Catalyst for producing 1,3-butadiene containing an aluminum-containing carrier having a high advantageous weight space velocity

Abstract

The present invention relates to a supported catalyst comprising a carrier and tantalum in an amount of 0.1 to 10% by weight calculated as Ta2O5 based on the total weight of the catalyst. The supported catalyst further comprises aluminum in an amount of 50 to 350 ppm and sodium in an amount of 1 to 50 ppm, respectively, based on the total weight of the catalyst. Furthermore, the present invention relates to a catalytic reaction tube for producing 1,3-butadiene comprising at least one filling of the supported catalyst defined herein, a reactor for producing 1,3-butadiene comprising one or more catalytic reaction 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 method for producing 1,3-butadiene defined herein and a method for producing the supported catalyst defined herein. Finally, the present invention relates to the use of the supported catalyst defined herein for producing 1,3-butadiene from a raw material containing ethanol and acetaldehyde, and to the use of an amount of aluminum in the range of 50 to 350 ppm in a supported catalyst for producing 1,3-butadiene from a raw material containing ethanol and acetaldehyde in order to enhance the 1,3-butadiene productivity of the catalyst.

Description

Technical Field

[0001] The present invention relates to a supported catalyst comprising a carrier and tantalum in an amount of 0.1 to 10% by weight calculated as Ta2O5 based on the total weight of the catalyst. The supported catalyst further comprises aluminum in an amount of 50 to 350 ppm and sodium in an amount of 1 to 50 ppm, respectively, based on the total weight of the catalyst. Further, the present invention relates to a catalytic reaction tube for producing 1,3-butadiene comprising at least one filling of the supported catalyst defined herein, a reactor for producing 1,3-butadiene comprising one or more catalytic reaction 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 method for producing 1,3-butadiene defined herein and a method for producing a supported catalyst defined herein. Finally, the present invention relates to the use of a supported catalyst defined herein for producing 1,3-butadiene from a raw material containing ethanol and acetaldehyde, and to a supported catalyst for producing 1,3-butadiene from a raw material containing ethanol and acetaldehyde, wherein an amount of aluminum in the range of 50 to 350 ppm is used to enhance the 1,3-butadiene productivity of the catalyst.

Background Art

[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 can be obtained, for example, as a by-product of ethylene production in naphtha steam cracking and can be separated by extractive distillation (Non-Patent Documents 1 to 3).

[0003] The depletion of non-renewable fossil fuel-derived resources and environmental considerations have recently become a powerful driving force for promoting the search for renewable resources of 1,3-butadiene and its precursors. Among the wide range of available renewable resources, biomass seems to hold the greatest potential in terms of being used for the production of 1,3-butadiene. This strategy has two main advantages: independence from fossil fuels and reduction of 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 methods: a one-step process (Lebedev process) and a two-step process (Ostromislensky process) reported in the literature.

[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 adjusted acid-base properties (Non-Patent Documents 4 and 5).

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

[0007] Patent Document 1 relates to a catalyst for converting a raw material containing ethanol and acetaldehyde into 1,3 - butadiene. The catalyst includes at least a tantalum element and at least one mesoporous oxide matrix that has undergone pickling and contains at least 90% by weight of silica before pickling. The mass of the tantalum element ranges from 0.1% to 30% of the mass of the mesoporous oxide matrix. The teaching of Patent Document 1 relies on the pickling of the mesoporous oxide support to enhance the selectivity of the catalyst to 1,3 - butadiene and / or the productivity of the catalyst to 1,3 - butadiene. At the end of the washing process and before the impregnation of the active element, the catalyst contains sodium in an amount in the range of 0 to 500 ppm. In Patent Document 1, the concentration of aluminum in the catalyst and the yield of 1,3 - butadiene are not disclosed.

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

[0009] Patent Document 3 relates to a mesoporous mixed - oxide catalyst containing 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, where the mass of metal M is 0.1 - 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 a supported tantalum catalyst obtained thereby. In one embodiment, the method includes selecting a tantalum precursor having appropriate reactivity with the surface hydroxyl groups of a solid oxide support material to provide a desired tantalum distribution in the catalyst precursor or catalyst. In another embodiment, the method includes achieving a desired tantalum distribution by controlling the number of available surface hydroxyls on a support material that reacts with a tantalum precursor by a thermal method such as calcination.

[0011] There is a continuing need to provide a catalyst for producing 1,3-butadiene that has both high selectivity to 1,3-butadiene and high 1,3-butadiene productivity.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Non-Patent Documents

[0013]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Non-Patent Document 5

[0014] In a first aspect, the present invention relates to (i) a carrier, and (ii) tantalum in an amount of 0.1 to 10% by weight, preferably 2 to 4% by weight, calculated as Ta2O5, based on the total weight of the catalyst, The supported catalyst contains or consists of these. The supported catalyst further contains aluminum in the range of 50 to 350 ppm, preferably 100 to 300 ppm, more preferably 150 to 275 ppm, most preferably 200 to 250 ppm, based on the total weight of the catalyst, and sodium in the range of 1 to 50 ppm, preferably 5 to 50 ppm, more preferably 10 to 40 ppm, most preferably 10 to 30 ppm, based on the total weight of the catalyst.

[0015] During the research underlying the present invention, in the synthesis of 1,3-butadiene, when both types of catalysts, the supported catalyst according to the present invention and a catalyst with a low aluminum content (less than 50 ppm), were tested under their respective preferred weight hourly space velocity (WHSV) conditions, it was found that the supported catalyst according to the present invention exhibited a lower total conversion rate compared to the catalyst with a low aluminum content (less than 50 ppm). However, surprisingly, it was found that the preferred WHSV conditions for the catalyst according to the present invention were at a significantly higher level compared to the catalyst with a low aluminum content. Therefore, the 1,3-butadiene productivity of the catalyst according to the present invention has the advantage of being significantly improved compared to the catalyst with a low aluminum content. Furthermore, advantageously, in the catalyst according to the present invention, the selectivity to 1,3-butadiene improves as the WHSV increases (see the following examples, Table 3 and Figures 2 to 4).

[0016] The preferred WHSV conditions referred to in this specification are first identified by the stable selectivity of the catalyst to 1,3-butadiene during a flow time (TOS) = 100 hours. Subsequently, with the preferred WHSV, the catalyst can reach the highest 1,3-butadiene productivity that meets the first requirement.

[0017] The levels of sodium and aluminum indicated in parts per million in this specification are related to the total weight of the supported catalyst containing tantalum as tantalum oxide. The same applies to the tantalum levels indicated in weight % in this specification.

[0018] In a preferred embodiment, the carrier of the supported catalyst according to the present invention includes one or more of a regular porous silica carrier and an irregular porous silica carrier, other porous oxide carriers, preferably from ZrO2, TiO2, MgO, ZnO, NiO, and CeO2, and mixtures thereof.

[0019] Most preferably, the carrier of the supported catalyst according to the present invention is a silica carrier, preferably a regular or irregular porous silica carrier. The supported catalyst can control the concentration and dispersion of active sites, is easy to prepare the catalyst by impregnation on carriers of any form and shape, and is particularly advantageous because reaction molecules can easily access all the active sites of the catalyst.

[0020] Preferably, the supported catalyst according to the present invention has a BET specific surface area in the range of 130 - 550 m 2 / g, preferably in the range of 190 - 280 m 2 / g. Preferably, the supported catalyst according to the present invention has an average pore diameter in the range of 3 - 30 nm (30 - 300 Å).

[0021] Preferably, the supported catalyst according to the present invention has a pore volume in the range of 0.2 - 1.5 cm 3 / g. The 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). First, the sample was degassed at 350 °C for at least 4 hours in an Autosorb-6 degassing device. The multi-point surface area was calculated using the BET theory with data points in the P / P0 range of 0.05 - 0.30. The measured value of the pore volume at P / P0 = 0.984 in the desorption range was recorded. Assuming cylindrical pores, the average pore diameter was calculated using the following formula.

[0022] [Number]

[0023] According to a preferred embodiment of the present invention, the weight ratio of aluminum to sodium in the supported catalyst is in the range of 1.0 - 350, preferably 1.2 - 70, more preferably 1.5 - 15.

[0024] Preferably, the weight ratio of aluminum to sodium in the supported catalyst according to the present invention is greater than 1, i.e., preferably, the supported catalyst contains more aluminum than sodium.

[0025] In a second aspect, the present invention relates to a catalytic reaction tube for the production of 1,3-butadiene comprising at least one filling of the supported catalyst according to the present invention and one or more fillings of an inert material. Preferably, the inert material is selected from the group consisting of silicon carbide, an inert ceramic bed, ceramic beads, extrudates, rings with a diameter of 2 - 7 mm, stainless steel mesh, foam, and mixtures thereof.

[0026] According to a preferred embodiment, the filling of the inert material contacts the filling of the supported catalyst according to the present invention, i.e., the reaction zone, and separates them from each other (when there are multiple fillings of the supported catalyst in the catalytic reaction tube). These are preferably arranged at the reactant supply inlet and outlet of the reaction tube.

[0027] According to one embodiment, one packing of the supported catalyst according to the present invention is preferably loaded into the catalytic reaction tube, preferably at the center of the catalytic reaction tube. The supported catalyst according to the present invention is in contact with packings of an inert material on both sides, that is, the packings of the inert material are preferably arranged at the supply inlet and the outlet of the catalytic reaction tube. According to this embodiment, the catalytic reaction tube includes one reaction zone.

[0028] According to another embodiment, the catalytic reaction tube is loaded alternately with packings of the supported catalyst according to the present invention and packings of an inert material. The packings of the inert material are preferably arranged at the supply inlet and the outlet of the catalytic reaction tube and are in contact with the packings of the supported catalyst according to the present invention. According to this embodiment, the catalytic reaction tube includes a plurality of reaction zones.

[0029] In a third aspect, the present invention relates to a reactor for producing 1,3-butadiene comprising one or more catalytic reaction tubes according to the present invention. In a fourth aspect, the present invention relates to a plant for producing 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 includes a pre-reactor for producing acetaldehyde comprising one or more reaction tubes with a supported or unsupported (bulk) catalyst containing one or more of zinc, copper, silver, chromium, magnesium, and nickel, preferably one or more of zinc and copper.

[0030] The tantalum oxide contained in the supported catalyst according to the present invention is inert to the oxidation of ethanol to acetaldehyde. Therefore, in order to produce 1,3-butadiene using the supported catalyst according to the present invention, the feed stream must not contain ethanol and acetaldehyde. This mixture of ethanol and acetaldehyde is produced, for example, in a pre-reactor for producing acetaldehyde in a plant containing the supported catalyst or unsupported (bulk) catalyst as defined above from ethanol, and then fed to a reactor for producing 1,3-butadiene containing one or more catalyst reaction tubes according to the present invention. Alternatively, ethanol and acetaldehyde can be obtained from a commercial source and fed directly to a reactor for producing 1,3-butadiene containing one or more catalyst reaction tubes according to the present invention.

[0031] In a fifth aspect, the present invention relates to a process for the production of 1,3-butadiene, said process comprising: (i) contacting a feedstock containing ethanol and acetaldehyde with the supported catalyst according to the present invention to obtain a crude product containing 1,3-butadiene.

[0032] Preferably, in the process 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 process according to the present invention, the contacting in (i) is carried out at a weight hourly space velocity in the range of 0.2 to 10 h -1 , preferably 1 to 7 h -1 , more preferably 2 to 6 h -1 , more preferably 3 to 6 h -1 , more preferably 4 to 6 h -1 , most preferably 4 to 5 h -1 .

[0033] 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), most preferably 0.1 to 0.2 MPaG (1 to 2 barg).

[0034] Preferably, the method according to the present invention further comprises the following steps: (ii) separating the crude product into a first portion containing at least 1,3-butadiene, a second portion containing acetaldehyde, and a third portion containing ethanol, and preferably at least a part of the second portion, the third portion, or both the second portion and the third portion is recycled to the raw material.

[0035] According to a preferred embodiment of the method according to the present invention, the contacting in (i) is carried out in a continuous flow of the raw material in a reactor as defined herein. According to another preferred embodiment of the method according to the present invention, the raw material contains at least 50% by weight of ethanol, preferably 60 - 75% by weight of ethanol, based on the total weight of the raw material.

[0036] According to another preferred embodiment of the method according to the present invention, the raw material contains at least 15% by weight of acetaldehyde, preferably 20 - 35% by weight of acetaldehyde, based on the total weight of the raw material.

[0037] 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 - 7, preferably 1.5 - 5, more preferably 1.7 - 4, and most preferably 2.0 - 3.0.

[0038] In a sixth aspect, the present invention relates to a method for producing a supported catalyst according to the present invention, comprising or consisting of the following steps: (i) forming a supported tantalum catalyst precursor by impregnating a carrier with a solution of a tantalum precursor at levels of aluminum and sodium 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 [Ta2O5] wt%) is defined, where M = Na or Al, catalyst [Na] LL = 1 ppm, catalyst [Al] LL = 50 ppm; and The upper limit is the carrier [M]UL = Catalyst [M] UL / (1 - wt% of Catalyst [Ta2O5]), where M = Na or Al, Catalyst [Na] UL = 50 ppm, Catalyst [Al] UL = 350 ppm; (ii) drying the supported tantalum catalyst precursor, and (iii) firing the dried supported tantalum catalyst precursor to form a supported tantalum catalyst.

[0039] In the above formula, Carrier [M] LL represents the lower limit value of the concentration (wt / wt) of metal M (where M is sodium or aluminum respectively) in the carrier used and impregnated in step (i), which depends on the following.

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

[0041] Similarly, in the above formula, Carrier [M] UL represents the upper limit value of the concentration (wt / wt) of metal M (where M is sodium or aluminum respectively) in the carrier used and impregnated in step (i), which depends on the following.

[0042] a. Catalyst [M], which is the upper limit value of the concentration (wt / wt) of metal M (where M is sodium or aluminum respectively) in the supported catalyst according to the present invention finally obtained in step (iii). UL and b. wt% of Catalyst [Ta2O5], which is the concentration (wt / wt) of Ta2O5 in the supported catalyst according to the present invention finally obtained in step (iii).

[0043] A preferred embodiment regarding the sodium and aluminum contents of the supported catalyst according to the first aspect of the present invention corresponds to the catalyst [M] according to the sixth aspect of the present invention LL and the catalyst [M] UL corresponds to the preferred embodiment regarding

[0044] In a preferred embodiment, the support impregnated in step (i) of the method according to the present invention comprises one or more of regular porous silica, irregular porous silica, other porous oxides preferably from ZrO2, TiO2, MgO, ZnO, NiO, and CeO2, and mixtures thereof.

[0045] Preferably, the support impregnated in step (i) of the method according to the present invention is a silica support, preferably a regular or irregular porous silica support. According to a preferred embodiment of the method for producing a supported catalyst according to the present invention, the supported catalyst is a silica-supported catalyst, and the method includes or consists of the following: (i) Reacting an aqueous silicate solution, preferably a sodium silicate solution, with an acid to form a hydrosol; (ii) Forming hydrogel beads from the hydrosol, preferably by dispersion by spraying, more preferably by spraying into air to decompose into droplets and gelation; (iii) One or more optional additional steps of (pre)-aging, acidification, washing, and pH adjustment; a. Aging of the hydrogel beads at temperature T1; b. Acidification of the aged hydrogel beads; c. Washing the acidified aged hydrogel beads, preferably with deionized water acidified to pH 3-4; d. Adjusting the pH of the washed hydrogel beads obtained in step (c) to a pH preferably in the range of about 8-10; (iv) Aging of the hydrogel beads at temperature T2, provided that T2>T1 (when applicable, for example, when one of the optional steps of (iii) is used); (v) Acidification of the aged hydrogel beads (obtained in step (iv)); (vi) Washing of the acidified aged hydrogel beads (obtained in step (v)) with preferably deionized water acidified to pH 3-4. (vii) Optionally, adjusting the pH of the washed hydrogel beads obtained in step (vi) to a pH preferably in the range of about 3-10, most preferably a pH of about 9. (viii) Obtaining a silica support by drying the washed hydrogel beads obtained in step (vi) or (vii), preferably using an oven. (ix) Optionally, sieving the silica support obtained in step (viii) (to collect the 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 in vacuo. (xii) Forming a supported tantalum catalyst by calcining the dried supported tantalum catalyst precursor at a temperature preferably in the range of about 400-600 °C for about 2-5 hours.

[0046] As used herein, "supported tantalum catalyst precursor" refers to, for example, an intermediate product before calcination. In contrast, "supported tantalum catalyst" is the product after calcination. Preferably, the temperature T1 in the method according to the present invention is in the range of 20-50 °C.

[0047] Preferably, the temperature T2 in the method according to the present invention is in the range of 40-100 °C. Preferred embodiments of specific aspects of the present invention (see aspects 1-10 above) correspond, or can be derived from, preferred embodiments of other aspects of the present invention (as defined above), insofar as technically meaningful.

[0048] 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 raw material containing ethanol and acetaldehyde, preferably for enhancing the 1,3-butadiene productivity.

[0049] In an eighth aspect, the present invention relates to the use of an amount of aluminum in the range of 50 to 350 ppm, preferably 100 to 300 ppm, more preferably 150 to 275 ppm, most preferably 200 to 250 ppm, based on the total weight of the catalyst, in a supported catalyst for producing 1,3-butadiene from a raw material containing ethanol and acetaldehyde. The catalyst is used to enhance the 1,3-butadiene productivity of the catalyst, · a carrier, · sodium in an amount of 1 to 50 ppm, preferably 5 to 50 ppm, more preferably 10 to 40 ppm, most preferably 10 to 30 ppm, based on the total weight of the catalyst, and · tantalum in an amount of 0.1 to 10% by weight, preferably 2 to 4% by weight, calculated as Ta2O5, based on the total weight of the catalyst comprises or consists of these.

[0050] In a ninth aspect, the present invention relates to the use of an amount of sodium in the range of 1 to 50 ppm, preferably 5 to 50 ppm, more preferably 10 to 40 ppm, most preferably 10 to 30 ppm, based on the total weight of the catalyst, in a supported catalyst for producing 1,3-butadiene from a raw material containing ethanol and acetaldehyde. The catalyst is used to enhance the 1,3-butadiene productivity of the catalyst, · a carrier, · aluminum in an amount of 50 to 350 ppm, preferably 100 to 300 ppm, more preferably 150 to 275 ppm, most preferably 200 to 250 ppm, based on the total weight of the catalyst, and · tantalum in an amount of 0.1 to 10% by weight, preferably 2 to 4% by weight, calculated as Ta2O5, based on the total weight of the catalyst comprises or consists of these.

[0051] In a tenth aspect, the present invention relates to the use of sodium in an amount in the range of 1 to 50 ppm, preferably 5 to 50 ppm, more preferably 10 to 40 ppm, and most preferably 10 to 30 ppm, and aluminum in an amount in the range of 50 to 350 ppm, preferably 100 to 300 ppm, more preferably 150 to 275 ppm, and most preferably 200 to 250 ppm, based on the total weight of the catalyst, in a supported catalyst for producing 1,3-butadiene from a raw material containing ethanol and acetaldehyde, wherein the catalyst is used to enhance the 1,3-butadiene productivity of the catalyst, · a carrier, · tantalum in an amount of 0.1 to 10% by weight, preferably 2 to 4% by weight, calculated as Ta2O5, based on the total weight of the catalyst and contains or consists of these.

Brief Description of the Drawings

[0052]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0053] Examples: 1. Preparation of Silica Carrier The following is an explanation of the overall process used to manufacture a silica support according to an embodiment of the present disclosure. A flowchart showing the overall process used to manufacture a silica support according to an embodiment of the present disclosure is shown in FIG. 1. A more detailed description of the silica support and its manufacturing method is described in co-pending U.S. Patent Application No. 16 / 804,610, which is incorporated herein by reference.

[0054] In one embodiment, a sodium silicate solution with a SiO2:Na2O weight ratio of 3.3 was first reacted with dilute sulfuric acid to form a hydrosol having the following composition: 12 wt% SiO2 and an H2SO4:Na2O molar ratio of 0.8. As a result, the obtained hydrosol was basic. In one embodiment, the sodium silicate solution contained about 250 ppm of aluminum on a SiO2 weight basis. In one embodiment, a high-purity silicate with a low aluminum content (less than 10 ppm on a SiO2 weight basis) was used to produce silica with a low aluminum content.

[0055] Next, when the hydrosol was sprayed into the air, the hydrosol decomposed there into droplets and solidified into beads having a diameter of several millimeters. This was recovered in a solution such as water, or a solution (such as an aqueous solution of ammonium sulfate, sodium bicarbonate, etc.) that buffers the pH of the bead / solution system to a basic pH of about 9. As the aging temperature increases and / or the aging time increases, the surface area of the silica decreases. Usually, to reach a surface area of about 300 m 2 / g for the hydrogel recovered in the ammonium sulfate solution, aging is carried out at 70 °C and a pH of about 9 for about 16 hours.

[0056] Next, an acid was added to lower the pH to about 2. Next, the hydrogel beads were washed with water acidified to pH about 3 to lower the sodium level. The hydrogel beads after aging and washing contained about 15 - 18% SiO2. After washing, the pH of the beads was raised to about 9 using an ammonium hydroxide solution. Then, the beads were dried using an oven. Finally, the beads were sieved to obtain the desired particle size fraction. It should be noted that the pH adjustment before drying is optional, and the beads are usually dried at pH 3 - 9.

[0057] In one embodiment, the described method can optionally be modified to include multiple aging steps while increasing the temperature, followed by acidification and washing steps after each aging step to obtain a desired combination of surface area and sodium level. In one embodiment, washing can optionally be performed before the aging step.

[0058] According to the above procedure, silica gel beads with a surface area of about 230 - 300 m 2 / g, a pore volume of about 0.95 - 1.05 cm 3 / g, less than 500 ppm of aluminum (varying depending on the purity of the silicate and / or the method and conditions used for performing the washing and aging steps), and less than 1000 ppm of sodium (varying depending on the degree of washing combined with multiple aging steps) can be obtained. In some cases, a silica hydrogel containing a small amount of aluminum and / or sodium (on a dry basis) was adjusted to the desired level of aluminum and / or sodium by contacting it with a solution of aluminum sulfate and / or sodium carbonate respectively before drying.

[0059] 2. Preparation of the Catalyst In any case, silica gel beads with a size of 2 - 5 mm were pre - dried at 120 °C until the loss on drying (LCD) measured before use was less than 0.5 wt%. The following is a general description of catalyst production based on the use of 100 g of silica support on a dry basis. Generally, the addition of the tantalum precursor to the silica was carried out by the incipient wetness impregnation method.

[0060] For 100 g of silica gel carrier (dry basis), about 5 - 6 g of tantalum precursor (for example, 5.7 g of tantalum ethoxide) and 2 - 3 g (for example, 2.8 g) of 2,4 - pentanedione (acetylacetone) were mixed to prepare a stabilized tantalum precursor solution. 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 carrier pore volume so that the solution was only contained within the silica pores and there was no free solution outside the pores. The impregnation took about 15 - 40 minutes. The impregnated silica gel was held 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 at 550 °C for 4 hours to obtain a finished catalyst containing about 3.0 wt% of Ta2O5. In one embodiment, Catalyst A was manufactured using this production method.

[0061] Preparation of Catalyst B: Silica gel beads with a size of 2 - 5 mm were pre - dried before use at 120 °C until the loss on drying (LOD) was less than 0.5 wt%. For 100 g (dry basis) of silica gel carrier, 5.7 g of tantalum ethoxide and 2.8 g of 2,4 - pentanedione (acetylacetone) were mixed to prepare a stabilized tantalum precursor solution. In total, 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. The impregnation took about 15 - 40 minutes. The impregnated silica gel was held in a sealed container for at least 1 hour and then heated under atmospheric pressure to evaporate the solvent. The dried material was calcined in air at 550 °C for 4 hours to obtain a finished catalyst containing 3.3 wt% of Ta2O5, 17 ppm of Na, and 225 ppm of Al.

[0062] Since Na and Al are substantially absent in Ta - ethoxide, acetylacetone, and isopropanol, Na and Al can be considered to be present in the carrier. The amounts of Na or Al in the carrier and the catalyst are related by the following formula: Support [M] = Catalyst [M] / (1 - wt% of Catalyst [Ta2O5]), M = Na or Al As a result, Na and Al in the support are calculated to be 17.6 ppm and 232 ppm, respectively.

[0063] Data on the catalyst synthesized according to the above procedure are summarized in Table 1 below.

[0064]

Table 1

[0065] 3. Analytical Method for Sodium and Aluminum The levels of sodium and aluminum in the catalyst composition were measured by atomic absorption spectrometry (AA) using a Perkin-Elmer PinAAcleTM 900F spectrometer and inductively coupled plasma (「ICP」) spectrometry using a Perkin Elmer Optima 8300 ICP-OES spectrometer, respectively. The catalyst sample was decomposed with hydrofluoric acid (HF). The resulting silicon tetrafluoride (SiF4) was removed by fumigation, and the residue was analyzed for sodium and aluminum. The levels of sodium and aluminum are reported as ppm relative to the catalyst after drying at 120 °C. If necessary, the amounts of sodium and aluminum in the support and tantalum starting materials can be determined, respectively.

[0066] 4. Analytical Method for Tantalum The level of tantalum in the catalyst composition was measured by inductively coupled plasma (「ICP」) spectrometry using a Perkin Elmer Optima 8300 ICP-OES spectrometer. The catalyst sample was decomposed with hydrofluoric acid (HF). The resulting silicon tetrafluoride (SiF4) was removed by fumigation, and the residue was analyzed for tantalum. The results are reported based on the dry weight of the catalyst calcined at 500 - 550 °C.

[0067] The physicochemical properties of the catalyst synthesized according to the above procedure are summarized in Table 2 below.

[0068]

Table 2

[0069] 5. Catalyst Activity Test 40 g of the catalyst synthesized according to the above procedure was placed in a stainless-steel reactor for continuous flow operation, respectively. The reactor was initially heated to 350 °C at a nitrogen flow rate of 500 ml / min. (Nitrogen was used only when heating the reactor, and the reaction was carried out without using the nitrogen flow and only with the specified organic raw materials.) Next, a mixture of 94 wt% aqueous ethanol solution and acetaldehyde with a mass ratio of 2.5:1 was used as the raw material (the mass fraction 2.5 of the 94 wt% aqueous ethanol solution is related to the total weight of water and ethanol), and the reaction was carried out at a pressure of 0.18 MPaG (1.8 barg) and a WHSV as shown below (for example, refer to Table 3). The composition of the effluent was periodically monitored by an on-line gas chromatograph (GC / MS) equipped with a flame ionization detector connected to a mass spectrometer.

[0070] The catalyst loses its activity for the production of 1,3-butadiene during operation and regeneration is required. The regeneration of the catalyst was carried out in the following four steps after 100 hours (h) of time on stream (TOS) in a stainless-steel reactor.

[0071] 1. Desorption and Removal of Organic Vapors The organic vapors were removed by purging with a nitrogen stream at 350 °C (gas hourly space velocity (GHSV) = 300 h -1 ) for 5 hours.

[0072] 2. Preliminary Combustion of Carbon Deposits The deposits were burned for 15 hours in an air stream diluted with steam (GHSV = 300 h -1 ). The oxygen content in the regeneration mixture (air / steam) was gradually increased from 1 vol% to 6 vol% so that the temperature in the reactor did not exceed 400 °C.

[0073] 3. Combustion of Carbon Deposits The temperature of the reactor was increased to 520 °C. The deposited material was finally combusted for 20 h with an air stream diluted with nitrogen (GHSV = 300 h -1 −1), and the oxygen content in the regeneration mixture (air / nitrogen) was 6 vol%.

[0074] 4. Cool-down The reactor was cooled to 350 °C in a nitrogen stream (GHSV = 300 h -1 −1). The overall conversion, selectivity, yield, and productivity were calculated as follows (EtOH = ethanol, AcH = acetaldehyde):

[0075]

Equation

[0076]

Equation

[0077]

Equation

[0078]

Equation

[0079] The average results of the catalytic activity tests of the unused (non-regenerated) catalyst are summarized in Table 3 below. When both catalysts, catalyst B according to the present invention and catalyst A, were tested under their respective preferred WHSV conditions, catalyst B according to the present invention showed a lower overall conversion compared to catalyst A (see the "WHSV" column in Table 3). However, it was found that the preferred WHSV conditions were at a significantly higher level compared to catalyst A. Therefore, the 1,3-butadiene productivity of catalyst B according to the present invention is surprisingly significantly improved compared to catalyst A (see also Figure 2. In Figure 2, for catalyst B, the WHSV ranges from 2 h -1 to 5 h -1It can be seen that as it increases, both the 1,3-butadiene productivity and the selectivity to 1,3-butadiene are improved).

[0080]

Table 3

[0081] Figure 3 further shows the influence of the impurity content of the unused catalyst over 100 hours of TOS. Again, catalyst B according to the present invention is compared with catalyst A in the above-described catalyst activity test. Catalyst A is tested at both a preferred WHSV of 2.3 h -1 ( * ) and a WHSV of 5 h -1 , and catalyst B is tested at a WHSV of 5 h -1 . As shown in Figure 3, for catalyst B at a WHSV of 5 h -1 , the selectivity to 1,3-butadiene is higher than that of catalyst A at both a WHSV of 2.3 h -1 and a WHSV of 5 h -1 . Furthermore, in catalyst B, the selectivity to heavy compounds (by-products containing 6 or more carbon atoms as by-products) as by-products is low, so the selectivity to 1,3-butadiene is more stable during the time on stream (TOS).

[0082] Figure 4 further shows the performance of catalysts A and B over 100 hours of TOS after 5 regeneration cycles each. Again, catalyst A is operated at a preferred WHSV of 2.3 h -1 ( * ), and catalyst B is operated at a preferred WHSV of 5 h -1 . As can be seen from Figure 4, the selectivity to 1,3-butadiene is higher for catalyst A in the first few hours, but gradually decreases with the time on stream (TOS). Although the selectivity of catalyst B to 1,3-butadiene is low at the start of this experiment, it advantageously stabilizes at the level reached by catalyst A and shows better stability and higher selectivity to 1,3-butadiene in the last 50 hours of the time on stream. Also, in catalyst B of the present invention, it is observed that the selectivity to heavy compounds (C6+) as by-products is low throughout the entire process of the experiment.

Claims

1. (i) A supported catalyst comprising a carrier and (ii) Based on the total weight of the catalyst, tantalum calculated as Ta ２ O ５ is 0.1 to 10% by weight of tantalum further comprising aluminum in the range of 50 to 350 ppm based on the total weight of the catalyst and sodium in the range of 1 to 50 ppm based on the total weight of the catalyst.

2. The carrier is a regular porous silica carrier and an irregular porous silica carrier, or other, preferably ZrO ２ , TiO ２ , MgO, ZnO, NiO, and CeO ２ The supported catalyst according to claim 1, comprising one or more of porous oxide carriers from and mixtures thereof.

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

4. The supported catalyst according to any one of Claims 1 to 3, wherein the weight ratio of aluminum to sodium is in the range of 1.0 to 350, preferably 1.2 to 70.

5. A catalytic reaction tube for producing 1,3-butadiene, comprising at least one packing of the supported catalyst according to 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 of the catalytic reaction tubes according to Claim 5.

7. A plant for producing 1,3-butadiene, comprising one or more of the reactors according to Claim 6 and means for regenerating the supported catalyst in the one or more reactors, preferably also comprising a pre-reactor for producing acetaldehyde, comprising one or more reaction tubes containing a supported or unsupported (bulk) catalyst containing one or more of zinc, copper, silver, chromium, magnesium, and nickel.

8. (i) Obtaining a crude product containing 1,3-butadiene by contacting a raw material containing ethanol and acetaldehyde with the supported catalyst according to any one of Claims 1 to 4 A method for producing 1,3-butadiene, comprising.

9. The method according to 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 carried out at a weight hourly space velocity in the range of 0.2 to 10 h －１ , preferably 1 to 7 h －１ , most preferably 4 to 5 h －１ The method according to claim 8 or 9, wherein the contact is carried out at a weight hourly space velocity in the range of

11. The method according to 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) Further comprising separating the crude product into a first part containing at least 1,3-butadiene, a second part containing acetaldehyde, and a third part containing ethanol, preferably, at least a part of the second part, the third part, or both the second part and the third part is reused as the raw material. The method according to any one of Claims 8 to 11.

13. The method according to any one of Claims 8 to 12, wherein the contacting in (i) is carried out in a continuous flow of the raw material in the reactor according to Claim 6.

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

15. The method for producing a supported catalyst according to claim 14, wherein the supported catalyst is a silica-supported catalyst, and the method comprises or consists of the following: (i) reacting an aqueous silicate solution, preferably a sodium silicate solution, with an acid to form a hydrosol; (ii) forming hydrogel beads by dispersion and gelation of the hydrosol; (iii) one or more optional additional steps of (pre)-aging, acidification, washing, and pH adjustment: a. aging the hydrogel beads at temperature T1; b. acidifying the aged hydrogel beads; c. washing the acidified aged hydrogel beads, preferably with deionized water acidified to pH 3-4; d. adjusting the pH of the washed hydrogel beads obtained in step (c) to a pH preferably in the range of about 8-10; (iv) aging the hydrogel beads at temperature T2, provided that T2 > T1; (v) acidifying the aged hydrogel beads; (vi) washing the acidified aged hydrogel beads, preferably with deionized water acidified to pH 3-4; (vii) optionally adjusting the pH of the washed hydrogel beads obtained in step (vi); (viii) obtaining a silica carrier by drying the washed hydrogel beads obtained in step (vi) or (vii), preferably at 2-4% by weight; (ix) optionally sieving the silica carrier obtained in step (viii); (x) impregnating the silica carrier 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) firing 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 raw material containing ethanol and acetaldehyde, preferably for enhancing the 1,3-butadiene productivity.

17. Use of an amount of aluminum in the range of 50 to 350 ppm based on the total weight of the catalyst in a supported catalyst for producing 1,3-butadiene from a raw material containing ethanol and acetaldehyde, wherein the catalyst is used for enhancing the 1,3-butadiene productivity of the catalyst, - a carrier, - sodium in an amount of 1 to 50 ppm based on the total weight of the catalyst, ・ Based on the total weight of the catalyst, Ta ２ O ５ calculated as tantalum is 0.1 to 10% by weight comprising.

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