CS216342B1 - Process for preparing heterogeneous catalysts for the upgrading of hydrocarbons - Google Patents

Abstract

The invention relates to a method for preparing heterogeneous catalysts for hydrocarbon upgrading by introducing active metal components onto an inorganic support, in which an aqueous suspension of hydrates of the carrier base is mixed with an aqueous solution of the salt of the desired active metal components and dehydrated by spraying at a pressure of 0.5 to 3 MPa into a stream of inert gaseous medium at a temperature of 500 to 100 °C, after which the resulting catalytic mass is treated by known methods. Dehydration after mixing in a mixing chamber by spraying through a nozzle with an opening of 0.2 and 2 mm is recommended.

Description

The invention relates to the preparation of heterogeneous catalysts for the upgrading of hydrocarbons, their mixtures and distillation fractions obtained from crude oil. The development of the production of motor fuels and petrochemical products is conditioned by the development of the oil processing industry - cracking, hydrocracking, reforming, hydrorefining, isomerization, etc.

These are mostly catalytic processes and the catalysts used here can be divided into several main groups:

-microspherical aluminosilicate, synthetic or natural, used in cracking processes

-AlgO^/Pt used for isomerization and reforming

-AlgO^/Co + Mo used for hydrotreating

In addition to these, others will apply, e.g.

AlgOj/W + Ni, or AlgO^/Mo, SiOg/Ni for deep hydr.ogenaoe,

AlgQ^/Cu for hydrogenation, AlgO^/Cu + Pi for detoxification, AlgO^/V, AlgO^/Ag for oxidation and longer combinations. The production of catalysts requires significant investment, operating and other costs, both direct and further included in the sectors preparing the necessary raw materials, energy and production equipment.

Economical ways of producing catalysts are represented by the construction of highly productive units and, in particular, by reducing the consumption of all living and materialized labor.

The AlgO^/Pt catalyst is a representative of a highly efficient catalyst that competes with other cheaper ones in the production of motor fuels and aromatics. The Al£ 0^/Co + Mo catalyst is a widely used type of catalyst in various variants of hydrorefining processes for upgrading hydrocarbons.

The production of these catalysts is primarily about finding the optimal limit of content and thus consumption of active metals, even though these are in a closed cycle between the production and application of the catalysts so that the catalyst provides the required activity for a long time for the specified type of reaction.

The properties of catalysts are determined mainly by the preparation conditions and chemical composition.

The working conditions of the preparation are reflected in the specific surface area, pore structure and pore dispersion, which then control the activity and selectivity. The dispersion of metals on the supporting selective support stabilizes the catalyst and thus indirectly affects its price. A heterogeneous catalyst can consist of a single component, such as alumina with a metal film, or it can be composed of multiple components.

Preparation techniques are simple or may include special preparation procedures ensuring maximum activity and selectivity of catalysts. Some catalysts are relatively independent of small changes in preparation conditions, but others show strict dependence on them. The surface of catalytically active components is usually obtained by applying them to a support. Perfect dispersion of the active component increases stability and activity, often mechanical and thermal resistance and indirectly price. The function of the support can be to increase the dispersion of the active component (AlgO^/Pt), or to obtain catalytic activity (AlgO^/Co+Mo) or thermal stability (AlgO^/Ni). In practice, however, the function is often combined.

An essential feature of the method of preparing heterogeneous catalysts used in catalytic refining is the method of introducing active components into the catalytic mass. Active components, consisting mostly of metals or their oxides, can be introduced in different ways and thus with different results.

216342 '2 ,

One way of combining the support base components, e.g. alumina, and the active metal components is to mix dissolved salts with a suitable form of base, mix them in a paste and shape the catalyst mass by ceramic molding. The technique is successful for its simplicity, but does not provide the best results (e.g. cat. A).

Active metal components can be coprecipitated together with the preparation of alumina in the form of a precipitate. However, the washing of impurities causes losses of active metals (Ex. 2 Cat. B). A third preparation option consists in impregnating the support base with solutions of separated metal salts subsequently or mixed solutions on thermally dehydrated aluminum oxide. This can be done with the support in powder or in a preformed state (Ex. 3 Cat. C).

From the point of view of the contact of the base with the saturating solution, impregnations can be used in excess of saturating solutions (equilibrium saturating) or by saturating according to the porosity of the carrier (saturating into pores) where the amount of solution used is lower than the absorbency, with the saturating base remaining dry after impregnation.

(e.g. 7 cat. G and e.g. 6 cat. H). Other options for introducing the active ingredient are combinations of the previous ones (e.g. 5 cat. E and e.g. 6 cat. P).

It has now been found that the optimal result in terms of laboriousness and economics of catalyst production and its efficiency can be achieved by using a technique that represents a new method of introducing metals (ex. 9 cat. K) and, compared to previous methods, eliminates their significant disadvantages.

The method of preparing heterogeneous catalysts for the upgrading of hydrocarbons by introducing active metal components onto an inorganic support consists in the principle that an aqueous suspension of the hydrate of the support base is mixed with an aqueous solution of salts of the desired active metal components and dehydrated by spraying under pressure into a stream of hot gaseous medium, inert to the catalytic mass, after which the heated catalytic mass is treated by methods known per se. The hydrates of the support base and salt solutions of the metal components, after mixing in a mixing nozzle under pressure of 0.5 to 3 MPa, are dehydrated by spraying through an opening of 0.2 to 2 mm into a stream of hot inert medium with a temperature of 500 to 100 °C in a closed space.

The preparation proceeds in such a way that a base prepared in a known manner consisting of pure hydrate of aluminum, silicon, magnesium, calcium, titanium or their combination, obtained e.g. under defined conditions of concentration, temperature and pH by mixing an alkaline solution containing the respective cationic component with an acidic solution containing an anionic component, inorganic or organic acids, is freed from mother liquors by drainage by filtration and impurities are further reduced below the prescribed limit by washing with clean water. The suspension of hydrates of the carrier base prepared in this way is dosed under pressure into a mixing nozzle and mixed with the addition of the desired salt of the active metal component, controllable by selecting the concentration of the aqueous solution, and sprayed into a closed space through which a warm drying medium flows. As active components, water-soluble metal salts are used, such as copper, silver, vanadium, chromium, molybdenum, tungsten, iron, nickel, palladium, rhenium, platinum, etc., with an anionic component consisting of carbonate, nitrate, halide or formate, acetate, oxalate, etc. Dehydration produces a catalytic mass with a suitable granulate size, porous structure of the carrier base and dispersity of the active component. The choice of spraying equipment, pressure and dehydration speed then affects the shape, binding and dispersity of the active component and thus, in the final effect, the function of the catalyst.

The catalytic mass thus prepared is formed in the usual manner by plastic extrusion or isostatic pressing, depending on the further use.

The catalyst is thermally activated in the final phase and converted into its own working form in order to modify the structure and texture, possibly under the influence of the chemical environment, and the chemical form of the active component is modified, i.e. oxidic, reductive, sulphidic, etc.

The advantage of the proposed procedure is the possibility of introducing any quantity and number of metals, all of which have the potential to be catalytically effective. There are no losses of metal

I components during the wet processing operation by washing or by inappropriate blockage of metals in the bond and carrier insert.

The same catalytic efficiency effect is achieved by ee compared to classically prepared catalysts and with a lower metal content. The production process is simplified because a number of demanding operations are eliminated, such as rehydration and dehydration during saturation and drying. During simultaneous heat treatment, the resulting water vapor is present, thus achieving the desired formation and dispersion of the active ingredient. The presence of water vapor then favorably affects the porous structure and creates a porous system that has practical utility in subsequent applications.

The described methods of introducing the metal component are evident from the following examples.

Example 1 - cat. A

A wet cake of washed precipitate prepared by precipitation of sodium aluminate with nitric acid is mixed in a kneader in an amount of 200 kg with 9 kg of ammonium molybdate and 6 kg of nickel nitrate. The consistency of the paste is adjusted during mixing by adding diluted ammonia water. After two hours of mixing, the paste is pressed through a die and holes 0 2 mm in a screw machine, which are further dried and heat-treated at a temperature of 450 °C.

Example 2 - cat. B

A solution of sodium aluminate and dissolved tungstic acid (160 g/l AlgO^ and 75 g/l Wo^) is precipitated with a solution of nickel nitrate (300 g/l NO^ and 25 g/l NiO) continuously at a temperature of 45 °C and pH 6.8 at a rate of 10 l per minute of suspension. The suspension is freed from the mother liquor by filtration and washed with 100 l of water per kg of solids to remove Na and N0y ions. After drying at 150 °C for 16 hours, the catalyst mass is either agglomerated and/or disintegrated to prepare a suitable granulation for plastic extrusion or dry pressing. The final operation is thermal activation.

Example 3 - cat. B

A solution of sodium aluminate (200 g/l AlgOj) is continuously precipitated with a solution of copper nitrate (16 g/l CuO) at a temperature of 50 °C and pH 7.1 at a rate of 12 liters per minute of suspension. The suspension, freed from mother liquors, is washed with condensate to a Na content below 0.5% by mass. It is dried at a temperature of 150 °C and shaped by tabletting into tablets of 5x5 mm. The heat-treated tablets are poured over with a solution of palladium nitrate (2 g/l Pd). After two hours, the excess solution is decanted (equilibrium saturation). The tablets are heat-treated in an oxide atmosphere at a temperature of 350 °C for 4 hours.

Example 4 - cat. D

The carrier prepared by coagulation of aluminum hydrate and addition of 10% kaolin and 2% nitric acid into the form of balls 3 to 5 mm in a layer of ammonia water is dried and calcined at 500 ^° C and in an amount of 130 kg is saturated in a vessel by pouring over 100 liters of condensate containing 20 kg of ammonia and 21 kg of ammonium molybdate and 16 kg of cobalt nitrate. After 30 minutes, the excess solution is poured off, the catalyst is dried and skimmed off and the saturation is repeated if necessary.

Example 5 - cat. E

A solution of sodium aluminate containing ammonium molybdenum (160 g/l AlgO^ ^and β/l MoO^) is continuously precipitated with a solution of cobalt nitrate (250 g/l. BO^ and 5g/l CoO) at a temperature of 35 °C and pH 6.6 at a rate of 500 1 per hour of suspension. After filtering the suspension, it is washed with condensate in an amount of 50 m^/t, when the Ma^O content drops below 0.1%. After drying at 250 °C for 16 hours, the catalyst grit is immersed in a solution of nickel nitrate (3 g/l BIO and 50 g/l HBO^). After equilibrium saturation, the excess solution is decanted and the mass is heat-treated at 300 °C and after agglomeration, the granulate is shaped by dry pressing into tablets measuring 5 x 5 mm with an internal hole of 2 mm.

Example 6 - cat P

The coprecipitated precipitate prepared as in Example 5 is agglomerated after washing and drying with the addition of 2% aluminum etherate and shaped by tabletting into 5x5 mm particles. The tablets are heat-treated at 300 to 400 °C and immersed in a solution prepared by adding metal carbonate to dilute nitric acid (5 g/l BiO and CoO). After equilibrium saturation and casting of the solutions, the tablets are thermally activated in an atmosphere containing hydrogen sulfide at a temperature of 200 to 450 °C. Example 7 - cat G

An annealed shaped support consisting of alpha AlgO^ containing 2% TiO^ in an amount of 20 kg is sprayed with a palladium nitrate solution (15 g Pd per 1 liter - pH after soda treatment 5^5) in an amount corresponding to 95% absorption (pore saturation). The saturated support remains dry and is thermally treated at a temperature of 350 °C in order to convert the metal into the active form.

Example β - cat. H

The prepared shaped gamma AlgO^ carrier in the amount of 100 kg is poured into the solution in the rotating β-saturation drum and is saturated in equilibrium. The solution is prepared by adding condensate to the circulating solution to a volume of 150 liters in which 0.4 kg of ammonium rhenium and 1.2 liters of chloroplatinic acid (250 g/1 Pt) acidified with 1 kg of HCl and 2 kg of acetic acid are dissolved. After equilibrium saturation for 2 hours, the remaining saturated solution is poured and the catalyst is heat-treated at 150 °C for 16 hours.

Example 9 - cat. K

A suspension of aluminum hydrate (15% by mass AlgOj) freed from impurities below 0.1% by mass is dosed by a pump into a nozzle and mixed with an aqueous solution of nickel acetate (5 g/1 BiO) and ammonium molybdate (15 g/1 MoO^), dosed by other pumps in a ratio of 5:1:2 and sprayed through a nozzle with a 1.1 mm opening at a pressure of 1.6 MPa in a spray dryer, where hot air flows with an inlet temperature of 450 °C and an outlet temperature of 160 °C in an amount corresponding to the evaporation of water of 40 kg/hour. The dryer produces 8 kg/hour of catalytic material with a particle size of 0.01 to 0.6 mm, which has a composition of 6.5% by mass MoO^ and 1.1% by mass BiO based on AlgO^. The granulate is further processed by dry pressing into tablets measuring 5 x 5 mm with a 2 mm hole and thermally activated in an environment containing 1.0% H ₂ S at a temperature of 250 to 450 °C.

The properties of the catalysts from the examples given are compared in the table.

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Catalyst ^{1 1} > ^{1 1} A —<- B C D £ P G H To Carrier ai ₂ ° ₃ ^M 2°3 A3. ₂ ^O 3 Algo ₃ Al ₂ 0$ ^A1 2 ⁰ 3 Al ₂ °3 +sio ₂ + TiO ₂ +those ₂ introduction technology in the dog- dill dill lmpr. dill dill impr. ' impr. new metal you +imp. +impr. +lmpr. metal anion NOW" well" NO no ₃ "well" what ₃ NO Cl" acetate active metal content Mon 10 W 25 Cu 5 Mon 8 Mon 9 Mon 8 Fri 0, 5Pt 0.3 Mon 5 % wt. Ni 3 Ni 8 Pd 0.05 What 2 Co 1.5 Co 2 Ni 1.5 Ni 2 Re 0.3 Ni 1 obaah impurities % wt. NagO 0.1 0.05 0.5 0.1 0.1 0.1 0.5 0.01 . 0.05 _{Fe203 ​} ,0.1 0.05 0.1 0.15 0.1 0.2 0.2 0.01 0.05 apparent density g/cm^ 1.80 1.40 ' 1.35 1.20 1.23 1.09 2.27 1.14 1.10 specific surface area m ² /g 115 150 165 170 185 145 5 215 195 pore volume c«/g 0.19 0.34 0.20 0.24 0.40 0.50 0.18 0.58 0.46

It is evident from the table that the physical properties of the catalyst prepared by the method according to the invention are comparable to those of catalysts prepared by known methods and some parameters (apparent density, specific surface area) reach above-average values. The comparison of the results in terms of catalytic efficiency was carried out in laboratory model conditions with catalysts A and K, prepared by the procedure in Examples 1 and 9.

Example 10

Working conditions of the functional test catalyst grain size 1 to 2 mm, volume 100 ml volumetric load of gasoline 5 1/1 cat. e hour gas quantity 100 1 Hg 98%ni/l gasoline pressure 3.0 MPa temperature 250 to 350 °C sulfurization with raw material at 300 °C 100 hours

Raw material gasoline distillation range 96 to 162 °C, hgQOg - 0.746

% aromatics 9.8 % naphthenes 21.0 % paraffins 68.8 % sulfur , 0.027

Results temperature residual sulfur content ppm in exhaust cat. A_cat. K

250°C 79.6 18.6 280°C 18.4 2.0 310°C 3.9 1.5 «η °r 1 9 o

Catalyst K achieves a higher desulfurization activity under comparable operating conditions, i.e. the same desulfurization at a temperature approximately 30 °C lower than catalyst A.

Claims (2)

SUBJECT OF THE INVENTION Process for the preparation of heterogeneous hydrocarbon catalysts by introducing active metal components onto an inorganic carrier, characterized in that the aqueous suspension of the carrier base hydrate is mixed with an aqueous salt solution of the desired active metal components and dehydrates. by spraying at a pressure of 0.5 to 3 MPa into a stream of inert gaseous medium at a temperature of 500 to 100 ° C in an enclosed space, after which the resulting catalytic mass is treated by methods known per se. 2. A process according to claim 1, wherein the carrier base hydrates and the salt solutions of the metal components are dehydrated by spraying through a 0.2 to 2 mm orifice in the mixing nozzle.