Method for producing a mixture of different olefins

Abstract

Disclosed herein is a method for producing two or more different C2-C6 linear or branched olefins. In one exemplary embodiment, the method can include contacting a first feedstream containing γ-valerolactone with one or more first catalysts in a first reactor to form a mixture. The mixture contains two or more different C2-C6 linear or branched olefins in at least 60% yield, and the one or more first catalysts include a doped zeolite. Also disclosed herein is a method for converting levulinic acid to γ-valerolactone.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 398,802, filed August 17, 2022, and U.S. Provisional Patent Application No. 63 / 404,465, filed September 7, 2022, each entitled "Conversion of Levulinic Acid from Cellulosic Biomass to Light Olefins," the disclosures of which are incorporated herein by reference in their entireties.

[0002] The subject matter described herein relates to methods for producing mixtures of different linear or branched olefins (eg, ethylene, propylene, butene, and butadiene).

[0003] Background technology Approximately 400 million tons of light olefins (ethylene, propylene, butene, butadiene, etc.) are produced annually in the polymer, chemical, and pharmaceutical industries. Prior art processes are based on naphtha stream cracking and are therefore fossil fuel dependent, resulting in significant environmental impacts. Catalytic production of light olefins from renewable plant biomass is a promising alternative, and many methods are being developed to survive future disruptions in the supply of biomass-derived commodity chemicals.

[0004] The decline of fossil resources has led to an urgent need for the utilization and development of renewable resources. Biomass, as a clean and renewable organic carbon source in nature, is widely used due to its abundance and easy availability. Among these, lignocellulose, as the most abundant biomass resource, can be converted into high-value-added chemicals, such as levulinic acid (LA) and gamma-valerolactone (GVL), by thermal catalytic conversion. GVL can be obtained through various chemical transformations and catalysts and further converted into chemicals and fuels, such as hydrogenation to obtain 1,4-pentanediol and 2-methyltetrahydrofuran. Furthermore, GVL decarboxylation under the action of an acid catalyst can yield C4 olefins, which can then be converted into C8 olefins. + It can be further polymerized to yield olefins, although known techniques for converting LA to GVL are limited in that they produce either butenes or butadiene.

[0005] Thus, there remains a need for improved catalyst technologies that can produce combinations of at least two or more different olefins, thereby providing greater flexibility in producing fuels and / or chemicals from bio-based feedstocks.

[0006] Summary of the Invention Aspects of the present subject matter relate to methods for producing two or more different C2-C6 linear or branched olefins. In some embodiments, one or more of the following features may optionally be included in any workable combination:

[0007] In one embodiment, an exemplary method for producing two or more different C2-C6 linear or branched olefins includes contacting a first feedstream comprising γ-valerolactone with one or more first catalysts in a first reactor to form a mixture, the mixture comprising the two or more different C2-C6 linear or branched olefins in at least 60% yield, and the one or more first catalysts comprising a doped zeolite.

[0008] In some embodiments, the doped zeolite can include one or more dopants. In certain embodiments, the one or more dopants can include boron, a phosphor, or a combination thereof.

[0009] In some embodiments, boron can be present in the doped zeolite in an amount of 1 wt.% to 3 wt.% based on the total weight of the doped zeolite, while in other embodiments, boron can be present in the doped zeolite in an amount of 1.5 wt.% to 2.5 wt.% based on the total weight of the doped zeolite. In some embodiments, the phosphor can be present in the doped zeolite in an amount of 1 wt.% to 4 wt.% based on the total weight of the doped zeolite, while in other embodiments, the phosphor can be present in the doped zeolite in an amount of 2 wt.% to 3.5 wt.% based on the total weight of the doped zeolite. Alternatively or additionally, in some embodiments, the one or more dopants can include Zr, W, Cu, Mg, Co, Mo, Zn, Ti, Ga, or any combination thereof.

[0010] In some embodiments, the doped zeolite can include ZSM-5.

[0011] In some embodiments, the two or more different C2-C6 linear or branched olefins can include one or more of butene and butadiene and at least one of ethylene or propylene.

[0012] In some embodiments, the two or more different C2-C6 linear or branched olefins can comprise one or more butenes. In such embodiments, the two or more different C2-C6 linear or branched olefins can comprise butadiene.

[0013] In some embodiments, the two or more different C2-C6 linear or branched olefins can include one or more linear butenes and butadienes.

[0014] In some embodiments, butadiene can be present in the mixture in an amount of about 1% to 50% by weight based on the total weight of the mixture, hi other embodiments, butadiene can be present in the mixture in an amount of about 10% to 45% by weight based on the total weight of the mixture.

[0015] In some embodiments, the yield of two or more different C2-C6 linear or branched olefins may be at least about 98%. In other embodiments, the yield of two or more different C2-C6 linear or branched olefins may be about 80% to 90%.

[0016] In some embodiments, the first reactor may be at a temperature of about 300°C to 500°C. In other embodiments, the first reactor may be at a temperature of about 380°C to 460°C.

[0017] In some embodiments, the first reactor can be at a pressure of about 0 psig to 300 psig, hi other embodiments, the first reactor can be at a pressure of about 0 psig to 100 psig.

[0018] In some embodiments, contacting the first feedstream with the one or more first catalysts is performed for at least 0.5 h. -1 contacting the first feed stream with one or more first catalysts at a weight hourly space velocity (WHSV) of 0.1 to 0.5 to form a mixture.

[0019] In some embodiments, contacting the first feedstream with the one or more first catalysts is performed for about 1 h. -1 ~10h -1 In some embodiments, contacting the first feed stream with the one or more first catalysts at a weight hourly space velocity (WHSV) of about 0.1 h to form a mixture can be performed. In some embodiments, contacting the first feed stream with the one or more first catalysts can be performed for about 0.1 h. -1 ~15h -1contacting the first feed stream with one or more first catalysts at a weight hourly space velocity (WHSV) of 0.1 to 0.5 to form a mixture.

[0020] In some embodiments, the method can include contacting a second feedstream comprising levulinic acid with a second catalyst in a second reactor to produce the first feedstream.

[0021] In some embodiments, γ-valerolactone may be produced in a yield of at least 25%. In some embodiments, γ-valerolactone may be produced in a yield of at least 50%. In some embodiments, γ-valerolactone may be produced in a yield of about 25% to 35%.

[0022] In some embodiments, the second catalyst can include a mixed metal oxide. In certain embodiments, the second catalyst can include ZnZrAlSi. In other embodiments, the second catalyst can include ZnZrSi.

[0023] In some embodiments, the second reactor may be at a temperature of about 300°C to 500°C. In other embodiments, the second reactor may be at a temperature of about 380°C to 450°C.

[0024] In some embodiments, the second reactor can be at a pressure between about 0 psig and 300 psig, while in other embodiments, the second reactor can be at a pressure between about 0 psig and 100 psig.

[0025] In some embodiments, contacting the second feedstream with the second catalyst is performed for at least 0.5 h. -1 In some embodiments, contacting the second feed stream with the second catalyst at a weight hourly space velocity (WHSV) of about 1 h to form the first feed stream. In some embodiments, contacting the second feed stream with the second catalyst at a weight hourly space velocity (WHSV) of about 1 h to form the first feed stream. -1 ~5h -1In some embodiments, contacting the second feed stream with the second catalyst at a weight hourly space velocity (WHSV) of about 0.1 h to form the first feed stream. In some embodiments, contacting the second feed stream with the second catalyst at a weight hourly space velocity (WHSV) of about 0.1 h to form the first feed stream. -1 ~10h -1 contacting the second feed stream with the second catalyst at a weight hourly space velocity (WHSV) of 0.1 to 0.5 to form the first feed stream.

[0026] In some embodiments, the first feed stream can include one or more angelicalactones. In such embodiments, the method can include removing the one or more angelicalactones from the first feed stream before contacting the first feed stream with the one or more first catalysts.

[0027] In another embodiment, an exemplary method for converting γ-valerolactone to two or more different C2-C6 linear or branched olefins comprises subjecting a reactor to a reaction at a temperature of about 300° C. to 500° C., a pressure of about 0 psig to 100 psig, and a reaction time of at least 1 hour. -1 and contacting a feed stream comprising γ-valerolactone with one or more catalysts at a weight hourly space velocity (WHSV) of 0.1 to 1.0 to form a mixture, the mixture comprising two or more different C2-C6 linear or branched olefins in at least 95% yield, wherein the one or more first catalysts comprise a boron- and phosphor-doped zeolite.

[0028] In some embodiments, boron can be present in the doped zeolite in an amount of 1 wt.% to 3 wt.% based on the total weight of the doped zeolite, and in some embodiments, the phosphor can be present in the doped zeolite in an amount of 1 wt.% to 4 wt.% based on the total weight of the doped zeolite.

[0029] In some embodiments, the two or more different C2-C6 linear or branched olefins can include ethylene, propylene, butene, butadiene, or any combination thereof.

[0030] In another embodiment, an exemplary method for converting levulinic acid to gamma-valerolactone includes contacting a feed stream comprising levulinic acid with a catalyst in a reactor to form a mixture, the mixture comprising gamma-valerolactone in at least 20% yield, and the catalyst can include ZnZrAlSi or ZnZrSi.

[0031] In some embodiments, γ-valerolactone may be produced in a yield of at least 25%. In some embodiments, γ-valerolactone may be produced in a yield of at least 50%. In some embodiments, γ-valerolactone may be produced in a yield of about 25% to 35%.

[0032] In some embodiments, the reactor may be at a temperature of about 300°C to 500°C. In some embodiments, the reactor may be at a temperature of about 380°C to 450°C.

[0033] In some embodiments, the reactor can be at a pressure of about 0 psig to 300 psig. In some embodiments, the reactor can be at a pressure of about 0 psig to 100 psig.

[0034] In some embodiments, contacting the feed stream with the catalyst is for at least 0.5 h. -1 In some embodiments, contacting the feed stream with the catalyst at a weight hourly space velocity (WHSV) of about 1 h to form a mixture can be performed. -1 ~5h -1 In some embodiments, contacting the feed stream with the catalyst at a weight hourly space velocity (WHSV) of about 0.1 h to form a mixture. In some embodiments, contacting the feed stream with the catalyst at a weight hourly space velocity (WHSV) of about 0.1 h to form a mixture. -1 ~10h -1 to form a mixture.

[0035] In some embodiments, the mixture can include one or more angelicalactones. In such embodiments, the method can include removing the one or more angelicalactones from the mixture.

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate certain embodiments of the subject matter disclosed herein and, together with the description, serve to explain some of the principles associated with the disclosed embodiments. [Brief explanation of the drawings]

[0037] [Figure 1] 1 is a graph showing the product olefin distribution in Examples 2 to 7.

[0038] MODE FOR CARRYING OUT THE INVENTION Certain exemplary embodiments will now be described to provide a general understanding of the principles of the structure, function, manufacture, and use of the systems and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the systems and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments, and that the scope of the invention is not defined solely by the claims. Features shown or described in connection with one exemplary embodiment may be combined with features of other embodiments. Such modifications and variations are intended to be within the scope of the present invention.

[0039] The terminology used herein is for the purpose of describing particular aspects and embodiments only and is not intended to be limiting. For example, as used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0040] In the description and claims, phrases such as "at least one of" or "one or more of" may appear followed by a concatenated list of elements or features. The term "and / or" may also appear with a list of two or more elements or features. Unless implicitly or explicitly contradicted by the context of use, such phrases are intended to mean any of the listed elements or features individually, or any of the listed elements or features in combination with any of the other listed elements or features. For example, the phrases "at least one of A and B," "one or more of A and B," and "A and / or B" are intended to mean "A alone, B alone, or A and B together," respectively. A similar interpretation is intended for lists containing more than two items. For example, the phrases "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, and / or C" are each intended to mean "A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together." Use of the term "based on" above and in the claims is intended to mean "based at least in part on," allowing for unrecited features or elements.

[0041] Although the terms "first" and "second" may be used herein to describe various features / elements (including steps), these features / elements should not be limited by these terms unless the context indicates otherwise. These terms may be used to distinguish one feature / element from another. Thus, a first feature / element described below could be referred to as a second feature / element, and similarly, a second feature / element described below could be referred to as a first feature / element, without departing from the teachings provided herein.

[0042] As used in this specification and claims, including in the examples, unless expressly specified otherwise, all numbers can be read as if preceded by the word "about" or "approximately," even if the term does not explicitly appear. The phrase "about" or "approximately" can be used in describing a magnitude and / or location to indicate that the stated value and / or location is within a reasonably expected range of value and / or location. For example, a numerical value can have a value of + / - 0.1% of the stated value (or range of values), + / - 1% of the stated value (or range of values), + / - 2% of the stated value (or range of values), + / - 5% of the stated value (or range of values), + / - 10% of the stated value (or range of values), etc. Any numerical value set forth herein should be understood to include approximately or approximately that value unless the context indicates otherwise. For example, if the value "10" is disclosed, "about 10" is also disclosed. Any numerical range recited herein is intended to include all subranges subsumed therein. As will be appreciated by those skilled in the art, when a value is disclosed, it is understood that "less than or equal to" that value, "greater than or equal to" that value, and possible ranges between those values are also disclosed. For example, if a value "X" is disclosed, "less than or equal to X" and "greater than or equal to X" (e.g., where X is a number) are also disclosed. It is also understood that throughout this application, data is provided in several different formats, and this data represents endpoints and starting points, as well as ranges for any combination of the data points. For example, if a specific data point "10" and a specific data point "15" are disclosed, it is understood that greater than, greater than, less than, less than, less than, and equal to 10 and 15, as well as 10 to 15, are considered disclosed. It is also understood that each unit between two specified units is disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0043] "WHSV" refers to weight hourly space velocity and is defined as the weight of feed flowing per unit weight of catalyst per hour.

[0044] As used herein, "aromatic" or "aromatic compound" refers to a cyclic organic carbon compound of six or more carbons, such as benzene.

[0045] All yields and conversions stated herein are by weight unless otherwise specified.

[0046] The present disclosure generally provides methods for producing a mixture of at least two different olefins (e.g., ethylene, propylene, butenes (e.g., linear or branched butenes), butadiene, and hexene) from GVL. While conventional methods use GVL as a starting material, these conventional methods do not produce a product stream that is a mixture of different olefins; instead, for example, the product stream includes either butenes or butadiene. The catalysts described herein enable the conversion of GVL to a product stream having two or more different olefins. As used herein, "different olefins" refers to two or more olefins that differ in the number and / or identity of atoms relative to each other. Examples of different olefins include 1-butene and 1,3-butadiene, because the former has the chemical formula CH and the latter has the chemical formula CH. Not different means that two or more olefins have the same chemical formula, even if they do not have the same stereochemistry or isomerism. Examples of not different olefins include isobutylene and cis-butene, because they both have the chemical formula CH.

[0047] Generally, the method includes contacting a feed stream (e.g., a first feed stream) containing at least GVL with one or more catalysts (e.g., one or more first catalysts) in a reactor to form a mixture containing two or more different C2-C6 linear or branched olefins in at least a 60% yield, wherein the one or more catalysts comprise a doped zeolite. In some embodiments, the yield of the two or more different C2-C6 linear or branched olefins can be about 80%-90%. In other embodiments, the yield of the two or more different C2-C6 linear or branched olefins can be at least about 98%.

[0048] In some embodiments, the feed stream can include angelicalactone. In such embodiments, the method can include removing angelicalactone from the first feed stream before contacting the first feed stream with the one or more first catalysts.

[0049] In some embodiments, the two or more different C2-C6 linear or branched olefins can comprise one or more butenes and butadiene. In such embodiments, the one or more butenes can comprise linear butenes, branched butenes (e.g., isobutylene), or both. For example, in certain embodiments, the two or more different C2-C6 linear or branched olefins can comprise one or more linear butenes and butadiene, while in other embodiments, the two or more different C2-C6 linear or branched olefins can comprise one or more butenes and butadiene. Alternatively or additionally, the two or more different C2-C6 linear or branched olefins can comprise ethylene. Alternatively or additionally, the two or more different C2-C6 linear or branched olefins can comprise propylene. In one embodiment, the two or more different C2-C6 linear or branched olefins can comprise one or more linear butenes, isobutylene, butadiene, ethylene, and propylene. It is also contemplated herein that the two or more different C2-C6 linear or branched olefins do not include isobutylene, ethylene, propylene, or any combination thereof.

[0050] In some embodiments, where the two or more different C2-C6 linear or branched olefins include butadiene, the butadiene can be present in the mixture in an amount of about 1 wt. % to 50 wt. % based on the total weight of the mixture. In other embodiments, the butadiene can be present in the mixture in an amount of about 10 wt. % to 45 wt. % based on the total weight of the mixture. It is also contemplated that the amount of butadiene present in the mixture will not fall outside any of these recited ranges. It is further contemplated that the amount of butadiene present in the mixture can be between any of these recited ranges.

[0051] The one or more catalysts used in the conversion of GVL to two or more different C2-C6 linear or branched olefins can, for example, involve the use of one or more doped zeolites. Non-limiting suitable examples of the one or more zeolites can include crystalline silicates of the group ZSM-5 (MFI or BEA framework), CHA, FER, FAU, MWW, MOR, EUO, MFS, ZSM-48, MTT, SAPO-34, MTP or TON having a Si / Al ratio greater than 10, or dealuminated crystalline silicates of the group ZSM-5 (MFI or BEA framework), CHA, FER, FAU, MWW, MOR, EUO, MFS, ZSM-48, MTT or TON having a Si / Al ratio greater than 10.

[0052] Undoped H +Suitable dopants particularly useful herein for adjusting zeolite acidity and hydrothermal stability to provide desirable yields and selectivities based on GVL conversion relative to the zeolite form are phosphors and / or boron, either together or separately. Thus, in some embodiments, one or more doped zeolites can include one or more dopants including boron, phosphors, or both. In some embodiments, boron can be present in the doped zeolite in an amount of 1 wt. % to 3 wt. % based on the total weight of the doped zeolite, and phosphors can be present in the doped zeolite in an amount of 1 wt. % to 4 wt. % based on the total weight of the doped zeolite. In some embodiments, the one or more doped zeolites can include ZSM-5 (MFI or BEA framework) with Si / Al greater than 10, phosphorus and / or boron modified crystalline silicates of the group CHA, FER, FAU, MWW, MOR, EUO, MFS, ZSM-48, MTT or TON, or silico-alumino-phosphate type molecular sieves of the group AEL.

[0053] In embodiments in which the one or more dopants include at least boron, in some embodiments, the boron can be present in the doped zeolite in an amount of 1 wt.% to 3 wt.%, based on the total weight of the doped zeolite. In other embodiments, the boron can be present in the doped zeolite in an amount of 1.5 wt.% to 2.5 wt.%, based on the total weight of the doped zeolite. It is also contemplated that the amount of boron present in the one or more dopants will not fall outside any of these recited ranges. It is further contemplated that the amount of boron present in the one or more dopants can be between any of these recited ranges.

[0054] In embodiments in which the one or more dopants include at least a phosphor, in some embodiments, the phosphor may be present in the doped zeolite in an amount of 1 wt.% to 4 wt.%, based on the total weight of the doped zeolite. In other embodiments, the phosphor may be present in the doped zeolite in an amount of 2 wt.% to 3.5 wt.%, based on the total weight of the doped zeolite. It is also contemplated that the amount of phosphor present in the one or more dopants may not fall outside any of these recited ranges. It is further contemplated that the amount of boron present in the one or more dopants may be between any of these recited ranges.

[0055] In some embodiments, the one or more catalysts (eg, the one or more first catalysts) comprise boron and phosphor-doped ZSM-5 with a Si / Al ratio of 55 or 90.

[0056] Additional additives for mixing with the doped zeolite can include a SiO2 support doped with a metal dopant. Non-limiting examples of suitable metal dopants can include iron (Fe), strontium (Sr), cobalt (Co), nickel (Ni), lanthanum (La), chromium (Cr), zirconium (Zr), ruthenium (Ru), molybdenum (Mo), iridium (Ir), magnesium (Mg), tungsten (W), copper (Cu), manganese (Mn), vanadium (V), zinc (Zn), titanium (Ti), rhodium (Rh), rhenium (Re), gallium (Ga), palladium (Pd), silver (Ag), indium (In), or any combination thereof. One or more of the above exemplary metal dopants can be used in place of or in addition to boron and / or phosphor.

[0057] In some embodiments, one or more of the catalysts described herein may be prepared by incipient wetness impregnation techniques.

[0058] In use, the method can be carried out at a variety of temperatures. In some embodiments, for example, the temperature of the reactor (e.g., the first reactor) can be from 100°C to 600°C. In other embodiments, the temperature of the reactor can be from about 300°C to 500°C, from about 380°C to 460°C, or from about 400°C to 500°C. It is contemplated that the reactor temperature will not fall outside any of these recited ranges. It is further contemplated that the reactor temperature can be between any of these recited ranges.

[0059] Alternatively or additionally, the method can be carried out under a variety of pressures. In some embodiments, for example, the reactor (e.g., first reactor) pressure can be from about 0 psig to 500 psig. In other embodiments, the reactor pressure can be from about 0 psig to 300 psig, or from about 0 psig to 100 psig. It is contemplated that the reactor pressure will not fall outside any of these recited ranges. It is further contemplated that the reactor pressure can be between any of these recited ranges.

[0060] Alternatively or additionally, the process can be carried out under various weight hourly space velocities. In some embodiments, for example, the WHSV is at least 0.5 h -1 Or at least 1h -1 In other embodiments, the WHSV may be about 0.1 h -1 ~15 h-1 , about 1 h-1 ~10 h-1 , or about 1 h-1 ~5 h-1 It is also contemplated that the WHSV of the reactor may not fall outside any of these recited ranges. It is further contemplated that the process may be carried out at a WHSV between any of these recited ranges.

[0061] In certain embodiments of the methods described herein, the method comprises heating at a temperature between 100° C. and 500° C., at a pressure between about 0 psig and 100 psig, and for at least 0.5 hours. -1In some embodiments, the process for converting GVL to two or more C2-C6 linear or branched olefins can be carried out in a reactor at a temperature of about 300° C. to 500° C., a pressure of about 0 psig to 100 psig, and for at least 1 hour. -1 and contacting a feed stream comprising γ-valerolactone with a boron and phosphor doped zeolite at a weight hourly space velocity (WHSV) of 0.1 to 1.0 to form a mixture, wherein the mixture comprises two or more different C2-C6 linear or branched olefins in at least 95% yield, and wherein the one or more first catalysts comprise the boron and phosphor doped zeolite.

[0062] GVL is produced from the conversion of LA. Thus, the methods presented herein can include a method of converting LA to GVL. Generally, a method of converting levulinic acid to γ-valerolactone (GVL) can include contacting a feed stream (e.g., a second feed stream) containing levulinic acid with a catalyst in a reactor (e.g., a second reactor) to form a mixture containing GVL. In some embodiments, GVL is produced in a yield of at least 20%, at least 25%, or at least 50%. In certain embodiments, GVL is produced in a yield of about 25% to 50%, about 20% to 50%, about 25% to 40%, or about 25% to 35%. It is also contemplated that the yield of GVL will not fall outside any of these recited ranges. It is further contemplated that the yield of GVL will be between any of these recited ranges.

[0063] In some embodiments, the catalyst can include ZnZrSi or ZnZrAlSi. These catalysts can be prepared by the hard-template method, the co-precipitation method, or the impregnation method with co-precipitation.

[0064] For example, in some embodiments, ZnZrSi mixed oxide catalysts can be prepared by coprecipitation with carbon black. In one such embodiment, precursor metal salts are added to deionized water to produce the appropriate zinc-to-zirconium ratio. In additional embodiments, a mixture of zinc and zirconium nitrate can be sonicated to produce a clear solution or heated to 60°C until a clear solution is produced. In yet another additional embodiment, the sonicated or heated zinc and zirconium nitrate mixture is added to a flask, followed by carbon black. The heterogeneous mixture is stirred for 5-10 minutes to ensure complete wetting of the carbon black, after which an appropriate amount of silicon dioxide is added, followed by stirring for an additional 5-10 minutes. The resulting mixture is precipitated at room temperature with vigorous stirring by the dropwise addition of 20 wt% NaOH, LiOH, or KOH until a final pH of 6.0-8.0 is obtained. The precipitated slurry is then stirred for an additional 60 minutes at room temperature. In yet additional embodiments, the coprecipitated ZnZrSi mixed oxide catalyst may be dried at 140°C and calcined at a temperature between 400°C and 550°C. In an exemplary embodiment, calcination is performed at a temperature of 500°C for 4 hours. In exemplary embodiments, the final ratio of Zn / Zr / Si (x:y:v) in the ZnZrSi mixed oxide catalyst is in the range of about 1:8:1 to about 1:36:4. In a more specific exemplary embodiment, the ratio of Zn / Zr / Si (x:y:v) in the ZnZrSi mixed oxide catalyst is about 1:12:2.

[0065] For example, in some embodiments, a ZnZrAlSi mixed oxide catalyst is prepared using a co-precipitation method with carbon black. In one such embodiment, precursor metal salts are added to deionized water to produce the appropriate zinc-to-zirconium ratio. In additional embodiments, a mixture of zinc and zirconium nitrate can be sonicated to produce a clear solution or heated to 60°C until a clear solution is produced. In yet another additional embodiment, the sonicated or heated zinc and zirconium nitrate mixture is added to a flask, followed by finely ground Al2O3, SiO2, and carbon black. The resulting mixture is precipitated at room temperature with vigorous stirring by dropwise addition of 20 wt% NaOH until a final pH of 7.0-8.0 is obtained. The precipitated slurry is then stirred at room temperature for an additional 60 minutes. In yet another additional embodiment, the co-precipitated ZnZrAlSi mixed oxide catalyst can be dried at 140°C and calcined at a temperature of 400°C-550°C. In an exemplary embodiment, calcination is performed at a temperature of 500°C for 4 hours. In a specific exemplary embodiment, the ratio of Zn / Zr / Al / Si (x:y:v:s) in the ZnZrAlSi mixed oxide catalyst is about 1:12:2:2.

[0066] In use, the conversion of LA to GVL can occur at a variety of temperatures. In some embodiments, for example, the reactor (e.g., the second reactor) is at a temperature of about 300°C to 500°C. In other embodiments, the reactor temperature can be about 350°C to 500°C, about 350°C to 400°C, or about 380°C to 450°C. It is contemplated that the reactor temperature will not fall outside any of these recited ranges. It is further contemplated that the reactor temperature can be between any of these recited ranges.

[0067] Alternatively or additionally, the method can be carried out under a variety of pressures. In some embodiments, for example, the reactor (e.g., first reactor) pressure can be from about 0 psig to 500 psig. In other embodiments, the reactor pressure can be from about 0 psig to 300 psig, or from about 0 psig to 100 psig. It is contemplated that the reactor pressure will not fall outside any of these recited ranges. It is further contemplated that the reactor pressure can be between any of these recited ranges.

[0068] Alternatively or additionally, the process can be carried out under various weight hourly space velocities. In some embodiments, for example, the WHSV is at least 0.5 h -1 Or at least 1h -1 In other embodiments, the WHSV may be about 0.1 h -1 ~10 h-1 , about 1 h-1 ~10 h-1 , or about 1 h-1 ~5 h-1 It is also contemplated that the WHSV of the reactor may not fall outside any of these recited ranges. It is further contemplated that the process may be carried out at a WHSV between any of these recited ranges.

[0069] In some embodiments, the conversion of LA can produce one or more angelicalactones in addition to GVL. Thus, in certain embodiments, the mixture can include one or more angelicalactones. The method can also include removing one or more angelicalactones from the mixture.

[0070] It should be noted that the method described herein for producing two or more C2-C6 linear or branched olefins can include the method described herein for converting LA to GVL, followed by the method described herein for converting GVL to two or more C2-C6 linear or branched olefins. For example, in some embodiments, the method for producing two or more C2-C6 linear or branched olefins can include contacting a first feed stream comprising levulinic acid with a first catalyst in a reactor to produce a second feed stream, and contacting a second feed stream comprising γ-valerolactone with one or more second catalysts in a separate reactor to form a mixture comprising two or more different C2-C6 linear or branched olefins, wherein the one or more first catalysts comprise a doped zeolite. In certain embodiments, the first catalyst can comprise ZnZrAlSi or ZnZrSi.

[0071] The following specific examples are intended to be illustrative and should not be construed as limiting the scope of the claims.

[0072] Example Reactor Configuration: LA conversion to GVL and GVL conversion to olefins were carried out at 300–500 °C through a fixed-bed reactor in which preheated (160 °C) vaporized feedstocks containing specific catalysts (e.g., LA, water, and formic acid (LA to GVL) or GVL and water (GVL to olefin mixture)) flowed downward over the fixed catalyst bed at atmospheric pressure or under moderate pressure (e.g., 0–30 bar) with nitrogen co-feed. The feed flow rate was controlled by a Teledyne Model 500D syringe pump, and the flow rate was adjusted to achieve the target olefin WHSV (weight hourly space velocity). The internal reaction temperature was maintained constant via a Thermo-Scientific Lindberg Blue M furnace. Conversions and selectivities were calculated by GC analysis of the liquid-phase reactor effluent for organics and water content and online GC analysis of non-condensed hydrocarbons (e.g., C2–C7 olefins) against nitrogen as an internal standard.

[0073] Example 1: LA conversion to AL and GVL - Single-stage reactor configuration: Reaction conditions: Feed - LA and formic acid (2 equivalents relative to LA) aqueous solution (36 wt%, 28 wt%, 36 wt%, respectively); T = 385°C in reactor, WHSV = 1.0 (based on LA), P = 0 bar; Catalyst - mixed metal oxide Zn / Zr / Al / Si (1 / 12 / 2 / 2 molar ratio); LA conversion = 80% Single Pass Reactor Effluent Composition - Area % of Total: 5-Me-2(3H)-furanone 27 5-Me-2(5H)-furanone 33 GVL 35 aromatic 4

[0074] Example 2: GVL conversion to olefins - Single-stage reactor configuration: Reaction conditions: Feed - aqueous GVL (40 wt%); T = 440°C in reactor, WHSV = 3.8 (based on GVL), P = 0 bar; Catalyst - MTP commercial catalyst; GVL conversion = 83% Single Pass Reactor Effluent Composition - Area % of Total: 2-Cyclopentenone 0.8 Ethylene 6.5 Propylene 24.8 Isobutylene 14.1 1-Butene 9.4 Butadiene (BD) 6.8 Trans-2-butene 17.3 cis-2-butene 12.5 Saturates (C2-C5) 5.0

[0075] Example 3: GVL conversion to olefins - Single-stage reactor configuration: Reaction conditions: Feed - aqueous GVL (40 wt%); T = 440°C in reactor, WHSV = 3.8 (based on GVL), P = 0 bar; Catalyst - SAPO-34 commercial catalyst; GVL conversion = 83% Single Pass Reactor Effluent Composition - Area % of Total: 2-Cyclopentenone 4.8 Ethylene 0.8 Propylene 1.2 Isobutylene 0.0 1-Butene 60.5 Butadiene (BD) 12.3 trans-2-butene 10.4 cis-2-butene 9.6 Saturates (C2-C5) 0.5

[0076] Example 4: GVL conversion to olefins - Single-stage reactor configuration: Reaction conditions: Feed - aqueous GVL (40 wt%); T = 440°C in reactor, WHSV = 3.8 (based on GVL), P = 0 bar; Catalyst - boron and phosphor doped ZSM5 H + Zeolite extrudate (Si / Al ratio = 90); GVL conversion = 98.9% Single Pass Reactor Effluent Composition - Area % of Total: 2-Cyclopentenone 2.6 Ethylene 7.3 Propylene 30.3 Isobutylene 11.7 1-butene 7.8 Butadiene (BD) 13.5 Trans-2-butene 13.2 cis-2-butene 9.6 Saturates (C2-C5) 1.5

[0077] Example 5: GVL conversion to olefins - Single-stage reactor configuration: Reaction conditions: Feed - aqueous GVL (40 wt%); T = 440°C in reactor, WHSV = 3.8 (based on GVL), P = 0 bar; Catalyst - boron and phosphor doped ZSM5 H + Zeolite powder (Si / Al ratio = 90); GVL conversion rate = 99.8% Single Pass Reactor Effluent Composition - Area % of Total: 2-Cyclopentenone 0.4 Ethylene 9.2 Propylene 40.8 Isobutylene 12.3 1-Butene 8.2 Butadiene (BD) 1.6 Trans-2-butene 9.9 cis-2-butene 7.2 Saturates (C2-C5) 3.7

[0078] Example 6: GVL conversion to olefins - Single-stage reactor configuration: Reaction conditions: Feed - aqueous GVL (40 wt%); T = 440°C in reactor, WHSV = 1.7 (based on GVL), P = 0 bar; Catalyst - boron and phosphor doped ZSM5 H + Zeolite extrudate (Si / Al ratio = 55); GVL conversion = 99.2% Single Pass Reactor Effluent Composition - Area % of Total: 2-Cyclopentenone 2.8 Ethylene 5.9 Propylene 20.4 Isobutylene 12.4 1-Butene 8.2 Butadiene (BD) 10.6 Trans-2-butene 18.6 cis-2-butene 13.2 C5 olefin 3.7 C2-C5 saturates 4.2

[0079] Example 7: GVL conversion to olefins - Single-stage reactor configuration: Reaction conditions: Feed - aqueous GVL (40 wt%); T = 440°C in reactor, WHSV = 3.8 (based on GVL), P = 0 bar; Catalyst - boron and phosphor doped ZSM5 H + Zeolite powder (Si / Al ratio = 55); GVL conversion rate = 99.8% Single Pass Reactor Effluent Composition - Area % of Total: 2-Cyclopentenone 2.7 Ethylene 0.4 Propylene 2.5 Isobutylene 0.0 1-Butene 15.3 Butadiene (BD) 41.3 Trans-2-butene 22.0 cis-2-butene 15.3 Saturates (C2-C5) Trace amounts

[0080] While various exemplary embodiments have been described above, any of several modifications can be made to the various embodiments without departing from the teachings herein. For example, the order in which various described method steps are performed may often be changed in alternative embodiments, and in other alternative embodiments, one or more method steps may be skipped entirely. Optional features of the various system and method embodiments may be included in some embodiments and not in others. Accordingly, the foregoing description has been provided primarily for illustrative purposes and should not be construed as limiting the scope of the claims.

[0081] The examples and illustrations contained herein illustrate, by way of illustration and not limitation, specific modes in which the subject matter may be practiced. As noted above, other modes may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of the present disclosure. Such modes of the inventive subject matter may be referred to herein individually or collectively by the term "invention," merely for convenience when more than one is actually disclosed, and without any intention to intentionally limit the scope of the present application to any single invention or inventive concept. Thus, while specific modes are shown and described herein, any configuration calculated to achieve the same purpose may be substituted for the specific mode shown. The present disclosure is intended to cover any and all adaptations or modifications of various modes. Combinations of the above modes, as well as other modes not specifically described herein, will be apparent to those skilled in the art upon reviewing the above description. The use of the term "based on" in the specification and claims is intended to mean "based at least in part on," allowing for unrecited features or elements.

[0082] The subject matter described herein may be embodied in systems, devices, methods, and / or articles, depending on the desired configuration. The embodiments set forth in the foregoing description do not represent all embodiments consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. While some variations have been described in detail herein, other modifications or additions are possible. In particular, additional features and / or variations may be provided in addition to those described herein. For example, the embodiments described herein may be directed to various combinations and subcombinations of the disclosed features and / or combinations and subcombinations of certain additional features disclosed herein. Additionally, the logic flow depicted in the accompanying figures and / or described herein does not necessarily require the particular order shown or sequence to achieve desirable results. Other embodiments may be within the scope of the following claims.

Claims

1. Two or more different C ２ -C ６ 1. A process for producing linear or branched olefins, comprising: contacting a first feedstream comprising gamma valerolactone with one or more first catalysts in a first reactor to form a mixture, wherein the mixture is produced from two or more different C ２ -C ６ containing linear or branched olefins, The method wherein the one or more first catalysts comprise a doped zeolite.

2. 10. The method of claim 1, wherein the doped zeolite comprises one or more dopants, the one or more dopants comprising boron, a phosphor, or a combination thereof.

3. 3. The method of claim 2, wherein the boron is present in the doped zeolite in an amount of 1 wt. % to 3 wt. % based on the total weight of the doped zeolite.

4. 3. The method of claim 2, wherein the boron is present in the doped zeolite in an amount of 1.5 wt. % to 2.5 wt. % based on the total weight of the doped zeolite.

5. 5. The method of claim 2, wherein the phosphor is present in the doped zeolite in an amount of 1% to 4% by weight based on the total weight of the doped zeolite.

6. 5. The method of claim 2, wherein the phosphor is present in the doped zeolite in an amount of 2% to 3.5% by weight based on the total weight of the doped zeolite.

7. 7. The method of any one of claims 1 to 6, wherein the doped zeolite comprises one or more dopants, wherein the one or more dopants comprise Zr, W, Cu, Mg, Co, Mo, Zn, Ti, Ga, or any combination thereof.

8. 8. The method of any one of claims 1 to 7, wherein the doped zeolite comprises ZSM-5.

9. The two or more different C ２ -C ６ 9. The process of any one of claims 1 to 8, wherein the linear or branched olefins comprise one or more of butene and butadiene and at least one of ethylene or propylene.

10. The two or more different C ２ -C ６ 9. The process of any one of claims 1 to 8, wherein the linear or branched olefin comprises one or more butenes.

11. The two or more different C ２ -C ６ 11. The process of claim 10, wherein the linear or branched olefin comprises butadiene.

12. The two or more different C ２ -C ６ 9. The process of any one of claims 1 to 8, wherein the linear or branched olefin comprises one or more linear butenes and butadiene.

13. 13. The method of any one of claims 9 to 12, wherein the butadiene is present in the mixture in an amount of about 1 wt% to 50 wt%, based on the total weight of the mixture.

14. 13. The method of claims 19 to 12, wherein the butadiene is present in the mixture in an amount of about 10% to 45% by weight, based on the total weight of the mixture.

15. The two or more different C ２ -C ６ 15. The process of any one of claims 1 to 14, wherein the yield of linear or branched olefins is at least about 98%.

16. The two or more different C ２ -C ６ 16. The process of any one of claims 1 to 15, wherein the yield of linear or branched olefins is about 80% to 90%.

17. 17. The method of any one of claims 1 to 16, wherein the first reactor is at a temperature of about 300°C to 500°C.

18. 18. The method of any one of claims 1 to 17, wherein the first reactor is at a temperature of about 380°C to 460°C.

19. 19. The method of any one of claims 1 to 18, wherein the first reactor is at a pressure of about 0 psig to 300 psig.

20. 19. The method of any one of claims 1 to 18, wherein the first reactor is at a pressure of about 0 psig to 100 psig.

21. contacting the first feed stream with the one or more first catalysts for at least 0.5 h －１ 21. The method of any one of claims 1 to 20, comprising contacting the first feed stream with the one or more first catalysts at a weight hourly space velocity (WHSV) of 0.1 to 0.5 to form the mixture.

22. contacting the first feed stream with the one or more first catalysts for about 1 h －１ ~10 hours －１ 21. The method of any one of claims 1 to 20, comprising contacting the first feed stream with the one or more first catalysts at a weight hourly space velocity (WHSV) of 0.1 to 0.5 to form the mixture.

23. Contacting the first feed stream with the one or more first catalysts is performed for about 0.1 h. －１ ~15 hours －１ 21. The method of any one of claims 1 to 20, comprising contacting the first feed stream with the one or more first catalysts at a weight hourly space velocity (WHSV) of 0.1 to 0.5 to form the mixture.

24. 24. The process of any one of claims 1 to 23, further comprising contacting a second feed stream comprising levulinic acid with a second catalyst in a second reactor to produce the first feed stream.

25. 25. The method of claim 24, wherein the gamma valerolactone is produced in a yield of at least 25%.

26. 25. The method of claim 24, wherein the gamma valerolactone is produced in a yield of at least 50%.

27. 25. The method of claim 24, wherein the gamma valerolactone is produced in a yield of about 25% to 35%.

28. 28. The method of any one of claims 24 to 27, wherein the second catalyst comprises a mixed metal oxide.

29. 29. The method of any one of claims 24 to 28, wherein the second catalyst comprises ZnZrAlSi.

30. 29. The method of any one of claims 24 to 28, wherein the second catalyst comprises ZnZrSi.

31. 31. The method of any one of claims 24 to 30, wherein the second reactor is at a temperature of about 300°C to 500°C.

32. 31. The method of any one of claims 24 to 30, wherein the second reactor is at a temperature of about 380°C to 450°C.

33. 33. The method of any one of claims 24 to 32, wherein the second reactor is at a pressure of about 0 psig to 300 psig.

34. 33. The method of any one of claims 24 to 32, wherein the second reactor is at a pressure of about 0 psig to 100 psig.

35. and contacting the second feed stream with the second catalyst for at least 0.5 h. －１ 35. The method of any one of claims 24 to 34, comprising contacting the second feed stream with the second catalyst at a weight hourly space velocity (WHSV) of 0.1 to 0.5 to form the first feed stream.

36. Contacting the second feed stream with the second catalyst is performed for about 1 h. －１ ~5 hours －１ 35. The method of any one of claims 24 to 34, comprising contacting the second feed stream with the second catalyst at a weight hourly space velocity (WHSV) of 0.1 to 0.5 to form the first feed stream.

37. Contacting the second feed stream with the second catalyst is performed for about 0.1 h. －１ ~10 hours －１ 35. The method of any one of claims 24 to 34, comprising contacting the second feed stream with the second catalyst at a weight hourly space velocity (WHSV) of 0.1 to 0.5 to form the first feed stream.

38. 38. The method of any one of claims 1 to 37, wherein the first feed stream further comprises one or more angelica lactones.

39. 39. The method of claim 38, further comprising removing the one or more angelica lactones from the first feed stream prior to contacting the first feed stream with the one or more first catalysts.

40. γ-valerolactone in a mixture of two or more different C ２ -C ６ 1. A process for converting linear or branched olefins, comprising the steps of: In the reactor, a temperature of about 300° C. to 500° C., a pressure of about 0 psig to 100 psig, and －１ and contacting a feed stream comprising γ-valerolactone with one or more catalysts at a weight hourly space velocity (WHSV) of 0.05 to 0.15 to form a mixture, wherein the mixture is a mixture of two or more different C ２ -C ６ containing linear or branched olefins, The method, wherein the one or more first catalysts comprise a boron and phosphor doped zeolite.

41. 41. The method of claim 40, wherein the boron is present in the doped zeolite in an amount of 1 wt. % to 3 wt. % based on the total weight of the doped zeolite.

42. 42. The method of claim 40 or 41, wherein the phosphor is present in the doped zeolite in an amount of 1 wt % to 4 wt %, based on the total weight of the doped zeolite.

43. The two or more different C ２ -C ６ 42. The method of claim 40 or 41, wherein the linear or branched olefin comprises ethylene, propylene, butene, butadiene, or any combination thereof.

44. 1. A process for converting levulinic acid into gamma valerolactone, comprising the steps of: contacting a feed stream comprising levulinic acid with a catalyst in a reactor to form a mixture, wherein the mixture comprises the gamma-valerolactone in at least 20% yield; The method wherein the catalyst comprises ZnZrAlSi or ZnZrSi.

45. 45. The method of claim 44, wherein the gamma valerolactone is produced in a yield of at least 25%.

46. 45. The method of claim 44, wherein the gamma valerolactone is produced in a yield of at least 50%.

47. 45. The method of claim 44, wherein the gamma valerolactone is produced in a yield of about 25% to 35%.

48. 48. The method of any one of claims 44 to 47, wherein the reactor is at a temperature of about 300°C to 500°C.

49. 48. The method of any one of claims 44 to 47, wherein the reactor is at a temperature of about 380°C to 450°C.

50. 50. The method of any one of claims 44 to 49, wherein the reactor is at a pressure of from about 0 psig to 300 psig.

51. 50. The method of any one of claims 44 to 49, wherein the reactor is at a pressure of about 0 psig to 100 psig.

52. Contacting the feed stream with the catalyst is for at least 0.5 h. －１ 52. The method of any one of claims 44 to 51, comprising contacting the feed stream with the catalyst at a weight hourly space velocity (WHSV) of

53. Contacting the feed stream with the catalyst is performed for about 1 hour. －１ ~5 hours －１ 52. The method of any one of claims 44 to 51, comprising contacting the feed stream with the catalyst at a weight hourly space velocity (WHSV) of

54. Contacting the feed stream with the catalyst is for about 0.1 h. －１ ~10 hours －１ 52. The method of any one of claims 44 to 51, comprising contacting the feed stream with the catalyst at a weight hourly space velocity (WHSV) of

55. 55. The method of any one of claims 44 to 54, wherein the mixture further comprises one or more angelica lactones.

56. 56. The method of claim 55, further comprising removing the one or more angelica lactones from the mixture.

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