Production method for alkenyl aromatic compound using dehydrogenation catalyst
Patent Information
- Application Number
- JP2025566233
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Priority Date
- 2023-12-25
- Filing Date
- 2024-10-07
- Publication Date
- 2025-07-03
Abstract
Description
Method for producing alkenyl aromatic compounds using a dehydrogenation catalyst
[0001] The present invention relates to a process for producing alkenylaromatic compounds from alkylaromatic compounds using a dehydrogenation catalyst.
[0002] The raw materials for synthetic rubber, ABS resin, and polystyrene include alkenyl aromatic compounds, particularly styrene monomer. Styrene monomer is conventionally produced by dehydrogenating ethylbenzene, an alkyl aromatic compound. The dehydrogenation reaction of alkyl aromatic compounds is an endothermic reaction accompanied by volume expansion. For example, the dehydrogenation reaction of ethylbenzene is shown in the following reaction formula (1). This reaction is generally carried out at high temperatures by contacting ethylbenzene gas with water vapor. C ６ H ５ C ２ H ５ →C ６ H ５ C ２ H ３ +H ２ -113kJ / mol (1)
[0003] Because the reaction produces two molecules from one, thermodynamic equilibrium can only occur at low pressures on the right side. Therefore, low pressure is desirable for this reaction. The reaction is endothermic, which means that high temperatures are required and coke formation occurs as a side reaction. To overcome this problem, water is added to the reaction. The high heat capacity of water aids in the energy transfer of the endothermic reaction and suppresses coke formation. Steam generation is expensive, and water pressure increases the overall pressure, which must be kept low to avoid adversely affecting the thermodynamic equilibrium of the reaction.
[0004] Therefore, there has been a trend in the industry over the last few years to reduce the amount of water, which is usually expressed as the weight ratio of water vapor to alkylaromatic compound (water / alkylaromatic compound ratio: W / A ratio).
[0005] Patent Document 1 (WO 2017 / 099161) discloses a dehydrogenation catalyst for alkyl aromatics, which contains sodium (Na), calcium (Ca), and yttrium (Y) in addition to a catalyst based on iron (Fe), potassium (K), and cerium (Ce). The dehydrogenation catalyst exhibits high activity at a low W / A weight ratio of 0.5 to 1.5. Patent Document 2 (WO 2022 / 128597) similarly discloses a dehydrogenation catalyst containing yttrium and having a gear-shaped cross section, which exhibits high activity even under conditions of a low W / A weight ratio.
[0006] WO2017 / 099161WO2022 / 128597
[0007] The above-mentioned conventional catalysts for dehydrogenating alkyl aromatic hydrocarbons have high activity even under conditions of a low W / A weight ratio, but they have the problem that they become brittle and wear with use, shortening the useful life of the catalyst.
[0008] An object of the present invention is to provide a catalyst for dehydrogenating alkylaromatic hydrocarbons that can be used for a long period of time with reduced wear even under conditions of a low W / A weight ratio, and a method for producing alkenylaromatic compounds using said catalyst.
[0009] The inventors have investigated the composition of the catalyst for dehydrogenation of alkyl aromatic hydrocarbons and have found that the catalyst becomes brittle due to the addition of alkali metals, particularly sodium, and that the wear rate associated with use of the catalyst can be sufficiently suppressed by removing calcium (Ca) from the catalyst and adjusting the contents of Ce and alkali metals.
[0010] That is, the method for producing an alkenyl aromatic compound of the present invention comprises a step of contacting an alkyl aromatic compound with steam in a reactor in the presence of a catalyst for dehydrogenation of the alkyl aromatic compound, wherein the weight ratio of the steam to the alkyl aromatic compound (water / alkyl aromatic compound ratio) is 0.4 to 1.5, and wherein the dehydrogenation catalyst is a catalyst containing Fe ２ O ３ 30 to 90% by weight of iron, K ２ 1 to 50% by weight of potassium, calculated as O, CeO ２1 to 50% by weight of cerium, calculated as ２ 0.1 to 15 wt. % sodium, calculated as 0, and no calcium, wherein said wt. % is based on the total weight of the dehydrogenation catalyst, and wherein the alkali metal oxide is K. ２ O and Na ２ Total amount of O and CeO ２ The weight ratio (alkali metal oxide / CeO ２ The ratio is 1.0 or more.
[0011] Another aspect of the present invention is Fe ２ O ３ 30 to 90% by weight of iron, K ２ 1 to 50% by weight of potassium, calculated as O, CeO ２ 1 to 50% by weight of cerium, calculated as ２ 0.1 to 15 wt. % sodium, calculated as 0, and no calcium, wherein said wt. % is based on the total weight of the dehydrogenation catalyst; and wherein the alkali metal oxide is K. ２ O and Na ２ Total amount of O and CeO ２ The weight ratio (alkali metal oxide / CeO ２ The dehydrogenation catalyst for alkyl aromatic compounds is characterized in that the ratio (R) is 1.0 or more.
[0012] Another aspect of the present invention is a method for producing the above-mentioned dehydrogenation catalyst, comprising: (i) mixing raw materials and water to obtain a mixture, wherein the raw materials contain an iron compound, a potassium compound, a cerium compound, and a sodium compound, but do not contain a calcium compound; (ii) molding the mixture to obtain a molded product; and (iii) calcining the molded product.
[0013] The method for producing an alkenylaromatic compound includes contacting an alkylaromatic compound with steam in a reactor in the presence of a catalyst for dehydrogenating the alkylaromatic compound.
[0014] The reactor may be a reactor containing a single catalyst bed, or may be a series of such reactors, in which, in one embodiment, the outlet of the first reactor is connected to the inlet of the second reactor, and so on.
[0015] In the above-described method for producing an alkenylaromatic compound, it is not necessary for all of the alkylaromatic compound in the feed to be converted to an alkenylaromatic compound, and at least a portion may be converted. When multiple reactors are used in series, the feed to the second reactor following the first reactor contains the alkenylaromatic compound produced in the first reactor and unreacted alkylaromatic compound. The feed to the second or subsequent reactors similarly contains the alkenylaromatic compound produced in the previous reactor and unreacted alkylaromatic compound. In one embodiment, the conversion of unreacted alkylaromatic compound is repeated through multiple consecutive reactors, and ultimately all of the alkylaromatic compound fed can be converted to an alkenylaromatic compound. In one embodiment, the alkylaromatic compound comprises ethylbenzene. In another embodiment, the alkylaromatic compound is ethylbenzene. In another embodiment, the alkenylaromatic compound comprises styrene. In another embodiment, the alkenylaromatic compound is styrene.
[0016] The weight ratio of the water vapor to the alkylaromatic compound as the hydrocarbon (water / alkylaromatic compound ratio: W / A ratio) is 0.40 to 1.50, in another embodiment 0.40 to 1.40, in another embodiment 0.40 to 1.30, in another embodiment 0.40 to 1.20, in another embodiment 0.41 to 1.40, in another embodiment 0.42 to 1.30, in another embodiment 0.43 to 1.25, in another embodiment 0.44 to 1.20, in another embodiment 0.45 to 1.15, in another embodiment 0.46 to 1.10, in another embodiment 0.47 to 1.10, and in another embodiment 0.48 to 1.05. , in another embodiment, 0.49 to 1.00, in another embodiment, 0.50 to 0.95, in another embodiment, 0.51 to 0.85, in another embodiment, 0.52 to 0.70, in another embodiment, 0.60 to 1.40, in another embodiment, 0.65 to 1.30, in another embodiment, 0.70 to 1.23, in another embodiment, 0.75 to 1.21, in another embodiment, 0.80 to 1.20, in another embodiment, 0.82 to 1.15, in another embodiment, 0.85 to 1.15, in another embodiment, 0.87 to 1.13, in another embodiment, 0.90 to 1.11, and in another embodiment, 0.95 to 1.10.
[0017] In one embodiment, the liquid hourly space velocity (LHSV) of the alkyl aromatic compound is 0.1 to 5 h －１ In another embodiment, 0.2 to 4.5 h －１ In another embodiment, 0.3 to 4.2 h －１ In another embodiment, 0.4 to 4.0 h －１ In another embodiment, 0.5 to 3.5 h －１ In another embodiment, 0.6 to 2.8 h －１ In another embodiment, 0.7 to 1.7 h －１ In another embodiment, 0.8 to 1.3 h －１ Here, LHSV refers to the ratio of the feed rate of the raw material liquid (liquid volume flow rate at 20°C) to the catalyst packed volume into the continuous reactor.
[0018] In one embodiment, the reactor includes an inlet and an outlet for supplying water and alkylaromatic compound, and the temperature at the inlet (inlet temperature) is 450 to 680°C in one embodiment, 520 to 665°C in another embodiment, 550 to 655°C in another embodiment, 580 to 640°C, or 600 to 630°C in another embodiment.
[0019] In one embodiment, the dehydrogenation reaction of the alkyl aromatic compound is an endothermic reaction as described above, and the temperature at the outlet of the reactor (outlet temperature) is lower than the inlet temperature. In one embodiment, the outlet temperature is 400 to 670°C, in another embodiment, 500 to 655°C, in another embodiment, 500 to 645°C, in another embodiment, 530 to 630°C, and in another embodiment, 550 to 620°C.
[0020] In another embodiment, in order to increase the efficiency of the dehydrogenation reaction of the alkyl aromatic compound, the reactor is maintained at an isothermal temperature regardless of the temperature drop caused by the reaction. When the reactor is maintained at an isothermal temperature in this manner, the outlet temperature of the reactor does not change significantly from the inlet temperature. In one embodiment, the outlet temperature is 400 to 680°C, in another embodiment, 450 to 675°C, in another embodiment, 490 to 670°C, in another embodiment, 510 to 665°C, in another embodiment, 540 to 655°C, in another embodiment, 560 to 650°C, in another embodiment, 570 to 640°C, in another embodiment, 580 to 630°C, in another embodiment, 590 to 635°C, and in another embodiment, 600 to 620°C.
[0021] "Inlet temperature" and "outlet temperature" mean the temperatures measured along the direction of feed flow within about 1 cm ahead of the inlet and 1 cm before the outlet, respectively.
[0022] In one embodiment, the absolute pressure in the reactor is 150 kPa or less, in another embodiment, 120 kPa or less, and in another embodiment, 110 kPa or less. In one embodiment, the pressure in the reactor is 1 kPa or more, in another embodiment, 10 kPa or more, in another embodiment, 30 kPa or more, in another embodiment, 40 kPa or more, in another embodiment, 50 kPa or more, in another embodiment, 70 kPa or more, and in another embodiment, 90 kPa or more. The absolute pressure in the reactor is, in another embodiment, 1 to 150 kPa, in another embodiment, 10 to 120 kPa, in another embodiment, 20 to 120 kPa, in another embodiment, 25 to 110 kPa, in another embodiment, 30 to 120 kPa, in another embodiment, 45 to 120 kPa, in another embodiment, 70 to 120 kPa, in another embodiment, 70 to 110 kPa, and in another embodiment, 90 to 110 kPa.
[0023] The dehydrogenation catalyst comprises Fe ２ O ３ 30 to 90% by weight of iron, K ２ 1 to 50% by weight of potassium, calculated as O, CeO ２ 1 to 50% by weight of cerium, calculated as ２ 0.1 to 15 wt. % sodium, calculated as 0.0, and no calcium, wherein said wt. % is based on the total weight of the dehydrogenation catalyst, wherein the alkali metal oxide is K. ２ O and Na ２ Total amount of O and CeO ２ The weight ratio (alkali metal oxide / CeO ２ The ratio is 1.0 or more.
[0024] The dehydrogenation catalyst contains iron (Fe) in the form of an iron compound, which in one embodiment may be iron oxide and / or a composite oxide of iron, where "composite oxide" refers to an oxide containing two or more non-oxygen atoms in the structure of the corresponding oxide.
[0025] Iron is based on the total weight of the dehydrogenation catalyst. ２ O ３In another embodiment, the total weight of the polymer is 30 to 90% by weight, in another embodiment, 40 to 85% by weight, in another embodiment, 45 to 80% by weight, in another embodiment, 50 to 81% by weight, in another embodiment, 65 to 75% by weight, and in another embodiment, 69 to 73% by weight, calculated as
[0026] The dehydrogenation catalyst contains potassium (K) in the form of a potassium compound. In one embodiment, the potassium compound is an oxide and / or a composite oxide of potassium. The potassium is present in an amount of K based on the total weight of the dehydrogenation catalyst. ２ In another embodiment, the content of PEG-100 is from 1 to 30% by weight, in another embodiment, from 8 to 26% by weight, in another embodiment, from 10 to 20% by weight, in another embodiment, from 11 to 18% by weight, and in another embodiment, from 13 to 16% by weight, calculated as O.
[0027] The dehydrogenation catalyst contains cerium (Ce) in the form of a cerium compound, which in one embodiment is an oxide and / or composite oxide of cerium. Cerium is present in an amount of CeO based on the total weight of the dehydrogenation catalyst. ２ In another embodiment, the total amount of the hydroxybenzoate is 3 to 30% by weight, in another embodiment, 5 to 26% by weight, in another embodiment, 7 to 25% by weight, in another embodiment, 7 to 24% by weight, in another embodiment, 7 to 22% by weight, in another embodiment, 8 to 20% by weight, in another embodiment, 8 to 19% by weight, in another embodiment, 9 to 18% by weight, in another embodiment, 9 to 17% by weight, in another embodiment, 10 to 16% by weight, and in another embodiment, 11 to 15% by weight.
[0028] The dehydrogenation catalyst contains sodium (Na) in the form of a sodium compound. In one embodiment, the sodium compound is an oxide and / or a composite oxide of sodium. The sodium is present in an amount of Na based on the total weight of the dehydrogenation catalyst. ２0 is 0.1 to 15 wt. %, in another embodiment 0.5 to 13 wt. %, in another embodiment 0.7 to 12 wt. %, in another embodiment 1.0 to 11.5 wt. %, in another embodiment 1.2 to 10.0 wt. %, in another embodiment 1.4 to 9.0 wt. %, in another embodiment 1.5 to 6.0 wt. %, in another embodiment 1.7 to 5.0 wt. %, in another embodiment 1.9 to 4.0 wt. %, and in another embodiment 1.5 to 3.0 wt. %, calculated as O.
[0029] In one embodiment, the weight ratio of potassium (K) and sodium (Na) contained in the dehydrogenation catalyst is K ２ O and Na ２ Calculate as O (K ２ O / Na ２ O ratio), 5-10, in another implementation variety, 5-9, in another implementation variety, 5-8, in another implementation variety, 6-9, in another implementation variety, 6-8, in another implementation variety, 7-9, in another implementation variety, 7-8.
[0030] In another embodiment, the dehydrogenation catalyst comprises yttrium (Y) in the form of an yttrium compound, which in one embodiment is an oxide and / or composite oxide of yttrium. In another embodiment, the yttrium is present in an amount of about 1000 to about 10 ... ２ O ３ In another embodiment, the yttrium in the catalyst is 0.01 to 1 wt. %, calculated as Y ２ O ３ In another embodiment, the total amount of the hydroxybenzoate is 0.05 to 0.9 wt. %, in another embodiment, 0.09 to 0.8 wt. %, in another embodiment, 0.11 to 0.7 wt. %, in another embodiment, 0.14 to 0.6 wt. %, in another embodiment, 0.17 to 0.5 wt. %, and in another embodiment, 0.25 to 0.4 wt. %, calculated as
[0031] The dehydrogenation catalyst does not contain calcium (Ca). Here, "free" means that the catalyst is substantially free of the component, and includes embodiments in which the target substance is present due to contamination. In one embodiment, calcium may be present in an amount of 0.1 wt. % or less, based on the total weight of the dehydrogenation catalyst, relative to the total weight of the composition. In one embodiment, calcium may be present in an amount of 0.01 wt. % or less, based on the total weight of the dehydrogenation catalyst, relative to the total weight of the composition.
[0032] The dehydrogenation catalyst contains, in its composition, an alkali metal oxide, K. ２ O and Na ２ Total amount of O and CeO ２ The weight ratio (alkali metal oxide / CeO ２ The weight ratio of the alkali metal oxide is 1.0 or more. ２ O and Na ２ Total amount of O and CeO ２In another embodiment, the weight ratio of is from 1.00 to 2.50, from 1.01 to 2.30, from 1.03 to 2.10, from 1.04 to 1.95, from 1.05 to 1.98, from 1.06 to 1.95, from 1.07 to 1.90, from 1.08 to 1.83, from 1.00 to 1.50, from 1.01 to 1.45, from 1.03 to 1.40, from 1.04 to 1.35, from 1.05 to 1.30, from 1.06 to 1.25, from 1.07 to 1.20, , 1.08 to 1.15, in another embodiment 1.09 to 1.79, in another embodiment 1.10 to 1.73, in another embodiment 1.15 to 1.70, in another embodiment 1.19 to 1.68, in another embodiment 1.20 to 1.66, in another embodiment 1.23 to 1.65, in another embodiment 1.26 to 1.62, in another embodiment 1.29 to 1.59, in another embodiment 1.30 to 1.57, in another embodiment 1.31 to 1.55, in another embodiment 1.33 to 1.54, in another embodiment 1.36 to 1.53, in another embodiment 1.38 to 1.51, in another embodiment 1.40 to 1.50, and in another embodiment 1.41 to 1.48.
[0033] In another embodiment, the dehydrogenation catalyst may further contain an alkali metal other than potassium and sodium. In another embodiment, the dehydrogenation catalyst contains lithium (Li). In another embodiment, the alkali metals contained in the dehydrogenation catalyst consist of potassium and sodium, and do not contain other alkali metals.
[0034] In another embodiment, the dehydrogenation catalyst further comprises a Group 6 element. In another embodiment, the Group 6 element is selected from the group consisting of chromium (Cr), molybdenum (Mo), tungsten (W), seaborgium (Sg), and mixtures thereof. In another embodiment, the Group 6 element is selected from the group consisting of molybdenum (Mo), tungsten (W), and mixtures thereof. In another embodiment, the Group 6 element comprises molybdenum (Mo). In another embodiment, the Group 6 element is molybdenum (Mo). In another embodiment, the dehydrogenation catalyst does not comprise chromium (Cr).
[0035] In one embodiment, the Group 6 element is present in an amount of 0.1 to 10 wt %, in another embodiment, 0.2 to 8.0 wt %, in another embodiment, 0.3 to 6.0 wt %, in another embodiment, 0.4 to 4.0 wt %, in another embodiment, 0.5 to 2.0 wt %, and in another embodiment, 0.6 to 1.0 wt %, calculated as the oxide of the Group 6 element, based on the total weight of the dehydrogenation catalyst.
[0036] In another embodiment, the dehydrogenation catalyst further comprises magnesium (Mg), calculated as MgO, in an amount of 0.3 to 10 wt. %, in another embodiment 0.5 to 8 wt. %, in another embodiment 0.6 to 3 wt. %, and in another embodiment 0.7 to 1.5 wt. %, based on the total weight of the dehydrogenation catalyst.
[0037] In another embodiment, the dehydrogenation catalyst optionally further comprises a precious metal. The precious metal is selected from the group consisting of gold, silver, platinum, palladium, rhodium, iridium, ruthenium, osmium, and mixtures thereof. In another embodiment, the precious metal is selected from the group consisting of gold, platinum, palladium, and mixtures thereof. In another embodiment, the precious metal is palladium.
[0038] In one embodiment, the noble metal is present in the catalyst in an amount from 0.1 to 200 ppm by weight, based on the total weight of the dehydrogenation catalyst. In another embodiment, the noble metal is present in an amount from 1 to 150 ppm, in another embodiment, from 5 to 100 ppm, in another embodiment, from 10 to 80 ppm, in another embodiment, from 13 to 68 ppm, in another embodiment, from 14 to 42 ppm, and in another embodiment, from 15 to 25 ppm, based on the total weight of the dehydrogenation catalyst.
[0039] The content of each element, such as iron, potassium, cerium, and sodium, in the dehydrogenation catalyst and the molar ratio between the elements can be determined using methods known to those skilled in the art, such as elemental analysis by X-ray fluorescence analysis (XRF analysis). For example, measurements can be performed using a ZSX Primus II model manufactured by Rigaku Corporation. First, a measurement sample of the dehydrogenation catalyst is pulverized and pressed at 20 MPa to produce a test sheet with a thickness of approximately 3 mm. This test sheet is then subjected to XRF analysis. Meanwhile, the amount of each element measured in this manner is calculated by comparing it with a calibration curve based on the XRF analysis results of a standard material containing the element to be measured. The amount of each element measured in this manner is expressed as the corresponding oxide (e.g., Fe for iron). ２ O ３ , potassium is K ２ The above content and molar ratio can be determined by appropriately converting the amount of the hydroxyl group to the total amount of the hydroxyl group (O) or the number of moles.
[0040] The dehydrogenation catalyst may be a metal oxide catalyst. The weight percentages are based on the total weight of the dehydrogenation catalyst, assuming all elements are fully oxidized.
[0041] The method for producing the dehydrogenation catalyst includes the following steps: (i) mixing a raw material with water to obtain a mixture, wherein the raw material contains an iron compound, a potassium compound, a cerium compound, and a sodium compound, but does not contain a calcium compound; (ii) molding the mixture to obtain a molded product; and (iii) calcining the molded product.
[0042] In one embodiment, the raw iron compound includes iron oxide, potassium ferrite (a composite oxide of iron and potassium), or sodium ferrite (a composite oxide of iron and sodium), and mixtures thereof. In another embodiment, the iron compound is iron oxide. Different forms of iron oxide, such as red, yellow, brown, and black iron oxide, can be used. In another embodiment, the raw iron oxide is selected from the group consisting of red iron oxide, yellow iron oxide, brown iron oxide, and black iron oxide, and mixtures thereof. In another embodiment, the raw iron oxide is red iron oxide (hematite, Fe ２ O ３ ), yellow iron oxide (goethite, Fe ２ O ３ ・H ２ In another embodiment, the raw iron oxide is red iron oxide. In another embodiment, the red iron oxide is hematite having a crystalline structure.
[0043] In one embodiment, the source potassium compound is selected from the group consisting of potassium oxide, potassium hydroxide, potassium carbonate, potassium bicarbonate, and mixtures thereof. In another embodiment, the source potassium compound is selected from the group consisting of potassium carbonate, potassium hydroxide, and mixtures thereof. In another embodiment, the source potassium compound comprises potassium carbonate.
[0044] In one embodiment, the raw cerium compound is selected from the group consisting of cerium oxide, cerium hydroxide, cerium carbonate, cerium nitrate, and mixtures thereof. In another embodiment, the cerium compound comprises cerium carbonate. In another embodiment, the cerium carbonate is selected from the group consisting of cerium carbonate hydrate, cerium carbonate hydroxide, and combinations thereof. In another embodiment, the cerium carbonate hydrate has a content of CeO based on the weight of the cerium carbonate hydrate. ２ In another embodiment, the cerium hydroxide carbonate may be, for example, (CeCO ３ OH xH ２ O), (Ce ２(CO ３ ) ２ (OH) ２ ・H ２ O), (Ce(CO ３ ) ２ O.H. ２ O, Ce ２ O(CO ３ ) ２ ・H ２ O and CeO(CO ３ ) ２ ・xH ２ O) is available.
[0045] In one embodiment, the source sodium compound is selected from the group consisting of sodium oxide, sodium hydroxide, sodium carbonate, sodium nitrate, sodium phosphate, sodium sulfate, sodium acetate, sodium chloride, sodium sulfide, and combinations thereof, hi another embodiment, the sodium compound comprises sodium carbonate.
[0046] In another embodiment, the raw material further comprises an yttrium compound. The yttrium compound, in one embodiment, is selected from the group consisting of yttrium oxide, yttrium hydroxide, yttrium carbonate, yttrium nitrate, yttrium phosphate, yttrium sulfate, yttrium acetate, yttrium chloride, yttrium sulfide, and mixtures thereof. In another embodiment, the yttrium compound is selected from the group consisting of yttrium oxide, yttrium nitrate, and mixtures thereof. In another embodiment, the yttrium compound comprises yttrium oxide.
[0047] In another embodiment, when the dehydrogenation catalyst comprises a Group 6 element, the feedstock comprises a Group 6 element compound. In another embodiment, the Group 6 element compound is selected from the group consisting of an oxide, a composite oxide, an oxoanion salt of a Group 6 element, and combinations thereof. In another embodiment, the feedstock comprises an oxide of a Group 6 element.
[0048] In another embodiment, when the dehydrogenation catalyst comprises magnesium, the feedstock is selected from the group consisting of magnesium oxides, composite oxides, oxoanion salts, and combinations thereof. In another embodiment, the feedstock comprises magnesium oxide.
[0049] When the dehydrogenation catalyst contains a precious metal, the feedstock contains a precious metal compound. In one embodiment, the feedstock precious metal compound is selected from the group consisting of oxides, hydroxides, carbonates, nitrates, phosphates, sulfates, acetates, chlorides, sulfides, and combinations thereof. The feedstock precious metal compound contains a precious metal nitrate.
[0050] The above raw materials are mixed with water to obtain a mixture. The amount of water can be adjusted to suit molding or depending on the type of raw materials. In one embodiment, the amount of water to be mixed is 2 to 50 parts by weight per 100 parts by weight of the raw materials.
[0051] The resulting mixture is molded to obtain a molded product. In one embodiment, the molding is extrusion molding using a matrix with holes of a desired shape. In another embodiment, the mixture is formed into pellets by extrusion molding. The cross section of the pellets can be selected to a desired shape depending on the shape of the holes in the matrix. In one embodiment, the cross section of the pellets is gear-shaped. The gear shape is described in U.S. Patent No. 5,949,493, which is incorporated herein by reference.
[0052] In one embodiment, the extruded product is optionally dried to remove free water. The drying temperature is in one embodiment 60 to 200° C., in another embodiment 70 to 170° C., and in another embodiment 110 to 150° C. The drying time is in one embodiment 5 minutes to 5 hours, in another embodiment 10 minutes to 2 hours, and in another embodiment 20 minutes to 1 hour.
[0053] The extruded product is calcined to obtain the dehydrogenation catalyst. In one embodiment, the calcination temperature is 400 to 1300° C., in another embodiment, 500 to 1150° C., and in another embodiment, 800 to 1000° C. In one embodiment, the calcination time is 30 minutes to 10 hours, in another embodiment, 1 hour to 6 hours, and in another embodiment, 1 hour to 3 hours.
[0054] The method for preparing the dehydrogenation catalyst is, in another embodiment, incorporated herein by reference to US Pat. Nos. 5,629,999 and 5,629,999.
[0055] The present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples in any way.
[0056] The following raw materials were weighed and mixed in a kneader while adding pure water little by little to form a paste: red iron oxide (hematite crystal structure), potassium carbonate, cerium carbonate hydrate (cerium is replaced by CeO ２ (Contains 50% by weight) Cerium carbonate hydroxide Sodium carbonate Molybdenum oxide Yttrium oxide Calcium hydroxide
[0057] The resulting paste-like mixture was extruded into cylindrical pellets with a diameter of 3 mm and a length of approximately 5 mm. The pellets were dried at 130°C for 30 minutes and then calcined at 900°C for 2 hours. The composition of the resulting catalyst is shown in Table 1. Table 1 shows the content of each component in the composition, calculated as an oxide, as a percentage (%) based on the total weight of the dehydrogenation catalyst. The weight ratios of potassium (K) and sodium (Na) contained in the dehydrogenation catalyst were K and Na, respectively. ２ O and Na ２ Calculate as O (K ２ O / Na ２ The total weight of each of the obtained dehydrogenation catalysts was 2 kg.
[0058] In order to measure the wear rate of the catalyst obtained above after use, a dehydrogenation reaction of ethylbenzene (EB) was carried out using the catalyst as follows. First, 100 cc of each of the obtained catalysts was packed into a reactor (volume 500 cc). Ethylbenzene gas and steam were fed from the inlet to the outlet of the reactor under the following reaction conditions to start the reaction. The reactor used was an isothermal reactor that can be adjusted to keep the temperature inside the reactor as isotropic as possible. Liquid hourly space velocity (LHSV) of ethylbenzene gas: 1.00 h －１ Steam / ethylbenzene weight ratio (W / A ratio): 1.0 Absolute pressure: 51 kPa Reactor inlet temperature: 600°C Reactor outlet temperature: 620°C Reaction time: 4 days After the reaction, the catalyst was removed from the reactor and the total weight of the catalyst after the reaction was measured. The entire catalyst was then placed in a cylindrical rotating drum (inner diameter 254 mm, length 152 mm) equipped with one baffle (Baffle, height 51 mm) and rotated at 60 rpm for 30 minutes. After the rotation was completed, the catalyst removed from the drum was sieved through a 1 mm mesh standard sieve, and the weight of the powder catalyst remaining under the sieve was measured. The percentage (%) of the total weight of the catalyst after the reaction was calculated as the wear rate using the following formula: Wear rate (%) = powder catalyst weight (g) ÷ total catalyst weight after the reaction (g) × 100
[0059] Next, to measure the EB conversion rate, an ethylbenzene dehydrogenation reaction was carried out in the same manner as in the above wear rate measurement, except for the following reaction conditions: Liquid hourly space velocity (LHSV) of ethylbenzene: 1.0 h －１ Steam / ethylbenzene weight ratio (W / A ratio): 0.68 Absolute pressure: 101 kPa Reaction time: 200 hours
[0060] The EB conversion rate was calculated by measuring the EB concentration (%) in the ethylbenzene gas supplied to the reactor and the EB concentration (%) in the product liquid obtained by liquefying the gas discharged from the outlet after passing through the catalyst bed in the reactor, and then using the following formula: EB conversion rate (wt%) = (EB concentration (wt%) in the supplied ethylbenzene gas - EB concentration (wt%) in the product liquid) / EB concentration (wt%) in the supplied ethylbenzene gas x 100
[0061] The wear rate and EB conversion rate of each catalyst are shown in Table 1. The wear rate is shown as a relative value with the value of Comparative Example 1 taken as 100, and the EB conversion rate is shown as an increase or decrease with the value of Comparative Example 1 as the reference value.
[0062]
[0063] Results Compared with the catalyst containing Ca (Comparative Example 1), the catalyst not containing Ca (Example 1) was able to reduce the wear rate to about half without reducing the EB conversion rate.
[0064] Next, the effect of the content ratio of alkali metals and cerium in the Ca-free catalyst composition was investigated. The dehydrogenation catalyst was prepared in the same manner as in Example 1, except that the composition of the obtained catalyst was as shown in Table 2 and that the total weight of each obtained catalyst was 10 kg. Using this dehydrogenation catalyst, the wear rate and EB conversion rate were measured in the same manner as in Example 1, except that a normal reactor was used instead of an isothermal reactor. The inlet and outlet temperatures of the reactor were as follows. The results are shown in Table 2. The wear rate is shown as a relative value, with the value of Comparative Example 2 set to 100. Reactor inlet temperature: 620°C Reactor outlet temperature: 540°C
[0065]
[0066] Results: The alkali metal oxide in the catalyst is K. ２ O and Na ２ Total amount of O and CeO ２ Weight ratio [(K ２ O + Na ２ O) / CeO ２ ] of 1.09 and 1.48 (Examples 2 and 3) had lower attrition rates of 74 and 59, respectively, compared to the catalyst with a ] of 0.96 (Comparative Example 2).
[0067] The effects of sodium and calcium on catalyst compositions containing no yttrium were investigated. The dehydrogenation catalyst was prepared in the same manner as in Example 1, except that the resulting catalyst had the composition shown in Table 3. The attrition rate and EB conversion rate were measured. The results are shown in Table 3. The attrition rate is shown as a relative value, with the value for Comparative Example 1 taken as 100, and the EB conversion rate is shown as an increase or decrease based on the value for Comparative Example 1.
[0068]
[0069] Result Na ２ Compared with the catalyst containing no O (Comparative Example 3), ２ The catalyst containing O improved the EB conversion rate from -7.1% to -2.6%, but the attrition rate increased from 101 to 105 (Comparative Example 4). ２ The catalyst containing O but not CaO (Example 4) was able to reduce the attrition rate to 58.
[0070] The present invention can also be provided by the following embodiments: Embodiment 1. A method for producing an alkylaromatic compound, comprising contacting an alkylaromatic compound with steam in a reactor in the presence of a dehydrogenation catalyst for the alkylaromatic compound, wherein the weight ratio of the steam to the alkylaromatic compound (water / alkylaromatic compound ratio) is 0.40 to 1.50, and wherein the dehydrogenation catalyst is selected from the group consisting of Fe, ２ O ３ 30 to 90% by weight of iron, calculated as ２ 1 to 50% by weight of potassium, calculated as O, CeO ２ 1 to 50% by weight of cerium, calculated as ２ 0.1 to 15 wt. % sodium, calculated as 0, and no calcium, wherein said wt. % is based on the total weight of the dehydrogenation catalyst, and wherein the alkali metal oxide is K. ２ O and Na ２ Total amount of O and CeO ２ The weight ratio (alkali metal oxide / CeO ２ The method for producing an alkenyl aromatic compound, wherein the ratio (R) is 1.0 or more.
[0071] Embodiment 2. The dehydrogenation catalyst further comprises Y ２ O ３ 2. The method of claim 1, comprising 0.01 to 1 wt. % yttrium, calculated as
[0072] Embodiment 3. The method of embodiment 1 or 2, wherein the reactor comprises an inlet for supplying the alkyl aromatic compound and steam and an outlet for discharging the alkyl aromatic compound and steam, and the temperature at the inlet is 450 to 680°C.
[0073] Embodiment 4. The process of any one of embodiments 1 to 3, wherein the alkyl aromatic compound is contacted with water vapor at a pressure of from 1 kPa to 150 kPa.
[0074] Embodiment 5. The alkyl aromatic compound is heated with water vapor for 0.1 to 5 hours. －１ 5. The process of any one of embodiments 1 to 4, wherein the contacting is performed at a liquid hourly space velocity (LHSV) of
[0075] Embodiment 6. The method of any one of embodiments 1 to 5, wherein the weight ratio of the water vapor to the alkyl aromatic compound (water / alkyl aromatic compound ratio) is 0.40 to 1.20.
[0076] Embodiment 7. The process of any one of embodiments 1 to 6, wherein the alkyl aromatic compound is ethylbenzene and the alkenylaromatic compound is styrene.
[0077] Embodiment 8. The process of any one of embodiments 1 to 7, wherein the dehydrogenation catalyst further contains 0.1 to 10 wt. % of a Group 6 element selected from the group consisting of chromium (Cr), molybdenum (Mo), tungsten (W), seaborgium (Sg), and mixtures thereof, calculated as the oxide of the Group 6 element.
[0078] Embodiment 9. The method of embodiment 8, wherein the Group 6 element is molybdenum (Mo).
[0079] Embodiment 10. The weight ratio of potassium (K) and sodium (Na) contained in the dehydrogenation catalyst is K ２ O and Na ２ Calculate as O (K ２ O / Na ２ 10. The method of claim 1, wherein the .O ratio is 5 to 10.
[0080] Embodiment 11. Fe ２ O ３ 30 to 90% by weight of iron, calculated as２ 1 to 50% by weight of potassium, calculated as O, CeO ２ 1 to 50% by weight of cerium, calculated as ２ 0.1 to 15 wt. % sodium, calculated as 0, and no calcium, wherein said wt. % is based on the total weight of the dehydrogenation catalyst, and wherein the alkali metal oxide is K. ２ O and Na ２ Total amount of O and CeO ２ The weight ratio (alkali metal oxide / CeO ２ A catalyst for dehydrogenation of alkyl aromatic compounds, characterized in that the ratio (R) is 1.0 or more.
[0081] Embodiment 12. Furthermore, Y ２ O ３ 12. The dehydrogenation catalyst of embodiment 11, comprising 0.01 to 1 wt. % yttrium, calculated as
[0082] Embodiment 13. The dehydrogenation catalyst of embodiment 11, wherein the dehydrogenation catalyst further contains 0.1 to 10 wt. % of a Group 6 element, calculated as the oxide of the Group 6 element, selected from the group consisting of chromium (Cr), molybdenum (Mo), tungsten (W), seaborgium (Sg), and mixtures thereof.
[0083] Embodiment 14. The dehydrogenation catalyst of embodiment 13, wherein the Group 6 element is molybdenum (Mo).
[0084] Embodiment 15. The weight ratio of potassium (K) and sodium (Na) contained in the dehydrogenation catalyst is K ２ O and Na ２ Calculate as O (K ２ O / Na ２ 15. The dehydrogenation catalyst of embodiments 11-14, wherein the .O ratio is 5 to 10.
[0085] Embodiment 16. A method for producing the dehydrogenation catalyst of embodiment 11, comprising: (i) mixing raw materials and water to obtain a mixture, wherein the raw materials contain an iron compound, a potassium compound, a cerium compound, and a sodium compound, but do not contain a calcium compound; (ii) molding the mixture to obtain a molded product; and (iii) calcining the molded product.
[0086] Embodiment 17. The method of embodiment 16, wherein the feedstock further comprises a yttrium compound.
[0087] Embodiment 18. A method for producing a hydrocarbon-based hydrocarbon-based hydrocarbon mixture, comprising contacting an alkylaromatic compound with steam in a reactor in the presence of an alkylaromatic compound dehydrogenation catalyst, wherein the weight ratio of the steam to the alkylaromatic compound (water / alkylaromatic compound ratio) is 0.40 to 1.50, and wherein the dehydrogenation catalyst is selected from the group consisting of Fe, ２ O ３ 30 to 90% by weight of iron, calculated as ２ 1 to 50% by weight of potassium, calculated as O, CeO ２ 1 to 50% by weight of cerium, calculated as ２ 0.1 to 15% by weight of sodium, calculated as O, and Y ２ O ３ 0.01 to 1 wt. % yttrium, calculated as yttrium, and no calcium, wherein said wt. % is based on the total weight of the dehydrogenation catalyst, and wherein K is an alkali metal oxide. ２ O and Na ２ Total amount of O and CeO ２ The weight ratio (alkali metal oxide / CeO ２ The method for producing an alkenyl aromatic compound, wherein the ratio (R) is 1.0 or more.
[0088] Embodiment 19. Fe ２ O ３ 30 to 90% by weight of iron, calculated as ２ 1 to 50% by weight of potassium, calculated as O, CeO ２ 1 to 50% by weight of cerium, calculated as ２0.1 to 15% by weight of sodium, calculated as O, and Y ２ O ３ 0.01 to 1 wt. % yttrium, calculated as yttrium, and no calcium, wherein said wt. % is based on the total weight of the dehydrogenation catalyst, and wherein K is an alkali metal oxide. ２ O and Na ２ Total amount of O and CeO ２ The weight ratio (alkali metal oxide / CeO ２ A catalyst for dehydrogenation of alkyl aromatic compounds, characterized in that the ratio (R) is 1.0 or more.
Claims
1. A process for producing an alkenyl aromatic compound, which comprises contacting an alkyl aromatic compound with steam in a reactor in the presence of a dehydrogenation catalyst for the alkyl aromatic compound, where the weight ratio of the steam to the alkyl aromatic compound (steam / alkyl aromatic compound ratio) is from 0.40 to 1.50, and where the dehydrogenation catalyst contains Fe ２ O ３ and calculated as Fe, 30 to 90% by weight of iron, K ２ O and calculated as K, 1 to 50% by weight of potassium, CeO ２ and calculated as Ce, 1 to 50% by weight of cerium, and Na ２ O and calculated as Na, 0.1 to 15% by weight of sodium, and does not contain calcium, where the above % by weight is based on the total weight of the dehydrogenation catalyst, and where the total amount of the alkali metal oxides K ２ O and Na ２ O and the weight ratio of CeO ２ (alkali metal oxide / CeO ２ ratio) is 1.0 or more. A process for producing an alkenyl aromatic compound, characterized by the above.
2. When the dehydrogenation catalyst further contains yttrium calculated as Y ２ O ３ in an amount of 0.01 to 1% by weight, the production method according to claim 1.
3. The manufacturing method according to claim 1, wherein the reactor includes an inlet for supplying an alkyl aromatic compound and steam and an outlet for discharging them, and the temperature at the inlet is 450 to 680°C.
4. The manufacturing method according to claim 1, wherein the alkyl aromatic compound is brought into contact with steam at a pressure of 1 kPa to 150 kPa.
5. The production method according to claim 1, wherein the alkyl aromatic compound is brought into contact with steam at a liquid hourly space velocity (LHSV) of 0.1 to 5 h －１ .
6. The manufacturing method according to claim 1, wherein the weight ratio of the steam to the alkyl aromatic compound (steam / alkyl aromatic compound ratio) is 0.40 to 1.
20.
7. The manufacturing method according to claim 1, wherein the alkyl aromatic compound is ethylbenzene and the alkenyl aromatic compound is styrene.
8. The manufacturing method according to claim 1, wherein the dehydrogenation catalyst further contains, calculated as an oxide of Group 6 elements, 0.1 to 10% by weight of a Group 6 element selected from the group consisting of chromium (Cr), molybdenum (Mo), tungsten (W), seaborgium (Sg), and mixtures thereof.
9. The manufacturing method according to claim 8, wherein the Group 6 element is molybdenum (Mo).
10. The weight ratio of potassium (K) and sodium (Na) contained in the dehydrogenation catalyst is 5 to 10, respectively, calculated as K ２ O and Na ２ O (K ２ O / Na ２ O ratio), according to the production method described in claim 1.
11. Fe ２ O ３ calculated as, 30 to 90% by weight of iron, K ２ O calculated as, 1 to 50% by weight of potassium, CeO ２ calculated as, 1 to 50% by weight of cerium, and Na ２ O calculated as, 0.1 to 15% by weight of sodium, and does not contain calcium, where the above % by weight is based on the total weight of the dehydrogenation catalyst, and where K ２ O and Na ２ The total amount of O and CeO ２ The weight ratio of (alkali metal oxide / CeO ２ ratio) is 1.0 or more, A dehydrogenation catalyst for alkyl aromatic compounds, characterized by this.
12. Further, Y ２ O ３ The dehydrogenation catalyst according to claim 11, which is calculated as and contains 0.01 to 1% by weight of yttrium.
13. The dehydrogenation catalyst according to claim 11, wherein the dehydrogenation catalyst further contains, calculated as an oxide of Group 6 elements, 0.1 to 10% by weight of a Group 6 element selected from the group consisting of chromium (Cr), molybdenum (Mo), tungsten (W), seaborgium (Sg), and mixtures thereof.
14. The dehydrogenation catalyst according to claim 13, wherein the Group 6 element is molybdenum (Mo).
15. The weight ratio of potassium (K) and sodium (Na) contained in the dehydrogenation catalyst is K ２ O and Na ２ O calculated as (K ２ O / Na ２ O ratio) is 5 to 10. The dehydrogenation catalyst according to claim 11.
16. The method for manufacturing a dehydrogenation catalyst according to claim 11, comprising: (i) a step of mixing a raw material and water to obtain a mixture, wherein the raw material includes an iron compound, a potassium compound, a cerium compound, and a sodium compound and does not include a calcium compound; (ii) a step of molding the mixture to obtain a molded product; and (iii) a step of calcining the molded product.
17. The manufacturing method according to claim 16, wherein the raw material further includes a yttrium compound.