BRPI1003423A2 - fixed bed hydroconversion process of a crude oil, whether or not distilled, with the aid of exchangeable reactors for the production of a pre-refined synthetic crude - Google Patents

Abstract

FIXED BED HYDROCONVERSION PROCESS OF A CRUDE OIL, DISTILLATED OR NOT, WITH THE AID OF EXCHANGEABLE REACTORS FOR THE PRODUCTION OF A PRE-REFINED SYNTHETIC GROSS. The invention relates to a pre-refining and hydroconversion process of a hydrocarbon heavy crude oil containing at least 0.5% by weight of asphalts and more than 10 ppm by weight of metals (nickel and / or vanadium). ) for the production of a pre-refined synthetic crude in which said charge passes into a hydrodemetallation section comprising at least 2 interchangeable reaction zones, and then at least a portion of the demetallized effluent is hydrocracked into a hydrocarbon section. cracking, and then at least a portion of the hydrocracked effluent is hydrodesulfurized and in which the hydrodesmetalation and hydrodesulfurization sections employ a special catalytic system.

Description

Report of the Invention Patent for "FIXED BED HYDROCONVERSION PROCESS OF A GRILLED OIL, DISTILLATED OR NOT, WITH THE AID OF EXCHANGEABLE REACTORS FOR THE PRODUCTION OF A PRE-REFINED SYNTHETIC GROSS".

The present invention relates to the refining and conversion to fixed bed of heavy, whole or distilled crude oil containing among other things sulfur, nitrogenous and metallic impurities for the purpose of producing a pre-refined synthetic crude.

Over the past forty years, demand in the petroleum products market has increasingly shifted towards light products such as gasolines and LPG and intermediate products such as kerosene and diesel. In parallel, the market share for heavy products, such as heavy fuel oils and bitumen, has been steadily decreasing since the 1970s. As a result, refineries must or should be equipped with conversion processes to convert the heavy fraction of crude oil (generally noted as the 343 ° C + or 350 ° C + fraction), or if it supplies itself to lighter crude oil that has a smaller amount of heavy fraction. A third option is to pre-refine a heavy crude oil into synthetic crude before sending it to a refinery to produce finished products in specifications.

The purpose of pre-refining and hydroconversion of heavy crude oils is to refine at the same time, meaning to substantially reduce its contents in metals, sulfur, nitrogen and other impurities and to improve the hydrogen to carbon (H / C) ratio at the same time. in which the heaviest fraction converts, at the same time as more or less partially turning it into lighter cuts in order to increase the content of light and intermediate cuts in the obtained synthetic crude. In fact, the synthetic crude thus obtained may then be treated directly in refineries which do not have the conversion units which allow direct treatment of the starting crude oil since the quantity as well as the quality of the heavy cuts (distilled under vacuum and residue under vacuum) are greatly improved. The problem posed by the pre-refining and hydroconversion of heavy crude oils is twofold: On the one hand, the metal, sulfur and nitrogenous impurities contained in these heavy crude oils greatly inhibit the catalytic activity of the hydrocracking and catalytic catalysts. hydrodesulfurization of the process itself; On the other hand, the asphaltines and metals contained in these fillers are gradually deposited on the catalyst in the form of coke and metal sulfides, and tend to deactivate and quickly fill the catalytic system, which requires a stop for replacement.

Crude oil pre-refining and hydroconversion processes should therefore be designed to allow as long an operating cycle as possible without paralyzing the unit, the aim being to achieve at least one operating cycle of 12 months.

It is an object of the present invention to make the length of the cycle considerably longer, and thus generally to be at least 12 months, with high performances in hydrodesulphurisation and hydrocracking while preserving the stability of the products.

According to the prior art, fixed bed pre-refining of heavy asphaltenes, Conradson Carbon and / or metal heavy crude oils would lead either to short cycle durations, or independent use and / or accumulated from a low hourly volume velocity (WH) and a very large hydrogen partial pressure level, for example. These changes in operating conditions and / or process design would greatly impact investments and operating costs in order to respect an economic cycle length of the industrial process. The present invention therefore proposes to release a change of operating conditions (WH and / or operating pressure, and even temperature) while respecting an economic cycle duration of the petroleum pre-refining and hydroconversion process. heavy gross.

The present invention therefore aims to propose a process which allows the direct treatment of crude oils which contain much higher levels in sulfur, nitrogen and metallic impurities or in admixture, thereby retaining an economic cycle duration. Fillers which can be treated according to the invention usually contain at least 0.5% by weight of asphaltenes and / or more than 10 ppm by weight of metals (nickel and vanadium).

The treatment of heavy crude oils is currently done in fixed bed processes. In such fixed bed processes, the charge circulates through several catalytic beds arranged in series in one or more reactors, the first catalytic bed (s) being used to perform the hydrodemetallation (HDM) of the charge therein as well as a portion thereof. hydrophore, the following catalytic bed (s) being used for hydrocracking the crude oil before deep refining of the cargo, and in particular hydrodesulfurization (HDS) and Conradson Carbon Content Reduction (HDCCR) , on or in the last catalytic beds. Effluents extracted after the last catalytic bed are, where appropriate, mixed with the light part of the crude oil recovered during stabilization to reconstitute the pre-refined synthetic crude.

In such processes, specific catalysts adapted to each section are most often used under average operating conditions, ie pressures generally comprised between 2 MPa and 30 MPa, preferably between 8 MPa and 20 MPa, and temperatures generally. between 330 ° C and 440 ° C.

The interest of the fixed bed processes is that high performances are obtained thanks to the great catalytic efficiency of the fixed beds. By contrast, in the classic pre-refining and hydroconversion processes, it is found that above a certain filler metal content (eg 50 ppm by weight) and a certain filler asphaltene content (eg 1.5 % by weight), although using the best catalytic systems, the performance and especially the operating time of these processes become insufficient: the catalysts (notably the HDM catalyst) are quickly charged to metals and therefore deactivated. This leads to a decrease in demetallation and de-asphaltenation performances, which leads to an accelerated reduction in the performance of hydrocracking and hydrodesulfurization catalysts. In fact, impurities (mainly metals and asphaltenes) pass in greater concentration over hydrocracking and hydrodesulfurization catalysts and deactivate them rapidly. To compensate for this deactivation, it is possible to increase temperatures to compensate for the loss of activity, but this favors coke formation and increased pressure losses; On the other hand, it is known that the first catalytic bed is likely to collapse quite quickly because of the asphaltenes, metals, and cargo contained in the cargo or as a result of an operating incident.

Although using the best catalytic systems, it can be seen that operating time can be significantly reduced when using loads containing more than 0.5 wt.% Asphalt and more than 10 ppm. metals. The result is that if the pre-refining and hydroconversion unit is brought to a standstill, the loss of activity being considered at a minimum every 2 to 6 months to replace the deactivated or clogged catalytic beds, this operation may be delayed. - more than one month which reduces the unit's operating factor to the same extent.

Another alternative is to send the heavy crude oil to an effervescent hydroconversion unit. In fact, this type of process allows you to replace a part of the catalyst that is in the unit while keeping the unit in operation. In contrast, the effervescent bed units operate with a large liquid product recycling in order to keep the catalyst in a fluidized state that allows the extraction of spent catalyst. Because of this, the hydrodynamics of an effervescent bed process closely approximates a perfectly stirred open reactor. This leads to a large decrease in bed efficiency, which requires working at a higher temperature and rapidly leads to stability problems of the produced synthetic crude. The interest of the fixed bed process is that it achieves high performance thanks to the high catalytic efficiency of the fixed bed, which allows it to work under milder conditions and to avoid the stability problems of the synthetic crude produced.

The applicant therefore sought to address the drawbacks of fixed bed arrangements in different ways.

The process of the present invention is an improvement of the prior art fixed bed crude oil pre-refining and hydroconversion processes by proposing a method for considerably lengthening the cycle time, and thus generally reaching at least 12%. months, with high performances in hydrodesulfurization and hydrocracking while preserving product stability. The process according to the present invention is composed of a so-called hydrodesmetallation (HDM) section, and then a so-called hydrocasting section (HCK), followed by a hydrodesulfurization (HDS) section, said hydrodesmetallation section comprising at least two interchangeable reaction zones.

One of the advantages of the present invention is that it considerably lengthens the cycle time and thus generally reaches at least 12 months, with high hydrodesulfurization and hydrocracking performances while retaining the stability of the products by use in the section. The hydrodemetallization process of the process according to the invention comprises at least two exchangeable reaction zones.

Detailed Description of the Invention

More precisely, the invention consists of a fixed bed pre-refining and hydroconversion process of a heavy crude oil hydrocarbon filler containing at least 0.5 wt% asphaltenes and / or more than 10 ppm weight metals (nickel and / or vanadium) for the production of a pre-refined synthetic crude, in which:

- said charge is hydrode-metallized in a hydrodesteral section (HDM) comprising at least 2 interchangeable reaction zones each containing at least one hydrodemetallation catalyst and possibly containing a hydrorephine catalyst,

- and then at least part of the effluent is at least partly demetalized and possibly partly hydroforinated in a hydrocracking section (HCK) containing at least one fixed bed hydrocracking catalyst,

- and then at least part of the at least partly hydrocracked effluent is hydrodesulfurised in a hydrodesulfurization (HDS) section containing at least one hydrodesulfurization catalyst, and wherein the HDM and HDS sections operate in the presence of a system. A catalyst comprising at least two catalysts, one for HDM and the other for HDS1, the HCK step being performed between the HDM and HDS steps, said HDM and HDS catalysts comprising at least one support consisting of an oxide. porous refractory, preferably alumina, at least one group VIB metal, preferably molten, and at least two group VIII metals, preferably selected from nickel and cobalt, of which one is the promoter. major group called VIII-1 and the one or the others are called copromotor VIII-i with i comprised between 2 and 5, and preferably equal to 2 and in those catalysts, the elements of group VIII being present in the proportions of defined by the atomic ratio [VIII-1 / (VIII-1 + ... + VIII-i)] from 0.5 to 0.85, preferably from 0.55 to 0.85, most preferably between 0.6 and 0.85, and even more preferably between 0.65 and 0.85.

"Reaction zones" means one or more reactors or one or more catalytic beds within the same reactor. In the text, they will be called "short circuit reaction zones", non-interchangeable bypass zones. By definition, a short circuit reaction zone can be disconnected from the set of other reaction zones, the catalyst it contains can then be regenerated and / or replaced with fresh or regenerated catalyst. The short circuit reaction zone is then reconnected to its initial position. In contrast, an exchangeable reaction zone may be reconnected after replacement of the catalyst, either in its initial position or in another position, that is, in an inverted position.

The filler used in the process according to the invention is a preferably full hydrocarbon heavy crude oil containing at least 0.5% by weight of asphaltenes and preferably at least 1% by weight of asphaltenes and more. 10 ppm by weight of metals and preferably more than 50 ppm by weight of metals (nickel and / or vanadium).

Preferably, the filler used in the process according to the invention is a distilled heavy crude oil, that is a crude oil in which the light fraction having a final cut-off point of between 100 and 300 ° C and preferably between 100 and 100 ° C. 200 ° C was taken, for example in a separating flask, a distillation column, or another separating apparatus, to obtain distilled crude oil at the boiling point of between 0 ° C and 300 ° C. Preferably between 0 and 200 ° C.

According to the invention, the hydrodemetalation section comprises at least two exchangeable reaction zones, each containing at least one hydrodemetalation catalyst and possibly a hydrorephine catalyst. Said exchangeable reaction zones are advantageously arranged in series for cyclic use consisting of successive repetition of steps b) and c) defined below:

(a) a stage in which the interchangeable reaction zones are all used together for a time not exceeding the off-time and / or clogging time of one of them;

(b) a step during which at least one of the exchangeable reaction zones is short-circuited and the catalyst it contains is regenerated and / or replaced by a fresh or regenerated catalyst;

(c) a step, during which the interchangeable reaction zones are all used together, the interchangeable reaction zones from which the catalyst has been regenerated and / or replaced during the preceding stage being reconnected, or in their initial positions, or at another position between the exchangeable zones, and said step being continued for a time at least equal to the deactivation and / or clogging time of one of the exchangeable reaction zones.

Preferably during step c) the exchangeable reaction zone from which the catalyst was regenerated during step b) is reconnected at another position between the exchangeable reaction zones, that is, so that their connection is different with respect to the one she had before she was shorted out during step b).

According to a variant of the process according to the invention, it is also advantageous that the hydrodemetallation section comprises, in addition to at least 2 interchangeable reaction zones, also at least one short-circuitable reaction zone.

Preferably, it is also advantageous to use in the hydrocracking and / or hydrodesulfurization sections at least one short-circuit reaction zone.

Thus, it is also advantageously possible to short circuit one or more of these reaction zones when the catalyst is deactivated and / or clogged by sediment, metals or coke to be regenerated and / or replaced with fresh or regenerated catalyst.

Preferably, one or more reaction zones of the hydrodemetal section and / or hydrocracking section and / or hydrodesulfurization section are shorted, for example every 6 months, to replace deactivated or clogged catalytic beds, this operation by improving the unit operating factor and the process cycle duration.

According to a preferred embodiment of this embodiment, the hydrodemetallation section comprising at least 2 exchangeable reaction zones also comprises at least one reaction zone comprising at least one short circuitable hydrodemetallation reactor containing at least a hydrodesmetallation catalyst and eventually a hydrodesulfurization catalyst and is arranged in series for cyclic use consisting of successive repetition of steps b) and c) and the following hydrocracking and hydrodesulfurization sections are composed of one or more zones reaction parameters preferably shorted separately or not according to the following steps d) and e):

(a) a step in which reaction zones are all used together,

(b) a step during which at least one of the exchangeable reaction zones is short-circuited and the catalyst it contains is regenerated and / or replaced by a fresh or regenerated catalyst;

c) a step, during which the reaction zones are all used together, the exchangeable zones from which the catalyst was regenerated and / or replaced during the preceding step being reconnected, or at their initial positions, or at another position between exchangeable reaction zones,

(d) A step in which at least one of the reaction zones of the hydrodemetal section and / or hydrocracking section and / or hydrodesulfurization section may be short-circuited during the cycle when the catalyst is deactivated and / or clogged; the catalyst it contains regenerated and / or replaced with fresh or regenerated catalyst,

e) a step, during which the reaction zones from which the catalyst was regenerated and / or replaced during the preceding step are reconnected to their initial positions.

According to a very preferred embodiment of this embodiment, the hydrodemetallation section comprises 2 interchangeable reaction zones, and also a reaction zone consisting of a short circuitable hydrodesmetallation reactor and the following hydrocracking and hydrodesulfurization sections are composed of a short circuit reaction zone.

According to a most preferred embodiment of this embodiment, during step c), the exchangeable reaction zone from which the catalyst was regenerated during step b) is reconnected to its initial position, that is, to its connection is identical to the one it had before it was shorted during step b).

According to an even more preferred embodiment of this embodiment, during step c), the exchangeable reaction zone from which the catalyst was regenerated during step b) is reconnected at another position between the exchangeable reaction zones, either. say so that your connection is different from what it had before it was shorted during step b).

Advantageously, the reaction zone of the upstream hydrodemetallation section in the global direction of charge circulation is progressively charged to metals, coke, sediment and other diverse impurities and is disconnected as desired and preferably when the catalyst is present. The content it contains is practically saturated with metals and various impurities.

In another embodiment of the process according to the invention, it is also advantageous to operate according to one of the following alternatives:

- at the same time the hydrocracking and hydrodesulphurisation sections comprise interchangeable reaction zones,

- all sections comprise at least one interchangeable reaction zone and at least one short circuit reaction zone,

- the hydrodemetallation section comprises the interchangeable reaction zones and preferably two interchangeable reaction zones and preferably also at least one short circuit reaction zone, the HCK and HDS sections consisting of short circuitable reaction zones and at least one of said zones in the HCK section and the HDS section is not shorted,

- the hydrodemetallation section comprises only interchangeable reaction zones, and preferably two interchangeable reaction zones, and the hydrocracking and hydrodesulfurization sections comprise only one non-shorted reaction zone.

This system of disconnecting and reconnecting the different reaction zones either in their initial position or in an inverted position is advantageously ensured by a special conditioning section allowing the permutation of these reaction zones into operation. without paralyzing the operation of the unit. In particular, a system operating at moderate pressure, preferably at a pressure of between 1 MPa and 5 MPa and preferably between 1.5 MPa and 2.5 MPa, ensures that the reactor or disconnected reaction zone ensures that operations are performed. washing, separating, cooling before discharging the used catalyst and after heating and sulfurisation after loading the fresh or regenerated catalyst. Another system of pressurization / depressurization and taps - valves of suitable technology then advantageously allows to exchange these reaction zones without paralyzing the unit, that is to say without affecting the operating factor, since all operation of Washing, separation, discharging of spent catalyst, fresh or regenerated catalyst reloading, heating, sulfurization are all done in the disconnected reactor or reaction zone.

In a preferred reaction mode, the unit comprises a conditioning section, not shown in the figures, provided with suitable circulation, heating, cooling and separation means that operate independently of the reaction section, which allow with the aid of conduits. and valves perform the preparation of the fresh or regenerated catalyst contained within the reactor and / or the short-circuit reactor just before being connected, unit in operation, namely: reactor preheating during permutation or shorting. circuit, sulfurisation of the catalyst it contains, placement in the required pressure and temperature conditions. When the permutation or short circuit operation of this reactor has been performed with the aid of the appropriate valve set, this same section will also allow conducting used catalyst conditioning operations contained within the reactor just after disconnection of the reaction section. , namely: washing and separating the spent catalyst under the required conditions, and then cooling before discharging the spent catalyst, and after replacement with fresh or regenerated catalyst.

The hydrodemetal section (HDM)

Preferably, the filler is subjected to a hydrodesalting treatment at a temperature preferably from 300 ° C to 450 ° C, most preferably from 360 ° C to 420 ° C, at a total pressure of 5 ° C to 450 ° C. 30 MPa1, preferably between 8 and 18 MPa, at a hydrogen to hydrocarbon ratio of between 200 Nm3 / m3 and 2000 Nm3 / m3, and preferably between 500 and 1500 Nm3 / m3. The operating conditions of the different HDM reaction zones may advantageously be different or identical to each other.

To perform hydrodemetalation, the ideal catalyst should be suitable for treating filler asphaltenes, while having a great demetallating power associated with high metal retention capacity and high coking resistance. Catalysts commonly used in the prior art contain group VIII and VIB metals placed on an amorphous support, most often alumina, and have a macroporous volume that is more or less higher than the degree of impurities ( asphaltenes, metals, ...) of the filler to be treated, such catalysts are known to the person skilled in the art. Applicants have developed such catalysts on special macroporous supports in EP-B-98764, EP-B-113297 and EP-B-113284, EP 1579 909 which give them precisely the qualities sought to perform such transformations. tions:

- Demetallation rate of at least 10% to 95%,

- macroporous volume (pore diameter> 25 nm) exceeding 5% of the total pore volume,

- Metal holding capacity generally greater than 10% of the weight of the new catalytic converter, allowing for longer operating cycles,

- High coking resistance even at temperatures above 390 ° C which contributes to lengthening cycle times often limited by increased pressure drop and loss of activity due to coke production.

According to the invention, the HDM section comprises at least two exchangeable reaction zones each containing at least one hydrodemetalation catalyst.

Especially advantageously, the hydrodemetallation section comprises a succession of 2 or several HDM catalysts whose mean diameter decreases in the direction of charge flow. In other words, the higher average diameter catalyst receives the charge, and it passes through increasingly smaller average diameter catalysts.

Advantageously, the HDM section operates with a succession of at least two hydrodemetalation catalysts, whose activity increases in the direction of charge flow. In other words, the catalyst that has the least activity receives the charge, and it goes through the catalysts that have the most activity.

Advantageously, the activities of the different HDM section catalysts vary according to the matrix (varying among other things the support used, the porosity, the specific surface, ...) and / or the catalytic formulation ( among other things, the active metals, the active metal contents, the types of dopants, the levels of dopants, ...).

Most advantageously, the invention proposes to use for the HDM and HDS reaction zones a special catalytic system (here referred to as "grading") which will be described hereinafter in connection with the hydrodesulphurisation section.

The hydrocracking section (HCK)

According to the invention, at least part and preferably all of the effluent at least partly demetalized and eventually partly hydrorefined, is hydrocracked into a hydrocracking section containing at least one hydrocracking catalyst. fixed bed, preferably at a temperature of from 300 to 45 ° C, preferably from 380 to 420 ° C, at a total pressure of preferably from 5 to 30 MPa, preferably from 8 to and 18 MPa1 and having a hydrogen to hydrocarbon ratio of from 200 Nm3 / m3 to 2000 Nm3 / m3, preferably from 500 to 1500 Nm3 / m3.

In order to activate the hydrocracking reactions itself, the catalyst must advantageously be a bifunctional catalyst, which has a hydrogenating phase in order to hydrogenate the aromatics and to balance the saturated compounds and the corresponding olefins and an acidic phase that allows them to be promoted. hydroisomerization and hydrocracking reactions. The acid function is advantageously brought about by large surface supports (usually 100 to 800 m2.g "1) which have a surface acidity, such as halogenated (chlorinated or notably fluorinated) alumina, the combination of boron oxides and amorphous silica-alumina and zeolites The hydrogenating function is advantageously brought either by one or more metals of the Vlll group from the periodic classification of elements such as iron, cobalt, nickel, ruthenium, rhodium, palladium, iridium and platinum, or by an association of at least one group VIB metal of the periodic classification such as molybdenum and tungsten and at least one group VIII metal.The hydrocracking catalyst must advantageously also have a high resistance to impurities. and asphalt due to the use of heavy crude oil as cargo.

Preferably, the hydrocracking catalysts used comprise at least one metal selected from the group consisting of the metals of groups VIIl and VIB, taken alone or in admixture and a support comprising 10 to 90% by weight of an iron-containing zeolite. 90 to 10% by weight of inorganic oxides. The group VIB metal used is preferably chosen from tungsten and molybdenum and the group VIII metal is preferably chosen from nickel and cobalt. Hydrocracking catalysts are preferably prepared according to the preparation method described in Japanese Patent Application No. 2-289419 (IKC).

Examples of such catalysts are described in JP 2966985, JP 2908959, JP 01 049399 and JP 61 028717, US 4,446,008, US 4,622,127, US 6,342,152, EP 0537500 EP 0622118.

The hydrodesulfurization section (HDS)

According to the invention, at least a portion and preferably all of the at least partly hydrocracked effluent is desulfurized in a hydrodesulfurization section containing at least one hydrodesulfurization catalyst at a temperature preferably comprised of VIII. present in the proportions defined by the atomic ratio [VIII-1 / (VIII-1 + ... + VIII-i)] from 0.5 to 0.85, preferably from 0.55 to 0.85, very closely. preferably between 0.6 and 0.85, and even more preferably between 0.65 and 0.85.

The support consisting of a porous refractory oxide is advantageously composed of compounds, used alone or in admixture, such as alumina, halogenated alumina, silica, silica-alumina, clays (chosen for example from natural clays such as such as kaolin or bentonite), magnesia, titanium oxide, boron oxide, zirconium oxide, aluminum phosphates, titanium phosphates, zirconium phosphates, coal, aluminates. Preferably, the matrix contains alumina in all such forms known in the art, and even more preferably the matrix is gamma alumina.

Preferably, said HDM and HDS catalysts comprise a support consisting of alumina, molybdenum as an element of group VIB, and nickel and cobalt as an element of group VIII, one of which is the major promoter called VIII- 1 and the other is called copromotor VIII-i with i equal to 2 and in these catalysts the elements of the group Vlll are present in the proportions defined by the atomic relationship [VIII-1 / (VIII-1 + VIII-2)] between 0.5 and 0.85.

Preferably, said HDM and HDS catalysts also advantageously comprise at least one doping element placed on said catalyst and selected from the group consisting of phosphorus, boron and silicon.

Preferably, the HDM catalyst (s) have a group VIB metal or metal content of from 2 to 9% by weight of group VIB metal trioxide relative to the total mass of the catalyst. preferably between 3 and 7% by weight and the sum of the group VIII metal contents is advantageously between 0.3 and 2% by weight of the group VIII metal oxide in relation to the total mass. of the catalyst, preferably between 0.55 and 1.5%, preferably between 0.6 and 1.5% by weight. VIII being present in the proportions defined by the atomic ratio [VIII-1 / (VIII-1 + ... + VIII-i)] from 0.5 to 0.85, preferably from 0.55 to 0.85 of most preferably between 0.6 and 0.85, and even more preferably between 0.65 and 0.85.

The support consisting of a porous refractory oxide is advantageously composed of compounds, used alone or in admixture, such as alumina, halogenated alumina, silica, silica-alumina, clays (chosen for example from natural clays such as such as kaolin or bentonite), magnesia, titanium oxide, boron oxide, zirconium oxide, aluminum phosphates, titanium phosphates, zirconium phosphates, coal, aluminates. Preferably, the matrix contains alumina in all such forms known in the art, and even more preferably the matrix is gamma alumina.

Preferably, said HDM and HDS catalysts comprise a support consisting of alumina, molybdenum as an element of group VIB, and nickel and cobalt as an element of group VIII, of which one is the major promoter called V11- 1 and the other is called copromotor VIII-i with i equal to 2 and in these catalysts the elements of the group Vlll are present in the proportions defined by the atomic relationship [VIII-1 / (VIII-1 + VIII-2)] between 0.5 and 0.85.

Preferably, said HDM and HDS catalysts also advantageously comprise at least one doping element placed on said catalyst and selected from the group consisting of phosphorus, boron and silicon.

Preferably, the HDM catalyst (s) have a group VIB metal or metal content of from 2 to 9% by weight of group VIB metal trioxide relative to the total mass of the catalyst. preferably between 3 and 7% by weight and the sum of the group VIII metal contents is advantageously between 0.3 and 2% by weight of the group VIII metal oxide in relation to the total mass. of the catalyst, preferably between 0.55 and 1.5%, preferably between 0.6 and 1.5% by weight. Preferably, the major promoter content (VIII-1) of said HDM1 catalyst (s), preferably the cobalt content, is between 0.25 and 1.7% by weight of the group VIII metal oxide relative to to the total mass of the catalyst and the copromotor content (VIII-2), preferably the nickel content is advantageously comprised between 0.05 and 1% by weight of the group III metal oxide relative to the total mass of the catalyst.

Preferably, the HDM catalyst (s) also advantageously comprises a dopant element content chosen from phosphorus and boron of from 0.1 to 2.5% by weight of boron trioxide and boron pentoxide. phosphorus to the total mass of the catalyst, preferably from 0,5 to 2% by weight. Most preferably, the doping element is phosphorus.

Preferably, the total porous volume of said HDM catalyst is advantageously at least 0.5 ml / g, preferably at least 0.65 ml / g, the macroporous volume of said HDM catalyst is advantageously. more than 5%, preferably 10% and even more preferably 20% of the total pore volume (VPT) and the mesoporous diameter is advantageously comprised between 10 and 36 nm and preferably between 10 and 20 nm.

Preferably, the HDS catalyst (s) have a group VIB metal or metal content strictly greater than 9% and less than 17% by weight of group VIB metal trioxide with respect to The total mass of the catalyst, preferably from 10% to 16% and preferably from 12 to 16% by weight and the sum of the group VIII metal contents, is advantageously strictly greater than 2 and less than 5% by weight. of the metal oxide of the group VIII to the total catalyst mass, preferably strictly greater than 2 and less than 4%, preferably between 2.5 and 4% by weight.

Preferably, the major promoter content (VIII-1) of said HDS catalyst (s), preferably cobalt content is from 1 to 4.5% by weight of the group III metal oxide relative to mass. catalyst content and the copromotor content (VIII-2), preferably the nickel content is advantageously between 0.15 and 2.5% by weight of the metal oxide of the group VIII relative to the total mass of the catalyst.

The hydrodesulfurization catalyst may advantageously comprise phosphorus. This compound brings, among other two main advantages to the hydrodesulfurization catalyst, a first advantage being a greater ease of preparation of said catalyst, especially when impregnating the hydrohydrogenating element, for example from nickel and molybdenum based solutions. . A second advantage brought by this compound is an increase in catalyst hydrogenation activity.

Preferably said HDS catalyst (s) advantageously comprises a doping element content chosen from phosphorus and boron of from 0.5 to 6% by weight of trioxide. of boron and phosphorus pentoxide in relation to the total mass of the catalyst, preferably from 1,5 to 5% by weight. Most preferably, the doping element is phosphorus.

The hydrodesulfurization catalyst may also comprise at least one element of group VIIA (preferred chlorine, fluorine), and / or at least one element of group VIIB (preferred manganese), optionally at least one element of group VB (preferred niobium).

Preferably, the total porous volume of said HDS catalyst is advantageously at least 0.3 ml / g, and preferably at least 0.4 ml / g, the macroporous volume is advantageously less than 10%, preferably 5%, even more preferably 1% of the total pore volume (VPT) and the mesoporous diameter is advantageously comprised between 5 nm and 20 nm and preferably between 6 and 15 nm.

According to an advantageous embodiment, said catalytic system is used in the first interchangeable input reaction zone (s) of the HDM section and in the first input reaction zone (s). of the HDS section, said HDM and HDS sections being separated by the HCK section according to the process according to the invention.

Catalysts constituting the catalytic system described above may advantageously be obtained by all methods well known to one skilled in the art. They are used as extruded supports having a diameter generally of from 0.5 to 10 mm, preferably 0.8 to 3.2 mm. In such extrudates or prior to extrusion forming, it is possible to introduce, by any known method and at any stage of preparation, preferably by impregnation or co-machining, all or part of the catalytic metals or a compound of the metals. catalysts of the final catalyst. Classically performed impregnation is so-called "dry" well-known in the art. It may be carried out in one step only by a solution containing all the constituent elements of the final catalyst, that is a solution containing at least one phosphorus or boron compound, at least two compounds of at least two metals of the final catalyst. group VIII of the periodic classification and at least one composed of at least one metal of group VIB.

Among the precursors which may be introduced into the solution as a source of group VIII elements are advantageously: citrates, oxalates, carbonates, hydroxycarbonates, hydroxides, phosphates, sulphates, aluminates, molybdates, tungstates, oxides, nitrates, halides, for example. chlorides, fluorides, bromides, acetates, or any mixture of the precursors set forth herein. As regards the well known sources of the element of the group V1, they are advantageously shown, for example, for molybdenum and tungsten: oxides, hydroxides, molybdic and tungstic acids and their salts, in particular ammonium salts, ammonium heptamolybdate, ammonium tungstate, phosphomolybdic acid, phosphotungstic acid and their salts. Preferably ammonium oxides or salts such as ammonium molybdate, ammonium heptamolybdate or ammonium tungstate are used. The preferred source of phosphorus is orthophosphoric acid, but salts and esters such as alkaline phosphates, ammonium phosphate, gallium phosphate or alkyl phosphates are also convenient. Phosphorous acids, for example hypophosphorous acid, phosphomolybdic acid and salts thereof, phosphotungstic acid and salts thereof may be advantageously employed. The source of boron may be boric acid, preferably orthoboric acid (H3BO3), ammonium biborate or pentaborate, boron oxide, or boric esters.

The support is generally shaped and calcined prior to impregnation. The forming may advantageously be accomplished by extrusion, pelleting, the oil drop method, granulation on the turntable or any other method well known in the art. Calcination may advantageously be operated at 500 to 100 ° C under dry or humid air.

An organic chelating agent may advantageously be introduced into the solution if the Practitioner deems it necessary. In this case the product is generally mature, dried and calcined under oxidizing atmosphere, for example under air, usually at a temperature of about 300 to 600 ° C and preferably 350 to 550 ° C.

Impregnation may also be advantageously performed at least twice. The different elements may thus be advantageously impregnated successively or one of the elements may also be impregnated in several sequences. One of the impregnations that is performed may notably serve for the use of an organic compound which the Professional would have wished to introduce in addition to the building blocks of the final catalyst.

The solution of the constituent compounds of the final catalyst elements may be advantageously prepared in an aqueous solvent, but also in a water-organic solvent mixture or in a pure organic solvent. Ethanol or toluene may thus be cited as an example of non-aqueous solvent. The pH of this solution may be modified by the eventual addition of an acid.

The present invention applies to the case where one or more of the catalysts would not have been calcined. In this case, after impregnation the catalyst is only advantageously dry.

At least a portion of the hydrodesulphurate effluent from the process according to the invention is then distilled by atmospheric distillation to obtain at least one atmospheric distillate cut and an atmospheric residue. Preferably, at least a portion of the atmospheric residue is recycled at the inlet of one of the process reaction zones, preferably at the inlet of the first exchangeable reaction zone of the operating HDM section, in order to increase the fraction conversion. heavy crude oil starting.

According to another advantageous embodiment, at least a portion of the atmospheric residue from the atmospheric distillation zone is sent to a vacuum distillation zone from which a vacuum distillate and a vacuum residue are recovered. At least a portion of the waste under vacuum is then advantageously recycled at the inlet of one of the reaction zones of the process according to the present invention, preferably at the inlet of the first exchangeable reaction zone of the HDM section in accordance with the present invention. operation. This allows the conversion of the heavy fraction of starting crude oil to be increased.

In another embodiment of the process according to the invention at least part of the atmospheric distillate is recycled at the entrance of one of the process reaction zones, preferably at the entrance of the first exchangeable reaction zone of the HDM section in operation.

In another embodiment of the process according to the invention, it is also possible to inject at the inlet of one of the process reaction zones an external hydrocarbon effluent which is preferably from another refining unit, for example. a portion of a waste, whether atmospheric or vacuum, from direct distillation said SR (from the Anglo-Saxon Straight Run term) from the initial fractionation of a crude, or waste from another refining unit.

The amount of atmospheric distillate and / or vacuum distillate and / or atmospheric and / or vacuum residue that is sent to the inlet of one of the process reaction zones represents, in relation to load, preferably 1 to 80%, preferably 5 to 45% and more preferably about 10 to 30%.

Figure 1 illustrates the invention by way of illustration.

In this figure, the process according to the invention is carried out in the 3 sections (the HDM1 section, the HCK section and the HDS section), each section itself consisting of 5 reaction zones. As mentioned above, these reaction zones may be composed of one or more different reactors or one or more different catalytic beds within the same reactor.

The HDM section (M1 to M5) is composed of 2 interchangeable reaction zones (M1, M2), which are followed by 3 short circuit reaction zones (M3, M4, M5). In order to simplify the description of the figure, the 3 sections are organized identically.

In figure 1, the valves that allow isolating, shorting or exchanging the different reaction zones, as well as the arrivals of the internal or external recyclers, are not represented either so as not to overload the figure. Similarly, the conditioning section of the catalytic converters, provided with adequate circulation, heating, cooling and separation means, which operate independently of the reaction zones, which allow, with the aid of ducts and valves, to perform the Preparations for fresh or regenerated catalyst contained in the short-circuit reaction zone just before being connected while the unit is running are also not represented. Lines that allow you to recycle oil cuts or inject external external oil cuts upstream of one or several reaction zones are also not represented.

In a start-up configuration, the charge arrives at the HDM section through conduit 2, where it is mixed with hydrogen coming from conduit 1. This mixture enters reaction zone M1 and effluent exits this reaction zone through conduit 3, which allows it to be forwarded to reaction area M2. From reaction zone M2, hydrocarbons and hydrogen pass through conduit 4 to reaction zone M3, then conduit 5 to reaction zone M4 and conduit 6 to reaction zone M5. The mixture then exits this reaction zone M5 through conduit 7. At least a portion (and generally all) of this effluent is sent through conduit 8 to the HCK section, the residual effluent being evacuated by conduit 9. Still in this configuration , the reaction mixture enters the HCK section through conduit 22, feeding the reaction zone K1. The effluent from this reaction zone K1 passes through conduit 23 to reaction zone K2. From reaction zone K2, the mixture of hydrocarbons and hydrogen passes through conduit 24 to reaction zone K3, then conduit 25 to reaction zone K4 and conduit 26 to reaction zone K5. The mixture then follows this reaction zone K5 through conduit 27. At least a portion (and generally all) of this effluent is sent through conduit 28 to the HDS section, any residual effluent being evacuated through the conduit. 29

Then, the reaction mixture enters the HDS section through conduit 42 which feeds reaction zone S1. The effluent from this reaction zone S1 passes through conduit 43 to reaction zone S2. From reaction zone S2, the mixture of hydrocarbons and hydrogen passes through conduit 44 to reaction zone S3, then conduit 45 to reaction zone S4 and conduit 46 to reaction zone S5. The mixture then leaves this reaction zone S5 via conduit 47. Synthetic crude is recovered via conduit 48.

In the embodiment of Figure 1, which uses 2 interchangeable reaction zones (M1, M2 or K1, K2 or S1, S2) and 3 short circuit reaction zones (M3 to M5, or K3 to K5, or S3 to S5 ) in each section (the HDM, HCK and HDS section), the two interchangeable reaction zones which each contain at least one catalyst are arranged in series for cyclical repetition use. of steps b) and c) defined below, and one or more reaction zones which may be shorted separately or not according to steps d) and e) defined below. For the HDM section, the mode of operation of the hydroconversion process of the invention shown in Figure 1 comprises the following steps:

- a step in which the reaction zones M1 to M5 of the HDM section are all used together for a time not exceeding the shutdown and / or clogging time of one of them, for which the flow of Fluids has been described above as the starting configuration.

- a step, during which the first exchangeable reaction zone M1 is short-circuited and the catalyst it contains is regenerated and / or replaced with fresh or regenerated catalyst, while the reaction mixture passes through conduit 11 to interchangeable reaction zone M2, exits conduit 4 to reaction zone M3, passes via conduit 5 to reaction zone M4, through conduit 6 to reaction zone M5 before leaving the HDM section through conduit 7 .

- a step, during which the reaction zones of the HDM section are all used together, the reaction zone M1 from which the catalyst was regenerated and / or replaced during the preceding step being reconnected behind the reaction zone M2. via conduit 12 (reconnection in an inverted position), the effluent from that zone being sent to reaction zone M3 by conduit 13, said step being continued for a time not exceeding the shutdown and / or clogging time of one of the reaction zones.

- a step in which at least one of the short-circuit reaction zones M3, M4 and M5 of the HDM section is shorted by conduits 14, 15 and / or 16 respectively when the catalyst is deactivated and / or sealed and the catalyst it contains regenerated and / or replaced with fresh or regenerated catalyst; for example zone M3 is shorted; since then the effluent from the last interchangeable reaction zone in operation passes directly to zone M4 through conduit 14 and the catalyst from zone M3 is regenerated and / or replaced with fresh or regenerated catalyst.

- a step, during which the reaction zones from which the catalyst has been regenerated and / or replaced during the preceding step are reconnected to their initial positions; for example the catalyst of zone M3 having been regenerated, zone M3 is reconnected, and effluent from the last interchangeable zone in operation passes to zone M3 via conduit 4, conduit 14 being closed.

For HCK and HDS sections, the operating mode of interchangeable reaction zones and short-circuit reaction zones is identical. The description is therefore completely analogous and will not therefore be repeated. We will simply list the concerned and referenced parts of Figure 1:

- section HCK: conduits for permutation: 31, 32, 33; conduits for short circuit: 34, 35, 36.

- HDS section: conduits for permutation: 51, 52, 53; short circuit ducts: 54, 55, 56.

It is readily understood from the description of FIG. 1 the operation of interchangeable or short circuit reaction zones. Figure 1 has shown by way of illustration a special arrangement of these zones in the sections. All combinations are possible. As indicated above, the preferred mode comprises (or consists of) 2 interchangeable reaction zones for the HDM section, 1 or 2 short circuit reaction zones for the HCK section and 1 or 2 reaction zones. shorted to the HDS section.

Claims (12)

1. Pre-refining and fixed-bed hydroconversion process of a hydrocarbon heavy crude oil cargo containing at least 0.5% by weight of asphaltenes and more than 10 ppm by weight of metals (nickel and / or vanadium) for producing a pre-refined synthetic crude in which: - the charge is hydrode-metallized in a hydrodemetallation section (HDM) comprising at least 2 interchangeable reaction zones each containing at least one hydrodemetallation catalyst; - and then at least part of the effluent is at least partly demetalized in a hydrocracking section (HCK) containing at least one fixed bed hydrocracking catalyst, - and then at least part of the effluent is hydrodesulfurized by least partially hydrocracked in a hydrodesulfurization section containing at least one hydrodesulfurization catalyst, and wherein the HDM and HDS sections operate in the presence of a catalytic system comprising at least two catalysts, one for HDM and the other for HDS, the HCK step being performed between the HDM and HDS steps, said HDM and HDS catalysts comprising at least one support consisting of a porous refractory oxide, at least one VlB group metal, and at least two group VIII metals, of which one is the major promoter called VIII-1 and the one or the other is called copromotor VIII-i with i comprised between 2 and 5 and in these catalysts, the elements of group V111 being present in the proportions defined by the atomic ratio [VIII-1 / (VIII-1 + ... + VIII-i)] comprised between 0.5 and 0.85. A process according to claim 1, wherein said exchangeable reaction zones are arranged in series for cyclic use consisting of the successive repetition of steps b) and c) defined below: a) a step, in whereas the interchangeable reaction zones are all used together for a maximum of equal to the shutdown and / or clogging time of one of them, (b) a step during which at least one of the reaction zones The exchangeable reaction zones are short-circuited and the catalyst it contains is regenerated and / or replaced with fresh or regenerated catalyst, c) a step, during which the interchangeable reaction zones are used together, the exchangeable reaction zones of which the catalyst has been regenerated and / or replaced during the preceding step being reconnected, or in its initial positions, or in another position between the interchangeable zones, and said step being continued for a time. at least equal to the deactivation and / or clogging time of one of the exchangeable reaction zones. A process according to claim 2, wherein during step c) the exchangeable reaction zone from which the catalyst was regenerated during step b) is reconnected at another position between the exchangeable reaction zones. A process according to claim 1 or 2, wherein the hydrodemetallation section also comprises at least one short circuit reaction zone. A process according to any one of claims 1 to 4, wherein the hydrocracking and / or hydrodesulfurization sections comprise at least one short circuit reaction zone. A process according to any one of claims 1 to 5, wherein the hydrodemetallation section comprising at least 2 exchangeable reaction zones also comprises at least one reaction zone comprising at least one short circuitable hydrodemetallation reactor containing at least one hydrodemetallation catalyst and is arranged in series for cyclic use consisting of the successive repetition of steps b) and c) and the following hydrocracking and deep hydrodesulfurization sections are composed of one or more reaction zones of preferably short circuit separately or not according to the following steps d) and e): a) a step, wherein the reaction zones are all used together, b) a step, during which at least one of the reaction zones exchangeable action is short-circuited and the catalyst it contains is regenerated and / or replaced with fresh or regenerated catalyst, d) one step, du where reaction zones are all used together, the interchangeable zones from which the catalyst was regenerated and / or replaced during the preceding step being reconnected, or at their initial positions, or at another position between the reaction zones. (e) a step in which at least one of the reaction zones of the hydrodemetal section and / or hydrocracking section and / or deep hydrodesulfurization section may be short-circuited throughout the cycle when the catalyst is deactivated and / or clogged and the catalyst containing it regenerated and / or replaced by fresh or regenerated catalyst, (f) a step during which reaction zones from which the catalyst was regenerated and / or replaced during the preceding step are reconnected in their initial positions. The process according to claim 6, wherein the hydrodemetallation section comprises 2 interchangeable reaction zones, and also a reaction zone consisting of a short circuitable hydrodemetallation reactor and the following hydrocracking and hydrocarbon sections. Desulphurization are composed of a short circuit reaction zone. A process according to claim 6 or 7, wherein during step c), the exchangeable reaction zone from which the catalyst was regenerated during step b) is reconnected at another position between the reaction zones. interchangeable. A process according to any one of claims 1 to 8, wherein said hydrocracking catalyst comprises at least one metal selected from the group consisting of the metals of groups VIIl and VIB, taken alone or in admixture and a support comprising 90% by weight of a zeolite containing iron and 90 to 10% by weight of inorganic oxides. A process according to any one of claims 1 to 9, wherein said HDM and HDS catalysts comprise a support consisting of alumina, molybdenum as an element of group VIB1 and nickel and cobalt as an element of group VIII. of which one is the major promoter called VIII-1 and the other is called copromotor VIII-i with i equal to 2 and in these catalysts the elements of group VIII being present in the proportions defined by the atomic ratio [VIII-1 / (VIII -1 + VIII-2)] comprised between 0.5 and 0.85. A process according to any one of claims 1 to 10, wherein said catalytic system is used in the first interchangeable input reaction zone (s) of the HDM section and the first one (s). HDS section input reaction zone (s), said HDM and HDS sections being separated by the HCK section. A process according to any one of claims 1 to 11, wherein at least a portion of the hydrodesulphurised effluent is then distilled by atmospheric distillation to obtain at least one atmospheric distillate and an atmospheric residue.