KR102355405B1 - Integrated process for the production of mesophase pitch and petrochemical products - Google Patents

Abstract

An integrated method for the production of mesophase pitch and petrochemicals. The method comprises the steps of supplying crude oil to a reaction vessel; heating the crude oil in the reaction vessel to a predetermined temperature for a predetermined time; reducing the asphaltene content in the crude oil by allowing polymerization to occur in the reaction vessel at elevated pressure in the absence of oxygen; producing a three-phase upgraded hydrocarbon product comprising a gaseous, liquid, and solid hydrocarbon component, wherein the liquid hydrocarbon component comprises deasphalted oil and the solid hydrocarbon component comprises a mesophase pitch; separating the gaseous, liquid, and solid hydrocarbon components; directly using the liquid hydrocarbon component for petrochemical production; and directly using the solid hydrocarbon component for carbon artifact production.

Description

Integrated process for the production of mesophase pitch and petrochemical products

Embodiments of the present disclosure relate to upgrading crude oil and crude oil resid. In particular, embodiments of the present disclosure relate to upgrading crude oil and crude oil resid to produce mesophase pitch and additional petrochemical products in an integrated process.

Crude oil and crude oil resid can be processed through an energy-intensive refining process to produce mesophase pitch (also known as MP). The condensed aromatic nature of the pitch provides thermal stability so that the mesophase pitch can be melt spun for use in carbon fiber applications. In some cases, melt spinning is preferably wet/dry spinning, which is used in the production of polyacrylonitrile (PAN)-based fibers and contains large amounts of solvents and waste by-products. High-quality carbon fibers can be produced from optically anisotropic or mesophase pitch (MP), but the production of these carbon fiber precursors requires extensive refining and complex processes, which means that producing carbon fibers from mesophase pitches is not feasible for PAN-based carbon fibers. less desirable than making

Carbon fibers combine high strength and tensile modulus with other desirable properties, such as being lightweight, chemically inert, having low thermal expansion, and having good electrical and thermal conductivity. Smaller structural defects in the fiber morphology and improved molecular orientation enable these properties, making carbon fibers suitable for a number of structural and functional applications.

In direct crude-oil-to-chemicals (C2C) technology, the heavy or asphaltene fraction of crude oil is often problematic, resulting in reactor and thermal surface fouling, catalyst deactivation, cracking ( cracking) decrease activity, and cause overall performance degradation. Separation of these heavy cuts prior to the cracking reactor reduces the economic advantage of cracking crude oil directly into chemicals. Again, C2C is more expensive to crack than vacuum gas oil (VGO) and refinery products such as naphtha.

Challenges associated with crude oil cracking, such as higher coking rates and metal poisoning of catalysts, drive specific research efforts into grime cracking (pyrolysis) and FCC. In some cases, the economics of energy intensive steam crackers are more favorable for lower value and heavier feedstocks such as crude oil. In practice, however, the asphalt and non-volatile fractions of these feedstocks can be placed in the tubes of the convection section of the pyrolysis furnace, thus impairing heat transfer and requiring frequent shutdowns. Several documents discuss handling the heavy resid of crude oil prior to steam cracker application, and many references disclose a pre-separation step for the non-volatile fraction of crude oil.

Direct catalytic cracking of crude oil is rarely discussed because metal poisons such as sulfur and nitrogen in crude oil are harmful to cracking catalysts and equipment. Cracking traditional feedstocks such as naphtha is already relatively easier than cracking feeds with crude oil and resid, and by applying a pre-separation step for asphaltenes and metals in the C2C process, crude oil prior to cracking The economic and competitive advantage of skipping refining is largely eliminated.

The present disclosure provides high quality mesophase pitch (MP) directly from crude oil or crude oil resid with or without hydrotreating by simultaneous removal of asphaltenes to reduce the viscosity and boiling point of heavy crude oil or resid. A heat treatment system and method for producing are provided. The solid (MP), liquid (deasphalted oil, DAO) and gaseous portions of the products of these systems and methods can be fractionated into refined products, direct C2C processes, including steam cracking processes and catalytic cracking processes. can be used as a feed for It is desirable to process crude oil and crude oil resid to produce mesophase pitch, which has a lower boiling point, which can be used to produce high quality carbon fibers. The DAO product can be used directly as gas oil and as a feedstock for cracking processes such as fluid catalytic cracking (FCC) or pyrolysis.

A new thermal pre-treatment method, process and system are disclosed for the production of high quality MP directly from crude oil or its resid with or without hydrotreating (HT). Embodiments of the present disclosure demonstrate that deasphalted oil (DAO) produced during the methods of the present disclosure can be used directly as a feed to a cracking furnace, thus addressing certain coking problems associated with direct crude oil cracking. Mesophase pitch is a valuable byproduct produced during embodiments of the present disclosure, which increases the efficiency of the process.

In embodiments of the present disclosure, a heavy crude oil, such as for example Arabian heavy (AH) crude oil, is converted directly into valuable compounds using heat and pressure. The resulting product in the processing vessel contains a solid phase at room temperature representing about 10% ± 5% by weight of the carbon fraction obtained (depending on feed, temperature, and polymerization time). The liquid phase (“cut”) represents about 80% ± 5% by weight of the carbon fraction obtained, and the gas phase is about 10% ± 5% by weight of the carbon fraction obtained. The liquid and gaseous portions of the products of these processes can be fractionated as petrochemical feedstocks or used as feeds for direct C2C processes including steam pyrolysis and catalytic cracking processes (eg, FCC).

Accordingly, disclosed herein is an integrated method for the production of mesophase pitch and petrochemicals, the method comprising: feeding crude oil to a reaction vessel; heating the crude oil in the reaction vessel to a predetermined temperature for a predetermined time; reducing the asphaltene content in the crude oil by allowing polymerization to occur in the reaction vessel at elevated pressure in the absence of oxygen; producing a three-phase upgraded hydrocarbon product comprising a gaseous, liquid, and solid hydrocarbon component, wherein the liquid hydrocarbon component comprises deasphalted oil and the solid hydrocarbon component comprises a mesophase pitch; separating the gaseous, liquid, and solid hydrocarbon components; directly using the liquid hydrocarbon component for petrochemical production; and directly using the solid hydrocarbon component to produce carbon artifacts.

In some embodiments of the method, the crude oil is a crude oil received directly from a wellhead after being separated from natural gas and dewatered, but not otherwise pretreated prior to the step of feeding the crude oil to the reaction vessel. In another embodiment, the predetermined temperature is from about 350 °C to about 575 °C. In some embodiments, the predetermined temperature is from about 400 °C to about 450 °C. In another embodiment, the method comprises heating the vessel to an initial pressure of from about 145 pounds per square inch gauge (psig) to about 870 psig prior to heating the crude oil in the reaction vessel to a predetermined temperature for a predetermined time. It further comprises the step of pressurizing.

In another embodiment, pressurizing the vessel to an initial pressure comprises evacuating oxygen from the reaction vessel using a gas comprising nitrogen. In certain embodiments, the method further comprises pressurizing the vessel to an initial pressure of about 435 psig to about 725 psig prior to heating the crude oil in the reaction vessel to a predetermined temperature for a predetermined time. In some embodiments, pressurizing the vessel to an initial pressure comprises evacuating oxygen from the reaction vessel using a gas comprising nitrogen. In another embodiment, the predetermined time is from about 2 hours to about 15 hours. In certain embodiments of the method, the predetermined time is from about 4 hours to about 8 hours.

In another embodiment, reducing the asphaltene content reduces the asphaltene content in the deasphalted oil to less than about 2% by weight. In certain other embodiments, the elevated pressure is greater than about 1,000 psig. In another embodiment, the elevated pressure is from about 1800 psig to about 1,900 psig. In certain embodiments of the method, directly using the liquid hydrocarbon component for petrochemical production comprises feeding the deasphalted oil to a fluid catalytic cracking process. In certain embodiments, directly using the liquid hydrocarbon component for petrochemical production comprises feeding the deasphalted oil to a steam cracking process.

In another embodiment, directly using the solid hydrocarbon component for producing the carbon artifact comprises producing carbon fibers from the mesophase pitch. In certain embodiments, the crude oil comprises: heavy crude oil; light crude oil; and at least one hydrocarbon selected from the group consisting of crude oil resid having a boiling point greater than about 500°C.

In another embodiment, the asphaltene compound content of the deasphalted oil is reduced by at least about 50% by weight compared to the asphaltene compound content of the crude oil. In certain embodiments, the asphaltenes content of the deasphalted oil is reduced by at least about 90% by weight relative to the asphaltenes content of the crude oil. Also in an alternative embodiment, the metal content in the liquid hydrocarbon component is less than the metal content in the crude oil. In some embodiments, the solid hydrocarbon component is at least about 90% pure mesophase pitch. In another embodiment, reducing the asphaltene content in the crude oil by allowing the polymerization reaction to occur in the reaction vessel at elevated pressure in the absence of oxygen increases the pressure in the reaction vessel from about 1,700 psig to about 2,500 psig.

Further disclosed herein is an integrated system for mesophase pitch and petrochemical production, the system comprising: a source of crude oil fluidly connected to a reaction vessel, the reaction vessel operable to be heated to a predetermined temperature for a predetermined time, and operable to reduce the asphaltene content in the crude oil source by allowing the polymerization reaction to occur in the reaction vessel at elevated pressure in the absence of oxygen; A three-phase gas, liquid, solid separator operable to separate a three-phase upgraded hydrocarbon product produced in the reaction vessel, the three-phase upgraded hydrocarbon product comprising a gaseous, liquid, and solid hydrocarbon component, wherein the liquid hydrocarbon component comprises deasphalted oil and the solid hydrocarbon component comprises mesophase pitch; and a cracking unit, wherein the cracking unit is fluidly connected to receive the liquid hydrocarbon component and crack the liquid hydrocarbon component for petrochemical production.

In some embodiments of the system, the system further comprises a unit for producing carbon fibers from the mesophase pitch. In some embodiments, the predetermined temperature is from about 350 °C to about 575 °C. In another embodiment, the predetermined temperature is from about 400 °C to about 450 °C. In another embodiment, the predetermined time is from about 2 hours to about 15 hours. In certain embodiments, the predetermined time is from about 4 hours to about 8 hours. In some embodiments, the asphaltene content in the deasphalted oil is less than about 2% by weight. In another embodiment, the elevated pressure is greater than about 1,000 psig. In certain embodiments, the elevated pressure is from about 1,800 psig to about 1,900 psig. In another embodiment, the cracking unit comprises a fluid catalytic cracking process.

In some embodiments, the cracking unit comprises a steam cracking process. In another embodiment, the crude oil comprises at least one hydrocarbon selected from the group consisting of: heavy crude oil, light crude oil, and crude oil resid having a boiling point greater than about 500 °C. In an embodiment of the continuous system, the asphaltenes content of the deasphalted oil is reduced by at least about 50% by weight relative to the asphaltenes content of the crude oil source. In another embodiment, the asphaltenes content of the deasphalted oil is reduced by at least about 90% by weight relative to the asphaltenes content of the crude oil source. In some embodiments, the metal content in the liquid hydrocarbon component is less than the metal content in the crude oil source.

In another embodiment of the system, the solid hydrocarbon component is at least about 90% pure mesophase pitch. In another embodiment, the elevated pressure in the reaction vessel is from about 1,700 psig to about 2,500 psig.

These and other features, aspects, and advantages of the present disclosure will be better understood in conjunction with the following description, claims, and accompanying drawings. It should be noted, however, that the drawings illustrate only several embodiments of the present disclosure and, therefore, are not to be considered limiting of the scope of the present disclosure, as other equally effective embodiments may be admitted.
1 is a mechanical flow diagram illustrating a system and method for one exemplary embodiment of a direct C2C production process.
2 is a mechanical diagram showing the experimental setup for the disassembly experiment of the present disclosure.
3 shows optical microscopy images of mesophase pitches obtained using embodiments of the present disclosure at 100 micrometer (μm), 50 μm, and 20 μm scales, wherein crude oil and crude oil resid samples were sampled at a temperature of 425° C. , and 650 revolutions per minute (rpm) for 6 h.
4 is a graph showing X-ray diffraction (XRD) data for mesophase pitch obtained using an embodiment of the present disclosure, wherein crude oil and crude oil resid samples were sampled at a temperature of 425° C. and 650 rpm for 6 hours. was processed at a stirring rate of

Accordingly, the features and advantages of the embodiments of the systems and methods of the integrated process for the production of mesophase pitch and petrochemical products in this manner, as well as others that will become apparent, may be understood in greater detail and of the embodiments of the present disclosure briefly summarized above. For a more specific description, reference may be made to embodiments thereof, illustrated in the accompanying drawings, which form a part hereof. It should be noted, however, that the drawings are not to be considered limiting of the scope of the present disclosure, as the drawings merely illustrate various implementations of the present disclosure, and thus may include other effective implementations as well.

Referring first to FIG. 1 , a mechanical flow diagram illustrating a system and method for one embodiment of a direct crude-to-chemicals (C2C) production process is provided. In an embodiment of the present disclosure, an integrated thermal pretreatment process to produce mesophase pitch (MP) in addition to upgraded crude oil, also referred to as deasphalted oil or DAO, with very low concentrations of asphaltenes and heavy metals. Different scenarios are shown for Products such as MP can be used directly for carbon fiber production, and DAO can be used as a direct feed in C2C technologies such as fluid catalytic cracking (FCC) and pyrolysis (steam cracking). An embodiment of the thermal pretreatment step includes extended thermal polymerization under mild decomposition conditions. The result is MP, gas cracking products, and liquid DAO. Liquid and gaseous products can be fractionated as petrochemical feedstocks or used directly as feeds for C2C processes. The process can be integrated with traditional steam/catalytic cracking systems, providing solutions to previously mentioned problems such as metal poisoning of catalysts and coke precursors.

The term crude oil in this disclosure includes reference to liquid crude oil from wellheads separated from natural gas. As defined, the crude oil feed of the present disclosure is subjected to a treatment process such as desalting which makes the feed suitable for transport, however, in some embodiments, the crude oil feed input is not subjected to any distillation or fractional pretreatment of any kind. Crude oil includes arabic light, extra light arabic, heavy arabic, and American petroleum varying from about 39° to about 6°, or varying from about 30° to about 6°, or varying from about 21° to about 6°. It may include other types of crude oil having an Association (API) number. In some embodiments described herein, "thermal" pretreatment of crude oil occurs at elevated temperature and pressure in a substantially inert atmosphere, such as under nitrogen or an inert atmosphere, such as argon, however, In some embodiments of the thermal pretreatment step, no solvent and other chemical reactants are added to the crude oil.

American Petroleum Institute (API) specific gravity is a measure of how "heavy" or "light" a petroleum liquid is. The relationship between API specific gravity and specific gravity (SG) at 60°F is API = (141.5 / SG)-131.5. Crude oil in Saudi Arabia with an API gravity greater than about 32° is referred to as Arabian Light or "AL", and crude oil with an API gravity less than about 28° is referred to as Arabian Heavy or "AH". Throughout this disclosure, hydrotreated ("AT") resid of Arabian Light Crude Oil is also referred to as "C2C" (Crude-to-Chemical) Reject, the term After that, the residue obtained with a boiling point greater than about 500° C. is identified. For example, on one scale, Arabian Heavy is about 10°≧API≧6°; Arabian medium is about 21°≧API≧10°; Arabian Hard is about 30°≧API≧21°; Arabic superhard is 39°≥API≥30°.

As shown in FIG. 1 , process 100 includes raw, optionally desalted and stabilized for transport from a well head separated from natural gas, but otherwise raw, unfractionated, and undigested. , starting with the crude oil source 102. An embodiment of the thermal pretreatment step for the crude oil source 102 includes heating the raw crude oil source 102 under an inert atmosphere or a substantially inert atmosphere, wherein the atmosphere is substantially free of oxygen (eg, , less than about 5% oxygen by volume, or less than about 1% oxygen by volume). As shown in FIG. 1 , the substantially inert atmosphere may include nitrogen gas in addition to or in place of one or more inert gases, such as argon or helium. Hydrogen (H ₂ ) and other treatment additives may optionally be added to the raw crude oil source 102 , but are not required.

Embodiments of the process of the present disclosure include heat treatment under an atmosphere of inert nitrogen or argon or helium, without additional additives. However, additives may be added to the inert gas stream or crude oil cofeed to improve polymerization yields and to adjust the properties of the mesophase pitch (eg to reduce its softening point). Optional additives may include hydrogen in addition to or alternatively to organic salts.

The incoming crude oil enters a high pressure high temperature (HPHT) heated reactor 106 at inlet 104 , which is optionally under agitation by a stirrer 108 . A volume of crude oil enters the HPHT heated reactor 106 to create an empty space near the top of the HPHT heated reactor 106, the volume of which can be changed and occupied by nitrogen in addition to or in lieu of other inert gases. have. The void space having an inert or substantially inert atmosphere can occupy from about 10% to about 80% by volume of the HPHT heated reactor 106 , or from about 30% to about 50% by volume of the HPHT heated reactor 106 . In some embodiments, the HPHT heated reactor 106 is heated and maintained to a predetermined (pre-selected) reaction temperature of from about 350 °C to about 575 °C, or from about 400 °C to about 450 °C.

The HPHT heated reactor 106 is initially maintained under an inert or substantially inert atmosphere devoid of oxygen at a pressure of from about 145 psig to about 870 psig, or from about 435 psig to about 725 psig, prior to heating, and heated The residence time is maintained during the period from about 2 hours to about 15 hours, or from about 4 hours to about 8 hours. During heating, the pressure within the HPHT heated reactor 106 may exceed about 1,000 psig, and may be between about 1,700 psig and about 2,500 psig.

The effluent from reactor outlet 110 proceeds to a gas, liquid, solid three-phase separator 112 , wherein the effluent flows from three-phase separator 112 to a gas stream comprising hydrocarbons, a liquid DAO stream, and substantially separated as a solid MP product. MP proceeds to MP product collection 116 by outlet 114 . MP can be used as a valuable by-product for integrated carbon fiber spinning, or other carbon artifacts, to convert MP into valuable carbon fiber and electrode materials for batteries at the facility.

The gaseous products are hydrogen, methane, ethane, propylene, propane, butane and butene, pentane and pentene as well as cracking products ranging from C ₁ to C ₅ paraffins and olefins. The three-phase separator 112 separates the products by density, where the gaseous product exits near the top of the three-phase separator 112, while solids and liquids, for example, in addition to precipitation or precipitation Alternatively to the separation by methods such as centrifugation.

DAO from the process exits directly by outlet 118 to a C2C purification process 120, which may include, for example, FCC in addition to or as an alternative to steam cracking (pyrolysis). In embodiments of the present disclosure the DAO may contain less than about 2 weight percent asphaltenes and may be used as a steam/catalytic cracking feed for petrochemical production.

In one example, for the purpose of thermal consolidation, the crude oil is brought below the cracking temperature in the tube of the convection section of the pyrolysis oven or in the regeneration section of the FCC unit, eg, from about 100° C. to about 350° C., depending on the type of crude oil feed. °C, or from about 250 °C to about 350 °C, or from about 200 °C to about 300 °C, or to less than about 200 °C. The preheated oil is then fed to a deasphalting unit, such as, for example, HPHT heat treatment reactor 106, where it is heat treated under pressure to produce mesophase pitch, liquid deasphalted oil, and gas cracking products, which It is separated in a three-phase separator such as, for example, a three-phase separator 112 . In some implementations, the DAO can be mixed with superheated steam (from a convective zone or regeneration section of the FCC) using, for example, an optional superheated steam stream 122 as shown in FIG. 1 . , it can be fed to the final preheating zone before severe disassembly.

In addition to or as an alternative to resid, upgraded deasphalted crude oil can be used as a feed for hydrocarbon cracking processes such as steam pyrolysis and catalytic fluid cracking, while asphaltenes in crude oil resid are produced simultaneously with the production of high quality MP. is removed Removal of asphaltenes from DAO is advantageous because these compounds cause grime pyrolysis and reactor coking in the FCC process. When DAO from an exemplary thermal treatment step of the present disclosure was used as the cracking feed, good selectivity to light olefins, particularly ethylene and propylene, was observed.

Experiment

In some experiments, a 10 liter autoclave reactor was charged with Arabian Heavy Crude Oil, and an empty space with a substantially inert atmosphere was maintained at the top of the autoclave. The autoclave was flushed several times with nitrogen gas (N ₂ ) to remove oxygen from the reaction environment. The autoclave was maintained under N ₂ pressure at about 600 psig at room temperature. The reactor temperature was increased to the desired temperature (eg, about 400° C., 410° C. and 425° C.) by 6° C./min with stirring at about 600 rpm. When the desired pre-determined reaction temperature was reached, the heat treatment was maintained for a predetermined polymerization time, optionally from about 6 to about 17 hours. The heat treatment time may also be from about 2 hours to about 15 hours, or from about 4 hours to about 8 hours. The pressure in the autoclave reactor reached at least 1,000 psig, from about 1,800 psig to about 1,900 psig. The product obtained consisted of three separate phases: gas, liquid and solid at room temperature. The cracked gas was withdrawn and the MP was separated from the DAO by centrifugation.

For some other, but similar experiments, Table 1 shows the saturated hydrocarbons, aromatics, resins, and asphaltenes for Arabian Heavy Crude Oil, Heat Treated Arabian Heavy Crude Oil, Hydrotreated Crude Oil Resid, and Heat Treated Hydrotreated Crude Oil Resid. represents a value for

Table 1. Saturated carbon, aromatic, resin, and asphaltene (SARA) fractions of crude oil and hydrotreated crude oil resid before and after treatment.

sample ID Saturates (wt.%) Aromatic (wt.%) Resin (wt.%) Asphaltene (wt.%) Arabian Heavy (AH) 32.4 35.4 21.8 10.8 Arabian Heavy Heat Treated Liquid Cut 9.57 78.3 10.94 1.19 Arabian Light Hydrotreated (HT) Resid 31.8 60 5.1 3.1 Arabian Light HT Resid Heat Treated Liquid Cut 34.6 58.4 5.2 1.8

Crude oil or its derivatives can be separated into four chemical group classifications: saturates such as alkanes and cycloparaffins, aromatics, resins, and asphaltenes, the so-called SARA fractions. SARA analysis is used to determine the distribution of saturates, aromatics, resins, and asphaltenes in topped petroleum samples. The procedure is divided into two steps. The first step involves precipitation and quantification of asphaltenes, while the second step is an open-column chromatographic separation that separates the deasphalted oil into saturates, aromatics, and resin fractions according to ASTM D-2007 methods.

In particular, Table 1 shows that the Arabian Heavy (AH) heat treated product was deasphalted as about 90% of the asphaltenes were removed. As shown in Table 1, a large portion of the asphaltene content is removed after processing the crude oil. Also shown in Table 1 is about a half reduction in resin content for Arabian Heavy Crude Oil. For the Arabian heavies, the aromatic content increased by over 100% from 35% to 78% by weight.

Table 2 presents the elemental analysis of both Arabian heavy crude oil and heat treated products. The obtained mesophase pitch hydrocarbon product (liquid + solid) also contains much less sulfur, nickel, and other metals such as, for example, vanadium, than its precursors, which produce mesophase pitch (solid) and deasphalted oil (liquid). , direct crude oil to chemical technology via steam cracking or catalytic cracking processes for DAO, and carbon fiber production for solid MP. In an inductively coupled plasma (ICP) mass spectrometer used for metal detection, the actual limits of quantitation (QPL) for the sample weight used (30 mg) were: nickel = 0.05 mg, sulfur = 0.4 mg, and vanadium = 0.05 mg.

Table 2. Elemental analysis of both Arabian heavy crude oil and its heat treated product (mesophase pitch).

sample ID Inductively Coupled Plasma (ICP) Mass Spectrometer Ni (mg) S (mg) V (mg) Processed Arabian Heavy Liquid not detected 2.34 not detected solid 0.0175 0.79 0.005 Arabian Heavy Crude Oil Whole 0.0021 3.29 0.006

As shown in Table 2, no heavy metal content (Ni and V) was detected in the liquid phase of the obtained product (DAO) (treated arabic heavy). The sulfur content in the liquid phase was also significantly reduced. The liquid composition analyzed by SIMDIS showed that 100% of the components after treatment with Arabic heavy oil had a boiling point of less than 500 °C and 96% of the components after resid treatment had a boiling point of less than 500 °C. The volatility of the different components in crude oil and resid, and in heat-treated crude oil and heat-treated resid, is measured by an Agilent Simulated Distillation ("SIMDIS") system by Agilent Technologies, Sugar Land, Texas. became SIMDIS follows the standard operating procedure (SOP) described in the reference manual, which method includes ASTM D7169.

SIMDIS properties show that the obtained DAO liquid contains hydrocarbons with a significantly lower boiling point than the original Arabian heavy crude oil. Thus, the hydrocarbon product could be a suitable feed for refining processes, hydrotreating processes, and particularly direct crude-to-chemical processes. In some embodiments, different precursors comprising a 500° C. or higher cut of arabic heavy oil and hydrothermally treated arabic hard arabic were tested. In some embodiments, the starting pressure of a pressure vessel, such as, for example, an autoclave, or any high pressure processing unit, is at least about 600 psig (at room temperature), and then the temperature is gradually raised to about 420 °C. During processing, the pressure in the high pressure vessel could reach from about 1700 psig to about 2500 psig, depending on the volume of the starting feed and the temperature reached.

Cracking of DAO is discussed with reference to FIG. 2 as follows, and with respect to the MP produced in the experiments of the present disclosure, FIG. 3 is an optical microscopic image of solid mesophase pitch obtained at 100 μm, 50 μm and 20 μm scales. where the mesophase pitch was obtained after treating the sample at a temperature of 425° C. and a stirring speed of 650 rpm for 6 hours. The mesophase pitch produced using embodiments of the present disclosure is a suitable, high quality precursor for pitch-based carbon fibers. The resulting mesophase pitch contains a suitable amount of alkyl side chains, a smaller softening point, and a favorable and consistent crystalline structure identified using polarized light microscopy and X-ray diffraction (XRD). The image of Figure 3 shows that the mesophase pitch is advantageously uniform throughout. Similar results were obtained with light microscopy images for both Arabian heavy and Arabian light HT resid (C2C reject) starting materials.

The purity of the mesophase pitch was determined by polarization microscopy by counting the percentage of mesophase regions that reflected light differently from the “non-intermediate” regions. The purity of the mesophase pitch in embodiments of the present disclosure may be greater than about 90% and greater than about 99%.

4 is a graph showing X-ray diffraction (XRD) data for mesophase pitch obtained using an embodiment of the present disclosure, wherein the mesophase pitch is at a temperature of 425° C. and at a stirring rate of 650 rpm for 6 hours. was obtained. The XRD graph shows a peak at 25.6, which identifies the mesophase pitch carbon material. The mesophase pitch obtained using the methods described herein also contained less asphaltenes than mesophase pitch precursors such as crude oil and crude oil resid. In some embodiments, asphaltene removal of up to about 90% was realized and mesophase pitch suitable for C2C applications, such as carbon fiber, was obtained. The final product characterization using XRD shows a general diffraction graph for the mesophase pitch, which is explained by heating polymerization of aromatic and resin compounds in crude oil into molecules of higher molecular weight.

In certain embodiments of the present disclosure, the heat treatment is performed in the absence or in the absence of any additives other than nitrogen in addition to or alternatively to one or more inert gases for pressurizing the heat treatment process. In some embodiments, greater than about 90% pure mesophase pitch product is obtained after heat treatment, and in some embodiments, greater than about 99% pure mesophase pitch product is obtained after heat treatment. Crude oil and HT crude resid can be simultaneously upgraded and deasphalted using the pressurized heat treatment of the present disclosure.

Referring now to FIG. 2 , a mechanical diagram showing an experimental setup for a direct C2C decomposition experiment of the present disclosure is provided. In experimental setup 200 , syringe pump 202 pumps helium as a carrier gas from helium tank 206 (which may be in addition to or alternative to nitrogen gas in nitrogen tank 208 ) and DAO from DAO inlet 204 . used to supply DAO was produced using the embodiment described in the previous experiment. The gravimetric space-time velocity (WHSV) used in the degradation experiments was 6 1/hr (h ⁻¹ ). The experimental apparatus 200 further includes an electric furnace 210 , a cracking catalyst 212 , a gas chromatograph 214 , and a condenser 216 . Liquid product was collected at product outlet 218 . The gas was analyzed by gas chromatography (GC). Carbon monoxide, carbon dioxide, oxygen, nitrogen, methane, light olefins, C ₁ to C ₇ hydrocarbons and BT (benzene and toluene) can be quantified.

The cracking temperature can be from about 450 °C to about 850 °C, for example from about 500 °C to about 650 °C depending on the feed type in catalytic cracking such as FCC, and from about 650 °C to about 850 °C in steam cracking, for example. The cracking catalyst used in some embodiments comprises a solid acid catalyst. In one or more embodiments, the solid acid catalyst layer can comprise an aluminosilicate zeolite, a silicate (eg, silicalite), or a titanosilicate. In a further embodiment, the solid acid catalyst is an aluminosilicate zeolite having a mordenite framework inversion (MFI) structure.

For example, but not by way of limitation, the MFI structured aluminosilicate zeolite catalyst can be a zeolite Soconi Mobil-5 (ZSM-5) catalyst. In a further embodiment, the ZSM-5 catalyst may be an H-ZSM-5 catalyst in which at least a portion of the ZSM-5 catalytic ion exchange site is occupied by H ⁺ ions. Also, the aluminosilicate zeolite catalyst, such as the H-ZSM-5 catalyst, may have a Si/Al molar ratio of at least 10. In further embodiments, the aluminosilicate zeolite catalyst can have a Si/Al molar ratio of at least 30, or at least 35, or at least 40. In addition, the aluminosilicate zeolite catalyst may include one or more additional components used to modify the structure and performance of the aluminosilicate zeolite catalyst. Specifically, the aluminosilicate zeolite catalyst may include phosphorus, boron, nickel, iron, tungsten, another metal, or a combination thereof. In various embodiments, the aluminosilicate zeolite catalyst can include 0-10% by weight of additional components, 1-8% by weight of additional components, or 1-5% by weight of additional components.

For example, but not by way of limitation, these additional components may be wet impregnated in ZSM-5, followed by drying and calcination. The aluminosilicate zeolite catalyst may contain a mesoporous structure. The catalyst may be sized to have a diameter of 25 to 2,500 micrometers (μm). In further embodiments, the catalyst can have a diameter of 400 to 1200 μm, 425 to 800 μm, 800 to 1000 μm, or 50 to 100 μm. The minimum size of the catalyst particles depends on the reactor design to prevent passage of the catalyst particles through the filter with the reaction products.

In Table 3 below, the degradation potential of DAO was demonstrated and the production of valuable products was shown.

Table 3. Exemplary conversion, yield, and selectivity for DAO produced using embodiments of the present disclosure.

feedstock DAO of Heavy Crude Oil DAO of HT Arabian Light Crude Resid (greater than 500°C Cut) heavy crude oil WHSV (h ^-1 ) 5.9 5.9 5.9 Conversion rate (wt. %) * 32.9 33.3 26.8 Yield to Olefin (wt. %) 20.4 21.0 17.9 Yield to Ethylene (wt. %) 4.9 4.7 4.7 Yield to propylene (wt. %) 11.4 11.8 9.9 Yield to C4 Olefin (wt. %) ** 4.1 4.5 3.4 Selectivity to Olefins *** (wt. %) 62.0 63.0 66.3 Selectivity to Ethylene *** (wt. %) 14.9 14.2 17.5 Selectivity to propylene *** (wt. %) 34.7 35.5 36.7 Selectivity to C4 Olefins***** (wt. %) 12.4 13.4 12.1

In Table 3, conversion (*) refers to the amount of gas phase formed from DAO in the cracking reaction performed in the apparatus of FIG. 2 ; C4 olefins (**) refer to 1-butene, cis and trans-2-butene, and isobutene; Selectivity (***) considers only the gaseous product formed. In the present disclosure, the processes and steps prior to cracking or other downstream chemical manufacturing steps, such as the production of carbon fibers, are not aimed at evaporating or isolating undesirable components of the crude oil feed, but instead of the non-volatile components of the asphalt fraction. Aromatic rings are targeted for extended thermal polymerization, under pressure, so that they can easily precipitate and separate, for example as mesophase pitches. Controlling the reaction temperature, pressure, and residence time ensures reproducibility and flexibility.

Certain advantages enabled by the methods and systems of the present disclosure include: reducing coke settling problems in steam crackers for crude oil and heavy feedstocks; reducing the problem of rapid catalyst deactivation by coking; reducing the problem of metals in crude oil poisoning cracking catalysts; Co-production of MP improves process economics; and higher hydrocarbon yields compared to cracking products from conventional refining processes such as using naphtha and vacuum gas oil (VGO). It is believed that upon treatment at elevated temperatures above about 400° C., branching of aromatics in addition to or alternatively to asphaltenes cracks into lower molecular weight hydrocarbons, leaving more hydrocarbons available for catalytic cracking.

Claims (39)

An integrated process for the production of mesophase pitch and petrochemicals, the process comprising the steps of:
supplying crude oil to the reaction vessel;
heating the crude oil in the reaction vessel to a predetermined temperature for a predetermined time, wherein the predetermined temperature is between 350° C. and 575° C., wherein the predetermined time is between 2 hours and 15 hours;
reducing the asphaltene content in the crude oil by allowing a polymerization reaction to occur in the reaction vessel at elevated pressure in the absence of oxygen, wherein the elevated pressure is greater than 1000 psig;
producing a three-phase upgraded hydrocarbon product comprising a gaseous, liquid, and solid hydrocarbon component, wherein the liquid hydrocarbon component comprises deasphalted oil and the solid hydrocarbon component comprises a mesophase pitch;
separating the gaseous, liquid, and solid hydrocarbon components;
directly using the liquid hydrocarbon component for petrochemical production; and
An integrated method for the production of mesophase pitch and petrochemicals, comprising the step of directly using said solid hydrocarbon component for production of carbon artifacts. The method according to claim 1,
The crude oil is the crude oil received directly from the wellhead after being separated from natural gas and dewatered, and is otherwise not pretreated prior to the step of feeding the crude oil to the reaction vessel. . delete The method according to claim 1,
and the predetermined temperature is between 400 °C and 450 °C. The method according to claim 1,
mesophase pitch and petrochemical production, further comprising pressurizing the vessel to an initial pressure of 145 psig to 870 psig prior to heating the crude oil in the reaction vessel to a predetermined temperature for a predetermined time period integrated method for 6. The method of claim 5,
and pressurizing the vessel to an initial pressure comprises evacuating oxygen from the reaction vessel using a gas comprising nitrogen. The method according to claim 1,
and pressurizing the vessel to an initial pressure of 435 psig to 725 psig prior to heating the crude oil in the reaction vessel to a predetermined temperature for a predetermined time. integrated method for 8. The method of claim 7,
and pressurizing the vessel to an initial pressure comprises evacuating oxygen from the reaction vessel using a gas comprising nitrogen. delete The method according to claim 1,
and the predetermined time is from 4 hours to 8 hours. The method according to claim 1,
and reducing the asphaltene content reduces the asphaltene content in the deasphalted oil to less than 2% by weight. delete The method according to claim 1,
wherein the elevated pressure is between 1,800 psig and 1,900 psig. The method according to claim 1,
and wherein directly using the liquid hydrocarbon component for petrochemical production comprises feeding the deasphalted oil to a fluid catalytic cracking process. The method according to claim 1,
and wherein directly using the liquid hydrocarbon component for petrochemical production comprises feeding the deasphalted oil to a steam cracking process. The method according to claim 1,
and wherein directly using said solid hydrocarbon component for carbon artifact production comprises producing carbon fibers from said mesophase pitch. The method according to claim 1,
The crude oil includes: heavy crude oil; light crude oil; and at least one hydrocarbon selected from the group consisting of crude oil resid having a boiling point greater than 500 °C. The method according to claim 1,
An integrated method for the production of mesophase pitch and petrochemical products, characterized in that the asphaltene compound content of the deasphalted oil is reduced by at least 50% by weight compared to the asphaltene compound content of the crude oil. The method according to claim 1,
An integrated method for the production of mesophase pitch and petrochemical products, characterized in that the asphaltene compound content of the deasphalted oil is reduced by at least 90% by weight compared to the asphaltene compound content of the crude oil. The method according to claim 1,
wherein the metal content in the liquid hydrocarbon component is less than the metal content in the crude oil. The method according to claim 1,
wherein the solid hydrocarbon component is at least 90% pure mesophase pitch. The method according to claim 1,
The step of reducing the asphaltene content in crude oil by allowing the polymerization reaction to occur in the reaction vessel at elevated pressure in the absence of oxygen increases the pressure in the reaction vessel to 1,700 psig to 2,500 psig Mesophase pitch and petrochemical An integrated method for product production. An integrated system for the production of mesophase pitch and petrochemicals, the system comprising:
a crude oil source fluidly connected to a reaction vessel, the reaction vessel operable to be heated to a predetermined temperature for a predetermined time period, and wherein the polymerization reaction occurs in the reaction vessel at an elevated pressure in the absence of oxygen to reduce the asphaltene content in the crude oil source operable to decrease, wherein the predetermined temperature is between 350° C. and 575° C., wherein the predetermined time period is between 2 hours and 15 hours, wherein the elevated pressure is greater than 1000 psig;
A three-phase gas, liquid, solid separator operable to separate a three-phase upgraded hydrocarbon product produced in the reaction vessel, the three-phase upgraded hydrocarbon product comprising a gaseous, liquid, and solid hydrocarbon component, wherein the liquid hydrocarbon component comprises deasphalted oil and the solid hydrocarbon component comprises mesophase pitch; and
a cracking unit, wherein the cracking unit receives the liquid hydrocarbon component and is fluidly connected to crack the liquid hydrocarbon component for petrochemical production, the mesophase pitch and integrated for petrochemical production system. 24. The method of claim 23,
An integrated system for the production of mesophase pitch and petrochemical products, further comprising a unit for producing carbon fibers from the mesophase pitch. delete 24. The method of claim 23,
The predetermined temperature is an integrated system for the production of mesophase pitch and petrochemical products, characterized in that 400 ℃ to 450 ℃. delete 24. The method of claim 23,
The integrated system for the production of mesophase pitch and petrochemical products, characterized in that the predetermined time is from 4 hours to 8 hours. 24. The method of claim 23,
An integrated system for the production of mesophase pitch and petrochemical products, characterized in that the asphaltene content in the deasphalted oil is less than 2% by weight. delete 24. The method of claim 23,
wherein the elevated pressure is between 1800 psig and 1,900 psig. 24. The method of claim 23,
and the cracking unit comprises a fluid catalytic cracking process. 24. The method of claim 23,
and the cracking unit comprises a steam cracking process. 24. The method of claim 23,
wherein said crude oil comprises at least one hydrocarbon selected from the group consisting of: heavy crude oil, light crude oil, and crude oil residue having a boiling point greater than 500 °C. 24. The method of claim 23,
An integrated system for the production of mesophase pitch and petrochemicals, characterized in that the asphaltene content of the deasphalted oil is reduced by at least 50% by weight compared to the asphaltene content of the crude oil source. 24. The method of claim 23,
An integrated system for the production of mesophase pitch and petrochemical products, characterized in that the asphaltene compound content of the deasphalted oil is reduced by at least 90% by weight compared to the asphaltene compound content of the crude oil source. 24. The method of claim 23,
wherein the metal content in the liquid hydrocarbon component is less than the metal content in the crude oil source. 24. The method of claim 23,
An integrated system for the production of mesophase pitch and petrochemical products, characterized in that the solid hydrocarbon component is at least 90% pure mesophase pitch. 24. The method of claim 23,
wherein the elevated pressure in the reaction vessel is between 1,700 psig and 2,500 psig.

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