Solid acid catalyst, process for its preparation and process for the preparation of long chain alkylbenzenes

Abstract

The present application relates to the field of catalysts, and discloses a solid acid catalyst, a preparation method thereof and a method for preparing long-chain alkylbenzene, the catalyst comprising a metal-modified molecular sieve, a heat-resistant inorganic oxide and a first metal; the first metal is selected from at least one of group VIII metals; the metal-modified molecular sieve comprises a molecular sieve and a second metal outside the molecular sieve framework; the content of the second metal is 8-30 wt% in terms of elements based on the total amount of the metal-modified molecular sieve; the second metal is selected from at least one of alkaline earth metals, group IIIB metals and group IIIA metals; in the metal-modified molecular sieve, the mass fraction of surface-phase metal measured by XPS is not more than 1.45 times the mass fraction of bulk-phase metal measured by XRF in terms of the mass fraction of elements. The solid acid catalyst can better inhibit skeletal isomerization of alkylbenzene products, improve the straight-chain degree of the products, and can be efficiently regenerated under mild conditions.

Description

Technical Field

[0001] This invention relates to the field of catalysts, specifically to a solid acid catalyst and its preparation method, as well as a method for preparing long-chain alkylbenzenes. Background Technology

[0002] As a crucial raw material for the synthesis of sodium alkylbenzene sulfonate in detergents, long-chain alkylbenzenes are primarily prepared through the alkylation reaction of long-chain olefins with monocyclic aromatic hydrocarbons. Current technologies mainly utilize HF or AlCl3 as catalysts, but these two catalytic systems pose significant safety and environmental risks and are gradually being phased out due to increasingly stringent safety and environmental requirements. Therefore, developing novel, non-corrosive, and pollution-free catalysts as alternative technologies has become an inevitable trend in the production of long-chain alkylbenzenes.

[0003] Currently, industrial solid acid processes use a fluorine-containing SiO2-Al2O3 solid acid catalyst (ZL93104573.8) developed in cooperation between UOP (USA) and Petresa (Spain). The catalyst is flushed with benzene every 24 hours to achieve long-term stable operation. However, since the catalyst itself contains fluorine, it is corrosive to the equipment and still poses certain safety and environmental risks.

[0004] Domestic and international research has largely focused on zeolite molecular sieve catalyst systems. On one hand, due to the relatively large size of long-chain alkylbenzene molecules, channels with ten-membered rings or smaller cannot enter. Only molecular sieves such as MOR, Y, and Beta, which have channels with twelve-membered rings or larger, exhibit good catalytic performance in the alkylation reaction of benzene with long-chain olefins (CatalSurvAsia (2014) 18:1-12; CatalToday (2017) 298:109-116). On the other hand, because branched alkylbenzenes are not easily degraded, national standards impose strict requirements on the linearity of alkylbenzene products. Furthermore, the biggest problems with molecular sieve-catalyzed synthesis of long-chain alkylbenzenes are their short lifespan and low linearity.

[0005] CN107867699A discloses a Y zeolite containing regular ultra-large micropores. By subjecting selected Y zeolite to template agent and acid-base treatment, a Y zeolite with regular ultra-large micropores of 1-2 nm is constructed. Due to the abundant acid centers and suitable reaction channels provided by the regular ultra-large micropores, higher conversion rate and selectivity are obtained.

[0006] CN110562995A discloses a method for synthesizing nano-Y zeolite and its application in the synthesis of straight-chain alkylbenzenes. Due to the small catalyst crystal size and low diffusion resistance, the activity and stability of long-chain olefin alkylation are improved.

[0007] CN102639471A discloses a method for producing linear alkylbenzenes, which uses a combination of two zeolites to limit skeletal isomerization and improve the linearity of the product.

[0008] The preparation process of molecular sieve catalysts in the current technology is complicated, and how to achieve repeated regeneration and stable operation of molecular sieve catalysts remains the main problem restricting their industrial application. Summary of the Invention

[0009] The purpose of this invention is to overcome the problems of short service life, low linearity of products, and poor stability after repeated regeneration in the alkylation reaction of long-chain olefins by molecular sieve catalysts in the prior art. This invention provides a solid acid catalyst, its preparation method, and a method for preparing long-chain alkylbenzenes. The solid acid catalyst contains metal-modified molecular sieves, which can effectively suppress skeletal isomerism of alkylbenzene products, improve the linearity of products, and extend the catalytic alkylation cycle life. At the same time, the catalyst can be recycled after hydrogen regeneration.

[0010] To achieve the above objectives, a first aspect of the present invention provides a solid acid catalyst comprising a metal-modified molecular sieve, a heat-resistant inorganic oxide, and a first metal; wherein the first metal is selected from at least one group VIII metal.

[0011] The metal-modified molecular sieve includes a molecular sieve and a second metal outside the molecular sieve framework; based on the total amount of the metal-modified molecular sieve, the content of the second metal is 8-30 wt% in terms of elements; the second metal is selected from at least one of alkaline earth metals, Group IIIB metals and Group IIIA metals;

[0012] In the metal-modified molecular sieve, the ratio of the mass fraction of the surface metal measured by XPS to the mass fraction of the bulk metal obtained by XRF test does not exceed 1.45, based on the mass fraction of elements.

[0013] A second aspect of the present invention provides a method for preparing a solid acid catalyst, the method comprising:

[0014] S1. The metal-modified molecular sieve is shaped and calcined once with a heat-resistant inorganic oxide and / or its precursor to obtain a semi-finished catalyst.

[0015] S2. The semi-finished catalyst is contacted with a solution of a soluble compound containing a first metal element, and then dried and calcined a second time to obtain the solid acid catalyst; the first metal is selected from at least one of Group VIII metals.

[0016] The metal-modified molecular sieve includes a molecular sieve and a second metal outside the molecular sieve framework; based on the total amount of the metal-modified molecular sieve, the content of the second metal is 8-30 wt% in terms of elements; the second metal is selected from at least one of alkaline earth metals, Group IIIB metals and Group IIIA metals;

[0017] In the metal-modified molecular sieve, the ratio of the mass fraction of the surface metal measured by XPS to the mass fraction of the bulk metal obtained by XRF test does not exceed 1.45, based on the mass fraction of elements.

[0018] A third aspect of the present invention provides a solid acid catalyst prepared by the above-described preparation method.

[0019] A fourth aspect of the present invention provides a method for preparing long-chain alkylbenzenes, the method comprising contacting a long-chain olefin and an aromatic hydrocarbon with a catalyst under alkylation reaction conditions to obtain long-chain alkylbenzenes;

[0020] The catalyst is a solid acid catalyst as described in the first or third aspect.

[0021] Preferably, the method further includes: regenerating the catalyst;

[0022] Preferably, the regeneration is carried out in a hydrogen atmosphere;

[0023] Preferably, the regeneration temperature is 200-500℃, the regeneration pressure is 1-5MPa, the regeneration time is 1-10h, and the hydrogen volume hourly space velocity is 300-5000h. -1 .

[0024] The solid acid catalyst provided by this invention contains a metal-modified molecular sieve. Through modification with a certain amount of extra-skeletal metal, the mass fraction of the surface metal measured by XPS and the mass fraction of the bulk metal measured by XRF do not exceed 1.45. The resulting solid acid catalyst can effectively suppress the skeletal isomerism of alkylbenzene products. Through the synergistic effect of the metal-modified molecular sieve, heat-resistant inorganic oxide and the first metal, the linearity of the product and the service life of the catalyst can be further improved. At the same time, the deactivated catalyst can be completely regenerated in a hydrogen-containing environment, and the regenerated catalyst maintains high catalytic activity.

[0025] The method for preparing solid acid catalysts provided by this invention is simple to operate and is conducive to industrialization.

[0026] The method for preparing long-chain alkylbenzenes provided by this invention significantly improves the linearity of the products due to the shape selectivity of the reaction products resulting from the molecular sieve modification of the solid acid catalyst. This increased selectivity also significantly extends the catalytic alkylation cycle life of the solid acid catalyst. Simultaneously, the deactivated catalyst can be completely regenerated in a hydrogen-rich environment, enabling continuous and stable operation of the catalytic reaction. Attached Figure Description

[0027] Figure 1 The XRD patterns of the metal-modified molecular sieve and HY molecular sieve prepared in Example 1 are shown in comparison. Detailed Implementation

[0028] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0029] The first aspect of this invention provides a solid acid catalyst comprising a metal-modified molecular sieve, a heat-resistant inorganic oxide, and a first metal; wherein the first metal is selected from at least one group VIII metal.

[0030] The metal-modified molecular sieve includes a molecular sieve and a second metal outside the molecular sieve framework; based on the total amount of the metal-modified molecular sieve, the content of the second metal is 8-30 wt% in terms of elements; the second metal is selected from at least one of alkaline earth metals, Group IIIB metals and Group IIIA metals;

[0031] In the metal-modified molecular sieve, the ratio of the mass fraction of the surface metal measured by XPS to the mass fraction of the bulk metal obtained by XRF test does not exceed 1.45, based on the mass fraction of elements.

[0032] In this invention, the solid acid catalyst uses a metal-modified molecular sieve as the active component. Through extensive research, the inventors of this invention have discovered that the presence of a certain amount of extra-skeletal metal inside the molecular sieve can effectively suppress the skeletal isomerism of alkylbenzene products, improve the linearity of the product, and significantly extend its catalytic alkylation cycle life. Furthermore, by loading a first metal, the catalyst can be recycled after hydrogen regeneration.

[0033] In this invention, the "second metal outside the molecular sieve framework" refers to the metal distributed in the molecular sieve cation sites in ionic form and / or loaded on the molecular sieve surface in oxide form. If the peak position of the characteristic peak of the metal-modified molecular sieve is the same as the peak position of the diffraction peak of the unmodified molecular sieve by XRD testing, that is, the characteristic peak is not shifted, it can be proved that the metal is located outside the molecular sieve framework.

[0034] In this invention, an X-ray powder diffractometer from PANalytical, Netherlands, was used for XRD testing. The test conditions included: tube voltage of 40 kV, tube current of 40 mA, Cu target Kα radiation, scanning speed of 2 (°) / min, and scanning range of 2θ = 5°-35°.

[0035] In this invention, the mass fraction of the surface metal refers to the mass fraction of the metal element obtained by XPS testing, and the mass fraction of the bulk metal refers to the mass fraction of the metal element obtained by XRF testing and calculation. It can be understood that XRF testing first obtains the mass fraction of the bulk metal as an oxide, and then the corresponding elemental mass fraction is calculated.

[0036] In this invention, an ESCALAB 250 X-ray photoelectron spectrometer (Thermo Fisher Scientific) was used for XPS testing. The test conditions included: monochromatic Al Kα X-rays, energy 1486.6 eV, power 150 W, and the charge shift was corrected using the C1s peak (284.8 eV) of contaminated carbon.

[0037] In this invention, an XRF test was performed using a Rigaku Electric Industrial Co., Ltd. 3271 X-ray fluorescence spectrometer. The test conditions included: the anode target material of the X-ray tube was a rhodium target; the laser voltage was 50 kV; and the laser current was 50 mA.

[0038] In this invention, the content range of each component in the solid acid catalyst is relatively wide and can be adjusted according to actual application needs. Preferably, based on the total amount of the solid acid catalyst, the content of the metal-modified molecular sieve is 18-98.99 wt%, the content of the heat-resistant inorganic oxide is 1-72 wt%, and the content of the first metal is 0.01-10 wt% (elementally). Preferably, based on the total amount of the solid acid catalyst, the content of the metal-modified molecular sieve is 50-90 wt%, the content of the heat-resistant inorganic oxide is 9.95-45 wt%, and the content of the first metal is 0.05-5 wt% (elementally).

[0039] In this invention, the content of the first metal is obtained by XRF testing, and the content of the other components is calculated by the amount of feed.

[0040] According to the present invention, preferably, on a dry basis, the weight ratio of the metal-modified molecular sieve to the heat-resistant inorganic oxide is 99:1-20:80, more preferably 95:5-25:75, and more preferably 90:10-50:50.

[0041] In this invention, the first metal is a metal with hydrogenation function; preferably, the first metal is selected from at least one of Fe, Co, Ni, Ru, Rh, Pd, Ir and Pt; more preferably, it is at least one of Pt, Pd, Ni and Co; using the above-mentioned preferred first metal helps to achieve catalyst regeneration under milder conditions.

[0042] In this invention, there are no special requirements for the selection of the heat-resistant inorganic oxide; conventional materials in the art can be used. Preferably, the heat-resistant inorganic oxide is selected from at least one of alumina, zirconium oxide, silicon dioxide, and titanium dioxide. Using the above-mentioned preferred heat-resistant inorganic oxide can further improve the catalytic performance of the solid acid catalyst.

[0043] The inventors of this invention have creatively discovered that the distribution of bulk and surface metals has a crucial impact on the performance of metal-modified molecular sieves. To further suppress byproduct formation and deactivation caused by olefin isomerization and polyalkylation reactions, and to achieve shape-selective catalysis, thereby improving product linearity and cycle life, preferably, in the metal-modified molecular sieve, the ratio of the mass fraction of the surface metal (measured by XPS) to the mass fraction of the bulk metal (measured by XRF) does not exceed 1.35, preferably 0.9-1.35; for example, it can be 0.95, 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, or a value between these two points. Under the above-mentioned preferred distribution, it is beneficial to improve the molecular sieve life and product linearity. If the ratio of the mass fraction of the surface metal to the mass fraction of the bulk metal is too high, it may lead to a shortened catalytic life of the molecular sieve; if the ratio is too low, it may lead to a decrease in product linearity.

[0044] In this invention, preferably, based on the total amount of the metal-modified molecular sieve, the content of the second metal, in terms of elemental composition, is 12-23 wt%. For example, the content of the metal, in terms of elemental composition, can be 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, or any value between any two points. In the above preferred embodiment, it is advantageous to ensure that the metal distribution is in an optimal position, thereby achieving shape-selective catalysis, improving catalyst lifetime and product linearity.

[0045] In this invention, preferably, the atomic radius of the second metal is 120-270 pm, more preferably 160-240 pm. Preferably, the second metal is selected from at least one of Mg, Ca, Sr, Ba, La, Ce, Pr, Rd, Sm, Eu, Yb, Sc, Y, Al, Ga, and In; more preferably, at least one of La, Ce, Sr, and Y. Using the above-mentioned preferred second metal facilitates matching with the molecular sieve channels, achieving optimal shape-selective catalysis, protecting the molecular sieve structure, and improving catalyst lifetime and product linearity.

[0046] In this invention, preferably, the metal-modified molecular sieve is a silica-alumina molecular sieve; preferably, the molar ratio of silica to alumina in the metal-modified molecular sieve is 1-100:1, and more preferably 3-20:1.

[0047] According to the present invention, preferably, the metal-modified molecular sieve is selected from at least one of X-type molecular sieves, Y-type molecular sieves, MCM-22 type molecular sieves, Beta type molecular sieves, and MOR type molecular sieves, and more preferably X-type molecular sieves and / or Y-type molecular sieves. Using the above-mentioned preferred types of molecular sieves is beneficial for further improving the catalytic activity of solid acid catalysts.

[0048] A second aspect of the present invention provides a method for preparing a solid acid catalyst, the method comprising:

[0049] S1. The metal-modified molecular sieve is shaped and calcined once with a heat-resistant inorganic oxide and / or its precursor to obtain a semi-finished catalyst.

[0050] S2. The semi-finished catalyst is contacted with a solution of a soluble compound containing a first metal element, and then dried and calcined a second time to obtain the solid acid catalyst; the first metal is selected from at least one of Group VIII metals.

[0051] The metal-modified molecular sieve includes a molecular sieve and a second metal outside the molecular sieve framework; based on the total amount of the metal-modified molecular sieve, the content of the second metal is 8-30 wt% in terms of elements; the second metal is selected from at least one of alkaline earth metals, Group IIIB metals and Group IIIA metals;

[0052] In the metal-modified molecular sieve, the ratio of the mass fraction of the surface metal measured by XPS to the mass fraction of the bulk metal obtained by XRF test does not exceed 1.45, based on the mass fraction of elements.

[0053] In this invention, it is understood that "first roasting" and "second roasting" do not refer to the order of operations, but are only used to distinguish the roasting conditions in different steps S1 and S2.

[0054] In this invention, there are no special requirements for the preparation method of the metal-modified molecular sieve, as long as the above composition is met. Preferably, the metal-modified molecular sieve is prepared by the following method, which includes:

[0055] (1) The molecular sieve precursor is subjected to a first ion exchange with a first exchange solution containing a soluble compound of a second metal;

[0056] (2) The product of the first ion exchange is subjected to a first calcination to obtain the first exchange molecular sieve;

[0057] (3) The first exchange molecular sieve is subjected to a second ion exchange with a second exchange solution containing a soluble compound of the second metal;

[0058] (4) The product of the second ion exchange is subjected to a second calcination, and the second ion exchange and second calcination are optionally repeated to obtain a second exchange molecular sieve.

[0059] (5) The second exchange molecular sieve is subjected to high temperature treatment in an oxygen-containing atmosphere to obtain the metal-modified molecular sieve;

[0060] The first calcination and / or the second calcination are carried out under an alkaline atmosphere.

[0061] Through the above preferred embodiments, specific extra-framework metal modification can be achieved by at least two cross-conversions and two calcinations, while ensuring the stability of the molecular sieve cell size before and after the reaction, thus avoiding the destruction of the molecular sieve structure due to multiple calcinations.

[0062] In this invention, the number of times the second ion exchange and the second calcination are repeated is not particularly limited and can be determined according to the effect of the ion exchange. The purpose is to ensure that the metal content in the molecular sieve meets the above-mentioned range requirements. For example, it can be repeated 1-3 times.

[0063] According to the present invention, preferably, the molar ratio of silicon oxide to aluminum oxide in the metal-modified molecular sieve is 1-100:1, more preferably 3-20:1.

[0064] In this invention, the molar ratio of silicon oxide to aluminum oxide in the molecular sieve remains essentially unchanged before and after metal modification, both satisfying the above-mentioned molar ratio range requirements.

[0065] According to the present invention, preferably, the molecular sieve precursor is selected from at least one of X-type molecular sieve, Y-type molecular sieve, MCM-22 type molecular sieve, Beta type molecular sieve and MOR type molecular sieve, and more preferably X-type molecular sieve and / or Y-type molecular sieve.

[0066] According to the present invention, preferably, the molecular sieve precursor is a hydrogen-form or sodium-form molecular sieve.

[0067] Preferably, the molecular sieve precursor is a sodium-type molecular sieve, and the first and / or second exchange liquids further include ammonium salts. For example, if the first exchange liquid contains ammonium salts, then step (1) includes ion co-exchange of the sodium-type molecular sieve with the first exchange liquid containing a metal-soluble compound and an ammonium salt.

[0068] In this invention, the ammonium salt can be any conventional choice in the art. Preferably, the ammonium salt is selected from at least one of ammonium nitrate, ammonium chloride, and ammonium sulfate.

[0069] In this invention, preferably, the concentration of the ammonium salt in the first exchange liquid and / or the second exchange liquid is 50-200 g / L, more preferably 70-150 g / L.

[0070] According to the present invention, when the molecular sieve precursor is a sodium-type molecular sieve, preferably, the preparation method further includes ammonium exchange of the second exchange molecular sieve with a third exchange solution containing ammonium salt, followed by the high-temperature treatment.

[0071] In this invention, the ammonium exchange can be carried out using methods and conditions conventional in the art. For example, the ammonium exchange process includes: contacting a second exchange molecular sieve with a third exchange solution containing ammonium salts, followed by filtration and drying. This process constitutes one ammonium exchange operation, which can optionally be repeated 1-3 times until the Na mass fraction in the molecular sieve is below 0.2%.

[0072] In this invention, the concentration of ammonium salt in the third exchange liquid can be in the same range as that in the first and / or second exchange liquids, which will not be elaborated here.

[0073] In this invention, there is no particular limitation on the specific type of soluble compound of the second metal, as long as a second metal source can be provided, it can be selected according to actual needs. Preferably, the soluble compound of the second metal is selected from at least one of the chloride, nitrate, phosphate and sulfate of the second metal.

[0074] Preferably, the first and second exchange solutions each independently include a solvent, and the solvent is preferably water.

[0075] In this invention, preferably, the concentration of the soluble compound of the second metal in the first exchange liquid and / or the second exchange liquid is 100-500 g / L, more preferably 130-400 g / L.

[0076] In this invention, preferably, the atomic radius of the second metal is 120-270 pm, more preferably 160-240 pm. Preferably, the second metal is selected from at least one of Mg, Ca, Sr, Ba, La, Ce, Pr, Rd, Sm, Eu, Yb, Sc, Y, Al, Ga, and In; more preferably, at least one of La, Ce, Sr, and Y. Using the above-mentioned preferred second metal facilitates matching with the molecular sieve channels, achieving optimal shape-selective catalysis, protecting the molecular sieve structure, and improving catalyst lifetime and product linearity.

[0077] According to the present invention, in order to make the first ion exchange more complete, preferably, the mass ratio of the first exchange liquid to the molecular sieve precursor is 2-8:1, and more preferably 3-6:1.

[0078] Preferably, the mass ratio of the second exchange liquid to the first exchange molecular sieve is 3-6:1, and more preferably 3-5:1.

[0079] In this invention, preferably, the conditions for the first ion exchange include: an exchange temperature of 50-90°C, more preferably 70-90°C; and an exchange time of 0.5-2 h, more preferably 0.8-1.5 h.

[0080] In this invention, the conditions for the second ion exchange can be the same as or different from those for the first ion exchange. Preferably, the conditions for the second ion exchange include: an exchange temperature of 50-120°C, more preferably 70-100°C; and an exchange time of 0.5-2 hours, more preferably 0.8-1.5 hours. Preferably, the exchange temperature of the second ion exchange is 0-15°C higher than that of the first exchange, more preferably 1-10°C. Adopting the above-mentioned preferred embodiments is beneficial for further improving the catalytic activity of the solid acid catalyst.

[0081] According to the present invention, preferably, based on the total amount of the metal-modified molecular sieve, the content of the second metal, in terms of elemental composition, is 12-23 wt%. For example, the content of the metal, in terms of elemental composition, can be 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, or any value between any two points. Using the above-mentioned preferred second metal content helps ensure that the metal distribution is in an optimal position, thereby achieving shape-selective catalysis and improving catalyst lifetime and product linearity.

[0082] In this invention, to further control the distribution of the second metal, the first calcination and / or the second calcination are carried out under an alkaline atmosphere. Preferably, both the first and second calcinations are carried out under an alkaline atmosphere. Adopting the above-mentioned preferred embodiments helps to protect the molecular sieve structure, further improve the lifetime of the solid acid catalyst, and increase the linearity of the product.

[0083] According to the present invention, preferably, the alkaline atmosphere is provided by an aqueous solution of an alkaline compound. It is understood that the aqueous solution of the alkaline compound rapidly vaporizes at the calcination temperature, thereby providing an alkaline atmosphere for the calcination process.

[0084] In this invention, the range of alkaline compounds is relatively wide. Preferably, the alkaline compound is selected from at least one of ammonia, ammonium carbonate, and urea, with ammonia being the most preferred.

[0085] In this invention, preferably, the concentration of the alkaline compound in the aqueous solution is 0.01-2 mol / L, more preferably 0.01-0.5 mol / L, and even more preferably 0.05-0.3 mol / L. Under the above preferred conditions, it is beneficial to the stability of the molecular sieve structure and to extend the cycle life of the solid acid catalyst catalyzing the alkylation reaction.

[0086] According to the present invention, preferably, the alkaline atmosphere introduction rate is 0.01-0.5 mL / min relative to 50 g of molecular sieve precursor, more preferably 0.05-0.2 mL / min. It is understood that the alkaline atmosphere introduction rate can be increased proportionally as the amount of molecular sieve precursor processed increases.

[0087] Preferably, the conditions for the first calcination include: a calcination temperature of 400-600℃, a calcination time of 0.5-3h, and a pressure of 0.01-0.1MPa, wherein the pressure is gauge pressure.

[0088] Preferably, the conditions for the second calcination include: a calcination temperature of 400-600℃, a calcination time of 0.5-3h, and a pressure of 0.01-0.1MPa, wherein the pressure is gauge pressure.

[0089] In this invention, the first and second roasting do not refer to the order of operations, but are only used to distinguish the roasting conditions in different steps. The conditions for the first and second roasting can be the same or different, as long as the above-mentioned requirements are met.

[0090] In this invention, before the first or second calcination, the product of the first or second ion exchange is subjected to solid-liquid separation and drying. The solid-liquid separation and drying can be performed using conventional operations in the art, and will not be described in detail here.

[0091] According to the present invention, preferably, the oxygen-containing atmosphere is air or a mixture of oxygen and an inert gas; the inert gas is preferably nitrogen.

[0092] In this invention, preferably, the oxygen content in the oxygen-containing atmosphere is 16-30 vol%, more preferably 18-25 vol%.

[0093] Preferably, the high-temperature treatment temperature is 50-100°C higher than the second calcination temperature.

[0094] According to the present invention, preferably, the conditions for the high-temperature treatment include: a temperature of 500-700℃, more preferably 550-650℃, and a treatment time of 2-12h, more preferably 4-8h.

[0095] According to the present invention, preferably, on a dry basis, the weight ratio of the metal-modified molecular sieve and the heat-resistant inorganic oxide is 99:1-20:80, more preferably 95:5-25:75, and more preferably 90:10-50:50.

[0096] In this invention, there are no special requirements for the specific selection of the heat-resistant inorganic oxide; conventional materials in the art can be used. Preferably, the heat-resistant inorganic oxide is selected from at least one of alumina, zirconium oxide, silicon dioxide, and titanium dioxide. The precursor of the heat-resistant inorganic oxide is a substance that can be obtained by calcination, which is well known to those skilled in the art. For example, the precursor of alumina can be boehmite.

[0097] In this invention, there is no particular limitation on the specific molding method. Molding methods conventionally defined in the art can be selected, such as extrusion molding. Specifically, the molding includes: mixing and molding a metal-modified molecular sieve, a heat-resistant inorganic oxide and / or its precursor, water, and optionally an extrusion aid and a binder.

[0098] In this invention, there is no particular limitation on the type of extrusion aid; any extrusion aid conventionally defined in the art is applicable. Preferably, the extrusion aid is selected from at least one of guar gum powder, cellulose, and starch. In this invention, there is no particular limitation on the amount of extrusion aid used. Preferably, the amount of extrusion aid used is 1-5 wt% of the total dry weight of the metal-modified molecular sieve, the heat-resistant inorganic oxide, and / or its precursor.

[0099] In this invention, the type of adhesive solvent is not particularly limited, and adhesive solvents conventionally defined in the art are applicable to this invention. Preferably, the adhesive solvent is selected from at least one of citric acid, nitric acid, and phosphoric acid. In this invention, the amount of adhesive solvent is not particularly limited. Preferably, the amount of adhesive solvent is 1-8 wt% of the dry weight of the metal-modified molecular sieve and the heat-resistant inorganic oxide and / or its precursor. In this invention, the amount of water is also not particularly limited, as long as it can ensure that the above components are mixed evenly to facilitate molding. Preferably, the ratio of the amount of water to the dry weight of the metal-modified molecular sieve and the heat-resistant inorganic oxide and / or its precursor is 0.3-1:1.

[0100] In this invention, the method further includes drying the shaped product to obtain a mixed-molded article. The drying can be performed using conventional methods in the art, such that the dry basis weight of the mixed-molded article is 40-85 wt% of the weight of the shaped product.

[0101] The molding and drying temperature is 50-180℃, preferably 100-160℃, and the molding and drying time is 2-24h, preferably 4-12h.

[0102] Preferably, the temperature of the first firing is 400-650℃, more preferably 450-600℃, and the firing time is 0.5-8h, more preferably 1-4h.

[0103] In this invention, there is no particular limitation on the specific type of soluble compound of the first metal element, as long as the first metal element can be provided. Preferably, the soluble compound of the first metal element is selected from at least one of the chloride, nitrate, phosphate and sulfate of the first metal.

[0104] In this invention, the soluble compound of the first metallic element may contain water of crystallization, which is well known to those skilled in the art and will not be described in detail here.

[0105] Preferably, the first metal is selected from at least one of Fe, Co, Ni, Ru, Rh, Pd, Ir and Pt; more preferably, it is at least one of Pt, Pd, Ni and Co.

[0106] Preferably, the amounts of the metal-modified molecular sieve, the heat-resistant inorganic oxide and / or its precursor, and the solution of the soluble compound containing the first metal element are such that, in the prepared solid acid catalyst, the content of the metal-modified molecular sieve is 18-98.99 wt%, the content of the heat-resistant inorganic oxide is 1-72 wt%, and the content of the first metal is 0.01-10 wt% by element; preferably, the content of the metal-modified molecular sieve is 50-90 wt%, the content of the heat-resistant inorganic oxide is 9.95-45 wt%, and the content of the first metal is 0.05-5 wt% by element.

[0107] According to the present invention, there are no particular limitations on the conditions of the contact. For example, the conditions of the contact include: a contact temperature of 30-90°C and a contact time of 0.5-10 hours.

[0108] According to the present invention, the preparation method further includes: subjecting the contacted product to low-temperature evaporation, followed by drying and secondary calcination. The low-temperature evaporation can be carried out under conventional water-removal conditions, and there are no particular limitations in this invention. For example, the low-temperature evaporation can be carried out under vacuum conditions.

[0109] In this invention, the drying and secondary calcination can be performed using conventional methods in the art. Preferably, the drying temperature is 70-170℃, more preferably 90-150℃; the drying time is 1-24h, more preferably 2-12h.

[0110] In this invention, the terms "first roasting" and "second roasting" do not refer to the order of operations, but are only used to distinguish the roasting conditions in different steps.

[0111] Preferably, the temperature of the secondary roasting is 350-600℃, more preferably 400-500℃; the time of the secondary roasting is 0.5-4h.

[0112] According to the present invention, preferably, the preparation method further includes: contacting the product obtained from secondary calcination with hydrogen to reduce it, thereby obtaining the solid acid catalyst.

[0113] In this invention, preferably, the reduction conditions include: a reduction temperature of 350-500℃, more preferably 350-450℃; a reduction time of 2-6 h, more preferably 3-4 h; a reduction pressure of 0.05-3 MPa, more preferably 0.05-1 MPa; and a hydrogen volume hourly space velocity of 500-3000 h⁻¹. -1 Preferably 1000-2000h -1 .

[0114] A third aspect of the present invention provides a solid acid catalyst prepared by the above-described preparation method.

[0115] A fourth aspect of the present invention provides a method for preparing long-chain alkylbenzenes, the method comprising contacting a long-chain olefin and an aromatic hydrocarbon with a catalyst under alkylation reaction conditions to obtain long-chain alkylbenzenes;

[0116] The catalyst is a solid acid catalyst as described in the first or third aspect.

[0117] According to the present invention, the metal-modified molecular sieve contained in the solid acid catalyst can achieve shape selectivity of the reaction products, which significantly improves the linearity of the products. The improved selectivity also significantly extends the catalytic alkylation cycle life of the solid acid catalyst.

[0118] In this invention, the alkylation reaction conditions can be those conventional in the art, as long as the alkylation reaction is carried out in a liquid phase and the pressure is always sufficient to ensure that the reaction proceeds in a single liquid phase. In this invention, "single liquid phase" refers to the condition where all reactants are in a liquid phase and the reaction conditions ensure that the reactants do not vaporize during the reaction.

[0119] Preferably, the alkylation reaction conditions include: a reaction temperature of 80-270°C, preferably 90-210°C; a reaction pressure of 0.1-8 MPa, preferably 2-5 MPa; a benzene-olefin molar ratio of 4-80:1, preferably 4-50:1, more preferably 10-50:1; and a long-chain olefin space velocity of 0.1-6 h⁻¹. -1 Preferably, it is 0.3-3.5h. -1 By employing the above-mentioned preferred reaction conditions, it is possible to minimize the isomerization of alkyl groups and the polyalkylation of benzene (or the aromatic moiety of other aryl compounds), while maximizing the consumption of olefins to maximize the product yield.

[0120] In this invention, there are no special requirements regarding the source of the long-chain olefins. For example, long-chain olefins obtained through dehydrogenation, cracking, or oligomerization of small molecule olefins can be used in this invention. Preferably, the long-chain olefins are long-chain olefins with double bonds at both the terminal and internal positions, and / or long-chain α-olefins with double bonds at the terminal position.

[0121] Preferably, the long-chain olefin is a C9-C30 long-chain olefin, more preferably a C9-C20 long-chain olefin, and even more preferably a C10-C16 long-chain olefin.

[0122] Preferably, the aromatic hydrocarbon is selected from at least one of benzene, toluene, and ethylbenzene, and is more preferably benzene.

[0123] According to the present invention, preferably, the method further includes: regenerating the catalyst. Preferably, the regeneration is carried out under a hydrogen atmosphere. By employing the above preferred embodiments, the catalyst is periodically regenerated at high temperatures in a hydrogen-containing atmosphere, enabling the reaction to operate over long periods.

[0124] Preferably, the regeneration temperature is 200-500℃, more preferably 250-450℃, the regeneration pressure is 1-5 MPa, more preferably 1.5-4 MPa, the regeneration time is 1-10 h, more preferably 1.5-6 h, and the hydrogen volume hourly space velocity is 300-5000 h⁻¹. -1 Preferably 350-1000h -1 .

[0125] In this invention, the timing of regeneration can be selected based on the actual reaction or the reaction progress or needs in production. To ensure the effectiveness of regeneration and the long-term stability of the solid acid catalyst performance, preferably, the regeneration is carried out when the conversion rate of long-chain olefins is below 95%, and more preferably, the regeneration is carried out when the conversion rate of long-chain olefins is below 98%.

[0126] The present invention will be described in detail below through embodiments.

[0127] In the following embodiments, the mass fraction of the bulk metal was determined by XRF testing. The mass fraction of the surface metal was determined by XPS testing.

[0128] In this invention, an ESCALAB 250 X-ray photoelectron spectrometer (Thermo Fisher Scientific) was used for XPS testing. The test conditions included: monochromatic Al Kα X-rays, energy 1486.6 eV, power 150 W, and the charge shift was corrected using the C1s peak (284.8 eV) of contaminated carbon.

[0129] In this invention, an XRF test was performed using a Rigaku Electric Industrial Co., Ltd. 3271 X-ray fluorescence spectrometer. The test conditions included: the anode target material of the X-ray tube was a rhodium target; the laser voltage was 50 kV; and the laser current was 50 mA.

[0130] The XRD test conditions include: the instrument used is an X-ray powder diffractometer from PANalytical, Netherlands; the test conditions include: tube voltage 40kV, tube current 40mA, Cu target Kα radiation, scanning speed 2° / min, and scanning range 2θ=5°-35°.

[0131] The molecular sieves used in the following examples were all purchased from Sinopec Catalyst Co., Ltd.

[0132] The following preparation examples illustrate the preparation of metal-modified molecular sieves.

[0133] Preparation Example 1

[0134] (1) Take 50g of HY molecular sieve (molar ratio of silicon oxide / alumina is 6, w(Na2O)=0.0628%), and perform the first ion exchange on the HY molecular sieve with lanthanum nitrate solution. The concentration of lanthanum nitrate is 300g / L, the exchange temperature is 80℃, the exchange time is 1h, and the mass ratio of lanthanum nitrate solution to HY molecular sieve is 3:1. After the exchange, the molecular sieve is filtered and dried, and then calcined at 550℃ for 1h under a pressure of 0.02MPa. During the calcination process, 0.1M ammonia water is introduced at 0.1mL / min. After calcination, the first exchange molecular sieve is obtained, and the mass fraction of lanthanum metal is calculated to be 10.65% by XRF detection.

[0135] (2) The first exchange molecular sieve is subjected to a second ion exchange and a second calcination to obtain a second exchange molecular sieve under the same conditions as in step 1. The mass fraction of lanthanum metal in the second exchange molecular sieve is calculated to be 17.33% by XRF detection.

[0136] (3) The second exchange molecular sieve is calcined in an air atmosphere in a muffle furnace at 600°C for 4 hours to obtain the finished molecular sieve, which is numbered Y1.

[0137] Through XRD testing, such as Figure 1 As shown, the characteristic peaks at 11.9° and 12.4° belong to the metal ions at the cation sites, and the characteristic peak at 29.0° belongs to the metal oxides on the surface of the molecular sieve. At the same time, by comparing with the diffraction peaks of HY molecular sieve, it can be seen that the peak positions of the characteristic peaks of the metal-modified molecular sieve are the same as those of the diffraction peaks of HY molecular sieve, that is, there is no shift. This proves that the metals are all located outside the molecular sieve framework.

[0138] The physicochemical properties of the molecular sieve Y1 obtained by testing are shown in Table 1.

[0139] Preparation Example 2

[0140] The method was followed as in Example 1, except that the HY-type molecular sieve in (1) was replaced with an equal mass of Hβ-type molecular sieve (the molar ratio of silicon oxide to aluminum oxide was 19, and w(Na2O) = 0.0171%). The resulting metal-modified molecular sieve was designated Y2.

[0141] The physicochemical properties of the molecular sieve Y2 obtained from the test are shown in Table 1.

[0142] Preparation Example 3

[0143] The method was the same as in Preparation Example 1, except that the lanthanum nitrate solution was replaced with a cerium nitrate solution. The resulting metal-modified molecular sieve was designated Y3.

[0144] The physicochemical properties of the molecular sieve Y3 obtained from the test are shown in Table 1.

[0145] Preparation Example 4

[0146] The method was the same as in Preparation Example 1, except that the lanthanum nitrate solution was replaced with a strontium nitrate solution. The resulting metal-modified molecular sieve was designated Y4.

[0147] The physicochemical properties of the molecular sieve Y4 obtained by testing are shown in Table 1.

[0148] Preparation Example 5

[0149] The method was the same as in Preparation Example 1, except that the mass ratio of lanthanum nitrate solution to HY molecular sieve was 2.5:1 in both the first and second ion exchanges. The resulting metal-modified molecular sieve was designated Y5.

[0150] The physicochemical properties of the molecular sieve Y5 obtained from the test are shown in Table 1.

[0151] Preparation Example 6

[0152] The method was the same as in Preparation Example 1, except that the mass ratio of lanthanum nitrate solution to HY molecular sieve was 3.8:1 in both the first and second ion exchanges. The resulting metal-modified molecular sieve was designated Y6.

[0153] The physicochemical properties of the molecular sieve Y6 obtained by testing are shown in Table 1.

[0154] Preparation Example 7

[0155] The method was the same as in Preparation Example 1, except that the ammonia flow rate was changed to 0.03 mL / min. The resulting metal-modified molecular sieve was designated Y7.

[0156] The physicochemical properties of the molecular sieve Y7 obtained from the test are shown in Table 1.

[0157] Preparation Example 8

[0158] (1) Take 50g of NaY molecular sieve (the molar ratio of silicon dioxide / alumina is 5, w(Na2O) = 12.8%), and use a mixed solution of ammonium chloride and lanthanum nitrate to carry out the first ion exchange of NaY molecular sieve. The concentration of ammonium chloride is 120g / L (calculated separately), the concentration of lanthanum nitrate is 300g / L (calculated separately), the exchange temperature is 80℃, the exchange time is 1h, and the mass ratio of the mixed solution to the molecular sieve is 3:1. After the exchange, the molecular sieve is filtered and dried, and then calcined at 550℃ for 1h under a pressure of 0.02MPa. During the calcination process, 0.1M ammonia water is introduced at 0.1mL / min. The first exchange molecular sieve is obtained after calcination.

[0159] (2) The first exchange molecular sieve is subjected to a second ion exchange and a second calcination to obtain a second exchange molecular sieve, under the same conditions as in step 1.

[0160] (3) The second exchange molecular sieve was exchanged with ammonium chloride solution. The concentration of ammonium chloride was 120 g / L, the exchange temperature was 80 °C, the exchange time was 1 h, and the mass ratio of ammonium chloride solution to molecular sieve was 3:1. After the exchange, the molecular sieve was filtered and dried, and then exchanged with ammonium chloride solution again under the same conditions as above. This was repeated twice to make the Na mass fraction in the molecular sieve less than 0.2%. The second exchange molecular sieve was then calcined in a muffle furnace at 600 °C for 4 h in an air atmosphere.

[0161] This is the finished molecular sieve, designated Y8. The physicochemical properties of the tested molecular sieve Y8 are shown in Table 1.

[0162] Preparation Example 9

[0163] The method was the same as in Preparation Example 1, except that the concentration of the lanthanum nitrate solution was 400 g / L. The resulting metal-modified molecular sieve was designated Y9.

[0164] The physicochemical properties of the molecular sieve Y9 obtained from the test are shown in Table 1 (continued).

[0165] Preparation Example 10

[0166] The method was the same as in Preparation Example 1, except that the concentration of the lanthanum nitrate solution was 200 g / L. The resulting metal-modified molecular sieve was designated Y10.

[0167] The physicochemical properties of the molecular sieve Y10 obtained from the test are shown in Table 1 (continued).

[0168] Preparation Example 11

[0169] The method was the same as in Preparation Example 1, except that the HY-type molecular sieve in (1) was replaced with an HX-type molecular sieve (the molar ratio of silicon oxide to aluminum oxide was 2, and w(Na2O) = 0.0156%). The metal-modified molecular sieve obtained was designated Y11.

[0170] The physicochemical properties of the molecular sieve Y11 obtained from the test are shown in Table 1 (continued).

[0171] Preparation Example 12

[0172] (1) Take 50g of HY molecular sieve (the molar ratio of silicon oxide / alumina is 6, w(Na2O)=0.0628%), and use lanthanum nitrate solution to carry out the first ion exchange of HY molecular sieve. The concentration of lanthanum nitrate is 300g / L, the exchange temperature is 80℃, the exchange time is 1h, and the mass ratio of lanthanum nitrate solution to HY molecular sieve is 3:1. After the exchange, the molecular sieve is filtered and dried, and then calcined at 550℃ for 1h under a pressure of 0.02MPa. During the calcination process, 0.1M ammonia water is introduced at 0.1mL / min to obtain the first exchange molecular sieve.

[0173] (2) The first exchange molecular sieve is subjected to a second ion exchange, which is different from the first ion exchange in that the second ion exchange temperature is 90℃; after calcination, the second exchange molecular sieve is obtained.

[0174] (3) The second exchange molecular sieve is calcined in an air atmosphere in a muffle furnace at 600°C for 4 hours to obtain the finished molecular sieve, which is numbered Y12.

[0175] The physicochemical properties of the molecular sieve Y12 obtained from the test are shown in Table 1 (continued).

[0176] Comparative Preparation Example 1

[0177] The untreated HY molecular sieve from Preparation Example 1 was used, designated DY1. The physicochemical properties of the obtained molecular sieve DY1 are shown in Table 1 (continued).

[0178] Comparative Preparation Example 2

[0179] (1) Take 50g of HY molecular sieve (molar ratio of silicon oxide / alumina is 6, w(Na2O) = 0.0628%), and perform the first ion exchange on the HY molecular sieve with lanthanum nitrate solution. The concentration of lanthanum nitrate is 150g / L, the exchange temperature is 80℃, the exchange time is 1h, and the mass ratio of solution to molecular sieve is 3:1. After the exchange, the molecular sieve is filtered and dried, and then calcined at 550℃ for 1h under a pressure of 0.02MPa. At the same time, 0.1M ammonia water is introduced at 0.1mL / min during the calcination process. After calcination, the first exchange molecular sieve is obtained, and the mass fraction of lanthanum metal is calculated to be 5.83% by XRF detection.

[0180] (2) The first exchange molecular sieve is subjected to a second ion exchange and a second calcination to obtain a second exchange molecular sieve under the same conditions as in step 1. The mass fraction of lanthanum metal in the second exchange molecular sieve is calculated to be 6.97% by XRF detection.

[0181] (3) The second exchange molecular sieve is calcined in an air atmosphere in a muffle furnace at 600°C for 4 hours to obtain the finished molecular sieve, which is numbered DY2.

[0182] The physicochemical properties of the molecular sieve DY2 obtained from the test are shown in Table 1 (continued).

[0183] Comparative preparation example 3

[0184] (1) Take 50g of HY molecular sieve (molar ratio of silicon oxide / alumina is 6, w(Na2O) = 0.0628%), and perform the first ion exchange on the HY molecular sieve with lanthanum nitrate solution at a concentration of 900g / L, an exchange temperature of 80℃, an exchange time of 1h, and a solution-to-molecular sieve mass ratio of 3:1. After the exchange, the molecular sieve is evaporated to remove water and dried, and then calcined at 550℃ for 1h under a pressure of 0.02MPa. At the same time, 0.1M ammonia water is introduced at 0.1mL / min during the calcination process. After calcination, the mass fraction of lanthanum metal in the molecular sieve is calculated to be 19.06% by XRF detection.

[0185] (2) The first exchange molecular sieve is subjected to a second ion exchange and a second calcination to obtain a second exchange molecular sieve. The method is the same as in step 1. The mass fraction of lanthanum metal in the second exchange molecular sieve is calculated to be 31.80% by XRF detection.

[0186] (3) The second exchange molecular sieve is calcined in an air atmosphere in a muffle furnace at 600°C for 4 hours to obtain the finished molecular sieve, which is numbered DY3.

[0187] The physicochemical properties of the molecular sieve DY3 obtained by testing are shown in Table 1 (continued).

[0188] Comparative preparation example 4

[0189] Following the method in Preparation Example 1, except that an equal amount of water was introduced to replace ammonia in both the first and second calcination processes, the resulting molecular sieve was denoted as DY4, and the physicochemical properties of the obtained molecular sieve DY4 are shown in Table 1 (continued).

[0190] Table 1

[0191]

[0192] Continued from Table 1

[0193]

[0194]

[0195] The following examples illustrate the preparation of the solid acid catalyst in this invention.

[0196] Example 1

[0197] Molecular sieve sample Y1 and pseudoboehmite (purchased from Sinopec Catalyst Co., Ltd.) were mixed at a dry weight ratio of 80:20. 3 wt% of guar gum powder and 3 wt% of nitric acid were added respectively (based on the total dry weight of molecular sieve and pseudoboehmite). Deionized water was added at a mass ratio of 1:1 based on the dry weight of molecular sieve and pseudoboehmite. After mixing evenly, the mixture was extruded and dried at 110℃ for 6 hours to make the dry weight of the mixed molding product 65 wt%. Then, it was calcined in air at 550℃ for 4 hours to obtain the semi-finished catalyst Z1.

[0198] Supported hydrogenation functional metal (using metallic Pt)

[0199] H2PtCl6 was selected as the precursor of platinum. Metal was loaded onto the semi-finished catalyst Z1 by impregnation with a 0.2wt% aqueous solution of H2PtCl6 at a temperature of 50℃ for 3 hours. Moisture was removed by low-temperature evaporation at a temperature of 75℃ and a vacuum of 0.08MPa. After evaporation, the catalyst was dried at 110℃ for 4 hours and then calcined at 400℃ for 2 hours.

[0200] The calcined product was then reduced by contacting hydrogen at 450℃ and 0.05 MPa for 4 hours, with a hydrogen volume hourly space velocity of 1000 h⁻¹. -1 Solid acid catalyst G1 was obtained. The content of metal-modified molecular sieve in G1 was 79.76 wt%, the content of alumina was 19.94 wt%, and the loading of Pt was 0.3 wt%.

[0201] The alkylation reaction of benzene with 1-dodecene was carried out at 150 °C and 2.5 MPa, with a hydrocarbon feed space velocity of 0.708 h⁻¹. -1 The molar ratio of benzene to feed was 10:1. After reacting for 30 h, the product was collected, and the conversion rate of 1-dodecene and the selectivity of monoalkylbenzene were calculated. The results are shown in Table 2.

[0202] When the conversion of 1-dodecene is below 98%, the catalyst is regenerated with hydrogen at 300°C and 2.5 MPa for 4 hours, with a hydrogen volume hourly space velocity of 500 h⁻¹. -1 After regeneration, the reaction was carried out again under the same conditions for 30 hours. The results are shown in Table 3.

[0203] Olefin conversion rate (%) = (Amount of olefins before reaction - Amount of olefins after reaction) / Amount of olefins before reaction × 100%.

[0204] Monoalkylbenzene selectivity (%) = Amount of monoalkylbenzene after reaction / Amount of all reaction products × 100%;

[0205] Straight-chain degree (%) = Amount of straight-chain alkylbenzene after reaction / Amount of monoalkylbenzene after reaction × 100%.

[0206] Example 2-12

[0207] Following the method in Example 1, except that Y1 was replaced by metal-modified molecular sieves Y2-Y12 from Preparation Examples 2-12 to obtain solid acid catalysts G2-G12.

[0208] Following the evaluation method in Example 1, alkylation reactions were carried out using the above-mentioned solid acid catalysts G2-G12, and the results are shown in Table 2.

[0209] Example 13

[0210] Molecular sieve sample Y1 was mixed with titanium dioxide at a dry weight ratio of 80:20. 3 wt% of guar gum powder and 3 wt% of nitric acid were added respectively (based on the total dry weight of molecular sieve and titanium dioxide). Deionized water was added at a mass ratio of 1:1 based on the dry weight of molecular sieve and titanium dioxide. After mixing evenly, the mixture was extruded and dried at 150°C for 6 hours to make the dry weight of the mixed molded product 70 wt%. Then, it was calcined in air at 600°C for 6 hours to obtain the semi-finished catalyst Z13.

[0211] Supported hydrogenated functional metal (using metallic Pd)

[0212] Dichlorotetraamminepalladium was selected as the palladium precursor. A 0.2 wt% aqueous solution of dichlorotetraamminepalladium was used to impregnate the semi-finished catalyst Z13 at 90°C for 10 hours. Moisture was removed by low-temperature evaporation at 75°C under a vacuum of 0.08 MPa. After evaporation, the catalyst was dried at 170°C for 1 hour and then calcined at 350°C for 4 hours. The calcined product was then reduced by contacting hydrogen at 400°C and 0.1 MPa for 3 hours, with a hydrogen volume hourly space velocity (HHSV) of 2000 h⁻¹. -1 Solid acid catalyst G13 was obtained. XRF analysis, combined with the composition of the feed, revealed that G13 contained 79.76 wt% metal-modified molecular sieve, 19.94 wt% titanium dioxide, and 0.3 wt% Pd loading.

[0213] The alkylation reaction of benzene with 1-hexadecene was carried out under reaction conditions of 210℃ and 5MPa, with a hydrocarbon feed space velocity of 0.3h. -1 The molar ratio of styrene to feed was 50:1. The results of the conversion rate of 1-hexadecene and the selectivity of monoalkylbenzenes are shown in Table 2.

[0214] When the conversion rate of 1-hexadecene was less than 98%, the catalyst was regenerated with hydrogen at 300℃ and 2.5MPa for 4 hours. After regeneration, the reaction was carried out again under the same conditions. The reaction results are shown in Table 3.

[0215] Example 14

[0216] Following the method in Example 1, except that the concentration of the aqueous solution of H2PtCl6 was 0.1 wt%, solid acid catalyst G14 was obtained. G14 contained 79.88 wt% metal-modified molecular sieve, 19.97 wt% alumina, and 0.15 wt% Pt loading.

[0217] Comparative Examples 1-4

[0218] Following the method in Example 1, except that Y1 was replaced by molecular sieves DY1-DY4 obtained in Comparative Preparation Examples 1-4 to obtain solid acid catalysts DG1-DG4.

[0219] Following the evaluation method in Example 1, alkylation reactions were carried out using the above-mentioned solid acid catalysts DG1-DG4, and the results are shown in Table 2.

[0220] Table 2

[0221]

[0222]

[0223] Table 3. Reaction results after one regeneration.

[0224]

[0225]

[0226] The results in Table 2 show that the obtained solid acid catalyst can effectively suppress the skeletal isomerism of alkylbenzene products. Through the synergistic effect of the metal-modified molecular sieve, the heat-resistant inorganic oxide, and the first metal, the linearity of the product can be further improved. Table 3 shows that the deactivated catalyst can be completely regenerated under hydrogen conditions, and the regenerated catalyst maintains high catalytic activity, which is beneficial for the continuous and stable operation of the reaction.

[0227] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A solid acid catalyst, characterized in that, The catalyst comprises a metal-modified molecular sieve, a heat-resistant inorganic oxide, and a first metal; the first metal is selected from at least one group VIII metal. The metal-modified molecular sieve comprises a molecular sieve and a second metal outside the molecular sieve framework; based on the total amount of the metal-modified molecular sieve, the content of the second metal is 12-23 wt% by element; the second metal is selected from at least one of alkaline earth metals, Group IIIB metals, and Group IIIA metals; the metal-modified molecular sieve is selected from at least one of X-type molecular sieves, Y-type molecular sieves, MCM-22 type molecular sieves, Beta type molecular sieves, and MOR type molecular sieves. In the metal-modified molecular sieve, the ratio of the mass fraction of the surface metal measured by XPS to the mass fraction of the bulk metal obtained by XRF testing is 0.9-1.35, based on the mass fraction of elements.

2. The solid acid catalyst according to claim 1, wherein, Based on the total amount of the solid acid catalyst, the content of the metal-modified molecular sieve is 18-98.99 wt%, the content of the heat-resistant inorganic oxide is 1-72 wt%, and the content of the first metal is 0.01-10 wt% by element.

3. The solid acid catalyst according to claim 2, wherein, Based on the total amount of the solid acid catalyst, the content of the metal-modified molecular sieve is 50-90 wt%, the content of the heat-resistant inorganic oxide is 9.95-45 wt%, and the content of the first metal is 0.05-5 wt% by element.

4. The solid acid catalyst according to claim 1, wherein, On a dry basis, the weight ratio of the metal-modified molecular sieve to the heat-resistant inorganic oxide is 99:1-20:

80.

5. The solid acid catalyst according to claim 4, wherein, On a dry basis, the weight ratio of the metal-modified molecular sieve to the heat-resistant inorganic oxide is 95:5-25:

75.

6. The solid acid catalyst according to claim 5, wherein, On a dry basis, the weight ratio of the metal-modified molecular sieve to the heat-resistant inorganic oxide is 90:10-50:

50.

7. The solid acid catalyst according to claim 1, wherein, The first metal is selected from at least one of Fe, Co, Ni, Ru, Rh, Pd, Ir and Pt; And / or, the heat-resistant inorganic oxide is selected from at least one of alumina, zirconium oxide, silicon dioxide and titanium dioxide.

8. The solid acid catalyst according to claim 7, wherein, The first metal is selected from at least one of Pt, Pd, Ni and Co.

9. The solid acid catalyst according to claim 1, wherein, The atomic radius of the second metal is 120-270 pm; And / or, the second metal is selected from at least one of La, Ce, Sr and Y.

10. The solid acid catalyst according to claim 9, wherein, The atomic radius of the second metal is 160-240 pm.

11. The solid acid catalyst according to claim 1, wherein, The molar ratio of silica to alumina in the metal-modified molecular sieve is 1-100:

1.

12. The solid acid catalyst according to claim 11, wherein, The molar ratio of silica to alumina in the metal-modified molecular sieve is 3-20:

1.

13. The solid acid catalyst according to claim 1, wherein, The metal-modified molecular sieve is an X-type molecular sieve and / or a Y-type molecular sieve.

14. A method for preparing the solid acid catalyst according to any one of claims 1-13, characterized in that, The preparation method includes: S1. The metal-modified molecular sieve is shaped and calcined once with a heat-resistant inorganic oxide and / or its precursor to obtain a semi-finished catalyst. S2. The semi-finished catalyst is contacted with a solution of a soluble compound containing a first metal element, and then dried and calcined a second time to obtain the solid acid catalyst; the first metal is selected from at least one of Group VIII metals.

15. The preparation method according to claim 14, wherein, The metal-modified molecular sieve is prepared by the following method, which includes: (1) The molecular sieve precursor is subjected to a first ion exchange with a first exchange solution containing a soluble compound of a second metal; (2) The product of the first ion exchange is subjected to a first calcination to obtain the first exchange molecular sieve; (3) The first exchange molecular sieve is subjected to a second ion exchange with a second exchange solution containing a soluble compound of the second metal; (4) The product of the second ion exchange is subjected to a second calcination, and the second ion exchange and the second calcination are optionally repeated to obtain the second exchange molecular sieve; (5) The second exchange molecular sieve is subjected to high temperature treatment in an oxygen-containing atmosphere to obtain the metal-modified molecular sieve; The first calcination and / or the second calcination are carried out under an alkaline atmosphere.

16. The preparation method according to claim 15, wherein, The molecular sieve precursor is a hydrogen-form or sodium-form molecular sieve.

17. The preparation method according to claim 16, wherein, The molecular sieve precursor is a sodium-type molecular sieve, and the first and / or second exchange liquids also contain ammonium salts.

18. The preparation method according to claim 17, wherein, The ammonium salt is selected from at least one of ammonium nitrate, ammonium chloride, and ammonium sulfate; And / or, in the first exchange solution and / or the second exchange solution, the concentration of the ammonium salt is independently 50-200 g / L.

19. The preparation method according to claim 15, wherein, The soluble compound of the second metal is selected from at least one of the chloride, nitrate, phosphate and sulfate of the second metal; And / or, the first and second exchange solutions each independently include a solvent, wherein the solvent is water.

20. The preparation method according to claim 15, wherein, In the first and / or second exchange solutions, the concentration of the soluble compound of the metal is independently 100-500 g / L.

21. The preparation method according to claim 15, wherein, The mass ratio of the first exchange liquid to the molecular sieve precursor is 2-8:1; And / or, the mass ratio of the second exchange liquid to the first exchange molecular sieve is 3-6:1; And / or, the conditions for the first ion exchange include: an exchange temperature of 50-90°C; and an exchange time of 0.5-2 hours. And / or, the exchange temperature of the second ion exchange is 0-15°C higher than the exchange temperature of the first ion exchange.

22. The preparation method according to claim 21, wherein, The conditions for the first ion exchange include: an exchange temperature of 70-90℃ and an exchange time of 0.5-1.5h; And / or, the exchange temperature of the second ion exchange is 1-10°C higher than the exchange temperature of the first ion exchange.

23. The preparation method according to claim 15, wherein, The alkaline atmosphere is provided by an aqueous solution of an alkaline compound.

24. The preparation method according to claim 23, wherein, The alkaline compound is selected from at least one of ammonia, ammonium carbonate, and urea.

25. The preparation method according to claim 23, wherein, The concentration of the alkaline compound in the aqueous solution is 0.01-2 mol / L.

26. The preparation method according to claim 15, wherein, The alkaline atmosphere was introduced at a rate of 0.01-0.5 mL / min relative to 50 g of molecular sieve precursor. And / or, the conditions for the first calcination include: a calcination temperature of 400-600℃, a calcination time of 0.5-3h, and a pressure of 0.01-0.1MPa, wherein the pressure is gauge pressure; And / or, the conditions for the second calcination include: a calcination temperature of 400-600℃, a calcination time of 0.5-3h, and a pressure of 0.01-0.1MPa, wherein the pressure is gauge pressure.

27. The preparation method according to claim 15, wherein, The oxygen-containing atmosphere is air or a mixture of oxygen and an inert gas.

28. The preparation method according to claim 27, wherein, The oxygen content in the oxygen-containing atmosphere is 16-30 vol.

29. The preparation method according to claim 28, wherein, The oxygen content in the oxygen-containing atmosphere is 18-25 vol.

30. The preparation method according to claim 15, wherein, The high-temperature treatment temperature is 50-100°C higher than the second calcination temperature; And / or, the conditions for the high-temperature treatment include: a temperature of 500-700℃ and a treatment time of 2-12h.

31. The preparation method according to claim 30, wherein, The conditions for the high-temperature treatment include: a temperature of 550-650℃ and a treatment time of 4-8 hours.

32. The preparation method according to claim 14, wherein, The temperature of the first roasting is 400-650℃, and the roasting time is 0.5-12h.

33. The preparation method according to claim 14, wherein, The soluble compound of the first metal element is selected from at least one of the chloride, nitrate, phosphate and sulfate of the first metal; And / or, the contact conditions include: a contact temperature of 30-90°C and a contact time of 0.5-10 hours; And / or, the drying temperature is 70-170℃, and the drying time is 1-24h; And / or, the temperature of the secondary calcination is 350-600℃, and the time of the secondary calcination is 0.5-4h.

34. The preparation method according to claim 14, wherein, The preparation method further includes: contacting the product from the secondary calcination with hydrogen to reduce it, thereby obtaining the solid acid catalyst.

35. The preparation method according to claim 34, wherein, The reduction conditions include: a reduction temperature of 350-500℃, a reduction time of 2-6 hours, a reduction pressure of 0.05-3 MPa, and a hydrogen volume hourly space velocity of 500-3000 h⁻¹. -1 .

36. A method for preparing long-chain alkylbenzenes, the method comprising contacting a long-chain olefin and an aromatic hydrocarbon with a catalyst under alkylation reaction conditions to obtain long-chain alkylbenzenes; Its features are, The catalyst is a solid acid catalyst as described in any one of claims 1-13.

37. The method of claim 36, wherein, The alkylation reaction conditions include: a reaction temperature of 80-270℃; a reaction pressure of 0.1-8 MPa; a benzene-to-olefin molar ratio of 4-80:1; and a space velocity of 0.1-6 h⁻¹ for the long-chain olefin. -1 ; And / or, the long-chain olefin is a long-chain olefin having double bonds at both the terminal and internal positions, and / or, a long-chain α-olefin having double bonds at the terminal position. And / or, the long-chain olefin is a C9-C30 long-chain olefin; And / or, the aromatic hydrocarbon is at least one of benzene, toluene, and ethylbenzene.

38. The method according to claim 37, wherein, The alkylation reaction conditions include: a reaction temperature of 90-210℃; a reaction pressure of 2-5 MPa; a benzene-to-olefin molar ratio of 5-50:1; and a space velocity of 0.3-3.5 h⁻¹ for the long-chain olefin. -1 ; And / or, the long-chain olefin is a C9-C20 long-chain olefin; And / or, the aromatic hydrocarbon is benzene.

39. The method according to claim 38, wherein, The long-chain olefins are C10-C16 long-chain olefins.

40. The method of claim 36, wherein, The method further includes regenerating the catalyst.

41. The method according to claim 40, wherein, The regeneration is carried out in a hydrogen atmosphere; And / or, the regeneration temperature is 200-500℃, the regeneration pressure is 1-5MPa, the regeneration time is 1-10h, and the hydrogen volume hourly space velocity is 300-5000h. -1 ; And / or, the regeneration is carried out when the conversion of long-chain olefins is less than 95%.

42. The method according to claim 41, wherein, The regeneration is carried out when the conversion rate of long-chain olefins is less than 98%.

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