Alkylation process

Abstract

The application belongs to the technical field of alkylation and particularly relates to an alkylation method. The method comprises: carrying out alkylation reaction of isomeric alkanes and ethylene in the presence of a hydrogen-containing atmosphere and a solid acid catalyst; the concentration of hydrogen in the hydrogen-containing atmosphere is 1-100% by volume; the solid acid catalyst comprises a molecular sieve, a binder and a hydrogenation active component, the content of the molecular sieve is 20-90% by weight based on the dry weight of the catalyst, the content of the binder is 5-79.99% by weight, and the content of the hydrogenation active component in terms of elements is 0.01-5% by weight; the increase range of the total pyridine infrared acid amount of the catalyst at 200 DEG C compared with the total pyridine infrared acid amount of the molecular sieve is 30-110%; and the increase range of the mesopore volume of the catalyst compared with the mesopore volume of the molecular sieve is 70-215%. The method can improve the conversion rate and yield of the catalyst in the alkylation reaction of isomeric alkanes and ethylene.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of alkylation, and in particular to an alkylation method. BACKGROUND

[0002] The reaction of isoparaffins with olefins to form alkylate oil on an acidic catalyst is an important process for producing high octane gasoline components in the petroleum industry. The reaction is an organic addition reaction between alkane molecules and olefin molecules following a carbonium ion chain reaction course under the action of an acidic catalyst.

[0003] With the increasing environmental protection requirements and energy saving and emission reduction requirements, in order to reduce the fuel consumption of automobiles, the number of hybrid automobiles is increasing. Since the engine of the hybrid automobile needs to be started and stopped frequently, a certain amount of lighter high-octane component will help the engine to start. The dimethylbutane and isopentane obtained by alkylation of isobutane and ethylene have high octane number, good combustion performance, and do not contain sulfides, aromatics and olefins, which are ideal light gasoline blending components.

[0004] Molecular sieves have a regular three-dimensional pore structure, suitable acidity and low price, which is conducive to the diffusion of reactant molecules in the pore of the molecular sieve and the reaction at the acidic center. Molecular sieve catalysts are widely used in petroleum and chemical industries, especially in the fields of catalytic cracking, hydrogenation, reforming, isobutane butene alkylation, benzene and olefin alkylation, etc. Therefore, the research on molecular sieve catalysts not only has important academic value, but also has wide application prospect.

[0005] However, the solid acid catalyst of the molecular sieve is easy to coking and deactivation in the process of catalyzing the alkylation reaction of isobutane and ethylene, and the service life of the catalyst needs to be improved for continuous production and the catalyst needs to be regenerated frequently. For the molecular sieve catalyst, improving the service life of the catalyst can increase the total acid amount of the catalyst, inhibit the occurrence of side reactions, and improve the diffusion performance of the catalyst to make the generated macromolecular products diffuse out of the pore in time. Generally, the diffusion performance of the molecular sieve catalyst is realized by improving the pore structure of the catalyst. However, in general, the pore expansion of the molecular sieve catalyst will destroy the acid sites of the catalyst, resulting in a decrease in the total acid amount. The catalyst after one-time calcination still contains some Na + Near the acid sites, the acid sites can be protected from being destroyed.

[0006] It is generally believed that the coking reaction on the catalyst starts from lower olefins, and then polyenes and low-ring aromatics are generated by polymerization and hydrogen transfer reactions, and hydrogen transfer, alkylation and cyclization reactions continue to occur to form difficult-to-volatile, multi-ring structure coke deposits. Alkylation reaction is carried out at a relatively low temperature, and the carbon deposit on the catalyst is generally long-chain alkanes, olefins and monocyclic aromatic compounds. These carbon deposits are called soft coke, which can be easily removed from the acid sites of the catalyst by hydrogenation reaction. SUMMARY

[0007] The alkylating method provided by the present application selects a solid acid catalyst with higher pyridine infrared total acid amount and specific mesopore volume, which can improve the conversion rate and yield of the catalyst in the isomerized alkane and ethylene alkylation reaction, is simple to operate and low in cost.

[0008] To achieve the above-mentioned purpose, the present application provides an alkylating method, which comprises: carrying out alkylation reaction of isomerized alkane and ethylene in the presence of a hydrogen-containing atmosphere and a solid acid catalyst; the concentration of hydrogen in the hydrogen-containing atmosphere is 1-100 vol%; the solid acid catalyst comprises a molecular sieve, a binder and a hydrogenation active component, the content of the molecular sieve is 20-90 wt% based on the dry weight of the catalyst, the content of the binder is 5-79.99 wt%, and the content of the hydrogenation active component is 0.01-5 wt% in terms of elements; the 200℃ pyridine infrared total acid amount of the catalyst is increased by 30-110% compared with that of the molecular sieve; and the mesopore volume of the catalyst is increased by 70-215% compared with that of the molecular sieve.

[0009] The alkylating method provided by the present application generates high-octane dimethylbutane and isopentane, reduces the loss of catalyst performance and structure caused by catalyst regeneration, reduces the energy loss caused by high-temperature hydrogen regeneration, reduces carbon emissions and reduces the reaction cost.

[0010] The alkylating method provided by the present application is reacted in a hydrogen atmosphere, uses the hydrogenolysis function of the supported platinum on the catalyst to inhibit the generation of carbon deposition, prolongs the reaction period, does not have a negative impact on the acidity and stability of the catalyst itself, realizes long-period continuous operation of the catalyst, is beneficial to industrial continuous production and greatly saves the production cost.

[0011] The alkylating method provided by the present application selects a solid acid catalyst with higher pyridine infrared total acid amount and specific mesopore volume, preferably, in the process of preparing the solid acid catalyst, the inventors of the present application find that, after one ammonium exchange of Na-type molecular sieve, molding and calcination with the binder, and one crystallization treatment of the catalyst, the residual Na + The method can improve the mesopore volume and acid accessibility of the catalyst without destroying the acidity of the catalyst, can make the supported active metal enter the Na cage, improve the metal dispersion degree and effectively improve the service life of the catalyst.

[0012] Compared with the short reaction cycle of the prior art catalyst, the alkylation method provided by the application greatly improves the labor and material costs in the reaction process, prolongs the service life of the catalyst and thus prolongs the reaction cycle, which can effectively reduce the frequent switching and regeneration of the reactor, is conducive to cost saving and carbon emission reduction. DETAILED DESCRIPTION

[0013] The endpoints of the ranges and any values claimed herein are not to be understood as being limited to the exact values recited as implicitly included within the range. Ranges can be expressed as from about one particular value to about another; however, when such a compound is recited, it is to be understood that values and sub-ranges between the recited values are included and form part of the range. Any numerical value, however, can inherently contain certain errors necessarily resulting from the round-off or measurement of its underlying data. Moreover, compounds described herein include all such variations.

[0014] The application provides an alkylation method, wherein the method comprises: carrying out alkylation reaction of isomeric alkanes and ethylene in the presence of a hydrogen-containing atmosphere and a solid acid catalyst; wherein the concentration of hydrogen in the hydrogen-containing atmosphere is 1-100% by volume; the solid acid catalyst comprises a molecular sieve, a binder and a hydrogenation active component, the content of the molecular sieve is 20-90% by weight based on the dry basis weight of the catalyst, the content of the binder is 5-79.99% by weight, and the content of the hydrogenation active component is 0.01-5% by weight in terms of elements; the increase amplitude of the total pyridine infrared acid amount of the catalyst at 200 DEG C compared with the total pyridine infrared acid amount of the molecular sieve is 30-110%; and the increase amplitude of the mesopore volume of the catalyst compared with the mesopore volume of the molecular sieve is 70-215%.

[0015] The method provided by the application selects a solid acid catalyst with a higher total pyridine infrared acid amount and a higher mesopore volume, and the total pyridine infrared acid amount and the mesopore volume have a specific matching relationship, so that the service life of the catalyst is longer; further, the method provided by the application loads a component with hydrogenation activity on the solid acid catalyst, which dissociates hydrogen into H protons in the reaction process, promotes the hydrogen transfer reaction in the alkylation reaction, inhibits the generation of carbon deposition, and greatly improves the service life of the catalyst.

[0016] According to a preferred embodiment of the application, the content of the molecular sieve is 25-84% by weight based on the dry basis weight of the catalyst, the content of the binder is 15-75% by weight, and the content of the hydrogenation active component is 0.1-1% by weight in terms of elements.

[0017] In this invention, the content of each substance in the catalyst is determined by X-ray fluorescence spectroscopy (XRF). Specific test conditions include: tungsten target, excitation voltage 40 kV, and excitation current 50 mA. The sample powder is pressed into tablets, with an applied pressure typically of 500-1000 kPa. Standard samples are measured, and a working curve is established. The content is determined from the working curve using interpolation.

[0018] According to a preferred embodiment of the present invention, the total pyridine infrared spectroscopy (RIS) content of the catalyst at 200°C is increased by 52-80% compared to that of the molecular sieve at 200°C. An advantage of this preferred embodiment is that the resulting catalyst has a suitable total pyridine infrared spectroscopy content for the alkylation reaction of ethylene isobutane.

[0019] According to a preferred embodiment of the present invention, the mesopore volume of the catalyst is increased by 110-215% compared with that of the molecular sieve. The advantage of this preferred embodiment is that the increase in the catalyst's mesopore volume is mainly concentrated on the disruption of the Na cages, with no significant impact on the original pore structure. While maintaining the original acidity, it exposes the Brønsted acid sites of the Na cages, thereby increasing the Brønsted acid content and the accessibility of the acidic centers in the catalyst.

[0020] In this invention, "dry weight" refers to the mass of a unit mass of catalyst after calcination at 600°C for 4 hours.

[0021] In this invention, the method for determining the pyridine adsorption of alkylated solid acid catalysts using infrared spectroscopy is as follows: Instrument: Bruker Tensor II Fourier transform infrared spectrometer; Test procedure: Approximately 25 mg of catalyst sample was pressed into a tablet at 20 MPa for 5 min, placed in the in-situ cell of the infrared spectrometer and sealed. The temperature was increased to 450 °C at a rate of 10 °C / min, and then evacuated to 10 °C. -6 After treatment at approximately 1540 nm for 2 hours and cooling to room temperature, the adsorbed pyridine was statically saturated. Subsequently, under vacuum, the temperature was gradually increased to 200 °C and 350 °C to desorb the adsorbed pyridine. The infrared spectra at both temperatures were measured, integrated, and calculated using a formula. The value of 1540 cm⁻¹ was also calculated. -1 The absorption peak at 1450 cm⁻¹ belongs to the B acidic site. -1 The absorption peak is attributed to the L acidic site.

[0022] C is the concentration of Brønsted acid or Lewis acid (mmol / g). B With C L The calculation formula is:

[0023] C B =1.88A B R 2 / W (Equation 1)

[0024] CL = 1.42 A L R 2 W (Formula 2)

[0025] A is the integral area of the B acid or L acid absorption peak; R is the radius of the sample piece (cm); and W is the mass of the sample piece (mg).

[0026] In the present application, it can be understood that the total pyridine infrared acid amount of different hydrogen type molecular sieves can be different, for example, the total pyridine infrared acid amount of HX type molecular sieve at 200°C is about 360 μmol / g, the total pyridine infrared acid amount of HY type molecular sieve at 200°C is about 310 μmol / g, and the total pyridine infrared acid amount of Hβ type molecular sieve at 200°C is about 560 μmol / g.

[0027] In the present application, it can be understood that the acid amount determined at 200°C is the total acid amount of the catalyst and the molecular sieve, and the acid amount determined at 350°C is the strong acid amount of the catalyst and the molecular sieve.

[0028] According to a preferred embodiment of the present application, the molecular sieve is selected from at least one of X type, Y type and β molecular sieves, and preferably is Y type molecular sieve. The advantage of using this preferred embodiment is that the preparation route of Y type molecular sieve is very mature, and is suitable for ethylene isobutane alkylation reaction.

[0029] According to a preferred embodiment of the present application, the binder is selected from at least one of alumina, silica, titania, kaolin and montmorillonite, and preferably is at least one of alumina, silica and titania.

[0030] According to a preferred embodiment of the present application, the alumina is alumina containing pseudo-boehmite phase and / or γ phase.

[0031] According to a preferred embodiment of the present application, the hydrogenation active component is selected from at least one of Pt, Pd, Ru and Ir, and preferably is Pt and / or Pd, and further preferably is Pt. The advantage of using this preferred embodiment is that the loading amount of Pt is less, the hydrogenation effect is better than other metals, the influence on the catalyst acidity and pore structure is less, and it is beneficial to improve the life and selectivity of the catalyst.

[0032] According to a preferred embodiment of the present application, the content of Pt in terms of element is 0.1-0.5% by weight based on the dry basis weight of the catalyst. The advantage of using this preferred embodiment is that while reducing the loading amount of noble metal Pt to reduce the cost of the catalyst, the proportion of active centers in the catalyst is improved, and the coverage of the metal particles to the acid sites of the catalyst is reduced, and the activity and stability of the catalyst are improved.

[0033] According to a preferred embodiment of the present application, the molecular sieve is X molecular sieve, the unit cell constant of the catalyst is 2.46-2.485nm, the total acid amount at 200℃ pyridine infrared is greater than 360μmol / g, preferably the total acid amount at 200℃ pyridine infrared is 430-540μmol / g, the mesopore volume is 0.048-0.106cm 3 / g.

[0034] According to a preferred embodiment of the present application, the molecular sieve is Y molecular sieve, the unit cell constant of the catalyst is 2.441-2.466nm, the total acid amount at 200℃ pyridine infrared is greater than 310μmol / g, preferably the total acid amount at 200℃ pyridine infrared is 372-465μmol / g, the mesopore volume is 0.07-0.128cm 3 / g.

[0035] According to a preferred embodiment of the present application, the molecular sieve is β molecular sieve, the unit cell constant of the catalyst is 1.249-1.262nm, the total acid amount at 200℃ pyridine infrared is greater than 560μmol / g, preferably the total acid amount at 200℃ pyridine infrared is 670-840μmol / g, the mesopore volume is 0.024-0.051cm 3 / g.

[0036] The unit cell constant of the catalyst in the present application refers to the unit cell constant of the molecular sieve in the catalyst, which is well known to those skilled in the art and is measured by fitting the XRD spectrum with the standard XRD spectrum library. The unit cell constant of different sodium type molecular sieves may be different, for example, the unit cell constant of sodium X molecular sieve is generally about 2.485nm, the unit cell constant of sodium Y molecular sieve is generally about 2.466nm, and the unit cell constant of sodium β molecular sieve is generally about 1.262nm.

[0037] In the present application, the mesopore volume of the catalyst is measured by BET method. The mesopore volume of different sodium type molecular sieves may be different, for example, the mesopore volume of sodium X molecular sieve is generally about 0.032cm 3 / g, the mesopore volume of sodium Y molecular sieve is generally about 0.04cm 3 / g, and the mesopore volume of sodium β molecular sieve is generally about 0.016cm 3 / g.

[0038] According to a preferred embodiment of the present application, the molecular sieve is X molecular sieve, the ratio of B acid / L acid of the catalyst at 200℃ pyridine infrared is 1.2-3, and the ratio of B acid / L acid of the catalyst at 350℃ pyridine infrared is 1-3.5. However, the ratio of B acid / L acid of the solid acid catalyst in the prior art is generally 0.5-1.

[0039] According to a preferred embodiment of the present application, the molecular sieve is a Y-type molecular sieve, and the catalyst has a pyridine infrared B acid / L acid ratio of 0.95-3.5, preferably 1.2-3.5 at 200℃, and a pyridine infrared B acid / L acid ratio of 0.95-3.5, preferably 1.5-3.5 at 350℃.

[0040] According to a preferred embodiment of the present application, the molecular sieve is a β molecular sieve, and the catalyst has a pyridine infrared B acid / L acid ratio of 1-2 at 200℃, and a pyridine infrared B acid / L acid ratio of 1-2 at 350℃.

[0041] According to a preferred embodiment of the present application, the preparation method of the solid acid catalyst comprises the following steps:

[0042] (1) mixing a sodium-type molecular sieve with a binder or a precursor thereof, an additive, an acid solution and water to form a mixture, and then drying and calcining the mixture to obtain a calcined product;

[0043] (2) sequentially subjecting the calcined product obtained in step (1) to a crystallization treatment, an ammonium exchange, an acid treatment and an introduction of a hydrogenation active component to obtain a solid acid catalyst.

[0044] The preparation method provided by the present application can expand the pores of the catalyst without damaging the framework of the catalyst, and can avoid the damage to the acidity caused by the ordinary acid-base treatment of the molecular sieve. The method provided by the present application can balance the pore structure and the acidity of the molecular sieve.

[0045] In the present application, the types and properties of the sodium-type molecular sieve have been described in the foregoing content, and will not be repeated here.

[0046] According to a preferred embodiment of the present application, in step (1), the sodium-type molecular sieve has a silicon-aluminum molar ratio of 1-1000, preferably 1.5-500.

[0047] In the present application, the types of the binder have been described in the foregoing content, and will not be repeated here.

[0048] In the present application, the type of the binder precursor in step (1) is not particularly limited. Preferably, the binder precursor mainly includes aluminum salts, silicates, titanium salts and zirconium salts. For example, the aluminum salts can include pseudo-boehmite, aluminum chloride (AlCl3), aluminum sulfate (Al2(SO4)3) and the like; the silicates can include sodium silicate, potassium silicate, calcium silicate and the like; the titanium salts can include titanium sulfate, titanium tetrachloride and the like; and the zirconium salts can include zirconium chloride, zirconium sulfate and the like.

[0049] According to a preferred embodiment of the present application, in step (1), the amount of the sodium type molecular sieve and the binder or the precursor thereof is such that the weight ratio of the sodium type molecular sieve to the binder in the catalyst is 90:10-20:80, preferably 90:10-50:50, on a dry basis.

[0050] In the present application, the acid solution and the additive in step (1) can be selected from a wide range of acid solutions and additives conventionally defined in the art. For example, the acid solution is selected from at least one of hydrochloric acid solution, nitric acid solution, oxalic acid solution and citric acid solution, and the additive is selected from at least one of sesbania gum, methyl cellulose, polyether, polyvinyl alcohol, cyclodextrin and chitosan.

[0051] In the present application, the acid solution is added or not added depending on the type of the binder or the precursor thereof. If the binder is alumina or the precursor of the binder is an aluminum salt, the acid solution is added. If the binder is silica, titania, zirconia or the precursor of the binder is a silicate, a titanium salt or a zirconium salt, the acid solution can be added or not added. In the present application, the additive functions to lubricate and form pores. The additive can be added or not added. When the additive is not added, the dried mixture is directly calcined to obtain the calcined product. When the additive is added, the dried mixture is first calcined and then air calcined to remove the additive, thereby obtaining the calcined product.

[0052] According to a preferred embodiment of the present application, in step (1), the amount of the acid solution and the additive is independently 0-5 wt% of the total dry weight of the sodium type molecular sieve and the binder.

[0053] In the present application, the amount of water is not particularly limited, as long as the mixture including the sodium type molecular sieve, the binder or the precursor thereof, the acid solution and the additive is uniformly mixed. Preferably, the weight ratio of water to the total dry weight of the other mixture is (0.5-10):1, wherein the other mixture refers to the mixture of the sodium type molecular sieve, the binder or the precursor thereof and the additive.

[0054] According to a preferred embodiment of the present application, in step (1), the drying condition is such that the dry weight of the dried mixture is 60 wt% or more.

[0055] According to a preferred embodiment of the present application, in step (1), the calcination includes one-stage calcination and two-stage calcination. The use of this preferred embodiment has the advantage of effectively removing organic substances such as lubricants added during the molding process and coke in the catalyst.

[0056] According to a preferred embodiment of the present application, the one-stage calcination conditions include a calcination temperature of 450-650℃, a calcination time of 0.5-12h, and a calcination pressure of 0-0.5MPa.

[0057] According to a preferred embodiment of the present application, the two-stage calcination conditions include a calcination temperature of 500-600℃, a calcination time of 1-6h, and a calcination pressure of normal pressure-0.3MPa.

[0058] By the above-mentioned preferred embodiments, the interaction between the molecular sieve and the binder is enhanced, and the organic matter in the catalyst is removed, thereby reducing the damage to the framework structure of the catalyst.

[0059] In the present application, the calcination atmosphere for the one-stage calcination and the two-stage calcination is not particularly limited, and the existing calcination atmosphere in the art can be used, for example, air atmosphere, ammonia water vapor atmosphere, water vapor atmosphere, N2 atmosphere, He atmosphere, or Ar atmosphere. Preferably, the one-stage calcination is performed in a water vapor or ammonia water vapor atmosphere, and the two-stage calcination is performed in an air atmosphere.

[0060] According to a preferred embodiment of the present application, in step (2), the crystallization treatment includes hydrothermal crystallization treatment of the calcination product in the presence of a template agent.

[0061] In the present application, the type of the template agent is selected from a wide range. Preferably, the template agent is at least one selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, cetyltrimethylammonium bromide, and dodecyltrimethylammonium bromide.

[0062] According to a preferred embodiment of the present application, the concentration of the template agent is 0.05-1.5mol / L.

[0063] According to a preferred embodiment of the present application, the crystallization treatment conditions include a temperature of 80-300℃, a time of 1-24h, and a liquid-solid mass ratio of 0.05-10:1.

[0064] In the present application, in step (2), the ammonium exchange conditions are familiar to those skilled in the art, and the present application does not have a particular requirement therefor. After the ammonium exchange, the Na2O content of the catalyst is reduced to below 1wt%, and preferably below 0.9wt%. In the present application, the type of the ammonium solution in the ammonium exchange is not particularly limited, and for example, can be at least one selected from the group consisting of an ammonium nitrate solution, an ammonium chloride solution, and an ammonium sulfate solution. In the present application, preferably, the concentration of NH4 + in the ammonium solution is 0.05-8mol / L. Preferably, in step (2), the ammonium exchange conditions include a temperature of 50-150℃, a liquid-solid mass ratio of 5-50, and a time of 2-24h.

[0065] In the present application, the product after ammonium exchange is sequentially subjected to washing, suction filtration and drying treatment. The present application does not have special limitations on the above operations, and the existing methods in the art can be used.

[0066] In the present application, the mesopore volume of the catalyst can be effectively increased by acid treatment. Preferably, in step (2), the acid treatment is carried out at a temperature of 10-350°C for 0.5-36h.

[0067] According to a preferred embodiment of the present application, the acid used in the acid treatment is selected from at least one of hydrochloric acid, nitric acid, sulfuric acid, oxalic acid, lactic acid, oxalic acid, fluosilicic acid, hydrofluoric acid and ammonium fluosilicate.

[0068] According to a preferred embodiment of the present application, the concentration of the acid is independently 0.01-20wt%.

[0069] In the present application, in step (2), the types of the hydrogenation active components have been described above and will not be repeated here.

[0070] According to a preferred embodiment of the present application, the hydrogenation active components are provided by a solution containing hydrogenation active component precursors, which are independently selected from soluble salts of each hydrogenation active component, preferably at least one of chloroplatinic acid, dichlorotetrammine platinum, tetraammine platinum nitrate, dinitrosodiammine platinum, tetraammine platinum acetate, palladium chloride, palladium nitrate, sodium chloropalladate and potassium chloropalladate, and further preferably at least one of dichlorotetrammine platinum, tetraammine platinum nitrate, sodium chloropalladate and potassium chloropalladate.

[0071] According to a preferred embodiment of the present application, in step (2), the amount of the hydrogenation active components is such that the content of the hydrogenation active components in the catalyst is 0.01-5wt%, preferably 0.1-1wt%, and further preferably 0.1-0.5wt%. The preferred embodiment has the advantage of complete degradation of carbon deposition and complete regeneration of the catalyst.

[0072] In the present application, in step (2), the method for introducing the hydrogenation active components can be a method conventionally defined in the art, such as impregnation, atomic deposition or rotary evaporation, preferably rotary evaporation, so that the hydrogenation active components are more uniformly dispersed.

[0073] In the present application, preferably, the method further comprises pretreating the sodium-type molecular sieve before mixing it with other reaction raw materials, and the pretreatment method comprises: ammonium exchanging the molecular sieve with an ammonium solution at 30-180°C for 0.1-10h, and then suction filtering and drying. Preferably, the concentration of NH4+ The concentration of the ammonium solution is 0.05-8 mol / L. Preferably, the ammonium solution is at least one selected from the group consisting of an ammonium nitrate solution, an ammonium chloride solution and an ammonium sulfate solution.

[0074] According to a preferred embodiment of the present application, the conditions of the alkylation reaction include: a temperature of 100-280℃, a pressure of 0.5-10 MPa, and a feed flow rate of 10-3000 mL / (g·h).

[0075] In the present application, the feed flow rate refers to the volume (mL) of isomeric alkanes and ethylene fed per hour per unit weight (g) of catalyst.

[0076] According to a preferred embodiment of the present application, the isomeric alkanes are C3-C5 isomeric alkanes, preferably isobutane.

[0077] According to a preferred embodiment of the present application, the molar ratio of the isomeric alkanes to ethylene is 1-100:1, further preferably 5-50:1.

[0078] According to a preferred embodiment of the present application, the alkylation reaction is carried out in a fixed bed reactor.

[0079] In the present application, the isomeric alkanes and ethylene are contacted with the solid acid catalyst to carry out the alkylation reaction according to the method of the present application, which can improve the cycle life of the catalyst while ensuring the selectivity of the target product.

[0080] Unless otherwise specified, the pressure in the present application refers to the gauge pressure.

[0081] The present application will be described in detail below through examples. In the following examples, unless otherwise specified, the various raw materials used can be obtained from commercial channels.

[0082] Y-type molecular sieve: a unit cell constant of 2.466 nm, a molar ratio of silicon to aluminum of 3, an average particle size of 1 μm, a total acid amount at 200℃ pyridine infrared of 310 μmol / g, a mesopore volume of 0.042 cm 3 / g, and Sinopec Catalyst Co., Ltd.

[0083] X-type molecular sieve: a unit cell constant of 2.485 nm, a molar ratio of silicon to aluminum of 1.8, an average particle size of 0.5 μm, a total acid amount at 200℃ pyridine infrared of 360 μmol / g, a mesopore volume of 0.032 cm 3 / g, and Sinopec Catalyst Co., Ltd.

[0084] β-type molecular sieve: cell constant 1.262 nm, silicon-to-aluminum molar ratio 50, average particle size 10 μm, total acidity of pyridine at 200℃ 560 μmol / g, mesopore volume 0.016 cm³. 3 / g, China Petrochemical Catalyst Co., Ltd.

[0085] Phobospore: average particle size 100 μm, Sinopec Catalyst Co., Ltd.

[0086] In the following examples, X-ray diffraction (XRD) was used to determine the cell constant and crystallinity of the catalyst molecular sieve.

[0087] The mesopore volume of the catalyst was measured using the BET method.

[0088] The method for determining the pyridine adsorption capacity of solid acid catalysts using infrared spectroscopy is as follows: Instrument: Bruker Tensor II Fourier transform infrared spectrometer; Test procedure: Approximately 25 mg of catalyst sample was pressed into a pellet at 20 MPa for 5 min, placed in the in-situ cell of the infrared spectrometer and sealed. The temperature was increased to 450 °C at a rate of 10 °C / min, and then evacuated to 10 °C. -6 After treatment at approximately 2 h (Pa), the mixture was cooled to room temperature for static saturation adsorption of pyridine. Subsequently, under vacuum, the adsorbed pyridine was desorbed by stepwise heating to 200 °C and 350 °C. The infrared spectra at both temperatures were measured and integrated. (1540 cm⁻¹) -1 The absorption peak at 1450 cm⁻¹ belongs to the B acidic site. -1 The absorption peak is attributed to the L acidic site.

[0089] C is the concentration of Brønsted acid or Lewis acid (mmol / g). B With C L The calculation formula is:

[0090] C B =1.88A B R 2 / W (Equation 1)

[0091] C L =1.42A L R 2 / W (Equation 2)

[0092] A is the integral area of ​​the absorption peak of Brønsted acid or Lewis acid;

[0093] R is the radius (cm) of the sample piece;

[0094] W is the mass (mg) of the sample piece.

[0095] The C5 and C6 selectivity distribution of the obtained alkylated oil was determined by gas chromatography using an Anglient-7890 gas chromatograph equipped with a high-pressure sampler (HP-PONA 50m×0.2mm capillary column).

[0096] In the following examples and comparative examples, the C5 and C6 selectivity distribution of the obtained alkylated oils was determined by gas chromatography using an Anglient-7890 gas chromatograph equipped with a high-pressure sampler (HP-PONA 50m × 0.2mm capillary column). The method for determining the single-pass lifetime of the solid acid catalyst was as follows: during normal reaction, when the ethylene conversion rate is 100%, if ethylene is detected by gas chromatography, it indicates that the solid acid catalyst has begun to deactivate; the reaction time experienced by the solid acid catalyst when the ethylene conversion rate is 95% is the single-pass lifetime of the solid acid catalyst.

[0097] Example 1

[0098] (1) At 80℃, ammonium chloride solution (NH4) was used. + The concentration of ammonium exchange (3 mol / L) was used to treat NaY molecular sieve for 2 hours, followed by filtration and drying.

[0099] (2) The ammonium-exchanged NH4NaY molecular sieve and pseudoboehmite were mixed at a dry weight ratio of 9:1. 3 wt% of guar gum powder and 1 wt% of nitric acid were added respectively (based on the total dry weight of the ammonium-exchanged Y-type molecular sieve and binder). Deionized water was added at a dry weight ratio of 1:1 to the total dry weight of water and other mixtures (a mixture of sodium molecular sieve, binder or its precursor and additives). After mixing evenly, the mixture was extruded and dried at 120°C so that the dry weight of the mixed molded product was 70 wt%. Then, it was calcined with steam at 600°C and a pressure of 0.15 MPa for 2 h, and calcined in air at 600°C for 4 h at atmospheric pressure.

[0100] (3) The obtained roasted product and 0.5 mol / L tetramethylammonium hydroxide solution were placed in a hydrothermal reactor at a mass ratio of 10:1 and hydrothermated at 200°C for 12 h. The obtained product was then washed, filtered and dried.

[0101] (4) with ammonium chloride solution (NH4) + The product was mixed with a concentration of 2 mol / L and a liquid-solid mass ratio of 50:1. Ammonium exchange was carried out at 80℃ for 24 h to reduce the Na2O content in the calcined product to 0.5 wt%. Then the product was washed, filtered and dried.

[0102] (5) The product obtained in step (4) is mixed with hydrochloric acid solution (concentration of 5wt%), acid-treated at 60°C for 1 hour, and then washed, filtered and dried.

[0103] (6) The product obtained in step (5) was subjected to rotary evaporation in a solution of dichlorotetraammineplatinum to obtain catalyst Y-1.

[0104] Example 2

[0105] (1) At 100℃, ammonium chloride solution (NH4) was used. + The concentration of ammonium exchange was 2 mol / L on NaY molecular sieve for 2 h, followed by filtration and drying.

[0106] (2) The ammonium-exchanged NH4NaY molecular sieve and pseudoboehmite were mixed at a dry weight percentage of 50:50, 5% nitric acid was added, and deionized water was added at a dry weight ratio of 1:1 to the total dry weight of water and other mixtures (sodium molecular sieve, binder or its precursor and additives). After mixing evenly, the mixture was extruded and dried at 120°C so that the dry weight of the mixed molded product was 70 wt%. Then, it was calcined with steam at 450°C for 2 h at a pressure of 0.3 MPa and calcined with air at 500°C for 3 h at a pressure of atmospheric pressure.

[0107] (3) The obtained roasted product and 0.05 mol / L tetraethylammonium hydroxide solution were placed in a hydrothermal reactor at a mass ratio of 5:1 and hydrothermated at 200°C for 1 h. The obtained product was then washed, filtered and dried.

[0108] (4) with ammonium chloride solution (NH4) + The product was mixed with a concentration of 2 mol / L, and the liquid-solid mass ratio was 50:1. Ammonium exchange was carried out at 120℃ for 24 h to reduce the Na2O content in the calcined product to 0.5 wt%. Then the product was washed, filtered and dried.

[0109] (5) The product obtained in step (4) is mixed with hydrochloric acid solution (concentration of 5wt%), acid-treated at 60°C for 1 hour, and then washed, filtered and dried.

[0110] (6) The product obtained in step (5) is subjected to rotary evaporation in a chloroplatinic acid solution to obtain catalyst Y-2.

[0111] Example 3

[0112] (1) At 60℃, ammonium chloride solution (NH4) was used. + The concentration of Naβ molecular sieve was 2 mol / L. The ammonium was exchanged for 10 h, and then filtered and dried.

[0113] (2) The ammonium-exchanged NH4Naβ molecular sieve and pseudoboehmite were mixed at a dry weight percentage of 75:25. 5% guar gum powder and 2% nitric acid were added. Deionized water was added at a dry weight ratio of 0.8:1 for water and the total dry weight of the other mixture (sodium molecular sieve, binder or its precursor and additives). After mixing evenly, the mixture was extruded and dried at 150°C so that the dry weight of the mixed molded product was 70 wt%. Then, it was calcined at 550°C with steam for 1 h at a pressure of 0.1 MPa and then calcined in air at 550°C for 2 h at atmospheric pressure.

[0114] (3) The obtained roasted product and 1 mol / L tetraethylammonium hydroxide solution were placed in a hydrothermal reactor at a mass ratio of 1:20 and hydrothermated at 100°C for 6 hours. The obtained product was then washed, filtered and dried.

[0115] (4) with ammonium chloride solution (NH4) + The product was mixed with a concentration of 1 mol / L, and the liquid-solid mass ratio was 5:1. Ammonium exchange was carried out at 60℃ for 2 hours to reduce the Na2O content in the calcined product to 0.1 wt%. Then it was washed, filtered and dried.

[0116] (5) The product obtained in step (4) is mixed with ammonium fluorosilicate solution (concentration of 5 wt%), acid-treated at 60°C for 1 h, and then washed, filtered and dried.

[0117] (6) The chloroplatinic acid solution obtained in step (5) is subjected to rotary evaporation to obtain catalyst β-1.

[0118] Example 4

[0119] The method is the same as in Example 1, except that the crystallization treatment is performed before calcination to obtain Y-3.

[0120] Example 5

[0121] Following the method of Example 1, except that deionized water was used instead of tetramethylammonium hydroxide in the hydrothermal treatment process, and the hydrothermal temperature was 300°C, to obtain catalyst Y-4.

[0122] Example 6

[0123] The method of Example 1 is followed, except that the concentration of hydrochloric acid in step (5) is 10 wt%, and the catalyst Y-5 is obtained by treating at 150°C for 24 h.

[0124] Example 7

[0125] Following the method of Example 1, except that X-type molecular sieve was selected to obtain catalyst X-1.

[0126] Example 8

[0127] According to the method of Example 1, except that the hydrothermal crystallization treatment of step (3) is not performed, catalyst Y-6 is obtained.

[0128] Comparative Example 1

[0129] Catalyst DY-1 is prepared according to the method of Example 1 of CN114054071A patent application, and the acid amount of the catalyst is determined according to the test method of Example 1 of the present application.

[0130] Comparative Example 2

[0131] According to the method of Example 1, except that the dichlorotetraamine platinum solution is not introduced, catalyst DY-2 is obtained.

[0132] In the above examples and comparative examples, the content of the hydrogenation active component in the catalyst is shown in Table 1, the structural parameters of the catalyst are shown in Table 2, and the acid amount of the catalyst is shown in Table 3.

[0133] Table 1

[0134]

[0135]

[0136] Table 2

[0137]

[0138] Table 3

[0139]

[0140] Test Example 1

[0141] The solid acid catalysts prepared in the above examples and comparative examples are respectively used in the isomerization of isobutane and the alkylation reaction of ethylene in a fixed bed reactor, and the reaction conditions are as follows: the molar ratio of isobutane to ethylene is 50, the reaction temperature is 280℃, the reaction atmosphere is a mixture of hydrogen and nitrogen, the volume percentage of hydrogen to nitrogen is 95:5, the reaction pressure is 3MPa, and the feed flow rate is 300mL / (g·h). Ethylene is detected in the product, which is considered as catalyst deactivation, and the reaction time before catalyst deactivation is defined as the cycle life of the catalyst. The results of the alkylation reaction are shown in Table 4, and in Table 4, C5, C6 selectivity represents the average result within the cycle life.

[0142] Comparative Test Example 1

[0143] The catalyst of Example 1 is selected, except that in the alkylation reaction, the reaction atmosphere is pure nitrogen, and the results of the alkylation reaction are shown in Table 4.

[0144] Wherein, the selectivity refers to the proportion of a component in the alkylated gasoline, and the selectivity is defined as

[0145] s n选择性 = A Cn × 100% (Formula 3)

[0146] In the formula, s n is the integral area ratio of butene in the gas chromatogram of the hydrocarbon with carbon number n at a moment; A Sn is the integral area ratio of the hydrocarbon with carbon number n in the alkylated gasoline in the gas chromatogram.

[0147] Table 4

[0148] Catalyst No. Life (h) [C5 selectivity (%)] [C6 selectivity (%)] Test Example 1 Y-1 86 67.5 24.9 Test Example 1 Y-2 73 61.8 30.1 Test Example 1 β-1 70 64.2 23.5 Test Example 1 Y-3 67 54.6 33.7 Test Example 1 Y-4 64 48.8 40.1 Test Example 1 Y-5 59 45.5 42.7 Test Example 1 X-1 43 36.8 50.9 Test Example 1 Y-6 12 43.7 44.5 Test Example 1 DY-2 52 51.8 35.2 Comparative Test Example 1 Y-1 47 60.7 30.4

[0149] From the above table 4, it can be seen that the reaction life of the catalyst prepared by the method provided by the application is not affected compared with the catalyst prepared by the traditional method, and the reaction period of the catalyst can be greatly improved under the hydrogenation reaction condition, and the service life of the catalyst is improved.

[0150] The preferred embodiments of the application are described in detail above, but the application is not limited thereto. Within the technical concept of the application, various simple modifications can be made to the technical solutions of the application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as the disclosed content of the application, and all belong to the protection scope of the application.

Claims

1. An alkylation method, characterized in that, The method includes: alkylating isoparaffins with ethylene in a hydrogen-containing atmosphere and in the presence of a solid acid catalyst; wherein the concentration of hydrogen in the hydrogen-containing atmosphere is 1-100% by volume; the solid acid catalyst comprises a molecular sieve, a binder, and a hydrogenation active component, wherein, based on the dry weight of the catalyst, the content of the molecular sieve is 20-90 wt%, the content of the binder is 5-79.99 wt%, and the content of the hydrogenation active component (elementally) is 0.01-5 wt%; the total acid content of pyridine in the 200°C infrared radiation of the catalyst is increased by 30-110% compared to that of the molecular sieve; the mesopore volume of the catalyst is increased by 110-215% compared to that of the molecular sieve. The preparation method of the solid acid catalyst includes the following steps: (1) Sodium molecular sieves are mixed with binders or their precursors, additives, acid and water to form a mold, and then dried and calcined to obtain the calcined product; (2) The calcined product obtained in step (1) is subjected to crystallization treatment, ammonium exchange, acid treatment and introduction of hydrogenation active components in sequence to obtain a solid acid catalyst.

2. The method according to claim 1, wherein, Based on the dry weight of the catalyst, the content of the molecular sieve is 25-84 wt%, the content of the binder is 15-75 wt%, and the content of the hydrogenation active component (by element) is 0.1-1 wt%. And / or, the total acid content of pyridine at 200°C is increased by 52-80% compared with that of molecular sieve at 200°C.

3. The method according to claim 1 or 2, wherein, The molecular sieve is selected from at least one of X-type, Y-type and β-type molecular sieves; And / or, the binder is selected from at least one of alumina, silica, titanium dioxide, kaolin, and montmorillonite; And / or, the hydrogenation active component is selected from at least one of Pt, Pd, Ru and Ir.

4. The method according to claim 3, wherein, The molecular sieve is a Y-type molecular sieve.

5. The method according to claim 3, wherein, The binder is selected from at least one of alumina, silicon dioxide, and titanium dioxide.

6. The method according to claim 3, wherein, The hydrogenation active component is Pt and / or Pd.

7. The method according to claim 6, wherein, The active hydrogenation component is Pt.

8. The method according to claim 1 or 2, wherein, The molecular sieve is an X-type molecular sieve, and the catalyst has a cell constant of 2.46-2.485 nm, a total acidity of pyridine at 200℃ greater than 360 μmol / g, and a mesopore volume of 0.048-0.106 cm³. 3 / g; And / or, the molecular sieve is a Y-type molecular sieve, the catalyst has a cell constant of 2.441-2.466 nm, a total acidity of pyridine at 200℃ greater than 310 μmol / g, and a mesopore volume of 0.07-0.128 cm³. 3 / g; And / or, the molecular sieve is a β-molecular sieve, the catalyst has a cell constant of 1.249-1.262 nm, a total acidity of pyridine at 200℃ greater than 560 μmol / g, and a mesopore volume of 0.024-0.051 cm³. 3 / g.

9. The method according to claim 8, wherein, The molecular sieve is an X-type molecular sieve, and the total acidity of pyridine in infrared spectroscopy at 200℃ is 430-540 μmol / g.

10. The method according to claim 8, wherein, The molecular sieve is a Y-type molecular sieve, and the total acidity of pyridine in infrared spectroscopy at 200℃ is 372-465 μmol / g.

11. The method according to claim 8, wherein, The molecular sieve is a β molecular sieve, and the total acidity of pyridine in infrared spectroscopy at 200℃ is 670-840 μmol / g.

12. The method according to claim 1 or 2, wherein, The molecular sieve is an X-type molecular sieve, and the ratio of β-acid to L-acid in the pyridine infrared radiation at 200℃ is 1.2-3, and the ratio of β-acid to L-acid in the pyridine infrared radiation at 350℃ is 1-3.

5. And / or, the molecular sieve is a Y-type molecular sieve, and the ratio of β-acid to L-acid in the pyridine infrared spectroscopy at 200℃ is 0.95-3.5, and the ratio of β-acid to L-acid in the pyridine infrared spectroscopy at 350℃ is 0.95-3.5; And / or, the molecular sieve is a β molecular sieve, and the ratio of β-acid to L-acid in the pyridine infrared radiation at 200℃ is 1-2, and the ratio of β-acid to L-acid in the pyridine infrared radiation at 350℃ is 1-2.

13. The method according to claim 1 or 2, wherein, In step (1), the amount of sodium molecular sieve and binder or its precursor is such that the weight ratio of sodium molecular sieve to binder in the catalyst is 90:10-20:80 on a dry basis.

14. The method according to claim 13, wherein, In step (1), the amount of sodium molecular sieve and binder or its precursor is such that, on a dry basis, the weight ratio of sodium molecular sieve to binder in the catalyst is 90:10-50:

50.

15. The method according to claim 1 or 2, wherein, In step (1), the amount of acid and additive used is independently 0-5 wt% of the total dry weight of the sodium molecular sieve and binder.

16. The method according to claim 1 or 2, wherein, In step (1), the drying conditions are such that the dry basis weight of the dried mixed molding is above 60 wt%.

17. The method according to claim 1 or 2, wherein, In step (1), the roasting includes a first-stage roasting and a second-stage roasting.

18. The method according to claim 17, wherein, The conditions for the first stage of calcination include: calcination temperature of 450-650℃, calcination time of 0.5-12h, and calcination pressure of 0-0.5MPa.

19. The method of claim 17, wherein, The conditions for the two-stage calcination include: a calcination temperature of 500-600℃, a calcination time of 1-6h, and a calcination pressure of atmospheric pressure to 0.3MPa.

20. The method according to claim 1 or 2, wherein, In step (2), the crystallization process includes: hydrothermal crystallization of the calcined product in the presence of a template agent.

21. The method according to claim 20, wherein, The template agent is selected from at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, hexadecyltrimethylammonium bromide, and dodecyltrimethylammonium bromide.

22. The method according to claim 20, wherein, The concentration of the template agent is 0.05-1.5 mol / L.

23. The method of claim 20, wherein, In step (2), the conditions for the hydrothermal crystallization treatment include: a temperature of 80-300℃, a time of 1-24h, and a liquid-to-solid mass ratio of 0.05-10:

1.

24. The method of claim 20, wherein, In step (2), the conditions for ammonium exchange include: a temperature of 50-150℃, a liquid-to-solid mass ratio of 5-50, and a time of 2-24h; And / or, in step (2), the acid treatment conditions include: a temperature of 10-350℃ and a time of 0.5-36h; And / or, the acid used for the acid treatment is selected from at least one of hydrochloric acid, nitric acid, sulfuric acid, oxalic acid, lactic acid, fluorosilicic acid, hydrofluoric acid, and ammonium fluorosilicate; And / or, the concentration of the acid is 0.1-20 wt%; And / or, the hydrogenation active component is provided by a solution containing a precursor of the hydrogenation active component, wherein each precursor of the hydrogenation active component is independently selected from a soluble salt of the respective hydrogenation active component; And / or, in step (2), the amount of the hydrogenation active component is such that the content of the hydrogenation active component in the catalyst, based on the dry weight of the catalyst and calculated by element, is 0.01-5 wt%.

25. The method according to claim 24, wherein, The hydrogenation active component precursor is selected from at least one of chloroplatinic acid, dichlorotetramineplatinum, tetramineplatinum nitrate, dinitrosodiamineplatinum, tetramineplatinum acetate, palladium chloride, palladium nitrate, sodium chloropalladiumate, and potassium chloropalladiumate.

26. The method according to claim 25, wherein, The hydrogenation active component precursor is at least one of dichlorotetramineplatinum, tetramineplatinum nitrate, sodium chloropalladium, and potassium chloropalladium.

27. The method according to claim 1 or 2, wherein, The conditions for the alkylation reaction include: a temperature of 100-280℃, a pressure of 0.5-10MPa, and a feed flow rate of 10-3000mL / (g·h).

28. The method according to claim 1 or 2, wherein, The isoalkanes are C3-C5 isoalkanes.

29. The method according to claim 28, wherein, The isoalkane is isobutane.

30. The method according to claim 1 or 2, wherein, The molar ratio of the isoparaffin to ethylene is 1-100:

1.

31. The method according to claim 30, wherein, The molar ratio of the isoalkanes to ethylene is 5-50:1.

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