KR100783448B1 - Process for hydrotreating a heavy hydrocarbon fraction with permutable reactors and reactors that can be short-circuited - Google Patents

Abstract

In the hydroprocessing process according to the invention, after the heavy hydrocarbon fractionation in the first hydrodesulfurization section is hydrotreated, the effluent from the first hydrodesulfurization section is introduced into the second hydrodesulfurization section. At least one guard zone is located before the hydrodemetallization section. The hydrogenation treatment step,

a) using a guard zone;

b) shorting the guard zone and regenerating and / or replacing the catalyst contained in the guard zone;

c) reconnecting the guard zone where the catalyst has been regenerated and / or replaced; And

d) shorting at least one of the reactors from the hydrodesulfurization section and / or the hydrodesulfurization section and regenerating and / or replacing the catalyst contained in the reactor

It includes.

Description

PROCESS FOR HYDROTREATING A HEAVY HYDROCARBON FRACTION WITH PERMUTABLE REACTORS AND REACTORS THAT CAN BE SHORT-CIRCUITED}

The present invention is particularly obtained from sulfur impurities and metal impurities (e.g. atmospheric residues, vacuum residues, deasphalted oils, pitches, asphalt mixed with aromatics, coal hydrides, heavy oils of any type, in particular bituminous schist or sand). Heavy oil) containing heavy hydrocarbons). Specifically, the present invention relates to the treatment of liquid raw materials. In addition, the scope of the present invention includes asphaltenes also contained in the liquid raw material.

Raw materials that can be treated according to the invention usually comprise at least 0.5 ppm by weight of metals (nickel and / or vanadium) and at least 0.5% by weight of sulfur.

The purpose of catalytic hydrogenation of such raw materials is twofold: to substantially reduce the content of the metal components, sulfur components and other impurities contained in them, at the same time converting the raw materials and making them harder than large or small. As a phosphorus fraction, it increases the ratio of hydrogen to carbon (H / C), and the other effluents thereby obtained are the basic raw materials for producing high quality fuels, gas oils and gasoline, or residue cracking or cracking decompression fractions. It can be used as a raw material for other units.

The problems associated with the catalytic hydrogenation of such raw materials stem from the fact that such impurities gradually accumulate in the catalyst in the form of metals and coke, rapidly dissipating the catalyst system and thus obstructing the catalyst system and thus stopping the catalyst system for replacement. Is caused.

Therefore, the process for hydroprocessing the raw material of this type should be designed to make the operation cycle as long as possible without stopping the unit, and the goal is to obtain an operation cycle of at least one year.

There are several types of treatments for this type of raw material. Until now, such processing,

In a process using a fixed catalyst bed (e.g. HYVAHL-F from Institut Francais du Petrole), or

A process comprising at least one reactor in which the catalyst can be replaced semi-continuously (eg HYVAHL-M mobile phase process from Institut Francais du Petrole)

Has been implemented.

The process of the present invention is an improvement on prior art processes, in particular fixed bed processes or ebullated bed processes. In such a process, the raw material is circulated through a plurality of reactors (preferably fixed bed reactors or boiling phase reactors) arranged in series. The first of the plurality of reactors is used in particular to carry out part of the hydrodesulfurization (HDM) of the raw materials and hydrodesulfurization. The final reactor is used for performing deep refining of the raw materials and in particular for hydrodesulfurization (HDS step). The effluent is withdrawn from the final HDS reactor.

In such a process, a catalyst specified for each stage is usually used, in which case the average operating conditions are from about 5 MPa to about 25 MPa, preferably from about 10 MPa to about 20 MPa, and the temperature is from about 370 ° C. to 420 ℃.

The ideal catalyst in the HDM stage should be suitable for the processing of asphaltene-rich raw materials, have a high demetallization capacity associated with high metal holding capacity and have high resistance to coking. The Applicant has developed a catalyst on a special macroporous support ("sea urchin" structure), which gives the catalyst the following characteristics exactly required for this step (European Patent EP-B-0 113 297). And EP-B-0 113 284).

Demetallization rate in the HDM step is at least 10% to 90%.

Metal holding capacity exceeding 10% by weight of new catalyst. This extends the operating cycle.

· Excellent resistance to coking at temperatures over 390 ℃. This contributes to extending the cycle duration, which is often limited by the loss of activity and increased pressure loss due to coke production. This excellent resistance allows most of the thermal conversion to be done at this stage.

The ideal catalyst for the HDS step should be hydrogenated so that the product can be subjected to depth purification (desulfurization, reducing the amount of Conradson carbon and possibly asphaltenes with continuous demetallization). Applicants have also developed catalysts (EP-B-0 113 297 and EP-B-0 113 284) which are particularly suitable for such types of raw materials.

The drawback of the catalyst of the above-described type, which is excellent in hydrogenation power, is that activity is quickly lost when metal or coke is present. For this reason, a combination of a suitable HDM catalyst capable of operating at relatively high temperatures and carrying out most of the conversion and demetallization and a suitable HDS catalyst protected from metals and other impurities by this HDM catalyst and capable of operating at relatively low temperatures, Refining performance is generally better than that achieved with a single catalyst system or with an array of HDMs / HDSs that result in rapid coking of HDS catalysts using profiles that raise the temperature. outstanding.

The significance of the fixed bed process is to obtain high purification performance due to the high catalytic efficacy of the fixed bed. However, if the amount of metal in the raw material exceeds a certain level (such as 50 to 150 ppm), even with a better catalyst, the performance of the process and in particular the operating period by such a method are insufficient. This is because the reactor (particularly the first HDM reactor) accumulates metal very quickly and loses activity. To compensate for such loss of activity, raising the temperature promotes coke formation and increases pressure loss. It is also known that the first catalyst phase can be blocked very quickly due to the asphaltenes and precipitates contained in the raw materials or due to operational problems.

As a result, the unit must be shut down at least every two to six months, and this operation to replace the lost or occluded first catalyst phase can take up to three weeks, further reducing the utilization of the unit.

The significance of the boiling phase is that it is possible to work at high temperatures, and the conversion performance is excellent. Applicant has developed a process that is very suitable for the processing of conventional heavy raw materials (Canada patent CA-2 171 894, French patent application FR-98 / 00530).

Although the best catalyst system is used, the operation time can be reduced when problems arise with the operation and / or when used on unsuitable raw materials. The unit is then stopped according to the amount of coke present in the reactor. Applicants have attempted to solve such manipulation problems and problems associated with the use of catalysts.

Applicants have also tried to overcome the drawbacks of the fixed phase approach in other ways.

Thus, one or more mobile phase reactors have been proposed, installed prior to the HDM stage (US Pat. No. US-A-3 910 834 or UK Pat. GB-B-2 124 252). Such mobile phases can be operated in co-current mode (eg SHELL's HYCON process) or in counter-current mode (eg Applicant's HYVAHL-M process). . This can protect the reactor, such as a fixed bed reactor, by carrying out part of the demetallic reaction and by filtering the particles contained in the raw material which may cause the blockage. In addition, in the mobile phase reactor the catalyst is replaced semi-continuously, eliminating the need to shut down the unit every three to six months.

The drawbacks of such mobile phase techniques are that their overall performance and efficiency are somewhat lower than those of fixed-size techniques of the same scale, which leads to abrasion in order to circulate the catalyst, which in turn impedes the flow in the stationary phase located downstream, under operating conditions in use. First of all, the risk of coking when using heavy feedstocks and the formation of catalyst aggregates exceed a particularly negligible level, especially when problems arise. Such catalyst agglomerates prevent the catalyst from circulating inside the reactor or the catalyst take-off line in use, and eventually cause the unit to shut down, resulting in the need to clean the reactor and the catalyst take-off line.

In order to maintain excellent performance while maintaining acceptable levels of utilization, it was considered to add a guard reactor, preferably a fixed bed reactor (space velocity HSV = 2 to 4) in front of the HDM reactor (US-A-4). 118 310 and US-A-3 968 026). Typically, this guard reactor can be shorted, in particular by using an isolation valve. The main reactor is then temporarily protected from occlusion. If the guard reactor is closed, it will be shorted, but then the main reactor may be blocked, resulting in a shutdown of the unit. In addition, the guard reactor is small in size, and in the case of a metal-rich raw material (for example, 100 ppm or more), it does not sufficiently perform a high degree of demetallization of the raw material, and thus does not sufficiently protect the main HDM reactor from metal deposition. . Thus, in these reactors, the frequency of loss of activity is accelerated, causing the unit to stop frequently, resulting in insufficient utilization.

FR-B1-2 681 871 handles raw materials with a high metal content (1 to 1500 ppm but mainly 100 to 1000 ppm, preferably 150 to 350 ppm), which has a system with good stationary phase performance and high utilization. Is disclosed. The system is carried out in at least two stages for the hydroprocessing of heavy hydrocarbon fractions containing sulfur impurities and metal impurities. In the first section, Hydrodemetallization, the hydrocarbon feedstock and hydrogen are hydrodemetallized catalyst under hydrodemetallization conditions. The effluent from the first section is then passed through a hydrodesulfurization catalyst under hydrodesulfurization conditions in a second step. In this process, the first hydrodemetallization section comprises at least one hydrodemetallization zone, preferably having a stationary phase, and in front of this hydrodemetallurgical zone, at least two hydrodemetallurgical guard zones which likewise have a stationary phase. Wherein the hydrodemetallization guard zones are arranged in series for cyclic use, consisting of successive repetitions of steps b) and c) defined as follows.

a) using the guard zones together for approximately the same period of time as the active dissipation time and / or occlusion time of one of the guard zones.

b) the loss of activity and / or occlusion guard zone is short-circuited and the catalyst contained in the guard zone is regenerated and / or replaced with a new catalyst.

c) a step in which all guard zones are used together, wherein the guard zone in which the catalyst has been regenerated in the preceding step is reconnected and is run for approximately the same period of time as the loss of activity and / or occlusion time of one of the guard zones.

This process typically has a cycle period of at least 11 months for the main HDM and HDS reactors, good purification and conversion performance, and maintains product stability. The overall desulfurization is about 90% and the overall demetallization is about 95%.

The disadvantages of this technique are that it is difficult to achieve a total desulfurization performance of more than about 90% and / or a total demetallization performance of more than about 95%, and a cycle time of 11 months regardless of the performance level. It is hard to exceed. Surprisingly, it has been found that shorting one or more reactors of the hydrodesulfurization section and / or hydrodesulfurization section allows for maintaining the activity of the catalyst and / or improving cycle time during each step.

1 is a diagram briefly illustrating the present invention.

The present invention relates to the possibility of shorting one or more reactors in order to regenerate the catalyst and / or replace it with a new or regenerated catalyst upon loss of activity of the catalyst and / or blockage by precipitate or coke. The present invention relates both to reactors from hydrodesulfurization sections and to reactors from hydrodesulfurization sections.

According to the invention, the reactor from the hydrodesulfurization section and / or the hydrodesulfurization section is shorted, eg every 6 months, to replace the lost or occluded catalyst bed, thereby improving the utilization of the unit. .

In the hydroprocessing process according to the invention, after the heavy hydrocarbon fractionation in the first hydrodesulfurization section is hydrotreated, the effluent from the first hydrodesulfurization section is introduced into the second hydrodesulfurization section. At least one guard zone is located before the hydrodemetallization section. The hydrogenation treatment step,

a) using a guard zone;

b) shorting the guard zone and regenerating and / or replacing the catalyst contained in the guard zone;

c) reconnecting the guard zone where the catalyst has been regenerated and / or replaced; And

d) shorting at least one of the reactors from the hydrodesulfurization section and / or the hydrodesulfurization section and regenerating and / or replacing the catalyst contained in the reactor

It includes.

One route for improving the performance of the stationary phase, also summarized below, is also described in Applicant's FR-A-2 784 687. The concept can also be applied to the present invention.

However, difficulties associated with high viscosity of the raw material and the overall liquid effluent, which can cause large pressure losses in the reactor, and operational difficulties of recycling compressors, which often lead to somewhat lower hydrogen pressures, resulting in poor hydrodemetallization or hydrodesulfurization. There is this. In addition, the gas oil fraction obtained has been found to be usually not directly usable since the sulfur component is higher than currently accepted specifications.

There is a need to improve the performance of the process as disclosed in the applicant's French applications FR-B1-2 681 871 and FR-A-2 784 687 and can do so. Specifically, since the process of the present invention can greatly reduce the viscosity of the liquid effluent, the pressure loss in the reactor is substantially lowered, so that the operation of the circulation compressor is improved, and higher hydrogen pressure can be obtained. As a result, the overall desulfurization is increased and the sulfur content in the gas oil fractionation is lower to meet the current specifications, which can be used directly in the gas oil pool of refineries. In addition, in the process of the present invention, the function of the preheating furnace is improved due to good thermal conductivity, so that the surface temperature of the preheating furnace can be lowered, and the service life of the preheating furnace is extended, contributing to the reduction of the operating cost of the unit.

The process of the present invention is a high performance reactor, preferably in combination with a fixed bed reactor or an boiling phase reactor, with a high utilization rate, a raw material rich in metal (1 to 1500 ppm, but usually 100 to 1000 ppm, preferably 150). To 350 ppm), but as one of its variants, it can be defined as a process for hydrotreating heavy hydrocarbon fractions containing sulfur impurities and metal impurities in at least two sections, according to this process, The hydrocarbon feedstock and hydrogen in the first hydrodesulfurization section are passed through a hydrodesulfurization catalyst under hydrodesulfurization conditions, and the effluent from this first step is passed through a hydrodesulfurization catalyst in a subsequent second section under hydrodesulfurization conditions, The first hydrodehydration section is at least one hydrodehydration, preferably in a stationary or boiling phase zone. At least one, or possibly two, hydrodesulfurization guard zones, which are preferably preferably stationary or boiling phases, are located in front of the hydrodesulfurization zone, wherein the hydrodesulfurization section is individually Or one or more reactors which may be shorted according to step d) as defined below. Hydrogenation process of the present invention,

a) all guard zones are used together for a period approximately equal to the time of active disappearance and / or occlusion of one of the guard zones;

b) short-circuit activity and / or occlusion guard zone and short-circuit the catalyst contained in the guard zone with regenerated and / or replaced with new or regenerated catalyst;

c) the guard zone in which the catalyst has been regenerated and / or replaced in the preceding step is reconnected and is run for approximately the same period of time or less than the active disappearance time and / or occlusion time of one of the guard zones; And

d) at least one of the reactors from the hydrodesulfurization section and / or hydrodesulfurization section when the catalyst requires regeneration of the catalyst upon activity loss and / or occlusion and / or replacement of the catalyst with a new or regenerated catalyst during the cycle. Steps to Short One

It is a hydrogenation process process containing.

Another variant of the process of the present invention is a process for hydroprocessing heavy hydrocarbon fractions containing sulfur impurities and metal impurities in at least two sections, wherein the hydrocarbon feedstock and hydrogen in the first hydrodemetallization section are hydrodemetallized. Pass the hydrodesulfurization catalyst under conditions, and the effluent from this first step is passed through a hydrodesulfurization catalyst in a subsequent second section under hydrodesulfurization conditions. The first hydrodemetallization section includes one or more hydrodemetallization zones, and at least one hydrodemetallization guard zone is located in front of the hydrodemetallization zone. The hydrodesulfurization section and / or hydrodesulfurization section consists of one or more reactors which can be shorted individually or in other ways after zone d) defined below. The hydrogenation treatment step,

a) the guard zone is used for approximately the same period of time as the loss of activity and / or occlusion time of the guard zone;

b) short-circuit activity and / or occlusion guard zone and short-circuit the catalyst contained in the guard zone with regenerated and / or replaced with new or regenerated catalyst;

c) reattaching the guard zone in which the catalyst has been regenerated and / or replaced in a preceding step, wherein the run is performed for approximately the same period of time as the loss of activity and / or occlusion of one of the guard zones; And

d) at least one of the reactors of the hydrodesulfurization section and / or the hydrodesulfurization section when the catalyst requires regeneration of the catalyst upon activity loss and / or occlusion and / or replacement with a new or regenerated catalyst during the cycle. Short circuit

It includes.

In one variant of the process of the invention, the raw materials used in the process are heavy hydrocarbon fractions containing sulfur impurities and metal impurities, generally at least 0.5 ppm by weight of metal, which can be obtained, for example, from vacuum distillation. In classification, it is referred to as reduced pressure fraction (VD).

During the process of the present invention, it is preferred that a certain amount of intermediate fraction is introduced into the first guard zone in an amount represented by about 0.5% to 80% by weight based on the hydrocarbon feed.

The amount of intermediate fraction introduced is more preferably from about 1% to about 50% by weight, most preferably from about 5% to about 25% by weight of the hydrocarbon feed.

In one specific embodiment, the middle fraction introduced with the hydrocarbon raw material is a direct gas oil.

In yet another embodiment, the product from the hydrodesulfurization step is sent to an atmospheric distillation zone, from which atmospheric pressure fraction and atmospheric residue are recovered, and at least a portion of the recovered atmospheric fraction is passed into the inlet of the first guard zone. Recirculation is carried out again to recover the atmospheric residue.

In one particular variant, at least a portion of the gas oil fraction from the atmospheric fraction is recycled. In this case, the gas oil fraction to be recycled is usually an oil having an initial boiling point of about 140 ° C and a final boiling point of about 400 ° C. This fraction is typically a 150-370 ° C. fraction or a 170-350 ° C. fraction.

In another possible variant of the process of the invention, the gas oil from the unit operating using the HYVAHL process can be recycled. Or from a catalytic cracking unit, commonly referred to as LCO (light cycle oil), where the initial boiling point is generally in the range of about 140 ° C to about 220 ° C and the final boiling point is generally in the range of about 340 ° C to about 400 ° C. Light gas oil may also be recycled. Also, heavy gas from catalytic cracking, commonly referred to as HCO (high cycle oil), where the initial boiling point is in the range of about 340 ° C to about 380 ° C, and the final boiling point is generally in the range of about 350 ° C to about 550 ° C. The oil fraction can also be recycled.

The amount of atmospheric oil and / or gas oil to be recycled is from about 1% to 50% by weight, preferably from 5% to 25%, more preferably from about 10% to 20% by weight of the raw material.

In another variation, at least a portion of the atmospheric residue from the atmospheric distillation zone is transferred to a reduced pressure distillation zone where the reduced pressure fraction is recovered and at least a portion of the recovered reduced pressure fraction is recycled to the inlet of the first guard zone, The vacuum residues are also recovered which can be transferred to the refinery fuel pool.

In another variant, at least a portion of the atmospheric residue and / or the reduced pressure fraction is conveyed to a catalytic cracking unit which is preferably a fluidized bed catalytic cracking unit, which is, for example, R2R developed by the applicant. It is a unit using a process. From this catalytic cracking unit, in particular LCO fractionation and HCO fractionation are recovered, and at least one of these fractions or mixtures thereof can be added to the fresh raw material fed to the hydroprocessing process of the invention. Usually, gas oil fractionation, gasoline fractionation and gas fractionation are also recovered. At least a portion of this gas oil fraction may optionally be recycled to the inlet of the first guard zone.

The catalytic cracking step can be carried out in a conventional manner known in the art, under suitable residue cracking conditions, to produce lower molecular weight hydrocarbon containing products. Descriptions of operations and catalysts that can be used for fluid bed cracking are described, for example, in US-A-4 695 370, EP-B-0 184 517, US-A-4 959 334, EP-B-0 323 297, US-A-4 965 232, US-A-5 120 691, US-A-5 344 544, US-A-5 449 496, EP-A-0 485 259, US-A-5 286 690, US- A-5 324 696 and EP-A-0 699 224, the disclosures of which are incorporated herein by reference.

The fluidized bed catalytic cracking reactor can be operated in either upflow mode or downflow mode. Although not a preferred embodiment of the present invention, catalytic cracking may be performed in a mobile phase reactor. Particularly preferred catalytic cracking catalysts are catalysts containing at least one zeolite, which are usually mixed with a suitable matrix such as alumina, silica or silica-alumina.

The process of the present invention comprises one particular variant, in which all guard zones are used together during step c) so that the guard zone where the catalyst is regenerated in step b) is shorted in step b). It is reconnected in the same way as before.

The process of the present invention includes another variant that constitutes a preferred embodiment of the present invention, which variant,

a) all guard zones are used together for about the same time period as the active disappearance time and / or occlusion time of the guard zone most upstream relative to the total circulation direction of the treated raw material;

b) the raw material is passed directly to the guard zone immediately following the guard zone upstream in the preceding stage, the guard zone upstream in the preceding stage is short-circuited, and the catalyst contained therein is regenerated and / or fresh Replacing with catalyst or regenerated catalyst;

c) all guard zones are used together, in which the guard zone where the catalyst has been regenerated and / or replaced in the preceding step is reconnected and positioned downstream of the set of guard zones, which is based on the overall circulation direction of the treated raw material. Continuing for about the same time period as the active disappearance time and / or occlusion time of the guard zone located most upstream during the step; And

d) shorting at least one of the reactor from the hydrodemetallization section and / or hydrodesulfurization section during a cycle for the loss of activity and / or occlusion of the catalyst during regeneration and / or replacement of the catalyst with a new or regenerated catalyst. Steps

It includes.

In a preferred embodiment of the process of the invention, the guard zone most upstream relative to the overall circulation direction of the raw material is gradually filled with metals, coke, precipitates, and various other impurities. This guard zone can be separated when needed, but usually when the contained catalyst is nearly saturated with metals and various impurities.

In one preferred embodiment, a special adjustment section is used that allows these guard zones to be exchanged during operation, i.e. without stopping the operation of the unit. First, using a system operating under an appropriate pressure (1 to 5 MPa, but preferably 1.5 to 2.5 MPa) and performing the following operation on a separate guard reactor: washing, prior to draining the used catalyst, Strip, cool; Next, the new catalyst is charged and then heated and sulfided; Thereafter, using appropriate techniques and by means of additional pressurization / depressurization and tap / valve systems, this guard zone is effectively exchanged without stopping the unit, ie without affecting utilization. Washing, stripping, evacuation, recharging of fresh catalyst, heating and sulfiding operations are all carried out in separate reactors or guard zones.

The reactor of the hydroprocessing unit usually operates at the following hourly space velocity (HSV).

HSV (h ^-1 ) HSV (h ^-1 ) Wide range Desirable range Total HDM Stage (with Guard Reactor) 0.2-4.0 0.3-0.4 Total HDS Stage 0.2-4.0 0.25-0.4 Full (HDM + HDS) 0.10-2.0 0.12-0.30

In a preferred mode, the overall HSV in the guard reactor or guard zone is manipulated to be about 0.1 to 4.0 h ⁻¹ , usually about 0.2 to 1.0 h ⁻¹ , but this is not the case for other processes using smaller guard reactors, in particular This process differs from the process using small guard reactors as disclosed in US Pat. No. 3,968,026. The HSV value of each guard reactor is preferably about 0.5 to 8 h ⁻¹ , usually about 1 to 2 h ⁻¹ . The overall HSV of the guard reactors and the HSV of each reactor are selected to maximize the hydrodemetallization (HDM) while controlling the reaction temperature (limiting pyrogenicity).

According to one advantageous embodiment, the unit comprises an adjustment section (not shown in the figure) provided with circulation means, heating means, cooling means and suitable separating means operating independently of the reaction section, whereby By operating the lines and valves, it is possible to carry out operations for preparing new or regenerated catalyst contained in the guard reactor and for the shorted reactor just before being connected to the operating unit, i.e. guard during exchange or short circuit. The reactor is preheated to sulfidate the catalyst contained therein, leading the guard reactor to the required pressure and temperature conditions. By performing a series of appropriate valve operations, when this guard reactor performs an exchange or short-circuit operation, the operation of adjusting the used catalyst contained in the guard reactor immediately after separation from the reaction section is performed for this same section. It is possible to carry out the operation of washing the used catalyst under the conditions required, removing it, cooling it, and then discharging the used catalyst and then replacing it with a new catalyst or regenerated catalyst.

Further, these catalysts are preferably catalysts disclosed in the applicant's patent EP-B-0 098 764 and the French patent application No. 97/07149. These catalysts comprise a carrier and contain from 0.1% to 30% by weight (expressed as metal oxide) of at least one metal or metal compound belonging to at least one of Groups V, VI and VIII in the periodic table. The shape is a plurality of juxtaposed aggregates each formed of a plurality of needle platelets, the platelets of each aggregate being oriented radially with respect to each other and to the center of the aggregate.

More specifically, this patent application relates to the treatment of heavy petroleum or petroleum fractionation, which aims to convert them to lighter fractionation and to be treated using transport or conventional refining processes. Oil from coal hydrides can also be treated. In this case, it is preferable to use a boiling phase reactor.

More specifically, the present invention is a high viscosity heavy oil which is rich in metals and sulfur and whose boiling point is higher than 520 ° C. exceeds 50%, and is impossible to transport. The content of the component having a boiling point higher than 520 ° C. is reduced to, for example, less than 20% by weight to solve the problem of converting into a stable, hydrocarbon-containing product.

In one particular embodiment, the raw materials are first mixed with hydrogen and then subjected to hydrovisbraking conditions before being sent to the guard reactor.

In another embodiment, the atmospheric residue or reduced pressure residue may be deasphalted using a solvent such as a hydrocarbon containing solvent or solvent mixture. The most frequently used hydrocarbon-containing solvents are paraffinic hydrocarbons, olefinic hydrocarbons or aliphatic ring hydrocarbons (or hydrocarbon mixtures) containing 3 to 7 carbon atoms. This treatment is generally carried out under conditions capable of producing a deasphalted product containing less than 0.05% by weight of asphaltene precipitated by heptane according to the AFNOR NF T 60115 standard. This deasphalting can be done using the procedure described in Applicant's patent US-A-4 715 946. The volume ratio of solvent to raw material is usually from about 3: 1 to about 4: 1, and the basic physicochemical operations (mixing-precipitation, gradient separation on asphaltenes, washing-precipitation on asphaltenes) involved in the overall deasphalting operation ) Is usually done individually. Thereafter, the product after deasphalting is usually at least partially recycled to the inlet of the first guard zone.

Usually, the solvent used for washing on asphaltenes is the same as that used for precipitation.

The mixture between the raw material for deasphalting and the solvent for deasphalting is typically set upstream of the exchanger, but this exchanger is intended to adjust the mixture to the required temperature so that proper precipitation occurs and good decanting is possible.

It is preferable that the mixture of the raw material and the solvent move inside the tube and not on the surface side of the exchanger.

The time for the mixture of raw material and solvent to stay in the mixed precipitation zone is generally from about 5 seconds to about 5 minutes, preferably from about 20 seconds to about 2 minutes.

The time for the mixture to stay in the gradient separation zone is usually from about 4 minutes to about 20 minutes.

The time for the mixture to stay in the washing zone is about 4 to 20 minutes.

The rate of rise of the mixture in the gradient separation zone and the washing zone is usually less than about 1 cm / s, preferably less than about 0.5 cm / s.

The temperature applied to the washing zone is usually lower than the temperature applied to the gradient separation zone. The temperature difference between these two zones is usually about 5 ° C to about 50 ° C.

The mixture from the washing zone is usually recycled to the decanter separator, advantageously to the upstream of the exchanger located at the inlet of the decanter separator zone.

The recommended ratio of solvent to asphaltene in the washing zone is from about 0.5: 1 to about 8: 1, preferably from about 1: 1 to about 5: 1.

The deasphalting treatment can consist of two stages, each stage comprising three basic phases: a settling phase, a gradient separation phase and a washing phase. In this precise case, the temperature recommended for each phase of the first step is preferably about 10 ° C. to about 40 ° C. lower than the temperature of the corresponding each phase of the second step.

The solvent used may be a C1 to C6 alcohol or a phenol or glycol solvent. However, it is very advantageous to use paraffinic solvents and / or olefinic solvents containing 3 to 6 carbon atoms.

In summary, in one variant, the process of the present invention is a process for hydroprocessing heavy hydrocarbon fractions containing sulfur impurities and metal impurities in at least two sections, according to the process, in the first hydrodemetallization section. The hydrocarbon feedstock and hydrogen are passed through a hydrodesulfurization catalyst under hydrodesulfurization conditions, and the effluent from this first step is passed through a hydrodesulfurization catalyst in a subsequent second section under hydrodesulfurization conditions, said first hydrodesulfurization section. Comprises at least one hydrodemetallization zone, in front of which is at least two hydrodemetallization zones, said hydrodesulfurization sections can be shorted individually or according to step d) defined below. It may comprise one or more reactors. The hydrogenation treatment step,

a) all guard zones are used together for a period approximately equal to the time of active disappearance and / or occlusion of one of the guard zones;

b) shorting the active loss and / or occlusion guard zone, regenerating the catalyst contained in the guard zone and / or replacing with a new catalyst or a regenerated catalyst;

c) the guard zone where the catalyst has been regenerated and / or replaced in the preceding step is reconnected and is run for approximately the same period of time as the active disappearance and / or occlusion time of one of the guard zones; And d) at least one of the reactor of the hydrodesulfurization section and / or the hydrodesulfurization section when the catalyst requires regeneration of the catalyst upon activity loss and / or occlusion and / or replacement with a new or regenerated catalyst during the cycle. Shorting

It includes.

delete

In another variant, the process of the present invention is a process for hydroprocessing a heavy hydrocarbon fraction containing sulfur impurities and metal impurities in at least two sections, wherein the hydrocarbon feedstock and hydrogen in the first hydrodemetallization section are hydrodemetallized. Conditions are passed through a hydrodesulfurization catalyst, and the effluent from this first step is passed through a hydrodesulfurization catalyst in a subsequent second section under hydrodesulfurization conditions, and the first hydrodesulfurization section passes through one or more hydrodesulfurization zones. At least one hydrodemetallization guard zone is located in front of the hydrodemetallization zone, wherein the hydrodemetallization section and / or hydrodesulfurization section consists of one or more reactors, these reactors being defined in step d) It can then be shorted individually or in other ways. The hydrogenation treatment step,

a) the guard zone is used for approximately the same period of time as the loss of activity and / or occlusion time of the guard zone;

b) short-circuit activity and / or occlusion guard zones, and regenerating and / or replacing the catalyst contained in the guard zone with new or regenerated catalysts;

c) the guard zone in which the catalyst has been regenerated and / or replaced in the preceding step is reconnected, said step being carried out for approximately the same time period as the active disappearance time and / or the occlusion time of one of the guard zones; And

d) at least one of the reactors of the hydrodesulfurization section and / or the hydrodesulfurization section when the catalyst requires regeneration of the catalyst upon activity loss and / or occlusion and / or replacement with a new or regenerated catalyst during the cycle. Short circuit

It includes.

In another variant, the process of the present invention is a process for hydroprocessing a heavy hydrocarbon fraction containing sulfur impurities and metal impurities in at least two sections, wherein the hydrocarbon feedstock and hydrogen in the first hydrodemetallization section are hydrodemetallized. Under conditions passes a hydrodesulfurization catalyst and the effluent from this first hydrodesulfurization section passes a hydrodesulfurization catalyst in a subsequent second section under hydrodesulfurization conditions. The first hydrodemetallization section comprises one or more hydrodemetallization zones, in front of which are at least two hydrodemetallurgical guard zones which are preferably stationary phase or boiling phase zones. These hydrodemetallization guard zones are arranged in series for use in a cycle consisting of successive repetitions of steps b) and c) defined below. The hydrodesulfurization section and / or hydrodesulfurization section consists of one or more reactors, which may be shorted individually or in other ways after step d) as defined below. The hydrogenation treatment step,

a) all guard zones are used together for a period substantially equal to the active disappearance time and / or occlusion time of the guard zone most upstream relative to the total circulation direction of the treated raw material;

b) the raw material is directly introduced into the guard zone immediately following the guard zone which was the most upstream in the preceding stage, the guard zone which was the most upstream in the preceding stage is shorted, and the catalyst contained therein is regenerated and / or fresh Replacing with catalyst or regenerated catalyst;

c) all guard zones are used together, and in step b) the guard zone where the catalyst has been regenerated and / or replaced is reconnected and positioned downstream of the set of guard zones, with reference to the overall circulation direction of the treated raw materials. Continuing for a period of time less than or equal to the active disappearance time and / or occlusion time of the guard zone located most upstream during this step; And

d) at least one of the reactors of the hydrodesulfurization section and / or the hydrodesulfurization section when the catalyst requires regeneration of the catalyst upon activity loss and / or occlusion and / or replacement with a new or regenerated catalyst during the cycle. Short circuit

It includes.

In the process of the invention, it is generally preferred that an intermediate fraction of an amount corresponding to from 0.5% by weight to 80% by weight of the hydrocarbon feed is introduced into the inlet of the first guard zone. More preferably, the middle fraction introduced with the hydrocarbon raw material is a direct gas oil.

In the process of the present invention, preferably, the product from the hydrodesulfurization step is transferred to an atmospheric distillation zone, from which the atmospheric oil and the atmospheric residue are recovered, and at least a portion of the recovered atmospheric oil recovered from the first guard zone. It is preferable to recycle to the inlet of to recover the atmospheric residue again. More preferably, a gas oil fraction is produced from the atmospheric distillation zone and at least a portion of the gas oil fraction is recycled to the inlet of the first guard zone.

In one preferred variant of the invention, the recycled gas oil fraction is an oil having an initial boiling point of about 140 ° C. and a final boiling point of about 400 ° C.

In these preferred variants, the amount of intermediate fraction introduced into the inlet of the first guard zone simultaneously with the raw material preferably corresponds to about 1% to 50% by weight of the raw material.

In addition, at least a portion of the atmospheric residue from the atmospheric distillation zone is transferred to a reduced pressure distillation zone whereby the reduced pressure fraction is recovered, and at least a portion of the recovered reduced pressure fraction is recycled to the inlet of the first guard zone, whereby It is also possible to recover. In this case, in one preferred variant, at least a portion of the atmospheric residue and / or the reduced pressure fraction is sent to a catalytic cracking unit where LCO fractionation and HCO fractionation are recovered and at least one of these fractions or mixtures thereof Some are transferred to the inlet of the first guard zone.

In one preferred embodiment of the process of the invention, the guard zone is used up during step c) and the guard zone where the catalyst is regenerated in step b) is reconnected so that the connection is the same as before the connection is shorted in step b). do.

In another preferred embodiment of the process of the invention, the adjusting section is associated with a single or a plurality of guard zones to enable shorting or exchange without interrupting the operation of the unit during operation of the guard zone. The regulating section is adjusted in the range of 1 MPa to 5 MPa in order to adjust the catalyst contained in the guard zone which is not in operation.

In one preferred embodiment of the process of the present invention, in order to process a raw material consisting of heavy oil or heavy oil fractions containing asphaltenes, the raw material is first mixed with hydrogen before being sent to a single or a plurality of guard zones and then hydrogenated bisbreaking. To be conditioned.

In one preferred embodiment of the process of the invention, the atmospheric residue obtained from the optional atmospheric distillation step is subjected to deasphalting with a solvent or mixture of solvents such that at least a portion of the deasphalted product is inlet to the first guard zone. To recycle.

In one preferred embodiment of the process of the present invention, the vacuum residue obtained from the optional vacuum distillation step is subjected to deasphalting with a solvent or solvent mixture such that at least a portion of the deasphalted product is at the inlet of the first guard zone. To recycle.

In another preferred embodiment of the process of the invention, all reactors are fixed bed reactors. In another preferred variant, at least one of the guard and / or hydrodesulfurization section and / or hydrodesulfurization section reactor is a boiling phase reactor. In another preferred variant, the reactor for the guard zone is a fixed bed reactor and the reactors in the hydrodesulfurization zone are all boiling phase reactors.

In another preferred variant, all of the reactors in the guard zone are fixed bed reactors, all of the reactors in the hydrodesulfurization zone are boiling phase reactors, and optionally, and very preferably all of the reactors in the hydrodesulfurization zone are also boiling phase reactors. It is also possible to operate the process of the invention with only the boiling phase reactor in the guard zone, the hydrodesulfurization section and the hydrodesulfurization section.

After the raw material reaches guard zones 1A and 1B via line 1, it leaves the guard zone via line 13, line 23 and / or line 24. The raw material leaving a single or multiple guard zones arrives via line 13 in the HDM section, shown as reaction section 2, which consists of one or more reactors, each of which can be shorted. The effluent from the reaction section 2 is withdrawn via line 14 and sent to the hydrodesulfurization section 3. This hydrodesulfurization section 3 comprises one or more reactors, which may be arranged in series, optionally shorted respectively. Effluent from the hydrodesulfurization section 3 is withdrawn via line 15.

As shown in FIG. 1, intermediate fractions are introduced via line 55 and mixed with hydrocarbon feedstock flowing through line 1.

In the case shown in FIG. 1, the guard zone comprises two reactors. In a preferred embodiment, the process comprises a series of cycles each comprising four consecutive periods as follows.

First period in which raw material passes continuously through guard zone 1A and guard zone 1B, and gas oil fractionation from the atmospheric pressure fraction being recycled is introduced into guard zone 1A with the raw material. During this first period (step a) of the process), the raw material is introduced into the guard reactor 1A via a line 21 comprising a line 31 and a valve 31 open towards the guard reactor 1A. . During this period the valves 32, 33 and 35 are closed. Effluent from the guard zone 1A is conveyed to the guard reactor 1B via line 26 and line 22 comprising line 23 and open valve 34. The effluent from the guard zone 1B is conveyed to the HDM section 2 via a line 24 comprising an open valve 36 and a line 13 comprising an open valve 37.

A second period in which the raw material passes only the guard zone 1B, and gas oil fractionation from the atmospheric pressure fraction recycled is introduced into the guard zone 1B together with the raw material. During this second period (step b) of the process) the valves 31, 33, 34 and 35 are closed and the raw material is guarded via a line 22 which comprises a line 1 and an open valve 32. 1B). During this period, the effluent from the guard zone 1B is conveyed to the HDM section 2 via a line 24 comprising an open valve 36 and a line 13 comprising an open valve 37. .

A third period in which the raw material passes continuously through the guard zone 1B and the guard zone 1A, and gas oil fractionation from the atmospheric pressure fraction recycled is introduced into the guard zone 1B together with the raw material. During this third period (step c) of the process), the valves 31, 34, and 36 are closed, and the valves 32, 33, and 35 are opened. Raw material is introduced into guard zone 1B via line 1 and line 22. Effluent from this guard zone 1B is sent to guard reactor 1A via lines 24, 27 and 21. Effluent from the guard zone 1A is conveyed to the HDM section 2 via a line 13 comprising a line 23 and an open valve 37.

A fourth period in which the raw material passes only the guard zone 1A and gas oil fractionation from the atmospheric pressure fraction recycled is introduced into the guard zone 1A together with the raw material.

The number of cycles performed for the guard reactor is a function of the duration of the operating cycle of the entire unit and the average exchange frequency of the guard zones 1A and 1B. During the fourth period, the valves 32, 33, 34 and 36 are closed and the valves 31 and 35 are open. Raw materials are introduced into guard zone 1A via lines 1 and 21. During this period, the effluent from the guard zone 1A is transferred to the HDM section 2 via a line 13 comprising a line 23 and an open valve 37.

In the case shown in FIG. 1, the hydrodemetallization (HDM) section 2 may comprise one or more reactors. Each or a plurality of these reactors may be temporarily sequestered for periodic update of the catalyst (step d) of the process). In a preferred embodiment, the process comprises a series of cycles each comprising three consecutive periods as follows.

First period in which the raw material passes continuously through the guard zones 1A and 1B and the HDM section 2 and finally the HDS section 3. During this period, gas oil fractionation from the recycled atmospheric fraction is introduced into the guard zone 1A with the raw materials. During this period the valves 32, 33, 35, 38 and 41 are closed. Raw materials are introduced into guard zone 1A via lines 1 and 21. Effluent from the guard zone 1A is conveyed to the guard reactor 1B via line 26 and line 22 comprising line 23 and open valve 34. The effluent from this guard zone 1B is conveyed to the HDM section 2 via a line 24 comprising an open valve 36 and a line 13 comprising an open valve 37. The effluent from this HDM section 2 is conveyed to the HDS section 3 via a line 14 comprising two open valves 42 and 39. The effluent from this HDS section 3 is then sent to a splitting unit (not shown) via a line 15 comprising an open valve 40.

Second period in which the raw material passes continuously through guard zones 1A and 1B and HDS section 3. During this period, gas oil fractionation from the recycled atmospheric fraction is introduced into the guard zone 1B with the raw materials. The valves 32, 33, 35, 37, 41 and 42 are closed during this operation. Raw materials are introduced into guard zone 1A via lines 1 and 21. Effluent from this guard zone 1A is conveyed to guard zone 1B via line 26 and line 22 comprising line 23 and open valve 34. Effluent from this guard zone 1B is conveyed to HDS section 3 via line 24 comprising open valve 36 and line 25 comprising two open valves 38 and 39. do. The effluent from this HDS section 3 is then sent to a splitting unit (not shown) via a line 15 comprising an open valve 40. During this time the HDM catalyst is updated, after which the catalyst is adjusted using the methods described herein. This control is particularly necessary when the catalyst is in oxide form.

A third period of time in which the raw material passes continuously through the guard zones 1A and 1B and the HDM section 2 and the HDS section 3. During this period, the recycled gas oil fractionation from the atmospheric distillation step is introduced into the guard zone 1B together with the raw materials. This situation is the same as the first period, allowing the reactor containing the new catalyst to be replaced at the same location in the fluid circuit as compared to the case described above with respect to the first period.

In the case shown in FIG. 1, the hydrodesulfurization section 3 may comprise one or more reactors. Each or a plurality of these reactors may be temporarily sequestered for periodic update of the catalyst (step d) of the process). In a preferred embodiment, the process comprises a series of cycles each comprising three consecutive periods as follows.

First period in which the raw material passes continuously through guard zones 1A and 1B and HDM section 2 and HDS section 3. During this period, gas oil fractionation from the recycled atmospheric fraction is introduced into the guard zone 1A with the raw materials. During this period the valves 32, 33, 35, 38 and 41 are closed. Raw materials are introduced into guard zone 1A via lines 1 and 21. Effluent from the guard zone 1A is conveyed to the guard reactor 1B via line 26 and line 22 comprising line 23 and open valve 34. The effluent from this guard zone 1B is conveyed to the HDM section 2 via a line 24 comprising an open valve 36 and a line 13 comprising an open valve 37. The effluent from this HDM section 2 is conveyed to the HDS section 3 via a line 14 comprising two open valves 42 and 39. The effluent from this HDS section 3 is then sent to a splitting unit (not shown) via a line 15 comprising an open valve 40.

A second period in which the raw material passes continuously through the guard zones 1A and 1B and the HDM section 2. During this period, gas oil fractionation from the recycled atmospheric fraction is introduced into the guard zone 1B with the raw materials. During this operation valves 32, 33, 35, 38, 39 and 40 are closed. Raw materials are introduced into guard zone 1A via lines 1 and 21. Effluent from this guard zone 1A is conveyed to guard zone 1B via line 26 and line 22 comprising line 23 and open valve 34. The effluent from this guard zone 1B is conveyed to the HDM section 2 via a line 24 comprising an open valve 36 and a line 13 comprising an open valve 37. The effluent from this HDM section 2 is then conveyed to a split unit (not shown) via line 14 comprising open valve 42 and line 16 comprising open valve 41. do. During this period the catalyst from the HDS section 3 is updated, after which the catalyst is adjusted using the methods described herein. This control is particularly necessary when the catalyst is in oxide form.

A third period of time in which the raw material passes continuously through the guard zones 1A and 1B and the HDM section 2 and the HDS section 3. During this period, the gas oil fraction recycled from the atmospheric distillation step is introduced into the guard zone 1B together with the raw materials. This situation is the same as the first period, allowing the reactor containing the new catalyst to be replaced at the same location in the fluid circuit as compared to the case described above with respect to the first period.

Claims (20)

A hydrotreatment process for hydrotreating heavy hydrocarbon fractions containing sulfur impurities and metal impurities in at least two sections, wherein the hydrocarbon feedstock and hydrogen are passed through a hydrodemetallurgical catalyst under hydrodesulfide conditions in a first hydrodemetallization section. The effluent from this first stage is passed through a hydrodesulfurization catalyst in a subsequent second section under hydrodesulfurization conditions, the hydrodesulfurization section comprising one or more hydrodesulfurization zones, one in front of the hydrodesulfurization zone. Wherein at least one hydrodesulfurization guard zone is located, the hydrodesulfurization section comprises at least one reactor which can be shorted individually or according to step d) defined below, wherein the hydroprocessing process comprises: a) using the guard zone together with the guard zone for approximately the same time period, either at the time of active loss or occlusion of one of the guard zones; b) shorting the lost or occluded guard zone and regenerating or replacing the catalyst contained in the guard zone with a new or regenerated catalyst; c) the guard zone in which the catalyst has been regenerated or replaced in the preceding step is reconnected and is run for approximately the same time period as either the active disappearance time or the occlusion time of one of the guard zones; And d) If the catalyst is lost or occluded during the cycle, either the regeneration of the catalyst or the replacement of the new or regenerated catalyst requires either a hydrodemetal section or a reactor in the hydrodesulfurization section. Short circuit Hydrogen treatment process comprising a. The process of claim 1 wherein at least two hydrodemetallization guard zones arranged in series for use in a cycle consisting of successive repetitions of steps b) and c) are located in front of the hydrodemetalization zone (s) And wherein all guard zones are used together for approximately the same period of time in either active dissipation time or occlusion time in one of the guard zones in steps c) and c). 3. The guard zone of claim 2, wherein the hydrodemetallization guard zone comprises one or more fixed bed reactors or boiling phase reactors, and step c) includes all guard zones used together and a guard zone in which the catalyst has been regenerated or replaced in the preceding step b). Is reconnected to the downstream of the set of guard zones, and continues for approximately the same time period as either the active disappearance time or the occlusion time of the zone located most upstream during this stage, based on the overall circulation direction of the treated raw material. Which is a step. The process of any one of claims 1 to 3, wherein an intermediate fraction in an amount represented by 0.5% to 80% by weight based on the hydrocarbon feed is introduced at the inlet of the first guard zone. The process of claim 4, wherein the intermediate fraction introduced with the hydrocarbon feedstock is a direct gas oil. The process according to any one of claims 1 to 3, wherein the product from the hydrodesulfurization step is transferred to an atmospheric distillation zone, from which atmospheric pressure fraction and atmospheric residue are recovered and at least of the recovered atmospheric fraction A portion of the hydrotreatment is recycled to the inlet of the first guard zone to recover atmospheric pressure residues. The process of claim 6, wherein a gas oil fraction is produced from the atmospheric distillation zone and at least a portion of the gas oil fraction is recycled to the inlet of the first guard zone. 8. The process of claim 7, wherein the gas oil fraction being recycled is an oil having an initial boiling point of 140 ° C and a final boiling point of 400 ° C. 5. The process of claim 4, wherein the amount of intermediate fraction introduced into the inlet of the first guard zone concurrently with the feed is between 1% and 50% by weight of the feed. The method of claim 6, wherein at least a portion of the atmospheric residue from the atmospheric distillation zone is transferred to a reduced pressure distillation zone, whereby the reduced pressure fraction is recovered from the reduced pressure distillation zone, and at least a portion of the recovered reduced pressure fraction is an inlet of the first guard zone. To recover the reduced pressure residue. 11. The process of claim 10 wherein at least a portion of either the atmospheric residue or the reduced pressure fraction is sent to a catalytic cracking unit to recover the LCO fraction and the HCO fraction from the catalytic cracking unit to recover one of these fractions or a mixture of these fractions. At least a portion of which is transferred to an inlet of the first guard zone. 4. A method according to any one of claims 1 to 3, wherein all guard zones are all used together during step c) such that the guard zone where the catalyst has been regenerated in step b) before the connection is shorted in step b). And reconnect to be equal to. The method according to any one of claims 1 to 3, wherein the adjustment section is associated with a single or a plurality of guard zones, allowing the guard zones to be shorted or exchanged without interrupting operation of the unit during operation. And adjusting said adjusting section to adjust the pressure in the range of 1 MPa to 5 MPa in order to adjust the catalyst contained in the guard zone not in use. 4. The raw material according to any one of claims 1 to 3, wherein the raw material is first mixed with hydrogen before the raw material is sent to a single or a plurality of guard zones for processing the raw material consisting of heavy oil or heavy oil fractions containing asphaltenes. A hydrotreating process subject to hydrovisbreaking conditions. 8. The process of claim 7, wherein the atmospheric residue is subjected to deasphalting treatment with a solvent or solvent mixture, wherein at least a portion of the deasphalted product is recycled to the inlet of the first guard zone. The process of claim 10 wherein the depressurized residue is subjected to deasphalting treatment with a solvent or solvent mixture, wherein at least a portion of the deasphalted product is recycled to the inlet of the first guard zone. The process of claim 1, wherein the reactors are all fixed bed reactors. 4. The hydroprocessing process according to claim 1, wherein at least one of the guard zone or the hydrodesulfurization section or the hydrodesulfurization section reactor is a boiling phase reactor. 5. 19. The process of claim 18, wherein all of the reactors for the guard zone are fixed bed reactors and all of the reactors in the hydrodesulfurization zone are boiling phase reactors. 19. The process of claim 18, wherein all of the reactors in the guard zone are fixed bed reactors and all of the reactors in the hydrodemetallization zone are boiling phase reactors.