Process for the purification and conversion of asphaltene-containing feedstocks

Abstract

The technology provides a method comprising the steps of: contacting a hydrocarbon feedstock with an effective amount of metallic sodium and an effective amount of an exogenous capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock, wherein the hydrocarbon feedstock comprises hydrocarbons having a sulfur content of at least 0.5 wt% and an asphaltene content of at least 1 wt%, the sulfur content comprising asphaltene sulfur and non-asphaltene sulfur, the converted feedstock comprises a hydrocarbon oil having a sulfur content lower than that in the hydrocarbon feedstock and a lesser asphaltene content than that in the hydrocarbon feedstock, and the ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than in the hydrocarbon feedstock.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63 / 027117, filed May 19, 2020, the entire contents of which are incorporated herein.

[0002] Technical Field The present technology relates to a method for reducing the sulfur and asphaltene content, as well as other impurities, in a hydrocarbon feedstock. The present technology further relates to a method for preferentially removing sulfur from asphaltene sulfur species relative to other sulfur-containing species in the feedstock. Furthermore, the present technology relates to a method for converting at least a portion of the asphaltenes in the feedstock into a hydrocarbon oil.

[0003] Technical Field The present technology relates to a method for reducing the sulfur and asphaltene content, as well as other impurities, in a hydrocarbon feedstock. The present technology further relates to a method for preferentially removing sulfur from asphaltene sulfur species relative to other sulfur-containing species in the feedstock. Furthermore, the present technology relates to a method for converting at least a portion of the asphaltenes in the feedstock into a hydrocarbon oil. [Background technology]

[0004] Technology Background Hydrocarbon oils, including many petroleum feedstocks, often contain difficult-to-remove impurities such as sulfur in the form of organosulfur compounds, metals, and other heteroatom-containing compounds that inhibit hydrocarbon utilization. Undesirable impurities present in hydrocarbon oils can be concentrated in resins and asphaltenes found in vacuum residue distillation fractions, typically defined by boiling points between 510°C and 565°C (950°F and 1050°F) or higher. Traditional refining configurations further concentrate undesirable impurities by separating the more valuable, lower-boiling distillation fractions (gasoline, diesel, jet, and gas oil) from the less valuable, higher-boiling bottoms fractions (atmospheric and vacuum residue). The lower-boiling distillation fractions can be easily processed and converted into end products using established processes, such as hydrotreating, alkylation, catalytic reforming, and catalytic cracking. High-boiling residue streams cannot be easily processed because their disproportionately high metal content fouls catalysts and the polyaromatic structure of asphaltenes prevents contact with impurities.

[0005] Sulfur species present in hydrocarbons can be characterized as asphaltene sulfur (i.e., sulfur-containing asphaltene species) and non-asphaltene sulfur (i.e., sulfur-containing species). Non-asphaltene sulfur generally includes thiols, sulfides, benzothiophenes, etc., and is primarily located in the vacuum residue fraction, but may also be present in saturates, aromatics, and resin components present in any distillate fraction. These sulfur species, particularly those present in gasoline, naphtha, kerosene, diesel, and gas oil fractions, can generally be removed using conventional catalytic or conversion processes such as hydrotreating, hydrodesulfurization, or hydrocracking. Asphaltene sulfur is located in the asphaltenes of the heaviest residue distillate fractions and is primarily characterized by condensed layers of sulfur-containing polynuclear aromatic compounds linked by sulfur to saturates. Dibenzothiophenes (DBT) and DBT derivatives and sulfur bridges may account for a large proportion of asphaltene sulfur species. Additionally, metals, including nickel, vanadium, and iron, are often concentrated in porphyrin-metal complexes present in the asphaltene fraction. Sulfur cannot be easily removed without subjecting the asphaltene sulfur to harsh operating conditions.

[0006] Residual thermal or catalytic conversion units typically operate under harsh operating conditions, including high temperatures (>350°C / 662°F), high hydrogen partial pressures (500-3000 psig), and specialized catalysts that are deactivated by metal and coke deposition. The difficulty of catalytically processing feedstocks with high asphaltene content is demonstrated by hydrotreating, where asphaltenes have been shown to slow the hydrotreating reaction, precipitate on the catalyst surface, act as coke precursors, and deactivate the catalyst. Ancheyta, et al., "Changes in Asphaltene Properties during Hydrotreating of Heavy Crudes," Energy and Fuels, 2003, 17, 1233-1238. In this study, this conventional catalytic process only reduced asphaltene sulfur content by 10%, while concentrating metals. Therefore, even after subjecting the residual stream to harsh operating conditions, a fraction of the sulfur and metals remains in the oil. As a result, the low-value residual underflow is either 1) converted to asphalt, 2) processed in a thermal conversion unit (such as a coker) to extract as many high-value intermediates as possible, or 3) blended into high-sulfur bunker fuel. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Ancheyta, et al., “Changes in Asphaltene Properties during Hydrotreating of Heavy Crudes” Energy and Fuels, 2003, 17, 1233-1238 Summary of the Invention

[0008] Technology Overview Surprisingly, a process has been discovered that preferentially removes sulfur and metals from asphaltenes and / or converts a portion of the asphaltene fraction of a hydrocarbon feedstock or residual feedstock into liquid hydrocarbon products other than asphaltenes. This process provides a converted feedstock with reduced sulfur (and other heteroatom) content and reduced metal content, particularly in the asphaltene fraction. Furthermore, pretreating a hydrocarbon feedstock to concentrate impurities in the residual feedstock may be desirable to improve the overall efficiency of a refinery by removing the impurities using an optimized process. Using this technology, impurities concentrated in the asphaltene fraction of a hydrocarbon or residual feedstock may be best removed by contacting such feed with metallic sodium, while impurities concentrated elsewhere may be best removed by conventional refining processes. Furthermore, reducing the high concentrations of impurities contained in the asphaltene fraction can optimize the operation of downstream process units and improve refinery operability and profitability.

[0009] Thus, in one aspect, the present technology provides a method comprising contacting a hydrocarbon feedstock with an effective amount of metallic sodium and an effective amount of an exogenous capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock, wherein the hydrocarbon feedstock comprises hydrocarbons having a sulfur content of at least 0.5 wt% and an asphaltene content of at least 1 wt%, wherein the sulfur content comprises asphaltene sulfur and non-asphaltene sulfur, and the converted feedstock comprises a hydrocarbon oil having a lower sulfur content than in the hydrocarbon feedstock, a lower asphaltene content than in the hydrocarbon feedstock, or both, and wherein the ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than in the hydrocarbon feedstock.

[0010] In a second aspect, the present technology provides a method comprising the steps of pretreating an impure hydrocarbon feedstock to provide a refined feedstock and a residual feedstock, wherein the refined feedstock has a lower concentration of impurities than the hydrocarbon feedstock before pretreatment, and the residual feedstock has a higher concentration of impurities than the refined feedstock; and contacting the residual feedstock with an effective amount of metallic sodium and an effective amount of an exogenous capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock, wherein the residual feedstock comprises hydrocarbons having a sulfur content of at least 0.5 wt% and an asphaltene content of at least 1 wt%, the sulfur content comprising asphaltene sulfur and non-asphaltene sulfur, and the converted feedstock comprises a hydrocarbon oil having a lower sulfur content than in the residual feedstock, a lower asphaltene content than in the residual feedstock, or both, and wherein the weight ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than in the residual feedstock.

[0011] In a third aspect, the present technology provides a method comprising contacting a residual feedstock comprising hydrocarbons having a sulfur content of at least 0.5 wt. % and an asphaltene content of at least 1 wt. % with metallic sodium in a less than stoichiometric amount relative to the sulfur content of the residual feedstock and an effective amount of an exogenous capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock, wherein the stoichiometric amount of metallic sodium relative to the sulfur content is the theoretical amount of metallic sodium required to convert the total sulfur content in the residual feedstock to sodium sulfide, and the converted feedstock comprises a hydrocarbon oil having a sulfur content less than that in the residual feedstock, a lesser asphaltene content than that in the residual feedstock, or both.

[0012] In certain embodiments, the method further comprises pretreating the hydrocarbon feedstock to provide a refined feedstock and a residual feedstock, wherein the refined feedstock contains a lower concentration of impurities than the hydrocarbon feedstock before pretreatment, and the residual feedstock contains a higher concentration of impurities than the refined feedstock.

[0013] In a fourth aspect, the present technology provides a method comprising: pretreating an impurity-containing hydrocarbon feedstock to provide a refined feedstock and a residual feedstock, wherein the refined feedstock contains a lower concentration of impurities than the hydrocarbon feedstock before pretreatment, and the residual feedstock contains a higher concentration of impurities than in the refined feedstock; and contacting the residual feedstock with an effective amount of metallic sodium and an effective amount of an exogenous capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock, wherein the residual feedstock contains hydrocarbons having a sulfur content of at least 0.5 wt% and an asphaltene content of at least 1 wt%, and the converted feedstock comprises a converted hydrocarbon oil having a lower sulfur content than in the residual feedstock, a lower asphaltene content than in the residual feedstock, or both, and at least a portion of the converted hydrocarbon oil is derived from the asphaltenes in the residual feedstock.

[0014] In any embodiment, the pretreatment step may include phase separation by an externally applied field, separation by the addition of heat, hydroconversion, thermal conversion, catalytic conversion, catalytic treatment, solvent extraction, solvent deasphalting, or a combination of any two or more thereof. In any embodiment, the pretreatment step may include contacting the hydrocarbon feedstock with exogenous hydrogen and / or a catalyst to remove one or more of sulfur, nitrogen, oxygen, metals, and asphaltenes.

[0015] In any embodiment of the method, the hydrocarbon feedstock may be or may be derived from virgin crude oil or the product of a thermal cracking process. Accordingly, the hydrocarbon feedstock may be selected from the group consisting of conventional crude oil, petroleum, heavy oil, bitumen, shale oil, and oil shale.

[0016] In any embodiment of the method, the sulfur content of the hydrocarbon feedstock or residual feedstock may be at least 0.5 wt%, at least 1 wt%, or in the range of 0.5 wt% to 15 wt%. In any embodiment of the method, the asphaltene content may be in the range of 1 wt% to 100 wt%. For example, the asphaltene content may be in the range of 2 wt% to 40 wt%.

[0017] In any embodiment of the method, the residual feedstock may comprise one or more of a refinery midstream, a hydrocracking residue, a hydrotreating residue, an FCC slurry, a residual FCC slurry, an atmospheric or vacuum residue, a solvent deasphalted tar, a deasphalted oil, a visbreaker tar, a high sulfur fuel oil, a low sulfur fuel oil, an asphaltenes, an asphalt, a steam cracking tar, an LC-Fining® residue, or an H-Oil® residue. In any embodiment of the method, the hydrocarbon feedstock or residual feedstock may have a viscosity of 1 to 10,000,000 cSt at 50°C and a viscosity of 800 to 1200 kg / m at 15.6°C. 3 For example, the hydrocarbon feedstock or residue feedstock may have a viscosity of 400 to 9,000,000 cSt at 50° C. Alternatively, the residue feedstock may be a solid at room temperature.

[0018] In any embodiment of the process, the residual feedstock may have a higher concentration of impurities than the hydrocarbon feedstock. In any embodiment, the sulfur content may include asphaltene sulfur and non-asphaltene sulfur, and the ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock may be lower than in the residual feedstock.

[0019] In any embodiment of the method, the viscosity of the converted feedstock may be reduced by at least 50 cSt at 50° C., or by at least 40%, and the density of the converted feedstock may be reduced by about 5 to about 25 kg / m per wt % reduction in the sulfur content of the converted feedstock compared to the hydrocarbon feedstock or the residual feedstock. 3 In any embodiment, the iron and vanadium content of the converted feedstock may be reduced by at least 40% compared to the hydrocarbon feedstock or residual feedstock. In any embodiment, the nickel content of the converted feedstock may be reduced by at least 40% compared to the hydrocarbon feedstock or residual feedstock.

[0020] In any embodiment of the present process, at least 40% of the asphaltene content in the residual feedstock may be converted to liquid hydrocarbon oils in the converted feedstock. In any embodiment, the asphaltene content may be at least partially converted to paraffins.

[0021] In any embodiment of the method, the exogenous capping agent may be hydrogen, hydrogen sulfide, natural gas, methane, ethane, propane, butane, pentane, ethene, propene, butene, pentene, diene, isomers thereof, or a mixture of any two or more thereof. In any embodiment, the residual feedstock may be combined with sodium metal at a pressure of about 500 psig to about 3000 psig. In any embodiment, the reaction of the residual feedstock with sodium metal may be carried out for a time period of 1 minute to 120 minutes.

[0022] In any embodiment of the method, the sodium salt may include one or more of sodium sulfide, sodium hydride, or sodium polysulfide.

[0023] In any embodiment of the method, the method may further include separating the sodium salts from the converted feedstock. The separating step may include (a) heating a mixture of the sodium salts and the converted feedstock with elemental sulfur at a temperature of about 150° C. to 500° C. to provide a sulfur-treated mixture comprising the agglomerated sodium salts, and (b) separating the agglomerated sodium salts from the sulfur-treated mixture to provide desulfurized liquid hydrocarbons and the separated sodium salts.

[0024] In any embodiment, the method may include electrolyzing the separated sodium salt to provide metallic sodium. In any embodiment, the electrolysis is carried out in an electrochemical cell comprising an anolyte compartment, a catholyte compartment, and a NaSICON membrane separating the anolyte compartment from the catholyte compartment, wherein a cathode comprising metallic sodium disposed in the catholyte within the catholyte compartment, an anode comprising a sodium salt disposed in the anolyte within the anolyte compartment, and a power source electrically connected to the anode and the cathode.

[0025] The summary of the present disclosure has been set forth above and contains, by necessity, simplifications, generalizations, and omissions of detail. Accordingly, those skilled in the art will appreciate that this summary is illustrative only and is not intended to be limiting in any way. Other aspects, features, and advantages of the methods described herein, as defined by the claims, will become apparent in the detailed description set forth herein and taken in conjunction with the accompanying drawings. [The present invention 1001] The following steps: 1. A process for pretreating an impure hydrocarbon feedstock to provide a refined feedstock and a residual feedstock, comprising: the refined feedstock contains a lower concentration of impurities than the hydrocarbon feedstock before pretreatment; the pre-treating step, wherein the residual feedstock contains a higher concentration of impurities than the purified feedstock; contacting the residual feedstock with an effective amount of metallic sodium and an effective amount of an extrinsic capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock; the residual feedstock comprises hydrocarbons having a sulfur content of at least 0.5 wt.% and an asphaltene content of at least 1 wt.%, the sulfur content includes asphaltene sulfur and non-asphaltene sulfur; the converted feedstock comprises a hydrocarbon oil having a sulfur content less than that in the residual feedstock and an asphaltene content less than that in the residual feedstock; and the weight ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than in the residual feedstock; A method comprising: [The present invention 1002] The following steps: contacting a hydrocarbon feedstock with an effective amount of metallic sodium and an effective amount of an extrinsic capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock; the hydrocarbon feedstock comprises hydrocarbons having a sulfur content of at least 0.5 wt.% and an asphaltene content of at least 1 wt.%, the sulfur content includes asphaltene sulfur and non-asphaltene sulfur; the converted feedstock comprises a hydrocarbon oil having a sulfur content less than that in the hydrocarbon feedstock and an asphaltene content less than that in the hydrocarbon feedstock; and the ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than in the hydrocarbon feedstock; A method comprising: [The present invention 1003] The following steps: a residual feedstock comprising hydrocarbons having a sulfur content of at least 0.5 wt. % and an asphaltene content of at least 1 wt. % to produce a mixture of sodium salts and a converted feedstock; a substoichiometric amount of metallic sodium relative to the sulfur content of the residual feedstock; and an effective amount of an exogenous capping agent and contacting the mixture at a temperature of 250 to 500°C, the stoichiometric amount of sodium metal relative to sulfur content is the theoretical amount of sodium metal required to convert the total sulfur content in the residual feedstock to sodium sulfide; the contacting step, wherein the converted feedstock comprises a hydrocarbon oil having a sulfur content less than that in the residual feedstock and an asphaltene content less than that in the residual feedstock. A method comprising: [The present invention 1004] The following steps: 1. A process for pretreating an impure hydrocarbon feedstock to provide a refined feedstock and a residual feedstock, comprising: the refined feedstock contains a lower concentration of impurities than the hydrocarbon feedstock before pretreatment; and the pre-treating step, wherein the residual feedstock contains a higher concentration of impurities than in the purified feedstock; contacting the residual feedstock with an effective amount of metallic sodium and an effective amount of an extrinsic capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock; the residual feedstock comprises hydrocarbons having a sulfur content of at least 0.5 wt.% and an asphaltene content of at least 1 wt.%, the converted feedstock comprises a converted hydrocarbon oil having a sulfur content less than that in the residual feedstock and an asphaltene content less than that in the residual feedstock; and wherein at least a portion of the converted hydrocarbon oil is derived from asphaltenes in the residual feedstock; A method comprising: [The present invention 1005] The following steps: Pretreating a hydrocarbon feedstock to provide a refined feedstock and said residual feedstock, comprising: the refined feedstock contains a lower concentration of impurities than the hydrocarbon feedstock before pretreatment; and the pre-treating step, wherein the residual feedstock contains a higher concentration of impurities than the purified feedstock. The method of the present invention 1003 further comprising: [The present invention 1006] The process of any of claims 1001, 1004 or 1005, wherein the pretreatment step comprises phase separation by an externally applied field, separation by the addition of heat, hydroconversion, thermal conversion, catalytic conversion, catalytic treatment, solvent extraction, solvent deasphalting, or a combination of any two or more thereof. [The present invention 1007] The method of any of claims 1001 to 1006, wherein the pretreatment step comprises contacting the hydrocarbon feedstock with exogenous hydrogen and / or a catalyst to remove one or more of sulfur, nitrogen, oxygen, metals, and asphaltenes. [The present invention 1008] The process of any one of claims 1001 to 1007, wherein said hydrocarbon feedstock is or is derived from virgin crude oil or the product of a thermal cracking process. [The present invention 1009] The method of any of claims 1001 to 1008, wherein said hydrocarbon feedstock is selected from the group consisting of petroleum, heavy oil, bitumen, conventional crude oil, shale oil, and oil shale. [The present invention 1010] The method of any one of claims 1001 to 1009, wherein the sulfur content is in the range of 0.5 wt% to 15 wt%. [The present invention 1011] The method of any one of claims 1001 to 1010, wherein the asphaltene content is in the range of 1 wt% to 100 wt%. [The present invention 1012] 1011. The method of claim 10, wherein the asphaltene content is in the range of 2 wt% to 40 wt%. [The present invention 1013] 3. The process of any of claims 1001 or 1003-1012, wherein the residual feedstock comprises one or more of a refinery midstream, a hydrocracking residue, a hydrotreating residue, an FCC slurry, a residual FCC slurry, an atmospheric or vacuum residue, a solvent deasphalted tar, a deasphalted oil, a visbreaker tar, a high sulfur fuel oil, a low sulfur fuel oil, an asphaltenes, an asphalt, a steam cracking tar, an LC-Fining® residue, or an H-Oil® residue. [The present invention 1014] The hydrocarbon feedstock or the residual feedstock has a viscosity of 1 to 10,000,000 cSt at 50°C and a viscosity of 800 to 1200 kg / m at 15.6°C 3 The method of any one of claims 1001 to 1013, wherein the density is [The present invention 1015] The process of claim 1014, wherein the hydrocarbon feedstock or the residual feedstock has a viscosity of 400 to 9,000,000 cSt at 50°C. [The present invention 1016] The process of any one of claims 1001 or 1003 to 1015, wherein the residual feedstock is a solid at room temperature. [The present invention 1017] The process of any one of claims 1001 or 1003 through 1016, wherein the residual feedstock has a higher concentration of impurities than the hydrocarbon feedstock. [The present invention 1018] The process of claim 1003 or claim 1005, wherein the sulfur content comprises asphaltene sulfur and non-asphaltene sulfur, and wherein the ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than in the residual feedstock. [The present invention 1019] The viscosity of the converted feedstock is reduced by at least 50 cSt at 50°C, or by at least 40%, and the density of the converted feedstock is reduced by about 5 to about 25 kg / m per wt% reduction in sulfur content of the converted feedstock compared to the hydrocarbon feedstock or residual feedstock. 3 Any of the methods of 1001 to 1018 of the present invention, wherein the amount of the ion exchange resin is reduced. [The present invention 1020] The process of any of claims 1001 to 1019, wherein the iron and vanadium content of said converted feedstock is reduced by at least 40% compared to said hydrocarbon feedstock or residual feedstock. [The present invention 1021] The process of any of claims 1001 to 1020, wherein the nickel content of said converted feedstock is reduced by at least 40% compared to said hydrocarbon feedstock or residual feedstock. [The present invention 1022] 1022. The process of any of claims 1004 or 1006 through 1021, wherein at least 40% of the asphaltene content in said residual feedstock is converted to liquid hydrocarbon oil in said converted feedstock. [The present invention 1023] The method of any of claims 1004 or 1006-1022, wherein the asphaltene content is at least partially converted to paraffins. [The present invention 1024] Any of the aforementioned methods of the invention, wherein the extrinsic capping agent is hydrogen, hydrogen sulfide, natural gas, methane, ethane, propane, butane, pentane, ethene, propene, butene, pentene, diene, an isomer thereof, or a mixture of any two or more thereof. [The present invention 1025] Any of the aforementioned processes of the invention, wherein the residual feedstock is combined with sodium metal at a pressure of from about 500 psig to about 3000 psig. [The present invention 1026] Any of the aforementioned processes of the invention, wherein the reaction of the residual feedstock with metallic sodium occurs for a period of from 1 minute to 120 minutes. [The present invention 1027] Any of the aforementioned processes of the present invention further comprising the step of separating said sodium salt from said converted feedstock. [The present invention 1028] The separating step comprises: a. heating said mixture of sodium salt and converted feedstock with elemental sulfur to a temperature of about 150°C to 500°C to provide a sulfur-treated mixture containing agglomerated sodium salt; b. separating the agglomerated sodium salt from the sulfur-treated mixture to provide desulfurized liquid hydrocarbons and separated sodium salt; The method of the present invention 1027, comprising: [The present invention 1029] 1028. The process of claim 1028, further comprising the step of electrolyzing the separated sodium salt to provide metallic sodium. [The present invention 1030] Any of the aforementioned methods of the invention, wherein the sodium salt comprises one or more of sodium sulfide, sodium hydrosulfide, or sodium polysulfide. [The present invention 1031] The method of claim 1029 or claim 1030, wherein the electrolyzing step is carried out in an electrochemical cell comprising an anolyte compartment, a catholyte compartment, and a NaSICON membrane separating the anolyte compartment from the catholyte compartment, wherein a cathode comprising metallic sodium is disposed in the catholyte within the catholyte compartment, and wherein an anode comprising the sodium salt is disposed in the anolyte within the anolyte compartment, and wherein a power source is electrically connected to the anode and the cathode. [Brief explanation of the drawings]

[0026] So that the manner in which the above-mentioned and other features and advantages of the present technology are obtained can be readily understood, a more particular description of the above-briefly described technology will be rendered by reference to specific embodiments thereof which are illustrated in the accompanying drawings, with the understanding that these drawings depict only typical embodiments of the technology and therefore should not be considered limiting of its scope, the present technology will be described and explained with additional specificity and detail through the use of the accompanying drawings.

[0027] [Figure 1] 1 is a flow diagram according to an exemplary embodiment of the method of the present technology. [Figure 2] FIG. 1 is a flow diagram according to an exemplary embodiment of a method of the present technology that includes at least one pre-processing step. [Figure 3]FIG. 1 is a flow diagram according to an exemplary embodiment of a method of the present technology that includes at least two pre-processing steps. DETAILED DESCRIPTION OF THE INVENTION

[0028] Detailed description of the technology The following terms are used throughout as defined below.

[0029] As used herein, in the context of describing elements (particularly in the context of the claims below), singular articles and similar reference words such as "a," "an," and "the" shall be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The recitation of ranges of values ​​herein is merely intended to serve as a shorthand method for individually referencing each individual value falling within the range, unless otherwise indicated herein, and each individual value is incorporated herein as if set forth individually herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context. The use of any and all examples or exemplary language (e.g., "etc.") provided herein is intended merely to better illuminate embodiments and does not limit the scope of the claims unless specifically stated otherwise. No language in the specification should be construed as requiring any non-claimed element.

[0030] As used herein, "about" will be understood by those of ordinary skill in the art and will vary to some extent depending on the context in which it is used. If there is a usage that is not clear to a person of ordinary skill in the art from the context in which the term is used, "about" will mean up to plus or minus 10% of the term in question.

[0031] As used herein, "asphaltenes" refer to components of oil that are insoluble in n-pentane. Asphaltenes may include polycyclic molecules containing one or more heteroatoms selected from S, N, and 0. The sulfur species contained in asphaltenes are collectively referred to herein as "asphaltene sulfur." ​​The non-asphaltene fractions of hydrocarbon oils and all other sulfur contained in those fractions are collectively referred to herein as "non-asphaltene sulfur." ​​The latter includes, for example, thiols, sulfates, thiophenes, including benzothiophenes, hydrogen sulfide, and other sulfides. The sulfur content in feedstocks, including, but not limited to, refined feedstocks, residual feedstocks, and converted feedstocks, includes asphaltene sulfur and non-asphaltene sulfur.

[0032] As used herein, "hydrocarbon feedstock" refers to any material that can be an input to a hydrocarbon-based refining, conversion, or other industrial process. Hydrocarbon feedstocks may be solid or liquid at room temperature and may contain non-hydrocarbon components such as heteroatom-containing (e.g., S, N, O, P, metal) organic and inorganic materials. Crude oil, refinery streams, chemical plant streams (e.g., steam cracking tar), and recycling plant streams (e.g., lubricating oils and pyrolysis oils from tires or municipal solid waste) are non-limiting examples of hydrocarbon feedstocks.

[0033] The present technology provides an upgrading process for hydrocarbon feedstocks, including residual feedstocks, to produce converted feedstocks with reduced impurity concentrations. Surprisingly, the present method has been found to preferentially reduce the asphaltene sulfur content of the starting feedstock relative to the non-asphaltene sulfur content. This is the opposite of commercial upgrading and desulfurization processes, allowing for much more efficient use of asphaltene-containing feedstocks. Thus, in a first aspect, the method includes contacting a hydrocarbon feedstock with an effective amount of metallic sodium and an effective amount of an exogenous capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock. The hydrocarbon feedstock of the present method includes hydrocarbons having a sulfur content of at least 0.5 wt% (as used herein, "wt%" means "weight percent") and an asphaltene content of at least 1 wt%. The sulfur content includes asphaltene sulfur and non-asphaltene sulfur. The converted feedstock includes a hydrocarbon oil having a sulfur content less than that in the hydrocarbon feedstock. In an optional embodiment, the converted feedstock further includes an asphaltene content less than that in the hydrocarbon feedstock. Furthermore, the ratio of asphaltene to non-asphaltene sulfur in the conversion feedstock is lower than that in the hydrocarbon feedstock.

[0034] In a second aspect, the present technology provides a method comprising pretreating an impurity-containing hydrocarbon feedstock to provide a refined feedstock and a residual feedstock. The refined feedstock contains a lower concentration of impurities than the hydrocarbon feedstock before pretreatment, and the residual feedstock contains a higher concentration of impurities than the refined feedstock. The method further comprises contacting the residual feedstock with an effective amount of metallic sodium and an effective amount of an exogenous capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock. The residual feedstock comprises hydrocarbons having a sulfur content of at least 0.5 wt% and an asphaltene content of at least 1 wt%. The sulfur content includes asphaltene sulfur and non-asphaltene sulfur. The converted feedstock comprises a hydrocarbon oil having a sulfur content less than that in the residual feedstock. In an optional embodiment, the converted feedstock further comprises a lower asphaltene content than that in the hydrocarbon feedstock. Furthermore, the weight ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than that in the residual feedstock.

[0035] In a third aspect, the present technology provides a method comprising pretreating an impurity-containing hydrocarbon feedstock to provide a refined feedstock and a residual feedstock, the refined feedstock having a lower concentration of impurities than the hydrocarbon feedstock prior to pretreatment, and the residual feedstock having a higher concentration of impurities than the refined feedstock. The method further comprises contacting the residual feedstock with an effective amount of metallic sodium and an effective amount of an exogenous capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock. In this aspect, the residual feedstock comprises a hydrocarbon oil having a sulfur content of at least 0.5 wt% and an asphaltene content of at least 1 wt%. The converted feedstock comprises a converted hydrocarbon oil having a sulfur content lower than that in the residual feedstock. In the converted feedstock, at least a portion of the converted hydrocarbon oil is derived from asphaltenes in the residual feedstock, and in some embodiments, the asphaltene content of the converted feedstock is lower than that in the residual feedstock. In other words, in this method, at least a portion of the asphaltenes in the residual feedstock are converted to a hydrocarbon oil. On the other hand, most, if not all, other commercial processes used to reduce asphaltene content only remove asphaltenes from the feed in forms that have little or no value (e.g., asphaltenes from coke or solvent deasphaltening asphaltene processes) and that can be very costly to dispose of or convert into usable products.

[0036] In a fourth aspect, the present technology provides a method for producing a mixture of sodium salts and a converted feedstock, the method comprising contacting a residual feedstock containing hydrocarbons having a sulfur content of at least 0.5 wt.% and an asphaltene content of at least 1 wt.%, with metallic sodium in a less-than-stoichiometric amount relative to the sulfur content of the residual feedstock, and an effective amount of an exogenous capping agent at a temperature of 250 to 500°C. The converted feedstock comprises a hydrocarbon oil having a sulfur content less than that in the residual feedstock. In an optional embodiment, the converted feedstock may contain a less-than-stoichiometric amount of metallic sodium relative to the sulfur content. In this method, less metallic sodium is required to convert all of the sulfur content in the residual feedstock to sodium sulfide (i.e., NaS) than is theoretically required.

[0037] In any embodiment of the method of the fourth aspect, the method may further comprise pretreating the hydrocarbon feedstock to provide a refined feedstock and a residual feedstock, the refined feedstock having a lower concentration of impurities than the hydrocarbon feedstock before pretreatment, and the residual feedstock having a higher concentration of impurities than the refined feedstock. In any embodiment, the sulfur content comprises asphaltene sulfur and non-asphaltene sulfur, and the ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than in the residual feedstock.

[0038] In any embodiment of the present method including a pretreating step (including, but not limited to, the method of the second, third, or fourth aspect), the pretreating step may include phase separation by an externally applied field, separation by the addition of heat, hydroconversion, thermal conversion, catalytic conversion or treatment, solvent extraction, solvent deasphaltening, or a combination of any two or more thereof. In any embodiment, the pretreating step may include contacting the hydrocarbon feedstock with exogenous hydrogen and / or a catalyst to remove one or more of sulfur, nitrogen, oxygen, metals, and asphaltenes. Examples of pretreatment steps that produce refined and residual feedstocks include atmospheric distillation, vacuum distillation, steam cracking, catalytic cracking, thermal cracking, fluid catalytic cracking (FCC), solvent deasphaltening, hydrodesulfurization, visbreaking, pyrolysis, catalytic reforming, and alkylation. It will be understood that certain of the aforementioned processes, such as atmospheric distillation and vacuum distillation, directly produce refined and residual feedstocks, while others require a subsequent separation step. For example, steam cracking, catalytic cracking, thermal cracking, FCC, pyrolysis, yield a mixture of products that is then separated into purified and residual feedstocks by distillation or other separation processes.

[0039] The hydrocarbon feedstock of the present process may be or be derived from virgin crude oil (e.g., petroleum, heavy oil, bitumen, shale oil, and oil shale). The hydrocarbon feedstock may also be a distillation fraction of virgin crude oil or a product from a thermal cracking process.

[0040] Residual feedstocks may be produced from hydrocarbon feedstocks by various pretreatment processes of the present technology and / or may be employed in various processes of the present technology to provide converted feedstocks. Thus, residual feedstocks may include distillation products of hydrocarbon feedstocks (atmospheric or vacuum residues, gasoline, diesel, kerosene, and gas oil), as well as refinery intermediate streams. Refinery intermediate streams may be converted feedstocks (e.g., solvent deasphalted tar, steam cracked tar, FCC slurry, visbreaker tar, hydrocracking, hydrocracking, or hydroconversion bottoms, coke, and asphalt) or processed feedstocks (e.g., hydrotreated oil and bunker oil). In any embodiment, the residual feedstock includes hydroprocessing products, hydrocracking residues, hydroconversion residues (e.g., LC Finer® (Chevron Global Lummus) residues, or H-oil® (Axens) residues), FCC slurry, residual FCC slurry, atmospheric or vacuum residues, solvent deasphalted tar, deasphalted oil, steam cracked tar, visbreaker tar, high sulfur fuel oil, low sulfur fuel oil, asphalt, and coke. The foregoing hydrocarbon and residual feedstocks may be derived from any geological formation (oil sands, conventional or tight reservoirs, shale oil, oil shale) or geographic location (North America, South America, Middle East, etc.).

[0041] In the process of the present technology, the hydrocarbon feedstock comprises hydrocarbons (e.g., hydrocarbon oils) and impurities. Similarly, the residual feedstock comprises hydrocarbons and impurities. In some embodiments, the residual feedstock has a higher concentration of impurities than the hydrocarbon feedstock. As used herein, "impurities" refers to heteroatoms (i.e., atoms other than carbon and hydrogen), such as sulfur, oxygen, nitrogen, phosphorus, and metals. Impurities may be contained in or include substances such as naphthenic acids, water, ammonia, hydrogen sulfide, thiols, thiophenes, benzothiophenes, porphyrins, Fe, V, and Ni. In any embodiment of the process, the hydrocarbon feedstock or residual feedstock comprises hydrocarbons having a sulfur content of at least 0.5 wt% and an asphaltene content of at least 1 wt%. The sulfur content, which includes asphaltene and non-asphaltene sulfur, is measured as the wt% of sulfur atoms in the feedstock. In any embodiment, the sulfur content may be in the range of 0.5 wt% to 15 wt%, inclusive, for example, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 wt%, or a range between and including any two of the foregoing values. Thus, the sulfur content may range from 1 wt% to 15 wt%, 0.5 wt% to 8 wt%, or 1.5 wt% to 10 wt% in any embodiment.

[0042] In the methods of the present technology, the asphaltene content is the total amount of asphaltene in the feedstock, measured as the n-pentane insoluble fraction in the feedstock. However, in some aspects and embodiments of the present methods, the asphaltene content is determined by measuring the total amount of asphaltene in the feedstock as the n-pentane insoluble fraction in the feedstock. 3-8 It may be measured as the insoluble fraction of a hydrocarbon feedstock or residual feedstock that has been precipitated or otherwise separated from the feedstock after mixing with an alkane. 3-8The alkane may be propane, butane, pentane, hexane, heptane, octane, an isomer thereof, or a mixture of any two or more thereof. Thus, in some embodiments, the asphaltene content of the feed can be defined as the components insoluble in heptane. By "sufficient amount," we mean an amount in which no further precipitation / separation of the insoluble fraction is observed from the hydrocarbon feedstock or residual feedstock. Details of the physical properties and structure of asphaltenes and the process conditions (temperature, pressure, solvent / oil ratio) required to produce specific asphaltenes are described in J.S. Speith, "Petroleum Asphaltenes Part 1: Asphaltenes, Resins and the Structure of Petroleum," Oil & Gas Science and Technology - Rev IFP, Vol. 59 (2004) pp. 467-477 (incorporated herein by reference in its entirety and for all purposes). The standard test method for determining heptane (C7) insoluble asphaltene content is described in ASTM standard D6560-17 and can be extended to any alkane, including pentane.

[0043] In any embodiment of the method, the asphaltene content of the hydrocarbon feedstock or residual feedstock can be at least 1 wt%, at least 2 wt%, at least 3 wt%, at least 4 wt%, or at least 5 wt%. For example, the asphaltene content can be in the range of 1 wt% to 100 wt%, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 70, 80, 90, 95, or 100 wt%, or a range between and including any two of the foregoing values. Thus, in any embodiment, the asphaltene content may range from 2 wt% to 100 wt%, 1 wt% to 30 wt%, 2 wt% to 30 wt%, 5 wt% to 100 wt%, 10 wt% to 100 wt%, or 20 wt% to 100 wt%.

[0044] In any embodiment of the present process, if the elevated asphaltene content in the hydrocarbon feedstock results in a viscosity that is too high for the sodium treatment process, it may be necessary to dilute the hydrocarbon feedstock with a diluent. Because asphaltenes are aromatic, the diluent typically contains an aromatic compound. This diluent may be a single compound (e.g., benzene, toluene, xylene, ethylbenzene, cumene, naphthalene, 1-methylnaphthalene), a mixture of any two or more thereof, or an aromatic refinery intermediate (e.g., light cycle oil, reformate). The amount of diluent required will vary depending on the asphaltene content of the feedstock and the viscosity required for the process. Feedstocks with high asphaltene content may require more diluent than feedstocks with low asphaltene content. It is within the skill of one of ordinary skill in the art to select the appropriate amount of diluent to enable asphaltenes to be processed in the present process.

[0045] The method may also reduce / eliminate naphthenic acid content and / or metal content in the converted feedstock relative to the hydrocarbon and residual feedstocks. In some embodiments, the hydrocarbon feedstock or residual feedstock contains (collectively or individually) about 1 to about 10,000 ppm metal. The metal may be a naturally occurring metal bound to the hydrocarbon structure or may be residual metal debris (e.g., corrosion products or catalyst debris) entrained in the residual feedstock during an upstream process. In some embodiments, the metal is selected from the group consisting of alkali metals, alkaline earth metals, transition metals, post-transition metals, and metalloids having an atomic weight equal to or less than 82. In some embodiments, the metal is selected from the group consisting of vanadium, nickel, iron, arsenic, lead, cadmium, copper, zinc, chromium, molybdenum, silicon, calcium, potassium, aluminum, magnesium, manganese, titanium, mercury, and combinations of any two or more thereof. In some embodiments, the metal is selected from the group consisting of vanadium, nickel, iron, and combinations of any two or more thereof. In any embodiment, the metal concentration of the hydrocarbon feedstock or residual feedstock may be (collectively or individually) from about 2 to about 10,000 ppm, from about 10 to about 10,000 ppm, from about 100 to about 10,000 ppm, from about 100 to about 5,000 ppm, from about 10 to about 1,000 ppm, from about 100 to about 1,000 ppm, etc.

[0046] The method of the present technology not only upgrades the employed hydrocarbon or residual feedstock by removing / reducing impurities, but also improves physical properties such as viscosity and density. The hydrocarbon or residual feedstock may have a viscosity of 1 to 10,000,000 cSt at 50°C. For example, the viscosity may be 1, 10, 25, 50, 100, 200, 300, 400, 500, 1,000, 2,000, 5,000, 10,000, 25,000, 50,000, 100,000, 500,000, 1,000,000, 2,000,000, 3,000,000, 4,000,000, 5,000,000, 6,000,000, 7,000,000, 8,000,000, or 9,000,000 cSt, or a range between and including any two of the foregoing values. Thus, in any embodiment, the viscosity of the hydrocarbon feedstock or residue feedstock may be, for example, 100 to 10,000,000 cSt, 380 to 9,000,000 cSt, 500 to 9,000,000 cSt, or 500 to 5,000,000 cSt.

[0047] Hydrocarbon or residual feedstocks are 800-1200 kg / m at 15.6°C or 60°F. 3 For example, the density may be 800, 825, 850, 875, 900, 925, 975, 1000, 1050, 1100, 1150, or 1200 kg / m 3 or may be a range between and including any two of the foregoing values. Thus, in any embodiment, the density may be, for example, 850 to 1200 kg / m 3 , 900~1200kg / m 3 , 950~1200kg / m 3 , or 925 to 1100 kg / m 3 It may be.

[0048] In the method of the present technology, a hydrocarbon feedstock or residual feedstock is contacted with an effective amount of metallic sodium and an effective amount of an exogenous capping agent. Any suitable source of metallic sodium can be used, including, but not limited to, electrochemically produced metallic sodium, as described in U.S. Patent No. 8,088,270, the entire contents of which are incorporated herein by reference.

[0049] The exogenous capping agent used in the present process is typically used to cap radicals formed when sulfur and other heteroatoms are abstracted by metallic sodium during the contacting step. While some feedstocks may contain small amounts of naturally occurring capping agents ("endogenous capping agents"), such amounts are insufficient to cap substantially all of the free radicals generated by the present process. An effective amount of exogenous (i.e., added) capping agent is used in the present process; for example, 1 to 1.5 moles of capping agent (e.g., hydrogen) may be used per mole of sulfur, nitrogen, or oxygen present. Based on the disclosure herein, it is within the skill of one of ordinary skill in the art to determine the effective amount of exogenous capping agent required to carry out the present process for a particular hydrocarbon or residual feedstock used. The exogenous capping agent may include hydrogen, hydrogen sulfide, natural gas, methane, ethane, propane, butane, pentane, ethene, propene, butene, pentene, dienes, isomers thereof, or mixtures of any two or more thereof. In any embodiment, the extrinsic capping agent is hydrogen and / or C 1-6 Acyclic alkanes and / or C 2-6 It may also be an acyclic alkene, or a mixture of any two or more thereof.

[0050] The effective amount of sodium used in the contacting step in the metallic state will vary depending on the levels of heteroatom, metal, and asphaltene impurities in the hydrocarbon and residual feedstocks, the desired degree of impurity conversion or removal, the temperature used, and other conditions. In any embodiment, a stoichiometric or greater than stoichiometric amount of metallic sodium may be used to remove all or nearly all of the sulfur content, e.g., 1 to 3 molar equivalents of metallic sodium to sulfur. In any embodiment, the hydrocarbon or residual feedstock is contacted with 1 or more molar equivalents of metallic sodium relative to the sulfur content therein, e.g., 1.1, 1.15, 1.2, 1.25, 1.3, 1.4, 1.5, 2, 2.5, or 3 molar equivalents of metallic sodium.

[0051] Surprisingly, a substoichiometric ratio of metallic sodium to sulfur content (in the hydrocarbon / residual feedstock) can be used to preferentially reduce the amount of asphaltene sulfur relative to non-asphaltene sulfur. Thus, in any embodiment, the residual feedstock (or alternatively, the hydrocarbon feedstock) can be contacted with a less-than-stoichiometric amount of metallic sodium relative to the sulfur content therein. It will be understood that, in the present technology, the stoichiometric amount of metallic sodium relative to the sulfur content is the theoretical amount of metallic sodium required to convert all of the sulfur content in the residual (or hydrocarbon) feedstock to sodium sulfide. For example, one skilled in the art will understand that the stoichiometric amount of metallic sodium required to convert all of the sulfur in a feedstock containing about 1 mole of sulfur atom to sodium sulfide is 2 moles of metallic sodium. A less-than-stoichiometric amount of metallic sodium relative to the sulfur content in such an example would be less than 2 moles, e.g., 1.6 moles, of metallic sodium, or 0.8 molar equivalents of metallic sodium. In any embodiment, the less-than-stoichiometric amount of metallic sodium relative to the sulfur content can be between 0.1 equivalents and less than 1 equivalent. Examples of such sub-stoichiometric amounts include less than 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1 equivalent of metallic sodium relative to the sulfur content, or ranges between and including any two of the foregoing values. Thus, in any embodiment, the sub-stoichiometric amount may range from 0.1 to 0.9 equivalents, 0.2 to 0.8 equivalents, 0.4 to 0.8 equivalents, etc.

[0052] The contacting step may be carried out at a temperature of about 250°C to about 500°C, so that the metallic sodium is in a molten (i.e., liquid) state. For example, the contacting step may be carried out at about 250°C, about 275°C, about 300°C, about 325°C, about 350°C, about 375°C, about 400°C, about 425°C, about 450°C, about 500°C, or a range between and including any two of the foregoing temperatures. Thus, in any embodiment, the contacting step may be carried out at about 275°C to about 425°C, or about 300°C to about 400°C (e.g., at about 350°C).

[0053] In any embodiment, the contacting step may be carried out at a pressure of about 400 to about 3000 psi, e.g., about 400 psi, about 500 psi, about 600 psi, about 750 psi, about 1000 psi, about 1250 psi, about 1500 psi, about 2000 psi, about 2500 psi, about 3000 psi, or a range between and including any two of the foregoing values.

[0054] The reaction between sodium metal and heteroatom contaminants in the hydrocarbon / resid feedstock is relatively fast, completing within minutes, if not seconds. Combining the feedstock with sodium metal further accelerates the reaction and is often used for this reaction on an industrial scale. However, in certain embodiments, extended residence times may be required to improve the degree of conversion, or operating conditions may be adjusted to target the removal of specific heteroatom impurities. Thus, in any embodiment, the contacting step is carried out for a time period ranging from about 1 minute to about 120 minutes, e.g., about 1, about 5, about 7, about 9, about 10, about 15 minutes, about 30, about 45, about 60, about 75, about 90, about 105, or about 120 minutes, or any range between and including any two of the foregoing values. Thus, in any embodiment, the time period may range from about 1 minute to about 60 minutes, from about 5 minutes to about 60 minutes, from about 1 minute to about 15 minutes, from about 60 minutes to about 120 minutes, etc.

[0055] The method produces a converted feedstock containing hydrocarbon oil that is less than the sulfur content in the hydrocarbon feedstock (or residual feedstock). In any embodiment, the sulfur content of the converted feedstock can be less than 0.5 wt%, e.g., less than or about 0.4 wt%, less than or about 0.4 wt%, less than or about 0.3 wt%, less than 0.2 wt%, less than or about 0.2 wt%, less than 0.1 wt%, or even less than or about 0.05 wt%, or a range between and including any two of the foregoing values. In any embodiment where sulfur is particularly difficult to remove or where less than stoichiometric amounts of sodium are used (see below), the sulfur content of the converted feedstock may be less than 2 wt%, less than 1.8 wt%, less than 1.6 wt%, less than 1.4 wt%, less than 1.2 wt%, less than 1 wt%, less than 0.8 wt%, less than 0.6 wt%, or a range between and including any two of the foregoing values. In some embodiments, the sulfur content of the converted feedstock is less than 1 wt%. The efficiency of removal of sulfur content from the hydrocarbon or residual feedstock relative to the converted feedstock (also known as conversion efficiency) can be at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% by weight, or a range between and including any two of the foregoing values, e.g., 40% to 99%, or 40% to 95%. When the effective amount of metallic sodium is greater than the stoichiometric amount, the efficiency of conversion of sulfur content can be very high, e.g., at least 90%.

[0056] When substoichiometric amounts of metallic sodium are used in the present methods (including, but not limited to, the methods of the first, second, third, and fourth embodiments), low conversion efficiencies are observed, but the sulfur content from asphaltene sulfur is preferentially reduced relative to that from non-asphaltene sulfur. For example, the (total) sulfur content conversion efficiency may be in the range of about 10% to about 80%, including about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, or between and including any two of the foregoing values. At the same time, the conversion efficiency of the corresponding sulfur content of asphaltene sulfur is higher at each point than the conversion efficiency of the total sulfur content. For example, the conversion efficiency of the sulfur content of asphaltene sulfur for any given feed may be in the range of 1% to 40% higher (e.g., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 22%, 24%, 25%, 27%, 30%, 32%, 35%, 37%, or 40% higher than the conversion efficiency of the corresponding total sulfur content, or a range between and including any two of the foregoing values).

[0057] The feedstock after conversion by the present technology has reduced metal concentrations compared to the hydrocarbon or residual feedstock. The metal content of the converted feedstock may be reduced by at least 20%, e.g., 20% to 100%, compared to the hydrocarbon or residual feedstock. Examples of reductions in metals (collectively or individually) in the converted feedstock compared to the hydrocarbon or residual feedstock include 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 97%, 98%, 99%, 100%, or ranges between and including any two of the foregoing values. Thus, in any embodiment, the reduction may be 20% to 99%, 20% to 95%, 70% to 99%, or 100%. The metal may be any of those disclosed herein. In some embodiments, the metal is selected from iron, vanadium, nickel, or a combination of any two or more thereof. For example, the iron and vanadium content of the converted feedstock is reduced by at least 20% compared to the hydrocarbon or residual feedstock. Similarly, in any embodiment, the nickel content of the converted feedstock is reduced by at least 20% compared to the hydrocarbon or residual feedstock.

[0058] The present process also provides a converted feedstock with improved physical properties compared to hydrocarbon feedstocks and residual feedstocks. However, it has been found that the physical properties of the converted feedstocks of the present process do not necessarily vary proportionally with the sodium to sulfur ratio. For example, the extent of metal demetallization, particularly metals detrimental to catalyst life including iron, vanadium, and nickel, is generally greater than the extent of desulfurization at a given sodium to sulfur ratio. Example 6 demonstrates the insensitivity of sodium treatment to initial metal content, unlike catalytic conversion processes. Sodium demetallization at low sodium / total sulfur addition ratios can be highly advantageous in pretreating hydrocarbon feeds with undesirably high metal contents prior to catalytic conversion or processing.

[0059] Additional physical properties that significantly reduce the value of heavy residual feedstocks are improved after treatment with sodium. Desulfurization of the asphaltene fraction occurs without the hydrogen saturation seen in hydroconversion or the carbon emissions exhibited by thermal cracking processes. As a result, at least a portion of the asphaltene content is converted by the present method into soluble, stable, and desulfurized converted liquid products, increasing the yield of more valuable liquid products (e.g., hydrocarbon oils derived from asphaltenes). Thus, the converted feedstock produced by the present method may have a lower asphaltene content than that in the hydrocarbon feedstock (or residual feedstock). In some embodiments, the present method converts at least a portion of the asphaltenes to hydrocarbon oils, such as paraffins. In some embodiments, at least 5%, at least 10%, at least 15%, or at least 20% or more of the asphaltene content in the residual feedstock is converted to liquid hydrocarbon oils in the converted feedstock. The conversion efficiency relative to the asphaltene content removed from the hydrocarbon or residual feedstock will vary depending on the amount of sodium used, but will generally be high, e.g., at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, up to 98%, up to 99%, or up to 99.9%, or 100%, or a range between and including any two of the foregoing values ​​(e.g., 70-100% or 75-99.9%, etc.).

[0060] Conversion of asphaltenes to smaller, lower molecular weight components with fewer attached functional groups typically results in a viscosity reduction of at least 40% and up to five orders of magnitude (10,000 times) and an increase in API gravity of about 1 to about 3 units per wt. % sulfur removal. In any embodiment, the viscosity of the converted feedstock may be reduced by at least 50 cSt at 50°C, or at least 40%. In any such embodiment, the viscosity is reduced by at least 100 cSt, at least 200 cSt, at least 300 cSt, or more at 50°C. For hydrocarbon or residual feedstocks disclosed herein having viscosities greater than 1,000 cSt (see above), the reduction may be particularly significant, and may be at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, or even 100% (e.g., at least a 40-99% viscosity reduction). In any embodiment, the density of the converted feedstock may be about 5 to about 25 kg / m for every 1 wt. % decrease in sulfur content of the converted feedstock compared to the hydrocarbon feedstock or residual feedstock. 3 For example, the density reduction may be about 5, about 10, about 15, about 20, about 25 kg / m³, or a range between and including any two of the foregoing values ​​(e.g., about 5 to about 20 kg / m³). 3 or about 10 to about 25 kg / m 3 etc.)

[0061] As mentioned above, in any embodiment, the method may include a step of pretreating the impurity-containing hydrocarbon feedstock before contacting it with metallic sodium. In some cases, the hydrocarbon feedstock may be pretreated to concentrate impurities in the residual feedstock, thereby reducing the amount of feedstock to be processed. For example, virgin crude oil can be distilled to produce one or more light fractions as a refined feedstock and an atmospheric residue (residual feedstock) having a higher sulfur content and higher asphaltene content than both the refined feedstock and the virgin crude oil (hydrocarbon feedstock). Alternatively, the hydrocarbon feedstock may be pretreated to remove some of the undesirable impurities, providing a refined feedstock with reduced impurity concentrations and a residue feedstock having impurities remaining after pretreatment. The residue feedstock may contain impurities due to the selected conversion level or because the pretreatment process is unable to remove the impurities. For example, vacuum residue may be processed in a hydroprocessing reactor (such as an LC Fining® unit or H-Oil® unit) to remove sulfur and convert the residue fraction into more valuable products. However, after hydrotreating in the presence of a catalyst at operating conditions exceeding 350°C and 1500-3000 psig, persistent sulfur and asphaltenes remain in the hydrotreated understream. The pretreatment process may include either a separation process, a thermal or catalytic conversion process, or a treatment process, or a combination of any two or more of these.

[0062] In any embodiment, the pretreatment process may include a separation process involving one or more of the following: physical separation using energy (heat), phase addition (solvent or absorbent), pressure change, or application of an external field or gradient to concentrate impurities in the residual feedstock. Separation processes may include gravity separation, flash evaporation, distillation, condensation, drying, liquid-liquid extraction, stripping, absorption, centrifugation, electrostatic separation, and variations thereof. Separation processes may also include solvent extraction processes, including solvent deasphalting processes such as Residual Oil Supercritical Extraction (ROSE®). For example, the hydrocarbon feedstock may be desalted to remove salt and water, an API separator may be used to separate water and solids from oil, or a distillation column may be used to separate low-boiling products from low sulfur and high-boiling products from high sulfur in the crude oil. Separation processes may also require solid agents or barriers, such as adsorption, filtration, permeation, or variations thereof. Each of the disclosed separation processes results in a refined feedstock with a lower impurity concentration than the hydrocarbon feedstock and a residual feedstock with a higher impurity concentration than the refined feedstock. In any embodiment, the residual feedstock contains a higher concentration of impurities than in the hydrocarbon feedstock. In any embodiment, the pretreatment process further provides a gaseous impurity stream (e.g., HS, water, NH, and light hydrocarbon gases such as methane, ethane, and propane). Such gaseous impurities may be removed by absorption processes, sulfur recovery processes, or other processes known in the art.

[0063] In any embodiment, the pretreatment process may include a thermal or catalytic process that alters the molecular structure or results in the removal of at least a portion of the carbon content of the hydrocarbon feedstock. Thermal conversion processes may include coker, visbreaker, or other processes that increase the yield of cracked distillates by removing carbon as coke. Catalytic processes may include fixed-bed and fluidized-bed processes, such as, but not limited to, catalytic cracking (FCC or residual FCC), hydrocracking, residual hydrocracking, and hydroconversion (e.g., LC Fining®, H-Oil®). The conversion process may be a hydrotreating process, which requires both hydrogen and a catalyst.

[0064] The pretreatment step of the present method may include a treatment process that results in hydrocarbon saturation or removal of specific impurities on a total feed basis. Thus, in any embodiment, the pretreatment process may include solvent deasphalting, hydrotreating, residual hydrotreating (RHT), hydrodesulfurization (RDS), hydrodemetallization (HDM), or hydrodenitrogenation (HDN), or a combination of two or more thereof. While the overall concentration of the impurity(s) is reduced, the treatment process generally produces a refined feedstock with lower impurity concentrations than the hydrocarbon feedstock and a residual feedstock with higher impurity concentrations than the refined feedstock. Nevertheless, the residual feedstock may have lower impurity concentrations than the hydrocarbon feedstock. Furthermore, catalytic treatment processes generally cannot process feedstocks with high impurity concentrations in the asphaltenes due to accelerated catalyst deactivation by metals and microcarbon residues.

[0065] The method of the present technology produces a mixture comprising a converted feedstock and sodium salts. The method may further include separating the sodium salts from the converted feedstock. The sodium salts are composed of particles that are very fine (e.g., <10 μm) and cannot be completely removed by standard separation methods (e.g., filtration or centrifugation). In an optional embodiment, the separating step may include: a. heating the mixture of sodium salts and the converted feedstock with elemental sulfur to a temperature of about 150° C. to 500° C. to provide a sulfur-treated mixture containing agglomerated sodium salts; and separating the agglomerated sodium salts from the sulfur-treated mixture to provide desulfurized liquid hydrocarbons and separated sodium salts. This separation may be carried out as described in U.S. Pat. No. 1,043,5631, the disclosure of which is incorporated herein in its entirety.

[0066] The method may further include recovering metallic sodium from the separated sodium salt. In any embodiment, the method may further include electrolyzing the separated sodium salt to provide metallic sodium. The separated sodium salt may include one or more of sodium sulfide, sodium hydrosulfide, or sodium polysulfide. Electrolysis may be carried out in an electrochemical cell, for example, according to U.S. Pat. No. 8,088,270 or U.S. Provisional Patent Application No. 62 / 985,287, the entire contents of each of which are incorporated herein by reference for all purposes. The electrochemical cell may include an anolyte compartment, a catholyte compartment, and a NaSICON membrane separating the anolyte compartment from the catholyte compartment. A cathode containing metallic sodium is disposed in the catholyte within the catholyte compartment. An anode containing a sodium salt is disposed in the anolyte within the anolyte compartment. A power source is electrically connected to the anode or the cathode. In any embodiment, the separated sodium salt is dissolved in an organic solvent prior to electrolyzing the salt to provide metallic sodium.

[0067] An exemplary embodiment of the method of the present technology will now be described with reference to the flow diagrams of Figures 1-3. With reference to the refining and conversion system 10 of Figure 1, a hydrocarbon feedstock 101 containing sulfur and asphaltene impurities as described herein (e.g., a sulfur content of at least 0.5 wt% (as used herein, "wt%" means "weight percent") and an asphaltene content of at least 1 wt%) is charged to a reactor 120 (continuous or batch) along with an effective amount of metallic sodium 103 and an extrinsic capping agent 105 as described herein. The reaction may be carried out at elevated temperatures and pressures as described herein and is typically completed within minutes to provide a mixture of sodium salt and converted feedstock 121. The converted feedstock, as described herein, comprises a hydrocarbon oil having a lower sulfur content than that in the hydrocarbon feedstock and a lower asphaltene content than that in the hydrocarbon feedstock. Furthermore, the ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than that in the hydrocarbon feedstock. Optionally, the mixture 121 is transported from the reactor 120 to another vessel 130, where the sodium salts are agglomerated into particles large enough to be easily separated from the converted feedstock. Any suitable agglomeration method can be used, including agglomeration with elemental sulfur 107 at elevated temperatures, as described herein. The resulting mixture 131 of agglomerated sodium salts, metals, and converted feedstock can then be separated by any suitable process and device 140, such as a centrifuge, to provide converted feedstock 141 free of metals 143 and sodium salts 145. Optionally, as described herein, the sodium salts 145 can be electrolyzed in an electrolytic cell 150 having a sodium ion-selective ceramic membrane 152, such as a NaSiCON membrane, to provide metallic sodium 153 and elemental sulfur 157, which can be reused as metallic sodium 153 and elemental sulfur 157, respectively, in the present process.

[0068] In some embodiments of the present process utilizing the refining and conversion system 10 of Figure 1, the hydrocarbon feedstock 101 is a residual feedstock. The effective amount of metallic sodium 103 may be less than the stoichiometric amount of metallic sodium relative to the sulfur content of the residual feedstock. The resulting converted feedstock 141 (also in mixture 121) comprises a hydrocarbon oil having a lower sulfur content than that in residual feedstock 121 and a lower asphaltene content than that in residual feedstock 121.

[0069] 2 illustrates another method of the present technology using a purification and conversion system 20 in which an impure hydrocarbon feedstock 201 is pretreated in a process / apparatus 210 to provide a residue feedstock 211 and a refined feedstock 213, and optionally gaseous impurities 215 (e.g., HO, NH, and light hydrocarbon gases). The refined feedstock 213 may contain a lower concentration of impurities than the hydrocarbon feedstock 201 before pretreatment, and the residue feedstock 211 may contain a higher concentration of impurities than the refined feedstock 213. The residue feedstock 211 comprises hydrocarbons having a sulfur content of at least 0.5 wt. % and an asphaltene content of at least 1 wt. Pretreatment steps can vary from various types of distillation to hydrocracking, solvent deasphalting, visbreaking, hydrotreating, catalytic reforming, and alkylation, as described herein. In some embodiments, the pretreatment process comprises two steps, where the hydrocarbon feedstock is first converted into a single stream comprising the converted and purified feedstocks (e.g., by cracking), which may then be separated, such as by distillation.

[0070] This residual feedstock 211 is charged to a reactor 220 along with metallic sodium 203 and an exogenous capping agent 205, similar to the method illustrated in FIG. 1 and described herein. The resulting mixture of sodium salts and converted feedstock 221 can be processed as described herein to agglomerate 230 and separate 240 the sodium salts 245 from the converted feedstock 241. The converted feedstock 241 comprises a hydrocarbon oil having a lower sulfur content than that in the residual feedstock 211 and a lower asphaltene content than that in the residual feedstock 201. Furthermore, the weight ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock 241 is lower than that in the residual feedstock 211. Again, the sodium salts 245 may be electrolyzed 250 to provide metallic sodium 253 and elemental sulfur 257, as described herein.

[0071] In some aspects and embodiments of the present method, the pretreatment process may include two pretreatment steps using a purification and conversion system 30 as shown in FIG. 3 . As such, an impure hydrocarbon feedstock 301 is subjected to a first pretreatment step / apparatus 300. Any suitable pretreatment process resulting in a first residual feedstock 302 and a first purified feedstock 304 can be used as described herein. The residual feedstock 302 may be further pretreated (310) to provide a second residual feedstock 311 and a purified feedstock 313. Optionally, one or more impurities (e.g., gaseous impurities such as H2S, NH3, water, light hydrocarbons, etc.) may be removed in a separate stream during the first and / or second (as shown) pretreatment steps. The second residual feedstock 311 may then be treated with metallic sodium 303 and an exogenous capping agent 305 in a reactor 320 as described herein to provide a mixture of sodium salts and a converted feedstock 321. The sodium salts of mixture 321 may then be agglomerated 330 and separated 340 as described above to provide converted feedstock 341, metals 343, and sodium salts 345. Sodium salts 345 may be electrolyzed in electrolytic cell 350 having a sodium ion-selective ceramic membrane 352 (e.g., NaSiCON) as described herein to provide recovered metallic sodium 353 and elemental sulfur 357. [Example]

[0072] Example 1 - Desulfurization of Hydrocarbon Feedstock with Sodium Various hydrocarbon feedstocks were treated with metallic sodium to demonstrate its broad applicability for impurity removal and property improvement. The hydrocarbon feedstocks included virgin crude oil from different geographic locations and topographies, as well as various converted and processed feedstocks from typical refinery and upgrading facilities. Seven hundred grams of hydrocarbon feedstock was treated in a 1.8-liter Parr continuous stirred tank reactor with an appropriate mass of sodium in a batch or semi-batch manner under the following conditions to yield a mixture of converted hydrocarbons and sodium salts. The reaction conditions, feed, and product properties are listed in Table 1.

[0073] The results in Table 1 show that molten metallic sodium effectively removes impurities and improves the physical properties of the conversion feedstock.

[0074] (Table 1) TIFF0007802691000001.tif22996

[0075] Example 2 - Desulfurization of Hydrocarbon Feedstock with Sodium To further demonstrate the broad applicability of sodium metal treatment for removing impurities and improving physical properties during continuous operation, various hydrocarbon and residual feedstocks were treated with sodium metal in a pilot plant using a continuous system essentially as shown in Figure 2. The hydrocarbon and residual feedstocks included virgin crude oil, vacuum residue, and partially converted feedstocks produced within typical refining and upgrading facilities. Each feedstock was treated with an effective amount of sodium in a 12-L continuous stirred-tank reactor under the following conditions to yield a mixture of converted hydrocarbons and sodium salts. Hydrogen was used as an exogenous capping agent in all test campaigns. The reaction conditions, feed, and product properties are listed in Table 2.

[0076] (Table 2) TIFF0007802691000002.tif239111

[0077] Example 3: Preferential removal of sulfur in the asphaltene fraction The mixed vacuum residue streams were individually treated essentially as in Example 1 (batch), but with increasing sodium to sulfur ratios (measured relative to 100% sulfur removal) in five experiments. 700 g of the mixed vacuum residue was contacted with sodium at 350° C. and 750 psig hydrogen partial pressure for 60 minutes. The main results are summarized in Table 3. The effect of treatment with sodium on favorable sulfur removal from the asphaltene fraction is summarized as follows: 1. The fraction of total sulfur in asphaltenes decreased from 28.5% to 7.9% of the converted product at a sulfur to sodium ratio of 0.94. 2. The ratio of sulfur in non-asphaltene to sulfur in asphaltene decreases as a function of increasing molar equivalents of sodium. The decrease in ratio demonstrates that at all practical sodium-to-sulfur ratios, a greater proportion of sulfur is removed from the sulfur containing asphaltene than from the non-asphaltene sulfur.

[0078] Table 3. Sulfur removal from various oil fractions TIFF0007802691000003.tif88170

[0079] Example 4: Preferential Removal of Sulfur and Metals from Asphaltene Fractions at Low Sodium / Sulfur Ratios Refinery intermediate streams (e.g., residual feedstocks) were essentially treated as in Figure 1 (batch), but substoichiometric moles of sodium equivalent were used to demonstrate favorable sulfur and metal removal from the asphaltene fraction. 700 g of each refinery intermediate was treated with sodium at 350 °C and 750 psig or 400 °C and 1500 psig hydrogen partial pressure for 60 minutes. In all cases, a greater proportion of sulfur was removed from the asphaltene fraction. Furthermore, the proportion of metals removed exceeded the proportion of total sulfur removed, indicating that a lower sodium / sulfur addition ratio may be advantageous for producing partially converted products with lower metal and asphaltene sulfur contents for further processing in downstream refinery processes.

[0080] (Table 4) TIFF0007802691000004.tif124170

[0081] Example 5: Removal of impurities remaining in residual feedstock after pretreatment The hydrocarbon feedstock was pretreated in a hydroconversion reactor in the presence of a catalyst at less than 350°C and 1500 psig of hydrogen partial pressure to produce a residual feedstock with 2.06 wt% S and 239 ppm V, Ni, and Fe, which were not removed during hydroconversion under severe operating conditions. 700 g of the hydroconverted residual feedstock was then contacted with sodium in a batch reactor (60-minute residence time) at 400°C and 1500 psig of hydrogen partial pressure, essentially as in Example 1. The results are shown in Table 5. Treatment with sodium removed the sulfur and metal contents not removed during hydroconversion. Sodium also converted a portion of the asphaltene fraction to a converted hydrocarbon oil, and a greater proportion of sulfur was removed from the asphaltene-containing sulfur than from the non-asphaltene sulfur. The converted feed with lower metal, asphaltene, and sulfur contents can be processed in the catalytic conversion process to produce higher-quality products.

[0082] (Table 5) TIFF0007802691000005.tif76169

[0083] Example 6: Desulfurization of Asphaltene with Sodium Solid asphaltene feedstock was produced by processing n-pentane-rich bitumen. 350 g of asphaltene was then mixed with 350 g of mineral oil and treated with sodium at 350°C and 1500 psig. The main results are summarized in Table 6. The results in Table 4 show that molten metallic sodium effectively removes impurities and improves the physical properties of asphaltene. The sulfur content was reduced by 97.4%, the 524°C cut was reduced by more than 48%, and metals were reduced by >97%.

[0084] Table 6. Main results of asphaltene desulfurization with sodium TIFF0007802691000006.tif95128

[0085] equivalent While particular embodiments have been illustrated and described, those skilled in the art, after reading the foregoing specification, may affect modifications, substitutions of equivalents, and other types of alterations to the methods and products of the technology described herein. Each of the above aspects and embodiments may also include or incorporate variations or aspects as disclosed with respect to any or all of the other aspects and embodiments.

[0086] The present technology is also not limited in terms of the specific embodiments described herein, which are intended as single examples of individual embodiments of the 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 technology, in addition to those recited herein, will be apparent to those skilled in the art from the foregoing description. Such modifications and variations are intended to be included within the scope of the appended claims. The present technology is not limited to particular methods, feedstocks, compositions, or conditions, which may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. Therefore, the specification is intended to be considered exemplary, with the breadth, scope, and spirit of the technology being indicated only by the appended claims, the definitions therein, and their equivalents.

[0087] The embodiments illustratively described herein may suitably be practiced in the absence of any element or elements, limitation, or limitations not specifically disclosed herein. Thus, for example, terms such as "comprising," "including," and "containing" are to be understood broadly and without limitation. Furthermore, the terms and expressions used herein are used as terms of description rather than limitation, and the use of such terms and expressions is not intended to exclude any equivalents of the shown and described features or portions thereof, but it is recognized that various modifications are possible within the scope of the claimed technology. Similarly, the use of the terms "comprising," "including," "containing," and the like shall be understood to disclose embodiments using the terms "consisting essentially of" and "consisting of," and the term "consisting essentially of" shall be understood to include the elements specifically mentioned and additional elements that do not materially affect the basic and novel characteristics of the claimed technology. The phrase "consisting of" excludes any unspecified elements.

[0088] Furthermore, when features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also described in terms of any individual members or subgroups of members of the Markush group. Each of the narrower species and subgeneric groupings falling within the generic disclosure also constitutes part of the invention. This includes any provisos or negative limitations that remove any subject matter from the generic description of the invention, regardless of whether the excluded material is specifically set forth herein.

[0089] It will be understood by those skilled in the art that, for any and all purposes, particularly in light of the provision of a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of those subranges. It will be readily recognized that the listed ranges can be fully described and broken down into at least half, third, quarter, fifth, tenth, etc. equivalents. As a non-limiting example, each range described herein can be readily broken down into a lower third, middle third, upper third, etc. It will also be understood by those skilled in the art that all language, such as "up to," "at least," "greater than," "less than," etc., refers to a range that is inclusive of the recited numbers and that can then be broken down into subranges, as described above. Finally, it will be understood by those skilled in the art that a range includes its individual members.

[0090] All publications, patent applications, issued patents, and other documents (e.g., journals, articles, and / or textbooks) mentioned herein are incorporated by reference as if each individual publication, patent application, issued patent, or other document were specifically and individually indicated to be incorporated by reference in its entirety. Definitions contained in text incorporated by reference are excluded to the extent they conflict with definitions in this disclosure.

[0091] Other embodiments are set forth in the following claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. The following steps:

1. A process for pretreating an impure hydrocarbon feedstock to provide a refined feedstock and a residual feedstock, comprising: the refined feedstock contains a lower concentration of impurities than the hydrocarbon feedstock before pretreatment; the pre-treating step, wherein the residual feedstock contains a higher concentration of impurities than the purified feedstock; contacting said residual feedstock with an effective amount of sodium metal and an effective amount of an extrinsic capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock; the residual feedstock comprises hydrocarbons having a sulfur content of at least 0.5 wt. % and an asphaltene content of at least 1 wt. %, the sulfur content includes asphaltene sulfur and non-asphaltene sulfur; the converted feedstock comprises a hydrocarbon oil having a sulfur content less than that in the residual feedstock and an asphaltene content less than that in the residual feedstock; and the weight ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than in the residual feedstock; A method comprising:

2. The following steps: contacting a hydrocarbon feedstock with an effective amount of metallic sodium and an effective amount of an extrinsic capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock; the hydrocarbon feedstock comprises hydrocarbons having a sulfur content of at least 0.5 wt % and an asphaltene content of 2 wt % to 40 wt %; the sulfur content includes asphaltene sulfur and non-asphaltene sulfur; the converted feedstock comprises a hydrocarbon oil having a sulfur content less than that in the hydrocarbon feedstock and an asphaltene content less than that in the hydrocarbon feedstock; and the ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than in the hydrocarbon feedstock; A method comprising:

3. The following steps:

1. A process for pretreating a hydrocarbon feedstock to provide a refined feedstock and a residual feedstock, comprising: the refined feedstock contains a lower concentration of impurities than the hydrocarbon feedstock before pretreatment; and the pre-treating step, wherein the residual feedstock contains a higher concentration of impurities than the purified feedstock; a residual feedstock comprising hydrocarbons having a sulfur content of at least 0.5 wt. % and an asphaltene content of at least 1 wt. % to produce a mixture of sodium salts and a converted feedstock; a substoichiometric amount of metallic sodium relative to the sulfur content of the residual feedstock; and an effective amount of an exogenous capping agent at a temperature of 250 to 500°C, the stoichiometric amount of sodium metal relative to sulfur content is the theoretical amount of sodium metal required to convert the total sulfur content in the residual feedstock to sodium sulfide; the converted feedstock comprises a hydrocarbon oil having a sulfur content less than that in the residual feedstock and an asphaltene content less than that in the residual feedstock; A method comprising:

4. The following steps:

1. A process for pretreating an impure hydrocarbon feedstock to provide a refined feedstock and a residual feedstock, comprising: the refined feedstock contains a lower concentration of impurities than the hydrocarbon feedstock before pretreatment; and the pre-treating step, wherein the residual feedstock contains a higher concentration of impurities than in the purified feedstock; contacting said residual feedstock with an effective amount of sodium metal and an effective amount of an extrinsic capping agent at a temperature of 250-500°C to produce a mixture of sodium salts and a converted feedstock; the residual feedstock comprises hydrocarbons having a sulfur content of at least 0.5 wt. % and an asphaltene content of at least 1 wt. %, the converted feedstock comprises a converted hydrocarbon oil having a sulfur content less than that in the residual feedstock and an asphaltene content less than that in the residual feedstock; and wherein at least a portion of the converted hydrocarbon oil is derived from asphaltenes in the residual feedstock; A method comprising:

5. 5. The method of any one of claims 1, 3, and 4, wherein the pretreatment step comprises phase separation by an externally applied field, separation by the addition of heat, hydroconversion, thermal conversion, catalytic conversion, catalytic treatment, solvent extraction, solvent deasphalting, or a combination of any two or more thereof.

6. 5. The method of any one of claims 1, 3, and 4, wherein the pre-treating step comprises contacting the hydrocarbon feedstock with exogenous hydrogen and / or a catalyst to remove one or more of sulfur, nitrogen, oxygen, metals, and asphaltenes.

7. 7. The method of any one of claims 1 to 6, wherein the hydrocarbon feedstock is or is derived from virgin crude oil or the product of a thermal cracking process.

8. 8. The method of any one of claims 1 to 7, wherein the hydrocarbon feedstock is selected from the group consisting of petroleum, heavy oil, bitumen, conventional crude oil, shale oil, and oil shale.

9. The method of claim 1, wherein the sulfur content of the residual feedstock or the hydrocarbon feedstock is in the range of 0.5 wt % to 15 wt %.

10. A method described in any one of claims 1 and 3 to 9, wherein the asphaltene content of the residual feedstock is in the range of 1 wt% to 100 wt%.

11. The method of claim 10, wherein the asphaltene content of the residual feedstock is in the range of 2 wt % to 40 wt %.

12. 12. The method of any one of claims 1 and 3-11, wherein the residual feedstock comprises one or more of a refinery midstream, a hydrocracking residue, a hydrotreating residue, an FCC slurry, a residual FCC slurry, an atmospheric or vacuum residue, a solvent deasphalted tar, a deasphalted oil, a visbreaker tar, a high sulfur fuel oil, a low sulfur fuel oil, an asphaltenes, an asphalt, a steam cracking tar, an LC-Fining® residue, or an H-Oil® residue.

13. The hydrocarbon feedstock or the residual feedstock has a viscosity of 1 to 10,000,000 cSt at 50°C and a viscosity of 800 to 1200 kg / m at 15.6°C ３ The method according to any one of claims 1 to 12, wherein the granules have a density of

14. 14. The method of claim 13, wherein the hydrocarbon feedstock or the residual feedstock has a viscosity of 400 to 9,000,000 cSt at 50°C.

15. 15. The method of any one of claims 1 and 3 to 14, wherein the residual feedstock is solid at room temperature.

16. 16. The method of any one of claims 1 and 3-15, wherein the residual feedstock has a higher concentration of impurities than the hydrocarbon feedstock.

17. 4. The method of claim 3, wherein the sulfur content comprises asphaltene sulfur and non-asphaltene sulfur, and the ratio of asphaltene sulfur to non-asphaltene sulfur in the converted feedstock is lower than in the residual feedstock.

18. The viscosity of the converted feedstock is reduced by at least 50 cSt at 50°C, or by at least 40%, and the density of the converted feedstock is reduced by about 5 to about 25 kg / m per wt% reduction in sulfur content of the converted feedstock compared to the hydrocarbon feedstock or residual feedstock. ３ The method according to any one of claims 1 to 17, wherein the amount of hydroxybenzoates in the hydroxybenzoates is reduced.

19. 19. The process of any one of claims 1 to 18, wherein the iron and vanadium content of the converted feedstock is reduced by at least 40% compared to the hydrocarbon or residual feedstock.

20. 20. The process of any one of claims 1 to 19, wherein the nickel content of the converted feedstock is reduced by at least 40% compared to the hydrocarbon or residual feedstock.

21. 21. The method of any one of claims 4 to 20, wherein at least 40% of the asphaltene content in the residual feedstock is converted to liquid hydrocarbon oil in the converted feedstock.

22. 22. The method of any one of claims 4 to 21, wherein the asphaltene content is at least partially converted to paraffins.

23. 23. The method of any one of claims 1 to 22, wherein the extrinsic capping agent is hydrogen, hydrogen sulfide, natural gas, methane, ethane, propane, butane, pentane, ethene, propene, butene, pentene, diene, an isomer thereof, or a mixture of any two or more thereof.

24. 24. The method of any one of claims 1 and 3-23, wherein the residual feedstock is combined with sodium metal at a pressure of from about 500 psig to about 3000 psig.

25. 25. The method of any one of claims 1 and 3 to 24, wherein the reaction of the residual feedstock with sodium metal occurs for a time period of from 1 minute to 120 minutes.

26. 26. The method of any one of claims 1 to 25, further comprising separating the sodium salt from the converted feedstock.

27. The separating step comprises: a. heating said mixture of sodium salt and converted feedstock with elemental sulfur to a temperature of about 150°C to 500°C to provide a sulfur-treated mixture comprising agglomerated sodium salt; b. separating said agglomerated sodium salts from said sulfur-treated mixture to provide desulfurized liquid hydrocarbons and separated sodium salts; 27. The method of claim 26, comprising:

28. 28. The method of claim 27, further comprising electrolyzing the separated sodium salt to provide metallic sodium.

29. 29. The method of any one of claims 1 to 28, wherein the sodium salt comprises one or more of sodium sulfide, sodium hydrosulfide, or sodium polysulfide.

30. 30. The method of claim 28 or claim 29, wherein the electrolyzing step is carried out in an electrochemical cell comprising an anolyte compartment, a catholyte compartment, and a NaSICON membrane separating the anolyte compartment from the catholyte compartment, wherein a cathode comprising metallic sodium is disposed in the catholyte within the catholyte compartment, and wherein an anode comprising the sodium salt is disposed in the anolyte within the anolyte compartment, and wherein a power source is electrically connected to the anode and the cathode.

31. The method described in any one of claims 1, 3, and 5-30, wherein at least a portion of the hydrocarbon oil is derived from asphaltenes in the residual feedstock.

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