IT201600087745A1 - MOBILE DEVICE TO REDUCE THE CONTENT OF SULFURED COMPOUNDS IN A DIESEL OIL - Google Patents

Description

"MOBILE DEVICE TO REDUCE THE CONTENT OF SULFUR COMPOUNDS IN A DIESEL"

DESCRIPTION

Scope of the invention

[0001] The present invention relates to a transportable apparatus for desulfurizing a hydrocarbon distillate by administering hydrogen (hydrotreating).

Notes on the prior art - Technical problem

[0002] In construction sites located far from normal fuel distribution circuits, powering the engines of common operating machines can be an important problem. In fact, the fuels available in the vicinity of such construction sites often have characteristics, primarily sulfur compounds content, which are not compatible with the power specifications of the engines, which require sulfur contents lower than 100 ppm, sometimes lower than 10 ppm.

[0003] For this reason, costs arise for the on-site transport of suitable fuels, and / or costs for wear or damage of engines powered in a way that does not conform to specifications.

[0004] Such is the case, for example, of construction sites dedicated to the construction of oil and gas wells, the laying of oil and gas pipelines, in which the construction site has to move to large areas, often desert, to mining, and other still.

[0005] The need is therefore particularly felt to have mobile equipment, that is, one that can be easily moved together with the construction site, which is capable of treating organic sulfur compounds present in fuels similar to diesel, naphtha, kerosene, light and medium distillates in general, ie mixtures of hydrocarbons with a number of carbon atoms between 5 and 30, in order to reduce the content of these sulfur compounds so as to be able to use said fuels to power engines, in particular diesel engines.

[0006] In the current art, the desulphurization of these hydrocarbon liquids is carried out by treatment with hydrogen or "hydrotreating" on suitable catalysts, normally containing Cobalt and Molybdenum, with the production of hydrogen sulphide.

[0007] Off-shore platforms constitute another sector in which it would be advantageous to have small and easily transportable units for treating hydrocarbon liquids with hydrogen, especially in the case of predominantly gas fields. In fact, in this case hydrocarbon condensates are obtained at the wellhead which, if exempt or once deprived of the lighter fractions, can advantageously be used to power diesel engines or other equipment in order to produce electricity, possibly in order to make energy autonomous the platform.

[0008] The success of a catalytic desulfurization depends on the presence of further compounds, other than the sulfur compounds to be removed, which tend to engage the active centers of the catalysts, reducing their catalytic activity. They are typical impurities of the starting distillates, in particular:

� polycyclic aromatic compounds, such as anthracene, phenanthrene and higher;

� nitrogenous compounds, for example pyridines and benzopyridines:

an albeit minimal content of nitrogen compounds, of the order of a few ppm, very frequent in the case of many pretreated distillates, is able to reduce the catalytic activity by up to 20-30%;

� olefins, which have a tendency to form a polymeric layer on the surface of the catalyst.

In addition to impairing catalyst desulphurization, excessive levels of these further compounds are themselves the cause of various drawbacks in diesel engines. These compounds are present, particularly in pretreated distillates produced by old-fashioned refineries, and are commercially available in less technologically advanced areas, such as East or West Africa and South East Asia.

[0010] For all these reasons, it is advantageous if not indispensable to reduce the concentration of these further compounds within certain acceptable limits, before proceeding with the desulphurization, or at the same time as it is. Also these compounds, in the current technique, are removed from the hydrocarbon liquid by treatment with hydrogen, on catalysts normally containing metals such as Nickel, but also Palladium, Platinum or more noble metals, in order to saturate the aromatic compounds and / or the double bonds of the olefins , and / or to remove nitrogen in the form of ammonia.

Other problems of industrial desulfurization processes are secondary cracking reactions, which remove hydrogen from desulfurization reactions, as well as high concentrations of hydrogen sulfide in the reaction product downstream of the first reactor, in a combination of series reactors .

[0012] In fact, the hydrogen treatments of the hydrocarbon distillates, and more specifically the extreme desulphurization, are industrially carried out using single desulphurization reactors or combinations of several reactors in series. These reactors can be of different types from each other, for example they can be boiled bed reactors, fixed bed reactors, and all operate on a predetermined hydrocarbon feed to be treated, even if with different catalysts and / or under operating conditions. different.

[0013] In the current art, the problems indicated above are addressed by significantly increasing the partial pressure of hydrogen, and / or the treatment temperature and / or the contact time on the catalyst.

[0014] GB 1 329 025 describes a reactor provided with a central vertical conduit open at the ends, containing free particles of a desulphurization catalyst, in which a hydrocarbon liquid is recirculated between the inside and the outside of the conduit, maintaining the contact with the catalyst In this reactor a lifting action is exploited that the gaseous hydrogen, fed in a lower position of the reactor, exerts on the catalytic particles. The suspension makes it necessary to break down the catalyst particles that come out of the duct due to the lifting effect. This reactor is suitable for desulphurizing very heavy charges in a strong way, a circumstance in which it is important not to dirty the catalyst with significant pitchy or carbonaceous fractions. The catalyst must be washed with the liquid mixture to remain active.

[0015] US 7,156,997 B2 discloses a hydrocracking method which solves the problem of how to control the level of hydrogenated impurities above the different catalytic beds. However, this method does not tolerate important variations in the flow rate of the feeds, and can give rise to "plugging" of the catalyst, in particular, in the case of a desulfurization reactor operating in trickle bed conditions as the first reactor of a series, to treat a very heavy charge or a charge rich in unsaturated hydrocarbons.

Summary of the invention

[0016] It is therefore an object of the present invention to provide an easily transportable apparatus, typically mounted on a skid, for treating a hydrocarbon liquid similar to a light or medium distillate with hydrogen on a solid catalyst, with the main purpose of removing sulfur compounds up to concentrations residuals below 100 ppm, in particular below 10 ppm, with a variable capacity between 0.5 and 2 t / hour.

[0017] It is also an object of the present invention to provide such an apparatus which is capable of operating successfully between a maximum nominal flow rate of liquid to be treated and a minimum flow rate much lower than the maximum flow rate.

[0018] It is also an object of the present invention to provide such an apparatus which is capable of removing, in addition to sulfur compounds, impurities such as nitrogen compounds and / or aromatic compounds, in particular polycyclic compounds, and / or olefins, so as to be able to treat , in particular, middle distillates ("Diesel Oil") of different origin, already pretreated in old generation refinery desulphurization plants, which operate with low partial pressure of hydrogen, and / or at low temperature and / or with a catalytic volume limited.

[0019] These and other objects are achieved by an apparatus for removing a sulfur compound from a hydrocarbon liquid by treatment with hydrogen on a catalyst, i.e. by catalytic hydrodesulfurization, comprising a reactor, in turn comprising:

- a container;

A wall arranged vertically inside the container, having a lower end and an upper end arranged at a predetermined distance respectively from a lower bottom and an upper bottom of the container, the wall defining in the container a first space and a second space;

� a grid support element and a grid containment element both arranged in the first space, in which the containment element is arranged above the support element;

� a catalytic bed placed between the grid support element and the grid containment element,

in which the catalytic bed comprises solid particles that have a catalyst configured to cause a desulfurization reaction of the sulfur compound in the presence of hydrogen at a predetermined treatment temperature;

in which the catalytic bed rests on the grid support element;

in which the grid containing element is arranged at a predetermined distance above a free upper surface of the catalytic bed, so as to form above the free upper surface an expansion space for the catalytic bed;

- a supply opening for the hydrocarbon liquid made through a wall of a lower portion of the container;

- a hydrogen dispenser arranged to introduce hydrogen into the first space, below the catalytic bed;

- an outlet opening made through a wall of an upper portion of the container,

so that, by introducing the hydrocarbon liquid into the container with a predetermined liquid flow rate through the feed opening and introducing hydrogen into the catalytic bed with a hydrogen flow rate dependent on the liquid flow through the dispenser, a current is formed of a two-phase mixture of hydrocarbon liquid and hydrogen having a lower density than the hydrocarbon liquid, so that the stream of the two-phase mixture has an upward direction inside or outside the catalytic bed, according to the support and containment grid elements and the catalytic bed are arranged in the internal or external space, favoring the contact between reactants and catalyst and therefore causing the desulphurization reaction and at the same time facilitating the disposal of the reaction heat, and a corresponding stream of recycled liquid has a downward direction through external or internal space respectively, outside the catalytic bed ico ,, in which a part of the stream of the two-phase mixture, containing a desulfurized hydrocarbon liquid and desulfurization products, exits the container through the outlet opening;

- thermostating means configured to bring and maintain the catalytic bed and the two-phase mixture at the treatment temperature and within a controlled temperature range,

so that by increasing / decreasing the liquid flow rate and therefore the hydrogen flow rate, the catalytic bed respectively increases / decreases in height by expanding / contracting in the expansion space.

[0020] In other words, the reactor is a "gaslift" type reactor, in which the catalyst particles undergo an upward thrust due to the flow of the reactant mixture, in which however the catalytic bed is confined between the grid the support grid, further down, and the containment grid, higher up, the distance between which defines, together with the quantity of catalyst, the degree of expandability allowed to the catalyst itself, without the possibility of leaving the space between the grids. This type of reactor is referred to herein as an expanded bed reactor.

[0021] In this reactor, the hydrocarbon liquid and hydrogen fed enter a lower portion of the reactor forming a reaction mixture that has a lower density than the hydrocarbon liquid, which rises through the catalytic bed. Hydrogen therefore acts as a entrainment gas for the liquid and, together with it, for the solid catalyst.

[0022] Furthermore, at the exit from the first containing the catalyst, the reagent mixture undergoes at least partial degassing, releasing in particular excess hydrogen and hydrogen sulphide produced by desulfurization, while the residual liquid falls respectively into the second space, not containing the catalyst , forming a column of recycled liquid which has a higher density than the reactant mixture. Due to the difference in density between the recycled liquid and the reagent mixture, a circulation is therefore established between the first and second space, that is, the degassed recycle liquid column pushes the reagent mixture that passes through the catalyst upwards.

[0023] The ratio between the degassed recycle hydrocarbon liquid and the mixture of gas oil and hydrogen fed to the reactor can be varied by changing the quantity of hydrogen introduced as lifting gas and, therefore, the density of the rising mixture.

[0024] Thanks to the expandability of the catalytic bed and to this possibility of adjusting the density difference between the recycled liquid and the reagent mixture, the apparatus according to the invention stands out for being particularly flexible, i.e. it is capable of desulphurizing streams very variable both in terms of capacity and quality. More in detail, the apparatus is capable of desulphurizing mixtures of liquid hydrocarbons of the various families of lighter refinery or petrochemical distillates, i.e. lighter distillates such as diesel, diesel, kerosene, naphtha from primary distillation or from conversion plants such as and of the USA or to the specifications for ULSD (“Ultra Low Sulfur Diesel”).

[0025] The apparatus is therefore particularly useful when you want to obtain limited quantities of diesel to be used as fuel in operating machines dedicated for example to the excavation and / or laying of pipelines in remote locations, far from modern refineries.

[0026] In one embodiment, the wall arranged inside the container is a tubular element, i.e. a duct, and the first space is chosen between a space inside the duct and a space outside the duct, so that the second space is respectively chosen between the space outside the duct and the space outside the duct. In other words, the catalytic bed can be arranged in the internal space or in the external space of the duct. In particular, the tubular element has a cylindrical shape with a circular section.

[0027] Advantageously, the distance between the grid containment element and the free upper surface of the catalytic bed exceeds the distance between the free upper surface and the grid support element by 15%. In particular, the distance between the grid containing element and the free upper surface of the catalytic bed exceeds by 30% the distance between the grid containing element and the free upper surface of the catalytic bed exceeds 30%, and is preferably less than 100% of the distance between the free upper surface and the grid support element.

[0028] Preferably, at least one end of the duct has a flare, in other words the diameter of the duct increases at this end. In this case, the end preferably has a curvilinear profile in a longitudinal section, for example the end has a trumpet shape. In this way, the circulation of the liquid and the two-phase liquid-solid mixture between the inside and the outside of the duct is favored. From another point of view, the pressure drops at the outlet and at the entrance to the duct are limited.

[0029] The solid particles of the catalyst are preferably substantially spherical in shape and have an abrasion percentage preferably lower than 1% by weight. In other words, a catalytic material comprising particles that have a low tendency to wear and therefore to the formation of smaller or finer particles is preferable.

[0030] In particular, the apparatus comprises means for feeding the hydrocarbon liquid to the reactor, typically in the form of one or more pumps, such as to provide a flow rate of hydrocarbon liquid feeding to the reactor such that the hydrocarbon liquid, during the treatment in the catalytic bed, has a specific surface velocity, or flow rate with respect to the predetermined volume of catalytic bed.

[0031] This surface speed is chosen on the basis of the characteristics of the treated liquid, in particular on the basis of the molecular weight and / or the sulfur content. For hydrocarbon liquids to be treated with a higher molecular weight and / or with a higher sulfur content, it is preferable to choose lower surface speeds than those possible in the case of hydrocarbon liquids to be treated with a lower molecular weight and / or with a lower sulfur content. For example, the surface velocity is chosen between 0.5 h <-1> and 5 h <-1> (m <3> / hr of liquid per m <3> of catalytic bed), the lower values of this range being preferable for higher molecular weight and / or higher sulfur content hydrocarbon liquids, such as high sulfur vacuum gas oils or very heavy distillates, the higher values being preferable for lower molecular weight and / or lower sulfur content liquids, such as naphtha .

[0032] Preferably, the catalyst is a catalyst selected from a Cobalt-Molybdenum catalyst and a Nickel-Molybdenum catalyst.

[0033] Cobalt-Molybdenum catalysts are suitable for desulfurization treatments. If the hydrocarbon liquid to be treated has a concentration of polycyclic aromatic compounds such as to reduce the efficiency of the desulphurization process, according to what was previously said, to lower this concentration it is advantageous to use a Nickel-Molybdenum catalyst which is however able to promote even the reactions of desulphurization. In this case, a hydrocarbon liquid with a substantially reduced content of polycyclic aromatics and generally partially desulphurized is extracted from the reactor. For this reason, this extracted hydrocarbon liquid is sent to a subsequent finishing desulphurization treatment, as described in greater detail below.

[0034] In particular, the catalyst bed comprises an amount of the catalyst, by volume, comprised between 0.5 m <3> and 1.5 m <3>, preferably between 0.8 m <3> and 1.0 m <3>. With this volume of catalytic mass, and taking into account the surface velocity values, the apparatus is able to treat flow rates of hydrocarbon liquid ranging from a few hundred l / H to about 5 l / h, the highest values of capacity being possible for lighter and less sulfur-rich liquids.

[0035] The apparatus comprises means for compressing the hydrogen to bring the hydrogen, at the inlet of the reactor, to a pressure such that the partial pressure of the hydrogen which comes into contact with the catalytic bed also has a selected value it based on the characteristics of the liquid being treated. In particular, for hydrocarbon liquids having a higher molecular weight and / or a higher sulfur content, it is preferable to choose higher hydrogen partial pressures than those sufficient in the case of liquids with a lower molecular weight and / or lower sulfur content. For example, the compression means are configured to bring the hydrogen pressure to a value such as to allow a partial pressure of hydrogen in contact with the catalytic bed chosen between 7 and 32 bars, the lower values of this range being preferable for hydrocarbon liquids with a molecular weight and / or lower sulfur content, such as naphtha, the higher values being preferable for liquids with a higher molecular weight and / or sulfur content, such as vacuum gas oils with high sulfur or very heavy distillates. These values refer to hydrogen as it is, i.e. net of impurities, typically of low molecular weight gaseous hydrocarbons, accumulated as a result of the recycling of unreacted hydrogen in the reactor, as described below.

[0036] In particular, the apparatus comprises means for feeding the hydrogen configured to supply a flow rate of hydrogen fed to the reactor chosen on the basis of the flow rate of hydrocarbon liquid to be treated, as well as the characteristics of the molecular weight and sulfur content of the liquid to be treated. In particular, for hydrocarbon liquids with a higher molecular weight and / or sulfur content, such as vacuum gas oils or very heavy distillates, it is preferable to choose specific hydrogen flow rates, referring to the corresponding flow rates of hydrocarbon liquid, greater than those sufficient in the case of liquids. with molecular weight and / or lower sulfur content, such as naphtha. For example, the hydrogen supply means are configured to provide a flow rate of hydrogen such that the ratio between the flow rate of hydrogen and that of the hydrocarbon liquid is chosen between 45 and 270 Smc / mc (m <3> / h of hydrogen under standard conditions, 15 ° C and 1 atmosphere, per m <3> / h of liquid), the lower values of this range being preferable for hydrocarbon liquids with a molecular weight and / or lower sulfur content, the higher values being preferable for liquids with molecular weight and / or higher sulfur content. A reference value for diesel / diesel is between 170 and 180 Smc / mc.

[0037] In particular, the apparatus comprises means for preheating the hydrocarbon liquid configured so as to bring the supplied hydrocarbon liquid to a predetermined supply temperature, so that the hydrocarbon liquid, once mixed with the hydrogen and in contact with the catalyst is at a desulphurization temperature suitable for the overall desulphurization reaction to take place.

[0038] The treatment temperature, and therefore also the feed temperature, is chosen on the basis of the characteristics of the liquid to be treated, the type of catalyst used, according to criteria known to those skilled in the art. To reach these temperatures, upstream of the feed opening of the hydrocarbon liquid to be treated, a preheating device is provided, configured to bring the hydrocarbon liquid to a feed temperature included in a predetermined range, in particular between 300 ° C and 380 ° C. . Temperatures higher than those indicated can excessively favor secondary reactions such as cracking reactions with the formation of hydrocarbon gases and lower molecular weight liquids, with unacceptable modifications of the distillation curve of the treated fuel.

In one embodiment, the reactor comprises an external recycle pipeline having a first end in hydraulic communication with the upper portion of the reactor, and a second end in hydraulic communication with the feed port of the reactor, so that a part of the recycle liquid stream flows through the external recycle pipeline, wherein the external recycle pipeline comprises a regulating valve for modifying the flow rate of the part of said recycle liquid stream which runs through the external recycle pipeline. In this way, it is possible to more reliably adjust, through the total pressure drops of the recycling, the overall flow rate of the recycled liquid, allowing to adapt the reactor in a simpler and more reliable way to flow rates of hydrocarbon liquid to be treated a lot. different.

In one embodiment, the reactor is a first stage reactor, the catalyst is a first stage catalyst, the container is a first container, and the treated hydrocarbons are first stage treated hydrocarbons obtained from a first stage reaction comprising the desulfurization reaction, the first stage reaction causing a transformation of a part of the sulfur compound into the desulfurization products, a remaining part of the sulfur compound remaining unconverted, the apparatus also comprises:

- a second stage reactor comprising:

- a second container;

- an amount of a second stage catalyst disposed within the second container, the second stage catalyst being suitable configured to cause a second stage desulfurization reaction of the remaining part of the sulfur compound, not converted, in the presence of the hydrogen to a predetermined second stage treatment temperature; - at least a second supply opening made through a wall of the second container for a liquid supply including the current part and for a hydrogen supply including an additional portion of hydrogen;

- a second outlet opening made through a wall of the second container;

- a pipeline configured to put in hydraulic communication the outlet opening of the first stage reactor with the second inlet opening, in which the inlet opening and the second outlet opening are arranged so that the liquid feed coming from the first stage reactor and containing dissolved hydrogen and first stage reaction gas, and the hydrogen feed, fed through the at least one second feed opening, come into contact with the second stage catalyst causing the second-stage desulfurization reaction and such that a stream of a second-stage product containing a second-stage desulfurized hydrocarbon liquid, excess hydrogen and desulfurization products exits the second outlet through the second outlet.

[0041] In one embodiment, said catalyst or said first and second stage catalysts are suitable to cause, respectively, said desulphurization reaction and said first and second stage reactions, a remaining part of the sulfur compound remaining unconverted, and furthermore, the apparatus can comprise

- a final stage reactor comprising in turn:

- an additional container;

- an amount of a final stage catalyst disposed within the further container, the final stage catalyst being configured to cause a final desulfurization reaction of said remaining part of said sulfur compound in the presence of hydrogen at a predetermined temperature of final stage treatment;

- at least one further supply opening, made through a wall of the further container for a liquid supply comprising a part of the stream or a part of the stream of a second-stage product;

- a further outlet opening made through a wall of the additional container;

- a pipeline configured to put in hydraulic communication the outlet opening of the first stage reactor or the second outlet opening, of the second stage reactor, and with the further supply opening, of the final stage reactor, the further feed port and the further outlet port being arranged so that the liquid feed and the hydrogen feed, fed through the at least one further feed port, come into contact with the amount of an end stage catalyst causing the end stage desulfurization reaction, and a stream of an end product containing an end stage desulfurized hydrocarbon liquid, excess hydrogen and desulfurization products to exit the end stage reactor through the further outlet port.

In particular, the amount of the second stage catalyst and / or the final stage catalyst forms a fixed catalytic bed.

[0043] The apparatus is based on a combination of diversified types of reactor, in particular with an expanded bed ("gas-expanded bed") and a fixed bed ("trickle-bed"), in which there is a catalytic system comprising several reaction zones. The respective catalysts of the reaction zones are selected according to combinations which depend on the catalytic functions necessary to treat streams containing, typically

- variable quantities of sulfur;

- Sulfur Nitrogen, or

- Aromatic Sulfur Nitrogen o

- Sulfur Nitrogen Aromatic Olefins.

[0044] In an advantageous embodiment,

- the first stage catalyst is a catalyst configured to also cause a hydrogenation reaction of a nitrogenous compound and / or a polycyclic aromatic compound and / or an olefin, comprising a metal selected from Nickel; Palladium; Platinum;

- the second stage catalyst and / or the final stage catalyst is a Cobalt-Molybdenum catalyst; - the catalytic bed of the second stage catalyst comprises an amount of the second stage catalyst comprised between 0.3 m <3> and 1 m <3>, in particular between 0.5 m <3> and 0.8 m < 3>.

[0045] The second stage reactor has the task of completing the removal of refractory sulfur compounds, that is to say those which are more difficult to desulphurize. Preferably, the second stage reactor is a fixed bed reactor. It can work with a higher H2 / hydrocarbon ratio, obtained by adding more hydrogen, and possibly adjusting the temperature with the hydrogen added to the hydrocarbon liquid extracted from the first reactor.

[0046] Furthermore, the second stage reactor, in the configuration described above, allows to carry out further removal reactions of sulfur compounds, favored by the partial reduction of polycyclic aromatics carried out in the first reactor and by the possible higher ratio H2 / refractory sulfur compounds, which will counteract the opposite reaction of the hydrogen sulfide formed and present in the reaction mixture.

[0047] Advantageously, the second stage and / or final stage catalyst is a Cobalt-Molybdenum catalyst, and the catalyst bed of the second stage and / or final stage catalyst comprises an amount of the second stage or stage catalyst final between 0.3 m <3> and 1 m <3>, in particular between 0.5 m <3> and 0.8 m <3>.

[0048] In this case, the heavier and more refractory sulfur components present in the hydrocarbon liquid, leaving the first or second stage reactor, are preferably added with further hydrogen, and further treated in the final stage reactor.

[0049] In particular, the temperature and / or pressure at which the final stage reactor operates are practically the same as those of the effluents from the second stage reactor.

[0050] Preferably, and in particular if both the second stage reactor and the final stage reactor are present / active, the apparatus comprises a high pressure separator tank arranged to receive the effluent of the second stage reactor and to separating a hydrocarbon liquid containing a heavier fraction of hydrocarbons, with the more refractory components to be desulfurized, from a gas and vapor mixture containing hydrogen sulfide, excess hydrogen and lighter hydrocarbons. The third stage reactor is then arranged to receive in feed the hydrocarbon liquid separated in the high pressure separator tank.

[0051] The apparatus may comprise equipment arranged to receive and treat the separated vapors in the high pressure separator tank, for example as described in the description of a preferred embodiment.

[0052] In the third stage reactor, the reaction of the highly refractory sulfur compounds present in the liquid leaving the second stage reactor is favored, since this reactor operates in the substantial absence of:

� hydrogen sulphide, removed from the high pressure separator tank;

� of polycyclic aromatic hydrocarbons, removed in the first and at least partly also in the second stage reactor.

[0053] Advantageously, the dispenser of the expanded bed reactor, or of the first stage reactor, is configured in such a way as to distribute the hydrogen below the catalytic bed, in particular the dispenser is arranged to deliver the hydrogen downwards . In this way, the formation of channels is limited, or preferential routes for the two-phase mixture within the catalytic bed.

[0054] Preferably, the reactor comprises means for homogenizing the stream of the two-phase mixture arranged below the catalytic bed. In particular, the homogenization means comprise a plurality of distributor plates.

[0055] Preferably, the apparatus comprises:

- a device for separating an excess of hydrogen from a desulphurized product;

- a compressor arranged to recycle at least part of the excess hydrogen feeding to the reactor.

[0056] The invention is applicable to cuts of middle distillates possibly extended to lighter distillates and heavier distillates.

[0057] The apparatus according to the invention is able to effectively treat hydrocarbon liquids containing olefins / unsaturated up to 1%, total aromatic hydrocarbons up to 30% or polycyclic aromatic hydrocarbons up to 12%. Beyond these values, the consumption of hydrogen and operating pressures would be much greater than those expected, and the high volume of catalyst would result in plant dimensions that would make the apparatus difficult to transport. It is therefore preferable to remove the quantities of olefins and / or aromatics exceeding these limit values with suitable hydrogenation or other processes.

Brief description of the drawings

[0058] The invention will be illustrated below with the description of some embodiments, made by way of non-limiting example, with reference to the attached drawings, in which:

- Figure 1 schematically shows a reactor of an apparatus according to the invention;

- Figures 2 and 3 show process diagrams of apparatuses, according to two embodiments of the invention, to treat middle distillates such as pre-treated diesel / gas oils, including a single catalytic reaction stage;

- figure 4 shows a process diagram of an apparatus, according to an embodiment of the invention comprising three catalytic reactors that can be selectively excluded from the flow, for the treatment of distillates more difficult to desulphurize, in particular, due to the presence of impurities .

Description of preferred embodiments

[0059] Figure 2 is a process diagram of an apparatus 100, according to an embodiment of the invention, comprising a single catalytic reactor 1 for carrying out a single reaction stage, suitable for desulfurizing a hydrocarbon liquid 40 such as a medium distillate such as a pre-treated diesel fuel, with a current of hydrogen 50.

[0060] The reactor 1, also shown in Figure 1, is a gas lift type reactor, more precisely an expanded bed reactor, comprising a container 10 and a wall, for example, as in Figure 2, a tubular element or duct 11 arranged vertically inside the container 10, having lower and upper ends 11 ', 11 "arranged at a predetermined distance respectively from the lower bottom 52 and from the upper bottom 54 of the container 10. In the embodiment of the reactor 1 shown in Figure 2, the the wall or the duct 11 defines in the container 10 a first space 18 and a second space 19 which, in the case shown, are respectively the internal space 18 of the duct 11 and the space 19 external to the duct. In the first space 18 there is a catalytic bed 13 confined between a support grid 12 ', on which the catalytic bed 13 is supported, and a containment grid 12 "arranged above the support grid 12'.

[0061] Preferably, the catalyst of the catalytic bed 13 is selected from a Cobalt-Molybdenum catalyst and a Nickel-Molybdenum catalyst, in an amount comprised between 0.5 m <3> and 1.5 m <3>, preferably between 0.8m <3> and 1.0m <3>. The solid particles of the catalyst are preferably substantially spherical in shape and have an abrasion percentage preferably lower than 1% by weight. For example, the catalyst can be Albemarle KF 757-1.3Q, Co-Mo on activated alumina, quadrilobate particles of nominal size 1.2x1.4 mm with 0.9% abrasion percentage.

Preferably, the container 10 is provided with a bottom drain 22 comprising an opening provided with a plug or, as shown, a valve 22, for periodically discharging fine particles of catalyst from the reactor 1. Fine particles can be formed from the disintegration of the particles of the original catalytic bed, due to the conditions of movement that occur there, and can fall away from the catalytic bed through the grid 12 ', collecting in the lower bottom 52 of the container 10.

[0063] In quiet conditions, ie in the absence of flow, the catalytic bed 13 has a free surface 13 'which is located at a distance H from the containment grid 12 ", in other words below the containment grid 12" an expansion space 14 is provided for the catalytic bed 13.

[0064] The apparatus 100 is associated with a storage, not shown, of the hydrocarbon liquid 40, as well as means for drawing and feeding the hydrocarbon liquid 40 from the storage to the reactor 1 comprising, for example, a pump 41 (Figure 3). Through a wall of a lower portion of the container 10 there is a supply opening 15 hydraulically connected with the means of feeding the hydrocarbon liquid 40.

[0065] The apparatus 100 is also associated with a storage, not shown, of the hydrogen 50, as well as means for withdrawing and feeding the hydrogen 50 from the storage to the reactor 1 comprising one or more hydrogen dispensers 16 arranged inside the container 10, in hydraulic communication with one or more respective hydrogen supply nozzles 58.

[0066] The supply opening 15 of the hydrocarbon liquid, the lower end 11 "of the wall 11, in this case the lower open end 11" of the duct 11, and the dispenser or dispensers 16 of the hydrogen 50 are arranged in such a way in a lower zone of the first space 18, in this embodiment in a lower zone of the catalysis duct or tube 11, inside it, a first two-phase gas / liquid mixture 46 is formed between the hydrogen 50 and the hydrocarbon liquid 40, which has a lower specific gravity than that of the hydrocarbon liquid 40 alone.

[0067] Preferably, homogenization means of the two-phase mixture 46 are provided, arranged below the catalytic bed 13, in this case, the homogenization means comprise a plurality of distributor plates 34.

[0068] Therefore, as better described below, the two-phase mixture 46 tends to rise inside the first space 18, in this embodiment, inside the duct 11, crossing the catalytic bed 13. Once the support 12 ', the two-phase mixture 46 and the solid particles of the catalyst 13 form a three-phase mixture 47 which overall undergoes an upward thrust. In other words, the gaseous hydrogen 50 acts as an entrainment gas for the hydrocarbon liquid 40 and for the solid catalyst of the catalytic bed 13.

[0069] The apparatus 100 comprises means for preheating and thermostating the hydrocarbon liquid 40 and / or hydrogen 50, described in greater detail below, with reference to Figure 3. The preheating and thermostating means are configured in a manner such that the three-phase mixture 47 in the catalytic bed 13 is at a desulphurization temperature suitable for carrying out a desulphurization reaction of the hydrocarbon liquid 40 as a whole.

[0070] In this way, in the catalytic bed 13 one or more transformation reactions take place of the sulfur compound or compounds contained in the hydrocarbon liquid charge 40 into non-sulfur organic compounds, mainly liquid, and into volatile sulfur compounds, gaseous at pressure and desulfurization temperature imposed in the catalytic bed 13.

[0071] In the catalytic bed 13 there are also inevitable and known secondary reactions, such as hydrocracking reactions, that is, the splitting of hydrocarbon chains by hydrogen.

[0072] In an upper portion of the first space 18, in this embodiment in an upper portion of the space 18 inside the catalysis tube 11, the three-phase mixture 47 is resolved into the solid 13, which is in any case retained within the first space 18 from the 12 "containment grid, and in a second two-phase mixture 48, comprising:

- the treated hydrocarbon liquid, ie with a lower content of sulfur compounds, in particular containing a modest quantity of naphtha;

- a gas containing partially consumed hydrogen and products of the desulfurization reaction (s) and secondary reactions, mainly H2S, NH3, light hydrocarbon gases such as Methane, Ethane, LPG, or C3 / C4 deriving from secondary hydrocracking reactions.

[0073] The reactor 1 comprises, in correspondence with the upper end 11 "of the wall 11, in this embodiment at the upper end 11" of the duct 11, and in the upper part of the second space 19, in this case outside of the duct 11, a degassing zone 24 configured so as to allow at least partial degassing of the two-phase mixture 48, and provided with an outlet opening 17, in this case lateral. In this way, the two-phase mixture 48 can be resolved in a recycle liquid 49 which falls into the second space 19, and in an extracted gas-liquid mixture 60 which leaves the reactor 1 through the opening 17.

The biphasic mixture 46,48 has a lower density than the hydrocarbon liquid 40 fed. Therefore, as anticipated, it moves upwards in the first space 18, in this case inside the duct 11, under the thrust of the degassed recycle liquid column 49 which from the head of the reactor 1 falls back into the second space 19 , in this case outside the duct 11 itself.

[0075] The apparatus 100 advantageously comprises adjustment means for varying the ratio between the flow rate of the degassed recycle hydrocarbon liquid 49 with respect to the flow rate of the two-phase mixture 46-48, in particular by changing the quantity of hydrogen 50 introduced as lifting gas through a regulating valve 57. In this way the density of the rising two-phase mixture 46-48 is modified. This also allows to vary the flow rate of the recycled hydrocarbon liquid 49 which recycles from the outlet of the catalytic bed 13, after degassing, down again towards the lower end 11 'of the wall 11, in this embodiment towards the lower end of the duct. or catalytic tube 11.

[0076] In an embodiment, indicated with a broken line again in Figure 2, the adjustment means comprise an external recycling pipe 78 in hydraulic communication with an opening 56 made in a wall of the upper portion of the container 10, through a first its own end, and with the supply opening 15, through a second end opposite the first. The regulating means can also comprise a regulating valve 79 installed on the external recycle pipe 78, to precisely vary the flow rate of a part 49 'of the recycle liquid stream 49 which runs through the pipe 78 and, therefore, the flow rate total of the recycle liquid 49 descending. Preferably, a static mixer 77 is installed along the supply pipe of the hydrocarbon liquid to be treated 40, having a side inlet hydraulically connected to the external recycling pipe 78.

[0077] Even if in the apparatuses according to the embodiments described with reference to Figures 2-4 the first space 18, within which the catalytic bed 13 is arranged, is always the internal space of the duct 11, it is possible, with obvious modifications for the skilled in the art, that the catalyst is arranged outside the duct 11, in other words that the first space 19 is the space outside the duct 119, and that the interior of the duct 11 is free for the passage of the recycled liquid 49 .

[0078] The catalyst in the catalytic bed 13 of the expanded bed reactor 1 is normally a Cobalt-Molybdenum catalyst. The shape of the catalyst is preferably spherical or cylindrical, mono- or polylobed, with a low length / diameter ratio.

[0079] Advantageously, the apparatus of the present invention comprises devices for treating the gas-liquid mixture 60 extracted from the reactor 1, containing an excess quantity of hydrogen and reaction products, extracted from the reactor 1 through the opening 17, and its components. This is described below, with reference to figure 2. This schematically represents an apparatus 200 which, compared to figure 1, shows the auxiliary equipment of the mobile unit, in a particular embodiment of the apparatus.

[0080] The heating and thermostating means can comprise one or more 45.55 heaters installed on the supply lines of the hydrocarbon liquid 40 and / or the hydrogen supply 50 respectively. Each of the heaters 45.55 can be, independently of the other, a heat exchanger fed with steam or with a diathermic fluid, or an electric heater. Means are also provided for regulating the thermal power transferred to the hydrocarbon liquid 40 and / or to the treatment hydrogen 50 in the 45.55 heating devices so that in the catalytic bed 13 the reaction mixture has a predetermined desulfurization temperature.

[0081] The apparatus 200 comprises a first high pressure separator tank 4 fluidically connected with the outlet opening 17, arranged to receive the extracted gas-liquid mixture 60. The high pressure separator 4 is configured to separate a gas stream 80 containing hydrogen sulphide, excess hydrogen and light hydrocarbons, from the heavier liquid components 66.

[0082] The heating and thermostating means may further comprise one or more heat exchangers 43,53 arranged with one side upstream respectively of the heater 45 and / or 55, and with the other side in hydraulic communication with the liquid 66 and / or gas stream 80 exit from the separator 4. In this way, it is possible to preheat the hydrocarbon liquid 40 and / or the supply hydrogen 50, recovering part of the heat supplied to the process fluids by the heater 45 and / or 55.

[0083] In particular, the vapors 80 from the separator tank 4 are preferably cooled in the heat exchanger 53, exchanging heat with the supply hydrogen stream 50, while the heavy liquid effluents 66 are cooled in the heat exchanger 43, exchanging heat with the hydrocarbon liquid 40 fed, i.e. fresh. The vapors 80 can undergo further cooling by mixing with the cooled heavy liquid effluents 66, obtaining a mixture of effluents 82.

[0084] A further heat exchanger 83, for example fed with water, preferably chilled, can be provided to cool the effluent mixture 82. A second high-pressure separator tank 6 can also be provided for separating the effluent mixture 82 in a recovery gas 88 and in a stream of non-stabilized treated hydrocarbon liquid 84.

The recovery gas 88 contains an excess of hydrogen, i.e. unreacted hydrogen, which is advantageously used to provide a portion of the feed hydrogen stream 50. For this purpose, purification means can be provided to remove the sulfur compounds formed during the desulfurization reaction in the catalytic reactor 1 from the recovery gas 88. As shown again in Figure 2, the purification means can comprise a scavenging reactor 5 of the sulfur. The scavenging reactor 5 can have an iron oxide adsorption bed 59 or a mixture of oxides, such as iron and zinc oxide, configured to adsorb, in particular, hydrogen sulphide, so as to obtain a stream of purified hydrogen 90. The adsorption bed 59 is discharged periodically, once its adsorbing capacity is exhausted. The scavenging reactor 5 is provided with a bottom drain 98 comprising an opening provided with a plug or a valve, to periodically discharge fine particles of catalyst from the reactor 1.

[0086] A recycling compressor 8 can be arranged to treat at least a part 94 of the purified hydrogen 90, bringing it to a predetermined working pressure, and forming a stream of recycled hydrogen.

Thus, the apparatus 200 is configured to form the feed hydrogen stream 50 by combining the recycle hydrogen stream 94 with a fresh hydrogen stream 50 ', taken from a storage, not shown, and brought to the working pressure by means of a primary compressor 51.

[0088] In one embodiment, the hydrogen compression means, in this case the primary compressor 51 and the recycle compressor 8, are suitable for bringing the hydrogen 50 entering the reactor to a working pressure such that the partial pressure of hydrogen in reactor 1 is between 7 and 32 bar.

[0089] The compression means, together with the other hydrogen supply means 50,50 ', such as pipes, are configured to supply the reactor 1 with a flow rate of hydrogen 50 such that the ratio between the flow rate of the supplied hydrogen 50 and the flow rate of the hydrocarbon liquid 40 fed to the reactor 1 is between 45 and 270 Smc of hydrogen / mc of hydrocarbon liquid fed.

[0090] A stripper 7 may also be provided, arranged in hydraulic communication with the outlet of the non-stabilized treated diesel 84 from the second separator tank 6 to purify the non-stabilized treated diesel 84 separated therein, i.e. to remove the last ppm of hydrogen sulphide and the light products (C1, C2, LPG and Nafta) coming from the secondary reactions of hydrocracking. Advantageously, the stripper 7 is also pneumatically connected with the outlet of the scavenging reactor 5, or in any case with the recovery gas line 90, to use part 92 of the recovery gas 90, possibly as purified, as stripping gas.

[0091] A regulating valve 91 configured to regulate the flow rate of the stripping gas 92 according to the requirements of the stripper 7 can be provided on the stripping gas supply line 92.

[0092] On the feed line of the non-stabilized treated hydrocarbon liquid 84 to the stripper 7, a further heater 87, for example electric, can also be provided to preheat the liquid 84 entering the stripper, in order to facilitate the 84 produced by the desulfurization 200

[0093] Figure 3 is a process diagram of an apparatus 300, according to another embodiment of the invention. The apparatus 300 differs from the apparatus 200 of figure 2 in that it comprises auxiliary catalytic reactors 2,3, more precisely a second stage catalytic reactor 2 and a final stage 3 catalytic reactor to carry out further liquid purification treatments hydrocarbon leaving catalytic reactor 1 already described with reference to Figure 1 and indicated below as first stage reactor 1.

[0094] The auxiliary catalytic reactors 2,3 comprise respective containers 20,30 provided with respective feed openings 25,35 and outlet 27,37 inside which respective fixed catalytic beds 23,33 are arranged.

[0095] In the apparatus 300, the second stage 2 and final stage 3 catalytic reactors are arranged to receive as liquid feed respectively the treated hydrocarbon liquid 60 extracted at the head of the first stage catalytic reactor 1 and the heavy liquid components 66 extracted from the separator tank 4.

[0096] In one aspect of the invention, the first stage catalyst 13 is a catalyst suitable for causing / promoting, in addition to the hydrodesulphurization reactions of sulfur compounds, also hydrogenation reactions of nitrogen compounds and / or polycyclic aromatic compounds and / or olefins. In particular, the first stage catalyst comprises a metal selected from among Nickel, Palladium and Platinum. The catalysts of the second stage 23 and / or final stage 33 catalytic beds are, independently of each other, Cobalt-Molybdenum catalysts. Preferably, the catalytic bed 23 of the second stage reactor 20 comprises an amount of second stage catalyst comprised between 0.3 m <3> and 1 m <3>, in particular between 0.5 m <3> and 0, 8 m <3>.

[0097] In order to isolate each auxiliary catalytic reactor 2,3 from the apparatus, shut-off valves 61,65; 67,71 can be provided, as well as pipes 64,68 and bypass valves 63,69. By operating on these valves, four configurations of the apparatus 300 can be obtained, i.e. configurations in which both the auxiliary catalytic reactors 2,3 or only one of the reactors 2,3 are used, in which the catalytic reactor 1 of figures 1 and 2 has the role of first stage reactor, plus a fifth configuration similar to that of figure 2, in which both auxiliary catalytic reactors 2,3 are excluded from the apparatus.

[0098] For each auxiliary catalytic reactor 2,3 there are also pipes with shut-off / regulation valves 73 ', 73 "of hydrogen, taken as streams 72', 72" from the hydrogen stream 50 ", in addition to the hydrogen 50 feeding to the first stage catalytic reactor 1.

[0099] Always referring to Figure 3, an apparatus 300 according to another aspect of the invention, for removing a sulfur compound from a hydrocarbon liquid 40 by catalytic hydrodesphulfurization, i.e. by treatment with hydrogen 50,50 'on a catalyst, provides a first stage reactor 1, comprising (Figure 1):

- a first container 10;

- a wall 11 arranged vertically inside said first container 10, having a lower end 11 'and an upper end 11 "(Figure 1) arranged at a predetermined distance respectively from a lower bottom (52) and from a bottom upper (54) of said first container 10, said wall 11 defining in said first container 10 a first space 18 and a second space 19 (Figure 1);

- a grid support element 12 'and a grid containment element 12 ", both arranged in said first space 18 of said duct 11, in which said containment element 12" is arranged above said support element 12';

- a catalytic bed 13 arranged between said grid support element 12 'and said grid containment element 12 ",

wherein said catalytic bed 13 comprises solid particles having a solid first stage catalyst suitable, at a predetermined treatment temperature, to cause a hydrogenation reaction of a nitrogenous compound and / or of a polycyclic aromatic compound and / or of a olefin, said first stage catalyst comprising a metal chosen, in particular, from:

- Nickel;

- Palladium;

- Platinum,

wherein said catalytic bed 13 rests on said grid support element 12 ';

wherein said grid containing element 12 "is arranged at a predetermined distance H (Figure 1) above a free upper surface 13 'of said catalytic bed 13, so as to form a space above said free upper surface 13' expansion 14 for said catalytic bed 13;

- a feed opening 15 of said hydrocarbon liquid 40 made through a wall of a lower portion of said first container 10;

- a dispenser 16 of said hydrogen 50 arranged to introduce said hydrogen into said first space 18, below said catalytic bed 13;

- an outlet opening 17 made through a wall of an upper portion of said first container 10, so that, by introducing said hydrocarbon liquid 40 into said first container 10 with a predetermined flow rate of liquid through said supply opening 15 and introducing said hydrogen 50 with a flow rate of hydrogen dependent on said flow rate of hydrocarbon liquid 40 in said catalytic bed 13 through said dispenser 16, a stream 46.48 (Figure 1) is formed of a two-phase mixture of said hydrocarbon liquid and said hydrogen, said stream 46.48 of a two-phase mixture being less dense than said hydrocarbon liquid 40, so that said stream 46.48 of a two-phase mixture has an upward direction inside said catalytic bed 13, causing said hydrogenation reaction, and a corresponding stream of recycled liquid 49 (Figure 1) in said outer space 19 or inner space 18, outside said catalytic bed 13, has a downward direction, in which a part 60 of said stream 48 of said two-phase mixture, containing a desulfurized hydrocarbon liquid and desulfurization products, exits from said first container 10 through said outlet opening 17;

- thermostating means configured to bring and maintain said catalytic bed 13 and said two-phase mixture 46 at said treatment temperature;

so that, by increasing / decreasing said liquid flow rate and therefore said hydrogen flow rate, said catalytic bed 13 respectively increases / decreases in height by expanding / contracting in said expansion space 14.

[0100] The apparatus 300 also comprises a second stage reactor 2 comprising:

- a second container 20;

- a quantity 23 of a second stage catalyst disposed inside said second container 20, said second stage catalyst being suitable, at a predetermined second stage treatment temperature, to cause a second stage desulphurization reaction of said part remainder of said sulfur compound, in the presence of said hydrogen 72 ';

- at least a second supply opening 25 made through a wall of said second container 20 for a liquid supply 62 comprising said part 60 of said current 48 and for a hydrogen supply comprising an additional portion 72 'of said hydrogen 50; a second outlet opening 27 made through a wall of said second container 20;

- a pipeline configured to put said outlet opening 17 of said first stage reactor 1 in hydraulic communication with said second supply opening 25,

wherein said second supply opening 25 and said second outlet opening 27 are arranged so that said liquid supply 62 and said supply of said additional portion of hydrogen 72 ', fed through said at least one second supply opening 25, come into contact with said amount of a second stage catalyst 23, causing said second stage desulfurization reaction, and in such a way that a stream 66 of a second stage product containing a second stage desulphurized hydrocarbon liquid flows out of said second outlet opening 27 and desulfurization products.

[0101] In particular, said amount of said second stage catalyst forms a fixed catalytic bed 23.

[0102] In particular, said apparatus 300 comprises a final stage reactor 3 comprising:

- a further container 30;

- a quantity 33 of a final stage catalyst disposed inside said further container 30, said final stage catalyst being suitable, at a predetermined final stage treatment temperature, to cause a final desulphurization reaction of said remaining part of said sulfur compound in the presence of said hydrogen 72 ";

- at least one further feed opening 35, made through a wall of said further container 30 for a liquid feed 68 comprising a part 60 of said stream 48 or a part 66 'of said stream 66 of a second stage product;

- a further outlet opening 37 made through a wall of said further container 30;

- a pipe configured to put in hydraulic communication said outlet opening 17 of said first stage reactor 1 or said second outlet opening 27 of said first stage reactor 2 with said further supply opening 35,

said further supply opening 35 and said further outlet opening 37 being arranged so that said liquid supply 68 and said hydrogen supply 72 ", fed through said at least one further supply opening 35, come into contact with said quantity of a final stage catalyst 33 causing said final stage desulfurization reaction, and from said further outlet port 37 exits a stream 76 of a final product containing a final stage desulfurized hydrocarbon liquid, excess hydrogen and desulfurization products.

[0103] In particular, said amount of said final stage catalyst forms a fixed catalytic bed 33.

[0104] In particular, said second stage catalyst and / or said final stage catalyst is a Cobalt-Molybdenum catalyst, and said catalytic bed 13 of said second stage catalyst comprises an amount of said second stage catalyst comprised between 0 , 3 m <3> and 1 m <3>, in particular between 0.5 m <3> and 0.8 m <3>.

[0105] The above description of embodiments of the invention is able to show the invention from the conceptual point of view so that others, using the known art, will be able to modify and / or adapt these specific embodiments in various applications without further research and without departing from the inventive concept, and, therefore, it is understood that such adaptations and modifications will be considered as equivalent to the specific embodiments. The means and materials for carrying out the various functions described may be of various nature without thereby departing from the scope of the invention. It is understood that the expressions or terminology used have a purely descriptive purpose and, therefore, are not limiting.

Claims (10)

CLAIMS 1. An apparatus (100,200,300) for removing a sulfur compound from a hydrocarbon liquid (40) by catalytic hydrodesulfurization, said apparatus comprising a reactor (1), wherein said reactor (11) comprises: � a container (10); � a wall (11) arranged vertically inside said container (10), having a lower end (11 ') and an upper end (11 ") arranged at a predetermined distance respectively from a lower bottom (52) and from an upper bottom (54) of said container (10), said wall (11) defining in said container (10) a first space (18) and a second space (19); � a grid support element (12 ') and a grid containment element (12 "), both arranged in said first space (18) of said duct (11), in which said containment element (12") is arranged above said support element (12 '); � a catalytic bed (13) arranged between said grid support element (12 ') and said grid containment element (12 "), wherein said catalytic bed (13) comprises solid particles having a solid catalyst configured to cause a desulfurization reaction of said sulfur compound in the presence of hydrogen (50) at a predetermined treatment temperature; in which said catalytic bed (13) rests on said grid support element (12 '); wherein said grid containing element (12 ") is arranged at a predetermined distance (H) above a free upper surface (13 ') of said catalytic bed (13), so as to form an expansion space ( 14) for said catalytic bed (13) over said free upper surface (13 '); � a feed opening (15) of said hydrocarbon liquid (40) made through a wall of a lower portion of said container (10); A dispenser (16) of said hydrogen (50) arranged to introduce said hydrogen into said first space, below said catalytic bed (13); � an outlet opening (17) made through a wall of an upper portion of said container (10), so that, by introducing said hydrocarbon liquid (40) into said container (10) with a predetermined flow rate of liquid through said supply opening (15) and introducing said hydrogen (50) with a flow rate of hydrogen dependent on said liquid flow (40) in said catalytic bed (13) through said dispenser (16), a stream (46,48) is formed of a two-phase mixture of said hydrocarbon liquid and said hydrogen, said stream (46,48) of a two-phase mixture having a lower density than said hydrocarbon liquid (40), so that said stream (46,48) of a two-phase mixture has an upward direction through said catalytic bed (13), during said desulfurization reaction, and a corresponding liquid stream (49) has a descending direction through said external (19) or internal (18) space, in which a part (60) of said stream (48) of said two-phase mixture, containing a desulphurized hydrocarbon liquid and desiccant products the perforation exits from said container (10) through said outlet opening (17); � thermostating means configured to bring and maintain said catalytic bed (13) and said two-phase mixture (46) at said treatment temperature; so that, by increasing / decreasing said liquid flow rate and therefore said hydrogen flow rate, said catalytic bed (13) respectively increases / decreases in height by expanding / contracting in said expansion space (14). 2. An apparatus (100,200,300) as per claim 1, in which said wall, arranged inside said container 10, is a tubular element, i.e. a duct (11), and said first space (18), containing said catalytic bed (13), is selected between an internal space of said tubular element (11) and a space external to said tubular element (11). 3. An apparatus (100,200,300) as per claim 1, in which said predetermined distance (H) is greater than 15% of a distance (H ') between said free upper surface (13') and said grid support element (12 '), in particular, said predetermined distance (H) is greater than 30% of said distance (H ') between said free upper surface (13') and said grid support element (12 '), in particular, said predetermined distance (H) is between 30% and 100% of said distance (H ') between said free upper surface (13') and said grid support element (12 '). 4. An apparatus (100,200,300) as per claim 1, wherein said reactor (1) comprises an external recycling pipe (78) having a first end in hydraulic communication with said upper portion of said container (10), and a second end in hydraulic communication with said supply opening (15), so that a part (49 ') of said recycle liquid stream (49) passes through said external recycle pipe (78), in which said external recycle pipe (78 ) comprises a regulating valve (79) for modifying a flow rate of said part (49 ') of said recycle liquid stream which runs through said external recycle pipe (78). 5. An apparatus (300) as per claim 1, in which said reactor (1) is a first stage reactor, said container is a first container, said catalyst (13) is a first stage catalyst and said treated hydrocarbons are hydrocarbons first stage treated products obtained from a first stage reaction comprising said desulfurization reaction, said first stage reaction causing a transformation of a part of said sulfur compound into said desulfurization products, a remaining part of said sulfur compound remaining unconverted, into wherein said apparatus (300) comprises: � a second stage reactor (2) comprising: � a second container (20); An amount (23) of a second stage catalyst disposed within said second container (20), said second stage catalyst being configured to cause a second stage desulfurization reaction of said remaining part of said sulfur compound, in presence of said hydrogen (72 '), at a predetermined second stage treatment temperature; At least one second feed opening (25,26) made through a wall of said second container (20) for a liquid feed (62) comprising said part (60) of said stream (48) and for a hydrogen feed comprising an additional portion (72 ') of said hydrogen (50); A second outlet opening (27) made through a wall of said second container (20); A pipeline configured to put in hydraulic communication said outlet opening (17) of said first stage reactor (1) with said second supply opening (25), wherein said second supply opening (25,26) and said second outlet opening (27) are arranged so that said liquid supply (62) and said hydrogen supply (72 '), fed through said at least one second delivery opening feed (25,26), come into contact with said quantity (23) of a second stage catalyst, causing said second stage desulfurization reaction, and so that a stream (66) of a second stage product containing a liquid second stage desulfurized hydrocarbon and desulfurization products exits from said second stage reactor (20) through said second outlet opening (27), in particular, said amount of said second stage catalyst forms a fixed catalytic bed (23). 6. An apparatus (300) as per claim 1 or 5, in which said catalyst (13) or said first and second stage catalysts (13,23) are suitable to cause, respectively, said desulphurization reaction and said reaction reactions first and second stage, a remaining part of said sulfur compound remaining unconverted, wherein said apparatus (300) comprises: � a final stage reactor (3) comprising: � an additional container (30); An amount (33) of a final stage catalyst disposed within said further container (30), said final stage catalyst being configured to cause a final desulfurization reaction of said remaining part of said sulfur compound in the presence of said hydrogen (72 ”), at a predetermined final stage treatment temperature; At least one further feed opening (35), made through a wall of said further container (20) for a liquid feed (68) comprising a part (60) of said stream (48) or a part (66 ') of said stream (66) of a second stage product; � a further outlet opening (37) made through a wall of said further container (30); A pipe configured to put in hydraulic communication said outlet opening (17) of said first stage reactor (1) or said second outlet opening (27) of said first stage reactor (2) with said further supply opening ( 35), said further supply opening (35) and said further outlet opening (37) being arranged so that said liquid supply (68) and said hydrogen supply (72 "), fed through said at least one further feed (35), come into contact with said amount (33) of an end stage catalyst causing said end stage desulfurization reaction, and a stream (76) of an end product containing an end stage desulfurized hydrocarbon liquid, hydrogen in excess and desulfurization products, exits from said final stage reactor (30) through said further outlet opening (37), in particular, said amount of said final stage catalyst forms a fixed catalytic bed (33). 7. An apparatus (100,200,300) as per claim 1, in which said catalyst is selected from: � a Cobalt-Molybdenum catalyst; � a Nickel-Molybdenum catalyst, and said catalytic bed (13) comprises an amount of said catalyst comprised between 0.5 m <3> and 1.5 m <3>, preferably between 0.8 m <3> and 1.0 m <3>. 8. An apparatus (300) according to claim 5 or 6, in which said first stage catalyst is a catalyst configured to also cause a hydrogenation reaction of a nitrogenous compound and / or of a polycyclic aromatic compound and / or of a olefin, said first stage catalyst comprising a metal chosen from: � Nickel; � Palladio; � Platinum, Said second stage catalyst and / or said final stage catalyst is a cobalt-molybdenum catalyst; Said catalytic bed (23,33) of said second stage catalyst and / or said final stage catalyst comprises an amount of said second stage and / or final stage catalyst comprised between 0.3 m <3> and 1 m <3>, in particular between 0.5 m <3> and 0.8 m <3>. 9. An apparatus (300) as per claim 5 or 6, wherein said second stage and / or final stage catalyst is a Cobalt-Molybdenum catalyst, and said catalytic bed (23,33) of said second stage catalyst and / or of the final stage comprises an amount of said second stage or final stage catalyst comprised between 0.3 m <3> and 1 m <3>, in particular between 0.5 m <3> and 0.8 m <3>. 10. An apparatus (100,200,300) as per claim 1, wherein said reactor (1) comprises homogenization means (34) of said stream (48) of said two-phase mixture arranged below said catalytic bed, in particular, said homogenization means comprise a plurality of distributing trays (34). p.p. SIME S.r.l.