Hydroprocessing process for hydrocarbons subject to temperature-accelerated fouling

Abstract

The invention relates to a novel method and processing configuration for the catalytic treatment of a hydrocarbon feedstock (1) into a treated hydrocarbon stream using an ebullated bed reactor (10). The invention is particularly suitable for the treatment of hydrocarbon feedstocks comprising compounds capable of precipitating and / or polymerizing to produce gums under high temperature. Figure 1 to be published

Description

Title of the invention: Method for hydroprocessing hydrocarbons subject to temperature-accelerated fouling Field of invention

[0001] The invention relates to the treatment of a hydrocarbon feedstock into a treated hydrocarbon stream, such a process using an ebullated bed reactor. The invention is particularly well suited to the treatment of hydrocarbon feedstocks comprising compounds capable of precipitating and / or polymerizing to produce gum under high temperature. Context

[0002] Hydroprocessing (literally translated as hydrotransformation or hydrotreatment) is a common chemical treatment process carried out on hydrocarbons for the production of fuels and petrochemicals. Hydroprocessing refers to a very broad range of processes, but generally refers to any process in which hydrogen chemically reacts with a stream consisting primarily of hydrocarbons to change the chemical composition of that stream. The resulting change may include the removal of heteroatoms such as sulfur, nitrogen, chlorine, bromine, fluorine, or oxygen from the hydrocarbons, or the modification of the hydrocarbons themselves, such as olefin and aromatic saturation or hydrocracking. While hydroprocessing can describe many different chemical reactions, in this document it will refer to one or a combination of the following: hydrodesulfurization, hydrodenitrification, hydrodeoxygenation, hydrodehalogenation, olefin saturation, aromatic saturation, hydrodemetallization, hydroisomerization, and / or hydrocracking.Hydroprocessing reactions often occur in contact with a supported catalyst in order to increase the rate at which these hydroprocessing reactions occur.

[0003] In parallel with the hydroprocessing reaction, many supported catalysts are capable of capturing certain components of the fluid with which they are in contact, effectively removing them from said fluid for purification purposes. Species of arsenic, silicon and other heavy metals can be removed from a hydrocarbon fluid in this manner. The accumulation of these species in or on the supported catalyst over time can decrease the catalytic activity of said supported catalyst, but the latter still remains an effective means of removing impurities from the fluid and the impact of said accumulation can be minimized through optimal formulation of the catalyst, namely properties such as the content of metals, type of support, morphology of the support, etc.

[0004] There are many different materials that can be hydroprocessed for different reasons, as well as many different ways of carrying out the hydroprocessing; regardless of the means used, the chemical reactions generally take place at high temperature and moderate or high pressure. A commonly used method for feedstocks requiring high severity treatment or being heavily contaminated is that using an ebullated bed reactor.

[0005] An ebullated bed reactor is a 3-phase reaction environment in which hydrogen gas and liquid feed are contacted with a supported catalyst to facilitate hydroprocessing reactions. The ebullated bed uses a recycled liquid stream to fluidize the supported catalyst, which distinguishes it from other reactor configurations, such as the fixed bed reactor. Fluidizing the bed within the vessel allows for good internal mixing, and the reactor therefore operates in a near-isothermal manner with a low and constant pressure drop. Fluidizing the catalyst also avoids the problems of catalyst bed clogging that can occur in a fixed bed reactor.The reactor is designed so that the supported catalyst can be regularly added and removed without interrupting the continuous process, thus maintaining the catalytic activity at a constant level over long periods of operation and eliminating the need to shut down the reactor to replace the catalyst when it has become deactivated, as is the case in a fixed-bed reactor. This type of reactor is therefore generally implemented for feeds that have a high reaction exothermicity, a strong tendency to foul, or that can rapidly deactivate the catalyst.

[0006] Multiple characteristics of the feedstock may cause it to have a high tendency to foul when exposed to reaction conditions. In the context of the invention, emphasis will be placed on feedstocks comprising compounds capable of forming gums or which at least partially precipitate when said feedstocks are heated to the high operating temperature of the ebullated bed reactor.

[0007] The phenomenon of gum formation is common in hydrocarbon streams comprising olefinic compounds and / or dienes and results from the polymerization of unsaturated compounds contained in the feedstock leading to the formation of high molecular weight molecules that can agglomerate and impede the flow of a fluid. In the presence of free radicals, polymerization of these compounds can occur rapidly and the molecules agglomerate to cause fouling during processing. Exposure to compounds such as molecular oxygen can introduce free radicals into the hydrocarbon stream.

[0008] Alternatively, free radicals may be generated from the feedstock itself when subjected to moderate or elevated temperatures; moderate temperatures can often induce gum formation by converting dienes to free radicals. Olefins and dienes may be measured by the bromine number according to ASTM DI 159 and the diene value according to UOP326, respectively. In many processes, a typical location where gum formation may initiate is heat transfer equipment such as heat exchanger tubes, heat exchanger plates, furnace tubes, or electric heating elements; in these scenarios, the process fluid capable of forming gums contacts a hot heat exchange surface that provides heat and creates conditions in which the precursors to gum formation are formed.Materials subject to this type of heat exchange include many high-olefinic materials, including cracked hydrocarbons such as FCC (Fluid Catalytic Cracking) hydrocarbons, coking hydrocarbons, pyrolysis oil (petroleum, plastic, or bio-based), lipids, etc.

[0009] Alternatively, some process streams may result in fouling by solid sediments or precipitates. The precipitates or sediments may be present in the raw material or form as the material approaches reaction conditions in a process. Examples of situations in which precipitates may form include heating or cooling a material or mixing the material with another process stream that causes a physical or chemical interaction of their constituent elements.An example includes the formation of salts or metal-ligand complexes, as when lipids also containing phospholipids, such as those derived from plant or animal materials, form precipitates composed of phosphorus and alkali metals after being subjected to temperatures moderately above ambient conditions; this can occur with lipids that are untreated or pretreated through processes such as degumming, bleaching, deodorization, etc. Other more conventional petroleum feedstocks, such as heavy crude or atmospheric or vacuum residue, may experience asphaltene precipitation when the temperature is changed or when blended with other hydrocarbon streams, particularly those with a very different hydrocarbon family composition (paraffin, naphthenes, aromatics, etc.).); in these cases, precipitation is the result of a decrease in solubility in the hydrocarbon phase after mixing. Similarly, sediments may form in the . pyrolysis oils when mixed with other hydrocarbon streams or by heat input.

[0010] An ebullated bed efficiently uses the heat of the reaction exotherm to heat the feed streams to the required reaction temperature in the ebullated bed vessel itself, thereby reducing the heat that must be applied to the feed upstream of the reactor inlet. However, the exotherm may not be sufficient to maintain the operating temperature, so, as in prior art processes, it is necessary to heat the feed upstream of the ebullated bed reactor.In the case of a feedstock with high gum formation potential or a feedstock that can chemically degrade at elevated temperatures, heating the feedstock to the required reactor inlet temperature may cause fouling of equipment upstream of the bubbling bed (e.g. valves, injection device, heater tubes and / or pipes), which then requires shutdown of the operating unit for cleaning and thus limits its operating life. Therefore, to manage fouling problems, one solution could be to limit the feed temperature, but this has the disadvantage of reducing the severity / efficiency of the bubbling bed reactor.

[0011] Ebullated beds are designed so that the supported catalyst does not leave the reactor with the effluent vapor or liquid; however, smaller solid particles (fines due to erosion or breakage of the catalyst particles) commonly exist in the system and may be present in the liquid effluent or in the recycled liquid. The recirculation pump and downstream equipment must therefore be designed to handle the potential presence of solid particles. An example of a risk to process equipment is solid particles that can cause erosion of heat exchange equipment or degrade heat transfer capacity as the solids settle or accumulate on heat exchange surfaces, such as furnace tubes, heat exchanger tubes, or heat exchanger plates.

[0012] In contrast, fixed bed reactor systems are designed with a supported catalyst load that remains static when the fluid contacts it during the process. Fixed beds have the advantage of being able to more easily and reliably achieve greater removal of targeted contaminants from the fluid to be treated compared to an ebullated bed due to the inherent advantage of plug flow kinetics over the kinetics of a continuously stirred tank reactor ("CSTR"). The main disadvantage of the fixed bed, however, is that the catalyst cannot be removed and replaced as part of the normal process. The cycle length of the fixed bed is then limited by its ability to trap contaminants, fouling accumulated by the formation of gums or particles, decreased catalytic activity due to the accumulation of poisons, or any combination thereof. In the prior art, it is common to implement a fixed bed upstream of the main hydroprocessing section to absorb, convert, or remove contaminants that could negatively impact the downstream process; such guard beds are effective, but may require frequent changes in the catalyst load when receiving highly contaminated streams.

[0013] In the current state of ebullated bed reactor design, an internal device is included at the top of the reactor, which is designed to separate the vapor from the liquid and provide a vapor-free liquid stream for internal recycling via the recirculation pump. The ability of this internal device to separate the vapor from the recycled liquid is important because recycling the vapor is detrimental to the recirculation pump.

[0014] In view of the foregoing, the applicants propose a treatment process which implements an ebullated bed reactor, said process being suitable for the treatment of hydrocarbon feedstocks comprising compounds which tend to polymerize and / or precipitate, the operability of which is improved in terms of fouling and erosion problems of the process equipment, and which produces a treated effluent stream comprising a low content of catalyst fines, the presence of which can lead to the clogging of downstream equipment such as the catalyst bed of a fixed bed reactor which can be implemented downstream of the ebullated bed reactor in order to apply additional treatment to the liquid effluent.

[0015] These and other features of the present invention will become more readily apparent from the description which follows with reference to the accompanying drawings. Summary of the invention

[0016] An object of the applicant's invention is to treat the effluent from the ebullated bed reactor in an external separator drum within the loop of the ebullated bed reactor in order to produce a recycled liquid substantially free of solid particles.

[0017] It is also an object of the applicant's invention to eliminate gum formation and fouling problems by using an ebullated bed reactor and applying the process-required heat to the low-fouling recycle liquid through a recycle liquid heater to maintain the operating temperature in the ebullated bed reactor, while applying minimal or no heat to the fresh feedstock, thereby allowing the ebullated bed to operate at a higher severity without upstream fouling problems.

[0018] Yet another object of the applicant's invention is to eliminate the need for a upstream fixed bed guard reactor system and to increase the catalyst cycle time of a possible downstream fixed bed reactor, such as a hydrotreating reactor.

[0019] Another object of the applicant's invention is to broaden the range of acceptable contaminants and to improve feed flexibility in the treatment process in order to anticipate variability in the process feed regime.

[0020] A further object of the applicant's invention is to ensure that no small catalyst particles or fines will be carried from the ebullated bed reactor to a downstream fixed bed reactor, thereby eliminating premature shutdowns of the fixed bed reactor.

[0021] Yet another object of the applicant's invention is to ensure that no small catalyst particles will be carried to the recycled liquid heating device, thereby eliminating the concern of erosion and degradation of the heat exchange surface of the heat transfer equipment.

[0022] A further object of the applicant's invention is to ensure that, if a fixed bed reactor is arranged downstream of the ebullated bed reactor, 100% of the effluent from the ebullated bed reactor is treated in said downstream fixed bed reactor.

[0023] Another object of the applicant's invention is to provide a complete vapor / liquid / solid separation which avoids all the limitations of the internal device of the ebullated bed reactor.

[0024] More particularly, the applicant's invention describes a novel processing unit configuration for processing hydrocarbon liquids comprising:

[0025] one or more ebullated bed reactor units, at least one of said ebullated bed reactor units comprising a reactor vessel, a separation vessel and a pump, and said at least one reactor vessel comprising at its bottom a hydrocarbon recycle liquid inlet, a supported catalyst used to create an effluent by contact with a hydrocarbon feedstock and hydrogen, and said separation vessel being configured to separate said effluent from said reactor vessel into a liquid stream comprising less than 1% by weight of solid particles, a vapor stream and a slurry stream comprising solid particles and a hydrocarbon liquid phase,and further said pump being connected to a heater for providing heat and being further connected to said hydrocarbon recycle liquid inlet from the bottom of said reactor vessel for recycling at least a portion of said liquid stream comprising less than 1% by weight of solid particles.

[0026] According to the invention, the heating device may be selected from a group comprising a heat exchanger heated with hot oil, a heat exchanger heated with steam, a furnace heated with gas or liquid fuel, an electrically powered resistive heating element or an electric furnace.

[0027] According to the invention, the separation tank may comprise baffles, de-misters, coalescing mattresses, cyclones and / or trays.

[0028] In another aspect, the applicant's invention describes a novel method for catalytically treating a hydrocarbon feedstock comprising:

[0029] a) sending a hydrocarbon feedstock and a hydrogen stream to one or more ebullated bed reactors, said ebullated bed reactor(s) comprising at least one reactor vessel and a separation vessel, said hydrocarbon feedstock and said hydrogen stream being contacted with a catalyst in said reactor vessel to provide a first effluent; and

[0030] b) sending said first effluent into said separation tank in order to provide a liquid stream comprising less than 1% by weight of solid particles, a vapor stream and a sludge stream, said sludge stream comprising solid particles and a liquid phase of hydrocarbons; and

[0031] c) recycling at least a portion of said liquid stream comprising less than 1% by weight of solid particles into said ebullated bed reactor(s); and

[0032] said liquid stream which comprises less than 1% by weight of solid particles being heated before being recycled into said ebullated bed reactor(s).

[0033] The method may further comprise a step of treating at least some portions of said liquid stream comprising less than 1% by weight of solid particles and / or at least some portions of said vapor stream in a downstream catalytic hydroprocessing reactor.

[0034] The temperature of the hydrocarbon feedstock is lower than the operating temperature of said ebullated bed reactor(s). The ebullated bed reactor may operate at a temperature of between 250°C and 500°C, preferably between 270°C and 450°C, and at a pressure of between 10 bara and 200 bara, preferably between 30 bara and 180 bara.

[0035] The ebullated bed reactor may operate at a temperature higher than that of the hydrocarbon feedstock, and the temperature of said hydrocarbon feedstock is less than 250°C, preferably less than 200°C.

[0036] The method according to the invention may use a supported catalyst which comprises one or more metals from group VIII and / or one or more metals from group VIB, on a mineral support comprising zeolites, alumina, silica, silico-aluminas, magnesia, clays, or mixtures of at least two of these minerals. The supported catalyst used in an ebullated bed reactor system is most often in the form of extrudates or beads, the diameter of which is generally of the order of 1 mm or less than 1 mm and which typically contain at least one hydro-dehydrogenating element deposited on a support. The supported catalyst generally comprises a metal from group VIII chosen from the group formed by Ni, Pd, Pt, Co, Rh, and / or Ru, in combination with a metal from group VIB selected from the group Mo and / or W, on a mineral support selected from the group formed by zeolites, alumina, silica, silico-aluminas, magnesia, clays, and mixtures of at least two of these minerals. CoMo / alumina and NiMo / alumina catalysts are the most common. The total content of oxides of the metallic elements from groups VIB and VIII is preferably between 0.1% and 40% by weight, preferably between 5% and 35% by weight, relative to the total weight of the catalyst. The weight ratio, expressed as metal oxide, between the metal(s) from group VIB relative to the metal(s) from group VIII is often between 1.0 and 20, preferably between 2.0 and 10.

[0037] The process may also use a finely dispersed catalyst comprising one or more Group VIII metals and / or one or more Group VIB metals or a liquid catalyst.

[0038] The hydrocarbon feedstock may be selected from the group consisting of plastic pyrolysis oil, tire pyrolysis oil, biologically derived pyrolysis oil, rapeseed oil, soybean oil, corn oil, coconut oil, olive oil, linseed oil, sunflower oil, palm oil, jatropha oil, mustard oil, peanut oil, hemp oil, cottonseed oil, pork fat, poultry fat, lard, butter, tallow, hydrothermal liquefaction effluent oil, gasification effluent oil, deasphalted oil, vacuum distillate, atmospheric distillate, vacuum gas oil, light recycle oil, heavy recycle oil, delayed coking hydrocarbon effluent, pitch based on petroleum, vacuum residues, atmospheric residues, or any combination of these products.

[0039] The hydrocarbon feedstock has a diene number greater than 1.0, or greater than 3.0, or greater than 5.0.

[0040] The hydrocarbon feedstock generally has a metal content greater than 5 ppm by weight, preferably greater than 10 ppm by weight or greater than 20 ppm by weight.

[0041] The hydrocarbon feedstock generally has an asphaltene content greater than 500 ppm by weight. Brief description of the drawings [Fig. 1]

[0042] [Fig. 1] represents a diagram describing an example of a process for treating hydrocarbon feedstocks comprising compounds capable of polymerizing or precipitating. [Fig. 2]

[0043] [Fig.2] shows an embodiment in which the bed treatment unit bubbling according to the invention is integrated into a downstream treatment unit designed for the hydroprocessing of the steam and the net liquid effluent recovered from the separator drum. Detailed description of the invention

[0044] The phenomenon of gum formation is common in hydrocarbon streams comprising olefinic compounds and / or dienes and results from the polymerization of alkenes in a feedstock to form large molecules that can agglomerate and impede fluid flow. In the presence of free radicals, polymerization of these compounds can occur rapidly and the molecules agglomerate to cause fouling during processing. Exposure to compounds such as molecular oxygen can introduce free radicals into the hydrocarbon stream.

[0045] Alternatively, free radicals can be generated from the stream itself by subjecting it to moderate or elevated temperatures; moderate temperatures can often induce gum formation by converting dienes to free radicals. Olefins and dienes can be measured by the bromine number according to ASTM DI 159 and the diene value according to UOP326, respectively. In many processes, a typical location where gum formation can initiate is heat transfer equipment such as heat exchanger tubes, heat exchanger plates, furnace tubes, or electric heating elements; in these scenarios, the gum-prone fluid contacts a hot heat exchange surface that provides heat and creates conditions in which gum-forming precursors form.Fluids that contain many high olefinic materials include cracked hydrocarbons such as FCC hydrocarbons, coking hydrocarbons, pyrolysis oil (petroleum, plastic or bio-based), lipids, etc.

[0046] Mitigation of gum formation by limiting the operating temperature may be carried out in conjunction with other mitigation measures such as removal of free radical precursors or the addition of one or more antioxidant compounds. When the feedstock is processed in the ebullated bed reactor system of the invention, the materials that cause gum formation are hydroprocessed and are not present in the recycled liquid stream at levels where gum formation is a significant risk. The recycled liquid stream generally has a measured diene number of less than 1 and a bromine number of less than 5.

[0047] The charge(s) which can be treated by the method according to the invention include take hydrocarbon-containing liquid streams comprising compounds that are capable of polymerizing to form gums or produce precipitates when the feedstock undergoes heat exchange or is mixed as it approaches reaction conditions. The process is particularly suitable for treating / upgrading heavy oil feedstocks, heavy crude, bitumen from oil sands, liquid hydrocarbons from delayed coking processes, liquid hydrocarbons from fluidized catalytic cracking processes, residues from conventional refining processes, or any other mixture of these products.

[0048] The feedstock may also include residues from atmospheric or vacuum distillation, vacuum distillates (generally referred to as VDS or VD in English) such as those from conversion processes such as those from coking, fixed bed hydroconversion such as those from the HYVAHL® processes for the treatment of heavy hydrocarbons, heavy hydrocarbon hydroconversion processes carried out in an ebullated bed, such as those from the H-OIL® processes, or solvent deasphalted oils, for example using propane, butane or pentane deasphalted oils from the deasphalting of straight run residues or vacuum residues from the H-OIL® or HYVAHL® processes. The feedstock may also include pitch recovered from visbreakers or solvent deasphalters.

[0049] In addition, the feedstock may be formed by mixing these various fractions in any proportions, in particular deasphalted oil (DAO) and vacuum distillate. It may also contain light cycle oil (LCO) of various origins, heavy cycle oil (HCO) of various origins, as well as diesel cuts resulting from catalytic cracking or coking, generally with a distillation range of about 150°C to about 370°C.

[0050] The feedstock may also be selected from pyrolysis oils obtained from the refining of crude oil or from the pyrolysis of biological materials, municipal waste, tires or plastics. The feedstock may also comprise a vegetable or animal oil such as rapeseed oil, soybean oil, corn oil, coconut oil, olive oil, linseed oil, sunflower oil, palm oil, jatropha oil, mustard oil, peanut oil, hemp oil, cottonseed oil, pork fat, poultry fat, lard, butter, tallow, effluent oil from hydrothermal liquefaction, effluent oil from gasification, or any combination thereof.

[0051] The filler may comprise heteroatoms such as sulfur (up to 8.0 wt. %) and nitrogen (up to 10,000 ppm wt.), elemental oxygen (up to 5% by weight), chlorine (up to 1,000 ppm by weight), Conradson carbon residue (MCR, also referred to as RCR or CCR, up to 50% by weight), metallic contaminants such as (but not limited to) nickel, vanadium, iron, sodium, potassium, magnesium, calcium, silicon (up to 1,000 ppm by weight), and asphaltenes (up to 50% by weight). For bio-based hydrocarbons such as lipids or bio-based pyrolysis oil, the feed may include heteroatom classes that exceed the values ​​that may be found in petroleum-derived streams, such as elemental oxygen (up to 15% by weight).

[0052] In one embodiment, the feedstock is a plastic pyrolysis oil or an SRF (Solid Recovered Fuels) pyrolysis oil, preferably in liquid form at room temperature, obtained from the pyrolysis of plastics, preferably plastic waste originating in particular from collection and sorting channels, or from the pyrolysis of SRF. It comprises in particular a mixture of hydrocarbon compounds, including paraffins, olefins, naphthenes and aromatics. At least 80% by weight of these hydrocarbon compounds preferably have a boiling point below 700°C, and preferably below 550°C. In particular, depending on the origin of the pyrolysis oil, it may comprise up to 90% by weight of paraffins, up to 90% by weight of olefins and up to 90% by weight of aromatics.It is understood that the sum of paraffins, olefins and aromatics represents 100% by weight of the hydrocarbon compounds.

[0053] Pyrolysis oil may, and most often does, include impurities such as metals (including iron), silicon, and halogenated compounds (including chlorinated compounds). These impurities may be present in the pyrolysis oil at high levels, for example, up to 500 ppm by weight or 1000 ppm by weight or even 5000 ppm by weight of halogenated elements contained in halogenated compounds, and up to 2500 ppm by weight, or even 10,000 ppm by weight of metallic or semi-metallic elements. Alkali metals, alkaline earth metals, transition metals, poor metals, and metalloids may be considered contaminants of a metallic nature, referred to as metals or metallic or semi-metallic elements.

[0054] The pyrolysis oil may comprise between about 200 ppm by weight and 1000 ppm by weight of silicon, and between about 15 ppm by weight and 100 ppm by weight of iron. The pyrolysis oil may also comprise other impurities such as heteroatoms, in particular sulfur compounds, oxygen compounds and / or nitrogen compounds, and the pyrolysis oils have contents generally less than 20,000 ppm by weight of any single heteroatom and preferably less than 10,000 ppm by weight of heteroatoms.

[0055] The method according to the invention is particularly well suited to the treatment of a pyrolysis oil having:

[0056] - an aromatic content of between 0 and 90% by weight, often between 0 and 70 % by weight and may be between 10 and 50% by weight;

[0057] - a halogen content of between 1 and 5,000 ppm by weight, often between 50 and 1000 ppm by weight and may be between 50 and 500 ppm by weight;

[0058] - a metal content (excluding silicon) of between 5 and 10,000 ppm in weight, often between 10 and 2,000 ppm by weight and which may be between 20 and 100 ppm by weight;

[0059] - an iron content of between 0 and 10,000 ppm by weight, often between 5 and 1000 ppm by weight, and may be between 10 and 500 ppm by weight;

[0060] - a silicon content of between 1 and 1000 ppm by weight, often between 10 and 500 ppm by weight, and which may be between 20 and 200 ppm by weight;

[0061] [Fig. 1] represents a diagram describing an example of a process for treating hydrocarbon feedstocks comprising compounds capable of polymerizing or precipitating.

[0062] As illustrated in [Fig.l], a feedstock 1 is introduced with a hydrogen stream 2 into an ebullated bed reactor system 10 for processing. (Although not illustrated in [Fig.l], it is possible to use more than one ebullated bed reactor system to process the feedstock 1.)

[0063] Feed 1 is injected into the ebullated bed reactor system 10 at a maximum temperature of 250°C, but preferably less than 200°C in order to mitigate the occurrence of gum formation and to limit fouling of the upstream equipment.

[0064] The ebullated bed reactor system 10 is loaded with a supported catalyst to facilitate the hydroprocessing reactions and generates an effluent 3 comprising liquid, vapor, and potentially a minor amount of solid particles. The liquid and vapor of the effluent 3 include hydrocarbons, light hydrocarbon gases, unreacted hydrogen, and possibly hydroprocessing by-products. Light hydrocarbon gases are defined as compounds comprising one or two carbon atoms (e.g., methane, ethane), but may also be extended to include compounds having three or four carbon atoms (e.g., propane, butane).

[0065] Hydroprocessing by-products are defined as compounds that are generated as a result of the removal of heteroatoms through the addition of hydrogen, such as ammonia, hydrogen sulfide, hydrogen chloride, water, other hydrogen halides, etc. The amount and proportion of the by-products of hydroprocessing depend on the type and quantity of heteroatoms present in feed 1 and the operating conditions of the ebullated bed reactor 10.

[0066] The effluent 3 from the ebullated bed reactor system 10 then flows to the separator drum 11 where it is separated into three streams - a vapor stream 4, a total effluent liquid stream 5, and an ebullated bed effluent fines stream 6. The separator drum 11 may include internal devices such as baffles, coalescing mats, cyclones, etc., to facilitate the vapor / liquid / solid separation.

[0067] The effluent fines stream from the ebullated bed 6 may comprise catalyst fines, precipitates formed from mineral compounds contained in the feedstock, corrosion products and possibly a liquid comprising primarily hydrocarbons. The effluent fines stream from the ebullated bed 6 is generally produced intermittently, allowing the solid content to accumulate in the separator drum 11 until the amount is large enough to be readily removed.

[0068] The vapor stream 4 from the separator drum 11 may be routed to a downstream (fixed bed hydroprocessing) reactor (not shown). There is no significant pressure loss between the ebullated bed reactor system 10 and the downstream reactor due to the inclusion of the separator drum. The expression "no significant pressure loss" means, in the context of the invention, that the drum is at a pressure no lower than 2 bar, preferably 1 bar, relative to the outlet pressure of the ebullated bed reactor system 10. The vapor stream 4 comprises a hydrocarbon fraction, excess or unreacted hydrogen, light gaseous hydrocarbons and possibly hydroprocessing by-products. The vapor stream 4 comprises the majority of the hydrogen present in the effluent stream 3 as well as a significant portion of the hydroprocessing by-products.

[0069] The temperatures of the vapor stream 4 and the total effluent liquid stream 5 from the separator drum 11 are also maintained at the outlet of the ebullated bed reactor system 10, although it is possible (even if it does not appear in the diagram) to control / adjust the temperature at the inlet of the downstream fixed bed hydroprocessing reactor.

[0070] The total effluent liquid stream 5 is divided into a net effluent liquid stream 7 and a recycle liquid stream 8. The total effluent liquid stream 5 and, by extension, the net effluent liquid stream 7 and the recycle liquid stream 8, comprises liquid hydrocarbons as well as minor amounts of hydrogen, light gaseous hydrocarbons, optionally hydroprocessing by-products dissolved in the liquid phase and less than 1% by weight of solids. The net effluent stream 7 from the separator drum 11 can be routed to a downstream (fixed bed hydroprocessing) reactor (not shown); if the steam stream 4 is also routed to a fixed bed hydroprocessing reactor, the same reactor can be used to treat a mixture of the steam stream 4 and the net effluent stream 7. Although [Fig.l] shows the net effluent stream 7 separated from the total effluent stream 5 before the recirculation pump 13, it is possible to separate it at any time before it reaches the ebullated bed reactor system 10.

[0071] In association with or in the absence of the described downstream fixed bed hydroprocessing reactor, components of vapor stream 4 and / or net effluent stream 7 may be used in other processes. A portion or all of the unreacted hydrogen from either stream may be used as a reactant in other hydroprocessing processes, or even recycled to the feed of ebullated bed reactor system 10; typical processing steps encountered by the hydrogen may include cooling followed by vapor / liquid separation in a pressure vessel to reduce heavy hydrocarbon compounds, water scrubbing to remove water-soluble compounds, amine or caustic sweetening to remove acid gases such as hydrogen sulfide and carbon dioxide, pressure swing adsorption for hydrogen purification, or combinations thereof.

[0072] The hydrocarbon fraction of the net effluent stream 7 may be separated into one or more liquid products through product fractionation or other techniques well known in the state of the art; such liquid products may undergo further hydroprocessing in other hydroprocessing processes or blended with other streams to produce fuels (gasoline, diesel, jet fuel, liquid bunker fuel, etc.) or used for petrochemical applications such as use as steam cracking furnace feedstock. The light gaseous hydrocarbons may be used for fuel applications; typical treatment of the light gaseous hydrocarbons prior to use as fuel may include water washing, amine sweetening, or adsorption of impurities by contact with a solid adsorbent bed.

[0073] The recycled liquid stream 8 is returned to the bubbling bed reactor system 10 by means of the recirculation pump 13, and it is this flow which fluidizes the catalyst bed and produces its expansion in this reactor. It is important that the recycled liquid stream 8 be free of vapor, since the recycling of vapor is detrimental to the recirculation pump 13. The recirculation pump 13 produces a discharge stream 9 which is then heated in a heater 12 to produce a heated boiling pump discharge stream 14, which is then fed to the bubbling bed reactor system 10. Heating the recirculation stream 9 Driving the boiling pump 9 into the device 12 allows the bubbling bed reactor system to achieve the necessary operating temperatures.

[0074] The heater 12 may provide heat to the discharge stream of the recirculation pump 9 in a variety of ways, including, but not limited to, combustion heat provided by fuel gas or fuel oil, electricity, steam, hot oil, heat exchange with process fluids, etc. Typical heaters may include those well known in the art, such as tube furnaces, shell and tube heat exchangers, plate heat exchangers, etc. Regardless of its type, the heater will include a heat exchange surface with which the process fluid will contact. The separation of solid particles in the separator drum 11 ensures that the recirculation pump discharge stream heated in the heater 12 also contains a minimum of solid particles.The low solids content of the recirculation pump discharge stream flowing through the heater 12 allows the heat exchange surface to provide good heat transfer over extended periods of operation and reduces degradation of the mechanical integrity of the equipment. The presence of solids in this stream may otherwise mechanically damage the heat exchange surface by increasing erosion, and may also deposit on the heat exchange surface, impairing the ability to provide good heat transfer to the process fluid.

[0075] As mentioned above, because the temperature of the feed 1 is limited, the possibility of gum formation upstream of the reactor is eliminated. When the feed 1 is processed in the ebullated bed reactor system 10, the materials that cause gum formation undergo hydroprocessing and are not present in the recycled liquid stream 8. In addition to this, with the same method, precipitates that are likely to form in the feed 1 by increasing the temperature or mixing with other fluids are not formed before entering the ebullated bed reactor system 10. In this way, solid precipitates are not formed before fluidization of the solids has been achieved and solid precipitates entrained in the effluent stream 3 can be removed in the separator drum 11 in order to keep them out of the recycled liquid 8.Therefore, by placing the heating device 12 on the recycled liquid stream 8 and adding a means for separating the solid particles in the separator tank 11, the problems of fouling by formation of gums and solid precipitates are eliminated.

[0076] Applicant's invention provides numerous processing advantages over the prior art by providing a configuration that can process feedstocks with high potential for gum formation or solids precipitation at high temperatures, without applying direct heat to streams that are normally subject to temperature-accelerated fouling.

[0077] Furthermore, the removal of solid particles by the fines stream of the ebullated bed effluent 6 in the separation drum has the advantage of preventing erosion in the tube(s) of the heater, because the recycled liquid stream 8 circulating therein is substantially free of solid particles. As used herein, the term "free of solid particles" means that the solid particle content is less than 1% by weight, although the effluent stream 3 may typically be less than 0.1% by weight.

[0078] [Fig.2] represents an embodiment in which the ebullated bed treatment unit according to the invention is integrated with downstream treatment equipment designed for hydroprocessing the steam and net liquid effluent recovered from the separator drum.

[0079] A feedstock 1 is fed together with make-up hydrogen 2 and recycled hydrogen 16 into an ebullated bed reactor system 30 for processing. (Although not illustrated in [Fig.l], it is possible to use more than one ebullated bed reactor system to process feedstock 1.)

[0080] The important thing here is that feed 1 is injected into the ebullated bed reactor system 30 at a temperature lower than that at which gum formation occurs and causes fouling of upstream equipment at said temperature. When feed 1 is processed in the ebullated bed reactor system 30, the materials that cause gum formation are destroyed and are not present in the effluent 3 and, by extension, in the recycled liquid 8. Feed 1 may be the same as that described in [Fig.l] above. The ebullated bed reactor system 30 operates at a temperature between 250°C and 500°C, preferably between 270°C and 450°C, and at a pressure between 10 bara and 200 bara, preferably between 30 bara and 180 bara.

[0081] The ebullated bed reactor system 30 is loaded with a supported catalyst to facilitate the hydroprocessing reactions and generates an effluent 3 comprising liquid, vapor, and potentially a small amount of solid particles. The supported catalyst used is as described above in the detailed description.

[0082] The effluent 3 from the ebullated bed reactor system 30 then flows to the separator drum 31 where it is separated into three streams - a vapor stream 4, a total effluent liquid stream 5, and an intermittent ebullated bed effluent fines stream 6. The separator drum 31 may include internal devices such as baffles, coalescing mats, cyclones, etc., to facilitate the vapor / liquid / solid separation.

[0083] The fines stream of intermittent ebullated bed effluent 6 includes catalyst fines, precipitates formed from mineral compounds and other precipitate precursors contained in feed 1, and corrosion products.

[0084] The total effluent liquid stream 5 is divided into a net effluent liquid stream 7 and a recycle liquid stream 8. Although [Fig.2] shows the net effluent stream 7 separated from the total effluent stream 5 before the recirculation pump 33, it is possible to separate it at any time before it reaches the ebullated bed reactor system 30 in the process flow.

[0085] The recycled liquid stream 8 is returned to the bubbling bed reactor system 30 via the recirculation pump 33. Importantly, it is this flow of recycled liquid 8 that causes the catalyst bed in the bubbling bed reactor system 30 to expand. The recirculation pump 33 produces a discharge stream 9 which is then heated in a heater 32 to produce a heated discharge stream 10, which is then fed to the bubbling bed reactor system 30. Heating the discharge stream 9 in the heater 32 ensures that the bubbling bed reactor system 30 reaches the necessary operating temperatures and provides a means of controlling the operating temperature of the system, even during changes or fluctuations in the composition of the feed stream 1.As described herein, the heating device 32 may apply heat to the discharge stream 9 in a variety of ways, including, but not limited to, combustion heat, electrical heating, steam, hot oil, process fluid exchange, etc.

[0086] As mentioned above, because the temperature of the feed 1 is limited, the possibility of gum formation upstream of the reactor is eliminated. When the feed 1 is processed in the ebullated bed reactor system 30, the materials that cause gum formation are destroyed and are not present in the recycled liquid stream 8. Therefore, by placing the heater 32 on the recycled liquid stream 8, gum formation problems are eliminated.

[0087] The vapor stream 4 from the separator drum 31, together with the net effluent liquid stream 7, is then routed to a finishing hydroprocessing section 34. There is no significant pressure loss between the ebullated bed reactor system 30 and the finishing hydroprocessing section 34 due to the inclusion of the separator drum 31. The expression "no significant pressure loss" means, in the context of the invention, that the drum is not at a pressure less than 2 bar, preferably 1 bar, relative to the outlet pressure of the ebullated bed reactor system.

[0088] The finishing hydroprocessing section typically consists of at least one fixed bed reactor vessel with one or more catalyst beds. The finishing hydroprocessing section may operate under the same or different conditions as the ebullated bed reactor system. As such, the finishing hydroprocessing section may operate at a temperature between 250°C and 500°C, preferably between 270°C and 450°C, and at a pressure between 200 psia and 3,000 psia, preferably between 500 psia and 2,500 psia.

[0089] It is more preferred, however, that the operating pressure difference between the ebullated bed reactor system and the finishing hydroprocessing section be less than 100 psi. The catalyst provided may be the same or different from that used in the ebullated bed reactor system 30, but generally comprises a supported catalyst comprising a Group VIII metal selected from the group consisting of Ni, Pd, Pt, Co, Rh and / or Ru in combination with a Group VIB metal selected from the group consisting of Mo and / or W, on a mineral support selected from the group consisting of zeolites, alumina, silica, silico-aluminas, magnesia, clays and mixtures of two or more of these minerals.Further hydroprocessing reactions occur in the finishing hydroprocessing section 34 while the hydrocarbons and hydrogen in the vapor stream 4 and the net effluent liquid stream 7 are in contact with the catalyst in said finishing hydroprocessing section 34. In addition, the catalyst system used in the finishing hydroprocessing section may comprise two or more catalyst formulations. This may be achieved when the different catalyst formulations exhibit greater activity or effectiveness in removing one category of contaminants or in facilitating one category of hydroprocessing reactions.

[0090] One such example would be the loading of a primary catalyst formulation having hydrodenitrification and hydrodesulfurization functionality in combination with a secondary catalyst formulation having hydrocracking functionality. A second example would be the loading of a primary catalyst formulation having a high silicon or arsenic scavenging capacity in combination with a secondary catalyst formulation having higher activity for one or more hydroprocessing reactions. In all cases, the finishing hydroprocessing section facilitates further hydroprocessing conversions to achieve higher reaction conversion (higher heteroatom removal, olefin / aromatic saturation, hydrocracking conversion to lighter hydrocarbons, etc.) which are otherwise difficult to achieve in an ebullated bed reactor system or other CSTR configuration reactor systems, without encountering the operational difficulties due to fouling or exothermic components which are greatly reduced in the ebullated bed reactor system.

[0091] The finishing hydroprocessing section 34 produces a finishing hydroprocessing effluent 20 which can then be mixed with wash water 21 before being sent to a cold separator 22. The cold separator 22 separates the mixture of finished hydrotreated effluent 20 and wash water 21 into an acid water stream 23, a gas stream 24 and a treated liquid stream 25.

[0092] The water used for the wash water 21 may be derived from various sources such as demineralized water, sour water from other upstream hydroprocessing processes, or effluent from other processes such as sour water stripping, reverse osmosis, ultrafiltration, distillation, ion exchange purification, etc. In some embodiments, a portion of the water from the sour water stream 23 is recycled with and blended with the wash water 21 to reduce the total amount of sour water product.

[0093] The gas stream 24 from the cold separator 22 is split into two streams - a purge gas stream 26 and a recycle gas stream 15. The flow rate of the purge gas stream 26 is generally low and adjusted to prevent the accumulation of light hydrocarbons such as methane and ethane in the reactor. The major portion of the gas stream 24 is recycled via the recycle gas stream 15 to the reactor inlet via the recycle compressor 27. The compressed recycle gas stream 16 is combined with the make-up hydrogen stream 2 and fed into the ebullated bed reactor system 30.

[0094] In some embodiments, a portion or all of the gas stream 26 may be subjected to additional treatment processes prior to reintroducing the constituent hydrogen into the ebullated bed reactor system. Such processes may include drying, caustic sweetening, amine sweetening, selective fixed bed adsorption, pressure swing adsorption, methanization, other hydroprocessing processes, or any combination thereof.

[0095] The treated liquid stream 25 from the cold separator 22 is then sent to a fractionator 36 to create a treated liquid product stream 37 and a fractionator vapor stream 38. The treated liquid product stream 37 primarily comprises hydrocarbons that may be useful as an end-use product or be separated into additional hydrocarbon fractions of different boiling ranges. Alternatively, a similar embodiment, although not illustrated, would produce multiple liquid products from the fractionator 36, which may have different boiling ranges for each of said liquid products.

[0096] End uses of the treated liquid product stream 37 may include use as a fuel such as diesel, jet fuel, fuel oil, or bunker fuel, or may be feedstocks for other downstream hydrocarbon processing processes such as hydrocracking, hydrotreating, or sludge cracking. steam.

[0097] The invention described herein has been disclosed with respect to specific embodiments and applications. However, these details are not intended to be limiting and other embodiments, in light of this demonstration, would be obvious to those skilled in the art. Thus, it is to be understood that the drawings and descriptions are illustrative of the principles of the invention and should not be construed as limiting their scope.

Claims

Claims

1. A treatment unit for treating hydrocarbon feedstocks, comprising: one or more ebullated bed reactor units, at least one of said ebullated bed reactor units comprising a reactor vessel (10, 30), a separation vessel (11, 31) and a pump (13, 33), and said at least one reactor vessel comprising at the bottom a hydrocarbon recycle liquid inlet, a supported catalyst used to create an effluent (3) by contact with a hydrocarbon feedstock (1) and hydrogen (2), and said separation vessel (11, 31) being configured to separate said effluent (3) from said reactor vessel (10, 30) into a liquid stream comprising less than 1% by weight of solid particles (5), a vapor stream (4) and a slurry stream (6) comprising solid particles and a hydrocarbon liquid phase, and further said pump (13, 33) being connected to a device for heating (12,32) intended to provide heat and being further connected to said hydrocarbon recycled liquid inlet from the bottom of said reactor vessel (10, 30) for recycling at least a portion (8) of said liquid stream comprising less than 1% by weight of solid particles (5).,

2. A hydrocarbon processing unit according to claim 1, wherein said heat from said heating device (12, 32) is selected from a group consisting of a heat exchanger heated with hot oil, a heat exchanger heated with steam, a furnace heated with gas or liquid fuel, an electrically powered resistive heating element or an electric furnace.

3. A method for catalytic treatment of a hydrocarbon feedstock comprising: a) sending a hydrocarbon feedstock (1) and a hydrogen stream (2) to one or more ebullated bed reactors, said ebullated bed reactor(s) comprising at least one reactor vessel (10, 30) and a separation vessel (11, 31), said hydrocarbon feedstock (1) and said hydrogen stream (2) being contacted with a catalyst in said reactor vessel (10, 30) to provide a first effluent (3); and b) sending said first effluent (3) to said separation vessel (11, 31) to provide a liquid stream comprising less than 1% by weight of solid particles (5), a vapor stream (4) and a sludge stream (6), said slurry stream comprising solid particles and a liquid phase of hydrocarbons; and c) recycling at least a portion (8) of said liquid stream comprising less than 1% by weight of solid particles (5) into said ebullated bed reactor(s) (10, 30); and said liquid stream which comprises less than 1% by weight of solid particles being heated before being recycled into said ebullated bed reactor(s).

4. A method according to claim 3, further comprising: d) treating at least some portions (7) of said liquid stream comprising less than 1% by weight of solid particles (5) and / or at least some portions of said vapor stream (4) in a downstream catalytic hydrotreatment reactor.

5. A method according to claim 3, wherein at least a portion of said hydrogen stream (2) is heated together with said portion of said liquid stream comprising less than 1% by weight of solid particles before entering said at least one ebullated bed reactor.

6. A method according to claim 3, wherein the temperature of said hydrocarbon feedstock (1) is lower than the operating temperature of said ebullated bed reactor(s).

7. A method according to claim 3, wherein the temperature of said hydrocarbon feedstock is less than 250°C.

8. A method according to claim 3, wherein the temperature of said hydrocarbon feedstock is less than 200°C.

9. A method according to claim 3, wherein said catalyst comprises one or more metals from group VIII and / or one or more metals from group VIB, deposited on a mineral support comprising zeolites, alumina, silica, silico-aluminas, magnesia, clays, or mixtures of at least two of these minerals.

10. A method according to claim 3, wherein said separation tank (11, 31) comprises baffles, mist blowers, coalescing mattresses, cyclones and / or trays.

11. A method according to claim 3, wherein said hydrocarbon feedstock (1) is selected from the group consisting of plastic pyrolysis oil, tire pyrolysis oil, biologically derived pyrolysis oil, rapeseed oil, soybean oil, corn oil, coconut oil, olive oil, linseed oil, sunflower oil, palm oil, jatropha oil, mustard oil,

12.

13.

14.

15.

16.

17.

18. peanut oil, hemp oil, cottonseed oil, pork fat, poultry fat, lard, butter, tallow, hydrothermal liquefaction effluent oil, gasification effluent oil, deasphalted oil, vacuum distillate, atmospheric distillate, vacuum gas oil, light recycle oil, heavy recycle oil, delayed coker hydrocarbon effluent, petroleum-based pitch, vacuum residue, atmospheric residue, or any combination thereof. The method of claim 3, wherein said hydrocarbon feedstock has a diene number greater than 1.

0. The method of claim 3, wherein said hydrocarbon feedstock has a diene number greater than 3.

0. The method of claim 3, wherein said hydrocarbon feedstock has a diene number greater than 5.

0. The process of claim 3, wherein said hydrocarbon feedstock has a metal content greater than 5 ppm by weight. The process of claim 3, wherein said hydrocarbon feedstock has a metal content greater than 10 ppm by weight. The process of claim 3, wherein said hydrocarbon feedstock has a metal content greater than 20 ppm by weight. The process of claim 3, wherein said hydrocarbon feedstock has an asphaltene content greater than 500 ppm by weight.

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