BRPI0519489B1 - process for converting heavy load raw materials - Google Patents

Abstract

process for converting heavy load raw materials. process for the conversion of heavy-load raw materials by the combined use of at least the following three process units: solvent asphalt removal (sda), suspended phase (ht) catalyst hydroconversion, distillation or vaporization (d) characterized in that it comprises the following steps that send the heavy load feedstock to an asphalt removal section (sda); mix the stream consisting of asphalt removal oil (dao) with a suitable hydrogenation catalyst precursor and send the obtained mixture to a hydrotreating reactor (ht) by sending the stream containing the hydrotreating reaction product and the catalyst into the dispersed phase to one or more distillation or flash evaporation steps (d), recycling at least a portion of the distillation residue (tar) or liquid coming from the vaporization unit.

Description

The present invention relates to a process for the conversion of heavy-duty feedstocks, including heavy crude oils, oilseed bitumen and distillation residues, by means of a process for the conversion of heavy-duty raw materials. of at least three process units: desphalting, hydroconversion of the feedstock using dispersed phase catalysts and distillation. The conversion of heavy crude oils, oil sands and oil residues into liquid products can be substantially effected in two ways: one exclusively thermally and the other by hydrogenation treatment.

Current studies are mainly directed with respect to hydrogenation treatment when thermal processes create problems with regard to the removal of by-products such as, in particular, coke (obtained in even higher amounts than 30% by weight with respect to raw material). raw material) and the poor quality of the conversion products.

Hydrogenation processes consist of treating the feedstock in the presence of hydrogen and suitable catalysts.

Hydroconversion technologies currently on the market utilize fixed or boiled bed reactors and make use of catalysts generally consisting of one or more transition metals (Mo, W, Ni, Co, etc.) supported on silica / alumina (or material). equivalent).

Fixed bed technologies have several problems in the treatment of particularly heavy-duty feedstocks containing high percentages of heteroatoms, metals and asphaltenes when these contaminants lead to rapid catalyst deactivation.

Boiling bed technologies have been developed and marketed for the treatment of these filler feedstocks, which have provided interesting performances but are complex and expensive.

Hydrotreating technologies using dispersed phase catalysts may be a solution of interest to the disadvantages of fixed and boiling bed technologies. Suspended processes, in fact, combine the advantage of high loading material flexibility with high conversion and updating performance, proving, at least in principle, to be simpler from a technological point of view. .

Suspension technologies are characterized by the presence of catalyst particles having very small average sizes and adequately dispersed in the medium: for this reason hydrogenation processes are easier and more immediate throughout the reactor. Coke formation is considerably reduced and the loading stock update is high. The catalyst may be introduced as a powder of sufficiently small size (US-4,303,634) or with an oil-soluble precursor (US-5,288,681). In the latter case, the active form of the catalyst (usually metal sulfide) is formed in situ by thermal decomposition of the compound used, during the reaction itself or after appropriate pretreatment (US-4,470,295).

The metal components of the dispersed catalysts are usually one or more transition metals (preferably Mo, W, Ni, Co or Ru). Molybdenum and tungsten perform much more satisfactorily with respect to nickel, cobalt or ruthenium, and even more with respect to vanadium and iron (N. Panariti et al., Appl. Ctal. A: Gen. 2000, 204, 203) .

Even if the use of dispersed catalysts solved most of the problems of the technologies described above, it has the disadvantages mainly due to the catalyst duration and the quality of the products obtained. The way these catalysts are used (type of precursors, concentrations, etc.) is extremely important from both an economic and environmental point of view. The catalyst can be used at a low concentration (a few hundred ppm) in one-time mode, but in this case the update of reaction products is generally unsatisfactory (N. Pnariti et al., Appl. Ctal. A: Gen., 2000, 204, 203 and 215). If very active catalysts are used (eg molybdenum) and with higher catalyst concentrations (thousands of ppm metal), the quality of the product obtained is certainly superior, but catalyst recycling is required. The catalyst at the reactor outlet may be recovered by separating the product obtained from hydrotreating (preferably from the bottom of the reactor downstream distillation column) by conventional methods such as, for example, settling, centrifuging or filtration (US-3,240. 718; US-4,762,812) which are, however, extremely complex if applied to poisonous heavy-duty raw materials.

Until chemical description of conversion processes is involved, it is very useful to introduce the concept of stability which, for a crude oil or an oil residue, expresses its tendency to precipitate the asphaltene component due to a change in operating conditions or chemical composition of oil and / or asphaltenes (incompatibility) following dilution with hydrocarbon fractions or chemical transformation induced by cracking, hydrogenation, etc. processes.

Conventionally, asphaltenes are hydrocarbons which may be precipitated from a crude oil or an oil residue by treatment with a number of carbon atoms ranging from 3 to 7, e.g. n-heptane under standard conditions provided by IP-143 regulation. From a quality standpoint, it can be stated that incompatibility phenomena occur when products having very different characteristics with respect to the nature of the maltene component, ie the non-asphaltene component, are mixed, as in the case of mixing paraffinic crude oils with aromatic oils, or diluting oil residues with cutting raw materials of a paraffinic nature (a typical case is the flow of tars from viscosity cancellation with lower aromatic gas oils).

In the processes of converting waste oil, oil sands and heavy crude oils into distillates, the maximum conversion level is limited by the stability of the waste produced. These processes, in fact, modify the chemical nature of oils and asphaltenes causing a progressive decrease in stability with an increase in the level of gravity. Beyond a certain limit, asphaltenes present in the filler can lead to phase separation (i.e. precipitate) and thus activate coke formation processes. From a physicochemical point of view, the phase separation phenomenon can be explained by the fact that the asphaltene phase becomes more and more aromatic with the advancement of conversion reactions due to the effect of dealkylating reactions and condensation.

Consequently, beyond a certain level, asphaltenes are no longer soluble in the maltene phase, also because, in the meantime, they become more “paraffinic”. Controlling the loss of stability of a heavy-load feedstock during thermal and / or catalytic conversion is therefore critical to achieving maximum conversion without creating problems due to coke formation or incmstation.

In one-time processes, optimal operating conditions (especially reaction temperature and residence time) are simply determined on the basis of reactor effluent stability through direct measurements of the unconverted residue (P value, Hot Filtration Test, Brand Test, etc.).

All of these processes allow higher or lower conversion levels to be achieved according to the feedstock and technology used, in any case generating a residue not converted to the stability limit, which we call tar, which case by case it may vary from 30 to 85% of the initial loading raw material. This product is used for the production of fuel oil, bitumen or can be used as the filler raw material in gasification processes.

Schemes have been proposed to increase the total conversion level of cracking processes, which include recycling more or less significant amounts of tar in the cracking unit.

In the case of hydroconversion processes with dispersed catalysts in the suspended phase, tar recycling also allows catalyst recovery, as described in patent application IT-95A001095, a process which allows recycling of recovered catalyst in the catalyst. hydrotreating reactor without the need for another regeneration step while obtaining a good quality product without waste production (“zero residue refinery”).

This process comprises the following steps: • mixing the heavy crude oil or distillation residue with a suitable hydrogenation catalyst and sending the obtained mixture to a hydrogenation reactor, introducing into it hydrogen or a mixture of hydrogen and H2S; Sending the stream containing the hydrotreating reaction product and the catalyst in the dispersed phase to a distillation zone where the most volatile fractions are separated; • send the high boiling fraction obtained in the distillation step to a de-asphalting step and the consequent formation of two streams, one consisting of de-asphalted oil (DAO) and the other consisting of asphalt, catalyst in the dispersed phase and possibly coke, and enriched with the metals that come from the initial filler raw material; • recycle at least 60%, preferably at least 80%, of the stream consisting of asphalt, catalyst in the dispersed phase and possibly coke, rich in metals in the hydrotreating zone.

Subsequent patent application IT-MI2001A001438 described different process configurations with respect to that described above. The process claimed here by the combined use of the following three process units: hydroconversion with catalysts in the suspended phase (HT), distillation or instantaneous evaporation (D), disphalting (SDA), is characterized by the fact that all three units operate in currents. mixtures consisting of freshly loaded feedstock and recycled streams, using the following steps: * send at least a fraction of the heavy-load feedstock to a disphalting section (SDA) in the presence of solvents, obtaining two streams, one consisting from asphalted oil (DAO), the other from asphalts; * mix the asphalt with a suitable hydrogenation catalyst and possibly with the remaining fraction of the heavy load raw material not sent to the dephalting section and send the mixture obtained to a hydrotreating reactor (HT) by introducing hydrogen or a reactor into the same reactor. mixture of hydrogen and H2S; * Send the stream containing the hydrotreating reaction product and the catalyst in the dispersed phase to one or more distillation or flash evaporation steps (D), whereby the most volatile fractions are separated, including the gases produced in the reaction. hydrotreating; * recycle at least 60% by weight of the distillation residue (tar) or liquid coming from the flash evaporation unit containing a catalyst in the dispersed phase rich in metal sulfides produced by the demetallization of the feedstock and possibly coke, in the dephalting zone.

With such configurations, the following advantages can be obtained: * maximization of conversion products into distillables (derived from both atmospheric and vacuum distillation), and de-asphalted oil (DAO), which in most cases may be more 95% with respect to load; * maximizing the degree of updating of the feedstock, ie the removal of poisonous products present (metals, sulfur, nitrogen, coal residue), minimizing coke production; * maximum flexibility in different treatment loads in nature of the hydrocarbon component (density) and level of pollutants present; * possibility to completely recycle the hydrogenation catalyst without the need for regeneration. Treatment of a heavy hydrocarbon feedstock by solvent desphalting allows the separation of two conventionally defined pseudo-components Desphalted Oil (DAO) and Cn asphaltenes (where n represents the number of carbon atoms in paraffin used in the de-galling operation (usually 3 to 6).

It has been surprisingly found that if DAO is subjected to a hydrotreating section and asphaltenes to a gasification section, the catalyst composition is reduced, following the significant decrease in the amount of purging required for heavy metal removal (Ni, V , Faith, etc.) present in the feed stream for hydrotreating itself. The process, object of the present invention, for converting heavy and extra heavy load feedstocks by the combined use of at least three following process units: solvent disphalting (SDA), hydroconversion with suspended phase catalysts (HT ), distillation or instantaneous evaporation (D), is characterized by the fact that it comprises the following steps: * sending the heavy-load raw material to a disphalting section (SDA) in the presence of solvents, obtaining two streams, one consisting of desphalted oil (DAO), the other asphaltenes; * mix the stream consisting of dephalting oil (DAO) with a suitable hydrogenation catalyst precursor and send the mixture obtained to a hydrotreating reactor (HT) by introducing hydrogen or a mixture containing hydrogen and H2S; * Send the stream containing the hydrotreating reaction product and the catalyst in the dispersed phase to one or more distillation or flash evaporation steps (D), whereby the most volatile fractions are separated, including the gases produced in the reaction. hydrotreating, distillation residue (tar) or liquid coming from the flash evaporation unit, containing catalyst in the dispersed phase, rich in metal sulfides produced by charge demetallization and possibly coke; * recycle at least part of the distillation residue (tar) or liquid from the flash evaporation unit containing catalyst in the dispersed phase rich in metal sulfides produced by charge demetallization and possibly coke in the hydrotreating zone.

Treated heavy-load feedstocks can be of a variable nature: they can be selected from heavy crude oils, distillate residues, heavy oils arising from catalytic treatments, eg fixed or boiled hydrotreated “unconverted oils” , “Heavy cycle oils” for catalytic cracking treatment, “thermal tars (arising for example from viscosity cancellation or similar thermal processes),“ oil sands ”bitumen, different coal species and any other high boiling charge of a hydrocarbon source, commonly known in the art as "black oils". The asphaltenes-containing stream obtained in the disphalting section (SDA) may optionally be mixed with the remaining portion of the distillation residue (tar) or the liquid arising from the instant evaporation unit, not recycled in the hydrotreating section (HT).

Said asphaltenes-containing stream, mixed or unmixed with part of the distillation residue (tar) or liquid coming from the flash evaporator unit, may be: * sent to a gasification section (POx) to obtain a mixture of H2 and CO; * sent to a coking or viscosity cancellation section; * used for fuel formulation or as a fuel for energy production * used in cement works. It is recommended for at least part of the distillation (tar) residue or liquid coming from the flash evaporation unit, preferably at least 80 wt%, more preferably at least 90 wt%, even more preferably at least 99 wt%, be recycled to the hydrotreating (HT) section while the remaining possible part is sent to the POx gasification section. Gasification may be effected by feeding to the gasification unit, in addition to feedstock, oxygen and steam which react under exothermic conditions at an ambient temperature of over 1300 ° C and a pressure ranging from 30 to 80 bar to mainly produce H2 and CO.

A syngas stream, or a mixture of H2 and CO, can be obtained from the gasification section, which can be further used as fuel by combined cycle combustion (IGCC) or transformed into paraffinic hydrocarbons by Fischer-Tropsch synthesis. or converted to methanol, dimethyl ether, formaldehyde and, more generally, the full range of products derived from the chemical Cl.

The same paraffinic hydrocarbons obtained by Fischer-Tropsch can be mixed with the various cut portions obtained from the distillation or instantaneous evaporation step, improving their compositional characteristics.

The catalyst precursors used may be selected from those obtained from readily decomposed oil-soluble precursors (metal naphthenates, phosphonic acid metal derivatives, metal carbonyls, etc.) or from preformed compounds based on one or more base metals. such as Ni, Co, Ru, W and Mo: the latter is preferable due to its superior catalytic activity. The catalyst concentration, defined on the basis of the concentration of the metal or metals present in the hydroconversion reactor, ranges from 350 to 30,000 ppm, preferably from 3,000 to 20,000 ppm, more preferably from 5,000 to 15,000 ppm. The hydrotreating (HT) step is preferably performed at a temperature ranging from 360 to 450 ° C, more preferably from 380 to 440 ° C, and at a pressure ranging from 3 to 30 MPa, preferably from 10 to 20 MPa. Hydrogen is fed into the reactor, which can operate in either a downflow or preferably an upflow mode. Said gas can be fed to various sections of the reactor.

Distillation steps are preferably carried out under reduced pressure, ranging from 0.001 to 0.5 MPa, preferably from 0.1 to 0.3 MPa. The hydrotreating (HT) step may consist of one or more reactors operating within the above mentioned condition range. Part of the distillates produced in the first reactor can be recycled in subsequent reactors of the same stage. The desphalting step (SDA), carried out by means of solvent extraction, or a hydrocarbon solvent or not, is usually performed at temperatures ranging from 40 to 200 ° C and a pressure of 0.1 to 7 MPa.

It may also consist of one or more sections operating with the same or different solvents; Solvent recovery can be performed under subcritical or supercritical multi-step conditions, thus allowing for further fractionation between the disasphalted oil and resins. It is recommended that the dephalting solvent be selected from light paraffins having from 3 to 6 carbon atoms, preferably from 4 to 5 carbon atoms, more preferably having 5 carbon atoms.

Using the gasification step (POx), in addition to obtaining a significant reduction in the amount of purging of the entire complex, there is hydrogen production, of which a part can be adopted for the hydrotreating (HT) reaction.

In the process according to the invention another secondary section may optionally be present for the post-treatment hydrogenation of the C2 fraction at 500 ° C, preferably the C5 fraction at 350 ° C, arising from the high pressure separator section considered at amount of distillation.

In this case, before being sent to one or more distillation or flash evaporation steps, the stream containing the hydrotreating reaction product and the catalyst in the dispersed phase is subjected to a high pressure pre-separation step. In order to obtain a light fraction and a heavy fraction, this heavy fraction alone is sent to said distillation step (s) (D). The light fraction obtained from the high pressure separation step can be sent to a hydrotreating section, producing a lighter fraction containing C1-C4 and H2S gas and a lighter fraction containing hydrotreated naphtha and diesel fuel. The possible insertion of the secondary post-treatment hydrogenation section of fraction C2 at 500 ° C, preferably fraction C5 at 350 ° C, exploits the availability of this fraction along with hydrogen at a relatively high pressure, which is that of the hydrotreating reactor. , allowing the following advantages to be obtained: • fuels can be obtained from oil-loading raw materials that are extremely sulfur-rich according to the most stringent sulfur content specifications (<10 to 50 ppm sulfur ) and improved as far as other diesel diesel characteristics are involved, such as density, polyaromatic hydrocarbon content and cetane number; • Distillates produced do not suffer from stability problems. Post-treatment hydrogenation in a fixed bed consists of the preliminary separation of reaction effluent from the hydrotreating reactor (HT) by one or more separators operating at elevated pressure and elevated temperature.

Since the heavy part extracted from the bottom is sent to the main distillation unit, the aliquot that is extracted from the top, a C5 fraction at 350 ° C, is sent to a secondary treatment section in the presence of hydrogen, available at high pressure where the reactor is of the fixed bed type and contains a typical desulphurization / dearomatization catalyst to obtain a product having a considerably reduced sulfur content and also low nitrogen contents, a lower total density and at the same time increased cetane numbers as far as the diesel fraction is involved. The hydrotreating section usually consists of one or more reactors in series; The product of this system may subsequently be further distilled off to obtain a completely desulphurized naphtha and diesel diesel within specification as a fuel. The fixed bed hydrodesulfurization step typically utilizes typical fixed bed catalysts for diesel hydrodesulfurization; said catalyst, or possibly a mixture of catalysts or a series of multi-catalyst reactors having different properties, causes a deep refinement of the light fraction, significantly reducing the sulfur and nitrogen content, increasing the degree of hydrogenation of the feedstock, thereby decreasing the density and increasing the cetane number of the diesel fraction while reducing coke formation. The catalyst usually consists of an amorphous part based on alumina, silica, silica-alumina and mixtures of different mineral oxides, in which a hydrodesulfurization component in association with a hydrogenation product is deposited (with various methods). Molybdenum or tungsten based catalysts with the addition of nickel and / or cobalt deposited in an amorphous mineral carrier are typical catalysts for this type of operation. The post-treatment hydrogenation reaction is performed at a slightly lower absolute pressure than that of the primary hydrotreating step, usually ranging from 7 to 14 MPa, preferably from 9 to 12 MPa; the hydrodesulfurization temperature ranges from 250 to 500 ° C, preferably from 280 to 420 ° C; The temperature usually depends on the required desulphurization level. Space velocity is another important variable in the quality control of the product obtained: it can range from 0.1 to 5 h "1, preferably from 0.2 to 2 h1. The amount of hydrogen mixed with the feedstock is fed at a flow rate ranging from 100 to 5,000 Nm3 / m3, preferably from 300 to 1,000 Nm3 / m3.

An embodiment of the present invention is now provided with the aid of the included figure 1, which is not to be construed as limiting the scope of the invention.

In fig. 1 the heavy load raw material (1) is sent to the disassembly unit (SDA): this operation is performed by means of a solvent extraction operation.

Two streams are obtained from the disphalting unit (SDA): one stream (2) consisting of de-asphalted oil (DAO), the other stream containing asphaltenes (3). The asphaltenes-containing stream (3) is sent to a gasification section (POx) to obtain singas, that is, a gas mixture of H2 and CO (4). The stream consisting of gas-scrubbed oil (2) is mixed with the freshly prepared catalyst (5) (required for the reintegration of this loss with the stream (15) described below) and the stream (14) (described below). ) coming from the bottom of the distillation or flash evaporation column (D) to form the stream (6) that is fed into the hydrotreating reactor (HT) into which hydrogen (or a mixture containing hydrogen and H2S) (7) is fed . Hydrogen feed can be part of the hydrogen that comes from the gasification step (POJ (not outlined in the figure).

A stream (8) from the reactor (HT), containing the hydrogenation product and the dispersed phase catalyst, which is fractionated into an instantaneous distillation or evaporation column (D) of which the lightest fraction (9) separates together with the distillables (10), (11) and (12) from the distillation residue (13) containing the dispersed catalyst and coke.

This stream (13) (called tarred) is mostly recycled (14) in the hydrotreating unit (HT), the remaining part (15) being sent to the gasification section (POx).

An example is provided for a better understanding of the invention, it being understood that the invention should not be construed as being limited to this or so.

Example 1 Following the scheme shown in Figure 1, the following experimentation was performed.

De -phalphalation step (SDA) • Cargo raw material; 250 g of Ural Crude Oil Vacuum Waste (Table 1) • Dephrasing agent: about 2.5 liters of n-pentane • Temperature: 180 ° € • Pressure: lóatm. The vacuum residue is autoclaved together with a volume of n-pentane of 8 to 10 times the volume of the residue. The mixture of feedstock and solvent is heated to a temperature of 180 ° C with stirring (800 rpm) by means of a mechanical booster for a period of 30 minutes. At the end of the operation, decantation occurs as well as the separation between the two phases, the asphaltene phase that is deposited at the bottom of the autodave and that of the diluted desphalting oil in the solvent. The decantation remains for about two hours. The DAO-solvent phase is transferred via a suitable recovery system to a second tank. The DAO-pentane phase is then recovered, and the solvent is subsequently evaporated off. The yield obtained by the described procedure is 82 wt.% Of the oil desphalted with respect to the starting vacuum residue.

The properties of RV Ural and de-asphalting (D AO C5) oil are shown in table 1.

Table 1: Characteristics of the vacuum residue Ural at 500 ° C and extracted n-C5 DAO DAO hydrotreating step

Catalytic tests were performed using a 30 cm3 agitated micro-autoclave according to the following general operating procedure: about 10 g of stock feedstock is introduced into the reactor and the catalyst precursor is added; The system is then pressurized with hydrogen and brought to temperature by an electrically heated furnace; The system is kept under agitation during the reaction by a spinning capillary system that operates at a rotational rate of 900 rpm; Moreover, the total pressure is kept constant by a system of automatic reintegration of the consumed hydrogen; the reaction is extinguished as soon as the test is completed; the autoclave is then depressurized and the gas collected in a sample bag; the gaseous samples are then sent for gas chromatographic analysis; The reactor products are recovered without the addition of any solvent, and analyzed for distillate distribution, sulfur content, nitrogen content, carbon residue and metal content.

Hydrotraiamenium tests were performed using DAO produced in the dephalting step according to the following procedure. The reactor was charged with DAO and the molybdenum compound and pressurized with hydrogen. The reaction was performed under the operating conditions shown in table 2, which indicates the data regarding product distribution and quality.

Table 2: Characteristics of the reaction product from the test according to Example 1 Example 2 The following experimentation was performed following the scheme shown in Figure 1, Desphalting Step (SDA) Performed as described in Example 1.

Hydrotreating step • Reactor; 3,500 in3 steel reactor equipped with magnetic stirring • Catalyst: 3,000 ppm Mo / charge added using an organometallic oil-soluble precursor containing 15% w / w metal • Temperature: 430 ° C • Pressure: 16 MPa hydrogen • Time Permanence: 3 h Using the DAO produced in the dephalting step, the hydrotreating tests were performed according to the procedure described below. The reactor was charged with DAO and the molybdenum compound and pressurized with hydrogen. The reaction was performed under the described operating conditions. Extinction was performed as soon as the test was completed; The autoclave was depressurized and the gas collected in a sample bag for gas chromatographic analysis. The liquid product present in the reactor was recovered and subjected to distillation in order to separate the residue by 500 ° C + from the other cut distillation portions. The distillation residue (500 ° C +) containing the catalyst was charged back to the reactor and mixed. with an adequate amount of DAO C5 previously prepared in order to keep the amount of the full-load raw material constant. This procedure was repeated until stabilization of the amount of residue obtained, that is, until stationary conditions were reached.

Distillation step • Carried out by laboratory equipment for the distillation of oil loading raw materials.

Experiment Results 6 consecutive DAO C5 hydrotreating tests were performed following the procedure mentioned above. The ratio between the amount of recycled waste and the amount of fresh feedstock achieved under these operating conditions was 0.47.

Claims (23)

1. Process for the conversion of heavy and extra-heavy feedstock by the combined use of at least three of the following process units: solvent disphalting (SDA), suspended phase catalyst (HT) hydroconversion, distillation or instantaneous evaporation (D), characterized by the fact that it comprises the following steps: * sending the heavy-load feedstock to a desphalting section (SDA) in the presence of solvents, obtaining two streams, one consisting of oil subjected to desphalation ( DÀO), the other containing asphaltenes; * mix the stream consisting of dephalting oil (DAO) with a suitable hydrogenation catalyst precursor with a concentration ranging from 350 to 30,000 ppm based on the concentration of the metal or metals present in the hydroconversion reactor, and send the obtained mixture to a hydrotreating (HT) reactor introducing hydrogen or a mixture containing hydrogen and H2S into the same reactor; * Send the stream containing the hydrotreating reaction product and the catalyst in the dispersed phase to one or more distillation or flash evaporation steps (D), by which the most volatile fractions are separated, including the gases produced in the reaction. hydrotreating, distillation residue (tar) or liquid coming from the flash evaporation unit containing a dispersed phase catalyst rich in metal sulphides produced by charge demetallization and possibly coke; * recycle at least part of the distillation residue (tar) or liquid from the flash evaporation unit containing catalyst in the dispersed phase rich in metal sulphides produced by charge demetallization and possibly coke in the hydrotreating section ( HT), * send the asphaltenes-containing stream obtained from the disphalting section (SDA) and the remaining portion of the distillation residue (tar) or liquid arising from the flash evaporation unit that has not been recycled into the hydrotreating section (HT) to a gasification section (POx) to obtain a mixture of H2 and CO. Process according to Claim 1, characterized in that the asphaltenes-containing stream obtained in the disphalting section (SDA) is sent to a coking or viscosity cancellation section. Process according to Claim 1, characterized in that the asphaltenes-containing stream obtained in the de-galling section (SDA) is used for fuel formulation or as a fuel for energy production or is used in cement works. Process according to Claim 1, characterized in that the gasification is effected by feeding to the gasification unit, in addition to the stock, oxygen and steam raw materials that react under exothermic conditions at a temperature of more than 1300 °. C and a pressure ranging from 30 to 80 bar, to produce mainly H2 and CO. Process according to Claim 1, characterized in that at least 80% by weight of the distillation residue (tar) or liquid arising from the vaporization unit is recycled in the hydrotreating section (HT). Process according to Claim 5, characterized in that at least 90% by weight of the distillation residue or liquid arising from the flash evaporation unit is recycled in the hydrotreating section (HT). Process according to Claim 6, characterized in that at least 99% by weight of the distillation residue or liquid arising from the flash evaporation unit is recycled in the hydrotreating section (HT). Process according to Claim 1, characterized in that part of the hydrogen obtained from the gasification section (POx) is sent to the hydrotreating step (HT). Process according to Claim 1, characterized in that the distillation steps are carried out under reduced pressure, ranging from 0.001 to 0.5 MPa. Process according to Claim 9, characterized in that the distillation steps are carried out under reduced pressure, ranging from 0.01 to 0.3 MPa. Process according to Claim 1, characterized in that the hydrotreating (HT) step is carried out at a temperature ranging from 360 to 450 ° C and at a pressure ranging from 3 to 30 MPa. Process according to Claim 11, characterized in that the hydrotreating (HT) step is carried out at a temperature ranging from 380 to 440 ° C and at a pressure ranging from 10 to 20 MPa. Process according to Claim 1, characterized in that the de-galling step (SDA) is carried out at a temperature ranging from 40 to 200 ° C and a pressure ranging from 0.1 to 7 MPa. A process according to claim 1, characterized in that the dephalting step (SDA) is a light paraffin having a number of carbon atoms ranging from 3 to 6. A process according to claim 14, characterized in that the dephalting step is a light paraffin having a number of carbon atoms ranging from 4 to 5. Process according to Claim 1, characterized in that the de-asphalting (SDA) step is carried out with solvent recovery in supercritical phase. Process according to Claim 1, characterized in that, prior to being sent to one or more distillation or instantaneous evaporation steps, the stream containing the hydrotreating reaction product and the dispersed phase catalyst is sent to a pre-separation step carried out under high pressure to obtain a light fraction and a heavy fraction, said heavy fraction alone being sent to said distillation step (s) (D). Process according to Claim 17, characterized in that the light fraction obtained by the high pressure separation step is sent to a secondary post-treatment hydrogenation step, thereby producing a lighter fraction containing gas. C 1 -C 4 and H 2 S and a heavier fraction containing hydrogenated naphtha and diesel fuel. Process according to Claim 18, characterized in that the post-treatment hydrogenation reaction is carried out at a pressure ranging from 7 to 14 MPa. Process according to Claim 1, characterized in that the hydrogenation catalyst is an easily decomposed precursor or a preformed compound based on one or more transition metals. Process according to Claim 20, characterized in that the transition metal is molybdenum. Process according to Claim 1, characterized in that the concentration of catalyst in the hydroconversion reactor ranges from 3,000 to 20,000 ppm. Process according to Claim 22, characterized in that the concentration of catalyst in the hydroconversion reactor ranges from 5,000 to 15,000 ppm.