A method to reduce coke formation in heavy oil upgrades using supercritical water.

Abstract

Processes to reduce the formation of coke and coke precursors in supercritical water may include the steps of: generating supercritical water by heating and pressurizing feedwater; mixing the supercritical water with heated and pressurized feedwater in a mixing unit to create a mixed feedstream; supplying the mixed feedstream to a supercritical water reactor to generate an upgrade product; generating a cooled and depressurized upgrade product; separating the cooled and depressurized product into a liquid hydrocarbon nodule and a hydrocarbon vapor stream in a fractional distillation unit; condensing the hydrocarbon vapor stream in a cooling unit to generate a light hydrocarbon water mixture and another gaseous product; and recirculating the light hydrocarbon water mixture and mixing it with feedwater upstream of the supercritical water reactor.

Description

Description of Related Applications

[0001] This application claims the benefit of U.S. Patent Application No. 18 / 194,974, filed on April 3, 2023, the entire disclosure of which is incorporated herein by reference.

Technical Field

[0002] Embodiments of the present disclosure broadly relate to supercritical water processes for upgrading heavy oils, and more particularly to preventing the formation of coke and coke precursors in the upgrading process.

Background Art

[0003] Conventionally, upgrading of heavy oils has been carried out by hydrogenation methods and carbon removal methods. In hydrogenation, heavy oil is delivered to one or more catalytic reactors while externally supplying hydrogen, and is decomposed, isomerized, alkylated, hydrogenated, desulfurized, denitrified, deoxygenated, and demetallized. Generally, the products from the hydrogenation route are in a state suitable for sale as fuels that customers can use or other appropriate petroleum products. However, the hydrogenation route requires high capital costs and operating expenses. In most refineries, for the large consumption of hydrogen, in addition to a catalytic reforming unit that aromatizes paraffinic naphtha to produce aromatic compounds and hydrogen, an additional hydrogen production plant is required. Furthermore, the processes operating in the hydrogenation route have strict restrictions on raw materials. For example, a certain fixed-bed hydrodesulfurization process cannot accept high-asphaltene raw materials because of the short catalyst life and the sudden increase in pressure in the reactor.

[0004] In contrast, conventional carbon removal pathway processes, such as coking, ideally do not require catalyst and hydrogen supply, but the products from these pathways often fail to meet market specifications. Supercritical water is a carbon removal pathway that minimizes the drawbacks of conventional carbon removal pathways while enjoying the advantages of eliminating the need for external hydrogen supply, including reduced complexity and lower operating costs. By using supercritical water, it becomes possible to uniformly transfer heat to hydrocarbons in crude oil during pyrolysis. Supercritical water also reduces coke formation and improves the yield of liquid products by diluting hydrocarbons in crude oil and forming a cage of supercritical water molecules around the hydrocarbons, thereby suppressing interradical reactions. By surrounding radical species with supercritical water, also known as the cage effect, the yield of the product can be better than that of conventional coking processes.

[0005] Despite the various advantages of supercritical water, the process presents technical challenges that need to be overcome, including high energy requirements and high equipment costs. Furthermore, due to the limited availability of hydrogen and the harsh reaction conditions, supercritical water upgrading processes can undesirably lead to the formation of materials that clog the reactor, such as solid coke.

[0006] In crude oil, light hydrocarbons and marten fractions have high solubility in supercritical water (ScW) and therefore dissolve quickly in supercritical water after contact. At the same time, heavy hydrocarbons and asphaltene fractions do not dissolve easily and therefore remain in the oil phase. Aromatic polycyclic hydrocarbons such as asphaltenes, which are precursors to solid coke, can be converted into solid coke when exposed to high temperatures, such as the temperature of supercritical water or temperatures exceeding 400°C. When coke is produced in this way, clogging increases undesirably and is therefore detrimental to the supercritical water upgrading process. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Therefore, improved supercritical water processes and systems are needed to reduce coke formation. [Means for solving the problem]

[0008] Embodiments of this disclosure satisfy the need to reduce coke formation by improving the dissolution and dispersion of aromatic polycyclic hydrocarbons such as asphaltenes in supercritical water. Specifically, embodiments of this disclosure improve the dissolution of aromatic polycyclic hydrocarbons such as asphaltenes by generating light hydrocarbon products, thereby suppressing coke formation without sacrificing process performance. Furthermore, this disclosure recycles light products consisting of light hydrocarbons and water. Referring to Figure 1, marten and asphaltenes have different coking profiles. Marten, which is highly soluble in supercritical water, requires a longer time to form coke than asphaltenes. The time required to form coke is called the induction period. When asphaltenes are mixed with martenes, the induction period of asphaltenes is extended. Therefore, by delaying the separation of asphaltenes and martenes into the separation phase for as long as possible, the exposure time of asphaltenes to high temperatures can be limited, thereby limiting coke formation. Although not theoretically limited, it was unexpectedly found that by recirculating a mixture of light hydrocarbons and water for reuse within the ScW reactor, these recirculated liquid hydrocarbons slowed the separation phase of asphaltenes and martennes, thereby extending the induction period for coke formation. This increases the residence time within the ScW and, therefore, improves the upgrading performance, i.e., increases conversion and desulfurization.

[0009] One or more of the present disclosures provide a process for reducing coke or coke precursors in supercritical water. The process may include the step of generating a supercritical water flow by heating and pressurizing feedwater. The process may further include the step of mixing the supercritical water flow with pressurized and heated feedwater in a mixer to create a mixed feedflow. The process may further include feeding the mixed feedflow into a supercritical water (ScW) reactor to produce an upgrade product, where the supercritical water reactor operates at a temperature higher than the critical temperature of water and a pressure higher than the critical pressure of water. The process may further include the steps of cooling and depressurizing the upgrade product to produce a cooled and depressurized upgrade product; separating the cooled and depressurized upgrade product into a liquid hydrocarbon flow and a hydrocarbon vapor flow in a fractional distillation unit; condensing the hydrocarbon vapor flow in a cooler to produce a light hydrocarbon water mixture and another gaseous product; and recirculating the light hydrocarbon water mixture and mixing it with feedwater upstream of the supercritical water reactor. [Brief explanation of the drawing]

[0010] The following detailed description of specific embodiments of this disclosure can be best understood when read in conjunction with the following drawings. [Figure 1] A graph showing the formation of coke at high temperatures by asphaltene compared to the coexistence of asphaltene and martenne (heptane-soluble fraction). [Figure 2] A schematic diagram of a method for reducing coke formation in heavy oil upgrading using supercritical water, according to one or more embodiments of the present disclosure. [Figure 3] Schematic diagram of a conventional supercritical water upgrading process [Modes for carrying out the invention]

[0011] definition As used throughout this disclosure, “crude oil” means whole-range crude oil, distilled crude oil, residue, head oil, product streams from oil refineries, product streams from steam cracking processes, liquefied coal, liquid products recovered from oil sands or tar sands, bitumen, oil shale, asphaltenes, biomass-derived hydrocarbons, liquid products from gas-to-liquid (GTL) processes, liquid products from chemical recycling of waste plastics / mundaneous waste, and other similar petroleum oils.

[0012] As used in this disclosure, “effluent” refers to the flow discharged from a reactor, reaction zone, or separation unit after a particular reaction or separation. Generally, effluent has a different composition from the flow that entered the separation unit, reactor, or reaction zone. It should be understood that if effluent is sent to another system unit, only a portion of the system flow will be sent. For example, a slip flow may carry away some of the effluent, meaning that only a portion of the effluent may enter the downstream system unit.

[0013] As used throughout this disclosure, “heavy fraction” refers to the portion of crude oil containing compounds having a boiling point of 650°F (approximately 340°C) or higher, as measured at true boiling point (TBP). In a non-limiting example, crude oil has 10% by mass of heavy fraction if 10% of the compounds in the crude oil have a boiling point of 650°F (approximately 340°C) or higher, as measured at true boiling point.

[0014] As used throughout this disclosure, “supercritical water” or “ScW” refers to water at a temperature higher than the critical temperature of water and at a pressure higher than the critical pressure of water.

[0015] As used herein, "marten" refers to a marten fraction soluble in alkanes such as n-heptane and n-pentane.

[0016] As used herein, “asphaltene” refers to an asphaltene fraction insoluble in alkanes such as n-heptane and n-pentane.

[0017] As used herein, “reactor” refers to a vessel in which one or more chemical reactions can take place between one or more reactants, in the presence of one or more catalysts as may be required. For example, a reactor may include a batch reactor, a continuous stirred tank reactor (CSTR), or a tank or tubular reactor configured to operate as a tubular reactor. Exemplary reactors include packed bed reactors, such as fixed bed reactors, and fluidized bed reactors. One or more “reaction zones” may be arranged within a reactor. As used herein, “reaction zone” refers to a volume in the reactor in which a particular reaction takes place. For example, a packed bed reactor with multiple catalyst beds may have multiple reaction zones, each reaction zone defined by the volume of each catalyst bed.

[0018] As used herein, “residence time” refers to the amount of time it takes for a feed stream to enter and exit the processing units, reactors, and separators described herein.

[0019] As used herein, “separation unit” or “separator” refers to any separation device that separates one or more chemical substances mixed in a process stream from each other, at least partially. For example, a separation unit can selectively separate different chemical species, phases, or materials of different sizes from each other to form one or more chemical fractions. Examples of separation units include, without limitation, distillation columns, distillation towers, flash drums, knockout drums, knockout pots, centrifuges, cyclones, filters, traps, scrubbers, expansion devices, membranes, solvent extractors, etc. It should be understood that the separation processes described herein may not completely separate all of one chemical component from all of another. It should be understood that the separation processes described herein separate different chemical components from each other “at least partially,” and that separation may include only partial separation, even if not explicitly stated otherwise. As used herein, one or more chemical components can be “separated” from a process stream to form a new process stream. Generally, a process stream enters a separation unit and may be divided or separated into two or more process streams of a desired composition. Furthermore, in some separation processes, a "low-boiling fraction" (sometimes referred to as a "light fraction" or "light fraction stream") and a "high-boiling fraction" (sometimes referred to as a "heavy fraction," "heavy hydrocarbon fraction," or "heavy hydrocarbon fraction stream") may exit the separation unit, where, on average, the contents of the low-boiling fraction stream have lower boiling points than the high-boiling fraction stream. Other streams may fall between the low-boiling and high-boiling fractions, such as an "intermediate-boiling fraction."

[0020] Referring to Figure 2, a system and method for suppressing coke formation in the upgrading of heavy oil using supercritical water are illustrated. This method includes the step of generating a supercritical water flow 50 by heating and pressurizing feedwater 7. As shown in the figure, feedwater 7 is supplied to a mixer 5, for example, a mixer tee that mixes feedwater 7 and recirculated feed 280 into mixed feedwater 40, as detailed below.

[0021] The feed water 7 may contain demineralized water, which may have a conductivity of less than 1 microsiemens (μS) / centimeter (cm), preferably less than 0.5 μS / cm, more preferably less than 0.1 μS / cm. The feed water may have a sodium content of less than 5 μg / l, preferably 1 μg / l; a chloride content of less than 5 μg / l, preferably 1 μg / l; and a silica content of less than 3 μg / l. The recirculation feed 280 and the mixed feed water 40 may have the same or similar composition.

[0022] Various temperatures are considered suitable for the feed water 7. For example, the temperature can be ambient temperature or higher. In addition, various pressures are considered for the feed water 7. In one or more embodiments, the pressure of the feed water 7 can be from 1 to 100 psig (about 6.9 to about 690 kPaG), or from 1 to 20 psig (about 6.9 to 140 kPaG). The recirculation feed 280 and the mixed feed water 40 may have the same or similar processing conditions.

[0023] The mixed feed water 40 can then be pressurized using a pressurizing device 10 such as a compressor to produce a pressurized feed water 45. The pressurized feed water 45 may have a pressure of at least 3,200 psig (about 22 MPaG), from 3,200 to 5,200 psig (about 22 to 36 MPaG), from 3,200 to 4,200 psig (about 22 to 29 MPaG), or from 3,500 to 4,500 psig (about 24 to 31 MPaG).

[0024] Next, the pressurized feed water 45 is heated in a heating device 22 such as a heat exchanger 22 to obtain supercritical water 50. The supercritical water 50 may have a pressure of at least 3,200 psig (about 22 MPaG), from 3,200 to 5,200 psig (about 22 to 36 MPaG), from 3,200 to 4,200 psig (about 22 to 29 MPaG), or from 3,500 to 4,500 psig (about 24 to 31 MPaG). The supercritical water 50 may have a temperature of at least 374 °C, from 374 to 600 °C, or from 400 to 500 °C.

[0025] Referring again to FIG. 2, the supercritical water 50 is mixed with the pressurized and heated fuel oil 70 in the mixing device 25 to create a mixed supply stream 80.

[0026] The fuel oil 3 may include any hydrocarbon derived from petroleum, coal, coal liquefied oil, biomass, plastic, whole range crude oil, distilled crude oil, residual oil, topped crude oil, product streams from petroleum refineries, product streams from steam cracking processes, liquefied coal, liquid products recovered from oil sands or tar sands, bitumen, oil shale, asphaltenes, biomass-derived hydrocarbons, or liquid hydrocarbons from thermal decomposition of plastics. The fuel oil may have a boiling point above 200°C or above 316°C. In certain embodiments, the fuel oil may contain more than 4% by mass sulfur, at least 2500 ppm nitrogen, and at least 15% by mass Conradson carbon residue.

[0027] Various temperatures are considered suitable for the fuel oil 3. For example, the temperature can be above ambient temperature. In certain embodiments, the fuel oil 3 may have a temperature of 25 to 300°C, 50 to 250°C, or 100 to 200°C. In addition, various pressures are considered for the fuel oil 3. In one or more embodiments, the pressure of the fuel oil 3 may be 1 to 100 psig (about 6.9 to about 690 kPaG), or 1 to 20 psig (about 6.9 to 140 kPaG).

[0028] The fuel oil 3 can then be pressurized using a pressurizing device 15 such as a compressor to produce a pressurized fuel oil 65. The pressurized fuel oil 65 may have a pressure of at least 3,200 psig (about 22 MPaG), 3,200 to 5,200 psig (about 22 to 36 MPaG), 3,200 to 4,200 psig (about 22 to 29 MPaG), or 3,500 to 4,500 psig (about 24 to 31 MPaG).

[0029] Next, the pressurized oil supply 65 is heated in the heating device 20 to obtain the pressurized and heated oil supply 70. The heating device 20 can be selected from an electric heater, a gas combustion heater, a fuel oil combustion heater, a heat exchanger, or a combination thereof. The pressurized and heated oil supply 70 may have a pressure of at least 3,200 psig (approximately 22 MPaG), 3,200 to 5,200 psig (approximately 22 to 36 MPaG), 3,200 to 4,200 psig (approximately 22 to 29 MPaG), or 3,500 to 4,500 psig (approximately 24 to 31 MPaG). The pressurized and heated oil supply 70 may have a temperature of at least 100°C, 100 to 300°C, 100 to 250°C, or 150 to 200°C.

[0030] Referring again to Figure 2, the supercritical water flow 50 is mixed with pressurized and heated oil 70 in the mixing device 25 to create a mixed feed flow 80. The mixing device 25 can be selected from a static mixer, an in-line mixer, an impeller-integrated mixer, a CSTR type mixer, and a combination thereof. In this embodiment, it is stated that the supercritical water 50 is mixed with the pressurized and heated oil 70 in the mixing device 25 located upstream of the supercritical water reactor 30, but other options are also conceivable, for example, mixing the supercritical water flow 50 and the pressurized and heated oil 70 within the supercritical water reactor 30.

[0031] The mixed feed stream 80 may have a pressure of at least 3,200 psig (approximately 22 MPaG), 3,200 to 5,200 psig (approximately 22 to 36 MPaG), 3,200 to 4,200 psig (approximately 22 to 29 MPaG), or 3,500 to 4,500 psig (approximately 24 to 31 MPaG). The mixed feed stream 80 may have a temperature of at least 374°C, 374 to 500°C, or 374 to 425°C.

[0032] As shown in Figure 2, the mixed feed stream 80 is supplied to the supercritical water (ScW) reactor 30 to produce the upgrade product 100. In some embodiments, the mixed stream may be preheated in a heater (not shown) before being supplied to the ScW reactor. The ScW reactor can be selected from tubular, tank, CSTR type, or a combination thereof. The preferred reactor type is tubular. The ScW reactor may have an external or internal heater to control the fluid temperature to a predetermined level. The heater can be selected from an electric heater, a combustion heater, and a heat exchanger.

[0033] The residence time in the reactor can range from 0.1 to 120 minutes, or from 1 to 60 minutes. The residence time is calculated assuming the internal fluid is 100% water (for density calculation purposes).

[0034] Next, the upgrade product 100 can be cooled using a cooling device 110 such as a heat exchanger to produce a cooled upgrade product 120. The cooled upgrade product 120 may have a temperature of less than 374°C, 100 to 350°C, 200 to 300°C, or 225 to 275°C.

[0035] Next, the cooled upgrade product 120 can be depressurized using a depressurizing device 130 such as a valve to produce a cooled and depressurized upgrade product 150. The cooled and depressurized upgrade product 150 may have a temperature of less than 374°C, 100 to 350°C, 150 to 300°C, or 150 to 200°C. The cooled and depressurized upgrade product 150 may have a pressure of less than 3,200 psig (approximately 22 MPaG), 10 to 650 psig (69 to 4500 kPaG), or 150 to 300 psig (approximately 1000 to 2100 kPaG).

[0036] Referring again to Figure 2, the cooled and depressurized upgrade product 150 can then be separated into a liquid hydrocarbon flow 400 and a hydrocarbon vapor flow 200 in a fractional distillation unit 160. The fractional distillation unit 160 may include various suitable devices, such as a flash drum. The flash drum may have internal structures such as mesh pads, diffusers, valves, or other components familiar to those skilled in the art. The flash drum may have external or internal heaters or coolers to control the temperature of the internal fluid to perform superheating or supercooling.

[0037] Each of the liquid hydrocarbon streams 400 and 200 may have a pressure of less than 3,200 psig (approximately 22 MPaG), between 10 and 650 psig (69 to 4500 kPaG), or between 150 and 300 psig (approximately 1000 to 2100 kPaG). Furthermore, each of the liquid hydrocarbon streams 400 and 200 may have a temperature of less than 374°C, between 100 and 350°C, between 150 and 300°C, or between 150 and 300°C.

[0038] In one or more embodiments, the hydrocarbon vapor stream from the fractional distillation unit 160 can be sent to a cooling device 210, such as a condenser, to produce a light hydrocarbon water mixture 280 and another gaseous product 260. The light hydrocarbon water mixture 280 can then be recirculated and mixed with feedwater 7 upstream of the supercritical water reactor 30. The gaseous product 260 may include H2, CO, CO2, H2S, NH3, H2O, and one or more C1-C5.

[0039] The light hydrocarbon aqueous mixture 280 may be mainly water, or 95% to 99.5% by mass of water. Furthermore, the light hydrocarbon aqueous mixture 280 may contain 0.5 to 5% by mass of hydrocarbons. The hydrocarbons in the light hydrocarbon aqueous mixture 280 include paraffins, olefins, naphthenes, and aromatic compounds. In the embodiment, the hydrocarbons may contain 30 to 60% by mass, 30 to 45% by mass, or 30 to 40% by mass of paraffins, based on the mass of hydrocarbons. In the embodiment, the hydrocarbons may contain 10 to 70% by mass, 20 to 60% by mass, or 40 to 50% by mass of olefins, based on the mass of hydrocarbons. Furthermore, the hydrocarbons may contain 0 to 10% by mass, 2 to 8% by mass, or 4 to 6% by mass of naphthenes, based on the mass of hydrocarbons. Furthermore, the hydrocarbons may contain 5 to 60% by mass, 5 to 40% by mass, 10 to 30% by mass, or 15 to 25% by mass of aromatic compounds, based on the mass of the hydrocarbons. Although not limited by theory, aromatic compounds assist in the dispersion and dissolution of heavy hydrocarbons and asphaltenes in supercritical water.

[0040] In the embodiments, the majority of the hydrocarbons may be C2-C8 hydrocarbons. Although not theoretically limited, the 90% distillation temperature (T90) of the hydrocarbons in the light hydrocarbon water mixture 280 is less than 450°C, or less than 380°C to ensure that the hydrocarbons dissolve immediately in supercritical water. Furthermore, the light hydrocarbon water mixture 280 is substantially free of inorganic impurities and is suitable for use as feedwater. As used herein, substantially free means that it contains less than 0.1% by mass, less than 0.01% by mass, or less than 0.001% by mass of impurities.

[0041] In the embodiment, the volume ratio of feedwater 7 to feedwater 3 in the ScW reactor may range from 1 / 0.1 to 1 / 10 or from 1 / 0.1 to 1 / 2 at standard ambient temperature and pressure (SATP). Furthermore, the ratio of light hydrocarbon water mixture 280 (i.e., recirculated) to feedwater 7 may range from 1 / 0.5 to 1 / 20 or from 1 / 2 to 1 / 5 at SATP. Although not theoretically limited, the mixture of feedwater 7 and light hydrocarbon water mixture 280 should contain more fresh feedwater than recirculated water. However, the recirculated water should be present in sufficient quantity to have a “solvent” effect on the hydrocarbons in the recirculated water.

[0042] Referring again to Figure 2, the liquid flow 400 may be exposed to gas, water, and oil 410, which generates gas phase products 420, oil phase products 430, and water products 440.

[0043] In an alternative embodiment as shown in Figure 2, the hydrocarbon vapor stream 200 is cooled in a cooler 210 before being supplied to the decomposition unit 225, where it can then be decomposed into two streams 230 and 240. One of the decomposition streams 240 can also be supplied to a gas-water-oil separator 410 for further processing. [Examples]

[0044] Various embodiments of processes and systems for reducing coke formation will become even more apparent in the following examples. These examples are illustrative in nature and should not be understood as limiting the subject matter of this disclosure.

[0045] Examples The example shown in Figure 2 was performed using Aspen HYSYS simulation software. The ScW reactor 30 was tubular with an inner diameter of 25.84 inches (approximately 65.63 cm) and a length of 180.428 feet (approximately 55.00 m). The reactor was vertical (30 feet (approximately 9.1 m) of upward flow, followed by 30 feet (approximately 9.1 m) of downward flow). The residence time of the fluid in the reactor was 1.5 minutes. The flow treatment conditions for the example are shown in Table 1, and the fueling and hydrocarbon properties of the products are shown in Table 2. The composition of the recirculated flow (liquid hydrocarbon flow mixture 280) is given in Table 3.

[0046] [Table 1]

[0047] [Table 2]

[0048] [Table 3]

[0049] Comparative Example The same raw materials were introduced into the comparative process shown in Figure 3. However, as illustrated, this process did not include recirculation. The operating conditions of the comparative process are given in Table 4, and the fueling and hydrocarbon properties of the products are shown in Table 5. The ScW reactors were the same size.

[0050] [Table 4]

[0051] [Table 5]

[0052] In the comparative example, the residence time was approximately 2.7 minutes, which was less than half the residence time of 5.7 minutes in the example. By recirculating hydrocarbons, the example was able to operate for longer residence times without facing clogging due to coke formation. In the comparative example, the residence time had to be minimized due to the risk of coking. In contrast, due to the longer residence time in the example, more desulfurization occurred, specifically achieving a final yield of 1.2% by mass, compared to 3.9% by mass in the comparative example. Furthermore, the example showed a significant reduction in nitrogen and Conradson carbon content compared to the comparative example.

[0053] This application discloses several technical aspects. The first aspect relates to a process for reducing the formation of coke and coke precursors in supercritical water. This process may include the steps of generating a supercritical water flow by pressurizing and heating feedwater, and mixing the supercritical water flow with pressurized and heated feedwater in a mixer to create a mixed feedflow. This process also includes the steps of supplying the mixed feedflow to a supercritical water (ScW) reactor to produce an upgrade product, where the supercritical water reactor operates at a temperature higher than the critical temperature and a pressure higher than the critical pressure of water. This process may also include the steps of generating a cooled and depressurized upgrade product by cooling and depressurizing the upgrade product, separating the cooled and depressurized upgrade product into a liquid hydrocarbon flow and a hydrocarbon vapor flow in a fractional distillation unit, condensing the hydrocarbon vapor flow in a cooler to produce a light hydrocarbon water mixture and another gaseous product, and recirculating the light hydrocarbon water mixture and mixing it with feedwater upstream of the supercritical water reactor.

[0054] A second aspect of this disclosure may include the first aspect, in which a liquid hydrocarbon stream from a fractional distillation unit is sent to a gas-water-oil separator.

[0055] A third aspect of this disclosure may include any of the prior aspects, wherein the fractionation apparatus includes a flash drum.

[0056] A fourth aspect of the present disclosure may include any of the preceding aspects, wherein the light hydrocarbon water mixture comprises 95% to 99.5% by mass of water and 0.5% to 5% by mass of hydrocarbons.

[0057] A fifth aspect of the present disclosure may include any of the preceding aspects, wherein the light hydrocarbon aqueous mixture comprises, on a basis of the mass of hydrocarbons, 30 to 60% by mass of paraffins, 10 to 70% by mass of olefins, 0 to 10% by mass of naphthenes, and 5 to 60% by mass of aromatic compounds.

[0058] A sixth aspect of the present disclosure may include any of the prior aspects, further comprising whole-range crude oil, distilled crude oil, residue, head-grained crude oil, product streams from oil refineries, product streams from cracking processes, liquefied coal, liquid products recovered from oil sands or tar sands, bitumen, oil shale, asphaltenes, biomass-derived hydrocarbons, liquid hydrocarbons from the thermal decomposition of plastics, or a combination thereof.

[0059] A seventh aspect of the present disclosure may include any of the prior aspects, wherein the water supply includes desalinated water having a conductivity of less than 1 microsiemens / centimeter, a sodium content of less than 5 micrograms / liter, a chloride content of less than 5 micrograms / liter, and a silica content of less than 3 micrograms / liter.

[0060] It should be noted that any description in this disclosure of a component being “operable” or “sufficient” in a particular way to embody a particular property or to function in a particular manner is a structural description, as opposed to a description of an intended use. More specifically, any reference in this disclosure to a component being “operable” or “sufficient” describes the existing physical state of the component and is therefore considered an explicit reference to the structural features of the component.

[0061] Furthermore, it should be noted that terms such as “preferably,” “generally,” and “typically,” when used herein, are not intended to limit the scope of the claimed invention or to imply that certain features are significant, essential, or even important to the structure or function of the claimed invention. Rather, these terms are intended simply to identify specific aspects of the embodiments of the disclosure or to highlight alternative or additional features that may or may not be used in specific embodiments of the disclosure.

[0062] Note that the term “here” is used as a transitional clause in one or more of the following claims. Note that for the purpose of defining the present invention, this term is introduced into the claims as an unrestricted transitional clause used to introduce an enumeration of a set of structural features and should be interpreted similarly to the more commonly used unrestricted postscript “includes.”

[0063] While the subject matter of this disclosure has been described in detail and with reference to specific embodiments, it should be noted that the various details disclosed in this disclosure should not be interpreted as implying that these details relate to elements that are essential components of the various embodiments described herein. Furthermore, it will be apparent that modifications and alterations are possible without departing from the scope of this disclosure, including, but not limited to, the embodiments defined in the appended claims.

[0064] The singular form includes multiple subjects unless it is clearly determined from the context that it does not.

[0065] Through this disclosure, a range is provided. Each discrete value included within the range is also assumed to be included. Furthermore, the range that may be formed by each discrete value included by the explicitly disclosed range is also assumed.

[0066] As used herein and in the appended claims, the words “comprise,” “has,” and “include,” and all their grammatical variations, are intended to have an open, non-restrictive meaning that does not exclude any additional elements or processes.

[0067] Where used herein, terms such as “First” and “Second” are arbitrarily assigned and intended solely to distinguish two or more examples or components. It should be understood that the words “First” and “Second” serve no other purpose, are not part of the names or descriptions of components, and do not necessarily define the relative location, position, or order of components. Furthermore, it should be understood that the mere use of the terms “First” and “Second” does not require the existence of any “Third” component, although such possibility is conceivable within the scope of this disclosure. [Explanation of symbols]

[0068] 3. Refueling 5 Mixer 7. Water supply 10, 15 Pressurizing device 20 Heating device 22 Heat exchanger 25 Mixing equipment 30 Supercritical Water Reactor 40 Mixed water supply 45 Pressurized water supply 50 Supercritical water 65 Pressurized lubrication 70 Pressurized and heated oil supply 80 Mixed feed stream 100 Upgrade Products 110, 210 Cooling device 120 cooled upgrade products 150 Cooled and depressurized upgrade product 160 Fractional distillation equipment 200 Hydrocarbon vapor flow 225 Decomposition equipment 280 Recirculated feed 400 liquid hydrocarbon flow 410 Gas, Water, and Oil Separator 420 Gas-phase products 430 Oil phase products 440 Water products

Claims

1. A process for reducing the formation of coke or coke precursors in supercritical water, A process to generate a supercritical water flow by pressurizing and heating the water supply. A process of mixing the supercritical water flow with pressurized and heated oil in a mixing device to create a mixed supply flow. The process involves supplying the aforementioned mixed feed stream to a supercritical water (ScW) reactor operating at a temperature higher than the critical temperature and a pressure higher than the critical pressure of water to produce an upgrade product. A step of producing a cooled and depressurized upgrade product by cooling and depressurizing the upgrade product, A step of separating the cooled and depressurized upgrade product into a liquid hydrocarbon stream and a hydrocarbon vapor stream in a fractional distillation unit. A step of condensing the hydrocarbon vapor stream in a cooling device to produce a light hydrocarbon water mixture and another gaseous product, and The process of recirculating the light hydrocarbon water mixture and mixing it with the feedwater upstream of the supercritical water reactor, A process that includes this.

2. The process according to claim 1, wherein the liquid hydrocarbon stream from the fractional distillation apparatus is sent to a gas-water-oil separator.

3. The process according to claim 1 or 2, wherein the fractionation apparatus includes a flash drum.

4. The process according to any one of claims 1 to 3, wherein the light hydrocarbon water mixture comprises 95% to 99.5% by mass of water and 0.5% to 5% by mass of hydrocarbons.

5. The process according to any one of claims 1 to 4, wherein the hydrocarbon in the light hydrocarbon aqueous mixture comprises, based on the mass of the hydrocarbon, 30 to 60% by mass of paraffins, 10 to 70% by mass of olefins, 0 to 10% by mass of naphthenes, and 5 to 60% by mass of aromatic compounds.

6. The process according to any one of claims 1 to 5, wherein the refueling further comprises whole-range crude oil, distilled crude oil, residue, scalded crude oil, product streams from petroleum refineries, product streams from cracking processes, liquefied coal, liquid products recovered from oil sand or tar sands, bitumen, oil shale, asphaltene, biomass-derived hydrocarbons, liquid hydrocarbons from the thermal decomposition of plastics, or a combination thereof.

7. The process according to any one of claims 1 to 6, wherein the feedwater includes desalinated water, the desalinated water having an conductivity of less than 1 microsiemens / centimeter, a sodium content of less than 5 micrograms / liter, a chloride content of less than 5 micrograms / liter, and a silica content of less than 3 micrograms / liter.

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