Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G55/00—Treatment of hydrocarbon oils, in the absence of hydrogen, by at least one refining process and at least one cracking process
  • C10G55/02—Treatment of hydrocarbon oils, in the absence of hydrogen, by at least one refining process and at least one cracking process plural serial stages only
  • C10G55/06—Treatment of hydrocarbon oils, in the absence of hydrogen, by at least one refining process and at least one cracking process plural serial stages only including at least one catalytic cracking step
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G21/00—Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents
  • C10G21/003—Solvent de-asphalting
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G65/00—Treatment of hydrocarbon oils by two or more hydrotreatment processes only
  • C10G65/14—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural parallel stages only
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G65/00—Treatment of hydrocarbon oils by two or more hydrotreatment processes only
  • C10G65/14—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural parallel stages only
  • C10G65/16—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural parallel stages only including only refining steps
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G67/00—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only
  • C10G67/02—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only plural serial stages only
  • C10G67/04—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only plural serial stages only including solvent extraction as the refining step in the absence of hydrogen
  • C10G67/0454—Solvent desasphalting
  • C10G67/0463—The hydrotreatment being a hydrorefining
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G67/00—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only
  • C10G67/02—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only plural serial stages only
  • C10G67/04—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only plural serial stages only including solvent extraction as the refining step in the absence of hydrogen
  • C10G67/0454—Solvent desasphalting
  • C10G67/049—The hydrotreatment being a hydrocracking
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G69/00—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one other conversion process
  • C10G69/14—Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one other conversion process plural parallel stages only
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/20—Characteristics of the feedstock or the products
  • C10G2300/30—Physical properties of feedstocks or products
  • C10G2300/301—Boiling range

Definitions

• the present invention relates to a new method for converting a heavy charge of hydrocarbons, in particular resulting from the atmospheric distillation or the vacuum distillation of crude oil.
• a pretreatment step upstream of the hydroconversion unit is often required, thus making it possible to eliminate the most refractory structures, which are not only difficult, but also essentially precursors of sediments.
• These pretreatment steps may be, in a non-exhaustive manner, a visbreaking, hydrovisbreaking, coking process or a deasphalting unit (referred to in the remainder of the text as classic or conventional SDA).
• deasphalting is based on separation by precipitation of an oil residue into two phases: i) a phase called “deasphalted oil”, also called “oil matrix” or “oil phase” or DAO (De-Asphalted Oil according to the terminology Anglo-Saxon); and ii) a so-called “asphalt” or sometimes “pitch” phase (according to Anglo-Saxon terminology) containing, among other things, the refractory molecular structures.
• deasphalted oil also called “oil matrix” or “oil phase” or DAO (De-Asphalted Oil according to the terminology Anglo-Saxon)
• a so-called “asphalt” or sometimes “pitch” phase containing, among other things, the refractory molecular structures.
• This patent describes a conventional deasphalting which, by its principle, suffers from a limitation in the yield of DAO deasphalted oil which increases with the molecular weight of the solvent (up to the C6/C7 solvent), then reaches a ceiling at a threshold specific to each filler and each solvent.
• One of the objectives of the present invention is to best maximize the yield of deasphalted oil sent to the bubbling bed unit while placing itself at the operability limit of the bubbling bed unit, that is to say at the limit of the specifications in terms of the content of C7 asphaltenes present in the feed entering the bubbling bed unit.
• the present invention aims to increase the level of conversion of the recoverable load while minimizing the formation of sediments in the hydroconversion units, in order to limit frequent shutdowns and therefore their operability.
• the Applicant in its research has developed a new process for converting a heavy load of hydrocarbons making it possible to overcome the aforementioned drawbacks, by integrating at least one stage of selective deasphalting making it possible to separate at least one asphalt fraction , at least a fraction of deasphalted oil. It has been observed that the implementation of the method according to the invention makes it possible to improve the flexibility and the operability of the load conversion scheme according to the invention.
• the present invention relates to a process for converting a heavy charge of hydrocarbons having an initial boiling temperature of at least 300° C., a Conradson carbon content greater than 5% by weight, and a sulfur content greater than 0 5% by weight, comprising the following steps: a) at least one step for selective deasphalting of the heavy hydrocarbon charge by liquid/liquid extraction, making it possible to separate at least one asphalt fraction, at least one deasphalted oil fraction, at at least one of said deasphalting steps being carried out by means of a mixture of at least one polar solvent and of at least one apolar solvent, the proportion of said polar solvent in said mixture of polar solvent and of apolar solvent being adjusted according to the properties of the treated charge and depending on the asphalt yield and/or the quality of the deasphalted oil desired (e)(s), and between 0.1 and 99.9% volume/volume, said polar solvent being chosen from chosen from pure aromatic or naptheno-aromatic solvents, polar solvents comprising hetero-element
• the method according to the invention further comprises a step d) of separating the liquid fraction from step c) into a light liquid fraction boiling at a temperature below 360° C. and a heavy liquid fraction boiling at a temperature above 360°C.
• step b) of hydroconversion operates under an absolute pressure of between 2 and 35 MPa, at a temperature of between 300 and 550° C., at an hourly space velocity (VVH) of between 0.1 h -1 and 10 h -1 and under a quantity of hydrogen mixed with the charge of between 50 and 5000 normal cubic meters (Nm3) per cubic meter (m3) of liquid charge.
• VVH hourly space velocity
• the hydroconversion catalyst is a catalyst comprising an alumina support and at least one metal from group VIII chosen from nickel and cobalt, said element from group VIII being used in combination with at least one metal from group VIB selected from molybdenum and tungsten.
• the polar solvent used in step a) of deasphalting is chosen from pure aromatic or naptheno-aromatic solvents, polar solvents comprising hetero-elements, or their mixture or cuts rich in aromatics such as cuts from FCC (Fluid Catalytic Cracking), cuts derived from coal, biomass or biomass/coal mixture.
• FCC Fluid Catalytic Cracking
• the apolar solvent used in step a) of deasphalting comprises a solvent composed of saturated hydrocarbon comprising a number of carbon atoms greater than or equal to 2, preferably between 2 and 9.
• step a) is implemented with a volume ratio of the mixture of polar and apolar solvents to the mass of the charge of between 1/1 and 10/1 expressed in liters per kilogram.
• the feedstock is crude oil or a feedstock resulting from the atmospheric distillation or the vacuum distillation of crude oil, or a residual fraction resulting from the direct liquefaction of coal or even a vacuum distillate or also a residual fraction resulting from the direct liquefaction of the lignocellulosic biomass alone or in a mixture with coal and/or a residual petroleum fraction.
• the method according to the invention has the advantage of maximizing the yield of deasphalted oil sent to the hydroconversion unit by placing itself as close as possible to the limiting specifications of said unit, namely the asphaltene content.
• the process according to the invention also makes it possible to improve the flexibility of the process diagram by making it possible to process a wider panel of loads, and consequently its profitability.
• the heavy charge of hydrocarbons according to the process of the invention is advantageously a heavy charge resulting from the atmospheric distillation or the vacuum distillation of crude oil, having boiling points of at least 300° C., preferably above 450°C, and containing impurities, in particular sulphur, nitrogen and metals.
• the feed may be crude oil.
• the feedstock according to the process of the invention can be of petroleum origin of the atmospheric residue type or vacuum residue from so-called conventional crude (degree API >20°), heavy (degree API between 10 and 20°) or extra heavy (API degree ⁇ 10°).
• the load can come from different geographical and geochemical origins (type I, II, IIS or III), from different degrees of maturity and biodegradation.
• the charge can also be a residual fraction from the direct liquefaction of coal (atmospheric residue or vacuum residue from the H-Coal TM process, for example) or even an H-Coal TM vacuum distillate or even a residual fraction from direct liquefaction of ligno-cellulosic biomass alone or mixed with coal and/or a residual petroleum fraction.
• This type of filler is generally rich in impurities with metal levels above 20 ppm, preferably above 100 ppm.
• the sulfur content is greater than 0.5%, preferably greater than 1%, and preferably greater than at 2% by weight.
• the content of C7 asphaltenes is advantageously greater than 1%, preferably the content of C7 asphaltenes is between 1 and 40% and more preferably between 2 and 30% by weight.
• C7 asphaltenes are compounds known to inhibit the conversion of residual cuts, both by their ability to form heavy hydrocarbon residues, commonly called coke, and by their tendency to produce sediments which severely limit the operability of the units. hydrotreating and hydroconversion.
• the Conradson carbon content is greater than 5% or even 35% by weight.
• the Conradson carbon content is defined by standard ASTM D 482 and represents for those skilled in the art a well-known evaluation of the quantity of carbon residues produced after combustion under standard conditions of temperature and pressure.
• the charge undergoes at least one selective deasphalting step by liquid/liquid extraction making it possible to separate at least one asphalt fraction, at least one deasphalted oil fraction, at least one of said deasphalting steps being carried out by means of a mixture of at least one polar solvent and of at least one apolar solvent, the proportions of said polar solvent and of said apolar solvent of the mixture of solvent being adjusted according to the properties of the treated load and according to the asphalt yield and/or the quality of the deasphalted oil desired (e)(s), said deasphalting steps being carried out under the subcritical conditions of the mixture of solvents used
• the proportions of said polar solvent and of said apolar solvent of the solvent mixture are adjusted according to the properties of the filler treated and according to the asphalt yield and/or the quality of the DAO desired.
• mixture of solvents according to the invention is understood to mean a mixture of at least one polar solvent and of at least one apolar solvent according to the invention.
• the selective deasphalting implemented in step a) makes it possible to go further in maintaining the solubilization in the oil matrix of all or part of the polar structures of the heavy resins and asphaltenes which are the main constituents of the asphalt phase. in the case of conventional deasphalting.
• the invention thus makes it possible to choose which types of polar structures remain dissolved in the oil matrix. Consequently, the selective deasphalting implemented in the invention makes it possible to selectively extract from the charge only part of this asphalt, that is to say the most polar and most refractory structures in the conversion processes and of refining.
• the method according to the invention allows, by virtue of specific deasphalting conditions, greater flexibility in the treatment of feedstocks depending on their nature but also depending on the quality and/or the yield of deasphalted oil intended to be treated in the hydroconversion unit. Furthermore, the deasphalting conditions according to the invention make it possible to overcome the limitations of yield of DAO deasphalted oil imposed by the use of paraffinic solvents.
• the asphalt extracted during the deasphalting according to the invention corresponds to the ultimate asphalt composed essentially of polyaromatic and/or heteroatomic molecular structures refractory in refining. This results in an improved recoverable deasphalted oil yield.
• Stage a) of selective deasphalting can be carried out in an extraction column, or in a mixer-settler.
• the mixture of solvents according to the invention is introduced into an extraction column or a mixer-settler, at two different levels.
• the mixture of solvents according to the invention is introduced into an extraction column or a mixer-settler, at a single level of introduction. This step is carried out by liquid/liquid extraction in at least one deasphalting step, preferably in two successive deasphalting steps.
• the liquid/liquid extraction of the deasphalting step(s) is carried out under subcritical conditions for the mixture of solvents used, that is to say at a temperature below the critical temperature of the mixture of solvents.
• step deasphalting is carried out under subcritical conditions for said solvent, that is to say at a temperature below the critical temperature of said solvent.
• the extraction temperature is advantageously between 50 and 350° C., preferably between 90 and 320° C., more preferably between 100 and 310° C., even more preferably between 120 and 310° C., even more preferably more preferably between 150 and 310° C.
• the pressure is advantageously between 0.1 and 6 MPa, preferably between 2 and 6 MPa.
• volume ratio of the mixture of solvents according to the invention (volume of polar solvent + volume of apolar solvent) on the mass of filler is generally between 1/1 and 10/1, preferably between 2/1 to 8/1 expressed in liters per kilogram.
• the boiling point of the polar solvent of the mixture of solvents according to the invention is higher than the boiling point of the apolar solvent.
• the polar solvent used is chosen from pure aromatic or napthenoaromatic solvents, polar solvents comprising heteroelements, or a mixture thereof.
• the aromatic solvent is advantageously chosen from monoaromatic hydrocarbons, preferably benzene, toluene or xylenes alone or as a mixture; diaromatics or polyaromatics; naphtheno-aromatic hydrocarbons such as tetralin or indan; heteroatomic aromatic hydrocarbons (oxygenated, nitrogenous, sulphurous) or any other family of compounds having a more polar character than saturated hydrocarbons such as for example dimethyl sulphoxide (DMSO), dimethyl formamide (DMF), tetrahydrofuran (THF).
• DMSO dimethyl sulphoxide
• DMF dimethyl formamide
• THF tetrahydrofuran
• the polar solvent used in the process according to the invention can also be a cut rich in aromatics.
• the aromatic-rich cuts according to the invention can be, for example, cuts derived from FCC (Fluid Catalytic Cracking) such as heavy gasoline or LCO (LCO (light cycle oil). Let us also mention cuts derived from coal, biomass or biomass/coal mixture with optionally a residual petroleum charge after thermochemical conversion with or without hydrogen, with or without catalyst
• Light petroleum cuts can also be used naphtha type, preferably light petroleum cuts of straight-run naphtha type.
• the polar solvent used is a monoaromatic hydrocarbon, pure or mixed with another aromatic hydrocarbon.
• the apolar solvent used in the process according to the invention is a solvent composed of saturated hydrocarbon(s) comprising a carbon number greater than or equal to 2, preferably between 2 and 9. These solvents are used pure or as a mixture (for example: mixture of alkanes and/or cycloalkanes or else of light petroleum cuts of the naphtha type, preferably light petroleum cuts of the straight-run naphtha type).
• the optimization of these adjustment keys makes it possible to separate the charge into at least two fractions : a so-called ultimate asphalt fraction enriched in impurities and in compounds refractory to recovery, a deasphalted oil fraction enriched in resin structures and the least polar non-refractory asphaltenes.
• a so-called ultimate asphalt fraction enriched in impurities and in compounds refractory to recovery a deasphalted oil fraction enriched in resin structures and the least polar non-refractory asphaltenes.
• the proportion of polar solvent in the mixture of polar solvent and apolar solvent is between 0.1 and 99.9% volume/volume, preferably between 0.1 and 95%, preferably between 1 and 95%, of more preferably between 1 and 90%, even more preferably between 1 and 85%, and very preferably between 1 and 80%.
• the proportion of polar solvent in the mixture of polar and apolar solvent depends on the nature of the heavy hydrocarbon charge, the molecular structures making up said charge varying from one charge to another. Not all fillers have an identical refractory character. The rate of asphalt to be extracted is therefore not necessarily the same depending on the nature of the load.
• the nature of the charge also depends on its origin, which may be oil, coal or biomass.
• Stage a) of selective deasphalting has the advantage of allowing a considerable improvement in the total yield of deasphalted oil DAO over a whole range hitherto unexplored by conventional deasphalting.
• the total yield of deasphalted oil obtained from which is capped at 75% (extraction with normal heptane) selective deasphalting makes it possible to cover, by adjusting the proportion of polar solvent and non-polar solvent, combined with the extraction conditions, the range 75-99.9% deasphalted oil yield.
• the total yield of deasphalted oil from step a) is advantageously between 50 and 99.9%, preferably between 75 and 99.9%, more preferably between 80 and 99.9%.
• Another advantage according to the invention is to allow, thanks to the selective deasphalting according to step a), the reduction of the asphalt fraction, the yield of which can be much lower compared to an implementation by conventional deasphalting, for a load given.
• this yield is reduced to the range 0.1 to 30% depending on the apolar/polar solvent ratio. It is all the more reduced as the proportion of polar solvent in the mixture is high.
• the asphalt extraction range with a yield in the range 0.1-50%, particularly 0.1-30%, preferably 0.1-25%, more preferably 0.1 -15% is now covered. It depends on the selectivity desired for a given load as well as the nature of the load. This is a point of interest knowing that the recovery of asphalt (penalizing fraction) always constitutes a real limitation for schemes including this type of process.
• step a) can be carried out in two steps. Indeed, the nature of the solvent and / or the proportion and / or the intrinsic polarity of the polar solvent in the solvent mixture can be adjusted depending on whether it is desired to extract the asphalt during a first deasphalting step or during a second stage of deasphalting.
• step a) of the process according to the invention is implemented in a so-called configuration of decreasing polarity, that is to say that the polarity of the mixture of solvents used during the first step deasphalting is greater than that of the solvent or mixture of solvents used during the second deasphalting step.
• This configuration makes it possible to extract, during the first deasphalting step, a so-called ultimate asphalt phase fraction and a complete deasphalted oil fraction known as complete DAO; two fractions called heavy deasphalted oil and light deasphalted oil being extracted from the complete DAO during the second deasphalting step.
• step a) of the process according to the invention is implemented in a so-called configuration of increasing polarity, that is to say that the polarity of the solvent or mixture of solvents used during the first deasphalting step is lower than that of the mixture of solvents used during the second deasphalting step.
• a so-called light deasphalted oil fraction and an effluent comprising an oil phase and an asphalt phase are extracted; said effluent being subjected to a second deasphalting step to extract an asphalt phase fraction and a heavy deasphalted oil fraction called heavy DAO.
• the first deasphalting step thus makes it possible to selectively extract, in an optimal manner and adapted to each load, a fraction of the so-called ultimate asphalt phase, enriched in impurities and in compounds refractory to recovery, while leaving solubilized in the oil fraction.
• complete deasphalted solution called DAO complete deasphalted solution called DAO completes all or part of the polar structures of heavy resins and less polar asphaltenes, which are not refractory for the downstream conversion and refining stages.
• DAO complete deasphalted solution
• the yield of deasphalted oil DAO can be considerably improved and in fact the yield of asphalt considerably minimized. This is a point of interest knowing that the recovery of the asphalt (penalizing fraction) always constitutes a real limitation for the diagrams including this type of process.
• the complete DAO deasphalted oil resulting from step a1) with at least partly the mixture of solvents is preferably subjected to at least one separation stage in which the complete deasphalted oil called complete DAO is separated from at least one part of the mixture of solvents, or at least one separation stage in which the complete deasphalted oil called complete DAO is separated only from the apolar solvent or only from the polar solvent, before being sent to stage a2).
• the complete deasphalted oil called complete DAO resulting from stage a1) with at least in part the mixture of solvents according to the invention is subjected to at least two successive separation stages making it possible to individually separate the solvents in each step.
• the apolar solvent is separated from the mixture of complete deasphalted oil called complete DAO and polar solvent; and in a second separation step, the polar solvent is separated from the complete deasphalted oil called complete DAO.
• the separation steps are advantageously carried out under supercritical or subcritical conditions.
• the complete deasphalted oil called complete DAO separated from the solvents can be sent beforehand to at least one stripping column before being sent to the second stage (stage a2) of deasphalting.
• the mixture of polar and apolar solvents or the individually separated solvents are advantageously recycled in the process as a mixture or by means of two tanks individually containing the polar solvent and the apolar solvent.
• only the apolar solvent is recycled in its make-up tank.
• the recycled solvents are mixed, the apolar/polar proportion is checked online in the process and readjusted if necessary via the make-up tanks individually containing the polar solvent and the apolar solvent.
• said solvents are individually recycled to the respective make-up tanks.
• the asphalt phase separated from the first deasphalting stage is preferably in the liquid state and is generally diluted at least in part with a portion of the mixture of solvents according to the invention, the amount of which may be up to 200%, of preferably between 30 and 80% of the volume of asphalt withdrawn.
• the asphalt extracted with at least in part the mixture of polar and apolar solvents at the end of the extraction step can be mixed with at least one fluxing agent so as to be withdrawn easier.
• the fluxing agent used can be any solvent or mixture of solvents capable of dissolving or dispersing the asphalt.
• the flux can be a polar solvent chosen from monoaromatic hydrocarbons, preferably benzene, toluene or xylene; diaromatics or polyaromatics; naphtheno-aromatic hydrocarbons such as tetralin or indan; heteroatomic aromatic hydrocarbons; polar solvents with a molecular weight corresponding to boiling temperatures of between 200° C.
• LCO light cycle oil from FCC
• HCO Heavy cycle oil from FCC
• slurry from FCC HCGO (heavy coker gas oil)
• aromatic extract or an extra-aromatic cut extracted from an oil chain VGO cuts resulting from a conversion of residual fractions and/or coal and/or biomass.
• the volume ratio of flux to the mass of asphalt is determined so that the mixture can be easily drawn off.
• the second deasphalting step can be implemented on at least a part, preferably all of the complete deasphalted oil called complete DAO resulting from the first deasphalting step in the presence of a mixture of at least one polar solvent and at least one apolar solvent under the subcritical conditions for the mixture of solvents used.
• the second deasphalting step can also be implemented on at least part, preferably all of the complete deasphalted oil called complete DAO resulting from the first deasphalting step in the presence of an apolar solvent under subcritical conditions for the solvent used.
• the polarity of said solvent or mixture of solvents is preferably lower than that of the solvent mixture used in the first deasphalting step.
• This extraction is carried out so as to obtain a heavy deasphalted oil fraction called heavy DAO mainly comprising the family of less polar resins and asphaltenes, and a light deasphalted oil fraction called light DAO mainly comprising the family of saturated hydrocarbons and the family of aromatic hydrocarbons.
• heavy DAO heavy deasphalted oil fraction
• light DAO light deasphalted oil fraction
• At least a part, preferably all of said heavy deasphalted oil fraction called heavy DAO is sent to stage b) of hydroconversion.
• At least part of the light deasphalted oil fraction called light DAO alone or mixed with at least part of the said vacuum distillate fraction boiling at a temperature between 360 and 520° C. or even 540° C. resulting from the step of separation of the heavy liquid fraction from step d) is advantageously sent to post-treatment units such as a hydrotreating and/or hydrocracking, or catalytic cracking unit.
• the order of extraction of product categories is reversed: the polarity of the solvent or solvent mixture used in the first deasphalting step is lower than that of the solvent mixture used in the second deasphalting step. deasphalting.
• the first deasphalting step thus makes it possible to selectively extract from the heavy hydrocarbon feed a light deasphalted oil fraction called light DAO and an effluent comprising an oil phase and an asphalt phase.
• the first deasphalting step (step a′1) can be carried out both with an apolar solvent and with a mixture of solvents according to the invention.
• the nature, the proportion and/or the polarity of the polar solvent in the solvent mixture is adapted, under the subcritical conditions of the solvent or the mixture of solvents used, so as to extract a fraction of light deasphalted oil mainly comprising the family of saturated hydrocarbons and the family of aromatic hydrocarbons.
• At least part of the light deasphalted oil fraction called light DAO alone or mixed with at least part of the said vacuum distillate fraction boiling at a temperature between 360 and 520° C. or even 540° C. resulting from the step of Separation of the heavy liquid fraction from step d) is advantageously sent to post-treatment units such as a hydrotreating and/or hydrocracking unit, or catalytic cracking unit.
• the effluent comprising an oil phase and an asphalt phase, extracted from the first deasphalting stage can contain at least in part the apolar solvent or the mixture of solvents according to the invention.
• said effluent is subjected to at least one separation step in which it is separated from at least part of the apolar solvent or from at least part of the mixture of solvents, or at least one separation step wherein said effluent is separated only from the apolar solvent or only from the polar solvent contained in the mixture of solvents, before being sent to step a'2).
• said effluent can be subjected to at least two successive separation stages making it possible to individually separate the solvents in each separation stage, before being sent to stage a′2).
• the separation steps are advantageously carried out under supercritical or subcritical conditions.
• the effluent comprising the oil phase and the asphalt phase separated from the solvent or from the mixture of solvents according to the invention can be sent beforehand to at least one stripping column before being sent in the second stage of deasphalting.
• the mixture of polar and apolar solvents or the individually separated solvents are advantageously recycled in the process as a mixture or by means of two tanks individually containing the polar solvent and the apolar solvent.
• only the apolar solvent is recycled in its make-up tank.
• the recycled solvents are mixed, the apolar/polar proportion is checked online in the process and readjusted if necessary via the make-up tanks individually containing the polar solvent and the apolar solvent.
• said solvents are individually recycled to the respective make-up tanks.
• the second deasphalting step is implemented on the effluent comprising an oil phase and an asphalt phase resulting from the first deasphalting step a'1) in the presence of a mixture of at least one polar solvent and at least an apolar solvent under the subcritical conditions for the mixture of solvents used.
• the polarity of said solvent mixture is preferably greater than that of the solvent or solvent mixture used in the first deasphalting step.
• This extraction is carried out in such a way as to selectively extract from the effluent, a so-called ultimate asphalt fraction, enriched in impurities and refractory compounds for recovery, while leaving dissolved in a heavy deasphalted oil fraction called heavy DAO all or part of the polar structures of the less polar resins and asphaltenes generally remaining contained in the asphalt fraction in the case of conventional deasphalting.
• a heavy deasphalted oil fraction called heavy DAO all or part of the polar structures of the less polar resins and asphaltenes generally remaining contained in the asphalt fraction in the case of conventional deasphalting.
• At least a part, preferably all of said heavy deasphalted oil fraction called heavy DAO is sent to stage b) of hydroconversion.
• step b) of the process according to the invention the deasphalted oil fraction from step a) undergoes a step b) of hydroconversion in the presence of hydrogen in at least one three-phase reactor, said reactor containing at least one hydroconversion catalyst and operating in an ebullated bed, with an ascending flow of liquid and gas and comprising at least one means for withdrawing said catalyst from said reactor and at least one means for making up fresh catalyst in said reactor, in conditions making it possible to obtain an effluent comprising a gaseous fraction mainly containing the compounds H 2 and H 2 S, and a liquid fraction with a reduced content of Conradson carbon, metals, sulfur and nitrogen,
• Stage b) of hydroconversion of the feedstock according to the invention is generally carried out under standard conditions for hydroconversion in an ebullated bed of a liquid hydrocarbon fraction.
• the operation is usually carried out under an absolute pressure of between 2 and 35 MPa, preferably between 5 and 25 MPa and preferably between 6 and 20 MPa, at a temperature of between 300 and 550° C. and preferably of between 350 and 500 °C.
• the hourly space velocity (HSV) and the partial pressure of hydrogen are important factors which are chosen according to the characteristics of the product to be treated and the desired conversion.
• the VVH is between 0.1 h -1 and 10 h -1 and more preferably between 0.15 h -1 and 5 h -1 .
• the quantity of hydrogen mixed with the charge is preferably between 50 and 5000 normal cubic meters (Nm 3 ) per cubic meter (m 3 ) of liquid charge and preferably between 100 and 2000 Nm 3 /m 3 , and very preferably between 200 and 1000 Nm 3 /m 3 .
• Step b) is advantageously carried out in one or more three-phase hydroconversion reactors, preferably one or more three-phase hydroconversion reactors with intermediate settling drums.
• Each reactor advantageously comprises a recirculation pump allowing the maintenance of the catalyst in the bubbling bed by continuous recycling of at least part of a liquid fraction advantageously drawn off at the top of the reactor and reinjected at the bottom of the reactor.
• the hydroconversion catalyst used in step b) of the process according to the invention is advantageously a granular catalyst with a size of the order of 1 mm.
• the catalyst is most often in the form of extrudates or beads.
• the catalyst comprises a support, the porous distribution of which is adapted to the treatment of the filler, preferably amorphous and very preferably alumina, a silica-alumina support also being possible in certain cases and at least one metal of the group VIII chosen from nickel and cobalt and preferably nickel, said element from group VIII preferably being used in combination with at least one metal from group VIB chosen from molybdenum and tungsten and preferably the metal from group VIB is molybdenum.
• the hydroconversion catalyst comprises nickel as a group VIII element and molybdenum as a group VIB element.
• the nickel content is advantageously between 0.5 and 15% expressed by weight of nickel oxide (NiO) and preferably between 1 and 10% by weight and the molybdenum content is advantageously between 1 and 40% expressed by weight of molybdenum trioxide (Mo03), and preferably between 4 and 20% by weight.
• Said catalyst may also advantageously contain phosphorus, the phosphorus oxide content preferably being less than 20% by weight and preferably less than 10% by weight.
• a catalytic precursor (or catalytic additive) can be injected either with the charge from the hydroconversion unit operating in an ebullated bed, or at the interstage separator between two reactors, or at the inlet of one of the other reactors .
• catalytic precursor or catalytic additive refers here to a hydroconversion catalyst whose size and density properties are such that it is driven by the conversion charge in the hydroconversion reaction zones, as opposed to the catalyst described above non-circulating.
• the used hydroconversion catalyst can, in accordance with the process according to the invention, be partly replaced by fresh catalyst by drawing off, preferably at the bottom of the reactor and by introducing, either at the top or at the bottom of the reactor, fresh or regenerated or rejuvenated catalyst, preferably at regular time intervals and preferably in puffs or almost continuously.
• the rate of replacement of spent hydroconversion catalyst with fresh catalyst is advantageously between 0.01 kilogram and 10 kilograms per cubic meter of feedstock treated, and preferably between 0.3 kilograms and 3 kilograms per cubic meter of feedstock treated. This withdrawal and this replacement are carried out using devices that advantageously allow the continuous operation of this hydroconversion step.
• Step b) of the process according to the invention is advantageously implemented under the conditions of the H-Oil TM process as described for example in the patents US-A-4,521,295 Or US-A-4,495,060 Or US-A-4,457,831 Or US-A-4,354,852 or in the article Aiche, March 19-23, 1995, HOUSTON, Texas, paper number 46d , Second generation ebullated bed technology.
• the hydroconversion catalyst used in stage b) of hydroconversion advantageously makes it possible to ensure both the demetallization and the desulphurization, under conditions making it possible to obtain an effluent comprising a gaseous fraction mainly containing the compounds H 2 and H 2 S, and a liquid fraction reduced in Conradson carbon, metals, sulfur and nitrogen.
• stage b) of hydroconversion then undergoes, in accordance with stage c) of the process according to the invention, a separation to obtain a gaseous fraction containing mainly the compounds H 2 and H 2 S and a liquid fraction reduced in Conradson carbon, metals, sulfur and nitrogen.
• This separation includes any separation means known to those skilled in the art.
• this separation is carried out by one or more flash balloons in series, and preferably by a sequence of two successive flash balloons.
• Step d) optional separation of the liquid fraction from step c)
• the liquid fraction resulting from stage c) then undergoes, in accordance with stage d), a separation stage to obtain a light liquid fraction boiling at a temperature below 360° C., preferably below 375°C and a heavy liquid fraction boiling at a temperature above 360°C, preferably above 375°C.
• step d) of separation the conditions are chosen so that the cut point is 360° C., preferably 375° C., making it possible to obtain two liquid fractions, a so-called light liquid fraction, and a heavy liquid fraction.
• the light liquid fraction directly obtained at the outlet from step d) of separation alone or mixed with the gaseous fraction from step c) is then advantageously separated from the light gases (H 2 , H 2 S, NH 3 and C 1 -C 4 ) by any means of separation known to those skilled in the art such as for example by passage through a flash drum, so as to recover the gaseous hydrogen which is advantageously recycled after purification in step b) d hydro conversion.
• Said light liquid fraction advantageously separated from said light gases and boiling at a temperature below 360°C, preferably below 375°C mainly comprises a fraction boiling at a temperature below 180°C corresponding to the gasoline fraction, a gas oil fraction boiling at a temperature between 180 and 360°C or even between 180 and 375°C.
• Said light liquid fraction is then advantageously sent to a separation step, preferably to an atmospheric distillation column to separate said fractions therefrom.
• the heavy liquid fraction obtained at the outlet of step d) and boiling at a temperature above 360° C., preferably above 375° C. contains at least a part of the gas oil fraction boiling between 250 and 375° C., a fraction boiling between 360 and 520°C or even 540°C, preferably between 375 and 520°C or even 540°C, called vacuum distillate (or VGO according to the English terminology) and an unconverted fraction boiling at a higher temperature at 520°C or even 540°C, called vacuum residue.
• Said vacuum distillate fraction (or VGO according to the Anglo-Saxon terminology) comprises a so-called light vacuum distillate fraction (or light VGO) boiling between 360 and 400°C or even 420°C and a so-called heavy vacuum distillate fraction (or heavy VGO) boiling between 400 and 520°C or even 540°C and preferably between 420 and 520°C or even 540°C.
• Said heavy liquid fraction is advantageously sent to a separation step, preferably to a vacuum distillation column to separate said fractions therefrom.
• the light (or light VGO) and heavy (or heavy VGO) vacuum distillate fractions may or may not be individually separated during said separation step.
• step a) of deasphalting mixed with the charge At least part of the vacuum residue boiling at a temperature above 520° C. or even 540° C. is returned to step a) of deasphalting mixed with the charge.
• VGO vacuum distillate
• Another advantage of such recycling is to provide an additional lever making it possible to go further in the solubilization in the deasphalted oil fraction (DAO) of the polar structures of heavy resins and asphaltenes.
• DAO deasphalted oil fraction
• VGO vacuum distillate
• DAO deasphalted oil fraction
• VGO vacuum distillate due to its preponderant aromatic character makes it possible, during its recycling in the bubbling bed, to stabilize the treated medium by solubilizing and/or peptizing and/or dispersing the molecular structures favorable to the formation of sediments and thus improve the operability of the scheme.
• step b) of hydroconversion in a mixture with the deasphalted oil fraction from the step a is returned to step b) of hydroconversion in a mixture with the deasphalted oil fraction from the step a).
• Example 1 (comparative) : conventional SDA followed by a hydroconversion step
• Example 2 (according to the invention): selective SDA followed by a hydroconversion step
• Example 3 (according to the invention): selective SDA followed by a hydroconversion step with recycling of the VGO cut
• the C7/toluene ratio is reduced to further improve the yield of deasphalted oil (DAO3).
• the asphaltene content in the selective DAO3 exceeds the maximum specification of 0.1% by weight set at the inlet of the hydroconversion unit.
• Part of the vacuum distillate (VGO) resulting from the stage of separation of the heavy liquid fraction separated from stage d) of the process is sent mixed with the deasphalted oil (DAO3) into the bubbling bed.
• the VGO/DAO3 weight ratio is set at 20/80 to comply with the maximum specification of 0.1% weight of C7 asphaltenes (C7 Asph). The characteristics of the mixture are presented in Table 5.
• the overall conversion of the 540+ fraction of the input charge is 84%. Diesel and gasoline selectivity has been improved by 2.76 wt% and 0.80 wt% respectively.

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