiling bed has an upward flow of both liquid and gas. The reactor contains at least one means of decanting (5) the catalyst from the reactor located near the base of the reactor, and at least one means of installing (4) the catalyst near the top of the reactor. (2) at least part of the effluent from (a) is sent to a treatment section in the presence of hydrogen, containing at least one reactor containing at least one hydrotreatment catalyst with an amorphous mineral support in conditions which allow an effluent with reduced sulphur content and high middle fraction content to be obtained. (3) Part of the effluent obtained from (b) is sent to a distillation zone from which a gaseous fraction, a petrol-type fraction and a heavy liquid (diesel) fraction are obtained. (4) The heavier fraction is then sent to a cracker in which it is treated in conditions allowing the production of a gaseous fraction, a petrol fraction, a diesel fraction and a heavy (slurry) fraction. At least part of the diesel and/or slurry from (d) is recycled to (a) and/or (b). The three fractions produced in (d) are sent to a petrol reservoir (pool); a diesel reservoir and a slurry reservoir respectively. The diesel and/or petrol fractions produced in (d) are recycled to the inlet to (d). The heavier liquid fraction obtained in (c) is at least in part returned to (a) and/or (b). An additional stage (a1) between (a) and (b) divides the product from (a) into a heavy fraction sent to (b) and a lighter fraction which is recovered.