Low-temperature processing of BIO-oil for commercial graphite production

Abstract

In one aspect, the disclosure relates to a method for producing graphite from bio-oil, the method including at least the steps of performing a low-temperature pretreatment of the bio-oil to produce a pre-treated bio-oil; admixing the pre-treated bio-oil with a catalyst; and performing graphitization on the bio oil. In one aspect, the low-temperature pretreatment converts the bio-oil to a powder. In some aspects, an acid washing step can be performed following the method to remove substantially all of the catalyst from the graphite. Also disclosed are graphite made by the method and articles such as, for example, lithium ion battery anodes, made from the graphite. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

Description

LOW-TEMPERATURE PROCESSING OF BIO-OIL FOR COMMERCIAL GRAPHITE PRODUCTIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 63 / 627,169, filed January 31 , 2024, which is incorporated herein by reference in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was made with government support under grant number DE-EE0009260 awarded by the U.S. Department of Energy. The government has certain rights in the invention. In addition, the United States Government has rights in this invention under Contract No. DE- AC36-08GO28308 between the United States Department of Energy and Alliance for Sustainable Energy, LLC, the Manager and Operator of the National Renewable Energy Laboratory.BACKGROUND

[0003] Graphite is a ubiquitous lithium-ion battery anode material and is expected to see significant growth in demand in the coming decades. However, conventional synthetic graphite is produced from crude oil or coal and requires high thermal processing over 2800 °C and has high carbon emissions.

[0004] Using renewable bio-oil as a feedstock for synthetic graphite can decrease cost and offer a significantly cleaner process with substantially lower carbon emissions compared to typical petroleum and coal feedstocks. However, processing of bio-oil presents numerous challenges including, but not limited to, high oxygen and water content, lower pH, and the resulting corrosive properties. Using standard approaches at pre-treating bio-oil results in significant foaming and swelling, preventing the production of high-quality battery-grade graphite.

[0005] Despite advances in graphite production research, there is still a scarcity of methods of producing graphite that are low cost and clean, with low carbon emissions. What is needed is a simple method for preparing graphite from bio-oil using low-temperature processing that addresses challenges associated with high oxygen content, high water content, low pH, and foaming and / or swelling. These needs and other needs are satisfied by the present disclosure.SUMMARY

[0006] In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, the disclosure, in one aspect, relates to a method for producing graphite from bio-oil, the method including at least the steps of performing a low-temperature pretreatment of the bio-oil to produce a pre-treated bio-oil; admixing the pre-treated bio-oil with a catalyst; and performing graphitization on the bio oil. In one aspect, the low-temperature pretreatment converts the bio-oil to a powder. In some aspects, an acid washing step can be performed following the method to remove substantially all of the catalyst from the graphite. Also disclosed are graphite made by the method and articles such as, for example, lithium ion battery anodes, made from the graphite.

[0007] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. In addition, all optional and preferred features and modifications of the described embodiments are usable in all aspects of the disclosure taught herein. Furthermore, the individual features of the dependent claims, as well as all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with one another.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

[0009] FIG. 1 shows the effect of temperature on bio-oil viscosity (insets show the image of heated bio-oil in the absence and presence of an iron catalyst).

[0010] FIGs. 2A-2I show foam formation stages: (FIG. 2A) fresh iron and bio-oil before mixing, (FIG. 2B) iron mixed bio-oil at room temperature, (FIG. 2C) after mixing for few minutes, (FIG. 2D) after resting at room temperature overnight, (FIG. 2E) stirring breaks the foam, (FIGs. 2F-2H) heating makes foam again, (FIG. 2I) stirring breaks the foam but some portion overflowed.

[0011] FIGs. 3A-3F show (FIG. 3A) temperature profile for pretreatment, (FIG. 3B) raw bio-oil before pretreatment, (FIG. 3C) top view of pretreated bio-oil, (FIG. 3D) crucible after removing the pretreated bio-oil, (FIG. 3E) side view of pretreated bio-oil, (FIG. 3F) pretreated bio-oil powder.

[0012] FIGs. 4A-4B show pretreatment of bio-oil at 100 °C for (FIG. 4A) 1 h and (FIG. 4B) 12 h.

[0013] FIGs. 5A-5C show pretreatment of bio-oil at 150 °C for (FIG. 5A) 1 h, (FIG. 5B) 2 h, and (FIG. 5C) 3 h.

[0014] FIGs. 6A-6C show pretreatment of bio-oil at 150 °C for (FIG. 6A) 4 h, (FIG. 6B) 5 h, and (FIG. 6C) 6 h.

[0015] FIGs. 7A-7B show pretreatment of bio-oil at 150 °C for (FIG. 7A) 9 h, and (FIG. 7B) 12 h.

[0016] FIGs. 8A-8H show (FIG. 8A) catalytic graphitization of pretreated bio-oil at 150 °C (5 h), (FIG. 8B) bio-oil powder + iron powder before mixing, (FIG. 8C) bio-oil powder + iron powder after uniform mixing, (FIG. 8D) graphite + iron mixture after catalytic graphitization, (FIG. 8E) milled graphite + iron mixture (150 °C pretreatment), (FIG. 8F) catalytic graphitization of pretreated biooil at 200 °C (1 h), (FIG. 8G) graphite + iron mixture after catalytic graphitization, (FIG. 8H) milled graphite + iron mixture (200 °C pretreatment).

[0017] FIGs. 9A-9C show (FIG. 9A) graphite XRD pattern for 150 °C 5 h pretreatment (1 step acid reflux), (FIG. 9B) graphite XRD pattern for 150 °C 5 h pretreatment (5 step acid reflux), (FIG. 9C) graphite XRD pattern for 200 °C 1 h pretreatment (1 step acid reflux). In this figure (insets) the meaning of the abbreviations are as follows PT: pretreatment, DC: delayed coking, CG: catalytic graphitization, Lc: stacking height (crystallite size along c-direction), intensity of (002) peak.

[0018] FIG. 10 shows Raman spectrum of graphite made from 150 °C (5 h) pretreatment.

[0019] FIGs. 11A-11C show (FIG. 11A) experimental setup for acid refluxing, (FIG. 11B) photograph showing the conversion of iron into acid-soluble iron chloride, (FIG. 11C) removal of graphite from iron chloride via filtration.

[0020] FIG. 12 shows complete removal of iron from graphite via 5-step acid refluxing with fresh and concentrated hydrochloric acid.

[0021] FIGs. 13A-13C show iron-catalyzed graphite production via delayed coking at (FIG. 13A) 400, (FIG. 13B) 500, and (FIG. 13C) 600 °C respectively.

[0022] FIGs. 14A-14C show XRD patterns of graphite samples produced via iron-catalyzed graphitization via delayed coking at (FIG. 14A) 400, (FIG. 14B) 500, and (FIG. 14C) 600 °C, respectively.

[0023] FIGs. 15A-15B show attempts to minimize foaming in bio-oil using (FIG. 15A) defoamers and (FIG. 15B) iron oxide.

[0024] FIGs. 16A-16B show (FIG. 16A) XRD patterns of iron and iron oxide, (FIG. 16B) XRD pattern of graphite made with iron oxide (after acid washing).

[0025] FIG. 17 shows minimization of foam formation adjusting pH to 7.0.

[0026] FIG. 18 shows minimization of foam formation by adjusting pH to 11.0.

[0027] FIG. 19 shows laboratory scale graphite production from bio-oil using iron added after delayed coking the raw bio-oil for different temperatures (300-500 °C). The top row shows the thermal profiles (heating and cooling) during the catalytic graphitization process. The bottom row shows the corresponding XRD patterns of the graphite after acid refluxing (the inset shows the image of swelled coke structures).

[0028] FIGs. 20A-20B show images of (FIG. 20A) swelled coke formed at 500 °C (arrows indicate edges of the crucible confirming significant volume expansion), (FIG. 20B) image of graphite after acid washing (arrows show spherical iron balls).

[0029] Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or can be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.DETAILED DESCRIPTION

[0030] Iron-catalyzed graphitization of renewable biocarbon feedstocks is a promising route for graphite synthesis, offering significantly lower temperature processing (-1500 °C) compared to the current commercial synthetic graphite production (>2800 °C) process. In one aspect, high temperature processing decreases viscosity and provides additional thermal energy to drive chemical reactions, but comes with significantly higher energy and handling costs.

[0031] Disclosed herein is a process for producing graphite from wood-derived bio-oil using reduced iron powder as the graphitization catalyst. In a further aspect, the graphite produced by the disclosed method is particularly suitable for lithium-ion battery (LIB) applications. In some aspects, high oxygen content, water content, and lower pH are potential hurdles for converting bio-oil into valuable industrial products. In a further aspect, efficient mixing of feedstock (bio-oil) and catalyst (iron) is a prerequisite for graphite production. However, in an aspect, extensive foaming is observed when metallic iron (zero valent) is mixed into bio-oil due to the presence of organic acids in bio-oil. In an alternative aspect, a pathway to avoid foaming is the preliminary conversion of bio-oil into char-like carbon structures (coke) at lower temperatures (300-500 °C). However, further in this aspect, a highly swelled coke carbon structure is formed when bio-oil is heat treated at 300-500 °C without iron under an inert nitrogen atmosphere. In one aspect, milling this swelled coke into fine powder has been found challenging, which leads to poor mixing with iron. In a further aspect, this ultimately leads to poorly crystalline graphite, which is inappropriate for LIB applications.

[0032] In one aspect, in the disclosed process, a low-temperature pretreatment (150 °C for 5 h) effectively converts the raw bio-oil into a physical powder form well suited for iron mixing and subsequent conversion into LIB-grade graphite anode, where the physical powder form is stable for storage purposes. In a further aspect, the disclosed process can be scaled up, thus making the process industrially useful.

[0033] In an aspect, in the disclosed process, various catalysts are contemplated including, but not limited to, metallic iron, cobalt, and / or nickel, and salts thereof. In another aspect, iron (II) nitrate can be a useful catalyst for the disclosed processes.Method for Producing Graphite from Bio-Oil

[0034] In one aspect, disclosed herein is a method for producing graphite from bio-oil, the method including at least the steps of:(a) performing a low-temperature pretreatment of the bio-oil to produce a pre-treated biooil;(b) admixing the pre-treated bio-oil with a catalyst; and(c) performing graphitization on the bio oil.

[0035] In another aspect, the pre-treated bio oil can be a dry powder. In still another aspect, the low-temperature pre-treatment can be carried out from about 150 °C to about 350 °C, or at about150, 175, 200, 225, 250, 275, 300, 325, or about 350 °C, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values. In another aspect, the low- temperature pretreatment is carried out for from about 1 min to about 12 h, or for about 1 , 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 min, or for about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , or 12 h, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values. In an aspect, the low-temperature pretreatment is carried out at 150 °C for 5 h.

[0036] In another aspect, the bio-oil is or includes a pyrolysis product of biomass, wherein the biomass can be selected from a hardwood, a softwood, algae, switchgrass or another energy crop, oil seeds, or any combination thereof. In another aspect, the bio-oil has a 10% to 50% fixed carbon content.

[0037] In still another aspect, the catalyst can be selected from or can include iron metal, an iron salt, cobalt metal, a cobalt salt, nickel metal, a nickel salt, or any combination thereof. In one aspect, the iron metal can be a powder. In another aspect, the catalyst can be loaded at 1 * to 3x the fixed carbon content of the bio-oil.

[0038] In one aspect, graphitization can be carried out in a thermal furnace, induction furnace, vacuum furnace, microwave furnace, electric furnace, hybrid furnace, or any combination thereof. In another aspect, graphitization can be carried out at from about 1000 °C to about 2000 °C, or at about 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, or about 2000 °C, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values. In another aspect, graphitization can be carried out for from about 30 min to about 20 h, or for 30 min, 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, or about 20 h, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values. In another aspect, graphitization can be carried out under an inert atmosphere such as, for example, N2or argon or a combination thereof, or can be carried out in a vacuum. In still another aspect, graphitization can be carried out in a crucible made from alumina, graphite, or quartz.

[0039] In one aspect, the disclosed method further includes an acid washing step to remove the catalyst from the graphite. In a further aspect, the acid washing step includes refluxing the catalyst and graphite in a strong acid for from about 5 min to about 5 h, or for about 5, 15, 30, 45, or 60 min, or 2, 3, 4, or 5 h, or a combination of any of the foregoing values, or a range encompassing any of the foregoing values. In a further aspect, filtration can be conducted to remove the solid phase containing the graphite from the liquid phase containing the catalyst after acid washing. In another aspect, the acid washing step can be carried out from 1 to 10 times or can be carried out1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10 times. In any of these aspect, following the acid washing step, less than about 0.01 weight% of the iron remains in the graphite.

[0040] In one aspect, prior to performing the acid washing step, the catalyst and graphite can be ball-milled, cryo-milled, ground, or crushed. In another aspect, the method further includes drying the graphite after performing the acid washing step. In one aspect, the graphite can be dried in an oven at 105 °C for 4 h, although other drying conditions are also contemplated and should be considered disclosed.

[0041] In any of these aspects, the bio-oil expands less than 10% by volume due to foaming during performance of the method, or foams less than 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1% during performance of the method, or does not foam.Graphite and Articles Produced Therefrom

[0042] In one aspect, disclosed herein is graphite or a graphite composition produced by the disclosed method. In another aspect, disclosed herein is an article or substance including the disclosed graphite. In still another aspect, the article or substance can be an anode for a lithium ion battery, a refractory material fora high-temperature environment, a lubricant, a carbon additive for steel production, a shaped graphite product, a carbon fiber composite, or any combination thereof.

[0043] Many modifications and other embodiments disclosed herein will come to mind to one skilled in the art to which the disclosed compositions and methods pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosures are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. The skilled artisan will recognize many variants and adaptations of the aspects described herein. These variants and adaptations are intended to be included in the teachings of this disclosure and to be encompassed by the claims herein.

[0044] Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

[0045] As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure.

[0046] Any recited method can be carried out in the order of events recited or in any other order that is logically possible. That is, unless otherwise expressly stated, it is in no way intended that any method or aspect set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not specifically state in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to arrangement of steps or operational flow, plain meaning derived from grammatical organization or punctuation, or the number or type of aspects described in the specification.

[0047] All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and / or materials in connection with which the publications are cited. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided herein can be different from the actual publication dates, which can require independent confirmation.

[0048] While aspects of the present disclosure can be described and claimed in a particular statutory class, such as the system statutory class, this is for convenience only and one of skill in the art will understand that each aspect of the present disclosure can be described and claimed in any statutory class.

[0049] It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed compositions and methods belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0050] Prior to describing the various aspects of the present disclosure, the following definitions are provided and should be used unless otherwise indicated. Additional terms may be defined elsewhere in the present disclosure.Definitions

[0051] As used herein, “comprising” is to be interpreted as specifying the presence of the stated features, integers, steps, or components as referred to, but does not preclude the presence or addition of one or more features, integers, steps, or components, or groups thereof. Moreover, each of the terms “by”, “comprising,” “comprises”, “comprised of,” “including,” “includes,” “included,” “involving,” “involves,” “involved,” and “such as” are used in their open, non-limiting sense and may be used interchangeably. Further, the term “comprising” is intended to include examples and aspects encompassed by the terms “consisting essentially of” and “consisting of.” Similarly, the term “consisting essentially of” is intended to include examples encompassed by the term “consisting of.

[0052] As used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a catalyst,” “a bio-oil,” or “an acid,” includes, but is not limited to, mixtures or combinations of two or more such catalysts, bio-oils, or acids, and the like.

[0053] It should be noted that ratios, concentrations, amounts, and other numerical data can be expressed herein in a range format. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Ranges can be expressed herein as from “about” one particular value, and / or to “about” another particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms a further aspect. For example, if the value “about 10” is disclosed, then “10” is also disclosed.

[0054] When a range is expressed, a further aspect includes from the one particular value and / or to the other particular value. For example, where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure, e.g. the phrase “x to y” includes the range from ‘x’ to ‘y’ as well as the range greater than ‘x’ and less than ‘y’. The range can also be expressed as an upper limit, e.g. 'about x, y, z, or less’ and should be interpreted to include the specific ranges of ‘about x’, ‘about y’, and ‘about z’ as well as the ranges of ‘less than x’, less than y’, and ‘less than z’. Likewise, the phrase ‘about x, y, z, or greater’ should be interpreted to include the specific ranges of ‘about x’, ‘about y’, and ‘about z’ as well as the ranges of ‘greater than x’, greater than y’, and ‘greater than z’. In addition, thephrase “about 'x’ to ‘y’”, where 'x’ and ‘y’ are numerical values, includes “about ‘x’ to about ‘y’”.

[0055] It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or subranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a numerical range of “about 0.1 % to 5%” should be interpreted to include not only the explicitly recited values of about 0.1 % to about 5%, but also include individual values (e.g., about 1%, about 2%, about 3%, and about 4%) and the sub-ranges (e.g., about 0.5% to about 1.1%; about 5% to about 2.4%; about 0.5% to about 3.2%, and about 0.5% to about 4.4%, and other possible sub-ranges) within the indicated range.

[0056] As used herein, the terms “about,” “approximate,” “at or about,” and “substantially” mean that the amount or value in question can be the exact value or a value that provides equivalent results or effects as recited in the claims or taught herein. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art such that equivalent results or effects are obtained. In some circumstances, the value that provides equivalent results or effects cannot be reasonably determined. In such cases, it is generally understood, as used herein, that “about” and “at or about” mean the nominal value indicated ±10% variation unless otherwise indicated or inferred. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about,” “approximate,” or “at or about” whether or not expressly stated to be such. It is understood that where “about,” “approximate,” or “at or about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.

[0057] As used herein, the term “effective amount” refers to an amount that is sufficient to achieve the desired modification of a physical property of the composition or material. For example, an “effective amount” of a catalyst refers to an amount that is sufficient to achieve the desired improvement in the property modulated by the formulation component, e.g. achieving the desired level of graphitization without foaming or swelling of the bio-oil. The specific level in terms of wt% in a composition required as an effective amount will depend upon a variety of factors including the amount and type of bio-oil, fixed carbon content of the bio-oil, particle size of the catalyst, and end use of the article made using the graphite produced by the disclosed process.

[0058] As used herein, the terms “optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0059] As used herein, “biomass” refers to organic matter used as a fuel or carbon source. Biomass feedstocks can include energy crops, agricultural crop residues, forestry residues, wood processing residues, municipal waste, wet waste, hardwoods, softwoods, algae, or any combination thereof. In an aspect, energy crops can be purpose grown herbaceous plants such as, for example, switchgrass, miscanthus, bamboo, sweet sorghum, tall fescue, wheat grass, and the like.

[0060] Unless otherwise specified, temperatures referred to herein are based on atmospheric pressure (i.e. one atmosphere).

[0061] Now having described the aspects of the present disclosure, in general, the following Examples describe some additional aspects of the present disclosure. While aspects of the present disclosure are described in connection with the following examples and the corresponding text and figures, there is no intent to limit aspects of the present disclosure to this description. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of the present disclosure.ASPECTS

[0062] The present disclosure can be described in accordance with the following numbered aspects, which should not be confused with the claims.

[0063] Aspect 1. A method for producing graphite from bio-oil, the method comprising:(a) performing a low-temperature pretreatment of the bio-oil to produce a pre-treated biooil;(b) admixing the pre-treated bio-oil with a catalyst; and(c) performing graphitization on the bio oil.

[0064] Aspect 2. The method of aspect 1 , wherein the pre-treated bio-oil comprises a dry powder.

[0065] Aspect 3. The method of aspect 1 or 2, wherein the low-temperature pretreatment is carried out at from about 150 °C to about 350 °C.

[0066] Aspect 4. The method of any one of aspects 1-3, wherein the low-temperature pretreatment is carried out for from about 1 min to about 12 h.

[0067] Aspect 5. The method of any one of aspects 1-4, wherein the low temperature pretreatment is carried out at 150 °C for 5 h.

[0068] Aspect 6. The method of any one of aspects 1-5, wherein the bio-oil comprises a pyrolysis product of biomass.

[0069] Aspect 7. The method of aspect 6, wherein the biomass comprises a hardwood, a softwood, algae, switchgrass or another energy crop, oil seeds, or any combination thereof.

[0070] Aspect 8. The method of any one of aspects 1-7, wherein the bio-oil has a 10-50% fixed carbon content.

[0071] Aspect 9. The method of any one of aspects 1-8, wherein the catalyst comprises iron metal, an iron salt, cobalt metal, a cobalt salt, nickel metal, a nickel salt, or any combination thereof.

[0072] Aspect 10. The method of aspect 9, wherein the iron metal comprises a powder.

[0073] Aspect 11. The method of any one of aspects 1-10, wherein the catalyst is loaded at 1-3* the fixed carbon content of the bio-oil.

[0074] Aspect 12. The method of any one of aspects 1-11 , wherein graphitization is carried out in a thermal furnace, induction furnace, vacuum furnace, microwave furnace, electric furnace, hybrid furnace, or any combination thereof.

[0075] Aspect 13. The method of any one of aspects 1-23, wherein graphitization is carried out at from about 1000 °C to about 2000 °C.

[0076] Aspect 14. The method of any one of aspects 1-13, wherein graphitization is carried out for from about 30 min to about 20 h.

[0077] Aspect 15. The method of any one of aspects 1-14, wherein graphitization is carried out under an inert atmosphere or in a vacuum.

[0078] Aspect 16. The method of aspect 15, wherein the inert atmosphere comprises N2, argon, or any combination thereof.

[0079] Aspect 17. The method of any one of aspects 1-16, wherein graphitization is carried out in an alumina crucible, a graphite crucible, or a quartz crucible.

[0080] Aspect 18. The method of any one of aspects 1-17, further comprising performing an acid washing step to remove the catalyst from the graphite.

[0081] Aspect 19. The method of aspect 18, wherein the acid washing step comprises refluxing the catalyst and graphite in a strong acid for from about 5 min to about 5 h.

[0082] Aspect 20. The method of aspect 18 or 19, further comprising performing filtration to remove a solid phase comprising the graphite from a liquid phase comprising the catalyst.

[0083] Aspect 21. The method of any one of aspects 18-20, wherein the acid washing step is carried out from 1 to 10 times.

[0084] Aspect 22. The method of any one of aspects 18-21 , wherein less than about 0.01 weight % of iron remains in the graphite following the acid washing step.

[0085] Aspect 23. The method of any one of aspects 18-22, further comprising ball-milling, cryomilling, grinding, or crushing the catalyst and graphite prior to performing the acid washing step.

[0086] Aspect 24. The method of any one of aspects 18-23, further comprising drying the graphite.

[0087] Aspect 25. The method of aspect 24, wherein the graphite is dried in an oven at 105 °C for 4 h.

[0088] Aspect 26. The method of any one of aspects 1-25, wherein the bio-oil expands from 0% to 10% by volume due to foaming during performance of the method.

[0089] Aspect 27. Graphite produced by the method of any one of aspects 1-26.

[0090] Aspect 28. An article or substance comprising the graphite of aspect 27.

[0091] Aspect 29. The article or substance of aspect 28, wherein the article or substance is an anode for a lithium ion battery, a refractory material for a high-temperature environment, a lubricant, a carbon additive for steel production, a shaped graphite product, a carbon fiber composite, or any combination thereof.EXAMPLES

[0092] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds, compositions, articles, devices and / or methods claimed herein are made and evaluated, and are intended to be purely exemplary of the disclosure and are not intended to limit the scope of what the inventors regard as theirdisclosure. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric.Example 1 : Materials and MethodsMaterials

[0093] Ensyn (Ontario, Canada) supplied the bio-oil used in this study, which was produced via pyrolysis of woody biomass (hardwoods). The appearance of the bio-oil was dark brown and the pH was measured to be 3.2 at room temperature. The reduced iron powder used as a catalyst was purchased from Sigma-Aldrich. The particle size of the iron powder (99.9% trace metals basis) was <10 pm. Iron (III) oxide powder (<5 pm, 96%) was also purchased from Sigma-Aldrich. The paraffin oil (mineral oil) was used as a defoamer in this study and was purchased from Sigma- Aldrich. Another defoamer used in this study (vegetable oil) was purchased from a local grocery store.Viscosity determination of bio-oil

[0094] Fresh and iron-loaded bio-oil viscosity was measured using a rotary viscometer at different temperatures.Catalytic graphitization

[0095] Catalytic graphitization was carried out in a tubular furnace at 1500 °C under nitrogen flow. The following ramping rate was maintained during the catalytic graphitization reaction: 25-600 °C (4 °C / min); 600-1500 °C (2 °C / min); 1500-600 °C (2 °C / min); 600-25 °C (4 °C / min). The entire process took ~24 h to complete.Acid washing for iron removal

[0096] After the graphitization, the graphite + iron solid mixture was milled for improved acid leaching. The mixture was refluxed under concentrated hydrochloric acid (37% w / w) for 3 h. For enhanced iron removal, 5-step reflux was followed for some samples.Characterization of graphite

[0097] X-ray diffraction (XRD) was applied as the preliminary screening tool to analyze the crystalline structure of graphite samples. Raman spectra were collected to support the XRD investigation. The purity of the graphite after acid washing was studied via XRF analysis.Pathwav I experimental

[0098] The fresh bio-oil was preheated in a tubular furnace at low temperatures (100-200 °C) for 1-12 h under an inert nitrogen atmosphere. These low-temperature pretreatment experiments converted the liquid bio-oil into an easily mixable (with catalyst) solid powder. Afterward, the iron powder (catalyst) was dry-mixed with the pretreated bio-oil powder. The iron loading was 2.5 times the fixed carbon (FC) content of the bio-oil used in this study. The uniform solid mixture was loaded inside an alumina crucible for catalytic graphitization. The catalytic graphitization experiments were carried out in the same tubular furnace at 1500 °C under a nitrogen atmosphere. The following ramping rates were maintained during the catalytic graphitization process: 25-600 °C (4 °C / min); 600-1500 °C (2 °C / min); 1500-600 °C (2 °C / min); 600-25 °C (4 °C / min). The entire process took approximately 24 h to complete. The catalytic graphitization process converted the bio-oil powder into a highly crystalline graphite thoroughly mixed residual iron catalyst. It was essential to completely remove the residual iron for making high-purity graphite. Washing the graphite + iron mixture with concentrated acid was applied as an effective strategy for iron removal. The graphite + iron solid mixture was milled in a mortar to enhance iron removal efficiency until the mixture turned into powder. The powdered mixture was then refluxed with concentrated hydrochloric acid (37% w / w) for 3 h. The reflux experiment was conducted 5 times with fresh acid to ensure nearly complete removal of iron from the graphite. After acid refluxing, vacuum filtration isolated the solid graphite powder from the liquid phase (iron chloride dissolved in hydrochloric acid). The residue left over the filter paper was graphite, which was dried in an oven at 105 °C for 4 h before further analysis.Example 2: Results and Discussion

[0099] The main goal of this study was to critically explore the effects of various issues that might pose technical challenges to scaling up the iron-catalyzed conversion of bio-oil into graphite for LIB applications. During commercial production, the handling cost for the sticky bio-oil feedstock will be determined by its viscosity, which is a function of temperature. As understood from FIG. 1 , the viscosity of raw bio-oil decreased continuously with temperatures up to 100 °C. When the temperature reached 100 °C, the bio-oil started boiling, so the experiments were not continued beyond 100 °C. When bio-oil was mixed with reduced iron powder, the viscosity showed approximately a 6-fold increase. The effect of temperature on the viscosity followed a similar trend to the fresh bio-oil. However, the major issue observed was the foaming of bio-oil as soon as iron was added and the intensity of foaming increased almost exponentially with the temperature rise.Due to extensive foam formation, it was not possible to measure the viscosity value correctly beyond 60 °C. The inset images (front and top views) in FIG. 1 clearly show the foaming issue when iron was mixed. An even better visualization of the foaming issue is understood from FIGs. 2A-2I, which demonstrates several sequential steps during foam formation. The foam formation at a larger scale will be even more challenging. Therefore, these experiments suggest that the process cannot be scaled up unless the foaming is strategically controlled. The foaming is considered to be the potential barrier to the commercialization of the technology. The pH of the bio-oil was measured to be 3.2, and oxidation of the reduced metallic iron powder is believed to be responsible for foaming. The organic acids present in bio-oil react with iron, releasing hydrogen gas, which is primarily responsible for foaming. To address foaming, five (5) different pathways have been identified and tested in this study, which are detailed in the following sections.Addressing swelling via low-temperature pretreatment of bio-oil (Pathway 1)

[0100] Pretreatment of bio-oil at 200 °C: Initially, the fresh bio-oil was pretreated at 200 °C for 1 h (FIG. 3A). After 1 h pretreatment, the bio-oil (FIG. 3B) was converted into a perforated solid (FIG. 3C). The solidified bio-oil was easily scrapped off the crucible. FIG. 3D shows the bottom of the crucible after product removal (the product was easily removed). A side view of the pretreated bio-oil is shown in FIG. 3E and the powdered bio-oil is demonstrated in FIG. 3F. The degree of swelling in this experiment was comparatively lower than the delayed coking experiments described below in Alternate Pathway 5.

[0101] Pretreatment of bio-oil at 100 °C: Inspired by this experiment, the pretreatment temperature was lowered to 100 °C. This low-temperature experiment aimed to test whether a similar powder can be made at 100 °C, which could cause minimum swelling. However, 1 h pretreatment at 100 °C was not able to completely dry the bio-oil (FIG. 4A). Therefore, the pretreatment time was increased to 12 h and interestingly, bio-oil was only partially dried with most of the fractions remaining sticky (FIG. 4B). Therefore, no bio-oil powder was achieved via 100 °C pretreatment. This experimental observation encouraged us to run further pretreatment experiments at 150 °C at different times to see if the bio-oil can be converted into powder similar to 200 °C 1 h pretreatment.

[0102] Pretreatment of bio-oil at 150 °C: A pretreatment experiment series was conducted at 150 °C for eight (8) different time periods (1 , 2, 3, 4, 5, 6, 9, 12 h). As understood from FIG. 5A, the bio-oil was partially dried when preheated for only 1 h. The yellow arrow in FIG. 5A points to the bottom of the crucible, showing a thick, sticky layer of bio-oil (not properly dried). The yellow arrowin FIG. 5B (2 h) indicates that a sticky layer remained, however in a lesser content than 1 h pretreatment (FIG. 5A). The drying of the bio-oil was even better when the pretreatment time was 3 h (FIG. 5C); however, a thin sticky layer still partially existed near the bottom of the crucible.

[0103] The extent of drying i.e., the success of pretreatment, was examined by observing no presence of a sticky bio-oil layer and ease of product removal from the crucible. The extent of drying improved further when the pretreatment temperature was increased to 4 h (FIG. 6A); however, it was still a little difficult to scrap off the product from the crucible completely. At 5 h pretreatment, the bio-oil completely dried and was most easily scrapped off the crucible (FIG. 6B) compared to the low pretreatment time (1-4 h). The yellow arrow in FIG. 6B shows the clean bottom of the crucible after product removal, confirming the success of pretreatment. Based on the above observation, 150 °C 5 h was selected as the optimum pretreatment condition to make bio-oil powder. The visual appearance and the ease of product removal were identical when the pretreatment time was extended beyond 5 h (FIG. 6C and FIGs. 7A-7B). It is worth noting that no significant swelling of bio-oil was observed at 150 °C pretreatment. In other words, it can be stated that the degree of swelling was minimal when the bio-oil was heated to 150 °C (5 h) compared to 200-500 °C heat treatment (1 h).

[0104] The bio-oil powder from the optimized condition (150 °C for 5 h) was selected for catalytic graphitization and for a fair comparison; the bio-oil powder obtained at 200 °C (1 h) was also catalytically graphitized at 1500 °C (FIGs. 8A-8H).

[0105] The appearance of the graphite made from two different temperatures (before acid washing) are demonstrated in FIG. 8E and FIG. 8H. The appearance of the final products (after iron removal) resembled commercial synthetic graphite. The XRD patterns of the two graphite samples were very sharp and similar to commercial graphite. However, the XRD pattern of the graphite from 150 °C (5 h) pretreatment (FIG. 9A) was found to be relatively better than 200 °C (1 h) pretreatment (FIG. 9C).

[0106] To further analyze the crystalline quality of the graphite made from 150 °C pretreatment (5 h), Raman spectra were recorded and the results are shown in FIG. 10. To get a representative idea of the graphite sample, the Raman spectra were collected at 10 different spots and interestingly there was less variation in the spectra collected at different positions. Overall, the G- band (~1578 cm-1) intensity was comparatively manifold sharper than the D-band (~1347 cm-1) intensity. Here, the G-band refers to the graphitic / ordered region, while the D-band refers to the amorphous / disordered region in the produced graphite.

[0107] Based on the XRD and Raman analyses, it can be stated that 150 °C pretreatment of biooil for 5 h is the optimized condition for iron-catalyzed graphite production.Acid reflux experiments

[0108] The purpose of acid washing the graphite + iron solid mixture was to remove the residual iron from the graphite completely. The graphite must be completely free from iron for application as an anode for lithium-ion batteries. Iron is highly undesired in electrodes, and a trace amount of iron can negatively affect the chemical reactions inside the battery during charging / discharging. The acid-washing experiments were conducted with concentrated hydrochloric acid (37% w / w) for 3 h under reflux (FIG. 11 A).

[0109] During the 3 h refluxing, the solid iron mixed with graphite was converted into iron chloride, which was soluble in the acid solution (FIG. 11B). A simple filtration (FIG. 11C) helped isolate the solid graphite from the liquid phase (iron chloride). The color of the iron chloride solution is visible in FIG. 11C. However, a single-step acid reflux was insufficient to remove the iron from the graphite completely. Therefore, the acid refluxing experiments were continued for 5 steps with fresh concentrated hydrochloric acid. The residue (graphite) from the first filtration was mixed with fresh acid and then refluxed for 3 h again and this process was continued up to 5 steps. FIG. 12 shows the gradual disappearance of the iron chloride in the filtrate. Interestingly, the filtrate was colorless after the last step (step 5) filtration. The XRF analysis was conducted with the graphite sample after the fifth step acid washing to understand the carbon purity and extent of residual inorganics (Table 1). As understood from the XRF investigation, the carbon content of the graphite was very high (99.935%) with a trace amount of residual iron (0.007%). The residual inorganics (-0.065%) should have negligible effect on the electrochemical performance of graphite. The XRD pattern of the graphite after 5-step acid refluxing is shown in FIG. 14B. The XRD pattern was sharp, indicating the graphite is ready to process further for applications. However, a closer inspection of this XRD pattern compared to FIG. 14A indicates that the graphite crystalline structure has been affected by acid washing. To conclude, this study successfully prepared high- purity graphite for battery applications.Catalvtic graphite production via delayed coking

[0110] It was understood that the Pathway 1 is highly successful in producing good quality graphite from bio-oil, avoiding foaming and swelling issues. Afterwards, 5-step acid refluxing was proved to be successful in producing high-purity graphite. These successful events made it promising to scale up the iron-catalyzed graphitization using bio-oil as a feedstock. For potential scale-up, it is essential to consider the weight loss of bio-oil during the process. The bio-oil used in this study had ~19% fixed carbon (FC), which means bio-oil lost a significant quantity of volatiles during the high-temperature thermal events. Most of these volatiles are pyrolysis products, not combustion products, as the whole process (pretreatment, delayed coking, catalytic graphitization) was conducted under an inert nitrogen atmosphere. The pyrolysis vapors could be captured and upgraded to transportation fuels such as sustainable aviation fuels (SAF). It is also understood that bio-oil loses most of these volatiles around 500 °C. Therefore, to scale up the process described in this study, it will be wise to add a delayed coking (DC) step after the pretreatment (PT) and before the catalytic graphitization (CG) unit. All the pyrolysis vapors could then be collected from the PT and DC units to improve the process economics. Delayed coking will certainly help capture most of the volatiles; however, it is necessary to test whether a delayed coking step affects the graphite crystalline structure. To address this issue, further graphitization experiments were designed and added delayed coking step (400-600 °C) between the pretreatment and catalytic graphitization steps. The experimental designs and the corresponding images are shown in FIGs. 13A-13C.

[0111] As understood from FIGs. 13A-13C, the visual appearance of all the graphite samples seemed nearly identical, irrespective of the delayed coking temperatures. It is also worth noting that the graphite appearance did not change compared to the process without a delayed coking step (FIG. 8A). All these samples after catalytic graphitization were subjected to 5-step acid refluxing and the XRD patterns of the final graphite samples were collected (FIGs. 14A-14C). It is understood that the crystallinity of the three graphite samples is nearly identical which means that for high purity and good quality graphite production, the delayed coking temperature (400- 600 °C) do not alter the graphite crystalline structure. Therefore, the concern for volatile capturing during commercial-scale graphite production using iron catalyst is resolved.Minimization of foaming using defoamers (Alternate Pathway 2)

[0112] Considering the current industrial practice, two different types of defoamers (paraffin oil and vegetable oil) were added to the fresh bio-oil separately before iron mixing (FIG. 15A).Interestingly, both defoamers failed to minimize the foam formation. The phenomenon of foaming experienced in this study is not a physical process (like surfactants) rather, it occurred due to the instantaneous chemical reactions (oxidation) of iron with bio-oil components. This is predicted to be the reason the widely used defoamers could not prevent foaming in iron-mixed bio-oil.Minimization of foaming using iron oxide (Alternate Pathway 3)

[0113] Iron oxidation was predicted to be the cause of foam formation. Highly oxidized iron oxide (Fe2O3) was used as a catalyst instead of reduced iron (Fe) to verify this hypothesis. Interestingly, no trace of foaming was observed when iron oxide was mixed into the same fresh bio-oil. More importantly, no foaming was observed even when the mixture was heated (FIG. 15B). Based on this experiment, it can be confidently stated that the oxidation of iron by the acidic compounds present in bio-oil is the cause for foaming in bio-oil. To uncover the catalytic performance of iron oxide, a graphitization experiment was conducted and the XRD data is shown in FIG. 16B. The XRD pattern is not sharp. The pattern has several additional peaks other than the characteristic peaks of graphite. For a better understanding, XRD patterns of the commercial iron and iron oxide catalyst (used in this study) were also recorded (FIG. 16A).

[0114] The summary of the discussion is that pathway 3 is better than pathway 2 regarding foam control; however, considering the graphite crystal quality, pathway 3 cannot be accepted. Hence, searching for other viable alternative approaches to control foam and make good graphite is necessary.Minimization of foam by controlling pH of bio-oil (Alternate Pathway 4)

[0115] Based on pathways 2 and 3, it is clear that the high acidity (pH 3.2) of raw bio-oil is the cause of foam formation. Therefore, an attempt was made to minimize foam formation by controlling the acidity of bio-oil before iron addition. To make a better understanding of the success of pathway 4, the pH of the fresh bio-oil was adjusted to neutral (pH 7.0) and highly alkaline (pH 11.0) using sodium hydroxide (NaOH) solution. After pH adjustment, iron was added to both of the bio-oil and heated up to 100 °C. Interestingly, no foaming was observed while heating the bio-oil and iron mixture (pH 7.0) until the temperature reached 80 °C (FIG. 17). After the temperature exceeded 80 °C, foam formation started. The other sample (pH 11.0) did not show foam formation even if the temperature exceeded 80 °C (FIG. 18). These two experiments further support that the low acidity and iron oxidation cause foaming in bio-oil. However, no attempt was made to make graphite from these two samples (pH 7.0, 11 .0). Making graphite froma highly alkaline (pH 11.0) bio-oil might not be economically attractive considering the possible challenge in handling the bio-oil and corrosion.Avoiding foam formation in bio-oil via delayed coking (Alternate Pathway 5)

[0116] To potentially avoid foaming in bio-oil, the raw bio-oil (without pH adjustment) was coked for 1 h under a nitrogen atmosphere at three different temperatures (300-500 °C). This delayed coking experiment aimed to make coke from bio-oil, which was later mixed with iron powder. This approach avoided the foaming issue as the bio-oil has been converted into a solid coke form, losing all the water and some volatiles. The outcome of these three experiments in terms of the physical appearance of coke and X-ray diffractograms (coke-derived graphite) was interesting (FIG. 19). For all three coke samples, significant swelling (volume expansion after delayed coking) was observed. Approximately 10 times volume expansion was observed.

[0117] A magnified photograph of the coke formed at 500 °C (FIG. 20A) shows that the whole crucible was covered due to bio-oil swelling during the delayed coking process. This significant volume expansion might pose technical challenges to designing a reactor for delayed coking.

[0118] The second important observation from these experiments was the difference in physical properties of the swelled coke. The delayed coking was initially predicted to convert the bio-oil into powdered coke. However, no powder was observed. The coke formed at 500 °C was difficult to mill in a mortar because the delayed coking process converted the bio-oil into a flaky carbon form floating in the air. Due to the flaky and floating nature, it was not easy to mill this coke. The coke was less brittle, having low density. Due to the milling difficulty, the catalyst (iron) was poorly mixed with the coke. As a result, the crystalline quality of the graphite was also poor, showing a broad XRD pattern. Additionally, the poor mixing resulted in the formation of spherical iron balls (agglomeration of unreacted iron) during graphitization (FIG. 20B). Three (3) h acid reflux was not even enough to dissolve these iron balls.

[0119] With the successive decrease in delayed coking temperature (400-300 °C), the milling became progressively easier as the formed coke was more brittle, less flaky, and less floating (high density). As a result, iron mixing with coke was progressively improved, which is reflected in the XRD patterns of graphite formed at 400 and 300 °C, respectively. The characteristic (002) graphite peak became sharper and taller (intense) with decreased delayed coking temperatures. However, the XRD pattern of graphite formed via delayed coking at 300 °C was still inferior to commercial graphite and the coke was highly swelled. Based on the observation, it was decided that pathway 5 is also unacceptable, and was still necessary to search for alternative pathwaysfor graphite production. However, this pathway successfully avoided the foaming issue. Pathway 5 also indicated that low-temperature pretreatment experiments could be worth exploring to minimize swelling and form better-quality crystalline graphite, which were explored in Pathway 1.Conclusion

[0120] Finally, it can also be concluded that out of the five pathways critically explored in this study, Pathway 1 stood out regarding foaming, swelling minimization, and graphite crystal quality. This low-temperature pretreatment could provide an additional advantage for commercial production. From earlier experiments (not shown here), it was found that aged bio-oil makes poorquality graphite. The mechanism of bio-oil aging was thoroughly studied previously by the group and was found to be largely controlled by the formation of phenol-formaldehyde (pyrolytic lignin condensation) resins. This polymerization reaction makes bio-oil more sticky and viscous than the raw bio-oil. Highly cross-linked resin structures negatively affect the process of catalytic graphitization. The organic acids in the bio-oil catalyze the phenol-formaldehyde resin formation. Pretreatment will remove these acids, and therefore, it is believed that PF resin formation will be dramatically reduced when bio-oil is converted into dry powder via pretreatment. It seems intelligent to store dried (pretreated) bio-oil powder for a long time instead of storing raw / fresh biooil. In this way, storing the bio-oil powder for longer without worrying about the aging effect on graphite crystal quality will be possible. As the bio-oil is converted into powder, the challenge of handling viscous bio-oil is also resolved. To conclude, the pretreatment pathway 1 successfully avoids the foaming, swelling, viscosity, and aging issues associated with bio-oil without affecting the graphite crystal quality. This is a remarkable achievement for transforming bio-oil into high- value graphite for battery applications not realized earlier. Therefore, the low-temperature pretreatment pathway holds tremendous potential for graphite production at a large scale.

[0121] It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the abovedescribed embodiment(s) without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.REFERENCES Sustainable Energy Reviews, 2020, 123:109763. ioenergy, 2015, 81:415-423. 2-415. ble Chem. Eng., 2018, 6:13199-13207. pplication Publication WO 2022120318. ent 9,840,671. ent 10,421,915. 23, Chinese Patent Publication CN 114989844.tent Application Publication 20190225497. nt Application Publication 20230113236. t Application Publication WO2022225405. tent 9,505,991 . atent Application Publication W02016130026. Chem Eng 2:2011-2018. doi:10.1021 / sc500223e. 23:. doi:10.1590 / 1980-5373-MR-2019-0686.

Claims

CLAIMSWhat is claimed is:

1. A method for producing graphite from bio-oil, the method comprising:(a) performing a low-temperature pretreatment of the bio-oil to produce a pre-treated bio-oil;(b) admixing the pre-treated bio-oil with a catalyst; and(c) performing graphitization on the bio oil.

2. The method of claim 1 , wherein the pre-treated bio-oil comprises a dry powder.

3. The method of claim 1 , wherein the low-temperature pretreatment is carried out at from about 150 °C to about 350 °C.

4. The method of claim 1 , wherein the low-temperature pretreatment is carried out for from about 1 min to about 12 h.

5. The method of claim 1 , wherein the low temperature pretreatment is carried out at 150 °C for 5 h.

6. The method of claim 1 , wherein the bio-oil comprises a pyrolysis product of biomass.

7. The method of claim 6, wherein the biomass comprises a hardwood, a softwood, algae, switchgrass or another energy crop, oil seeds, or any combination thereof.

8. The method of claim 1 , wherein the bio-oil has a 10-50% fixed carbon content.

9. The method of claim 1 , wherein the catalyst comprises iron metal, an iron salt, cobalt metal, a cobalt salt, nickel metal, a nickel salt, or any combination thereof.

10. The method of claim 9, wherein the iron metal comprises a powder.

11. The method of claim 1 , wherein the catalyst is loaded at 1-3* the fixed carbon content of the bio-oil.

12. The method of claim 1 , wherein graphitization is carried out in a thermal furnace, induction furnace, vacuum furnace, microwave furnace, electric furnace, hybrid furnace, or any combination thereof.

13. The method of claim 1 , wherein graphitization is carried out at from about 1000 °C to about 2000 °C.

14. The method of claim 1 , wherein graphitization is carried out for from about 30 min to about15. The method of claim 1 , wherein graphitization is carried out under an inert atmosphere or in a vacuum.

16. The method of claim 15, wherein the inert atmosphere comprises N2, argon, or any combination thereof.

17. The method of claim 1 , wherein graphitization is carried out in an alumina crucible, a graphite crucible, or a quartz crucible.

18. The method of claim 1 , further comprising performing an acid washing step to remove the catalyst from the graphite.

19. The method of claim 18, wherein the acid washing step comprises refluxing the catalyst and graphite in a strong acid for from about 5 min to about 5 h.

20. The method of claim 18, further comprising performing filtration to remove a solid phase comprising the graphite from a liquid phase comprising the catalyst.21 . The method of claim 18, wherein the acid washing step is carried out from 1 to 10 times.

22. The method of claim 18, wherein less than about 0.01 weight % of iron remains in the graphite following the acid washing step.

23. The method of claim 18, further comprising ball-milling, cryo-milling, grinding, or crushing the catalyst and graphite prior to performing the acid washing step.

24. The method of claim 18, further comprising drying the graphite.

25. The method of claim 24, wherein the graphite is dried in an oven at 105 °C for 4 h.

26. The method of claim 1 , wherein the bio-oil expands from 0% to 10% by volume due to foaming during performance of the method.

27. Graphite produced by the method of any one of claims 1-26.

28. An article or substance comprising the graphite of claim 27.

29. The article or substance of claim 28, wherein the article or substance is an anode for a lithium ion battery, a refractory material for a high-temperature environment, a lubricant, a carbon additive for steel production, a shaped graphite product, a carbon fiber composite, or any combination thereof.

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