Process for catalytic conversion of C1-C5 alcohols to a mixture of C2-C5 olefins

Abstract

Methods are provided for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins. In an exemplary embodiment, the method can be a one-step process for the direct conversion of C1-C5 alcohols to a mixture of olefins (e.g., C2-C5) carried out in a reactor using a catalyst comprising a zeolite doped with boron and a phosphor. Systems for carrying out these processes are also provided.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application No. 17 / 975,461, filed October 27, 2022, and entitled "Systems and Processes for Catalytic Conversion of C1-C5 Alcohols to C2-C5 Olefin Mixtures," the entire contents of which are incorporated herein by reference for all purposes.

[0002] Systems and methods are provided for the catalytic conversion of C1-C5 alcohols, and more specifically, catalytic processes that result in the direct conversion of bio-based C1-C5 alcohols to a mixture of olefins (C2-C5).

[0003] Background technology There is an increasing demand for the use of biomass to partially replace petroleum resources for the synthesis of fuels. Therefore, the use of bioethanol for the synthesis of fuel base stocks is of great interest. The fundamental reactions in the process of converting ethanol to fuel base stocks are ethanol dehydration followed by ethylene oligomerization.

[0004] In most ethanol dehydration processes, ethanol conversion is nearly complete. Improving C2 selectivity while maintaining high ethanol conversion is important for increasing process efficiency and eliminating expensive downstream separation / purification steps. It is well known that dehydration occurs readily over acidic solids at temperatures above 300 °C. The reaction products are primarily water and ethylene, with ethylene being obtained with selectivities as high as 96% or higher. The most commonly used catalysts are high-purity gamma-alumina, silica-alumina, untreated zeolite (ZSM-5), or zeolite modified by steam treatment. Furthermore, the presence of water in the ethanol feed also has the effect of limiting deactivation of the catalyst surface.

[0005] U.S. Patent No. 4,302,357 relates to an activated alumina catalyst used in the process for producing ethylene from ethanol via dehydration. The LHSV of ethanol is described as 0.25 to 5 h. -1 , preferably 0.5 to 3 hours -1 In the example, the temperature is 370°C and LHSV is 1h. -1 The process is carried out at 315°C to 360°C, 1.7 bar (absolute), and 0.3 h WHSV (on ethanol), with ethylene yields ranging from 65 to 94%. Process Economics Reviews PEP 79-3 (SRI International), December 1979, describes the dehydration of an ethanol-water (95 / 5 wt%) mixture over a silica-alumina catalyst in a tubular fixed bed at 315°C to 360°C, 1.7 bar (absolute), and 0.3 h WHSV (on ethanol). The ethanol conversion is 99%, and the ethylene selectivity is 94.95%. It also describes the dehydration of an ethanol-water (95 / 5 wt%) mixture over a silica-alumina catalyst in a tubular fixed bed at 399°C, 1.7 bar (absolute), and 0.7 h WHSV (on ethanol). -1 also describes the dehydration of an ethanol-water (9575 wt%) mixture over a silica-alumina catalyst in a fluidized bed at 2000 K. The ethanol conversion is 99.6% and the ethylene selectivity is 99.3%.

[0006] The oligomerization of ethylene requires high pressures, generally in the range of 2-4 MPa, but lower temperatures, generally 20-200°C. The catalysts used are mostly transition metals deposited on silica-alumina type supports, zeolites (ZSM-5) or mesoporous solids (MCM-41), as described in V. Hulea et al., J. Catal., 225 (2004) and Heveling et al., J. Applied Catalysis A: General 174 (1998). However, direct oligomerization of ethylene requires relatively small amounts of C (about 40% of the highest reported level). 10+ or diesel fraction. Alternatively, C of ethylene 8+ Oligomerization to olefins can be achieved by a two-stage process. The first stage involves dimerization of the purified ethylene stream to butenes, followed by a second stage to convert the butenes to C 8+It oligomerizes to olefins, which after hydrogenation provide the base stock for fuels.

[0007] U.S. Patent No. 8,552,241 relates to a single-step process for converting ethanol to diesel fuel basestock, which involves contacting ethanol with an acid catalyst at reaction temperatures between 300 and 500°C. The catalyst used is a 50 / 50 mixture of gamma-alumina combined with the commercially available Axens catalyst, Type IS463, marketed as an alumina-based catalyst for the skeletal isomerization of C4 and C5 olefin cuts. Typical single-pass product distributions consisted of a 40-50% hydrocarbon fraction and a 5-20% organic liquid phase yield. The organic liquid phase consisted of approximately 50% olefins, with the majority being C6 olefins, and approximately 40% having a boiling point above 150°C, making it compatible with the diesel pool. The 40-50% hydrocarbon vapor phase contained primarily ethylene and ethane, with trace amounts of C1, C3, C4, and C5. In this case, the yield to the organic liquid phase was relatively low, at approximately 20%, with boiling points above 150°C. The remaining 80% of the organic liquid and hydrocarbon fraction is primarily ethylene and ethane, with trace amounts of C1, C3, C4 and C5 and C6 olefins.

[0008] U.S. Patent No. 9,840,676 relates to a method for converting ethanol into a fuel that can be utilized as a full performance fuel or military jet fuel or diesel fuel in a three-stage process. However, the process begins with ethylene formation, followed by trimerization to hexene, and finally oligomerization to jet and diesel fractions.

[0009] Therefore, there remains a need for improved, efficient, and cost-effective catalytic processes that result in the direct conversion of bio-based alcohols to olefin mixtures.

[0010] Summary of the Invention Aspects of the present subject matter relate, inter alia, to systems and methods for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins.

[0011] In one exemplary embodiment, a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins includes contacting an input stream containing one or more C1-C5 linear or branched alcohols with at least a first catalyst and a second catalyst in a single-bed reactor to form an output stream. The output stream contains one or more C2-C5 olefins. The single-bed reactor is operated at a temperature of about 350°C to about 750°C, a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 0.5 to about 5.0. The first catalyst is a doped or undoped alumina catalyst and includes one or more of zirconium (Zr), titanium (Ti), tungsten (W), or silicon (Si) in neutral or ionic form to form a first mixture, and the second catalyst is a doped or undoped zeolite catalyst.

[0012] In some embodiments, the single-bed reactor can be a fixed-bed reactor, hi other embodiments, the single-bed reactor can be a fluidized-bed reactor.

[0013] In some embodiments, contacting the input stream can further comprise contacting the input stream with a third catalyst in the single-bed reactor. The third catalyst can comprise a doped or undoped SiO2 catalyst.

[0014] In some embodiments, the C1-C5 straight chain or branched alcohols are bio-based and can be produced by a fermentation process. In some embodiments, the C1-C5 straight chain or branched alcohols cannot be derived from petroleum.

[0015] In some embodiments, one or more C2-C5 olefins may be present in the output stream in an amount that may be at least 80 wt%, at least 85 wt%, at least 90 wt%, or at least 95 wt%.

[0016] In some embodiments, the output stream comprises one or more aromatic compounds (C 7+ In some embodiments, the output stream may contain one or more aromatic (C) compounds in an amount not exceeding 10 wt.%. 7+ ) compounds.

[0017] In some embodiments, the method can include removing at least a portion of the C2 olefins from the output stream. In some embodiments, the method can include removing at least a portion of the C4 olefins from the output stream. In some embodiments, the method can include removing at least a portion of the C5 olefins from the output stream.

[0018] In some embodiments, the temperature can be from about 550°C to about 750°C. In some embodiments, the temperature can be from about 350°C to about 550°C.

[0019] In some embodiments, the WHSV can be from about 0.5 to about 1.0, and in some embodiments, the WHSV can be from about 2.0 to about 5.0.

[0020] In another exemplary embodiment, a method for converting methanol to one or more C2-C5 olefins includes contacting an input stream comprising methanol with at least a first catalyst and a second catalyst in a single-bed reactor to form an output stream. The output stream comprises one or more C2-C5 olefins. The single-bed reactor is at a temperature of about 350°C to about 750°C, a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 0.5 to about 5.0. The first catalyst is a doped or undoped alumina catalyst and comprises one or more of zirconium (Zr), titanium (Ti), tungsten (W), or silicon (Si) in neutral or ionic form, and the second catalyst is a doped or undoped zeolite catalyst.

[0021] In some embodiments, the single-bed reactor can be a fixed-bed reactor, hi other embodiments, the single-bed reactor can be a fluidized-bed reactor.

[0022] In some embodiments, contacting the input stream can further comprise contacting the input stream with a third catalyst in the single-bed reactor. The third catalyst can comprise a doped or undoped SiO2 catalyst.

[0023] In some embodiments, the C1-C5 straight chain or branched alcohols are bio-based and can be produced by a fermentation process. In some embodiments, the C1-C5 straight chain or branched alcohols cannot be derived from petroleum.

[0024] In some embodiments, one or more C2-C5 olefins may be present in the output stream in an amount that may be at least 80 wt%, at least 85 wt%, at least 90 wt%, or at least 95 wt%.

[0025] In some embodiments, the output stream comprises one or more aromatic compounds (C 7+In some embodiments, the output stream may contain one or more aromatic (C) compounds in an amount not exceeding 10 wt.%. 7+ ) compounds.

[0026] In some embodiments, the method can include removing at least a portion of the C2 olefins from the output stream. In some embodiments, the method can include removing at least a portion of the C4 olefins from the output stream. In some embodiments, the method can include removing at least a portion of the C5 olefins from the output stream.

[0027] In some embodiments, the temperature can be from about 550°C to about 750°C. In some embodiments, the temperature can be from about 350°C to about 550°C.

[0028] In some embodiments, the WHSV can be from about 0.5 to about 1.0, and in some embodiments, the WHSV can be from about 2.0 to about 5.0.

[0029] In another exemplary embodiment, a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins includes contacting an input stream comprising one or more C1-C5 linear or branched alcohols with a first catalyst in a stacked-bed reactor at a temperature of about 350°C to about 550°C, a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 1.0 to about 2.0 to form a first mixture. The first catalyst is a doped or undoped alumina catalyst comprising one or more of zirconium (Zr), titanium (Ti), tungsten (W), or silicon (Si) in neutral or ionic form. The method further includes contacting the first mixture with at least a second catalyst in the stacked-bed reactor to form an output stream comprising one or more C2-C5 olefins, wherein the second catalyst is a doped or undoped zeolite catalyst.

[0030] In some embodiments, the stacked bed reactor can be a fixed bed reactor, hi other embodiments, the stacked bed reactor can be a fluidized bed reactor.

[0031] In some embodiments, contacting the first mixture can further include contacting the first mixture with a third catalyst in a stacked bed reactor. The third catalyst can include a doped or undoped SiO catalyst.

[0032] In some embodiments, the C1-C5 straight chain or branched alcohols are bio-based and can be produced by a fermentation process. In some embodiments, the C1-C5 straight chain or branched alcohols cannot be derived from petroleum.

[0033] In some embodiments, one or more C2-C5 olefins may be present in the output stream in an amount that may be at least 80 wt%, at least 85 wt%, at least 90 wt%, or at least 95 wt%.

[0034] In some embodiments, the output stream comprises one or more aromatic compounds (C 7+ In some embodiments, the output stream may contain one or more aromatic (C) compounds in an amount not exceeding 10 wt.%. 7+ ) compounds.

[0035] In some embodiments, the method can include removing at least a portion of the C2 olefins from the output stream. In some embodiments, the method can include removing at least a portion of the C4 olefins from the output stream. In some embodiments, the method can include removing at least a portion of the C5 olefins from the output stream.

[0036] In some embodiments, the temperature can be from about 550°C to about 750°C. In some embodiments, the temperature can be from about 350°C to about 550°C.

[0037] In some embodiments, the WHSV can be from about 0.5 to about 1.0, and in some embodiments, the WHSV can be from about 2.0 to about 5.0.

[0038] In another exemplary embodiment, a method for converting methanol to one or more C2-C5 olefins includes contacting an input stream comprising methanol with a first catalyst in a stacked-bed reactor at a temperature of about 350°C to about 550°C, a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 1.0 to about 2.0 to form a first mixture. The first catalyst comprises a doped or undoped alumina catalyst comprising one or more of zirconium (Zr), titanium (Ti), tungsten (W), or silicon (Si) in neutral or ionic form. The method further includes contacting the first mixture with at least a second catalyst in the stacked-bed reactor to form an output stream comprising one or more C2-C5 olefins, wherein the second catalyst is a doped or undoped zeolite catalyst.

[0039] In some embodiments, the stacked bed reactor can be a fixed bed reactor, hi other embodiments, the stacked bed reactor can be a fluidized bed reactor.

[0040] In some embodiments, contacting the first mixture can further include contacting the first mixture with a third catalyst in a stacked bed reactor. The third catalyst can include a doped or undoped SiO catalyst.

[0041] In some embodiments, the C1-C5 straight chain or branched alcohols are bio-based and can be produced by a fermentation process. In some embodiments, the C1-C5 straight chain or branched alcohols cannot be derived from petroleum.

[0042] In some embodiments, one or more C2-C5 olefins may be present in the output stream in an amount that may be at least 80 wt%, at least 85 wt%, at least 90 wt%, or at least 95 wt%.

[0043] In some embodiments, the output stream comprises one or more aromatic compounds (C 7+ In some embodiments, the output stream may contain one or more aromatic (C) compounds in an amount not exceeding 10 wt.%. 7+ ) compounds.

[0044] In some embodiments, the method can include removing at least a portion of the C2 olefins from the output stream. In some embodiments, the method can include removing at least a portion of the C4 olefins from the output stream. In some embodiments, the method can include removing at least a portion of the C5 olefins from the output stream.

[0045] In some embodiments, the temperature can be from about 550°C to about 750°C. In some embodiments, the temperature can be from about 350°C to about 550°C.

[0046] In some embodiments, the WHSV can be from about 0.5 to about 1.0, and in some embodiments, the WHSV can be from about 2.0 to about 5.0.

[0047] In another exemplary embodiment, a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins using a single catalyst system can include contacting an input stream comprising one or more C1-C5 linear or branched alcohols with a catalyst in a reactor to form an output stream comprising one or more C2-C5 olefins, the catalyst consisting essentially of a boron- and phosphor-doped zeolite. The reactor is operated at a temperature of about 300° C. to about 600° C., a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 0.25 to about 10.

[0048] In some embodiments, the reactor can be a single-bed reactor. In some embodiments, the single-bed reactor can be a fixed-bed reactor. In some embodiments, the single-bed reactor can be a fluidized-bed reactor. In some embodiments, the single-bed reactor can be a moving-bed reactor.

[0049] In some embodiments, the one or more C2-C5 olefins may be present in the output stream in an amount from about 50% to about 99% by weight of the total hydrocarbon product. In some embodiments, the one or more C2-C5 olefins may be present in the output stream in an amount from about 85% to about 99% by weight of the total hydrocarbon product.

[0050] In some embodiments, boron can be present in the catalyst in an amount of from about 0.01% to about 10% by weight, hi some embodiments, boron can be present in the catalyst in an amount of at least 0.05% by weight.

[0051] In some embodiments, the phosphor may be present in the catalyst in an amount of about 0.1% to about 7% by weight, hi some embodiments, the phosphor may be present in the catalyst in an amount of at least 1.5% by weight.

[0052] In some embodiments, the zeolite can be a ZSM-5 zeolite.

[0053] In another exemplary embodiment, a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins using a single catalyst system includes contacting an input stream containing one or more C1-C5 linear or branched alcohols with a single catalyst in a reactor to form an output stream containing one or more C2-C5 olefins. The single catalyst includes a zeolite doped with boron and a phosphor. The reactor is operated at a temperature of about 350°C to about 750°C, a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 0.25 to about 5.

[0054] In some embodiments, the single catalyst may consist essentially of a zeolite doped with boron and a phosphor.

[0055] In some embodiments, the reactor can be a single-bed reactor. In some embodiments, the single-bed reactor can be a fixed-bed reactor. In some embodiments, the single-bed reactor can be a fluidized-bed reactor. In some embodiments, the single-bed reactor can be a moving-bed reactor.

[0056] In some embodiments, the one or more C2-C5 olefins may be present in the output stream in an amount from about 50% to about 99% by weight of the total hydrocarbon product. In some embodiments, the one or more C2-C5 olefins may be present in the output stream in an amount from about 85% to about 99% by weight of the total hydrocarbon product.

[0057] In some embodiments, boron can be present in the catalyst in an amount of from about 0.01% to about 10% by weight, hi some embodiments, boron can be present in the catalyst in an amount of at least 0.05% by weight.

[0058] In some embodiments, the phosphor may be present in the catalyst in an amount of about 0.1% to about 7% by weight, hi some embodiments, the phosphor may be present in the catalyst in an amount of at least 1.5% by weight.

[0059] In some embodiments, the zeolite can be a ZSM-5 zeolite.

[0060] In another exemplary embodiment, a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins using a single catalyst system includes contacting an input stream containing one or more C1-C5 linear or branched alcohols with a catalyst in a reactor to form an output stream containing one or more C2-C5 olefins. The catalyst consists essentially of a ZSM-5 zeolite doped with boron and a phosphor. The reactor is at a temperature of about 350°C to about 475°C, a gauge pressure of 0 to about 5 bar, and a weight hourly space velocity (WHSV) of about 0.25 to about 10. The boron is present in the catalyst in an amount of about 0.05% to about 5% by weight, and the phosphor is present in the catalyst in an amount of about 0.2% to about 7% by weight.

[0061] It should be understood that all combinations of the foregoing concepts and additional concepts discussed in more detail below (unless such concepts are mutually inconsistent) are considered to be part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter of the present disclosure are considered to be part of the inventive subject matter disclosed herein. It should also be understood that terms explicitly used herein that may also appear in any disclosure incorporated by reference should be given the meaning most consistent with the specific concepts disclosed herein. [Brief explanation of the drawings]

[0062] [Figure 1] 1 illustrates an exemplary process concept for intentional propylene make-up of a single fixed-bed reactor system with closed-loop recycle of C2, C4, and C5 olefins consistent with the practice of the present invention. [Figure 2] FIG. 10 is a graph showing the data results of Example 10. [Figure 3] FIG. 1 is a graph showing the data results of Example 11. [Figure 4] FIG. 12 is a graph showing the data results of Example 12.

[0063] MODE FOR CARRYING OUT THE INVENTION In the following description, certain specific details are set forth to provide a thorough understanding of various embodiments. However, those skilled in the art will understand that the present disclosure may be practiced without these details. In other instances, well-known structures have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments. Unless the context requires otherwise, throughout the specification and the claims that follow, the word "comprise" and variations thereof, such as "comprises" and "comprising," should be interpreted in an open and inclusive sense, i.e., "including, but not limited to." Additionally, the headings provided herein are for convenience only and are not intended to interpret the scope or meaning of the claimed disclosure.

[0064] References throughout this specification in the description to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Moreover, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Furthermore, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It should also be noted that the term "or" is generally used to include "and / or" unless the context clearly dictates otherwise.

[0065] The word "about" immediately preceding a numerical value means a range of plus or minus 10% of that value, for example, "about 50" means 45 to 55, and "about 25,000" means 22,500 to 27,500. Additionally, the phrases "less than about a certain value" or "greater than about a certain value" should be understood in light of the definition of the term "about" provided herein.

[0066] "Oxygenate" refers to a compound that contains oxygen in its chemical structure. Examples of oxygenates include, but are not limited to, water, alcohols, esters, and ethers.

[0067] "WHSV" refers to weight hourly space velocity and is defined as the weight of the feed flowing through one unit weight of catalyst per hour.

[0068] As used herein, "aromatic" or "aromatic compound" refers to a cyclic organic carbon compound of six or more carbons (e.g., benzene).

[0069] As used herein, "trace amount" or "trace level" refers to a level of less than 2%. In some embodiments, trace amount or trace level can refer to a level of less than about 1.5%, less than about 1%, less than about 0.5%, less than about 0.1%, between about 0.1% and about 1.8%, or between about 1% and about 1.5%.

[0070] "Single-stage conversion" refers to a process carried out in a single reactor system.

[0071] All yields and conversions reported herein are by weight unless otherwise specified.

[0072] It is understood that the examples and embodiments described herein are for illustrative purposes only, and that various modifications or changes in light thereof will be suggested to those skilled in the art and are to be included within the spirit and scope of this application and the appended claims. All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes.

[0073] As previously disclosed in International Publication No. 2021 / 067294, the entirety of which is incorporated herein, alcohols can be converted into an olefin mixture containing primarily C2-C7 olefins with low levels of aromatic compounds. This method provides a route to an economical method for converting alcohols, such as ethanol, into base stocks for fuel production. Furthermore, the method described herein can be carried out at lower pressures and higher temperatures, with higher olefin yields, compared to previously available approaches. This method converts an aqueous bioalcohol feedstock derived from biomass into a C2-C7 olefin mixture. 10+ This may involve a single-stage conversion to a high-molecular-weight olefin mixture that can be readily oligomerized into hydrocarbon or diesel fractions in high yields. Single-stage or two-stage reactor configurations use specific catalyst systems that minimize the production of aromatic compounds and thus maximize the production of middle distillates. The method described in WO 2021 / 067294 efficiently and economically converts C2-C5 alcohols as base stocks for fuels. The high-yield conversion of C2-C5 alcohols to desired fuel product precursors (e.g., C3-C7 olefins) reduces processing costs.

[0074] Embodiments of the subject matter disclosed herein improve upon earlier approaches by, among other things, providing a method for converting C2-C5 linear or branched alcohols to C2-C7 olefins in high yields, with low levels of aromatics, and at competitive costs using a two-catalyst system. Consistent with this disclosure, the method for directly converting biobased C1-C5 alcohols to an olefin mixture (e.g., C2-C5) with low levels of aromatics can be carried out in a single fixed-bed reactor. The C2-C5 olefins can be readily oligomerized in high yields to base stocks used in the production of fuels.

[0075] In some embodiments, the methods described herein can be carried out in a single-bed reactor. In other embodiments, the methods described herein can be carried out in a single stacked-bed reactor. For example, in certain embodiments, alcohols, such as methanol or ethanol, can be converted to an olefin mixture (e.g., C2-C5) in a single reactor having a first catalyst in an upper stage of the reactor and a second catalyst disposed in a stage of the reactor below the first catalyst. In either a one-stage process (e.g., using a single-bed reactor) or a two-stage process (e.g., using a stacked-bed reactor), the resulting C2-C5 olefin mixture is suitable for oligomerization at relatively low temperatures and pressures to either gasoline, jet, or diesel fuel cuts, depending on the oligomerization catalyst selected. Furthermore, in some embodiments, the single-bed reactor or stacked-bed reactor can be defined as a fixed-bed reactor, while in other embodiments, a fluidized-bed reactor can be used.

[0076] Systems and methods are provided for the catalytic conversion of C1-C5 alcohols. Generally, catalytic processes consistent with the present disclosure involve alcohol dehydration, followed by skeletal carbon buildup, and then "cracking" to produce low-molecular-weight olefins (e.g., C2-C5) in high yields. In this single-step process, the catalyst mixture can produce a C2-C5 olefin mixture, providing access to low-molecular-weight olefins in yields with good carbon accountability, defined by moles of carbon fed to the system relative to moles of ethanol incorporated into the C2-C5 olefin mixture. Furthermore, the use of a recycle stream of specific olefins (e.g., C2-C5) advantageously provides the ability to maximize the targeted formation of desired olefins, such as propylene, butene, or mixtures thereof. In some embodiments, the mixture of olefins is suitable for oligomerization to either gasoline, jet, or diesel fuel cuts at relatively low temperatures and pressures, depending on the oligomerization catalyst selected.

[0077] As previously mentioned, most C2-C5 alcohols are dehydrated in a single unit operation at 300-500 °C in the presence of a dehydration catalyst, resulting in the production of C2-C5 olefins along with water. The water is removed, and the C2-C5 olefins are further processed / purified to remove unreacted C2-C5 alcohols and / or impurities before conversion to chemicals and / or fuels. For ethanol (C2 alcohol), the classical approach to conversion to chemicals and / or fuels utilizes separate unit operations to achieve: i) dehydration to ethylene; ii) ethylene purification followed by dimerization to butenes; iii) cracking to propylene; iv) oligomerization of butenes to unsaturated jet and / or diesel fuel precursors; or v) direct oligomerization of ethylene to unsaturated jet and / or diesel fuel precursors. Similarly, approaches for converting C4 or C5 alcohols to chemicals and / or fuels utilize separate unit operations to accomplish i) dehydration to C4 or C5 olefins, ii) olefin purification to remove oxygenates and / or unreacted alcohol, and iii) oligomerization to unsaturated jet and / or diesel fuel precursors. With regard to methanol, industrial processes primarily convert coal-derived methanol to olefins over mesoporous catalysts (e.g., SAPO-34) in a single step with olefin recycle.

[0078] The concept of simultaneously dehydrating, oligomerizing, and cracking C1-C5 alcohols or mixtures thereof in one reactor is difficult due to the need for higher temperatures (e.g., about 300°C to about 500°C) for complete dehydration and the presence of large amounts of water. Implementing a single-unit operation capable of simultaneously dehydrating, oligomerizing, and cracking olefins derived from C1-C5 alcohol dehydration requires that the catalyst used be able to withstand high temperatures along with large amounts of water and other oxygenates.

[0079] To address these challenges and define an approach for converting C1-C5 alcohols in high yields into viable fuel-producing feedstocks, a process has been developed that can convert C1-C5 alcohols in high yields into a mixture of C2-C5 olefins that can be easily separated for use as chemical feedstocks or easily oligomerized in high yields into fuel-producing feedstocks in a single unit operation (e.g., a single reactor). As presented herein, the ability to accomplish multiple unit operations and chemical conversions in a single reactor offers practitioners favorable economics by reducing fixed and variable costs, reducing capital investments, saving energy, and improving productivity.

[0080] To this end, consistent with the present disclosure, the conversion of methanol, and / or mixtures of methanol and C2-C5 alcohols, as well as C2-C5 olefin mixtures, proceeds with high yields and carbon accountability. Exemplary single reaction steps include: i) dehydration; ii) C2-C5 olefin dehydration; 4+ oligomerization to olefins, iii) backbone rearrangement, and iv) small amounts of C 4+ It involves the cracking of olefins and aromatics, essentially to propylene. Thus, when a vaporized stream of methanol and ethanol is passed over a single fixed catalyst bed containing a physical mixture of a first portion of silicate-, zirconate-, titanate-, niobium-, or fluorinated γ-alumina combined with a doped zeolite (boron-, phosphorus-, or combinations thereof) as a second catalyst portion at about 300°C to about 450°C, a mixture of C2-C5 olefins is obtained, which can be separated for sale or oligomerized "as is" to primarily jet fuel and / or diesel fuel after removing condensed water. This catalyst combination in a single fixed bed reactor is used for the following purposes: i) dehydration; ii) C 4+ oligomerization to olefins, iii) backbone rearrangement, and iv) cracking, leading to longer catalyst on-time (ToS), improved hydrothermal stability, and improved selectivity to olefins with reduced amounts of saturated and aromatic compounds.

[0081] Additionally, the present systems and methods may optionally include recycling one or more specific olefin fractions (e.g., C2+C4+C5 or C2+C5, etc.) in a closed-loop process configuration while co-feeding C1-C5 alcohols. This may result in maximizing the intended yield of selected olefins. For example, recycling the C2+C4+C5 olefin fraction in combination with co-feeding C1-C5 alcohols using the present systems and methods provided herein unexpectedly resulted in an intended propylene carbon yield of greater than 80 wt%. Selective recycling of the C2+C5 olefin fraction results in an intended propylene and butene combined carbon yield of greater than 80 wt%. Example 8 provides more details regarding the unexpected yields achieved when using the recycling of specific olefin fractions described herein. Additionally, recycling the C4+C5 olefin fraction may result in an intended ethylene and propylene combined carbon yield of greater than 80 wt%. An exemplary single-step reaction includes: i) in situ dehydration; ii) C 3+ oligomerization to olefins, iii) backbone rearrangement, and iv) small amounts of C 5+ It can involve cracking to C2-C5 olefins, including the formation of olefins and aromatics. Thus, recycling selected olefin fractions can enable intentional olefin production for chemical and / or fuel production.

[0082] Unlike the conversion of ethylene, propylene and other higher molecular weight olefins (C 4+) can be readily oligomerized over a wide range of catalysts, both zeolitic and non-zeolitic. The present disclosure, which enables the conversion of C1-C5 alcohols to an olefin mixture containing primarily C2-C5 olefins with low levels of aromatics in a single-stage or two-stage reactor configuration in series, offers an avenue toward an economical process for converting C1-C5 alcohols to base stocks for chemicals and / or fuels. The method according to the present invention allows aqueous C1-C5 bioalcohol feedstocks obtained from biomass to be separated to isolate important low molecular weight olefins used throughout industry as chemical building blocks, or C 10+ A scheme is implemented that involves a "one" stage conversion to a mixture of mainly C2-C5 olefins that can be easily oligomerized in high yields to hydrocarbon or diesel fractions. Two-stage or one-stage configurations using specific catalyst systems make it possible to minimize the production of aromatic compounds and thus maximize the production of middle distillates, which constitutes both an asset advantage for the ethanol refinery and from the point of view of sustainable development.

[0083] WO 2010 / 097175 A1 relates to the direct conversion of alcohols and oxygenates by a two-stage process in which both the first and second reactors in series are loaded with a commercially available type of ZSM-5 zeolite catalyst (Zeolyst CBV-28014). The temperature of the first reactor is brought to 460°C, and the temperature of the second reactor is brought to 320°C. After the temperatures have stabilized, a feed consisting of 86% methanol, 9% isopropanol, and 5% water is initiated. Single-pass conversions of methanol are typically >95%, and the reported final liquid products are primarily C zeolite with n > 5. n Light C with olefins 60-85% and n=2-4 n It consists of 15-40 wt% olefins and <10% aromatics. The final liquid product is preferably hydrogenated to yield a gasoline cut or oligomerized according to conventional processes to yield a mixture of gasoline, kerosene, and diesel.

[0084] Conversion of C1-C5 alcohols to desired fuel products, or fuel product precursors in the case of C1-C5 alcohols (e.g., C2-C5 olefins), or mixtures thereof, in a single fixed-bed reactor configuration can reduce processing costs. In one exemplary embodiment, a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins is provided. The method includes contacting an input stream comprising one or more C1-C5 linear or branched alcohols with at least a first catalyst and a second catalyst in a single-bed reactor to form an output stream comprising one or more C2-C5 olefins, the single-bed reactor being at a temperature of about 350°C to about 750°C, a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 0.5 to about 5.0.

[0085] An exemplary physically mixed catalyst combination in a single fixed bed reactor for C2-C5 olefin formation includes a portion (e.g., first catalyst) of a doped zeolite, such as a crystalline silicate of the group ZSM-5 (MFI or BEA framework) with Si / Al greater than 10, CHA, FER, FAU, MWW, MOR, EUO, MFS, ZSM-48, MTT, or TON, or ... , FER, FAU, MWW, MOR, EUO, MFS, ZSM-48, MTT or TON dealuminated crystalline silicates, or phosphor- and / or boron-modified crystalline silicates of group ZSM-5 (MFI or BEA framework), CHA, FER, FAU, MWW, MOR, EUO, MFS, ZSM-48, MTT or TON having a Si / Al greater than 10, or silico-aluminophosphate type molecular sieves of group AEL. Additional additives for mixing with the doped zeolite include a SiO2 support doped with a metal dopant, including 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), and indium (In). The second portion of the catalyst mixture (e.g., the second catalyst) can include silicate, zirconium oxide, titanate, niobium, or fluorinated γ-alumina. As an example, the exemplary catalyst combinations described above efficiently dehydrate C1-C5 alcohols to their respective olefins, while the doped zeolites yield C2-C5 olefins with reduced amounts of saturates and aromatics in oligomerization and cracking compared to literature reports utilizing single component zeolite catalysts or metal oxide catalysts.

[0086] The following representative examples show the conversion of C1-C5 alcohols or mixtures thereof to lesser amounts of C1-C5 alcohols in a single unit operation with quantitative C1-C5 alcohol conversion. 5+ The process involves the conversion of olefins and aromatics (BTX) to primarily propylene and butenes with a carbon yield of >85 wt%. Furthermore, desirable carbon accountability is achieved, as further demonstrated by the absence of detectable carbon monoxide or carbon dioxide, along with traces of methane. Unreacted olefin fractions (e.g., C2-C5 olefins) can be separated and recycled, resulting in high yields of intentional formation and carbon accountability for the desired olefins.

[0087] Granular or extruded catalysts can be used in the reactions described herein. For example, in some embodiments, the granular or extruded catalyst can have a particle size of at least about 0.05 mm, about 0.1 mm or more, or from about 0.05 mm to about 2.5 mm, including all subranges therebetween. In one embodiment, the granular or extruded catalyst can have a particle size of from about 0.4 mm to about 2.0 mm.

[0088] The present disclosure describes a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins. In certain embodiments, the method includes contacting an input stream comprising one or more C1-C5 linear or branched alcohols with at least a first catalyst and a second catalyst in a single-bed reactor to form an output stream comprising one or more C2-C5 olefins, the single-bed reactor having a temperature of about 350°C to about 750°C, a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 0.5 to about 5.0, the first catalyst comprising a doped or undoped alumina catalyst comprising one or more of zirconium (Zr), titanium (Ti), tungsten (W), or silicon (Si) in neutral or ionic form, and the second catalyst comprising a doped or undoped zeolite catalyst.

[0089] The present disclosure also describes a method for converting methanol to one or more C2-C5 olefins. In certain embodiments, the method includes contacting an input stream containing methanol with at least a first catalyst and a second catalyst in a single-bed reactor to form an output stream containing one or more C2-C5 olefins. The single-bed reactor operates at a temperature of about 350°C to about 750°C, a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 0.5 to about 5.0. The first catalyst includes a doped or undoped alumina catalyst containing one or more of zirconium (Zr), titanium (Ti), tungsten (W), or silicon (Si), in neutral or ionic form. The second catalyst includes a doped or undoped zeolite catalyst.

[0090] The present disclosure also provides a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins. In certain embodiments, the method includes contacting an input stream containing one or more C1-C5 linear or branched alcohols with a first catalyst in a stacked-bed reactor to form an output stream containing one or more C2-C5 olefins. The stacked-bed reactor is operated at a temperature of about 350°C to about 550°C, a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 1.0 to about 2.0. The first catalyst includes a doped or undoped alumina catalyst containing one or more of zirconium (Zr), titanium (Ti), tungsten (W), or silicon (Si), in neutral or ionic form. The method further includes contacting the first mixture with at least a second catalyst, the second catalyst including a doped or undoped zeolite catalyst.

[0091] The present disclosure also provides a method for converting methanol to one or more C2-C5 olefins. In certain embodiments, the method includes contacting an input stream containing methanol with a first catalyst in a stacked-bed reactor to form a first mixture. The stacked-bed reactor is operated at a temperature of about 350°C to about 550°C, a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 1.0 to about 2.0. The first catalyst includes a doped or undoped alumina catalyst containing one or more of zirconium (Zr), titanium (Ti), tungsten (W), or silicon (Si) in neutral or ionic form to form the first mixture. The first mixture is then contacted with at least a second catalyst to form an output stream containing one or more C2-C5 olefins, the second catalyst including a doped or undoped zeolite catalyst.

[0092] In some embodiments of the subject method, contacting the input stream or the first mixture further comprises contacting the input stream or the first mixture with a third catalyst. The third catalyst may be a doped or undoped SiO2 catalyst. The reactor may be a fixed-bed reactor and / or a fluidized-bed reactor. Suitable C1-C5 linear or branched alcohols include those that are biobased, produced by fermentation processes, and not petroleum-derived.

[0093] With respect to the output stream, the C2-C5 olefins may be present in an amount of at least 80 wt% of the output stream. The C2-C5 olefins may be present in an amount of 80 wt% to 99 wt% of the output stream, including all subranges therebetween. The C2-C5 olefins may be present in an amount of at least 85 wt% of the output stream. The C2-C5 olefins may be present in an amount of at least 90 wt% of the output stream. The C2-C5 olefins may be present in an amount of at least 95 wt%. Additionally, with respect to the output stream, the methods disclosed herein may further include removing at least a portion of the C2 olefins from the output stream. The methods may include removing at least a portion of the C4 olefins from the output stream. The methods may include removing at least a portion of the C5 olefins from the output stream.

[0094] With respect to the reactor, the reactor may be operated at a temperature of about 350°C to about 550°C, including all subranges therebetween. The reactor may be operated at a temperature of about 550°C to about 750°C, including all subranges therebetween. The reactor may be operated at a WHSV of about 0.5 to about 1.0, including all subranges therebetween. The reactor may be operated at a WHSV of about 2.0 to about 5.0, including all subranges therebetween. The reactor may be a fixed-bed reactor. The reactor may be a fluidized-bed reactor.

[0095] The present disclosure also describes a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins using a single catalyst system. In other words, these disclosed methods use a system having only one catalyst. The use of a single catalyst system may be desirable in various instances, such as those practiced in fluidized or moving bed reactors, where a portion of the unconverted C1-C5 linear or branched alcohols and associated oxygenates are tolerated in the output stream, or where the catalyst is continuously regenerated during operation. In some embodiments, the one or more C1-C5 linear or branched alcohols may be one or more C1-C5 linear or branched monohydric alcohols.

[0096] The conversion of C1-C5 alcohols to desired fuel products, or fuel product precursors in the case of C1-C5 alcohols (e.g., C2-C5 olefins), or mixtures thereof, using a single catalyst system can, for example, reduce processing costs and simplify and optimize the conversion process, which is not possible with two-catalyst systems in particular. In these processes, the single catalyst system includes only one catalyst, such as a doped zeolite. In some embodiments, the only catalyst is not a doped or undoped alumina catalyst. In certain embodiments, the zeolite can be a zeolite doped with boron and a phosphor. Non-limiting examples of olefin-forming zeolites can include some (e.g., first catalyst) doped zeolites, such as crystalline silicates of the group ZSM-5 (MFI or BEA framework), CHA, FER, FAU, MWW, MOR, EUO, MFS, ZSM-48, MTT, or TON, with a Si / Al 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, with a Si / Al greater than 10. In some embodiments, when the zeolite is a ZSM-5 zeolite, the ZSM-5 zeolite can have a Si / AlO ratio of about 20 to about 300. In particular embodiments, the ZSM-5 zeolite can have a Si / AlO ratio of about 50 to about 150.

[0097] In some embodiments, the single catalyst system includes only a zeolite doped with boron and a phosphor. Without being bound by any one theory, it is believed that the presence of boron increases the stability of the phosphor during the time on stream (TOS) while maintaining selectivity. That is, the presence of boron in such cases can minimize the formation of saturates and aromatics in the output stream.

[0098] The boron and phosphor can be present in a variety of different concentrations within the single catalyst system. In some embodiments, boron can be present in the single catalyst system in an amount of about 0.01 wt. % to about 10 wt. %, including all subranges therebetween. In certain embodiments, boron can be present in the single catalyst system in an amount of about 0.05 wt. % to about 5 wt. %, including all subranges therebetween. In certain embodiments, boron can be present in the single catalyst system in an amount of about 0.05 wt. % to about 3 wt. %, including all subranges therebetween. In one embodiment, boron can be present in the single catalyst system in an amount of at least 0.05 wt. In some embodiments, the phosphor can be present in the single catalyst system in an amount of about 0.1 wt. % to about 7 wt. %, including all subranges therebetween. In certain embodiments, the phosphor can be present in the single catalyst system in an amount of about 1.5 wt. % to about 6 wt. %, including all subranges therebetween. In one embodiment, the phosphor can be present in the single catalyst system in an amount of at least 3 wt. In certain embodiments, boron can be present in the single catalyst system in an amount of about 0.5% to about 3% by weight, and the phosphor can be present in the single catalyst system in an amount of about 2% to 6% by weight.

[0099] In one exemplary embodiment, a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins using a single catalyst system can include contacting an input stream comprising one or more C1-C5 linear or branched alcohols with a catalyst in a reactor to form an output stream comprising one or more C2-C5 olefins, the catalyst consisting essentially of a boron- and phosphor-doped zeolite. The reactor is operated at a temperature of about 300° C. to about 600° C., a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 0.25 to about 10.

[0100] In another exemplary embodiment, a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins using a single catalyst system can include contacting an input stream containing one or more C1-C5 linear or branched alcohols with a single catalyst in a reactor to form an output stream containing one or more C2-C5 olefins. The single catalyst comprises a zeolite doped with boron and a phosphor. The reactor is at a temperature of about 350°C to about 750°C, a gauge pressure of 0 to about 30 bar, and a weight hourly space velocity (WHSV) of about 0.25 to about 5.0. In certain embodiments, the single catalyst consists essentially of the zeolite doped with boron and a phosphor.

[0101] In some embodiments, the method can include contacting the input stream with the catalyst in the reactor and then regenerating the catalyst. In some embodiments, regeneration of the catalyst can be carried out by purging any gaseous or liquid hydrocarbons or oxygenates from the reactor and then introducing air and / or oxygen, optionally diluted with an inert gas or steam, to combust any solid carbon deposits on the catalyst. In some embodiments, the method can include a system in which the catalyst is cycled between a reactor in which the input stream is contacted and a regeneration reactor in which the catalyst is contacted with air and / or oxygen, optionally diluted with an inert gas or steam, to combust any solid carbon deposits on the catalyst.

[0102] In some embodiments, the method can further include contacting another input stream comprising one or more C1-C5 linear or branched alcohols with the regenerated catalyst (e.g., the catalyst after regeneration) in the reactor to form another output stream comprising one or more C2-C5 olefins. Those skilled in the art will understand that the regenerated catalyst can have a reduced concentration of boron, phosphor, or both compared to the catalyst before regeneration.

[0103] With respect to the reactor, the reactor may be operated at a temperature of about 300°C to about 750°C, including all subranges therebetween. The reactor may be operated at a temperature of about 350°C to about 700°C, including all subranges therebetween. The reactor may be operated at a temperature of about 300°C to about 600°C. The reactor may be operated at a gauge pressure of 0 to about 30 bar, including all subranges therebetween. The reactor may be operated at a gauge pressure of 0 to about 5 bar, including all subranges therebetween. The reactor may be operated at a gauge pressure of about 6 or less. The reactor may be operated at a WHSV of about 0.1 to about 10, including all subranges therebetween. The reactor may be operated at a WHSV of about 0.25 to about 10, including all subranges therebetween. The reactor may be operated at a WHSV of about 0.25 to about 5, including all subranges therebetween. The reactor may be operated at a WHSV of about 1 to about 10, including all subranges therebetween. The reactor may be a fixed bed reactor. The reactor may be a fluidized bed reactor. The reactor may be a moving bed reactor.

[0104] With respect to the output stream, the C2-C5 olefins can be present in the output stream in an amount of at least 50 wt% of the total hydrocarbon products. The total hydrocarbon products in the output stream include any water that may be present in the output stream. The C2-C5 olefins can be present in the output stream in an amount of about 50 wt% to about 85 wt% of the total hydrocarbon products, including all subranges therebetween. The C2-C5 olefins can be present in the output stream in an amount of about 50 wt% to about 99 wt% of the total hydrocarbon products, including all subranges therebetween. The C2-C5 olefins can be present in the output stream in an amount of about 70 wt% to about 99 wt% of the total hydrocarbon products, including all subranges therebetween. The C2-C5 olefins can be present in the output stream in an amount of about 85 wt% to about 99 wt% of the total hydrocarbon products, including all subranges therebetween. The C2-C5 olefins can be present in the output stream in an amount of at least 85 wt% of the total hydrocarbon products. The C2-C5 olefins can be present in the output stream in an amount of at least 90 wt% of the total hydrocarbon products. The C2-C5 olefins may be present in the output stream in an amount of at least 95 wt. % of the total hydrocarbon products.

[0105] Additionally, with respect to the output stream, the methods disclosed herein can further include removing at least a portion of the C2 olefins from the output stream. The methods can include removing at least a portion of the C3 olefins from the output stream. The methods can include removing at least a portion of the C4 olefins from the output stream. The methods can include removing at least a portion of the C5 olefins from the output stream.

[0106] In one exemplary embodiment, a method for converting one or more C1-C5 linear or branched alcohols to one or more C2-C5 olefins using a single catalyst system can include contacting an input stream containing one or more C1-C5 linear or branched alcohols with a catalyst in a reactor to form an output stream containing one or more C2-C5 olefins. The catalyst consists essentially of a ZSM-5 zeolite doped with boron and a phosphor. The reactor is operated at a temperature of about 350°C to about 475°C, a gauge pressure of 0 to about 5 bar, and a weight hourly space velocity (WHSV) of about 0.25 to about 10. The boron is present in the catalyst in an amount of about 0.05% to about 5% by weight, and the phosphor is present in the catalyst in an amount of about 0.2% to about 7% by weight.

[0107] The following specific examples are intended to illustrate the present invention and should not be construed as limiting the scope of the invention as defined by the appended claims.

[0108] The foregoing detailed description has been given for clarity of understanding only, and no unnecessary limitations should be understood therefrom since modifications will be apparent to those skilled in the art.

[0109] While the invention has been described in relation to particular embodiments thereof, it will be understood that the invention is capable of further modifications, and this application is generally intended to cover any variations, uses, or adaptations of the invention which come within known or customary practice within the art to which this invention pertains, in accordance with the principles of the invention, including departures from the present disclosure as may be applied to the essential features set forth in the appended claims.

[0110] Example Example 1: Reactor Setup Conversion of alcohols (i.e., C1-C5) to C2-C5 olefins was carried out at 300-500 °C in a fixed-bed reactor containing a specific catalyst and co-fed with nitrogen at atmospheric or moderate pressure (i.e., 0-30 bar) while preheated (160 °C) vaporized alcohol flowed downflow over the fixed catalyst bed. The alcohol flow rate was controlled by a Teledyne Model 500D syringe pump, and the flow rate was adjusted to obtain the target olefin WHSV (weight hourly space velocity). The internal reaction temperature was maintained constant via a Thermo-Scientific Lindberg Blue M furnace. Alcohol conversion and selectivity were calculated by GC analysis of the liquid-phase reactor effluent for organic and water content, online GC analysis of non-condensed hydrocarbons (i.e., C2-C5 olefins), and an online thermal conductivity detector for quantification of CO, CO2, and CH4 relative to nitrogen as an internal standard. Thus, when a vaporized stream of C1-C5 alcohols is passed over a combination of catalysts in a single fixed-bed reactor at 350°C to 450°C, C2-C5 olefins are formed in high yields.

[0111] Example 2: Preparation of Impregnated Zr-γ-alumina (Nominal 5 wt% Zr Metal) Catalyst The Zr-γ-alumina catalyst was prepared by the incipient wetness technique as described. Precursor metal salt (Sigma Aldrich): 2.64 g of zirconium(IV) oxynitrate hydrate was dissolved in 14.9 mL of deionized water. Once the salt was dissolved, the solution was added dropwise to 15 g of γ-alumina support. The resulting mixed metal oxide was mixed manually to ensure complete wetting, and the resulting impregnated catalyst was dried at 160°C for 1 hour and then calcined at 500°C for 4 hours.

[0112] Example 3: Preparation of Impregnated Boron / Fluorescent-Impregnated ZSM-5 Zeolite Catalyst Boron and phosphor-impregnated zeolite catalysts were prepared by the incipient wetness technique as described. 0.78 g of phosphoric acid (85%) and 0.96 g of boric acid (99+%) were dissolved in deionized water (7.4 mL). Once heated and dissolved, the solution was added to 6 g of ZSM-5 zeolite support (i.e., Zeolyst type CBV-5524 H + The resulting impregnated catalyst was dried at 160°C for 1 hour and then calcined at 550°C for 3 to 15 hours.

[0113] Example 4: Single-stage reactor One-stage reactor configuration: Reaction conditions: T = 355°C in reactor, WHSV = 2.5 (based on methanol), P = 0 bar; catalyst-doped ZSM-5 zeolite and physically mixed zirconium oxide (4.0 wt%) γ-alumina.

[0114] [Table 1]

[0115] Ethylene conversion was approximately 68% mass yield.

[0116] Example 5: Single-stage reactor One-stage reactor configuration: Reaction conditions: T = 425 °C in reactor, WHSV = 4.5 (based on ethanol), P = 0 bar; catalyst-doped ZSM-5 zeolite and zirconium oxide (4.0 wt%) γ-alumina physically mixed with Ni-doped SiO2.

[0117] [Table 2]

[0118] Ethylene conversion was approximately 62% mass yield.

[0119] Example 6: Single-stage reactor Single-stage reactor configuration: Reaction conditions: Feed preheater T = 160 °C, reactor T = 445 °C, total WHSV = 3.4 (including recycle), P = 0-1 bar; Catalyst: Zirconate oxidation (4.0 wt%) γ-alumina physically mixed with doped ZSM-5 zeolite; Feed composition: aqueous ethanol (92%) = 0.15 ml / min, ethylene recycle = 70 ml / min (0.087 g / min); mixed butenes = 23 ml / min (0.057 g / min), mixed pentenes = 0.035 ml / min, nitrogen = 10 ml / min.

[0120] [Table 3]

[0121] [Table 4]

[0122] The process concept and mass balance for the intentional propylene (81% yield) formation with closed-loop recycle of C2, C4, and C5 olefins based on the experimental data from Example 6 are shown in Figure 1. The recycle of C2, C4, and C5 olefins maximizes the formation of eligible olefins. Figure 1 shows a single-stage reactor system 1000. As shown in the figure, an input 100, e.g., aqueous ethanol (92%), can be fed to a fixed-bed reactor 300 to produce an output 200, e.g., a C2-C5 olefin mixture with a final output shown in Table 4 above. Additionally, recycle streams R1, R2, and R3 can recycle C2, C4, and C5 olefins, respectively, back to the input 100 and can be fed back to the fixed-bed reactor 300. Wastewater 400 can also be produced in situ by the fixed-bed reactor 300 via the dehydration of ethanol to ethylene, and thus can be condensed and removed as part of the output 200.

[0123] Example 7: Simultaneous dehydration, dimerization, backbone rearrangement, and cracking of C1-C5 bio- or petroleum-based alcohols and their mixtures to C2-C7 olefins The purpose of this example is to provide data illustrating the conversion of C1-C5 bio- or petroleum-based alcohols to a mixture of C2-C7 olefins with low levels of aromatics. Details of the reactor setup and resulting effluent, as well as yield data, are provided below.

[0124] One-stage reactor configuration: Reaction conditions: T = 425 °C in reactor, WHSV = 4.5 (based on ethanol), P = 0 bar; catalyst-doped ZSM-5 zeolite and zirconium oxide (4.0 wt%) γ-alumina physically mixed with Ni-doped SiO2.

[0125] [Table 5]

[0126] Ethylene conversion was approximately 62% mass yield.

[0127] Example 8: Increasing propylene yield using recycle of olefin fraction Provided herein is data showing the increased yields using the C2 / C3 / C4 olefin fraction recycle disclosed herein.

[0128] Single-stage reactor configuration for the data in Table 6: Reaction conditions: Feed preheater T = 160 °C, reactor T = 445 °C, total WHSV = 4.35, P = 0-1 bar; Catalyst: zirconium oxide (4.0 wt%) γ-alumina.

[0129] [Table 6]

[0130] Single-stage reactor configuration for the data in Table 7: Reaction conditions: Feed preheater T = 160 °C, reactor T = 445 °C, total WHSV = 3.7 (including recycle), P = 0-1 bar; Catalyst: zirconium oxide (4.0 wt%) γ-alumina.

[0131] [Table 7]

[0132] Example 9: Conversion of ethanol over boron and phosphor doped zeolites Data are provided herein illustrating the use of boron and phosphor doped zeolites in the conversion of alcohols to mixed olefins.

[0133] Single-stage reaction conditions: Feed preheater T = 165°C, reactor T = 445°C, total WHSV = 3.53, P = 0-1 bar; catalyst: 5 gm of ZSM-5 zeolite (Si / Al2 = 90) doped with 2 wt% B and 3 wt% P; feed composition: 0.3 mL / min 92% ethanol, 40 standard cubic centimeters per minute (SCCM) ethylene, 10 SCCM nitrogen. Table 7 provided below lists the gaseous hydrocarbon products after 24 hours of time on stream (TOS). [Table 8]

[0134] Example 10: Repeated Use of Boron and Phosphor-Doped Zeolite Containing Zr-Alumina Single-stage reaction conditions: Feed preheater T = 165°C, reactor T = 445°C, P = 0-1 bar; mixed catalyst: Part 1: 2.5 gm ZSM-5 zeolite (Si / Al2 = 90) doped with 2% B and 3% P; Part 2: 2.5 gm γ-Al2O3 doped with 4% Zr; Feed: 0.35 mL / min 92% ethanol, 60 SCCM ethylene, 10 SCCM nitrogen. Regeneration conditions: The mixed catalyst was removed from the reactor and placed in a static muffle furnace at 500°C overnight. The mixed catalyst was subjected to a 24-hour on-stream period, then repeatedly regenerated and resubmitted to the reaction conditions. The data shown in FIG. 2 indicates that the activity (e.g., C conversion / gram / hour) of the 2% B, 3% P doped ZSM-5 zeolite (Si / Al2=90) (Part 1) can be repeatable and therefore substantially similar over multiple runs, Runs 1-4 in this example.

[0135] Example 11: Effect of boron and phosphor loading on catalyst activity and stability One-step reaction conditions were: Feed preheater T = 165 °C, Reactor T = 445 °C, P = 0-1 bar; Catalyst mixture: First portion: 2.5 gm ZSM-5 zeolite (Si / Al2 = 90) doped with 2% B and 3% P; Second portion: 2.5 gm γ-Al2O3 doped with 4% Zr; Feed: 0.35 mL / min 92% ethanol, 60 SCCM ethylene, 10 SCCM nitrogen. The catalyst was subjected to a 24-hour on-stream run. Data shown in Figure 3 demonstrates ethylene conversion using various doping concentrations of boron and phosphor on ZSM-5 zeolite according to this example. As shown in Figure 3, the exemplary catalyst with the highest doping concentrations of boron and phosphor (i.e., 2% B and 3% P) exhibits the greatest stability compared to the other exemplary catalysts.

[0136] Example 12: Repeated use of phosphor-doped zeolite containing Zr-alumina This is a comparative example for Example 10. Single-step reaction conditions: Feed preheater T = 165°C, reactor T = 445°C, P = 0-1 bar; mixed catalyst: Part 1: 2.5 gm of 3% P-doped ZSM-5 zeolite (Si / Al2 = 90); Part 2: 2.5 gm of 4% Zr-doped γ-Al2O3; Feed: 0.35 mL / min 92% ethanol, 60 SCCM ethylene, 10 SCCM nitrogen. Regeneration conditions: The catalyst was removed from the reactor and placed in a static muffle furnace at 500°C overnight. The catalyst was subjected to a 24-hour on-stream period, then repeatedly regenerated and resubmitted to the reaction conditions. Data shown in Figure 4 demonstrates ethylene conversion over repeated use of the phosphor-doped zeolite. Comparing the data in Figure 4 to that in Figure 2, the exemplary cycle using the boron- and phosphor-doped zeolite (Example 10) is more stable than the exemplary cycle using the phosphor-doped zeolite (Example 12). As a result, the presence of boron can enable greater C2 conversion over longer run times and also provide more consistent catalyst activity.

Claims

1. One or more C １ -C ５ A linear or branched alcohol is used in combination with one or more C ２ -C ５ 1. A method for converting a hydrocarbon into an olefin, comprising: The one or more C １ -C ５ An input stream comprising linear or branched alcohols is contacted with a catalyst in a reactor to produce one or more C ２ -C ５ forming an output stream comprising olefins, wherein the catalyst consists essentially of a zeolite doped with boron and a phosphor; The process wherein the reactor is at a temperature of from about 300°C to about 600°C, a gauge pressure of from 0 to about 30 bar, and a weight hourly space velocity (WHSV) of from about 0.25 to about 10.

2. 10. The process of claim 1, wherein the reactor is a single-bed reactor.

3. 3. The process of claim 2, wherein the single-bed reactor is a fixed-bed reactor.

4. 3. The process of claim 2, wherein the single-bed reactor is a fluidized-bed reactor.

5. 3. The process of claim 2, wherein the single-bed reactor is a moving-bed reactor.

6. The one or more C ２ -C ５ 10. The process of claim 1, wherein olefins are present in said output stream in an amount from about 50 wt. % to about 99 wt. % of the total hydrocarbon product.

7. The one or more C ２ -C ５ 10. The process of claim 1, wherein olefins are present in said output stream in an amount from about 85 wt. % to about 99 wt. % of the total hydrocarbon product.

8. 10. The method of claim 1, wherein the boron is present in the catalyst in an amount of from about 0.01% to about 10% by weight.

9. 10. The method of claim 1, wherein the boron is present in the catalyst in an amount of at least 0.05 wt.%.

10. The method of claim 1 , wherein the phosphor is present in the catalyst in an amount of from about 0.1% to about 7% by weight.

11. The method of claim 1 , wherein the phosphor is present in the catalyst in an amount of at least 1.5% by weight.

12. 2. The method of claim 1, wherein the zeolite is a ZSM-5 zeolite.

13. One or more C １ -C ５ A linear or branched alcohol is used in combination with one or more C ２ -C ５ 1. A method for converting a hydrocarbon into an olefin, comprising: The one or more C １ -C ５ An input stream comprising linear or branched alcohols is contacted with a single catalyst in a reactor to produce said one or more C ２ -C ５ forming an output stream comprising olefins, wherein the single catalyst comprises a zeolite doped with boron and a phosphor; The process wherein the reactor is at a temperature of from about 350°C to about 750°C, a gauge pressure of from 0 to about 30 bar, and a weight hourly space velocity (WHSV) of from about 0.25 to about 5.

14. 14. The method of claim 13, wherein the single catalyst consists essentially of a zeolite doped with boron and a phosphor.

15. 14. The method of claim 13, wherein the reactor is a single-bed reactor.

16. 16. The method of claim 15, wherein the single-bed reactor is a fixed-bed reactor.

17. 16. The method of claim 15, wherein the single-bed reactor is a fluidized-bed reactor.

18. 16. The method of claim 15, wherein the single-bed reactor is a fluidized-bed reactor.

19. The one or more C ２ -C ５ 14. The process of claim 13, wherein olefins are present in said output stream in an amount from about 50 wt. % to about 99 wt. % of total hydrocarbon products.

20. The one or more C ２ -C ５ 14. The process of claim 13, wherein olefins are present in said output stream in an amount from about 85 wt. % to about 99 wt. % of the total hydrocarbon product.

21. 14. The method of claim 13, wherein the boron is present in the catalyst in an amount of from about 0.01% to about 10% by weight.

22. 14. The method of claim 13, wherein the boron is present in the catalyst in an amount of at least 0.05 wt.%.

23. The method of claim 13, wherein the phosphor is present in the catalyst in an amount of about 0.1% to about 7% by weight.

24. 14. The method of claim 13, wherein the phosphor is present in the catalyst in an amount of at least 1.5% by weight.

25. 14. The method of claim 13, wherein the zeolite is a ZSM-5 zeolite.

26. One or more C １ -C ５ A linear or branched alcohol is used in combination with one or more C ２ -C ５ 1. A method for converting a hydrocarbon into an olefin, comprising: The one or more C １ -C ５ An input stream comprising linear or branched alcohols is contacted with a catalyst in a reactor to produce one or more C ２ -C ５ forming an output stream comprising olefins, wherein the catalyst consists essentially of ZSM-5 zeolite doped with boron and phosphor; the reactor is at a temperature of about 350° C. to about 475° C., a gauge pressure of 0 to about 5 bar, and a weight hourly space velocity (WHSV) of about 0.25 to about 10; The method wherein boron is present in the catalyst in an amount of about 0.05% to about 5% by weight and the phosphor is present in the catalyst in an amount of about 0.2% to about 7% by weight.

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