CA2793655A1 - Method for the hydroconversion of petroleum feedstocks via a slurry technology enabling the recovery of metals from the catalyst and from the feedstock using a coking step - Google Patents

Abstract

A process for hydroconversion of heavy petroleum charges comprising a stage of hydroconversion of the charge in at least one reactor containing a slurry catalyst and allowing the recovery of the metals in the unconverted residual fraction, in particular those used as catalysts. The process comprises a hydroconversion stage, a gas / liquid separation stage, a coking stage, a combustion stage, a metal extraction stage and a stage of preparation of catalytic solutions which are recycled in stage d hydroconversion.

Description

PROCESS FOR HYDROCONVERSION OF PETROLEUM LOADS THROUGH TECHNOLOGY
SLURRY FOR RECOVERING METALS FROM CATALYST AND LOAD
IMPLEMENTING A COKEFACTION STEP

The invention relates to a process for hydroconversion of heavy loads in lighter products, recoverable as fuels and / or Contents first for petrochemicals. More particularly, the invention relates to a process of hydroconversion of heavy oil loads comprising a step hydroconversion of the charge in at least one reactor containing a catalyst in slurry and allowing the recovery of metals in the residual fraction no converted, especially those used as catalysts, in order to enhance their catalytic solutions and recycle them upstream of the conversion process into slurry. The method comprises a hydroconversion step, a step of separation gas / liquid, a coking step, a combustion step, a step of metal extraction and a step of preparing solution (s) catalytic (s) is / are recycled in the hydroconversion stage.

The conversion of heavy oil loads into liquid products can occur make by heat treatments or by hydrogenation treatments, also called hydroconversion. Current research is mainly focused on hydroconversion because heat treatments generally produce products of poor quality and a significant amount of coke.
The hydroconversion of heavy loads includes the conversion of the load in the presence of hydrogen and a catalyst. The commercialized processes use depending on the load, fixed bed technology, bed technology bubbling or slurry technology.
The hydroconversion of heavy loads in fixed bed or bubbling bed is made supported catalysts comprising one or more transition metals (Mo, W, Ni, Co, Ru) on supports of silica / alumina or equivalent type.
For the conversion of heavily loaded heavy loads into heteroatoms, metal and asphaltenes, the fixed bed technology is generally limited because contaminants cause rapid deactivation of catalyst thus requiring a frequency of renewal of the bed catalytic too high and therefore too expensive. In order to be able to handle such charges, bubbling bed processes have been developed. However, the level of conversion WO 2011/128518

2 PCT / FR2011 / 000160 bubbling bed technologies is usually limited to levels lower 80% because of the catalytic system used and the design of the unit.

Hydroconversion technologies running with slurry technology provide an attractive solution to the disadvantages encountered in the use of fixed bed or bubbling bed. Indeed, the slurry technology allows treat heavy loads heavily contaminated with metals, asphaltenes and heteroatoms, while having conversion rates generally above 85%.

Slurry residue hydroconversion technologies use a catalyst dispersed as very small particles, which are smaller in size at 1 mm and preferably a few tens of microns or less (usually 0.001 at 100 μm). Thanks to this small size of the catalysts, the reactions hydrogenation are facilitated by a uniform distribution throughout the reaction zone and the Coke formation is greatly reduced. Catalysts, or their precursors, are injected with the charge to be converted at the reactor inlet. Catalysts through the reactors with the loads and products in the process of conversion and then they are driven with the reaction products out of the reactors. Is the finds after separation into the heavy residual fraction, such as residue under unconverted vacuum. The catalysts used in slurry are generally of the sulfurized catalysts preferably containing at least one element selected from the group formed by Mo, Fe, Ni, W, Co, V and / or Ru. Generally, molybdenum and the tungsten show much more satisfactory performance than the nickel, the cobalt or ruthenium and even more than vanadium and iron (N. Panariti et al., Applied Catalysis A: General 204 (2000), 203-213).

Hydroconversion technologies for heavy slurry loads marketed are known. For example, the licensed EST technology ENI, the VRSH technology licensed by Chevron-Lummus-Global, the HDH and HDHPLUS technologies licensed by Intevep, SRC-Uniflex technology licensed by UOP, technology (HC) 3 licensed by Headwaters, etc ...
Although the small size of the slurry catalysts makes it possible to obtain of very high conversion, this size is problematic with regard to the separation and recovery of the catalyst (s) after the reaction WO 2011/128518

3 PCT / FR2011 / 000160 hydroconversion .. The catalysts are found after separation in the fraction heavy residual, such as unconverted vacuum residue. In certain processes, a part of the vacuum residue containing the non-converted and the catalysts, is recycled directly into the reactor hydroconversion for increase the conversion yield. However, these recycled catalysts have generally no activity or activity very small compared to that a fresh catalyst. In addition, the vacuum residue is traditionally used as combustible. for the production of heat, electricity and ashes. These ashes contain metals and are generally dumped. In that case, the metals are therefore not recovered.
In addition, deactivation of catalysts requires regular replacement creating a demand for fresh catalysts. Heavy loads treated contain a high concentration of metals, mainly vanadium and of nickel. These metals are largely removed from the charge by depositing sure the catalysts during the reaction. They are swept away by the particles of catalysts leaving the reactor. Similarly, the deactivation of the catalysts is accentuated by the formation of coke, especially from the strong concentration of asphaltenes contained in these charges.
The continuous renewal of the catalytic phase finely dispersed in the reaction zone allows the contact of dissolved hydrogen in the phase liquid to hydrogenate and hydrotreat the injected heavy load. To ensure a level of high conversion and maximum hydrotreatment of the feed, the amount of solution catalytic injection is quite important which represents costs operating relatively high industrial scale. Thus, the processes hydroconversion slurry are generally consumer of large amount of catalysts, especially in molybdenum which has the most active catalyst, but also the more expensive. The costs of fresh catalysts, separation of catalysts and recovery of metals have a major impact on the profitability of such processes. The Selective recovery of molybdenum-and its recycling as a catalyst are two indispensable elements for the industrial valorization of processes in slurry.
This recovery is also accompanied by those of other metals such as nickel (the one injected and the one recovered in the charge) and the vanadium recovered in the WO 2011/128518

4 PCT / FR2011 / 000160 the contents of which are comparable to those of molybdenum and which may be resold for metallurgical applications.
Apart from these economic aspects, the recovery of metals is essential also for environmental reasons. Indeed, the ashes from the combustion of the residual fraction have been classified in many countries as hazardous waste because the metals contained in the ashes waste collection pose a hazard to the water table.
There is therefore a real need for recovery and recycling of metals from catalysts and heavy load of slurry hydroconversion process.

Prior art Metal recovery processes of slurry processes are known in the state of the art.

Thus, patent application US2008 / 0156700 describes a separation process of catalysts in the form of ultrafine particles resulting from a process of hydroconversion to slurry comprising a precipitation step or flocculation of a heavy fraction including metal parts by solvents of type heptane, a step of separation of the heavy fraction of the light fraction by centrifugation and a coking step between 350 and 550 C under atmosphere inert to obtain coke containing the catalyst. This coke can be subject to step of extracting metals.

US 6153555 discloses a metal recovery process, molybdenum, catalysts used in processes hydroconversion of heavy loads. This method comprises a step of coking between 300 and 1000 C, at atmospheric pressure and under atmosphere inert. The coked product is then divided and subjected to one or two stages of combustion under air at temperatures between 800 and 1900 C in order to sublimate the molybdenum which is then condensed by cooling on the ashes.
Molybdenum is subsequently recovered by an extraction step using a mixture of ammonia and (NH4) 2CO3.

WO 2011/128518

5 PCT / FR2011 / 000160 US Pat. No. 6,511,937 describes a slurry hydroconversion process for heavy charges comprising, after the hydroconversion reaction, a step of separation in a high pressure separator, low temperature allowing separate a very light fraction, a deasphalting step of the whole fraction residual using paraffinic C3 to C5 solvents at room temperature, a coking step (427-649 C, without air) and / or a combustion step in below 649 C to produce ash containing the catalyst. This catalyst can be subsequently subjected to metal extraction steps and recycled in the process.

Object of the invention The specificity of slurry processes being to have a catalyst finely dispersed and unsupported on a mineral phase makes the recovery of metals much more complex than those of the supported catalysts of refining used traditionally. The challenge for the industrial development of processes of hydroconversion by slurry technology is the need to recover and to recycle the metals from the catalysts.
The present invention aims at improving hydroconversion processes of heavy loads by known slurry technology by allowing the valorization a unconverted residual fraction from conversion to slurry, fraction strongly concentrated in metals and heteroelements and ultimately including recovery said metals in the said unconverted fraction and the production of precursors to recycle them upstream of the conversion process to. fashion slurry.
The method comprises a hydroconversion step, a separation step gas / liquid, a coking step, a combustion step, a step of metal extraction and a step of preparing solution (s) catalytic (s) is / are recycled in the hydroconversion stage.
The research work carried out by the applicant on hydroconversion heavy loads led him to discover that, surprisingly, this process including a separation to maximize the light fraction from the hydroconversion reactor and minimize the residual fraction, coupled with a coking step, then a moderate combustion step avoiding the sublimation WO 2011/128518

6 PCT / FR2011 / 000160 metals, made it possible to prepare the extraction of the metals contained in ash in such a way that very good metal recovery rates recyclable in the process are possible. Indeed, the critical stages of this recovery are firstly the concentration of the metals on the matrix carbonaceous (via coking) then the formation of a mineral phase (via combustion moderate) containing the metallic elements from the catalyst (Mo and Ni) But also the charge (Ni, V and Fe) devoid of carbon.
An advantage of the process according to the invention is the recovery of a fraction unconverted residual strongly concentrated in metals and hetero elements allowing the recovery of said metals and the production of precursors catalytic systems to recycle them upstream of the conversion process into slurry.
Another interest is the optimization of the conversion of hydroconversion by a gas / liquid separation after hydroconversion operating under conditions close to those of the reactor and allowing effective separation in one single stage of a light fraction including future fuel bases (the gas, naphtha, light diesel or heavy diesel) of the residual fraction no converted containing solids such as metals. The performance of the fraction is thus maximized at the same time as the residual fraction converted is minimized thereby facilitating by its reduced amount the concentration of metals over there after. The maintenance of the operating conditions during the separation allows also the economic integration of a further hydrotreatment treatment and or hydrocracking of the light fraction without the need for compressors additional.
Another interest is the coking of the unconverted fraction and containing the metals for effective metal concentration.
Another advantage of the process is the combustion at moderate temperature to separate the organic phase from the inorganic phase containing the metals in order to facilitate the subsequent extraction of metals from the inorganic while avoiding spraying and / or sublimation (and therefore loss) of metals during combustion.

WO 2011/128518

7 PCT / FR2011 / 000160 Another advantage of the method is that this method does not require a step of deasphalting and the disadvantages associated with (solvent handling, often toxic; need for solvent recycling after extraction ...).

detailed description The invention relates to a process for hydroconversion of heavy loads oil slurry for the recovery and recycling of metals in the unconverted residual fraction, especially those used as catalysts.
More particularly, the invention relates to a hydroconversion process of heavy petroleum fillers containing metals comprising:
a) a step of hydroconversion of the feedstock in at least one reactor containing a slurry catalyst containing at least one metal, and possibly a solid additive, b) a step of separation of the hydroconversion effluent without decompression into a so-called light fraction containing the compounds boiling at at plus 500 C and in a residual fraction, b ') optionally a fractionation step comprising a vacuum separation of said residual fraction as obtained in step b), and it is obtained a vacuum residue concentrated in metals, . c) a coking step of said residual fraction as obtained at step b) and / or said vacuum residue as obtained in step b ') allowing get a solid effluent containing coke, d) a step of burning said solid effluent containing coke to a temperature between 200 and 700 C making it possible to obtain ashes concentrated in metals, e) a step of extracting the metals from the ashes obtained in step combustion, f) a step of preparation of (s) metallic solution (s) containing at least the metal of the catalyst which is / are recycled as a catalyst in step hydroconversion.

WO 2011/128518

8 PCT / FR2011 / 000160 hydroconversion The method according to the invention comprises a step of hydroconversion of the charge in at least one reactor containing a slurry catalyst and possibly a solid additive.
Hydroconversion is understood to mean. hydrogenation reactions, hydrotreatment, hydrodesulfurization, hydrodenitrogenation, hydrodemetallisation and hydrocracking.
The heavy loads concerned are petroleum hydrocarbon feedstocks such as oil residues, crude oils, crude oils headstocks, deasphalted oils, asphalts or de-asphalting pitches, oil conversion processes (for example: HCO, FCC slurry, GO
heavyNGO coking, visbreaking residue or similar thermal process, etc.
...), tar sands or their derivatives, oil shales or their derivatives, or mixtures of such fillers. More generally, we will regroup here under the term "heavy load" hydrocarbon feedstock containing at least 50 wt% of product distilling above 250 C and at least 25% w distilling above of 350 C.
The heavy loads concerned according to the invention contain metals, essentially V and / or Ni, generally at least 50 ppm wt and the more often 100-2000 ppm by weight, at least 0.5% by weight sulfur, and at least 1% by weight asphaltenes (asphaltenes to heptane), often more than 2% wt or 5%
wt, 25% wt% or more of asphaltenes attainable;
they also contain condensed aromatic structures that may contain of the heteroelements refractory to conversion.
Preferably, the heavy loads concerned are non-conventional heavy crude type (APIs between 18 and 25 and one viscosity between 10 and 100 cP), extra-heavy crudes (APIs between 7 and 20 and a viscosity of between 100 and 10,000 cP) and oil sands (API
between 7 and 12 API and a viscosity of less than 10000 cP) present in large quantities in the Athabasca region of Canada and the Orinoco Venezuela where reserves are estimated at 1700 Gb and 1300 Gb respectively.

WO 2011/128518

9 PCT / FR2011 / 000160 These unconventional oils are also characterized by -residu under vacuum, asphaltenes and heteroelements (sulfur, nitrogen, oxygen, vanadium, nickel, ...) which requires processing steps in commercial products of the gasoline, diesel or heavy fuel oil type.

The heavy load is mixed with a stream of hydrogen and a catalyst too as dispersed as possible to obtain a hydrogenating activity as uniformly distributed as possible in the hydroconversion reaction zone. Of preference, a solid additive favoring the hydrodynamics of the reactor is also added. This mixture feeds the catalytic hydroconversion section into slurry. This section consists of a preheating furnace for the charge and hydrogen and a section reaction consisting of one or more reactors arranged in series and / or in parallel, depending on the capacity required. In the case of series reactors, one or several separators may be present on the effluent at the head of each of the reactors. In the reaction section, hydrogen can feed one, several or all of the reactors and this in equal proportions or different.
In the reaction section, the catalyst can feed a single, several or all the reactors and that in equal or different proportions. The catalyst is kept in suspension in the reactor, flows from the bottom to the top of the reactor with the gas and the charge, and is evacuated with the effluent. Preferably, one at least (and preferably all) reactors is equipped with a recirculation pump internal.
The operating conditions of the catalytic hydroconversion section in slurry are generally a pressure of 2 to 35 MPa, preferably 10 to 25 MPa a hydrogen partial pressure ranging from 2 to 35 MPa and preferentially of 10 at 25 MPa, a temperature of between 300 ° C. and 500 ° C., preferably 420 ° C.
VS
at 480 C, a contact time of 0.1 h to 10 h with a preferred duration of 0.5h to 5 h.
These operating conditions coupled with the catalytic activity allow to obtain conversion rates per pass of. vacuum residue 500 C + can to go from 20 to 95%, preferably from 70 to 95%. The conversion rate above mentioned is defined as the mass fraction of organic compounds having a boiling point greater than 500 C at the entrance to the section reaction minus the mass fraction of organic compounds having a boiling point greater than 500 C at the exit of the reaction section, all divided by fraction mass of organic compounds with a boiling point greater than 500 C
at the entry of the reaction section.
The slurry catalyst is in dispersed form in the reaction medium.
he can be formed in situ but it is best to prepare it outside the reactor and to inject it, usually continuously, with the load. The catalyst promotes the hydrogenation of the radicals resulting from thermal cracking and reduces the formation of coke. When coke is formed, it is removed by the catalyst.
The slurry catalyst is a sulfurized catalyst preferably containing at least minus one element selected from the group consisting of Mo, Fe, Ni, W, Co, V, Ru. These catalysts are usually monometallic or bimetallic (combining by example, a non-noble element VIIIB (Co, Ni, Fe) and an element of group VIB (Mo, W)). NiMo, Ni or Fe catalysts are preferably used.
catalysts used may be heterogeneous solid powders (such as of the natural ores, iron sulphate, etc.), dispersed catalysts of water soluble dispersed catalyst ("water soluble dispersed catalyst") such as acid phosphomolybdic, ammonium molybdate, or a mixture of Mo or Ni oxide with aqueous ammonia. Preferably, the catalysts used are from soluble precursors in an organic phase ("oil soluble dispersed Catalyst ").
Precursors are organometallic compounds such as naphthenates of Mo, Co, Fe, or Ni or such as multi-carbonyl compounds of these metals, for example 2-ethyl hexanoates of Mo or Ni, acetylacetonates of Mo or Ni, salts of C7-C12 fatty acids of Mo or W, etc ... They can be used in the presence a surfactant to improve. the dispersion of metals, when catalyst is bimetallic. The catalysts are in the form of dispersed particles, colloidal or not depending on the nature of the catalyst. Such precursors and catalysts for use in the process according to the invention are widely described in the literature.
In general, the catalysts are prepared before being injected into the charge.
The preparation process is adapted according to the state in which find it precursor and its nature. In all cases, the precursor is sulphurated (ex-situ or in-situ) to form the catalyst dispersed in the feedstock. For the case favorite of so-called oil-soluble catalysts, in a typical process, the precursor is .

mixed with a petroleum charge (which can be a part of the charge to treat, a external charge, recycled charge ...), the mixture is eventually dried at less in part, then or simultaneously sulphurized by addition of a compound sulfur (H2S preferred) and heated. The preparations of these catalysts are described in art prior.
The preferred solid additives are inorganic oxides such as alumina, silica, mixed oxides AI / Si, used catalysts supported (by example, on alumina and / or silica) containing at least one group VIII element (such as Ni, Co) and / or at least one group VIB element (such as Mo, W). For example, the catalysts described in US2008 / 177124. Carbonaceous solids low hydrogen content (for example 4% hydrogen), optionally pretreated, can also be used. It is also possible to use mixtures of such additives. Their particle sizes are preferably less than 1 mm.
Content any solid additive present at the inlet of the reaction zone of the process hydroconversion in slurry is between 0 and 10% by weight preferentially enter 1 and 3 wt%, and the content of the catalytic solutions is between 0 and

10% wt, preferably between 0 and 1 wt%.

The processes of hydroconversion of heavy loads by slurry technology known are EST ENI operating at temperatures of the order of 400-420 C, under pressures of 10-16 MPa with a particular catalyst (molybdenite);
(HC) 3 of Headwaters operating at temperatures in the range of 400-450 C, under pressures of 10-15 MPa with Fe pentacarbonyl or 2-ethyl hexanoate Mo, the catalyst being dispersed in the form of colloidal particles; HDH and HDHPLUS licensed by Intevep / PDVSA operating at temperatures of the order of 420-480 C, at pressures of 7-20 MPa, using a metal catalyst scattered ; Chevron CASH using a sulfide catalyst of Mo or W prepared by aqueous route; SRC-Uniflex of UOP operating at temperatures of the order of 430-480 ° C, under pressures of 10-15 MPa; VCC developed by Veba and owned by BP operating at temperatures in the range of 400-480 C, under pressures of 15-30 MPa, using an iron-based catalyst; Microcat Exxonmobil; etc ...

All these slurry processes can be used in the process according to the invention.
Separation The totality of the effluent resulting from the hydroconversion is directed towards a section separation, usually in a high pressure separator and high temperature (HPHT), which separates a fraction converted to the state gas, so-called light fraction, and an unconverted liquid fraction containing solid, so-called residual fraction.
This separation section is preferably operated under conditions close to those of the reactor which are in general a pressure of 2 to 35 MPa with a preferred pressure of 10 to 25 MPa, a partial pressure hydrogen ranging from 2 to 35 MPa and preferably from 10 to 25 MPa and a temperature between 300 ° C. and 500 ° C., preferably 380 ° C. to 460 ° C..
effluent stay in this separation section is 0.5 to 60 minutes and of preferably from 1 to 5 minutes. The light fraction contains very predominantly the compounds boiling at not more than 300 C, or not more than 400 C or 500 C; they correspond to the compounds present in gases, naphtha, light diesel, indeed heavy diesel. It is indicated that the cup contains, for the most part, these compounds because the separation is not made according to a precise cutting point, it is similar rather to a flash. If we had to speak in terms of cutting point, we could say he is between 200 and 400 or 450 C.

The valuation of the light fraction is not the object of this invention and these methods are well known to those skilled in the art. The light fraction obtained after the separation may undergo at least one hydrotreating step and / or hydrocracking, the objective being to bring the different cuts to the specifications (sulfur content, smoke point, cetane, aromatic content, etc ...). The fraction light weight can also be mixed with another load before being directed towards a hydrotreatment and / or hydrocracking section. An external cut from generally from another process existing in the refinery or possibly except refinery can be brought before hydrotreatment and / or hydrocracking, advantageously the external cut is for example the VGO from the fractionation of crude oil (VGO straight-run), the VGO resulting from a conversion, an LCO
(light cycle oil) or an FCC (heavy cycle oil).
In general, hydrotreatment and / or hydrocracking after hydroconversion can be done conventionally via a section of Intermediate classical separation (with decompression) using after high pressure high temperature separator for example, a high separator low temperature pressure and / or atmospheric distillation and / or distillation under vacuum. Preferably, the hydrotreatment and / or hydrocracking section is directly integrated in the hydroconversion section without decompression intermediate. In this case, the light fraction is sent directly without steps additional separation and no-decompression section hydrotreating and / or hydrocracking. This last embodiment makes it possible to optimize the pressure and temperature conditions, avoids additional compressors and thus minimizes the costs of additional equipment.

The residual fraction resulting from the separation (for example by the separator HPHT) and containing the metals and a fraction of solid particles used as possible additive and / or formed during the reaction can be directed to a step splitting. This splitting is optional and includes a separation under emptied, for example one or more flash balloons and / or, preferably, a vacuum distillation, which makes it possible to concentrate balloons or column one metal-rich vacuum residue and recover at the top of column one or many effluents. Preferably, the residual fraction resulting from the separation without decompression is fractionated by vacuum distillation in at least one fraction vacuum distillate and a vacuum residue fraction, at least a portion and of preferably all of said vacuum residue fraction being sent to the stage of coking, at least a part and preferably all of said distillate fraction under vacuum being preferably subjected to at least one hydrotreating step and or hydrocracking.
The liquid effluent (s) of the vacuum distillate fraction and the Product (s) is (are) usually headed for a small part towards the unit hydroconversion into slurry where they can be directly recycled into the zoned reactive or else it (s) can (wind) be used for the preparation of precursors catalytic before injection into the load. Another part of the Effluent (s) is directed to the hydrotreatment and / or hydrocracking section, optionally in mixture with other fillers, such as for example the light fraction from HPHT separator or vacuum distillate from another unit, in of the equal or different proportions depending on the quality of the products obtained.
The purpose of vacuum distillation is to increase the yield of effluent liquids for further hydrotreatment and / or hydrocracking treatment and so to increase the yield of fuel bases. At the same time, the quantity of the residual fraction containing the metals is reduced, thus facilitating the concentration metals.

coking The residual fraction resulting from the separation without decompression (for example via the HPHT separator) and / or the vacuum residue fraction of the separation under vacuum (eg withdrawn at the bottom of vacuum distillation) are then directed towards a thermal conversion step of the coking type. This step has as objective of to concentrate the metals in the effluent to be subsequently treated by combustion, in reducing its amount, and to maximize the liquid effluent yield for the treatment by hydrotreatment and / or hydrocracking.
The coking step may be by delayed coking or by coking in fluid bed ("fluid-coking" or "flexi-coking"). In the case a fluid bed coking the reactor temperature is greater than 490 C, of preferably between 500-550 C, at atmospheric pressure. Preferably, the coking takes place by delayed coking, in at least two maturation. Before being sent to the maturation balloon, the charge is heated by heating ovens. The operating conditions are a temperature to the output of the heating furnaces of the load between 460 and 530 C, preferably 480 and 510 C and a temperature at the exit of the balloons of maturation greater than 420 ° C., preferably between 430 and 490 ° C., and pressure less than 0.5 MPa, preferably 0.1 to 0.3 MPa. The rate recycles the unconverted fraction of the maturation balloon is less than 20% of the charge cool, preferably less than 10% by weight. Coking takes place under a inert atmosphere. The coking of the fresh load is ensured continuously grace at the regular swapping between two maturation balloons, one being in phase of while the other is in the decocking phase. The coking step delayed release produces a solid effluent containing coke (and metals) and a effluent liquid. The liquid effluent is generally separated by distillation.
At least a portion, and preferably all, of the liquid effluent produced during coking and having a boiling point below a temperature range between 300 and 400 C (Liquid Cycle Gas Oil, LCGO) can be sent to the section hydrotreatment and / or hydrocracking mixture with the light fraction of the HPHT separator and / or with an external cut.
Liquid effluent produced during coking having a boiling point greater than 300 to 400 C (Heavy Cycle Gas Oil, HCGO) is preferably mixed with the heavy hydrocarbon feedstock upstream of the hydroconversion section in slurry. It can also be sent to the section hydrotreatment and / or hydrocracking mixture with the light fraction of the HPHT separator and / or with an external cut. It can also be sent towards the vacuum distillation step mixed with the residual fraction of separator HPHT.
At least a portion, and preferably all, of the solid effluent containing coke strongly concentrated in metals is directed to a combustion stage moderate. Optionally, a portion of the solid effluent containing coke may be recycled as an additive in the hydroconversion stage.

Combustion The solid effluent containing coke is directed to a combustion stage at moderate temperature and in the presence of oxygen. Before you can recover metals by conventional metal mining methods described below, a preliminary step is necessary in order to separate the organic phase (the coke) of the inorganic phase containing the metals. So the goal of the stage of combustion is to get ash containing metals easily recoverable in the subsequent metal recovery units, by burning the organic phase or carbon phase of the solid effluent at a temperature and pressure that limit the vaporization and / or sublimation of metals, in particular molybdenum (Sublimation temperature of about 700 C for Mo03). So the stage of reduction of the organic phase consists of a combustion at moderate temperature in order to concentrate the metals, without noticeable loss by vaporization and / or sublimation towards the fumes, in a mineral phase which may contain a proportion of from 0 to 100 wt%, preferably from 0 wt% to 40 wt%. The operating conditions of this combustion are generally a pressure of -0.1 to 1 MPa, preferably from 0.1 to 0.5 MPa, a temperature of 200 to 700 ° C., preferably from 400 to 550 ° C. The combustion is carried out in the presence of air.
The gaseous effluent resulting from the combustion requires purification steps to reduce the emission of sulfur and nitrogen compounds into the atmosphere.
The processes conventionally used by those skilled in the field of air treatment are carried out under the operating conditions required to meet the standards in force in the country of operation of such treatment a hydrocarbon feed.
The solid resulting from the combustion is a mineral phase containing in full, or almost all the metal elements contained in the extract, under made of ashes.
The direct treatment of the solid effluent leaving the coking by a method of extracting metals as described below without combustion watch an insufficient metal recovery rate.

Metal recovery Ashes from combustion are sent to a stage of metals extraction in which the metals are separated from each other others in one or more sub-step (s). This recovery of metals is necessary, because the simple ash recycling in the hydroconversion stage shows a activity catalytic very low. In general, the extraction step of metals allows to obtain several effluents, each effluent containing a metal specific, for example Mo, Ni or V, usually in the form of salt or oxide.
Each effluent containing a catalyst metal is directed to a step of preparation of an aqueous or organic solution based on the same metal as catalyst or its precursor used in the hydroconversion stage.
The effluent containing a metal from the charge being non-recoverable as catalyst (like vanadium for example) can be valorized outside the process.
Operating conditions, fluids and / or extraction methods used for the different metals are considered as known to those skilled in the art and already used industrially, as for example described in Marafi et al., resources Conservation and Recycling_53 (2008) 1-26, US4432949, US4514369, US4544533, US4670229 or US2007 / 0025899. The different metal extraction routes known generally include leachate solutions acids and / or alkaline, ammonia or ammonium salts, bioleaching by microorganisms, low temperature heat treatment (roasting) by salts of sodium or potassium, chlorination or the recovery of metals by electrolytic route. The leaching by acids can be done by acids inorganic (HCI, H2SO4, HNO3) or organic acids (oxalic acid, lactic acid, acid citric, glycolic acid, phthalic acid, malonic acid, acid succinic acid salicylic, tartaric acid ...). For basic leaching use is General ammonia, salts of ammonia, soda or Na2CO3. In both oxidizing agents (H202, Fe (N03) 3, Al (N03) 3 ...) may be present for facilitate extraction. ' Once the metals in solution, they can be isolated by selective precipitation (at different pH and / or with different agents) and / or by extraction agents (oximes, beta-diketone ...).
Preferably, the metal extraction step according to the invention comprises a leaching with at least one acidic and / or basic solution.

Preparation of catalytic solution (s) Metals recovered after the extraction stage are generally under form of salt or oxide. The preparation of catalytic solutions for produce the organic or aqueous solutions is known to those skilled in the art and has been described in the hydroconversion part. The preparation of catalytic solutions concerned molybdenum and nickel metals, vanadium being generally valued as vanadium pentoxide, or in combination with iron, for the development of ferrovanadium, outside the process.
. Recovered metal recovery rate as a catalyst for the process of hydroconversion to slurry or vanadium is at least 50% wt, preferably at least 65% by weight and more generally 70% by weight.

Description of figures Figure 1 shows a process for hydroconversion of heavy loads oil companies incorporating a slurry technology without metal recovery.
Figure 2 describes a process for the hydroconversion of heavy oil loads according to the invention. The installation and the process are essentially described according to the invention. We will not repeat the operating conditions described previously.

In Figure 1, the load 1 feeds the hydroconversion section catalytic in slurry A. This section of catalytic hydroconversion into slurry is consisting of a Preheating furnace for charge 1 and hydrogen 2 and a section reaction consisting of one or more reactors arranged in series and / or in parallel, according to capacity required. Catalyst 4 or its precursor is also injected, as well as the optional additive 3. Catalyst 4 is kept in suspension in the reactor, flows from the bottom to the top of the reactor with the charge, and is evacuated with the effluent.
The effluent 5 from the hydroconversion is directed to a section of separation to high pressure and high temperature B that separates a fraction converted in the gaseous state 6, said light fraction, and a residual fraction not converted liquid / solid 8. The light fraction 6 can be directed to a section hydrotreatment and / or hydrocracking C. An external cut 7 from generally from another process existing in the refinery or possibly except refinery can be brought before hydrotreatment and / or hydrocracking. The unconverted residual fraction 8 containing the catalyst and a fraction of solid particles used as a possible additive and / or formed during the reaction is directed to a fractionation step D. The step of splitting D
is preferably vacuum distillation to concentrate in the foot of column the metal-rich vacuum residue 10 and recover at the top of column one or more effluents 9. In this recovery scheme of a load heavy by a traditionally used slurry hydroconversion process, the residual under Vacuum 10 rich in metals is valued as a very high viscosity fuel or as a solid fuel after pelleting, for example to produce heat and electricity on site or outside or like fuel in cement plant. Metals are, a priori, not recovered. The effluent (s) 9 so product (s) is (are) usually directed via line 24 for a weak share towards the hydroconversion unit in A slurry where they can be directly recycled in the reaction zone or else it (s) can (wind) be used for the preparation of precursors catalytic before injection into the charge 1 and for another towards Single hydrotreatment and / or hydrocracking C via the line 25 in mixture with the effluents 6 and / or 7 in equal or different proportions depending on the the quality of the products obtained.

In Figure 2, the steps (and reference signs) of hydroconversion, HPHT separation, hydrotreating and / or hydrocracking and distillation under are the same as in FIG. 1. The vacuum residue 10 withdrawn at the bottom of distillation under vacuum D is directed to a thermal conversion step of type coking E
to concentrate the effluent 10. The liquid effluent produced during the coking and having a boiling point below a temperature between 300 and 400 C
(LCGO)

11 can be sent to the hydrotreatment / hydrocracked section C in mixed via line 22 with effluent 6 and / or 7. The liquid product having a point boiling greater than a temperature between 300 and 400 C (HCGO) 12 is preferably sent to the slurry A conversion section via line 23 in mix with the load 1. It can also be sent to the section hydrotreatment / hydrocracking mixture C via line 28 with the effluent 6 and or 7, and / or to the vacuum distillation step D via the mixed line 29 with the effluent 8. The solid effluent containing coke 13 strongly concentrated in metals is directed in part, and preferably entirely, to a step of reducing the sentence organic by a moderate temperature combustion F so very strongly concentrate the metals, without noticeable loss by vaporization and / or sublimation towards the fumes. A smaller portion of the solid effluent 13 can be sent as additive 3 via line 50 in the hydroconversion step A. The effluent gaseous from combustion 14 requires purification steps (not shown) to to reduce the emission of sulfur and nitrogen compounds into the atmosphere. The product 15 from the combustion F is a mineral phase containing all, or almost all, the metallic elements contained in the solid 13, under made of ashes. The product is sent to a metal extraction step G
in which metals are separated from one another into one or more steps). The effluent 16 resulting from the extraction G is composed of a metal of the type molybdenum in the form of salt or oxide. This effluent 16 is then directed towards a preparation step H of an organic or aqueous solution based on molybdenum 18 identical to catalyst 4 or its precursor recycled in part or in totality in the hydroconversion step in slurry A via line 40. The effluent 17 from of the extraction G is composed of a nickel-type metal in salt form or oxide.
This effluent 17 is then directed to a preparation step I of a solution organic or aqueous nickel-based 19 identical to the catalyst 4 or its precursor recycled in part or in full in the hydroconversion step in slurry A via line 41. The effluent 20 from the extraction G is composed of a metal Of type vanadium as salt or oxide. This effluent can be recovered by example as vanadium pentoxide, or in combination with iron, for the development of ferrovanadium.

In the preferred case of a slurry hydroconversion using catalyst based on molybdenum and nickel, hydroconversion uses a catalytic converter finely dispersed nickel and molybdenum type of respective concentration of 25. ppm wt and 600 ppm wt under hydrogen pressure. Considering that Single industrial has a capacity of 50,000 barrels per day and a rate of 90%
per year, the quantity of nickel and molybdenum consumed per year is therefore 0.4 and 1.6 kt / year respectively. Considering a nickel cost of $ 25k / t and Molybdenum at $ 60k / t, representative of the average costs observed in the market of the metals over the last 5 years, the operating cost is 100 million dollar per year.

The method according to the invention allows a valuation of a large part of the metals, nickel and molybdenum, present in the unconverted fraction of effluent derived from the hydroconversion into slurry. The metal recovery rate valued as a catalyst for the slurry hydroconversion process is at least 50%
wt, preferably at least 65 wt%, and more generally 70 wt%. This recycling of metals can reduce the operating cost of 100 million dollars per year at $ 30 million a year. The economy thus achieved is 70 million dollar allows in a first time to pay additional investments necessary for the recovery of these metals. On the other hand, present vanadium in the heavy load at 400 ppm wt can be upgraded, such as ferrovanadium. In Whereas a recovery rate of at least 50% by weight, preferably at least % wt, and more generally 70 wt%, the sale of vanadium is estimated, in considering an average observed cost of $ 40 k / t on the metals market recent years at $ 12 million a year. This sale will allow also in a first time to pay the extra investments necessary for the recovery of these metals.
Recovery of these metals in the unconverted residual fraction reduces the overall amount of nickel and molybdenum used and reduce thus the environmental impact of the hydroconversion process in slurry. In considering a recovery of 70% by weight of metals present at the entrance of the zoned reaction, the amount of catalyst added is reduced to 0.1 t / year for nickel and 0: 5 t / yr for molybdenum vs. 0.4 t / yr and 1.6 t / yr without recycle.

Claims (13)

22 1. Process for the hydroconversion of heavy petroleum feedstocks containing metals comprising:
a) a step of hydroconversion of the feedstock in at least one reactor containing a slurry catalyst containing at least one metal, and possibly a solid additive, b) a step of separation of the hydroconversion effluent without decompression into a so-called light fraction containing the compounds boiling at not more than 500 ° C and in a residual fraction, b ') optionally a fractionation step comprising a vacuum separation of said residual fraction as obtained at step b), and there is obtained a vacuum residue concentrated in metals, c) a coking step of said residual fraction as obtained at step b) and / or said vacuum residue as obtained in step b ') to obtain a solid effluent containing coke, d) a step of burning said solid effluent containing coke to a temperature between 200 and 700 ° C making it possible to obtain concentrated ash of metals, e) a step of extracting the metals from the ashes obtained in step combustion, f) a step of preparation of (s) metallic solution (s) containing at least minus the catalyst metal which is / are recycled as a catalyst in the hydroconversion stage. 2. Method according to claim 1 wherein said so-called light fraction from the step of separation without decompression is subjected to at least one step hydrotreatment and / or hydrocracking. 3. Method according to one of the preceding claims wherein the step of coking is a delayed coking and operates at a temperature at the exit charging furnaces of between 460 and 530 ° C, preference 480 and 510 ° C, and a temperature at the outlet of the maturation balloons better than 420.degree. C., preferably between 430 and 490.degree.
lower pressure at 0.5 MPa, preferably from 0.1 to 0.3 MPa, under an inert atmosphere. 4. Method according to one of the preceding claims wherein the step of combustion operates at a temperature of 400 to 550 ° C, in the presence oxygen. 5. Method according to one of the preceding claims wherein the step of combustion operates at a pressure of - 0.1 to 1 MPa, preferably of - 0.1 at 0.5 MPa and at a temperature of 400 to 550 ° C, in the presence of oxygen. 6. Method according to one of the preceding claims wherein the step metal extraction comprises leaching by at least one solution acid and / or basic. 7. Method according to one of the preceding claims wherein said fraction residuals from the no-decompression separation stage is split by vacuum distillation in at least one vacuum distillate fraction and a fraction vacuum residue, at least a part and preferably all of said fraction vacuum residue being sent to the coking step, at least a portion and of preferably all of said vacuum distillate fraction being subjected to at least a hydrotreatment and / or hydrocracking step. 8. Method according to one of the preceding claims wherein a part of the coker-containing solid effluent of the coking step is recycled as additive in the hydroconversion stage. 9. Method according to one of the preceding claims wherein the load heavy oil is a hydrocarbon feed containing at least 50% by weight of product distilling above 250 ° C and at least 25% w distilling above 350 ° C, and contains at least 50 ppm of metals, at least 0.5% by weight of sulfur and at least minus 1% wt of asphaltenes (asphaltenes with heptane). 10. Method according to one of the preceding claims wherein the load heavy oil is selected from petroleum residues, crude oils, oils raw beheaded, deasphalted oils, asphalts or pitches deasphalting, derivatives of processes for the conversion of oil, tar sands or their derivatives, oil shales or their derivatives, or mixtures thereof loads. 11.Procédé according to one of the preceding claims wherein the step hydroconversion operates at a pressure of 2 to 35 MPa, preferably 10 to 25 MPa, a hydrogen partial pressure of 2 to 35 MPa, preferably 10 to MPa, a temperature of between 300 ° C and 500 ° C, preferably from 420 ° C to 480 ° C and a contact time of 0.1 h to 10 h, preferably 0.5h to 5 h. 12. Method according to one of the preceding claims wherein the catalyst in slurry is a sulphurized catalyst containing at least one element selected from group formed by Mo, Fe, Ni, W, Co, V, Ru. 13. Method according to one of the preceding claims wherein the additive is selected from the group consisting of mineral oxides, used catalysts supported by at least one Group VIII element and / or at least one group VIB, low hydrogen content carbonaceous solids or mixtures of such additives, said additive having a particle size lower than 1 mm.