RU2671413C1 - Method for obtaining a spherical catalyst and isobutane alkylation catalyst with isobutene - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention relates to the preparation of isobutane alkylation catalysts with isobutene and can be used in the technology for the production of isobutane alkylation catalysts with alkenes and also for the production of isomerization catalysts. Method for the preparation of a spherical isobutane alkylation catalyst with isobutene based on zeolite of NaNHY type with a residual sodium oxide content of not more than 0.8 wt%, including impregnation with stirring of zeolite crystals with an aqueous solution of lanthanum nitrate in an amount providing a lanthanum content in the zeolite of 3.0 wt%, mixing the resultant slurry with a second slurry obtained by peptizing with an aqueous solution of nitric acid to pH of 2–3 in an aluminum hydroxide powder of pseudo-boehmite modification, introducing sulfated tetragonal zirconia with a content of 5 wt% of SOand natural silicate into the slurry mixture when mixing the powder, granulation of the molding composition, wilting granules at room temperature (18–24) h, drying with a temperature rise of 2 degrees per minute and exposure at 110±10 °C for at least 5 hours and calcination with a temperature rise of 10 degrees per minute and a exposure speed of 280±10 °C for not less than 4 hours and at 510±10 °C for at least 4 hours. Powders of the zeolite and aluminum hydroxide of the pseudo-boehmite modification, sulfated zirconia have a particle size of less than 10 mcm. Sulphated coarse mesoporous powder θ-AlO, containing 5 wt% of SO,and zirconium silicate ZrSiO,with particles smaller than 10 mcm are introduced into the molding mass when mixing. Molding mass is granulated by spherical formation by spheronization on a planetary granulator, with the following ratio of components in the molding mass, % by weight: zeolite of NaNHY type with a residual sodium content of not more than 0.8 wt% – (17.5–21.5), lanthanum nitrate – (1.25–1.55), aluminum hydroxide (pseudo-boehmite) – (21.4–23.8), sulfated zirconium oxide – (7.8–10.5), sulfated θ-AlO– (4.2–6.3) and zirconium silicate ZrSiO– (1.5–2.6), nitric acid – (0.40–0.45), water – up to 100. Catalyst prepared by said method comprises a zeolite of the NaLaHY type with a residual sodium oxide content of not more than 0.8 wt% and a modified with 3.0 wt% of lanthanum, aluminum γ-oxide, sulfated tetragonal zirconium oxide containing 5 wt% of SO, natural silicate and further includes sulphated θ-AlO, containing 5 wt% of SO. Natural silicate is ZrSiO. Catalyst components are in the following weight ratio, %: zeolite of the NaLaHY type (35–42), aluminum γ-oxide – (30–32), sulfated zirconium oxide – (15–19), aluminum oxide – (30–32), sulphated aluminum θ-oxide – (8–12), zirconium silicate – (3–5).EFFECT: improved catalyst properties; increased plasticity of the molding mass and strength of granules; presence of the developed volume of large mesopores facilitating the transport of reactants to the active zeolite centers in the catalyst granules and the removal of reaction products from the volume of the catalyst granules; decreased catalyst coking; high conversion and selectivity of alkylation; high mechanical abrasion and crushing strength.2 cl, 1 tbl

Description

The invention relates to the field of production of isobutane alkylation catalysts with isobutene and can be used in the production technology of isoalkanes alkylation catalysts with alkenes, as well as the production technology of isomerization catalysts.

The development and research of alkylation catalysts and methods for their preparation are both of practical importance in connection with the unmet need for the target alkylation product, and of undoubted scientific interest. The latter circumstance is due to the complexity of the alkylation process and the specific requirements for the catalyst. Given the expected abandonment of the use of methyl tert-butyl ether as an octane enhancing additive to produce high-quality gasolines, it is becoming increasingly important to develop catalysts for the production of 2,2,4-trimethylpentane (100 octane), an isobutane alkylation product of isobutene.

Modern industrial alkylation is based on the use of liquid acids, sulfuric and hydrofluoric, which have such serious disadvantages as high specific consumption, toxicity and corrosiveness, the need for disposal of waste acids. Progressive trends in industrial alkylation are associated with the use of solid (heterogeneous or heterogenized) catalysts that would eliminate these technical, economic and environmental problems and obtain technological and economic advantages.

At present, a variety of solid systems have been proposed as catalysts for isobutane alkylation with alkenes: zeolites, heterogenized liquid acids, aluminum chloride complexes, ion exchange resins, heteropoly acids, chlorinated and sulfated metal oxides, etc. Their main difficulty in the widespread use of such alkylation catalysts has been their fast deactivation, which is associated with the blocking of active centers and the porous structure by side formations from high mol eco hydrocarbons. Proposed solutions to this problem are the development of both catalysts with optimized chemical and phase compositions, acidity and a porous structure that reduce the likelihood of blocking, and the working conditions of solid alkylation catalysts, including their multiple regeneration. The latter circumstance puts forward additional stringent requirements for alkylation catalysts, namely, the requirement of increased mechanical strength while maintaining high catalytic activity (conversion and selectivity). At the same time, it is necessary to optimize the geometric shape and size of the granules / grains of the catalysts. Given the effective influence on the alkylation process — reduction of the size of the catalyst particles, intensification by stirring, and the need for periodic movement of the catalyst particles through the product pipeline to a remote regenerator — the fine-spherical form of the catalyst is optimal.

The experience of studying isobutane alkylation with isobutene in the presence of solid catalysts showed the fundamental importance of the presence of both Lewis and Brønsted acid centers in the catalyst (LCC and BCC, respectively), as well as the positive effect of maintaining the catalyst in a suspended state, i.e. carrying out the process under conditions of mixing the catalyst granules or their movement in the reaction medium. The implementation of these process conditions ensures the achievement of the best results with respect to the activity, selectivity and duration of operation of solid alkylation catalysts.

% - массовой долей целевой фракции - триметилпентанов (ТМП) в продукте реакции) в сочетании с •прочностью гранул на раздавливание (для цилиндрических гранул: по торцу

МПа и по образующей

МПа и на истирание Р_и, мас. %, а для сферических - на раздавливание Р_сф, МПа и на истирание Р_и, мас. %) - становится возможным лишь при его целенаправленном синтезе с учетом следующего: как механическая прочность, так и каталитическая активность во многом определяются химическим и фазовым составами, кислотностью и пористой структурой и условиями их создания, включая способ формования, то есть находятся в многофакторной и сложной зависимости.Therefore, ensuring high catalyst performance: • activity in the alkylation reaction (estimated degree of isobutene conversion X,% and selectivity

% - mass fraction of the target fraction - trimethylpentanes (TMP) in the reaction product) in combination with • crush strength of granules (for cylindrical granules: at the end

MPa and generatrix

MPa and abrasion P _and , wt. %, and for spherical - crushing P _sf , MPa and abrasion P _and , wt. %) - becomes possible only with its purposeful synthesis, taking into account the following: both mechanical strength and catalytic activity are largely determined by chemical and phase compositions, acidity and porous structure and the conditions of their creation, including the molding method, that is, they are multifactorial and complex addictions.

In the patent [1], the inventors relating to the processes for producing a high-octane gasoline component by alkylating isobutane with a butane-butylene fraction on heterogeneous catalysts proposed a solid heterogeneous catalyst, which is a solid porous superacid based on zirconium, hafnium metallosilicates or mixtures thereof promoted with two- or tricharged metal cations with doubly charged anions, and having the general formula (EO ₂ ⋅ a SiO ₂ ) ⋅b (M _c X _d ), where E = Zr, Hf or their mixtures, a = 17-34, b = 0.5 with c = 1 and d = 1, M = Ni ²⁺ , Zn ²⁺ and ZrO ²⁺ , X = SO ₄ ^2- , ZrF ₆ ^2- ; b = 0.1666 with c = 2 and d = 3, M = Sc ³⁺ , Y ³⁺ Ga ³⁺ , X = SO ₄ ^2- , and the coefficients a and b may deviate up or down relative to the indicated values 20% for coefficient “ a ” and 5% for coefficient “b”. A method is also claimed for producing a high-octane component of gasoline-alkylate automobile fuel by alkylating isobutane with an industrial butane-butene fraction in the presence of said catalyst at a temperature of 75 to 102 ° C, a pressure of 1.7 to 2.5 MPa, and an isobutane / butene molar ratio of 10 15, a flow rate of feed from 6.4 to 8.5 g / (cm ³ kat.⋅ch and possible subsequent regeneration of this catalyst technical result -. high rates of conversion, alkylate yield, productivity and resource action Single alizatora. However, the invention does not shows the mechanical strength of the catalyst. Playback of the solid catalyst according to Example 2 of the invention [1] and assessment of characteristics of the obtained sample accordance with the following procedures showed its high activity and selectivity, respectively, X = 86.8% and

Hereinafter, the indicated characteristics of the catalyst were evaluated by the results of the alkylation process under the following conditions: volume ratio of isobutane / isobutene - 19/1; pressure in the feed line - 6 bar; feed temperature - 20 ° C; volumetric feed rate - 3 h ^-1 ; reactor parameters: - reactor type - flow-through, volume of backfill of the catalyst fraction 1-2 mm - 15 cm ³ ; the temperature in the catalyst bed is 80 ° C, the pressure in the reactor is 6 ati; sampling frequency - 30 min., the duration of the feed - 4 hours. The activity was evaluated by the degree of conversion of isobutene:

X = 100⋅ [(C ⁿ _{iC4 =} -C ^to _{iC4 =} ) / C ⁿ _{iC4 =} ],%,

- селективность по триметилпентанам (ТМП) рассчитывали по формуле:where cⁿ _{iC4 =} and C^to _{iC4 =}, accordingly, the initial and final concentration of isobutene in the reaction mixture. Selectivity

 - selectivity for trimethylpentanes (TMP) was calculated by the formula:

where C _{TMP prod} - concentration of TMP in products; With _prod - concentration of products.

The indicators of the mechanical strength of the granules amounted to:

и по образующей

определяемые, здесь и далее, на приборе МП-2.- Abrasion resistance P _and = 66 wt. %, determined, hereinafter, according to GOST 16188 and calculated by the formula: P _and = 100⋅ (m _con / m _ref ), wt. %, where m _kon and m _{ex is the} mass of granules of the target fraction, respectively, after abrasion under the conditions of GOST and the original - before exposure. End crush strength

and by generatrix

defined hereinafter on the MP-2 device.

- раздавливание по торцу цилиндрической гранулы с равными диаметром d и высотой h=d; при этом цилиндрическая гранула расположена вертикально и разрушающая нагрузка F_i прилагается на площадь поперечного сечения гранулы, равную 0,785d², и

•

- crushing at the end of a cylindrical granule with equal diameter d and height h = d; wherein the cylindrical granule is vertical and the breaking load F _{i is} applied to the cross-sectional area of the granule equal to 0.785d ² , and

- раздавливание по образующей гранулы с равными диаметром d и высотой h=d; при этом цилиндрическая гранула расположена горизонтально и разрушающая нагрузка прилагается на площадь продольного сечения гранулы, равную d h, и

•

- crushing along the forming granules with equal diameter d and height h = d; wherein the cylindrical granule is horizontal and the breaking load is applied to the longitudinal sectional area of the granule equal to dh, and

и

принимаются средние значения для выборок из 26 гранул.For the result of the determination

and

average values are taken for samples of 26 granules.

Known [1] the catalyst and the method for its preparation described in the examples have the following significant disadvantages.

так и на истирание (Р_и). Причины недостаточной прочности - •характер пористой структуры катализатора, представленной преимущественно макропорами (по данным авторов, 80-300 и 100-1000 нм для образцов К2 и К3), являющихся, как известно, концентраторами внутренних напряжений, ослабляющих твердое пористое тело.Firstly, low strength characteristics as to crush resistance

and abrasion (P _and ). The reasons for the lack of strength are • the nature of the porous structure of the catalyst, represented mainly by macropores (according to the authors, 80-300 and 100-1000 nm for samples K2 and K3), which are known to be concentrators of internal stresses that weaken a solid porous body.

Secondly, the used method of tabletting the catalyst is by dry pressing, which does not provide, taking into account the conditions of the final heat treatment, the formation of crystallization-condensation contacts between the particles of the catalyst components that are strong and resistant to the liquid reaction medium.

Also known is a solid heterogeneous catalyst for the process of alkylation of isoparaffin hydrocarbons with olefins and the method for its preparation described in RF patent [2] No. 2505357, class. IPC B01J 37/30, B01J 29/08, B01J 29/12, C07C 2/58, publ. 01/27/2014.

In [2], a method for producing an isobutane alkylation catalyst by olefins based on a zeolite of the NaNH ₄ Y type with a residual sodium oxide content of not more than 0.8 wt. %, in which the zeolite with stirring is impregnated with an aqueous solution of lanthanum nitrate, taken in an amount providing a lanthanum content in the final catalyst of 0.5 wt. % -6.0% - get a suspension; the boehmite structure aluminum hydroxide powder is peptized with an acid solution to a pH of 1-3 and another suspension is obtained. Then both suspensions are mixed, evaporated to formability and molded into granules. After which the obtained granules are dried at room temperature, dried at 50-120 ° C for at least 5 hours and calcined at 150-500 ° C for at least 4 hours. In the particular case, after calcination, palladium chloride is applied to the catalyst. A method for the alkylation of isobutane with olefins in the presence of said catalyst is also provided. EFFECT: simplification and cheapening of the process of producing a catalyst.

The catalyst obtained according to [2] contains, in accordance with the examples given: a zeolite of the NaNH ₄ Y type (with a residual content of sodium oxide of not more than 0.8 wt.%), - (64.0-79.5) wt. %; lanthanum - (0.5-6.0) wt. % and alumina - (20-30) wt. %, in a particular case - palladium - 0.2 wt. % and has, according to the authors, the following characteristics: butylene conversion - 99-100%, TMP selectivity - 63.1-71.2%. Unfortunately, there are no data on the mechanical strength of the catalyst in the patent.

Показатели механической прочности гранул составили: на раздавливание -

и

на истирание - Р_и=71 мас. %.Reproduction of the catalyst preparation method in accordance with Example 4 of the invention [2] and evaluation of the characteristics of the obtained catalyst according to the above methods showed its rather high activity and selectivity in the process of isobutane alkylation with isobutene, respectively, X = 92.6% and

Indicators of mechanical strength of the granules amounted to: crushing -

and

abrasion - P _and = 71 wt. %

Known [2] the method of producing the catalyst and the catalyst described in the examples of the patent have the following significant disadvantages.

Firstly, the catalyst is characterized by low mechanical strength of the granules both crushing and abrasion; the reason for this is the use of boehmite modification (Al hydroxide AlO (ОН) as an Al ₂ O ₃ -binding - aluminum hydroxide, which is not sufficiently reactive with peptizing acids and, therefore, is low (for example, compared with pseudoboehmite modification of aluminum hydroxide - aluminum monohydroxide AlOOH⋅nH ₂ O) plasticizing properties that would contribute to the optimal packing of zeolite particles during molding and the formation of granules after heat treatment as max of the possible number of contacts per contact section unit, as well as the high strength of individual contacts, namely, these factors are one of the main ones that form the strength properties of granules.

и

отличаются почти в 2 раза, что свидетельствует об анизотропии сформированной пористой структуры и наличии значительных внутренних напряжений, а это может стать причиной разрушения гранул при регенерации.Secondly, crush strength indicators of catalyst granules

and

differ by almost 2 times, which indicates the anisotropy of the formed porous structure and the presence of significant internal stresses, and this can cause destruction of the granules during regeneration.

Closest to the claimed are a method of preparing a catalyst and alkylation of isobutane with isobutene, described in patent [3] of the Russian Federation No. 2579512, class. IPC B01J 37/30, B01J 29/08, B01J 29/12, C07C 2/58, publ. 04/10/2016, bull. No. 10 (prototype).

и длиной микроигл

при следующем соотношении компонентов в формовочной массе, мас. %: цеолит типа NaNH₄Y с остаточным содержанием натрия не более 0,8 мас. % - (36,2-40,4), нитрат лантана (1,8-2,1), гидроксид алюминия (псевдобемит) - (9,8-16,0), сульфатированный оксид циркония - (9,4-12,5) и микроигольчатый волластонит - природный силикат кальция CaSiO₃ с характеристическим отношением

при длине микроигл

- (1,2-2,9), азотная кислота - (0,4-0,5), вода - до 100.The prototype [3] describes a method for preparing a catalyst based on a zeolite of the NaNH ₄ Y type with a residual content of sodium oxide of not more than 0.8 wt. %, including the impregnation with stirring of the crystals of zeolite with an aqueous solution of lanthanum nitrate in an amount providing a lanthanum content in the zeolite of 3.0 wt. %, mixing the resulting suspension with a second suspension obtained by peptization with an aqueous solution of nitric acid to a pH of 1-3 aluminum hydroxide powder, granulating the molding mass, drying at room temperature for 18-24 hours, drying with a temperature rise of 2 degrees per minute and holding at 110 ± 10 ° C for at least 5 hours and annealing with a temperature increase of 10 degrees per minute and holding at 280 ± 10 ° C for at least 4 hours and at 510 ± 10 ° C for at least 4 hours; powders of zeolite and aluminum hydroxide of pseudoboehmite modification have a particle size of less than 40 microns, and a powder of sulfated tetragonal zirconium dioxide with a content of 5 wt. % SO ₄ ^2- and with particles less than 40 microns in size, as well as non-modified microneedle wollastonite - natural calcium silicate CaSiO ₃ with a characteristic ratio

and microneedle length

in the following ratio of components in the molding material, wt. %: zeolite type NaNH ₄ Y with a residual sodium content of not more than 0.8 wt. % - (36.2-40.4), lanthanum nitrate (1.8-2.1), aluminum hydroxide (pseudoboehmite) - (9.8-16.0), sulfated zirconium oxide - (9.4-12 , 5) and microneedle wollastonite - natural calcium silicate CaSiO ₃ with a characteristic ratio

with microneedle length

- (1.2-2.9), nitric acid - (0.4-0.5), water - up to 100.

и длиной микроигл

а компоненты катализатора находятся в массовом соотношении, %: цеолит типа NaLaHY - (49-55), γ-оксид алюминия - (22-30), сульфатированный оксид циркония (18-25), силикат кальция - (2-4). Технический результат - достаточно высокие показатели активности и селективности в процессе алкилирования изобутана изобутеном в условиях эксперимента, а именно: при отработке 0,5 ч - Х=89,3-95,7 мас. %, а

Оценка стабильности характеристик X и

показала их снижение за 4 часа работы на 4-10%. Показатели механической прочности гранул составили: на раздавливание -

и

на истирание - Р_и=75,1-90,1 мас. %.The prototype [3] also describes a catalyst comprising a zeolite of the NaLaHY type with a residual content of sodium oxide of not more than 0.8 wt. % and modified 3.0 wt. % lanthanum, γ-alumina, optionally containing sulfated tetragonal zirconia with 5 wt. % SO ₄ ^2- , and microneedle wollastonite - natural calcium silicate CaSiO ₃ with a characteristic ratio

and microneedle length

and the components of the catalyst are in a mass ratio,%: zeolite of the NaLaHY type - (49-55), γ-alumina - (22-30), sulfated zirconium oxide (18-25), calcium silicate - (2-4). EFFECT: rather high indices of activity and selectivity in the process of isobutane alkylation with isobutene under experimental conditions, namely: when working out for 0.5 hours, X = 89.3-95.7 wt. %, but

Assessment of the stability of the characteristics of X and

showed their decrease over 4 hours by 4-10%. Indicators of mechanical strength of the granules amounted to: crushing -

and

abrasion - P _and = 75.1-90.1 wt. %

The known method of producing the catalyst and the catalyst described in the examples of the patent prototype [3], have the following significant disadvantages.

Firstly, the catalyst obtained by the prototype method is characterized by insufficiently high mechanical strength of the granules both for crushing and abrasion; the reason for this is the overestimated content of zeolite crystals (-48-56 wt.% in the catalyst) that do not exhibit plasticity and astringent properties, especially in combination with fairly large particles (up to 40 microns) of sulfated tetragonal zirconia, in connection with which the number of single contacts in the composition of the molding mass and granules per unit of their contact section requires an increase.

Secondly, the non-optimal (compared to the preferred spherical) form of the catalyst (extruded cylindrical or granular after crushing of the granules), which are much more susceptible to abrasive loads when carrying out the process under conditions of mixing the catalyst granules and their movement in the reaction medium or when applying to regeneration. This disadvantage of the catalyst is dictated by the limited capabilities of the method of its granulation - extrusion, the choice of which, in turn, is due to the composition of the molding material. It is characterized by an increased content of relatively large particles of zeolite and zirconium oxide (up to 40 μm) with respect to pseudoboehmite peptized with nitric acid, which forms colloidal interlayers at the points of contact (zeolite, zirconium oxide) of particles that are practically not involved in peptization.

Thirdly, the presence of the catalyst obtained by the prototype method, a tendency to decrease over 4 hours of operation indicators of activity and selectivity in the process of alkylation of isobutane with isobutene under experimental conditions. The reason may be the deposition of high molecular weight olefin hydrocarbons that deactivate active centers and shield the zeolite cavity and acid centers on the surface of sulfated zirconium oxide.

The objective of the invention is to achieve a technical result - the development of a method for preparing a spherical catalyst and an isobutane alkylation catalyst with isobutene with increased mechanical strength of spherical granules and maintaining high process performance - isobutene conversion and trimethylpentane selectivity and their stability during mining.

The basis of the solution of the stated technical problem is to increase the operational properties of a heterogeneous catalyst, which is expressed in optimizing the shape of its granules and increasing the mechanical strength of the catalyst while ensuring high rates of its catalytic activity - the degree of conversion of isobutene and selectivity for trimethylpentanes, and their stability during mining during the alkylation process.

EFFECT: improved properties of the catalyst compared to the prototype achieved by: 1) Changes in the content in the molding material and reduction in the content of zeolite and zirconium crystals in the catalyst, increase in the content of peptized pseudoboehmite in the molding composition while increasing their dispersion to particle size less than 10 microns, which ensures their more uniform distribution in the volume of mass and granules, increasing the number of individual contacts of particles through peptized layers pseudoboehmite - binder and plasticizer; as a result, an increase in the plasticity of the molding material and the strength of the granules. 2) An additional introduction of finely dispersed (less than 10 μm) particles of sulfated (5 wt.% SO ₄ ^2- ) coarse mesoporous θ-Al ₂ O ₃ into the molding composition and granules of the inert additive, contributing to the development of the volume of large mesopores due to the additive contribution of the intrinsic volume then, and due to the influence on the packing of particles in the mass and the formation of secondary mesopores; as a result, the presence in the catalyst granules of a developed volume of large mesopores facilitating transport of: reagents to the active centers of the zeolite and reaction products from the volume of the catalyst granules; this helps to reduce the coking capacity of the catalyst; 3) introducing into the composition of the molding material and granules a catalyst as a natural silicate - a highly dispersed (less than 10 microns) zirconium silicate, which is a medium strength solid acid and contributes to ensuring high conversion rates and selectivity of alkylation and increasing their stability during mining, in including due to the effect on the packing of particles in the mass and granules, i.e. in the formation of secondary pores; 4) molding the mass into spherical granules by the method of rolling on a planetary granulator, which ensures the optimum shape of the catalyst and its high mechanical strength, both abrasion and crushing without the effect of anisotropy due to the significant centrifugal pelletizing forces created, which in the aggregate of all production conditions and ingredient the composition of the catalyst provides high performance and their stability during testing in the target process.

The problem is achieved due to the method of preparing an isobutane alkylation catalyst with isobutene based on a NaNH ₄ Y type zeolite with a residual sodium oxide content of not more than 0.8 wt. %, including the impregnation with stirring of the crystals of zeolite with an aqueous solution of lanthanum nitrate in an amount providing a lanthanum content in the zeolite of 3.0 wt. %, mixing the resulting suspension with a second suspension obtained by peptization with an aqueous solution of nitric acid to pH = (2-3) pseudoboehmite modification of aluminum hydroxide, introducing into the mixture of suspensions with stirring powders of sulfated tetragonal zirconium dioxide with a content of 5 wt. % SO ₄ ^2- and natural silicate, granulating the molding material, drying granules at room temperature (18-24) h, drying with a temperature rise of 2 degrees per minute and holding at 110 ± 10 ° C for at least 5 hours and calcination with a temperature increase 10 degrees per minute and exposure at 280 ± 10 ° C for at least 4 hours and at 510 ± 10 ° C for at least 4 hours, characterized in that the powders of zeolite and aluminum hydroxide pseudoboehmite modification, sulfated zirconia have a particle size of less than 10 μm, and powders are additionally added to the molding mass with stirring sulfated coarse mesoporous θ-Al ₂ O ₃ containing 5 wt. % SO ₄ ^2- , and zirconium silicate ZrSiO ₄ with particles smaller than 10 microns, granulate the molding material by sphering by rolling on a planetary granulator, with the following ratio of components in the molding material, wt. %: zeolite type NaNH ₄ Y with a residual sodium content of not more than 0.8 wt. % - (17.5-21.5), lanthanum nitrate (1.25-1.55), aluminum hydroxide (pseudoboehmite) - (21.4-23.8), sulfated zirconium oxide - (7.8-10 5), sulfated θ-Al ₂ O ₃ - (4.2-6.3) and zirconium silicate ZrSiO ₄ (1.5-2.6), nitric acid - (0.40-0.45), water - up to 100.

The problem is also solved by means of a spherical catalyst with increased mechanical strength, high catalytic activity — the degree of isobutene conversion, and selectivity for trimethyl pentanes during their stabilization during mining. The catalyst includes a zeolite of the NaLaHY type with a residual sodium oxide content of not more than 0.8 wt. % and modified 3.0 wt. % lanthanum, γ-alumina, sulfated tetragonal zirconium oxide containing 5 wt. % SO ₄ ^2- , and natural silicate, characterized in that it further includes sulfated θ-Al ₂ O ₃ containing 5 wt. % SO ₄ ^2- , natural silicate is ZrSiO ₄ , and the catalyst components are in the following weight ratio,%: NaLaHY type zeolite - (35-42), γ-alumina - (30-32), sulfated zirconia (15 -19), sulfated θ-alumina (8-12), zirconium silicate - (3-5).

A significant difference of the present invention (a method of producing a catalyst) is the use in the preparation of the catalyst molding material containing from 17.5 to 21.5 wt. % crystals of zeolite type NaNH ₄ Y (with a residual sodium content of up to 0.8 wt.%), impregnated with an aqueous solution of lanthanum nitrate from 1.25 to 1.55 wt. % of its content in mass, and from 21.4 to 23.8 wt. % aluminum hydroxide pseudoboehmite modification peptized with nitric acid to a pH of 2-3, from 7.8 to 10.5 wt. % sulfated tetragonal zirconia with a content of 5 wt. % SO ₄ ^{2 -} and with particles less than 10 microns in size, and also as a natural silicate - from 1.5 to 2.6 wt. % zirconium silicate with a particle size of less than 10 microns, and additionally from 4.2 to 6.3 wt. % coarse mesoporous θ-alumina with a particle size of less than 10 μm, the molding mass contains from 0.40 to 0.45 wt. % nitric acid, water - up to 100; and granulation of the molding material is carried out by sphere formation by the rolling method on a planetary granulator, in contrast to extrusion, in the case of the prototype.

In the prior art, a similar set of conditions for obtaining a spherical catalyst for the alkylation of isobutane with isobutene, including the combination of ingredients in the molding composition with the indicated mass ratio (%), was not found; obtaining a spherical catalyst with increased strength and high rates of catalytic activity and their stabilization during mining during the alkylation process is due to the following:

• optimization of the packing of particles in the molding material with the introduction of zeolite, pseudoboehmite, θ-alumina, zirconium oxide and zirconium silicate in the form of powders with a particle size of less than 10 microns and the distribution between them of aluminum oxynitrates formed by peptization with nitric acid, which are effective plasticizing and binders substances that in the aggregate of the entire ingredient composition of the molding material and calcined catalyst pellets, strengthens them;

• optimization of the shape of the granules by obtaining them spherical by rolling on a planetary granulator, ensuring their high strength properties and guaranteeing wear resistance during mixing during operation, which ultimately allows us to predict an increase in the number of regeneration cycles while maintaining the target properties of the catalyst;

• optimization of the balance of the Brønsted and Lewis acid sites of the catalyst when introducing into its composition in certain proportions both protonized and lanthanum-substituted zeolite type U, and sulfated coarse mesoporous θ-alumina, sulfated zirconia, zirconium silicate, which, in total, of the entire composition catalyst, provided high rates of its catalytic activity - isobutene conversion and selectivity for trimethylpentane;

the introduction of additives — sulfated coarse mesoporous θ-alumina and zirconium silicate into the molding composition, reinforcing the texture of the molding composition and calcined catalyst granules and contributing to the formation of coarse mesoporous pores, which ensure the removal of reaction products from them, which together increases the stability indicators in the process of alkylation by reducing the likelihood of deposition of high molecular weight olefin hydrocarbons, des tiviruyuschih active centers and the shielding cavity zeolite.

A significant difference of the present invention (catalyst) is also the formation of a spherical catalyst containing the ingredients in the following weight ratio,%: zeolite of the NaLaHY type - (35-42), γ-alumina - (30-32), sulfated zirconium oxide (15- 20), sulfated θ-alumina (8-12), zirconium silicate - (3-5).

In the prior art, a similar set of catalyst ingredients with the indicated mass ratio (%) in combination with the spherical shape of the catalyst granules was not found; obtaining a catalyst with increased strength, high catalytic activity and an increase in their stability during mining during the alkylation process is due to the following:

• interaction when drying and calcining the ingredients of the composition of the granules and the formation of a larger, compared with the prototype, the number of unitary strong crystallization-condensation contacts between highly dispersed particles of zeolite, sulfated θ-alumina, sulfated zirconium oxide, zirconium silicate having sizes less than 10 μm, and distributed between contacts - layers of γ-Al ₂ O ₃ -bond (formed during the thermal decomposition of basic aluminum salts, - reaction products of the pseudoboehmite and ki lots-peptizer HNO _3);

• the balance of the Brandsted and Lewis acid sites of the catalyst when introduced into its composition in certain proportions of both protonized and lanthanum-substituted zeolite type U, and sulfated coarse mesoporous θ-alumina, sulfated zirconia, zirconium silicate, which, in total, the entire composition of the catalyst , provided high rates of its catalytic activity - isobutene conversion and selectivity;

• the formation, due to packing of the aggregate of particles and the content of coarse mesoporous θ-alumina and particles of zirconium silicate in this aggregate, — catalyst textures with coarse mesoporous transport pores that facilitate the supply of raw materials and the removal of reaction products, but not soften granules, unlike macropores.

Thus, the claimed combination of features of the claimed method for producing a catalyst and a catalyst is essential and corresponds to an inventive step.

The preparation of a spherical catalyst is as follows.

A portion of the zeolite powder type NaNH ₄ Y with a residual content of sodium oxide of not more than 0.8 wt. % and a particle size of less than 10 microns are impregnated with stirring with an aqueous solution of lanthanum nitrate in an amount providing a lanthanum content in the zeolite of 3.0 wt. % (suspension 1).

A portion of the powder of aluminum hydroxide pseudoboehmite modification with a particle size of less than 10 microns with stirring is peptized with an aqueous solution of nitric acid to pH 1-3 (suspension 2).

Suspensions 1 and 2 are mixed and weighed samples of powders with a particle size of not more than 10 μm: sulfated coarse mesoporous θ-alumina with a content of 5 wt. % SO ₄ ^2- , sulfated tetragonal zirconia with a content of 5 wt. % SO ₄ ^2- , zirconium silicate and homogenize the resulting mixture for 20 minutes until a uniform color and humidity, adding distilled water to the total moisture content of the molding material f = 39-40 wt. %, depending on the ingredient composition, after which they are further homogenized for another 10 minutes until the consistency of plasticine. At the same time, the ratio of components, wt. %: zeolite type NaNH ₄ Y with a residual sodium content of not more than 0.8 wt. % - (17.5-21.5), lanthanum nitrate (1.25-1.55), aluminum hydroxide (pseudoboehmite) - (21.4-23.8), sulfated zirconium oxide - (7.8-10 5), sulfated θ-Al ₂ O ₃ - (4.2-6.3) and zirconium silicate ZrSiO ₄ (1.5-2.6), nitric acid - (0.40-0.45), water - up to 100.

The prepared molding material is rubbed through a sieve with a hole diameter of 2.5 mm, the resulting "grain" is granulated in portions by pelletizing on a planetary granulator with a pelletizing time of 20 minutes. After unloading from the granulator, freshly formed spherical granules are placed in a layer of no more than 20 mm high on an enamel tray and are “dried” at room temperature for 18-24 hours, dried in an electric cabinet with a temperature rise of 2 degrees per minute and holding at 110 ± 10 ° C for at least 5 h, then transferred to porcelain cups and calcined in a muffle electric furnace in an air atmosphere with a temperature rise of 10 degrees per minute and exposure at 280 ± 10 ° C for at least 4 hours and at 510 ± 10 ° C for at least 4 hours.

After cooling to room temperature, the spherical granules are scattered on a sieve with the allocation of the target fraction of 1-2 mm, which is stored in a desiccator. The finished spherical catalyst contains the ingredients in the following weight ratio,%: zeolite of the NaLaHY type (35-42), γ-alumina - (30-32), sulfated zirconia (15-20), sulfated θ-alumina (8 -12), zirconium silicate - (3-5).

Before testing in the alkylation process, the granules are dehydrated and calcined at 350 ° C before being loaded into the catalytic reactor.

Going beyond these parameters leads to a deterioration in sphere formation during pelletizing in a planetary granulator, a decrease in the mechanical strength of the granules, and indicators of catalytic activity during alkylation. catalyst.

The invention is illustrated by examples 1-8, the preparation conditions of the catalysts for these examples and their characteristics are presented in table 1. Obtained in examples 1-8, the samples and the sample according to the example of the patent prototype were tested according to the above indicators.

Information sources

1 - RF Patent No. 2313391,

2 - RF Patent No. 2505357,

3 - RF Patent No. 2579512.

Measurements of the structural and strength characteristics of the samples of the examples presented in table 1 showed that all samples of the spherical catalyst prepared by the claimed method are characterized by increased indicators of mechanical strength, namely:

и

Р_и=87,1 мас. % (для примеров 1-10 [3] эти показатели изменяются в интервалах, соответственно:

Р_и=75,1-90,1 мас. %)by crushing P _sf = 11.9-16.2 MPa and by abrasion P _and = 97.8-99.7 wt. % compared with the strength properties for the prototype of example 4 [3] -

and

P _and = 87.1 wt. % (for examples 1-10 [3], these indicators vary in intervals, respectively:

P _and = 75.1-90.1 wt. %)

at high, not inferior to the "prototype", indicators of catalytic activity:

X, wt. %: 98.3-99.8 at τ = 0.5 h and 98.0-99.1 at τ = 4 h, whereas in [3], respectively: 89.3-95.7 and 79.8 -91.0;

мас. %: 82,4-84,7 при τ=0,5 ч и 80,3-82,6 при τ=4 ч, тогда как в [3], соответственно, 76,1-86,9 и 67,3-81,2,

wt. %: 82.4-84.7 at τ = 0.5 h and 80.3-82.6 at τ = 4 h, whereas in [3], respectively, 76.1-86.9 and 67.3 -81.2

which indicates the receipt according to the claimed method of the catalyst is not inferior to the prototype stability under conditions of alkylation.

Thus, the inventive method provides, in the aggregate of all conditions, the preparation of a spherical catalyst and an increase in its mechanical strength at high catalytic activity, characterized by isobutene conversion and selectivity for trimethyl pentanes and the stability of these indicators when working out the catalyst during isobutane alkylation with isobutene due to the use of: • a molding composition of a certain composition, additionally containing sulfated θ-alumina and zirconium silicate When changing the content of zeolite in it NaNH ₄ Y, lanthanum nitrate and sulfated zirconia and peptized pseudoboehmite; • more highly dispersed powders of solid components with a particle size of less than 10 microns; • pelletizing method by pelletizing in a planetary granulator,

as a result, to obtain the inventive spherical catalyst, providing a combination of: • spherical shape; • a certain ingredient composition with, in comparison with the prototype, * a modified content of zeolite, sulfated zirconium oxide and γ-alumina formed during thermal decomposition of pseudoboehmite, * an additional content of sulfated coarse mesoporous θ-alumina and zirconium silicate, * exclusion of calcium silicate; improved operational characteristics: • increased mechanical strength; • high catalytic activity, characterized by the conversion of isobutene and selectivity for trimethylpentenes and the stability of these indicators when working out the catalyst during the alkylation of isobutene with isobutene.

Claims (2)

1. A method of producing a spherical catalyst for the alkylation of isobutane with isobutene based on a zeolite of the NaNH ₄ Y type with a residual content of sodium oxide of not more than 0.8 wt.%, Comprising impregnating zeolite crystals with an aqueous solution of lanthanum nitrate in an amount that ensures the content of zeolite 3, 0 wt.% Lanthanum, mixing the resulting suspension with a second suspension obtained by peptization with an aqueous solution of nitric acid to a pH of 2-3 aluminum hydroxide powder of pseudoboehmite modification, introducing suspensions into the mixture during alternating Shivani powder sulfated tetragonal zirconia with a content of 5 wt.% SO ₄ ^2-, granulation molding composition wilting at room temperature (18-24) hours, with the drying temperature rise of 2 degrees per minute and holding at 110 ± 10 ° C not less 5 hours and calcination with a temperature rise of 10 degrees per minute, holding at 280 ± 10 ° C for at least 4 hours and at 510 ± 10 ° C for at least 4 hours, characterized in that the powders of zeolite and aluminum hydroxide are pseudoboehmite modification, sulfated zirconia have a particle size of less than 10 microns, and in the bulk mass is additionally introduced with stirring powders of sulfated coarse mesoporous θ-Al ₂ O ₃ containing 5 wt.% SO ₄ ^2- and zirconium silicate ZrSiO ₄ with particles less than 10 μm in size, the molding mass is granulated by spheroidizing by rolling on a planetary granulator, with the following ratio of components in the molding composition, weight% zeolite type NaNH ₄ Y with a residual sodium content of not more than 0.8 wt% - (17,5-21,5), lanthanum nitrate - (1,25-1.,. 55), aluminum hydroxide (pseudoboehmite) - (21.4-23.8), sulfated zirconium oxide - (7.8-10.5), s ultrafated θ-Al ₂ O ₃ - (4.2-6.3) and zirconium silicate ZrSiO ₄ - (1.5-2.6), nitric acid - (0.40-0.45), water up to 100. 2. The catalyst prepared according to claim 1, comprising a zeolite of the NaLaHY type with a residual content of sodium oxide of not more than 0.8 wt.% And a modified 3.0 wt.% Of lanthanum, γ-alumina, sulfated tetragonal zirconium oxide containing 5 wt. .% SO ₄ ^2- , and natural silicate, characterized by a spherical shape and in that it further includes sulfated θ-Al ₂ O ₃ containing 5 wt.% SO ₄ ^2- , the natural silicate is ZrSiO ₄ , and the catalyst components are in following mass ratio,%: zeolite of the NaLaHY type - (35-42), γ-alumina - (30-32), su flated zirconia - (15-19), sulfated θ-alumina - (8-12), zirconium silicate - (3-5).