RU2773853C2 - Improved method for residue conversion, combining deep hydroconversion stage and deasphalting stage - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to methods for the conversion of hydrocarbon raw materials. A method for the conversion of hydrocarbon raw materials, at least 50 wt.% of which, preferably at least 80 wt.%, boils at a temperature of at least 300°C, is described, including following successive stages: at a stage a), the first deep hydroconversion of the specified hydrocarbon raw materials is optionally carried out in the presence of hydrogen, at a stage b), a light fraction is separated from part or all of a flow leaving the specified first hydroconversion to obtain at least one heavy fraction, at least 80 wt.% of which has a boiling point of at least 250°C, at a stage c), the second deep hydroconversion of part or all of the liquid flow leaving the stage a) or the heavy fraction leaving the stage b) is carried out in the presence of hydrogen, wherein the total volume hourly rate for stages a)-c) is below 0.1 h^-1, where the total rate is the consumption of liquid raw materials at the stage a) of hydroconversion, reduced to standard conditions for temperature and pressure, related to the total volume of reactors of stages a) and c), wherein a hydroconversion catalyst of the stage a) and a hydroconversion catalyst of the stage c) are used in the form of extrudates or balls, a stage d) of the separation of part or all of a flow leaving the specified second hydroconversion into at least one light fraction and at least one heavy fraction, at least 80 wt.% of which has a boiling point of at least 300°C, a stage e) of the deasphalting of the specified heavy fraction obtained at the stage d), a stage f) of the conversion of part or all of the specified deasphalted DAO fraction, possibly distilled, wherein part or all of the DAO fraction is directed, preferably directly, to a conversion stage acting according to a method selected from a group consisting of hydrocracking in a fixed layer, catalytic cracking in a fluidized bed, hydroconversion in a boiling layer, wherein these methods may include preliminary hydrotreatment, wherein a catalyst of hydroconversion in the boiling layer is preferably used in the form of extrudates or balls.

EFFECT: increase in the degree of conversion of raw materials.

8 cl, 1 dwg, 25 tbl, 7 ex

Description

The present invention relates to the conversion of heavy hydrocarbon feedstock, at least 50 wt.% which is a fraction having a boiling point of at least 300°C. This may be crude oil or feedstock coming, directly or after processing, from atmospheric distillation and/or vacuum distillation of crude oil, such as atmospheric or vacuum residues.

The use of these oil residues is rather difficult from both technological and economic points of view. Indeed, the new regulatory limits require a sharp reduction in the maximum allowable sulfur content in liquid fuels (from 3 wt.% to 0.5 wt.% sulfur). In addition, there is an increasing market demand for fuels that can be distilled at atmospheric pressure at temperatures below 380°C or even below 320°C.

State of the art

Patent FR 2906814 from the authors of the present application describes a method comprising sequentially performing a deasphalting stage (SDA) producing deasphalted oil, a hydroconversion stage of said deasphalted oil to obtain a stream, and a distillation stage of said stream to obtain a residue, which is returned along with the feed to the deasphalted stage. This patent describes a flowsheet in which the hydroconversion step is carried out at classical space velocities (VVH) of 0.1-5 h ^-1 and the SDA step is carried out before the hydroconversion step. The high amount of asphalt produced limits the maximum level of overall conversion in the process.

Patent FR-2964386 from the authors of this application describes a technological scheme for the processing of raw materials obtained from crude oil or as a result of atmospheric or vacuum distillation of crude oil. This process includes a fluidized bed hydroconversion step (called H-Oil® or LC-Fining process) followed by a light fraction separation step (boiling point below 300°C, preferably below 375°C), and the resulting heavy fraction is directly subjected to a deasphalting step with obtaining deasphalted oil (DAO). DAO can be hydrocracked or hydrotreated or fractionated.

The fluidized bed hydroconversion step is carried out at space velocities (VVH) of 0.1 h ^-1 to 10 h ^-1 . The example in said patent is implemented on part of the fluidized bed at VVH=0.3 h ^-1 and conversion (relative to the residue 540°C+, ie boiling at a temperature of 540°C or higher) of about 60 wt.%.

This simple and economical process allows for thermal integration in the same reaction section and produces good quality DAO, however the asphalt yield is high, limiting the maximum overall conversion achievable with this process.

It is also known (US Pat. No. 7,938,952) to use two fluidized bed hydroconversion steps with combined space velocities of at least 0.1 h ⁻¹ (known as the H-Oil® process) with an intermediate separation to separate the light fraction and pass the resulting heavy fraction to the second hydroconversion stage, and then the second hydroconversion effluent is immediately distilled. By "total space velocity" is meant the flow rate of hydrocarbon feedstock normalized to standard temperature and pressure conditions divided by the sum of the reactor volumes comprising the hydroconversion stages.

Patent FR-3033797 from the authors of this application describes a method of processing raw materials obtained from crude oil or as a result of atmospheric or vacuum distillation of crude oil, at least 80 wt.% which has a boiling point of at least 300°C. This method includes a hydroconversion step (first hydroconversion) followed by separation of the light fraction (boiling point below 350°C), and the resulting heavy fraction is subjected to a hydroconversion (second hydroconversion) separate from the first, the resulting stream is then fractionated by distillation. This hydroconversion process operates at a low total VVH, preferably from 0.05 h ^-1 to 0.09 h ^-1 .

The advantage of a low total VVH is a significant cleanup, resulting in a low asphaltene and low Conradson residue at a high residue conversion rate (>75%). The stability of the liquid outflow streams is improved. The content of sediments at the outlet of the hydroconversion is reduced, which leads to better manufacturability of the method. The overall conversion of this process is limited by the heavy unreacted stream.

The essence of the invention

Currently, there is a need for a process with improved performance, in particular, with a high degree of conversion into fuel (naphtha, kerosene, diesel oil) to adapt to the market.

It would be possible to modify the method according to the latest state of the art (FR 3033797) to increase the conversion of the deep hydroconversion stages while further reducing the total VVH.

The Applicants have found that the best solution would be to add a deasphalting step to the state of the art process, which would allow for an increased yield and quality of the DAO cut, and to process the DAO in at least one conversion step, which preferably operates at a higher VVH, and thereby maximize conversions while delivering markedly better manufacturability and significant capital savings and better return on investment. The present invention also makes it possible to further reduce the amount of asphalt produced compared to methods with a higher total VVH.

More specifically, the invention relates to a process for the conversion of hydrocarbon feedstock, at least 50 wt.%, preferably at least 80 wt.% of which boils at a temperature of at least 300°C, comprising the following successive stages:

- at stage a) the first deep hydroconversion of the specified hydrocarbon feedstock is carried out in the presence of hydrogen, at an absolute pressure of 2 MPa to 35 MPa, a temperature of 300°C to 550°C, an amount of hydrogen from 50 Nm ³ /m ³ to 5000 Nm ³ / m ³ , with a catalyst containing at least one group VIII metal selected from nickel and cobalt, and at least one group VIB metal selected from molybdenum and tungsten,

optionally, step b) separating the light fraction from part or all of the stream leaving said first hydroconversion to obtain at least one heavy fraction, at least 80% by weight of which has a boiling point of at least 250°C,

- at stage c) a second deep hydroconversion of a part or all of the liquid stream leaving stage a) or the heavy fraction leaving stage b) is carried out in the presence of hydrogen, at an absolute pressure of 2 MPa to 35 MPa, a temperature of 300°C up to 550°C, the amount of hydrogen from 50 Nm ³ /m ³ to 5000 Nm ³ /m ³ , with a catalyst containing at least one metal of group VIII selected from nickel and cobalt, and at least one metal of group VIB selected from molybdenum and tungsten

moreover, the total space hourly velocity for stages a)-c) is below 0.1 h ^-1 , where the total rate means the consumption of liquid feedstock in stage a) of hydroconversion, reduced to standard conditions for temperature and pressure, related to the total volume of the reactors of stages a) and c)

- stage d) separating part or all of the stream leaving said second hydroconversion into at least one light fraction and at least one heavy fraction, at least 80 wt.% of which has a boiling point of at least 300°C,

- stage e) deasphalting said heavy fraction obtained in stage d), at a temperature of from 60°C to 250°C, with at least one hydrocarbon solvent containing 3-7 carbon atoms, and at a solvent/feed volume ratio of 4 /1 to 9/1, to obtain a deasphalted DAO fraction and asphalt.

Preferably, the method includes step f) converting some or all of said deasphalted DAO fraction, optionally distilled.

Preferably, the DAO fraction is distilled before conversion step f) to separate the heavy fraction, at least 80% by weight of which has a boiling point of at least 375°C, or at least 400°C, or at least 450°C, or at least 500°C, and preferably at least 540°C, and part or all of said heavy fraction is sent to stage f) conversion.

Preferably, part or all of the DAO fraction is passed, preferably directly, to a conversion step operating in a process selected from the group consisting of fixed bed hydrocracking, fluidized catalytic cracking, fluidized bed hydroconversion, which processes may include pre-treatment hydrotreating.

In one preferred embodiment, part or all of the deasphalted DAO fraction is hydrocracked in a fixed bed in the presence of hydrogen, at an absolute pressure of 5 MPa to 35 MPa, a temperature preferably of 300°C to 500°C, a VVH of 0.1 h ^-1 to 5 h ^-1 and the amount of hydrogen from 100 Nm ³ /m ³ to 1000 Nm ³ /m ³ (normal cubic meters (Nm ³ ) per cubic meter (m ³ ) liquid feed), and in the presence of a catalyst containing at least one a non-noble element of group VIII and at least one element of group VIB and containing a substrate comprising at least one zeolite.

In another preferred embodiment, some or all of the deasphalted DAO fraction is subjected to fluid catalytic cracking (FCC) in the presence of a catalyst, preferably a non-metal containing alumina, silica, aluminosilicate, and preferably containing at least one zeolite.

In one preferred embodiment, part or all of the deasphalted DAO fraction is subjected to hydroconversion in a fluidized bed, carried out in the presence of hydrogen, at an absolute pressure of from 2 MPa to 35 MPa, a temperature of from 300°C to 550°C, an amount of hydrogen from 50 Nm ³ /m ³ up to 5000 Nm ³ /m ³ (normal cubic meters (Nm ³ ) per cubic meter (m ³ ) of liquid feed), at VVH from 0.1 h ^-1 to 10 h ^-1 and in the presence of a catalyst containing a substrate and at least at least one Group VIII metal selected from nickel and cobalt; and at least one Group VIB metal selected from molybdenum and tungsten.

At least a portion of said deasphalted DAO fraction can be returned to step a) and/or step c).

Preferably, in separation step d), the effluent from said second hydroconversion is separated into at least one light cut and at least one heavy cut, at least 80% by weight of which has a boiling point of at least 375°C, or at least 400°C, or at least 450°C, or at least 500°C, preferably at least 540°C.

Typically, steps a) and c) are carried out at an absolute pressure of 5 MPa to 25 MPa, preferably 6 MPa to 20 MPa, a temperature of 350°C to 500°C, preferably 370°C to 430°C and more preferably 380 °C to 430°C, hydrogen amount from 100 Nm ³ /m ³ to 2000 Nm ³ /m ³ and very preferably from 200 Nm ³ /m ³ to 1000 Nm ³ /m ³ , at a space hourly velocity (VVH) of at least least 0.05 h ^-1 , preferably from 0.05 h ^-1 to 0.09 h ^-1 .

Usually stage e) is carried out with a solvent selected from the group consisting of butane, pentane or hexane, as well as mixtures thereof.

Detailed description of the invention

Raw material

The feedstock to be processed in the context of the present invention is a feedstock of at least 50 wt%, preferably at least 80 wt% of which has a boiling point of at least 300°C (T20=300°C), preferably at least at least 350°C or at least 375°C.

This may be crude oil or heavy hydrocarbon fractions obtained from atmospheric or vacuum distillation of crude oil. It can also be atmospheric residues and/or vacuum residues, in particular atmospheric and/or vacuum residues coming from hydrotreating, hydrocracking and/or hydroconversion. It can also be vacuum distillates, fractions coming from a catalytic cracker such as an FCC (Fluid Bed Catalytic Cracker), a coker or a visbreaker.

Preferably, residues are used as raw materials. Typically, these residues are fractions, at least 80 wt.% which boils at a boiling point of at least 450°C or higher, most often at a temperature of at least 500°C or 540°C.

Also suitable as raw materials are aromatic fractions taken from the lubricant production plant, deasphalted oils (raffinates from the deasphalting plant), asphalts (residues from the deasphalting plant).

The feedstock can also be a residual fraction from direct coal liquefaction (atmospheric residue and/or vacuum residue obtained, for example, in the H-Coal® process), vacuum distillate obtained from direct coal liquefaction (for example, in the H-Coal® process) , residues from the pyrolysis of coal or shale oils, or a residual fraction obtained from direct liquefaction of lignocellulosic biomass, alone or mixed with coal and/or oil fraction.

All these types of raw materials can be used alone or in a mixture.

The above raw materials contain impurities such as metals, sulfur, nitrogen, Conradson carbon residue and compounds insoluble in heptane, also called C ₇ asphaltenes. Metal content usually exceeds 20 wpm, most often above 100 wpm. The sulfur content exceeds 0.1%, often above 1 wt.% or 2 wt.%. The level of C ₇ asphaltenes (heptane-insoluble asphaltenes according to NFT60-115) is at least 0.1% by weight and often exceeds 3% by weight. The content of carbon residue according to Conradson is at least 3 wt.%, often at least 5 wt.%. The Conradson carbon content is determined in accordance with ASTM D-482 and is a well-known estimate of the amount of carbon residue obtained after pyrolysis under standard conditions of temperature and pressure to those skilled in the art. These contents are expressed in wt.% of the total weight of the raw material.

The first stage of deep hydroconversion (stage a))

The feed is processed in step a) hydroconversion comprising at least one or more three-phase reactors installed in series and/or in parallel. These hydroconversion reactors may, among other things, be fixed bed, moving bed, fluidized bed and/or hybrid bed reactors, depending on the feedstock being processed. In this application, the term "hybrid bed" refers to a mixed bed of catalysts with very different granulometric properties, containing simultaneously at least one catalyst that is retained in the reactor (typical fluidized bed operation) and at least one entrained catalyst (called "slurry" in English), which enters the reactor along with the feedstock and which is entrained out of the reactor along with the outgoing streams (typical operation of the entrained bed).

The invention is particularly well suited to fluidized bed reactors. Thus, this step can be advantageously carried out using the technology and under the conditions of the H-Oil® process as described, for example, in US Pat. , Texas, paper number 46d, "Second generation ebullated bed technology". Each reactor preferably contains a recycle sludge to keep the catalyst in the fluidized bed by continuously recirculating at least a portion of the liquid fraction, preferably withdrawn from the top of the reactor and re-introduced from the bottom of the reactor.

In step a), said feedstock is converted under specific hydroconversion conditions. Step a) is carried out at an absolute pressure of 2 MPa to 35 MPa, preferably 5 MPa to 25 MPa and preferably 6 MPa to 20 MPa, at a temperature of 300°C to 550°C, preferably 350°C to 500°C , preferably from 370°C to 430°C and more preferably from 380°C to 430°C. The amount of hydrogen preferably mixed with the feedstock is preferably 50 Nm ³ /m ³ to 5000 Nm ³ /m ³ liquid feedstock, based on standard temperature and pressure conditions, preferably 100 Nm ³ /m ³ to 2000 Nm ³ / m ³ and very preferably from 200 Nm ³ /m ³ to 1000 Nm ³ /m ³ .

The hydroconversion catalyst used in step a) contains one or more elements of groups 4-12 of the Periodic Table of the Elements which are deposited on a support. One can advantageously use a catalyst containing a support, preferably amorphous, such as silica, alumina, aluminosilicate, titanium dioxide, or combinations of these structures, and very preferably alumina.

The catalyst contains at least one Group VIII base metal selected from nickel and cobalt, preferably nickel, and at least one Group VIB metal selected from molybdenum and tungsten, preferably the Group VIB metal is molybdenum.

Preferably, the hydroconversion catalyst in step a) is a catalyst containing an alumina support and at least one Group VIII metal selected from nickel and cobalt, preferably nickel, and at least one Group VIB metal selected from molybdenum and tungsten, preferably a metal group VIB is molybdenum. Preferably, the hydroconversion catalyst contains nickel and molybdenum.

Generally, the Group VIII non-noble metal content (particularly nickel) expressed as weight of the metal oxide (particularly NiO) is preferably 0.5 to 10% by weight, preferably 1 to 6% by weight, and the Group VIB metal content (in particular molybdenum), expressed as the weight of metal oxide (in particular MoO ₃ ), is preferably 1 to 30% by weight, preferably 4 to 20% by weight.

This catalyst is preferably used in the form of extrudates or pellets.

The balls have, for example, a diameter of 0.4 mm to 4.0 mm.

The extrudates are, for example, in the form of a cylinder with a diameter of 0.5 mm to 4.0 mm and a length of 1 mm to 5 mm. The extrudates may also be objects of other shapes, such as regular or irregular shamrocks, quatrefoils, or other multi-lobed shapes. Other forms of catalysts can also be used.

The size of these different forms of catalysts can be characterized by an equivalent diameter. The equivalent diameter is defined as 6 times the ratio of the volume of the particle to the outer surface of the particle. Thus, the catalyst used in the form of extrudates, beads or other forms has an equivalent diameter of 0.4 mm to 4.4 mm.

These catalysts are well known to the skilled person. The metal content is expressed based on the total weight of the catalyst.

In one embodiment of the invention, stage a) of deep hydroconversion is carried out in a hybrid bed containing simultaneously at least one catalyst that is retained in the reactor and at least one entrained catalyst that enters the reactor along with the feed and which is entrained from the reactor along with outgoing streams. In this case, the entrained catalyst, also referred to as slurry catalyst, is used in addition to the catalyst retained in the fluidized bed reactor in the process according to the invention. Said entrained catalyst differs from the catalyst retained in the reactor by a particle size distribution and density suitable for entraining it. By catalyst entrainment is meant its circulation in one or more three-phase reactors, caused by liquid streams, and the specified catalyst moves from bottom to top together with the feed in the specified three-phase reactors and is removed from the specified three-phase reactors with the product liquid stream. Due to its small size, which can vary from a few nanometers to a hundred micrometers (typically 0.001 µm to 100 µm), the entrained catalyst is very well dispersed in the feedstock being converted, thereby greatly improving the hydrogenation and hydroconversion reactions throughout the reactor, which reduces the formation coke and increases the conversion of the heavy fraction of raw materials. These entrained catalysts are well known to those skilled in the art.

The entrained catalyst can be formed and activated ex situ, ie. outside the reactor under conditions suitable for activation, and then introduced along with the feed. The entrained catalyst can also be formed and activated in situ under the reaction conditions of one of the hydroconversion steps.

The entrained catalyst or its precursor is introduced into the reactor inlet together with the feedstock to be converted. The catalyst passes through the reactor with feedstock and products during the conversion, then it is carried away with the reaction products from the reactor. Entrained catalysts exist either in powder form (US Pat. No. 4,303,634), which is the case with supported entrained catalysts described below, or as a catalyst called soluble (US Pat. No. 5,288,681). In the reactor, the entrained catalyst is in the form of dispersed solids, colloids, or molecular particles dissolved in the feed, depending on the nature of the catalyst. Such entrained catalyst precursors suitable for use in the process of the invention are widely described in the literature.

Entrained catalysts used can be powders of heterogeneous solids (such as natural minerals, ferrous sulfate, etc.), particulate catalysts prepared from water-soluble precursors such as phosphomolybdic acid, ammonium molybdate, or a mixture of Mo or Ni oxide with aqueous ammonia , or can be obtained from precursors soluble in the organic phase. The entrained catalysts used are preferably prepared from precursors soluble in the organic phase. Precursors soluble in the organic phase are preferably selected from the group of organometallic compounds consisting of Mo, Co, Fe or Ni naphthenates or multicarbonyl compounds of these metals, for example Mo or Ni 2-ethylhexanoates, Mo or Ni acetylacetonates, molybdenum or tungsten salts of fatty acids. acids C ₇ -C ₁₂ , etc. Preferably, the precursor is Mo naphthenate. Entrained catalysts can be used in the presence of a surfactant to improve the dispersion of metals, particularly when the catalyst is bimetallic.

In one embodiment, entrained catalysts, referred to as oil soluble, are used and the precursor is mixed with a carbon feed (which may be part of the feed to be treated, external feed, etc.), the mixture is dried, if necessary, at least partially, then or simultaneously sulfonated by adding a sulfur compound and heated. The preparation of these entrained catalysts is described in the prior art.

Additives can be added during the preparation of the entrained catalyst or to the entrained catalyst prior to its introduction into the reactor. These can be, for example, gas oil, flavor additive, particulate matter preferably less than 1 mm, etc. Preferred additives are mineral oxides such as alumina, silica, Al/Si mixed oxides, spent supported catalysts (e.g. supported by alumina and/or silica) containing at least one Group VIII element (such as Ni , Co) and/or at least one element of group VIB (such as Mo, W). Mention may be made, for example, of the catalysts described in US 2008/177124. You can also use coke, possibly pre-treated. These additives are widely described in the literature. Entrained catalyst can advantageously be obtained by introducing at least one active phase precursor directly into one or more hydroconversion reactors and/or into the feed prior to introducing said feed to the hydroconversion stage or stages. The precursor additive may be introduced continuously or discontinuously (depending on the operation, the type of raw materials being processed, the specifications for the desired products and manufacturability). According to one or more embodiments, the entrainment catalyst precursor or precursors are premixed with a hydrocarbon oil consisting, for example, of at least 50% by weight of hydrocarbons based on the total weight of the hydrocarbon oil, have a boiling point in the range of 180°C to 540 °C to form a dilute precursor premix. According to one or more embodiments, the precursor or diluted precursor pre-blend is dispersed in the heavy hydrocarbon feed, e.g., dynamic agitation (e.g., with a rotor, agitator, etc.), static agitation (e.g., with an injector, through a probe , by means of a static mixer, etc.) or simply added to the raw material to obtain a mixture. Any combination and mixing methods known to those skilled in the art may be used to disperse the precursor or dilute mixture of precursors in the feed for one or more hydroconversion steps.

Said unsupported catalyst active phase precursor or precursors may be in liquid form, such as, for example, metal precursors soluble in organic media, such as, for example, molybdenum octoate and/or molybdenum naphthenate, or water-soluble compounds, such as, for example, phosphomolybdic acids and/or or ammonium heptamolybdate, among others.

Said entrained catalyst may be formed and activated ex situ, i. e. outside the reactor under conditions suitable for activation, and then introduced along with the feed. Said entrained catalyst may also be formed and activated in situ under the reaction conditions of one of the hydroconversion steps.

According to one embodiment, said entrained catalyst may be supported, ie, supported for the active phase. In this case, the supported catalyst can be successfully obtained:

- by grinding a supported hydroconversion catalyst, fresh or used, or by grinding a mixture of fresh and used catalysts, or

- by impregnating a support having a granulometric size suitable for catalyst entrainment, preferably from 0.001 to 100 µm, with at least one active phase precursor.

Said entrained supported catalyst preferably comprises a support such as silica, alumina, aluminosilicate, titanium dioxide, clays, carbon, coal, coke, carbon black, lignite, or a combination of these structures, very preferably the support consists of alumina.

The active phase of said entrained supported catalyst contains one or more elements of groups 4-12 of the Periodic Table of the Elements, which may or may not be deposited on the support. The active phase of said entrained catalyst preferably contains at least one Group VIB metal selected from molybdenum and tungsten, preferably the Group VIB metal is molybdenum. Said Group VIB metal may be combined with at least one Group VIII non-noble metal selected from nickel, cobalt, iron, ruthenium, preferably nickel.

In the present description, groups of chemical elements are given in accordance with the CAS classification (CRC Handbook of Chemistry and Physics, CRC press, D.R. Lide Ed., 81 edition, 2000-2001). For example, Group VIII metals in the CAS classification correspond to metals in columns 8, 9 and 10 in the new IUPAC classification.

In the case of supported entrainment catalysts, the content of non-noble Group VIII metal, in particular nickel, expressed as weight of metal oxide (in particular NiO) is preferably 0.5 to 10% by weight, preferably 1 to 6% by weight. The content of the Group VIB metal, in particular molybdenum, expressed as the weight of the metal oxide (in particular molybdenum trioxide MoO ₃ ), is preferably 1 to 30% by weight, preferably 4 to 20% by weight. Metal contents are expressed as weight percent metal oxide based on the weight of entrained catalyst on the support.

Preferably, the supported catalyst may also contain at least one doping element selected from phosphorus, boron and halogens (group VIIA or group 17 according to the new entry of the Periodic Table of the Elements), preferably phosphorus.

In one embodiment of the process according to the invention, in particular in a fluidized bed reactor, each reactor in hydroconversion step a) can use its own catalyst, matched to the feedstock fed to that reactor.

In another embodiment of the process of the invention, several different types of catalysts may be used in each reactor.

In a preferred embodiment, each reactor of step a) may contain one or more catalysts suitable for fluidized bed operation and optionally one or more additional entrained catalysts.

According to conventional technology (described in the prior art, eg FR 3033797), the spent hydroconversion catalyst can be partially replaced by fresh catalyst by draining, the spent catalyst being preferably withdrawn from the bottom of the reactor and the fresh catalyst introduced into the reactor. The fresh catalyst may be replaced, partially or completely, by a used and/or regenerated catalyst (without coke) and/or a rejuvenated catalyst (regenerated catalyst supplemented with a catalyst activity enhancing compound) and/or a catalyst reactivated by removing poisons and inhibitors such as as precipitated metals originating from hydrodemetalation reactions and removal of formed coke.

Step b) separation (optional)

The method preferably includes step b).

At least a portion, and preferably all, of the effluent from hydroconversion step a) may be subjected to one or more separation steps.

The purpose of the separation step is to separate from the stream at least one light fraction (called the first light fraction) and obtain at least one heavy liquid fraction, at least 80 wt.% of which has a boiling point of at least 250°C, preferably at least measure 300°C.

The light end can then be sent, at least in part, to a fractionation section, where it is then preferably separated from the light gases (H ₂ and C ₁ -C ₄ ), for example by passage through a flash column. The hydrogen gas is recovered and then preferably returned to the deep hydroconversion stage a) or sent to the deep hydroconversion stage c) and/or other refineries. The light liquid fraction, separated from the light gases, can then be successfully sent to stage d) fractionation. This separated light liquid fraction contains dissolved light gases, naphtha (the fraction boiling below 150°C), kerosene (the fraction boiling between 150°C and 250°C) and at least one gas oil fraction boiling between 250 °C to 375°C.

The heavy liquid fraction obtained in step b) contains compounds boiling at 250°C, preferably at 300°C or higher, in particular compounds with boiling points from 375°C to at least 540°C (vacuum distillate) and compounds boiling at a temperature greater than or equal to 540°C, which correspond to the vacuum residue (representing the unreacted fraction). Thus, it may contain part of the gas oil fraction, ie compounds boiling between 250°C and 375°C.

This heavy liquid fraction is carried out, in whole or in part, to hydroconversion step c).

The separation step may be carried out by any separation method known to those skilled in the art. Preferably, separation step b) is carried out in one or more flash columns connected in series, and preferably in a single flash column. Preferably, the flash column is operated at a pressure and temperature close to the operating conditions in the last reactor of hydroconversion step a).

In another embodiment, the separation step is carried out in a cascade of several flash columns operating under operating conditions different from those in the last reactor of hydroconversion step a) and allowing several light liquids to be obtained. They can then be sent, in whole or in part, to the fractionation section.

In another embodiment, the separation step is carried out in one or more stripping columns (cascade) with steam and/or hydrogen stripping. As a result, the effluent from hydroconversion step a) will be separated into a light fraction and a heavy liquid fraction.

In another embodiment, the separation step may be carried out by a single atmospheric distillation column or followed by a vacuum distillation column.

The separation step may also be a combination of these different options.

Optionally, before being sent to stage c) hydroconversion according to the invention, the heavy liquid fraction can be subjected to the stage of separation of compounds with a boiling point less than or equal to 540°C. At least 80% by weight of the resulting heavy fraction has a boiling point of at least 540°C. This separation can be carried out by steam and/or hydrogen stripping using one or more stripping columns.

Second deep hydroconversion (stage c))

The liquid stream leaving step a) or the heavy fraction from separation step b) is subjected to deep hydroconversion in step c). This may or may not be carried out the return of the specified stream or the specified fractions to stage a). Stages a) and c) are different stages implemented in separate zones.

Used ranges of operating conditions and catalysts are described for stage a).

The operating conditions in step c) are identical or different from the operating conditions in step a).

According to the invention, the total space hourly velocity (VVH), i.e. the flow rate of liquid feedstock in stage a) hydroconversion, reduced to standard conditions for temperature and pressure, referred to the total volume of the reactors for stages a) and c), is below 0.1 h ^{- 1} and is usually at least 0.05 h ^-1 , preferably from 0.05 h ^-1 to 0.09 h ^-1 .

Step d) Fractionation

The stream leaving stage c) hydroconversion, then subjected, in whole or in part, stage d) fractionation. This fractionation can be carried out in one or more flash columns connected in series, preferably in a cascade of at least two flash columns in series, preferably in one or more steam and/or hydrogen light ends columns, more preferably in an atmospheric distillation column, even more preferably in one atmospheric distillation column and one atmospheric residue vacuum distillation column, even more preferably in one or more flash columns, atmospheric distillation column and atmospheric residue vacuum distillation column. This fractionation may also be carried out by a combination of the various separation means described above.

The fractionation step is carried out in order to separate light gases and distillates suitable for processing (gasoline, gas oil) and to obtain at least one heavy liquid fraction, at least 80 wt.% of which boils at a temperature of at least 300°C, or at least 350°C, preferably at least 375°C, or at least 400°C, or at least 450°C, or at least 500°C, preferably a residual fraction is obtained, 80 wt.% of which boils at a temperature of at least 540°C or higher. Preferably, a vacuum residue is separated (by distillation at atmospheric pressure followed by vacuum distillation of an atmospheric residue) having an initial boiling point of 540°C.

Stage e) deasphalting

According to the process of the invention, said heavy liquid fraction obtained in step d) and said residue fraction are then subjected to step e) of deasphalting to obtain a deasphalted hydrocarbon fraction called DAO and asphalt.

Deasphalting is usually carried out at a temperature of 60°C to 250°C with at least one hydrocarbon solvent containing 3-7 carbon atoms, butane, pentane or hexane is preferably used as a solvent, as well as mixtures thereof, optionally supplemented with at least one additive. The solvent/feedstock volume ratios in deasphalting are typically 4/1 to 9/1, often 4/1 to 8/1.

Suitable solvents and additives are widely described. It is also possible, and advantageously, to carry out the recovery of the solvent in an optically critical manner, ie using the solvent under supercritical conditions in the separation section. This method makes it possible, in particular, to noticeably improve the economy of the process as a whole. Said deasphalting may be carried out in one or more mixer-decanters or in one or more extraction columns.

You can use a method using at least one extraction column, preferably a single one (for example, the method of Solvahl ^TM ).

The deasphalting unit produces a deasphalted DAO hydrocarbon fraction (also called deasphalted oil oil or deasphalted raffinate) that is substantially free of C ₇ asphaltenes and residual asphalt, which concentrates most of the impurities from the residue and which are removed.

The yield of DAO is typically between 40 and 90% by weight, depending on the properties of the incoming heavy liquid fraction, the operating conditions and the solvent used.

The following table shows typical ranges of operating conditions for deasphalting depending on the solvent.

Solvent propane butane pentane hexane heptane Pressure, MPa 3-4 3-4 2-4 2-4 2-4 Temperature, °C 45-90 80-130 140-210 150-230 160-250 Solvent/raw material ratio, v/v 6-10 5-8 3-6 3-6 3-5

The deasphalting conditions are adapted to the quality of the obtained DAO fraction and to the feedstock supplied to the deasphalting process.

These conditions make it possible to significantly reduce the content of coke residue according to Conradson and the content of asphaltenes C ₇ . The resulting deasphalted DAO hydrocarbon fraction preferably has a C ₇ asphaltene content of less than 0.5 wt%, preferably less than 0.1 wt%, preferably less than 0.08 or less than 0.07 wt% of the total weight of said fraction.

In one embodiment, all or preferably part of said deasphalted DAO fraction is recycled to step a) and/or step c).

DAO fraction conversion (step f))

The DAO fraction can be sent, in whole or in part, to an additional stage f) conversion. Preferably, the DAO is carried out directly to the conversion step. Preferably, the entire DAO fraction is sent directly to the conversion step, i.e. it is not subjected to any treatment except possibly one or more fractionation steps.

This stage makes it possible to bring the conversion of the process to a very high level (relative to the 540°C+ fraction), most often to a level above 90%. Conversion processes contemplated at this stage are fixed bed hydrocracking, FCC fluidized catalytic cracking, fluidized bed hydroconversion (H-Oil DC), and these conversion processes may be preceded by hydrotreating.

If desired, said deasphalted DAO hydrocarbon fraction may be distilled at atmospheric pressure, optionally followed by vacuum distillation, in particular when step c) does not include distillation.

Processable product cuts are a gasoline cut (150°C-), one or more middle distillate cuts (150-375°C), and one or more heavier cuts with a boiling point of 375°C or higher.

This or these heavier fractions are preferably sent to stage f) conversion.

The characteristics of this cut are particularly advantageous (low Conradson carbon residue, low C ₇ asphaltenes, low S, metals).

In one embodiment, the deasphalted DAO hydrocarbon cut is preferably distilled in admixture with at least a portion, and preferably all, of the light liquid cut obtained in step b).

In another embodiment, the specified mixture can be sent to stage f) conversion without prior fractionation (distillation).

For distillation, the DAO fraction can also be mixed with raw materials external to the process, such as, for example, fractions of vacuum distillate, atmospheric residue or vacuum residue obtained from primary fractionation (crude oil) in a refinery.

The method is preferably carried out without distillation. In such a case, the DAO fraction is carried out, partially or completely, to step f).

The conversion step may be fixed bed hydrocracking. It can be successfully implemented in one or more reactors or in a single reactor containing one or more catalyst beds.

Hydrocracking in a fixed bed is realized by acid catalysis in the presence of hydrogen.

The presence of nitrogen and other impurities in said mixture requires pre-treatment to avoid deactivation of the catalyst. This typically involves at least one fixed bed of hydrotreating catalyst followed by at least one fixed bed of hydrocracking catalyst. These catalysts are well known to those skilled in the art. You can successfully use one of the catalysts described by the applicant in patents EP-B-113297 and EP-B-113284.

The catalysts contain at least one non-noble element of group VIII (Ni and/or Co) and at least one element of group VIB (Mo and/or W). The content of Group VIII elements is preferably 1 to 10 wt.% oxides based on the total weight of the catalyst, preferably 1.5 to 9 wt.% and very preferably 2 to 8 wt.%. The content of Group VIB elements is preferably 5 to 40 wt.% oxides based on the total weight of the catalyst, preferably 8 to 37 wt.% and very preferably 10 to 35 wt.%. These contents are expressed on the total weight of the catalyst.

The hydrotreating catalyst support is typically alumina; hydrocracking catalyst supports contain one or more zeolites (most commonly Y or β zeolites), usually in admixture with alumina and/or aluminosilicate. The weight content of zeolite is usually less than 80% by weight.

The hydrotreating and hydrocracking catalysts may also contain at least one organic additive.

Operate preferably at an absolute pressure of 5 MPa to 35 MPa, preferably 10 MPa to 20 MPa, at a temperature advantageously between 300°C and 500°C, preferably between 350°C and 450°C. VVH and hydrogen partial pressure are selected depending on the characteristics of the feedstock being processed and the desired conversion. Preferably, VVH is from 0.1 h ^-1 to 5 h ^-1 , preferably from 0.15 h ^-1 to 2 h ^-1 . The amount of hydrogen preferably mixed with the feed is preferably 100 Nm ³ /m ³ to 1000 Nm ³ /m ³ liquid feed, preferably 500 Nm ³ /m ³ to 3000 Nm ³ /m ³ .

The fluidized bed hydroconversion step treating the DAO (H-Oil® DC) fraction can be successfully carried out at an absolute pressure of 2 MPa to 35 MPa, preferably 5 MPa to 25 MPa and preferably 6 MPa to 20 MPa, at a temperature 300°C to 550°C, preferably 350°C to 500°C, more preferably 380°C to 470°C, and more preferably 400°C to 450°C. The amount of hydrogen preferably added to the feedstock is preferably 50 Nm ³ /m ³ to 5000 Nm ³ /m ³ liquid feedstock under standard temperature and pressure conditions, preferably 100 Nm ³ /m ³ to 2000 Nm ³ /m ³ and very preferably from 200 Nm ³ /m ³ to 1000 Nm ³ /m ³ . Preferably, the VVH at this stage is from 0.1 h ^-1 to 10 h ^-1 , preferably from 0.15 h ^-1 to 5 h ^-1 .

The hydroconversion catalyst used in the fluidized bed contains one or more elements of groups 4-12 of the Periodic Table of the Elements, which are deposited on a support. One can advantageously use a catalyst containing a support, preferably amorphous, such as silica, alumina, aluminosilicate, titanium dioxide, or combinations of these structures, very preferably alumina. The catalyst contains at least one Group VIII metal selected from nickel and cobalt, preferably nickel, and at least one Group VIB metal selected from molybdenum and tungsten, preferably the Group VIB metal is molybdenum.

Preferably, the hydroconversion catalyst is a catalyst comprising an alumina support and at least one Group VIII metal selected from nickel and cobalt, preferably nickel, and at least one Group VIB metal selected from molybdenum and tungsten, preferably the Group VIB metal is molybdenum. Preferably, the hydroconversion catalyst contains nickel and molybdenum.

The nickel content expressed in weight of nickel oxide (NiO) is preferably 0.5 wt% to 10 wt%, preferably 1 wt% to 6 wt%, and the molybdenum content expressed in terms of molybdenum trioxide (MoO ₃ ), preferably from 1 wt.% to 30 wt.%, preferably from 4 to 20 wt.%. The contents are expressed based on the total weight of the catalyst.

Said catalyst is preferably used in the form of extrudates or pellets. The extrudates have, for example, a diameter in the range of 0.5 mm to 2.0 mm and a length of 1 mm to 5 mm. These catalysts are well known to the skilled person.

According to conventional technology (described in the prior art, eg FR-3033797), the spent hydroconversion catalyst can be partially replaced by fresh catalyst by draining, the spent catalyst being preferably withdrawn from the bottom of the reactor and the fresh catalyst introduced into the reactor. The fresh catalyst may be replaced, partially or completely, by a used and/or regenerated catalyst (without coke) and/or a rejuvenated catalyst (regenerated catalyst supplemented with a catalyst activity increasing compound) and/or a catalyst reactivated by removing poisons and inhibitors such as as precipitated metals originating from hydrodemetalation reactions and removal of formed coke.

The stream from conversion step f) is then typically distilled to recover the recyclable gasoline and gas oil fractions. The unreacted residual fraction is returned to one of the stages of the process.

In another embodiment, conversion step f) may be carried out in a fluid catalytic cracking unit. DAO can be processed on its own or by co-processing with one or more heavy feedstocks such as VGO, HDT VGO, residues.

The catalytic fluidized bed cracker may comprise a single reactor treating both heavy feedstock and DAO, or only DAO, or two separate reactors, one of which treats heavy feedstock and the other DAO. In addition, each reactor may be an upflow or downflow reactor. Most often, both reactors will have the same flow regime.

When catalytic cracking is implemented by co-processing one or more feedstocks and DAO:

1) in a single riser reactor, the reactor outlet temperature (ROT) is from 450°C to 650°C, preferably from 470°C to 620°C, and the C/O ratio is from 2 to 20, preferably from 4 to fifteen,

2) in a single downflow reactor, the reactor outlet temperature (ROT) is between 480°C and 650°C and the C/O ratio is between 10 and 50,

3) in two separate riser reactors, the first reactor, in which one or more heavy feedstocks are cracked, operates at a reactor outlet temperature (ROT1) of 450°C to 650°C, preferably 470°C to 620°C C and the C/O ratio is from 2 to 20, preferably from 4 to 15. The second DAO cracking reactor is operated at a reactor outlet temperature (ROT2) of 500°C to 600°C, preferably from 520°C to 580°C, C/O ratio from 2 to 20,

4) in two separate downflow FCC reactors, the first FCC reactor, in which one or more heavy feedstocks are cracked, operates at a reactor outlet temperature (ROT1) of 480°C to 650°C at a C/O ratio of 10 up to 50. The second DAO cracking FCC reactor operates at a reactor outlet temperature (ROT2) of 570°C to 600°C at a C/O ratio of 10 to 50.

When catalytic cracking is carried out only on the DAO fraction:

1) in a riser reactor: the reactor is operated at a reactor outlet temperature (ROT) of 500°C to 600°C, preferably 520°C to 580°C, with a C/O ratio of 2 to 20,

2) in a downflow reactor: the reactor is operated at a reactor outlet temperature (ROT2) of 570°C to 600°C, with a C/O ratio of 10 to 50.

The spent catalyst stream exiting the two FCC reactors is separated from the cracking streams using any gas-solid separation system known to those skilled in the art and regenerated in a common regeneration zone.

The effluent from the catalytic cracking reactor (or two streams in the case of two reactors) is sent to a fractionation zone. The separation plant usually includes a primary separation of streams, allowing, among other things, to obtain fractions that allow processing, such as gasoline fractions, middle distillate and heavy distillate. The unreacted residual fraction can be returned to one of the stages of the process.

The catalyst in the fluidized catalytic cracking step typically consists of particles with an average diameter typically in the range of 40 µm to 140 µm, most commonly 50 µm to 120 µm.

The catalytic cracking catalyst contains at least one suitable matrix, such as alumina, silica or aluminosilicate, with or without the presence of Y-type zeolite, distributed in this matrix.

In addition, the catalyst may contain at least one zeolite having shape selectivity selected from one of the following structure types: MEL (for example, ZSM-11), MFI (for example, ZSM-5), NES, EUO, FER, CHA (e.g. SAPO-34), MFS, MWW. It may also contain one of the following zeolites: NU-85, NU-86, NU-88 and IM-5, which also have shape selectivity.

These zeolites having shape selectivity have the advantage of achieving better propylene/isobutene selectivity, ie a higher propylene/isobutene ratio in the cracking effluents.

The proportion of zeolite having form selectivity to the total amount of zeolite may vary depending on the feedstock used and the structure of the desired products. Often 0.1 to 60% by weight is used, preferably 0.1 to 40% by weight, in particular 0.1 to 30% by weight of a zeolite having shape selectivity.

Said one or more zeolites can be distributed in a matrix based on silica, alumina or aluminosilicate, with the proportion of zeolite (of all zeolites taken together) often ranging from 0.7 to 80 wt.% of the weight of the catalyst, preferably from 1 to 50 wt.% and even more preferably from 5 to 40 wt.%.

In the case where multiple zeolites are used, they may be incorporated into a single matrix or into several different matrices. The content of zeolite having form selectivity is less than 30% by weight of the total composition.

The catalyst used in the catalytic cracking reactor may consist of an ultra-stable Y-type zeolite dispersed in a matrix of alumina, silica or aluminosilicate, to which additives based on ZSM5 zeolite are added, and the amount of ZSM5 crystals is less than 30 wt.% of the total composition.

Description of the figure

Figure 1 illustrates the invention.

It includes a deep hydroconversion section A in which deep hydroconversion step a) is carried out. Feedstock 1 is converted in the presence of hydrogen 2 and the resulting stream 3 is separated (step b, possibly followed by step b') in separation section B. Light cut 4 and heavy cut 5 are obtained. The latter is sent to deep hydroconversion section C, where it is subjected to stage c) deep hydroconversion in the presence of hydrogen 6. The resulting stream 7 is separated into a light fraction 8 and a heavy fraction 9, which is sent to the deasphalting section E, where the deasphalting stage e) is carried out using a solvent 12. The deasphalted oil DAO 10 is carried to the section conversion F, where conversion step f) takes place and asphalt 11 is recovered. The effluent 13 from conversion step f) is then typically sent to a separation step to recover recyclable fractions such as gasoline and gas oil.

Examples

Examples 1 and 2 are compared at the same conversions (75% conversion of the 540°C+ fraction to the 540°C- fraction), and examples 3 and 4 are run at the same temperatures. Examples 5 and 6 are compared at the same conversions (75% conversion of the 540°C+ fraction to the 540°C- fraction), and examples 7 and 8 are run at the same temperatures.

Raw material

The heavy feedstock is a vacuum residue (RSV) obtained from Urals oil, the main characteristics of which are shown in table 1 below. This heavy RSV feed is the same fresh feed for different examples.

Table 1 : Composition of technological raw materials

Raw Stage A Raw material RSV Urals Density 1,000 Content 540°C+ the weight.% 77.9 Viscosity at 100°C cSt 880 Coke residue according to Conradson the weight.% 17.0 Asphaltenes C ₇ the weight.% 6.8 Nickel+vanadium h/m 233 Nitrogen h/m 6010 Sulfur the weight.% 2.715

Example 1 (not according to the invention) : High space hourly velocity and high temperature scheme (total VVH=0.3 h ^-1 +431/431°C) + deasphalting stage (SDA)

In this example, two fluidized bed reactors (first and second deep hydroconversion sections) in series operate at high space hourly velocity (VVH) and high temperature with an intermediate separation section and a deasphalting process downstream.

Hydroconversion section A

The fresh feed according to Table 1 is sent entirely to the first hydroconversion section A in the fluidized bed in the presence of hydrogen, which contains a three-phase reactor, and the hydroconversion catalyst "NiMo/alumina" has a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas.

The conditions used in hydroconversion section A are shown in Table 2.

Table 2 . Operating conditions in hydroconversion section A

Section A full P MPa 16 temperature °C 431 amount of hydrogen Nm ³ /m ³ 500

These operating conditions make it possible to obtain a liquid stream with a reduced content of carbon residue according to Conradson, metals and sulfur.

Separation section B

The liquid stream exiting section A is then sent to separation section B, consisting of a single gas-liquid separator operating at the pressure and temperature of the reactor of the first hydroconversion section A. As a result, a fraction called light and a fraction called heavy are separated. The so-called light fraction consists mainly of molecules with a boiling point below 350°C, while the heavy fraction consists mainly of hydrocarbon molecules boiling at a temperature of at least 350°C.

Hydroconversion Section C

The heavy fraction exiting the separation section B is sent, solely and completely, to the second hydroconversion section C in the presence of hydrogen. Said section contains a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas.

The conditions used in hydroconversion section C are shown in Table 4.

Table 4. Operating conditions in hydroconversion section C

Section C full P MPa 15.6 temperature °C 431 amount of hydrogen Nm ³ /m ³ 300

Fractionation section D

The stream exiting the hydroconversion section C is sent to a fractionation section D, consisting of distillation at atmospheric pressure and subsequent vacuum distillation, in which the unreacted heavy fraction is recovered: vacuum residue (RSV), boiling at a temperature of at least 540 ° C, the yield of which relative to fresh raw materials and properties are shown in Table 5 below.

Table 5 . Yield and Properties of RSV Produced in Fractionation Section D

Fraction Unreacted vacuum residue Yield relative to fresh raw materials (A) the weight.% 19.42 Content 540°C+ the weight.% 100 Density g/cm ³ 1.0157 Coke residue according to Conradson the weight.% 22.2 Nickel+vanadium h/m 91.4 Nitrogen h/m 8870 Sulfur the weight.% 1.028 Saturated compounds the weight.% 15.5 Aromatics the weight.% 36.2 resins the weight.% 38.9 Asphaltenes C ₇ the weight.% 9.4

Deasphalting section E

The vacuum residue exiting section D is sent to the deasphalting section E. The conditions applied in the deasphalting unit are described in Table 6.

Table 6 . Operating conditions of the E stage SDA plant

Raw material Vacuum residue from section D Solvent butane Extractor pressure MPa 3.0 T _cf in the extractor °C 95 Solvent/raw material ratio v/v eight

The E section produces a DAO cut that can be recycled in a conversion process (fixed bed hydrocracking, FCC) or recycled to a mild fluidized bed hydroconversion process), and a cut called asphalt, which is difficult to process. The yield and properties of these two products are shown in Table 7.

Table 7 . Yield and properties of products leaving the deasphalting section E

Fraction DAO Asphalt Yield relative to unreacted RSV (D) the weight.% 49.9 50.1 Yield relative to fresh raw materials (A) the weight.% 9.7 9.7 Density g/cm ³ 0.9474 1.0942 Coke residue according to Conradson the weight.% 7.42 36.9 Asphaltenes C ₇ the weight.% 0.09 18.7 Nickel+vanadium h/m < 2 181 Nitrogen h/m 4520 13210 Sulfur the weight.% 0.836 1.220

General characteristics

With this non-inventive scheme, at a VVH of 0.3 h ^-1 and elevated temperatures (431°C/431°C), the heavy cut conversion of 540°C+ is 75.1 wt% before the deasphalting step . In addition, unreacted RSV has significant levels of Conradson carbon residue and C ₇ asphaltenes (22.2 wt% and 9.4 wt%, respectively), resulting in only 49.9 wt% of unreacted RSV being recovered. in the form of a DAO. Thus, this classic scheme is accompanied by a significant formation of asphalt, at a level of 9.7 wt.% from the initial fresh feedstock. If the DAO cut is then fully reacted in the hydrocracking unit, the total conversion of the 540° C.+ heavy cut in the entire circuit will be 87.5 wt%.

Example 2 (according to the invention) : Scheme according to the invention with low space hourly velocity (total VVH=0.089 h ^-1 +411/411°C) and low temperature+SDA

In this example, the present invention is illustrated in a flow diagram with two fluidized bed reactors installed in series and operating at low space hourly velocity (VVH=0.089 h ^-1 ) and low temperature (411/411°C) with an intermediate separation section and a deasphalting process below according to the scheme, as described in connection with figure 1.

Hydroconversion section A

The fresh feed according to Table 1 is carried entirely into the first hydroconversion section A in the fluidized bed in the presence of hydrogen, which contains a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentage the proportions are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas.

The conditions used in hydroconversion section A are shown in Table 8.

Table 8. Operating conditions in hydroconversion section A

Section A full P MPa 16 temperature °C 411 amount of hydrogen Nm ³ /m ³ 600

Separation section B

The liquid stream exiting section A is then sent to separation section B, consisting of a single gas-liquid separator operating at the pressure and temperature of the reactors of the first hydroconversion section A. As a result, a fraction called light and a fraction called heavy are separated. The light fraction consists mainly of molecules with a boiling point below 350°C, and the heavy fraction consists mainly of hydrocarbon molecules boiling at a temperature greater than or equal to 350°C.

Hydroconversion Section C

The heavy fraction leaving the separation section B is sent one and all to the second hydroconversion section C in a fluidized bed in the presence of hydrogen. Said section contains a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas.

These operating conditions make it possible to obtain a liquid stream with a reduced content of carbon residue according to Conradson, metals and sulfur.

The conditions used in hydroconversion section C are shown in Table 9.

Table 9. Operating conditions in hydroconversion section C

Section C full P MPa 15.6 temperature °C 411 amount of hydrogen Nm ³ /m ³ 250

Fractionation section D

The stream exiting the hydroconversion section C is sent to a fractionation section D, consisting of distillation at atmospheric pressure and subsequent vacuum distillation, which recovers the unreacted heavy fraction: vacuum residue (RSV), boiling at a temperature of at least 540 ° C, the yield of which relative to fresh raw materials and properties are shown in table 10 below.

Table 10 . Yield and Properties of RSV Produced in Fractionation Section D

Fraction unreacted vacuum residue Yield relative to fresh raw materials (A) the weight.% 19.33 Content 540°C+ the weight.% 100 Density g/cm ³ 0.9924 Coke residue according to Conradson the weight.% 16.4 Nickel+vanadium h/m 21.7 Nitrogen h/m 7120 Sulfur the weight.% 0.687 Saturated compounds the weight.% 19.0 Aromatics the weight.% 41.6 resins the weight.% 34.9 Asphaltenes C ₇ the weight.% 4.6

Deasphalting section E

The vacuum residue leaving section D is sent to the deasphalting section E. The conditions used in the deasphalting unit are described in Table 11.

Table 11 . Operating conditions in the E SDA plant

Raw material Vacuum residue from section D Solvent butane Extractor pressure MPa 3.0 T _cf in the extractor °C 95 Solvent/raw material ratio v/v eight

The E section produces a DAO cut that can be recycled in a conversion process (fixed bed hydrocracking, FCC) or recycled to a mild fluidized bed hydroconversion process), and a cut called asphalt, which is difficult to process.

The yield and properties of these two products are shown in Table 12.

Table 12 . Yield and properties of products leaving the deasphalting section E

Fraction DAO Asphalt Yield relative to unreacted RSV (D) the weight.% 68.2 31.8 Yield relative to fresh raw materials (A) the weight.% 13.2 6.1 Density g/cm ³ 0.9495 1.0988 Coke residue according to Conradson the weight.% 8.1 34.1 Asphaltenes C ₇ the weight.% 0.07 14.2 Nickel+vanadium h/m < 2 67.4 Nitrogen h/m 4590 12530 Sulfur the weight.% 0.610 0.849

General characteristics

With this scheme according to the invention, with a total VVH=0.089 h ^-1 , the conversion of the heavy fraction 540°C+ is 75.2 wt.% before the deasphalting stage, i.e. comparable to example 1. However, unreacted RSV has lower levels of Conradson carbon residue and asphaltenes C ₇ compared to example 1, which allows you to recover more DAO from unreacted RSV (in this example, you can recover 68.2 wt.% against 49.9 wt.% in example 1). Thus, this scheme according to the invention is accompanied by a lower formation of asphalt, corresponding to 6.1 wt.% from the initial fresh raw materials. If the DAO cut is then completely reacted in the hydrocracking unit, in this example according to the invention, a complete conversion of the original heavy cut 540°C + 92.1 wt.% can be obtained, i.e. 4.6 conversion points higher than in example 1. Thus, the scheme according to the invention allows to achieve a conversion of more than 90 wt.% from fresh feed.

Example 3 (not according to the invention): Scheme with high space hourly velocity and moderate temperature (total VVH=0.3 h ^-1 +420/420°C) + SDA deasphalting stage

This example operates with two fluidized bed reactors in series (first and second deep hydroconversion), operating at high space hourly velocity (VVH) and moderate temperature (420°C), with an intermediate separation section and a deasphalting process downstream.

Hydroconversion section A

Fresh feed according to table 1 is carried out completely in the hydroconversion section A in a fluidized bed, in the presence of hydrogen. The three-phase reactor contains a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas. The conditions used in hydroconversion section C are shown in Table 13.

Table 13. Operating conditions in hydroconversion section A

Section A full P MPa 16 temperature °C 420 amount of hydrogen Nm ³ /m ³ 350

These operating conditions make it possible to obtain a liquid stream with a reduced content of carbon residue according to Conradson, metals and sulfur.

Separation section B

The liquid stream exiting section A is then sent to separation section B, consisting of a single gas-liquid separator operating at the pressure and temperature of the reactors of the first hydroconversion section A. As a result, a fraction called light and a fraction called heavy are separated. The light fraction consists mainly of molecules with a boiling point below 350°C, and the heavy fraction consists mainly of hydrocarbon molecules boiling at a temperature greater than or equal to 350°C.

Hydroconversion Section C

The heavy fraction leaving the separation section B is sent one and all to the second hydroconversion section C in a fluidized bed in the presence of hydrogen. Said section contains a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas.

The conditions used in hydroconversion section C are shown in Table 14.

Table 14. Operating conditions in hydroconversion section C

Section C full P MPa 15.6 temperature °C 420 amount of hydrogen Nm ³ /m ³ 200

Fractionation section D

The stream exiting the hydroconversion section C is sent to a fractionation section D, consisting of distillation at atmospheric pressure and subsequent vacuum distillation, which recovers the unreacted heavy fraction: vacuum residue (RSV), boiling at a temperature of at least 540 ° C, the yield of which relative to fresh raw materials and properties are shown in table 15 below.

Table 15 . Yield and Properties of RSV Produced in Fractionation Section D

Fraction unreacted vacuum residue Yield relative to fresh raw materials (A) the weight.% 31.75 Content 540°C+ the weight.% 100 Density g/cm ³ 1.0098 Coke residue according to Conradson the weight.% 20.7 Nickel+vanadium h/m 98.0 Nitrogen h/m 8230 Sulfur the weight.% 1.246 Saturated compounds the weight.% 16.4 Aromatics the weight.% 37.5 resins the weight.% 37.9 Asphaltenes C ₇ the weight.% 8.2

Deasphalting section E

The vacuum residue leaving section D is sent to the deasphalting section E. The conditions applied in the deasphalting unit are described in Table 16.

Table 16 . Operating conditions in the E SDA plant

Raw material vacuum residue from section D Solvent butane Extractor pressure MPa 3.0 T _cf in the extractor °C 95 Solvent/raw material ratio v/v eight

The output of section E is a DAO fraction, which can be processed in the conversion process (hydrocracking, FCC) or returned to the hydroconversion process), and a fraction called asphalt, which is difficult to process. The yield and properties of these two products are shown in Table 17.

Table 17 . Yield and properties of products leaving the deasphalting section E

Fraction DAO Asphalt Yield relative to unreacted RSV the weight.% 54.1 45.9 Yield relative to fresh raw materials (A) the weight.% 17.2 14.6 Density g/cm ³ 0.9478 1.0943 Coke residue according to Conradson the weight.% 7.53 36.3 Asphaltenes C ₇ the weight.% 0.08 17.8 Nickel+vanadium h/m < 2 212.4 Nitrogen h/m 4420 12730 Sulfur the weight.% 1.036 1.493

General characteristics

With this scheme, at a gross space hourly velocity (VVH) of 0.3 h ^-1 and moderate temperatures (420/420°C), the conversion of the heavy fraction of 540°C+ before the deasphalting step is 59.2 wt.%. In addition, the unreacted RSV has significant levels of Conradson carbon residue and C ₇ asphaltenes (20.7 wt% and 8.2 wt%, respectively), resulting in a total of 54.1 wt% of the unreacted RSV being collected. in the form of a DAO. Thus, this classical scheme is accompanied by a significant formation of asphalt, 14.6 wt.% from the initial fresh feedstock. Even if all of the DAO fraction is reacted in the hydrocracker, this state of the art scheme will result in a complete conversion of only 81.3 wt% of the original 540° C.+ heavy fraction. Therefore, it does not allow conversion levels of the 540° C.+ heavy fraction above 90% by weight to be achieved.

Example 4 (according to the invention) : Scheme according to the invention with low space hourly velocity (total VVH=0.089 h ^-1 +420/420°C) and low temperature + SDA deasphalting stage

In this example, the present invention is illustrated in a process flow diagram with two fluidized bed reactors installed in series and operating at low space hourly velocity (VVH=0.089 h ^-1 ) and moderate temperature (420/420°C), with an intermediate separation section and a process deasphalting below according to the scheme, in accordance with the scheme shown in figure 1.

Hydroconversion section A

Fresh feed according to table 1 is carried out completely in the hydroconversion section A in a fluidized bed, in the presence of hydrogen. Said section includes a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas. The conditions used in hydroconversion section A are shown in Table 18.

Table 18. Operating conditions in hydroconversion section A

Section A full P MPa 16 temperature °C 420 amount of hydrogen Nm ³ /m ³ 700

These operating conditions make it possible to obtain a liquid stream with a reduced content of carbon residue according to Conradson, metals and sulfur.

Separation section B

The liquid stream exiting section A is then sent to separation section B, consisting of a single gas-liquid separator operating at the pressure and temperature of the reactors of the first hydroconversion section A. As a result, a fraction called light and a fraction called heavy are separated. The light fraction consists mainly of molecules with a boiling point below 350°C, and the heavy fraction consists mainly of hydrocarbon molecules boiling at a temperature greater than or equal to 350°C.

Hydroconversion Section C

In this comparative scheme, the heavy fraction leaving the separation section B is sent alone and completely to the second hydroconversion section C in a fluidized bed in the presence of hydrogen. Said section contains a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas. The conditions used in hydroconversion section C are shown in Table 19.

Table 19. Operating conditions in hydroconversion section C

Section C full P MPa 15.6 temperature °C 420 amount of hydrogen Nm ³ /m ³ 350

Fractionation section D

The stream exiting the hydroconversion section C is sent to a fractionation section D, consisting of distillation at atmospheric pressure and subsequent vacuum distillation, which recovers the unreacted heavy fraction: vacuum residue (RSV), boiling at a temperature of at least 540 ° C, the yield of which relative to fresh raw materials and properties are shown in table 20 below.

Table 20 . Yield and Properties of RSV Produced in Fractionation Section D

Fraction unreacted vacuum residue Yield relative to fresh raw materials (A) the weight.% 10.8 Content 540°C+ the weight.% 100 Density g/cm ³ 0.9952 Coke residue according to Conradson the weight.% 17.05 Nickel+vanadium h/m 19.4 Nitrogen h/m 7350 Sulfur the weight.% 0.582 Saturated compounds the weight.% 18.5 Aromatics the weight.% 41.4 resins the weight.% 35.4 Asphaltenes C ₇ the weight.% 4.8

Deasphalting section (E)

The vacuum residue leaving section D is sent to the deasphalting section E. The conditions used in the deasphalting unit are described in Table 21.

Table 21 . Operating conditions in the E SDA plant

Raw material Vacuum residue from section D Solvent butane Extractor pressure MPa 3.0 T _cf in the extractor °C 95 Solvent/raw material ratio v/v eight

At the outlet of section E, a DAO fraction is obtained, which can be processed in the conversion process (hydrocracking, FCC) or returned to the hydroconversion process, and a fraction called asphalt, which is difficult to process. The yield and properties of these two products are shown in Table 22.

Table 22 . Yield and properties of products leaving the deasphalting section E

Fraction DAO Asphalt Yield relative to unreacted RSV the weight.% 66.8 33.2 Yield relative to fresh raw materials (A) the weight.% 7.2 3.6 Density g/cm ³ 0.9505 1.0995 Coke residue according to Conradson the weight.% 8.3 34.6 Asphaltenes C ₇ the weight.% 0.07 14.2 Nickel+vanadium h/m < 2 57.9 Nitrogen h/m 4670 12750 Sulfur the weight.% 0.515 0.716

General characteristics

With this scheme according to the invention, with a total VVH=0.089 h ^-1 and a moderate temperature (420/420°C), the conversion of the heavy fraction of 540°C+ is 86.1 wt.% before the stage of deasphalting, that is, it is 26.9 wt.% higher compared to example 3 at the same temperature level. Thus, the amount of unreacted RSV recovered in Example 4 is about 3 times less. In addition, unreacted RSV from Example 4 has lower levels of Conradson carbon residue and C7 asphaltenes compared to Example ₃ , allowing more DAO to be recovered from unreacted RSV (in this example, 66.8 wt% can be recovered vs. 1 wt.% in example 3). Thus, this scheme according to the invention is accompanied by a lower formation of asphalt, corresponding to 3.6 wt.% original fresh raw materials. If the DAO cut is then completely reacted in the hydrocracking unit, the circuit according to the invention achieves a very high conversion of the original heavy cut 540°C+ of 96.4 wt.%.

Example 5 (not according to the invention) : High space hourly velocity and high temperature scheme (total VVH=0.3 h ^-1 +431/431°C) + deasphalting stage (SDA) + DAO conversion stage in an FCC unit

In this example, two fluidized bed reactors (first and second deep hydroconversion sections) installed in series operate at high space hourly velocity (VVH) and high temperature, with an intermediate separation section and a deasphalting process downstream. The DAO fraction is then converted in an FCC unit.

Hydroconversion section (A)

The fresh feed according to Table 1 is carried entirely into the fluidized bed hydroconversion section A in the presence of hydrogen, comprising a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages the proportions are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas. The conditions used in hydroconversion section A are shown in Table 2. These operating conditions produce a liquid stream with a reduced Conradson, metal and sulfur content.

Separation section (B)

The liquid stream exiting section A is then sent to separation section B, consisting of a single gas-liquid separator operating at the pressure and temperature of the reactors of the first hydroconversion section A. As a result, a fraction called light and a fraction called heavy are separated. The light fraction consists mainly of molecules with a boiling point below 350°C, and the heavy fraction consists mainly of hydrocarbon molecules boiling at a temperature greater than or equal to 350°C.

Hydroconversion section (C)

The heavy fraction leaving the separation section B is sent one and all to the second hydroconversion section C in a fluidized bed in the presence of hydrogen. Said section contains a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas. The conditions used in hydroconversion section C are shown in Table 4.

Fractionation section (D)

The stream exiting the hydroconversion section C is sent to a fractionation section D, consisting of distillation at atmospheric pressure and subsequent vacuum distillation, which recovers the unreacted heavy fraction: vacuum residue (RSV), boiling at a temperature of at least 540 ° C, the yield of which relative to fresh raw materials and properties are shown in table 5.

Deasphalting section (E)

The vacuum residue leaving section D is sent to the deasphalting section E. The conditions applied in the deasphalting unit are described in Table 6. At the outlet of section E, a DAO fraction and a fraction called asphalt, which is difficult to process, are obtained. The yield and properties of these two products are shown in Table 7.

DAO conversion section (F)

The DAO fraction leaving the deasphalting section E is then sent to a catalytic fluidized bed cracker, also called FCC. This conversion unit allows the DAO cut, which is the 540°C+ cut, to be converted into lighter cuts. Thus, it allows to increase the overall conversion of the feedstock (vacuum residue, RSV, originating from Urals oil, the characteristics of which are presented in table 1). On the other hand, the liquid fraction from the FCC unit still contains a small unreacted fraction of 540°C+, the yield of which is 1.1 wt.% relative to the FCC feed, as indicated in table 23. Compared to example 1, where the entire DAO fraction was reacted in the unit hydrocracking, in this example the DAO conversion is not complete.

Table 23 . Yield and properties of streams obtained at the FCC F facility

Installation FCC Gasoline outlet (C5-220°C) the weight.% 40.9 Gas oil output (220-360°C) the weight.% 14.2 Vacuum distillate output (360-540°C) the weight.% 14.2 Vacuum residue output (540°C+) the weight.% 1.1

General characteristics

With this scheme according to the invention with a total VVH=0.3 h ^-1 and elevated temperatures (431/431°C) conversion of the heavy fraction 540°C+ before the stage of deasphalting is 75.1 wt.%. The unreacted RSV has significant levels of Conradson carbon residue and C ₇ asphaltenes (22.2 wt% and 9.4 wt%, respectively), resulting in only 49.9 wt% of the unreacted RSV being collected as DAO . Thus, this classic scheme is accompanied by a significant formation of asphalt: 9.7 wt.% from the initial fresh raw materials. In this example, the DAO fraction is converted in the FCC setup. With this non-inventive circuit, for cumulative hourly space velocity VVH=0.30 h ^-1 and elevated temperatures (431/431° C.), the total conversion of the 540° C.+ heavy fraction in the entire circuit is 86.8 wt%.

Example 6 (according to the invention) : Scheme according to the invention with low space hourly velocity (total VVH=0.089 h ^-1 +411/411°C) and low temperature + deasphalting stage (SDA) + DAO conversion stage in an FCC unit

In this example, the present invention is illustrated in a flow diagram with two fluidized bed reactors installed in series and operating at low space hourly velocity (VVH=0.089 h ^-1 ) and low temperature (411/411°C), with an intermediate separation section and a process deasphalting below according to the scheme, as described in connection with figure 1. Then the DAO fraction is converted in the FCC unit.

Hydroconversion section (A)

The fresh feed according to Table 1 is carried entirely into the fluidized bed hydroconversion section A in the presence of hydrogen, comprising a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages the proportions are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas. The conditions used in hydroconversion section A are shown in Table 8.

Separation section (B)

The liquid stream exiting section A is then sent to separation section B, consisting of a single gas-liquid separator operating at the pressure and temperature of the reactors of the first hydroconversion section A. As a result, a fraction called light and a fraction called heavy are separated. The light fraction consists mainly of molecules with a boiling point below 350°C, and the heavy fraction consists mainly of hydrocarbon molecules boiling at a temperature greater than or equal to 350°C.

Hydroconversion section (C)

The heavy fraction leaving the separation section B is sent one and all to the second hydroconversion section C in a fluidized bed in the presence of hydrogen. Said section contains a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas. These operating conditions make it possible to obtain a liquid stream with a reduced content of carbon residue according to Conradson, metals and sulfur. The conditions used in hydroconversion section C are shown in Table 9.

Fractionation section (D)

The effluent from the hydroconversion section C is sent to a fractionation section D, consisting of distillation at atmospheric pressure and subsequent vacuum distillation, which recovers a heavy fraction of unreacted vacuum residue (RSV), boiling at a temperature of at least 540 ° C, the yield of which is relatively fresh raw materials and properties are shown in table 10.

Deasphalting section (E)

The vacuum residue leaving section D is sent to the deasphalting section E. The conditions applied in the deasphalting unit are described in Table 11. At the outlet of section E, a DAO fraction and a fraction called asphalt, which is difficult to process, are obtained. The yield and properties of these two products are shown in Table 12.

DAO conversion section (F)

The DAO fraction leaving the deasphalting section E is then sent to a catalytic fluidized bed cracker, also called FCC. This conversion unit allows the DAO cut, which is the 540°C+ cut, to be converted into lighter cuts. Thus, it allows to increase the overall conversion of the feedstock (vacuum residue, RSV, originating from Urals oil, the characteristics of which are presented in table 1). On the other hand, the liquid fraction from the FCC unit still contains a small unreacted fraction of 540°C+, the yield of which is 1.2 wt.% relative to the FCC feed, as indicated in table 24. Compared to example 2, where the entire DAO fraction was reacted in the unit hydrocracking, in this example the DAO conversion is not complete.

Table 24 . Yield and properties of streams obtained at the FCC F facility

Installation FCC Gasoline outlet (C5-220°C) the weight.% 41.6 Gas oil output(220-360°C) the weight.% 14.3 Vacuum distillate output (360-540°C) the weight.% 15.2 Vacuum residue output(540°C+) the weight.% 1.2

General characteristics

With this scheme according to the invention, with a total VVH=0.089 h ^-1 , the conversion of the heavy fraction 540°C+ before the deasphalting step is 75.2 wt.%, i.e. comparable to example 5. However, unreacted RSV has a lower Conradson carbon content and C ₇ asphaltenes compared to Example 5, allowing more DAO to be recovered from unreacted RSV (68.2 wt% can be recovered in this example versus 49.9 wt% in Example 5). Thus, this scheme according to the invention is accompanied by a lower formation of asphalt, corresponding to 6.1 wt.% original fresh raw materials. In this example, the DAO fraction is converted in an FCC unit. With this scheme according to the invention, at a total space hourly velocity (VVH) of 0.089 h ^-1 and low temperatures (411/411°C), the total conversion of the 540°C+ heavy fraction in the entire scheme is 91.0 wt.% of the original heavy fraction 540 °C+, ie 4.2 points higher than the conversion in example 5. Thus, the scheme according to the invention allows to achieve a conversion of more than 90 wt.% relative to fresh feed.

Example 7 (not according to the invention): High space hourly velocity and moderate temperature scheme (total VVH=0.3 h ^-1 +420/420°C) + deasphalting stage (SDA) + DAO conversion stage in an FCC unit

This example operates with two fluidized bed reactors in series (first and second deep hydroconversion), operating at high space hourly velocity (VVH) and moderate temperature (420°C), with an intermediate separation section and a deasphalting process downstream. The DAO fraction is then converted in an FCC unit.

Hydroconversion section (A)

Fresh feed according to table 1 is carried out entirely in the hydroconversion section A in a fluidized bed in the presence of hydrogen. The three-phase reactor contains a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas.

The conditions used in hydroconversion section A are shown in Table 13. These operating conditions produce a liquid stream with reduced Conradson carbon residue, metals and sulfur.

Separation section (B)

The liquid stream exiting section A is then sent to separation section B, consisting of a single gas-liquid separator operating at the pressure and temperature of the reactors of the first hydroconversion section A. As a result, a fraction called light and a fraction called heavy are separated. The light fraction consists mainly of molecules with a boiling point below 350°C, and the heavy fraction consists mainly of hydrocarbon molecules boiling at a temperature greater than or equal to 350°C.

Hydroconversion section (C)

The heavy fraction leaving the separation section B is sent one and all to the second hydroconversion section C in a fluidized bed in the presence of hydrogen. Said section contains a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas. The conditions used in hydroconversion section C are shown in Table 14.

Fractionation section (D)

The stream exiting the hydroconversion section C is sent to a fractionation section D, consisting of distillation at atmospheric pressure and subsequent vacuum distillation, which recovers the unreacted heavy fraction: vacuum residue (RSV), boiling at a temperature of at least 540 ° C, the yield of which relative to fresh raw materials and properties are shown in table 15.

Deasphalting section (E)

The vacuum residue leaving section D is sent to the deasphalting section E. The conditions applied in the deasphalting unit are described in Table 16. At the outlet of section E, a DAO fraction and a fraction called asphalt, which is difficult to process, are obtained. The yield and properties of these two products are shown in Table 17.

DAO conversion section (F)

The DAO fraction leaving the deasphalting section E is then sent to a catalytic fluidized bed cracker, also called FCC. This conversion unit allows the DAO cut, which is the 540°C+ cut, to be converted into lighter cuts. Thus, it allows to increase the overall conversion of the feedstock (vacuum residue, RSV, originating from Urals oil, the characteristics of which are presented in table 1). On the other hand, the liquid fraction from the FCC unit still contains a small unreacted fraction of 540°C+, the yield of which is 1.9 wt.% relative to the FCC feed, as indicated in table 25. Compared to example 3, where the entire DAO fraction was reacted in the unit hydrocracking, in this example the DAO conversion is not complete.

Table 25 . Yield and properties of streams obtained at the FCC F facility

Installation FCC Gasoline outlet (C5-220°C) the weight.% 30.9 Gas oil output(220-360°C) the weight.% 16.7 Vacuum distillate output (360-540°C) the weight.% 22.5 Vacuum residue output(540°C+) the weight.% 1.9

General characteristics

With this scheme, at a gross space hourly velocity (VVH) of 0.3 h ^-1 and moderate temperatures (420/420°C), the conversion of the heavy fraction of 540°C+ before the deasphalting step is 59.2 wt.%. In addition, the unreacted RSV has significant levels of Conradson carbon residue and C ₇ asphaltenes (20.7 wt% and 8.2 wt%, respectively), resulting in a total of 54.1 wt% of the unreacted RSV being collected. in the form of a DAO. Thus, this classical scheme is accompanied by a significant formation of asphalt, 14.6 wt.% from the initial fresh feedstock. The DAO fraction is then converted in an FCC facility. With this non-inventive circuit, at a gross space hourly velocity (VVH) of 0.30 h ^-1 and moderate temperatures (420/420° C.), the total conversion of the 540° C.+ heavy fraction in the entire circuit is 80.0 wt%. Therefore, this scheme according to the prior art does not allow conversion levels of the heavy fraction 540°C+ above 90 wt.%.

Example 8 (according to the invention) : Scheme according to the invention with low space hourly velocity (total VVH=0.089 h ^-1 +420/420°C) and low temperature + deasphalting step (SDA) + DAO to FCC conversion step

In this example, the present invention is illustrated in a flow diagram with two fluidized bed reactors installed in series and operating at low space hourly velocity (VVH=0.089 h ^-1 ) and moderate temperature (420/420°C) with an intermediate separation section and a deasphalting process. below according to the scheme, according to the scheme from figure 1. Then the DAO fraction is converted in the FCC unit.

Hydroconversion section (A)

Fresh feed according to table 1 is carried out entirely in the hydroconversion section A in a fluidized bed in the presence of hydrogen. Said section includes a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas. The conditions used in hydroconversion section A are shown in Table 18. These operating conditions produce a liquid stream with reduced Conradson, metals and sulfur content.

Separation section (B)

The liquid stream exiting section A is then sent to separation section B, consisting of a single gas-liquid separator operating at the pressure and temperature of the reactors of the first hydroconversion section A. As a result, a fraction called light and a fraction called heavy are separated. The light fraction consists mainly of molecules with a boiling point below 350°C, and the heavy fraction consists mainly of hydrocarbon molecules boiling at a temperature greater than or equal to 350°C.

Hydroconversion section (C)

In this comparative scheme, the heavy fraction leaving the separation section B is sent alone and completely to the second hydroconversion section C in a fluidized bed in the presence of hydrogen. Said section contains a three-phase reactor containing a NiMo/alumina hydroconversion catalyst having a NiO content of 4 wt.% and a MoO ₃ content of 9 wt.%, where the percentages are expressed on the total weight of the catalyst. The section operates with a fluidized bed with an upward flow of liquid and gas. The conditions used in hydroconversion section C are shown in Table 19.

Fractionation section (D)

The stream exiting the hydroconversion section C is sent to a fractionation section D, consisting of distillation at atmospheric pressure and subsequent vacuum distillation, from which the unreacted heavy fraction: vacuum residue (RSV) is recovered, boiling at a temperature of at least 540 ° C, the yield of which is relative to fresh raw materials and properties are shown in table 20.

Deasphalting section (E)

The vacuum residue leaving section D is sent to the deasphalting section E. The conditions used in the deasphalting unit are described in Table 21. At the outlet of section E, a DAO fraction is obtained, which can be processed in the conversion process (hydrocracking, FCC) or returned to the hydroconversion process , and a fraction called asphalt, which is difficult to process. Yields and properties of these two products are shown in Table 22.

DAO conversion section (F)

The DAO fraction leaving the deasphalting section E is then sent to a fluid catalytic cracker, also called FCC. This conversion unit makes it possible to convert the DAO cut, which is the 540°C+ cut, into lighter cuts. Thus, it allows to increase the overall conversion of the feedstock (vacuum residue (RSV) originating from Urals oil, the characteristics of which are presented in table 1). In contrast, the liquid fraction leaving the FCC still contains a small fraction of the unreacted 540°C+ fraction, which yields 1.2 wt% of the FCC feed, as shown in Table 26. Compared to example 4, where the entire fraction of DAO was converted in a hydrocracking unit, here the DAO conversion is not complete.

Table 26 . Yield and properties of streams obtained at the FCC F facility

Installation FCC Gasoline outlet (C5-220°C) the weight.% 42.0 Gas oil output(220-360°C) the weight.% 14.2 Vacuum distillate output (360-540°C) the weight.% 13.8 Vacuum residue output(540°C+) the weight.% 1.2

Summary characteristics

With this scheme according to the invention at a total VVH=0.089 h ^-1 and a moderate temperature (420/420°C), the conversion of the heavy fraction of 540°C+ is 86.1 wt.% before the stage of deasphalting, that is, it is 26.9 wt. % lower than in example 7 for the same temperature level. Thus, the amount of unreacted RSV isolated in example 4 is about 3 times less. In addition, the unreacted RSV from Example 8 has lower Conradson carbon residue and C ₇ asphaltenes than Example 7, allowing a greater amount of DAO to be recovered from the unreacted RSV (in this example, 66.8 wt% can be recovered versus 54 .1 wt.% in example 7). Thus, the scheme according to the invention leads to less asphalts, corresponding to only 3.6 wt.% from the initial fresh raw materials. In this case, the DAO fraction is converted in the FCC installation. With this sequence of operations according to the invention, with a total space hourly velocity VVH=0.089 h ^-1 and moderate temperatures (420/420°C), the total degree of conversion of the heavy fraction 540°C+ in the entire scheme is 94.4 wt.% of the original heavy fraction 540°C+, ie a conversion of 14.4 points higher than in example 7. Thus, the scheme according to the invention allows you to achieve conversions above 90 wt.% from fresh feed.

In the deasphalting process, other solvents such as pentane (C5) can be used instead of the butane (C4) used in the 8 examples described herein. Deasphalting to C5 improves the yield of DAO and enhances the benefits of the invention.

Claims (17)

1. Method for the conversion of hydrocarbon feedstock, at least 50 wt.% of which, preferably at least 80 wt.% boils at a temperature of at least 300°C, comprising the following successive stages: - at stage a) the first deep hydroconversion of the specified hydrocarbon feedstock is carried out in the presence of hydrogen at an absolute pressure of 2 MPa to 35 MPa, a temperature of 300°C to 550°C, the amount of hydrogen per cubic meter of liquid feedstock from 50 Nm ³ /m ³ to 5000 Nm ³ /m ³ , with a catalyst containing at least one Group VIII metal selected from nickel and cobalt and at least one Group VIB metal selected from molybdenum and tungsten, optionally step b) separating the light fraction from part or all of the stream leaving said first hydroconversion to obtain at least one heavy fraction, at least 80% by weight of which has a boiling point of at least 250°C, - at stage c) a second deep hydroconversion of a part or all of the liquid stream leaving stage a) or the heavy fraction leaving stage b) is carried out in the presence of hydrogen at an absolute pressure of 2 MPa to 35 MPa, a temperature of 300°C to 550°C, the amount of hydrogen per cubic meter of liquid feed from 50 Nm ³ /m ³ to 5000 Nm ³ /m ³ , with a catalyst containing at least one Group VIII metal selected from nickel and cobalt, and at least one metal group VIB, selected from molybdenum and tungsten, moreover, the total space hourly velocity for stages a)-c) is below 0.1 h ^-1 , where the total rate means the consumption of liquid feedstock in stage a) of hydroconversion, reduced to standard conditions for temperature and pressure, related to the total volume of the reactors of stages a) and c) wherein the hydroconversion catalyst of step a) and the hydroconversion catalyst of step c) are used in the form of extrudates or pellets, - step d) separating part or all of the stream leaving said second hydroconversion into at least one light fraction and at least one heavy fraction, at least 80% by weight of which has a boiling point of at least 300°C, - stage e) deasphalting said heavy fraction obtained in stage d), at a temperature of from 60°C to 250°C with at least one hydrocarbon solvent containing 3-7 carbon atoms, and with a solvent/feedstock volume ratio of 4/ 1 to 9/1 to obtain a deasphalted DAO fraction and asphalt, step f) converting part or all of said deasphalted DAO fraction, optionally distilled, wherein part or all of the DAO fraction is sent, preferably directly, to a conversion step operating according to a process selected from the group consisting of fixed bed hydrocracking, catalytic cracking in fluidized bed hydroconversion, fluidized bed hydroconversion, which processes may include pre-treatment, the fluidized bed hydroconversion catalyst preferably being used in the form of extrudates or pellets. 2. Process according to claim 1, wherein the DAO is distilled prior to conversion step f) to separate a heavy fraction, at least 80% by weight of which has a boiling point of at least 375°C, or at least 400°C, or at least 450° C., or at least 500° C., and preferably at least 540°, and part or all of said heavy fraction is sent to stage f) conversion. 3. Process according to claim 1 or 2, wherein part or all of the deasphalted DAO fraction is hydrocracked in a fixed bed in the presence of hydrogen at an absolute pressure of 5 MPa to 35 MPa, a temperature preferably of 300°C to 500°C, space hourly velocity VVH from 0.1 h ^-1 to 5 h ^-1 , the amount of hydrogen per cubic meter of liquid feedstock from 100 Nm ³ /m ³ to 1000 Nm ³ /m ³ liquid feedstock and in the presence of a catalyst containing at least one non-noble element of group VIII and at least an element of group VIB and having a substrate containing at least one zeolite. 4. Process according to claim 1 or 2, wherein part or all of the deasphalted DAO fraction is subjected to FCC fluid catalytic cracking in the presence of a catalyst, preferably non-metal containing alumina, silica, aluminosilicate, and preferably containing at least one zeolite. 5. The method according to claim 1 or 2, moreover, part or all of the deasphalted DAO fraction is subjected to hydroconversion in a fluidized bed, carried out in the presence of hydrogen at an absolute pressure of 2 MPa to 35 MPa, a temperature of 300°C to 550°C, an amount of hydrogen per cubic meter of liquid feed from 50 Nm ³ /m ³ to 5000 Nm ³ /m ³ , space hourly velocity VVH from 0.1 h ^-1 to 10 h ^-1 and in the presence of a catalyst containing a support and at least one metal of group VIII , selected from nickel and cobalt, and at least one Group VIB metal selected from molybdenum and tungsten. 6. Process according to one of the preceding claims, wherein at least a portion of said deasphalted DAO fraction is returned to step a) and/or step c). 7. Process according to any one of the preceding claims, wherein in step d) separation, the effluent from said second hydroconversion is separated into at least one light fraction and at least one heavy fraction, at least 80% by weight of which has a boiling point at least 375°C, or at least 400°C, or at least 450°C, or at least 500°C, preferably at least 540°C. 8. The method according to any of the previous paragraphs, and - steps a) and c) are carried out at an absolute pressure of from 5 MPa to 25 MPa, preferably from 6 MPa to 20 MPa, at a temperature of from 350°C to 500°C, preferably from 370°C to 430°C and more preferably from 380°C to 430°C, hydrogen amount from 100 Nm ³ /m ³ to 2000 Nm ³ /m ³ , very preferably from 200 Nm ³ /m ³ to 1000 Nm ³ /m ³ , the space hourly velocity VVH being at least least 0.05 h ^-1 , preferably from 0.05 h ^-1 to 0.09 h ^-1 , - stage e) is carried out with a solvent selected from the group consisting of butane, pentane or hexane, as well as mixtures thereof.

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