CN1331992C - Process for the conversion of heavy feedstocks such as heavy crude oils and distillation residues - Google Patents

Abstract

Process for the conversion of heavy feedstocks selected from heavy crude oils, distillation residues, heavy oils coming from catalytic treatment, thermal tars, oil sand bitumens, various kinds of coals and other high-boiling feedstocks of a hydrocarbon origin known as black oils, by the combined use of the following three process units: hydroconversion with catalysts in slurry phase (HT), distilla tion or flash (D), deasphalting (SDA), comprising the follow ing steps: mixing at least part of the heavy feedstock and/or at least most of the stream containing asphaltenes obtained in the deasphalting unit with a suitable hydrogenation catalyst and sending the mixture obtained to a hydrotreatment reactor (HT) into which hydrogen or a mixture of hydrogen and H2S is charged; sending the stream containing the hydrotreatment reaction product and the catalyst in dispersed phase to one or more distillation or flash steps (D) whereby the different frac tions coming from the hydrotreatment reaction are separated; recycling at least part of the distillation residue (tar) or liquid leaving the flash unit, containing the catalyst in dispersed phase, rich in metal sulfides produced by demetallation of the feedstock and possibly coke, to the deasphalting zone (SDA) in the presence of solvents, optionally also fed with at least a fraction of the heavy feedstock, obtaining two streams, one consisting of deasphalted oil (DAO) and the other containing asphaltenes, characterized in that the stream containing the hydrotreatment reaction product and the catalyst in dispersed phase, before being sent to one or more distillation or flash steps, is subjected to a high pressure separation pre-step in order to obtain a light fraction and a heavy fraction, the heavy fraction alone being sent to said distillation step(s) (D).

Description

Process for the conversion of heavy feedstocks such as heavy crude oil and distillation residues

The present invention relates to a method for converting heavy feedstocks, including heavy crude oil, oil sand bitumen, distillation residues and various coals, by using a properly connected mixture consisting of fresh feedstock and conversion products Three main process units with stream as feed: hydroconversion of heavy feedstock unit with dispersed phase state catalyst, distillation unit and deasphalting unit, adding a light distillate, naphtha and gas to the three main units oil aftertreatment unit

The conversion of heavy crude oil, oil sands bitumen and petroleum residues into liquid products can be achieved essentially in two ways: one using only heat, and the other through a hydrotreating step.

Current research is mainly focused on hydroprocessing, since the thermal treatment process has some problems with the disposal of by-products, especially coke (obtained in quantities greater than 30% by weight relative to the feedstock), and the poor quality of the conversion products.

Hydroprocessing is the treatment of feedstock in the presence of hydrogen and a suitable catalyst.

Hydroconversion processes currently on the market use fixed-bed reactors or ebullated-bed reactors and usually consist of one or more transition metals (Mo, W, Ni, Co) supported on silica/alumina (or equivalent materials). etc.) catalysts.

Fixed-bed processes have considerable problems in handling exceptionally heavy feedstocks with high heteroatom, metal and asphaltene content, since these impurities can deactivate the catalyst rapidly.

A variety of ebullating bed processes have been developed and commercialized for processing these feedstocks, their performance is interesting, but they are complex and expensive.

Hydroprocessing processes operating with catalysts in the dispersed phase state may offer an attractive solution to the disadvantages encountered with fixed or ebullated bed processes. The fact that slurry processes are able to combine the advantages of great feedstock flexibility with high performance in terms of conversion and upgrading will, in principle, make them simpler from a process point of view.

The characteristic of the slurry process is that the catalyst particles exist in the form of small average particle size and can be effectively dispersed in the medium, so the hydrogenation process is simpler and plays a greater role in all positions of the reactor. The amount of coke generated is greatly reduced, and the quality of the modified raw material is higher.

The catalyst can be introduced in the form of a powder or an oil-soluble precursor of sufficiently small size. In the latter case, the active form of the catalyst (usually a metal sulfide) is formed in situ during its reaction or after appropriate pretreatment by means of thermal decomposition of the compounds used.

The metal component of the dispersed phase catalyst is typically one or more transition metals (preferably Mo, W, Ni, Co or Ru). Molybdenum and tungsten have more satisfactory properties than nickel, cobalt or ruthenium and even vanadium and iron (N. Panariti et al., Appl. Catal. A: Gen. 2000, 204, 203).

Although the use of dispersed phase catalysts solves most of the problems listed in the above process, there are still some disadvantages related to the lifetime of the catalyst itself and the quality of the resulting product.

In fact, the conditions of use of these catalysts (type of precursor, concentration, etc.) are extremely important from both an economic point of view as well as environmental impact.

Catalysts can be used in low concentrations (hundreds of ppm) in a "single-pass" process layout, but in this case the modification of the reaction product is usually insufficient (A. Delbianco et al., Chemtech, November 1995, 35). When operating with very high activity catalysts (such as molybdenum) and high catalyst concentrations (thousands of ppm metals), the resulting product is of much better quality, but it is necessary to recycle the catalyst.

The catalyst leaving the reactor can be recovered by separating it from the hydrotreated product (preferably obtained from the bottom of the distillation column downstream of the reactor) by conventional methods such as decantation, centrifugation or filtration (US-3240718, US-4762812). A portion of the catalyst is recycled back to the hydrogenation process without further treatment. However, catalyst recovered using known hydroprocessing methods is generally less active than fresh catalyst, and appropriate regeneration steps are necessary to restore catalytic activity and to recycle at least a portion of said catalyst back to the hydroprocessing reactor. Furthermore, these methods of catalyst recovery are expensive and extremely complicated from a process point of view.

The level of conversion achievable by all of the above hydroconversion processes depends on the feedstock and the type of process used, but in any case some unconverted residue (here referred to as tar) is produced at the limit of stability, depending on the situation The amount may vary from 15% to 85% of the starting material. The product is used to produce fuel oil, bitumen or as a feedstock for gasification processes.

In order to increase the overall conversion level of the resid cracking process, various schemes have been proposed which include the step of recycling more or less large amounts of tar in the cracking unit. In the hydroconversion process that adopts the catalyst to be dispersed in the slurry phase, the circulation of the tar makes the catalyst be recovered. A process whereby the recovered catalyst is recycled to the hydroprocessing reactor without additional regeneration steps while obtaining high quality product under favorable conditions.

This method includes the following steps:

Mixing heavy crude oil or distillation residue with a suitable hydrogenation catalyst and feeding the resulting mixture into a hydrotreating reactor filled with hydrogen or a mixture of hydrogen and _H2S ;

Send the stream containing the hydroprocessing reaction product and the catalyst in the dispersed phase state to the distillation zone to separate the volatile components (naphtha or gas oil);

The high boiling components from the distillation step are sent to the deasphalting step, thus producing two streams, one comprising deasphalted oil (DAO) and the other comprising asphaltenes, catalyst in dispersed phase state and possibly coke and rich in metals from the original raw material;

• Recycle of at least 60%, preferably at least 80%, of the metal-rich stream comprising asphaltenes, catalyst in dispersed phase state and possibly coke to the hydrotreatment zone.

As described in patent application IT-MI2001A-001438, it was later found that, in the case of the above-mentioned processes, the upgrading of heavy crude oil or oil sands bitumen into complex hydrocarbon mixtures for further conversion into components Different process layouts are available for raw materials for the oil process.

The heavy feedstock conversion method described in patent application It-MI2001A-001438 uses the combination of the following three process units: a hydroconversion unit (HT) with a catalyst in the slurry phase, a distillation or flash unit (D), a deasphalting unit ( SDA), characterized in that the three units start operating with a mixed stream of fresh raw material and recycled material, using the following steps:

Sending at least a portion of the heavy feedstock to a deasphalting section (SDA) in the presence of a solvent to produce two streams, one consisting of deasphalted oil (DAO) and the other consisting of asphaltenes;

Mixing the asphaltenes stream with the remainder of the heavy feedstock not sent to the deasphalting zone and a suitable hydrogenation catalyst and sending the resulting mixture to a hydrotreating reactor (HT) filled with hydrogen or a mixture of hydrogen and _H2S );

sending the stream containing the product of the hydroprocessing reaction and the catalyst in the dispersed phase state to one or more distillation or flashing steps (D), whereby volatile components are separated, including gases formed in the hydroprocessing reaction, naphtha and gas oil;

More preferably at least 80 wt% of the distillation residue (tar) or liquid leaving the flash unit comprising catalyst in dispersed phase state, metal-rich sulfides and possibly coke and various carbonaceous residues from the demetallization step of the feedstock At least 95 wt% is recycled to the deasphalting zone.

Flushing of the asphaltene stream leaving the deasphalting section (SDA) is usually required to ensure that these elements do not accumulate too much in the hydrotreating reactor and, in the event of catalyst deactivation, to remove a portion of the catalyst and replace it with fresh catalyst. This is generally unnecessary when the catalyst retains its activity for a long period of time, but when flushing is necessary for the reasons mentioned above, it is clear that some catalysts must be discarded even if they are far from completely deactivated. Furthermore, although the amount of purge streams (0.5-4% relative to feedstock) is extremely limited compared to other hydrotreating processes, they still present considerable utilization or disposal problems.

When it is necessary to use the heavy components of the complex hydrocarbon mixture (distillation column bottoms) produced by the process as feedstock for a catalytic cracking unit with simultaneous hydrocracking (HC) and fluid catalytic cracking (FCC), Said applications are particularly applicable.

The combination of catalytic hydrogenation unit (HT) and extraction process (SDA) enables the production of deasphalted oil with low content of impurities (metals, sulfur, nitrogen, carbonaceous residues), which can be more easily processed in the catalytic cracking process. be processed in.

However, another aspect to consider is that the naphtha and gas oil directly produced by the hydrotreating unit still contain many impurities (sulphur, nitrogen...) which must in any case be reprocessed in order to produce the final product.

It has now been found that the two components described in patent application IT-MI2001A-001438 and patent application IT-95A001095 can be decomposed by inserting an additional second post-treatment hydrogenation stage of C ₂ -500°C, preferably C ₅ -350°C components. A method (all incorporated into this patent application as a reference) is further improved.

The second post-treatment hydrogenation stage is to further hydrotreat the C ₂ -500°C component, preferably the C ₅ -350°C component, from the high pressure separator upstream of the distillation process.

It is an object of the present invention to be able to convert heavy oils selected from heavy crude oils, distillation residues, heavy oils from catalytic processes, thermal tars, oil sands bitumen, various coals, and other heavy The method for raw material conversion, this method has used following three process units in combination: adopt the hydroconversion (HT) unit of slurry phase state catalyst, distillation (D) unit, deasphalting (SDA) unit, comprise the following steps:

● mixing at least a part of the heavy feedstock and/or at least the majority of the asphaltenes-containing stream obtained in the deasphalting unit with a suitable hydrogenation catalyst and sending the resulting mixture to a tank charged with hydrogen or a mixture of hydrogen and _H2S Hydrotreating reactor (HT);

● sending the stream containing the hydroprocessing reaction product and the catalyst in the dispersed phase state to one or more distillation or flashing steps (D), thereby separating the different components from the hydroprocessing reaction;

● Recycle at least a portion of the distillation residue (tar) or liquid leaving the flash unit to the deasphalting area (SDA) where the solvent is present, containing catalyst in dispersed phase state, metal-rich sulphides from Optionally also at least a portion of the heavy feedstock as feed, resulting in two streams, one consisting of deasphalted oil (DAO) and the other consisting of asphaltenes, the process being characterized in that it contains hydrotreating reaction products and the stream of catalyst in the dispersed phase state will be subjected to a high-pressure separation pretreatment step before being sent to one or more distillation or flash steps to obtain a light component and a heavy component, and the heavy component is sent to the separate Distillation step (D) described above.

Light fractions from the high pressure separation step can be sent to the hydrotreating section to produce lighter fractions containing C ₁ -C ₄ gases and H ₂ S and heavier fractions containing hydrotreated naphtha and gas oil .

The method of inserting a second post-treatment hydrogenation section of a _C2-500 °C component, preferably a _C5-350 °C component, exploits the possibility of utilizing this component together with hydrogen at a higher pressure close to the hydrotreating reactor, Can get the following benefits:

It can produce fuels that can meet the most stringent sulfur content specifications (<10-50ppm sulfur) from extremely sulfur-rich oil feedstocks, and other characteristics of diesel engine gas oils such as density, PAH content and sixteenth Improvement in alkane number;

·The produced distillate has no stability problem.

The post-hydroprocessing process on a fixed bed is the pre-separation of the reaction output from the hydroprocessing reactor (HT) by means of one or more separators operating at high pressure and high temperature. The heavy part taken from the bottom is sent to the main distillation unit, and the part taken from the top, that is, the C ₂ -500°C component, preferably the C ₅ -350°C component, is sent to the second treatment zone where high-pressure hydrogen exists, and the reactor is a fixed bed reactors, with typical desulfurization/dearomatization catalysts, in order to obtain very low sulfur and nitrogen content, low overall density products, and increased cetane number for the gas oil fractions of interest .

The hydrotreating section usually consists of one or more reactors in series; the product of this system can then be further fractionated by distillation to produce fully desulfurized naphtha and diesel gas oil meeting fuel specifications.

The fixed bed hydrodesulfurization step usually uses a typical gas oil hydrodesulfurization fixed bed catalyst, which may be a catalyst mixture or a set of reactors equipped with catalysts of various properties. By significantly reducing sulfur and nitrogen content, increase the degree of hydrogenation of raw materials, thereby reducing the density of gas oil fractions and increasing the cetane number, while reducing the formation of coke, the light components are considerably refined.

The catalyst usually contains an amorphous part based on alumina, silica, silica-alumina and mixtures of various inorganic oxides, on which the hydrodesulfurization components are deposited (by various means) together with the hydrogenation reagent. Catalysts based on molybdenum or tungsten are typical catalysts for this type of operation, in addition to nickel and/or cobalt deposited on an amorphous material support.

The hydrogenation post-treatment reaction is carried out at an absolute pressure slightly lower than the pressure of the first hydrotreatment step, usually 7-14MPa, preferably 9-12MPa; the hydrodesulfurization temperature is 250-500°C, preferably 280-420°C; The temperature generally depends on the desired level of desulfurization. The space velocity is another important variable when the quality of the product obtained is to be controlled: it may be from 0.1 to 5 hours ⁻¹ , preferably from 0.2 to 2 hours ⁻¹ .

The amount of hydrogen mixed with the feedstock and fed into the stream is between 100-5000 Nm ³ /m ³ , preferably 300-1000 Nm ³ /m ³ .

In addition to the second aftertreatment hydrogenation section, there may optionally be a further second aftertreatment section for the purge stream.

Said second hydrogenation stage is an aftertreatment of the purge stream in order to significantly reduce its amount, allowing at least a portion of the still active catalyst to be recycled back to the hydrotreatment reactor.

In this case, the asphaltene-containing stream from the deasphalting section (SDA), called the purge stream, is sent to a treatment section with a suitable solvent, where the product is separated into a solid and a liquid Remove the solvent.

Optional flush effluent (preferably 0.5-10% by volume of fresh feedstock) treatment stage deoiling steps from solvent (toluene or gas oil or other stream rich in aromatics components) and liquid components vs. solid components Separate step composition.

At least a portion of said liquid components may be fed into:

· "Fuel oil pool", fed as is or after separation of the solvent and/or addition of an appropriate diluent;

• and/or sent as such to the hydrotreating reactor (HT).

In some specific cases, solvent and diluent liquid can be the same.

The solid components may be treated as such or, more advantageously, sent to selective recovery of transition metals or metals contained in transition metal catalysts (e.g. molybdenum) (relative to other metals present in the raw residue, nickel and vanadium), and optionally recycling the transition metal (molybdenum) rich stream back to the hydrotreatment reactor (HT).

Compared with traditional methods, this comprehensive approach has the following advantages:

The number of rinse components is greatly reduced;

Most of the flushing components can be converted into fuel oil by separating out metals and coke;

• The amount of fresh catalyst added to the feed to the first hydroprocessing step is reduced since at least a portion of the molybdenum extracted from the selective recovery treatment step is recycled.

The deoiling step is the treatment of the purge stream, which represents the minimization of the asphaltene component from the deasphalting section (SDA) of the heavy feedstock first hydrotreater, using solvents that bring the maximum possible amount of organic compounds into the The liquid phase leaves metal sulfides, coke, and more refractory carbonaceous residues (insoluble in toluene or similar products) in the solid phase.

Given the potential for spontaneous combustion of metallic components under very dry conditions, it is reasonable to operate in an inert atmosphere containing as little oxygen and moisture as possible.

Various solvents are advantageously used in this deoiling step; among them aromatic solvents such as toluene and/or xylene blends, hydrocarbon feedstocks obtained in plants such as gas oil produced or in refineries Available hydrocarbon feedstocks are eg light cycle oil from FCC units or thermal gas oil from visbreaking/thermal cracking units.

The operating rate can be increased by increasing the temperature and reaction time within a certain range, but for economic reasons, an excessive increase is not desirable.

The operating temperature depends on the solvent used and the pressure conditions employed; however, the recommended temperature range is 80-150°C; the reaction time may vary from 0.1-12 hours, preferably 0.5-4 hours.

The solvent/flush stream volume ratio is also an important variable to consider and can vary from 1-10 (vol/vol), preferably 1-5, more preferably 1.5-3.5.

Once the phase of mixing between the solvent and flushing streams is complete, the output is sent to the separation of the liquid and solid phases while maintaining agitation.

The operation method of this step can be one of the commonly used operation methods in industrial practice, such as decantation, centrifugation or filtration.

The liquid phase is then sent to the solvent stripping and recovery section, where the solvent is recycled back to the purge stream first treatment step (deoiling). The remaining heavies are preferred for refinery use because the stream is virtually metal-free and low in sulfur. If, for example, gas oil is used for processing operations, a portion of the gas oil may remain in the heavy product, bringing it into compliance with fuel oil pool specifications.

Alternatively the liquid phase is recycled to the hydrogenation reactor.

The solid portion can be disposed of as is, or otherwise treated to selectively recover catalyst (molybdenum) for recycling back to the hydroprocessing reactor.

In fact, it has been found that by adding a metal-free heavy feed such as a portion of deasphalted oil (DAO) from the plant's own deasphalting unit to the above solid phase and combining said system with acidified water (usually with a mineral acid) ) mixing, almost all of the molybdenum remains in the organic phase, while most of the other metals move into the aqueous phase. The two phases can be easily separated, after which the organic phase is preferably recycled to the hydrotreating reactor.

The solid phase is dispersed in a sufficient amount of organic phase (eg deasphalted oil from the same process) to which acidified water is added.

The ratio of the aqueous phase to the organic phase may vary from 0.3 to 3; the pH value of the aqueous phase may vary from 0.5 to 4, preferably from 1 to 3.

A wide range of heavy feedstocks can be processed: they can be selected from heavy crude oil, oil sands bitumen, various types of coal, distillation residues, heavy oils from catalytic processes such as heavy cycle oil from catalytic cracking processes, hydroconversion Process bottoms, thermal tars (e.g. from visbreaking or similar thermal processes) and other high boiling hydrocarbon feedstocks derived from what is commonly referred to in the art as black oil.

As far as common process conditions are concerned, reference may be made to the conditions specified in patent applications IT-MI2001A-001438 and IT-95A001095.

As described in patent application IT-95A001095, all heavy feedstocks can be mixed with a suitable hydrogenation catalyst before being sent to the hydrotreatment reactor (HT), provided that at least 60%, preferably at least 80% of the asphaltene-containing And the stream also containing catalyst in dispersed phase state and possibly coke and enriched in metals from the initial feedstock is recycled to the hydroprocessing zone.

As described in patent application IT-MI2001A-001438, a part of the heavy feedstock and at least mostly asphaltene-containing stream, which also contains catalyst in the dispersed phase state and possibly coke, is mixed with a suitable hydrogenation catalyst and sent to hydrotreatment reactor, while the rest of the heavy feedstock is sent to the deasphalting section.

As described in patent application IT-MI2001A-001438, at least a major part of the asphaltenes-containing stream (consisting essentially of said asphaltenes) is mixed with a suitable hydrogenation catalyst and fed to a hydrotreatment reactor, whereas All heavy feedstock is sent to the deasphalting section.

When only a portion of the distillation residue (tar) or liquid leaving the flash unit is recycled back to the deasphalting section (SDA), at least a portion of the remaining amount of said distillation or flash residue is optionally combined with at least a portion from the deasphalting The asphaltene-containing stream from section (SDA) is sent together to the hydrotreating reactor.

The catalyst used is selected from precursors decomposable in situ (metal naphthenates, metal derivatives of phosphoric acid, metal carbonyls, etc.) or from catalysts based on one or more transition metals such as Ni, Co, Ru, W and Mo The preformed compound of the latter is preferred because of its high catalytic activity.

The catalyst concentration ranges from 300 to 20000 ppm, preferably from 1000 to 10000 ppm, based on the metal or multimetal concentration present in the hydroconversion reactor.

The hydrotreating step is preferably carried out at 370-480°C, more preferably 380-440°C and 3-30 MPa, more preferably 10-20 MPa.

The hydrogen is fed into the reactor, which can be operated in both downflow and upflow modes and is preferably operated in an upflow mode. Said gases can be fed to different sections of the reactor.

The distillation step is preferably carried out under reduced pressure in the range of 0.0001-0.5 MPa, more preferably 0.001-0.3 MPa.

The hydroprocessing step may consist of one or more reactors operating within the conditions specified above. Part of the distillate produced in the first reactor can be recycled to subsequent reactors.

The deasphalting step by means of hydrocarbon or non-hydrocarbon (eg _C3 - _C6 alkanes or isoparaffins) solvent extraction is usually carried out at a temperature in the range of 40-200°C and a pressure in the range of 0.1-7 MPa. It can also be composed of one or more sections operating with the same or different solvents, and the solvent recovery step can be carried out in one or more steps under subcritical or supercritical conditions, so that the deasphalted oil (DAO) and residual oil can be further processed Fractionation.

The deasphalted oil (DAO) containing stream can optionally be blended with distillates and used as such as a synthetic crude, or as a feedstock for a fluid catalytic cracking or hydrocracking process.

Preferably, depending on the characteristics of the crude oil (metal content, sulfur and nitrogen content, carbonaceous residues) the heavy residue is fed either to the deasphalting unit or to the hydrotreating unit or both Change the feeding method of the whole process and adjust:

· The ratio between the heavy residue (fresh feedstock) sent to the hydrotreatment section and the heavy residue to be sent to deasphalting, said ratio is preferably 0.01-100, more preferably 0.1-10, even more preferably 1-5;

· The circulation ratio between the fresh raw material and tar sent to the deasphalting section, said ratio preferably varies between 0.01-100, more preferably 0.1-10;

· the recycle ratio of fresh feedstock to asphaltenes fed to the hydrotreatment section, said ratio being variable according to variations of these ratios mentioned above;

• The recycle ratio of tars and asphaltenes fed to the hydrotreatment section, which ratio can be varied according to variations of the aforementioned ratios.

This flexibility is particularly useful for fully exploiting the complementary characteristics of the deasphalting unit (reduction of dispersed nitrogen and removal of aromatics) and the hydrogenation unit (high removal of metals and sulfur).

Depending on the type of crude oil, the stability of the stream under study and the quality of the product obtained (also related to the specific downstream processing steps), the fraction of fresh feedstock fed to the deasphalting and hydrotreatment stages can be optimally adjusted.

When the heavy components (distillation bottoms) of the complex hydrocarbon mixture produced by the process are used as feedstock to a catalytic cracking unit carrying out simultaneous hydrocracking (HC) and fluid catalytic cracking (FCC), said application Especially applicable.

The combination of catalytic hydrogenation unit (HT) and extraction process (SDA) enables the production of deasphalted oil with low content of impurities (metals, sulphur, nitrogen, carbonaceous residues) and thus easier to process in catalytic cracking process deal with.

A preferred embodiment of the invention is presented below with the aid of the accompanying drawing 1, which should in no way be considered as limiting the scope of the invention itself.

The heavy feedstock (1) or at least a part thereof (1a) is sent to a deasphalting unit (SDA), which is operated by means of solvent extraction.

Two streams are produced from the deasphalting unit (SDA): one is the deasphalted oil (DAO) containing stream (2) and the other is the asphaltene containing stream (3).

Combine the asphaltene-containing stream except the flushing stream (4) with the additional fresh catalyst (5) required to compensate for the loss with the flushing stream (4), and a part of the heavy raw material (1b) that has not been sent to the deasphalting section , a portion of the tar (24) not sent to the deasphalting section (SDA) and optionally a stream (15) from the flushing treatment section (described further below) are mixed to form a stream (6) which is sent to hydrogen charging ( or hydrogen and H ₂ S mixture) (7) of the hydroprocessing reactor (HT). A stream ( 8 ) comprising hydrogenation products and catalyst in dispersed phase state leaves the reactor and is first fractionally distilled in one or more separators (HP Sep) operated at high pressure. The top component (9) is sent to a fixed bed hydrotreating reactor (HDTC ₅ -350) to produce a light component (10) containing C ₁ -C ₄ gas and H ₂ S and hydrogenated naphtha _C5 -350°C Components of Oils and Gas Oils (11). Heavies (12) leave the bottom of the high pressure separator and undergo fractional distillation in a fractionation column (D) to separate the vacuum gas oil (13) from the distillation residue containing dispersed catalyst and coke. This stream, called tar (14), is recycled to the deasphalting reactor (SDA) in its entirety or in its major part (25) excluding the aforementioned components (24).

The flushing stream (4) can be sent together with the solvent (16) to a hydrotreatment section (deoiling), forming a mixture (17) comprising liquid and solid components. The mixture is sent to a solids treatment section (solid separation), from which a solid effluent ( 18 ) is separated, as well as a liquid effluent ( 19 ), the latter being sent to a solvent recovery section (solvent recovery). The recovered solvent (16) is sent back to the deoiling section, while the heavy effluent (20) is sent to the fuel oil fractionation process (22) as it is or with the addition of possible diluent liquid (21).

The solid component (18) can be disposed of as such, or, as described below and in the examples, optionally it can be sent to an additional processing zone (filter cake processing), resulting in a substantially molybdenum-free component to be sent for disposal (23) and the molybdenum-rich component (15) to be recycled back to the hydrotreating reactor.

In order to better illustrate the present invention, some examples are provided below, but they should not be regarded as limiting the scope of the present invention in any way.

Example 1

According to the flowchart shown in Figure 1, the following experiments were carried out.

Deasphalting step

Feedstock: 300 g vacuum residue from Urals crude oil (Table 1)

· Deasphalting reagent: 2000 ml liquid propane (repeated extraction three times)

·Temperature: 80℃

·Pressure: 35 bar

Table 1: Properties of 500°C ⁺ Ural Vacuum Residue

API Severity 10.8 Sulfur (% (weight)) 2.6 Nitrogen (% (weight)) 0.7 Kang's carbon residue (% (weight)) 18.9 Ni+V(ppm) 80+262

Hydrotreating step

Reactor: 3000 ml, steel, suitable shape and equipped with magnetic stirrer

Catalyst: 3000ppm Mo/adding raw material, using molybdenum naphthenate as precursor

·Temperature: 410℃

·Pressure: 16MPa hydrogen pressure

·Stay time: 4 hours

flash step

· Performed with a liquid evaporation laboratory apparatus (T = 120°C)

Experimental results

In order to fully recycle the catalyst added in the first experiment, 10 consecutive deasphalting experiments were carried out, each experiment using the usual deasphalting reaction obtained from the Ural residue (fresh feedstock) and the _C3 asphaltene hydrotreating reaction in the previous step. Raw material composed of pressed residue. For each step, a certain amount of feedstock consisting of Urals vacuum residue (fresh feedstock) and _C3 asphaltenes from the deasphalting unit is fed into the autoclave so that the total mass of fed feedstock (fresh feedstock + The recycled _C3 asphaltenes) reached an initial value of 300 g.

Under these operating conditions, the ratio between the amount of fresh feedstock and the amount of recycled product is 1:1.

The relevant data (% by weight relative to starting material) for the discharge stream after the last cycle are given below.

Gas: 7%

Naphtha (C ₅ -170°C): 8%

Atmospheric gas oil (AGO, 170-350°C): 17%

·Deasphalted oil (VGO+DAO): 68%

The asphaltene stream recovered at the end of the experiment contained all the catalyst initially fed, metal Ni and V sulfides formed during the 10 hydrotreating reactions, and about 1 wt. coke. In the described examples, no flushing step of the recycle stream is required. Table 2 lists the properties of the products obtained.

Table 2: According to the experimental reaction product characteristic of embodiment 1

Sulfur (% (weight)) Nitrogen (% (weight)) Specific gravity (g/ml) RCC (% (weight)) Ni+V(ppm) Naphtha C ₅ -170°C 0.06 450 0.768 - - AGO 170-350℃ 0.52 2100 0.870 - - VGO+DAO 1.45 2500 0.938 3 1

Example 2

Following the scheme shown in Figure 1, the product exiting the top of the high pressure separator is sent to a fixed bed reactor where it is fed with a downwardly flowing reagent stream. The reactor was loaded with a typical commercially available hydrodesulfurization catalyst based on molybdenum and nickel.

The operating conditions are as follows:

LHSV: 0.5 hours ^-1

Hydrogen pressure: 10MPa

Reactor temperature: 390°C

Table 3 shows the quality of the feed to the fixed bed reactor and the quality of the product produced.

Table 3: Hydrotreating of C ₅ -350°C components obtained from 500°C ⁺ Ural residue treatment

raw material product Specific gravity (g/ml) 0.8669 0.8294 Monocyclic aromatic hydrocarbons (% (weight)) 30.1 19.5 Bicyclic aromatic hydrocarbons (% (weight)) 8.3 1.2 Tricyclic aromatic hydrocarbons (% (weight)) 2.8 0.4 PAH (% (weight)) 11.1 1.6 Sulfur (ppm) 5300 37 Nitrogen (ppm) 2280 3 Distillation curve T ₁₀ (℃) 187 145 T ₅₀ (℃) 271 244 T ₉₀ (℃) 365 335

Example 3

20.7 g of the flush stream from the Ural resid 500°C ⁺ conversion unit (composition listed in Table 4) was treated with 104 g of toluene (solvent/flush stream weight ratio 5) at 100°C for 3 hours. The resulting fractions were filtered. 3.10 g of solids (composition listed in Table 5) and 17.60 g of heavy oil (after evaporative removal of toluene) with the metal content listed in Table 6 were collected.

Table 4: Properties of flushing stream from Ural residue processing 500°C ⁺

Specific gravity (g/ml) 1.1 S (% (weight)) 2.4 Mo (% (weight)) 0.68 Ni (% (weight)) 0.12 V (% (weight)) 0.36 Fe(%(weight)) 0.07

Table 5: Solids (filter cake) properties from treatment of Urals resid 500°C ⁺ flush stream with toluene

C (% (weight)) 82.0 H(%(weight)) 3.9 S (% (weight)) 4.8 Mo (% (weight)) 4.1 Ni (% (weight)) 0.6 V (% (weight)) 2.2 Fe(%(weight)) 0.4

Table 6: Metals content in heavy oil extracted from Ural residue 500°C ⁺ treatment flush stream

Mo(ppm) 10 Ni(ppm) 26 V(ppm) twenty three Fe(ppm) 10

Example 4

Using the same steps described in Example 3, 10.6 grams of flushing stream (composition listed in Table 4) was treated with 62 milliliters of gas oil (produced during the Ural residue hydrotreating experiment carried out according to the steps described in Example 1 above) and having the qualities listed in Table 2), the ratio of gas oil/flush stream was 5, and the operation was carried out at 130° C. for 6 hours. The produced fractions were centrifuged (5000 rpm). 1.78 grams of solids (composition listed in Table 7) and 8.82 grams of heavy oil (after gas oil removal by evaporation) were collected.

Table 7: Solids (filter cake) properties obtained from treatment of Ural 500°C ⁺ flush stream with gas oil

Mo (% (weight)) 3.43 Ni (% (weight)) 0.53 V (% (weight)) 1.75

Example 5

1.0 g of the solid residue (obtained from the process described in Example 3, composition listed in Table 5) was mixed with 50 ml of acidified water (pH=2) and 50 ml of deasphalted oil (DAO) of the composition listed in Table 8 to process.

After 24 hours at 70°C, the liquid phase was decanted and both phases were analyzed for metals.

The entire amount (>99%) of molybdenum remained in the organic phase, while nickel and vanadium were found in the aqueous phase, in amounts corresponding to extraction yields of 23.5% and 24.4%, respectively.

Then the molybdenum-containing organic phase is sent to the hydrotreating experiment together with the fresh Ural residue oil, and the steps described in Example 1 are carried out, and the molybdenum keeps its catalytic activity property.

Table 8: DAO characteristics from Ural 500°C ⁺ residue treatment process

Sulfur (% (weight)) Nitrogen (ppm) Specific gravity (g/ml) RCC (% (weight)) Ni+V(ppm) DAOs 1.02 2100 0.934 3 <1

Example 6

The same procedure as described in Example 5 was followed, but using gas oil produced during the hydrotreatment of the Ural residue (see Example 1) (instead of DAO) and acidified water (pH=2).

The entire amount of molybdenum remained in the organic phase, while nickel and vanadium were found in the aqueous phase in amounts corresponding to extraction yields of 41.0% and 26.8%, respectively.

Claims (36)

1. an energy will be selected from the method that heavy crude, distillation residue, the heavy oil from the catalytic treatment process, thermal tar, oil sands bitumen, various coal and some other heavy feed stock that is derived from the hydro carbons high boiling point raw material that is called dirty oil transform, described method is used in combination following three technique units: adopt hydrocracking unit, distillation or flash evaporation unit, the diasphaltene unit of slurry phase state catalyzer, may further comprise the steps:

● the materials flow of at least a portion heavy feed stock and/or most of at least asphaltenes that obtains in the diasphaltene unit is mixed with suitable hydrogenation catalyst, and the mixture that obtains delivered to charge into hydrogen or hydrogen and H ₂The hydrotreating reactor of S mixture;

● one or more distillation or flash distillation step are sent in the materials flow that will contain hydrotreatment reaction product and disperse phase state catalyzer, thereby will separate from the different components of hydrotreatment reaction;

● contain rich metallic sulfide that disperse phase state catalyzer, raw material demetalization process generate and distillation residue that may coke or liquid circulation to the diasphaltene district that has solvent with what at least a portion was left flash evaporation unit, optional also have at least a portion heavy feed stock as charging, obtain two bursts of materials flows, one is made of deasphalted oil and another strand is made of bituminous matter;

Be characterised in that: the materials flow that contains hydrotreatment reaction product and disperse phase state catalyzer wanted advanced horizontal high voltage to separate pre-treatment step before being sent to one or more distillation or flash distillation step, obtain light component and heavy component, separately heavy component is delivered to described distilation steps.

2. contain C by the process of claim 1 wherein that the light component that the high pressure separating step is obtained sends into the second hydrogenation aftertreatment section, generating ₁-C ₄Gas and H ₂S than light constituent and contain hydrotreated naphtha and the heavy component of gas oil.

3. by the method for claim 2, wherein hydrogenation aftertreatment reaction is what to carry out under the pressure of 7-14MPa scope.

4. by at least one method among the claim 1-3, wherein all heavy feed stocks to be mixed with the hydrogenation catalyst that is fit to, and send into hydrotreating reactor, and asphaltenes that will at least 60% and also contain disperse phase state catalyzer and may coke and the materials flow of being rich in from the initial feed metal be recycled to the hydrotreatment district.

5. by the method for claim 4, wherein general at least 80% asphaltenes materials flow is recycled to the hydrotreatment district.

6. press the method for claim 1, wherein with a part of heavy feed stock and most of at least asphaltenes and also contain disperse phase state catalyzer and materials flow that may coke mixes with suitable hydrogenation catalyst, and send into hydrotreating reactor, and the heavy feed stock of remainder is sent into the diasphaltene section.

7. by the process of claim 1 wherein, constitute by described bituminous matter substantially, mix with the hydrogenation catalyst that is fit to, and send into hydrotreating reactor, and all heavy feed stocks are sent into the diasphaltene section most at least asphaltenes materials flow.

8. by the process of claim 1 wherein that distillation residue or liquid circulation that a part is left flash evaporation unit go back to the diasphaltene district and the described distillation or the flash distillation residual oil of at least a portion residual content are sent into hydrotreating reactor.

9. by the method for claim 8, wherein at least a portion distillation or flash distillation residual oil are sent into hydrotreating reactor with at least a portion from the asphaltenes materials flow of diasphaltene section.

10. by the process of claim 1 wherein that the distillation residue with at least 80 weight % is recycled to the diasphaltene district.

11. by the method for claim 10, wherein the distillation residue with at least 95 weight % is recycled to the diasphaltene district.

12. by the process of claim 1 wherein that the residual content distillation residue that at least a portion is not recycled to the diasphaltene district is recycled to the hydrotreatment section.

13. by the process of claim 1 wherein that distilation steps carries out under the reduced pressure of 0.0001-0.5MPa scope.

14. by the method for claim 13, wherein distilation steps carries out under the reduced pressure of 0.001-0.3MPa scope.

15. by the process of claim 1 wherein that hydrotreating step carries out under 370-480 ℃ of range temperature and 3-30MPa pressure.

16. by the method for claim 15, wherein hydrotreating step carries out under the pressure of the temperature of 380-440 ℃ of scope and 10-20MPa scope.

17. by the process of claim 1 wherein that the diasphaltene step carries out under the pressure of the temperature of 40-200 ℃ of scope and 0.1-7MPa.

18. by the process of claim 1 wherein that deasphalting solvent is C ₃-C ₇Light paraffins.

19. by the process of claim 1 wherein the diasphaltene step under subcritical or super critical condition, divide one or multistep carry out.

20. by the process of claim 1 wherein that the materials flow that deasphalted oil constitutes carries out fractionation with traditional distillation method.

21. by the process of claim 1 wherein that the materials flow that deasphalted oil is constituted mixes with separated products after the distilation steps condensation.

22. by the process of claim 1 wherein that but hydrogenation catalyst is decomposition of precursors or the premolding compound based on one or more transition metal.

23. by the method for claim 22, wherein transition metal is a molybdenum.

24. by the process of claim 1 wherein that the concentration of catalyzer in the hydroconversion reactions device is 300-20000ppm by the metal concentration that exists.

25. by the method for claim 24, wherein the concentration of catalyzer in the hydroconversion reactions device is 1000-10000ppm.

26. method by claim 1, wherein the part that is called the asphaltenes materials flow of washing materials flow from the diasphaltene section to be sent into the treatment zone of suitable solvent, so that product is separated into solid ingredient and liquid ingredient, from liquid ingredient, shift out described solvent subsequently.

27., wherein wash materials flow R amount and be the 0.5-10 volume % of fresh feed by the method for claim 26.

28. by the method for claim 26, wherein from the liquid ingredient of flushing treatment zone in statu quo or isolate solvent and/or add and be fit to dilution and send into later in the oil fuel component with liquid with at least a portion.

29., wherein at least a portion is recycled to hydrotreating reactor from the liquid ingredient that washes treatment zone by the method for claim 28.

30. by the method for claim 26, wherein the solvent that uses in flushing materials flow processing section is aromatic solvent or that produce or that refinery provides the certainly gas oil mixture of present method.

31. by the method for claim 30, wherein aromatic solvent is toluene and/or xylene mixture.

32. by the method for claim 26, wherein the volume ratio of solvent/flushing materials flow is 1-10.

33. by the method for claim 32, wherein the volume ratio of solvent/flushing materials flow is 1-5.

34. by the method for claim 33, wherein the volume ratio of solvent/flushing materials flow is 1.5-3.5.

35. by the method for claim 26 and 22, the solid ingredient that wherein will handle product is delivered to the treating processes of the contained transition metal of further selective recovery hydrogenation catalyst.

36., wherein the transition metal that reclaims is recycled to hydrotreating reactor by the method for claim 35.