KR102211995B1 - Method for separating particles containing alkali metal salts from liquid hydrocarbons - Google Patents

Abstract

The present technology includes heating a first mixture of particles comprising elemental sulfur and alkali metal sulfide in a liquid hydrocarbon to a temperature of at least 150° C. to provide a sulfur-treated mixture comprising agglomerated particles; And separating the agglomerated particles from the sulfur-treated mixture to provide a desulfurized liquid hydrocarbon and a separated solid. The present invention can be used as part of a series of methods for desulfurizing liquid hydrocarbons contaminated with organosulfur compounds and other heteroatom-based pollutants. The present technology further provides methods for converting carbon-rich solids (eg petroleum coke) into fuel.

Description

Method for separating particles containing alkali metal salts from liquid hydrocarbons

Cross-reference to related applications

This application is for U.S. Provisional Application No. 62/404119 filed on October 4, 2016, U.S. Provisional Application No. 62/513871 filed on June 1, 2017, and U.S. Provisional Application No. 62/513871 filed on March 1, 2017. Claims the benefit of Application No. 15/446299 and priority thereto, the contents of which are incorporated herein by reference in their entirety.

Technical field

The present technology relates to a method for removing particles containing alkali metal salts such as alkali metal sulfides from liquid hydrocarbons. The present technology further relates to a method for converting carbon-rich solids into fuel.

Liquid hydrocarbons, including many oil feedstocks, are often difficult to remove sulfur in the form of organosulfur compounds as well as metals and other heteroatom-containing compounds that hinder the use of hydrocarbons. Sulfur can cause air pollution and can eliminate the action of catalysts used in petroleum processing or catalysts designed to remove hydrocarbons and nitrogen oxides from automobile exhaust. There is a worldwide trend to limit the amount of sulfur in hydrocarbon fuels, including marine bunker oils, such as gasoline, diesel, and fuel oils. The metals contained in the hydrocarbon stream can also eliminate the action of catalysts typically used for sulfur removal through standard and improved hydro-desulfurization processes, whereby hydrogen reacts under extreme conditions and contains organosulfur molecules. Decomposes sulfur.

Sodium has been recognized as being potentially effective in the treatment of high-sulfur hydrocarbons, including petroleum-based oil distillates, crude oil, heavy oil, bitumen, and shale oil. Sodium can react with oil and its contaminants to dramatically reduce sulfur, nitrogen, oxygen, and metal content through the formation of sodium sulfide compounds (sulfides, polysulfides and hydrosulfides) as well as other by-products. However, it can be difficult to remove these by-products from the treated feedstock. Suspensions and/or emulsions from which by-products may form often cannot be completely removed using standard separation techniques and can be difficult to perform efficiently on an industrial scale. In fact, large-scale desulfurization using sodium metal or other alkali metals is not regularly commercially used, in part due to this problem.

The present technology provides a method for separating particles containing alkali metal salts from liquid hydrocarbons. Such mixtures result from the use of alkali metals (in the metallic state) to remove nitrogen, sulfur, oxygen and heavy metals from liquid hydrocarbons ( eg oil feedstocks) contaminated with compounds containing such heteroatoms. The method includes heating a first mixture of particles comprising elemental sulfur and alkali metal sulfide in a liquid hydrocarbon to a temperature of at least 150° C. to provide a sulfur-treated mixture comprising agglomerated particles. The method further includes separating the agglomerated particles from the sulfur-treated mixture to provide a desulfurized liquid hydrocarbon and a separated solid. The present technology further provides a method for removing residual alkali metals from desulfurized liquid hydrocarbons and producing separated solids for electrochemical regeneration of alkali metals. The resulting desulfurized and demetallized liquid hydrocarbons typically have less than 0.5% by weight of sulfur and less than 100 ppm of alkali metal and, for example, meet the contaminant limits for bunker oil without further treatment. The invention is also applicable to a method for converting carbon-rich solids into fuels.

The foregoing is a summary of the present disclosure and thus includes simplification, generalization, and omission of details as needed. Consequently, one of ordinary skill in the art will understand that the summary is illustrative only and is not intended to be limiting in any way. Other aspects, features, and advantages of the methods described herein will become apparent from the detailed description set forth herein and taken in conjunction with the accompanying drawings, as defined by the claims.

In order to facilitate understanding of the above-cited technology and the manner in which other features and advantages of the technology are obtained, a more detailed description of the technology described briefly above will be provided with reference to the specific implementations thereof illustrated in the accompanying drawings. . These drawings show only typical embodiments of the present technology and, therefore, the present technology will be described and described with additional specificity and detail through the use of the accompanying drawings, provided that it is not considered to limit its scope.
1 is a process for removing particles containing alkali metal sulfide from liquid hydrocarbons and optional additional processes for removing residual alkali metals from product hydrocarbons and preparing separated solids for the regeneration of alkali metals, as well as particles and liquids. Shows a process flow diagram for an exemplary embodiment of a process for removing impurities from oil using an alkali metal to form a mixture of hydrocarbons.
2 shows a process flow diagram for an exemplary embodiment of the present technology for reducing or removing sulfur, metals and other heteroatoms while converting coke to liquid fuel.

The following terms are used everywhere as defined below.

As used herein and in the appended claims, single articles such as "a and an" and "the" and similar designations in the context of describing the elements (especially in the context of the following claims) Is construed to encompass both the singular and the plural unless otherwise indicated herein or clearly contradicted by context. List of ranges of values herein is intended to serve as a shorthand method of individually referring to each individual value falling within the range, unless otherwise indicated herein, each individual value as if individually recited herein. Incorporated herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or illustrative language ( eg , “such as”) provided herein is intended only to better illustrate the embodiments and is not otherwise stated in the scope of the claims. Do not limit. No language in the specification should be construed as necessarily representing any unclaimed element.

As used herein, “about” will be understood by those skilled in the art and will vary to some extent depending on the context in which it is used. In the case of use of a term that is not clear to one of skill in the art, taking into account the context in which it is used, “about” will mean up to ± 10% of the particular term.

The present technology provides a method for separating particles containing alkali metal salts, including alkali metal sulfides, from liquid hydrocarbons. Separation methods include liquid hydrocarbons as well as petroleum oil distillates, crude oil, heavy oil, bitumen, shale oil, and refinery intermediate streams (e.g., solvent deasphalted tar, vapor cracked tar, atmospheric or vacuum by-products, FCC slurries, Desulfurization of metals and other heteroatom contaminants from carbon-rich solids in liquid hydrocarbons, including but not limited to, visbreaker tar, hydrotreater, hydrocracker or hydroconversion bottom, coke and asphalt), as well as bunker oils. Or otherwise used as part of a series of methods to remove.

The sulfur compound(s), and optionally one or more nitrogen compounds, oxygen compounds, and liquid hydrocarbons contaminated with heavy metals are sodium, potassium to remove heteroatoms and provide a mixture of liquid hydrocarbons and particles comprising alkali metal sulfides. Or it can be desulfurized and decontaminated by contacting a hydrocarbon with a dissolved alkali metal (in its metallic state) such as lithium (or mixtures or alloys thereof). Capping agents are typically used to cap radicals formed when sulfur and other heteroatoms are extracted by alkali metals. The capping agent may be hydrogen, C _1-6 acyclic alkanes, C _2-6 acyclic alkenes, hydrogen sulfide, ammonia, or a mixture of any two or more thereof. The contacting step is at a temperature of about 250° C. to about 400° C. , For example, about 250° C., about 300° C., about 350° C., about 400° C., or between and including any two of the aforementioned temperatures. In some embodiments, the contacting occurs at about 300° C. to about 400° C. ( eg , 350° C.). Contact is at a pressure of about 400 psi to about 1500 psi, for example , about 400 psi, about 500 psi, about 600 psi, about 750 psi, about 1000 psi, about 1250 psi, about 1500 psi, or any of the foregoing values. It may occur between and inclusive of the two values of.

The amount of alkali metal in its metallic state used in the contacting step will vary depending on the level of heteroatomic contaminants in the liquid hydrocarbon, the temperature used and other conditions. For example, 1-3 molar equivalents of a metal alkali metal and 1-1.5 molar capping agent ( eg , hydrogen) may be required per mole of sulfur, nitrogen or oxygen. In addition, excess metal alkali metal can be used to induce the reaction in the direction of completion, e.g. in excess of 10%, 15%, 20%, 25%, 30%, 40%, 50% or more on a molar equivalent basis. Can be used. In some embodiments, the molten alkali metal used is sodium metal. Any suitable source of molten alkali metal may be used, including, but not limited to, electrochemically produced sodium, for example , to US 8,088,270, which is incorporated herein by reference in its entirety.

The reaction of metal alkali metals and heteroatomic contaminants is relatively fast in liquid hydrocarbons and is completed within minutes, otherwise seconds. Mixing a combination of a liquid hydrocarbon and a metallic alkali metal further accelerates the reaction and is typically used for such reactions on an industrial scale. Therefore, in some embodiments, the contacting step is performed for 1 minute to about 5 minutes, about 6 minutes, about 7 minutes, about 9 minutes, about 10 minutes, about 15 minutes, or about 20 minutes, or any of the foregoing values. It is performed for a period of time between and including the two values of.

The desulfurization reaction described above produces a mixture comprising particles comprising a liquid hydrocarbon and an alkali metal sulfide. The particles are quite fine ( e.g. , <10 μm) and standard separation techniques ( e.g. , filtration or centrifugation) at this stage, especially where the liquid hydrocarbon has a high viscosity, e.g., a bottom and a fuel oil. ) May not be completely removed. In addition, unreacted metal alkali metal may be present in such a mixture. Additional treatment as described below may be required to separate the particles and provide a desulfurized liquid hydrocarbon. In some cases, if the liquid hydrocarbon is particularly high viscosity, the hydrocarbon feed is optionally thermally pretreated prior to reaction with the alkali metal, eg at 300-450° C. for 30-60 minutes. Such heat treatment can reduce the heteroatom content of the liquid hydrocarbon, thereby reducing the amount of alkali metal required and simplifying the subsequent separation step.

Surprisingly, a separation method comprising heating a first mixture of particles comprising elemental sulfur and alkali metal sulfide ( e.g. sodium sulfide) in a liquid hydrocarbon to a temperature of at least 150° C. currently results in separable agglomerated particles. It has been found that it gives a sulfur-treated mixture comprising. Thus, the separation method further comprises separating the agglomerated particles from the sulfur-treated mixture to provide a desulfurized liquid hydrocarbon and a separated solid.

The separation method includes mixing the first mixture during heating. Depending on the conditions ( e.g. whether mixing is used, how high the temperature is, etc. ) , The first mixture can be heated for a longer or shorter period. In some embodiments, the period is at least 15 minutes. In others, the first mixture is about 15 minutes to about 2 hours, for example , about 15 minutes, about 30 minutes, about 45 minutes, about 1 hour, about 1.25 hours, about 1.5 hours, about 1.75 hours, about 2 Heated for a period of time, or a range between and including any two of the foregoing values.

In some embodiments of the separation method, the first mixture is about 150° C. to about 450° C., for example , about 150° C., about 200° C., about 250° C., about 300° C., about 350° C., about 400° C., about 450 It is heated to a temperature of °C, or to a temperature in the range between and including any two of the foregoing values. In some embodiments, the first mixture is heated to a temperature of about 300°C to about 400°C.

The pressure at which the separation process occurs is not critical and can be carried out at a wide range of pressures including atmospheric pressure. In some embodiments, the pressure is about 15 psi to about 1500 psi, for example , about 15 psi, about 25 psi, about 50 psi, about 100 psi, about 200 psi, about 300 psi, about 400 psi, about 500 psi , About 750 psi, about 1000 psi, about 1250 psi, about 1500 psi, or a range between and including any two of the foregoing values. More typically, the pressure can be between about 100 psi and about 400 psi. The pressurized gas in the vessel a separation process takes place includes a hydrogen (predominant), but also CO, CO _2, H ₂ S, and C ₁ - ₆ alkane and an alkene (e.g., methane, ethane, ethylene, propane, Pro Pen, butane, etc.) .

In addition to the alkali metal sulfide, the first mixture may also comprise an alkali metal in its metallic state, referred to herein as “remaining alkali metal”. This is particularly the case when a molar excess of metal alkali metal is used to produce a mixture of liquid hydrocarbon and alkali metal sulfide particles. In some embodiments of the separation method, the first mixture comprises 1-100% by weight of an alkali metal in its metallic state relative to the weight of the alkali metal in the alkali metal sulfide. The first mixture may also comprise alkali metal oxides and/or metals other than alkali metals.

The amount of elemental sulfur to be added ranges from about 0.5 equivalents to about 2 equivalents or even about 3 equivalents of sulfur atom per 2 equivalents of free sodium atoms present ( i.e. , non-ionic, metallic). You can do this. In some embodiments, the amount of elemental sulfur added is between and includes 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.5, 1.75, 2, 2.5, 3.0 equivalents or any two of the foregoing values. This is the range. In some embodiments, 0.8 to 1.2 equivalents of elemental sulfur are added. Depending on how much elemental sulfur has been added, the agglomerated particles may comprise alkali metal sulfide and/or alkali metal hydrosulfide ( e.g. , sodium sulfide (Na ₂ S) or sodium hydrosulfide (NaHS)). It has been surprisingly found that when more elemental sulfur is added than a stoichiometric amount ( i.e. , more than 1 equivalent of sulfur atom per 2 equivalents of sodium atom), sodium hydrosulfide begins to form in place of the expected sodium polysulfide. Thus, in some embodiments, alkali metal hydrosulfides may predominate.

In some embodiments of the separation method, separating the agglomerated particles from the sulfur-treated mixture comprises filtering, sedimenting, or centrifuging the sulfur-treated mixture to provide a separated solid. The step of separating the agglomerated particles from the sulfur-treated mixture can be conveniently carried out by centrifuging the sulfur-treated mixture, for example at about 15°C to about 150°C. In some embodiments, centrifugation occurs at about 120°C to about 140°C.

In some embodiments, the separation method comprises mixing the separated solid and an organic liquid (suitable for dissolving any liquid hydrocarbons in the separated solid phase) and separating the separated solid from the organic liquid to provide a washed solid. Include more. Any suitable organic liquid may be used including, but not limited to, toluene, xylene, hexane, diesel ( eg , coker diesel) and/or condensates ( eg , BTX condensates). The cleaning liquid containing the residual desulfurized liquid hydrocarbon can be sent to a recovery process ( eg, distillation) to recover the organic liquid for reuse or can be mixed with the desulfurized liquid hydrocarbon as a product oil. The cleaned solid can be dried using standard means, if desired, and electrolyzed as described in US Pat. No. 8,088,270, to recover metallic alkali metal ( eg sodium) for reuse.

Desulfurized liquid hydrocarbons resulting from the separation process typically contain up to 0.5% by weight sulfur. In some embodiments, the desulfurized liquid hydrocarbon contains no more than 0.4%, 0.3%, 0.2%, 0.1% or even 0.05% sulfur by weight. In certain embodiments, for those specifically intended for blending with lower sulfur content hydrocarbons, the desulfurized liquid hydrocarbon contains slightly more than 0.5% sulfur, for example 0.6% by weight. Thus, in some embodiments, the desulfurized liquid hydrocarbon contains from about 0.05% to about 0.6% by weight. When alkali metal sulfides and metals have been separated from liquid hydrocarbons, sulfur and metals are substantially removed, and nitrogen is moderately removed; Also, both viscosity and density are decreased (API gravity is increased).

Depending on the nature of the desulfurized liquid hydrocarbon, there can be a significant alkali metal content remaining, for example up to 1% by weight and sometimes in excess. In some embodiments, such residual alkali metal is from about 400 ppm to about 10,000 ppm, for example , about 400, about 600, about 800, about 1,000, about 1,200, about 1,400, about 1,600, about 2,000, about 2,500, about 3,000, about 4,000, about 5,000, about 7,500 or even about 10,000 ppm, or between and inclusive of any two of the foregoing values. Some of the alkali metal content is sulfur, oxygen, or nitrogen in which heavy metals have occupied their original positions, are ionicly associated with naphthenates, or are finely dispersed in a metallic state, or are still bound to organic molecules in the oil. It may be ionicly related at the site ionicly associated with.

Removal of residual alkali metal from the oil is required because the alkali metal content is not acceptable in most product applications, and most downstream purification methods are also sensitive to the presence of alkali metals. Also, if a significant amount of alkali metal leaves the system, a large amount of make-up will be required to maintain the process.

Therefore, in another aspect, the present technology provides a method of demetallization comprising the step of adding a salt-forming substance to a desulfurized liquid hydrocarbon to form a second mixture, wherein the salt-forming substance To convert the remaining alkali metal into an alkali metal salt. Any suitable salt-forming substance can be used as long as the resulting salt is readily removed from the liquid hydrocarbon. In some embodiments, the salt-forming substance can be selected from the group consisting of elemental sulfur, hydrogen sulfide, formic acid, acetic acid, propanoic acid and water. In some embodiments, acetic acid is used to form the sodium acetate salt, which is relatively easy to remove in its solid form. Typically, the amount of salt-forming substance added is about 1 to about 4 times the molar amount of residual alkali metal, e.g., 1, 1.25, 1.5, 2, 2.5, 3, 3.5 molar equivalents or any of the foregoing values. It is equal to the range between and including the two values of. For example, in some embodiments, the amount is equal to about 1 to about 2 molar equivalents.

In some embodiments, the addition of the salt-forming substance is at a temperature of at least 150°C, for example , about 150°C, about 200°C, about 250°C, about 300°C, about 350°C, about 400°C, about 450°C. , Or at a temperature within a range including and between any two of the aforementioned values. In some embodiments, the addition of the salt-forming substance can be carried out at a temperature of about 150°C to about 450°C.

In certain embodiments, the addition of the salt-forming substance is performed at a pressure of at least about 15 psi. In some embodiments, the addition of the salt-forming substance is about 15 psi, about 25 psi, about 50 psi, about 100 psi. , At a pressure of about 150 psi, about 200 psi, about 250 psi, about 300 psi, about 400 psi, about 500 psi, about 1,000 psi, about 1,500 psi, about 2,000 psi, about 2,500 psi, or any of the foregoing values. It is carried out at a pressure between and within the range encompassing the two values. For example, in some embodiments, the addition is performed at about 50 psi to about 2,500 psi.

The demetallization process may include separating the alkali metal salt from the second mixture to provide a desulfurized and demetallized liquid hydrocarbon. For example, separating the alkali metal salt from the second mixture comprises filtering, sedimenting, or centrifuging the second mixture to remove the alkali metal salt and providing a desulfurized and demetallized liquid hydrocarbon. can do.

Embodiments of the present technology may be understood with reference to the drawings, and like parts are designated by like numbers throughout. It will be readily understood that components of the present technology, as generally described and illustrated in the drawings herein, may be arranged and designed in a wide variety of different configurations. Accordingly, the following more detailed description of an implementation of the method and system of the present technology as indicated in FIG. 1 is not intended to limit the scope of the present technology as claimed, but merely represents a current implementation of the present technology. In particular, although the present technology can be used to separate any mixture of alkali metal sulfides from liquid hydrocarbons, Figure 1 shows an embodiment in which the mixture is produced by reaction of a liquid hydrocarbon contaminated with an alkali metal and an organosulfur compound. . An optional method for removing residual alkali metals from the desulfurized hydrocarbons and producing separated alkali metal sulfides for further processing is also described.

As shown in FIG. 1, the oil feedstock 10 may be supplied through an optional heat exchanger 101 and preheated to about 150° C. to about 350° C. before entering the reactor 202. The alkali metal 12 in the molten state is also fed to the reactor, along with a radical capping agent 14 which may be hydrogen and/or hydrocarbons such as methane, ethane, natural gas and the like. The alkali metal is typically a sodium metal but may also be a lithium metal, a potassium metal, or an alloy or a mixture containing any two or more of these metals. The reactor is batchwise in a temperature range above the melting temperature of the alkali metal, typically between 150-400 °C, but more preferably between 300-360 °C, to provide faster reaction kinetics and reduce or avoid thermal cracking. batch-wise) or continuously. The reaction is typically carried out at a pressure of 500-2000 psi. Under these conditions, the alkali metal often reacts with sulfur and other heteroatomic contaminants every few minutes ( eg , 1-20 minutes) to produce fine particles of alkali metal salts including alkali metal sulfides. See, for example , U.S. Patent No. 8,088,270.

The final mixture of liquid hydrocarbon and alkali metal salt/sulfide particles exits the reactor via line 15 and is fed to a maturation vessel 204. There, it is combined with elemental sulfur, which is conveniently in liquid form (but not required to be in liquid form) via line 16 ( eg at 130°C-160°C) for a period of 15-120 minutes, Typically while mixing, it can be heated to a temperature of at least about 150°C. More typically, the mixture is heated to about 300°C to about 450°C, or in some embodiments, about 300°C to about 400°C. The processes in the reactor 202 and vessel 204 are preferably carried out continuously, but they can be carried out in the same vessel if the process is carried out in batch mode. The sulfur-treated mixture contains agglomerated particles and exits vessel 204 via line 17, flows into an optional heat exchanger 103 where heat is removed, and optionally a liquid hydrocarbon supply via heat exchanger 101. It passes back to the water. The cooled sulfur-treated mixture ( e.g. , at about 60-180° C., or even about 100-140° C.) is fed via line 18 to the solid/liquid separation device 206, which is typically It includes a centrifugal separator, but may also include a filter. The separated solid 30 leaves the separation device for further processing. The final desulfurized liquid hydrocarbon is free or substantially free of solids, but may contain from about 400 to about 4,000 ppm or more of residual alkali metal in its metallic form.

The desulfurized liquid hydrocarbon is pumped from the separation device 206 via line 19 using a pump 105 and, if present, an optional heat exchanger that heats the desulfurized liquid hydrocarbon to about 250° C. to about 350° C. It is sent over line 20 to 107. The liquid hydrocarbon desulfurized therefrom flows through line 21 and is combined with a salt-forming substance such as acetic acid from line 24 as described above. The combination of acetic acid or other salt-forming substance and the remaining alkali metal forms an additional solid comprising the alkali metal salt. These solids are removed by a second separation device 208 ( eg , a centrifugal separator) to yield a desulfurized and demetallized liquid hydrocarbon product 26 and an alkali metal salt solid 28.

The solids 30 separated from the device 206 are transported to the cleaning tank 210 via a chute or other suitable means, where they are an organic liquid 32 (as defined above) such as toluene, xylene, hexane. , Diesel, condensate, or a combination of any two or more thereof or some other organic liquid suitable for cleaning. Now, the cleaned solid is pumped out of the cleaning tank via line 33 and via line 34 to another solid-liquid separation device 212 where most of the organic liquid 35 is recovered. Is pumped. If the recovered organic liquid is , for example , diesel, it is stored with other desulfurized liquid hydrocarbons for later sale as a product. If the recovered organic liquid is not a fuel product, it is reused as a cleaning liquid. The cleaned solid is transported to a dryer where any residual organic cleaning liquid is removed in dryer 214. In the drying step, the cleaned solid is heated in a non-oxidizing atmosphere to a temperature of, for example , 150-350° C. to recover the cleaning liquid 38 which can be returned to the process as a cleaning liquid in the cleaning tank 210. The dryer may be any commercially available method including a paddle dryer, spray dryer or indirect combustion kiln. The dry cleaned solid is ready to be recycled, for example by electrochemical treatment, to recover the alkali metal in its metallic state, as described in, for example , US Pat. Nos. 8,088,270 or 8,747,660.

In yet another aspect, the technology also provides a method for converting carbon-rich solids into fuel. Carbon-rich solids are solids containing at least 75% by weight of carbon (at room temperature). Examples include petroleum coke, asphaltene, and coal. Such carbon-rich solids generally have at least 0.5% by weight sulfur prior to treatment by this method. Therefore, in one aspect, the present technology provides a slurry or suspension of carbon-rich solids having at least 0.5% by weight of sulfur in a liquid hydrocarbon molten alkali metal and a capping agent (hydrogen, C _1-6 acyclic alkanes, C _2-6 acyclic alkene, hydrogen sulfide, ammonia, or a mixture of any two or more thereof). This method is carried out at elevated temperature and pressure. The method converts at least some of the carbon-rich solids into liquid fuels ( eg, residual fuels or refinery feedstocks) and particles comprising alkali metal sulfides. The liquid fuel has a reduced sulfur, metal and heteroatom content compared to the starting solid, for example up to 0.2 or even 0.1% by weight sulfur. Liquid fuels of the present technology include any hydrocarbon or hydrocarbon mixture that is used in a liquid state and can be burned as fuel. Thus, liquid fuels include gasoline, kerosene and diesel, as well as fuel oil, residual fuel and the like.

In some embodiments, the method comprises treating a slurry or suspension of petroleum coke in a liquid hydrocarbon with molten alkali metal and at least one capping agent at an elevated temperature and pressure to mix at least a portion of the petroleum coke with liquid fuel and liquid hydrocarbon. Conversion to an inorganic solid.

Carbon-rich solids, such as petroleum coke , are not soluble in liquid hydrocarbons and thus exist as a slurry or suspension. The slurry or suspension may contain , for example , 1% to 20% by weight, based on the total mass of solid and liquid hydrocarbons. Slurries/suspensions can be in this range such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20% by weight, Or any suitable percentage of carbon between and within a range encompassing any two of the foregoing values, such as 1-15%, 3-15%, or 4 or 5%-10 or 11% by weight. It will be understood that it may contain rich solids.

The liquid hydrocarbons used in the slurry or suspension are chosen to provide both good slurry or suspension and to dissolve the liquid fuel produced. Thus, heavy hydrocarbons having a density sufficient to fluidize petroleum coke or other carbon-rich solids can be used, including , for example, hydrocarbons having a density of 800 to 1100 kg/m ³ at room temperature. Suitable densities include ranges between and including 800, 900, 1000, and 1100 kg/m ³ or any two of the foregoing values. Suitable liquid hydrocarbons include virgin crude oil, bitumen, refinery intermediates, such as fluid catalytic cracker slurries, hydrocracker sediments or vacuum residues, shale oils, or residual fuel oils, and may be the same or different from the liquid fuel produced by the method. have. In some embodiments, the liquid hydrocarbon itself may be part of a composition that requires desulfurization because it contains sulfur and optionally other heteroatoms such as nitrogen, oxygen and metals ( eg , vanadium).

Prior to suspension in a liquid hydrocarbon, petroleum coke or other carbon-rich solid is crushed and ground into powder or dust to reduce particle size and promote reaction with molten alkali metal. For example, the solid can be ground so that a number of particles have a diameter of 1 mm or less. In some embodiments, multiple particles range in size from 1 um to 1 mm.

In this method, it is believed that the molten alkali metal ( ie in its metallic state) reacts with coke (or other carbon-rich solid) and forms a liquid hydrocarbon that can be used as a fuel. In some embodiments, the alkali metal can be lithium, sodium, potassium, or an alloy thereof. Without wishing to be bound by theory, it is believed that during the present process, alkali metals, such as sodium, react with coke and hydrogen according to the following reactions:

RSR' + 2Na → R· + R'· + Na ₂ S (Equation 1)

R+ R'+ H ₂ → RH + R'-H (Equation 2)

In these formulas, R and R'represent the carbon rich organic constituents found in coke, each of which is covalently bonded to a sulfur atom. It is believed that sodium is oxidized, giving electrons to the carbon-rich organic components R and R'to form reactive radicals. These radicals can react with a capping agent such as hydrogen (ie H ₂ ) to form carbon-rich hydrocarbon molecules RH and R'-H. The novel molecules RH and R'-H are shorter, have a lower specific gravity than the original molecule RS-R' and are now suitable for dissolution into hydrocarbon liquids, thus increasing the mass and volume of the final liquid phase. The solid phase contains inorganic constituents including sodium sulfide and any coke that does not enter solution, as well as other inorganic constituents such as metals, alkali oxides and hydroxides, and nitrides. Solids can be separated from the liquid by one of a number of methods including centrifugation, filtration or gravimetric settling.

The reaction conditions for converting carbon-rich solids such as petroleum coke to fuel are within the same range and described above for the desulfurization of liquid hydrocarbons alone. For example, the radical capping agent may be hydrogen, methane or other agents as described above for the desulfurization of liquid hydrocarbons. Likewise, the conversion reaction proceeds at elevated pressure and temperature in the same range as the desulfurization reaction described above.

Using this method, a significant portion of the carbon-rich solid is converted into liquid fuel and particles comprising alkali metal sulfide. For example, the portion of fibrous coke converted to particles comprising liquid fuel and alkali metal sulfide may be at least 20% by weight. In some embodiments, the portion to be converted is at least 20, 30, 40, or 50% by weight or a range between and inclusive of any two of the foregoing values, eg , 20-50% by weight.

After reaction with the alkali metal and the capping agent, the alkali-metal treated slurry may contain not only unreacted particles of a carbon-rich solid, but also particles comprising an alkali metal salt. These particles can be separated from the liquid hydrocarbon/fuel mixture using the same elemental sulfur process described herein. In addition, any subsequent process described herein for treating sulfur-treated liquid hydrocarbons and separated solids may also be used. Alternatively, to aid in the separation of the alkali metal sulfide-containing solid form, a fuel slurry, water or hydrogen sulfide may be used in place of sulfur while mixing at the same temperature and pressure described herein. In the preferred case, the separation method of U.S. Patent No. 9,688,920 (incorporated herein by reference) can be used.

The method of the present technology may further comprise separating particles comprising alkali metal sulfide and any residual carbon-rich solids ( eg petroleum coke) from the mixture of liquid hydrocarbons and liquid fuels. The same technique described above for the first mixture of liquid hydrocarbons and particles can also be used for this aspect.

Those skilled in the art will appreciate that additional heaters and coolers may be located between the various vessels and reactors to heat or cool the oil or slurry to an appropriate process operating temperature or to more easily recover the heat generated in the process.

2 shows an exemplary implementation of the method. Finely ground ( eg, a large number of particles between 1 μm and 1 mm) petroleum coke 40 is added to a stream of liquid hydrocarbons, eg , oil feedstock 10. The final slurry or suspension may be an alkali metal 12 ( e.g. metal sodium) and a radical capping agent 14 at an elevated temperature and pressure, such as hydrogen gas, methane and/or other hydrocarbons, hydrogen sulfide, or ammonia, ( Or any two or more mixtures). Under the reaction conditions, the alkali metal is in a molten state. The reactants are for a period of time ( e.g., for a period of time to allow conversion of coke to liquid fuel to occur and removal of heteroatoms (such as sulfur and nitrogen) and other heavy metals from the liquid hydrocarbon feedstock 10 and coke 40). 5-60 minutes) mixed in the reactor by means of a mixer 306. The product, a mixture of desulfurized feedstocks, liquid fuels and inorganic solids such as alkali metal sulfides, nitrides, heavy metals and unreacted coke are sent to a maturation vessel 204, where the mixture is as described above for FIG. It is treated with elemental sulfur (16). The (selectively cooled) sulfur-treated mixture is fed to a solid/liquid separation device 206, which typically includes a centrifuge but may also include a filter. The separated solid 30 leaves the separation unit for further processing, and the upgraded oil feedstock 39 containing liquid fuel produced from petroleum coke can be further processed as described above with respect to FIG. 1. The solid 30 may include , for example , alkali metal sulfide, alkali metal nitride, heavy metal, and unreacted residual coke. The solid 110 can also be further processed as described for FIG. 1 to regenerate the alkali metal.

Example

Example 1-Desulfurization with sodium followed by sulfur treatment and solid separation

The vacuum residual oil feedstock was treated with sodium metal in a pilot plant using a continuous system essentially as shown in Figure 1 under the following conditions to yield a mixture of the treated oil and fine particles comprising sodium sulfide.

Oil feed rate: 66 kg/h

Sodium feed rate: 2.1 kg/h

Hydrogen feed rate: 250 g/h

Reaction temperature: 352℃

Reaction pressure: 1425 psi

Aliquots of a mixture of oil and fine particles were mixed with elemental sulfur under the following batch conditions (Table 1). The amount of sulfur remaining in the oil was measured.

Example 2-Continuous desulfurization with sodium followed by continuous sulfur treatment and solid separation

The vacuum residual oil feedstock was treated with sodium metal in a pilot plant using a continuous system essentially as shown in Figure 1 under the following four test conditions to yield a mixture of fine particles comprising the treated oil and sodium sulfide. Became.

Tests 2A-2D consist of sodium-reacted oil feedstock and particles containing sodium sulfide treated in a continuous manner in a pilot plant using this separation method according to the conditions of tests 3A to 3D shown in Figure 1 and Table 3 below. Four mixtures were provided. The amount of sulfur was measured in the desulfurized liquid hydrocarbon.

Example 3-Removal of residual sodium from liquid desulfurized hydrocarbons.

After desulfurization and separation of solids according to the procedure of Example 2, the desulfurized liquid hydrocarbon was treated with a mixture of acetic acid and sodium acetate according to the process of FIG. 1 and under the conditions indicated in Table 4 below.

Example 4-Desulfurization of Petroleum Coke

10 grams of petroleum coke was mixed with 90 grams of residual fuel oil, heated to 80° C., and then centrifuged at the same temperature. Petroleum coke solids were separated from the residual fuel oil. Petroleum coke and residual fuel had the composition shown in Table 5 below.

Example 5:

A 5 wt% mixture of petroleum coke and the balance residue fuel oil from Example 4 was prepared. 700 grams were placed into a 1.8L Parr reactor with gas guided impeller and cooling loop. The reactor was purged with hydrogen. After purging, the sample was heated to an operating temperature of 358° C. and a pressure of 1514 psig. 22.71 grams of molten sodium was pumped into the reactor using an electromagnetic pump. Hydrogen pressure was maintained by pumping hydrogen into the system while maintaining the flow. At the end of the run, the reactor contents were allowed to cool. The gas was released slowly. The flow rate of the gas was measured using a flow meter and analyzed using an Agilent Technologies Gas Chromatograph, Model 7890A. The reactor contents were centrifuged to separate the solids from the liquid and then the solids were rinsed with toluene to remove the attached liquid. The toluene rinse was evaporated off using a rotary evaporator and the residual liquid was bound to the liquid from the centrifuge. The solid was rinsed again with pentane. Pentane was evaporated off using a rotary evaporator and the residual liquid was combined with the liquid from the centrifuge. Solids and liquids were characterized in the same way as the original sample and mass balance was calculated to determine the liquid yield. The final liquid had the composition shown in Table 6 below.

Hydrogen consumption was 14.7 standard liters. The liquid yield was 94.8% by weight. Sulfur was substantially removed as well as a small amount of nitrogen. Of the 35 grams of coke charged, containing nearly 6% sulfur, approximately 11.3 grams went into the product liquid where the product was only 0.26% sulfur. Thus, excluding the sulfur portion of the coke, 33 grams were charged. Thus, approximately 34% by weight of solid coke was introduced into the liquid fuel product. The initial residual fuel had a specific gravity of 994 kg/m ³ while the desulfurized product was 980 kg/m ³ due to the addition of coke. The portion of the material considered to be a residue was as indicated in Table 7.

Example 6:

Example 5 was repeated except not 5% by weight petroleum coke, and in the same way 10% by weight coke was prepared and then only 21.07 grams of sodium was added and the operating pressure was slightly lowered to 1499 psig. Was manipulated. The final liquid had the composition shown in Table 7.

The hydrogen consumption was 17.1 standard liters. The liquid yield was 85.45% by weight. Sulfur was substantially removed as well as a small amount of nitrogen. Of the 70 grams of coke charged, containing nearly 6% sulfur, approximately 19.4 grams went into the product liquid where the product was only 0.17% sulfur. Thus, excluding the sulfur portion of the coke, 65.9 grams were charged. Thus, approximately 29% of solid coke was introduced into the liquid fuel product. The initial residual fuel had a specific gravity of 994 kg/m ³ while the desulfurized product was 984 kg/m ³ due to the addition of coke.

Based on the specific gravity of the desulfurized product, the final fuel is still a residual fuel, but now it meets the sulfur specification, which may be in very high demand, whereas the starting material, especially coke, is priced significantly below the price of the product. It will ask for a price similar to the distillate.

The solid can be treated and the sodium can be recycled according to the procedure of US Pat. No. 8,088,270 to Gordon et al . so that it can be recycled to the process.

Of course, other hydrocarbon liquids capable of dissolving carbon-rich organic molecules could have been used in addition to those selected. For example, if the soluble liquid already had a low sulfur content, then less sodium could have been added to the reaction and less hydrogen donation would be required. It can be noted that when 5% coke was added, 34% of the desulfurized coke went into the liquid phase, while when 10% coke was added, only 29% of the desulfurized coke went into the liquid phase. However, if the coke has an extremely low value and the product is priced at a similar price to the distillate, then it may be more desirable to accommodate the lesser portion that goes into the liquid phase. Conversely, if a smaller relative amount of coke is added, it is expected that the portion that goes into the liquid phase is larger. Also, other liquids can help increase the solubility of the treated coke. For example, asphaltene is soluble in toluene. Adding certain hydrocarbons can help increase the solubility of molten sodium treated petroleum coke and is part of the scope of the present invention.

Equivalent

While certain embodiments have been illustrated and described, those skilled in the art may, after reading the foregoing specification, make modifications to the methods and products thereof as set forth herein, substitutions of equivalents, and other types of modifications. Each aspect and implementation described above may also include or incorporate such variations and aspects as disclosed in connection with any or all of the other aspects and implementations therewith.

The present technology is also not limited in terms of the particular aspects described herein, which are intended as a single example of individual aspects of the present technology. Many modifications and variations of the present technology can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods within the scope of the present technology, in addition to those listed herein, will be apparent to those skilled in the art from the foregoing description. Such modifications and variations are intended to be within the scope of the appended claims. It is to be understood that this technology is not limited to any particular method, feedstock, composition, or conditions, which, of course, may vary. In addition, it should be understood that the terms used herein are for the purpose of describing only certain aspects and are not intended to be limiting. Accordingly, it should be noted that the specification is to be considered as illustrative with the breadth, scope and spirit of the subject technology dictated only by the appended claims, definitions therein, and any equivalents thereof.

The embodiments exemplarily described herein may be suitably practiced in the absence of any element or elements, limitations or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising”, “including”, “containing”, etc. will be interpreted broadly and without limitation. Additionally, the terms and expressions used herein are used in terms of description and not limitation, and are not intended as use of such terms and expressions to exclude any equivalents of features or portions thereof shown and described, but various It should be appreciated that variations are possible within the scope of the claimed technology. Additionally, the phrase “consisting essentially of” will be understood to include those elements specifically recited and those additional elements that do not materially affect the basic and novel characteristics of the claimed technology. . The phrase "consisting of" excludes any element not specified.

Furthermore, where a feature or aspect of the present disclosure is described in terms of a Markush group, those skilled in the art will appreciate that the present disclosure is also described in terms of members of any individual member and subgroup of the Markush group thereby. Will recognize. Each of the narrower species and subgenus groupings that fall within the general disclosure also form part of the invention. This includes the general description of the invention, regardless of whether the deleted material is specifically recited herein, with clues or negative limitations removing any subject matter from the genus.

As will be appreciated by one of ordinary skill in the art, for any and all purposes, particularly in view of providing written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges. Any recited range can be readily recognized by sufficiently describing the same range and allowing it to be subdivided into at least equivalent 1/2, 1/3, 1/4, 1/5, 1/10, etc. As a non-limiting example, each range discussed herein can be readily broken down to the lower third, middle third and upper third, etc. Also, as understood by those skilled in the art, all languages such as "up to", "at least", "greater than", "less than", etc. Refers to a range that includes the recited numbers and may be subsequently subdivided into subranges as discussed above. Finally, as will be appreciated by those of skill in the art, the range includes each individual member.

All publications, patent applications, issued patents, and other documents (e.g., journals, articles and/or textbooks) referred to herein are referenced in their entirety by each individual publication, patent application, issued patent, or other document. Is incorporated herein by reference as specifically and individually indicated to be incorporated by reference. Definitions included in the text incorporated by reference are excluded to the extent that they contradict the definitions of the present disclosure.

Other embodiments are set forth in the claims below, along with the full scope of equivalents to which such claims are entitled.

Claims (51)

A method comprising the following steps:
Heating the first mixture of particles comprising elemental sulfur and alkali metal sulfide in a liquid hydrocarbon to a temperature of at least 150° C. to provide a sulfur-treated mixture comprising agglomerated particles; And
Separating the agglomerated particles from the sulfur-treated mixture to provide a desulfurized liquid hydrocarbon and a separated solid. The method of claim 1, wherein the alkali metal sulfide comprises sodium sulfide. The method of claim 1 further comprising mixing the first mixture during heating. The method of claim 1, wherein the first mixture is heated to a temperature of 150°C to about 450°C. The method of claim 1, wherein the method occurs at a pressure of about 15 psi to about 1500 psi. The method of claim 1, wherein the first mixture is heated for a period of 15 minutes to about 2 hours. The method of claim 1, further comprising forming the first mixture by combining elemental sulfur and the liquid hydrocarbon comprising particles. The method of claim 1, wherein the first mixture further comprises an alkali metal in a metallic state. The method of claim 1, wherein the first mixture comprises 1-100% by weight of an alkali metal in a metallic state based on the weight of the alkali metal in the alkali metal sulfide. The method of claim 1, wherein the first mixture further comprises an alkali metal oxide and/or a metal other than an alkali metal. The method of claim 1, wherein the agglomerated particles comprise alkali metal sulfide and/or alkali metal hydrosulfide. The method of claim 1, wherein the agglomerated particles comprise sodium sulfide and/or sodium hydrosulfide. The method of claim 1, wherein separating the agglomerated particles from the sulfur-treated mixture comprises filtering, sedimenting, or centrifuging the sulfur-treated mixture. The method of claim 1, wherein separating the agglomerated particles from the sulfur-treated mixture comprises centrifuging the sulfur-treated mixture at 15°C to 150°C. The method of claim 1, wherein the desulfurized liquid hydrocarbon contains up to 0.5% sulfur by weight. The method of claim 1, wherein the desulfurized liquid hydrocarbon comprises residual alkali metal. The method of claim 16, wherein the residual alkali metal is present at 400 ppm to 2000 ppm. The method of claim 16, further comprising adding a salt-forming substance to the desulfurized liquid hydrocarbon to form a second mixture, wherein the salt-forming substance converts the residual alkali metal into an alkali metal. Converting to a salt, method. 19. The method of claim 18, wherein the salt-forming substance is selected from the group consisting of elemental sulfur, hydrogen sulfide, formic acid, acetic acid, propanoic acid and water. 19. The method of claim 18, wherein the amount of salt-forming substance added is equal to about 1 to about 4 times the molar amount of residual alkali metal. 19. The method of claim 18, wherein the addition of the salt-forming substance is carried out at a temperature of about 150°C to about 450°C. 19. The method of claim 18, wherein the addition of the salt-forming substance is carried out at a pressure of about 50 psi to about 2,500 psi. 19. The method of claim 18, further comprising separating the alkali metal salt from the second mixture to provide a desulfurized and demetallized liquid hydrocarbon. The method of claim 23, wherein the step of separating the alkali metal salt from the second mixture comprises filtering, sedimenting, or centrifuging the second mixture to remove the alkali metal salt and the desulfurized and demetallized Providing a liquid hydrocarbon. The method of claim 1, further comprising mixing the separated solid and an organic liquid and separating the separated solid from the organic liquid to provide a washed solid. 26. The method of claim 25, wherein the organic liquid is selected from toluene, xylene, hexane and diesel. 26. The method of claim 25, further comprising drying the washed solid. The method of claim 1, further comprising contacting a liquid hydrocarbon containing a sulfur compound with a molten alkali metal in a metallic state and a capping agent to provide a mixture of particles comprising the liquid hydrocarbon and alkali metal sulfide. Way. 29. The method of claim 28, wherein the alkali metal is sodium. The method of claim 28, wherein the capping agent is hydrogen or a C1-C6 acyclic hydrocarbon, hydrogen sulfide, ammonia, or a mixture of any two or more thereof. 29. The method of claim 28, wherein the contacting occurs at a temperature of 250°C to 400°C. The method of claim 28, wherein the contacting occurs at a pressure of 400 to 1500 psi. 29. The method of claim 28, wherein said mixture of particles comprising said liquid hydrocarbon and alkali metal sulfide is produced in a reactor vessel, and said first mixture and sulfur-treated mixture are produced in separate vessels. 29. The method of claim 28, further comprising electrochemically producing the alkali metal in the metallic state. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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