Butadiene production using junked tires

Abstract

A method comprising (a) providing a waste tire feedstock; (b) gasifying the waste tire feedstock to produce a gas stream, wherein the gas stream comprises carbon monoxide, hydrogen and carbon dioxide; (c) thermochemically converting at least a portion of the carbon monoxide, hydrogen and carbon dioxide within the gas stream to produce a first product stream; (d) converting at least a portion of the first product stream to a second product stream, wherein the second product stream comprises acetaldehyde and hydrogen; (e) directing a portion of the hydrogen within the second product stream to the step of thermochemically converting at least a portion of carbon monoxide, hydrogen and carbon dioxide within the gas stream; and (f) converting at least a portion of the acetaldehyde to butadiene monomers.

Description

TECHNICAL FIELD

[0001] Embodiments of the present invention are directed to a method for converting scrap tires into butadiene monomer. BACKGROUND

[0002] Butadiene monomer is polymerized into polybutadiene and butadiene copolymers such as poly(styrene-co-butadiene), poly(isoprene-co-butadiene), and poly(styrene-co-isoprene-co-butadiene). Although these polymers have many uses, they are primarily used in the manufacture of tires. On the other hand, scrap tires are not easily recyclable and have been landfilled or incinerated for fuel value. Methods have been proposed to thermally decompose tires into syngas and then convert the syngas into useful materials. These methods lack industrial applicability and thus there is a need for improvements to this general approach. SUMMARY

[0003] One or more embodiments of the present invention provide a method comprising (a) providing a scrap tire feedstock; (b) gasifying the scrap tire feedstock to produce a gas stream, wherein the gas stream comprises carbon monoxide, hydrogen, and carbon dioxide; (c) thermochemically converting at least a portion of the carbon monoxide, hydrogen, and carbon dioxide within the gas stream to produce a first product stream; (d) converting at least a portion of the first product stream into a second product stream, wherein the second product stream comprises acetaldehyde and hydrogen; (e) directing a portion of the hydrogen within the second product stream to the step of thermochemically converting at least a portion of the carbon monoxide, hydrogen, and carbon dioxide within the gas stream; and (f) converting at least a portion of the acetaldehyde into butadiene monomer.

[0004] Other embodiments of the present invention provide a method comprising (a) providing a scrap tire feedstock; (b) optionally providing a co-feed comprising carbon-containing material other than the scrap tire feedstock; (c) gasifying the scrap tire feedstock and optional co-feed to produce a gas stream, wherein the gas stream comprises carbon monoxide, hydrogen, and carbon dioxide; (d) introducing the gas stream into a thermochemical reactor, wherein the carbon monoxide, hydrogen, and carbon dioxide are converted into a first product stream; (e) converting the first product stream into a second product stream, wherein the second product stream comprises acetaldehyde and hydrogen; (f) separating the hydrogen from the second product stream, thereby forming a hydrogen stream; and (g) converting the acetaldehyde into a final product stream, wherein the final product stream comprises butadiene.

[0005] Still other embodiments of the present invention provide a vulcanizable composition of matter comprising a polybutadiene or butadiene copolymer prepared by the method as provided above.

[0006] Yet other embodiments of the present invention provide a tire component prepared from the vulcanizable composition as provided above.

[0007] Other embodiments of the present invention provide tires manufactured using tire components as described above. Attached Figure Description

[0008] This figure is a schematic diagram of a system used to implement embodiments of the present invention. Detailed Implementation

[0009] Embodiments of the present invention are based, at least in part, on discoveries of methods for producing butadiene and optionally acetaldehyde from waste tires. According to one or more embodiments, waste tires are thermally decomposed to form a gas stream, which is then converted into ethanol by a thermochemical process. The ethanol is then converted into acetaldehyde, a reaction producing a hydrogen byproduct stream for upstream production of ethanol. Acetaldehyde can be purified and / or converted into butadiene monomer by reacting it with ethanol. It has been found that the overall process efficiency and economy depend on the amount of hydrogen available during ethanol production. Therefore, the present invention provides downstream hydrogen production in the absence of carbon byproducts, thereby providing overall carbon efficiency. This is particularly advantageous in the present invention because waste tires are the primary feedstock and contain a higher carbon-to-hydrogen molar ratio than other feedstocks such as biomass. In one or more embodiments, butadiene is polymerized to form polybutadiene or butadiene copolymers, which are used to prepare vulcanizable compositions manufactured into tire parts.

[0010] Process System and Overview

[0011] Embodiments of the present invention can be described with reference to the accompanying drawings, which depict a system 20 for converting waste tires into butadiene and optionally acetaldehyde. System 20 includes a pyrolysis unit 31, downstream of which a reactor 51, which may be referred to as a thermochemical reactor 51, is connected in series. The pyrolysis unit 31 is directly or indirectly fluidly connected to the reactor 51 via a gas flow pipe 33. Downstream of the reactor 51, an acetaldehyde synthesis unit 71 (also referred to as an acetaldehyde production unit 71) is directly or indirectly fluidly connected to the reactor 51 via an ethanol product pipe 53. A butadiene synthesis unit 91 (also referred to as a butadiene production unit 91) is downstream of the acetaldehyde synthesis unit 71 and is directly or indirectly fluidly connected to the acetaldehyde synthesis unit 71 via an acetaldehyde product pipe 73. The acetaldehyde synthesis unit 71 is also directly or indirectly fluidly connected to a hydrogen byproduct pipe 75, which is fluidly connected to the reactor 51.

[0012] According to an embodiment of the invention, the pyrolysis unit 31 is adapted to receive tire raw materials and optional co-feeds, and to heat-treat them to produce a gas stream comprising carbon monoxide (CO), hydrogen (H2), and optionally carbon dioxide (CO2). The reactor 51 includes one or more catalysts adapted to convert carbon monoxide, hydrogen, and optionally carbon dioxide into ethanol in the presence of heat. Ethanol is transferred to the acetaldehyde synthesis unit 71, where it is converted to acetaldehyde and a hydrogen byproduct is produced. Acetaldehyde can be transferred to the butadiene synthesis unit 91, where it is converted to butadiene. The hydrogen byproduct from the acetaldehyde synthesis unit 71 can be transferred to the reactor 51 via conduit 75 or via conduit 99, which is in direct or indirect fluid communication with the butadiene synthesis unit 91.

[0013] In one or more embodiments, the gas stream exiting the pyrolysis unit 31 is treated before being introduced into the reactor 51. For example, and as shown, the gaseous product stream may be cooled within a heat exchanger 41. In one or more embodiments, the heat exchanger may receive cooling water from one or more downstream processes or units, such as distillation column 61, which will be described in more detail below. Additionally, the gas stream may be treated before being introduced into the reactor 51 to remove one or more components. For example, and as shown, the gas stream may be treated with a scrubber 45.

[0014] In any case, carbon monoxide, hydrogen, and optionally carbon dioxide are converted into ethanol within reactor 51. As shown, reactor 51 may include external inputs of hydrogen and water. In one or more embodiments, the ethanol produced in reactor 51 is transferred from reactor 51 via pipe 53 within the crude product stream. In one or more embodiments, the crude ethanol product stream may be filtered as it exits reactor 51 or downstream thereof by employing, for example, a filter unit 55.

[0015] Before introducing the crude ethanol product stream into the acetaldehyde synthesis unit 71, the crude ethanol stream can be concentrated or otherwise purified. For example, ethanol can be separated from the crude ethanol product stream within a distillation unit 61, wherein the overhead product (i.e., distillate) including concentrated ethanol is directed via pipe 65 to the acetaldehyde synthesis unit 71 and / or via pipe 67 to the butadiene production unit 91, and the bottom product from the distillation can be recycled back to, for example, reactor 51 via an aqueous bottom product pipe 63.

[0016] Ethanol is converted into acetaldehyde in acetaldehyde production unit 71 (which may be referred to as acetaldehyde synthesis unit 71 or acetaldehyde reactor 71). Acetaldehyde synthesis produces a crude product stream containing acetaldehyde and hydrogen as byproducts. In one or more embodiments, the crude acetaldehyde product stream may be transferred directly or indirectly to butadiene synthesis unit 91 via conduit 73. In other embodiments, the crude acetaldehyde is transferred directly or indirectly to separation unit 81 (e.g., a distillation column, which may also be referred to as purification unit 81) via conduit 79, where the byproduct hydrogen is separated from the acetaldehyde. The byproduct hydrogen may be directed directly or indirectly back to reactor 51 via conduit 75. The acetaldehyde stream from separation unit 81 may be directed to a market source via conduit 83 or to butadiene reactor 91 via conduit 85.

[0017] Acetaldehyde is converted into butadiene within synthesis unit 91 to produce a crude butadiene product stream, which can exit synthesis unit 91 directly or indirectly via conduit 93. In one or more embodiments, butadiene is separated from the crude butadiene stream in distillation column 95 to produce a purified butadiene stream, which can be removed from the system via conduit 97. In those embodiments in which a crude acetaldehyde stream including hydrogen is fed into butadiene production unit 91, purification unit 95 (e.g., distillation unit 95) will produce a byproduct hydrogen stream, which can be guided back to reactor 51 via conduit 99.

[0018] Additionally, as shown in the figure, the acetaldehyde synthesis unit 71 and / or the butadiene production unit 91 can be supplemented with an external source of ethanol via pipe 77. This external source can come from, for example, the fermentation of crops (such as corn). In another embodiment, this external source can come from cellulosic ethanol produced from grass, wood, algae, or other plants.

[0019] Although the systems and methods of the present invention are shown as a single integrated system, wherein each unit is in direct or indirect fluid communication with other units upstream and / or downstream, those skilled in the art will be able to readily conceive of less directly connected but still integrated systems and methods. For example, a system may exist in which a vaporization unit 31 and reactor 51 are located at a first facility, and an acetaldehyde production unit 71 and butadiene production unit 91 are located at a second facility. The first facility (e.g., vaporization unit 31 and reactor 51) may be indirectly connected to the second facility (e.g., acetaldehyde reactor 71 and butadiene reactor 91) via, for example, a pipeline that can transport ethanol from the first facility to the second facility. Alternatively, ethanol may be transported from the first facility to the second facility via other forms of transport, including trucks or railcars. Similarly, hydrogen produced at the acetaldehyde reactor 71 may be transferred back to reactor 51 via pipeline, tanker truck, truck, or by exchange with a local hydrogen source (i.e., from the second facility to the first facility). For the purposes of this specification, and unless otherwise specifically stated, indirect fluid communication will be understood to include these connections between the various units.

[0020] Properties of tires and carbon-containing raw materials

[0021] In one or more embodiments, the feedstock to the pyrolysis unit 31 includes tire raw material from waste tires, which may also be referred to as waste tire raw material or simply tire raw material. As understood by those skilled in the art, tire raw material may include vulcanized polymers, carbon black fillers, silica, resins, oils, fiber yarns, and metals. Vulcanized polymers may include sulfur crosslinking residues of natural rubber and / or one or more synthetic elastomers, including diene polymers and copolymers. In one or more embodiments, waste tire raw material may include shredded or otherwise ground tires, wherein one or more components of the waste tire are removed. For example, tire raw material can be treated by methods known in the art (e.g., magnetic separation) to remove metals. Alternatively or in combination with the foregoing, waste tire raw material may optionally be treated to remove fiber reinforcements such as fiber yarns or cords, which those skilled in the art understand are commonly found with vulcanized rubber in many tire components. Alternatively or in combination with the foregoing, waste tire raw material may optionally be treated to remove inorganic materials such as silica fillers, which those skilled in the art recognize as frequently found in waste tire components. In any case, tire raw materials can be processed into tire fragments, tire chips, or ground or granular rubber and fed into the pyrolysis unit.

[0022] In one or more embodiments, the tire feedstock is characterized by a relatively low amount of metal, which may be due to pretreatment of the tire feedstock to remove at least a portion of the metals typically present in waste tires. In one or more embodiments, after pretreatment of the waste tires to remove metals, the tire feedstock may include less than 25% by weight, less than 15% by weight in other embodiments, and less than 1% by weight of metal, based on the total weight of the feedstock fed to pyrolysis according to the invention.

[0023] In one or more embodiments, the tire raw material is characterized by a relatively low amount of fiber yarn or plugging cord, which may be due to pretreatment of the tire raw material to remove at least a portion of the yarn or plugging cord typically present in waste tires. In one or more embodiments, after pretreatment, based on the total weight of the raw material fed to pyrolysis according to the invention, the tire raw material contains less than 5% by weight in other embodiments, less than 4% by weight in other embodiments, less than 3% by weight in other embodiments, less than 2% by weight in other embodiments, and less than 3% by weight in other embodiments of fiber yarn or plugging cord.

[0024] In one or more embodiments, the tire raw material is characterized by a relatively low amount of inorganic filler (e.g., silica), which may be due to pretreatment of the tire raw material to remove at least a portion of the inorganic filler typically present in waste tires. In one or more embodiments, after pretreatment, based on the total weight of the raw material fed to pyrolysis according to the invention, the tire raw material contains less than 30% by weight, less than 20% by weight in other embodiments, less than 10% by weight in other embodiments, and less than 5% by weight of inorganic filler.

[0025] In one or more embodiments, waste tire material includes tire residues from passenger tires. In other embodiments, waste tire material includes tire residues from non-passenger tires, such as, but not limited to, truck and bus tires, off-road vehicle tires, agricultural tires, and racing tires.

[0026] In one or more embodiments, waste tires are mechanically processed (e.g., ground or shredded) to form ground or shredded material (i.e., the raw material is ground or shredded). This ground or shredded material (i.e., the raw material) may also be referred to as debris, characterized by a favorable compaction density. For example, the raw material may have a density greater than 640 kg / m³. 3 In other implementation schemes, it is greater than 720 kg / m 3 And in other implementations, it is greater than 770 kg / m 3 The compaction density, wherein the density is determined by ASTM D 698-07.

[0027] In one or more embodiments, the feedstock provided to the pyrolysis unit includes waste tires and optional supplementary feedstock. In one or more embodiments, the supplementary feedstock (also referred to as co-feed) comprises carbonaceous materials other than tire feedstock. Carbonaceous materials refer to any carbonaceous material in a solid, liquid, gaseous, or plasma state. Non-limiting examples of carbon-containing materials include carbon-containing liquid products, industrial liquid recyclables, municipal solid waste (MSW or MSW) (including municipal solid waste with high biomass content and / or reduced recyclable material content), municipal waste, agricultural materials, forestry materials, wood waste, building materials, nutritional materials, industrial waste, fermentation waste, petrochemical co-products, alcohol production co-products, coal, plastics, waste plastics, coke oven tar, lignin, black liquor, polymers, waste polymers, polyethylene terephthalate (PETA), polystyrene (PS), sewage sludge, animal waste, crop residues, energy crops, forest processing residues, wood processing residues, livestock waste, poultry waste, food processing residues, ethanol co-products, waste grains, waste microorganisms, municipal waste, construction waste, demolition waste, biomedical waste, hazardous waste, or combinations thereof. In one or more embodiments, the carbon-containing material includes biomass. In one or more embodiments, the biomass is bagasse, including but not limited to bagasse from sugarcane, sorghum, and guayule plants. In one or more embodiments, the raw materials comprise a blend of waste tires and municipal solid waste, wherein the municipal solid waste may include biomass. In other embodiments, the raw materials comprise waste tires and municipal solid waste that is substantially free of biomass (i.e., substantially petroleum-based solid municipal waste). In other embodiments, the raw materials comprise waste tires and biomass. In still other embodiments, the raw materials comprise waste tires and municipal solid waste from which most recyclable plastics have been removed (i.e., substantially free of recyclable plastics). In its sub-implementation, recyclable glass and metal are also substantially removed from the municipal solid waste component.

[0028] In another embodiment, *Gynostemma pentaphyllum* bagasse is produced as a result of a method for extracting rubber and resin from *Gynostemma pentaphyllum* plants, as described in U.S. Publication No. 2022 / 0356273 A1, which is incorporated herein by reference. A method for desolventizing *Gynostemma pentaphyllum* bagasse is described in U.S. Patent No. 10,132,563, which is also incorporated herein by reference. In one or more embodiments, *Gynostemma pentaphyllum* bagasse contains no more than 1 wt% organic solvent (based on the total weight of the dried bagasse). In some embodiments, the dried bagasse contains no more than 0.5 wt% organic solvent (based on the total weight of the dried bagasse). In one or more embodiments, the dried bagasse may contain a certain amount of water and higher-boiling-point terpenes. In some embodiments, the total amount of water and higher-boiling-point terpenes in the dried bagasse may be higher than the content of organic solvent.

[0029] In one or more embodiments, the co-feed (e.g., biomass or municipal waste) may be characterized by a compaction density of less than 600 kg / m³. 3 In other implementation schemes, it is less than 580 kg / m 3 And in other implementations, it is less than 560 kg / m 3 The density was determined by ASTM D 698-07.

[0030] The raw material can be characterized by the amount of co-feed (e.g., biomass or municipal waste). In one or more embodiments, the raw material comprises about 0 wt% to about 95 wt%, in other embodiments about 1 wt% to about 75 wt%, and in other embodiments about 2 wt% to about 55 wt% of co-feed, with the remainder comprising waste tires. In one or more embodiments, the raw material comprises less than 95 wt%, in other embodiments less than 80 wt%, and in other embodiments less than 70 wt% of co-feed. In these or other embodiments, the raw material comprises more than 10 wt%, in other embodiments more than 20 wt%, in other embodiments more than 30 wt%, in other embodiments more than 40 wt%, in other embodiments more than 50 wt%, and in other embodiments more than 70 wt% of waste tires, with the remainder comprising supplementary raw materials.

[0031] Thermal decomposition of tires and optional biomass

[0032] According to embodiments of the invention, raw materials (including tire stock and optional co-feeds) are thermally decomposed into a gas stream comprising hydrogen, carbon monoxide, and optionally carbon dioxide using techniques generally known in the art. As those skilled in the art will understand, these methods may include gasification methods, and these methods are also known to be tailored to control the chemical properties of the resulting gas stream. For example, the degree of combustion can be controlled by controlling the amount of oxygen present during the thermal decomposition process. In one or more embodiments, the thermal decomposition step is carried out in a substantially inert environment.

[0033] Methods that can be used in the thermal decomposition step may include pyrolysis reactions disclosed in U.S. Publications No. 20210207037; 20190295734; 20190249089; 20180273415; 20170009162; 20170002271; 20160107913; 20160068773; 20160024404; 20140182205; 20140157667; and 20140100294, which are incorporated herein by reference.

[0034] In one or more embodiments, where the feedstock comprises both tire feedstock and co-feed, the tire feedstock and co-feed can be introduced simultaneously into the same pyrolysis unit. For example, the tire feedstock and co-feed can be premixed at a desired ratio to form the feedstock to the pyrolysis unit. Alternatively, separate streams of the tire feedstock and co-feed can be fed separately and individually into the pyrolysis unit at desired rates. In yet another embodiment, the two feedstocks (i.e., tire feedstock and co-feed) can be processed sequentially within the same pyrolysis unit. In yet another embodiment, the two feedstocks (i.e., tire feedstock and co-feed) can be processed in separate pyrolysis units operating in parallel, and the gas streams generated by the respective units can then be combined to obtain a desired ratio of gas composition.

[0035] Characteristics of gaseous product streams

[0036] As described above, the gaseous product stream generated by the thermal decomposition unit 31 comprises carbon monoxide, hydrogen, and optionally carbon dioxide. In one or more embodiments, the gaseous product stream comprises about 5% to about 50% by volume, or about 7% to about 25% by volume in other embodiments, or about 8% to about 15% by volume in other embodiments, carbon dioxide. In these or other embodiments, the gaseous product stream comprises about 10% to about 85% by volume, or about 20% to about 65% by volume in other embodiments, or about 25% to about 45% by volume in other embodiments, hydrogen. In these or other embodiments, the gaseous product stream comprises about 20% to about 85% by volume, or about 30% to about 75% by volume in other embodiments, or about 40% to about 60% by volume in other embodiments, carbon monoxide. In one or more embodiments, based on the total weight of the gaseous product stream, the gaseous product stream generated by thermal decomposition comprises about 40 wt% to about 80 wt%, about 45 wt% to about 75 wt% in other embodiments, and about 50 wt% to about 70 wt% of carbon (i.e., carbon within the carbon-based compound) in other embodiments.

[0037] Airflow regulation

[0038] In one or more embodiments, the gas stream is conditioned (i.e. treated) before being supplied to reactor 21. In one or more embodiments, the gaseous product stream from pyrolysis carried by conduit 33 may be pressurized. In one or more embodiments, the gas stream is pressurized to a pressure sufficient to overcome reaction forces within the reactor. As those skilled in the art will understand, this will allow gas to flow through the reactor and allow an inert gas (e.g., nitrogen) within the gas stream to enter the headspace of the reactor. In one or more embodiments, the gas stream is pressurized to a pressure of approximately 5 bar to approximately 20 bar.

[0039] Additionally, the airflow may be cooled at heat exchanger 41. As those skilled in the art will understand, heat exchanger 41 may include a water cooling unit. In one or more embodiments, the airflow is cooled to a temperature below which would otherwise have a detrimental effect on the microbial culture within the reactor. In one or more embodiments, the airflow is cooled to a temperature of approximately 25°C to approximately 45°C before being delivered to the reactor.

[0040] Furthermore, the gas stream can be treated with scrubber 45 before being introduced into the reactor. In one or more embodiments, this may include using a catalyst (e.g., iron oxide) to remove sulfur compounds such as hydrogen sulfide. The stream may also be treated to remove acids (e.g., with calcium carbonate or sodium carbonate, with particular focus on removing hydrogen cyanide).

[0041] Syngas to Ethanol

[0042] As described above, syngas is converted to ethanol within reactor 51 using thermochemical techniques. Those skilled in the art will understand that several thermochemical techniques exist for converting syngas to ethanol. For example, there are two-step methods whereby syngas can be converted to methanol using a 2:1 ratio of hydrogen to carbon monoxide. These reactions are typically carried out in the gas phase using copper-based catalysts. The resulting product stream (which is typically saturated with water) can be purified using known distillation techniques. The methanol can then be catalytically converted to ethanol. One-step catalytic techniques are also known. Exemplary thermochemical methods for converting syngas to ethanol are described in U.S. Patent No. 9,115,046, which is incorporated herein by reference.

[0043] Ethanol-containing product stream from the reactor

[0044] As described above, ethanol exits reactor 51 in an ethanol product stream. This ethanol product stream can be processed at unit 55, such as by filtration.

[0045] Ethanol Concentration / Separation

[0046] As indicated above, following optional processing at unit 55, the ethanol-containing product stream can be treated to separate the ethanol from other components within the stream. This may include distilling the ethanol-containing stream within separation unit 61. According to these embodiments, ethanol can be collected as an overhead stream, characterized by an ethanol concentration greater than 80 wt%, greater than 90 wt% in other embodiments, and greater than 93 wt% in other embodiments. In these or other embodiments, the overhead stream (i.e., the ethanol-containing stream) may contain less than 10 wt%, less than 8 wt% in other embodiments, and less than 1 wt% water in other embodiments.

[0047] In one or more embodiments, the overhead ethanol stream may optionally be further treated to purify the ethanol stream before it is introduced into the acetaldehyde production unit 71. For example, the ethanol stream may be dehydrated or dried by treating it in one or more water adsorption beds comprising a dry material such as a molecular sieve.

[0048] Acetaldehyde production

[0049] As described above, ethanol is converted into acetaldehyde within production unit 71. In one or more embodiments, substantially all of the ethanol produced in reactor 51 (i.e., substantially all of the ethanol in the ethanol product stream) is introduced into acetaldehyde production unit 71. In these or other embodiments, ethanol obtained outside the method of the invention (e.g., ethanol from crop fermentation) is also introduced into acetaldehyde production unit 71 to supplement acetaldehyde production. In one or more embodiments, the weight ratio of ethanol supplied from reactor 51 to acetaldehyde production unit 71 to ethanol supplied from other sources (e.g., ethanol from crop fermentation) is from about 1:0 to about 1:10, in other embodiments from about 1:0.3 to about 1:7, and in other embodiments from about 1:1 to about 1:5.

[0050] As those skilled in the art will understand, the synthesis of acetaldehyde involves the partial dehydrogenation of ethanol to produce a hydrogen byproduct stream. As described above, hydrogen can be directed to reactor 51, which can advantageously compensate for hydrogen deficiency in the process. Those skilled in the art will understand that if additional ethanol is converted to acetaldehyde, the introduction of ethanol from a source outside the reactor process (i.e., outside reactor 51) will further alleviate the hydrogen deficiency within reactor 51, which will allow for the production of more hydrogen.

[0051] In one or more embodiments, within acetaldehyde production unit 71, ethanol undergoes dehydrogenation at elevated temperatures over a suitable catalyst, such as a copper-based catalyst. For example, the reaction may be carried out in a fixed-bed reactor. In one or more embodiments, the ethanol dehydrogenation within unit 71 is carried out at a temperature of about 200°C to about 350°C, or in other embodiments at a temperature of about 250°C to about 300°C.

[0052] In one or more embodiments, ethanol can be converted to acetaldehyde via oxidative dehydrogenation. In one or more embodiments, the conversion of ethanol to acetaldehyde can be carried out by partial oxidation of ethanol in an exothermic reaction. During this partial oxidation, the reaction can be carried out over a silver catalyst at about 500°C to about 650°C. In one or more embodiments, the conversion of ethanol to acetaldehyde may include avoiding or inhibiting the production of acetic acid relative to acetaldehyde. This can be achieved by selecting a catalyst and / or reaction conditions known to avoid the production of acetic acid relative to acetaldehyde. In one or more embodiments, the conversion of ethanol to acetaldehyde is carried out without evaporating acetaldehyde. In one or more embodiments, the conversion of ethanol to acetaldehyde is carried out at relatively low pressure and in the gas phase to increase selectivity for acetaldehyde.

[0053] Acetaldehyde to butadiene

[0054] In one or more embodiments, acetaldehyde produced in unit 71 is converted into butadiene monomer within butadiene production unit 91. In one or more embodiments, butadiene production comprises reacting ethanol and acetaldehyde to produce 1,3-butadiene using reaction techniques generally known in the art, such as those described in Zhang, *Mechanistic Insight into the Meerwein-Ponndorf-Verley Reaction and Relative Side Reactions over MgO in the Process of Ethanol to 1,3-butadiene: a DFT Study*, Ind. Eng. Chem. Res., 2021, 60, 2871-2880. As those skilled in the art will understand, this reaction can be carried out at elevated temperatures on a suitable catalyst, such as a tantalum-promoted porous silica catalyst. Additionally, other catalysts for converting acetaldehyde and ethanol into butadiene are known and can be used in the art, including tantalum oxide, zirconium oxide, silver oxide, and combinations thereof. This method may be referred to as the Ostromislensky method.

[0055] In one or more embodiments, the reaction is carried out in a fixed-bed reactor operated at a temperature of about 300°C to about 450°C, or in other embodiments operated at a temperature of about 350°C to about 400°C. In one or more embodiments, the method may include supplementing the ethanol-acetaldehyde mixture with additional ethanol and / or acetaldehyde to achieve a desired ratio.

[0056] In one or more embodiments, the reactant feed into the butadiene production unit 91 comprises a molar ratio of ethanol to acetaldehyde (i.e., the number of moles of ethanol to the number of moles of acetaldehyde) of at least 1:1, at least 2:1 in other embodiments, at least 2.5:1 in other embodiments, at least 4:1 in other embodiments, and in other embodiments, in the range of about 1:1 to about 5:1.

[0057] The feed into butadiene production unit 91 is characterized by low levels of impurities (i.e., components other than acetaldehyde and ethanol). In one or more embodiments, the feed stream into butadiene production unit 91 contains less than 10 wt% based on the total weight of the input stream, less than 5 wt% in other embodiments, and less than 2 wt% impurities in still other embodiments.

[0058] The crude butadiene stream exiting butadiene reactor 91 via conduit 93 typically contains 1,3-butadiene monomer, unreacted ethanol, unreacted acetaldehyde, water as a reaction byproduct, and other byproducts. In one or more embodiments, the yield of 1,3-butadiene based on acetaldehyde is greater than 20 mol%, in other embodiments greater than 30 mol%, and in still other embodiments greater than 40 mol%. In these or other embodiments, the yield of 1,3-butadiene based on acetaldehyde is less than 70 mol%, in other embodiments less than 60 mol%, and in still other embodiments less than 55 mol%.

[0059] In one or more embodiments, the crude butadiene product stream undergoes a first separation, which may include distillation. In one or more embodiments, butadiene is separated as the overhead stream, and the remaining components of the stream are separated as the bottom stream. Subsequently, the bottom stream may be further separated to separate ethanol and acetaldehyde from water and other components of the stream. The ethanol and acetaldehyde that can be separated as the overhead stream can then be recycled back to butadiene production unit 91 for conversion into butadiene.

[0060] In an alternative embodiment, ethanol in an ethanol stream can be converted to butadiene (e.g., 1,3-butadiene) via a one-step synthesis, also referred to as direct synthesis. In one or more embodiments, the direct synthesis of butadiene from ethanol is carried out as a condensation reaction in the presence of a multifunctional catalyst, including those disclosed in U.S. Patent No. 8,921,635, which is incorporated herein by reference. Another known synthetic method for the direct conversion of ethanol to butadiene is the Lebedev method. Further methods for the direct conversion of ethanol to butadiene include those marketed by ETB Catalytic Technologies and those marketed by Synthos.

[0061] As those skilled in the art will understand, the direct conversion of ethanol to butadiene can include two-stage extractive distillation using n-methylpyrrolidone (NMP) as a solvent. Direct conversion techniques may also include conventional distillation for the recovery of butadiene.

[0062] Industrial applicability

[0063] In one or more embodiments, the butadiene monomer (e.g., 1,3-butadiene) produced by the method of the present invention can be used to produce polybutadiene or butadiene copolymers (which may also be referred to as polybutadiene copolymers). For the purposes of this specification, these polymers may be referred to as recycled synthetic rubber or recycled synthetic polybutadiene to butadiene copolymers. In one or more embodiments, the recycled synthetic rubber can be used to manufacture tire components. Therefore, the practice of the present invention provides a method by which waste materials, particularly waste materials from waste tires, are converted back into usable tires. In other words, a tire recycling or tire recycling method is provided.

[0064] The synthesis of polybutadiene or polybutadiene copolymers from butadiene monomers is well known and can be achieved through several synthetic routes (i.e., polymerization mechanisms and techniques). For example, monomers can be polymerized via free radical emulsion polymerization, anionic polymerization, or coordination catalysis using catalyst systems such as nickel-based or neodymium-based catalysts.

[0065] As understood by those skilled in the art, comonomers that can be copolymerized with butadiene to form polybutadiene copolymers include, but are not limited to, vinyl aromatic monomers (such as styrene) and other diene monomers (such as isoprene). In one or more embodiments, the comonomer is a sustainable comonomer. For example, styrene can be obtained from biosynthetic feedstocks (such as bioethanol) that are subsequently converted into styrene; see, for example, U.S. Patent No. 9,663,445. Alternatively, styrene can be synthesized from bio-based materials (such as cinnamic acid or hydrogenated cinnamic acid); see U.S. Patent No. 9,868,853. Other examples include styrene obtained from the depolymerization of polystyrene from post-consumer waste; see U.S. Publication No. 2022 / 0411351. Those skilled in the art also understand that styrene can be obtained from bio-based, bio-circulating, or circular methods that have been quality balanced to comply with the International Sustainability and Carbon Certification (ISCC) designations.

[0066] It should be understood that the polybutadiene polymer prepared by polymerizing the butadiene of the present invention has a relatively high percentage of monomer units derived from butadiene produced by the present invention, and therefore the polybutadiene polymer of the present invention has a relatively high sustainability content. In one or more embodiments, the polybutadiene polymer synthesized by polymerizing the butadiene of the present invention contains more than 50 mol%, more than 60 mol%, more than 70 mol%, more than 80 mol%, more than 90 mol%, more than 95 mol%, and more than 99 mol% of sustainable monomer units obtained by polymerizing butadiene obtained by the present invention (i.e., monomer units obtained by synthesizing monomers from a gas stream obtained by gasification of a carbon-containing material). Similarly, in the case where the synthesized polymer is a polybutadiene copolymer obtained by copolymerizing butadiene monomers obtained by the practice of the present invention with sustainable comonomers, the resulting polybutadiene copolymer has a relatively high sustainability content. In one or more embodiments, the polybutadiene copolymer synthesized by polymerizing the butadiene of the present invention with a sustainable comonomer contains more than 50 mol%, more than 60 mol%, more than 70 mol%, more than 80 mol%, more than 90 mol%, more than 95 mol%, and more than 99 mol% of sustainable monomer units (i.e., monomer units obtained from monomers synthesized by gasification of carbonaceous materials and other sustainable comonomers).

[0067] Polymers synthesized from butadiene monomers produced through embodiments of the present invention may be referred to as vulcanizable polymers or elastomeric polymers, and generally include polydienes and polydiene copolymers. Specific polymers that can be produced and used in tire manufacturing include, but are not limited to, polybutadiene, poly(styrene-co-butadiene), poly(styrene-co-isoprene-co-butadiene), poly(isoprene-co-butadiene), and their functionalized derivatives.

[0068] The polybutadiene and polybutadiene copolymers produced by this invention exhibit excellent viscoelasticity and are particularly suitable for manufacturing various tire components, including but not limited to tire treads, sidewalls, subtreads, and bead cores. These polymers can be used as all or part of the elastomer component of tire compounds. When the polymers produced by this invention are used with other vulcanizable polymers to form the elastomer component of tire compounds, these other vulcanizable polymers may include natural rubber, synthetic rubber, and mixtures thereof. Examples of synthetic rubbers include polyisoprene, poly(styrene-co-butadiene), and other polybutadienes, poly(styrene-co-butadiene-co-isoprene), and mixtures thereof, having low and / or low cis-1,4-bond content. The polymers of this invention can also be used to manufacture hoses, belts, shoe soles, window seals, other seals, vibration damping rubbers, and other industrial products.

[0069] The present invention not only provides a method for recycling tires by using waste tires as raw materials to produce polymers that can be formulated back into tires, but also advantageously provides a method for producing tires with a relatively high content of sustainable components, including recycled materials, naturally derived materials, and / or materials synthesized from biosynthetic raw materials or bio-based materials. Furthermore, these tires or tire components include a threshold amount of recycled synthetic rubber while being characterized by a high sustainable content. For example, the tires or tire components of the present invention may contain more than 40 wt%, more than 50 wt% in other embodiments, and more than 60 wt% of sustainable materials in other embodiments. In these or other embodiments, the tires or tire components contain about 40 wt% to about 90 wt%, about 45 wt% to about 85 wt% in other embodiments, and about 50 wt% to about 80 wt% of sustainable materials in other embodiments. In combination therewith, the rubber component of the tires or tire components of the present invention contains more than 10 wt%, more than 20 wt% in other embodiments, more than 30 wt% in other embodiments, more than 40 wt% in other embodiments, more than 45 wt% in other embodiments, and more than 50 wt% of recycled synthetic rubber, which includes synthetic rubber produced according to embodiments of the present invention.

[0070] As described above, the vulcanizable composition of the present invention includes a rubber component. This rubber component includes recycled synthetic rubber produced according to aspects of the present invention. The rubber component may also include other synthetic rubbers, such as synthetic rubber derived from petroleum-based raw materials that have not yet been recycled and synthetic rubber derived from other sustainable processes, as well as natural rubber. As understood by those skilled in the art, natural rubber is synthesized from and obtained from plants. For example, natural rubber can be obtained from Hevea rubber tree, sage bush, gopher plant, mariola, rabbitbrush, milkweed, goldenrod, pale Indian plantain, rubber vine, Russian dandelion, mountain mint, American germander, and tall bellflower.

[0071] If used, other synthetic polymers include, but are not limited to, synthetic polyisoprene, polybutadiene, polyisobutylene-co-isoprene, chloroprene rubber, poly(ethylene-co-propylene), poly(styrene-co-butadiene), poly(styrene-co-isoprene), poly(styrene-co-isoprene-co-butadiene), poly(isoprene-co-butadiene), poly(ethylene-co-propylene-co-diene), polysulfide rubber, acrylic rubber, polyurethane rubber, silicone rubber, epichlorohydrin rubber, and mixtures thereof. These elastomers can have a wide variety of macromolecular structures, including linear, branched, and star-shaped structures.

[0072] Generally speaking, based on the total weight of the tire assembly components, the rubber composition of the present invention contains about 30 wt% to about 65 wt%, about 35 wt% to about 60 wt% in other embodiments, and about 40 wt% to about 55 wt% of elastomer in other embodiments.

[0073] As described above, the rubber composition contains fillers, such as organic and inorganic fillers. Examples of organic fillers include carbon black and starch. Examples of inorganic fillers include silica, aluminum hydroxide, magnesium hydroxide, mica, talc (hydrated magnesium silicate), and clay (hydrated aluminum silicate). In some embodiments, mixtures of different fillers may be advantageously used.

[0074] The total filler content used in the rubber composition can be up to about 150 parts by weight of rubber (phr), typically about 30 phr to about 125 phr, or about 40 phr to about 110 phr. In some embodiments, the total filler content is greater than about 100 phr. In other embodiments, the total filler content is about 50 phr to about 100 phr, and in other embodiments it is about 55 phr to about 95 phr.

[0075] Conventional carbon blacks known in the art can be used. In one or more embodiments, the carbon black includes furnace black, channel black, and lamp black. More specific examples of carbon black include ultra-abrasion furnace black, medium-ultra-abrasion furnace black, high-abrasion furnace black, fast extrusion furnace black, fine furnace black, semi-reinforced furnace black, medium-process channel black, difficult-to-process channel black, conductive channel black, and acetylene black.

[0076] In a particular embodiment, the surface area (EMSA) of the carbon black may be at least 20 m². 2 / g, and in other embodiments at least 35m 2 / g; Surface area values ​​can be determined using the cetyltrimethylammonium bromide (CTAB) technique according to ASTM D-1765. Carbon black can be in granular or non-granular flocculent form. The preferred form of carbon black may depend on the type of mixing equipment used to blend the rubber compounds.

[0077] In one or more embodiments, the carbon black may be derived from recycled materials. Such recycled materials may include recovered or recycled vulcanized rubber, which is typically recovered from manufactured articles such as pneumatic tires, industrial conveyor belts, power transmission belts, and rubber hoses. Recycled carbon black can be obtained by pyrolysis processes or other methods known for obtaining recycled carbon black. On one hand, recycled carbon black may be formed from the incomplete combustion of recycled rubber raw materials or rubber articles. On the other hand, recycled carbon black may be formed from the incomplete combustion of raw materials, including oils produced from tire pyrolysis processes. The carbon black used in the preparation of vulcanizable elastomer compositions may be in granular form or as a non-granular flocculent material.

[0078] The amount of carbon black used in the rubber composition can be up to about 75 parts by weight per 100 parts by weight of rubber (phr), typically about 5 phr to about 60 phr, or about 10 phr to about 55 phr.

[0079] The rubber composition may also contain fillers in granular form or in the form of one or more recycled rubbers. Recycled granular rubber is typically decomposed and recovered (or recycled) by any of a variety of methods, including physical decomposition, milling, chemical decomposition, desulfurization, cryogenic milling, combinations thereof, etc. The term recycled granular rubber can refer to both vulcanized rubber and desulfurized rubber, wherein desulfurized recycled or recycled rubber (recycled rubber) refers to rubber that has been vulcanized, milled into granules, and may further undergo substantial or partial desulfurization. In one example, the recycled granular rubber used in the rubber composition is substantially free of recycled rubber produced by desulfurization. In cases where the vulcanized rubber contains filament or textile fiber reinforcement, this filament or fiber reinforcement can be removed by any suitable method, such as magnetic separation, air suction, and / or air flotation steps. In some embodiments, "recycled granular rubber" includes cured, i.e., vulcanized (crosslinked) rubber that has been milled or pulverized into granules having the median average particle size described below.

[0080] Certain types of silica can be considered sustainable materials. Some commercially available silicas that can be used as sustainable materials in this invention include Hi-Sil. ™ 215. Hi-Sil ™ 233 and Hi-Sil ™ 190 (PPG Industries, Inc., Pittsburgh, Pa.). Other commercially available sources of silica include Grace Davison (Baltimore, Md.) of Baltimore, Maryland; Degussa Corp. (Parsippany, NJ) of Parsippany, NJ; Rhodia Silica Systems (Cranbury, NJ) of Cranbury, NJ; and JM Huber Corp. (Edison, NJ) of Edison, NJ. Other sustainable sources of silica include silica derived from rice husk ash.

[0081] In one or more embodiments, silica can be characterized by its surface area, which provides a measure of its reinforcing properties. The Brunauer, Emmet, and Teller (“BET”) method (described in J. Am. Chem. Soc., 1939, Vol. 60, pp. 309-319) is a recognized method for determining surface area. The BET surface area of ​​silica is typically less than 450 m². 2 / g. Available surface areas range from approximately 32 to approximately 400 m². 2 / g, approximately 100 to approximately 250m 2 / g, and about 130 to about 240m 2 / g, and approximately 170 to approximately 220m 2 / g. In some embodiments, silica may have a concentration of 190 to about 280. 2 / g BET surface area. The pH of silica is typically from about 5 to about 7 or slightly above 7, or from about 5.5 to about 6.8 in other embodiments.

[0082] In one or more embodiments, when silica is used as a filler (alone or in combination with other fillers), coupling agents and / or masking agents may be added to the rubber composition during mixing to enhance the interaction between silica and the elastomer. Available coupling agents and masking agents are described in U.S. Patent Nos. 3,842,111; 3,873,489; 3,978,103; 3,997,581; 4,002,594; 5,580,919; 5,583,245; 5,663,396; 5,674,932; and 5,684,1 The following patents are disclosed in No. 71; No. 5,684,172; No. 5,696,197; No. 6,608,145; No. 6,667,362; No. 6,579,949; No. 6,590,017; No. 6,525,118; No. 6,342,552; and No. 6,683,135, which are incorporated herein by reference.

[0083] The amount of silica used in the rubber composition can be from about 1 phr to about 150 phr, or in other embodiments from about 5 phr to about 130 phr. The upper limit is limited by the high viscosity imparted by silica. In some embodiments, the silica used in the rubber composition is derived solely from rice husk ash, and in other embodiments, the rubber composition does not contain silica derived from methods other than rice husk ash. When silica is used with carbon black, the amount of silica or carbon black can each be as low as about 1 phr. Generally, the amounts of coupling agents and masking agents range from about 4 wt% to about 20 wt% based on the weight of silica used. In one or more embodiments, when carbon black and silica are used together as fillers, the weight ratio of silica to total filler can be from about 5 wt% to about 99 wt% of the total filler, from about 10 wt% to about 90 wt% of the total filler in other embodiments, or from about 50 wt% to about 85 wt% of the total filler in other embodiments. In some embodiments, the silica and carbon black fillers used in the rubber composition are selected from the group consisting of silica derived from sustainably pyrolyzed carbon black and / or rice husk ash.

[0084] Many types of rubber curing agents (also known as vulcanizing agents) can be used, including sulfur-based or peroxide-based curing systems. Curing agents are described in the following literature: Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 20, pp. 365-468 (3rd edition, 1982), especially Vulcanization Agents and Auxiliary Materials, pp. 390-402; and A.Y. Coran, Vulcanization, Encyclopedia of Polymer Science and Engineering (2nd edition, 1989), which are incorporated herein by reference. Vulcanizing agents can be used alone or in combination.

[0085] Other components commonly used in rubber compounding may also be added to the rubber composition. These components include accelerators, accelerator activators, oils, plasticizers, waxes, scorch inhibitors, processing aids, zinc oxide, tackifying resins, reinforcing resins, fatty acids (such as stearic acid), plasticizers, and anti-degradation agents (such as antioxidants and ozone degraders).

[0086] Regarding oils, sustainable oils can be used, including plant-based oils and bio-based oils. Plant-based oils may include plant-based triglycerides. Exemplary oils include, but are not limited to, palm oil, soybean oil (also referred to herein as soybean oil), rapeseed oil, sunflower oil, peanut oil, cottonseed oil, oil derived from palm kernels, coconut oil, olive oil, corn oil, grapeseed oil, hemp seed oil, flaxseed oil, rice oil, safflower oil, sesame oil, mustard oil, and flaxseed oil. Other examples include nut-derived oils, such as those obtained from beech nuts, cashews, mongongo nuts, macadamia nuts, pine nuts, hazelnuts, chestnuts, acorns, almonds, pecans, pistachios, walnuts, or Brazil nuts. As those skilled in the art will understand, these oils can be produced by any suitable method, such as mechanical extraction (e.g., using an oil mill), chemical extraction (e.g., using solvents such as hexane or carbon dioxide), pressure extraction, distillation, leaching, impregnation, purification, refining, hydrogenation, jetting, etc.

[0087] Bio-based oils, also known as bio-oils, can include oils produced by recombinant cells. For example, bio-oils produced by recombinant cells can be produced using selected strains of algal cells that are fed with sugars (e.g., sucrose) and subsequently allowed to ferment and produce bio-oils with selected characteristics; after sufficient growth or fermentation has occurred, the bio-oils are separated from the cells and collected.

[0088] Generally, the rubber composition of the present invention may contain about 1 part by weight to about 70 parts by weight per 100 parts by weight of rubber, or about 5 parts by weight to about 50 parts by weight of total oil in other embodiments. The amount of oil sustaining may be about 1 wt% to about 99 wt% relative to the total weight of the oil included, or about 20 wt% to about 80 wt% in other embodiments.

[0089] Regarding waxes, the rubber composition may contain one or more sustainable waxes, including natural waxes. Natural waxes or waxes that do not use petroleum as their raw material may include carnauba wax, candelilla wax (e.g., extracted from candelilla flowers), rice wax (e.g., separated from rice bran oil), and Japanese wax (e.g., extracted from the Japanese wax tree).

[0090] Generally, the rubber composition of the present invention comprises about 1 to about 20 parts by weight of rubber per 100 parts by weight, or about 2 to about 15 parts by weight of total wax in other embodiments. The amount of sustainable wax may be about 1 wt% to about 99 wt% of the total wax, or about 20 wt% to about 80 wt% in other embodiments, relative to the total weight of the included wax. In some embodiments, the rubber composition comprises only sustainable wax.

[0091] All components of the rubber composition can be mixed using standard mixing equipment such as Banbury or Brabender mixers, extruders, kneaders, and two-roll mills. In one or more embodiments, the components are mixed in two or more stages. In the first stage (often referred to as the masterbatch mixing stage), a so-called masterbatch is prepared, which typically contains rubber components and fillers. To prevent premature vulcanization (also known as scorching), the masterbatch may be vulcanizing agent-free. The masterbatch can be mixed at an initial temperature of about 25°C to about 125°C and an outlet temperature of about 135°C to about 180°C. Once the masterbatch is prepared, a vulcanizing agent can be introduced and mixed into the masterbatch in the final mixing stage, which is typically carried out at relatively low temperatures to reduce the chance of premature vulcanization. Optionally, an additional mixing stage, sometimes referred to as re-mixing, can be used between the masterbatch mixing stage and the final mixing stage. In cases where the rubber composition contains silica as a filler, one or more re-mixing stages are typically used. Various components, including the polymers of the present invention, can be added during these re-mixing processes.

[0092] Mixing procedures and conditions particularly suitable for silica-filled tire formulations are described in U.S. Patent Nos. 5,227,425, 5,719,207, and 5,717,022, and European Patent No. 890,606, which are incorporated herein by reference. In one embodiment, the initial masterbatch is prepared by including a polymer and silica in the substantially absence of coupling agents and masking agents.

[0093] To manufacture tire components using the polymers produced by this invention, those skilled in the art recognize that the polymer is mixed with various other components (e.g., fillers and curing agents) to produce a rubber composition (also known as a vulcanizable composition), and then the vulcanizable composition is processed into tire components according to common tire manufacturing techniques, which typically include standard rubber molding and molding techniques. Tire components may include, but are not limited to, tire treads, sidewalls, sub-treads, carcass ply layers, and bead cores. The various tire components are then assembled into a green tire (i.e., an uncured tire), placed in a mold, and then vulcanized. Vulcanization is typically achieved by heating the vulcanizable composition in the mold; for example, it may be heated to about 140°C to about 180°C. The cured or crosslinked rubber composition may be referred to as vulcanized rubber, which typically contains a thermosetting three-dimensional polymer network. Other components (such as fillers and processing aids) may be uniformly dispersed throughout the crosslinked network. Pneumatic tires can be manufactured as described in U.S. Patents 5,866,171, 5,876,527, 5,931,211, and 5,971,046, which are incorporated herein by reference.

[0094] In one or more embodiments, the tire may include fabric reinforcements made by using non-petroleum materials instead of synthetic fibers. For example, mechanically recycled fibers, chemically recycled fibers, or bio-based fibers may be used. Similarly, the tire may include metal reinforcements made of recycled steel and / or other recycled or sustainable metals. These non-petroleum fabrics and recycled metals may be used solely within the tire or in combination with conventional fabric and / or metal reinforcements.

[0095] Various modifications and alterations without departing from the scope and spirit of the invention will be apparent to those skilled in the art. The invention should not be unduly limited to the exemplary embodiments shown herein.

Claims

1. A method, the method comprising: (a) Providing waste tire raw materials; (b) Gasifying the waste tire material to generate a gas stream, wherein the gas stream contains carbon monoxide, hydrogen and carbon dioxide; (c) Thermochemically converting at least a portion of the carbon monoxide, hydrogen and carbon dioxide in the gas stream to produce a first product stream; (d) Converting at least a portion of the first product stream into a second product stream, wherein the second product stream comprises acetaldehyde and hydrogen; (e) the step of directing a portion of the hydrogen in the second product stream to thermochemically convert at least a portion of the carbon monoxide, hydrogen, and carbon dioxide in the gas stream; and (f) Convert at least a portion of acetaldehyde into butadiene monomer.

2. The method of claim 1, wherein the first product stream comprises ethanol.

3. The method according to any one of the preceding claims, the method further comprising the step of polymerizing the butadiene monomer into polybutadiene or a polybutadiene copolymer.

4. The method according to any one of the preceding claims, further comprising the step of manufacturing a tire component using the polybutadiene or polybutadiene copolymer.

5. The method according to any one of the preceding claims, wherein the gasification step comprises gasifying waste tire raw materials and a co-feed containing carbonaceous materials other than waste tire raw materials.

6. A method, the method comprising: (a) Providing waste tire raw materials; (b) Optionally, a co-feed containing carbonaceous materials other than waste tire stock may be provided; (c) Gasifying the waste tire material and optional co-feed to generate a gas stream, wherein the gas stream contains carbon monoxide, hydrogen and carbon dioxide; (d) The gas stream is introduced into a thermochemical reactor, wherein the carbon monoxide, hydrogen and carbon dioxide are converted into a first product stream; (e) Converting the first product stream into a second product stream, wherein the second product stream comprises acetaldehyde and hydrogen; (f) Separating the hydrogen gas from the second product stream to form a hydrogen gas stream; as well as (g) Converting the acetaldehyde into a final product stream, wherein the final product stream comprises butadiene.

7. The method according to any one of the preceding claims, wherein the first product stream comprises ethanol.

8. The method according to any one of the preceding claims, wherein the ethanol is converted into the second product stream.

9. The method according to any one of the preceding claims, the method further comprising the step of separating the ethanol from the first product stream.

10. The method according to any one of the preceding claims, the method further comprising the step of separating the butadiene from the final product stream.

11. The method according to any one of the preceding claims, wherein the gasification step is carried out by plasma-induced oxidation.

12. The method according to any one of the preceding claims, wherein the airflow is neutralized before being introduced into the aqueous medium.

13. The method according to any one of the preceding claims, wherein the airflow is cooled.

14. The method according to any one of the preceding claims, wherein the step of converting syngas into ethanol is carried out at an elevated temperature.

15. The method according to any one of the preceding claims, wherein the step of separating the ethanol from the first product stream comprises distilling the ethanol as an overhead stream from the first product stream, and the method further comprises the step of directing the bottom stream from the distillation step to a recirculation stream.

16. The method according to any one of the preceding claims, the method further comprising the step of introducing the recirculated stream into the reactor.

17. The method according to any one of the preceding claims, the method further comprising the step of introducing the recirculated flow into the step of cooling the airflow.

18. The method according to any one of the preceding claims, the method further comprising the step of introducing the recirculation flow into the step of neutralizing the airflow.

19. The method according to any one of the preceding claims, the method further comprising filtering the first product stream to remove microorganisms from the first product stream prior to the step of converting the first product stream into the second product stream.

20. The method according to any one of the preceding claims, wherein the hydrogen gas stream is introduced into the aqueous medium.

21. The method according to any one of the preceding claims, the method further comprising the step of introducing a second hydrogen gas stream into the reactor.

22. The method according to any one of the preceding claims, wherein the step of converting the ethanol into a second product stream is carried out in an acetaldehyde reactor, and the method further comprises the step of introducing a second ethanol stream from an external source into the acetaldehyde reactor.

23. The method according to any one of the preceding claims, wherein the step of converting the ethanol to acetaldehyde converts more than 90 molar percentages of the ethanol to acetaldehyde, and the method further comprises the step of introducing ethanol into the second product stream prior to the step of converting the acetaldehyde to butadiene.

24. The method according to any one of the preceding claims, the method further comprising converting the butadiene into polybutadiene or a butadiene copolymer.

25. The method according to any one of the preceding claims, the method further comprising producing tire material from the polybutadiene or butadiene copolymer.

26. The method according to any one of the preceding claims, wherein the gasification step comprises gasifying the tire raw material and the co-feed.

27. The method according to any one of the preceding claims, wherein the co-feed comprises biomass.

28. The method according to any one of the preceding claims, wherein the biomass comprises bagasse.

29. The method according to any one of the preceding claims, wherein the bagasse is bagasse from a silver chrysanthemum plant.

30. The method according to any one of the preceding claims, wherein the tire raw material and co-feed are combined to form a mixture prior to the gasification step.

31. The method according to any one of the preceding claims, wherein the mixture of waste tire raw material and co-feed is characterized in that it contains less than 25 wt% metal based on the total weight of the mixture.

32. The method according to any one of the preceding claims, wherein the mixture of waste tire raw material and co-feed is characterized in that it contains less than 5 wt% fiber yarn or cord based on the total weight of the mixture.

33. The method according to any one of the preceding claims, wherein the mixture of waste tire raw material and co-feed is characterized in that it contains less than 30 wt% inorganic filler based on the total weight of the mixture.

34. The method according to any one of the preceding claims, wherein the mixture has a concentration greater than 640 kg / m³ according to ASTM D 698-07. 3 The compaction density.

35. The method according to any one of the preceding claims, wherein the mixture comprises about 1 wt% to about 75 wt% of co-feed, and the remainder comprises waste tires.

36. A vulcanizable composition of a substance comprising the polybutadiene or butadiene copolymer prepared by the method according to any one of the preceding claims.

37. The vulcanizable composition according to any one of the preceding claims, wherein the vulcanizable composition further comprises a filler, an oil, and a curing agent for rubber.

38. The vulcanizable composition according to any one of the preceding claims, wherein the filler comprises silica.

39. The vulcanizable composition according to any one of the preceding claims, wherein the filler comprises silica derived from rice husk ash.

40. The vulcanizable composition according to any one of the preceding claims, wherein the filler comprises recycled carbon black.

41. The vulcanizable composition according to any one of the preceding claims, wherein the oil comprises bio-oil or plant-based oil.

42. The vulcanizable composition according to any one of the preceding claims, wherein the vulcanizable composition further comprises a natural wax.

43. The vulcanizable composition according to any one of the preceding claims, wherein, based on the total weight of the vulcanizable composition, the vulcanizable composition comprises about 30 wt% to about 65 wt% of rubber, and wherein more than 10 wt% of the rubber is the polybutadiene or polybutadiene copolymer prepared by any one of the preceding claims.

44. The vulcanizable composition according to any one of the preceding claims, wherein the vulcanizable composition comprises about 30 parts by weight to about 150 parts by weight of filler per 100 parts by weight of rubber, and wherein the filler comprises carbon black and silica in a weight ratio of about 5% to about 99% by weight of the filler.

45. The vulcanizable composition according to any one of the preceding claims, wherein the vulcanizable composition comprises about 1 part by weight to about 70 parts by weight of oil per 100 parts by weight of rubber, and wherein at least 1 wt% of the oil is a bio-oil or vegetable oil.

46. ​​The vulcanizable composition according to any one of the preceding claims, comprising about 1 to about 20 parts by weight of wax per 100 parts by weight of rubber, wherein at least 1 wt% of the wax is a natural wax.

47. A tire component, said tire component being prepared from a vulcanizable composition according to any one of the preceding claims.

48. A tire, said tire being manufactured using a tire component according to any one of the preceding claims.

49. The tire according to any one of the preceding claims, wherein the tire contains more than 40 wt% sustainable materials.

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