WO2018165158A1

WO2018165158A1 - Isomerization catalysts

Info

Publication number: WO2018165158A1
Application number: PCT/US2018/021144
Authority: WO
Inventors: Joseph C. DELLAMORTE; Dieter G. VON DEAK; Burcu BAYRAM; I. Ilgaz SOYKAL
Original assignee: Basf Corporation
Priority date: 2017-03-08
Filing date: 2018-03-06
Publication date: 2018-09-13
Also published as: TW201838712A

Abstract

Disclosed is a catalyst formulation including a formed mass including a metal oxide, a metal hydroxide or a combination thereof, where the formed mass has Hg pore volume of at least 0.35 cc/g to about 1.0 cc/g as measured by mercury intrusion porosimetry. Also disclosed is a method of isomerization including contacting 1-butene with the catalyst formulation to form a 2-butene. Also disclosed is a method of forming propylene including contacting 2-butene with ethylene in the presence of the catalyst formulation and a metathesis catalyst to produce propylene. Also is disclosed a method of forming propylene including contacting a feed stream containing n-butene, n-pentene, or mixtures thereof with ethylene in the presence of the catalyst formulation and a metathesis catalyst to produce propylene. Also is disclosed, a method of isomerization including contacting 3-hexene with the catalyst formulation to form a mixture of 1-hexene, 2-hexene, and 3-hexene.

Description

ISOWIERIZATION CATALYSTS

TECHNICAL FIELD

[0001 ] The present disclosure is directed towards isomerization catalysts. More specifically, embodiments of the present disclosure are directed to a catalyst formulation having improved surface area and pore volume and its use thereof.

BACKGROUND

[0002] Propylene is a widely used starting product in the petrochemical industry and is a raw material for a variety of products (polypropylene, films, packaging, caps, closures, and so forth) and chemicals (e.g., propylene oxide, acrylonitrile, cumene, butyraldehyde, and acrylic acid).

[0003] Propylene can be formed by using isomerization catalysis. Magnesium oxide (MgO) is used as a catalyst for double-bond isomerization of 1 -butene to 2-butene. The 2-butene is then reacted with ethylene over a metathesis catalyst to form propylene.

[0004] Tablets of MgO are used as a co-catalyst in the metathesis reaction of 2- butene with ethylene to form propylene. The metathesis reactions to form propylene includes the following reactions:

(ethylene) (2-butene) (propylene)

(2) CH₂=CHGH₂GH₃ + CHCH₃=GHGH₃ <→ CH₃CH=CH₂ + CH₂=CH(CH₂)₂CH₃

(1 -butene) (2-butene) (propylene) (1 -pentene)

(3) (CH₃)₂C=CH₂ + CHCH₃=CHCH₃ <-> CH₃CH=CH₂ + (CH₃)₂C=CHCH₃

(isobutene) (2-butene) (propylene) (2-methyl-2-butene)

[0005] Isomerization catalysts in tablet form exhibit a crush strength that permits the catalyst to withstand the pressures and stress that are exerted on the catalysts during use.

[0006] For commercial application, a mixture of MgO and Mg(OH)₂ can be formed into cylinders using a tablet press. The catalytic performance may be improved by decreasing the tablet diameter. However, with smaller tablet diameters, bulk crush strength decreases and pressure drop across the catalyst bed increases which impose a practical limit in particle size. [0007] Accordingly, there is a need for an improved double-bond isomerization catalyst having improved isomerization activity which exhibits acceptable crush strength so the catalyst can withstand the pressure of hydrocarbon flow in the catalyst system as well as the stress placed on the catalyst when packed into a reactor.

[0008] In conventional metathesis, the focus is to maximize reaction (1 ) to produce propylene, and thus to maximize the selectivity to propylene. As such, excess ethylene is used to reduce the extent of the reactions of butenes with themselves. The theoretical ratio is 1/1 molar or 0.5 weight ratio of ethylene to n-butenes, but it is common in conventional metathesis to employ significantly greater ratios (e.g., 13 or larger molar ratio) to minimize reactions that form larger carbon number olefins. Under conditions of excess ethylene and due to the fact that both isobutylene and 1 -butene do not react with ethylene, two process sequences are employed. First, the isobutylene is removed prior to metathesis. If isobutylene is not removed, it will build up as the n- butenes are recycled to achieve high yield. Second, 1 -butene is isomerized to 2-butene by including a double bond isomerization catalyst such as magnesium oxide admixed with the metathesis catalyst. Note that this catalyst will not cause significant skeletal isomerization (e.g., isobutylene to normal butylenes), but will primarily shift the double bond from the 1 position to the 2 position for the normal butenes. Thus, reaction (1 ) is maximized by operating with excess ethylene, eliminating isobutylene from the metathesis feed prior to reaction, and employing a double bond isomerization catalyst.

[0009] When there is limited or no fresh ethylene (or excess butylenes for the ethylene available), there are limited options available for propylene production. One option is first removing the isobutylene and then processing the normal butenes with whatever ethylene is available. The entire n-butenes-only-mixture is subjected to metathesis with the available ethylene. Ultimately, if there is no fresh ethylene available, the C₄s react with themselves (auto metathesis). Under low ethylene conditions, reactions (2) and (3) will occur, both leading to lower propylene selectivity (e.g., 50% or lower versus 100% for reaction (1 )). The lower selectivity results in lower propylene production. The molar flows of ethylene and butenes can be matched by limiting the flow of butenes to produce conditions where there is a high selectivity of the normal butenes to propylene via reaction (1 ). By limiting the flow of n-butenes to match ethylene, the production of propylene is limited by the reduced butenes flow.

[0010] Pentenes and some hexenes are formed to some extent in the conventional metathesis case with low ethylene. The volume of these components will depend upon the ethylene-to-n-butenes ratio with a lower ratio producing more C_s and C₆ components. When ssobutylene is removed before any metathesis, C₅ and C₆ olefins are norma! olefins since no skeletal isomerization occurs. It is possible to recycle these olefins back to the metathesis step where, for example, the reaction with ethylene and 2- pentene will occur, yielding propylene and 1 -butene. The 1 -butene is recovered and recycled. Note however, with limited ethylene, reaction (1 ) can occur only to the limit of the ethylene availability. Ultimately, these non-selective byproducts, pentenes and hexenes, must be purged from the system.

[0011 ] U.S. Pat. No. 6,777,582 discloses a process for the auto-metathesis of olefins to produce propylene and hexene. Therein, auto-metathesis of a mixed normal butenes feed in the presence of a metathesis catalyst operates without any ethylene in the feed mix to the metathesis reactor. Some fraction of the 2-butene feed may be isomerized to 1 -butene and the 1 -butene formed plus the 1 -butene in the feed react rapidly with the 2-butene to form propylene and 2-pentene. The feed to the reactor also includes the recycle of the 2-pentene formed in the reactor with unreacted butenes to simultaneously form additional propylene and hexene. The 3-hexene formed in the reaction may be isomerized to 1 -hexene,

[0012] In U.S. Pat. No. 6,727,398, ethylene and hexene- 1 are produced from butene-1 by metathesis of butene-1 and isomerization of the hexene-3 produced therein to hexene-l. The initial starting material is a mixed butene stream, where butene- 1 is isomerized to butene-2 with ssobutylene being separated therefrom, followed by isomerization of butene-2 to butene-l, with the butene-1 being the feed to the metathesis.

[0013] In U.S. Pat. No. 7,21 ,841 , the C₄ cut from a hydrocarbon cracking process is first subjected to auto-metathesis prior to any isobutyiene removal and without any ethylene addition, favoring the reactions which produce propylene and pentenes. The ethylene and propylene produced are then removed leaving a stream of the C₄s and heavier components. The C₅ and heavier components are then removed leaving a mixture of 1 -butene, 2-butene, isobutyiene, and iso- and normal butanes. The isobutyiene is next removed preferably by a catalytic distillation hydroisomerization de- isobutyleneizer. The isobutyiene -free C₄ stream is then mixed with the product ethylene removed from the auto-metathesis product together with any fresh external ethylene needed and subjected to conventional metathesis producing additional propylene.

[0014] Processes to produce propylene using low amounts of ethylene or no ethylene are of interest due to the limited commercial availability of ethylene, especially with respect to the quantity of butenes commercially available. Also, ethylene is an expensive feedstock and limiting the quantities of ethylene used may result in significant cost savings. However, as the ratio of ethylene to butenes is decreased, there is a greater tendency for the butenes to react with themselves, which reduces the overall selectivity to propylene.

[0015] There is also a need for isomerization catalysts having higher reaction rates and improved propylene productivity, selectivity, and catalyst life for a dual catalyst system for metathesis and double-bond isomerization.

SUMMARY

[0016] The following presents a simplified summary of various aspects of the present disciosure in order to provide a basic understanding of such aspects. This summary is not an extensive overview of the disciosure. It is intended to neither identify key or critical elements of the disclosure, nor delineate any scope of the particular embodiments of the disclosure or any scope of the claims. Its sole purpose is to present some concepts of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0017] In one embodiment, a catalyst formulation includes a formed mass including a metal oxide, a metal hydroxide or a combination thereof, where the formed mass has a Hg pore volume at least about 0.25 cc/g (cm³/g) to about 1 .0 cc/g as measured by mercury intrusion porosimetry.

[0018] In another embodiment, a catalyst formulation includes a formed mass including a metal oxide, a metal hydroxide or a combination thereof, where the formed mass includes bimodal pore distribution, a first plurality of pores of the bimodal pore distribution has a first average pore radius centered around 2 nm, and a second plurality of pores of the bimodal pore distribution has a second average pore radius centered around 6 nm.

[0019] In another embodiment, a method of isomerization includes contacting 1 - butene with a catalyst formulation to form a 2-butene.

[0020] In another embodiment, a method of forming propylene includes contacting a feed stream containing n-butene, n-pentene, or mixtures thereof with ethylene in the presence of a catalyst formulation and a metathesis catalyst to produce propylene. [0021 ] Sn another embodiment, a method of isomerization includes contacting 3- hexene with the catalyst formulation to form a mixture of 1 -hexene, 2-hexene, and 3~ hexene, separate the 1 -hexene as a product, and recycling the 2-hexene and the 3- hexene back in contact with the catalyst formulation,

[0022] The term "bimodal," as used herein, refers to a statistical distribution having two distinct maxima.

[0023] The term "bimodal pore distribution," as used herein, refers to a material having two distinct distributions of nanoscaie pores (e.g., as observable via N₂ adsorption), with each distribution (if modeled as Gaussian distributions) being centered at particular pore radius or diameter, which may be referred to as an "average pore radius" or "average pore diameter," respectively for the distribution. Although a composition may include additional distributions of pores (e.g., macropores), the term "bimodal pore distribution" is intended to refer to only those pore distributions having average pore radii that are less than 5000 A.

[0024] The term "particles," as used herein refers to a collection of discrete portions of a material, each having a largest dimension ranging from 0.1 μηι to 50 mm. The morphology of particles may be crystalline, semi-crystalline, or amorphous. The term "particle" may also encompass powders down to 1 nm in radius. The size ranges disclosed herein can be mean or median size. It is noted also that particles need not be spherical, but may be in a form of cubes, cylinders, discs, or any other suitable shape as would be appreciated by one of ordinary skill in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which:

[0026] FIG. 1 is a plot of pore size distribution of a first plurality of compositions, according to one embodiment.

[0027] FIG. 2 is a block diagram illustrating a method for preparing a catalyst formulation, according to one embodiment.

[0028] FIG. 3 illustrates the 2-butene to 1 -butene molar ratio of compositions A,

B, C, and D, according to one embodiment.

[0029] FIG. 4 illustrates the propylene selectivity of compositions A, B, G, and D, according to one embodiment. [0030] FIG. 5 illustrates the propylene productivity of compositions A, B, C, and

D, according to one embodiment.

DETAILED DESCRIPTION

[0031 ] Before describing several exemplary embodiments of the disclosure, it is to be understood that the disclosure is not limited to the details of construction or process steps set forth in the following description. The disclosure is capable of other embodiments and of being practiced or being carried out in various ways.

[0032] A first aspect of the present disclosure pertains to a catalyst formulation including a formed mass. The formed mass may include a metal oxide, a metal hydroxide, or a combination thereof.

[0033] In one embodiment, the formed mass includes a basic metal oxide selected from the group consisting of magnesium oxide, calcium oxide, barium oxide, lithium oxide, strontium oxide, and combinations thereof. In one embodiment, the basic metal oxide is present in the catalyst formulation in an amount of at least 50 wt. %. In another embodiment, the basic metal oxide is present in the in an amount from about 70 wt. % to about 85 wt. %. In another embodiment, basic metal oxide is present in an amount of at least about 80 wt. %. In another embodiment, the basic metal oxide is magnesium oxide.

[0034] In another embodiment, the formed mass includes a basic metal hydroxide selected from the group consisting of magnesium hydroxide, calcium hydroxide, barium hydroxide, lithium hydroxide, and combinations thereof. In another embodiment, basic metal hydroxide is present in the catalyst formulation in an amount in the range from about 10 wt. % to about 40 wt. %. In another embodiment, basic metal hydroxide is present in an amount of at least about 15 wt. %. In another embodiment, the basic metal oxide is magnesium hydroxide.

[0035] In another embodiment, the formed mass consists essentially of the metal oxide, the metal hydroxide, or the combination thereof. In another embodiment, the formed mass includes magnesium oxide and magnesium hydroxide.

[0036] In one embodiment, the formed mass has a diameter of from any of about

0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5 mm, about 1 .0 mm, about 1 .5 mm, about 2.0 mm or about 2.5 mm to any of about 3.0 mm, about 3.5 mm, about 4,0 mm, about 4.5 mm, about 5.0 mm, about 5.5 mm, about 6.0 mm, about 6.5 mm, about 7.0 mm, about 7.5 mm, about 8.0 mm, about 8.5 mm, about 9.0 mm, about 9.5 mm or about 10.0 mm. In another embodiment, the formed mass has a diameter of from about 3.0 mm to about 5.0 mm. In one embodiment, the formed mass has a density of from any of about 1 .0 g/cc (g/cm³), about 1 .5 g/cc, about 2.0 g/cc, about 2.5 g/cc or about 3.0 g/cc to any of about 3.5 g/cc, about 4.0 g/cc, about 4.5 g/cc or about 5.0 g/cc.

[0037] The formed mass may be in the form of one or more shapes including at least one of an extrudate, a tablet (e.g., a cylinder, pill), trilobe, quadralobe, hollow cylinder, star shape, etc. In one embodimeni, the Brunauer-Emmett-Teller (BET) specific surface area of the formed mass is from any of about 100 m²/g, about 150 m²/g, about 200 m²/g, about 250 m²/g, about 300 m²/g or about 350 m²/g to any of about 400 m²/g, about 450 m²/g, about 500 m /g, about 550 m²/g or about 600 m²/g. In another embodiment, the BET specific surface area of the formed mass is from about 100 m²/g to about 500 rrr/g. BET specific surface may be determined by ASTM D3663.

[0038] In one embodiment, the catalyst formulation includes basic metal oxides such as magnesium oxide, calcium oxide, barium oxide, and lithium oxide, either individually, or in combination. In another embodiment, other oxides such as sodium oxide or potassium oxide are incorporated into the catalyst formulation as promoters. In another embodiment, the catalyst formulation for use in an isomerization method is MgO. Although the disclosure may be described in terms of MgO, other basic metal oxides mentioned herein and their equivalents are also within the scope of the disclosure.

[0039] In one embodiment, the catalyst formulation includes magnesium oxide catalysts that are high purity magnesium oxides in that they contain, in parts by weight, no more than about 2000 ppm (parts per million) of sulfur and/or phosphorous, and no more than about 500 ppm of transition metal, preferably no more than about 1000 ppm of sulfur and/or phosphorous and no more than about 400 ppm of transition metal, and most preferably no more than about 75 ppm of sulfur and/or phosphorous and no more than about 330 ppm of transition metals. The high purity magnesium oxide used herein shall be referred to as "high purity" magnesium oxide or with a similar designation and it is understood that the terms magnesium oxide and high purity magnesium oxide include minor amounts of magnesium hydroxide as described hereinabove. These magnesium oxides and their activation are described in in U.S. Pat. No. 6,875,901 which is incorporated herein by reference for its teachings in this regard.

[0040] In one or more embodiments, the catalyst formulation excludes or is substantially free of any intentionally added binders (e.g., silica, alumina, silica/alumina, and clays}. In another embodiment, the catalyst formulation excludes or is substantially free of stabilizers (e.g., zirconia). As used herein, "substantially free" or "substantially no" may mean "not purposefully added", for instance≤ 5%, < 4%, < 3%, < 2%, < 1 %, < 0.5%, or < 0.25%, by weight of such materials may be present.

[0041 ] In one embodiment, the formed mass exhibits a side crush strength from any of about 5 lbs. (pounds force), about 10 lbs., about 15 lbs., about 20 lbs., about 25 lbs., about 30 lbs. or about 35 lbs. to any of about 40 lbs., about 45 lbs. or about 50 lbs. As used herein, the term "crush strength" shall include the resistance of formed catalysts to compressive forces, in other words, the catalysts exhibit a crush strength that provides an indication of the ability of the catalyst to maintain its physical integrity during handling and use. Piece crush strength may be measured by placing a cylindrical individual catalyst piece between dies having area width of about 0.125 in (3 mm). The force required to crush the piece between the dies may be measured by a force transducer.

[0042] Sn one embodiment, an organic compound (e.g., organic pore former) is present in the catalyst formulation no more than about 5 wt. %. In another embodiment, an organic compound is present in the catalyst formulation from any of about 0,5 wt. %, about 1 .0 wt. %, about 1 .5 wt. %, about 2.0 wt. %, about 2.5 wt. % or about 3.0 wt. % to any of about 3.5 wt. %, about 4.0 wt. %, about 4.5 wt. % or about 5.0 wt. %, In another embodiment, the organic compound is present in the catalyst formulation no more than about 2.0 wt. %. In one embodiment, the organic compound includes an organic pore former selected from the group consisting of cellulose, cellulose gel, microcrystailine cellulose, methyl cellulose, flours, starches (e.g., potato starch), modified starches, graphite, polymers, carbonates, bicarbonates, microcrystailine wax, organic metal salts, palmitic acid, stearic acid, sugar alcohols (e.g., sorbitol), or mixtures thereof. In another embodimeni, the organic compound includes an organic pore former is selected from the group consisting of Mg palmitate, Mg stearate, and mixtures thereof. In another embodiment, the organic pore former is Mg stearate.

[0043] Sn one embodiment, a catalyst formulation has a bimodal pore

distribution. In another embodiment, a first catalyst formulation that includes an organic pore compound (e.g., Mg stearate) has a bimodal pore distribution, whereas a second catalyst formulation that does not include an organic pore compound does not have a bimodal pore distribution. In another embodiment, a third catalyst formulation that has a bimodal pore distribution does not include an organic pore compound. In another embodiment, a third catalyst formulation that has a bimoda! pore distribution was not formed with an organic pore compound. The first plurality of pores of the bimodal pore distribution may have a first average pore radius centered around 2 nm and a second plurality of pores of the bimodal pore distribution may have a second average pore radius centered around 8 nm. In some embodiments, a first average pore radius may be from any of about 0.8 nm, about 1 .0 nm, about 1 .2 nm, about 1 .5 nm, about 1 .7 nm or about 2,0 nm to any of about 2,2 nm, about 2.5 nm, about 2.7 nm, about 3.0 nm, about 3.2 nm or about 3.4 nm. in some embodiments, a second average pore radius may be from any of about 3.8 nm, about 4.0 nm, about 4.2 nm, about 4.5 nm, about 4.7 nm or about 5.0 nm to any of about 5.2 nm, about 5.5 nm, about 5.7 nm, about 6.0 nm, about 6.2 nm or about 6.4 nm.

[0044] In another embodiment, the formed mass has an average pore radius from any of about 1 .5 nm, about 2.0 nm, about 2.5 nm, about 3.0 nm, about 3.5 nm or about 4.0 nm to any of about 4.5 nm, about 5.0 nm, about 5.5 nm, about 6.0 nm, about 6.5 nm, about 7.0 nm, about 7.5 nm or about 8 nm.

[0045] FIG. 1 is a plot of pore size distribution of a first plurality of compositions, according to one embodiment. The first plurality of compositions includes Composition A, Composition C, Composition D and Composition K.

[0046] In FIG. 1 , the Composition A is the reference composition and does not include an organic pore former. The manufacturing process for Composition A involves hydration of magnesium oxide to magnesium hydroxide. The highest log differential intrusion for Composition A is about 0.78 mL/g at a pore radius of about 80 A. The Composition A does not have a bimodal pore distribution.

[0047] The Composition D is magnesium stearate (MgSt) added to the

Composition A, where the MgSt has a 1 wt. %. The Composition D has a bimodal pore distribution, where a first plurality of pores of the bimodal pore distribution has a first average pore radius of about 24 A and contributes 35% of the total pore volume and a second plurality of pores of the bimodal pore distribution has a second average pore radius centered of about 60 A with 65% contribution to the total pore volume.

[0048] The Composition C is magnesium stearate (MgSt) added to the composition A, where the MgSt has a 0.5 wt. %. The Composition C has a bimodal pore distribution, where a first plurality of pores of the bimodal pore distribution has a first average pore radius of about 22 A and contributes 37% of the total pore volume and a second plurality of pores of the bimodal pore distribution has a second average pore radius centered of about 56 A with 63% contribution to the total pore volume.

The composition K is sorbitol added to the composition A, where the sorbitol has a 0.5 wt. %. The composition K has a bimodal pore distribution, where a first plurality of pores of the bimodal pore distribution has a first average pore radius of about 22 A and contributes 36.5% of the total pore volume and a second plurality of pores of the bimodal pore distribution has a second average pore radius centered of about 56 A with 63,5% contribution to the total pore volume.

[0049] In one embodiment, Composition C, Composition D and Composition K was formed with an organic pore former of Mg stearate. A formed mass including an organic pore former may have a higher intrusion than a formed mass that does not include an organic pore former. Also, a formed mass including an organic pore former of Mg stearate has bimodal distribution whereas a formed mass that does not include an organic pore former may not have bimodal distribution. Both the higher intrusion and the bimodal distribution allows the formed mass with an organic pore former of Mg stearate to have an improved surface area and pore volume to act as a catalyst for isomerization of 1 -butene to form a 2-butene and for forming propylene by contacting 2-butene with ethylene. In another embodiment, a formed mass without an organic pore former of Mg stearate may have an improved surface area and pore volume to act as a catalyst for isomerization of 1 -butene to form a 2-butene and for forming propylene by contacting 2- butene with ethylene.

[0050] As illustrated by FIG. 1 , the formed mass may have Hg pore volume of at least 0.25 cc/g to about 1 .0 cc/g as measured by mercury intrusion porosimetry. In another embodiment, the formed mass has a mercury intrusion porosimetry of 0.35 cc/g to 1 .5 cc/g. Mercury intrusion porosimetry may be determined by the American Society for Testing and Materials (ASTM) D4284. In another embodiment, the pore volume may be determined by nitrogen physisorption.

[0051 ] In another embodiment, a catalyst formulation that includes an organic pore former may have a higher pore size radius and intrusion without bimodal pore distribution.

[0052] FIG. 2 is a block diagram illustrating a method 200 for preparing a catalyst formulation, according to one embodiment.

[0053] At block 210, a mixture is prepared, the mixture including a) a metal oxide, a metal hydroxide, or a combination thereof; b) water; and c) at least one organic pore former. In one embodiment, the mixture includes the metal oxide, metai hydroxide, or combination thereof from about 70% by wt. up to about 85 wt. %. In another embodiment, the mixture includes the organic pore former from about 0.1 wt. % up to about 5 wt. %. In another embodiment, the mixture is substantially free of binders and stabilizers. In another embodiment, the mixture does not include any pore formers.

[0054] In one embodiment, the mixture includes the water from about 0.1 wt. % up to about 10 wt. %. In another embodiment, the amount of water used in forming the mixture depends on the amount of magnesium hydroxide present in the magnesium oxide used in forming the mixture. One of ordinary skill in the art would be able to determine the appropriate amount of water. In another embodiment, the amount of water used in forming the mixture is from about 30 wt. % to about 80 wt. % of the mixture. In another embodiment, the amount of water used in forming the mixture is from about 40 wt. % to 50 wt. %.

[0055] At block 220, the mixture is tabieted or extruded. In another embodiment, slugs are produced from the mixture on a press.

[0056] At block 230, the tabieted or extruded mixture is dried. In another embodiment, the mixture is dried at a temperature and for a time sufficient to remove substantially all of the unbound water from the mixture before forming the dried mixture into a shape (e.g., before block 220).

[0057] At block 240, the tablet or extrudate is calcined at a temperature and for a sufficient time to remove the majority of the organic component of the tablet or extrudate. The organic component may include at least one organic pore former.

[0058] In one embodiment, the dried formed shape is calcined for a time and at a temperature sufficient to remove greater than about 50% by wt. of the organic component of the formed mixture. The time and temperature may depend on the particular pore former used and one of ordinary skill in the art would be able to determine the appropriate time and temperature of calcination. Calcination temperatures may be "mild", for example from any of about 300 °C, about 325 °C, about 350 °C or about 375 °C to any of about 400 °C, about 425 °C, about 450 °C, about 475 °C or about 500 °C.

[0059] In other embodiments, a calcination step is not required in a method of preparing a catalyst formulation. It may be possible to control a weight/weight ratio of a basic metal oxide to a basic metal hydroxide with the calcination conditions. In some embodiments, a weight/weight ratio of basic metal oxides to basic metai hydroxides in the formed mass is from any of about 99/1 , about 95/5 about 90/10, about 85/15, about 80/20, about 75/25, about 70/30, about 65/35, about 60/40, about 55/45 or about 50/50 to any of about 45/55, about 40/60, about 35/65, about 30/70, about 25/75, about 20/80, about 15/85, about 10/90, about 5/95 or about 1/99.

[0060] The catalyst formulation may be used for isomerization. !n one

embodiment, a method of isomerization includes converting C₄-C₆ 1 -olefins to C -C₆ 2- oiefins (e.g., contacting at least one C₄-C₆ 1 -olefin with a catalyst formulation). Sn another embodiment, the method of isomerization includes contacting 1 -butene with the catalyst formulation to form a 2-butene. In another embodiment, the method of isomerization includes contacting 3-hexene with the catalyst formulation to form a mixture of 1 -hexene, 2-hexene, and 3-hexene. The 1 -hexene may be separated as a product. The 2-hexene and the 3-hexene may be recycled back into contact with the catalyst formulation. The catalyst formulation may include a formed mass including a metal oxide, a metal hydroxide, or a combination thereof. The formed mass may have Hg pore volume of at least about 0.25 cc/g to about 1 .0 cc/g as measured by mercury intrusion porosimetry. In some embodiments, a Hg pore volume is from any of about 0.25 cc/g (cm³/g), about 0.30 cc/g, about 0.35 cc/g, about 0.40 cc/g or about 0.45 cc/g to any of about 0.50 cc/g, about 0.55 cc/g, about 0.60 cc/g, about 0.65 cc/g, about 0.70 cc/g, about 0.75 cc/g, about 0.80 cc/g, about 0.85 cc/g, about 0.90 cc/g, about 0.95 cc/g or about 1 .00 cc/g.

[0061 ] Prior to its initial use in an olefin isomerization reaction, the metal oxide

(e.g., magnesium oxide, magnesium oxide catalyst, and so forth) may be activated by heating the metal oxide in a dry inert atmosphere at sufficiently high temperature to remove substantially all activity-affecting amounts of water and carbon dioxide. A suitable initial activation treatment of the metal oxide can be performed in one or more steps. A two-step process may be employed. In one embodiment, the drying first step includes preheating the magnesium oxide catalyst for at least about 15 hours at a temperature of least 350 °C in a dry inert atmosphere. In another embodiment, the drying first step includes passing a flow of dry pure inert gas (e.g., nitrogen) through a bed of metal oxide at a temperature of at least about 350 °C for at least about 15 hours while the effluent is monitored for release of water and carbon dioxide. The effluent water concentration is brought down to less than 1 ppm. In one embodiment, the drying first step is the same as block 230.

[0062] In one embodiment, in a second step, the catalyst is activated by contact with an inert gas (e.g., nitrogen) at about at least 500 °C for at least about 6 hours. In another embodiment, in the second step, the catalyst is activated by contact with the inert gas at about at least 550 °C for at least about 8 hours. The second step removes even more C0₂ and H₂0. In one embodiment, the second step is the same as block 240.

[0063] In one embodiment, a method of forming propylene includes contacting a feed stream containing n-butene, n-pentene, or mixtures thereof with ethylene in the presence of the catalyst formulation and a metathesis catalyst to produce propylene. The n-butene may be one or both of 1 -butene or 2-butene. The n-pentene may be one or both of 1 -pentene or 2-pentene. In another embodiment, a method of forming propylene includes contacting 2-butene with ethylene in the presence of a catalyst formulation and a metathesis catalyst to produce propylene. In another embodiment, the method of forming propylene includes contacting a mixture of 2-butene and ethylene over a catalyst bed including a mixture of a) metathesis catalyst and b) at least one catalyst formulation. The metathesis catalyst and at least one catalyst formulation may have been activated (e.g., in the same fashion as described above). The catalyst formulation includes a formed mass that includes a metal oxide, a metal hydroxide, or a combination thereof. The formed mass may have Hg pore volume of at least about 0.25 cc/g to about 1 .0 cc/g as measured by mercury intrusion porosimetry.

[0064] The metathesis catalyst may contain material known to be active for the metathesis reaction as described or referenced in Olefin metathesis by supported metal oxide catalysts," Lwin, S., et al., ACS Catalysis, 2014, 4, 2505-2520. A metathesis catalyst may include a W0₃ supported on silica.

[0065] The following non-limiting examples shall serve to illustrate various embodiments of the present disclosure.

[0066] Composition A is made by the following process. Approximately 80 parts deionized water is added to 100 parts of high purity magnesium oxide while mixing at standard temperature and pressure (STP). The hydrated material is dried until it is substantially free of unbound water and crushed to form a powder. The crushed material is tableted into a formed shape of approximately 3 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%. Heat treatment conditions are identifiable by somebody skilled in the art.

[0067] Composition B is made by the following process. Approximately 80 parts deionized water is added to 100 parts of high purity magnesium oxide while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 5 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0068] Composition C is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 0.5 parts magnesium stearate while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 3 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0069] Composition D is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 1 part magnesium stearate while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 3 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0070] Composition E is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 0.5 parts magnesium stearate while mixing at STP. The hydrated material is until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 5 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0071 ] Composition F is made by the following process. Approximately 80 parts deionized water is added to approximately 100 parts of a high purity magnesium oxide and 1 part magnesium stearate while mixing at STP, The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 5 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0072] Composition G is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 0.5 parts methyl cellulose while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 3 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0073] Composition H is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 1 part methyl cellulose while mixing at STP. The hyd rated material is dried until it is

substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 3 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0074] Composition I is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 0.5 parts methyl cellulose while mixing at STP. The hydrated material is dried until it is

substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 5 mm thai is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0075] Composition J is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 1 part methyl cellulose while mixing at STP. The hydrated material is dried until it is

substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 5 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0076] Composition K is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 0.5 parts sorbitol while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 3 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0077] Composition L is made by the following process. Approximately 80 parts deionized water is added to 100 parts of high purity magnesium oxide and 1 part sorbitol while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 3 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0078] Composition M is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 0.5 parts sorbitol while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 5 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0079] Composition N is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 1 part sorbitol while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 5 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0080] Composition O is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 0.5 parts potato starch while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 3 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0081 ] Composition P is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 1 part potato starch while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 3 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%. [0082] Composition Q is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 0.5 parts potato starch while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 5 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0083] Composition R is made by the following process. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 1 part potato starch while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 5 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material is heat treated under air to a loss on ignition of between 9 - 15%.

[0084] Composition S1 and S2 are prepared as follows. Approximately 80 parts deionized water is added to 100 parts of a high purity magnesium oxide and 0.5 parts magnesium stearate while mixing at STP. The hydrated material is dried until it is substantially free of unbound water. The dried material is crushed to form a powder. The crushed material is tableted into a formed shape of approximately 3 mm that is substantially free of any intentionally added stabilizers or binders. The tableted material

51 is heat treated under air {calcined} to a loss on ignition of 16%. The tableted material

52 is not calcined. Sample S2 exhibits crush strength of 27 lbs. and sample SI 19 lbs. Sample S2 exhibits attrition 20 mesh (%) and 5 mesh (%) of 4 and 4, respectively;

sample S1 exhibits attrition 20 mesh {%) and 5 mesh (%) of 9 and 17, respectively (ASTM D4058). Samples S1 and S2 are activated as described herein. Post activation, Sample SI has a surface area and pore volume of 130 m²/g and 0.39 cm³/g, respectively; Sample S2 has a surface area and pore volume of 132 m²/g and 0.42 crrfVg, respectively.

[0085] Composition Z is made by the following process. A catalyst composite is prepared based on Example 1 in WO 02/100535, which is incorporated by reference herein. The catalyst composite featured high purity silica granules impregnated with ammonium meta-tungstate. The resulting catalyst contained about 5 wt. % W0₃.

[0086] Table 1 displays data for examples A-R and Table 2 displays the conditions for material reaction testing for examples A-Z. The piece crush strength of each of isomenzation catalysts A, B, and D-R is shown in Table 1 . Where the crush strength was less than 1 .5 lbs/mm or fresh isomerization rate was poor as described in US201 1021858, the isomerization testing was discontinued.

TABLE 1 . Characterization of Example Materials

TABLE 2. Reaction Conditions (based on US2014235914)

Weight hourly space velocity (WHSV) = 26.55 Fir^"1 based on Z

1 1 /16 inch internal diameter stainless steel reactor tube

Reactant entrance: 3 g of A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, or R

Reactant exit: mixture of 3 g Z and 12 g of A, B, C, D, E, F, G, H, I, J, K, L, M, N,

O, P, Q, or R 250-355 μηι sized silicon carbide packed into the void spaces

300 °C; 400 psig

Ethylene to 1 -Butene feed ratio of 1 .8

[0087] FIG. 3 illustrates the 2-butene to 1 -butene molar ratio of compositions A,

B, C, and D, according to one embodiment. FIG. 3 illustrates the 2-butene to 1 -butene molar ratio resulting from the testing of compositions A, B, G, and D according to the parameters provided in Table 2. As described in examples A-D, compositions A-B do not include an organic pore former and compositions C-D include the organic pore former of Mg stearate. As shown in FIG. 3, the compositions with the organic pore former have a higher 2-butene/1 -butene molar ratio than the compositions without the organic pore former,

[0088] FIG. 4 illustrates the propylene selectivity of compositions A, B, C, and D, according to one embodiment. FSG. 4 illustrates the propylene selectivity resulting from the testing of compositions A, B, C, and D according to the parameters provided in Table 2. As shown in FIG. 4, the compositions with the organic pore former have higher propylene selectivity than the compositions without the organic pore former,

[0089] FIG. 5 illustrates the propylene productivity of compositions A, B, C and

C, and D, according to one embodiment. FIG. 5 illustrates the propylene productivity resulting from the testing of Compositions A, B, C and D according to the parameters provided in Table 2. Compositions C and D include organic pore former, whereas compositions A and B do not. Composition D has a higher propylene producitivty than compositions A and B and composition C has a higher propylene productivity than composition B.

[0090] Any ranges herein are inclusive. The term "about" used throughout is used to describe and account for small fluctuations. For instance, "about" may mean the numeric value may be modified by ± 5%, ± 4%, ± 3%, ± 2%, ± 1 %, ± 0,5%, ± 0.4%, ± 0.3%, ± 0.2%, ± 0.1 % or ± 0.05%. All numeric values are modified by the term "about" whether or not explicitly indicated. Numeric values modified by the term "about" include the identified value. For example "about 5.0" includes 5.0.

[0091 ] U.S. patents, U.S. patent applications and published U.S. patent applications discussed herein are hereby incorporated by reference. [0092] Unless otherwise indicated, all parts and percentages are by weight.

Weight percent (wt. %), if not otherwise indicated, is based on an entire composition free of any volatiles.

[0093] In this description, numerous specific details are set forth, such as specific materials, dimensions, processes parameters, etc., to provide a thorough understanding of the embodiments of the present disclosure. The particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments. The words "example" or "exemplary" are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the words "example" or "exemplary" is intended to present concepts in a concrete fashion. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X includes A or B" is intended to mean any of the natural inclusive permutations. That is, if X includes A; X includes B; or X includes both A and B, then "X includes A or B" is satisfied under any of the foregoing instances. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Reference throughout this specification to "an embodiment", "certain embodiments", or "one embodiment" means thai a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase "an embodiment", "certain embodiments", or "one embodiment" in various places throughout this specification are not necessarily ail referring to the same embodiment, and such references mean "at least one".

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

What is claimed Is:

1. A catalyst formulation comprising a formed mass comprising a metal oxide, a metal hydroxide, or a combination thereof, wherein the formed mass comprises a bsmodal pore distribution, a first plurality of pores of the bsmodal pore distribution has a first average pore radius from about 1 .0 nm to about 3.0 nm, and a second plurality of pores of the bimodal pore distribution has a second average pore radius from about 4 nm to about 8 nm, wherein the formed mass has an average Hg pore volume of at least about 0.25 cc/g to about 1 .00 cc/g as measured by mercury intrusion porosimetry.

2. The catalyst formulation of claim 1 , wherein the formed mass has a density of about 1 ,0 g/cc to about 5.0 g/cc.

3. The catalyst formulation of claim 1 , wherein the formed mass has a side crush strength from about 5 lbs. to about 50 lbs.

4. The catalyst formulation of claim 1 , wherein the formed mass has an average pore radius from about 45 angstroms to about 75 angstroms.

5. The catalyst formulation of claim 1 , wherein the formed mass has an average Brunauer-Emmett-Teller (BET) specific surface area from about 1 00 m²/g to about 600 rrr/g.

6. The catalyst formulation of claim 1 , wherein the formed mass consists essentially of the metal oxide, the metal hydroxide, or the combination thereof.

7. The catalyst formulation of claim 1 , wherein the formed mass has a diameter of from about 0.1 mm to about 1 0.0 mm.

8. The catalyst formulation of claim 1 , wherein the formed mass has a diameter of from about 3.0 mm to about 5,0 mm.

9. The catalyst formulation of any of claims 1 -8 comprising magnesium oxide and magnesium hydroxide.

10. The catalyst formulation of any of claims 1-8, wherein the formed mass comprises an organic pore former.

11. The catalyst formulation of claim 10, wherein the organic pore former is selected from the group consisting of cellulose, cellulose gel, microcrystaliine cellulose, methyl cellulose, flours, starches, modified starches, graphite, polymers, carbonates, bicarbonates, microcrystaliine wax, organic metal salts, palmitic acid, stearic acid, sugar alcohols, and mixtures thereof.

12. The catalyst formulation of claim 10, wherein the organic pore former is selected from the group consisting of magnesium palmitate, magnesium stearate, and mixtures thereof.

13. The catalyst formulation of claim 10, wherein the organic pore former consists essentially of magnesium stearate.

14. The catalyst formulation of claim 10, wherein the organic pore former is present in the catalyst formulation no more than about 5.0 wt. %.

15. The catalyst formulation of claim 10, wherein the organic pore former is present in the catalyst formulation from about 0.5 wt. % to about 5.0 wt. %.

16. The catalyst formulation of claim 10, wherein the organic pore former is present in the catalyst formulation no more than about 2.0 wt. %.

17. A method of isomerization, the method comprising contacting 1 -butene, 1 - pentene, or mixtures thereof with the catalyst formulation of any of claims 1-16 to form 2- butene, 2-pentene, or mixtures thereof.

18. A method of forming propylene comprising contacting a feed stream containing n-butene, n-pentene, or mixtures thereof with ethylene in the presence of the catalyst formulation of any of claims 1-16 and a metathesis catalyst to produce propylene.

19. The method of claim 18, wherein the n-butene comprises 1 -butene and 2-butene.

20. The method of claim 19, wherein the n-pentene comprises 1 -pentene and 2- pentene.

21. A method of isomerization comprising:

contacting 3-hexene with the catalyst formulation of any of claims 1-16 to form a mixture of 1 -hexene, 2-hexene, and 3-hexene;

separating the 1 -hexene as product; and

recycling the 2-hexene and the 3-hexene back in contact with the catalyst formulation.

22. A method for preparing a catalyst formulation of any of claims 1-16, the method comprising

preparing a mixture comprising a) a metal oxide, a metal hydroxide, or a combination thereof, b) water, and c) one or more organic pore formers;

forming the mixture into a shape; and

optionally calcining the formed shape.

23. The method of claim 21 , wherein the mixture is dried to remove water prior to, or after forming the mixture into a shape.

24. The method of claim 22, wherein forming the mixture into a shape comprises tableting or extrusion.

25. The method of claim 22, comprising calcining the formed shape.