Catalyst based on support containing aluminum and sodium for high yield production of 1, 3-butadiene

Abstract

The present invention relates to a supported catalyst comprising a support and 0.1 to 10% by weight, based on the total weight of the catalyst, of tantalum, based on Ta2O5, and further comprising 50 to 350 ppm of aluminum and 300 to 500 ppm of sodium, based on the total weight of the catalyst. Furthermore, the present invention relates to a catalyst reaction tube for producing 1, 3-butadiene comprising at least one filler layer of the supported catalyst as defined herein; a reactor for producing 1, 3-butadiene, comprising one or more catalyst reaction tubes as defined herein; and a production facility for producing 1, 3-butadiene, comprising one or more reactors as defined herein. The invention also relates to a method for preparing 1, 3-butadiene as defined herein and a method for preparing the supported catalyst. Finally, the invention relates to the use of the supported catalyst as defined herein for the production of 1, 3-butadiene from a feed comprising ethanol and acetaldehyde, and to the use of 50 to 350 ppm of aluminum in a supported catalyst for the production of 1, 3-butadiene from a feed comprising ethanol and acetaldehyde for increasing the yield of 1, 3-butadiene.

Description

[0001] The present invention relates to a supported catalyst comprising a carrier and 0.1 to 10% by weight of tantalum calculated as Ta2O5 and based on the total weight of the catalyst, and the supported catalyst further comprises 50 to 350 ppm of aluminum and 300 to 500 ppm of sodium, based on the total weight of the catalyst. In addition, the present invention relates to a catalyst reaction tube for the production of 1,3-butadiene, comprising at least one filler of a supported catalyst as defined herein; to a reactor for the production of 1,3-butadiene, comprising one or more catalyst reaction tubes as defined herein; and to a production facility (plant) for the production of 1,3-butadiene, comprising one or more reactors as defined herein. The present invention also relates to a method for preparing 1,3-butadiene as defined herein and a method for preparing a supported catalyst as defined herein. Finally, the present invention relates to the use of a supported catalyst as defined herein for the production of 1,3-butadiene from a feed comprising ethanol and acetaldehyde, and to the use of aluminum in an amount of 50 to 350 ppm in a supported catalyst for the production of 1,3-butadiene from a feed comprising ethanol and acetaldehyde for increasing the yield of 1,3-butadiene.

[0002] 1,3-Butadiene is one of the most important raw materials in the synthetic rubber industry, where it is used as a monomer for the production of various synthetic polymers (e.g., polybutadiene rubber, acrylonitrile-butadiene-styrene polymer, styrene-butadiene rubber, nitrile rubber, and styrene-butadiene latex). For example, 1,3-butadiene is obtained as a by-product of the manufacture of ethylene in naphtha steam cracking and can be separated by extractive distillation (Chem. Soc. Rev., 2014, 43, 7917; Chem Sus Chem, 2013, 6, 1595; Chem. Central J., 2014, 8, 53).

[0003] The depletion of non-renewable fossil fuel-derived resources and environmental considerations have recently become a strong driving force for exploring renewable resources of 1,3-butadiene and its precursors. Among the wide range of renewable resources, biomass appears to have the greatest potential in the production of 1,3-butadiene. This strategy has two main advantages: independence from fossil fuels and reduction of CO2 emissions (ChemSusChem, 2013, 6, 1595).

[0004] The conversion of ethanol (eg obtainable from biomass) to 1,3-butadiene can be carried out in two ways reported in the literature: a one-step process (Lebedev process) and a two-step process (Ostromislensky process).

[0005] The one-step process (reported by Lebedev in the early 20th century) is carried out by converting ethanol directly into 1,3-butadiene using a multifunctional catalyst with acid-base properties adjusted (J. Gen. Chem., 1933, 3, 698; Chem. Ztg., 1936, 60, 313).

[0006] On the other hand, the so-called two-step process can be carried out by converting ethanol into acetaldehyde in the first step. The purpose of this first step is to feed this mixture of ethanol and acetaldehyde into the second step or reactor. In the second step, the mixture containing ethanol and acetaldehyde is converted into 1,3-butadiene by (on a tantalum catalyst supported on, for example, silica) (Catal. Today, 2016, 259, 446).

[0007] US 2018 / 0208522 A1 relates to a catalyst for converting a feed containing ethanol and acetaldehyde into 1,3-butadiene. The catalyst comprises at least elemental tantalum and at least one acid-washed mesoporous oxide matrix, the mesoporous oxide matrix comprising at least 90% by weight of silica before washing, and the mass of elemental tantalum is in the range of 0.1% to 30% of the mass of the mesoporous oxide matrix. The teaching of US 2018 / 0208522 A1 relies on the acid washing of the mesoporous oxide support to improve the selectivity of the catalyst to 1,3-butadiene and / or the productivity of the catalyst to 1,3-butene. At the end of the washing step and before impregnation of the active element, the catalyst contains sodium in an amount in the range of 0 to 500 ppm. The concentration of aluminum in the catalyst and the yield of 1,3-butadiene are not disclosed in US 2018 / 0208522 A1.

[0008] WO 2020 / 126920 A1 relates to a method for producing 1,3-butadiene from ethanol, comprising two reaction steps: step a) converting ethanol into acetaldehyde, and step b) converting into 1,3-butadiene. Step b) simultaneously performs the reaction step and the regeneration step in \((n+n / 2)\) fixed bed reactors (\(n=4\) or a multiple thereof), the method uses a catalyst, the regeneration step comprises four consecutive regeneration stages, and step b) also implements three regeneration cycles.

[0009] US 2018 / 200694 A1 relates to a mesoporous mixed oxide catalyst containing silicon and at least one metal M (the metal M is selected from elements of Group 4 and Group 5 of the periodic table and mixtures thereof), and the mass of the metal M accounts for 0.1%-20% of the mass of the mixed oxide.

[0010] WO 2022 / 165190 A1 relates to a method for preparing a supported tantalum oxide catalyst precursor or catalyst (with controllable tantalum distribution) and the resulting supported tantalum catalyst. In one embodiment, the method includes selecting a tantalum precursor with a suitable reactivity to react with the surface hydroxyl groups of a solid oxide support material to form a target tantalum distribution in the catalyst precursor or catalyst; in another embodiment, the method includes controlling the number of available surface hydroxyl groups on the support by a thermal method to achieve reaction with the tantalum precursor to achieve the target tantalum distribution.

[0011] Therefore, there has been a need to provide a catalyst for producing 1,3-butadiene which shows high activity and is capable of providing a high yield of 1,3-butadiene.

[0012] A supported catalyst comprising or consisting of (i) a carrier, and (ii) 0.1 to 10 wt.-%, preferably 2 to 4 wt.-%, tantalum, calculated as Ta2O5 and based on the total weight of the catalyst, wherein the supported catalyst further comprises 50-350 ppm, preferably 75-350 ppm, more preferably 100-350 ppm, more preferably 100-300 ppm, more preferably 100-275 ppm, most preferably 150-250 ppm of aluminum, based on the total weight of the catalyst, and 300-500 ppm, preferably 350-500 ppm, more preferably 380-500 ppm, more preferably 380-450 ppm, most preferably 380-410 ppm of sodium, based on the total weight of the catalyst.

[0013] During the research process related to the present invention, it was found that increasing the sodium content in the catalyst increased the total conversion rate compared to an ultrapure catalyst containing 6 ppm aluminum and 31 ppm sodium (based on the total weight of the catalyst, respectively), however, this had a great negative impact on the selectivity of 1,3-butadiene. Therefore, if only the sodium content in the catalyst is increased, the obtained 1,3-butadiene yield and production efficiency will be reduced. However, surprisingly, it was found that increasing the aluminum content at the same time can offset the adverse effects of the increase in the sodium content in the catalyst. In the catalytic test of the catalyst of the present invention, not only the total conversion rate was improved, but also the selectivity loss to 1,3-butadiene was very small, so that the overall 1,3-butadiene yield and production efficiency were advantageously achieved (see Table 2 and the following examples).

[0014] The sodium and aluminum contents expressed herein in parts per million (ppm) relate to the total weight of the supported catalyst comprising tantalum in the form of tantalum oxide. The same applies to the tantalum contents expressed herein in % by weight.

[0015] In a preferred embodiment, the support of the supported catalyst according to the present invention comprises one or more of ordered and disordered porous silica supports, other porous oxide supports and mixtures thereof, preferably from ZrO2, TiO2, MgO, ZnO, NiO and CeO2.

[0016] Most preferably, the support of the supported catalyst according to the present invention is a silica support, preferably an ordered or disordered porous silica support.

[0017] Supported catalysts are particularly advantageous because they allow control over the concentration and dispersion of active sites, simple preparation of the catalysts by impregnation of supports of any form and shape, and easy access of all active sites of the catalyst to the reacting molecules.

[0018] Preferably, the supported catalyst according to the present invention has a 2 / g range, preferably between 190 and 280 m 2 / g range of BET specific surface area.

[0019] Preferably, the supported catalyst according to the present invention has a The average pore size in the range.

[0020] Preferably, the supported catalyst according to the present invention has a 3 / g range of pore volume.

[0021] 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). The sample was first degassed at 350°C for at least 4 hours on an Autosorb-6 degassing unit. Multi-point surface areas were calculated using BET theory using data points in the P / P0 range of 0.05 to 0.30. Pore volume measurements were recorded on the desorption leg at a P / P0 of 0.984. Assuming cylindrical pores, the average pore size was calculated using the following equation:

[0022] 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 0.1 to 1.2, preferably 0.2 to 1.0, more preferably 0.3 to 0.8, most preferably 0.4 to 0.7.

[0023] In a second aspect, the present invention relates to a catalyst reaction tube for producing 1,3-butadiene, comprising at least one supported catalyst packing layer (zone) according to the present invention and one or more inert material packing layers.

[0024] Preferably, the inert material is selected from silicon carbide, inert ceramic beds, ceramic beads, extrudates, rings with a diameter of 2-7 mm, stainless steel mesh, foams and mixtures thereof.

[0025] According to a preferred embodiment, the packing layer of inert material is in contact with and separated from the packing layer of supported catalyst according to the present invention (i.e., reaction zone) (if there is more than one supported catalyst packing layer in the catalyst reaction tube). They are preferably located at the reactant feed inlet and outlet of the reaction tube.

[0026] According to one embodiment, the catalyst reaction tube is loaded with a supported catalyst packing layer according to the present invention, preferably at the center of the catalyst reaction tube. The supported catalyst according to the present invention is in contact with an inert material packing layer on either side, i.e., the inert material packing layer is preferably located at the feed inlet and outlet of the catalyst reaction tube. According to this embodiment, the catalyst reaction tube comprises a reaction zone.

[0027] According to another embodiment, the catalyst reaction tube is alternatively loaded with multiple supported catalyst packing layers according to the present invention and multiple inert material packing layers. The inert material packing layer is preferably located at the feed inlet and outlet of the catalyst reaction tube and is in contact with the supported catalyst packing layer according to the present invention. According to this embodiment, the catalyst reaction tube includes more than one reaction zone.

[0028] In a third aspect, the present invention relates to a reactor for producing 1,3-butadiene, comprising one or more catalyst reaction tubes according to the present invention.

[0029] In a fourth aspect, the present invention relates to a production facility for the production of 1,3-butadiene, comprising one or more reactors as defined herein, and a device for regenerating a supported catalyst in the one or more reactors, preferably, wherein the production facility also comprises a pre-reactor for the production of acetaldehyde having one or more reaction tubes, the pre-reactor comprising a supported or unsupported (bulk) catalyst, the supported or unsupported (bulk) catalyst comprising one or more of zinc, copper, silver, chromium, magnesium and nickel, preferably comprising one or more of zinc and copper.

[0030] Tantalum oxide contained in the supported catalyst according to the present invention is inactive in the oxidation of ethanol to acetaldehyde. Therefore, in order to produce 1,3-butadiene with the supported catalyst according to the present invention, the feed stream must contain ethanol and acetaldehyde. This mixture of ethanol and acetaldehyde can be produced from ethanol, for example, in a pre-reactor for producing acetaldehyde containing a supported or non-supported (bulk type) catalyst as defined above in a production facility, 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 commercial sources 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 method for producing 1,3-butadiene, the method comprising: (i) contacting a feed comprising ethanol and acetaldehyde with a supported catalyst according to the present invention to obtain a crude product comprising 1,3-butadiene.

[0032] Preferably, in the process according to the invention, the contacting of (i) is carried out at a temperature of 200-500°C, preferably 250-450°C, more preferably 300-400°C.

[0033] In a preferred embodiment of the method according to the invention, the contacting of (i) is carried out for 0.2 to 10 h. -1 , preferably 1 to 7 hours -1 , more preferably 2 to 5 hours -1 The experiment was carried out at a weight space velocity of .

[0034] Preferably, the contacting of (i) is performed at a pressure in the range of 0 to 10 bar, preferably 1 to 3 bar, most preferably 1 to 2 bar.

[0035] Preferably, the method according to the present invention further comprises the following steps: (ii) separating the crude product into at least a first portion comprising 1,3-butadiene, a second portion comprising acetaldehyde and a third portion comprising ethanol, Preferably, at least a portion of the second portion, at least a portion of the third portion, or at least a portion of both the second portion and the third portion are recycled to the feed.

[0036] According to a preferred embodiment of the process of the invention, the contacting of (i) is carried out in a continuous flow of the feed in the reactor as defined herein.

[0037] According to another preferred embodiment of the process according to the invention, the feed comprises at least 50 wt. % ethanol, preferably 60 to 75 wt. % ethanol, based on the total weight of the feed.

[0038] According to another preferred embodiment of the process according to the invention, the feed comprises at least 15% by weight of acetaldehyde, preferably 20 to 35% by weight of acetaldehyde, based on the total weight of the feed.

[0039] According to another preferred embodiment of the process of the present invention, the molar ratio of ethanol to acetaldehyde in the feed is in the range of 1 to 7, preferably 1.5 to 5, more preferably 1.7 to 4, most preferably 2.0 to 3.0.

[0040] In a sixth aspect, the present invention relates to a method for producing a supported catalyst according to the present invention, the method comprising or consisting of the following steps: (i) impregnating a support having aluminum and sodium contents defined by the following formula based on the weight of the catalyst support with a tantalum precursor solution to form a supported tantalum catalyst precursor, where the lower limit is defined by: carrier [M] LL = Catalyst [M] LL / (1-catalyst [Ta2O5] weight %), where M = Na or Al; where catalyst [Na] LL =300ppm and catalyst [Al] LL =50ppm; and The upper limit is defined by: Carrier [M] UL = Catalyst [M] UL / (1-catalyst [Ta2O5] weight %), where M = Na or Al; where catalyst [Na] UL =500ppm and catalyst [Al] UL =350ppm; (ii) drying the supported tantalum catalyst precursor, and (iii) calcining the dried supported tantalum catalyst precursor to form a supported tantalum catalyst.

[0041] In the above formula, the carrier [M] LL represents the lower limit of the concentration (wt. / wt.) of the metal M (M is respectively sodium or aluminum) in the support to be used and impregnated in step (i), which depends on a. Catalyst [M] LL , i.e. the lower limit of the concentration (wt / wt.) of the metal M (M is respectively sodium or aluminum) in the supported catalyst according to the present invention finally obtained in step (iii), and b. Catalyst [Ta2O5] weight %, ie the concentration (wt. / wt.) of Ta2O5 in the supported catalyst according to the present invention finally obtained in step (iii).

[0042] Similarly, in the above formula, the carrier [M] UL represents the upper limit of the concentration (wt. / wt.) of the metal M (M is respectively sodium or aluminum) in the support to be used and impregnated in step (i), which depends on a. Catalyst [M] UL , the upper limit of the concentration (wt / wt.) of the metal M (M is respectively sodium or aluminum) in the supported catalyst according to the present invention finally obtained in step (iii), and b. Catalyst [Ta2O5] wt. %, concentration of Ta2O5 (wt. / wt.) in the supported catalyst according to the present invention finally obtained in step (iii).

[0043] Preferred embodiments of the sodium and aluminum contents of the supported catalyst according to the first aspect of the present invention correspond to those of the catalyst [M] according to the sixth aspect of the present invention. LL and catalyst [M] UL A preferred embodiment of the present invention.

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

[0045] Preferably, the support impregnated in step (i) of the process according to the invention is a silica support, preferably an ordered or disordered porous silica support.

[0046] 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 comprises or consists of: (i) reacting an aqueous silicate solution, preferably sodium silicate, with an acid to form a hydrosol, (ii) dispersing, preferably by spraying, more preferably by spraying into the air and breaking into droplets, and gelling the hydrosol to form hydrogel beads, (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. acidifying the aged hydrogel beads, c. washing the aged and acidified hydrogel beads, preferably with deionized water acidified to pH 3-4, d. adjusting the pH of the washed hydrogel beads obtained in step (c), preferably to a pH of about 8 to 10, (iv) aging 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) acidifying the aged hydrogel beads (obtained in step (iv), (vi) washing the aged and acidified hydrogel beads (obtained in step (v)), preferably with deionized water acidified to pH 3-4, (vii) adjusting the pH of the washed hydrogel beads obtained in step (c), preferably to a pH in the range of about 3 to about 10, most preferably to a pH of about 9, (viii) drying the washed hydrogel beads obtained in step (vi) or (vii), preferably by using an oven, to obtain a silica support, (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 tantalum precursor solution to form a supported tantalum catalyst precursor, preferably wherein the tantalum precursor is tantalum ethoxide, most preferably wherein the tantalum ethoxide precursor is stabilized with 2,4-pentanedione and / or dissolved in a suitable organic solvent (e.g. isopropanol), (xi) drying the supported tantalum catalyst precursor, preferably by heating under atmospheric pressure or vacuum, and (xii) calcining the dried supported tantalum catalyst precursor, preferably at a temperature of about 400-600° C. for about 2-5 hours, to form a supported tantalum catalyst.

[0047] As used herein, "supported tantalum catalyst precursor" refers to an intermediate product (eg, before calcination). In contrast, "supported tantalum catalyst" is the product after calcination.

[0048] Preferably, in the method according to the invention the temperature T1 is in the range of 20-50°C.

[0049] Preferably, in the method according to the invention the temperature T2 is in the range of 40-100°C.

[0050] 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 feed comprising ethanol and acetaldehyde, preferably for increasing the yield of 1,3-butadiene.

[0051] 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, 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 feed comprising ethanol and acetaldehyde for increasing the yield of 1,3-butadiene, the catalyst comprising or consisting of: - carrier, - 300 to 500 ppm, preferably 350 to 500 ppm, more preferably 380 to 500 ppm, more preferably 380 to 450 ppm, most preferably 380 to 410 ppm of aluminum, based on the total weight of the catalyst, and 0.1 to 10% by weight, preferably 2 to 4% by weight, of tantalum, calculated as Ta2O5 and based on the total weight of the catalyst.

[0052] In a ninth aspect, the present invention relates to the use of 300 to 500 ppm, preferably 350 to 500 ppm, more preferably 380 to 500 ppm, more preferably 380 to 450 ppm, most preferably 380 to 410 ppm of aluminum, based on the total weight of the catalyst, in a supported catalyst for producing 1,3-butadiene from a feed comprising ethanol and acetaldehyde to increase the yield of 1,3-butadiene, the catalyst comprising or consisting of: - a carrier, - 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, most preferably 150 to 250 ppm, based on the total weight of the catalyst, and 0.1 to 10% by weight, preferably 2 to 4% by weight, of tantalum, calculated as Ta2O5 and based on the total weight of the catalyst.

[0053] In a tenth 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, 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 feed comprising ethanol and acetaldehyde to increase the yield of 1,3-butadiene; and the use of aluminum in an amount ranging from 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, most preferably 150 to 250 ppm based on the total weight of the catalyst in a supported catalyst for producing 1,3-butadiene from a feed comprising ethanol and acetaldehyde to increase the yield of 1,3-butadiene. The catalyst comprises or consists of: - carrier, 0.1 to 10% by weight, preferably 2 to 4% by weight, of tantalum, calculated as Ta2O5 and based on the total weight of the catalyst.

[0054] The preferred embodiments of a certain aspect of the present invention (see the first to tenth aspects above) respectively correspond to or can be derived from the preferred embodiments of other aspects of the present invention (as defined above), as long as it is technically feasible. Example:

[0056] 1. Silica support preparation

[0057] The following describes the general steps for making a silica support according to one embodiment of the present disclosure. Figure 1 A flow chart showing the general steps used in making a silica support according to one embodiment of the present disclosure is shown in . A more detailed description of the silica support and methods of making it is found in co-pending US Patent Application No. 16 / 804,610, which is incorporated herein by reference.

[0058] In one embodiment, a dilute sodium silicate solution having a weight ratio of 3.3 SiO2:Na2O is first reacted with dilute sulfuric acid to form a hydrosol having the following composition: 12 wt% SiO2 and a H2SO4:Na2O molar ratio of 0.8. As a result, the resulting hydrosol is alkaline. In one embodiment, the sodium silicate solution contains about 250 ppm aluminum (based on the weight of SiO2). In one embodiment, a high purity silicate with low aluminum (based on the weight of SiO2, <10 ppm) is used to prepare silica with a lower aluminum content.

[0059] The hydrosol is then sprayed into the air where it breaks into droplets and solidifies into beads with a diameter of several millimeters, which are then captured in a solution, such as water or a solution buffering the pH of the bead / solution system at an alkaline pH of about 9 (e.g., aqueous solutions of ammonium sulfate, sodium bicarbonate, etc.). Higher aging temperatures and / or longer aging times reduce the silica surface area. Typically, for capture in ammonium sulfate solution to obtain about 300 m 2 For a hydrogel having a surface area of ​​1.25 g / g, aging was performed at 70° C. and a pH of about 9 for about 16 hours.

[0060] Acid is then added to lower the pH to about 2. The hydrogel beads are then washed with water acidified to about pH 3 to reduce the sodium level. The aged and washed hydrogel beads contain about 15-18% SiO2. Once washed, the pH of the beads is raised to about 9 using an ammonium hydroxide solution. The beads are then dried using an oven. Finally, the beads are sieved to obtain the desired particle size fraction. Note that pH adjustment prior to drying is optional and the beads are typically dried from pH 3-9.

[0061] In one embodiment, the described method can be modified to optionally include multiple aging steps at elevated temperatures, wherein each aging step is followed by an acidification and washing step to obtain the desired combination of surface area and sodium level. In one embodiment, washing can optionally be performed prior to the aging step.

[0062] Following the procedure outlined above, a surface area of ​​approximately 230-300m 2 / g, pore volume is about 0.95-1.05cm 3 / g, aluminum <500 ppm (depending on the silicate purity and / or the process and conditions used to carry out the washing and aging steps) and sodium <1000 ppm (depending on the extent of washing combined with multiple aging steps). In some cases, the silica hydrogel containing small amounts of aluminum and / or sodium (on a dry basis) is contacted with a solution of aluminum sulfate and / or sodium carbonate, respectively, and then dried to adjust the aluminum and / or sodium to the desired levels.

[0063] 2. Catalyst preparation

[0064] In all cases, silica gel beads 2-5 mm in size were pre-dried to a loss on drying (LOD) <0.5 wt % measured at 120°C prior to use. The following is a general description of the preparation of the catalyst based on the use of 100 g of silica support on a dry basis. Broadly speaking, the tantalum precursor was added to the silica via incipient wetness impregnation.

[0065] For every 100 g (dry basis) of silica gel support, a stabilized tantalum precursor solution is prepared by mixing approximately 5-6 g of tantalum precursor (e.g., 5.7 g of tantalum ethoxide) with 2-3 g (e.g., 2.8 g) of 2,4-pentanedione (acetylacetone). Typically, 8.5 g of the stabilized tantalum precursor solution is dissolved in 65-76 g of isopropanol and then added to the pre-dried silica gel beads. The amount of isopropanol is adjusted based on the support pore volume so that the solution is contained only in the silica pores and there is no free solution outside the pores. The impregnation takes approximately 15-40 minutes. The impregnated silica gel is kept in a sealed container for at least 1 hour and then the solvent is evaporated by heating at atmospheric pressure or vacuum. The dried material is then calcined in air to 550° C. for 4 hours to obtain a finished catalyst having approximately 3.0 wt % Ta2O5. In one embodiment, Catalyst A is prepared using this preparation method.

[0066] Preparation of Catalyst B:

[0067] Prior to use, silica gel beads of 2-5 mm in size were pre-dried to a loss on drying (LOD) <0.5 wt % measured at 120°C. For 100 g (dry basis) of silica gel support, a stabilized tantalum precursor solution was prepared by mixing 5.7 g of tantalum ethoxide with 2.8 g of 2,4-pentanedione (acetylacetone). 8.5 g of the stabilized tantalum precursor solution was dissolved in 73 g of isopropanol and then added to the pre-dried silica gel beads. Impregnation took approximately 15-40 minutes. The impregnated silica gel was kept in a sealed container for at least 1 hour and then the solvent was evaporated by heating at atmospheric pressure. The dried material was then calcined in air to 550°C for 4 hours to obtain a finished catalyst having 2.9 wt % Ta2O5, 372 ppm Na and 8 ppm Al.

[0068] It can be assumed that Na and Al are present in the support, since there are no substantial quantities of Na or Al in Ta-ethanol, acetylacetone or isopropanol. The amount of Na or Al in the support and catalyst is then related by the following formula: Support [M] = catalyst [M] / (1-catalyst [Ta2O5] weight %), where M = Na or Al

[0069] Therefore, the Na and Al in the support were calculated to be 383 ppm and 8.2 ppm, respectively.

[0070] Preparation of Catalyst C

[0071] Prior to use, silica gel beads with a particle size of 2-5 mm were pre-dried at 120°C until the loss on drying (LOD) was less than 0.5 wt.%. For 100 g (dry basis) of silica gel support, a stable tantalum precursor solution was prepared by mixing 5.7 g of tantalum ethoxide with 2.8 g of 2,4-pentanedione (acetylacetone). 8.5 g of this stable tantalum precursor solution was dissolved in 70 g of isopropanol and then added to the pre-dried silica gel beads. The impregnation process took approximately 15-40 minutes. The impregnated silica gel was placed in a sealed container for at least 1 hour before heating to evaporate the solvent at atmospheric pressure. Subsequently, the dried material was heated to 550°C in air and calcined for 4 hours to produce a finished catalyst containing 3.3 wt.% Ta2O5, 392 ppm of sodium (Na) and 230 ppm of aluminum (Al).

[0072] Since there is no significant amount of sodium or aluminum in tantalum ethoxide, acetylacetone or isopropanol, it can be assumed that the sodium and aluminum are present in the support. Then, the sodium or aluminum content in the support and catalyst can be related by the following formula: Support [M] = catalyst [M] / (1-catalyst [Ta2O5] weight %), where M = Na or Al.

[0073] Therefore, the sodium and aluminum contents in the support were calculated to be 405 ppm and 238 ppm, respectively.

[0074] Table 1: Data of Catalysts A, B and C

[0075] 3. Analytical methods for sodium and aluminum

[0076] The levels of sodium and aluminum in the catalyst composition were determined by atomic absorption spectroscopy (AA) using a Perkin-Elmer PinAAcleTM 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 smoked off and the residue was analyzed for sodium and aluminum. The sodium and aluminum contents are reported as parts per million of the catalyst after drying at 120°C. If desired, the amounts of sodium and aluminum of the support and tantalum starting material may be determined accordingly.

[0077] 4. Analytical Methods for Tantalum

[0078] The level of tantalum in the catalyst composition was measured by inductively coupled plasma ("ICP") spectroscopy using a Perkin Elmer Optima 8300 ICP-OES spectrometer. The catalyst samples were digested with hydrofluoric acid (HF). The resulting silicon tetrafluoride (SiF4) was smoked off and the residue was analyzed for tantalum. The results are reported based on the dry weight of the catalyst calcined at 500 to 550°C.

[0079] 5. Catalytic test

[0080] 40 g of the catalyst synthesized according to the above procedure was placed in each stainless steel reactor operated in continuous flow. The reactor was initially heated to 350°C under a nitrogen flow rate of 500 mL / min. (Nitrogen was used only when heating the reactor, and the reaction was carried out without nitrogen flow, but only with the specified organic feed.) Then, at 5.0 h -1 The reaction was carried out at a weight hourly space velocity (WHSV, weight space velocity) of 1.50 and a pressure of 1.8 bar, using a 94 wt.% aqueous ethanol solution mixed with acetaldehyde in a mass ratio of 2.5:1 as feed (the mass fraction of 2.5 of the 94 wt.% aqueous ethanol solution is related to the total weight of water and ethanol). The composition of the effluent was regularly monitored by an online gas chromatograph equipped with a flame ionization detector coupled to a mass spectrometer (GC / MS).

[0081] The catalyst loses its activity for producing 1,3-butadiene during operation and needs to be regenerated. The catalyst regeneration is carried out in situ in a stainless steel reactor after 110 hours (h) of run time (TOS) in the following four stages.

[0082] 1. Desorption and removal of organic vapors

[0083] The mixture was heated at 350 °C with a nitrogen stream (gas hourly space velocity (GHSV) = 300 h -1 ) was purged for 5 hours to remove organic vapors.

[0084] 2. Initial combustion of carbon deposits

[0085] The sediment is burned in a steam-diluted air stream (GHSV = 300 h -1 ) for 15 hours. 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.

[0086] 3. Combustion of carbon deposits

[0087] The temperature of the reactor was raised to 520° C. The deposits were finally combusted in a nitrogen-diluted air stream (GHSV=300 h -1) for 20 hours. The oxygen content in the regeneration mixture (air / nitrogen) was 6% by volume.

[0088] 4. Cooling

[0089] The reactor was cooled to 350°C (GHSV = 300 h -1 ).

[0090] The overall conversion, selectivity, yield and production efficiency were calculated as follows (EtOH - ethanol; AcH - acetaldehyde):

[0092] The catalytic test results of catalyst B (not the catalyst of the present invention) in Table 2 show that the increase in sodium content improves the overall conversion rate compared to ultrapure catalyst A (not the catalyst of the present invention), however, this has a great negative impact on the selectivity of 1,3-butadiene. Therefore, compared with catalyst A, the yield and production efficiency of 1,3-butadiene achieved by catalyst B are lower.

[0093] The catalytic test results of catalyst C (catalyst of the present invention) in Table 2 show that the increase in aluminum content surprisingly offsets the adverse effects of the increase in sodium content. In the catalytic test of catalyst C, not only the overall conversion rate is improved, but also the selectivity loss to 1,3-butadiene is very small. Therefore, in general, the use of the catalyst of the present invention is advantageous in achieving a double increase in 1,3-butadiene yield and production efficiency.

Claims

1. A supported catalyst comprising (i) a carrier, and (ii) 0.1 to 10% by weight of tantalum, calculated as Ta2O5 and based on the total weight of the catalyst, The supported catalyst further comprises 50-350 ppm of aluminum based on the total weight of the catalyst and 300-500 ppm of sodium based on the total weight of the catalyst.

2. The supported catalyst according to claim 1, wherein the support comprises one or more of ordered and disordered porous silica supports, other porous oxide supports and mixtures thereof, preferably selected from ZrO2, TiO2, MgO, ZnO, NiO and CeO2.

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

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

0.

5. A catalyst reaction tube for producing 1,3-butadiene, comprising at least one packing layer of a supported catalyst as defined in any one of claims 1 to 4 and one or more packing layers of an inert material.

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

7. A production facility for producing 1,3-butadiene, comprising one or more reactors as defined in claim 6, and means for regenerating the supported catalyst in the one or more reactors, Preferably, the production facility further comprises a pre-reactor for producing acetaldehyde having one or more reaction tubes, wherein the pre-reactor comprises a supported or unsupported (bulk) catalyst, wherein the supported or unsupported (bulk) catalyst comprises one or more of zinc, copper, silver, chromium, magnesium and nickel.

8. A method for producing 1,3-butadiene, the method comprising: (i) contacting a feed comprising ethanol and acetaldehyde with a supported catalyst as defined in any one of claims 1 to 4 to obtain a crude product comprising 1,3-butadiene.

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

10. The method according to claim 8 or 9, wherein the contacting of (i) is carried out for 0.2 to 10 hours. -1 , preferably 1 to 7 hours -1 The experiment was carried out at a weight spacespeed within a range of .

11. The method according to any one of claims 8 to 10, wherein the contacting of (i) is performed at a pressure in the range of 0 to 10 bar, preferably 1 to 3 bar.

12. The method according to any one of claims 8 to 11, further comprising (ii) separating the crude product into at least a first portion comprising 1,3-butadiene, a second portion comprising acetaldehyde and a third portion comprising ethanol, Preferably, at least a portion of the second portion, at least a portion of the third portion, or at least a portion of both the second portion and the third portion are recycled to the feed.

13. The process according to any one of claims 8 to 12, wherein the contacting of (i) is carried out in a reactor as defined in claim 6 in the form of a continuous flow of the feed.

14. A method for producing a supported catalyst as defined in any one of claims 1 to 4, comprising or consisting of the following steps: (i) impregnating a support having aluminum and sodium contents defined by the following formula based on the weight of the catalyst support with a tantalum precursor solution to form a supported tantalum catalyst precursor, where the lower limit is defined by: carrier [M] LL = Catalyst [M] LL / (1-catalyst [Ta2O5] weight %), where M = Na or Al; where catalyst [Na] LL =300ppm and catalyst [Al] LL =50ppm; and The upper limit is defined by: Carrier [M] UL = Catalyst [M] UL / (1-catalyst [Ta2O5] weight %), where M = Na or Al; where catalyst [Na] UL =500ppm and catalyst [Al] UL =350ppm; (ii) drying the supported tantalum catalyst precursor, and (iii) calcining the dried supported tantalum catalyst precursor to form a supported tantalum catalyst.

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: (i) reacting an aqueous silicate solution, preferably an aqueous 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. aging the hydrogel beads at temperature T1, b. acidifying the aged hydrogel beads, c. washing the aged and acidified hydrogel beads, preferably with deionized water acidified to pH 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 the hydrogel beads at a temperature T2, wherein T2>T1, (v) acidifying the aged hydrogel beads, (vi) washing the aged and acidified hydrogel beads, preferably with deionized water acidified to pH 3-4, (vii) optionally subjecting the washed hydrogel beads obtained in step (vi) to pH adjustment, (viii) drying the washed hydrogel beads obtained in step (vi) or (vii) to obtain a silica support, (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 a supported catalyst as defined in any one of claims 1 to 4 for producing 1,3-butadiene from a feed comprising ethanol and acetaldehyde, preferably for increasing the yield of 1,3-butadiene.

17. Use of aluminum in an amount in the range of 50-350 ppm based on the total weight of the catalyst for increasing the yield of 1,3-butadiene in a supported catalyst for producing 1,3-butadiene from a feed comprising ethanol and acetaldehyde, the catalyst comprising - carrier, - 300 to 500 ppm of sodium, based on the total weight of the catalyst, - 0.1 to 10% by weight of tantalum, calculated as Ta2O5 and based on the total weight of the catalyst.

Images