Highly active catalyst for the production of 1,3-butadiene

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 weight of the catalyst. The supported catalyst further comprises 5 to 60 ppm aluminum and 35 to 75 ppm sodium, 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 sodium in an amount in the range of 35 to 75 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 5 to 60 ppm aluminum and 35 to 75 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 sodium in an amount in the range of 35 to 75 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. [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] 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]

[0009] [Patent Document 1] US Patent Application Publication No. 2018 / 0208522 [Non-patent literature]

[0010] [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

[0011] In a first aspect, the present invention provides a method for producing a medicament for the treatment of a pulmonary arthritis, comprising: (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. % wherein the supported catalyst further comprises aluminum in the range of 5 to 60 ppm, preferably 5 to 40 ppm, more preferably 6 to 30 ppm, more preferably 7 to 20 ppm, based on the total weight of the catalyst, and sodium in the range of 35 to 75 ppm, preferably 40 to 60 ppm, more preferably 40 to 50 ppm, based on the total weight of the catalyst.

[0012] During the research underlying the present invention, it was found that a supported catalyst according to the present invention containing certain levels of sodium (and aluminum) impurities as defined in the first aspect above exhibits nearly identical selectivity to 1,3-butadiene as a catalyst prepared using an ultra-high purity silica support (e.g., a catalyst containing 6 ppm aluminum and 31 ppm sodium, respectively, based on the total weight of the catalyst). Furthermore, it was surprisingly found that the catalytic activity of the supported catalyst according to the present invention is higher than the catalytic activity of a catalyst prepared from an ultra-high purity silica support, advantageously resulting in a significantly higher yield of 1,3-butadiene (see Examples below, Table 2, and Figures 2 and 3).

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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).

[0017] 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:

[0018]

number

[0019] According to a preferred embodiment of the present invention, the weight ratio of aluminum to sodium in the supported catalyst ranges from 0.06 to 1.71, preferably from 0.10 to 1.0, and most preferably from 0.15 to 0.5.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] Preferably, the contact in (i) is carried out at a pressure in the range of 0 to 1 MPaG (0 to 10 barg), more preferably 0.1 to 0.3 MPaG (1 to 3 barg), and most preferably 0.1 to 0.2 MPaG (1 to 2 barg).

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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 =35ppm, catalyst [Al] LL = 5 ppm; and The upper limit is the carrier [M] UL =Catalyst [M] UL / (1-catalyst [Ta2O5] wt%), M = Na or Al, catalyst [Na] UL = 75 ppm, catalyst [Al] UL = 60 ppm; (ii) drying the supported tantalum catalyst precursor; and (iii) calcining the dried supported tantalum catalyst precursor to form a supported tantalum catalyst.

[0034] 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:

[0035] 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).

[0036] Similarly, in the above formula, the carrier [M] UL denotes the upper 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:

[0037] 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).

[0038] 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. LL and catalyst [M] UL This corresponds to a preferred embodiment of the present invention.

[0039] 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.

[0040] 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 preferably in the range of 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.

[0041] 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.

[0042] 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.

[0043] In an eighth aspect, the present invention relates to the use of sodium in an amount ranging from 35 to 75 ppm, preferably from 40 to 60 ppm, more preferably from 40 to 50 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, in order to increase the yield of 1,3-butadiene. Carriers, aluminum in an amount of 5 to 60 ppm, preferably 5 to 40 ppm, more preferably 6 to 30 ppm, and most preferably 7 to 20 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:

[0044] In a ninth aspect, the present invention relates to the use of aluminum in an amount ranging from 5 to 60 ppm, preferably from 5 to 40 ppm, more preferably from 6 to 30 ppm, and most preferably from 7 to 20 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, 35 to 75 ppm, preferably 40 to 60 ppm, more preferably 40 to 50 ppm 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:

[0045] In a tenth aspect, the present invention relates to the use of sodium in an amount ranging from 35 to 75 ppm, preferably from 40 to 60 ppm, and most preferably from 40 to 50 ppm, and aluminum in an amount ranging from 5 to 60 ppm, preferably from 5 to 40 ppm, more preferably from 6 to 30 ppm, and most preferably from 7 to 20 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 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:

[0046] 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]

[0047] [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. [Figure 2] A comparison of the activity and selectivity of virgin catalysts A, B, and C (Reg0) is shown. [Figure 3] A comparison of the activity and selectivity of catalysts A and B after the first regeneration step (Reg1) is shown. DETAILED DESCRIPTION OF THE INVENTION

[0048] 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.

[0049] 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, a high-purity silicate with a low aluminum content (less than 10 ppm by weight of SiO) was used to produce a low-aluminum silica.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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 support pore volume to ensure 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.

[0056] Preparation of catalyst B: Silica gel beads of 2-5 mm size were pre-dried to a loss on drying (LOD) of less than 0.5 wt % measured at 120°C before use.

[0057] A stabilized tantalum precursor solution was prepared by mixing 7.1 g of tantalum ethoxide and 3.5 g of 2,4-pentanedione (acetylacetone) with 125 g (dry basis) of silica gel support. 10.6 g of the stabilized tantalum precursor solution was dissolved in 95 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 and then 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 3.0 wt% Ta2O5, 41 ppm Na, and 7 ppm Al.

[0058] 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 42.3 ppm and 7.2 ppm, respectively.

[0059] 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.

[0060] 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.

[0061] [Table 1]

[0062] 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 with 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 2.3 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).

[0063] 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:

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 4. Cool Down The reactor was subjected to a nitrogen flow (GHSV = 300 h -1 ) and cooled to 350°C. The results were calculated as follows and are shown in Table 2 below (EtOH - ethanol; AcH - acetaldehyde):

[0068]

number

[0069]

number

[0070]

number

[0071] [Table 2]

[0072] FIG. 2 shows a comparison of the activity and selectivity of virgin catalysts A, B, and C (Reg0). FIG. 3 shows a comparison of the activity and selectivity of catalysts A and B after the first regeneration step (Reg1). Figure 2 (fresh catalyst), Figure 3 (catalyst after first regeneration), and Table 2 show that Catalyst B exhibits nearly the same selectivity to 1,3-butadiene as Catalyst A, which was produced using an ultra-high purity silica support. Furthermore, Catalyst B has the advantage of higher catalytic activity, resulting in a higher yield of 1,3-butadiene. In comparison, Catalyst C, which contains higher amounts of both sodium and aluminum impurities, exhibits inferior catalytic properties: lower selectivity to 1,3-butadiene and lower activity, resulting in a lower yield of 1,3-butadiene. Catalyst C also exhibits higher selectivity to undesirable C6+ products (= by-products containing six or more carbon atoms).

Claims

1. (i) carrier, and (ii) Based on the total weight of the catalyst, Ta ２ O ５ Calculated as 0.1 to 10% by weight of tantalum A supported catalyst comprising, further comprising 5 to 60 ppm of aluminum based on the total weight of the catalyst, and 35 to 75 ppm of sodium based on the total weight of the catalyst.

2. The carrier is a regularly porous silica carrier and a non-regular porous silica carrier, and other, preferably ZrO ２ , TiO ２ , MgO, ZnO, NiO, and CeO ２ The supported catalyst according to claim 1, comprising one or more porous oxide supports and mixtures thereof.

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

4. The supported catalyst according to claim 1 or 2, wherein the weight ratio of aluminum to sodium is in the range of 0.06 to 1.71, preferably 0.10 to 1.

0.

5. A catalyst reaction tube for producing 1,3-butadiene, comprising at least one packing material of the supported catalyst according to claim 1 or 2, and one or more packing materials of an inert material.

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

7. A plant for producing 1,3-butadiene, comprising one or more reactors as described in claim 6, and means for regenerating supported catalysts in the one or more reactors, Preferably, the plant also includes a pre-reactor for acetaldehyde production, comprising one or more reaction tubes containing a supported or unsupported (bulk) catalyst comprising one or more of zinc, copper, silver, chromium, magnesium, and nickel.

8. (i) A crude product containing 1,3-butadiene is obtained by contacting a raw material containing ethanol and acetaldehyde with the supported catalyst described in claim 1 or 2. A method for producing 1,3-butadiene, including the following:

9. The contact in (i) above is A temperature in the range of 200 to 500°C, preferably 250 to 450°C, more preferably 300 to 400°C. A gravitational space velocity in the range of 0.2 to 10 h⁻¹, preferably 1 to 7 h⁻¹, and Pressure in the range of 0 to 1 MPaG (0 to 10 barg), preferably 0.1 to 0.3 MPaG (1 to 3 barg) The method according to claim 8, wherein at least one of the following is performed.

10. (ii) The crude product is further separated into a first portion containing at least 1,3-butadiene, a second portion containing acetaldehyde, and a third portion containing ethanol. Preferably, the method according to claim 8, wherein at least a portion of the second portion, the third portion, or both the second and third portions is reused as the raw material.

11. The method according to claim 8, wherein the contact in (i) is carried out in a continuous flow of the raw materials in a reactor including one or more catalytic reaction tubes, each containing at least one packing of the supported catalyst and one or more packings of an inert material.

12. A method for producing a supported catalyst according to claim 1 or 2, comprising the following steps: (i) Form a supported tantalum catalyst precursor by impregnating the carrier with a solution of tantalum precursor at aluminum and sodium levels defined by the following formula based on the weight of the catalyst carrier. The lower limit is the carrier [M] ＬＬ = catalyst [M] ＬＬ / (1 - catalyst [Ta ２ O ５ wt%) and is defined as M = Na or Al, catalyst [Na] ＬＬ = 35 ppm, catalyst [Al] ＬＬ = 5 ppm; and The upper limit is the carrier [M] ＵＬ =Catalyst [M] ＵＬ / (1-Catalyst [Ta ２ O ５ Defined as % by weight, where M = Na or Al, catalyst [Na] ＵＬ = 75 ppm, catalyst [Al] ＵＬ = 60 ppm; (ii) Drying the supported tantalum catalyst precursor, and (iii) Forming a supported tantalum catalyst by calcining the dried supported tantalum catalyst precursor. A method comprising or consisting of the following steps.

13. The supported catalyst is a silica-supported catalyst, and the method for producing a supported catalyst according to claim 12 comprises or consists of the following: (i) Forming a hydrosol by reacting an aqueous silicate solution, preferably a sodium silicate solution, with an acid. (ii) Forming hydrogel beads by dispersing and gelling the hydrosol, (iii) (Preliminary) One or more optional additional steps of maturation, acidification, washing and pH adjustment, a. Maturation of hydrogel beads at temperature T1, b. Acidification of matured hydrogel beads, c. Washing of acidified matured hydrogel beads with water that has been deionized and acidified to pH 3-4. d. Adjust the pH of the washed hydrogel beads obtained in step (c) to a pH in the range of approximately 8 to 10. (iv) Maturation of hydrogel beads at temperature T2, where T2 > T1. (v) Acidification of matured hydrogel beads, (vi) Washing of acidified matured hydrogel beads with water that has been deionized and acidified to pH 3-4. (vii) Optionally, adjust the pH of the washed hydrogel beads obtained in step (vi). (viiii) A silica support is obtained by drying the washed hydrogel beads obtained in step (vi) or (vii). (ix) Optionally, the silica support obtained in step (viiii) is sieved. (x) A supported tantalum catalyst precursor is formed by impregnating the silica support obtained in step (viiii) or (ix) with a solution of the tantalum precursor. (xi) Dry the supported tantalum catalyst precursor, and (xi) A supported tantalum catalyst is formed by calcining the dried supported tantalum catalyst precursor.

14. Use of the supported catalyst according to claim 1 or 2 for producing 1,3-butadiene from raw materials containing ethanol and acetaldehyde, preferably for increasing the yield of 1,3-butadiene.

15. The use of sodium in a supported catalyst for producing 1,3-butadiene from raw materials containing ethanol and acetaldehyde, in an amount ranging from 35 to 75 ppm based on the total weight of the catalyst, wherein the catalyst is used to increase the yield of 1,3-butadiene. ・Carrier, - Based on the total weight of the catalyst, 5 to 60 ppm of aluminum, Based on the total weight of the catalyst, Ta ２ O ５ Calculated as 0.1 to 10% by weight of tantalum Includes, use.

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