TITANIUM-LATED CATALYSERS, METHOD FOR THE MANUFACTURING OF TITANIUM-LATED CATALYSERS AND METHOD FOR EPOXIDING

Description

BACKGROUND

[0001] Titanated silica systems are catalysts for propylene epoxidation processes that rely on hydroperoxides, such as t-butyl hydroperoxide (TBHP), 1-ethylbutyl hydroperoxide (EBHP), or cumene hydroperoxide (CHP). These processes include the treatment of silica supports with titanium chloride or one or more titanium alkoxides. Titanium alkoxides and titanium halides, however, may be moisture sensitive, pyrophoric, or a combination thereof. Although relatively inexpensive to purchase, titanium chloride may be moisture sensitive, corrosive, and toxic, thereby making it expensive to handle.

[0002] U.S. Patent Application Publication No. 2015 / 0182959, discloses a process for preparing a titanium catalyst system for epoxidation reactions that includes (i) impregnating a silica carrier with a liquid solution of a titanium compound in an inorganic solvent system, (ii) drying the carrier, (iii) calcinating (i.e., "calcining") the dried product, and (iv) silylating the calcinated (i.e., "calcined") product.

[0003] There remains a need for improved processes for preparing the foregoing catalysts, especially high-volume commercial catalysts, that are efficient, safer, cheaper, more environmentally friendly, or a combination thereof.

[0004] Many fixed bed epoxidation catalysts include titanated silica supports. The supports may have a weight average particle size of 0.2 mm to 3mm, and may include unevenly shaped particles. An example of supports is disclosed at WO 2017 / 080962. The supports of WO 2017 / 080962 have a surface area of 330 m 2< / g to 450 m 2< / g. These supports, however, may suffer from one or more disadvantages, such as a large delta pressure that may be associated with their use in fixed bed reactors.

[0005] US 6,187,934 discloses a method tor making a titanated-silica catalyst tor propene oxidation with hydroperoxides such as tert-butyl hydroperoxide. The silica is impregnated with a titanium solution.

[0006] WO 00 / 72961 discloses titanium on silica catalysts made by impregnating silica gel with a solution ot a Ti complex in an organic solvent

[0007] There remains a need for catalyst supports, including titanated silica supports, that overcome one or more of these disadvantages, and / or perform better in fixed bed reactors.BRIEF SUMMARY

[0008] Provided herein are methods of preparing titanated silica catalysts that are safe, relatively inexpensive, and / or environmentally friendly. The titanated silica catalysts can exhibit improved catalyst performance, such as in epoxidation processes, and the degree of improvement is surprising for example, the titanated silica catalysts can exhibit a surprising reduction in delta pressure compared to other catalyst systems.

[0009] In one aspect, a method of preparing titanated silica catalysts is provided, as descriebd in the claims.

[0010] In some embodiments, the methods include providing a silica support that includes a plurality of spherical silica beads having an average diameter of 0.1 mm to 5 mm.

[0011] In some embodiments, the methods include providing a liquid that includes (i) a water soluble organic compound, and (ii) titanium (IV) bis(ammonium lactato) dihydroxide; and contacting a silica support with the liquid to deposit at least a portion of the titanium(IV) bis(ammonium lactato)dihydroxide on the silica support to form a titanium-treated silica support. The methods may also include calcinating the titanium-treated silica support, and / or silylating the titanium-treated silica support to form a titanated silica catalyst. The plurality of spherical silica beads also may have a surface area of 400 m 2< / g to 600 m 2< / g, a pore volume of 1 cc / g to 2.5 cc / g, or a combination thereof. Textural properties are measured by nitrogen adsorption isotherms collected at 77 k in the region of P / P0<0.3 (BET surface area) and P / P0>0.95 (pore volume).

[0012] Additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the aspects described herein. The advantages described herein will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Fig. 1 is a plot of epoxide conversion percentages achieved with three embodiments of liquids that include titanium(IV) bis(ammonium lactato)dihydroxide.DETAILED DESCRIPTION

[0014] Provided herein is a method of preparing titanated silica catalysts. The titanated catalysts provided herein may include a titanium-treated silica support. The titanium-treated silica support may include a plurality of spherical silica beads having (i) an average diameter of 0.1 mm to 5 mm, (ii) a surface area of 400 m 2< / g to 600 m 2< / g, and (iii) a pore volume of 1 cc / g to 2.5 cc / g.Methods of Preparing Titanated Silica Catalysts

[0015] Methods of preparing titanated silica catalysts are provided as described in the claim s. In some embodiments, the methods provided herein include providing a liquid that includes (i) a water soluble organic compound, and (ii) titanium(IV) bis(ammonium lactato)dihydroxide; and contacting a silica support with the liquid to deposit at least a portion of the titanium(IV) bis(ammonium lactato)dihydroxide on the silica support to form a titanium-treated silica support. A material is "on the silica support" when it is deposited on and / or in any portion of the silica support, such as a surface, a pore, an internal area (e.g., interstitial space), etc.

[0016] The contacting of a silica support with a liquid may be achieved in any manner, including any technique. In some embodiments, the contacting of the silica support with the liquid includes impregnating the silica support with the liquid. A silica support is "impregnated" with a liquid when at least a portion of the liquid contacts a non-surface portion of the silica support. For example, impregnating a silica support with a liquid may result in the presence of at least a portion of the liquid in one or more internal spaces of the silica support.

[0017] In some embodiments, the impregnating of a silica support includes subjecting the silica support to an incipient wetness impregnation process. In some such embodiments, a vacuum-assisted incipient wetness impregnation process may be used. A vacuum-assisted incipient wetness impregnation process may rely at least in part on capillary action to impregnate a silica support with a liquid. In some embodiments, the methods provided herein include providing a silica support that includes a plurality of spherical silica beads having an average diameter of 0.1 mm to 5 mm; contacting the silica support with a water soluble organic compound, and titanium(IV) bis(ammonium lactato)dihydroxide to form a titanium-treated silica support. The method may also include calcinating the titanium-treated silica support to form a calcinated titanium-treated silica support; and silylating the calcinated titanium-treated silica support to form the titanated silica catalyst.

[0018] In some embodiments, the methods provided herein include calcinating a titanium-treated silica support; and silylating the titanium-treated silica support to form a titanated silica catalyst.

[0019] In some embodiments, the calcinating of the titanium-treated silica support includes subjecting the titanium-treated silica support to an elevated temperature of 100° C to 1,000° C, 300° C to 800° C, or 600° C to 800° C. In some embodiments, the calcinating of a titanium-treated silica support includes heating the titanium-treated silica support in air to a temperature of 500 °C to 750 °C for 1 hour to 3 hours. In some embodiments, a temperature gradient is used. In some embodiments, a titanium-treated silica support is heated to 100° C for 15 minutes, then to 250° C for 15 minutes, and then to 700° C for 2 hours. In some embodiments, the calcination is performed under an inert atmosphere, such as nitrogen or a noble gas. In some embodiments, at least a first portion of the calcination is performed under an inert gas, and then at least a second portion of the calcination is performed in air. In some embodiments, the calcination is carried out in an atmosphere which includes oxygen. In some embodiments, the calcination is carried out in the absence of oxygen.

[0020] Optionally, after the calcinating of a titanium-treated silica support, the calcinated titanium-treated silica support may be washed.

[0021] In some embodiments, a titanium-treated silica support is washed with a solvent.. In some embodiments, the solvent is a hydroxyl containing liquid. In some embodiments, the hydroxyl containing liquid includes an alcohol, water, or a combination thereof. The alcohol may include a C 1 -C 18 hydrocarbyl substituted with at least one hydroxyl moiety. In some embodiments, a titanium-treated silica support is washed with a hydroxyl containing liquid at ambient temperature.

[0022] A washed titanium-treated silica support may be dried. In some embodiments, the drying includes subjecting the washed titanium-treated silica support to an elevated temperature. In some embodiments, the temperature is greater than 50° C. In some embodiments, the temperature is 50° C to 200° C. In some embodiments, the temperature is 100° C to 150° C. In some embodiments, the washed titanium-treated silica support is dried under a stream of an inert gas. In some embodiments, the washed titanium-treated silica support is dried for a time of 0.1 hours to 2 hours. In some embodiments, the washed titanium-treated silica support is dried for a time of 1 hour to 4 hours. In some embodiments, the time is 2 hours.

[0023] In some embodiments, the silylating of the titanium-treated silica support includes contacting the titanium-treated silica support with a silylating agent. Any silylating agent may be used. In some embodiments, the silylating agent is an organosilane, an organosilylamine, an organosilazane, or a combination thereof. Examples of silylating agents are disclosed at U.S. Patent No. 10,017,484.

[0024] In some embodiments, silylating agent is an organodisilazane of the following formula:         R 3 SiNHSiR' 3 , wherein each R and R' is independently selected from a C 1 -C 6 hydrocarbyl. In some embodiments, the silylating agent includes hexamethyldisilazane.Silica Support

[0025] Any silica support may be used in the methods provided herein. Non-limiting examples of silica supports include those disclosed at U.S. Patent No. 10,017,484.

[0026] In some embodiments, the silica support includes an inorganic siliceous solid, such as silicon oxide. In some embodiments, the siliceous solid is an amorphous silicon oxide. In some embodiments, the silica support is porous. A silica support is porous when it includes one or more pores and / or interstices within its structure.

[0027] In some embodiments, the silica support includes a plurality of spherical silica beads, tablets, extrudates and particulates. A bead is "spherical" when [1] it is spherical, [2] its smallest diameter is equal to or greater than 95 % of its largest diameter (e.g., a smallest diameter of at least 1.9 mm and a largest diameter of 2 mm), and / or [3] it would satisfy element [1] and / or [2], but for an imperfection, such as a surface imperfection (e.g, trench, depression, etc.). Non-limiting examples of spherical silica beads include AlphaCat ®< 4000 silica beads available from PQ Corporation (Malvern, Pennsylvania, USA).

[0028] In some embodiments, the silica support of the catalyst includes silicon oxide. In some embodiments, the silica support includes silicon oxide and titanium oxide. In some embodiments, the silica support includes at least 90 % by weight of silicon oxide, based on the weight of the silica support. In some embodiments, the silica support includes at least 95 % by weight of silicon oxide, based on the weight of the silica support. The percentage of silicon oxide and one or more other oxides in the silica support may be measured using XRF (x-ray fluorescence spectroscopy). In some embodiments, the one or more other oxides, such as titanium oxide, account for less than 10 % by weight of the silica support, based on the weight of the silica support. In some embodiments, the one or more other oxides account for 0.01 % by weight to 9.9 % by weight of the silica support, based on the weight of the silica support.

[0029] In some embodiments, the silicon oxide includes silicon oxide that is flocculated and / or otherwise linked together to form densely packed masses of silica oxide. In some embodiments, the silicon oxide includes synthetic silica powder. The synthetic silica powder may be a powder that is flocculated into open-packed, easily disintegrated, and / or loosely knit aggregates.

[0030] In some embodiments, the silica support includes silica-alumina, silica-magnesia, silica-zirconia, silica-alumina-boria, silica-aluminum-magnesia, or a combination thereof. In some embodiments, the silica support includes a plurality of molecular sieves. The plurality of molecular sieves may include large pore and / or mesoporous molecular sieves, such as MCM-41, MCM-48, M41S, or a combination thereof.

[0031] In some embodiments, the silica support has a surface area of 300 m 2< / g to 700 m 2< / g. Textural properties are measured by nitrogen adsorption isotherms collected at 77 k in the region of P / P0<0.3 (BET surface area) and P / P0>0.95 (pore volume). In some embodiments, the silica support has a surface area of 400 m 2< / g to 600 m 2< / g. In some embodiments, the silica support has a surface area of 450 m 2< / g to 550 m 2< / g. In some embodiments, the silica support has a surface area of 400 m 2< / g to 600 m 2< / g, and the silica support includes a plurality of spherical silica beads. In some embodiments, the silica support has a surface area of 450 m 2< / g to 550 m 2< / g, and the silica support includes a plurality of spherical silica beads. In some embodiments, the silica support has a surface area of 450 m 2< / g to 460 m 2< / g. In some embodiments, the silica support has a surface area of 530 m 2< / g to 540 m 2< / g.

[0032] In some embodiments, the silica support has a relatively high surface area, e.g., greater than 800 m 2< / g. In some embodiments, the surface area of the silica support is 800 m 2< / g to 1200 m 2< / g. In some embodiments, the surface area of the silica support is 900 m 2< / g to 1100 m 2< / g. In some embodiments, the surface area of the silica support is 910 m 2< / g to 970 m 2< / g. In some embodiments, the surface area of the silica support is 950 m 2< / g. In some embodiments, the surface area of the silica support is greater than 1000 m 2< / g.

[0033] In some embodiments, the silica support has a pore volume of 1 g / cm 3< to 3 g / cm 3< . In some embodiments, the silica support has a pore volume of 1 g / cm 3< to 2.5 g / cm 3< . In some embodiments, the silica support has a pore volume of 1 g / cm 3< to 1.5 g / cm 3< . In some embodiments, the silica support has a pore volume of 1 g / cm 3< to 2.5 g / cm 3< , and the silica support includes a plurality of spherical silica beads.

[0034] In some embodiments, the silica support has a relatively high pore volume, e.g., greater than 1.25 g / cm 3< . In some embodiments, the pore volume of the silica support is 1.25 g / cm 3< to 3.50 g / cm 3< . In some embodiments, the pore volume of the silica support is 1.5 g / cm 3< to 3.0 g / cm 3< . In some embodiments, the pore volume of the silica support is 2.0 g / cm 3< to 2.5 g / cm 3< . In some embodiments, the pore volume of the silica support is 2.20 g / cm 3< to 2.5 g / cm 3< . In some embodiments, the pore volume of the silica support is greater than 2.0 g / cm 3< . The pore volume and / or surface area of a silica support may be measured using nitrogen porosimetry.

[0035] In some embodiments, the silica support has an average pore diameter greater than 70 Å. In some embodiments, the average pore diameter of the silica support is 70 Å to 150 Å. In some embodiments, the average pore diameter of the silica support is 90 Å to 110 Å. In some embodiments, the average pore diameter of the silica support is 91 Å to 108 Å.

[0036] In some embodiments, the silica support has a high surface area and a high pore volume, e.g., a surface area greater than 800 g / cm 3< and a high pore volume greater than 1.25 g / cm 3< .

[0037] The silica support may have any desired particle size. In some embodiments, a desired particle size of the silica support is obtained through crushing and / or extruding. In some embodiments, a desired particle size of the silica support is obtained by classifying the silica support through a sieve. In some embodiments, the average diameter of the silica support is less than 5.0 mm. In some embodiments, the average diameter of the silica support is 0.1 mm to 5.0 mm. In some embodiments, the average diameter of the silica support is 0.2 mm to 4 mm. In some embodiments, the silica support includes a plurality of spherical silica beads having an average diameter of 0.5 mm to 3 mm. In some embodiments, the silica support includes a plurality of spherical silica beads having an average diameter of from 0.3 mm to 2 mm. In some embodiments, the silica support includes a plurality of spherical silica beads having an average diameter of from 0.4 mm to 4 mm. In some embodiments, the silica support includes a plurality of spherical silica beads having an average diameter of from 0.5 mm to 4 mm.

[0038] In some embodiments, the silica support is dried before the silica support is contacted with a liquid. In some embodiments, the drying of the silica support includes heating the silica support to a temperature of 100° C to 850° C. In some embodiments, the temperature is greater than 120° C. In some embodiments, the temperature is 150° C to 300° C. In some embodiments, the silica support is dried in a vacuum. In some embodiments, the silica support is dried under a flowing stream of an inter gas, such as nitrogen or a noble gas. In some embodiments, the silica support is dried for a time of 1 hour to 48 hours. In some embodiments, the silica support is dried for a time of 2 hours to 24 hours.

[0039] A water soluble organic compound may be adsorbed to a silica support. In some embodiments, the silica support includes less than 3 % by weight of carbon, based on the weight of the silica support. In some embodiments, the silica support includes 0.05 % by weight to 3 % by weight of carbon, based on the weight of the silica support. In some embodiments, the silica support includes 1 % by weight to 2 % by weight of carbon from an adsorbed water soluble organic compound and / or other materials. In some embodiments, the carbon content of the silica support is measured using carbon nitrogen analysis by converting the carbon into carbon dioxide at a high temperature.Titanium(IV) Bis(Ammonium Lactato)Dihydroxide

[0040] The methods described herein include providing a liquid that includes titanium(IV) bis(ammonium lactato)dihydroxide, which may have the following structure:

[0041] In some embodiments, titanium(IV) bis(ammonium lactato)dihydroxide is present in a liquid at an amount of 5 % to 70 % by weight, based on the weight of the liquid. In some embodiments, titanium(IV) bis(ammonium lactato)dihydroxide is present in a liquid at an amount of 30 % to 70 % by weight, based on the weight of the liquid. In some embodiments, titanium(IV) bis(ammonium lactato)dihydroxide is present in a liquid at an amount of 40 % to 60 % by weight, based on the weight of the liquid. In some embodiments, titanium(IV) bis(ammonium lactato)dihydroxide is present in a liquid at an amount of 50 % by weight, based on the weight of the liquid.Water Soluble Organic Compound

[0042] The water soluble organic compound includes ethylene glycol.

[0043] Unless otherwise indicated, the term "substituted," when used to describe a chemical structure or moiety, refers to a derivative of that structure or moiety wherein one or more of its hydrogen atoms is substituted with a chemical moiety or functional group such as a hydroxyl, alkoxy, alkanoyloxy, alkoxycarbonyl, alkenyl, alkyl (e.g., methyl, ethyl, etc.), alkynyl, alkylcarbonyloxy (-OC(O)alkyl), amide (-C(O)NH-alkyl- or -alkylNHC(O)alkyl), tertiary amine (such as alkylamino, arylamino, arylalkylamino), azo, carbamoyl (-NHC(O)O-alkyl- or -OC(O)NH-alkyl), carbamyl (e.g., CONH 2 , as well as CONH-alkyl, CONH-aryl, and CONH-arylalkyl), carboxyl, carboxylic acid, cyano, ester, ether (e.g., methoxy, ethoxy), halo, haloalkyl (e.g., -CCl 3 , -CF 3 , -C(CF 3 ) 3 ), heteroalkyl, isocyanate, isothiocyanate, nitrile, nitro, phosphodiester, sulfide, sulfonamido (e.g., SO 2 NH 2 , SO 2 NR'R"), sulfone, sulfonyl (including alkylsulfonyl, arylsulfonyl and arylalkylsulfonyl), sulfoxide, thiol (e.g., sulfhydryl, thioether) or urea (-NHCONH-alkyl-).Methods of Epoxidation

[0044] The catalysts described herein may be used in the production of epoxides from an olefin. The methods may include contacting an olefin with a titanated silica catalyst, as described herein, in the presence of an oxidant and in conditions effective to epoxidize the olefin to form an epoxidized olefin.

[0045] The methods of epoxidation described herein may include batch epoxidation methods, or continuous expoxidation methods.

[0046] In some embodiments, the catalysts described herein result in relatively higher conversion of an olefin into a product. In some embodiments, at least 35 mol % of an olefin is converted to an epoxidized olefin in the methods of epoxidation described herein. In some embodiments, at least 45 mol % of an olefin is converted to an epoxidized olefin in the methods of epoxidation described herein. In some embodiments, at least 50 mol % of an olefin is converted to an epoxidized olefin in the methods of epoxidation described herein. In some embodiments, at least 55 mol % of an olefin is converted to an epoxidized olefin in the methods of epoxidation described herein. In some embodiments, at least 65 mol % of an olefin is converted to an epoxidized olefin in the methods of epoxidation described herein. In some embodiments, at least 75 mol % of an olefin is converted to an epoxidized olefin in the methods of epoxidation described herein. In some embodiments, at least 85 mol % of an olefin is converted to an epoxidized olefin in the methods of epoxidation described herein.

[0047] Any oxidant, i.e., oxidizing agent, may be used in the methods described herein. In some embodiments, the oxidizing agent is a hydroperoxide. In some embodiments, the hydroperoxide is an alkylhydroperoxide. In some embodiments, the alkyl group has from 1 to 12 carbon atoms. In some embodiments, the alkyl group is tert-butyl. In other embodiments, the hydroperoxide is an aralkylhydroperoxide. In some embodiments, the aralkyl group has from 1 to 24 carbon atoms. In some embodiments, the aralkyl group has from 1 to 12 carbon atoms. In some embodiments, the aralkyl group is ethylbenzyl or cumyl.

[0048] In some embodiments, the oxidizing agent is an organic hydroperoxide, such as tert-butyl hydroperoxide (TBHP), cumene hydroperoxide (CHP), ethylbenzene hydroperoxide, or 1-ethylbutyl hydroperoxide (EBHP).

[0049] Any olefin may be used in the methods of epoxidation described herein. As used herein, the term "olefin" may refer to any hydrocarbyl, such as a C 1 -C 30 hydrocarbyl, that includes at least one non-aromatic double bond. In some embodiments, the olefin has 1 to 24 carbon atoms. In some embodiments, the olefin has 1 to 12 carbon atoms. In some embodiments, the olefin is propylene, 1-octene, or a combination thereof. In some embodiments, the olefin is substituted with one or more other functional groups, such as a hydroxyl or halide.

[0050] Any ratio of olefin to oxidant may be used in the methods of epoxidation described herein. In some embodiments, the molar ratio of olefin to oxidizing agent is from 1:1 to 20:1, or 10:1 to 12:1.

[0051] In some embodiments, at least a portion of an epoxidation reaction occurs in the liquid phase. In some embodiments, the liquid phase includes one or more liquids (e.g., one or more solvents) or inert diluents. In some embodiments, the liquid is a hydrocarbon precursor of the hydroperoxide (e.g., either a corresponding alkane or alcohol). If, for example, the hydroperoxide, in some embodiments, is tert-butyl hydroperoxide, then the liquid that may be optionally used may be tert-butanol.

[0052] The methods of epoxidation described herein may be modified by adjusting the pressure and / or the temperature. In some embodiments, the methods of epoxidation are carried out, at least in part, at a temperature from 25° C to 200° C. In some embodiments, the temperature is from 50° C to 160° C. In some embodiments, the temperature is from 70° C to 140° C. In some embodiments, the methods of epoxidation are carried out, at least in part, at a pressure that is from ambient pressure to greater than atmospheric pressure. In some embodiments, the pressure is from 0.138 MPa to 10.342 MP (20 psi to 1500 psi) . In some embodiments, propylene used as the olefin, and the pressure is from 2.758 Mpa to 6.895 Mpa ( 400 psi to 1000 psi).

[0053] In some embodiments, the epoxidation reaction includes multiple phases. For example, at least a portion of the reactants may be in a gaseous phase, and / or at least a portion of the reactants may be in a liquid phase, and / or at least a portion of the catalyst may be in a solid phase. In some embodiments, both reactants are in the liquid phase, and the catalyst is in the solid phase, such that the catalyst in the reaction mixture is used heterogeneously.

[0054] In some embodiments, the methods of epoxidation are performed in any commercially useful reactor. In some embodiments, the reactor is selected from a continuous or batch process reactor. Non-limiting examples of reactors include a fixed bed or a slurry reactor. When any of these reactors are used, the reaction may also include separating the reactants and catalyst from the products. In some embodiments, the methods of epoxidation include a fractional distillation, a selective extraction, filtration, and / or a similar separation technique. In some embodiments, at least a portion of any unreacted reactants, a liquid, and / or a catalyst is reused in the epoxidation reaction.

[0055] The terms "a," "an," and "the" are intended to include plural alternatives, e.g., at least one. For instance, the disclosure of "a silica support," "an olefin," , is meant to encompass one, or mixtures or combinations of more than one silica support, olefin, , unless otherwise specified.

[0056] In the descriptions provided herein, the terms "includes," "is," "containing," "having," and "comprises" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to." When methods or systems are claimed or described in terms of "comprising" various components or steps, the methods or systems can also "consist essentially of" or "consist of" the various components or steps, unless stated otherwise.

[0057] Various numerical ranges may be disclosed herein. When Applicant discloses or claims a range of any type, Applicant's intent is to disclose or claim individually each possible number that such a range could reasonably encompass, including end points of the range as well as any sub-ranges and combinations of sub-ranges encompassed therein, unless otherwise specified. Moreover, numerical end points of ranges disclosed herein are approximate. As a representative example, Applicant discloses, in one embodiment, that a plurality of spherical silica beads has a pore volume of 1 cc / g to 2.5 cc / g. This range should be interpreted as encompassing values in a range of 1 cc / g to 2.5 cc / g, and further encompasses " " each of 1.1 cc / g, 1.2 cc / g, 1.3 cc / g, 1.4 cc / g, 1.5 cc / g, 1.6 cc / g, 1.7 cc / g, 1.8 cc / g, 1.9 cc / g, 2 cc / g, 2.1 cc / g, 2.2 cc / g, 2.3 cc / g, and 2.4 cc / g, including any ranges and sub-ranges between any of these values.

[0058] Throughout this application, the term " " is used to indicate that a value includes a variation of error, such as for the device, the method being employed to determine the value, or the variation that exists among the study subjects. The term " " is used to imply the natural variation of conditions and represent a variation of plus or minus 5% of a value. In some embodiments, the variation is plus or minus 1% of a value.

[0059] The processes described herein may be carried out or performed in any order as desired in various implementations. Additionally, in certain implementations, at least a portion of the processes may be carried out in parallel. Furthermore, in certain implementations, less than or more than the processes described may be performed.

[0060] Many modifications and other implementations of the disclosure set forth herein will be apparent having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosure is not to be limited to the specific implementations disclosed and that modifications and other implementations are intended to be included within the scope of the appended claimsEXAMPLES

[0061] The present disclosure is further illustrated by the following examples, which are not to be construed in any way as imposing limitations upon the scope thereof.Example 1 - Epoxidation Performance of Titanated Silica Catalysts

[0062] In this example, a silica support (AlphaCat ®< 4000, PQ Corporation, USA) was impregnated with three different liquids that included titanium(IV) bis(ammonium lactato)dihydroxide. The impregnation was achieved with an incipient wetness technique, and the impregnated silica support was calcined in air at 700 °C for 2 hours, and silylated with hexamethyldisilazane (HMDS) at 200 °C.

[0063] Each of the three liquids included 50 % by weight of the titanium(IV) bis(ammonium lactato)dihydroxide, based on the weight of each liquid. The first liquid included water and the titanium(IV) bis(ammonium lactato)dihydroxide. The second liquid included water, ethylene glycol, and titanium(IV) bis(ammonium lactato)dihydroxide. The third liquid included ethylene glycol and titanium(IV) bis(ammonium lactato)dihydroxide.

[0064] The performance of each of the titanated silica catalysts prepared with the three liquids of this example was tested in an octene / 1-ethylbutyl hydroperoxide epoxidation process. The results of these tests are depicted at the following table: Table 1 - Results of Example 1Diluent Used in Liquid Containing 50 % by weight of titanium(IV) bis(ammonium lactato)dihydroxide Ethylene Glycol Volume Fraction in Diluent 1-Ethylbutyl hydroperoxide conversion to Octene Epoxide (%) Water011Water and Ethylene Glycol0.4519Ethylene Glycol145

[0065] These results indicated that the third liquid, which included ethylene glycol and titanium(IV) bis(ammonium lactato)dihydroxide surprisingly outperformed the first and second liquids, which included water.

[0066] A plot of the results of Table 1 is provided at the Figure.

[0067] Three grams of the catalyst from Example 1 (where the diluent contained only ethylene glycol (no water)) was put into a 0.62" ID reactor with an oil jacket for heating. This catalyst was prepared by impregnation of 2.1mm silica spheres as described above. The feed to the reactor was 50 gram / hour of pure propylene and 150 gram / hour of caustic washed and dried 1-ethylbutyl hydroperoxide (EBHP) oxidate containing 9 wt% EBHP and 88 % ethylbenzene, the remainder being methyl benzyl alcohol and acetophenone. The pressure of the reactor was 800 psig. After 100 hours on stream, the catalyst temperature necessary to convert 50% of the EBHP in the first reactor was 190 F. The effluent from the first reactor described above was sent to a second reactor containing 6 grams of the same catalyst and the temperature of the second reactor was adjusted to convert the remaining EBHP. The molar selectivity of propylene oxide with respect to EBHP converted in both reactors was 95.7%.

Claims

1. A method of preparing a titanated silica catalyst, the method comprising: providing a liquid comprising (i) a water soluble organic compound and (ii) a water soluble titanium compound; and contacting a silica support with the liquid to deposit at least a portion of the water soluble titanium compound on the silica support to form a titanium-treated silica support; wherein the water soluble titanium compound is titanium(IV) bis(ammonium lactato)dihydroxide and wherein the water soluble organic compound comprises ethylene glycol.

2. The method of claim 1, wherein the titanium(IV) bis(ammonium lactato)dihydroxide is present in the liquid at an amount of from about 5% to about 70 % by weight, based on the weight of the liquid.

3. The method of claim 1, wherein the titanium(IV) bis(ammonium lactato)dihydroxide is present in the liquid at an amount of about 40 % to about 60 % by weight, based on the weight of the liquid.

4. The method of claim 1, wherein the contacting of the silica support with the liquid comprises impregnating the silica support with the liquid.

5. The method of claim 4, wherein the impregnating of the silica support comprises subjecting the silica support to an incipient wetness impregnation process.

6. The method of claim 1, further comprising: calcinating the titanium-treated silica support; and silylating the titanium-treated silica support to form the titanated silica catalyst.

7. The method of claim 6, wherein the calcinating of the titanium-treated silica support comprises heating the titanium-treated silica support in air to a temperature of about 300 °C to about 800 °C for about 1 hour to about 3 hours.

8. The method of claim 6, wherein the silylating of the calcinated titanium-treated silica support comprises contacting the calcinated titanium-treated silica support with an organodisilazane of the following formula:         R3SiNHSiR'3, wherein each R and R' is independently selected from a monovalent C1-C6 hydrocarbyl.

9. The method of claim 8, wherein the silylating agent comprises hexamethyldisilazane.