Method for Hydroprocessing Hydrocarbons with Temperature Accelerated Fouling

Abstract

Applicants describe a novel process and processing configuration for catalytically treating hydrocarbon feedstock (1) into a treated hydrocarbon stream utilizing an ebullated-bed reactor (10). The invention is particularly adapted for treating hydrocarbon feedstock comprising compounds prone to precipitate and / or to polymerize to make gums under high temperature.Figure 1 to be published.

Description

Method for Hydroprocessing Hydrocarbons with Temperature Accelerated FoulingField of the inventionThe invention relates to the processing of hydrocarbon feedstock into a treated hydrocarbon stream, such process utilizing an ebullated-bed reactor. The invention is particularly well-suited for treating hydrocarbon feedstock comprising compounds prone to precipitate and / or to polymerize to make gum under high temperature.BackgroundHydroprocessing is a common chemical treatment process performed on hydrocarbons for the production of fuels and petrochemicals. Hydroprocessing refers to a very wide array of various processes, but commonly refers to any process where hydrogen is chemically reacted with a predominantly hydrocarbon stream to alter the chemical composition of said stream. The change resulting from this reaction can include removal of heteroatoms such as sulfur, nitrogen, chlorine, bromine, fluorine, or oxygen from the hydrocarbons, or alteration of the hydrocarbons themselves such as olefin and aromatics saturation or hydrocracking. Though 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, aromatics saturation, hydrodemetallization, hydroisomerization, and / or hydrocracking. Hydroprocessing reactions often occur in contact with a supported catalyst to increase the rate at which said hydroprocessing reactions occur.Concurrently with the hydroprocessing reaction, many supported catalysts are able to capture some components of the fluid they are in contact with, effectively removing them from said fluid as a means of purification. Species of arsenic, silicon, and other heavy metals may be removed from a hydrocarbon fluid in this way. Accumulation of these species in or on the supported catalyst over periods of time can decrease the catalytic activity of said supported catalyst, however this is still an effective means of removal from the fluid and the impact of said accumulation can be minimized through optimal catalyst formulation, namely properties such as metals content, support type, support morphology, etc.There are many different materials that may be hydroprocessed for different reasons, as well as many different ways to achieve the hydroprocessing; regardless of the means used, the chemical reactions typically take place at high temperature and moderate or high pressure. One such method commonly used for high severity feedstocks or highly contaminated feedstocks is an ebullated bed reactor.An ebullated bed reactor is a 3-phase reaction environment wherein the hydrogen gas and liquid feedstock is contacted with supported catalyst to facilitate the hydroprocessing reactions. The ebullated bed utilizes a liquid recycle stream to fluidize the supported catalyst, distinguishing it from other reactor configurations, such as a fixed bed reactor. The fluidization of the bed within the vessel allows for good internal mixing and thus the reactor operates nearly isothermally with a low and constant pressure drop. The fluidization of the catalyst also prevents catalyst bed plugging issues that can occur in a fixed bed reactor. The reactor is designed such that supported catalyst can regularly be added and withdrawn without interrupting the continuous process, allowing for catalytic activity to be maintained at a consistent level over long periods of operation and eliminating the need to shut down the reactor for catalyst replacement when the catalyst has deactivated as in a fixed bed reactor. Thus, this kind of reactor is commonly implemented for feedstocks that have high reaction exotherm, have high fouling tendency, or can rapidly deactivate the catalyst.Multiple feed characteristics can cause a stream to have a high fouling tendency when exposed to reaction conditions. In the context of the invention, the focus will be on feedstocks comprising compounds that are susceptible to gumming or that at least partially precipitate when said feedstocks are heated to the elevated operating temperature of the ebullated bed reactor. The phenomenon of gumming is common in hydrocarbon streams comprising olefinic components and / or dienes and is a result of the polymerization of alkenes within a feed to form large molecules that may agglomerate to inhibit a fluid’s flow. In the presence of free radicals, polymerization of these components can occur rapidly and agglomerate molecules to cause the fouling during processing. Exposure to components such as molecular oxygen can introduce free radicals into the hydrocarbon stream. Alternatively free radicals can be generated from the stream itself by subjecting it to moderate or elevated temperatures; often moderate temperatures can induce gumming by causing the dienes to become free radicals. Olefins and dienes may be measured as Bromine Number according to ASTM D1159 and Diene Value according to UOP326 respectively. In many processes, a typical location in which gumming can initiate is in heat transfer equipment such as heat exchanger tubes, heat exchanger plates, furnace tubes or electrical heating elements; in these scenarios, the process fluid susceptible to gumming comes into contact with a hot heat exchange surface that provides heat and creates conditions in which the initiators for gumming are formed. Materials subject to this include many highly olefinic materials, including cracked hydrocarbons such as FCC product hydrocarbons, coker product hydrocarbons, pyrolysis oil (petroleum, plastic, or biologically derived), lipids, etc. Alternatively, some process streams may cause fouling via sediments or solid precipitates. Precipitates or sediments may be present in the raw material or may form as the material approaches reaction conditions in a process. Examples of situations in which precipitates may form include the heating or cooling of the material or by mixing the material with another process stream which cause physical or chemical interaction of their constituent components. One example includes formation of salts or metal-ligand complexes, such as when lipids that also contain phospholipids, like those derived from plant or animal matter, form precipitates composed of phosphorous and alkali metals after being subjected to temperatures moderately higher than ambient conditions; this can occur in lipids that are untreated or pretreated through processes such as degumming, bleaching, deodorizing, etc. Other more conventional petroleum feedstocks such as heavy crude or atmospheric or vacuum residue may experience precipitation of asphaltenes as temperature is changed or from blending or mixing with other hydrocarbon streams, particularly those that have a much different composition of hydrocarbon families (paraffin, naphthenes, aromatics, etc.); in these cases the precipitation is a result of a decrease in solubility in the hydrocarbon phase after mixing. In a similar manner, sediments may form in pyrolysis oils when mixed with other hydrocarbon streams or upon addition of heat. An ebullated bed efficiently uses the heat from the reaction exotherm to heat the feed streams to the required reaction temperature in the ebullated bed vessel itself, thus decreasing the heat that must be applied to the feedstock upstream of the reactor inlet. However, the exotherm may not be sufficient to maintain the operating temperature such that, as in prior art processes, it is necessary to heat the feedstock upstream the ebullated-bed reactor. When considering a feedstock with high gumming potential or a feedstock that may chemically degrade at high temperatures, heating the feed to the necessary reactor inlet temperature could cause fouling of equipment located upstream of the ebullated bed (e.g. valves, injection device, heater tubes and / or pipes) which then requires a shutdown of the operating unit for cleaning and limits its run length. Thus, in order to manage fouling issues, a solution would be to limit the feed temperature, however the drawback to this is a reduction in the severity / effectiveness of the ebullated-bed reactor. Ebullated beds are designed such that the supported catalyst does not leave the reactor with the effluent vapor or liquid, however smaller solid particulates (fines due to catalyst particle erosion or breakage) commonly exist in the system and may be present in the liquid effluent or in the liquid recycle. The ebullating pump and the downstream equipment have to be thus designed to handle the potential presence of solid particles. As an example of a risk posed to process equipment, solid particulates may cause erosion of the heat exchange equipment or degrade the heat transfer capability as the solids deposit or accumulate on heat exchange surfaces, such as furnace tubes, heat exchanger tubes, or heat exchanger plates.By contrast, fixed bed reactor systems are designed with a load of supported catalyst that remains static as fluid is contacted with it during the process. Fixed beds have the advantage of being able to more easily and reliably reach greater removal of targeted contaminants from the process fluid compared to an ebullated bed due to the inherent advantage of plug-flow kinetics versus continuously stirred tank reactor (“CSTR”) kinetics. The primary disadvantage of the fixed bed however is that catalyst cannot be actively removed and replaced as part of the normal process. Cycle length of the fixed bed is then limited by its ability to trap contaminants, fouling accumulated through either gumming or particulates, catalytic activity decreased by accumulation of poisons, or any combination thereof. In prior art, it is common to implement a fixed bed upstream of the main hydroprocessing section to absorb, convert, or remove contaminants that would might negatively impact the downstream process; such guard beds are effective, but may require frequent changes in catalyst load when receiving highly contaminated streams.In the current state of the art ebullated bed reactor design, an internal device is included at the top of the reactor that is designed to separate vapor from liquid and to provide a vapor-free liquid stream for internal recycle via the ebullating pump. The ability of this internal device to separate vapor from the liquid recycle is important, as recycling vapor is harmful to the ebullating pump. In light of the above, Applicants have provided a process treatment implementing an ebullated bed reactor, said process being adapted to treat hydrocarbon feedstocks comprising compounds which are prone to polymerize and / or to precipitate, whose operability is improved in terms of process equipment fouling and erosion issues, and which provides a treated effluent stream comprising a low content of catalyst fines whose presence may cause plugging of downstream equipment such as the catalyst bed of a fixed bed reactor which may be implemented downstream of the ebullated bed reactor to further treat the liquid effluent.These and other features of the present invention will be more readily apparent from the following description with reference to the accompanying drawings.Summary of the inventionIt is an object of Applicant’s invention to process ebullated bed reactor effluent in an external separator drum within the ebullated bed reactor loop to produce a substantially solids-free recycle liquid.It is a further object of Applicant’s invention to eliminate gumming and fouling concerns by using an ebullated-bed reactor and by applying required process heat via a recycle liquid heater on the low-fouling liquid recycle to maintain operating temperature in ebullating bed reactor, while applying minimal, if any, heat to the fresh feed thus allowing the ebullated bed to operate at higher severity without upstream fouling concerns.It is yet another object of Applicant’s invention to eliminate the need for an upstream fixed bed guard reactor system and to increase catalyst cycle length in a possible downstream fixed bed reactor, such as a hydrotreatment reactor.It is still another object of Applicant’s invention to expand the acceptable contaminant range and improve feed flexibility in processing to anticipate feed diet variability.It is a further object of Applicant’s invention to ensure that no small catalyst particles or fines will be carried from the ebullated bed reactor to a downstream fixed bed reactor, eliminating premature shutdowns that would occur in the fixed bed. It is still another object of Applicant’s invention to ensure that no small catalyst particles will be carried to the recycle liquid heater, thereby eliminating the concern for erosion and heat transfer degradation of the heater heat exchange surface. It is an additional object of Applicant’s invention to ensure that, should a downstream fixed bed reactor be included in the flowscheme, 100% of the ebullated bed reactor effluent is treated in the said downstream fixed bed reactor.It is yet a further object of Applicant’s invention to provide a complete vapor / liquid / solid separation that avoids any limitations of the ebullated-bed reactor internal device.More particularly, Applicant’s invention describes a novel process unit configuration for processing hydrocarbon liquids comprising:one or more ebullated-bed reactor unit(s), wherein at least one of said ebullated-reactor unit(s) comprises a reactor vessel, a separation vessel, and a pump assembly and wherein said reactor vessel(s) comprise a bottom hydrocarbon liquid recycle inlet, a supported catalyst utilized to create an effluent from contact with a hydrocarbon feedstock and hydrogen, and wherein said separation vessel is configured to separate said effluent from said reactor vessel into a liquid stream comprising less than 1wt. % solids, a vapor stream, and a slurry stream comprising solids and a liquid hydrocarbon phase, and further wherein said pump assembly is connected to a heating device to provide heat and is further connected to said bottom hydrocarbon liquid recycle inlet of said reactor vessel to recycle at least a portion of said liquid stream comprising less than 1wt. % solids.According to the invention, the heating device can be selected from a group comprising, a hot oil heated heat exchanger, steam heated heat exchanger, a gas or liquid fuel fired furnace, an electrically powered resistive heating element, or an electrical furnace.According to the invention, the separation vessel may comprise baffles, demister pads, coalescer pads, cyclones, and / or trays.In another aspect, Applicant’s invention describes a novel process for catalytically treating a hydrocarbon feedstock comprising:a) feeding a hydrocarbon feedstock and a hydrogen stream to one or more ebullated-bed reactor(s), said ebullated-bed reactor(s)comprising at least one reactor vessel and a separation vessel, wherein said hydrocarbon feedstock and said hydrogen stream are contacted with a catalyst in said reactor vessel to provide a first effluent; andb) feeding said first effluent to said separation vessel to provide a liquid stream comprising less than 1wt. % solids, a vapor stream, and a slurry stream, said slurry stream comprising solids and a liquid hydrocarbon phase; andc) recycling at least a portion of said liquid stream comprising less than 1 wt.% solids to said ebullated bed reactor(s); and wherein said liquid stream comprising less than 1 wt.% solids is heated prior to recycling to said ebullated-bed reactor(s).The process may further comprise a step of processing at least some portion of said liquid stream comprising less than 1wt. % solids and / or at least some portion of said vapor stream in a downstream catalytic hydroprocessing reactor.The temperature of the hydrocarbon feedstock is less than the operating temperature of said ebullated-bed reactor(s). The ebullated-bed reactor may operate 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.The ebullated-bed reactor can be operated at a temperature above the temperature of the hydrocarbon feedstock, and the temperature of said hydrocarbon feedstock is less than 250°C, preferably less than 200°C.The process according to the invention can implement a supported catalyst which comprises metal(s) from group VIII and / or metal(s) from group VIB, on a mineral support comprising zeolites, alumina, silica, silica-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, whose diameter is generally of the order of 1 mm or less than 1 mm and typically contain at least one hydro-dehydrogenating element deposited on a support. Generally, the supported catalyst 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 chosen from the group Mo and / or W, on a mineral support chosen from the group formed by zeolites, alumina, silica, silica-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 metal elements of groups VIB and VIII is preferably between 0.1% and 40% by weight, preferably from 5% to 35% by weight, relative to the total weight of the catalyst. The weight ratio expressed as metal oxide between the metal (or metals) of group VIB relative to the metal (or metals) of group VIII is often between 1.0 and 20, preferably between 2.0 and 10.The process can also make use of a fine dispersed catalyst comprising metal(s) from group VIII and / or metal(s) from group VIB or a liquid catalyst.The hydrocarbon feedstock can be selected from the group comprising 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, effluent oil from hydrothermal liquefaction, effluent oil from gasification, deasphalted oil, vacuum distillate, atmospheric distillate, vacuum gasoil, light cycle oil, heavy cycle oil, delayed coker hydrocarbon effluents, petroleum based pitch, vacuum residue, atmospheric residue, or any combination thereof.The hydrocarbon feedstock has a diene value greater than 1.0, or greater than 3.0 or greater than 5.0.The hydrocarbon feedstock has generally a metals content greater than 5 wppm, preferably greater than 10 wppm or greater than 20 wppm.The hydrocarbon feedstock has generally an asphaltene content of greater than 500 wppm.Brief description of the drawingsFigure 1 shows a schematic outlining an exemplary process for processing hydrocarbon feedstocks comprising compounds which are prone to polymerize or precipitate. Figure 2 shows an embodiment wherein the ebullated bed processing unit of the invention is integrated to a downstream treating unit designed to hydroprocess the vapor and net liquid effluent recovered from the separator drum.Detailed description of the inventionThe phenomenon of gumming is common in hydrocarbon streams comprising olefinic components and / or dienes and is a result of the polymerization of alkenes within a feed to form large molecules that may agglomerate to inhibit a fluid’s flow. In the presence of free radicals, polymerization of these components can occur rapidly and agglomerate molecules to cause the fouling during processing. Exposure to components such as molecular oxygen can introduce free radicals into the hydrocarbon stream. Alternatively free radicals can be generated from the stream itself by subjecting it to moderate or elevated temperatures; often moderate temperatures can induce gumming by causing the dienes to become free radicals. Olefins and dienes may be measured as Bromine Number according to ASTM D1159 and Diene Value according to UOP326 respectively. In many processes, a typical location in which gumming can initiate is in heat transfer equipment such as heat exchanger tubes, heat exchanger plates, furnace tubes or electrical heating elements; in these scenarios, the process fluid susceptible to gumming comes into contact with a hot heat exchange surface that provides heat and creates conditions in which the initiators for gumming are formed. Materials subject to this include many highly olefinic materials, including cracked hydrocarbons such as FCC product hydrocarbons, coker product hydrocarbons, pyrolysis oil (petroleum, plastic, or biologically derived), lipids, etc. Gumming mitigation through the limitation of operating temperature may be done in conjunction with other mitigation measures such as removal of free radical precursors or addition of antioxidant component(s). When the feedstock is processed in the ebullated-bed reactor system of the invention, the materials that cause gumming are hydroprocessed and are not present in the recycle liquid stream at levels that gumming is a significant risk. The recycle liquid stream typically has a measured Diene Value of less than 1 and the Bromine Number to be less than 5.The feedstock(s) which can be treated by the process according to the invention include hydrocarbon containing liquid streams comprising compounds that are capable to polymerize to form gums or to make precipitates when the feedstock undergoes heat exchange or mixed as it approaches reaction conditions. The process is especially adapted to treat / upgrade heavy oil feedstock, heavy crude, oil sands bitumen, liquid hydrocarbons from delayed coking processes, liquid hydrocarbons from fluidized catalytic cracking processes, residuum left over from conventional refinery process, or any mixture thereof.The feedstock can also include residues from atmospheric or vacuum distillation, vacuum distillates (usually termed VD) such from conversion processes such as those from coking, from fixed bed hydroconversion such as those from HYVAHL® processes for treating heavy hydrocarbons, heavy hydrocarbon hydroprocessing processes carried out in an ebullated bed such as those from H-OIL® processes, or solvent deasphalted oils, for example using propane, butane, or pentane deasphalted oils originating from deasphalting straight run vacuum residues or vacuum residues from H-OIL® or HYVAHL® processes. The feedstock can further include pitch recovered from visbreakers or solvent deasphalters. Additionally, the feedstock can be formed by mixing those various fractions in any proportions, in particular deasphalted oil (DAO) and vacuum distillate. It can also contain a light cycle oil (LCO) of various origins, a heavy cycle oil (HCO) of various origins, and also gas oil cuts from catalytic cracking or coking generally with a distillation range of about 150°C to about 370°C.The feedstock can also be chosen among pyrolysis oils obtained from the refining of petroleum crude or the pyrolysis of either biological material, municipal waste, tires, or plastic material. The feedstock can also comprise a vegetal 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.The feedstock can comprise heteroatoms such as sulfur (up to 8.0 wt%) and nitrogen (up to 10,000 wppm), elemental oxygen (up to 5 wt%), chlorine (up to 1,000 wppm), Microcarbon residue (MCR, can also be denoted as RCR or CCR, up to 50 wt%), metal contaminants such as (but not limited to) nickel, vanadium, iron, sodium, potassium, magnesium, calcium, silicon (up to 1,000 wppm), and asphaltenes (up to 50 w%). For biologically derived hydrocarbons such as lipids or biologically derived pyrolysis oil, the feedstock can comprise classes of heteroatoms that exceed values that might be found in petroleum derived streams such as elemental oxygen (up to 15 wt%).In one embodiment, the feedstock is a plastic pyrolysis oil or SRF (Solid Recovered Fuels) pyrolysis oil, preferably in liquid form at room temperature, obtained from the pyrolysis of plastics, preferably plastic waste from 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 percent by weight of these hydrocarbon compounds preferably have a boiling point below 700°C, and preferably less than 550°C. In particular, depending on the origin of the pyrolysis oil, it may comprise up to 90% weight of paraffins, up to 90% weight of olefins and up to 90% weight of aromatics. It is understood that the sum of paraffins, olefins and aromatics is 100 percent weight of hydrocarbon compounds.Pyrolysis oil may include, and most often includes, impurities such as metals (including iron), silicon, and halogen compounds (including chlorine compounds). These impurities may be present in pyrolysis oil at high contents, for example up to 500 ppm weight or 1000 ppm weight or even 5000 ppm weight of halogen elements provided by halogen compounds, and up to 2500 ppm weight, or even 10000 ppm weight of metallic or semi-metallic elements. Alkali metals, alkaline earth metals, transition metals, poor metals and metalloids can be assimilated to contaminants of a metallic nature, called metallics or metallic or semi-metallic elements. Pyrolysis oil can comprise in the range of approximately between 200 ppm weight to 1000 ppm weight of silicon, and in the range of approximately between 15 ppm weight to 100 ppm weight of iron. Pyrolysis oil may also comprise other impurities such as heteroatoms, in particular sulfur compounds, oxygen compounds and / or nitrogen compounds, and pyrolysis oils have contents generally less than 20000 ppm weight of any single heteroatom and preferably less than 10000 ppm weight of heteroatom.The method according to the invention is particularly well suited to treat a pyrolysis oil having:- an aromatic content between 10 and 50 percent weight, often between 0 and 70 percent weight, and may be between 0 and 90 percent weight;- a halogen content between 50 and 500 ppm weight, often between 50 and 1000 ppm weight, and which may be between 1 and 5000 ppm weight;- a metals (excluding silicon) content between 20 and 100 ppm weight, often between 10 and 2000 ppm weight, and which may be between 5 and 10000 ppm weight;- an iron content between 10 and 500 ppm weight, often between 5 and 1000 ppm weight, and which may be between 0 and 10000 ppm weight;- a silicon element content between 20 and 200 ppm weight, often between 10 and 500 ppm weight, and which can be between 1 and 1000 ppm weight.Figure 1 shows a schematic outlining an exemplary process for processing hydrocarbon feedstocks comprising compounds which are prone to polymerize or precipitate.As shown in Figure 1, a feedstock 1 is fed along with a hydrogen stream 2 to an ebullated-bed reactor system 10 for processing. (Although not shown in Figure 1, more than one ebullated-bed reactor system may be utilized to process the feedstock 1).The feedstock 1 is injected into the ebullated-bed reactor system 10 at a temperature no more than 250°C, but preferably below 200°C to mitigate the onset of gumming and limit fouling in upstream equipment.The ebullated-bed reactor system 10 is loaded with supported catalyst to facilitate the hydroprocessing reactions and generates an effluent 3 comprising liquid, vapor and potentially a minor amount of solid particulates. The liquid and vapor of effluent 3 comprise hydrocarbons, light hydrocarbon gases, unreacted hydrogen, and possibly hydroprocessing byproducts. Light hydrocarbon gases are defined to include components with one or two carbon atoms (e.g. methane, ethane) but can also be expanded to include components with three or four carbon atoms (e.g. propane, butane). Hydroprocessing byproducts are defined as components that are generated as a result of the removal of heteroatoms through hydrogen addition, such as ammonia, hydrogen sulfide, hydrogen chloride, water, other hydrogen halides, etc. The amount and proportion of hydroprocessing byproducts is dependent on the type and amount of heteroatoms present in feedstock 1 and the operating conditions of the ebullated bed reactor 10.The effluent 3 from the ebullated-bed reactor system 10 thereafter 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 may 11 include internal devices such as baffles, coalescer pad, cyclones, etc. to facilitate the vapor / liquid / solid separation. The ebullated-bed effluent fines stream 6 may comprise catalyst fines, precipitates formed from mineral compounds contained in the feedstock, corrosion products, and possibly a liquid comprising primarily hydrocarbons. The ebullated-bed effluent fines stream 6 is typically produced intermittently, allowing the solids content to accumulate in separator drum 11 until the quantity is sufficiently large that it can be easily removed.The vapor stream 4 from the separator drum 11 may be routed to a (fixed-bed hydroprocessing) downstream 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 term “no significant pressure loss” means in the context of the invention that the drum is not at a pressure below 2 bars, preferably 1 bar, than the outlet pressure of the ebullated-bed reactor system 10. The vapor stream 4 comprises a hydrocarbon fraction, excess or unreacted hydrogen, light hydrocarbon gases, and possibly hydroprocessing byproducts. Vapor stream 4 includes a majority of the hydrogen present in effluent stream 3 as well as a significant portion of the hydroprocessing byproducts. The temperature of the vapor stream 4 and total effluent liquid stream 5 from the separator drum 11 are also maintained from the outlet of the ebullated-bed reactor system 10, although (while not shown on the diagram) there is the opportunity to control / adjust the temperature at the inlet of the downstream fixed-bed hydroprocessing reactor. The total effluent liquid stream 5 is split into a net effluent liquid stream 7 and a recycle liquid stream 8. Total effluent liquid stream 5, and by extension net effluent liquid stream 7 and recycle liquid stream 8, comprises liquid hydrocarbons as well as minor amounts of hydrogen, light hydrocarbon gases, possibly hydroprocessing byproducts dissolved in the liquid phase and less than 1wt% solids. The net effluent stream 7 from the separator drum 11 may be routed to a (fixed-bed hydroprocessing) downstream reactor (not shown); if vapor stream 4 is also routed to a fixed-bed hydroprocessing reactor, then the same reactor may be utilized to treat a mixture of vapor stream 4 and net effluent stream 7. Although Figure 1 shows the net effluent stream 7 being split off from the total effluent stream 5 prior to the ebullating pump 13, it is possible to split it off at any time prior to reaching the ebullated-bed reactor system 10.In conjunction with or in the absence of the described downstream fixed bed hydroprocessing reactor, the components in vapor stream 4 and / or net effluent stream 7 may be utilized in other processes. A portion or all of the unreacted hydrogen from either stream may be utilized as reactant in other hydroprocessing processes, or even recycled to the feed of the 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 the heavy hydrocarbon components, water washing for removal of water soluble components, amine or caustic sweetening for removal of acid gases such as hydrogen sulfide and carbon dioxide, Pressure Swing Adsorption for hydrogen purification, or combinations thereof. The hydrocarbon fraction of the net effluent stream 7 may be separated into a single or multiple liquid products via product fractionation or other techniques well known in the art; such liquid products may be hydroprocessed further in other hydroprocessing processes or blended with other streams for fuel applications (gasoline, diesel, jet, bunker fuel oil, etc.) or used for petrochemical applications such as steam cracker furnace feedstock. Light hydrocarbon gases may be utilized for fuel applications; typical processing for light hydrocarbon gases prior to use as fuel may include water washing, amine sweetening, or impurity adsorption through contact with a solid adsorbent bed.The recycle liquid stream 8 is returned to the ebullated bed reactor system 10 via the ebullating pump 13, and it is this flow that fluidizes and expands the catalyst bed in that reactor. It is important that the recycle liquid stream 8 be vapor-free, since recycling vapor is harmful for the ebullating pump 13. The ebullating pump 13 produces an ebullating pump discharge stream 9 which is thereafter heated in a heater 12 to produce a heated ebullating pump discharge stream 14 which is thereafter routed to the ebullated-bed reactor system 10. Heating the ebullating pump discharge stream 9 in the heater 12 ensures that the ebullated-bed reactor system is able to achieve the necessary operating temperatures. The heater 12 may apply heat to the ebullating pump discharge stream 9 in a number of ways, including but not limited to, fired heat such as that supplied by fuel gas or fuel oil, electricity, steam, hot oil, process fluid exchange, etc. Typical heaters may include those well-known through prior art such as tubular furnaces, shell & tube heat exchangers, plate heat exchangers, etc. Regardless of the heater type, it will include a heat exchange surface that the process fluid will be contacted with. The separation of solids in the separator drum 11 ensures that the ebullating pump discharge stream being heated in heater 12 also has minimal solids. The low solids content in the ebullating pump discharge stream flowing through heater 12 allows the heat exchange surface to provide good heat transfer over long periods of operation and reduces the degradation of the equipment’s mechanical integrity. The presence of solids in this stream otherwise can mechanically damage the heat exchange surface by increasing erosion, and can also deposit on the heat exchange surface which impedes the ability to provide good heat transfer to the heater process fluid.As mentioned above, because the temperature of the feedstock 1 is limited, the possibility of gumming upstream of the reactor is eliminated. When the feedstock 1 is processed in the ebullated-bed reactor system 10, the materials that cause gumming are hydroprocessed and are not present in the recycle liquid stream 8. Additionally with the same process, precipitates from the feedstock 1 formed by temperature increase or mixing with other fluids are not formed until entering the ebullated-bed reactor system 10. In this way, solid precipitates are not formed until solids fluidization has been achieved and entrained solid precipitates in effluent stream 3 can be removed in separator drum 11 to keep them out of recycle liquid 8. Therefore, by locating the heater 12 on the liquid recycle stream 8, and adding a means of separating solids in the separator drum 11, gumming and solids fouling concerns are eliminated. Applicant’s invention teaches numerous processing advantages over the prior art by teaching a configuration that can process feeds with high gumming potential or solids precipitation at elevated temperatures, without applying direct heat to streams subject to temperature accelerated fouling.In addition, the removal of solid particles from ebullated bed effluent fines stream 6 in the separation drum 11 has the benefit of preventing erosion in the heater tube(s) since the liquid recycle stream 8 circulating therein is substantially free of solid particles. As used herein, “free of solid particles” means that the solid particles content is lower than 1 wt %, although typically the effluent stream 3 could be less than 0.1 wt%.Figure 2 shows one embodiment wherein the ebullated bed processing unit of the invention is integrated with downstream processing equipment designed to hydroprocess the vapor and net liquid effluent recovered from the separator drum.A feedstock 1 is fed along with make-up hydrogen 2 and recycled hydrogen 16 to an ebullated-bed reactor system 30 for processing. (Although not shown in Figure 1, more than one ebullated-bed reactor system may be utilized to process the feedstock 1).Importantly, the feedstock 1 is injected into the ebullated-bed reactor system 30 at a temperature below which gumming occurs and causes fouling in upstream equipment at said temperature. When the feedstock 1 is processed in the ebullated-bed reactor system 30, the materials that cause gumming are destroyed and are not present in the effluent 3 and by extension, recycle liquid 6. The feedstock 1 may be the same as described in Figure 1 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.The ebullated-bed reactor system 30 is loaded with supported catalyst to facilitate the hydroprocessing reactions and generates an effluent 3 comprising liquid, vapor, and potentially a small amount of solid particulates. The supported catalyst utilized is as described above in the detailed description.The effluent 3 from the ebullated-bed reactor system 30 thereafter 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 may 31 include internal devices such as baffles, coalescer pad, cyclones, etc. to facilitate the vapor / liquid / solid separation. The intermittent ebullated-bed effluent fines stream 6 comprises catalyst fines, precipitates formed from mineral compounds and other precipitate precursors contained in the feedstock 1, and corrosion products. The total effluent liquid stream 5 is split into a net effluent liquid stream 7 and a recycle liquid stream 8. Although Figure 2 shows the net effluent stream 7 being split off from the total effluent stream 5 prior to the ebullating pump 33, it is possible to split it off at any time prior to reaching the ebullated-bed reactor system 30 in the process flow.The recycle liquid stream 8 is returned to the ebullated bed reactor system 30 via the ebullating pump 33. Importantly, it is this flow of the recycle liquid stream 8 than expands the catalyst bed in the ebullated-bed reactor system 30. The ebullating pump 33 produces an ebullating pump discharge stream 9 which is thereafter heated in a heater 32 to produce a heated ebullating pump discharge 10 which is thereafter routed to the ebullated-bed reactor system 30. Heating the ebullating pump discharge stream 9 in the heater 32 ensures that the ebullated-bed reactor system 30 is able to achieve the necessary operating temperatures and provides a means of controlling the operating temperature of the system, even during changes or fluctuations of stream composition in feedstock 1. As described herein, the heater 32 may apply heat to the ebullating pump discharge stream 9 in a number of ways, including but not limited to, fired heat, electricity, steam, hot oil, process fluid exchange, etc.As mentioned above, because the temperature of the feedstock 1 is limited, the possibility of gumming upstream of the reactor is eliminated. When the feedstock 1 is processed in the ebullated-bed reactor system 30, the materials that cause gumming are destroyed and are not present in the liquid recycle stream 8. Therefore, by locating the process heater 32 on the liquid recycle stream 8, gumming concerns are eliminated. The vapor stream 4 from the separator drum 31 along with the net effluent liquid stream 7 is thereafter routed to a finishing hydroprocessing section 34. There is no significant pressure loss between the ebullated-bed reactor system 30 reactor and the finishing hydroprocessing section 34 due to the inclusion of the separator drum 31. The term “no significant pressure loss” means in the context of the invention that the drum is not at a pressure below 2 bars, preferably 1 bar, than the outlet pressure of the ebullated-bed reactor system.The finishing hydroprocessing section is typically at least one fixed bed reactor vessel with one or more catalyst beds. The finishing hydroprocessing section may operate at the same or different conditions than 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 3000 psia, preferably between 500 psia and 2500 psia. Most preferably however, the difference in operating pressure between the ebullated-bed reactor system and the finishing hydroprocessing section is less than 100 psi. Catalyst provided may be the same or different from that used in the ebullated-bed reactor system 30, but typically comprises supported catalyst comprising 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 chosen from the group Mo and / or W, on a mineral support chosen from the group formed by zeolites, alumina, silica, silica-aluminas, magnesia, clays, and mixtures of at least two of these minerals. Additional hydroprocessing reactions occur in the finishing hydroprocessing section 34 while the hydrocarbons and hydrogen in vapor stream 4 and net effluent liquid stream 7 are in contact with the catalyst in said finishing hydroprocessing section 34. Furthermore, the catalyst used in the finishing hydroprocessing section may comprise two or more catalyst formulations. This may be done when the different catalyst formulations have greater activity or effectiveness in removing a class of contaminants or facilitating a class of hydroprocessing reactions. One such example would be loading a primary catalyst formulation with hydrodenitrification and hydrodesulfurization functionality in combination with a secondary catalyst formulation with hydrocracking functionality. A second example would be loading a primary catalyst formulation with high trapping capacity for silicon or arsenic in combination with a secondary catalyst formulation with higher activity for one or multiple hydroprocessing reactions. In any case, the finishing hydroprocessing section facilitates further hydroprocessing conversions to achieve a higher reaction conversion (greater removal of heteroatoms, saturation of olefins / aromatics, hydrocracking conversion to lighter hydrocarbons, etc.) that are otherwise difficult to achieve in an ebullated-bed reactor system or other CSTR configuration reactor systems, without incurring the operational difficulties due to fouling or exothermic components which are greatly reduced in the ebullated-bed reactor system.The finishing hydroprocessing section 34 produces a finished hydroprocessed effluent 20 which may be thereafter mixed with wash water 21 before being sent to a cold separator 22. The cold separator 22 separates the finished hydroprocessed effluent 20 and wash water 21 mixture into a sour water stream 23, a gas stream 24, and a finished liquid stream 25.Water utilized for 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 water from sour water stream 23 is recycled to and mixed with wash water 21 to reduce the total amount of sour water product. 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 purge gas stream 26 flow is typically small and set to prevent build-up of light hydrocarbons such as methane and ethane in the reactor. The main portion of the gas stream 24 is recycled via the recycle gas stream 15 to the inlet of the reactor via the recycle compressor 27. The compressed recycle gas stream 16 is combined with the make-up hydrogen stream 2 and fed to the ebullated bed reactor system 30.In some embodiments, a portion or all of the gas stream 26 may encounter additional treatment processes prior to reintroducing the constituent hydrogen into the ebullated-bed reactor system. Such processes could include drying, caustic sweetening, amine sweetening, selective fixed bed adsorption, pressure swing adsorption, methanation, other hydroprocessing processes, or any combination thereof.The finished liquid stream 25 from the cold separator 22 is thereafter sent to a fractionator 36 to create a treated liquid product stream 37 and a fractionator vapor stream 38. Treated liquid product stream 37 comprises primarily hydrocarbons which may be suitable as an end-use product or may also be separated into further hydrocarbon fractions of differing boiling ranges. Alternatively, a similar embodiment, although not shown, would produce multiple liquid products from fractionator 36 which may have differing boiling ranges for each of said liquid products.End uses of the treated liquid product stream 37 may include fuel use such as diesel, jet, fuel oil, or bunker fuel, or may be feedstocks for other downstream hydrocarbon processes such as hydrocracking, hydrotreating, or steam cracking. The invention described herein has been disclosed in terms of specific embodiments and applications. However, these details are not meant to be limiting and other embodiments, in light of this teaching, would be obvious to persons skilled in the art. Accordingly, it is to be understood that the drawings and descriptions are illustrative of the principles of the invention, and should not be construed to limit the scope thereof.Claims1. A processing unit for processing hydrocarbon feedstocks comprising:one or more ebullated-bed reactor unit(s), wherein at least one of said ebullated-reactor unit(s) comprises a reactor vessel (10, 30), a separation vessel (11, 31), and a pump assembly (13, 33) and wherein said reactor vessel(s) comprise a bottom hydrocarbon liquid recycle inlet, a supported catalyst utilized to create an effluent (3) from contact with a hydrocarbon feedstock (1) and hydrogen (2), and wherein said separation vessel (11, 31) is configured to separate said effluent (3) from said reactor vessel (10, 30) into a liquid stream comprising less than 1wt. % solids (5), a vapor stream (4), and a slurry stream (6) comprising solids and a liquid hydrocarbon phase, and further wherein said pump assembly (13, 33) is connected to a heating device (12, 32) to provide heat and is further connected to said bottom hydrocarbon liquid recycle inlet of said reactor vessel (10, 30) to recycle at least a portion (8) of said liquid stream comprising less than 1wt. % solids (5).2. The hydrocarbon processing unit according to claim 1, wherein said heat from said heating device (12, 32) is selected from a group comprising, a hot oil heated heat exchanger, steam heated heat exchanger, a gas or liquid fuel fired furnace, an electrically powered resistive heating element, or an electrical furnace.3. A process for catalytically treating a hydrocarbon feedstock comprising:a) feeding a hydrocarbon feedstock (1) and a hydrogen stream (2) to one or more ebullated-bed reactor(s), said ebullated-bed reactor(s)comprising at least one reactor vessel (10, 30) and a separation vessel (11, 31), wherein said hydrocarbon feedstock (1) and said hydrogen stream (2) are contacted with a catalyst in said reactor vessel (10, 30) to provide a first effluent (3); andb) feeding said first effluent (3) to said separation vessel (11, 31) to provide a liquid stream comprising less than 1wt. % solids (5), a vapor stream (4), and a slurry stream (6), said slurry stream comprising solids and a liquid hydrocarbon phase; andc) recycling at least a portion (8) of said liquid stream comprising less than 1 wt.% solids (5) to said ebullated bed reactor(s) (10, 30); and wherein said liquid stream comprising less than 1 wt.% solids is heated prior to recycling to said ebullated-bed reactor(s).4. The process according to claim 3, further comprising:d) processing at least some portion (7) of said liquid stream comprising less than 1wt. % solids (5) and / or at least some portion of said vapor stream (4) in a downstream catalytic hydroprocessing reactor.5. The process according to claim 3 wherein at least a portion of said hydrogen stream (2) is heated along with said portion of said liquid stream comprising less than 1 wt% solids prior to entering said ebullated-bed reactor(s).6. The process according to claim 3 wherein the temperature of said hydrocarbon feedstock (1) is less than the operating temperature of said ebullated-bed reactor(s). 7. The process according to claim 3 wherein said hydrocarbon feedstock temperature is less than 250°C. 8. The process according to claim 3 wherein said hydrocarbon feedstock temperature is less than 200°C.9. The process according to claim 3 wherein said catalyst comprises metal(s) from group VIII and / or metal(s) from group VIB, and is on a mineral support comprising zeolites, alumina, silica, silica-aluminas, magnesia, clays, or mixtures of at least two of these minerals.10. The process according to claim 3 wherein said separation vessel (11, 31) comprises baffles, demister pads, coalescer pads, cyclones, and / or trays. 11. The process according to claim 3 wherein said hydrocarbon feedstock (1) is selected from the group comprising 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, effluent oil from hydrothermal liquefaction, effluent oil from gasification, deasphalted oil, vacuum distillate, atmospheric distillate, vacuum gasoil, light cycle oil, heavy cycle oil, delayed coker hydrocarbon effluents, petroleum based pitch, vacuum residue, atmospheric residue, or any combination thereof.12. The process according to claim 3 wherein said hydrocarbon feedstock has a diene value greater than 1.0.13. The process according to claim 3 wherein said hydrocarbon feedstock has a diene value greater than 3.0.14. The process according to claim 3 wherein said hydrocarbon feedstock has a diene value greater than 5.0.15. The process according to claim 3 wherein said hydrocarbon feedstock has a metals content greater than 5 wppm.16. The process according to claim 3 wherein said hydrocarbon feedstock has a metals content greater than 10 wppm.17. The process according to claim 3 wherein said hydrocarbon feedstock has a metals content greater than 20 wppm.18. The process according to claim 3 wherein said hydrocarbon feedstock has an asphaltene content of greater than 500 wppm.AbstractApplicants describe a novel process and processing configuration for catalytically treating hydrocarbon feedstock (1) into a treated hydrocarbon stream utilizing an ebullated-bed reactor (10). The invention is particularly adapted for treating hydrocarbon feedstock comprising compounds prone to precipitate and / or to polymerize to make gums under high temperature.Figure 1 to be published

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 heating device (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 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.

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 slurry 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 ebullated bed reactor(s).

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

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

11. The method of 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, peanut oil, hempseed 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 cycle oil, heavy cycle oil, delayed coker hydrocarbon effluent, petroleum-based pitch, vacuum residue, atmospheric residue, or any combination thereof.

12. The method of claim 3, wherein said hydrocarbon feedstock has a diene number greater than 1.

0.

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

0.

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

0.

15. The method of claim 3, wherein said hydrocarbon feedstock has a metal content greater than 5 ppm by weight.

16. The method of claim 3, wherein said hydrocarbon feedstock has a metal content greater than 10 ppm by weight.

17. The method of claim 3, wherein said hydrocarbon feedstock has a metal content greater than 20 ppm by weight.

18. The method of claim 3, wherein said hydrocarbon feedstock has an asphaltene content greater than 500 ppm by weight.

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