FIELD: oil, gas and coke-chemical industries.
SUBSTANCE: invention relates to a process for refining crude oil which includes the use of a specific hydroconversion unit. In particular, the invention relates to a method that optimises the refinement of petroleum feedstock in an oil refinery equipped with a coking plant. Process for refining crude oil includes the following steps: feeding crude oil to one or more atmospheric distillation units to separate at least heavy residue(s); feeding the heavy residue(s) separated in the atmospheric distillation unit(s) to a sub-atmospheric distillation unit with the extraction of at least two liquid streams: vacuum residue and light separated fraction; feeding the vacuum residue separated in the sub-atmospheric distillation unit to a hydroprocessing unit comprising at least one hydroconversion reactor in a slurry phase into which is fed hydrogen or a mixture of hydrogen and H2S in the presence of a suitable dispersed hydrogenation catalyst, the particle sizes of which range from 1 nm to 30 mcm, to produce a product in vapour phase and a by-product in slurry phase, where said product in vapour phase is treated and separated in a gas/liquid treatment and separation section, obtaining fractions both in the vapour phase and the liquid phase, and also; feeding a light separated fraction obtained in the sub-atmospheric distillation unit to hydrodesulphuration unit of light gasoils (HDS1); feeding the liquid fraction separated in the hydroconversion unit and having a boiling point above 350°C, to hydrodesulphuration and/or hydrocracking unit of heavy gasoils (HDS/HDC); feeding the liquid fraction separated in the hydroconversion unit and having a boiling point of 170 to 350°C, to hydrodesulphuration unit of medium gasoils (HDS2); feeding the liquid fraction separated in the hydroconversion unit and having a boiling point ranging from the boiling point of C5 products to 170°C, to desulphuration unit of naphtha (HDS3); feeding the liquid stream separated in the distillation unit at atmospheric pressure and having a boiling point ranging from the boiling point of C5 products to 170°C, to said desulphuration unit of naphtha (HDS3), wherein the hydroconversion unit, in addition to one or more slurry phase hydroconversion reactors, includes a first separator into which the residue is fed in slurry phase, followed by a second separator, a stripping unit at atmospheric pressure and a separation unit, and in addition to treatment in the hydroconversion reactor, the process comprises the following steps: separating the by-product in slurry phase in the first separator to obtain a lower product and an upper product, separating said upper product in the second separator into which is fed a liquid stream having a boiling point above 170°C and obtained in the gas/liquid treatment and separation section, to form liquid and gaseous streams, both of which are fed to the stripping unit at atmospheric pressure into zones at different heights of the apparatus; and treatment in the stripping unit at atmospheric pressure using the vapour of said liquid and gaseous streams obtained in the second separator, wherein the stream leaving the bottom of the stripping unit at atmospheric pressure is recycled to the hydroconversion unit and / or to the sub-atmospheric distillation unit, and obtaining from said stripping unit a heavy liquid stream and a light liquid stream which is fed to a separation unit into which is fed a liquid stream having a boiling point below 500°C and obtained in the gas / liquid treatment and separation section to obtain at least three fractions: a fraction with a boiling point above 350°C, a fraction with a boiling point from 170 to 350°C and a fraction with a boiling point ranging from the boiling point of C5 products to 170°C.
EFFECT: technical result is reduction in the number of single operations, storage tanks for raw materials, semi-finished products and costs, as well as an increase in profit from oil refining.
11 cl, 4 tbl, 4 dwg
