Etherification Method

Abstract

To provide methods of etherification.SOLUTION: Embodiments of the present disclosure are directed towards methods of etherification including reducing templates of a zeolite catalyst to provide a reduced template zeolite catalyst having from 3 to 15 wt.% of templates maintained following calcination of the zeolite catalyst; and contacting the reduced template zeolite catalyst with an olefin and an alcohol to produce a monoalkyl ether.SELECTED DRAWING: None

Description

[Technical Field]

[0001] Embodiments of the present disclosure relate to a process for etherification, and more particularly, embodiments relate to a process for etherification that includes reducing the template of a zeolite catalyst to provide a reduced-template zeolite catalyst, and contacting the reduced-template zeolite catalyst with an olefin and an alcohol to produce a mono-alkyl ether. [Background technology]

[0002] Monoalkyl ethers are useful in many applications, such as, for example, solvents, surfactants, and chemical intermediates. There is a continuing focus in the industry to develop new and improved materials and / or methods that can be utilized to produce monoalkyl ethers. Summary of the Invention

[0003] The present disclosure provides a method for etherification, the method comprising reducing the template of a zeolite catalyst to provide a reduced-template zeolite catalyst having 3 to 15 wt. % template retained after calcination of the zeolite catalyst, and contacting the reduced-template zeolite catalyst with an olefin and an alcohol to produce a mono-alkyl ether.

[0004] The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. More particularly, the present specification exemplifies exemplary embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list. DETAILED DESCRIPTION OF THE INVENTION

[0005] Disclosed herein is a process for etherification that includes reducing the template of a zeolite catalyst to provide a reduced-template zeolite catalyst, and contacting the reduced-template zeolite catalyst with an olefin and an alcohol to produce a mono-alkyl ether.

[0006] Advantageously, the etherification methods disclosed herein can provide improved, i.e., higher, mono-alkyl ether selectivity compared to etherification that does not utilize a reduced template zeolite catalyst, as further discussed herein. Improved mono-alkyl ether selectivity can be desirable for many applications, such as use as a chemical intermediate. As an example, mono-alkyl ethers can be used to produce surfactants by ethoxylation processes, and mono-alkyl ethers can have a desirable effect on surfactant properties, for example, compared to di-alkyl ethers.

[0007] Furthermore, the etherification methods disclosed herein can provide improved, i.e., lower, dialkyl ether selectivity compared to etherification that does not utilize a reduced template zeolite catalyst, as further discussed herein. Improved, lower, dialkyl ether selectivity can be desirable for many applications, such as the production of surfactants by ethoxylation processes, where dialkyl ethers can have an undesirable effect on surfactant properties, for example, compared to monoalkyl ethers. In other words, dialkyls are undesirable products.

[0008] Zeolite catalysts are crystalline metallosilicates, e.g., aluminosilicates, composed of repeating tetrahedral units of, e.g., TO4, where T can be Si, Al, or P (or a combination of tetrahedral units). These units interconnect to form a framework with regular intracrystalline cavities and / or channels of molecular dimensions, e.g., micropores.

[0009] An embodiment of the present disclosure provides that the zeolite catalyst is a synthetic zeolite catalyst. Synthetic zeolite catalysts can be produced, for example, by the known process of crystallizing silica-alumina gel in the presence of an alkali and a template. Examples include zeolite Beta (BEA), Linde Type A (LTA), Linde Types X and Y (Al-rich and Si-rich FAU), silicalite-1, ZSM-5 (MFI), Linde Type B (Zeolite P), Linde Type F (EDI), Linde Type L (LTL), Linde Type W (MER), and SSZ-32 (MTT), which are described using IUPAC codes according to the nomenclature of the International Zeolite Association's Structure Committee. The IUPAC codes describing the crystal structures depicted by the International Zeolite Association's Structure Committee refer to the most recent designations as of the priority date of this document, unless otherwise specified.

[0010] One or more embodiments provide a zeolite catalyst, zeolite beta (BEA) catalyst, that contains many Bronsted acid sites, i.e., sites that donate protons.

[0011] The zeolite catalyst can have a SiO2 / Al2O3 molar ratio of 5:1 to 1500:1 as measured using neutron activation analysis. All individual values ​​and subranges from 5:1 to 1500:1 are included, for example, the zeolite catalyst can have a SiO2 / Al2O3 molar ratio from a lower limit of 5:1, 10:1, 15:1, or 20:1 to an upper limit of 1500:1, 750:1, 300:1, or 100:1.

[0012] The zeolite catalyst can have an average pore diameter of 5 to 12 angstroms, including all individual values ​​and subranges from 5 to 12 angstroms, for example, the zeolite catalyst can have an average pore diameter from a lower limit of 5 or 7 angstroms to an upper limit of 11 or 12 angstroms.

[0013] Zeolite catalyst is 130 to 1000m 2 / g of surface area. 2 All individual values ​​and subranges are included, e.g., zeolite catalysts may have lower limits of 130, 150, 175, 300, 400, or 500 m / g. 2 / g~upper limit 1000, 900 or 800m 2 / g. Surface area is measured according to ASTM D4365-19.

[0014] As mentioned above, zeolite catalysts are prepared by a process utilizing a template, sometimes referred to as an organic template. The template may also be referred to as a templating agent and / or structure-directing agent (SDA). The template may be added to a reaction mixture for preparing the zeolite catalyst to, for example, induce, e.g., direct, the molecular shape and / or pattern of the framework of the zeolite catalyst. Upon completion of the zeolite catalyst preparation process, the zeolite catalyst comprises a template, e.g., a template located in the micropores of the zeolite catalyst. The template is utilized in the formation of the zeolite catalyst. One or more embodiments provide that the template comprises ammonium ions. Templated zeolite catalysts can be prepared by known processes. Templated zeolite catalysts are commercially available. Examples of suitable commercially available metallosilicate catalysts include CP814E, CP814C, CP811C-300, CBV712, CBV720, CBV760, CBV2314, CBV10A from ZEOLYST INTERNATIONAL™ of Conshohocken, PA.

[0015] A variety of templates are known that can be utilized to prepare zeolite catalysts, including, among others, tetraethylammonium hydroxide, N,N,N-trimethyl-1-adamanteammonium hydroxide, hexamethyleneimine, and dibenzylmethylammonium.

[0016] As previously discussed, the methods disclosed herein involve reducing the template of a zeolite catalyst to provide a reduced-template zeolite catalyst. Embodiments of the present disclosure provide that the template of the zeolite catalyst can be reduced by calcination. Embodiments of the present disclosure provide that not all of the template of the zeolite catalyst is removed by calcination.

[0017] To reduce the template, the zeolite catalyst can be calcined at a temperature between 300° C. and 510° C. All individual values ​​and subranges between 300° C. and 510° C. are included, for example, the zeolite catalyst can be calcined from a lower limit of 300° C., 310° C., or 315° C. to an upper limit of 510° C., 505° C., or 500° C.

[0018] To reduce the template, the zeolite catalyst can be calcined in a number of known calcination environments, for example, the zeolite catalyst can be calcined in an air environment or a nitrogen environment.

[0019] To reduce the template, the zeolite catalyst can be calcined, i.e., exposed to temperatures of 300°C to 510°C in a calcination environment for 1 hour to 24 hours. All individual values ​​and subranges from 1 hour to 24 hours are included; for example, the zeolite catalyst can be calcined from a lower limit of 1 hour, 3 hours, or 6 hours to an upper limit of 24 hours, 18 hours, or 12 hours.

[0020] Embodiments of the present disclosure provide for reducing the weight of a zeolite catalyst by calcination to obtain a reduced-template zeolite catalyst. The weight of the zeolite catalyst is reduced by calcination by reducing the template, i.e., by removing some of the template from the zeolite catalyst. The weight of the zeolite catalyst can be reduced by 5 wt % to 15 wt %, based on the total weight of the initial zeolite catalyst and template. All individual values ​​and subranges between 5 wt % and 15 wt % are included. For example, the zeolite catalyst can be reduced by a lower limit of 5, 5.3, or 5.5 wt % to an upper limit of 15, 14.7, or 14.5 wt %, based on the total weight of the zeolite catalyst and template. For example, if a zeolite catalyst weighs 90 grams and contains 10 grams of template, and the zeolite catalyst is calcined to reduce the template, the resulting reduced-template zeolite catalyst weighs 90 grams and contains 5 grams of template, and the weight of the zeolite catalyst is reduced by 5 wt %, based on the total weight of the initial zeolite catalyst and template.

[0021] Embodiments of the present disclosure provide reduced-template zeolite catalysts by reducing the template of the zeolite catalyst. The reduced-template zeolite catalyst can have 3 wt. % to 15 wt. % of the template remaining after calcination of the zeolite catalyst, based on the total weight of the zeolite catalyst and the remaining template. In other words, embodiments of the present disclosure provide that not all of the template is removed by calcination to provide the reduced-template zeolite catalyst. All individual values ​​and subranges between 3 wt. % and 15 wt. % are included. For example, the reduced-template zeolite catalyst can have a lower limit of 3, 4, or 5 wt. % to an upper limit of 15, 14, 13, or 12 wt. % of the template remaining after calcination of the zeolite catalyst.

[0022]

[0001] Embodiments of the present disclosure relate to a method of etherification. Etherification refers to a chemical process, e.g., a chemical reaction, that produces ethers. The method disclosed herein includes contacting a reduced template zeolite catalyst with an olefin and an alcohol to produce a mono-alkyl ether.

[0023] As used herein, "olefin" refers to a compound that is a hydrocarbon having one or more carbon-carbon double bonds. Embodiments of the present disclosure provide that the olefin contains from 6 to 30 carbon atoms. All individual values ​​and subranges from 6 to 30 carbon atoms are included; for example, the olefin can have a lower limit of 6, 8, or 10 carbon atoms to an upper limit of 30, 20, or 14 carbon atoms.

[0024] The olefin may be an alpha (α) olefin, an internally disubstituted olefin, or a cyclic structure (e.g., C3-C 12 Examples of suitable olefins include alkenes such as cycloalkene. Alpha olefins contain unsaturated bonds at the α-position of the olefin. Suitable α-olefins may be selected from the group consisting of propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-icosene, 1-docosene, and combinations thereof. Internal disubstituted olefins contain unsaturated bonds that are not at the terminal positions of the olefin. The internal olefin may be selected from the group consisting of 2-butene, 2-pentene, 2-hexene, 3-hexene, 2-heptene, 3-heptene, 2-octene, 3-octene, 4-octene, 2-nonene, 3-nonene, 4-nonene, 2-decene, 3-decene, 4-decene, 5-decene, and combinations thereof. Other exemplary olefins may include butadiene and styrene.

[0025] Examples of suitable commercially available olefins include NEODENE™ 6-XHP, NEODENE™ 8, NEODENE™ 10, NEODENE™ 12, NEODENE™ 14, NEODENE™ 16, NEODENE™ 1214, NEODENE™ 1416, NEODENE™ 16148 from Shell, The Hague, Netherlands.

[0026] Embodiments of the present disclosure provide that the alcohol may contain a single hydroxyl group, two hydroxyl groups, i.e., glycol, or three hydroxyl groups. The alcohol may contain one or more carbon atoms, or two or more carbon atoms, or three or more carbon atoms, or four or more carbon atoms, or five or more carbon atoms, or six or more carbon atoms, or seven or more carbon atoms, or eight or more carbon atoms, or nine or more carbon atoms, but may also contain ten or fewer carbon atoms, or nine or fewer carbon atoms, or eight or fewer carbon atoms, or seven or fewer carbon atoms, or six or fewer carbon atoms, or five or fewer carbon atoms, or four or fewer carbon atoms, or three or fewer carbon atoms, or two or fewer carbon atoms. The alcohol may be selected from the group consisting of methanol, ethanol, monoethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, polyethylene glycol, monopropylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-propanediol, 1,2-butanediol, 2,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanemethanediol, glycerol, and combinations thereof. One or more embodiments provide that the alcohol is selected from the group consisting of monoethylene glycol, diethylene glycol, glycerol, and combinations thereof. One or more embodiments provide that the alcohol is a (poly)alkylene glycol, such as monoethylene glycol, diethylene glycol, propylene glycol, or triethylene glycol. Examples of (poly)alkylene glycols include monoethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, monopropylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-propanediol, 1,2-butanediol, 2,3-butanediol, 1,4-butanediol, 1,6-hexanediol, paraxylene glycol, glycerol, and 1,4-cyclohexanemethanediol. One or more embodiments provide that the (poly)alkylene glycol is monoethylene glycol.

[0027] Embodiments of the present disclosure provide for reacting an alcohol with an olefin in a molar ratio of alcohol to olefin of, for example, 0.05:1 to 20:1, including all individual values ​​and subranges from 0.05:1 to 20:1, for example, the alcohol and olefin can be reacted in a molar ratio of alcohol to olefin of from a lower limit of 0.05:1, 0.075:1, or 0.1:1 to an upper limit of 20:1, 18:1, or 15:1.

[0028] As previously described, the method disclosed herein involves contacting a reduced-template zeolite catalyst with an olefin and an alcohol to produce a monoalkyl ether. The olefin and alcohol can be contacted with the reduced-template zeolite catalyst under known etherification conditions, utilizing known reactor equipment and known reaction components. For example, the olefin and alcohol can be contacted with the reduced-template zeolite catalyst in a slurry reactor, a fixed-bed reactor, or a fluidized-bed reactor. The reactor can be operated in batch or continuous mode. The reduced-template zeolite catalyst can be used in an amount of, for example, 1 wt. % to 50 wt. % reduced-template zeolite catalyst, based on the total weight of the olefin. The olefin and alcohol can be contacted with the reduced-template zeolite catalyst at a reaction temperature of 80°C to 200°C, or 100°C to 150°C. The reaction pressure can vary depending on the application. For example, the reaction pressure can be reduced, atmospheric, or elevated.

[0029] When a reduced template zeolite catalyst is contacted with an olefin and an alcohol, a mono-alkyl ether is produced. Various mono-alkyl ethers can be produced for different applications, for example, by varying which olefin is utilized and / or by varying which alcohol is utilized. Mono-alkyl ethers are utilized in many applications, for example, as solvents, surfactants, and chemical intermediates. Advantageously, the etherification methods disclosed herein can provide improved, i.e., higher, mono-alkyl ether selectivity compared to etherification that does not utilize a reduced template zeolite catalyst, as described herein.

[0030] Additionally, the etherification methods disclosed herein can provide improved, i.e., less dialkyl ether selectivity, compared to etherification that does not utilize a reduced template zeolite catalyst as described herein.

[0031] The etherification processes disclosed herein can provide mono-ether selectivities of greater than 85% at olefin conversions of 0.1% to 50%. For example, mono-ether selectivities can be greater than 86%, 87%, or 88% at olefin conversions of 0.1% to 50%.

[0032] Surprisingly, the improved mono- and di-alkyl ether selectivities according to the embodiments disclosed herein are not achieved by impregnating the zeolite catalyst with a compound similar to, or the same as, the template. In other words, a template-free zeolite catalyst that is subsequently impregnated with a compound similar to the template does not provide the improved mono- and di-alkyl ether selectivities achieved when utilizing a reduced-template zeolite catalyst, as discussed herein. [Example]

[0033] In the present examples, various terms and names for materials are used, including, for example:

[0034] Zeolite beta catalyst (CP814E, CAS number 1318-02-1, SiO2 / Al2O3 molar ratio of 25:1, average pore diameter 6.7 Å, surface area 680 m 2 / g, all organic templates removed by commercial supplier prior to receipt, obtained from Zeolyst International), Zeolite Beta catalyst (CP806EL, CAS number 1318-02-1, SiO2 / Al2O3 molar ratio of 25:1, average pore diameter 6.7 Å, surface area 177 m 2 / g, obtained from Zeolyst International, containing organic templates obtained from commercial sources).

[0035] Thermogravimetric analysis (TGA) was used to determine the weight loss rate of zeolite Beta catalyst (CP806EL, including the resulting template), i.e., the weight percent lost due to calcination based on the initial total weight of the zeolite Beta catalyst and the included template. The zeolite Beta catalyst was calcined at 800 °C in an air environment at a ramp rate of 10 °C / min from a starting temperature of 28 °C. The weight of the zeolite Beta catalyst was measured during calcination. Furthermore, based on TGA experiments of the reduced-template zeolite catalyst, the weight percent of template retained after calcination was also calculated. In TGA analyses where weight loss up to 110 °C was due to the removal of adsorbed water and weight loss up to 110 °C was not due to template loss for the reduced-template zeolite catalyst, the template was assumed to be completely removed at 800 °C, i.e., 100% template loss. The weight percent of template retained after various calcinations was calculated by (weight of catalyst at 110 °C - weight of catalyst at 800 °C) / (weight of catalyst at 110 °C) × 100. Similar determinations were made for the reduced template zeolite catalysts obtained from various calcination conditions herein, and the results are reported herein.

[0036] Example 1 was carried out as follows: Zeolite Beta catalyst (CP806EL, approximately 30 grams) was calcined in an air environment at 350°C for 8 hours to obtain a reduced-template zeolite Beta catalyst with a calcination weight loss of 5.6, based on the total weight of the initial calcined zeolite Beta catalyst containing the template. The reduced-template zeolite Beta catalyst had a weight percent template retention of 8.7 (based on the total weight of the zeolite and residual template) after calcination of the zeolite Beta catalyst. Etherification was carried out as follows: Reduced-template zeolite Beta catalyst (0.75 grams) was added to a 40 mL vial reactor equipped with a rare earth magnetic stir bar (part number: VP 772FN-13-13-150, V&P Scientific, Inc.), 1-dodecene (6.2 grams) and monoethylene glycol (6.7 grams) were added to the vial reactor, and the contents of the vial reactor were heated to 125°C and stirred for 3 hours for etherification. The contents of the vial reactor were then analyzed by gas chromatography. Gas chromatography samples were prepared by adding 100 μL of the contents of the vial reactor to 10 mL of an internal standard solution (1 mL of hexadecane dissolved in 1 L of ethyl acetate) and then analyzed offline using an Agilent GC (7890). For analysis, dioxane, 1-dodecene (1-C 12 ) and its isomers (C 12 ), 2-dodecanol, diethylene glycol, mono-alkyl ethers and their isomers, and di-alkyl ethers and their isomers were included for product quantification to obtain the weight percent of species of interest (mono-alkyl ethers, di-alkyl ethers, 1-dodecene-derived species including 2-dodecanol, 1-dodecene, and all C other than 1-dodecene). 12 (total amount of dodecene including isomers).

[0037] The dodecene-derived species were the monoether, diether, and 2-dodacanol.

[0038] Total amount of dodecene-derived species = moles of monoether + 2 × moles of diether + 2 dodecanol, The total amount of dodecane includes 1-dodecene and all other C of non-1-dodecene. 12 It contains isomers, Dodecyl monoether (ME) selectivity (%) was calculated as [total amount of ME] / [C 12 The total amount of the species of origin was determined as [total amount of the species of origin] × 100%.

[0039] Dodecyl diether (DE) selectivity (%) was calculated as 2 × [total amount of DE] / [C 12 The total amount of the species of origin was determined as [total amount of the species of origin] × 100%.

[0040] The olefin conversion rate (%) was calculated by [C 12 Total amount of seeds of origin] / [C 12 The total amount of species of origin + total amount of dodecene × 100% was determined.

[0041] The dodecyl monoether (ME) yield (%) was calculated by 12 It was determined as conversion x dodecyl monoether selectivity.

[0042] The results are reported in Table 1.

[0043] Examples 2 and 3 were carried out similarly to Example 1 with the modifications shown in Table 1.

[0044] Comparative Example A was carried out in the same manner as Example 1, with the following changes: zeolite beta catalyst (CP814E) was utilized instead of zeolite beta catalyst (CP806EL), and the zeolite beta catalyst was calcined for 12 hours; other changes are shown in Table 1. [Table 1]

[0045] The data in Table 1 show that each of Examples 1-3 had improved, ie, greater, mono-alkyl ether selectivity and mono-alkyl ether yield compared to Comparative Example A.

[0046] The data in Table 1 show that each of Examples 1-3 had improved, ie, less dialkyl ether selectivity, compared to Comparative Example A.

[0047] Examples 4-7 were carried out similarly to Example 1, with the exception that the contents of each vial reactor were heated to 150°C instead of 125°C for etherification, and Example 7 was stirred for 1.5 hours instead of 3 hours for etherification, and any further modifications are shown in Table 2. The results are reported in Table 2.

[0048] Comparative Example B was carried out similarly to Example 1, with the exception that the contents of the vial reactor were heated to 150°C instead of 125°C for etherification, Comparative Example B was stirred for 1.0 hour instead of 3 hours for etherification, and any further modifications are shown in Table 2. The results are reported in Table 2. [Table 2]

[0049] The data in Table 2 show that each of Examples 4-7 had improved, ie, greater, mono-alkyl ether selectivity compared to Comparative Example B.

[0050] The data in Table 2 show that each of Examples 4-7 had improved, ie, less dialkyl ether selectivity, compared to Comparative Example B.

[0051] Example 8 was carried out similarly to Example 1, with the exception that the contents of the vial reactor were heated to 150° C. instead of 125° C. for etherification, and Example 8 was stirred for 1.0 hour instead of 3 hours for etherification, and any further modifications are shown in Table 3. The results are reported in Table 3.

[0052] Comparative Example C was carried out as follows: A zeolite beta catalyst (CP806EL) was calcined in an air environment at 550°C for 12 hours to remove the template (tetraethylammonium hydroxide) located in the micropores of the zeolite beta catalyst. The zeolite beta catalyst (6.05 grams) was then impregnated with tetraethylammonium hydroxide (18.35 grams, 35% aqueous tetraethylammonium hydroxide solution) by stirring in a container for 10 minutes. The zeolite beta catalyst was then dried in a box oven at 100°C for 1 hour and subsequently calcined in an air environment at 400°C for 8 hours. Etherification was carried out in the same manner as in Example 1, except that the contents of the vial reactor were heated to 150°C instead of 125°C for 1 hour (the etherification and reaction time), and 0.35 grams of zeolite beta catalyst was used instead of 0.75 grams. The results are reported in Table 3. [Table 3]

[0053] The data in Table 3 show that Example 8 had improved, ie, greater, mono-alkyl ether selectivity compared to Comparative Example C.

[0054] The data in Table 3 show that Example 8 had improved, ie, less dialkyl ether selectivity, compared to Comparative Example C.

[0055] The data in Table 3 show that improved mono- and di-alkyl ether selectivity is not achieved by impregnation of the zeolite Beta catalyst with a template-like compound, i.e., tetraethylammonium hydroxide.

Claims

1. 1. A process for etherification, said process comprising: reducing the template of a zeolite catalyst to provide a reduced-template zeolite catalyst having 3 to 15 wt. % template retained after calcination of said zeolite catalyst; contacting the reduced template zeolite catalyst with an olefin and an alcohol to produce a mono-alkyl ether; The process wherein the zeolite catalyst is a zeolite beta catalyst and the alcohol is a (poly)alkylene glycol.

2. 10. The method of claim 1, wherein the weight of the zeolite catalyst is reduced by 5 wt % to 15 wt %, based on the total weight of the zeolite catalyst and template.

3. 3. The method of any one of claims 1 to 2, wherein reducing the template of the zeolite catalyst comprises calcining the zeolite catalyst at a temperature of from 300°C to 510°C.

4. 4. The method of claim 3, wherein the zeolite catalyst is calcined for 1 hour to 24 hours.

5. The method of any one of claims 1 to 4, wherein the template comprises an ammonium ion.

6. 6. The process of any one of claims 1 to 5, wherein the olefin contains from 6 to 30 carbon atoms.

7. The olefin is １２ -C １４ The method according to any one of claims 1 to 6, wherein the copolymer is an olefin.

8. 8. The method of any one of claims 1 to 7, wherein the alcohol is selected from the group consisting of monoethylene glycol, diethylene glycol, glycerol, and combinations thereof.

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