Process and catalyst for linear alpha olefin purification

Abstract

The present invention provides processes and catalysts for improving a linear alpha olefin product stream from an oligomerization reaction. A catalyst composition is provided that includes a first zeolite and a second zeolite each having an average pore size greater than about # imgabs0 # wherein the catalyst composition has a Bronsted acid site (BAS) equivalent weight of about 1.0 mmol / g catalyst or less, and wherein the first zeolite is at least partially subjected to metal ion exchange and the second zeolite is at least partially subjected to metal ion exchange. And the second zeolite is at least partially of the H + type. Also provided is a process for producing a purified linear alpha olefin (LAO) comprising introducing a LAO product stream comprising an alkyl butene fraction into a catalyst bed comprising a zeolite catalyst and fluidly connected to the LAO product stream to catalytically isomerize the alkyl butene fraction to an alkyl pentene fraction.

Description

Technical Field

[0001] The present disclosure relates to methods and catalysts for improving the purity of linear alpha olefin product streams. Background Art

[0002] Linear alpha olefins (LAOs) represent a class of hydrocarbon compounds used commercially as raw materials in the petrochemical industry. Within LAOs, an important subclass of these compounds includes unbranched olefins whose double bonds are located at the ends of the chains, one of the most commercially desirable compounds of which is 1-hexene. 1-Hexene is also valuable as a major component in many polymeric resins, including high performance polyethylene (PE) compositions, in many synthetic processes involving the production of dyes, flavorings, and fragrances.

[0003] It is desirable to increase the concentration of 1-hexene and other commercially valuable alpha olefin products to a maximum level, for example, to a concentration level of about 99.5 wt % or more. However, such an increase in concentration and associated purity may be challenging using conventional separation methods due to, for example, the presence of one or more impurities characterized by a boiling point comparable to that of the alpha olefin product of interest. Therefore, there is still a need in the art to improve the enhancement and purification of commercially valuable LAO products. Summary of the invention

[0004] Example embodiments of the present disclosure relate to methods and catalytic articles for purification and quantitative enhancement of linear alpha olefin (LAO) product streams. In particular, the methods and catalytic articles of the present disclosure relate to the use of a zeolite catalyst positioned to receive a LAO product stream containing an alkyl butene fraction through one or more catalyst beds, the zeolite catalyst being regenerable in a non-oxidizing environment and being capable of isomerizing the alkyl butene fraction to an alkyl pentene fraction. In this way, the zeolite catalyst can improve the purification of commercially desirable LAOs to significantly greater concentrations.

[0005] The present disclosure includes, but is not limited to, the following embodiments.

[0006] Embodiment 1: A catalyst composition comprising a first zeolite and a second zeolite, each of the first zeolite and the second zeolite having a catalyst content greater than about wherein the catalyst composition comprises a Bronsted acid site (BAS) equivalent of about 1.0 mmol / g catalyst or less, and wherein the first zeolite is metal ion exchanged and the second zeolite is H + type.

[0007] Embodiment 2: The catalyst composition of Embodiment 1, wherein the first zeolite is metal ion exchanged with one or more metals selected from the group consisting of alkali metals, alkaline earth metals, and combinations thereof.

[0008] Embodiment 3: The catalyst composition of Embodiment 1 or 2, wherein the first zeolite is metal ion exchanged with sodium.

[0009] Embodiment 4: The catalyst composition of any one of Embodiments 1-3, wherein each of the first zeolite and the second zeolite has a 12-membered ring framework structure independently selected from the group consisting of AFI, AFR, AFS, AFY, ASV, ATO, ATS, BEA, BEC, BOG, BPH, BSV, CAN, CON, CZP, DFO, EMT, EON, EZT, FAU, GME, GON, IFR, ISV, ITG, IWR, IWS, IWV, IWW, JSR, LTF, LTL, MAZ, MEI, MOR, MOZ, MSE, MTW, NPO, OFF, OKO, OSI, RON, RWY, SAF, SAO, SBE, SBS, SBT, SEW, SFE, SFO, SFS, SFV, SOF, SOS, STO, SSF, SSY, USI, UWY, VET, and combinations thereof.

[0010] Embodiment 5: The catalyst composition of any one of Embodiments 1-4, wherein each of the first zeolite and the second zeolite has a FAU or BEA framework structure, and each of the first zeolite and the second zeolite has a silica to alumina ratio (SAR) of about 1 to about 100, such as about 2 to about 30 or about 3 to about 20 or about 4 to about 15.

[0011] Embodiment 6: The catalyst composition of any of Embodiments 1-5, wherein each of the first zeolite and the second zeolite is X zeolite, Y zeolite, or Beta zeolite.

[0012] Embodiment 7: The catalyst composition of any one of Embodiments 1-6, wherein the first zeolite is Na + Type Y zeolite (NaY) and the second zeolite is H + Type Y zeolite (HY).

[0013] Embodiment 8: The catalyst composition of any of Embodiments 1-7, wherein the first zeolite and the second zeolite are present in a weight ratio of first zeolite:second zeolite in a range of about 5:1 to about 15:1.

[0014] Embodiment 9: The catalyst composition of any of Embodiments 1-8, wherein the catalyst composition comprises a Bronsted acid site (BAS) equivalent of about 0.9 mmol / g catalyst or less.

[0015] Embodiment 10: The catalyst composition of any one of Embodiments 1-9, wherein the catalyst composition comprises a Bronsted acid site (BAS) equivalent of about 0.5 mmol / g catalyst or less.

[0016] Embodiment 11: The catalyst composition of any of Embodiments 1-10, further comprising a metal oxide binder.

[0017] Embodiment 12: Use of the catalyst composition of any one of Embodiments 1-11 for isomerizing an alkylbutene fraction in a linear alpha olefin (LAO) product stream into an alkylpentene fraction.

[0018] Embodiment 13: A method for isomerizing an alkyl butene fraction in a linear alpha olefin (LAO) product stream to an alkyl pentene fraction, comprising contacting the LAO product stream with the catalyst composition of any one of Embodiments 1-11.

[0019] Embodiment 14: A method for producing a purified linear alpha olefin (LAO) product stream, the method comprising: introducing a LAO product stream comprising an alkyl butene fraction into a catalyst bed comprising a regenerable zeolite catalyst and connected to a LAO product stream fluid to catalytically isomerize the alkyl butene fraction into an alkyl pentene fraction and form a treated LAO product stream; and directing the treated LAO product stream to at least one distillation tower having a plurality of stacked stages to produce a purified LAO product stream.

[0020] Embodiment 15: The method of Embodiment 14, wherein the zeolite catalyst comprises a catalyst composition comprising a first zeolite and a second zeolite, the first zeolite and the second zeolite each having a catalyst content greater than about wherein the catalyst composition comprises a Bronsted acid site (BAS) equivalent of about 1.0 mmol / g catalyst or less, and wherein the first zeolite is metal ion exchanged and the second zeolite is H + type.

[0021] Embodiment 16: The method of Embodiment 14 or 15, wherein the alkylbutene is 2-ethyl-1-butene (2E1B) and the alkylpentene is cis-3-methyl-2-pentene or trans-3-methyl-2-pentene.

[0022] Embodiment 17: The method of any of Embodiments 14-16, wherein the LAO product stream has a 2-ethyl-1-butene (2E1B) concentration of about 0.7 weight percent or more, and the treated LAO product stream is characterized by a 2E1B concentration equal to or less than about 0.3 weight percent.

[0023] Embodiment 18: The method of any of Embodiments 14-17, wherein the treatment with a zeolite catalyst results in catalytic isomerization of more than about 90 wt% of 2-ethyl-1-butene (2E1B) and less than about 1.0 wt% of 1-hexene in the LAO product stream.

[0024] Embodiment 19: The method of any of Embodiments 14-18, wherein the LAO product stream comprises 1-hexene in an amount greater than 90 wt%.

[0025] Embodiment 20: The method of any of Embodiments 14-19, wherein the purified LAO product stream is characterized by a 1-hexene product purity of greater than about 99.5 wt%.

[0026] Embodiment 21: The method of any one of Embodiments 14-20, wherein the introducing step is performed under one or more of the following conditions: about 0.5h -1 About 10 hours -1 Liquid hourly space velocity (LHSV); pressure below about 5 pounds per square inch gauge (psig) and temperature from about 40°C to about 60°C.

[0027] Embodiment 22: The method of any of Embodiments 14-21, wherein at least two catalyst beds comprising a zeolite catalyst are operated in parallel and fluidly connected to the LAO product stream such that at least one catalyst bed can be regenerated while continuing to process the LAO product stream.

[0028] Embodiment 23: The method of any of Embodiments 14-22, further comprising regenerating the catalyst bed by treating the catalyst bed with an inert gas stream in an environment substantially free of oxygen at a temperature in the range of about 150°C to about 400°C.

[0029] These and other features, aspects and advantages of the present disclosure will become apparent from reading the following detailed description in conjunction with the accompanying drawings briefly described below. The present disclosure includes any combination of two, three, four or more features or elements set forth in the present disclosure, regardless of whether such features or elements are explicitly combined or otherwise described in the specific example embodiments described herein. The present disclosure is intended to be read as a whole, so that any individual feature or element of the present disclosure should be considered combinable in any of its aspects and example embodiments, unless the context of the present disclosure clearly provides or suggests otherwise.

[0030] It will be appreciated that the foregoing summary of the invention is provided for the general purpose of summarizing certain example embodiments to provide a basic understanding of some aspects of the present disclosure. Therefore, it will be appreciated that the example embodiments described above are only non-limiting examples and should not be construed as limiting the scope or spirit of the present disclosure in any way. Additional example embodiments, aspects, and advantages will become apparent from the following detailed description in conjunction with the accompanying drawings, which illustrate the principles of some of the described example embodiments by way of example. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Having thus described aspects of the present disclosure in the foregoing general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale. The drawings are merely exemplary and are not to be construed as limiting the present disclosure.

[0032] Figure 1 is a block diagram of a LAO product stream processing system according to an example embodiment of the present disclosure;

[0033] Figure 2 Graphing the results of the catalytic isomerization of 2-ethyl-1-butene to 3-methyl-2-pentene (upper trace) and the loss of 1-hexene (lower trace) according to aspects of the present disclosure;

[0034] Figure 3 Graphing additional results of the catalytic isomerization of 2-ethyl-1-butene to 3-methyl-2-pentene (upper trace) and the loss of 1-hexene (lower trace) at time points before and after catalyst regeneration according to aspects of the present disclosure;

[0035] Figure 4 Graphing additional results of the catalytic isomerization of 2-ethyl-1-butene to 3-methyl-2-pentene (upper trace) and the loss of 1-hexene (lower trace) at time points before and after catalyst regeneration according to aspects of the present disclosure;

[0036] Figure 5 Graphing the results of the catalytic isomerization of 2-ethyl-1-butene to 3-methyl-2-pentene (upper trace) and the loss of 1-hexene (lower trace) according to aspects of the present disclosure;

[0037] Figure 6 Graphing additional results for the catalytic isomerization of 2-ethyl-1-butene to 3-methyl-2-pentene (upper trace) and the loss of 1-hexene (lower trace) according to aspects of the present disclosure;

[0038] Figure 7illustrates additional results for the catalytic isomerization of 2-ethyl-1-butene to 3-methyl-2-pentene (upper trace) and the loss of 1-hexene (lower trace) at time points before and after catalyst regeneration according to aspects of the present disclosure; and

[0039] Figure 8 Graphed are the results of the catalytic isomerization of 2-ethyl-1-butene to 3-methyl-2-pentene (upper trace) and the loss of 1-hexene (lower trace) according to aspects of the present disclosure. DETAILED DESCRIPTION

[0040] Some embodiments of the present disclosure will now be described more fully below with reference to the accompanying drawings, in which some but not all embodiments of the present disclosure are shown. In fact, various embodiments of the present disclosure can be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these example embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. The same reference numerals always refer to the same elements. Unless the context clearly dictates otherwise, as used in the specification and the appended claims, the singular forms "a", "an", "the" include plural referents.

[0041] Unless otherwise specified or clear from the context, references to first, second, etc. should not be construed as implying a particular order. A feature described as being above another feature (unless otherwise specified or clear from the context) may alternatively be below the other feature, and vice versa; and similarly, a feature described as being to the left of another feature may alternatively be to the right, and vice versa. Furthermore, while reference may be made herein to quantitative measurements, values, geometric relationships, and the like, any one or more (if not all) of these may be absolute or approximate, unless otherwise specified, to take into account acceptable variations that may occur, such as variations due to engineering tolerances, and the like.

[0042] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., a range of "up to 25 wt %, or, more specifically, 5 wt % to 20 wt %" includes the endpoint and all intermediate values ​​of the range of "5 wt % to 25 wt %, etc.). "Combination" includes blends, mixtures, alloys, reaction products, and the like.

[0043] As used herein, unless otherwise specified or clear from the context, an "or" of a set of operands is an "inclusive or," and is thus true if and only if one or more of the operands is true, as opposed to an "exclusive or," which is false if all of the operands are true. Thus, for example, "[A] or [B]" is true if [A] is true or if [B] is true, or if both [A] and [B] are true.

[0044] Linear alpha olefin (LAO) purification method and catalyst system

[0045] Linear alpha olefins (LAO) are x H 2x The olefins represented by the invention include 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, C 20 -C 24 , C 24 -C 30 and C 20 -C 30 Advanced blends of olefins. LAOs can be distinguished from other monoolefins of similar molecular formula, for example, by the linearity of their hydrocarbon chains and the position of the double bond at the primary (or "alpha") position. Linear alpha olefins comprise a class of commercially valuable compounds and are used as intermediates in the production of detergents, synthetic lubricants, copolymers, coatings, plasticizers, and other products.

[0046] Existing methods for producing linear alpha olefins typically rely on the oligomerization of ethylene. For example, linear alpha olefins can be prepared by catalytic oligomerization of ethylene in the presence of various catalyst systems. Such a reaction can be carried out in any reactor, such as a loop reactor, a plug flow reactor or a bubble column reactor. Oligomerization can occur at a temperature of 10 to 200°C, such as 20 to 100°C, such as 50 to 90°C, such as 55 to 80°C, such as 60 to 70°C. The operating pressure can be 1 to 5 MPa (MPa), such as 2 to 4 MPa. The method can be continuous, and the average residence time can be 10 minutes to 20 hours, such as 30 minutes to 4 hours, such as 1 to 2 hours. The residence time can be selected to achieve the desired conversion rate with high selectivity. The resulting product stream containing linear alpha olefins is then subjected to a purification process.

[0047] Many commercially available methods for enhancing the desired species contained in linear alpha olefin (LAO) streams are based on distillation. For example, the enrichment of LAOs such as 1-hexene can be carried out by commercial distillation methods characterized by being able to remove impurities having a boiling point significantly different (lower or higher) from 1-hexene (boiling point of about 63-64°C), such as extractive distillation or azeotropic distillation. Distillation can occur, for example, at a temperature in the range of about 30°C to about 80°C, such as about 35°C to about 70°C, such as about 40°C to about 65°C, such as about 45°C to about 60°C. The operating pressure can be in the range of about 0.5 atmospheres (atm) to 5 atmospheres (atm), such as about 1atm to about 2atm.

[0048] The oligomerization process can be carried out in solution using an inert solvent that is advantageously non-reactive with the catalyst composition. Examples of desirable organic solvents can include, but are not limited to, aromatic hydrocarbon solvents that can be unsubstituted or halogen-substituted, such as toluene, benzene, xylene, monochlorobenzene, dichlorobenzene, chlorotoluene; aliphatic paraffins, such as pentane, hexane, heptane, octane, nonane, decane; alicyclic hydrocarbon compounds, such as cyclohexane, decahydronaphthalene; and halogenated alkanes, such as dichloroethane and dichlorobutane.

[0049] According to the present disclosure, a catalyst is positioned to receive a LAO product stream, the catalyst being capable of isomerizing an alkyl butene fraction into an alkyl pentene fraction to enhance separation of one or more impurities in the LAO product stream. Figure 1 As shown in FIG. 1 , system 10 may include a reactor 12, a linear alpha olefin (LAO) reactant stream 14, and a distillation column 16. In a normal production mode, reactant 14, such as a LAO reactant stream containing 1-hexene and impurities such as alkyl butenes (including 2-ethyl-1-butene), may be fed to reactor 12, which contains a catalyst system, such as a zeolite catalyst system, such as a zeolite catalyst system capable of regeneration, typically in the form of a packed bed of catalyst material. Typical operating conditions for the catalyst bed will include a pressure of less than about 5 psig, a temperature in the range of about 40° C. to about 60° C., and a temperature of about 0.5 h. -1 About 10 hours -1 Liquid Hourly Space Velocity (LHSV) within the range.

[0050] The zeolite catalyst system of reactor 12 can catalytically isomerize impurities such as 2-ethyl-1-butene into isomers that can be more easily separated from the resulting LAO product stream. For example, the zeolite catalyst can be optimally configured to isomerize 2-ethyl-1-butene into either (cis or trans) isomer of 3-methyl-2-pentene, both of which are characterized by a boiling point (about 67-68° C.) significantly higher than 2-ethyl-1-butene (boiling point about 63.4° C.), which has a boiling point similar to 1-hexene (boiling point about 63.85° C.).

[0051] The number of reactors 12 (which are interchangeably referred to herein as catalyst beds in some aspects) operable within the system 10 can vary. For example, the system may have 1 to 5 reactors, including systems having two reactors. In certain embodiments, two or more reactors in the system 10 may be in direct fluid communication with each other. Alternatively, each of the two or more reactors of the system 10 may be operated as an independent reactor, and each of the two or more reactors is configured to regenerate the zeolite catalyst therein in an environment that is substantially free of oxygen, such as under an inert gas stream. Substantially free of oxygen may be a stream having less than 100 ppm, less than 50 ppm, less than 20 ppm, less than 10 ppm, less than 5 ppm, or less than 1 ppm of oxygen. In a related embodiment, two or more reactors may be positioned (in series or in parallel) and fluidly integrated with at least one distillation column 16.

[0052] After the reaction, the treated LAO product stream 20 may be directed to one or more distillation columns 16, wherein the treated LAO product stream may include the produced linear alpha olefins, such as C4-C 20+ Olefins (including 1-hexene). One or more distillation columns 16 can be configured to separate one or more linear alpha olefins in the LAO product stream by increasing or decreasing the operating temperature based on the boiling point of the desired linear alpha olefin(s). For example, the distillation separation of 1-hexene can be achieved by operating the distillation column 16 at approximately the boiling point of 1-hexene (about 63.85° C.).

[0053] After processing one or more LAO reactant streams, the zeolite catalyst may become saturated and / or deactivated. In some aspects, the regeneration of the zeolite catalyst may be achieved by treating the catalyst under appropriate conditions for regeneration. For example, the regeneration of the zeolite catalyst may include treating the zeolite catalyst in a substantially oxygen-free environment, such as in the presence of a continuous inert gas stream, such as in a nitrogen (N2) or argon (Ar) stream, at a temperature in the range of about 150°C to about 400°C, such as about 250°C to about 300°C.

[0054] In certain aspects, the light alpha olefin (LAO) reactant stream can be processed and / or manipulated to maximize the concentration and weight percent of 1-hexene in the stream. In this regard, 1-hexene is characterized by a boiling point of about 63-64°C, while the common isomers of 2-ethyl-1-butene, a common impurity in the LAO stream, have a similar boiling point of about 64.67°C. However, an isomerization catalyst can be used to convert 2-ethyl-1-butene into a second higher boiling isomer, such as cis-3-methyl-2-pentene or trans-3-methyl-2-pentene. This equilibrium limited reaction can be illustrated as follows:

[0055]

[0056] Applies to Figure 1 The isomerization catalyst of the system includes a zeolite material. In particular, the isomerization catalyst used in the present disclosure will advantageously include a combination of zeolite materials. The combination may include a first zeolite and H exchanged with a metal ion. + Reference to a metal ion exchanged zeolite includes zeolites wherein at least a portion of their ion exchange sites include metal ions, such as the promoter metals mentioned below. + Reference to a zeolite of the type zeolite includes zeolites in which at least a portion of their ion exchange sites contain hydrogen. An example zeolite combination is + Type Y zeolite (HY) combined with Na + Form Y zeolite (NaY).

[0057] Without being bound by theory of operation, it is believed that the metal ion exchanged zeolite and H + The combination of metal ion exchanged zeolites and H 2O zeolites, particularly when both are large pore zeolites, provides a catalyst characterized by high 2-ethyl-1-butene (2E1B) isomerization, minimal conversion of undesirable linear alpha olefins, and stable performance over time. + Pairing with zeolites of this type can balance the acidity level of the catalyst, thereby providing strong performance and good catalyst stability. + The zeolites may also include some metal ion exchange sites without departing from the invention.

[0058] The relative amounts of each zeolite in the combination can vary, with the metal ion exchanged zeolites and H + Typical weight ratios for zeolites of this type range from about 5: 1 to about 15: 1, such as about 7: 1 to about 12: 1 or about 8: 1 to about 10: 1. In some embodiments, the weight ratio can be about 5: 1 or more, or about 6: 1 or more, or about 7: 1 or more, or about 8: 1 or more.

[0059] As used herein, the term "zeolite" refers to a framework aluminosilicate comprising or consisting of an extended array of a three-dimensional network of tetrahedra connected via SiO4 and AlO4, which can be used as a catalyst, for example in particulate form, in combination with one or more promoter metals. Zeolites exhibit an extensive network with a substantially uniform pore distribution, wherein the average pore size is typically no greater than The pore size is defined by the framework ring size. According to one or more embodiments, it will be appreciated that defining zeolites by their structure type is intended to include zeolites having that structure type and any and all isotype framework materials having the same structure type, such as SAPO, AlPO and MeAPO materials.

[0060] In more specific embodiments, reference to aluminosilicate zeolite structure types limits the material to zeolites that do not purposely include phosphorus or other substituted metals in the framework. For clarity, as used herein, "aluminosilicate zeolite" does not include aluminophosphate materials such as SAPO, AlPO and MeAPO materials, and the broader term "zeolite" is intended to include aluminosilicates and aluminophosphates. Aluminosilicate zeolites are crystalline materials understood to have an open three-dimensional framework structure composed of corner-sharing TO4 tetrahedra, where T is Al or Si.

[0061] In some embodiments, each zeolite is a zeolite having greater than about The large pore zeolite (e.g., X zeolite, Y zeolite, or beta zeolite) has an average pore size of about 1.5-2.5 W. Exemplary large pore zeolites have a framework type selected from the group consisting of AFI, AFR, AFS, AFY, ASV, ATO, ATS, BEA, BEC, BOG, BPH, BSV, CAN, CON, CZP, DFO, EMT, EON, EZT, FAU, GME, GON, IFR, ISV, ITG, IWR, IWS, IWV, IWW, JSR, LTF, LTL, MAZ, MEI, MOR, MOZ, MSE, MTW, NPO, OFF, OKO, OSI, RON, RWY, SAF, SAO, SBE, SBS, SBT, SEW, SFE, SFO, SFS, SFV, SOF, SOS, STO, SSF, SSY, USI, UWY, VET, and mixtures or intergrowths thereof. For example, in some embodiments, the large pore zeolite is selected from the group consisting of framework types AFI, BEA, FAU, MAZ, MOR, and OFF.

[0062] Zeolites typically comprise a silica to alumina (SAR) molar ratio of 1 or more. The zeolites used in the disclosed catalyst compositions are not particularly limited in terms of SAR values, although in some embodiments, the particular SAR value associated with a zeolite may affect the performance of the catalyst composition into which it is incorporated (e.g., particularly after aging). The silica to alumina molar ratio ("SAR") of the zeolites used in the present disclosure can vary over a wide range, but is typically greater than 2. For example, the first zeolite or the second zeolite may have a SAR of about 1 to about 1000, or about 2 to about 100, or about 3 to about 50 (e.g., a range of about 2 to about 30, or about 3 to about 20, or about 4 to about 15).

[0063] The first zeolite and the second zeolite can be, for example, the same type of zeolite framework with the same silica to alumina ratio, the same type of zeolite framework with different silica to alumina ratios, or different zeolite frameworks. The cations balancing the charge of the anionic framework are loosely associated with the framework oxygen of the zeolite, and the remaining pore volume may potentially be filled with water molecules. Non-framework cations are generally exchangeable, and water molecules are removable.

[0064] In certain embodiments, a zeolite having a FAU crystal structure is used, which is formed by a 12-membered ring structure and has about . Examples of such zeolites include faujasite, X zeolite, Y zeolite, LZ-210 and SAPO-37. Such zeolites are characterized by a three-dimensional pore structure with pores extending perpendicularly to each other in the x, y and z planes, with secondary structural units 4, 6 and 6-6. Exemplary SAR ranges for bulk FAU zeolite materials are from about 3 to about 6, typically with a unit cell size range of 24.35 to 24.65, as determined by X-ray diffraction analysis (XRD). Y zeolite is particularly suitable for use in certain embodiments of the present invention. In certain embodiments, one of the selected FAU zeolites is in an alkali metal form, such as Na + Form of use.

[0065] As is known in the art, zeolites may be metal ion exchanged or metal promoted, which refers to zeolites that contain one or more metals that are intentionally added, rather than zeolites that contain impurities that may be inherent in the zeolite. Thus, for example, a metal promoter is a component that is intentionally added to enhance the activity of a catalyst compared to a catalyst without an intentionally added promoter. The promoter metal may typically be selected from alkali metals and alkaline earth metals.

[0066] Zeolites containing promoter metals such as alkali metals are commercially available, such as from Zeolyst International, Inc. (PA, USA), Clariant AG (Muttenz, Switzerland), KMI Zeolite, Inc. (Pahrump, NV, USA), and WR Grace & Co. (Columbia, MD, USA). The alkali metal content of the zeolite is typically produced by a zeolite formation process, which may include, for example, mixing a reaction mixture containing water, an aluminum source, a silicon source (which may be an alkali metal silicate), and a structure directing agent to form an aluminosilicate-containing solution known as a "synthesis gel" or "gel", and subjecting the synthesis gel to a crystallization process to crystallize the zeolite. + Type zeolites are commercially available, for example, from Fisher Scientific (Waltham, MA, USA), Alfa Aesar (Tewksbury, MA, USA), and Sigma-Aldrich Inc. (St. Louis, MO, USA). Alternatively, H + Type zeolites can be formed by ion exchange methods known in the art, such as by reacting with NH4 + Ion exchange followed by calcination to obtain H + type.

[0067] Catalyst compositions comprising a variety of zeolites can be formed by mixing a variety of zeolite materials with a binder, then extruding and grinding to a desired size. Suitable binders include metal oxides such as silicon dioxide, aluminum oxide, titanium dioxide, zirconium oxide, ceria or a combination thereof. Alumina binders include aluminum oxides, aluminum hydroxides and aluminum hydroxides. Colloidal forms of aluminum salts and aluminum oxides can also be used. Silica binders include various forms of SiO2, including silicates and colloidal silicon dioxide. Based on the gross weight of the catalyst composition, the loading of the binder is typically from about 1 wt % to about 50 wt %. As an example, the binder can include a BET (N2 adsorption) surface area of ​​200-400 m 2 / g, and an average grain size in the range of about 1 micrometer (μm) to about 10 micrometers (μm), for example, in the range of about 1.5 μm to about 3.5 μm, and contains aluminum oxide having an average pore size in the range of about 3 nanometers (nm) to about 10 nanometers (nm), for example, in the range of about 5 nm to about 8 nm.

[0068] The acidity of the catalyst composition of the present disclosure, such as the combination of the first zeolite and the second zeolite, can be expressed in several ways. For example, the acidity can be calculated based on the chemical formula or unit cell (uc) composition of the zeolite material. In this way, the Bronsted acid site (BAS) equivalent can be calculated. For example, the BAS of HZSM-5 (see CBV5524 in Table 2 below) is calculated as follows: The chemical formula of the zeolite H 3.69 Al 3.69 Si 92.31 O 192 Each unit cell or each 5769.89g (MW of uc) of zeolite powder contains 3.69H + (or BAS) molar equivalent, i.e. 0.64 mmol H + In certain embodiments, the Bronsted acid site (BAS) equivalent is about 1.0 mmol / g catalyst or less, such as about 0.9 mmol / g catalyst or less, or about 0.5 mmol / g catalyst or less, and exemplary ranges include about 0.1 mmol / g catalyst to about 1.0 mmol / g catalyst or about 0.2 to about 0.9 or about 0.3 to about 0.7.

[0069] As described above, the Bronsted acid sites (BAS) of the catalyst can be calculated based on the chemical formula of the zeolite content of the zeolite. And the total acid site BAS (contributed by the zeolite) plus the Lewis acid sites (contributed by both the zeolite and the alumina binder) can be characterized by the programmed temperature desorption (TPD) of NH. For example, the isomerization catalyst can have an ammonia desorption distribution, wherein each gram of catalyst desorbs less than about 2.0mmol NH, the NH-TPD peak maximum is, for example, below about 500°C, or each gram of catalyst desorbs less than about 1.5mmol NH, or each gram of catalyst desorbs less than about 1.0mmol NH, for example, each gram of catalyst desorbs about 0.5 to about 2.0mmol NH. The test scheme of the TPD of NH is given in the Examples section.

[0070] In certain embodiments, the characteristics of the LAO product stream to be treated according to the present disclosure can be 1-hexene content and 2-ethyl-1-butene (2E1B) content. Exemplary product streams include 1-hexene in an amount of 90 wt % or more (e.g., 95 wt % or more or 97 wt %), such as 90 wt % to about 98 wt %. Exemplary product streams include about 0.7 wt % or more (e.g., about 0.8 wt % or more or about 0.9 wt %), such as about 0.7 wt % to about 2.0 wt % 2E1B concentration.

[0071] In some aspects, the isomerization catalyst can be characterized based on how much of the undesirable first isomer is converted into the second isomer. For example, in certain embodiments, the isomerization catalyst is capable of converting more than about 90% by weight of 2-ethyl-1-butene (e.g., more than about 95% by weight or more than about 97% by weight or more than about 99% by weight), such as about 95% by weight to about 99.5% into the second isomer. In some embodiments, the treated LAO product stream is characterized in that the 2E1B concentration is equal to or less than about 0.3% by weight or less than about 0.2% by weight or less than about 0.1% by weight (e.g., about 0.05% by weight to about 0.3% by weight).

[0072] The isomerization catalyst can also be characterized based on how much 1-hexene is undesirably converted to different isomers, with example ranges including about 1.0 wt % or less of 1-hexene (e.g., about 0.75% or less or about 0.5% or less), such as about 0.1% to about 1.0%, or about 0.1% to about 0.75%, or about 0.1% to about 0.5%.

[0073] The technology is broadly applicable to isomerization reactions that can enrich the concentration of commercially valuable compounds such as the C6 compounds described herein, but can also be applied to other reactions where equilibrium is limited. For example, such other reactions include the isomerization of other linear alpha olefins, and C2 to C 12 Metathesis of olefins, etherification of C4 and C5 olefins with alcohols (such as methanol, ethanol or isoamyl alcohol) to form gasoline additives that increase the octane rating of the fuel, esterification, acetalization and related processes.

[0074] experiment

[0075] Example 1

[0076] Analysis of typical linear alpha olefin (LAO) composition streams, particularly with respect to 1-hexene (1H) isomer composition streams, was compiled as shown in Table 1 and evaluated based on the boiling points and combined stream concentrations of the 1-hexene isomers present. 2-Ethyl-1-butene (2E1B) was initially targeted, at least in part due to the importance of the close boiling point (bp) of 1-hexene (bp 63.85°C) relative to the isomer 2-ethyl-1-butene (bp 63.4°C).

[0077] Table 1

[0078] LAO components Boiling point(℃) Concentration of 1-hexene isomers (wt%) 2-Ethyl-1-butene 63.4 0.763 3-Methyl-1-pentene 54.0 0.00216 N-Hexane 68.73 0.133 trans-3-hexene 67 0.049 cis-3-hexene 67 0.017 trans-2-hexene 67.9 0.261 cis-2-hexene 67.9 0.347 trans-3-methyl-2-pentene 67-68 0.00438 cis-3-methyl-2-pentene 67-68 0.00354 1-Hexene 63.85 -

[0079] A series of laboratory reactor tests were conducted with various isomerization catalysts to determine the feasibility of using such catalysts to convert 2-ethyl-1-butene (2E1B) into different isomers such as cis-3-methyl-2-pentene or trans-3-methyl-2-pentene. The percent conversion (wt %) of both 2E1B and 1H was determined at a temperature of about 45°C, a pressure of about 1 atm, and at the liquid hourly space velocity (LHSV) described in Table 2. The catalysts tested were used in the form of extrudates comprising 80 wt % zeolite and 20 wt % alumina binder.

[0080] The catalysts tested were as follows: extrudates of sodium Y zeolite (NaY) with a SAR of 5.1 (Example 1; also referred to as CBV100); + Extrudates of type Y zeolite (HY) (Example 2; also referred to as CBV400); steam or acid stabilized H + Extrudates of type Y zeolite (stabilized HY) (Example 3; also referred to as CBV720); steam or acid stabilized HY with a SAR of 60 + Extrudates of type Y zeolite (stabilized HY) (Example 4; also referred to as CBV760); sodium Y zeolite (NaY) with a SAR of 5.1 and H + Extrudate of a 9:1 weight ratio mixture of type Y zeolite (HY) (Example 5); H with a SAR of 50 + Extrudate of Socony Mobil-5 (HZSM-5) zeolite (Example 6; also known as CBV5524); H + Extrudates of HZSM-5 zeolite (Example 7; also known as CBV28014); and 15 (Example 8). Note that the catalysts designated CBV100, CBV400, CBV720, CBV760, CBV5524, and CBV28014 were obtained from Zeolyst International, Inc.

[0081] Table 2A (Powder)

[0082]

[0083] Table 2B (Extrudate)

[0084]

[0085]

[0086] 1Estimated Brønsted acid sites (BAS) based on chemical formula estimation and depending on the SiO2 / Al2O3 ratio (SAR) and H + exchange

[0087] 2 SiO2 / Al2O3 ratio (SAR) of powdered zeolite

[0088] 3 Extruded catalyst, powdered zeolite bound with 20 wt% alumina binder

[0089] 4 NH4 + The exchanged CBV100 was calcined to become H + NH4 exchange of zeolite powder can be accomplished using NH4 brine solutions and is well known in the art.

[0090] 5 High SiO2 / Al2O3 ratio (SAR) HY zeolites are stabilized by steam or acid treatment, also known as ultrastable Y (USY) zeolites, and contain extra-framework alumina

[0091] 6 9:1 ​​ratio of CBV100:CBV400, based on weight

[0092] The zeolite unit cell composition, acid sites and catalytic test results are shown in Table 2. As described in Table 2, many of the tested catalysts are characterized by high 1H conversion and / or rapid catalyst deactivation. However, it is beneficial to find that Example 5, which comprises a mixture of CBV100 / CBV400 (NaY / HY) with a weight ratio of 9:1 relative to NaY:HY, exhibits high 2E1B conversion and low 1H conversion (e.g. Figure 2 Examples 6 and 7 using medium pore ZSM-5 zeolite showed unacceptably high 1H conversions and rapid degradation of catalyst performance.

[0093] The accompanying drawings also provide a separate NaYCBV100 ( Figure 3 ), single HY / CBV400( Figure 4 ), stabilized HY( Figure 5 )、HZSM-5(50) / CBV5524( Figure 6 )、HZSM-5(280) / CBV28014( Figure 7 )and 15( Figure 8 ) additional 2E1B and 1H catalytic conversion curves.

[0094] Example 2

[0095] The test of Example 1 was repeated for several catalyst samples, and the data are provided in Table 3 below. The acidity of some of the tested materials was also quantified using temperature programmed desorption (TPD) of NH3. In the present disclosure, the total acidity of the catalyst was determined by NH3-TPD analysis using a conventional TCD-TPD instrument (AutoChem II 2920; Micromeritics Instrument Corp., Norcross, GA, USA). The total acidity of the catalyst was determined by heating the catalyst under a He flow (30 cm 3 A weighed amount (typically 200 mg) of the catalyst was preactivated by drying at a maximum temperature of 550° C. at 400 ° C. / min and, after cooling to 100° C., by heating with 5% NH3 in He at 30 cm 3 / min flow rate at 100 ° C for 30 min to adsorb NH3 on the catalyst. Then, He (50 cm 3 / min) at 100 °C for 1 h to remove physically adsorbed NH3. Then, the NH3 was removed by flowing at a rate of 10 °C / min and at 30 cm 3 The catalyst sample was heated from 100°C to 550°C under a helium flow rate of 1 / min to desorb ammonia. The TCD signal attributed to the desorbed NH3 was measured as a function of time and temperature. The acid sites were determined from the amount of NH3 desorbed under the peak area.

[0096] Table 3

[0097]

[0098] 1 The numbers shown in brackets are the SiO2 / Al2O3 ratio (SAR) of the powdered zeolite.

[0099] 2 Extruded catalyst, powdered zeolite bound with 20 wt% alumina binder.

[0100] a LHSV / h shown in brackets

[0101] b The desorbed NH3 shows a broad peak between 100℃ and 500℃, with the maximum peak at 200℃

[0102] c Physical mixture (9:1 weight ratio)

[0103] The results are shown in Table 3. All tested catalysts were able to convert a large percentage of 2E1B into isomers that could be more easily removed from the resulting LAO product stream. However, the physical mixture of NaY(5.1) / NaHY(5.1) provided the strongest and most stable performance, consistent with Example 1.

[0104] Generally, the present invention may alternatively include, consist of, or consist essentially of any suitable components disclosed herein. The present invention may additionally or alternatively be formulated to lack or be substantially free of any components, materials, ingredients, adjuvants, or species used in prior art compositions or that are not necessary to achieve the functions and / or purposes of the present invention.

[0105] Many modifications and other embodiments of the present disclosure will occur to those skilled in the art with the benefit of the foregoing description and the teachings presented in the associated drawings. Therefore, it is to be understood that the present disclosure is not limited to the specific embodiments disclosed herein, and modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used only in a general and descriptive sense, and not for the purpose of limitation.

Claims

1. A catalyst composition comprising a mixture of a first zeolite and a second zeolite and an optional metal oxide binder, wherein the first zeolite and the second zeolite each have a molecular weight greater than about wherein the catalyst composition comprises less than about 1.0 mmol / g catalyst of Bronsted acid sites (BAS) equivalent, and wherein the first zeolite is at least partially metal ion exchanged with one or more metals selected from alkali metals, alkaline earth metals, and combinations thereof, and the second zeolite is H + type, and wherein the first zeolite and the second zeolite are present in a weight ratio of first zeolite to second zeolite in the range of about 5:1 to about 15:

1.

2. The catalyst composition of claim 1, wherein the first zeolite is at least partially metal ion exchanged with sodium.

3. The catalyst composition of claim 1, wherein each of the first zeolite and the second zeolite has a 12-membered ring framework structure independently selected from the group consisting of AFI, AFR, AFS, AFY, ASV, ATO, ATS, BEA, BEC, BOG, BPH, BSV, CAN, CON, CZP, DFO, EMT, EON, EZT, FAU, GME, GON, IFR, ISV, ITG, IWR, IWS, IWV, IWW, JSR, LTF, LTL, MAZ, MEI, MOR, MOZ, MSE, MTW, NPO, OFF, OKO, OSI, RON, RWY, SAF, SAO, SBE, SBS, SBT, SEW, SFE, SFO, SFS, SFV, SOF, SOS, STO, SSF, SSY, USI, UWY, VET, and combinations thereof.

4. The catalyst composition of claim 1, wherein each of the first zeolite and the second zeolite has a FAU or BEA framework structure, and each of the first zeolite and the second zeolite has a silica to alumina ratio (SAR) of about 1 to about 100.

5. The catalyst composition according to claim 4, wherein each of the first zeolite and the second zeolite is X zeolite, Y zeolite or beta zeolite, wherein the first zeolite is Na + Type Y zeolite (NaY) and the second zeolite H + Type Y zeolite (HY).

6. The catalyst composition of claim 1, wherein the first zeolite and the second zeolite are present in a weight ratio of first zeolite to second zeolite in a range of about 7:1 to about 12:

1.

7. The catalyst composition of claim 1, wherein the catalyst composition comprises a Bronsted acid site (BAS) equivalent of about 0.9 mmol / g catalyst or less, such as about 0.5 mmol / g catalyst or less.

8. The catalyst composition of claim 1, wherein the catalyst composition is in the form of an extrudate comprising a mixture of the first zeolite, the second zeolite, and a binder.

9. Use of the catalyst composition according to any one of claims 1 to 8 for isomerizing the alkylbutenes fraction in a linear alpha olefin (LAO) product stream to an alkylpentenes fraction.

10. A process for isomerizing an alkylbutene fraction in a linear alpha olefin (LAO) product stream to an alkylpentene fraction comprising contacting the LAO product stream with a catalyst composition according to any one of claims 1 to 8.

11. A process for producing a purified linear alpha olefin (LAO) product stream, the process comprising: a) introducing a LAO product stream comprising an alkyl butene fraction into a catalyst bed comprising a catalyst composition according to any one of claims 1 to 8, said catalyst composition being capable of being regenerated in an environment substantially free of oxygen, and wherein said catalyst composition is fluidly connected to said LAO product stream to catalytically isomerize said alkyl butene fraction into an alkyl pentene fraction and form a treated LAO product stream; and b) directing the treated LAO product stream to at least one distillation column having a plurality of stacked stages to produce a purified LAO product stream.

12. The method according to claim 11, wherein the alkyl butene is 2-ethyl-1-butene (2E1B) and the alkyl pentene is cis-3-methyl-2-pentene or trans-3-methyl-2-pentene.

13. The method according to claim 12, wherein: a. the LAO product stream has a 2E1B concentration of about 0.7 wt% or more, and the treated LAO product stream is characterized by a 2E1B concentration of equal to or less than about 0.3 wt%; and / or b. treating with a zeolite catalyst to catalyze isomerization of more than about 90 wt% of 2E1B and less than about 1.0 wt% of 1-hexene in the LAO product stream; and / or c. the LAO product stream comprises 1-hexene in an amount greater than 90 wt.%; and / or d. The purified LAO product stream is characterized by a 1-hexene product purity of greater than about 99.5 wt%.

14. The method of claim 11, wherein the introducing step is performed under one or more of the following conditions: a. About 0.5h -1 About 10 hours -1 Liquid hourly space velocity (LHSV); b. a pressure of about 5 psig or less; and c. A temperature of about 40°C to about 60°C.

15. A method according to claim 11, wherein at least two catalyst beds comprising zeolite catalysts are operated in parallel and connected to the LAO product feed stream fluid so that at least one catalyst bed can be regenerated in a substantially oxygen-free environment while continuing to process the LAO product feed stream, and wherein the method further includes regenerating one of the catalyst beds by treating the catalyst bed with an inert gas feed stream at a temperature in the range of about 150°C to about 400°C.

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