KR20140104446A - Carrier for ethylene oxide catalysts - Google Patents

Abstract

An improved carrier for ethylene epoxidation is provided. The carrier comprises an alumina component containing a first alumina particle portion having an average primary particle size of from 2 mu m to 6 mu m and a second alumina particle portion having a particle size of less than 2 mu m. An improved catalyst comprising the above described carrier and an improved process for the epoxidation of ethylene with the catalyst are also provided.

Description

[0001] CARRIER FOR ETHYLENE OXIDE CATALYSTS [0002]

The present invention relates generally to catalysts useful for the epoxidation of olefins to olefin oxides, and more particularly to supports for such catalysts.

As is known in the art, high selectivity catalysts (HSCs) for the epoxidation of ethylene have a higher selectivity than the high activity catalysts (HACs) used for the same purpose Catalyst " means < / RTI > Both types of catalysts contain silver as the active catalyst component in the refractory support (i.e., carrier). Typically, one or more accelerators are included in the catalyst to enhance or control the properties of the catalyst, such as selectivity.

Generally, HSCs achieve a higher selectivity (typically, greater than 87 mol%) by including rhenium as a promoter. Typically, it is possible to remove from an alkaline metal (e.g. cesium), an alkaline earth metal, a transition metal (e.g. tungsten compound), and main group metals (e.g. sulfur and / or halide compounds) One or more additional promoters to be selected are also included.

There are also ethylene epoxidation catalysts that may not have the selectivity values associated with HSCs, although the selectivity values are comparable to those of HACs. These types of catalysts may be considered to belong to the class of HSCs or alternatively may be regarded as belonging to a distinct class, for example, "medium selectivity catalysts" or "MSCs" have. Catalysts of this type typically exhibit a selectivity of more than 83 mol% to less than 87 mol%.

In contrast to HSCs and MSCs, the HACs are generally rhenium-free ethylene epoxidation catalysts and, for this reason, do not provide selectivity values for HSCs or MSCs. Typically, HACs contain cesium (Cs) as the only promoter.

Efforts have long been made to improve the activity and selectivity of ethylene oxidation catalysts. Much of this effort is focused on the compositional and physical properties of the carrier (typically alumina), and more specifically variations of the surface area or pore size distribution of the carrier. For example, U.S. Patent Nos. 4,226,782, 4,242,235, 5,266,548, 5,380,697, 5,395,812, 5,597,773, 5,831,037 and 6,831,037, and U.S. Published Patent Applications 2004/0110973 Al 2005/0096219 A1.

Although higher surface areas of the support are known to improve catalytic activity, higher surface areas typically result in lower pore sizes (i.e., generally less than 1 micron size) By the increase in the number. As a result, the increased amount of smaller pores has a negative effect on the maximum achievable selectivity of the catalyst. Likewise, attempts to improve selectivity by lowering the volumetric contribution of smaller pores have the effect of reducing the surface area of the catalyst, resulting in a decrease in catalytic activity. Thus, there is a long-standing unanswered problem encountered in the art of ethylene oxide catalysts, in which the activity enhancement of the catalyst negatively affects the selectivity of the catalyst, and likewise, the improvement in selectivity has a negative effect on the activity It continues.

Thus, there remains a need in the art to improve the catalytic activity without adversely affecting the selectivity of the catalyst, or simultaneously improving the selectivity of the catalyst. There will be special advantages in achieving this by means of readily integratable and easy and cost-effective means to existing process designs.

In one embodiment, the invention relates to a carrier for an ethylene epoxidation catalyst. Wherein the carrier comprises a first portion of alumina particles having a particle size of from 2 탆 to 6 탆 and a second portion of alumina particles having a particle size of less than 2 탆, Containing alumina component.

In certain embodiments, the carrier comprises an alumina component that contains a first alumina particle portion having a particle size of 3 mu m to 6 mu m and a second alumina particle portion having a particle size of 2 mu m or less.

By including a combination of the larger carrier particles and smaller carrier particles described above, the surface area of the carrier can be adjusted independently from the surface area change due to the pore size distribution of the carrier particles. For this reason, a sufficiently high surface area (i. E., To suitably increase catalytic activity) in the support is increased by an increase in the pore volume distribution of a smaller pore size (typically less than 1 micron) to the point where it has a detrimental effect on selectivity . ≪ / RTI >

Accordingly, the present invention advantageously provides a carrier that can be used to prepare an ethylene oxidation catalyst having increased catalyst activity and continuing or enhanced selectivity.

The present invention also relates to an ethylene oxide (i.e., epoxidation) catalyst comprising a carrier as described above together with a silver amount of catalyst deposited on the carrier and / or silver, and preferably a catalytic amount of rhenium will be.

The present invention relates to a process for the gas phase conversion of ethylene to ethylene oxide (EO) in the presence of oxygen. The process comprises reacting a reaction mixture containing ethylene and oxygen in the presence of the ethylene epoxidation catalyst described above.

DETAILED DESCRIPTION OF THE INVENTION [

In one aspect, the invention relates to an improved carrier (i.e., a support) for an ethylene epoxidation catalyst. The carrier comprises an alumina component containing an appropriately controlled larger particle size component (i.e., a thicker component) and a smaller particle size component (i.e., a finer component), and as a result, There is provided an epoxidation catalyst having increased activity while maintaining or improving selectivity, or conversely, having improved selectivity while maintaining or improving activity.

Preferably, the alumina component comprises a first alumina particle portion (coarse particle) having a particle size of 2 mu m or more and 6 mu m or less and a second alumina particle portion (fine particle) having a particle size of less than 2 mu m do. In another embodiment, the first alumina particle portion may have a thickness of less than or equal to 2 microns, for example, 2 microns, 2.1 microns, 2.2 microns, 2.3 microns, 2.4 microns, 2.5 microns, 2.6 microns, 2.7 microns, 2.8 microns, 2.9 microns, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, , 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, or 6, or any two of these (For example, 2-3 占 퐉, 2-4 占 퐉, 2-5 占 퐉, 3-5 占 퐉, 3-5.5 占 퐉, 3-4 占 퐉, 4-6 占 퐉, or 5- 6 < RTI ID = 0.0 > um). ≪ / RTI > In another embodiment, the second alumina particle portion may have a particle size of, for example, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, (For example, from 0.1 to 0.8 .mu.m) bounded by any two of these numerical values, for example, 0.8 .mu.m, 0.7 .mu.m, 0.6.mu.m, 0.5.mu.m, 0.4.mu.m, 0.3.mu.m, 0.2.mu.m, 0.1-1.5 탆, 0.1-1 탆, 0.1-0.8 탆, 0.1-0.6 탆, 0.2-1.8 탆, 0.2-1.5 탆, 0.2-1 탆, 0.2-0.8 탆, 0.2-0.6 탆, 0.3-1.8 0.3-1.5 mu m, 0.3-1 mu m, 0.3-0.8 mu m, 0.3-0.6 mu m, 0.4-1.8 mu m, 0.4-1.5 mu m, 0.4-1 mu m, 0.4-0.8 mu m, 0.4-0.6 mu m, 0.5-1.8 Mu m, 0.5-1.5 mu m, 0.5-1 mu m, 0.5-0.8 mu m, 0.6-1.8 mu m, 0.6-1.5 mu m, 0.6-1 mu m, 0.6-0.8 mu m, 0.7-1.8 mu m, 0.7-1.5 mu m, Mu] m, 0.8-1.8 mu m, 0.8-1.5 mu m, 0.8-1 mu m, 0.9-1.8 mu m, 0.9-1.5 mu m, 1-1.8 mu m, and 1-1.5 mu m).

In some embodiments, the alumina component contains a first alumina particle portion having a particle size of 3 mu m or more and 6 mu m or less, and a second alumina particle portion having a particle size of 2 mu m or less. In other embodiments, the first alumina particle portion may have a thickness of less than about 3 microns, for example, less than or equal to 3 microns, 3.1 microns, 3.2 microns, 3.3 microns, 3.4 microns, 3.5 microns, 3.6 microns, 3.7 microns, 3.8 microns, 3.9 microns, 4.6, 4.7, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, um, 4.1, 4.5, , 5.8 占 퐉, 5.9 占 퐉, or 6 占 퐉, or a specific range (for example, 3-5 占 퐉, 3-5.5 占 퐉, 3-4 占 퐉, 4-6 Mu m, or 5-6 mu m). In another embodiment, the second alumina particle portion may have a thickness of less than or equal to 2 microns, for example, 2 microns, 1.9 microns, 1.8 microns, 1.7 microns, 1.6 microns, 1.5 microns, 1.4 microns, 1.3 microns, 1.2 microns, 1.1 microns, (For example, about 0.1 mm, 0.8 mm, 0.7 mm, 0.6 mm, 0.5 m, 0.4 m, 0.3 m, 0.2 m, or 0.1 m or less, or any two of these values 0.1 to 1.5 m, 0.1 to 0.1 m, 0.1 to 0.8 m, 0.1 to 0.6 m, 0.2 to 2 m, 0.2 to 1.5 m, 0.2 to 1 m, 0.2 to 0.8 m, 0.2 to 0.6 m, 0.3-2 mu m, 0.3-1.5 mu m, 0.3-1 mu m, 0.3-0.8 mu m, 0.3-0.6 mu m, 0.4-2 mu m, 0.4-1.5 mu m, 0.4-1 mu m, 0.4-0.8 mu m, ). ≪ / RTI >

When the particles are spherical or close to spherical, the particle size described above means diameter. When the particle is substantially deviated from the sphere, the particle size described above is based on the equivalent diameter of the particle. As is known in the art, the term "equivalent diameter" refers to the size of the irregularly-shaped object by expressing the size of the object by the term diameter of the sphere having the same volume as the irregularly- Lt; / RTI > The average particle size referred to herein as "D50 " is measured using a laser diffraction / scattering type, MT3300 or HRA (X100) by Nikkiso Co., Ltd., Particle size with equivalent spherical equivalent volume of particles and smaller particles.

In some embodiments, the alumina particles are crystalline. The crystalline particles may include single crystal or polycrystalline particles. In another embodiment, the alumina particles are amorphous, i.e., amorphous.

Coarse alumina particles are typically produced by calcining aluminum hydroxide by the Bayer process. The Bayer process generally results in agglomerated alumina particles. A comprehensive review of the Bayer process, for example, [ Kirk-Othmer Encyclopedia of Chemical Technology , Fourth Edition, Vol. 2, John Wiley & Sons, (c) 1992, pp. 252-261. Due to the agglomeration, the coarse alumina particles have a primary particle size (i.e., individual particles or grains contained in the aggregate) and a secondary particle size, generally referred to as the size of agglomeration. For example, coarse alumina particles can be composed of agglomerates having an average (secondary) particle size (e.g., D ₅₀ ) of 40 μm, and each of the agglomerates has an average (primary) particle size of 3-5 μm The branches can be composed of primary particles. In other embodiments, the coarse alumina particles may be, for example, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, Lt; RTI ID = 0.0 > 120 < / RTI >

Microalumina particles are generally larger and typically produced by crushing (e.g., crushing) agglomerated particles. Thus, the microalumina particles are generally in a non-agglomerated form.

At least the first alumina particle portion (i.e., larger particles of 2-6 占 퐉) and the second alumina particle portion (i.e., smaller particles of 2 占 퐉 or smaller) must be present in the carrier, 1 alumina particle fraction is not an amount of 100 wt% and the second alumina particle fraction is not an amount of 100 wt%, wherein the wt% is relative to the weight of the alumina component of the support. In another embodiment, the first alumina particle portion or the second alumina particle portion comprises at least 1 wt%, 2 wt%, 5 wt%, 10 wt%, 20 wt%, 25 wt%, 30 wt%, 40 wt% %, 50 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, 95 wt%, 98 wt%, or 99 wt% % (wt%). In one embodiment, the alumina component essentially comprises only a first alumina particle portion and a second alumina particle portion, wherein the wt% A of one alumina particle portion and the other alumina particle portion are 100 wt%. In yet another embodiment, the alumina component comprises one or more other alumina particulate components (for example, as described above) that do not have the widest range of particle sizes suggested for the first and second alumina particulate components, Third particle portion). In this case, the A weight percent of the first alumina particle portion does not correspond to 100-A weight percent with respect to the second alumina particle portion. Preferably, the one or more other alumina particulate components (i.e., other than the particle size ranges of the first and second alumina particulate components) comprise 50 wt%, 40 wt%, 30 wt%, 25 wt%, 20 wt% %, 15 wt%, 10 wt%, 5 wt%, 2 wt%, 1 wt%, 0.5 wt%, 0.2 wt%, or less than 0.1 wt%.

The coarse alumina particles and the fine alumina particles may have any suitable weight ratio. For example, in other embodiments, the support can be at least one of 95: 5, 90:10, 85:15, 80:20, 75:25, 70:30, 65:35, 60:40, 55:45, 50 : 50, 45:55, 40:60, 35:65, 30:70, 25:75, 20:80, 15:85, 10:90, or 5:95, or alternatively any two of the above ratios Alumina-to-microalumina weight ratio within the range bounded by the < / RTI >

In some embodiments, the carrier is not considered to contribute to the weight percent of the support, and may include minor components (e.g., less than or equal to 1 wt%, 0.5 wt%, 0.1 wt%, or 0.05 wt% ), It is composed solely of alumina, and in particular, it consists of coarse alumina and fine alumina components only. In another embodiment, other components than alumina are not included in a trace amount, and generally at least 1% by weight or more is included. In this embodiment, the additional component amount X is selected such that X does not replace the coarse alumina component and / or the fine alumina component (i.e., both the coarse alumina component and the fine alumina component are present) And / or the ratio of any of the exemplary coarse alumina: fine alumina described above by subtracting X from the ratio of fine alumina, and the amount of X generally does not exceed the total amount or individual amount of alumina in the support (and more Usually less). For example, the additional component amount X can be incorporated in a coarse alumina: fine alumina ratio of 80:20 by any of the following formulas: (80-X): 20: X, 80: Or (80-X ₁ ): (20-X ₂ ): X, wherein the sum of X ₁ and X ₂ is X. The amount of X can be, for example, 1, 2, 3, 4, 5, 10, 15, 20, 25, or 30 of any of the typical coarse alumina: fine alumina: But may be in the range bounded by any two values.

The alumina particles can be preferably formed by any of the refractory alumina compositions known in the art for use in ethylene oxidation catalysts. Preferably, the alumina is alpha (alpha) -alumina. The alpha-alumina used in the carrier of the present invention is preferably a very high purity, i.e., at least about 95%, and more preferably at least 98% alpha-alumina. Preferably, the alpha-alumina is low sodium alumina or low sodium reactive alumina. The term "reactive alumina " as used herein generally refers to alpha-alumina having good sinterability and very fine, i.e., generally a particle size of 2 microns or less. Generally, a "low sodium alumina" material has a sodium content of less than or equal to 0.1%. Alternatively or additionally, "low sodium alumina" may refer to an alumina material having less than 0.1 mg of sodium. Good sinterability is generally derived from particle sizes below 2 microns.

The remaining components can be other phases of alumina, silica, alkali metal oxides (e.g., sodium oxide), and trace amounts of other metal-containing and / or non-metal-containing additives or impurities. Suitable alumina compositions are prepared and / or are typically available, for example, from Noritake, Nagoya, Japan, and the NorPro Company of Akron, Ohio.

In order to provide an epoxidation catalyst with improved stability and / or selectivity, the carrier may optionally contain a stability-enhancing amount of mullite (e.g., additional component X). As used herein, "mullite" [ "Night PO Sela (porcelainite)," also known as; the SiO ₂ Means an aluminum silicate mineral having an Al ₂ O ₃ component blended as a solid solution with a phase wherein the Al ₂ O ₃ component comprises at least about 40 mol% and typically at least about 80 mol% ≪ / RTI > More typically, the mullite comprises the Al ₂ O ₃ component in a concentration of 60 ± 5 mol%, and is thus roughly expressed as an equation of 3Al ₂ O ₃ .2SiO ₂ (ie, Al ₆ Si ₂ O ₁₃ ) .

Because mullite's natural resources are rare, most commercial sources of mullite are synthesized. A variety of synthetic methods are known in the art for the production of mullite. In one embodiment, the mullite used is a mixture of components other than the alumina and silica components described above, except for one or more components that may be present in minor amounts (e.g., 0.1 mole percent or less by weight percent) . In another embodiment, the mullite used may comprise one or more additional ingredients. For example, sodium oxide (Na ₂ O) may be included in small amounts (typically about 1.0 mole percent or less by weight). Other components such as zirconia (Zr ₂ O) or silicon carbide (SiC) may also be included to increase, for example, fracture toughness. A number of other metal oxide logistics may also be included to modify the characteristics of the mullite.

The stability-improving amount of mullite is typically from about 0.5% to about 20% by weight, based on the total weight of the support, of mullite. In one embodiment, the mullite is present in the carrier in an amount from about 1 wt.% To about 20 wt.%, About 15 wt.%, About 12 wt.%, About 10 wt.%, , About 6 wt%, about 5 wt%, about 4 wt%, about 3 wt%, or up to about 2 wt%. In another embodiment, the mullite is present in the carrier in an amount from about 3 wt% to about 20 wt%, about 15 wt%, about 12 wt%, about 10 wt%, about 8 wt% , About 6 wt%, about 5 wt%, or about 4 wt% or less. In yet another embodiment, the mullite is present in the carrier in an amount from about 5% to about 20%, about 15%, about 12%, about 10%, about 8% %, About 7 wt%, or about 6 wt% or less. In yet another embodiment, the mullite is present in the carrier in an amount from about 7% to about 20%, about 15%, about 12%, about 10%, about 9% %, Or about 8% by weight or less. In yet another embodiment, the mullite is present in the carrier in an amount of about 0.5-15 wt%, 0.5-12 wt%, 0.5-10 wt%, 0.5-8 wt%, 0.5-6 wt% %, 0.5-5 wt%, 0.5-3 wt%, 0.5-2 wt%, 8-20 wt%, 9-20 wt%, 10-20 wt%, 8-15 wt%, 9-15 wt% Or 10-15% by weight of the composition.

In one embodiment, the outer surface of the bulk alumina carrier or alumina particles themselves is coated by mullite. The outer surface may be connected to a subsurface or interior portion of the carrier that also includes a mullite or, alternatively, in the absence of an interior surface or interior portion of the carrier comprising mullite, . In another embodiment, the inner surface or inner portion of the carrier comprises mullite, while the outer surface of the alumina carrier or the alumina particles themselves is not coated by mullite.

Generally, a suitable catalyst carrier is prepared by a process in which alumina of various particle sizes and, optionally, mullite particles are bonded together by a bonding agent. For example, suitable catalyst carriers may be selected from the group consisting of alumina components, mullite components, solvents such as water, temporary binders or burnout materials, permanent binders, and / or porosity controlling agents ), And then firing (i.e., calcining) the mixture by methods well known in the art.

The temporary binders, or exhaustion materials, can be selected from the group consisting of cellulose, substituted cellulose, such as methylcellulose, ethylcellulose, and carboxyethylcellulose, stearates (e.g., , Organic stearate esters such as methyl or ethyl stearate), waxes, granulated polyolefins (e.g., polyethylene and polypropylene), walnut shell flour, and the like . The binders serve to impart porosity to the carrier material. The spent material is primarily used to ensure the preservation of the porous structure in a green (i.e., unfired phase) process in which the mixture can be formed into particles by molding or extrusion processes do. The depleted materials are essentially completely removed during the sintering process to produce the final support.

The supports of the present invention are preferably prepared comprising a binder material in an amount sufficient to substantially prevent the formation of crystalline silica compounds. Permanent binders include inorganic clay-type materials such as, for example, silica and alkali metal compounds. A convenient binder material that can be incorporated into the alumina particles is a mixture of boehmite, ammonia-stabilized silica sol, and soluble sodium salt.

The formed paste is extruded or shaped into the desired shape, and is typically calcined at a temperature of from about 1200 [deg.] C to about 1600 [deg.] C to form the carrier. In other embodiments, the sintering temperature may be, for example, 1200 C, 1250 C, 1300 C, 1350 C, 1400 C, 1450 C, 1500 C, 1550 C, 1600 C or 1650 C, It may be a range bounded by any two temperatures. In embodiments where the particles are formed by extrusion, it may be desirable to include conventional extrusion aids. In general, when the carrier is immersed in a solution of an acid such as sodium hydroxide, potassium hydroxide, or nitric acid, as described in U.S. Published Patent Application 2006/0252643 Al, Performance is improved. After the treatment, the carrier is preferably washed with water or the like to remove unreacted solubilizing material and treatment solution, and then selectively dried.

The carrier of the present invention is preferably porous and typically has a BET surface area of 20 m ² / g or less. The BET surface area is more typically in the range of about 0.1 to 10 m ² / g, and more typically in the range of 1 to 5 m ² / g. In other embodiments, the supports of the present invention have a specific surface area of from about 0.3 m ² / g to about 3 m ² / g, preferably from about 0.6 m ² / g to about 2.5 m ² / g, It characterized in that it contains the ² / g to BET surface area of about 2.0 m ² / g. The BET surface area as described herein can be measured by any suitable method, but more preferably from [Brunauer, S., et al., J. Am . Chem . Soc . , 60, 309-16 (1938). The final support typically has a water absorption value ranging from about 0.2 cc / g to about 0.8 cc / g, more typically from about 0.25 cc / g to about 0.6 cc / g.

As long as the carrier has any suitable surface area, the surface area does not substantially degrade the ability of the carrier to function according to its intended utility. The surface area is, for example, about ^{0.7 m 2 / g, 0.75 m} 2 / g, 0.8 m 2 / g, 0.85 m 2 / g, 0.9 m 2 / g, 0.95 m 2 / g, 1.0 m 2 / g ^{, 1.05 m 2 / g, 1.1} m 2 / g, 1.2 m 2 / g, 1.3 m 2 / g, 1.4 m 2 / g, 1.5 m 2 / g, 1.6 m 2 / g, 1.7 m 2 / g, 1.8 m ² / g, 1.9 m ² / g, and 2.0 m ² / g. ^{2.5 m 2 / g, 3.0 m} 2 / g, 3.5 m 2 / g, 4.0 m 2 / g, 4.5 m 2 / g, 5.0 m 2 / g, 5.5 m 2 / g, 6.0 m 2 / g, 6.5 m ^{2 / g, 7.0 m 2 /} g, 7.5 m 2 / g, 8.0 m 2 / g, 8.5 m 2 / g, 9.0 m 2 / g, 9.5 m 2 / g, 10 m 2 / g, 11 m 2 / g, 12 m ² / g, 15 m ² / g, or 20 m ² / g or greater, less than or less than, or a range bounded by any two of the above values.

The carrier may have any suitable pore diameter distribution. As used herein, the "pore diameter" is used interchangeably with "pore size ". The pore volume (and pore size distribution) described herein can be measured by any suitable method, but more preferably, for example, as described in Drake and Ritter, Ind . Eng . Chem. Anal . Ed . , 17, 787 (1945). ≪ / RTI >

Preferably, the pore diameter is at least about 0.01 micron (0.01 micron), and more typically at least about 0.1 micron. In yet other embodiments, the pore diameter is about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, about 1.0, about 1.2 Mu m, about 1.4 mu m, about 1.6 mu m, or about 1.8 mu m or more. In other embodiments, the pore diameter may be about 2.0, about 2.5, about 3, about 3.5, about 4, about 4.5, about 5, about 5.5, about 6, About 7 microns, about 7.5 microns, about 8 microns, about 8.5 microns, about 9 microns, about 9.5 microns, about 10 microns, or about 10.5 microns or less. Any ranges derived from the above-described minimum and maximum example values are also suitable herein. In certain embodiments, the support has a mesopore diameter of 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0, Lt; RTI ID = 0.0 > pore < / RTI >

In other embodiments, the percentage of pores having a size of 0.5 m, 1 m, 1.5 m, or 2 m or less, or within this range (e.g., 1-2 m) (i.e., ) Is less than or equal to 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 2%, or 1% Lt; RTI ID = 0.0 > values. ≪ / RTI > In other embodiments, 20%, 15%, 10%, 5%, 2%, or 1% or less of the pores have a size greater than 2 [mu] m. In certain embodiments, at least 50%, 60%, 70%, 80%, 90%, 95%, 98%, 99%, or 100% 1-5 mu m, 2-6 mu m, 3-6 mu m, 0.1-5 mu m, 0.5-5 mu m, 1-5 mu m, 1.5-5 mu m, 2-5 mu m, 3-5 mu m, 0.1 mu m 1-4 mu m, 0.5-4 mu m, 1-4 mu m, 1.5-4 mu m, 2-4 mu m, 0.1-3 mu m, 0.5-3 mu m, 1-3 mu m, 1.5-3 mu m, 0.1-2.5 mu m, 0.5 -2.5 占 퐉, 1-2.5 占 퐉, 0.1-2 占 퐉, 0.5-2 占 퐉, or 1-2 占 퐉.

The carrier typically has a pore size distribution characterized by the presence of one or more pore sizes of peak concentration, i.e., one or more maximum values (where the slope is substantially zero) in the distribution of pore size to number of pores. (For example, within the above-described range). The maximum pore size is also referred to herein as the peak pore size, the peak pore volume, or the peak pore concentration. In a preferred embodiment, the pore size distribution is characterized by the presence of a peak pore size of 2 mu m or less. In other embodiments, the pore size distribution is about 2, 1.8, 1.6, 1.4, 1.2, 1.0, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2 Mu] m, or 0.1 [mu] m, or a peak pore size within a certain range bounded by any two of the above values.

In addition, each pore size distribution can be characterized by a single average pore size (mean pore diameter) value. Thus, a given average pore size value for a pore size distribution essentially corresponds to a range of pore sizes that yields the indicated average pore size value. Any of the above-described exemplary pore sizes may alternatively be understood to represent an average (i.e., average or weighted average) pore size.

As long as the carrier has any suitable total pore volume, the total pore volume does not substantially degrade the ability of the carrier to function according to its intended utility. G., 0.40 mL / g, or 0.45 mL / g, less than or equal to, or less than, or less than, or equal to or greater than 0.25 mL / g, May be a range bounded by any two of the values. The total pore volume is related to porosity (i.e., apparent porosity). The porosity may range, for example, from about 35%, 40%, 45%, 50%, 55%, or 60% or more, less than or less than, or a range bounded by any two of the above values .

In certain embodiments, the carrier has a multimodal pore size distribution within any range of the pore size ranges described above. The multimodal pore size distribution is characterized by the presence of different pore sizes (i.e., different peak pore sizes) of the peak concentration in the pore size versus pore number distribution. The different pore sizes are preferably within the range of the pore sizes described above. Each peak pore size can be considered to be within its own pore size distribution (mode), i.e., where the pore size concentration on each side of the distribution falls to almost (substantially or theoretically) zero. The multimodal pore size distribution may be, for example, having a bimodal, a trimodal, or a higher modality. In one embodiment, different pore size distributions, each having a peak pore size, do not overlap by being separated by the concentration (i.e., at baseline) of the pores of approximately zero. In another embodiment, the different pore size distributions, each having a peak pore size, are not separated by the concentration of pores of approximately zero and overlap.

In certain embodiments, the difference between the average pore diameter of the first mode of pores and the average pore diameter of the second mode of pores (i.e., the "difference in average pore diameter") in the multimodal pore size distribution is greater than or equal to about 0.1 μm . In other embodiments, the difference in average pore diameter may be, for example, 0.2, or 0.3, or 0.4, or 0.5, or 0.6, or 0.7, or 0.8, Or 1.0 占 퐉, or 1.2 占 퐉, or 1.4 占 퐉, or 1.5 占 퐉, 1.6 占 퐉, or 1.8 占 퐉, or 2.0 占 퐉 or more.

The carrier of the present invention may be of any suitable shape or shape. For example, the carrier may be particles, chunks, pellets, rings, spheres, or the like, preferably of a size suitable for use in fixed bed reactors. , Three-holes, wagon wheels, cross-partitioned hollow cylinders, and the like.

As long as the carrier has any suitable water uptake, the water uptake does not substantially lower the ability of the carrier to function according to its intended utility. The moisture uptake may range, for example, from about 20%, 25%, 30%, 35%, 40%, or 45% .

As long as the carrier has any suitable crush strength, the crush strength value does not substantially degrade the ability of the carrier to function according to its intended utility. The crush strength may be, for example, about 40 Newtons (40 N), 45 N, 50 N, 55 N, 60 N, 65 N, 70 N, 75 N, 80 N, 85 N, 90 N, 100 N, 105 N, 110 N, 115 N, or 120 N, or a range bounded by any two of the above values.

In one embodiment, the support of the present invention can be made of alumina alone, or only alumina and mullite components, in the absence of other metals or compounds, except that trace amounts of other metals or compounds may be present . Trace amounts are small enough so that the trace species does not have an observable effect on the ability or function of the catalyst.

In another embodiment, the carrier of the present invention comprises at least one promoting species. As used herein, an "amount of catalyst" of a particular component of a catalyst refers to the amount of component that effectively acts to provide one or more improvements in the catalytic properties of the catalyst, . Examples of catalytic properties include, among others , operability (resistance to runaway), selectivity, activity, conversion, stability and yield. It is understood by those skilled in the art that one or more of the individual catalytic properties may be enhanced by the "acceleration amount" while other catalytic properties may not be enhanced or improved, or even reduced. It is also understood that different catalytic properties can be improved under different operating conditions. For example, a catalyst with enhanced selectivity in a set of operating conditions can be operated on a different set of conditions that exhibit an improvement in activity over selectivity.

For example, the carrier of the present invention may comprise an accelerating amount of an alkali metal, or a mixture of two or more alkali metals. Suitable alkali metal promoters include, for example, lithium, sodium, potassium, rubidium, cesium, or combinations thereof. Cesium is often preferred, and combinations of different alkali metals and cesium are also preferred. The amount of the alkali metal is expressed as alkali metal, based on the total weight of the catalyst, and is typically from about 10 ppm to about 3000 ppm, more typically from about 15 ppm to about 2000 ppm, more typically from about 20 ppm to about 1500 ppm, And even more typically in the range of from about 50 ppm to about 1000 ppm.

The carrier of the present invention may also comprise a promoting amount of a mixture of IIA alkaline earth metals, or of two or more IIA alkaline earth metals. Suitable alkaline earth metal promoters include, for example, beryllium, magnesium, calcium, strontium, and barium or combinations thereof. The amounts of the alkaline earth metal promoters are used in amounts similar to the amounts of the alkali metal promoters described above.

The carrier of the present invention may also comprise a promoting amount of a main group element, or a mixture of two or more parent elements. Suitable family elements include any of the elements of groups IIIA (boron) to VIIA (halogen) in the Periodic Table of the Elements. For example, the catalyst may comprise one or more sulfur compounds, one or more phosphorus compounds, one or more boron compounds, one or more halogen-containing compounds, or combinations thereof. The catalyst may also comprise, in addition to the halogen elements, the elemental element in its elemental form.

The carrier of the present invention may also comprise a promoting amount of a transition metal or a mixture of two or more transition metals. Suitable transition metals include, for example, Group IIIB (Scandium), IVB (Titanium Group), VB (Vanadium Group), VIB (Chromium Group), VIIB (Manganese Group), VIIIB (Iron, Cobalt, Nickel) in the Periodic Table of the Elements Family elements), IB (copper group), and IIB (zinc group), and combinations thereof. More typically the transition metal is selected from the group consisting of Group IIIB, Group IVB, Group VB, etc., such as hafnium, yttrium, molybdenum, tungsten, rhenium, chromium, titanium, zirconium, vanadium, tantalum, niobium, Or the transition metal of the VIB family.

The carrier of the present invention may also comprise a promoting amount of a rare earth metal or a mixture of two or more rare earth metals. The rare earth metals include any of the elements having atomic numbers 57 to 103. Some examples of these elements include lanthanum (La), cerium (Ce), and samarium (Sm).

The transition metal or rare earth metal promoters are represented by a metal and typically represent about 0.1 占 퐉 ol / g to about 10 占 퐉 ol / g, more typically 0.2 占 퐉 ol / g to about 5 占 퐉 ol / g per gram of total catalyst, In an amount from about 0.5 [mu] mol / g to about 4 [mu] mol / g.

All of these promoters, other than the alkali metals, may be in any suitable form, including, for example, zerovalent metals or higher valent metal ions.

Of the listed promoters, rhenium (Re) is particularly desirable as an effective promoter for ethylene epoxidized high selectivity catalysts. The rhenium component in the catalyst may be any suitable form, but may more typically be one or more rhenium-containing compounds (e.g., rhenium oxide) or complexes. The rhenium may be present in an amount of, for example, from about 0.001 wt% to about 1 wt%. More typically, the rhenium is present in an amount of from about 0.005% to about 0.5% by weight, and even more typically from about 0.01% to about 0.5% by weight, expressed as a rhenium metal, based on the total weight of the catalyst, About 0.05% by weight.

In another aspect, the present invention relates to an ethylene epoxidation catalyst prepared from the above described carrier. For the catalyst preparation, a carrier having the above-mentioned characteristics is provided with a catalytically effective amount of silver in the carrier phase and / or in the carrier. The catalyst is prepared by impregnation using silver ions, compounds, complexes, and / or salts dissolved in an appropriate solvent sufficient to support the silver precursor compound in the carrier phase and / or in the carrier. By any conventional methods known in the art, such as, for example, by excess solution impregnation, incipient wetness impregnation, spray coating, etc., the support may be coated with any desired accelerators Can be impregnated and incorporated with rhenium and silver. Typically, the carrier material is left in contact with the silver-containing solution until a sufficient amount of the solution is absorbed by the carrier. Preferably, the amount of the silver-containing solution used to impregnate the support does not exceed the amount required to fill the pore volume of the support. Infusion of the silver-containing solution into the carrier can be assisted by applying vacuum. A single impregnation or series of impregnations may be used, depending on the concentration of the silver component in the solution, with or without intermediate drying. The impregnation processes are described, for example, in U.S. Patent Nos. 4,761,394, 4,766,105, 4,908,343, 5,057,481, 5,187,140, 5,102,848, 5,011,807, 5,099,041, and 5,407,888 , All of which are incorporated herein by reference. Known methods for pre-deposition, co-deposition, and post-deposition of the various promoters can also be used.

Silver compounds useful for impregnation include, for example, silver oxalate, silver nitrate, silver oxide, silver carbonate, silver carboxylate, Silver carboxylate, silver citrate, silver phthalate, silver lactate, silver propionate, silver butyrate and high fatty acid salts fatty acid salts, and combinations thereof. The silver solution used for impregnating the carrier may contain any suitable solvent. The solvent may be, for example, water-based, organic-based, or a combination thereof. The solvent may have any suitable degree of polarity, including highly polar, moderately polar, or nonpolar, or substantially or completely nonpolar. The solvent typically has sufficient solvating power to solubilize the solution components. Some examples of water-based solvents include water and water-alcohol mixtures. Some examples of organic-based solvents include alcohols (e.g., alkanols), glycols (e.g., alkyl glycols), ketones, aldehydes, amines, tetrahydrofuran, nitrobenzene, nitrotoluene, But are not limited to, glymes (e.g., glyme, diglyme and tetraglyme), and the like, and combinations thereof. Organic-based solvents having from 1 to about 8 carbon atoms per molecule are preferred.

Various types of complexing agents or solubilizing agents may be used to solubilize silver in the desired concentration in the impregnated medium. Useful complexing agents or solubilizing agents include amines, ammonia, lactic acid, and combinations thereof. For example, the amine may be an alkylenediamine having 1 to 5 carbon atoms. In certain embodiments, the solution comprises an aqueous solution of silver oxalate and ethylenediamine. The complexing / solubilizing agent is present in the impregnation solution in an amount of about 0.1 to about 5.0 moles of ethylenediamine per Ag (Ag) mole, preferably about 0.2 to about 4.0 moles of ethylene diamine per mole, and more preferably about 0.3 to about 3.0 moles It can be present in an amount.

The concentration of salt in the solution is typically in the range of from about 0.1 wt% to the maximum allowed by the solubility of the particular silver salt in the solubilizing agent used. More typically, the silver salt concentration is from about 0.5 wt% to 45 wt%, and more typically from about 5 to 35 wt%, by weight of silver.

The ethylene oxide (EO) catalyst comprises a catalytically effective amount of silver metal for catalysing the synthesis of ethylene oxide from ethylene and oxygen. The silver may be located on the surface of the pores of the refractory support and / or throughout the pores. The catalytically effective amount of silver can be, for example, less than or equal to about 45 weight percent of silver, expressed as metal, based on the total weight of the catalyst comprising the support. More typically, silver contents of about 1 wt% to about 40 wt%, expressed as metal, based on the total weight of the catalyst, are typical. In other embodiments, the silver content may be, for example, about 1 to 35%, 5 to 35%, 1 to 30%, 5 to 30%, 1 to 25%, 5 to 25% %, 5-20%, 8-40%, 8-35%, 8-30%, 10-40%, 10-35%, 10-25%, 12-40%, 12-35%, 12-30 %, Or 12 to 25%.

The rhenium is preferably also incorporated into the silver-containing catalyst for providing a highly selective catalyst. The rhenium can be incorporated at the same time, or subsequently in the abovementioned promoted amount, before the deposition of the silver (i. E. By pre-incorporation into the carrier).

Any one or more promoting species may also be incorporated before, simultaneously with, or subsequently into the carrier. In a preferred embodiment, the additional promoter is at least one selected from cesium (Cs), lithium (Li), tungsten (W), fluorine (F), phosphorus (P), gallium Lt; / RTI > species. In another preferred embodiment, the further promoter comprises at least one species selected from cesium (Cs), lithium (Li), and sulfur (S).

After impregnation with silver and optional promoters, the impregnated support is removed from the solution and sintered for a sufficient time to reduce the silver component to metallic silver and form volatile decomposition products from the silver- products. The sintering may be performed by heating the impregnated support at a temperature of from about 200 캜 to about 600 캜, more typically from about 200 캜 to about 500 캜, more typically from about 250 캜 to about 250 캜, Deg.] C to about 500 < 0 > C, and more typically about 200 [deg.] C or 300 [deg.] C to about 450 [deg.] C. Generally, the higher the temperature, the shorter the required sintering period. A wide range of heating periods are described in the prior art for the heat treatment of the impregnated support. For example, U.S. Pat. No. 3,563,914 discloses heating for less than 300 seconds, and U.S. Patent No. 3,702,259 discloses a method for reducing the silver salt in the catalyst by heating at a temperature of 100 ° C to 375 ° C for 2 to 8 hours And the like. Continuous or staged heating programs may be used for this purpose.

During sintering, the impregnated support is typically exposed to a gaseous atmosphere comprising an inert gas such as nitrogen. The inert gas may also include a reducing agent.

In another aspect, the present invention relates to a method for vapor phase production of ethylene oxide by converting ethylene into ethylene oxide in the presence of oxygen using the catalyst described above. Generally, the ethylene oxide manufacturing process is performed at a desired mass rate (mass) at a temperature range from about 180 DEG C to about 330 DEG C, more typically from about 200 DEG C to about 325 DEG C, and more typically from about 225 DEG C to about 270 DEG C is carried out by continuously contacting the oxygen-containing gas with ethylene in the presence of the catalyst under various pressures of from about atmospheric pressure to about 30 atmospheres, depending on the reaction conditions, e.g. Pressure from about atmospheric pressure to about 500 psi is generally employed. However, higher pressures can be employed within the scope of the present invention. The residence time in a large-scale reactor is generally from about 0.1 to about 5 seconds. A typical process for the oxidation of ethylene to ethylene oxide involves the gas phase oxidation of ethylene using molecular oxygen in the presence of the catalyst of the present invention in a fixed bed tubular reactor. Typical commercial fixed bed ethylene oxide reactors are typically in the form of a plurality of parallel extension tubes (within suitable shells). In one embodiment, the tubes have an outer diameter (OD) of approximately 0.7 to 2.7 inches filled with catalyst and an inner diameter (ID) of 0.5 to 2.5 inches and a length of 15 to 45 feet.

The catalysts described herein have shown that using molecular oxygen is a particularly selective catalyst for the oxidation of ethylene to ethylene oxide. The conditions for carrying out such an oxidation reaction in the presence of the catalysts described herein broadly include those described in the prior art. This may be achieved, for example, by a suitable temperature, pressure, residence time, diluent (e. G., Nitrogen, carbon dioxide, steam, argon, methane or other saturated hydrocarbons), moderating agent (For example, 1,2-dichloroethane, vinyl chloride or ethyl chloride), employing a recycle operation to increase the yield of ethylene oxide, or employing a continuous conversion in different reactors The desirability of doing so, and any other special conditions that can be selected in the process for the production of ethylene oxide. Molecular oxygen used as the reactant can be obtained from conventional sources. A suitable oxygen charge may be relatively pure oxygen, or a concentrated oxygen stream, or air, containing a major amount of oxygen and a lesser amount of one or more diluents, such as nitrogen or argon.

In the preparation of ethylene oxide, the reactant feed mixture is mixed with a balance comprising a relatively inert material, including materials such as nitrogen, carbon dioxide, methane, ethane, argon, etc., % Ethylene and from about 3 to about 15% oxygen. Only a fraction of the ethylene is typically passed through the catalyst. Unreacted materials are typically returned to the oxidation reactor after separating the desired ethylene oxide product and removing the appropriate purge stream and carbon dioxide to prevent uncontrolled accumulation of inert products and / or byproducts. For purposes of illustration only, the following are conditions that are often used in current commercial ethylene oxide reactor unit: a gas hourly space velocity (GHSV) of from 1500 to 10,000 h ^-1 , from 150 to 400 psig Reactor inlet pressure, coolant temperature of 180-315 ° C, oxygen conversion level of 10-60%, and EO production (work rate) of 100-300 kg of ethylene oxide (EO) per 1 m ³ catalyst per hour. Typically, the feed composition at the reactor inlet is comprised of 1-40% ethylene, 3-12% oxygen, 0.3-40% carbon dioxide, 0-3% ethane, 0.3-20 ppmv total concentration of organochlorine modifier moderator, and balance of the feed comprising argon, methane, nitrogen, or mixtures thereof.

In other embodiments, the ethylene oxide manufacturing process includes adding an oxidizing gas to the feed to increase the efficiency of the process. For example, U.S. Patent No. 5,112,795 discloses adding 5 ppm nitric oxide to a gas feed having the following general composition: 8 vol% oxygen, 30 vol% ethylene, about 5 ppmw ethyl Chloride, and balance nitrogen.

The ethylene oxide obtained is recovered separately from the reaction product using methods known in the art. The ethylene oxide process may include a gas recycle process wherein substantially all or substantially all of the reactor effluent is returned to the reactor inlet after substantially or partially removing the ethylene oxide product and any byproducts have. In the recycle mode, the carbon dioxide concentration in the gas influent to the reactor may be, for example, from about 0.3 to about 6 vol%.

BRIEF DESCRIPTION OF THE DRAWINGS For the purposes of further explanation of the invention, embodiments are provided below. The scope of the present invention is not limited in any way by the following examples set forth herein.

Example 1

Synthesis of alumina-based porous support

Low sodium alumina (Na ₂ O content) having a mean particle size (D 50) of 3.2 μm (average agglomerated particle (secondary particle) size (D 50) of 40 μm, surface area of 0.5 m ² / g to 1.0 m ² / g) , Less than 0.08%), 72 parts by weight of coarse particles, 18 parts by weight of fine alumina particles having an average particle size (D50) of 0.6 m (5 m ² / g to 10 m ² / g surface area) 10 parts by weight of a mullite-based inorganic binder having an average particle size (D50) of < RTI ID = 0.0 > The particle size distribution was measured using a particle size analyzer (laser diffraction / scattering type, MT3300 or HRA (X100)) from Nikkiso Co.,

To 100 parts by weight of the alumina raw material, 8.0 parts by weight of an organic molding aid (containing an organic binder) was added together with 2.0 parts by weight of a walnut powder as a pore-forming agent, and then 20 parts by weight of water Was added. Cellulose aid and wax formulation were used as molding aids. The amount of molding aid and water can be adjusted so that the mixture can be extruded. The resulting mixture was blended with a kneader and extruded to obtain a hollow tube molded body having an outer diameter of 8 mm, an inner diameter of 4 mm, and a length of 8 mm. The extruded blend was dried at 60 DEG C to 100 DEG C for about 2 hours and then placed in a refractory saggar. The inner fire wall was composed of a sintered setter equipped with a sintered frame. The extruded blend underwent a firing process using a roller hearth kiln. In the sintering process, the sagger was increased in temperature to or below 1400 ° C for 2 hours and maintained at this temperature for 0.5 hours.

The resulting support had a surface area of 0.89 m ² / g, a water absorption ratio of 31.6%, and an apparent porosity of 55%. The total volume of the micropores was found to be 0.32 mL / g. The peak of the pore volume distribution was found to be about 1.2 탆. The pore volume ratio to the total pore volume of pores having a diameter of 1 mu m or less was 33.1%. In pores having a diameter of from 1 탆 to 2 탆, the pore volume ratio to total pore volume was 45.5%; The pore volume ratio to the total pore volume in the pores having a diameter of from 2 mu m to 10 mu m was 15.2%; And pores having a diameter of 10 mu m or more, the pore volume ratio to the total pore volume was 6.2%.

Example 2

Synthesis of alumina-based porous support

(Na ₂ O content of less than 0.08%) having an average particle size (D50) of 3.2 μm (mean coagulated particle size (D50) of 40 μm, surface area of 0.5 m ² / g to 1.0 m ² / g) 68 parts by weight of coarse particles, 22 parts by weight of fine alumina particles having an average particle size (D50) of 0.6 m (5 m ² / g to 10 m ² / g surface area) and an average particle size of 10 μm or more 10 parts by weight of a mullite-based inorganic binder having a weight average molecular weight (D50) were mixed to obtain an alumina raw material.

To 100 parts by weight of the alumina raw material, 3.0 parts by weight of an organic molding aid (containing an organic binder) was added together with 7.0 parts by weight of a walnut powder as a pore-forming agent, and then 22 parts by weight of water was added. Cellulose preparations and wax preparations were used as molding aids. The amount of molding aid and water can be adjusted so that the mixture can be extruded. The resultant mixture was blended by a kneader and then extruded to obtain a hollow tube compact having an outer diameter of 8 mm, an inner diameter of 4 mm, and a length of 8 mm. The extruded blend was dried at 60 DEG C to 100 DEG C for about 2 hours and then placed in a fire resistant fireproof box. The inner shell was composed of a sintered setter equipped with a sintered frame. The extruded blend was subjected to a sintering process using a roller washer kiln. In the firing process, the temperature was increased to or below 1400 ° C for 2 hours and maintained at this temperature for 0.5 hours.

The resulting support had a surface area of 0.93 m ² / g, a water absorption ratio of 31.7%, and an apparent porosity of 57%. The total volume of the micropores was found to be 0.32 mL / g. The peak of the pore volume distribution was found to be about 1.1 탆. The pore volume ratio to the total pore volume of the pores having a diameter of 1 mu m or less was 35.1%. In pores having a diameter of from 1 탆 to 2 탆, the pore volume ratio to total pore volume was 30.8%; The pore volume ratio to total pore volume in pores having a diameter of from 2 mu m to 10 mu m was 26.7%; And in the pores having a diameter of 10 mu m or more, the pore volume ratio to the total pore volume was 7.4%.

Example 3

Synthesis of alumina-based porous support

(Na ₂ O content of less than 0.08%) having an average particle size (D50) of 3.2 μm (mean coagulated particle size (D50) of 40 μm, surface area of 0.5 m ² / g to 1.0 m ² / g) 77 parts by weight of coarse particles, 13 parts by weight of fine alumina particles having an average particle size (D50) of 0.6 占 퐉 (5 m ² / g to 10 m ² / g surface area) and an average particle size of 10 μm to 12 μm D50) were mixed to obtain an alumina raw material.

To 100 parts by weight of the alumina raw material, 3.0 parts by weight of an organic molding aid (containing an organic binder) was added together with 7.0 parts by weight of a walnut powder as a pore-forming agent, and then 22.5 parts by weight of water was added. Cellulose preparations and wax preparations were used as molding aids. The amount of molding aid and water can be adjusted so that the mixture can be extruded. The resultant mixture was blended by a kneader and then extruded to obtain a hollow tube compact having an outer diameter of 8 mm, an inner diameter of 4 mm, and a length of 8 mm. The extruded blend was dried at 60 DEG C to 100 DEG C for about 2 hours and then placed in a fire resistant fireproof box. The inner shell was composed of a sintered setter equipped with a sintered frame. The extruded blend was subjected to a sintering process using a roller washer kiln. In the firing process, the temperature was increased to or below 1400 ° C for 2 hours and maintained at this temperature for 0.5 hours.

The resulting support had a surface area of 0.82 m ² / g, a water absorption ratio of 36.5%, and an apparent porosity of 58%. The total volume of the micropores was found to be 0.35 mL / g. The peak of the pore volume distribution was found to be about 1.3 탆. The pore volume ratio to the total pore volume of the pores having a diameter of 1 mu m or less was 21.1%. In the pores having a diameter of from 1 탆 to 2 탆, the pore volume ratio to the total pore volume was 42.7%; The pore volume ratio to the total pore volume in the pores having a diameter of 2 mu m or more to 10 mu m was 28.6%; And in the pores having a diameter of 10 mu m or more, the pore volume ratio to the total pore volume was 7.6%.

Example 4

Synthesis of alumina-based porous support

(Na ₂ O content of less than 0.08%) having an average particle size (D50) of 2.0 μm (average agglomerated particle size (D50) of 70 μm, surface area of 0.5 m ² / g to 1.0 m ² / g) 72 parts by weight of coarse particles, 18 parts by weight of fine alumina particles having an average particle size (D50) of 0.6 占 퐉 (5 m ² / g to 10 m ² / g surface area), and an average particle size of 10 μm or more 10 parts by weight of a mullite-based inorganic binder having a weight average molecular weight (D50) were mixed to obtain an alumina raw material.

To 100 parts by weight of the alumina raw material, 3.0 parts by weight of an organic molding aid (containing an organic binder) was added together with 5.0 parts by weight of a walnut powder as a pore-forming agent, and then 22 parts by weight of water was added. Cellulose preparations and wax preparations were used as molding aids. The amount of molding aid and water can be adjusted so that the mixture can be extruded. The resultant mixture was blended by a kneader and then extruded to obtain a hollow tube compact having an outer diameter of 8 mm, an inner diameter of 4 mm, and a length of 8 mm. The extruded blend was dried at 60 DEG C to 100 DEG C for about 2 hours and then placed in a fire resistant fireproof box. The inner shell was composed of a sintered setter equipped with a sintered frame. The extruded blend was subjected to a sintering process using a roller washer kiln. In the firing process, the temperature was increased to or below 1400 ° C for 2 hours and maintained at this temperature for 0.5 hours.

The resulting support had a surface area of 1.04 m ² / g, a water absorption ratio of 33.5%, and an apparent porosity of 56%. The total volume of the micropores was found to be 0.34 mL / g. The peak of the pore volume distribution was found to be about 1.3 탆. The pore volume ratio to the total pore volume of the pores having a diameter of 1 mu m or less was 43.4%. In pores having a diameter of from 1 탆 to 2 탆, the pore volume ratio of the total pore volume was 47.5%; 4.4% with respect to the pore volume ratio of the total pore volume in pores having diameters of from 2 mu m to 10 mu m; And the pore volume having a diameter of 10 mu m or more, the pore volume ratio to the total pore volume was 4.7%.

Example 5

Synthesis of alumina-based porous support

(Na ₂ O content of less than 0.08%) having an average particle size (D50) of 2.0 μm (average agglomerated particle size (D50) of 70 μm, surface area of 0.5 m ² / g to 1.0 m ² / g) 72 parts by weight of coarse particles, 18 parts by weight of fine alumina particles having an average particle size (D50) of 0.5 占 퐉 (5 m ² / g to 10 m ² / g surface area) and 18 parts by weight of an average particle size And 10 parts by weight of a mullite-based inorganic binder having a weight average molecular weight (D50) were mixed to obtain an alumina raw material.

100 parts by weight of alumina raw material and 3.0 parts by weight of an organic molding aid (containing an organic binder) were added together with 5.0 parts by weight of walnut powder as a pore-forming agent, and then 22 parts by weight of water was added. Cellulose preparations and wax preparations were used as molding aids. The amount of molding aid and water can be adjusted so that the mixture can be extruded. The resultant mixture was blended by a kneader and then extruded to obtain a hollow tube compact having an outer diameter of 8 mm, an inner diameter of 4 mm, and a length of 8 mm. The extruded blend was dried at 60 DEG C to 100 DEG C for about 2 hours and then placed in a fire resistant fireproof box. The inner shell was composed of a sintered setter equipped with a sintered frame. The extruded blend was subjected to a sintering process using a roller washer kiln. In the firing process, the temperature was increased to or below 1400 ° C for 2 hours and maintained at this temperature for 0.5 hours.

The resulting support had a surface area of 1.01 m ² / g, a water absorption ratio of 32.6%, and an apparent porosity of 55%. The total volume of the micropores was found to be 0.33 mL / g. The peak of the pore volume distribution was found to be about 1.3 탆. The pore volume ratio to the total pore volume of the pores having a diameter of 1 mu m or less was 41.8%. In pores having a diameter of 1 [mu] m to 2 [mu] m, the pore volume ratio of the total pore volume was 48%; The pore volume ratio to the total pore volume in pores having a diameter of from 2 mu m to 10 mu m was 4.5%; And the pore volume having a diameter of 10 mu m or more, the pore volume ratio to the total pore volume was 5.7%.

Example 6

Synthesis of alumina-based porous support

Low sodium alumina (less than 0.08% Na ₂ O) having an average particle size (D50) of 2.0 μm (average aggregate particle size (D50) of 70 μm, surface area of 0.5 m ² / g to 1.0 m ² / g) 72 parts by weight of particles, 18 parts by weight of fine alumina particles having an average particle size (D50) of 0.4 占 퐉 (5 m ² / g to 10 m ² / g surface area), and an average particle size of 10 μm or more 10 parts by weight of a mullite-based inorganic binder having a weight average molecular weight (D50) were mixed to obtain an alumina raw material.

To 100 parts by weight of the alumina raw material, 3.0 parts by weight of an organic molding aid (containing an organic binder) was added together with 5.0 parts by weight of a walnut powder as a pore-forming agent, and then 22 parts by weight of water was added. Cellulose preparations and wax preparations were used as molding aids. The amount of molding aid and water can be adjusted so that the mixture can be extruded. The resultant mixture was blended by a kneader and then extruded to obtain a hollow tube compact having an outer diameter of 8 mm, an inner diameter of 4 mm, and a length of 8 mm. The extruded blend was dried at 60 DEG C to 100 DEG C for about 2 hours and then placed in a fire resistant fireproof box. The inner shell was composed of a sintered setter equipped with a sintered frame. The extruded blend underwent a sintering process using a roller hearth kiln. In the firing process, the temperature was increased to 1400 DEG C or higher for 2 hours and maintained at the temperature for about 0.5 hour.

The resulting support had a surface area of 0.99 m ² / g, a water absorption ratio of 31.8%, and an apparent porosity of 55%. The total volume of the micropores was found to be 0.32 mL / g. The peak of the pore volume distribution was found to be about 1.3 탆. The pore volume ratio to the total pore volume of the pores having a diameter of 1 mu m or less was 41.7%. In the pores having a diameter of 1 mu m or more and 2 mu m or less, the pore volume ratio of the total pore volume was 49.5%; The pore volume ratio to the total pore volume in the pores having a diameter of 2 mu m or more to 10 mu m was 4.2%; And in the pores having a diameter of 10 mu m or more, the pore volume ratio to the total pore volume was 4.6%.

Example 7

Synthesis of alumina-based porous support

(Na ₂ O content of less than 0.08%) having an average particle size (D50) of 2.2 μm (mean coagulated particle size (D50) of 90 μm, surface area of 0.5 m ² / g to 1.0 m ² / g) 72 parts by weight of coarse particles, 18 parts by weight of fine alumina particles having an average particle size (D50) of 0.4 占 퐉 (5 m ² / g to 10 m ² / g surface area) and 18 parts by weight of an average particle size And 10 parts by weight of a mullite-based inorganic binder having a weight average molecular weight (D50) were mixed to obtain an alumina raw material.

To 100 parts by weight of the alumina raw material, 3.0 parts by weight of an organic molding aid (containing an organic binder) was added together with 5.0 parts by weight of a walnut powder as a pore-forming agent, and then 22 parts by weight of water was added. Cellulose preparations and wax preparations were used as molding aids. The amount of molding aid and water can be adjusted so that the mixture can be extruded. The resultant mixture was blended by a kneader and then extruded to obtain a hollow tube compact having an outer diameter of 8 mm, an inner diameter of 4 mm, and a length of 8 mm. The extruded blend was dried at 60 DEG C to 100 DEG C for about 2 hours and then placed in a fire resistant fireproof box. The inner shell was composed of a sintered setter equipped with a sintered frame. The extruded blend was subjected to a sintering process using a roller washer kiln. In the firing process, the temperature was increased to or below 1400 ° C for 2 hours and maintained at this temperature for 0.5 hours.

The resulting support had a surface area of 0.98 m ² / g, a water absorption ratio of 35.0%, and an apparent porosity of 57%. The total volume of the micropores was found to be 0.35 mL / g. The peak of the pore volume distribution was found to be about 1.3 탆. The pore volume ratio to the total pore volume of the pores having a diameter of 1 mu m or less was 38.4%. In the pores having a diameter of 1 mu m or more to 2 mu m, the pore volume ratio to the total pore volume was 53.7%; The pore volume ratio to the total pore volume in the pores having a diameter of from 2 mu m to 10 mu m was 3.6%; And for pores having a diameter of 10 [mu] m or more, the pore volume ratio to the total pore volume was 4.3%.

Example 8

Analysis and Characterization of Supports Generated According to Examples 1 to 7

The following Tables 1 and 2 summarize some properties of the alumina support produced according to Examples 1 to 7. The main properties recorded are surface area, moisture absorption, apparent porosity, crush strength, pore volume distribution, pore volume, and pore diameter peak. Table 3 below summarizes the characteristics of the coarse alumina A, B, and C used in Examples 1 to 7. Table 4 below summarizes the respective properties of the fine alumina a, b, and c used in Examples 1 to 7.

As shown by comparing the results of Examples 1 to 3, an increase in the amount of fine particles tends to increase the surface area and the crush strength, while the water absorption generally decreases. Examples 4 to 7 represent the cohesion of coarse and fine particles that provide the same, substantially identical, or even improved properties as compared to the supports described in Examples 1 to 3, A combination of 40 탆 thick alumina and 3 탆 to 5 탆 fine alumina is used. For example, Examples 4 through 6 combine 70 탆 thick alumina with 0.6 탆, 0.5 탆, or 0.4 탆 fine alumina, respectively, while Example 7 uses 90 탆 coarse alumina and 0.4 탆 fine alumina Used in combination. The different properties found in these supports can make some parts of the support more suitable or incompatible than the different parts. Any of the above described exemplary supports may be more advantageous or disadvantageous than the different supports depending on the end-application, the setting of the conditions under consideration, or the desired result, since the end-application and condition may vary between uses of the support have.

Example 9

Synthesis of Different Alumina-Based Porous Supports

70 parts by weight of low sodium alumina secondary particles, 20 parts by weight of fine alumina particles, and 10 parts by weight of mullite-based inorganic binder were mixed to obtain an alumina raw material. The low sodium alumina secondary particles contained more than 99.0% Al ₂ O ₃ and had an average aggregate particle size (D50) of 40 μm, a mean particle size (D50) of 3.2 μm, a density of 0.5 m ² / g to 1.0 m ² / g Surface area, Na ₂ O content of 0.1% or less). The fine alumina particles contained more than 99.0% of Al ₂ O ₃ and had a mean particle size of 0.5 μm (D 50), a surface area of 5 m ² / g to 10 m ² / g, a Na ₂ O content of less than 0.1% . The mullite-based inorganic binder had an average particle size (D50) of 10 [mu] m or less and represented 10% of the total weight.

1.0 part by weight of microcrystalline cellulose and 10 parts by weight of wax emulsion were added as a molding aid and an organic binder together with 5.0 parts by weight of walnut powder as a pore-forming agent to 100 parts by weight of alumina raw material, Weight parts were added. The resultant mixture was blended by a kneader and then extruded to obtain a hollow tube compact having an outer diameter of 8 mm, an inner diameter of 4 mm, and a length of 8 mm. The extruded blend was dried at 60 DEG C to 100 DEG C for about 2 hours and then placed in a fire resistant fireproof box. The inner shell was composed of a sintered setter equipped with a sintered frame. The extruded blend was subjected to a sintering process using a roller washer kiln. In the firing process, the extruded blend was subject to a maximum sintering temperature (e.g., less than 1600 占 폚 in the embodiment) for 2 hours and was maintained at 1400 占 폚 for 0.5 hours.

The resulting support had a surface area of 0.9 m ² / g, a water absorption ratio of 32%, and an apparent porosity of 55%. The total volume of the micropores was found to be 0.35 mL / g. The peak of the pore volume distribution was found to be about 1.5 탆. The pore volume in the range of 1 탆 to 2 탆 was 47%, and the pore volume in the range of less than 1 탆 was less than 35%.

While the invention has been shown and described with respect to preferred embodiments thereof, other and further embodiments may be made without departing from the spirit and scope of the invention as described in the present application, It will be understood by those skilled in the art that the present invention may include all such modifications within the disclosed range.

Claims (44)

As the carrier for the ethylene epoxidation catalyst,
A first alumina particle portion having an average primary particle size (D50) of from 2 占 퐉 to 6 占 퐉 and an alumina containing a second alumina particle portion having an average primary particle size (D50) of less than 2 占 퐉. carrier. The method according to claim 1,
Wherein the first alumina particle portion has an average primary particle size (D50) of 2 [mu] m to 5 [mu] m. The method according to claim 1,
Wherein said second alumina particle portion has an average primary particle size (D50) of 1.5 [mu] m or less. The method according to claim 1,
Wherein the second alumina particle portion has an average primary particle size (D50) of 1 [mu] m or less. The method according to claim 1,
Wherein the first alumina particle portion has an average primary particle size (D50) of 3 [mu] m to 5 [mu] m and the second alumina particle portion has an average primary particle size (D50) of 1.5 [mu] m or less. The method according to claim 1,
Wherein the first alumina particle portion has an average primary particle size (D50) of 3 [mu] m to 5 [mu] m and the second alumina particle portion has an average primary particle size (D50) of 1 [mu] m or less. The method according to claim 1,
Wherein the first alumina particle portion has an average primary particle size (D50) of 2 [mu] m to 4 [mu] m and the second alumina particle portion has an average primary particle size (D50) of 1 [mu] m or less. The method according to claim 1,
Wherein the first alumina particle portion has an average primary particle size (D50) of 2 [mu] m to 3 [mu] m and the second alumina particle portion has an average primary particle size (D50) of 1.0 [mu] m or less. The method according to claim 1,
Wherein at least 10 wt% and less than 100 wt% of said carrier particles have a size (D50) of less than 2 mu m, wherein said wt% is relative to the weight of said alumina in said carrier. The method according to claim 1,
Wherein at least 10 wt% and less than 100 wt% of said carrier particles have a size (D50) of 1 mu m or less, wherein said wt% is relative to the weight of said alumina in said carrier. The method according to claim 1,
Wherein the alumina component is alpha (alpha) -alumina. The method according to claim 1,
Further comprising a stability-improving amount of mullite. 13. The method of claim 12,
Wherein the stability-improving amount of the mullite is about 0.5% to 20% mullite relative to the total weight of the support. 13. The method of claim 12,
Wherein the stability-improving amount of the mullite is about 1% to 15% mullite relative to the total weight of the support. 13. The method of claim 12,
Wherein the stability-improving amount of the mullite is about 3% to 12% mullite relative to the total weight of the support. The method according to claim 1,
Lt; RTI ID = 0.0 > rhenium < / RTI > The method according to claim 1,
Further comprising a promoting amount of an alkali metal or an alkaline earth metal. The method according to claim 1,
Further comprising a promoting amount of cesium. The method according to claim 1,
Wherein the carrier has a pore size distribution characterized by a peak pore size of 2 [mu] m or less. The method according to claim 1,
And wherein 45% or less of the pores have a pore size of 1 [mu] m or less. An ethylene epoxidation catalyst comprising:
a) a carrier comprising alumina containing a first alumina particle portion having an average primary particle size (D50) of 2 [mu] m to 6 [mu] m and a second alumina particle portion having an average primary particle size (D50) of less than 2 [mu] m;
b) a catalytic amount of silver deposited on and / or within said carrier; And
c) a promoted amount of rhenium supported on and / or within said carrier. 22. The method of claim 21,
Wherein the first alumina particle portion has an average primary particle size (D50) of 2 [mu] m to 5 [mu] m. 22. The method of claim 21,
Wherein the second alumina particle portion has an average primary particle size (D50) of 1.5 [mu] m or less. 22. The method of claim 21,
Wherein the second alumina particle portion has an average primary particle size (D50) of less than or equal to 1 占 퐉. 22. The method of claim 21,
Wherein the first alumina particle portion has an average primary particle size (D50) of 3 [mu] m to 5 [mu] m and the second alumina particle portion has an average primary particle size (D50) of 1.5 [mu] m or less. 22. The method of claim 21,
Wherein the first alumina particle portion has an average primary particle size (D50) of 3 [mu] m to 5 [mu] m and the second alumina particle portion has an average primary particle size (D50) of 1 [mu] m or less. 22. The method of claim 21,
Wherein the first alumina particle portion has an average primary particle size (D50) of 2 [mu] m to 4 [mu] m and the second alumina particle portion has an average primary particle size (D50) of 1 [mu] m or less. 22. The method of claim 21,
Wherein the first alumina particle portion has an average primary particle size (D50) of 2 [mu] m to 3 [mu] m and the second alumina particle portion has an average primary particle size (D50) of 1.0 [mu] m or less. 22. The method of claim 21,
Wherein at least 10 wt% and less than 100 wt% of the first alumina particle portion has a size (D50) of less than 2 mu m, wherein the wt% is relative to the weight of the alumina in the carrier. 22. The method of claim 21,
Wherein at least 10 wt% and less than 100 wt% of the first alumina particle portion has a size (D50) of 1 mu m or less, wherein the wt% is relative to the weight of the alumina in the carrier. 22. The method of claim 21,
Wherein the carrier has a pore size distribution characterized by a peak pore size of 2 [mu] m or less. 22. The method of claim 21,
And 45% or less of the pores have a pore size of 1 m or less. As a method for the gas phase conversion of ethylene to ethylene oxide in the presence of oxygen,
Comprising reacting a reaction mixture comprising ethylene and oxygen in the presence of a catalyst comprising:
a) a carrier comprising alumina containing a first alumina particle portion having an average primary particle size (D50) of 2 [mu] m to 6 [mu] m and a second alumina particle portion having an average primary particle size (D50) of less than 2 [mu] m;
b) the amount of silver supported in the carrier phase and / or in the catalytic amount; And
c) a promoted amount of rhenium carried on and / or in the carrier. 34. The method of claim 33,
Wherein the first alumina particle portion has an average primary particle size (D50) of 2 [mu] m to 5 [mu] m. 34. The method of claim 33,
Wherein the second alumina particle portion has an average primary particle size (D50) of 1.5 [mu] m or less. 34. The method of claim 33,
Wherein the second alumina particle portion has an average primary particle size (D50) of 1 [mu] m or less. 34. The method of claim 33,
Wherein the first alumina particle portion has an average primary particle size (D50) of 3 [mu] m to 5 [mu] m and the second alumina particle portion has an average primary particle size of 1.5 [mu] m or less. 34. The method of claim 33,
Wherein the first alumina particle portion has an average primary particle size (D50) of 3 [mu] m to 5 [mu] m and the second alumina particle portion has an average primary particle size of 1 [mu] m or less. 34. The method of claim 33,
Wherein the first alumina particle portion has an average primary particle size (D50) of 2 mu m to 4 mu m and the second alumina particle portion has an average primary particle size of 1 mu m or less. 34. The method of claim 33,
Wherein the first alumina particle portion has an average primary particle size (D50) of 2 [mu] m to 3 [mu] m and the second alumina particle portion has an average primary particle size (D50) of 1.0 [mu] m or less. 34. The method of claim 33,
Wherein at least 10 wt% and less than 100 wt% of said first alumina particle portion has a size (D50) of less than 2 mu m, wherein said wt% is relative to the weight of said alumina in said carrier. 34. The method of claim 33,
Wherein at least 10 wt% and less than 100 wt% of the first alumina particle portion has a size (D50) of 1 mu m or less, wherein the wt% is relative to the weight of the alumina in the carrier. 34. The method of claim 33,
Wherein the carrier has a pore size distribution characterized by a peak pore size of 2 [mu] m or less. 34. The method of claim 33,
Wherein 45% or less of the pores have a pore size of 1 [mu] m or less.