CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63/265,304, filed on December 13, 2021, the entire contents of which are incorporated herein by reference FIELD

[0002] The present disclosure relates to processes for producing pitch compositions from heavy hydrocarbon feedstocks, and pitch compositions suitable for manufacturing into carbon articles.

BACKGROUND

[0003] Petroleum pitch is a highly aromatic hydrocarbon, considered as an excellent precursor for a wide range of carbon materials (e.g., mesophase pitch-based carbon fiber, general purpose carbon fibers, binder pitch, graphitizable carbon microbeads, solid lubricants, carbon-carbon composites, activated carbon fiber, battery anodes, carbon foams, and carbon molecular sieves). Upgrading low-value refinery streams into a suitable pitch for cost-effective manufacturing of said carbon materials remains a substantial challenge to achieve. The quality of a mesophase pitch can be characterized by, for example, its mesophase content, softening point, coalescence, and its appropriate flowability at processing conditions.

[0004] Conventional methods for pitch production rely on the conversion processes (e.g., thermal and/or catalytic processes) of hydrocarbon feedstocks (typically highly aromatic) under drastic conditions (e.g., elevated temperatures, vigorous stirring, and long residence times), wherein a series of reaction and separation processes need to be carried out. Further, high temperatures are often required to effectively carry out said separation processes, often based on differences in volatility, and are frequently carried out under vacuum. The application of vacuum adds cost to the process, limits throughput, and can only be used to remove the lowest molecular weight compounds. Furthermore, as the temperature of the separation processes increases, undesirable chemical side reactions occur, leading to the formation of a mixture comprising coke and a pitch of poor qualities, which is unfit for the production of carbon materials. Additionally, non-volatile impurities (e.g., ashes, metal contaminants, and other undesirable particulate) present in the hydrocarbon feedstock and formed during the reaction, mainly remain in the pitch, thus making the pitch unsuitable for carbon products manufacturing. Conventional distillation processes are not sufficient to mitigate/eliminate said impurities.

[0005] Visbreaking is a mild, non-catalytic thermal cracking process used to convert fuel oil (e.g., atmospheric or vacuum residues) into gas, naphtha, lighter distillates, and visbroken residue via thermal cracking. Conversion of visbreaking bottoms fraction of crude oils into a petroleum pitch has been commonly used. However, the visbreaking thermal severity (500-1000 equivalent seconds at 800°F) is limited by the reactivity of the hydrocarbon feedstock, and is found to be insufficient to form a pitch of high-quality and suitable for carbon articles manufacturing. Further, higher conversion of the feed by increasing the visbreaking thermal severity usually leads to higher production of coke, consequently fouling the visbreaker coils. On the other hand, FLEXICOKING™ technologies and delayed coking processes can provide higher thermal severity than visbreaking, yet both are found to downgrade a portion of the feedstock into coke or low BTU gas. Hence, there remains the need for conversion processes of hydrocarbon feedstocks to produce a petroleum pitch suitable for carbon articles manufacturing (e.g., carbon fiber), which enables mitigation/elimination of coke and other undesirable contaminants and control of its flow performance.

SUMMARY

[0006] In some aspects what is shown is a process comprising: heat treating a heavy hydrocarbon feedstock in a heat treatment unit to produce a first effluent comprising a heat treated product; at least partially separating a mixture of gas and distillate from the first effluent in a first separation unit to produce a second effluent comprising a second effluent; deasphalting the second effluent in a deasphalter unit in the presence of a first solvent to produce : a soluble product fraction comprising a first portion of the first solvent, a deasphalted oil (DAO) product, and a first pitch product; an insoluble product fraction comprising a second portion of the first solvent and a portion of the first pitch product; and at least partially removing the second portion of the first solvent from the first pitch product in a third separation unit to produce a purified pitch product.

[0007] In some or other aspects is shown a process comprising heat treating a heavy hydrocarbon feedstock in a heat treatment unit to produce a first effluent comprising a heat treated product comprising a gas, a distillate, and a product; at least partially separating a mixture of gas and distillate from the first effluent in a first separation unit to produce a second effluent; hydrotreating the second effluent to produce a hydrotreated product; at least partially separating any gas or distillate from the hydrotreated product in a second separation unit to produce a third effluent; deasphalting the third effluent in a first deasphalter unit in the presence of a first solvent to produce: a first soluble fraction comprising a first portion of the first solvent, a deasphalted oil (DAO) product, and a first pitch product; a first insoluble product fraction comprising a second portion of the first solvent and a portion of the first pitch product; and at least partially separating a mixture of gas and distillate from the first insoluble fraction in a third separation unit to produce a fourth effluent 344 comprising a first isotropic pitch; deasphalting the first soluble product fraction in a second deasphalter unit in the presence of a second solvent to produce: a second soluble portion and second insoluble portion; the second soluble portion comprising a first isotropic pitch, a deasphalted oil product, and a first portion of the second solvent; the second insoluble product fraction comprising a second isotropic pitch and a second portion of the second solvent; and optionally heat treating the first and/or the second isotropic pitch to produce a mesophase pitch product having a mesophase content from about 5 vol. % to 100 vol. %, based on the total volume of the mesophase pitch product, an MCR in the range of about 50 wt% to about 95 wt%, based on the total weight of the mesophase pitch product(s), and a softening point Tsp in the range of about 200°C to about 400°C, wherein the mesophase pitch product is suitable for spinning into carbon articles.

[0008] In some or other aspects is shown a pitch composition suitable for spinning comprising: a pitch having a mesophase content from 5 vol. % to 100 vol. %, based on the total volume of the pitch, an MCR in the range of about 50 wt. % to about 95 wt. %, based on the total weight of the pitch, and a softening point Tsp in the range of about 10°C to about 400°C.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following figures are included to illustrate certain aspects of the present disclosure, and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, as will occur to one having ordinary skill in the art and having the benefit of this disclosure. To assist those of ordinary skill in the relevant art in making and using the subject matter hereof, reference is made to the appended drawings, wherein:

[0010] FIG. 1 is a non-limiting example flow diagram of a method 100 for producing spinnable pitches from heavy hydrocarbon feedstocks of the present disclosure.

[0011] FIG. 2 is a non-limiting example flow diagram of a method 200 for producing spinnable pitches from heavy hydrocarbon feedstocks of the present disclosure.

[0012] FIG. 3 is a non-limiting example flow diagram of a method 300 for producing spinnable pitches from heavy hydrocarbon feedstocks of the present disclosure.

[0013] FIG. 4 is a non-limiting example flow diagram of a method 400 for producing spinnable pitches from heavy hydrocarbon feedstocks of the present disclosure.

[0014] FIG. 5 is a non-limiting example flow diagram of a method 500 for producing spinnable pitches from heavy hydrocarbon feedstocks of the present disclosure.

[0015] FIG. 6 is a graph illustrating the impact of isolation processes on pitch softening points versus deasphalting temperature (°C) of pitch samples having different solvent oil ratio.

[0016] FIG. 7A is a polarized light microscopy image of a mesophase pitch material produced after pyrolysis of its corresponding isotropic pitch (220°C, solventoil ratio of 6: 1) at 400°C for 1 h. FIG. 7B is a polarized light microscopy image of a mesophase pitch material produced after pyrolysis of its corresponding isotropic pitch (20°C, solvent oil ratio of 10: 1) at 400°C for 1 h.

[0017] FIG. 8 is a polarized light microscopy image of a mesophase pitch material produced after pyrolysis at 400°C for 3 h under flowing nitrogen in an open reactor and a polarized light microscopy image of a mesophase pitch material produced after pyrolysis at 400°C for 1 h in a closed reactor.

DETAILED DESCRIPTION

[0018] The present disclosure relates to processes for producing pitch compositions from crude oils, and pitch compositions suitable for manufacturing into carbon articles (e.g., fibers).

[0019] Particularly, the present disclosure relates to processes for producing isotropic and mesophase pitch compositions from solvent assisted visbreaking (SAVB) and solvent deasphalting (SDA) of crude oils, which advantageously enable mitigation/elimination of contaminants (e.g., particulates such as ashes, metal contaminants, and other impurities present in the hydrocarbon feedstock, or formed during the reaction) otherwise present under current separation conditions (e.g., atmospheric or vacuum distillation).

[0020] Solvent deasphalting (SDA) and related processes of the present disclosure, particularly a two-stage solvent deasphalting process that relies on two solvents with different solubility parameters, advantageously promote mitigation of metals and particulates contaminants within a pitch. It is understood that solvent deasphalting processes of the present disclosure may comprise two or more-stage solvent deasphalting processes. Another surprising and significant advantage of SDA is that, when in combination with distillation, it controls the pitch softening point and the mesophase content, improves the flowability of the pitch, and facilitates the pitch coalescence. Processes of the present disclosure, particularly the processes comprising a solvent assisted heat treatment process (e.g., solvent assisted visbreaking), a series of separation processes (e.g., flash distillation, vacuum distillation), and one or more solvent deasphalting processes, enable control and tailoring of the pitch softening point.

[0021] Additionally, as discussed above, a traditional visbreaking process can be detrimental to the production of high quality pitch compositions, due in part to the formation of coke under typical visbreaking conditions. On the other hand, the solvent assisted visbreaking (SAVB) disclosed herein provides an efficient way for producing high quality pitch compositions with tunable properties, which can be spun into carbon fibers or formed into carbon articles. By reason of mixing a solvent (e.g., heavy aromatic solvent) with a hydrocarbon feedstock, SAVB can increase the solubility of the large aromatic molecules formed during the thermal cracking process. The solvent prevents these molecules from phase separating during the production, and is in direct contrast to the base case, where no solvent is added. Thus SAVB reduces/eliminates the risk of coking and fouling that might otherwise occur. Without being bound by any theory or mechanism, it is believed that the solvent used for SAVB (e.g., steam cracked gasoil, heavy coker gasoil, heavy vacuum gas oil, heavy extract from lubes production, and the like) retains the high aromaticity of the liquid phase of the hydrocarbon feedstock, thus enabling extension to the thermal severity range of a traditional visbreaking process. Further, the SAVB process of the present disclosure enables the visbreaker reactor to operate at much higher thermal severity than traditional visbreaker reactors (>2000 equivalent seconds at 800°F) while producing high-quality pitch from heavy feeds (e g., vacuum residue). In addition, due to their high aromaticity, a vast number of solvents suitable for SAVB can be considered for use. Yet, SAVB enables upgrading both the hydrocarbon feedstock and the solvent streams simultaneously to yield a high-value product.

[0022] Before describing the processes and compositions of the present disclosure in further detail, a listing of terms follows to aid in better understanding the present disclosure.

Definitions and Test Methods

[0023] The new notation for the Periodic Table Groups is used as described in Chemical and Engineering News, 63(5), 27 (1985).

[0024] The following abbreviations are used herein: T _g is glass transition temperature, Tsp is softening point temperature; MCR is microcarbon residue; QI is quinoline insoluble; wt. % is weight percent; mol. % is mole percent; vol. % is volume percent; psig is pounds per square in gauge; LHSV is liquid hourly space velocity; N/A is not applicable; N/D is not determined; wppm is Weight Parts per Million.

[0025] All numerical values within the detailed description and the claims herein are modified by “about” or “approximately” with respect to the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art. Unless otherwise indicated, ambient temperature (room temperature) is about 18°C to about 20°C.

[0026] As used in the present disclosure and claims, the singular forms “a,” “an,” and “the” include plural forms unless the context clearly dictates otherwise.

[0027] The term “and/or” as used in a phrase such as “A and/or B” herein is intended to include “A and B,” “A or B,” “A,” and “B.”

[0028] Where the term “between” is used herein to refer to ranges, the term encompasses the endpoints of the range. That is, “between 2% and 10%” refers to 2%, 10% and all percentages between those terms. [0029] The term “independently,” when referenced to selection of multiple items from within a given Markush group, means that the selected choice for a first item does not necessarily influence the choice of any second or subsequent item. That is, independent selection of multiple items within a given Markush group means that the individual items may be the same or different from one another.

[0030] As used herein, the term “hydrocarbon” refers to an organic compound or mixture of organic compounds that includes primarily, if not exclusively, the elements hydrogen and carbon. Optionally substituted hydrocarbons may also include other elements, such as, but not limited to, halogens, metallic elements, nitrogen, oxygen, sulfur, and any combination thereof. Unless otherwise specified, hydrocarbons may be one or more of linear, branched, cyclic, acyclic, saturated, unsaturated, aliphatic, or aromatic.

[0031] The term “heavy hydrocarbon feed” or “heavy hydrocarbon feedstock, and “initial feed” or “initial feedstock” may correspond to a heavy hydrocarbon feed as described in the “Feedstocks” section below. In order to transport a heavy hydrocarbon feed from an extraction site to the location of the conversion system, an extraction site diluent may be added to the heavy hydrocarbon feed. In some aspects, the extraction site diluent can correspond to a naphtha fraction. In such aspects, the heavy hydrocarbon feed plus the extraction site diluent used to transport the heavy hydrocarbon feed to the conversion system can be referred to as an “initial feed” or “initial feedstock”. A separation can be performed to remove some or all of the extraction site diluent prior to further processing of the heavy hydrocarbon feed and/or prior to incorporation of the heavy hydrocarbon feed into the partially upgraded heavy hydrocarbon product. Such a separation performed on an “initial feedstock” can be used to recover a fraction corresponding to extraction site diluent, and a fraction corresponding to the heavy hydrocarbon feed that optionally still contains a remaining portion of the extraction site diluent. In other aspects, the extraction site diluent can include distillate and/or vacuum gas oil boiling range components. Such distillate and/or vacuum gas oil boiling range components of an extraction site diluent can be processed in the same manner as other distillate and/or vacuum gas oil boiling range components. It is noted that unless otherwise specified (such as based on boiling range) references to “heavy hydrocarbon feed” do not exclude the possible presence of extraction site diluent.

[0032] As used herein, the term "pitch" refers to hydrocarbons with softening points above 50°C, consisting of mainly aromatic and alkyl-substituted aromatic compounds. These aromatic compounds are primarily hydrocarbons, but heteroatoms and traces of metals can be present within these materials. When cooled from a melt, a pitch can solidify into an amorphous solid. Pitches may include petroleum pitches, coal tar pitches, natural asphalts, pitches contained as by- products in the naphtha cracking industry, pitches of high carbon content obtained from petroleum asphalt and other substances having properties of pitches produced as products in various industrial production processes. Pitches exhibit a broad softening temperature range and are typically derived from petroleum, coal tar, plants, or catalytic oligomerization of small molecules (e.g., acid-catalyzed oligomerization). A pitch can also be referred to as tar, bitumen, or asphalt. When a pitch is produced from plants, it is also referred to as resin. Various pitches may be obtained as products in the gas oil or naphtha cracking industry as a carbonaceous residue consisting of a complex mixture of primarily aromatic organic compounds, which are solids at room temperature, and exhibit a relatively broad softening temperature range. Hence, a pitch can be obtained from heat treatment and distillation of petroleum fractions. A “petroleum pitch" refers to the residuum carbonaceous material obtained from distillation of crude oils and from the catalytic cracking of petroleum distillates. A "coal tar pitch" refers to the material obtained by distillation of coal.

[0033] As used herein, the term "mesophase" refers to a discotic liquid crystalline material consisting of planar aromatic molecules with a broad molecular weight distribution. A “mesophase pitch” consists of “mesophase” and optionally an isotropic phase. The mesophase exhibits optical anisotropy (birefringence) when examined using a polarized light microscope. For example, a mesophase pitch can be a pitch containing more than about 10 vol. % mesophase, based on the total volume of the pitch. A mesophase content of a pitch can be measured, according to ASTM D4616 (Standard Test Method for Microscopical Analysis by Reflected Light and Determination of Mesophase in a Pitch), from reflected polarized light microscopy images by imbedding various samples of the pitch in epoxy, followed by polishing the samples until they become highly reflective. A series of images can be recorded in order to quantify the anisotropic content.

[0034] As used herein, “hydroprocessing” refers to a process that uses a hydrogen-containing gas with suitable catalyst(s) for a particular application. All hydroprocessing technologies consume hydrogen and typically convert heavy oil fractions into lighter and more valuable products. In many instances, hydroprocessing is generally accomplished by contacting the selected feedstock in a reaction vessel or zone with the suitable catalyst under conditions of elevated temperature and pressure in the presence of hydrogen. It includes hydrotreating and hydrocracking.

[0035] As used herein, “hydrotreating” refers to a process in which hydrogen gas is contacted with a hydrocarbon stream in the presence of suitable catalysts which are primarily active for the removal of heteroatoms, such as sulfur (i.e, hydrodesulfurization), nitrogen (i.e., hydrodenitrification), and metals (i.e., hydrodemetallization) from the hydrocarbon feed. In hydrotreating, hydrocarbons with double and triple bonds may be saturated.

[0036] Numerical ranges used herein include the numbers recited in the range. For example, the numerical range “from 1 wt. % to 10 wt. %” includes 1 wt. % and 10 wt. % within the recited range and all points within the range.

[0037] The “softening point” (Tsp) refers to a temperature or a range of temperatures at which a substance softens. Herein, the softening point is measured using a METTLER TOLEDO dropping point instrument, such as METTLER TOLEDO DP70, according to a procedure analogous to ASTM D3104.

[0038] The “microcarbon residue test”, also referred to as “MCRT”, is a standard test method for the determination of microcarbon residue (micro method). The microcarbon residue (MCR) value of the various petroleum materials serves as an approximation of the tendency of the material to form carbonaceous type deposits under degradation conditions similar to those used in the test method, and can be useful as a guide in manufacture of certain stocks. However, care needs to be exercised in interpreting the results. This test method covers the determination of the amount of carbon residue formed after evaporation and pyrolysis of petroleum materials under certain conditions and is intended to provide some indication of the relative coke forming tendency of such materials. Herein, the MCRT is measured according to the ASTM D4530-15 standard test method.

[0039] The term “Tx” refers to the temperature at which the weight fraction “x” of a sample has boiled or distilled. For example, if when a sample is heated to a boiling point of 343°C and a cumulative 40 wt. % value has been recorded, the sample can be described as having a T40 distillation point of 343°C. In this discussion, boiling points can be determined by a convenient method based on the boiling range of the sample. This can correspond to ASTM D2887, or for heavier samples ASTM D7169.

[0040] In various aspects of the present disclosure, reference may be made to one or more types of fractions generated during distillation of a petroleum feedstock, intermediate product, and/or product. Such fractions may include naphtha fractions, distillate fuel fractions, and vacuum gas oil fractions. Each of these types of fractions can be defined based on a boiling range, such as a boiling range that includes at least 90 wt. % of the fraction, or at least 95 wt. % of the fraction. For example, for naphtha fractions, at least 90 wt. % of the fraction, or at least 95 wt. %, can have a boiling point in the range of 85°F (29°C) to 350°F (177°C). It is noted that 29°C roughly corresponds to the boiling point of isopentane, a Cs hydrocarbon. For a distillate fuel fraction, at least 90 wt. % of the fraction, or at least 95 wt. %, can have a boiling point in the range of 350°F (177°C) to 650°F (343°C). For a vacuum gas oil fraction, at least 90 wt. % of the fraction, or at least 95 wt. %, can have a boiling point in the range of 650°F (343°C) to 1050°F (566°C). Fractions boiling below the naphtha range can sometimes be referred to as light ends. Fractions boiling above the vacuum gas oil range can be referred to as vacuum residue fractions or pitch fractions.

[0041] Alternately, specification of various types of boiling ranges can be based on a combination of T5 (or T10) and T95 (or T90) distillation points. For example, in some aspects, having at least 90 wt. % of a fraction boil in the naphtha boiling range can correspond to having a T5 distillation point of 29°C or more and a T95 distillation point of 177°C or less. In some aspects, having at least 90 wt. % of a fraction boil in the distillate boiling range can correspond to having a T5 distillation point of 177°C or more and a T95 distillation point of 343°C or less. In some other aspects, having at least 90 wt. % of a fraction boil in the vacuum gas oil range can correspond to having a T5 distillation point of 343°C or more and a T95 distillation point of 566°C or less.

[0042] Alternatively, the boiling range of components in a feed, intermediate product, and/or final product may be described based on describing a weight percentage of components that boil within a defined range. The defined range can correspond to a range with an upper bound, such as components that boil at less than 150°C (referred to as 150°C-); a range with a lower bound, such as components that boil at greater than 500°C (referred to as 500°C+); or a range with both an upper bound and a lower bound, such as 150°C - 500°C.

Processes and Compositions.

[0043] As discussed above, the present disclosure relates to processes for producing pitch compositions from solvent assisted visbreaking (SAVB) and solvent deasphalting (SDA) visbroken products, and pitch compositions with tailored properties suitable for manufacturing into carbon articles (e.g., fibers, binder pitch, graphitizable carbon microbeads, solid lubricants, activated carbon fiber, battery anodes, and carbon foams).

[0044] Conventional methods for mesophase pitch production involve a semi-batch pyrolysis of isotropic pitch, using elevated temperatures with vigorous stirring and long residence times. Advantageously, the present disclosure provides processes that are operable in a batch, semibatch, or continuous mode, that are more suited to increasing production rates by operating at higher temperatures with shorter residence times.

[0045] Further, processes of the present disclosure enable control of pitch properties by varying/tailoring the separation processes for the pitch production. Hence, processes of the present disclosure provide the following advantages: (a) control of the pitch softening point (Tsp); (b) reduction of metals content within a pitch; (c) control of pitch MCRT; (d) control of mesophase coalescence and flowability by separation procedure of the isotropic pitch feed, and the mesophase pitch product; (e) removal of solid particulates from heat treated heavy hydrocarbon feedstock (e.g., pyrolyzed bitumen) by filtration processes, or deasphalting process.

[0046] In some aspect, processes of the present disclosure may comprise: heat treating (e.g., solvent assisted visbreaking) a heavy hydrocarbon feedstock in a heat treatment unit (e.g., a visbreaker) in presence of a first solvent (e.g., an aromatic solvent) to produce a first effluent comprising a heat treated product (e g., a visbroken product); at least partially removing a mixture of gas and distillate from the first effluent in a first separation unit (e.g., a distillation unit) to produce a second effluent comprising a separation bottom product; deasphalting the second effluent in a second separation unit in the presence of a second solvent to produce (a) a soluble product fraction comprising a first portion of the second solvent and deasphalted oil (DAO), and (b) an insoluble product fraction comprising a second portion of the second solvent and a first pitch product; and at least partially removing the second portion of the second solvent from the first pitch product in a third separation unit to produce a purified first pitch product.

Feedstocks

[0047] In various aspects, a heavy hydrocarbon feed, also referred to as “heavy oil”, can be processed to form a partially upgraded heavy hydrocarbon product. Examples of heavy hydrocarbon feeds may include, but are not limited to, highly aromatic sources such as Fluid Catalytic Cracker (FCC) bottoms, heavy crude oils, oils (such as bitumen) from oil sands, and heavy oils derived from coal, and blends of such feeds.

[0048] In at least one embodiment, the heavy hydrocarbon feed is selected from the group consisting of: bitumen, vacuum residue, atmospheric residue, main column bottoms, steam cracker tar, heavy coker gas oil, coker gas oil, light coker gas oil, and any combination thereof.

[0049] In some aspects, the compositions described herein can be formed by processing of a bitumen derived from Canadian oil sands, such as western Canadian oil sands). In some aspects, heavy hydrocarbon feeds can also include at least a portion corresponding to a heavy refinery fraction, such as distillation residues, heavy oils coming from catalytic treatment (such as heavy cycle slurry oils or main column bottoms from fluid catalytic cracking), and/or thermal tars (such as oils from visbreaking, steam cracking, or similar thermal or non-catalytic processes).

[0050] Heavy hydrocarbon feeds can be liquid or semi-solid. Such heavy hydrocarbon feeds can include a substantial portion of the feed that boils at 300°C or higher. For example, the portion of a heavy hydrocarbon feed that boils at less than 300°C can correspond to 5 wt. % to 40 wt. % of the feed, or 10 wt. % to 30 wt. % of the feed, or 5 wt. % to 20 wt. % of the feed. In such aspects, the heavy hydrocarbon feed can have a T40 distillation point of 300°C or higher, or a T30 distillation point of 300°C or higher, or a T20 distillation point of 300°C or higher. Additionally or alternately, a substantial portion of a heavy hydrocarbon feed can also correspond to compounds with a boiling point of 500°C or higher. In some aspects, 50 wt. % or more of a heavy hydrocarbon feed can have a boiling point of 500°C or more, or 60 wt. % or more, or 70 wt. % or more, or 80 wt. % or more, such as up to substantially all of the heavy hydrocarbon feed corresponding to components with a boiling point of 500°C or more. In some aspects, 50 wt. % or more of a heavy hydrocarbon feed can have a boiling point of 550°C or more, or 60 wt. % or more, or 70 wt. % or more, or 80 wt. % or more, such as up to substantially all of the heavy hydrocarbon feed corresponding to components with a boiling point of 550°C or more. Herein, boiling points can be determined by any suitable standard test method boiling points, such as ASTM D2887, ASTM D7169, for example.

[0051] Density, or weight per volume, of the heavy hydrocarbon can be determined according to ASTM D287 - 92 (2006) Standard Test Method for API Gravity of Crude Petroleum and Petroleum Products (Hydrometer Method), and may be provided in terms of API gravity. In general, the higher the API gravity, the less dense the oil. API gravity can be 30° or less, 25° or less, 20° or less, 18° or less, 16° or less, 14° or less, 12° or less, or 10° or less.

[0052] Heavy hydrocarbon feeds may be high in metals. For example, the heavy hydrocarbon feed can be high in total nickel, vanadium and iron contents. The heavy hydrocarbon feed may contain at least 0.00005 grams of Ni/V/Fe (50 ppm) or at least 0.0002 grams of Ni/V/Fe (200 ppm) per gram of hydrocarbon feed, on a total elemental basis of nickel, vanadium and iron. In other aspects, the heavy oil can contain at least about 500 wppm of nickel, vanadium, and iron, such as at least about 1000 wppm.

[0053] Heteroatoms such as nitrogen and sulfur are typically found in heavy hydrocarbon feeds, often in organically-bound form. Nitrogen content may range from about 0.1 wt. % to about 5 wt. % elemental nitrogen, or 0.5 wt. % to 4.5 wt. %, or 1 wt. % to 4 wt. %, or 1.5 wt. % to 3.5 wt. %, or 1 wt. % to 3 wt. %, or 0.1 wt. % to 2 wt. %, or 0.1 wt. % to 1 wt. %, based on total weight of the heavy hydrocarbon feed. The nitrogen containing compounds can be present as basic or non-basic nitrogen species. Examples of basic nitrogen species may include quinolines and substituted quinolines. Examples of non-basic nitrogen species may include carbazoles and substituted carbazoles.

[0054] Processes of the present disclosure may particularly be suited to treating heavy hydrocarbon feed containing at least 0.05 wt. % sulfur, based on total weight of the heavy hydrocarbon feed. Generally, the sulfur content may range from 0.5 wt. % to 10 wt. % elemental sulfur, or 1 wt. % to 7.5 wt. %, or 1.5 wt. % to 5 wt. %, or 2 wt. % to 2.5 wt. %, or 0.1 wt. % to 5 wt. %, based on total weight of the heavy hydrocarbon feed. Examples of said sulfur compounds may include the class of heterocyclic sulfur compounds such as thiophenes, tetrahydrothiophenes, benzothiophenes and their higher homologs and analogs. Other organically bound sulfur compounds may include aliphatic, naphthenic, and aromatic mercaptans, sulfides, di- and polysulfides.

[0055] Heavy hydrocarbon feeds may be high in n-heptane asphaltenes. In some aspects, the heavy hydrocarbon feed can contain 1 wt. % to 80 wt. % of n-heptane asphaltenes, or 5 wt. % to 80 wt. %, or 10 wt. % to 70 wt. %, or 15 wt. % to 60 wt. %, or 20 wt. % to 50 wt. %, or 5 wt. % to 50 wt. %, or 5 wt. % to 40 wt. %, or 5 wt. % to 30 wt. %, or 5 wt. % to 20 wt. %, based on the total weight of the heavy hydrocarbon feed. In aspects where the heavy hydrocarbon feed includes a portion of a bitumen formed by conventional paraffinic froth treatment of oil sands, the heavy hydrocarbon feed may contain 10 wt. % to 30 wt. % of asphaltenes, based on the total weight of the heavy hydrocarbon feed.

[0056] Alternate method for characterizing a heavy hydrocarbon feed may be based on the Conradson carbon residue (CCR) of the feedstock, or alternatively the micro carbon residue (MCR) content. The Conradson carbon residue or micro carbon residue content of the heavy hydrocarbon feed can be 5 wt. % to 50 wt. %, or 10 wt. % to 40 wt. %, or 15 wt. % to 30 wt. %, or 20 wt. % to 50 wt. %, or 5 wt. % to 10 wt. %, based on the total weight of the heavy hydrocarbon feed.

[0057] In various aspects, examples of upstream handling of a heavy hydrocarbon feed may correspond to the addition of an extraction site diluent to form an initial feed. Adding diluent at the extraction site and/or froth treatment site may facilitate transport of the initial feed to the location of the reaction system for forming the partially processed heavy hydrocarbon product. The amount of extraction site diluent present in the initial feed can vary depending on a variety of factors.

[0058] Particles content in a heavy hydrocarbon feedstock may be considered. For crude oils derived from conventional extraction sites, the particle content of the crude oil is typically low. However, an increasing proportion of crude oil production corresponds to non-traditional crudes, such as crude oils derived from oil sands. Initial extraction of non-traditional crudes can present some additional challenges. For example, during mining or extraction of oil sands, a large percentage of non-petroleum material (such as sand) may be included in the raw product.

[0059] The particle content and/or content of other non-petroleum materials of oil sands may be quite large, corresponding to 30 wt. % or more of the heavy hydrocarbon feedstock. An initial reduction in the particle content may be performed by first mixing the raw product with water. Air is typically bubbled through the water to assist in separating the bitumen from the nonpetroleum material. Accordingly, a large proportion of the solid, non-petroleum material in the raw product may be removed. However, smaller particles of non-petroleum particulate solids may remain with the oil phase at the top oil phase of the mixture. Said top oil phase may be referred to as a froth. The particles present in said froth may correspond to 5 wt. % or more of the froth, such as 10 wt. % or more, such as to 20 wt. % or more.

[0060] Separation of smaller non-petroleum particulate solids may be achieved by adding a solvent to the froth of the aqueous mixture. This is referred to as a froth treatment. Examples of froth treatments may include paraffinic froth treatment (PFT) and naphthenic froth treatment (NFT). For PFT, suitable solvents may include isopentane, pentane, and other light paraffins (such as Cs - Cs paraffins) that are liquids at room temperature. Other solvents such as C3 - C10 alkanes might also be suitable for use as a solvent for forming an asphaltene-depleted crude, depending on the conditions during the PFT. For NFT, a mixture of naphtha boiling range compounds may be used, where the mixture may include aromatics, naphthenes, and optionally paraffins. It is noted that the solvents for PFT may roughly correspond to naphtha boiling range compounds as well, so that the difference between the solvents for PFT and NFT may be based on compound class (e.g., aromatic, naphthene, paraffin) rather than boiling range.

[0061] During a froth treatment, addition of the solvent to the froth may result in a two phase mixture, with the crude and the solvent forming one of the phases. The smaller particulate solids of non-petroleum material may be “rejected” from the oil phase and join the aqueous phase. The crude oil and solvent phase may then be separated from the aqueous phase. During conventional PFT, after separation from the aqueous phase, the resulting bitumen may have a combined water and particle content of 1 wt. % or less. Higher particles content can be present in bitumen formed using NFT.

[0062] When PFT is performed under conventional conditions, the PFT may impact the amount of asphaltenes that are retained in the bitumen product. When a paraffinic solvent is added to the mixture of raw product and water, about 30 % to about 60 % of the n-heptane asphaltenes in the crude oil may be “rej ected” and lost to the water phase along with the smaller non-petroleum particulate solids. As a result, the bitumen that is separated out from the non-petroleum material after PFT may correspond to an asphaltene-depleted crude oil. By using PFT to knock out small particulate solids, the asphaltene content of the crude can be reduced or depleted by at least about 30 wt. %, such as at least about 40 wt. %, or at least about 45 wt. %, based on the total weight of the crude. In other words, the asphaltene-depleted crude will have about 30 wt. % less asphaltenes than the corresponding raw crude, such as at least about 40 wt. %, or at least about 45 wt. %. Typically, PFT reduces or depletes the asphaltenes in the crude by about 60 wt. % or less, such as about 55 wt. % or less, or about 50 wt. % or less, based on the total weight of the of the crude. The amount of asphaltenes that may be removed or depleted can depend on a variety of factors. Possible factors that may influence the amount of asphaltene depletion may include the nature of the solvent, the amount of solvent relative to the amount of crude oil, the temperature during the PFT process, and the nature of the raw crude being exposed to PFT.

Solvent Separation Processes

[0063] Processes of the present disclosure may comprise solvent separation (or extraction) processes prior to traditional processing, thus enabling the production of valuable visbroken hydrocarbon products with improved properties for pitch production, while mitigating coke formation and fouling of the process unit.

Solvent Separation Processes: Solvent Assisted Visbreaking

[0064] Heavy hydrocarbon feedstocks may be subject to thermal cracking processes, such as visbreaking, in order to increase the yield of more valuable middle distillates and to decrease the viscosity of the thermally converted liquid product. Traditional visbreaking is typically achieved at thermal severities ranging from about 500 equivalent seconds to about 1000 equivalent seconds, at 800°F. The thermal severity a feedstock can experience is limited by the reactivity of the hydrocarbon feedstock and the phase behavior of the thermally reacted product. If a material is too reactive, coke may form, if the liquid has insufficient solvating capability, a cracked intermediate can precipitate out and foul the reactor. Each of these affects the reliability of the process and the quality of the pitch, and can render a pitch unsuitable for producing high-quality carbon articles. Further, higher conversion of the feed by increasing the visbreaking thermal severity usually leads to higher production of coke, consequently fouling the visbreaker coils.

[0065] In at least one embodiment, processes of the present disclosure comprise solvent assisted visbreaking (SAVB) of heavy hydrocarbon feedstock in the presence of a solvent, under suitable visbreaking conditions, enabling the production of valuable visbroken hydrocarbon products with improved properties for pitch production, while mitigating coke formation and fouling of the process unit. Solvents for SAVB may be primarily used to prevent the molecules of the hydrocarbon feedstock from converting into coke, or from depositing as precipitated asphaltenes during thermal conversion. Hence, SAVB can be carried out at higher temperature and pressure conditions when compared to traditional visbreaking.

[0066] Solvent assisted visbreaking of heavy hydrocarbon feedstocks may be carried out in a visbreaker unit, upstream of the heavy hydrocarbon feedstock processing, particularly prior to any separation/purification processes such as distillation, deasphaltenation, desulfurization, denitrogenation, and/or demetallation, thus advantageously preventing any risk of fouling downstream of the heavy hydrocarbon feedstock processing. Particularly, when conducted in the presence of a solvent, SAVB of heavy hydrocarbon feedstocks enables the production of a visbroken product with reduced coke content (Total Liquid Product (TLP) coke of about 2 wt. % or less, based on the total weight of the blend comprising the solvent and the heavy hydrocarbon feedstock), when compared to SAVB conducted in absence of a solvent, even at higher severity in the visbreaker unit. SAVB also prevents fouling from occurring by increasing the solubility blending number of the liquid, increasing the solubility of highly dealkylated and aromatic core molecules.

[0067] Suitable solvents for SAVB may be selected from the group consisting of: steam cracked gasoil, heavy coker gasoil, heavy vacuum gas oil, heavy extract from lubes production, hydrocracked residue gasoil, steam cracked naphtha, coker naphtha, light cycle oil (LCO), reformate, BTX, and any combination thereof. For example, synthetic crude oil, also referred to as “Syncrude oil” or “SCO”, may be use as a solvent for SAVB of heavy hydrocarbon feedstocks. [0068] The volume ratio of solvent to feed in a solvent assisted visbreaking (SAVB) process may be at least 1 :99 volume ratio (vol. %). Alternate volume ratio ranges of solvent to feed at which the SAVB may be carried out may range from 1 :99 to 50:50 volume ratio (vol. %), or from 5:95 to 45:55, or from 10:90 to 40:60, or from 15:85 to 35:65 volume ratio (vol. %). For example, SAVB may be comprise blending a solvent with a heavy hydrocarbon feedstock at a volume ratio of solvent to heavy hydrocarbon feedstock of 15:85 (vol. %).

[0069] Solvent assisted visbreaking of heavy hydrocarbon feedstocks may be carried out at a temperature ranging from 350°C to 550°C (or from 375°C to 525°C, or from 400°C to 500°C); a pressure ranging from 10 psig to 2000 psig (or from 50 psig to 1500 psig, or from 100 psig to 1000 psig, or from 200 psig to 500 psig); a residence time of about 5 minutes or greater; and an LHSV in the range of about 0.1 hr' ¹ to about 12 hr' ¹ (or about 0.5 hr' ¹ to about 10 hr' ¹ , or about 1 hr' ¹ to about 8 hr' ¹ , or about 2 hr' ¹ to about 12 hr' ¹ ).

[0070] Accordingly, heat treating (e.g., SAVB) a heavy hydrocarbon feedstock in a heat treatment unit (e.g., a visbreaker) in presence of a solvent (e.g., an aromatic solvent) may be conducted in order to produce a first effluent comprising a heat treated product (e g., a visbroken product). Heat treating (e.g., SAVB) of the heavy hydrocarbon feedstock may be followed by at least a partial removal of a mixture of gas and distillate from said first effluent in a first separation unit (e.g., a flash distillation unit) in order to produce a second effluent comprising a separation bottom product. Said separation bottom product may be further subjected to deasphaltenation in a deasphalter unit to produce a pitch via solvent deasphalting (SDA), which is discussed further hereinafter.

[0071] In some aspects, solvent(s) used for the SAVB process and present in the separation unit may be recycled and further combined directly with the heavy hydrocarbon feed prior to SAVB in the visbreaker, or directly back to the visbreaker unit. Said solvent recycling advantageously provide cost-effective processes for pitch production.

Solvent Separation Processes: Solvent Deasphalting

[0072] A solvent deasphalting (SDA) process is a solvent-based extraction process based on the separation by polarity, in which residues are selectively separated by molecular type using solvents, and precipitating out of solution asphaltenes and other residue heavy components. SDA produces a low-contaminant, relatively high hydrogen deasphalted oil (DAO) product and a pitch product that may contain the majority of the residue’s contaminants (e.g., metals, asphaltenes, Conradson carbon residue (CCR)). Depending on the DAO quality, the DAO product may be used for lubes base oil feedstock, for vacuum gas oil (VGO) conversion feedstock, or as feed to a secondary deasphalting process to produce a pitch containing low-contaminant levels. Contaminants present in the feed may comprise oxygenates, moisture, metals, heteroatoms, coke, particulates, and the like. Solvent deasphalting (SDA) processes of the present disclosure enable removal of said contaminants.

[0073] Processes of the present disclosure for producing pitch compositions may comprise a one-stage solvent deasphalting, the one-stage solvent deasphalting comprising: solvent deasphalting the second effluent comprising the separation bottom product obtained after visbreaking and distillation, in a deasphalter unit, in the presence of a solvent to produce (a) a soluble product fraction comprising a first portion of said solvent and deasphalted oil (DAO), and (b) an insoluble product fraction comprising a second portion of said solvent and a first pitch product (e.g., isotropic pitch product). Processes of the present disclosure may further comprise: at least partially removing the portion of the solvent from the first pitch product in another separation unit (e.g., distillation) to produce a purified first pitch product.

[0074] Softening point of a pitch is an important qualitative characteristic of a pitch, a key parameter that is required for carbon products manufacturing. The softening point is a crude measure for when sufficient portion the pitch has softened such that it can flow out of a hole in a cup, and is often used as a pitch specification. The ability to control pitch softening point by tailoring the pitch properties through the separation processes disclosed herein creates flexible processes that enhance and facilitate the access to a wide range of carbon products. [0075] Solvent deasphalting of a separation bottom, particularly a separation bottom that is distilled and subsequently solvent deasphalted, enables the isolation of a pitch with greater control than traditional distillation methods. Said traditional distillation methods operate at high temperature and vacuum, and are only effective in removing the most volatile compounds. In contrast, solvent deasphalting, and particularly two-stage solvent deasphalting, enables the isolation of different pitch compositions because such solvent-deasphatling processes are solubility -based rather than volatility -based. Consequently, solvent deasphalting can promote the production of pitch compositions with lower softening point than pitch composition produced without solvent deasphalting, and can also enable removal of coke and particulates from the pitch that distillation methods would leave in. Controlling pitch softening point is crucial for producing high-quality pitch that can be manufactured into desirable carbon materials. Without being bound by any theory, it is believed that the softening point is controlled by both distillation and solvent deasphalting conditions because of the different pitch compositions that can be achieved. The overall solvent deasphalting process provides an isotropic pitch with reduced metals, coke, and particulates, which improves the downstream manufacture of carbon materials (e.g. carbon fiber). [0076] In some aspects, processes of the present disclosure may comprise two or more solvent deasphalting processes. Hence, solvent deasphalting may be performed more than once to improve pitch quality.

[0077] In some aspects, processes of the present disclosure may comprise a two-stage deasphalting process which enables mitigation of metals, coke, higher molecular weight and more polar compounds, and ash content within a pitch. Herein, the two-stage deasphalting process relies on the use of two solvents with different solubility parameters. A two-stage deasphalting process may comprise: in a first deasphalter unit, solvent deasphalting an effluent comprising a visbroken product that has been purified by distillation, wherein solvent deasphalting in the first deasphalter unit is conducted in the presence of a first solvent (e.g., heptane) to produce: (a) a first fraction comprising a mixture of a first pitch product (sacrificial pitch) and contaminants (e.g., metals, coke, and the like), wherein the first pitch product is an isotropic pitch product; and (b) a second fraction comprising a mixture of a deasphalted oil (DAO) product and a second pitch product, wherein the second pitch product may be used as-is for further processing (e.g., pyrolysis to produce mesophase pitch products). In the two-stage deasphalting process, the second fraction comprising the mixture of a deasphalted oil (DAO) product and the second pitch product may be further deasphalted in a second deasphalter unit in the presence of a second solvent (e.g., pentane), wherein the second solvent has a solubility parameter lower than the first solvent. Deasphalting the second fraction comprising the mixture of a deasphalted oil (DAO) product and the second pitch product enables separation of the deasphalted oil (DAO) product from the second pitch product, wherein the second pitch product is demetallated, free of contaminant particles. The deasphalted oil (DAO) product may be used for further processing. Dewaxing may be conducted, if needed.

[0078] Advantageously, solvent deasphalting in the second deasphalter unit provides at least 5% metals content reduction in the second pitch product (such as 50% to 99% metals content reduction, such as 55% to 95% metals content reduction, such as 60% to 90% metals content reduction, such as 65% to 85% metals content reduction). For example, solvent deasphalting in the second deasphalter unit may provide at least 20% to 25% metals content reduction in the second pitch product. The demetallated pitch product may be used as-is or further processed (e.g., conversion into a mesophase pitch).

[0079] It is noted that, prior to the second deasphalting process, the first solvent may be removed from the insoluble product fraction produced in the first deasphalter unit.

[0080] As discussed above, the first solvent used for the first solvent deasphalting has a higher solubility parameter (i.e., more polar) than the second solvent used for the second solvent deasphalting, advantageously resulting in the precipitation of the metals, particulates, and higher polarity hydrocarbons in the first-stage of the deasphalting process. Both solvents used during the first and the second solvent deasphalting processes may be paraffinic solvents (e.g., heptane, pentane).

[0081] Alternatively, the first solvent used herein can be lower in solubility parameter than the second solvent. In such instance, the first pitch produced from the first stage deasphalting unit would be used as the feed to the second stage deasphalting unit, and the second pitch extracted from the first pitch using the higher solubility parameter second solvent.

[0082] The two-stage deasphalting process of the present disclosure further enables efficient enhancement of a pitch demetallation by easily tuning the solubility of the first solvent versus the second solvent. Hence, composition of the first pitch produced in the first deasphalter unit is different than the composition of the second pitch produced in the second deasphalter unit, in terms of molecular weight, aromaticity, heteroatoms, and softening point. Deasphalting with solvents of high polarity index may enable rejection of higher molecular weight products.

[0083] Suitable diluents/solvents for solvent deasphalting may be selected from the group consisting of: straight and branched-chain hydrocarbons, and aromatic solvents such as isobutane, ethane, propane, butanes, pentanes, isopentane, hexanes, isohexane, heptanes, isoheptanes, octanes, dodecanes, benzene, toluene, xylenes, naphthalene, methylnaphthalenes, pyridine, quinoline and mixtures thereof; cyclic and alicyclic hydrocarbons, such as cyclopentane, cyclohexane, methylcyclopentane, cycloheptane, methylcyclohexane, methylcycloheptane, and mixtures thereof; perhalogenated hydrocarbons, such as perfluorinated C4-10 alkanes, chlorobenzene, and aromatic and alkyl -substituted aromatic compounds, such as benzenes (e.g., dimethylbenzenes), toluene, mesitylene, and xylene; and polar solvents (e.g., acetone, N,N- dimethylformamide, acetonitrile, pyridine, quinoline, dimethyl sulfoxide, A'-mcthylpyrrolidonc, and mixtures thereof), aromatic cuts from refining, or chemicals processes such as decant oil, reformate, tar distillation cuts, or any isomers therefrom, and any combination thereof.

[0084] In at least one embodiment, diluents/solvents for solvent deasphalting are selected from the group consisting of: propane, butanes, pentanes, hexanes, heptanes, reformate, furfural, N-methylpyrrolidone, heavy coker gas oil, coker gas oil, light coker gas oil, light cycle oil, steam cracked naphtha, coker naphtha, reformate, BTX, and any combination thereof.

[0085] Solvents used during the solvent deasphalting processes may be the same or different than the solvents used during SAVB.

[0086] For example, in a two-stage deasphalting process, the first solvent in the first deasphalting may be heptane and the second solvent in the second deasphalting may be pentane (less polar solvent). In another example of a two-stage deasphalting process, the first solvent in the first deasphalting may be a mixture of heptane/toluene (higher polarity than using heptane solely) at various volume ratio of heptane/toluene (e.g., 90/10 volume ratio of heptane/toluene), and the second solvent in the second deasphalting may be heptane (less polar solvent than the mixture).

[0087] The volume ratio of solvent to feed in a solvent deasphalting (SDA) process may be at least 1 : 1 volume ratio. Alternate ranges at which the SDA may be carried out may range from 0.1:1 to 100: 1, or from 0.5:1 to 50:1, or from 1 : 1 to 40:1, or from 2: 1 to 30:1, or from 3: 1 to 20:1, or from 4:1 to 10:1.

[0088] Solvent deasphalting (SDA) process may be conducted at a deasphalting temperature (°C) ranging from 10°C to about 400°C (or from about 20°C to about 350°C, or from about 30°C to about 300°C, or from about 40°C to about 250°C, or from about 50°C to about 200°C).

[0089] Solvent deasphalting (SDA) process may be conducted at a deasphalting pressure (psig) ranging from about 1 psig to about 2000 psig (or from about 5 psig to about 1500 psig, or from about 10 psig to about 1000 psig, or from about 50 psig to about 900 psig, or from about 100 psig to about 800 psig).

[0090] The first pitch product may be an isotropic pitch product having a softening point T _sp of less than about 400°C (or about 350°C or less, or about 300°C or less, or about 250°C or less, or about 200°C or less, or about 150°C or less, or about 100°C or less), as determined according to a procedure analogous to the ASTM D 3104 test method, wherein the procedure can be carried out under nitrogen, at a 2°C/min ramp rate up to a temperature of 400°C. The first pitch product may have a softening point Tsp of about 50°C or greater (or about 100°C or greater, or about 150°C or greater, or about 200°C or greater, or about 250°C or greater, or about 300°C or greater).

[0091] The first pitch product may be an isotropic pitch product having a glass transition temperature (Tg) of less than about 350°C (or about 325°C or less, or about 300°C or less, or about 275°C or less, or about 235°C or less, or about 195°C or less, or about 155°C or less, or about 115°C or less, or about 75°C or less, or about 70°C or less), as determined using the second heating scan of a differential scanning calorimetry (DSC) experiment at 10°C/min heating and cooling rate performed under inert atmosphere (N2).

[0092] The first pitch product may be an isotropic pitch product having a hydrogen content (wt. %) of about 10 wt. % or less, such as from about 2.5 wt. % to about 10 wt. % (or from about 3 wt. % to about 8 wt. %, or from about 3.5 wt. % to about 7 wt. %, or from about 4 wt. % to about 7 wt. %, or from about 4.5 wt. % to about 7 wt. %), based on the total weight of the first pitch product.

[0093] The first pitch product may be an isotropic pitch product having a quinoline insoluble (QI) content of about 40 wt. % or less, from about 0.01 wt. % to about 40 wt. % (or from about 0.5 wt. % to about 20 wt. %, or from about 1 wt. % to about 10 wt. %, or from about 2 wt. % to about 8 wt. %, or from about 0.01 wt. % to about 10 wt. %, or from about 0.05 wt. % to about 5 wt. %, or from about 0.1 wt. % to about 2 wt. %), based on the total weight of the first pitch product.

[0094] The first pitch product may be an isotropic pitch product having an MCR of from about 10 wt. % to about 90 wt. % (or from about 20 wt. % to about 80 wt. %, or from about 30 wt. % to about 70 wt. %), based on the total weight of the first pitch product.

[0095] The second pitch product may be an isotropic pitch product having a softening point Tsp of less than about 400°C (or about 350°C or less, or about 300°C or less, or about 250°C or less, or about 200°C or less, or about 150°C or less, or about 100°C or less), as determined according to a procedure analogous to the ASTM D 3104 test method, wherein the procedure can be carried out under nitrogen, at a 2°C/min ramp rate up to a temperature of 400°C. The second pitch product may have a softening point T _S p of about 100°C or greater (or about 150°C or greater, or about 200°C or greater, or about 250°C or greater, or about 300°C or greater, or about 350°C or greater).

[0096] The second pitch product may be an isotropic pitch product having a glass transition temperature (T _g ) of less than about 350°C (or about 325°C or less, or about 300°C or less, or about 275°C or less, or about 235°C or less, or about 195°C or less, or about 155°C or less, or about 115°C or less, or about 75°C or less, or about 70°C or less), as determined using the second heating scan of a differential scanning calorimetry (DSC) experiment at 10°C/min heating and cooling rate performed under inert atmosphere (N2).

[0097] The second pitch product may be an isotropic pitch product having a hydrogen content (wt. %) of about 10 wt. % or less, such as from about 2.5 wt. % to about 10 wt. % (or from about 3 wt. % to about 8 wt. %, or from about 3.5 wt. % to about 7 wt. %, or from about 4 wt. % to about 6.5 wt. %, or from about 4.5 wt. % to about 6 wt. %), based on the total weight of the second pitch product.

[0098] The second pitch product may be an isotropic pitch product having a quinoline insoluble (QI) content of about 75 wt. % or less, from about 0.01 wt. % to about 70 wt. % (or from about 0.5 wt. % to about 65 wt. %, or from about 1 wt. % to about 60 wt. %, or from about 2 wt. % to about 50 wt. %, or from about 0.01 wt. % to about 40 wt. %, or from about 0.05 wt. % to about 30 wt. %, or from about 0.1 wt. % to about 20 wt. %), based on the total weight of the second pitch product.

[0099] The second pitch product may be an isotropic pitch product having an MCR of from about 10 wt. % to about 90 wt. % (or from about 20 wt. % to about 85 wt. %, or from about 30 wt. % to about 80 wt. %), based on the total weight of the second pitch product

[0100] The first and/or second pitch product(s) may be an isotropic pitch product that may be used as-is or further converted into a mesophase pitch product via heat treatment (e.g., pyrolysis). The heat treatment (e.g., pyrolysis) can be run in a batch, semi-batch, or continuous mode. Thus, processes of the present disclosure may further comprise heat treating (e.g., pyrolyzing) the isotropic pitch product at a temperature of about 300°C or greater, for a period of time sufficient to form mesophase. Conversion of an isotropic pitch product to a mesophase pitch product may include a seeding agent which enables the acceleration of the mesophase transformation during heat treatment (e.g., pyrolysis) of an isotropic feed in a reaction zone. Hence, greater rates of mesophase formation can occur by the addition of mesophase pitch to an isotropic feed prior to pyrolysis.

[0101] In some aspects, heat treating may be carried out at a temperature ranging from 350°C to 500°C (such as from 375°C to 450°C, or 400°C to 425°C) at a residence time of about 10 minutes to about 180 minutes, for example.

[0102] Processes of the present disclosure may further comprise: optionally sparging a gas through the first pitch product and/or the second pitch product and/or the purified pitch product and/or the second purified pitch product to produce a mesophase pitch. [0103] Without being bound by any theory, it is believed that a substantial amount of pressure in the reaction zone is beneficial during the pyrolysis process of the isotropic pitch, and that light components that would otherwise be lost to the gas phase, may be necessary to facilitate secondary condensation reactions to increase the molecular weight of the pitch. As additional condensation, cyclization, and dehydrogenation reactions continue, the shape of the molecules and molecular weight may become sufficiently high to facilitate mesophase formation directly within the reactor. Such occurrence directly contrasts with traditional processes for mesophase pitch production, which typically include vigorous sparging in order to strip away any volatiles during pyrolysis. Hence, combination of tailored separation processes described above and pyrolysis under pressure of the isotropic pitch product may produce a mesophase pitch with tailored and improved properties (e.g., improved flowability, controlled softening point) suitable for carbon articles manufacturing.

[0104] Pyrolysis of the isotropic pitch product may be conducted at a temperature ranging from about 300°C to about 500°C, such as from about 350°C to about 450°C, such as from about 400°C to about 430°C.

[0105] Pyrolysis of the isotropic pitch product may be conducted at a pressure ranging from about 10 psig to about 1000 psig, such as from about 20 psig to about 800 psig, such as from about 50 psig to about 600 psig.

[0106] Pyrolysis of the isotropic pitch product may be conducted for a period of time of about 1 minute or greater (or about 5 minutes or greater, or about 10 minutes or greater, or about 15 minutes or greater, or about 30 minutes or greater, or about 1 hour or greater, or about 2 hours or greater, or about 3 hours or greater, or about 4 hours or greater, or about 5 hours or greater, or about 6 hours or greater, or about 8 hours or greater, or about 10 hours or greater). For example, the isotropic pitch product of the present disclosure may be pyrolyzed in a reaction zone at a residence time of about 2 hours to 24 hours.

[0107] The mesophase pitch product may have a mesophase content of 5 vol. % or less, based on the total volume of the mesophase pitch product. Alternately, the mesophase pitch product may have a mesophase content of 5 vol. % to 100 vol. %, based on the total volume of the mesophase pitch product.

[0108] The mesophase pitch product may have a QI content of about 80 wt% or less, or about 70 wt% or less, or about 60 wt% or less, or about 50 wt% or less, or about 40 wt% or less, or about 30 wt% or less, based on the total weight of the mesophase pitch product.

[0109] The mesophase pitch product may have a softening point Tsp of less than about 400°C (or about 350°C or less, or about 300°C or less, or about 250°C or less, or about 200°C or less, or about 150°C or less, or about 100°C or less), as determined according to a procedure analogous to the ASTM D 3104 test method, wherein the procedure can be carried out under nitrogen, at a 2°C/min ramp rate up to a temperature of 400°C. The mesophase pitch product may have a softening point T _sp of about 200°C or greater (or about 250°C or greater, or about 275°C or greater, or about 300°C or greater, or about 350°C).

[0110] The mesophase pitch product may have a glass transition temperature (Tg) of less than about 350°C (or about 325°C or less, or about 300°C or less, or about 275°C or less, or about 235°C or less, or about 195°C or less, or about 155°C or less, or about 115°C or less, or about 75°C or less, or about 70°C or less), as determined using the second heating scan of a differential scanning calorimetry (DSC) experiment at 10°C/min heating and cooling rate performed under inert atmosphere (N2).

[0111] The mesophase pitch product may have a hydrogen content (wt. %) of about 10 wt. % or less, such as from about 2.5 wt. % to about 10 wt. % (or from about 3 wt. % to about 8 wt. %, or from about 3.5 wt. % to about 7 wt. %, or from about 4 wt. % to about 6.5 wt. %, or from about 4.5 wt. % to about 6 wt. %), based on the total weight of the mesophase pitch product.

[0112] The mesophase pitch product may have an MCR of from about 10 wt. % to about 95 wt. % (or from about 20 wt. % to about 90 wt. %, or from about 30 wt. % to about 80 wt. %), based on the total weight of the mesophase pitch product.

[0113] The pitch products may be further subj ected to melt-blowing for the production of, for example, fiber mat, chopped fibers, or melt spun into continuous carbon fiber. The mesophase pitch product may be used for producing a carbon article, such as fiber, carbon fiber, oxidized fiber, carbonized fiber, graphitized fiber, fiber web, oxidized fiber web, carbonized fiber web, or graphitized fiber web. The mesophase pitch product may be further used as binder pitch, or for impregnation pitch, carbon foam production, or carbon/carbon composites production. End uses are described further below. The pitch products may be used as binder pitch, impregnation pitch, for carbon foam manufacture, or needle coke production.

[0114] As described above, heavy hydrocarbon feedstocks may comprise a substantial amount of particulates. Thus, processes of the present disclosure may further comprise additional separation process, after SAVB and/or prior to further processing (e g., prior to second deasphalting process). Said separation process may include chromatographic separation, membrane-filtration, and any combination thereof. Therefore, processes of the present disclosure may further comprise: (a) removing particulates from the first effluent to produce a filtered effluent by filtration prior to removing the mixture of gas and distillate in the first separation unit; and/or (b) removing particulates from the fraction comprising the mixture of the deasphalted oil (DAO) product and the pitch product by filtration prior to the second deasphalting process.

[0115] Additionally, prior to any solvent deasphalting processes, a separation/purification process may be conducted such as a feed may be fractionated by atmospheric distillation, vacuum distillation, flash distillation, and any combination thereof. For example, an effluent comprising visbroken bottom product(s) produced during SAVB may be fractionated in a flash drum at a pressure and temperature suitable for separating volatiles from the bottom product(s). The fractionation results in two phases: a vapor phase, enriched in the more volatile components, and a liquid (viscous) phase, enriched in the less volatile components. The effluent may be pressurized and heated, then passed through a throttling valve or nozzle into the flash drum unit. Because of the large drop in pressure, part of the effluent may be vaporized. The vapor may be taken off overhead, while the liquid drains to the bottom of the drum, where it is withdrawn.

[0116] In some aspects, processes of the present disclosure may comprise: hydrotreating (HDT) a separation bottom product produced from a visbroken product fractionated in a hydrotreater unit, to produce a hydroteated product; at least partially removing a mixture of gas and heteroatoms contaminants (e.g., sulfur, nitrogen, oxygen), oxygenates, and metals from the hydroteated product in the hydrotreater unit to produce an effluent comprising a purified hydrotreated product that is hydrodesulfurized, hydrodenitrification, hydrodemetallation. The purified hydrotreated product may be further subjected to an additional separation process in another separation unit (e g., flash drum unit), prior to solvent deasphalting in a first deasphalter unit.

[0117] Processes of the present disclosure may comprise further comprising: hydroprocessing or oxidizing, before or after heat treating the heavy hydrocarbon feedstock to reduce sulfur content.

[0118] Hydrotreatment may be carried out at a pressure ranging from about 200 psi to about 2,000 psi, such as from about 250 psi to about 1,750 psi, such as from about 300 psi to about 1,500 psi, such as from about 350 psi to about 1,250 psi, such as from about 400 psi to about 1,000 psi. [0119] Hydrotreatment may be carried out at a temperature ranging from about 350°C to about 450°C, such as from about 360°C to about 440°C, such as from about 370°C to about 440°C, such as from about 380°C to about 430°C, such as from about 390°C to about 420°C.

[0120] Hydrotreatment may be carried out at a liquid hour space velocity (LHSV) ranging from about 0.1 h' ¹ to about 2 h' ¹ , such as from about 0.2 h' ¹ to about 1.8 h' ¹ , such as from about 0.4 h' ¹ to about 1.6 h' ¹ , such as from about 0.6 h' ¹ to about 1.4 h' ¹ , such as from about 0.8 h' ¹ to about 1.2 h' ¹ . [0121] Production of a purified hydrotreated product that is hydrodesulfurized, and/or hydrodenitrification enables production of a pitch product that is substantially free of heteroatoms, oxygenates, metals, and other contaminants.

[0122] Embodiments of the present disclosure will now be described in further detail with reference to the drawings. With respect to the drawings, one having ordinary skill in the art will recognize other components that may be included for proper and safe operation of the apparatuses and processes depicted therein. Examples of components that may not be expressly depicted include, but are not limited to, flow meters, sensors, connections for filling and emptying fluids, safety devices, valves, pumps, and the like.

[0123] The processes of the present disclosure are discussed further hereinafter with reference to FIGS. 1-5.

[0124] FIG. 1 is a nonlimiting example flow diagram of a first configuration of a process for producing pitch compositions suitable for manufacturing into carbon articles. Process 100 may include solvent heat treating (such as visbreaking) 104 of heavy hydrocarbon feed 102 in presence of a solvent (e.g., an aromatic solvent), at a given solvent: heavy hydrocarbon feed 102 volume ratio, by introducing heavy hydrocarbon feed 102 into a visbreaker unit, removing lights components 106 (e.g., volatiles 106), and producing first effluent 108 comprising a visbroken product. Optional removal of particulates from first effluent 108 may be conducted via filtration 110. First effluent 108 is directed to first separation unit 112 (e.g., flash drum, vacuum distillation unit, distillation column, and the like) to at least separate a mixture 114 of gas and distillate from a second effluent 116. Second effluent 116 comprising a separation bottom product is directed to deasphalter unit 118, wherein deasphalting second effluent 116 is carried out in the presence of solvent 120, at a given solvent: second effluent 116 volume ratio to produce: (a) soluble product fraction 122 comprising a first portion of solvent 120 and a deasphalted oil (DAO) product; and (b) insoluble product fraction 124 comprising a portion of solvent 120 and a first pitch product, wherein the first pitch product is an isotropic pitch product. Soluble product fraction 122 is removed and may be used for further processing. Insoluble product fraction 124 comprising a portion of solvent 120 and a first pitch product is directed to separation unit 126 (e.g., flash drum, vacuum distillation unit, distillation column, and the like) to at least partially remove (stream 128) solvent 120 from the first pitch product, and to produce second pitch product 130, wherein the second pitch product 130 is an isotropic pitch product. Compositions of first pitch product and second isotropic pitch product 130 are different. Isotropic pitch product 130 may be used as-is for further processing (e.g., pyrolysis). [0125] Common reference characters are used in the remaining figures to describe elements having a similar function to those shown in FIG. 1. In the interest of brevity, such features are not described in detail again.

[0126] FIG. 2 is a nonlimiting example flow diagram of a first variant of a process for producing pitch compositions. In process 200, a two-stage solvent deasphalting process is conducted in order to remove contaminants such as contaminants comprising metals, and other particulates. Hence, soluble product fraction 122 is directed to deasphalter unit 236 (e.g., second deasphalter unit 236) in presence of solvent 238 to produce pitch product 242. Optional removal of particulates from soluble product fraction 122 may be conducted in separation unit 232 via filtration prior to second solvent deasphalting 236, to produce a filtered product fraction 234. Alternately, soluble product fraction 122 may be directed to separation unit 232 (e.g., flash drum, vacuum distillation unit, distillation column, and the like) prior to second solvent deasphalting 236 in order to at least partially remove any remaining gas and distillate from soluble product fraction 122.

[0127] In some aspects, contaminants (e.g., metals, coke) may be present in isotropic pitch product 130. Thus, isotropic pitch product 130 may be further purified to remove said contaminants, and to produce a modified isotropic pitch product, in that case isotropic pitch product 130 is sent to flash drun 132 along with a solvent and results in the solvent flash 134 and isotropic pitch containing coke and metals 136.

[0128] FIG. 3 is a nonlimiting example flow diagram of a second variant of a process for producing pitch compositions comprising hydrotreated products formed from dual solvent deasphalting processes. Process 300 in FIG. 3 differs from process 200 in FIG. 2 in that second effluent 116 comprising a separation bottom product is directed to hydrotreater unit 318, wherein second effluent 116 is hydrotreated in presence of hydrogen 320, under hydrotreating conditions suitable to produce hydrotreated product 324. Hydrotreating second effluent 116 enables removal of contaminants 322 (such as contaminants comprising heteroatoms, such as sulfur, nitrogen, oxygen, coke and metals). Additionally, and not shown, demetallization, desulfurization, denitrification, and/or coke removal of second effluent 116 prior to hydrotreating may advantageously promote the production of pitch products with little to no contaminant. Hydrotreated product 324 is further directed to second separation unit 326 (e.g., flash drum, vacuum distillation unit, distillation column, and the like) prior to first solvent deasphalting 332 in order to at least partially remove any remaining gas and distillate 328 from hydrotreated product 324 to produce third effluent 330. [0129] Third effluent 330 is directed to first deasphalter unit 332, wherein deasphalting of effluent 330 is carried out in the presence of first solvent 334, at a given solvent affluent volume ratio to produce: (a) a first soluble fraction 336 comprising a first portion of solvent 334, a deasphalted oil (DAO) product, and a first pitch product; and (b) a first insoluble fraction 338 comprising a portion of solvent 334 and a portion of the first pitch product, wherein the first pitch product is an isotropic pitch product. First insoluble fraction 338 is directed to third separation unit 340 (e.g., flash drum, vacuum distillation unit, distillation column, and the like) to at least partially remove (stream 342) solvent 334 from the first pitch product, and to produce second pitch product 344, wherein the second pitch product 344 is an isotropic pitch product. Compositions of first pitch product and second isotropic pitch product 344 are different. Isotropic pitch product 344 may be used as-is for further processing (e.g., pyrolysis). In some aspects, contaminants (e.g., metals, coke) may be present in isotropic pitch product 344. Thus, isotropic pitch product 344 may be further purified to remove said contaminants, and to produce a modified isotropic pitch product (not shown).

[0130] Further, first soluble fraction 336 is directed to second deasphalter unit 350 (e.g., second deasphalter unit 350) in the presence of solvent 352 to produce second soluble portion 356 and second insoluble portion 354. Optional removal of particulates from first fraction 336 may be conducted in separation unit 346 via filtration prior to second solvent deasphalting 350, to produce a filtered product fraction 348. Alternately, first fraction 336 may be directed to separation unit 346 (e.g., flash drum, vacuum distillation unit, distillation column, and the like) prior to second solvent deasphalting 350 in order to at least partially remove any remaining gas and distillate from first fraction 336.

[0131] FIG. 4 is a nonlimiting example flow diagram of a process for producing pitch compositions. In process 400, solvent used for solvent assisted visbreaking 104 is recycled. First effluent 108 is directed to separation unit 412 (e.g., flash drum, vacuum distillation unit, distillation column, and the like). Light components (e.g., gas) 414 are removed from separation unit 412. Solvent of first effluent 108 is also removed from separation unit 412 as recycled stream 442, and is recycled back, directly to solvent visbreaking 104, and/or blended with heavy hydrocarbon feed 102 prior to solvent visbreaking 104 (not shown).

[0132] FIG. 5 is a nonlimiting example flow diagram of a process for producing pitch compositions. In process 500, heavy hydrocarbon feed 102 is combined with a solvent to produce blend 502, prior to solvent assisted visbreaking 504, at a given solvent:heavy hydrocarbon feed 102 volume ratio suitable for blending.

[0133] End Uses. [0134] Various uses for the carbon fiber composites and carbon articles formed from the pitch compositions of the present disclosure are also discussed herein. Such a carbon fiber composite may be useful in numerous applications where weight reductions paired with strength and stiffness enhancements are desired. Said carbon fiber composite may also be useful in offshore drilling (e.g., offshore drilling for oil and gas production) to improve corrosion resistance, fatigue and heat resistance, production components including, but not limited to platforms, risers, tethers, anchors, drill stems or related equipment and systems. Additional product applications can include automotive (e.g., body parts such as deck lids, hoods, front end, bumpers, doors, chassis, suspension systems such as leaf springs, drive shafts), aerospace (aircraft and space systems), sports equipment (e.g., golf club, tennis racket, bikes, ski boards, snowboards, helmets, rowing or water skiing equipment), construction (non- structural and structural systems), military (e.g., flying drones, armor, armored vehicles, military aircraft), wind energy industries, energy storage applications, fireproof materials, carbon-carbon composites, carbon fibers, in many insulating and sealing materials used in construction and road building (e.g., concrete), turbine blades, light weight cylinders and pressure vessels, off-shore tethers and drilling risers, medical equipment, for example.

[0135] Embodiments disclosed herein include:

[0136] Embodiment A: A process comprising: heat treating a heavy hydrocarbon feedstock in a heat treatment unit to produce a first effluent comprising a heat treated product; at least partially separating a mixture of gas and distillate from the first effluent in a first separation unit to produce a second effluent comprising a second effluent; deasphalting the second effluent in a deasphalter unit in the presence of a first solvent to produce: a soluble product fraction comprising a first portion of the first solvent, a deasphalted oil (DAO) product, and a first pitch product; an insoluble product fraction comprising a second portion of the first solvent and a portion of the first pitch product; and at least partially removing the second portion of the first solvent from the first pitch product in a third separation unit to produce a purified pitch product.

[0137] Embodiment B: In some or other aspects is shown a process comprising heat treating a heavy hydrocarbon feedstock in a heat treatment unit to produce a first effluent comprising a heat treated product comprising a gas, a distillate, and a product; at least partially separating a mixture of gas and distillate from the first effluent in a first separation unit to produce a second effluent; hydrotreating the second effluent to produce a hydrotreated product; at least partially separating any gas or distillate from the hydrotreated product in a second separation unit to produce a third effluent; deasphalting the third effluent in a first deasphalter unit in the presence of a first solvent to produce: a first soluble fraction comprising a first portion of the first solvent, a deasphalted oil (DAO) product, and a first pitch product; a first insoluble product fraction comprising a second portion of the first solvent and a portion of the first pitch product; and at least partially separating a mixture of gas and distillate from the first insoluble fraction in a third separation unit to produce a fourth effluent 344 comprising a first isotropic pitch; deasphalting the first soluble product fraction in a second deasphalter unit in the presence of a second solvent to produce: a second soluble portion and second insoluble portion; the second soluble portion comprising a first isotropic pitch, a deasphalted oil product, and a first portion of the second solvent; the second insoluble product fraction comprising a second isotropic pitch and a second portion of the second solvent; and optionally heat treating the first and/or the second isotropic pitch to produce a mesophase pitch product having a mesophase content from about 5 vol. % to 100 vol. %, based on the total volume of the mesophase pitch product, an MCR in the range of about 50 wt% to about 95 wt%, based on the total weight of the mesophase pitch product(s), and a softening point Tsp in the range of about 200°C to about 400°C, wherein the mesophase pitch product is suitable for spinning into carbon articles.

[0138] Embodiment C: In some or other aspects is shown a pitch composition suitable for spinning comprising: a pitch having a mesophase content from 5 vol. % to 100 vol. %, based on the total volume of the pitch, an MCR in the range of about 50 wt. % to about 95 wt. %, based on the total weight of the pitch, and a softening point Tsp in the range of about 10°C to about 400°C. [0139] Embodiments A, B, can C may have one or more of the following additional elements in any combination:

[0140] Element 1: wherein the heavy hydrocarbon feedstock comprises a second solvent, wherein the second solvent is selected from the group consisting of: steam cracked gasoil, heavy coker gasoil, heavy vacuum gas oil, heavy extract from lubes production, hydrocracked residue gasoil, steam cracked naphtha, coker naphtha, light cycle oil, reformate, BTX, and any combination thereof.

[0141] Element 2: wherein the first solvent is selected from the group consisting of: propane, butanes, pentanes, hexanes, heptanes, reformate, furfural, N-methylpyrrolidone, heavy coker gas oil, coker gas oil, light coker gas oil, light cycle oil, and any combination thereof.

[0142] Element 3: (ONLY A) deasphalting the soluble product fraction in a second deasphalting unit in the presence of a second solvent to produce: a second soluble product fraction comprising a first portion of the third solvent, and a deasphalted oil (DAO); a second insoluble fraction comprising a second portion of the third solvent and a second pitch product; and wherein the second solvent has a solubility parameter lower than the first solvent. [0143] Element 4: (ONLY B): wherein the second solvent has a solubility parameter lower than the first solvent.

[0144] Element 5: wherein deasphalting the soluble product fraction provides at least 20% to 25% metals content reduction in the second pitch product.

[0145] Element 6: removing particulates from the first effluent by filtration to produce a filtered effluent prior to removing the mixture of gas and distillate in the first separation unit.

[0146] Element 7: removing particulates from the soluble product fraction comprising the first portion of the first solvent, the deasphalted oil (DAO) product, and the first pitch product, by filtration prior to deasphalting the soluble product fraction in the fourth separation unit.

[0147] Element 8: optionally recycling at least a portion of the second solvent present in the first separation unit to produce a recycled solvent stream; combining the recycled solvent stream with the heavy hydrocarbon feedstock prior to heat treating in the heat treatment unit or directly in the heat treatment unit.

[0148] Element 9: wherein heat treating the heavy hydrocarbon feedstock in a heat treatment unit comprise one or more of: a temperature ranging from 350°C to 550°C; a pressure ranging from 10 psig to 2000 psig; a residence time of about 5 minutes or greater; and an LHSV in the range of about 0.1 hr' ¹ to about 12 hr' ¹ .

[0149] Element 10: hydroprocessing or oxidizing, before or after heat treating the heavy hydrocarbon feedstock to reduce sulfur content

[0150] Element 11: heat treating the first pitch product and/or the isotropic pitch product to produce a mesophase pitch.

[0151] Element 12: optionally sparging a gas through the first pitch product and/or the isotropic pitch product to produce a mesophase pitch.

[0152] Element 13: producing a fiber from the first pitch product, the second pitch product, the purified pitch product, the second purified pitch product, or the mesophase pitch product, wherein the fiber is an oxidized fiber, carbonized fiber, graphitized fiber, fiber web, oxidized fiber web, carbonized fiber web, or graphitized fiber web.

[0153] By way of non-limiting example, illustrative combinations applicable to A and B include, but are not limited to, Embodiment A or B with Elements 1 and 2; Embodiment A, B, or C with Elements 11 and 13; Embodiment A, B, or C with Elements 12 and 13; Embodiment A with Element 3; Embodiment A with Element 4; Embodiment A or B with Elements 9 and 10; Embodiment A or B with Elements 6 and 7; Embodiment A or B with Elements 4 and 5. [0154] To facilitate a better understanding of the present disclosure, the following examples of preferred or representative embodiments are given. In no way should the following examples be read to limit, or to define, the scope of the invention.

EXAMPLES

[0155] A series of isotropic and mesophase pitches were produced via processes (e g., a continuous modified visbreaker or batch autoclave) as described in FIG. 1, using Kearl bitumen as a feed, a heavy, high sulfur diluted bitumen. The Kearl bitumen has an API gravity of 9.2° and contains 82.9 wt. % carbon, 4.5 wt. % sulfur, and 11.5 wt. % micro carbon residue (MCR), based on the total weight of the bitumen. The pitches produced herein were found to be suitable for a variety of applications including carbon fiber production.

[0156] In general, mesophase pitches were produced from isolated isotropic pitch fractions. Isotropic pitches were pyrolyzed at temperatures ranging from 400°C to 450°C, at reactor pressures ranging from 50 psi to 700 psi. During the pyrolysis of the Kearl bitumen, gases and light liquids evolved and were vented out of the reactor. The remaining liquid product was subsequently distilled and deasphalted, or deasphalted directly.

[0157] Example 1: Control of Pitch Softening Point under Distillation and Deasphalting Conditions. The control of the softening point of the pitches by distillation and deasphalting was conducted by using two batches of visbroken Kearl bitumen, Sample 1, and Sample 2. Samples 1 and 2 were both produced at an equivalent severity of 300 equivalent seconds, using a reference temperature of 468°C (875°F), but their isolation procedure differed. Consequently, Samples 1 and 2 produced pitches with different compositions despite similar thermal severities.

[0158] Production of Sample 1: Kearl bitumen was continuously passed through a 150 cc rector operated at 425°C, at a residence time of 50 minutes. The reaction pressure was maintained at 800 psig. Yields of 97 wt. % liquid product, 2.9 wt. % gases, and 0.1 wt. % coke were obtained. The liquid product was distilled under vacuum to yield an atmospheric equivalent boiling point cut of 482°C (900°F), where the heavy cut (900°F+) was deasphalted at a temperature of 220°C and pressure of 700 psi, using n-heptane as a solvent, at a solvent-to-oil ratio of 6:1 (v/v). The isolated isotropic pitch was obtained in 17.7 wt. % yield, based on the starting feed, and had a softening point of 224.4 °C and an MCRT of 62 wt. %.

[0159] Production of Sample 2: The Kearl bitumen (123 g) was charged into a 300 mL autoclave and pyrolyzed at 425°C for 50 min. The reaction pressure was maintained at 250 psig under a continuous flow of hydrogen to remove the volatile compounds, the hydrogen flow rate was 450 mL/min. After the reaction was complete, the autoclave was rapidly cooled to about 200°C and filtered through a 2.5 micron filter. The yields for the following products are: 1.4 wt. % coke, 15 wt. % distilled and recoverable liquids, 7 wt. % gas/lights, 76.6 wt. % reactor liquids. The reactor liquids were then deasphalted at ambient temperature using a 10: 1 mL:g ratio of n- heptane to reactor liquids, thus producing the isotropic pitch in 14.7 wt.% yield based on starting feed and had a softening point of 237.8 °C and an MCRT of 73.6 wt.%.

[0160] FIG. 6 is a graph illustrating the impact of isolation processes on pitch softening points versus deasphalting temperature (°C) of pitch samples having different solvent: oil ratio. FIG. 6 depicts the impact of the isolation methods (e.g., distillation or not) on the resulting isotropic pitch softening points as a function of deasphalting temperature (°C). As shown in FIG.6, at least a 50°C variation in the pitch softening point was attained, depending on how the isolation processes were conducted

[0161] Example 2: Two-Stage Deasphalting. The reduction of metals content within a pitch was achieved using a two-stage deasphalting process as illustrated in FIG. 2. The two-stage deasphalting process relied on two solvents, n-heptane (Solvent 1) and n-pentane (Solvent 2), with the solubility parameter of Solvent 1 being higher than that of Solvent 2. n-heptane (Solvent 1) deasphalting occurred at 220°C, while n-pentane (Solvent 2) deasphalting occurred at 160°C. Such condition process resulted in the precipitation of metals, particulates, and higher polarity hydrocarbons in the first-stage of the deasphalting process, in the first deasphalter. The resulting deasphalted oil include the first pitch product (Pitch 1) was obtained with little to no precipitates (e.g., metals, particulates, and higher polarity hydrocarbons), and further sent to a second deasphalter to precipitate out the remaining isotropic pitch (Pitch 2). The overall process resulted in an isotropic pitch (Pitch 2) with reduced metals and particulates. Table 1 illustrates the demetallation of visbroken pitches by a two-stage deasphalting process. Results summarized in Table 1 showed that carrying out a second deasphalting enabled at least a 60% to 65% reduction in metals content in the pitch (Pitch 2).

Table 1. [0162] Example 3: Impact of the Isotropic Pitch Isolation Process on the Properties of the Corresponding Mesophase Pitch. The nature of the isolation process of an isotropic pitch was found to have a significant impact on the properties of its corresponding mesophase pitch obtained upon pyrolysis of said isotropic pitch. Table 2 illustrates the comparison of the properties of two isotropic pitches (Samples 3 and 4) used to produce mesophase pitches (Samples 5 and 6) in Figures 7A and 7B and the corresponding mesophase pitch properties in Table 3. The isotropic pitches in Table 2 were isolated using analogous procedures described in the production of Samples 1 and 2, the deasphalting temperature and pressure are listed in Table 2. Kearl bitumen was used as the feed for pyrolysis to produce the isotropic pitches and n-heptane was used for the deasphalting. The isotropic pitches (Samples 3 and 4) were isolated in two different manners from Kearl bitumen pyrolyzed at the same equivalent severity, at 300 equivalent seconds, at 468.3 °C (875°F). Samples 3 and 4 were further subjected to pyrolysis for 1 h at 400°C in a mini-bomb reactor consisting of a SWAGELOK™ cap and plug. The resulting mesophase pitch properties were measured similar to the following procedures: quinoline insolubles ASTM D7280, elemental analysis (wt.% C, H, N) ASTM D5291, wt.% sulfur ASTM D1552, wt.% MCRT ASTM D4530, and softening point according to ASTM D3104.

Table 2.

[0163] FIGS. 7A-7B, and Table 3 illustrate a comparison of the mesophase pitch properties from two isotropic pitches isolated in different manners and the comparison of the pyrolyzing conditions on mesophase coalescence. FIG. 7A is a polarized light microscopy image of a mesophase pitch material (Sample 5) produced after pyrolysis of its corresponding isotropic pitch (Sample 3, 220°C, solventoil ratio of 6:1) at 400°C for 1 h. FIG. 7B is a polarized light microscopy image of a mesophase pitch material (Sample 6) produced after pyrolysis of its corresponding isotropic pitch (Sample 6, 20°C, solventoil ratio of 10:1) at 400°C for 1 h.

[0164] As shown in Table 3, the resulting mesophase pitch properties varied significantly even though both pitches yielded about 33 vol. %-34 vol. % mesophase content, based on the total volume of the pitch. The mesophase pitch produced from deasphalting at 220°C (Sample 5) was unable to flow as evidenced by the fact that it exceeded the temperature limit of the instrument, hence Tsp > 380°C. The softening point of Sample 5 was higher than 380°C. Interestingly, the mesophase pitch produced by deasphalting at 20°C (Sample 6), which yielded a similar mesophase content of Sample 5, was able to flow at 288°C. Thus, one isotropic pitch isolation method provided a mesophase pitch (Sample 5) unsuitable for carbon fiber production, whereas another isotropic pitch isolation method yielded a mesophase pitch (Sample 6) capable of flowing and consequently suitable for carbon fiber production.

Table 3.

[0165] Example 4: Influence of Pressure and Thermal Severity on Mesophase Production and Coalescence During Isotropic Pitch Pyrolysis. FIGS. 8A and 8B illustrate the effect of the pyrolyzing conditions on the mesophase droplet size and coalescence from the same pitch. FIG. 8A is a polarized light microscopy image of a mesophase pitch material produced after pyrolysis at 400°C for 3 h (Sample 7), in an open reactor with flowing nitrogen (PAC™ Micro Carbon Residue Tester). FIG. 8B is a polarized light microscopy image of a mesophase pitch material produced after pyrolysis at 400°C for 1 h (Sample 8), in a closed system mini-bomb reactor consisting of a SWAGELOK™ cap and plug, so that any cracked components could not escape. As shown in FIGS. 8 A and 8B, the closed system enabled the production of the mesophase pitch (Sample 8) having large droplets (about 7pm to 50 pm) with domains displaying greater alignment when compared to the mesophase pitch (Sample 7) produced in the opened reactor (about 5 pm or less). Without being bound by any theory, it is believed that applying a certain amount of pressure during the pyrolysis process is beneficial for the production of mesophase pitches because the low molecular weight material that would otherwise volatilize and escape the reactor was forced to remain within the reacting medium, decreasing the viscosity of the reacting mixture and enabling coalescence. The same rationale exists for material cracked during pyrolysis of the isotropic pitch. The light cracked ends were forced to remain within the solution, decreasing the viscosity and enabling coalescence.

[0166] Example 5: Solvent Effect on the Visbreaking Process.

[0167] Visbreaking of three different feeds was conducted in the presence or absence of a solvent, synthetic crude oil, also referred to as “Syncrude oil” or “SCO” (available from Sarnia refinery). SCO was obtained by full upgrading of bitumen and tar, and included naphtha, distillate, and gasoil. SCO contains little to no contaminants, such as sulfur, nitrogen, and metals, as well as no residue fraction. [0168] Tables 4-6 illustrate the impact of SCO on the visbreaking of the following feeds: bitumen prepared by performing a paraffinic froth treatment (PFT) on oil sands froth derived from Western Canadian oil sands; deasphalted bitumen; and Kearl vacuum residue. As shown in Table 4, a blend ofPFT-bitumen and SCO (Sample 2, PFT-bitumen/SCO ratio of 85/15 vol. %) produced less coke (Total Liquid Product (TLP) coke of 0.39 wt. %, based on the total weight of the blend), when compared to PFT bitumen itself (Sample 1), even at higher severity in the visbreaker.

Table 4.

[0169] Table 5 illustrate the impact of SCO on the visbreaking of deasphalted bitumen used herein as a feedstock. Deasphalted bitumen was produced by solvent deasphalting of bitumen. Sample 4, a blend of deasphalted bitumen and SCO (85/15 vol. %), was found to produce less coke (TLP coke of 0.38 wt. %, based on the total weight of the blend) at substantially similar severity in the visbreaker than Sample 3 (deasphalted bitumen only, TLP coke of 0.58 wt. %, based on the total weight of the deasphalted bitumen).

Table 5.

[0170] Table 6 illustrates the impact of SCO in visbreaking of Kearl vacuum resid. A blend of Kearl vacuum residue and SCO (Sample 6, 85/15 vol. %) was found to produce significantly less coke (TLP coke of <0.20 wt. %, based on the total weight of the blend) even at higher severity in the visbreaker, when compared to TLP coke content of Kearl vacuum residue after visbreaking (TLP coke of 1.50 wt. %, based on the total weight of the Kearl vacuum residue). Table 6.

[0171] Any alterations, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description without departing from the spirit or scope of the present disclosure and that when numerical lower limits and numerical upper limits are listed herein, ranges from any lower limit to any upper limit are contemplated.

[0172] All documents described herein are incorporated by reference herein for purposes of all jurisdictions where such practice is allowed, including any priority documents and/or testing procedures to the extent that they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the disclosure have been illustrated and described, various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, it is not intended that the disclosure be limited thereby. For example, the compositions described herein may be free of any component, or composition not expressly recited or disclosed herein. Any method may lack any step not recited or disclosed herein. Likewise, the term “comprising” is considered synonymous with the term “including.” Whenever a method, composition, element or group of elements is preceded with the transitional phrase “comprising,” it is understood that we also contemplate the same composition or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

[0173] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the present specification and associated claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the embodiments of the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claim, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0174] Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces.

[0175] All numerical values within the detailed description herein are modified by “about” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.

[0176] One or more illustrative embodiments are presented herein. Not all features of a physical implementation are described or shown in this application for the sake of clarity. It is understood that in the development of a physical embodiment of the present disclosure, numerous implementation-specific decisions must be made to achieve the developer's goals, such as compliance with system-related, business-related, government-related and other constraints, which vary by implementation and from time to time. While a developer's efforts might be timeconsuming, such efforts would be, nevertheless, a routine undertaking for one of ordinary skill in the art and having benefit of this disclosure.

[0177] While compositions and methods are described herein in terms of “comprising” or "having" various components or steps, the compositions and methods can also “consist essentially of’ or “consist of’ the various components and steps.

[0178] Therefore, the present disclosure is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present disclosure may be modified and practiced in different but equivalent manners apparent to one having ordinary skill in the art and having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope and spirit of the present disclosure. The embodiments illustratively disclosed herein suitably may be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein.