Catalyst for producing 1,3-butadiene with high yields based on a support containing aluminum and sodium

Abstract

The present invention relates to a supported catalyst comprising a support and 0.1 to 10 wt. % tantalum, calculated as Ta2O5, based on the total catalyst weight. The supported catalyst further comprises 50 to 350 ppm aluminum and 300 to 500 ppm sodium, based on the total catalyst weight. Furthermore, the present invention relates to a catalytic reactor tube for producing 1,3-butadiene, comprising at least one packing of the supported catalyst defined herein; a reactor for producing 1,3-butadiene, comprising one or more catalytic reactor tubes defined herein; and a plant for producing 1,3-butadiene, comprising one or more reactors defined herein. The present invention also relates to a process for producing 1,3-butadiene, as defined herein, and a process for producing the supported catalyst defined herein. Finally, the present invention relates to the use of a supported catalyst as defined herein for producing 1,3-butadiene from a feedstock comprising ethanol and acetaldehyde, and to the use of aluminum in an amount in the range of 50 to 350 ppm in a supported catalyst for producing 1,3-butadiene from a feedstock comprising ethanol and acetaldehyde to enhance the yield of 1,3-butadiene.

Description

[Technical Field]

[0001] The present invention relates to a supported catalyst comprising a support and 0.1 to 10 wt. % tantalum, calculated as Ta2O5, based on the total weight of the catalyst. The supported catalyst further comprises 50 to 350 ppm aluminum and 300 to 500 ppm sodium, each based on the total weight of the catalyst. Furthermore, the present invention relates to a catalytic reactor tube for producing 1,3-butadiene, comprising at least one packing of the supported catalyst defined herein; a reactor for producing 1,3-butadiene, comprising one or more catalytic reactor tubes defined herein; and a plant for producing 1,3-butadiene, comprising one or more reactors defined herein. The present invention also relates to a process for producing 1,3-butadiene, as defined herein, and a process for producing the supported catalyst defined herein. Finally, the present invention relates to the use of a supported catalyst as defined herein for producing 1,3-butadiene from a feedstock comprising ethanol and acetaldehyde, and to the use of aluminum in an amount in the range of 50 to 350 ppm in a supported catalyst for producing 1,3-butadiene from a feedstock comprising ethanol and acetaldehyde, in order to increase the yield of 1,3-butadiene. [Background technology]

[0002] 1,3-Butadiene is one of the most important raw materials in the synthetic rubber industry and is used as a monomer in the production of a wide range of synthetic polymers, such as polybutadiene rubber, acrylonitrile butadiene styrene polymer, styrene butadiene rubber, nitrile butadiene rubber, and styrene butadiene latex. 1,3-Butadiene is obtained, for example, as a by-product of ethylene production by naphtha steam cracking and can be separated by extractive distillation (Non-Patent Documents 1-3).

[0003] The depletion of non-renewable fossil fuel-derived resources and environmental concerns have recently been strong drivers for the search for renewable sources of 1,3-butadiene and its precursors. Among the wide range of available renewable resources, biomass appears to have the greatest potential for use in the production of 1,3-butadiene. This strategy has two main advantages: independence from fossil fuels and reduced CO2 emissions (Non-Patent Document 2).

[0004] The conversion of ethanol (e.g., obtained from biomass) to 1,3-butadiene can be carried out by two processes reported in the literature: a one-stage process (Lebedev process) and a two-stage process (Ostromislensky process).

[0005] This one-step process, reported by Lebedev in the early 20th century, is carried out by directly converting ethanol to 1,3-butadiene using a multifunctional catalyst with tailored acid-base properties (Non-Patent Documents 4, 5).

[0006] Alternatively, a so-called two-stage process can be carried out by converting ethanol to acetaldehyde in a first stage. The purpose of this first stage is to feed a mixture of ethanol and acetaldehyde to a second stage or reactor. In the second stage, the mixture of ethanol and acetaldehyde is converted to 1,3-butadiene, for example, over a silica-supported tantalum catalyst (Non-Patent Document 6).

[0007] Patent Document 1 relates to a catalyst for converting a feedstock containing ethanol and acetaldehyde to 1,3-butadiene. The catalyst comprises at least elemental tantalum and at least one mesoporous oxide matrix that has been subjected to acid washing and contains at least 90 wt. % silica prior to washing, with the mass of elemental tantalum ranging from 0.1% to 30% of the mass of the mesoporous oxide matrix. The teachings of Patent Document 1 rely on acid washing of the mesoporous oxide support to enhance the catalyst's selectivity to 1,3-butadiene and / or productivity to 1,3-butadiene. At the end of the washing step and before impregnation with the active element, the catalyst contains sodium in an amount ranging from 0 to 500 ppm. Patent Document 1 does not disclose the aluminum concentration in the catalyst or the yield of 1,3-butadiene.

[0008] Patent Document 2 relates to a method for producing 1,3-butadiene from ethanol in two reaction steps, including step a) converting ethanol into acetaldehyde and step b) converting ethanol into 1,3-butadiene, in which step b) the reaction step and the regeneration step are simultaneously carried out in (n+n / 2) fixed-bed reactors (n is 4 or a multiple thereof) containing a catalyst, the regeneration step including four successive regeneration phases, and three regeneration loops are also carried out in step b).

[0009] Patent document 3 relates to a mesoporous mixed oxide catalyst comprising silicon and at least one metal M selected from the group consisting of elements of groups 4 and 5 of the periodic table and mixtures thereof, wherein the mass of metal M is 0.1 to 20% of the mass of the mixed oxide.

[0010] Patent Document 4 relates to a method for producing a supported tantalum oxide catalyst precursor or catalyst having a controlled tantalum distribution, and the resulting supported tantalum catalyst. In one embodiment, the method comprises selecting a tantalum precursor having appropriate reactivity with the surface hydroxyl groups of the solid oxide support material to provide the desired tantalum distribution in the catalyst precursor or catalyst. In another embodiment, the method comprises achieving the desired tantalum distribution by controlling the number of surface hydroxyls available on the support material to react with the tantalum precursor through a thermal process such as calcination.

[0011] Therefore, there is a continuing need to provide catalysts for producing 1,3-butadiene that exhibit high activity and can provide high yields of 1,3-butadiene. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] US Patent Application Publication No. 2018 / 0208522 [Patent Document 2] International Publication No. 2020 / 126920 [Patent Document 3] US Patent Application Publication No. 2018 / 200694 [Patent Document 4] International Publication No. 2022 / 165190 [Non-patent literature]

[0013] [Non-Patent Document 1] Chem.Soc.Rev.,2014,43,7917 [Non-patent document 2] ChemSusChem,2013,6,1595 [Non-patent document 3] Chem.Central J.,2014,8,53 [Non-patent document 4] J. Gen. Chem., 1933, 3, 698 [Non-Patent Document 5] Chem.Ztg.,1936,60,313 [Non-patent document 6] Catal.Today,2016,259,446 Summary of the Invention

[0014] The supported catalyst is (i) a carrier, and (ii) 0.1 to 10 wt. % of tantalum, calculated as Ta2O5, based on the total weight of the catalyst, preferably 2 to 4 wt. % The supported catalyst further comprises, based on the total weight of the catalyst, 50 to 350 ppm, preferably 75 to 350 ppm, more preferably 100 to 350 ppm, more preferably 100 to 300 ppm, more preferably 100 to 275 ppm, and most preferably 150 to 250 ppm of aluminum, and 300 to 500 ppm, preferably 350 to 500 ppm, more preferably 380 to 500 ppm, more preferably 380 to 450 ppm, and most preferably 380 to 410 ppm of sodium.

[0015] During the research underlying the present invention, it was discovered that increasing the sodium level in the catalyst compared to the sodium level of an ultra-high purity catalyst containing 6 ppm aluminum and 31 ppm sodium (each based on the total weight of the catalyst) increases the overall conversion but has a significant adverse effect on selectivity to 1,3-butadiene. Thus, increasing the sodium level alone in the catalyst reduces both the achieved 1,3-butadiene yield and 1,3-butadiene productivity. Surprisingly, however, it was discovered that the adverse effect of increasing the sodium level in the catalyst can be offset by simultaneously increasing the aluminum level. Catalytic activity testing of the catalyst according to the present invention not only increased the overall conversion, but also reduced the selectivity to 1,3-butadiene to a lesser extent, resulting in an overall advantageous improvement in both the yield and productivity of 1,3-butadiene (see Table 2 and the Examples below).

[0016] Sodium and aluminum levels given herein in parts per million relate to the total weight of the supported catalyst containing tantalum as tantalum oxide. The same applies to tantalum levels given herein in weight percent.

[0017] In a preferred embodiment, the support of the supported catalyst according to the present invention comprises one or more of ordered and non-ordered porous silica supports, other porous oxide supports preferably from ZrO2, TiO2, MgO, ZnO, NiO, and CeO2, and mixtures thereof.

[0018] Most preferably, the support of the supported catalyst according to the present invention is a silica support, preferably an ordered or irregular porous silica support. Supported catalysts are particularly advantageous because the concentration and distribution of active sites can be controlled, the catalysts are easily prepared by impregnation into supports of any form and shape, and reactant molecules have easy access to all active sites of the catalyst.

[0019] Preferably, the supported catalyst according to the present invention has a molecular weight of 130 to 550 m 2 / g, preferably 190 to 280 m 2 / g. Preferably, the supported catalyst according to the present invention has an average pore size in the range of 3 to 30 nm (30 to 300 Å).

[0020] Preferably, the supported catalyst according to the present invention has a thickness of 0.2 to 1.5 cm 3 / g. Surface area (SA) and pore volume (PV) were measured by nitrogen porosimetry using an Autosorb-6 test unit from Quantachrome Corporation (now Anton Paar GmbH). Samples were first degassed in an Autosorb-6 degasser at 350°C for at least 4 hours. Multipoint surface areas were calculated using BET theory with data points ranging from 0.05 to 0.30 P / P. Pore volume measurements were recorded at P / P of 0.984 during the desorption interval. Assuming cylindrical pores, the average pore diameter was calculated using the following equation:

[0021]

number

[0022] According to a preferred embodiment of the present invention, the weight ratio of aluminum to sodium in the supported catalyst ranges from 0.1 to 1.2, preferably from 0.2 to 1.0, more preferably from 0.3 to 0.8, and most preferably from 0.4 to 0.7.

[0023] In a second aspect, the present invention relates to a catalytic reactor tube for the production of 1,3-butadiene comprising at least one charge of a supported catalyst according to the present invention and one or more charge of an inert material. Preferably, the inert material is selected from the group consisting of silicon carbide, inert ceramic beds, ceramic beads, extrudates, rings of 2 to 7 mm diameter, stainless steel mesh, foams, and mixtures thereof.

[0024] According to a preferred embodiment, packings of inert material contact and separate the packings of supported catalyst according to the invention, i.e., reaction zones, from one another (if there are several packings of supported catalyst in the catalytic reactor tube), and are preferably located at the reactant feed inlet and outlet of the reactor tube.

[0025] According to one embodiment, the catalytic reactor tube is loaded with one packing of the supported catalyst according to the present invention, preferably in the center of the catalytic reactor tube. The supported catalyst according to the present invention is in contact with packings of inert material on both sides, i.e., the packings of inert material are preferably located at the feed inlet and outlet of the catalytic reactor tube. According to this embodiment, the catalytic reactor tube comprises one reaction zone.

[0026] According to another embodiment, the catalytic reactor tube is loaded with alternate packings of the supported catalyst according to the present invention and packings of inert material. The packings of inert material are preferably located at the feed inlet and outlet of the catalytic reactor tube and are in contact with the packings of the supported catalyst according to the present invention. According to this embodiment, the catalytic reactor tube comprises multiple reaction zones.

[0027] In a third aspect, the present invention relates to a reactor for the production of 1,3-butadiene comprising one or more catalytic reactor tubes according to the present invention. In a fourth aspect, the present invention relates to a plant for the production of 1,3-butadiene comprising one or more reactors as defined herein and means for regenerating the supported catalyst in said one or more reactors, preferably said plant also comprising a pre-reactor for the production of acetaldehyde equipped with one or more reactor tubes containing a supported or unsupported (bulk) catalyst comprising one or more of zinc, copper, silver, chromium, magnesium, and nickel, preferably one or more of zinc and copper.

[0028] The tantalum oxide contained in the supported catalyst of the present invention is inactive in the oxidation of ethanol to acetaldehyde. Therefore, to produce 1,3-butadiene using the supported catalyst of the present invention, the feed stream must contain ethanol and acetaldehyde. This mixture of ethanol and acetaldehyde is produced, for example, in a plant, from ethanol in a pre-reactor for acetaldehyde production containing a supported or unsupported (bulk) catalyst as defined above, and then fed to a reactor for 1,3-butadiene production containing one or more catalytic reactor tubes of the present invention. Alternatively, ethanol and acetaldehyde can be obtained from a commercial source and fed directly to a reactor for 1,3-butadiene production containing one or more catalytic reactor tubes of the present invention.

[0029] In a fifth aspect, the present invention relates to a method for producing 1,3-butadiene, said method comprising: (i) contacting a feedstock containing ethanol and acetaldehyde with a supported catalyst according to the present invention to obtain a crude product containing 1,3-butadiene.

[0030] Preferably, in the method according to the present invention, the contacting in (i) is carried out at a temperature in the range of 200 to 500°C, preferably 250 to 450°C, more preferably 300 to 400°C. In a preferred embodiment of the method according to the present invention, the contacting in (i) is carried out for 0.2 to 10 hours. -1 , preferably 1 to 7 hours -1 , more preferably 2 to 5 hours -1 The pressure is applied at a weight hourly space velocity in the range of 100 psi.

[0031] Preferably, the contacting in (i) is carried out at a pressure in the range of 0 to 1 MPaG (0 to 10 barg), preferably 0.1 to 0.3 MPaG (1 to 3 barg), and most preferably 0.1 to 0.2 MPaG (1 to 2 barg).

[0032] Preferably, the method according to the invention further comprises the following steps: (ii) separating the crude product into a first portion comprising at least 1,3-butadiene, a second portion comprising acetaldehyde, and a third portion comprising ethanol, and preferably recycling at least a portion of the second portion, the third portion, or both the second and third portions into the feedstock.

[0033] According to a preferred embodiment of the process according to the invention, the contacting in (i) is carried out in a continuous flow of the feedstock in a reactor as defined herein. According to another preferred embodiment of the method according to the invention, the feedstock comprises at least 50% by weight of ethanol, preferably 60-75% by weight of ethanol, based on the total weight of the feedstock.

[0034] According to another preferred embodiment of the process according to the invention, the feedstock comprises at least 15% by weight of acetaldehyde, preferably 20-35% by weight of acetaldehyde, based on the total weight of the feedstock.

[0035] According to another preferred embodiment of the method according to the present invention, the molar ratio of ethanol to acetaldehyde in the raw material is in the range of 1 to 7, preferably 1.5 to 5, more preferably 1.7 to 4, and most preferably 2.0 to 3.0.

[0036] In a sixth aspect, the present invention relates to a method for preparing a supported catalyst according to the invention, comprising or consisting of the following steps: (i) forming a supported tantalum catalyst precursor by impregnating a support with a solution of a tantalum precursor at aluminum and sodium levels based on the weight of the catalyst support as defined by the following formula: The lower limit is the carrier [M] LL =Catalyst [M] LL / (1-catalyst [Ta2O5] wt%), M = Na or Al, catalyst [Na] LL =300ppm, catalyst [Al] LL = 50 ppm; and The upper limit is the carrier [M] UL =Catalyst [M] UL / (1-catalyst [Ta2O5] wt%), M = Na or Al, catalyst [Na] UL = 500 ppm, catalyst [Al] UL = 350 ppm; (ii) drying the supported tantalum catalyst precursor; and (iii) calcining the dried supported tantalum catalyst precursor to form a supported tantalum catalyst.

[0037] In the above formula, the carrier [M] LL denotes the lower limit of the concentration (wt / wt) of metal M (M being sodium or aluminum, respectively) in the support used and impregnated in step (i), which depends on:

[0038] a. Catalyst [M], which is the lower limit of the concentration (wt / wt) of metal M (M is sodium or aluminum, respectively) in the supported catalyst according to the present invention finally obtained in step (iii). LL , and b. Catalyst [Ta2O5] wt% is the concentration of Ta2O5 (wt / wt) in the supported catalyst according to the present invention finally obtained in step (iii).

[0039] Similarly, in the above formula, the carrier [M] UL indicates the upper limit of the concentration (wt / wt) of metal M (M being sodium or aluminum, respectively) in the support used in step (i) and impregnated, which depends on:

[0040] a. The upper limit of the concentration (wt / wt) of the metal M (M is sodium or aluminum) in the supported catalyst according to the present invention finally obtained in step (iii), catalyst [M] UL , and b. Catalyst [Ta2O5] wt% is the concentration of Ta2O5 (wt / wt) in the supported catalyst according to the present invention finally obtained in step (iii).

[0041] A preferred embodiment of the sodium and aluminum content of the supported catalyst according to the first aspect of the present invention is the catalyst [M] according to the sixth aspect of the present invention. LLand catalyst [M] UL This corresponds to a preferred embodiment of the present invention.

[0042] In a preferred embodiment, the support impregnated in step (i) of the method according to the invention comprises one or more of ordered and non-ordered porous silica, other porous oxides preferably from ZrO2, TiO2, MgO, ZnO, NiO and CeO2, and mixtures thereof.

[0043] Preferably, the support impregnated in step (i) of the process according to the invention is a silica support, preferably an ordered or irregular porous silica support. According to a preferred embodiment of the method for producing a supported catalyst according to the invention, the supported catalyst is a silica supported catalyst, said method comprising or consisting of: (i) reacting an aqueous silicate solution, preferably a sodium silicate solution, with an acid to form a hydrosol; (ii) dispersing the hydrosol, preferably by spraying, more preferably by spraying into air to break it into droplets, and gelling to form hydrogel beads; (iii) one or more optional additional steps of (pre-)aging, acidification, washing and pH adjustment; a. Maturation of hydrogel beads at temperature T1; b. Acidification of aged hydrogel beads; c. Washing the acidified aged hydrogel beads with water, preferably deionized and acidified to a pH of 3-4; d. adjusting the pH of the washed hydrogel beads obtained in step (c) to a pH of preferably about 8 to 10; (iv) maturation of the hydrogel beads at a temperature T2, where T2>T1 (if applicable, e.g., if one of the optional steps in (iii) is used); (v) acidification of the matured hydrogel beads (obtained in step (iv)); (vi) washing the acidified matured hydrogel beads (obtained in step (v)) with water, preferably deionized and acidified to a pH of 3-4; (vii) optionally adjusting the pH of the washed hydrogel beads obtained in step (vi), preferably to a pH in the range of about 3 to 10, most preferably to a pH of about 9; (viii) drying the washed hydrogel beads obtained in step (vi) or (vii), preferably using an oven, to obtain a silica carrier; (ix) optionally sieving the silica support obtained in step (viii) (to collect a desired particle size fraction); (x) impregnating the silica support obtained in step (viii) or (ix) with a solution of a tantalum precursor to form a supported tantalum catalyst precursor, preferably the tantalum precursor is tantalum ethoxide, and most preferably the tantalum ethoxide precursor is stabilized with 2,4-pentanedione and / or dissolved in a suitable organic solvent such as isopropanol; (xi) drying the supported tantalum catalyst precursor, preferably by heating under atmospheric pressure or vacuum; (xii) The dried supported tantalum catalyst precursor is preferably calcined at a temperature of about 400 to 600° C. for about 2 to 5 hours to form a supported tantalum catalyst.

[0044] As used herein, a "supported tantalum catalyst precursor" refers to the intermediate product, for example, before calcination, whereas a "supported tantalum catalyst" is the product after calcination. Preferably, the temperature T1 in the method according to the invention is in the range of 20 to 50°C.

[0045] Preferably, the temperature T2 in the method according to the invention is in the range of 40 to 100°C. In a seventh aspect, the present invention relates to the use of a supported catalyst according to the present invention for producing 1,3-butadiene from a feedstock comprising ethanol and acetaldehyde, preferably for increasing the yield of 1,3-butadiene.

[0046] In an eighth aspect, the present invention relates to the use of aluminum in an amount ranging from 50 to 350 ppm, preferably from 75 to 350 ppm, more preferably from 100 to 350 ppm, more preferably from 100 to 300 ppm, more preferably from 100 to 275 ppm, and most preferably from 150 to 250 ppm, based on the total weight of the catalyst, in a supported catalyst for producing 1,3-butadiene from a feedstock comprising ethanol and acetaldehyde. Carriers, 300 to 500 ppm, preferably 350 to 500 ppm, more preferably 380 to 500 ppm, more preferably 380 to 450 ppm, and most preferably 380 to 410 ppm of sodium based on the total weight of the catalyst, and 0.1 to 10 wt. % of tantalum, calculated as Ta2O5, based on the total weight of the catalyst, preferably 2 to 4 wt. % It comprises or consists of:

[0047] In a ninth aspect, the present invention relates to the use of sodium in an amount ranging from 300 to 500 ppm, preferably 350 to 500 ppm, more preferably 380 to 500 ppm, more preferably 380 to 450 ppm, and most preferably 380 to 410 ppm based on the total weight of the catalyst in a supported catalyst for producing 1,3-butadiene from a feedstock comprising ethanol and acetaldehyde, wherein the catalyst comprises: Carriers, aluminum in an amount of 50 to 350 ppm, preferably 75 to 350 ppm, more preferably 100 to 350 ppm, more preferably 100 to 300 ppm, more preferably 100 to 275 ppm, and most preferably 150 to 250 ppm, based on the total weight of the catalyst, and 0.1 to 10 wt. % of tantalum, calculated as Ta2O5, based on the total weight of the catalyst, preferably 2 to 4 wt. % It comprises or consists of:

[0048] In a tenth aspect, the present invention relates to the use of sodium in an amount ranging from 300 to 500 ppm, preferably from 350 to 500 ppm, more preferably from 380 to 500 ppm, more preferably from 380 to 450 ppm, and most preferably from 380 to 410 ppm, and aluminum in an amount ranging from 50 to 350 ppm, preferably from 75 to 350 ppm, more preferably from 100 to 350 ppm, more preferably from 100 to 300 ppm, more preferably from 100 to 275 ppm, and most preferably from 150 to 250 ppm, respectively, based on the total weight of the catalyst, in a supported catalyst for producing 1,3-butadiene from a feedstock comprising ethanol and acetaldehyde, wherein the catalyst is Carriers, 0.1 to 10 wt. % of tantalum, calculated as Ta2O5, based on the total weight of the catalyst, preferably 2 to 4 wt. % It comprises or consists of:

[0049] Preferred embodiments of certain aspects of the present invention (see aspects 1 to 10 above) correspond to or can be derived from preferred embodiments of other aspects of the present invention (as defined above), respectively, insofar as this is technically meaningful. [Brief explanation of the drawings]

[0050] [Figure 1] 1 shows a flow chart illustrating the overall process used to manufacture a silica support according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0051] Working Example: 1. Preparation of Silica Support The following is a description of the overall process used to manufacture a silica support in accordance with one embodiment of the present disclosure. A flow chart illustrating the overall process used to manufacture a silica support in accordance with one embodiment of the present disclosure is shown in Figure 1. A more detailed description of the silica support and methods for its manufacture is provided in co-pending U.S. patent application Ser. No. 16 / 804,610, which is incorporated herein by reference.

[0052] In one embodiment, a dilute sodium silicate solution with a SiO:NaO weight ratio of 3.3 was first reacted with dilute sulfuric acid to form a hydrosol with the following composition: 12 wt% SiO and a 0.8 HSO:NaO molar ratio. The resulting hydrosol was basic. In one embodiment, the sodium silicate solution contained approximately 250 ppm aluminum based on the weight of SiO. In one embodiment, a high-purity silicate with a low aluminum content (less than 10 ppm based on the weight of SiO) was used to produce silica with a low aluminum content.

[0053] The hydrosol was then sprayed into the air, where it broke down into droplets and solidified into beads several millimeters in diameter. These were then collected in a solution such as water or a solution that buffered the pH of the bead / solution system to a basic pH of about 9 (e.g., aqueous solutions of ammonium sulfate, sodium bicarbonate, etc.). Higher aging temperatures and / or longer aging times resulted in a decrease in the surface area of ​​the silica. Typically, the surface area of ​​the hydrogel collected in the ammonium sulfate solution was about 300 m. 2 To achieve a saturation of 0.01g / g, aging is carried out at 70°C and a pH of about 9 for about 16 hours.

[0054] Acid was then added to lower the pH to approximately 2. The hydrogel beads were then washed with water acidified to a pH of approximately 3 to reduce the sodium level. After aging and washing, the hydrogel beads contained approximately 15-18% SiO2. After washing, the pH of the beads was increased to approximately 9 using ammonium hydroxide solution. The beads were then dried using an oven. Finally, the beads were sieved to obtain the desired particle size fraction. Note that adjusting the pH before drying is optional; beads are typically dried at a pH of 3-9.

[0055] In one embodiment, the described method can be optionally modified to include multiple aging steps at increasing temperatures, each followed by an acidification and washing step to achieve the desired combination of surface area and sodium level. In one embodiment, washing can optionally occur before the aging step.

[0056] Following the above procedure will result in a surface area of ​​approximately 230-300 m 2 / g, pore volume is approximately 0.95 to 1.05 cm 3 / g, silica gel beads with less than 500 ppm aluminum (depending on the purity of the silicate and / or the methods and conditions used to carry out the washing and aging steps) and less than 1000 ppm sodium (depending on the extent of washing in combination with multiple aging steps) are obtained. In some cases, the aluminum and / or sodium were adjusted to the desired levels by contacting silica hydrogels containing small amounts of aluminum and / or sodium (dry basis) with solutions of aluminum sulfate and / or sodium carbonate, respectively, before drying.

[0057] 2. Catalyst Preparation In each case, silica gel beads, 2-5 mm in size, were pre-dried prior to use to a loss on drying (LCD) of less than 0.5 wt. % as measured at 120°C. The following is a general description of the catalyst preparation based on the use of 100 g of silica support on a dry basis. In general, the addition of the tantalum precursor to the silica was accomplished by the incipient wetness impregnation method.

[0058] A stabilized tantalum precursor solution was prepared by mixing approximately 5-6 g of tantalum precursor (e.g., 5.7 g of tantalum ethoxide) and 2-3 g (e.g., 2.8 g) of 2,4-pentanedione (acetylacetone) per 100 g of silica gel support (dry basis). In total, 8.5 g of the stabilized tantalum precursor solution was dissolved in 65-76 g of isopropanol and added to the pre-dried silica gel beads. The amount of isopropanol was adjusted based on the pore volume of the support so that the solution was contained only within the silica pores and no free solution was present outside the pores. Impregnation took approximately 15-40 minutes. The impregnated silica gel was kept in a sealed container for at least 1 hour and then heated under atmospheric pressure or vacuum to evaporate the solvent. The dried material was calcined in air to 550 °C for 4 hours to yield the finished catalyst containing approximately 3.0 wt. % Ta2O5. In one embodiment, Catalyst A was produced using this manufacturing method.

[0059] Preparation of catalyst B: Prior to use, 2-5 mm silica gel beads were pre-dried to a loss on drying (LOD) of less than 0.5 wt.% measured at 120 °C. A stabilized tantalum precursor solution was prepared by mixing 5.7 g of tantalum ethoxide and 2.8 g of 2,4-pentanedione (acetylacetone) with 100 g (dry basis) of silica gel support. 8.5 g of the stabilized tantalum precursor solution was dissolved in 73 g of isopropanol and added to the pre-dried silica gel beads. Impregnation took approximately 15-40 min. The impregnated silica gel was kept in a sealed container for at least 1 h before being heated at atmospheric pressure to evaporate the solvent. The dried material was calcined in air to 550 °C for 4 h to yield the finished catalyst containing 2.9 wt.% Ta2O5, 372 ppm Na, and 8 ppm Al.

[0060] Since Na and Al are substantially absent from Ta-ethoxide, acetylacetone, and isopropanol, they can be considered to be present in the support. The amounts of Na or Al in the support and catalyst are related by the following equation: Support [M] = catalyst [M] / (1 - catalyst [Ta2O5] wt%), M = Na or Al From this, the Na and Al contents in the support are calculated to be 383 ppm and 8.2 ppm, respectively.

[0061] Preparation of catalyst C: Prior to use, 2-5 mm silica gel beads were pre-dried to a loss on drying (LOD) of less than 0.5 wt.% measured at 120 °C. A stabilized tantalum precursor solution was prepared by mixing 5.7 g of tantalum ethoxide and 2.8 g of 2,4-pentanedione (acetylacetone) with 100 g of silica gel support (dry basis). 8.5 g of the stabilized tantalum precursor solution was dissolved in 70 g of isopropanol and added to the pre-dried silica gel beads. Impregnation took approximately 15-40 min. The impregnated silica gel was kept in a sealed container for at least 1 h before being heated at atmospheric pressure to evaporate the solvent. The dried material was calcined in air to 550 °C for 4 h to yield the finished catalyst containing 3.3 wt.% Ta2O5, 392 ppm Na, and 230 ppm Al.

[0062] Since Na and Al are substantially absent from Ta-ethoxide, acetylacetone, and isopropanol, they can be considered to be present in the support. The amounts of Na or Al in the support and catalyst are related by the following equation: Support [M] = catalyst [M] / (1 - catalyst [Ta2O5] wt%), M = Na or Al From this, the Na and Al contents in the support are calculated to be 405 ppm and 238 ppm, respectively.

[0063] [Table 1]

[0064] 3. Analytical methods for sodium and aluminum The sodium and aluminum levels in the catalyst compositions were measured by atomic absorption spectroscopy (AA) using a Perkin-Elmer PinAAcle™ 900F spectrometer and inductively coupled plasma ("ICP") spectroscopy using a Perkin-Elmer Optima 8300 ICP-OES spectrometer, respectively. Catalyst samples were digested with hydrofluoric acid (HF). The resulting silicon tetrafluoride (SiF4) was removed by fumigation, and the residue was analyzed for sodium and aluminum. Sodium and aluminum levels are reported as ppm relative to the catalyst after drying at 120°C. If desired, the sodium and aluminum amounts of the support and tantalum starting material, respectively, can be determined.

[0065] 4. Tantalum Analysis Method The levels of tantalum in the catalyst compositions were measured by inductively coupled plasma ("ICP") spectroscopy using a Perkin Elmer Optima 8300 ICP-OES spectrometer. Catalyst samples were digested with hydrofluoric acid (HF). The resulting silicon tetrafluoride (SiF4) was removed by fumigation, and the residue was analyzed for tantalum. Results are reported based on the dry weight of the catalyst calcined at 500-550°C.

[0066] 5. Catalytic Activity Test 40 g of the catalyst synthesized according to the above procedure was placed in a stainless steel reactor operated in continuous flow mode. The reactor was initially heated to 350 °C with a nitrogen flow rate of 500 ml / min. (Nitrogen was used only when heating the reactor; the reaction was carried out without nitrogen flow and using only the specified organic feedstock.) Next, a 94 wt% aqueous ethanol solution mixed with acetaldehyde in a mass ratio of 2.5:1 was used as the feedstock (the mass ratio of 2.5 in the 94 wt% aqueous ethanol solution relates to the total weight of water and ethanol), and the weight hourly space velocity (WHSV) was set to 5.0 h. -1 The reaction was carried out at a pressure of 0.18 MPaG (1.8 barg). The composition of the effluent was monitored periodically by an on-line gas chromatograph equipped with a flame ionization detector coupled to a mass spectrometer (GC / MS).

[0067] The catalyst loses activity for the production of 1,3-butadiene during operation and requires regeneration. The catalyst regeneration was carried out in four stages after 110 hours (h) of time on stream (TOS) in a stainless steel reactor:

[0068] 1. Desorption and removal of organic vapors The organic vapor was heated to 350 °C in a nitrogen stream (gas hourly space velocity (GHSV) = 300 h -1 ) for 5 hours.

[0069] 2. Pre-burning of carbon deposits The deposits were then placed in a stream of air diluted with water vapor (GHSV = 300 h -1 The oxygen content in the regeneration mixture (air / steam) was gradually increased from 1% to 6% by volume so that the temperature in the reactor did not exceed 400°C.

[0070] 3. Burning of carbon deposits The temperature of the reactor was increased to 520°C. A stream of air diluted with nitrogen (GHSV = 300 h -1 The deposit was finally combusted for 20 hours at 1000 K. The oxygen content in the regeneration mixture (air / nitrogen) was 6% by volume.

[0071] 4. Cool Down The reactor was subjected to a nitrogen flow (GHSV = 300 h -1 ) and cooled to 350°C. The total conversion, selectivity, yield, and productivity were calculated as follows (EtOH = ethanol, AcH = acetaldehyde):

[0072]

number

[0073]

number

[0074]

number

[0075]

number

[0076] [Table 2]

[0077] The catalytic activity test results for Catalyst B (not according to the invention) in Table 2 show that increasing the sodium level increases the overall conversion compared to ultra-high purity Catalyst A (not according to the invention), but has a significant adverse effect on the selectivity to 1,3-butadiene. Thus, Catalyst B achieves both lower 1,3-butadiene yields and lower productivity compared to Catalyst A.

[0078] The catalytic activity testing results of Catalyst C (in accordance with the present invention) in Table 2 show that the concomitant increase in aluminum level surprisingly offsets the adverse effect of increasing sodium level. Catalytic activity testing of Catalyst C not only increased overall conversion, but also showed a small decrease in selectivity to 1,3-butadiene, and overall, the catalyst of the present invention advantageously achieved both improved 1,3-butadiene yield and productivity.

Claims

1. (i) a carrier, and (ii) Ta based on the total weight of the catalyst ２ O ５ 0.1 to 10% by weight of tantalum calculated as 1. A supported catalyst comprising: a supported catalyst comprising: a supported catalyst having a catalyst weight of from 50 to 350 ppm aluminum based on the total weight of the catalyst; and a supported catalyst weight of from 300 to 500 ppm sodium based on the total weight of the catalyst.

2. The support may be an ordered porous silica support or an irregular porous silica support, other than ZrO ２ , TiO ２ , MgO, ZnO, NiO, and CeO ２ 10. The supported catalyst of claim 1, comprising one or more of the porous oxide supports from

3. The supported catalyst has a thickness of 130 to 550 m ２ / g, preferably 190 to 280 m ２ 3. The supported catalyst of claim 1 or 2, having a BET specific surface area in the range of 1 / g.

4. 4. The supported catalyst of any one of claims 1 to 3, wherein the weight ratio of aluminium to sodium is in the range of 0.1 to 1.2, preferably 0.2 to 1.

0.

5. A catalytic reactor tube for the production of 1,3-butadiene comprising at least one packing of the supported catalyst of any one of claims 1 to 4 and one or more packings of an inert material.

6. A reactor for producing 1,3-butadiene, comprising one or more catalytic reaction tubes according to claim 5.

7. 10. A plant for producing 1,3-butadiene comprising one or more reactors according to claim 6 and means for regenerating the supported catalyst in said one or more reactors, comprising: Preferably, the plant also includes a pre-reactor for the production of acetaldehyde, which is equipped with one or more reactor tubes containing a supported or unsupported (bulk) catalyst comprising one or more of zinc, copper, silver, chromium, magnesium, and nickel.

8. (i) A raw material containing ethanol and acetaldehyde is contacted with the supported catalyst according to any one of claims 1 to 4 to obtain a crude product containing 1,3-butadiene. A method for producing 1,3-butadiene, comprising:

9. 9. The method of claim 8, wherein the contacting in (i) is carried out at a temperature in the range of 200 to 500°C, preferably 250 to 450°C, more preferably 300 to 400°C.

10. The contact in (i) is for 0.2 to 10 hours. －１ , preferably 1 to 7 hours －１ 10. The method according to claim 8 or 9, carried out at a weight hourly space velocity in the range of

11. 11. The method of any one of claims 8 to 10, wherein the contacting in (i) is carried out at a pressure in the range of 0 to 1 MPaG (0 to 10 barg), preferably 0.1 to 0.3 MPaG (1 to 3 barg).

12. (ii) separating the crude product into a first portion comprising at least 1,3-butadiene, a second portion comprising acetaldehyde, and a third portion comprising ethanol; The method according to any one of claims 8 to 11, wherein preferably at least part of the second part, the third part, or both the second part and the third part is recycled into said feedstock.

13. The method of any one of claims 8 to 12, wherein the contacting of (i) is carried out in a continuous flow of the feedstock in the reactor of claim 6.

14. A method for producing a supported catalyst according to any one of claims 1 to 4, comprising the following steps: (i) forming a supported tantalum catalyst precursor by impregnating a support with a solution of a tantalum precursor at aluminum and sodium levels based on the weight of the catalyst support as defined by the following formula: The lower limit is the carrier [M] ＬＬ =Catalyst [M] ＬＬ / (1-catalyst [Ta ２ O ５ ]% by weight, M=Na or Al, catalyst [Na] ＬＬ =300ppm, catalyst [Al] ＬＬ = 50 ppm; and The upper limit is the carrier [M] ＵＬ =Catalyst [M] ＵＬ / (1-catalyst [Ta ２ O ５ ]% by weight, M=Na or Al, catalyst [Na] ＵＬ = 500 ppm, catalyst [Al] ＵＬ = 350 ppm; (ii) drying the supported tantalum catalyst precursor; and (iii) calcining the dried supported tantalum catalyst precursor to form a supported tantalum catalyst. A method comprising or consisting of the steps of:

15. 15. The method of claim 14, wherein the supported catalyst is a silica supported catalyst, and the method comprises or consists of: (i) reacting an aqueous silicate solution, preferably a sodium silicate solution, with an acid to form a hydrosol; (ii) dispersing and gelling the hydrosol to form hydrogel beads; (iii) one or more optional additional steps of (pre-)aging, acidification, washing and pH adjustment; a. Maturation of hydrogel beads at temperature T1; b. Acidification of aged hydrogel beads; c. Washing the acidified aged hydrogel beads with water, preferably deionized and acidified to a pH of 3-4; d. adjusting the pH of the washed hydrogel beads obtained in step (c), preferably to a pH of about 8-10; (iv) aging of the hydrogel beads at a temperature T2, where T2 > T1; (v) acidification of the aged hydrogel beads; (vi) washing the acidified aged hydrogel beads with water, preferably deionized and acidified to a pH of 3-4; (vii) optionally adjusting the pH of the washed hydrogel beads obtained in step (vi); (viii) drying the washed hydrogel beads obtained in step (vi) or (vii) to obtain a silica carrier; (ix) optionally sieving the silica support obtained in step (viii); (x) impregnating the silica support obtained in step (viii) or (ix) with a solution of a tantalum precursor to form a supported tantalum catalyst precursor; (xi) drying the supported tantalum catalyst precursor; and (xii) Calcining the dried supported tantalum catalyst precursor to form a supported tantalum catalyst.

16. Use of the supported catalyst according to any one of claims 1 to 4 for producing 1,3-butadiene from a feedstock comprising ethanol and acetaldehyde, preferably for increasing the yield of 1,3-butadiene.

17. 1. The use of aluminum in an amount ranging from 50 to 350 ppm based on the total weight of the catalyst in a supported catalyst for producing 1,3-butadiene from a feedstock comprising ethanol and acetaldehyde, wherein the catalyst comprises: - a carrier, 300 to 500 ppm sodium based on the total weight of the catalyst, and Ta based on the total weight of the catalyst ２ O ５ 0.1 to 10% by weight of tantalum calculated as Including, use.

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