Pitch Compositions and Methods Related to Pitch Compositions

Abstract

Pitch compositions having controlled pitch composition properties, and methods of making and using same. Pitch properties are predicted based on infrared structural parameters, and two or more pitch compositions can be blended to achieve desired pitch properties including softening point, microcarbon residue, hydrogen / carbon ratio, and % pitch volatiles. Predicting these properties aids in end use optimization, particularly in the production of spinnable pitches for carbon fibers, mesocarbon microbeads, matrices for carbon / carbon composites, and other pitch-derived carbon products.

Description

[Technical field]

[0001] The present disclosure relates to pitch compositions and, more particularly, to controlled pitch composition properties and methods of making and using same. [Background technology]

[0002] Pitch is a carbon-containing raw material that can be classified as isotropic pitch or mesophase pitch. Both isotropic pitch and mesophase pitch can be complex mixtures of aromatic molecules, but the aromatic molecules of isotropic pitch are randomly oriented, whereas in mesophase pitch, at least some of these aromatic molecules are ordered. Mesophase pitch can have a heterogeneous two-phase structure that includes the ordered aromatic molecules (e.g., anisotropic regions) and isotropic regions. Generally, the formation of isotropic pitch precedes the formation of mesophase pitch. In this specification, both types of pitch are collectively referred to as "pitch" unless otherwise specified.

[0003] Pitches can be produced, for example, from the acid-catalyzed oligomerization of petroleum, coal tar, biomass tar, or low molecular weight (e.g., naphthalene) feedstocks. Typical chemical components of pitches include, but are not limited to, alkanes, cycloalkanes, aromatics, hydroaromatics, phenols, alkenes, ketones, carboxylic acids, sulfur-containing compounds, oxygen-containing compounds, and nitrogen-containing compounds. These components vary depending on the starting materials and process conditions.

[0004] Pitch is used in many product applications, including carbon fiber, binder pitch, impregnating pitch, etc. Major markets for pitch include high performance and general purpose carbon fiber, refractories, carbon / carbon composites, artificial graphite, graphite components, binder and impregnating pitch for electrodes, binder and impregnating pitch for anodes and cathodes for aluminum production, impregnating pitch for steel electric furnace electrodes, mesocarbon microbeads for anodes for lithium ion batteries, and thermal conductivity applications. 12,13and carbon foam for sound absorption applications, roofing products, lubricants, consumer products (such as cosmetics), and the like.

[0005] Given the chemical diversity of pitches, the properties of a pitch depend at least on, but are not limited to, its feedstock, production (e.g., pyrolysis), and separation (e.g., distillation) conditions. Depending on the specific end use, different pitch properties are specified, each with its own range of acceptable specification values, such as, but not limited to, softening point, microcarbon residue, percent mesophase, and other applicable property ranges. However, currently there is no way to predict or control these properties, and the typical means to obtain suitable pitch property specifications for a particular end use is based solely on trial and error and past experience, which entails significant costs, at least in terms of production time and raw materials (e.g., pitch material). In fact, such trial and error approaches require many sets of experiments with multiple different conditions and product properties before the desired pitch properties are reached. Although significant research and development efforts have been expended to identify the appropriate feeds and processes to produce specific commercial pitches, such as ASHLAND A240, and suitable pitch blends, such as binder pitches, this has proven impossible when the pitch feedstock remains constant. Furthermore, this trial and error approach does not take into account the pitch composition and is only effective if the pitch composition is fairly constant. If a mass market is desired for a new pitch product, such as carbon fiber composites for infrastructure applications, the trial and error approach is even less favorable because raw material variations are inevitable and therefore the pitch composition will vary consistently.

[0006] Therefore, a method for tailoring properties and enabling the production of controlled pitch compositions with reproducible properties is highly desirable. Summary of the Invention

[0007] Non-limiting aspects of the present disclosure include compositions that include a pitch composition having one or both of an A-factor in the range of about 0.4 to about 0.8 and / or an aromaticity in the range of about 0.3 to about 1.3.

[0008] In a non-limiting embodiment of the disclosure, a method is provided that includes pyrolyzing at least a first pitch composition and a second pitch composition, where pyrolysis of the first pitch composition and the second pitch composition is performed separately, the first pitch composition being a composition from a first pitch feed, and the second pitch composition being a composition from a second pitch feed; acquiring a first infrared spectrum of the at least first pitch composition, and selecting at least one first infrared parameter based on (1) the first infrared spectrum and a calibration curve or (2) the first infrared spectrum and chemometric modeling; acquiring a second infrared spectrum of the at least second pitch composition, and selecting at least one second infrared parameter based on (1) the second infrared spectrum and a calibration curve or (2) the second infrared spectrum and chemometric modeling. The selected first and second infrared parameters are at least one or both of an A-factor in the range of about 0.4 to about 0.8 and / or an aromaticity in the range of about 0.3 to about 1.3, and the first and second pitch compositions are blended in a ratio that achieves the selected first and second infrared parameters, thereby forming the blended pitch composition.

[0009] In a non-limiting embodiment of the present disclosure, a method is provided that includes extruding a pitch composition to produce green carbon fiber, and then stabilizing the extruded pitch composition. The stabilizing includes obtaining an infrared spectrum of the extruded pitch composition, and selecting at least one infrared parameter based on (1) the first infrared spectrum and a calibration curve, or (2) the first infrared spectrum and chemometric modeling, the at least one infrared parameter being at least A-factor and aromaticity. The stabilization is stopped based on the at least one infrared parameter.

[0010] These and other features and attributes of the disclosed methods for producing pitch compositions having tailored and reproducible properties of the present disclosure, as well as their advantageous applications and / or uses, will become apparent from the following detailed description. [Brief description of the drawings]

[0011] To assist those of ordinary skill in the relevant art in making and using the subject matter herein, reference is made to the accompanying drawings. The following drawings are included to illustrate certain aspects of the present disclosure and should not be considered as exclusive in construction. The disclosed subject matter is capable of significant modification, alteration, combinations, and equivalents in form and function, as would occur to one skilled in the art and having the benefit of this disclosure.

[0012] [Figure 1A] FIG. 1A shows a diffuse reflectance infrared Fourier transform (DRIFT) spectrum of a pitch sample, according to one or more embodiments of the present disclosure. [Figure 1B] FIG. 1B shows a diffuse reflectance infrared Fourier transform (DRIFT) spectrum of a pitch sample, according to one or more embodiments of the present disclosure. [Figure 1C] FIG. 1C shows a diffuse reflectance infrared Fourier transform (DRIFT) spectrum of a pitch sample, according to one or more embodiments of the present disclosure. [Figure 1D]FIG. 1D shows a diffuse reflectance infrared Fourier transform (DRIFT) spectrum of a pitch sample, according to one or more embodiments of the present disclosure. [Figure 2A] FIG. 2A is a trend chart of infrared parameters based on DRIFT spectra of pitch samples that change with pyrolysis, in accordance with one or more embodiments of the present disclosure. [Figure 2B] FIG. 2B is a trend chart of infrared parameters based on DRIFT spectra of pitch samples that change with pyrolysis, in accordance with one or more embodiments of the present disclosure. [Figure 2C] FIG. 2C is a trend chart of infrared parameters based on DRIFT spectra of pitch samples that change with pyrolysis, in accordance with one or more embodiments of the present disclosure. [Figure 2D] FIG. 2D is a trend chart of infrared parameters based on DRIFT spectra of pitch samples that change with pyrolysis, in accordance with one or more embodiments of the present disclosure. [Figure 3A] FIG. 3A shows a correlation diagram between infrared parameters based on DRIFT spectra and pitch properties of pitch samples, in accordance with one or more embodiments of the present disclosure. [Figure 3B] FIG. 3B shows a correlation diagram between infrared parameters based on DRIFT spectra and pitch properties of pitch samples, in accordance with one or more embodiments of the present disclosure. [Figure 3C] FIG. 3C shows a correlation diagram between infrared parameters based on DRIFT spectra and pitch properties of pitch samples, in accordance with one or more embodiments of the present disclosure. [Figure 3D] FIG. 3D shows a correlation diagram between infrared parameters based on DRIFT spectra and pitch properties of pitch samples, in accordance with one or more embodiments of the present disclosure. [Figure 4A] FIG. 4A shows a parity plot of predicted pitch characteristics based on the DRIFT structure correlation versus the experimental values ​​of FIGS. 3A-3D, in accordance with one or more embodiments of the present disclosure. [Figure 4B]FIG. 4B shows a parity plot of predicted pitch characteristics based on the DRIFT structure correlation versus the experimental values ​​of FIGS. 3A-3D, in accordance with one or more embodiments of the present disclosure. [Figure 4C] FIG. 4C shows a parity plot of predicted pitch characteristics based on the DRIFT structure correlation versus the experimental values ​​of FIGS. 3A-3D, in accordance with one or more embodiments of the present disclosure. [Figure 4D] FIG. 4D shows a parity plot of predicted pitch characteristics based on the DRIFT structure correlation versus the experimental values ​​of FIGS. 3A-3D, in accordance with one or more embodiments of the present disclosure. [Diagram 5] FIG. 5 shows a partial least squares (PLS) modeled correlation diagram of representative pitch properties of pitch samples, in accordance with one or more embodiments of the present disclosure. [Figure 6A] FIG. 6A shows a parity plot of pitch characteristics predicted using a PLS model correlation against experimentally determined pitch characteristics, in accordance with one or more embodiments of the present disclosure. [Figure 6B] FIG. 6B shows a parity plot of pitch characteristics predicted using a PLS model correlation against experimentally determined pitch characteristics, in accordance with one or more embodiments of the present disclosure. [Figure 6C] FIG. 6C shows a parity plot of pitch characteristics predicted using a PLS model correlation against experimentally determined pitch characteristics, in accordance with one or more embodiments of the present disclosure. [Figure 6D] FIG. 6D shows a parity plot of pitch characteristics predicted using a PLS model correlation to experimentally determined pitch characteristics, in accordance with one or more embodiments of the present disclosure. [Figure 7A] FIG. 7A shows a prediction chart of pitch characteristics of pitch samples using least squares analysis (LSA) modeling correlations, in accordance with one or more embodiments of the present disclosure. [Figure 7B] FIG. 7B shows a prediction chart of pitch characteristics of pitch samples using least squares analysis (LSA) modeling correlations, in accordance with one or more embodiments of the present disclosure. [Figure 7C]FIG. 7C shows a prediction chart of pitch characteristics of pitch samples using least squares analysis (LSA) modeling correlations, in accordance with one or more embodiments of the present disclosure. [Figure 7D] FIG. 7D shows a prediction chart of pitch characteristics of pitch samples using least squares analysis (LSA) modeling correlations, in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure relates to pitch compositions and, more particularly, to controlled pitch composition properties and methods of making and using same.

[0014] There is a need for a methodology for producing pitch compositions with tailored and reproducible properties suitable for one or more specific end uses. The present disclosure provides a methodology with compositional details that allow for rapid identification of pitch properties. In particular, disclosed herein is a method for tailoring pitch properties based on infrared structural parameters specific to the pitch composition. The methods described herein are particularly suited for developing pitch blending rules, optimizing carbon fiber spinning, informing reaction engineering, and enabling scale-up of pitch-based carbon material production.

[0015] As described herein above, the methods of the present disclosure produce pitch compositions with tailored pitch properties; these properties include softening point, microcarbon residue, hydrogen / carbon ratio, and percent pitch volatiles. Predicting these properties can aid in end-use optimization of, among other things, the production of spinnable pitch for carbon fibers, matrices for carbon / carbon composites, and other pitch-derived carbon products as described herein above.

[0016] The disclosed method of producing tailored pitch properties is advantageously derived based on modeling based on the composition of the pitch: (1) correlation (prediction) of IR parameters (e.g., ratios of infrared spectroscopic absorbance bands that correlate with pitch properties) regardless of the specific pitch-forming reaction (e.g., pyrolysis, air oxidation, etc.), and (2) multivariate analysis of infrared spectra.

[0017] In other embodiments, the disclosed methods of generating tailored pitch properties are advantageously derived based on modeling based on the chemometric composition of pitch: (1) correlation (prediction) of IR parameters (e.g., ratios of infrared spectroscopic absorbance bands that correlate with pitch properties) regardless of the particular pitch type, (2) multivariate analysis of infrared spectra, and (3) partial least squares (PLS) modeling and analysis. In this manner, the particular correlations developed are independent or can be considered universal for any particular pitch composition.

[0018] Using the methodology of the present disclosure, the properties of the starting pitch composition can be used to determine the composition of the blend pitch to meet a particular desired pitch value or range. In particular, infrared spectra from various pitch compositions can be summed together or PLS models can be used to generate pitch blends with particular desired properties or characteristics. It will be appreciated that since the pitch blend ratio depends on the starting pitch blend composition, multiple solutions using multiple starting pitch compositions can be advantageously used to achieve the desired final pitch properties. Thus, the method of the present disclosure and compositions produced therefrom allow for substantial customization and rapid identification of suitable (and unsuitable) starting pitch compositions and blends without the traditional trial and error method involving substantial resources.

[0019] Definitions and Test Methods All numerical values ​​set forth in the detailed description and claims herein are modified by "about" or "approximately" to the indicated value to account for expected experimental error and variations that would be expected by one of ordinary skill in the art. Unless otherwise indicated, ambient temperature (room temperature or "RT") is about 25°C.

[0020] As used in this disclosure and claims, the singular forms "a," "an," and "the" include the plural forms unless the context clearly indicates otherwise.

[0021] The term "and / or" as used herein in expressions such as "A and / or B" is intended to include "A and B," "A or B," or "A" and "B."

[0022] The following definitions apply to this disclosure and its claims.

[0023] As used herein, the terms "pitch" or "pitch composition" and grammatical variations thereof include petroleum pitch, coal tar pitch, natural asphalt, biomass pitch, pitch produced from aromatic oligomerization and / or polymerization, and pitch obtained as a by-product in the naphtha cracking industry.

[0024] The terms "pyrolysis" or "pyrolyzing", and grammatical variations thereof, refer to thermal reactions (e.g., dehydrogenation, cyclization, cracking, condensation, etc.) induced by high temperature.

[0025] As used herein, the terms "softening point" or "SP", and grammatical variations, refer to the temperature or temperature range at which a substance softens, where softening point is measured using a Mettler Toledo Drop Point Tester, such as a Mettler Toledo DP70, following a procedure similar to American Society for Testing and Materials (ASTM) ASTM D3104-14a.

[0026] As used herein, the term "microcarbon residue" or "MCR" and grammatical variations thereof refer to the amount of carbonaceous residue formed following evaporation and pyrolysis of petroleum materials under certain conditions. As used herein, the term "microcarbon residue test" or "MCRT" and grammatical variations thereof refer to the standard method for measuring MCR and is measured in accordance with ADTM D4530(2020).

[0027] As used herein, the term "mesocarbon microbeads" refers to porous graphitic carbon materials with an inner core made of amorphous carbon and an outer shell made of graphitic carbon. Both the inner core and the outer shell are porous. Mesocarbon microbeads have a diameter of 10 microns to 100 microns.

[0028] As used herein, "hydrogen / carbon ratio" or "H / C ratio" and grammatical variations thereof refer to the amount of elemental hydrogen relative to elemental carbon in a pitch composition. H / C ratio is measured according to ASTM D5291-21.

[0029] The terms "percent pitch volatiles" or "%PV" and grammatical variations thereof refer to the amount of volatile materials, such as pyrene, phenanthrene, acridine, chrysene, anthracene, benzo(a)pyrene, etc., that may become airborne in a pitch composition upon heating. PV% is measured by recording the mass loss after a given pyrolysis reaction. %PV will vary from run to run because different temperatures and times are used. When pitch % volatiles is measured by weight, it is referred to herein as "wt%PV."

[0030] Herein, the H / C ratio may be referred to as the "elemental analysis."

[0031] As used herein, the terms "infrared parameters" or "infrared structural parameters" or simply "IR parameters", and grammatical variations thereof, refer to the methyl to methylene ratio, A-factor, aromaticity, and degree of condensation determined from the infrared spectrum.

[0032] As used herein, the term "Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectrum" or "DRIFT spectroscopy" and grammatical variations thereof refer to an FTIR spectrometer equipped with a DRIFT peripheral. DRIFT spectra can provide both chemical and structural information about the measured sample. The FTIR used in the examples described herein was a Thermo Fisher Scientific Inc. NICOLET™ 3700 FTIR spectrometer (Waltham, Massachusetts), and the DRIFT peripheral used in the examples described herein was a Pike Technologies DIFFUSIR™ (Madison, Wisconsin). The FTIR spectrometer was further equipped with a Thermo Fisher Scientific Inc. deuterated triglycine sulfate (DGTS) detector.

[0033] As used herein, the term "methyl to methylene ratio" or "CH3 / CH2 ratio" and grammatical variations thereof refer to an infrared parameter based on the infrared spectrum, which is the asymmetric stretch of CH3 divided by the asymmetric stretch of CH2 of a sample. The CH3 / CH2 ratio is an indication of the length of the aliphatic chains approximated by the asymmetric stretch vibrations of CH3 and CH2, and / or the degree of branching of the aliphatic moiety. The height (intensity) or integrated area of ​​the infrared absorption bands can be used to derive the calculated ratio. For example, based on the center of integration in wavenumber space, CH3 / CH2 ratio = I2960÷I2918.

[0034] As used herein, the term "A-factor" and grammatical variations thereof refer to an infrared parameter that correlates the aliphatic and aromatic content of a sample based on its infrared spectrum. The A-factor represents the change in integrated intensity of absorbance from the aliphatic CH2 to the aromatic C=C ring stretching vibration of the sample. Based on the center of integration in wavenumber space, A-factor = [I2850 + I2918] ÷ [I2850 + I2918 + I1600].

[0035] As used herein, "aromaticity" and grammatical variations thereof refer to an infrared parameter that represents the ratio of aromatic CH stretches to absorbance from CH3 and CH2 vibrations of a sample based on its infrared spectrum. Aromaticity is a measure of the relative content of aromatic and aliphatic carbons in a sample. Based on the center of integration in wavenumber space, aromaticity=I3000 / [I2960+I2918+I2870+I2850].

[0036] As used herein, the term "degree of condensation" or "DoC" and grammatical variations thereof refer to the ratio of aromatic CH stretches to aromatic C=C ring stretches of a sample based on an infrared spectrum. DoC represents the number of hydrogens directly attached to the ring structure and indicates the degree of aromatic substitution versus ring condensation of the sample. Based on the center of integration in wavenumber space, DoC=I3000 / I1600.

[0037] The integral center of the wavenumber space term "I2960" is representative of the asymmetric stretch of CH3, and is used herein for example at 2941 cm -1 ~2991cm -1 The calculation is, but is not limited to,

[0038] The integral center of the wavenumber space term "I2918" represents the asymmetric stretch of CH2, and is used herein for example at 2902 cm -1 ~2941cm -1 The calculation is within the range of, but is not limited to,

[0039] The integral center of the wavenumber space term "I2850" represents the symmetric stretching of CH2, and is used herein for example in the range from 2819 to 2864 cm -1 The calculation is within the range of, but is not limited to,

[0040] The integral center of the wavenumber space term "I1600" is representative of the aromatic C=C ring stretch, and is used herein for example, between 1570 and 1632 cm -1 The calculation is within the range of, but is not limited to,

[0041] The integral center of the wavenumber space term "I3000" is representative of the aromatic CH stretch, and is used herein for example at 2991 cm -1 ~3101cm -1 The calculation is within the range of, but is not limited to,

[0042] The integral center of the wavenumber space term "I2870" is representative of the symmetric stretching of CH3, and is used herein for example at 2864 cm -1 ~2889cm -1 The calculation is within the range of, but is not limited to,

[0043] Method for producing pitch composition The present disclosure provides a method that includes blending two or more prepared pitch compositions, measuring their infrared structural parameters, and selecting at least one final structural infrared parameter based on a calibration curve or chemometric modeling. Thereafter, the two or more prepared pitch compositions are blended to obtain a blended pitch composition having a desired final infrared structural parameter.

[0044] Pitch, as described above, is prepared from (or otherwise is a residual product of) the pyrolysis of various feedstock sources such as petroleum, coal tar, biomass tar, or the acid-catalyzed oligomerization of small molecules (e.g., naphthalene), and is itself an intermediate product. Pyrolysis of pitch for use in the various methods described herein is carried out in a pyrolysis reactor at a temperature ranging from about 200° C. to about 600° C., including any value therebetween and any subset thereof, for example, from about 200° C. to about 500° C., or from about 200° C. to about 400° C., or from about 200° C. to about 300° C., or from about 300° C. to about 600° C., or from about 400° C. to about 500° C., or from about 500° C. to about 600° C. A gas may be present in the reactor, and the gas may include, for example, one or more or all of hydrogen, air, oxygen, hydrogen peroxide, carbon monoxide, carbon dioxide, formic acid, nitrogen dioxide, and / or ozone. Other suitable pyrolysis gases may also be suitable without departing from the scope of the present disclosure. Additionally, the pyrolysis reactor is operated at a pressure ranging from about 0.3 to about 2500 pounds per square inch (psi), or from about 0.3 to about 100 psi, or from about 1 to about 75 psi, or from about 5 to about 50 psi, or from about 10 to about 25 psi, or from about 50 to about 2.000 psi, or from about 100 to about 1500 psi, or from about 200 to about 1.000 psi, or from about 400 to about 1.000 psi, or from about 500 to about 1.000 psi. After pyrolysis, the resulting pitch effluent may be further separated to obtain the desired pitch, such as by distillation separation, deasphalting separation, membrane separation, and any combination thereof. Thus, the present disclosure provides for the preparation of pitch compositions as described herein for further analysis to determine pitch properties and appropriate blend ratios based on desired structural parameters.

[0045] In one or more embodiments of the present disclosure, the pyrolysis reaction may be used to tailor a pitch composition to have one or more undesirable structural characteristics, as described herein below. That is, a particular pitch feed (also referred to interchangeably herein as "feedstock") may have one or more particular undesirable IR parameters, and the feed is pyrolyzed to achieve the desired IR parameters (and resulting pitch properties) by adjusting the pyrolysis reaction conditions. For example, in one or more embodiments, the desired pitch may have one or both of an A-factor in the range of about 0.6 to about 0.8 and / or an aromaticity in the range of about 0.3 to about 0.6, but the pitch feed has dissimilar IR parameters; or, the desired pitch may have one or both of an A-factor in the range of about 0.4 to about 0.6 and / or an aromaticity in the range of about 0.5 to about 0.8, but the pitch feed has dissimilar IR parameters. In each case, the feed may be fed to a pyrolysis reactor at a temperature ranging from about 200° C. to about 600° C. and a pressure greater than about 0.3 psi to achieve the particular desired pitch IR parameters (i.e., structural properties). The pitch effluent may then be separated as described herein. When at least two pitch compositions are blended, two pyrolysis reactions are performed on separate pitch feeds, two optional separations are performed separately, two infrared spectra are measured separately, and two selections of desired IR parameters are performed separately prior to blending.

[0046] Further, the structural properties of the present disclosure may be measured (using DRIFT or other IR techniques, or other techniques capable of measuring or approximating the intensities of the vibrational bands described above, such as Raman spectroscopy, photothermal techniques, photoacoustic techniques, multivariate optical computing, spectrophotometers, filter photometer towers) after the prepared pitch composition leaves the reactor, including those used in-line in carbon fiber (e.g., green carbon fiber) manufacturing processes. Here, the infrared spectrum is measured (using DRIFT or other IR techniques) and IR parameters are selected during stabilization in a carbon fiber stabilization process in which the carbon fiber is contacted with a reactive gas (i.e., reaction zone) after the carbon fiber leaves the extrusion die. The IR parameters can be utilized to stop stabilization when the desired IR parameters are reached, as described later in this specification. The reactive gas can include any of those listed above, which are oxidizing gases, as well as hydrogen peroxide and nitrogen dioxide, in any combination, without limitation.

[0047] The spinning zone may be a spinneret operating in an inert environment at a temperature range relative to the softening point of the pitch, from about Tsp-10°C to about Tsp+50°C, typically from about 50°C to about 500°C, and sometimes 350°C, including any value and subset therebetween. A spinneret is a type of die for extruding carbon fiber filaments through small holes. In some embodiments, the pitch composition may be blown through an extrusion die, such as a spinneret or other suitable die. After the filaments or extrudates are formed, they may be oxidized in a reaction zone. The reaction zone may be an oven, such as a batch oven or a continuous oven, that can heat the fibers or extrudates in the presence of a reactive gas to a temperature in the range of about -5°C to about 50°C, including any value and subset therebetween. In one or more embodiments, the extruded pitch composition for forming carbon fibers may be spooled prior to contact with the reactive gas.

[0048] Pyrolysis can result in significant reactions that can change the composition and / or properties of the pitch based on thermal reactions driven by radical reactions initiated by homolytic bond cleavage. Such reactions include, but are not limited to, dealkylation (e.g., demethylation), dehydrogenation, cyclization, condensation reactions, and the like, and combinations thereof. If these pyrolysis reactions result in off-gassing, separation of low molecular weight compounds from high molecular weight compounds may also occur. To account for these potentially significant changes, the present disclosure uses infrared spectroscopy and multivariate analysis to blend pitch compositions to achieve desired compositional and structural properties.

[0049] The type of infrared spectroscopy for obtaining the infrared spectrum of the pitch composition of the present disclosure may preferably be multivariate FTIR, including an FTIR spectrometer coupled to a gas handling system (e.g., N2, air, vacuum, etc.), although it will be understood that dispersive infrared spectroscopy may also be used without departing from the scope of the present disclosure. In one or more embodiments, the FTIR spectrometer may further comprise a diffuse reflectance infrared Fourier transform (DRIFT) peripheral. The DRIFT peripheral allows for temperature control of the sample up to 1000°C. The DRIFT spectrum can provide both chemical and structural information about the measured sample diluted with potassium bromide (KBr), although other DRIFT spectroscopy compatible diluents may be used without departing from the scope of the present disclosure.

[0050] In one or more embodiments of the present disclosure, for DRIFT spectroscopy analysis, samples may be diluted with KBr in the range of about 0.1 weight percent (wt%) to about 10 wt%, including any value and subset therebetween, such as about 0.1 wt% to about 1 wt%, or about 0.1 wt% to about 2 wt%, or about 0.2 wt% to about 1 wt%, or about 1 wt% to about 5 wt%, or about 5 wt% to about 10 wt%.

[0051] The DRIFT spectrum used in this disclosure is at approximately 200 cm -1 About 6000cm from -1and any value and subset therebetween, for example, about 200 cm -1 About 4000cm from -1 , or about 400 cm -1 About 4000cm from -1 , or about 400 cm -1 About 2000cm from -1 , or about 1000 cm -1 About 6000cm from -1 may be in the range.

[0052] In one or more embodiments of the present disclosure, the acquired pitch DRIFT spectrum is evaluated to determine certain structural IR parameters, including, but not limited to, methyl-methylene ratio ("CH3 / CH2 ratio"); A-factor; aromaticity; and degree of condensation (DoC).

[0053] It should be noted that as the pitch feed is pyrolyzed, the alkyl side chains are cracked and removed from the pyrolysis system. In many cases, the weak CC bond adjacent to the aromatic ring leaves behind a methyl group on the aromatic where the alkyl group was. Generally, the CH3 / CH2 ratio will at least increase due to the loss of these CH2 units from the alkyl side chains. However, this is not true for all feeds. For example, highly aromatic steam cracker tars (e.g., SOP2 sample in the Examples below) and isotropic pitches (e.g., M50 sample in the Examples below) may show generally opposite trends in CH3 / CH2 ratios with increasing pyrolysis time. Furthermore, the loss of alkyl side chains during pyrolysis generally results in a decrease in the A-factor. This is because the A-factor is a measure of the size of the alkyl side chains on the aromatic core, and the chain length decreases as the cracking proceeds. However, aromaticity generally increases due to the possible removal of these aliphatic side chains and dehydrogenation of the hydroaromatics. As pyrolysis proceeds, DoC decreases due to increased aromaticity from cyclization, dehydrogenation, and condensation reactions. This correlation can be seen in the results of the examples shown below.

[0054] Furthermore, it has been observed that pitch properties are best predicted from structural IR parameters using pitch-specific correlations, and as explained with reference to the examples herein, pitch properties have been found to be particularly correlated with A-factors and aromaticity.

[0055] Thus, the present disclosure provides a method for determining pitch properties by obtaining an infrared spectrum of a pitch composition (prepared as described herein) and correlating the obtained infrared spectrum with at least one structural IR parameter using a calibration curve. In a further aspect, the present disclosure provides a method for adjusting one or more pitch properties by obtaining a first infrared spectrum of a first pitch composition (prepared as described herein) and obtaining at least a second infrared spectrum of a second pitch composition (prepared as described herein), correlating the obtained infrared spectrum with at least one structural IR parameter using a calibration curve, and blending the first and second pitch compositions in a ratio to obtain a blended pitch composition having at least one desired pitch property.

[0056] As provided above, chemometric modeling of infrared spectra to correlate (predict) structural IR parameters can be used in accordance with the present disclosure, including but not limited to, by using multivariate statistical analysis techniques such as partial least squares (PLS). However, it is understood that other chemometric modeling types can be used without departing from the scope of the present disclosure. The chemometric approach is particularly useful for understanding and predicting pitch properties, for example, from samples undergoing air oxidation. Air oxidation is a key process used in the air blowing process (including any reactive gases described herein) used to stabilize green carbon fibers and increase the SP of the pitch. In stabilizing green fibers, the objective is to produce a pourable solid that will not flow or adhere to adjacent fibers during subsequent carbonization and graphitization (referred to herein as carbon fiber processing). The objective of air blowing is to increase the SP of the pitch, but still produce a pitch that softens and flows at moderate temperatures. These different objectives and processes result in quite different pitch compositions. Thus, the chemometric approach is believed to be particularly useful for predicting pitch composition properties, including blended pitch compositions, during stabilization of green carbon fibers, although the IR parameter approach described above in this specification can also be used for blended pitch compositions.

[0057] Thus, the present disclosure provides a method for determining pitch properties by obtaining an infrared spectrum of a pitch composition (prepared as described herein) and inputting the spectrum into chemometric modeling, such as PLS or other modeling techniques. In a further aspect, the present disclosure provides a method for tuning one or more pitch properties by obtaining a first infrared spectrum of a first pitch composition (prepared as described herein) and obtaining at least a second infrared spectrum of a second pitch composition (prepared as described herein), modeling at least one structural IR parameter using the infrared spectra using chemometric modeling, and blending the first and second pitch compositions in a ratio to obtain a blended pitch composition having at least one desired pitch property.

[0058] Pitch Composition The present disclosure provides various compositions of pitch compositions, which may include two or more pitch compositions blended in specific ratios according to the methods described herein to obtain the desired structural characteristics thereof. Single pitches (unblended) may also be evaluated according to the methodology of the present disclosure, without limitation.

[0059] In one or more embodiments, the pitch composition or blended pitch composition comprises an A-factor in the range of about 0.4 to about 0.8, including any value and subset therebetween, such as about 0.4 to about 0.7, or about 0.4 to about 0.6, or about 0.4 to about 0.5, or about 0.5 to about 0.8, or about 0.6 to about 0.8, or about 0.7 to about 0.8.

[0060] In various embodiments of the present disclosure, the pitch composition or blended pitch composition comprises an aromaticity ranging from about 0.3 to about 0.9, including any value and subset therebetween, such as from about 0.3 to about 0.8, or from about 0.3 to about 0.7, or from about 0.3 to about 0.6, or from about 0.3 to about 0.5, or from about 0.4 to about 0.8, or from about 0.5 to about 0.8, or from about 0.6 to about 0.8, or from about 0.7 to about 0.8, or from about 0.8 to about 0.9.

[0061] In certain embodiments, the pitch composition or blended pitch composition comprises an A-factor in the range of about 0.6 to about 0.8, including any value and any subset thereof, or an aromaticity in the range of about 0.3 to about 0.6, including any value and any subset thereof. In other particular embodiments, the pitch composition or blended pitch composition comprises an A-factor in the range of about 0.4 to about 0.6, including any value or any subset thereof, or an aromaticity in the range of about 0.5 to about 0.8, including any value or any subset thereof.

[0062] The pitch composition or blended pitch composition of the present disclosure can have an SP in the range of about 90°C to about 350°C, including any value and subset therebetween, such as about 90°C to about 300°C, or about 90°C to about 250°C, or about 90°C to about 200°C, or about 90°C to about 150°C, or about 150°C to about 350°C, or about 200°C to about 300°C.

[0063] In various embodiments, the pitch compositions and blended pitch compositions of the present disclosure may comprise an SP of less than 150° C., for example between 90° C. and 150° C., including any value and any subset therebetween, and a mesophase volume (vol%) of less than about 20 vol% (including 0%), including any value and any subset therebetween. In various other embodiments, the pitch compositions and blended pitch compositions of the present disclosure may comprise an SP of about 150° C. to about 350° C., including any value and any subset therebetween, and a mesophase volume (vol%) of greater than 50% (including 100%), including any value and any subset therebetween.

[0064] In certain embodiments, the pitch composition or blended pitch composition comprises: (1) an A-factor in the range of about 0.4 to about 0.8, inclusive, or an aromaticity in the range of about 0.3 to about 1.3, inclusive, or any subset thereof; and (2) an SP in the range of about 90° C. to about 150° C., inclusive of any value and any subset thereof; and (3) Contains less than about 20% by volume mesophase (including 0%), inclusive of any value and any subset thereof. In various other specific embodiments, the pitch composition or blended pitch composition comprises: (1) an A-factor in the range of about 0.4 to about 0.6, inclusive, or an aromaticity in the range of about 0.5 to about 0.8, inclusive, or any subset thereof; and (2) an SP in the range of about 250° C. to about 350° C., inclusive of any value and any subset thereof; and (3) Contains greater than about 30% mesophase vol%, including 100%, inclusive of any value and any subset thereof.

[0065] In various embodiments of the present disclosure, the pitch composition or blended pitch composition has an MCR in the range of about 45 wt% to about 100 wt%, including any value and subset therebetween, such as about 55 wt% to about 95 wt%, or about 60 wt% to about 90 wt%, or about 65 wt% to about 85 wt%, or about 70 wt% to about 80 wt%.

[0066] The present disclosure, in one or more embodiments, provides pitch compositions or blended pitch compositions having a wt% PV of less than about 70 wt%, such as in the range of 0 wt% to about 70 wt%, including any value and subset therebetween, for example, from 5 wt% to about 65 wt%, or from 10 wt% to about 60 wt%, or from 15 wt% to about 55 wt%, or from about 20 wt% to about 50 wt%.

[0067] In one or more embodiments of the present disclosure, the pitch or blended pitch composition has an H / C ratio in the range of about 0.5 to about 1.0, including any value and subset therebetween, such as, for example, about 0.5 to about 0.9, or about 0.5 to about 0.8, or about 0.5 to about 0.7, or about 0.5 to about 0.6, or about 0.6 to about 0.7, or about 0.7 to about 0.8, or about 0.8 to about 0.9, or about 0.9 to about 1.0.

[0068] It will be understood that any combination of SP, MCR, wt% PV, and H / C ratio values ​​may be applied to a particular pitch based on the values ​​and ranges provided herein, without limitation. That is, a pitch composition or blended pitch composition according to the present disclosure may have one or more or all of a SP in the range of about 90° C. to about 350° C., a MRC in the range of about 5° C. to about 100° C., a wt% PV of less than about 90 wt%, and a H / C ratio in the range of about 0.5 to about 1.0.

[0069] Carbon Fiber Applications The present disclosure also relates to a method for producing carbon fibers, including green carbon fibers, comprising combining one or more carbon fibers derived from a pitch composition or blended pitch composition prepared according to the present disclosure. In some embodiments, the carbon fibers derived from pitch can be combined with a thermosetting polymer (e.g., cyclopentadiene, dicyclopentadiene, epoxy, pitch, phenolic resin, vinyl ester, polyimide and polyester), a thermoplastic polymer (e.g., a thermoplastic polymer including one or more of polyethylene, polypropylene, high density polyethylene, linear low density polyethylene, low density polyethylene, polyamide, polyvinyl chloride, polyetheretherketone, polyetherketone, polyaryletherketone, polyetherimide, polyphenylene sulfide), cement, concrete, ceramic, metal, metal alloy, or combinations thereof. In other examples, the pitch itself can be used as a matrix and / or binder to produce carbon fibers, allowing for the production of carbon-carbon composites.

[0070] In addition to carbon fibers, other suitable products can also be prepared from the pitch or blended pitch compositions according to the present disclosure. For example, mesocarbon microbeads, graphite, and / or needle coke can be produced from the pitch or blended pitch compositions. Any suitable technique can be used to produce the mesocarbon microbeads, including condensation processes, including thermal polycondensation of the pitch or blended pitch compositions. Other techniques for producing mesocarbon microbeads include emulsion or suspension processes.

[0071] Thus, the present disclosure provides two methods of using the IR spectroscopy methods described herein to predict pitch properties using structural IR parameters: the first method examines structural IR parameters to predict pitch properties from a given pitch feedstock, and the second method uses a wide variety of different feedstocks and IR parameters to develop a feed-agnostic model for predicting pitch properties.

[0072] Exemplary embodiments Non-limiting exemplary embodiments of the present disclosure include:

[0073] Embodiment A: A composition comprising a pitch composition having one or both of an A-factor in the range of about 0.4 to about 0.8 and / or an aromaticity in the range of about 0.3 to about 1.3.

[0074] Non-limiting exemplary embodiment A can include one or more of the following elements:

[0075] Element 1: Wherein the A-factor is in the range of about 0.6 to about 0.8 and the aromaticity is in the range of about 0.3 to about 0.6.

[0076] Element 2: Further, the composition has a softening point in the range of about 90° C. to about 150° C. and less than about 20% by volume of a mesophase (or intermediate phase).

[0077] Element 3: Wherein the A-factor is in the range of about 0.4 to about 0.6 and the aromaticity is in the range of about 0.5 to about 0.8.

[0078] Element 4: Further comprising a softening point in the range of about 250° C. to about 350° C. and greater than about 30% by volume of mesophase.

[0079] Element 5: Further comprising a softening point in the range of about 150° C. to about 350° C. and greater than about 50% by volume of mesophase.

[0080] Element 6: The pitch composition is comprised of a blend of pitches including at least a first pitch composition and a second pitch composition.

[0081] As non-limiting examples, exemplary combinations applicable to embodiment A include: A having 1 and 2, A having 1 and 4, A having 1 and 5, A having 1 and 6, A having 1, 2 and 6, A having 1, 4 and 6, A having 1, 5 and 6, A having 2 and 3, A having 2 and 6, A having 2, 3 and 6, A having 3 and 4, A having 3 and 5, A having 3 and 6, A having 3, 4 and 6, A having 4 and 6, A having 5 and 6.

[0082] Embodiment B: A method comprising: pyrolyzing at least a first pitch composition and a second pitch composition; wherein the pyrolysis of the first pitch composition and the second pitch composition is carried out separately; the first pitch composition is a composition from a first pitch feed; the second pitch composition is a composition from a second pitch feed; acquiring a first infrared spectrum of at least a first pitch composition, and selecting at least one first infrared parameter based on (1) the first infrared spectrum and a calibration curve or (2) the first infrared spectrum and chemometric modeling; and acquiring a second infrared spectrum of at least a second pitch composition, and selecting at least one second infrared parameter based on (1) the second infrared spectrum and a calibration curve or (2) the second infrared spectrum and chemometric modeling; and wherein the selected first and second infrared parameters are at least one or both of an A-factor in the range of about 0.4 to about 0.8 and / or an aromaticity in the range of about 0.3 to about 1.3; and blending the first and second pitch compositions in a ratio that achieves the selected first and second infrared parameters, thereby forming a blended pitch composition.

[0083] Non-limiting exemplary embodiments A, B, C, or D may include one or more of the following elements:

[0084] Element 7: The selected first and second infrared parameters further include a softening point in the range of about 90° C. to about 150° C. and less than about 20% mesophase by volume.

[0085] Element 8: wherein the selected first and second infrared parameters further include a softening point in the range of about 250° C. to about 350° C. and greater than about 30% by volume mesophase.

[0086] Element 9: Wherein the selected first and second infrared parameters further include a softening point in the range of about 150° C. to about 350° C. and greater than about 50% by volume mesophase.

[0087] Element 10: Further comprising using the blended pitch to spin or produce one or both of carbon fibers and / or carbon fiber composites.

[0088] Element 11: Further comprising using the blended pitch to produce one or more of mesocarbon microbeads, graphite, and / or needle coke.

[0089] Element 12: Prior to pyrolysis, further comprising: obtaining a first initial infrared spectrum of the first pitch feed and selecting at least one first initial infrared parameter based on (1) the first initial infrared spectrum and a calibration curve, or (2) the first initial infrared spectrum and chemometric modeling; obtaining a second initial infrared spectrum of the second pitch feed, and selecting at least one second initial infrared parameter based on (1) the second initial infrared spectrum and a calibration curve, or (2) the second initial infrared spectrum and chemometric modeling; and The first and second initial infrared parameters selected are one or both of an initial A-factor excluding the range of about 0.4 to about 0.8 and / or an initial aromaticity excluding the range of about 0.3 to about 1.3.

[0090] Element 13: The pyrolysis further includes contacting the first and second pitch feeds with a reactive gas at a temperature in the range of about 200° C. to about 600° C. and at a pressure greater than 0.3 psi, thereby producing a first pitch effluent (or eluate, or effluent) consisting of the first pitch composition and a second pitch effluent consisting of the second pitch composition.

[0091] Element 14: After pyrolysis: separating the first pitch composition from the first pitch effluent and separating the second pitch composition from the second pitch effluent; Here, the separation is selected from distillation separation, deasphalting separation, membrane separation, or any combination thereof.

[0092] Element 15: The reactive gas is selected from the group consisting of hydrogen, air, oxygen, ozone, hydrogen peroxide, carbon monoxide, carbon dioxide, formic acid, nitrogen dioxide, and any combination thereof.

[0093] As non-limiting examples, exemplary combinations applicable to embodiment B include: B having 7 and 10; B having 7 and 11; B having 7, 10 and 12; B having 7, 11 and 12; B having 7, 12 and 13; B having 7, 10, 12 and 13; B having 7, 11, 12 and 13; B having 7, 12, 13 and 14; B having 7, 10, 12, 13 and 14; B having 7, 11, 12, 13 and 14; B having 7, 12, 13, 14 and 15; B having 7, 10, 12, 13, 14 and 15; B having 7, 11, 12, 13, 14 and 15 B;B with 7, 10, 12, 13, and 15;B with 7, 11, 12, 13, and 15;B with 7, 12, 13, and 15;B with 8, 10;B with 8, 11;B with 8, 10, 12;B with 8, 11, 12;B with 8, 12, 13;B with 8, 10, 12, and 13;B with 8, 11, 12, and 13;B with 8, 12, 13, and 14;B with 8, 10, 12, 13, and 14;B with 8, 11, 12, 13, and 14;B with 8, 12, 13, and 14;B with 8, 12, 13, and 14;B with 8, 10, 12, 13, and 14;B with 8, 12, 13, and 14, and 15;B with 8, 10 ... B with 1, 12, 13, 14, and 15;B with 8, 10, 12, 13, and 15;B with 8, 11, 12, 13, and 15;B with 8, 12, 13, and 15;B with 9, 10;B with 9, 11;B with 9, 10, and 12;B with 9, 11, and 12;B with 9, 12, and 13;B with 9, 10, 12, and 13;B with 9, 1011, 12, and 13;B with 9, 12, 13, and 14;B with 9, 10, 12, 13, and 14;B with 9, 11, 12, 13, and 14;B with 9, 12, 13, and 14, and 15;B with 9, 10, and 12 B having 13, 14 and 15;B having 9, 11, 12, 13, 14 and 15;B having 9, 10, 12, 13 and 15;B having 9, 11, 12, 13 and 15;B having 9, 12, 13 and 15;B having 10 and 12;B having 11 and 12;B having 10, 12 and 13;B having 11, 12 and 13;B having 10, 12, 13 and 14;B having 11, 12, 13 and 14 ... and 15;B having 11, 12, 13 and 14;B having 10, 12, 13 and 14 and 15;B having 11, 12, 13 and 14;B with 10, 12, 13 and 15; B with 11, 12, 13 and 15; B with 12, 13 and 15; B with 12 and 13; B with 12 and 15; B with 12, 13 and 14; B with 12, 13, 14 and 15. ;

[0094] Embodiment C: A method comprising: extruding the pitch composition to produce green carbon fibers; and thereafter stabilizing the extruded pitch composition; wherein the stabilizing includes obtaining an infrared spectrum of the extruded pitch composition and selecting at least one infrared parameter based on (1) the first infrared spectrum and a calibration curve or (2) the first infrared spectrum and chemometric modeling; wherein the at least one infrared parameter is at least A-factor and aromaticity; and Stopping stabilization based on at least one infrared parameter.

[0095] As non-limiting examples, exemplary combinations applicable to embodiment C include:

[0096] Element 15: The pitch composition is extruded through a spinneret, and the method further includes spooling the extruded pitch composition prior to stabilization, the stabilization being performed with a reactive gas.

[0097] Element 16: Extruding includes blowing the pitch composition through an extrusion die.

[0098] Element 17: The reactive gas is selected from the group consisting of hydrogen, air, oxygen, ozone, nitrogen dioxide, hydrogen peroxide, carbon monoxide, carbon dioxide, formic acid, and any combination thereof.

[0099] Element 18: The at least one infrared parameter selected is at least one or both of A-factor and aromaticity, and stabilization is stopped when the A-factor is in the range of about 0.4 to about 0.8 and / or when the aromaticity is in the range of about 0.3 to about 1.3.

[0100] As non-limiting examples, exemplary combinations applicable to embodiment C include: C having 15 and 17; C having 16 and 17; C having 15 and 18; C having 16 and 18; C having 15, 17 and 18; C having 16, 17 and 18; C having 17 and 18.

[0101] Embodiment D. A method comprising: pyrolyzing a pitch composition from the pitch feed; obtaining an infrared spectrum of the first pitch composition, and selecting at least one infrared parameter based on (1) the infrared spectrum and a calibration curve or (2) the infrared spectrum and chemometric modeling; The at least one infrared parameter selected is at least one or both of an A-factor in the range of about 0.4 to about 0.8 and / or an aromaticity in the range of about 0.3 to about 1.3.

[0102] As non-limiting examples, exemplary combinations applicable to embodiment D include:

[0103] Element 18: The selected at least one infrared parameter further includes a softening point in the range of about 90° C. to about 150° C. and less than about 20% mesophase by volume.

[0104] Element 19: The selected at least one infrared parameter further includes a softening point in the range of about 250° C. to about 350° C., and greater than about 30% by volume mesophase.

[0105] Element 20: The selected at least one infrared parameter further includes a softening point in the range of about 150° C. to about 350° C. and greater than about 50% by volume mesophase.

[0106] Element 21: Further comprising using the pitch composition to spin or manufacture one or both of carbon fibers and / or carbon fiber composites.

[0107] Element 22: Before pyrolysis, obtaining an initial infrared spectrum of the pitch feed and selecting at least one initial infrared parameter based on (1) the initial infrared spectrum and a calibration curve, or (2) the initial infrared spectrum and chemometric modeling; The at least one initial infrared parameter selected is one or both of an initial A-factor excluding the range of about 0.4 to about 0.8 and / or an initial aromaticity excluding the range of about 0.3 to about 1.3.

[0108] Element 23: The pyrolysis further includes contacting the pitch feed with a reactive gas at a temperature in the range of about 200° C. to about 600° C. and at a pressure greater than 0.3 psi, thereby producing a pitch effluent comprising the pitch composition.

[0109] Element 24: Further comprising separating the pitch composition from the pitch effluent after pyrolysis, wherein the separation is selected from distillation separation, deasphalting separation, membrane separation, or any combination thereof.

[0110] Element 25: The reactive gas is selected from the group consisting of hydrogen, air, oxygen, ozone, hydrogen peroxide, carbon monoxide, carbon dioxide, formic acid, nitrogen dioxide, and any combination thereof.

[0111] As a non-limiting example, exemplary combinations applicable to embodiment D include: D having 18 and 21; D having 18 and 22; D having 18, 21 and 22; D having 18, 22 and 23; D having 18, 21, 22 and 23; D having 18, 22, 23 and 24; D having 18, 21, 22, 23 and 24; D having 18, 21, 22, 23 and 24; D having 18, 21, 22, 23, 24 and 25; D having 18, 21, 22, 23, 24 and 25; D having 19 and 21; D having 19 and 22; D having 19, 21 and 22; D having 19, 22 and 23; D having 19, 21, 22 and 23; D having 19, 22, 23 and 24; D having 19, 21, 22, 23 and 24; D having 19, 21, D with 22, 24, and 25;D with 19, 21, 22, 23, 24, and 25;D with 18 and 21;D with 18 and 22;D with 18, 21, and 22;D with 18, 22, and 23;D with 18, 21, 22, and 23;D with 18, 22, 23, and 24;D with 18, 21, 22, 23, and 24;D with 18, 21, 22, and 22 D having 3, 24 and 25; D having 18, 21, 22, 23, 24 and 25; D having 21 and 22; D having 21, 22 and 23; D having 21, 22, 23 and 24; D having 21, 22, 23 and 25; D having 22, 23 and 24; D having 22 and 23; D having 22, 23 and 25; D having 22, 23, 24 and 25.

[0112] In order to facilitate a better understanding of the embodiments of the present invention, examples of preferred or representative embodiments are given below. In no way should the following examples be read to limit or define the scope of the present invention.

[0113] Working Example In the following non-limiting examples, representative methodologies of the present disclosure for adjusting pitch characteristics are provided.

[0114] Background Infrared Spectra - For Examples 1 and 2 Infrared spectra of various prepared pitch compositions were obtained using DRIFT. Pitch samples were prepared by filling approximately 2 grams (g) of the ingredients described below into glass vials and placing them in a PAC™ Micro Carbon Residue Tester. Nitrogen gas (600 mL min -1 The sample was heated to 100°C for 10 min under running water. Immediately thereafter, it was cooled to 30°C for -1 and 600 mL min -1 The sample was heated to 400 °C using a nitrogen flow rate of 100 mL min−1. Once 400 °C was reached, the flow rate was reduced to 150 mL min−1. -1 The temperature was lowered to 400°C and the sample was held at 400°C for 0 to 6 hours. After the specified heat soak, the sample was heated in an oven for several hours in nitrogen gas at a flow rate of 600 mL min. -1 The sample was cooled to room temperature.

[0115] The results and pyrolysis parameters (heating time (hr) and temperature (°C)) are shown below in Table 1. Sample pitch compositions were obtained from the following sources: (1) Solvent-assisted tar conversion (SATC) bottom stream samples (denoted as SATC-1–SATC-8); (2) “seed” SATC PDU bottom stream samples (denoted sSATC-1–s-SATC-8) formed from the blending of a 0-h non-heat-treated SATC bottom stream (SATC-1) with a 5-h treated SATC bottom stream (SATC-6); (3) Tar from steam crackers (labeled SOP2-1 to SOP2-5); (4) heavy vacuum gas oil pitch (bottom stream with temperatures between 986°F and 1038°F, or 524°C and 559°C) (designated HVGO-1 and HVGO-2); (5) bituminous pitches from Kearns (designated KB-1 through KB-6); (6) hydrotreated mesocarbon microbead pitch (designated MCB-1 and MC-2); and (8) Isotropic petroleum pitch available from Marathon Oil Corporation, Findlay, Ohio (designated M-50, M50-1 through M50-4).

[0116] Elemental analyses of SP, MCR, H / C ratio and %PV were measured as defined herein. An "N / A" entry in Table 1 indicates that the particular pitch property was not measured or an unknown measurement error occurred. A superscript "*" in Table 1 indicates that the value is at the lower limit because the measuring instrument had an error at that temperature and the material did not fully soften. [Table 1]

[0117] Each sample in Table 1 was diluted with potassium bromide (KBr) at a sample loading of 2 wt% pitch, and the respective DRIFT spectra (using an FT-IR spectrometer equipped with the DRIFT peripherals and detectors provided herein) were measured at RT. DRIFT data were collected from 400–4000 cm -1 The spectra were collected over a spectral range of 100 nm and the ratio of the sample spectrum to the room temperature spectrum in KBr was used to calculate the OMNIC spectrum of Thermo Fisher Scientific Inc. TM The measurements were converted to absorbance using the Happ-Genzel attenuation function at a resolution of 4 cm. -1 256 scans were acquired per sample.

[0118] Representative results are shown in Figures 1A-1D. Figure 1A shows the DRIFT spectra of samples HVGO-1 and HVGO-2, Figure 1B shows the DRIFT spectra of samples KB-1 to KB-6, Figure 1C shows the DRIFT spectra of samples MCB-1 and MCB-2, and Figure 1D shows the DRIFT spectra of samples M50-1 to M50-4.

[0119] As shown in Figures 1A-1D, the DRIFT spectra show that as the thermal treatment progresses (i.e., the time at 400 °C increases), there is an increase in the aromatic CH stretching (approximately 2991-3100 cm -1 range), while at the same time, there is a decrease in aliphatic CH stretching (approximately 2820-3000 cm -1 Similar results were observed in the DRIFT spectra of the remaining samples in Table 1.

[0120] Example 1 - Drift Spectral Analysis + Infrared Parameters Representative DRIFT spectra were obtained as described above for samples SATC-1 to SATC-6 and SATC-8 (labeled with diamonds); and samples sSATC-1 to sSATC-8 (labeled with circles). Then, the infrared structural parameters CH3 / CH2 ratio, A-factor, aromaticity, and DoC defined above were measured based on the obtained DRIFT spectra. Figure 2A shows the measurement results of the infrared parameter CH3 / CH2 ratio, Figure 2B shows the measurement results of the infrared parameter A-factor, Figure 2C shows the measurement results of the infrared parameter aromaticity, and Figure 2D shows the measurement results of the infrared parameter DoC.

[0121] As shown in Figures 2A-2D, the CH3 / CH2 ratio and aromaticity increase with increasing pyrolysis time (400°C in this example), while the A-factor and DoC decrease with increasing pyrolysis time. The decrease in DoC with increasing thermal conversion time indicates an increase in ring condensation. Similar results were observed for the infrared parameters of the remaining samples in Table 1 (not shown).

[0122] As described above, DRIFT spectra were acquired and infrared parameters (CH3 / CH2 ratio, A-factor, aromaticity, and DoC) were measured for each sample shown in Table 1. Each infrared parameter was then correlated with each pitch property (SP, MCR, H / C ratio, and %PV). The infrared parameters are intended to track the various major structural changes that occur during the pyrolysis of the pitch.

[0123] From the correlation between infrared parameters and structural properties of pitches, it was observed that the best fitting correlation was based on A-factor and aromaticity. Figures 3A-3D show representative correlation diagrams between A-factor and MCR (Figure 3A); A-factor and SP (Figure 3B); aromaticity and MCR (Figure 3C); and aromaticity and SP for each sample in Table 1. As shown in Figures 3A-3D, infrared parameters and pitch properties are correlated, but differ depending on the pitch type, so this example depends on the pitch type. As mentioned above, the average of A-factor and / or aromaticity is used to predict specific structural pitch properties.

[0124] Based on the determined average A-factors and average aromaticity, parity plots between predicted and measured values ​​of A-factor and aromaticity properties were created for each of the pitch properties MCR (%), SP (°C), H / C ratio, and %PV. Representative samples with sufficient data and sufficient reference (measured) data were selected. The parity plots are shown in Figures 4A-4D, where Figure 4A shows the parity plot for MCR, Figure 4B shows the parity plot for SP (dashed line indicates the instrument limit above 380°C), Figure 4C shows the parity plot for H / C ratio, and Figure 4D shows the parity plot for %PV. As can be observed, there is significant parity between predicted and actual pitch properties for all infrared parameters.

[0125] Thus, this example illustrates the methodology of the present disclosure that utilizes correlations between DRIFT infrared parameters and pitch-type predictions of their structural properties.

[0126] Example 2 - DRIFT Spectral Analysis + Chemometric Analysis In this example, chemometric modeling was used to predict pitch characteristics based on the DRIFT spectra and based on Table 1 and representative Figures 1A-1B. Chemometric approaches, as described herein above, allow for the prediction of pitch characteristics independent of pitch type ("agnostic" pitch models).

[0127] Each of the four pitch properties described herein (MCR, SP, H / C ratio, %PV) was evaluated using the PLS modeling technique described above.

[0128] Now referring to Figure 5, a PLS model correlation diagram of a representative pitch characteristic MCR is shown, in which the MCR is predicted based on PLS and compared with the actual MCR values ​​in Table 1. As shown in Figure 5, there is a significant correlation between the MCR predicted by PLS and the actual MCR values.

[0129] Similar to Example 1, parity plots were also made for this example, and the results of the parity plots are shown in Figures 6A-6D. Figure 6A shows the parity plot of MCR, Figure 6B shows the parity plot of SP, Figure 6C shows the parity plot of H / C ratio, and Figure 6D shows the parity plot of %PV. As can be observed, there is significant parity between the predicted and actual pitch characteristics for all infrared parameters.

[0130] 7A-7D show the predicted pitch properties based on the chemometric approach of this example using IR structure parameter least squares analysis (LSA) (polynomial order 2) for the SATC-1, SATC-4, SATC-8, sSATC-1, sSATC-4, and sSATC-8 samples in Table 1. Compared with the values ​​in Table 1, the predicted values ​​were within the range of the measured values ​​for each sample.

[0131] All documents described herein, including priority documents and / or testing procedures, to the extent not inconsistent herewith, are incorporated herein by reference for purposes of all jurisdictions where such practice is permitted. As is apparent from the general description and specific embodiments set forth above, while forms of the disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the disclosure. Accordingly, the disclosure is not intended to be limited thereby. For example, the compositions described herein may not include any component or composition that is not expressly described or disclosed herein. Any method may be devoid of any step that is not described or disclosed herein. Similarly, the term "comprising" is considered synonymous with the term "including". It is understood that whenever the transitional phrase "comprising" precedes a method, composition, element, or group of elements, the transitional phrase "consisting essentially of", "consisting of", "selected from the group of consisting of", or "is" also contemplates the same composition or group of elements preceded by the composition, element, or group of elements.

[0132] Unless otherwise indicated, all numerical values ​​expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and the like used in the specification and appended claims are understood to be modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending upon the desired properties sought to be obtained by embodiments of the present invention. At the very least, and without any attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should, at the very least, be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0133] Whenever a numerical range with a lower limit and an upper limit is disclosed, any numerical value falling within the range and any range included therein, including the lower and upper limits, are specifically disclosed. In particular, any numerical range disclosed herein (in the form of "about a to about b", or equivalently "about a to b", or equivalently "about a to a b") is understood to define any numerical value and range encompassed within the broader numerical range. In addition, the terms described in the claims have their plain and ordinary meaning unless expressly and unambiguously defined by the patentee. Furthermore, the indefinite article "a" or "an" used in the claims is defined herein to mean one or more of the element it introduces.

[0134] One or more exemplary embodiments are presented herein. For the sake of clarity, not all features of a physical embodiment are described or shown in this application. It is understood that in developing a physical embodiment of the present disclosure, numerous embodiment-specific decisions must be made to achieve the developer's goals, such as compliance with system-related, business-related, government-related, and other constraints that vary from embodiment to embodiment and from time to time. Although the developer's efforts may be time-consuming, such efforts would nevertheless be a routine undertaking for one of ordinary skill in the art and having the benefit of this disclosure.

[0135] Thus, the present disclosure is fully adapted to achieve the objects and advantages mentioned, as well as those inherent therein. The specific embodiments disclosed above are merely exemplary, as the present disclosure may be modified and implemented in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Moreover, no limitations to the details of construction or design shown herein are intended, other than as set forth in the following claims. Thus, it is apparent that the specific exemplary embodiments disclosed above may be altered, combined or modified, and all such variations are deemed to be within the scope and spirit of the present disclosure. The embodiments illustratively disclosed herein may suitably be practiced in the absence of elements not specifically disclosed herein and / or any elements disclosed herein.

Claims

1. A composition comprising a pitch composition having one or both of an A-factor in the range of about 0.4 to about 0.8 and / or an aromaticity in the range of about 0.3 to about 1.

3.

2. 10. The composition of claim 1, wherein the A-factor is in the range of about 0.6 to about 0.8 and the aromaticity is in the range of about 0.3 to about 0.

6.

3. 3. The composition of claim 1 or 2, further comprising a softening point in the range of about 90° C. to about 150° C. and less than about 20% by volume of mesophase.

4. 10. The composition of claim 1, wherein the A-factor is in the range of about 0.4 to about 0.6 and the aromaticity is in the range of about 0.5 to about 0.

8.

5. 5. The composition of any one of claims 1, 2 or 4, further comprising a softening point in the range of about 250°C to about 350°C and greater than about 30% by volume of mesophase.

6. 5. The composition of any one of claims 1, 2 or 4, further comprising a softening point in the range of about 150°C to about 350°C and greater than about 50% by volume of mesophase.

7. 10. The composition of claim 1 , wherein the pitch composition comprises a blend of pitches comprising at least a first pitch composition and a second pitch composition.

8. pyrolyzing at least a first pitch composition and a second pitch composition; wherein the pyrolysis of the first pitch composition and the second pitch composition is carried out separately; the first pitch composition is a composition from a first pitch feed; the second pitch composition is a composition from a second pitch feed; acquiring a first infrared spectrum of at least a first pitch composition, and selecting at least one first infrared parameter based on (1) the first infrared spectrum and a calibration curve or (2) the first infrared spectrum and chemometric modeling; acquiring a second infrared spectrum of at least a second pitch composition, and selecting at least one second infrared parameter based on (1) the second infrared spectrum and a calibration curve or (2) the second infrared spectrum and chemometric modeling; and wherein the selected first and second infrared parameters are at least one or both of an A-factor in the range of about 0.4 to about 0.8 and / or an aromaticity in the range of about 0.3 to about 1.3; and blending first and second pitch compositions in a ratio that achieves selected first and second infrared parameters, thereby forming a blended pitch composition.

9. 9. The method of claim 8, wherein the selected first and second infrared parameters further comprise a softening point in the range of about 90° C. to about 150° C. and less than about 20% by volume mesophase.

10. 9. The method of claim 8, wherein the selected first and second infrared parameters further comprise a softening point in the range of about 250° C. to about 350° C. and greater than about 30% by volume mesophase.

11. 9. The method of claim 8, wherein the selected first and second infrared parameters further comprise a softening point in the range of about 150° C. to about 350° C. and greater than about 50% by volume mesophase.

12. The method of any one of claims 8 to 11, further comprising using the blended pitch to spin or produce one or both of carbon fibers and / or carbon fiber composites.

13. The method of any one of claims 8 to 11, further comprising using the blended pitch to produce one or more of mesocarbon microbeads, graphite, and / or needle coke.

14. Before pyrolysis, acquiring a first initial infrared spectrum of the first pitch feed and selecting at least one first initial infrared parameter based on (1) the first initial infrared spectrum and a calibration curve, or (2) the first initial infrared spectrum and chemometric modeling; acquiring a second initial infrared spectrum of the second pitch feed; and selecting at least one second initial infrared parameter based on (1) the second initial infrared spectrum and a calibration curve, or (2) the second initial infrared spectrum and chemometric modeling; and 9. The method of claim 8, wherein the selected first and second initial infrared parameters are one or both of an initial A-factor excluding the range of about 0.4 to about 0.8 and / or an initial aromaticity excluding the range of about 0.3 to about 1.

3.

15. 15. The method of claim 14, wherein the pyrolysis further comprises contacting the first and second pitch feeds with a reactive gas at a temperature in the range of about 200° C. to about 600° C. and at a pressure greater than 0.3 psi, thereby producing a first pitch effluent comprising the first pitch composition and a second pitch effluent comprising the second pitch composition.

16. After pyrolysis, further comprising separating a first pitch composition from the first pitch effluent and separating a second pitch composition from the second pitch effluent; 16. The method of claim 15, wherein the separation is selected from distillation separation, deasphalting separation, membrane separation, or any combination thereof.

17. 17. The method of claim 15 or 16, wherein the reactive gas is selected from the group consisting of hydrogen, air, oxygen, ozone, hydrogen peroxide, carbon monoxide, carbon dioxide, formic acid, nitrogen dioxide, and any combination thereof.

18. extruding the pitch composition to produce green carbon fibers; and thereafter stabilizing the extruded pitch composition; wherein the stabilizing includes obtaining an infrared spectrum of the extruded pitch composition, and selecting at least one infrared parameter based on (1) the first infrared spectrum and a calibration curve, or (2) the first infrared spectrum and chemometric modeling; wherein the at least one infrared parameter is at least A-factor and aromaticity; and and stopping stabilization based on the at least one infrared parameter.

19. 20. The method of claim 18, wherein the pitch composition is extruded through a spinneret, the method further comprising spooling the extruded pitch composition prior to stabilization, the stabilization being performed with a reactive gas.

20. 20. The method of claim 18, wherein extruding comprises blowing the pitch composition through an extrusion die.

21. 21. The method of any one of claims 18 to 20, wherein the reactive gas is selected from the group consisting of hydrogen, air, oxygen, ozone, nitrogen dioxide, hydrogen peroxide, carbon monoxide, carbon dioxide, formic acid, and any combination thereof.

22. 22. The method of any one of claims 18 to 21, wherein the at least one infrared parameter selected is at least one or both of A-factor and aromaticity, and stabilization is stopped when A-factor is in the range of about 0.4 to about 0.8 and / or aromaticity is in the range of about 0.3 to about 1.3.

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