Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G29/00—Refining of hydrocarbon oils, in the absence of hydrogen, with other chemicals
  • C10G29/04—Metals, or metals deposited on a carrier
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G19/00—Refining hydrocarbon oils in the absence of hydrogen, by alkaline treatment
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G31/00—Refining of hydrocarbon oils, in the absence of hydrogen, by methods not otherwise provided for
  • C10G31/09—Refining of hydrocarbon oils, in the absence of hydrogen, by methods not otherwise provided for by filtration
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G53/00—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more refining processes
  • C10G53/02—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more refining processes plural serial stages only
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B1/00—Electrolytic production of inorganic compounds or non-metals
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
  • C25C1/00—Electrolytic production, recovery or refining of metals by electrolysis of solutions
  • C25C1/02—Electrolytic production, recovery or refining of metals by electrolysis of solutions of light metals
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/20—Characteristics of the feedstock or the products
  • C10G2300/201—Impurities
  • C10G2300/202—Heteroatoms content, i.e. S, N, O, P
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/20—Characteristics of the feedstock or the products
  • C10G2300/201—Impurities
  • C10G2300/205—Metal content

Definitions

• the present invention relates to a process for removing nitrogen, sulfur, and heavy metals from sulfur-, nitrogen-, and metal-bearing shale oil, bitumen, or heavy oil. More particularly, the invention relates to a method of regenerating alkali metals and sulfur from sulfides and polysulfides that were obtained from the sulfur-, nitrogen-, and metal-bearing shale oil, bitumen, or heavy oil.
• nitrogen is typically around 2% and sulfur around 1 % in most samples of shale oil (Heavy metals are also present.) Heavy metals contained in shale oil pose a large problem to upgraders trying to upgrade this shale oil for commercial use. For example, sulfur and nitrogen typically are removed from the shale oil via hydrotreating at elevated temperatures and pressures using catalysts such as C0-M0/AI2O3 or Ni-Mo/AI 2 03. However, such catalysts are deactivated (poisoned) by the presence of heavy metals as the heavy metals operate to mask the catalysts.
• M is an alkali metal such as sodium or lithium and 3 moles alkali metal and 1.5 moles hydrogen (H 2 ) may be needed per mole nitrogen according to the following initial reaction:
• the '874 application describes a method of upgrading an oil feedstock (such as heavy oil, shale oil, bitumen, etc.) by combining the oil feedstock with an alkali metal and an upgradant hydrocarbon material. This reaction operates to remove the sulfur, nitrogen and/or heavy metals contained within the oil feedstock.
• an oil feedstock such as heavy oil, shale oil, bitumen, etc.
• heavy metals contained in the shale oil may also be removed via the use of alkali metals such as sodium.
• Heavy metals contained in organometallic molecules such as complex porphyrins are reduced to the metallic state by the alkali metal. Once the heavy metals have been reduced, they can be separated from the oil because they no longer are chemically bonded to the organic structure.
• the nitrogen heteroatoms in the structure are exposed for further denitrogenation.
• a gravimetric separation such as centrifugation or filtering, can separate the organic, upgraded oil, from the salt phase, metallic phase, and organic solids which may be formed.
• Downs-cell such as the cell described in U.S. Patent No. 1 ,501 ,756.
• Such cells electrolyze sodium chloride that is dissolved in a molten salt electrolyte to form molten sodium at the cathode and chlorine gas at the anode.
• the cells operate at a temperature near 600 °C, a temperature compatible with the electrolyte used.
• the chlorine anode is utilized commercially both with molten salts as in the co-production of sodium and with saline solution as in the co-production of sodium hydroxide.
• the present embodiments are designed to provide a cost-effective and efficient method for the regeneration of alkali metals used in the desulfurization, denitrogenation, and demetallation of hydrocarbon streams.
• the present invention is able to remove contaminants and separate out unwanted material products from desulfurization/denitrogenation/demetallation reactions, and then recover those materials for later use.
• the present embodiments relate to a denitrogenation and desulfurization technology that is insensitive to the heavy metal content and at the same time demetallizes very effectively.
• the deep demetallization provides an enormous benefit because additional hydrotreating processes will not be affected by the metals originally contained in the shale oil and tar sands.
• the present embodiments provide a process for removing nitrogen, sulfur, and heavy metals from sulfur-, nitrogen-, and metal-bearing petroleum feedstocks such as shale oil, bitumen, coker diesel or heavy oil.
• the present embodiments further provide an electrolytic process of regenerating alkali metals from sulfides, polysulfides, nitrides, and polynitrides of those metals.
• the present embodiments further provide an electrolytic process of removing sulfur from a polysulfide solution.
• One non-limiting embodiment within the scope of the invention includes a process for oxidizing alkali metal polysulfides electrochemically.
• the process utilizes an electrolytic cell having an alkali ion conductive membrane configured to selectively transport alkali ions, the membrane separating an anolyte compartment configured with an anode and a catholyte compartment configured with a cathode.
• An anolyte is introduced into the anolyte compartment.
• the anolyte includes an alkali metal sulfide species and an anolyte solvent that dissolves alkali metal sulfide species.
• a catholyte is introduced into the catholyte compartment.
• the catholyte may be comprised of molten alkali metal or may include alkali metal ions and a catholyte solvent.
• the catholyte solvent may include one of many nonaqueous solvents such as tetraglyme, diglyme, dimethyl carbonate, dimethoxy ether, propylene carbonate, ethylene carbonate, diethyl carbonate.
• the catholyte may also include an alkali metal salt such as an iodide or chloride of the alkali metal.
• Applying an electric current to the electrolytic cell oxidizes sulfur in the anolyte compartment to form elemental sulfur, causes alkali metal ions to pass through the alkali ion conductive membrane from the anolyte compartment to the catholyte compartment, and reduces the alkali metal ions in the catholyte compartment to form elemental alkali metal.
• Sulfur has higher specific gravity than the anolyte and is easily separated from the anolyte by gravimetric means, centrifugal separation or may be recovered by removing a portion of the anolyte solution from the anolyte compartment, cooling the removed anolyte solution to precipitate solid phase sulfur from the anolyte solution, separating the precipitated sulfur from the anolyte solution.
• the cell is operated at 1 15 °C or greater such that the sulfur formed at the anode is in the liquid phase. If the alkali metal is sodium, then the sodium formed at the cathode is also liquid phase.
• the cathode may be periodically withdrawn from the catholyte compartment to remove the alkali metal.
• the cathode may be configured as a flexible band which continuously or semi-continuously loops from inside the catholyte compartment to outside the catholyte compartment and electrolytic cell housing, enabling the alkali metal to be continuously scraped or removed from the cathode.
• the present invention may provide certain advantages, including but not limited to the following: • Operating an electrolytic cell to process an alkali metal sulfide or polysulfide at temperatures below the melting temperature of the alkali metal;
• Figure 1 shows an overall process for upgrading an oil feedstock that removes nitrogen, sulfur, and heavy metals from sulfur-, nitrogen-, and metal- bearing oil sources using an alkali metal and regenerates the alkali metal;
• Figure 2 shows a schematic cross-section of an electrolytic cell that may be used to regenerate the alkali metal and sulfur used to react with sulfur-, nitrogen-, and metal-bearing oil sources;
• Figure 3 shows a schematic of a process for upgrading the oil and regenerating the sulfur and alkali metal
• Figure 4 shows a schematic of an apparatus which can process electrolytic cell anolyte to extract sulfur
• Figure 5 shows a schematic of another embodiment of a process for upgrading the oil and regenerating the sulfur and alkali metal
• Figure 6 shows a schematic of another embodiment of a process for upgrading the oil and regenerating the sulfur and alkali metal
• Figure 7 shows a schematic drawing of a process for upgrading the oil feedstock that includes post-treating the petroleum liquid.
• an oil source 102 such as high- sulfur petroleum oil distillate, crude, heavy oil, bitumen, or shale oil, is introduced into a reaction vessel 104. As described above, this oil source 102 may have heavy metals, sulfur and/or nitrogen containing compounds within the oil feedstock 102.
• An alkali metal (M) 106 such as sodium or lithium, is also introduced into the reaction vessel 104, together with a quantity of hydrogen gas 108 or other gas which may cap the radicals formed when the bonds with heteroatoms, and metals are broken.
• the alkali metal 106 and hydrogen 108 react with the oil source 102 and its contaminants to dramatically reduce the sulfur, nitrogen, and metal content through the formation of sodium sulfide compounds (sulfide, polysulfide and hydrosulfide) and sodium nitride compounds.
• M is an alkali metal such as sodium or lithium and
• R, R', R" represent portions of organic molecules or organic rings.
• Solids from the reaction of alkali metal with petroleum feedstocks may be separated in numerous ways including gravimetric, centrifugal methods, and filtering. Such separation of the solids may be conducted within a separator 1 14.
• the upgraded oil product 1 1 1 which has reduced amounts of heavy metals, sulfur and nitrogen containing compounds, may be obtained from the separator 1 14.
• the solids may be washed with a light petroleum substance such as hexane, heptane, toluene or mixtures of these substances, or natural gas condensate, other hydrocarbon liquids, or the like to remove adhered liquid product.
• a light petroleum substance such as hexane, heptane, toluene or mixtures of these substances, or natural gas condensate, other hydrocarbon liquids, or the like to remove adhered liquid product.
• the light petroleum substance may be stripped away by distillation for example to leave behind product liquid that is re-added to the upgraded oil.
• the light petroleum substance may be reused for further washing of solids.
• Solids separated from the petroleum reacted with alkali metal typically are a mixture of organic and inorganic constituents.
• the solids may be treated by heating in the substantial absence of oxygen or water. Such heating may occur, for example under the presence of nitrogen, or hydrocarbon gases such as methane. Such heating may involve heating to a temperature above 400 °C and preferably above 500 °C. During this heating process, light gases are formed and may be recovered. (These gases may be, for example, methane or other hydrocarbons.) This heating process may be referred to as "heat treating" 109.
• the alkali metal sulfides found in the solid materials may be dissolved in solvent such as formamide, methyl formamide, dimethyl formamide, acetamide, methyl acetamide, dimethyl acetamide, ethylene glycol, propylene glycol, 1 ,2-ethanediol, 1 ,2- propanediol, propylene carbonate, ethylene carbonate, diethyl carbonate, N-methyl pyrrolidone, tetraethylene glycol dimethyl ether (tetralglyme), acetonitrile, dimethyl sulfoxide, liquid ammonia, methyl amine or 1 ,3-Dimethyl-3,4,5,6-tetrahydro-2(1 H)- pyrimidinone (DMPU) or combinations of the above.
• solvent such as formamide, methyl formamide, dimethyl formamide, acetamide, methyl acetamide, dimethyl acetamide, ethylene glycol, propylene glycol, 1 ,2-ethan
• any undissolved portion of solids 122 may be removed by filtration or centrifugal means. These undissolved solids may be rich with metals that were originally in the petroleum feedstock. The dissolved sulfides may be fed into the anolyte compartment of the electrolytic cell.
• the solid material dissolved in the solvent (which includes the alkali metal sulfides, hydrogen sulfides or polysulfides), as shown by arrow 105, may be further processed in an electrolytic cell 120 to remove and recover sulfur and to remove and recover the alkali metal.
• the electrolytic cell 120 receives a solution of the alkali sulfide or polysulfide in a solvent such as formamide, methyl formamide, dimethyl formamide, acetamide, methyl acetamide, dimethyl acetamide, ethylene glycol, propylene glycol, 1 ,2-ethanediol, 1 ,2-propanediol, propylene carbonate, ethylene carbonate, diethyl carbonate, N-methyl pyrrolidone, tetraethylene glycol dimethyl ether (tetralglyme), acetonitrile, dimethyl sulfoxide, liquid ammonia, methyl amine, or 1 ,3-Dimethyl- 3,4,5,6-tetrahydro-2(1 H)-pyrimidinone (DMPU) or combinations of the above.
• a solvent such as formamide, methyl formamide, dimethyl formamide, acetamide, methyl acetamide, dimethyl acetamide, ethylene glycol
• alkali metal (M) 126 Under the influence of a source electric power 124, alkali metal ions are reduced to form the alkali metal (M) 126, which may be recovered and used as a source of alkali metal 106. Sulfur 128 is also recovered from the process of the electrolytic cell 120.
• M alkali metal
• Sulfur 128 is also recovered from the process of the electrolytic cell 120.
• the treatment of the solid material by heating before dissolving in the polar solvent may be beneficial to the overall process for upgrading the petroleum product. If this "heat-treating" 109 of the solid is not performed, when the materials are added to the electrolytic cell 120, the electrolytic cell will ultimately be “gummed up” or failed. Specifically, organic materials that are present in the materials, if not removed via heat treating, will be deposited on the electrodes, thereby causing the electrodes to fail. However, by heating the solids in the manner described above, the organic materials that would normally fail the electrodes are removed (such as through conversion into methane or another gaseous product). Thus, by heat-treating 109 the solids in the manner outlined herein, significant advantages may be obtained.
• Figure 2 shows a schematic cross-section of an electrolytic cell 200 which utilizes many of the features within the scope of the invention. As described above, after "heat treating" 109 the solid material (and removing the solids), the liquid containing dissolved sodium and sulfides may be added to an electrolytic cell. Figure 2 shows one example of this type of cell that will receive the "heat treated" liquid.
• electrolytic cell housing 202 is constructed to enclose a liquid solvent mixture.
• the material of construction preferably is an electrically insulative material such as most polymers.
• the material also is preferably chemically resistant to solvents.
• Polytetrafluoroethylene (PTFE) is particularly suitable, as well as Kynar® (which is a commercially available synthetic resin), polyvinylidene fluoride, or high density polyethylene (HDPE).
• the cell housing 202 may also be fabricated from a non-insulative material and non-chemically resistant materials, provided the interior of the housing 202 is lined with such an insulative and chemically resistant material.
• Other suitable materials would be inorganic materials such as alumina, silica, alumino-silicate and other insulative refractory or ceramic materials.
• the internal space of housing 202 is divided into a catholyte compartment 204 and anolyte compartment 206 by a divider 208.
• the divider 208 preferably is substantially permeable only to cations and substantially impermeable to anions, polyanions, and dissolved sulfur.
• the divider 208 may be fabricated in part from an alkali metal ion conductive material. If the metal to be recovered by the cell is sodium, a particularly well suited material for the divider is known as NaSICON which has relatively high ionic conductivity at room temperature.
• a typical NaSICON composition substantially would be Nan.xZr2SixP3.xO12 where 0 ⁇ x ⁇ 3. Other NaSICON compositions are known in the art.
• a particularly well suited material for the divider would be lithium titanium phosphate (LTP) with a composition that is substantially, Li(i +x+ 4y)AlxTi(i-x-y)(P04)3 where 0 ⁇ x ⁇ 0.4, 0 ⁇ y ⁇ 0.2.
• LTP lithium titanium phosphate
• Other suitable materials may be from the ionically conductive glass and glass ceramic families and have the general composition Lin.xAlxGe2.xPO4.
• Other lithium conductive materials are known in the art.
• the divider 208 may have a portion of its thickness which has negligible through porosity such that liquids in the anolyte compartment 206 and catholyte compartment 204 cannot pass from one compartment to the other, but substantially only alkali ions (M + ) 210, such as sodium ions or lithium ions, can pass from the anolyte compartment 206 to the catholyte compartment 204.
• the divider may also be comprised in part by an alkali metal conductive glass-ceramic such as the materials produced by Ohara Glass of Japan.
• the anode 212 is located within the anolyte compartment 206. It may be fabricated from an electrically conductive material such as stainless steel, nickel, iron, iron alloys, nickel alloys, and other anode materials known in the art.
• the anode 212 is connected 214 to the positive terminal of a direct current power supply.
• the anode 212 may be a mesh, monolithic structure or may be a monolith with features to allow passage of anolyte through the anode structure.
• Anolyte solution is fed into the anolyte compartment through an inlet 216 and passes out of the compartment through and outlet 218.
• the electrolytic cell 200 can also be operated in a semi-continuous fashion where the anolyte compartment is fed and partially drained through the same passage.
• the electronically conductive cathode 220 is in the form of a strip or band that has a portion within the catholyte compartment 204 and a portion outside the catholyte compartment 204 and cell housing 202, such that the alkali metal 222 can plate onto the cathode 220 while it is in the catholyte compartment 204.
• the alkali metal 222 can be stripped off the cathode while it is outside the catholyte compartment.
• Rotating rollers 224 can define the path of the cathode 220 where the path passes near the divider 208 in the catholyte compartment 204, exits the housing 202, passes through a section where the alkali metal is removed from the cathode band 220, then re-enters the housing and returns near the divider 208.
• One or more of the rollers may be driven by a motor or driving mechanism (not shown) to cause the cathode 220 to move through an opening 226 in the housing 202 and pass out of the housing continuously, semi-continuously or periodically.
• One or more of the rollers may be attached to tensioning devices 228 to allow the cathode 220 to remain at an acceptable level of tension as the cathode band expands or contracts with temperature fluctuations and strains from stress.
• Wiping seals 230 remove catholyte solution from the cathode 220 as it egresses the cell so that the catholyte is returned back to the catholyte compartment.
• the cathode band may be fabricated from steel, flexible metal alloys, and other conductive materials suitable for its intended purpose.
• a scraper 232 can be used to remove the plated alkali metal 222 from the cathode 220 as it moves.
• the cathode may be exposed to a heated zone 234 that melts the alkali metal off of the cathode 220.
• the removed alkali metal 236 may fall into a container 238 which may have a conveyance system (not shown) to transfer the alkali metal 236 away from the cell 200 to a storage area or point of use.
• the cathode 220 is polarized by a connection 240 to the negative terminal of a power supply. This connection may be made with an electronically conductive brush 242 that contacts the cathode 220 or it may be made through one or more of the rollers 224 contacting the cathode belt.
• the catholyte compartment 204 may have an inlet port 244 and an outlet port 246 to transfer catholyte solution in and out of the catholyte compartment 204 when required.
• an alkali ion conductive liquid which may include a polar solvent.
• suitable polar solvents are tetraglyme, diglyme, dimethyl carbonate, dimethoxy ether, propylene carbonate, ethylene carbonate, diethyl carbonate and such.
• An appropriate alkali metal salt such as a chloride, bromide, iodide, perchlorate, hexafluorophosphate or such, is dissolved in the polar solvent to form that catholyte solution.
• Anolyte solution containing approximately 60-100% polar solvent such asformamide, methyl formamide, dimethyl formamide, acetamide, methyl acetamide, dimethyl acetamide, ethylene glycol, propylene glycol, 1 ,2- ethanediol, 1 ,2-propanediol, propylene carbonate, ethylene carbonate, diethyl carbonate, N-methyl pyrrolidone, tetraethylene glycol dimethyl ether (tetralglyme), acetonitrile, dimethyl sulfoxide, liquid ammonia, methyl amine or 1 ,3-Dimethyl- 3,4,5,6-tetrahydro-2(1 H)-pyrimidinone (DMPU) or combinations of the above, and 0- 40% apolar solvent such as ⁇ , ⁇ -dimethylaniline (DMA) or quinoline, and 1 % to saturation,
• DMA ⁇ , ⁇ -dimethylaniline
• DMPU 1,3-
• the electrodes are energized such that there is an electrical potential between the anode 212 and the cathode 220 that is greater than the decomposition voltage which ranges between about 1.8 V and about 2.5 V depending on the composition.
• sodium ions pass through the divider into the cathode compartment 204, sodium ions are reduced to the metallic state and plate onto the cathode belt 220, and polysulfide is oxidized at the anode such that low polysulfide anions become high polysulfide anions and/or elemental sulfur forms at the anode. While sulfur is formed it is dissolved into the anolyte solvent in entirety or in part.
• the sodium plated onto the belt is removed from the cell as the cathode belt is advanced then subsequently the alkali metal 222 is removed from the cathode belt 220 by scraping or melting outside of the cell.
• the catholyte is comprised of a polar solvent such as tetraglyme and a salt to increase the ionic conductivity.
• a polar solvent such as tetraglyme
• sodium halide salt such as sodium chloride can be used to increase the ionic conductivity and the decomposition voltage of sodium chloride is much higher than the decomposition of sodium polysulfide.
• the electrolytic cell 200 is operated at a temperature below the melting temperature of sodium.
• the anode and cathode may be spaced relatively close to the divider 208, within a few millimeters. Adjustments to cell temperature can be made using a heat exchanger on the flow of anolyte entering and exiting the cell through ports 216, 218.
• the cell shown in Figure 2 has a general horizontal orientation but could also be configured in a generally vertical or other orientation.
• x ranges from 0 to about 8 but may be greater than 8.
• the method 600 includes an oil source 102 of the type described herein.
• This oil source 102 is reacted within a reactor 104 with a quantity of an alkali metal 106, in the manner outlined above.
• a liquid material 602 is produced.
• This liquid material 602 may simply be referred to as "liquid 602.”
• This liquid 602 may be the upgraded oil product.
• a quantity of solid materials 605 (which may be simply called “solids”) are produced.
• the produced solids 605 may be washed with a light petroleum substance such as hexane, heptane, toluene, or mixtures of these substances, or natural gas condensate, or the like to remove adhered liquid product 602.
• the light petroleum substance may be stripped away by distillation, for example, to leave behind liquid product. This liquid product may then be re-added to the liquid 602.
• the light petroleum substance, which was stripped away, may be re-used in washing another batch of solids 605.
• the solids 605 may include quantities of heavy metals, coke, organic solids, sodium sulfide, sodium nitride, etc. These solids 605 may then be subjected to a heat treatment step 610.
• the solids 605 are heated in a substantial absence of oxygen or water, for example under the presence of nitrogen, an inert gas or hydrocarbon gases such as methane.
• Such heating may involve heating the solids 605 to a temperature above 400 °C and preferably above 500 °C.
• a quantity of treated solids 615 are produced.
• a quantity of gases 612 (such as methane or other organic gases) is also produced.
• this heat treatment step 610 operates to convert some of the organic products, such as coke, within the solids 605 into methane or other volatile organics, such that these gases are removed from the solids 605.
• the weight of the treated solids 615 is generally less than the weight of the solids 605 (given that some of the mass of the solids 605 has been lost as organic gases.)
• the solids 615 may be more granular than they were previously.
• the treated solids 615 may then be dissolved, in step 620, in a solution comprising a polar solvent 621. Once dissolved, the material is added to a separator 1 14. Within this separator 1 14, solids 630 will be removed. Such solids 630 may include residual coke and heavy metal products. Such solids 630 can literally fall to be bottom of the separator 1 14, and thus may be removed by gravimetric processes, filtration or other methods.
• This liquid 632 may be yellowish to clear in color as a result of the presence of dissolved sodium sulfide. (Polysulfide and/or hydrogen sulfide anions may also be present.)
• This liquid 632 may be introduced into an electrolytic cell 120. Any electrolytic cell may be used, including the cells 120, 200 described above. Other types of electrolytic cells, including those described in the '270 patent or the '874 application, may also be used.
• This regenerated alkali metal 652 may then be re-used in the reaction vessel 104 as a means of upgrading a further batch of oil products.
• a portion of the anolyte from the cells 120 may serve as the polar solvent 621 .
• the anolyte solution may be preferably selected to dissolve polysulfides and sulfur.
• U.S. Patent No. 6,852,450 to Hwang et al. discloses a high cathode (sulfur electrode) utilization by using a mixture of polar and apolar solvents.
• the polar solvents were useful for dissolving most of the polysulfides that are polar in nature and the apolar solvent is useful for dissolving the sulfur that is apolar in nature.
• a mixture of polar and apolar solvents may be used in anolyte solution within the scope of the present invention, but it is not required.
• Hwang measured the solubility of sulfur and found numerous solvents with relatively high solubility. Hwang did not report the solubility of polysulfides. The top eight solvents were cyclohexane, benzene, trifluortoluene, toluene, fluorbenzene, tetrahydrofurane (THF) and 2-methyl tetrahydrofurane (2-MeTHF).
• the first six have solubilities above 80 mM while the last two have solubilities above 40 mM.
• a portion of the anolyte from the high polysulfide cells will be bled off and processed, as discussed herein.
• Some of the sulfur may be removed by cooling and gravimetrically separating or through filtration. Other methods may also be used such as vaporizating the apolar solvent then using gravimetric or filtration means.
• Table 3 lists the eight solvents with highest sulfur solubility based on the findings of U.S. Patent No. 6,852,450. This patent did not specify but the solubilities listed are probably for temperatures near 25 °C and would be higher at elevated temperatures. Table 3 also lists the boiling points of those solvents. The data is arranged in order of boiling point temperature. Based on this data, the most suitable solvents to be added to the anolyte are xylene, toluene and trifluorotoluene. Operation at pressures above ambient may be desirable to keep the solvent from vaporizing at operating temperatures near 120 °C, particularly since most of the domestic shale oil would be processed at elevations between 4000-8000 feet above sea level.
• Tetraglyme alone can dissolve sulfur formed at the anode to an extent, particularly if the cells operate at elevated temperatures above 50 °C. Addition of selected solvents such as DMA enables the solvent to dissolve more sulfur, preventing polarization at the anode.
• a stream of anolyte solution near saturation can be brought outside the electrolytic cell and chilled using a heat exchanger or other means to cause sulfur to precipitate.
• the sulfur can be removed by one of several means such as filtration, gravimetrically, centrifugation, and such. Sulfur has nearly two (2) times the specific gravity of the solvent mixture and is easily separated. The sulfur depleted solvent then can be returned to the anolyte to reduce the overall sulfur concentration in the anolyte.
• the chilled anolyte 310 enters an enclosed thickener 312 to allow settling of solid phase sulfur or sulfur liquid phase.
• a stream heavily containing sulfur solids 314 flows to a rotary filter 316.
• Liquid anolyte flows into the filter while solid sulfur remains on the filter media on the outside of the drum 318.
• Overflow anolyte from the thickener 320 enters a tank 322 that also receives make-up solvent mixture 324. Together this stream is used as a spray 326 to wash the sulfur filter cake.
• the sulfur filter cake is removed from the rotary filter enclosure by a conveyor means (not shown). Chilled and low sulfur bearing anolyte 327 is pumped from the filter drum back to the electrolytic cell.
• anolyte solvents which may be utilized to increase sulfur solubility in the anolyte solution include: tetrahydrofuran, 2-methyl tetrahydrofuran, benzene, cyclohexane, fluorobenzene, thrifluorobenzene, toluene and xylene.
• Other polar solvents which may be used to dissolve polysulfides include: tetraglyme, diglyme, isopropanol, ethyl propional, dimethyl carbonate, dimethoxy ether, ethanol and ethyl acetate, propylene carbonate, ethylene carbonate, diethyl carbonate and such.
• the '270 patent discloses an embodiment in which after the oil stream has been reacted with an alkali metal, the product stream may further be reacted with H 2 S, thereby converting the sodium sulfide products into NaHS (and the nitride products into ammonia gas and NaHS). It should be noted that once these reactions have occurred, the solid products (which contain the heavy metals and the NaHS products) may be washed with the toluene (or other solvent) in the manner outlined herein. This washing liquid will then be removed and the formed liquid (which includes upgraded oil products) may be re-added to the liquid upgraded oil feedstock.
• This heat-treated solid material (which contains NaHS) may then be dissolved in a polar solvent so that the heavy metals may be separated out.
• the resulting liquid material which includes dissolved NaHS and the polar solvent, is added to a cell so that the S and the Na may be recovered, in the manner outlined herein.
• a gas 707 may be added to the reactor 104 to facilitate the reaction of the oil feedstock 701 and the alkali metal 702.
• This reaction with the gas 707 (which may be hydrogen, methane, or another hydrocarbon gas) is described above and in the '874 application.
• the solids 705 and liquids 703 may be separated from each other. This separation may occur within a separator 706. This separation produces separated liquid materials 712 and separated solids 715. The separated solid materials 715 may then be washed, as shown in washing step 720.
• This washing may involve washing 720 the solids 715 with an organic washing liquid 730 such as hexane, heptanes, toluene or mixtures of these substances, or natural gas condensate, or another hydrocarbon liquid.
• the purpose of this washing 720 is to collect any residual oil materials that may have been adhered to the solids 715. (Once washed, the solids may be referred to as "washed solids" or washed solid materials 725.)
• the organic washing liquid 730 may be removed 735. More specifically, the washing liquid 730 will be evaporated off, leaving the organic products that were adhered to the solids 715. These resulting products may then be added/re-mixed with the separated liquids 712, as shown by arrow 719.
• This loss of mass also corresponds with an increase in the carbon to hydrogen ratio of the solid material.
• the heat treating 744 converts some of the coke/organic product within the solids 725 into gases 751 that are emitted during the heat treatment but may be collected for gas products or process value. These gases may be methane or another hydrocarbon gas. (It is the loss of this gas 751 that causes the mass of the solids 725 to be reduced.) Moreover, because a hydrocarbon gas is emitted (such as methane) the overall carbon to hydrogen ratio within the solid materials 725 may be increased.
• the remaining solid materials 753 may be added to a solution comprising a polar solvent 756. More specifically, the solid materials 753 are dissolved 752 (or partially dissolved) in a solution comprising a polar solvent 756.
• This solution comprising a polar solvent 756 has a boiling temperature above 130 °C and specific gravity less than 2 g/cc.
• the solid materials 753 contain some sulfide, hydrogen sulfide and/or polysulfide anions contained therein. Accordingly, the polar solvent 756 must be selected so that at least some sulfide, hydrogen sulfide and/or polysulfide anions dissolve 752 therein.
• the catholyte compartment 784 at least partially houses a cathode 793.
• the catholyte compartment 784 also includes a catholyte 787.
• the cell 775 further comprises an alkali ion conductive membrane 795.
• This membrane 795 is substantially impermeable to sulfide, hydrogen sulfide or polysulfide anions, the catholyte, the anolyte, and sulfur. This membrane 795 separates the catholyte compartment 784 from the anolyte compartment 780.
• the alkali ion conductive membrane 795 allows alkali metal ions to pass through the alkali metal ion conductive membrane 795 from the anolyte compartment 780 to the catholyte compartment 784.
• the alkali ion conductive membrane 795 is selected from the group consisting of an alkali metal conductive ceramic, a glass ceramic; and a solid MSICON (Metal Super Ion CONducting) material, where M is Na or Li.
• Alkali metal ions in the catholyte compartment 784 are reacted to form elemental alkali metal 798.
• the cell 775 and/or the anolyte compartment 780 is maintained at a temperature that is greater than or equal to 1 15 °C such that the produced sulfur 797 is in the liquid phase.
• the catholyte 787 in the catholyte compartment may comprise an alkali metal salt selected from the group consisting of an alkali metal chloride, bromide, iodide, perchlorate, and hexafluorophosphate.
• the catholyte 787 may also include a catholyte solvent selected from group consisting of tetraglyme, diglyme, dimethyl carbonate, dimethoxy ether, propylene carbonate, ethylene carbonate, and diethyl carbonate. Also if the temperature is above the melting temperature of the alkali metal, the molten alkali metal may serve as the catholyte.
• These heat treated solid materials 814 may then be dissolved 816 in a solution comprising polar solvent 813.
• This dissolving forms a liquid material 832 and a solid material 830.
• the liquid materials may be separated (using separating techniques 826) such that the liquid materials 832 are isolated from the remaining solids 830.
• These remaining solids 830 may comprise heavy metals or other materials that were formed during the reaction between the organic oil feedstock and the alkali metal.
• the solution comprising polar solvent 813 used to dissolve the materials may have a boiling temperature above 130 °C and specific gravity less than 2 g/cc.
• This solution comprising polar solvent 813 should be selected such that sulfide anions, polysulfide anions and/or hydrogen sulfide anions have at least some solubility in the solution comprising polar solvent 813.
• the liquid materials 832 which includes the solution comprising polar solvent 813 and sulfide anions, polysulfide anions and/or hydrogen sulfide anions is added (as shown by arrow 840) to an electrolytic cell 875.
• This electrolytic cell 875 may be electrolyzed. In general, this electrolyzing may occur at a temperature that is greater or equal to 1 15 °C so that any sulfur formed in the cell 875 is in its liquid phase.
• the cell 875 comprises an anode 893 and a cathode 891.
• the anode 893 is at least partially housed in an anolyte compartment 884.
• the anolyte compartment 884 will generally include a liquid anolyte 887.
• the liquids 832 mix with the liquid anolyte 887.
• the cell 875 may also include a catholyte compartment 880.
• the anolyte compartment 884 and the catholyte compartment 880 are separated by an alkali metal ion conductive membrane 895.
• x ranges from 0 to about 8 but may be greater.
• some of the anolyte 887 may be removed (as shown by arrow 866) from the bottom 867 of the electrolytic cell 875.
• the removed anolyte 866 comprises a portion of the produced elemental sulfur 870.
• This elemental sulfur 870 may then be separated from the anolyte 866 via a separator 862. Once separated, the sulfur 870 may then be sold, used etc. Further, after the sulfur 870 has been separated, the anolyte may be returned to the cell 875, as shown by arrow 869.
• the sulfur free anolyte may also serve as the solution comprising polar solvent, 813.
• Figure 4 shows one example of the way in which sulfur 870 may be separated; however, other embodiments for separating the sulfur 870 may also be used.
• the rollers 871 facilitate the transfer of the outside portion 891 b to within the cell 875 and facilitate the movement of the inside portion 891 a outside of the cell 875.
• the inside portion 891 a of the cathode 891 can be transferred outside the catholyte compartment 880 and the outside portion 891 b can be transferred inside the catholyte compartment 880 without substantially interrupting the operation of the electrolytic cell 875.
• the reacted feedstock 902 may be filtered 910, such that filtered solids 91 1 are removed.
• This filtering may remove suspended solids such as suspended alkali metal sulfides or other alkali metal salts such as napthanic acid salts.
• a solution comprising polar solvent 912 may be added to the liquid (as shown by line 919).
• the solution comprising polar solvent 912 comprises water 912a.
• other polar solvents may be used as the solution comprising polar solvent 912.
• This solution comprising polar solvent 912 may include water mixed with another polar solvent.
• This polar solvent 912/water 912a is designed to dissolve alkali metal salts that are present in the liquid stream.
• a polar organic solvent was mixed with the heat treated solids.
• the polar solvent liquid went from clear to yellow indicating dissolution of the sodium sulfide.
• the liquid solution was filtered to remove any undissolvable solids and then the liquid was added to an electrolysis cell with NaSICON membrane.
• the cell was operated at 130 °C and constant current of 60 milliamps per centimeter squared current density.
• the cell initially had an open circuit potential of 1 .8 V which later steadily rose to 2.5 V at which time 95% of the sulfur had been electrochemically reduced to its elemental form.
• An electrolytic flow cell may utilize a 1 " diameter NaSICON membrane with approximately 3.2 cm 2 active area.
• the entire system may preferably have temperature control with a maximum temperature of 150 °C and also be configured to be bathed in a dry cover gas.
• the system preferably may also have a power supply capable of delivering to 5 VDC and up to 100 mA/cm 2 .

Landscapes

• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Inorganic Chemistry (AREA)
• Electrolytic Production Of Metals (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=48905789

Family Applications (1)

Country Status (8)

Families Citing this family (2)

Family Cites Families (16)

• 2013
  • 2013-01-30 EP EP13744384.2A patent/EP2809748B1/de active Active
  • 2013-01-30 SG SG11201404513XA patent/SG11201404513XA/en unknown
  • 2013-01-30 WO PCT/US2013/023850 patent/WO2013116340A1/en active Application Filing
  • 2013-01-30 KR KR1020147024289A patent/KR101926905B1/ko active IP Right Grant
  • 2013-01-30 JP JP2014555672A patent/JP6099676B2/ja active Active
  • 2013-01-30 ES ES13744384.2T patent/ES2650952T3/es active Active
  • 2013-01-30 CA CA2863357A patent/CA2863357C/en active Active
• 2015
  • 2015-03-27 HK HK15103142.4A patent/HK1202573A1/xx not_active IP Right Cessation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events