RU2800947C1 - Method for producing catalyst for making isopropyl alcohol - Google Patents

Abstract

FIELD: organic chemistry.

SUBSTANCE: invention relates to preparation of catalysts used in the chemical industry for the production of isopropyl alcohol by hydrogenation of acetone with hydrogen, which is widely used as a solvent in the production of surfactants, plasticizers, oil additives, medicines. A method is presented for preparing a catalyst for the production of isopropyl alcohol in the process of acetone hydrogenation, which includes in its composition the active metal Ni and/or Cu and/or Co with a mass content of not more than 40%, as well as aluminium oxide or its mixture with oxides of Mg or Ca, or Sr, or Ba, or Zn, characterized in that they carry out hydrothermal treatment of a mixture comprising, as a source of aluminium, the product of centrifugal thermal activation of gibbsite, Ni and/or Cu and/or Co salts, or mixtures thereof, Mg or Ca salts, or Sr, or Ba, or Zn and urea, to obtain precursors – layered mixed hydroxides with a hydrotalcite structure or mixtures thereof with individual hydroxides, and the resulting catalyst precursor is calcined and activated, and the hydrothermal treatment of the mixture is carried out at a temperature not exceeding 150°C followed by a drying stage, the calcination of the precursor is carried out in air at a temperature of 200-900 C, and subsequent activation in hydrogen at a temperature of 200-700°C.

EFFECT: production of a catalyst comprising Ni and/or Cu and/or Co with a content of up to 40 wt.%, as well as Al oxide or a mixture thereof with oxides of Mg or Ca, or Sr, or Ba, or Zn, which shows almost 100% conversion of acetone and high selectivity for the target product, isopropyl alcohol.

3 cl, 8 ex

Description

The invention relates to the field of organic chemistry, and in particular to the field of preparation of catalysts used in the chemical industry to produce isopropyl alcohol by hydrogenation of acetone with hydrogen. Isopropyl alcohol is widely used as a solvent in the production of surfactants, plasticizers, oil additives, pharmaceuticals, etc.

Various catalysts for the hydrogenation of acetone are known: massive, based on oxides or spongy metals, and deposited on various carriers. Massive catalysts may include oxides of Ni, Cu, Co, Cr, Mg, Al [RU 2047590, C07 C31/10, 10.11.1995; RU 2050195, B01J 37/04, 12/20/1995] or are Raney Ni and its alloys [US 7041857, C07 C29/136, 05/09/2006, US 8283504B, C07 C29/14, 10/09/2012], spongy Cu, Ru , Pd. The applied catalysts contain transition and/or noble metals on SiO ₂ , aluminosilicates, Al ₂ O ₃ , TiO ₂ , ZrO ₂ and other media [RU 2472766, С07С 31/10, 20.01.2013; US 2013035517, C07C 29/143, 02/07/2013; US 8283504, C07C 29/14, 10/09/2012; US 4472593, B01J 23/86, 09/18/1984].

Massive catalysts based on mixed oxides are usually obtained by co-precipitation from aqueous solutions of salts (nitrates, chlorides, etc.) using NaOH, Na ₂ CO ₃ , NH ₄ CO ₃ , NH ₄ OH as precipitants. A typical precipitation method using the example of cobalt-zinc-aluminum hydrogenation catalysts containing 15-75 wt.% Co is described in the Johnson Matthey patent [WO2005105299, B01J21/04, B01J23/00, 10.11.2005]. Precipitation is carried out with sodium carbonate from solutions of the corresponding salts at pH~7, the resulting precipitate of mixed hydroxides is dried and calcined at 120 and 250-450°C, respectively. The catalysts are reduced in a stream of hydrogen-containing gas at 300-500°C and passivated in a stream of carbon dioxide or nitrogen containing air or oxygen. This method is multi-stage, requires a large amount of wash water that must be disposed of [Ch. Setterfield / Practical course of heterogeneous catalysis. - Moscow. - Publishing house: Mir. - 1988; D. Li, Y. Cai, Y. Ding, R. Li, M. Lu, L. Jiang // IJHE, 40 (2015) 10016-10025].

There is also known a method of mixing the initial components with further calcination and recovery. In the patent [RU 2050195, B01J37/04, 12/20/1995], a method for preparing a catalyst for the hydrogenation of ketones and aldehydes includes mixing chromic acid with carbonate or copper oxide, followed by mixing the resulting paste with ammonia water and introducing into the reaction mixture insoluble compounds of metals of the second group and /or manganese in the amount of 0.1-10 mol per oxide. Then the mixture is heat treated, shaped and reduced with hydrogen.

Most often, as hydrogenation catalysts, in particular, the process of hydrogenation of acetone to isopropyl alcohol, Ni, Cu, Co, Ru, Pd metals deposited on SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ are used [RU 2472766, С07С 31 /10, 01/20/2013; US 2013035517, C07C 29/143, 02/07/2013; US 8283504, C07C 29/14, 10/09/2012; US 4472593, B01J 23/86, 09/18/1984].

In the patent [RU 2666893, С07С 29/145, 09/13/2018] for the hydrogenation of acetone in the liquid phase, a catalyst is used containing 10-30 wt.% Cu deposited on SiO ₂ in the form of granules with a size of 2.8-7.0 mm , specific surface 290-330 m ² /g. The catalyst is activated at a temperature of 150–180°C in a mixture flow (hydrogen:nitrogen) = 1:1 for 2–3 h, then in a hydrogen flow for 0.5 h.

In patents [US 6930213, C07B 61/00, 16.08.2005; RU 2472766, С07С 31/10, 20.01.2013] the hydrogenation of acetone in the liquid phase is carried out in the presence of a catalyst containing Ni (10 wt.%) on a neutral carrier (α-Al ₂ O ₃ ).

In the patent [CN103706365A, B01J 23/755; B01J 29/03, 2014-04-09] describes a deposition method for preparing a supported bimetallic copper-nickel catalyst. Precipitation of copper and nickel hydroxides from salts dissolved in ethanol with the addition of surfactant (cetyltrimethylammonium bromide), carried out in the presence of a carrier using hydrazine hydrate and sodium hydroxide.

Supported catalysts are usually prepared by impregnating solid carriers (SiO ₂ , Al ₂ O ₃ ) with appropriate salt solutions, both aqueous and, for example, alcoholic [RU 2666893, С07С 29/145, 09/13/2018; RU 2675362, С07С 29/145, 12/19/2018; JP2015166315A, C07C 29/145, 09/24/2015; RU 2288210, C07C 31/10, 11/27/2006; US 6878851B2; C07B 61/00, 04/12/2005; CN103539635, B01J 23/755, 01/29/2014; US 6939995, C07B 61/00, 09/06/2005]. The disadvantage of this method is the uneven size distribution of active metal particles, especially at high concentrations, which leads to a decrease in the stability and activity of the catalysts.

An analysis of known data on acetone hydrogenation catalysts shows that the most efficient are catalysts containing Ni or Cu (up to 40 wt.%), with a highly developed surface and porous structure, and a narrow pore size distribution. In addition, the introduction of such promoters as Co, Cr, Zn, Ru, Pd helps to increase the selectivity with respect to the target product - isopropanol and increase the stability of the catalyst [US 8283504 С07С 29/14, 09.10.2012; US 2013035517, C07C 29/143, 02/07/2013].

A known method for producing multicomponent catalysts based on alumina by calcining the products of hydrothermal treatment at atmospheric or elevated pressure solutions of salts or suspensions of the corresponding hydroxides obtained by precipitation [M. Xu, M. Wei // Adv. Funct. mater. 2018. V. 28, No. 47. 1802943]. The use of this method makes it possible to obtain mixed oxides in a wide range of compositions and concentrations of components and catalysts based on them with high dispersion of active metals (Ni, Cu, Cr, Co), high surface and porosity due to the formation of precursors - layered mixed hydroxides [D. Tichit, C. Gerardin, B. Coq // Topics Catal. 2006. V. 39, no. 1-2. R. 89-96]. However, the use of sodium hydroxide or carbonate (NaOH or Na ₂ CO ₃ ) as a hydrolyzing agent (precipitator) requires the use of a large amount of washing water to remove sodium.

A known method for producing layered mixed hydroxides of Mg and Al in the process of hydrothermal treatment (HTT) of a mixture of aluminum hydroxide (gibbsite) or its heat treatment product (flash) and magnesium oxide or its salts at temperatures of 65-170 ° C, however, in all cases, the interaction of the components incomplete, and unreacted gibbsite is present in the TRP products [CA 2320441, B01J21 / 16, 08/19/1999].

Known oxygen-containing hydrated aluminum compound obtained by rapid thermal shock treatment of aluminum hydroxide at elevated temperature, followed by forced cooling (the product of centrifugal thermal activation - CTA) [RU 2237019, C01F 7/02, 27.09.2004]. Thermolysis of the original aluminum hydroxide is carried out under conditions far from thermodynamic equilibrium, which allows the formation of an amorphous phase with increased reactivity from crystalline aluminum hydroxide [RU 2360196, F26B 17/10, 27.01.2009]. The use of a highly reactive CTA product makes it possible to obtain mixed hydroxides and oxides under mild conditions.

It is known that the introduction of urea into salt solutions promotes their hydrolysis during hydrothermal treatment and an increase in the fineness of the catalysts obtained after calcination [CN105327693A, B01J 21/06, 02.17.2016].

The closest to the declared technical essence and the achieved effect is the method of preparing a catalyst for the process of hydrogenation of acetone to isopropyl alcohol [RU 2738656, B01J 37/00, C07C 31/10, 12/15/2020], in which mechanochemical or microwave activation of the initial individual salts is carried out , hydroxides or oxides of Ni or Cu, as well as Al, Mg or Ca, or Sr, or Ba, or Zn, and / or mixtures thereof, then hydrothermal treatment is carried out to obtain precursors - layered mixed hydroxides with a hydrotalcite structure or mixtures thereof with individual hydroxides/oxides, and the resulting catalyst precursor is calcined and activated, while the hydrothermal treatment of individual salts, hydroxides or oxides of metals and/or their mixtures after mechanochemical or microwave activation is carried out at a temperature not exceeding 150°C, and the calcination of the precursor is carried out in air at a temperature 400-900°C and subsequent activation in hydrogen is carried out at a temperature of 200-500°C.

However, in this invention, gibbsite with low reactivity is used as a source of aluminum, for the activation of which additional stages of mechanochemical and microwave processing are introduced, which complicates the process of preparing the catalyst. In addition, the hydrothermal treatment of activated suspensions in salt solutions is carried out in the absence of a precipitating agent, which complicates the process of their hydrolysis.

The invention solves the problem of developing a simple method for preparing an effective multicomponent catalyst for the hydrogenation of acetone to isopropyl alcohol.

EFFECT: obtaining a catalyst containing Ni and/or Cu and/or Co with a content of up to 40 wt.%, as well as Al oxide or its mixture with oxides of Mg or Ca, or Sr, or Ba, or Zn. The resulting catalyst shows almost 100% conversion of acetone and high selectivity for the target product, isopropyl alcohol.

The problem is solved by the proposed method of preparing a catalyst for isopropyl alcohol production in the process of acetone hydrogenation. In order to prepare a catalyst with a high surface area (> 100 m ² /g) and porosity (V _pore ~ 0.3-1 cm ³ /g), a narrow pore size distribution, which includes the active metal Ni and/or Cu and/or With a content not exceeding 40 wt.%, as well as aluminum oxide or its mixture with oxides of Mg or Ca, or Sr, or Ba, or Zn, a method is proposed, characterized in that a hydrothermal treatment of a mixture containing a product as a source of aluminum centrifugal thermal activation of gibbsite (CTA of gibbsite), salts of Ni and/or Cu and/or Co, or mixtures thereof, as well as salts of Mg or Ca, or Sr, or Ba, or Zn and urea, to obtain precursors - layered mixed hydroxides with the structure of hydrotalcite or mixtures thereof with individual hydroxides/oxides. The resulting catalyst precursor is calcined and activated, while hydrothermal treatment of the mixture is carried out at a temperature not exceeding 150°C, calcination of the precursor is carried out in air at a temperature of 200-900°C, and subsequent activation in hydrogen at a temperature of 200-700°C.

In the proposed method for preparing a catalyst, an amorphous CTA product of gibbsite with high reactivity is used as the initial source of aluminum. To prepare the catalyst, a suspension of gibbsite CTA is prepared in an aqueous solution of the corresponding metal salts (Me) and urea as a hydrolyzing agent at a molar ratio (sum ΣMe): urea = 2-10, mainly 3-5. The suspension is placed in a Top-Industrie 3002.0000 autoclave. Hydrothermal treatment (HTP) of the resulting suspensions is carried out at a temperature not exceeding 150°C for 1-24 hours, depending on the reagents. The obtained TRP products, which are a mixture of layered mixed hydroxides with a hydrotalcite structure or mixtures thereof with individual hydroxides, are separated by centrifugation, dried at 120°C for 10 hours and calcined at a temperature of 200-900°C, mainly 300-900°C. After calcination, mixed oxides are activated in a stream of hydrogen directly in the hydrogenation reactor at a temperature of 200-700°C.

For the hydrogenation of acetone, 5 g of catalyst mixed with silicon carbide in a ratio of 1:2 is placed in the isothermal zone of a stainless steel flow reactor with external heating. The recovery of the catalyst is carried out as follows: a mixture of hydrogen and nitrogen (1:1) is passed through the reactor, increasing the temperature from room temperature to a predetermined value at a rate of 4°C/min. After reaching the desired temperature, the catalyst is kept in a mixture of hydrogen and nitrogen (1:1) for 1 h, then a hydrogen flow is fed into the reactor and the catalyst is kept at the reduction temperature for 3 h.

In the examples according to the invention, the hydrogenation of acetone is carried out in a flow reactor at a temperature of 100°C, a pressure of 2.0 MPa, a space velocity of 1.5 g of acetone/(g of catalyst h), a molar ratio of H ₂ :Acetone = 1.2:1. At the end of the recovery procedure, the temperature in the reactor is reduced to the reaction temperature, and a mixture containing 12.5 wt.% acetone and 87.5 wt.% isopropanol is fed into the reactor.

The essence of the invention is illustrated by the following examples.

Example 1

From the CTA product gibbsite, an aqueous solution of nickel nitrate, taken in stoichiometric quantities to obtain a catalyst containing Ni - 20 wt.%, Al₂O₃ - 80 wt.%, and urea, taken in a molar ratio of Ni:urea = 2, prepare a suspension and place in an autoclave. Hydrothermal treatment is carried out at a temperature of 125°C for 6 hours. The TRP products (predecessors) are separated by centrifugation, dried at 120°C for 10 hours, and calcined in air at a temperature of 500°C to obtain a catalyst. The resulting mixed oxide catalyst, containing 20 wt.% Ni, the rest- Al₂O₃, activated in a stream of hydrogen directly in the acetone hydrogenation reactor at a temperature of 450°C.

The activity of the catalyst in the acetone hydrogenation reaction is tested in a flow reactor containing 5 g of catalyst at a temperature of 100°C, a pressure of 2.0 MPa, a space velocity of 1.5 g of acetone/(g of catalyst h), a molar ratio of H ₂ : Acetone = 1 ,2:1. For hydrogenation, a mixture containing 12.5 wt.% acetone in isopropyl alcohol is used, the conversion of acetone is 98.2%, the selectivity of the conversion of acetone to isopropyl alcohol is 98.3%.

Example 2

From the CTA product gibbsite, an aqueous solution of magnesium and nickel nitrates, taken in stoichiometric quantities to obtain a catalyst with a Ni content of 20 wt.%, (MgO + Al₂O₃) - 80 wt.%, and urea, taken in a molar ratio of ΣMe(Ni+Mg):urea=3, prepare a suspension and place in an autoclave. Hydrothermal treatment is carried out at a temperature of 125°C for 6 hours. The TRP products (precursors) are separated by centrifugation, dried at 120°C for 10 hours, and calcined in air at a temperature of 200°C to obtain a catalyst. The resulting mixed oxide catalyst, containing 20 wt.% Ni, the rest- (MgO+Al₂O₃), activated in a stream of hydrogen directly in the acetone hydrogenation reactor at a temperature of 300°C.

Testing the catalyst in the reaction of hydrogenation of acetone is carried out similarly to Example 1. The conversion of acetone is 99.5%, the selectivity of the conversion of acetone to isopropyl alcohol is 99.6%.

Example 3

From the CTA product gibbsite, an aqueous solution of calcium and copper nitrates, taken in stoichiometric quantities to obtain a catalyst containing Cu - 30 wt.%, (СаO+Al ₂ O ₃ ) - 70 wt.%, and urea, taken in the molar ratio ΣMe (Cu+Ca): urea=5, prepare a slurry and autoclave. Hydrothermal treatment of the suspension is carried out at a temperature of 140°C for 4 hours. The TRP products are separated by centrifugation, dried at 120°C for 10 hours, and calcined in air at a temperature of 900°C to obtain a catalyst. Calcined mixed oxide catalyst containing 30 wt.% Cu, the rest - (CaO+Al ₂ O ₃ ) activate in a stream of hydrogen directly in the acetone hydrogenation reactor at 700°C.

Testing the catalyst in the reaction of hydrogenation of acetone is carried out similarly to Example 1. The conversion of acetone is 100%, the selectivity of the conversion of acetone to isopropyl alcohol is 99.6%.

Example 4

From a mixture of CTA product gibbsite, aqueous solution nickel and barium nitrates, taken in stoichiometric amounts to obtain a catalyst with a Ni content of 40 wt.%, (BaO + Al₂O₃) - 60 wt.%, and urea, taken in the ratio ΣMe (Ni + Ba): urea = 6, an aqueous suspension is prepared and hydrothermal treatment is carried out at a temperature of 150 ° C for 10 hours. The TRP products are separated by centrifugation, dried at 120 ° With 10 h and to obtain a catalyst calcined in air at a temperature of 400°C. Calcined mixed oxide catalyst containing 40 wt% Ni, balance-(BaO+Al₂O₃), activated in a stream of hydrogen directly in the acetone hydrogenation reactor at 200°C.

Testing the catalyst in the reaction of hydrogenation of acetone is carried out similarly to Example 1. The conversion of acetone is 99.8%, the selectivity of the conversion of acetone to isopropyl alcohol is 99.5%.

Example 5

From a mixture of the CTA product gibbsite, an aqueous solution of strontium and nickel nitrates, taken in stoichiometric quantities to obtain a catalyst with a Ni content of 10 wt.%, (SrO+Al ₂ O ₃ ) - 90 wt.%, and urea, taken in the ratio ΣMe (Ni + Sr): urea = 10, an aqueous suspension is prepared and hydrothermal treatment is carried out at a temperature of 150°C for 10 hours. The TRP products are separated by centrifugation, dried at 120°C for 10 hours and calcined in air at a temperature of 400°C to obtain a catalyst WITH. Calcined mixed oxide catalyst containing 10 wt.% Ni, the rest - (SrO+Al ₂ O ₃ ), activate in a stream of hydrogen directly in the acetone hydrogenation reactor at 250°C.

Testing the catalyst in the reaction of hydrogenation of acetone is carried out similarly to Example 1. The conversion of acetone is 100%, the selectivity of the conversion of acetone to isopropyl alcohol is 99.6%.

Example 6

From a mixture of the CTA product gibbsite, an aqueous solution of nickel and zinc nitrates, taken in stoichiometric quantities to obtain a catalyst containing Ni - 30 wt.%, (ZnO + Al ₂ O ₃ ) - 70 wt.%, and urea, taken in the ratio ΣMe (Ni+Zn): urea=10, prepare an aqueous suspension. Further, all operations, as in example 4.

Testing the catalyst in the reaction of hydrogenation of acetone is carried out similarly to Example 1. The conversion of acetone is 100%, the selectivity of the conversion of acetone to isopropyl alcohol is 99.5%.

Example 7

From a mixture of the CTA product gibbsite, an aqueous solution of cobalt and magnesium nitrates, taken in stoichiometric quantities to obtain a catalyst containing Co - 20 wt.%, (MgO + Al ₂ O ₃ ) - 80 wt.%, and urea, taken in the ratio ΣMe (Co+Mg):urea=5, prepare an aqueous suspension. Further, all operations, as in example 1.

Testing the catalyst in the reaction of hydrogenation of acetone is carried out similarly to Example 1. The conversion of acetone is 99.2%, the selectivity of the conversion of acetone to isopropyl alcohol is 99.3%.

Example 8

From a mixture of CTA product gibbsite, an aqueous solution of nickel, copper and cobalt nitrates, taken in stoichiometric quantities to obtain a catalyst containing Ni - 10, Cu - 10, Co - 5 wt.%, Al₂O₃ - 75 wt.%, and urea, taken in the ratio ΣMe(Ni+Cu+Co):urea=4, prepare an aqueous suspension. Further, all operations, as in example 2.

Testing of the catalyst in the reaction of hydrogenation of acetone is carried out similarly to Example 1. The conversion of acetone is 100%, the selectivity of the conversion of acetone to isopropyl alcohol is 99.8%.

Claims (3)

1. A method of preparing a catalyst for the production of isopropyl alcohol in the process of hydrogenation of acetone, which includes in its composition the active metal Ni and/or Cu and/or Co with a mass content of not more than 40%, as well as aluminum oxide or its mixture with oxides of Mg or Ca, or Sr, or Ba, or Zn, characterized in that a hydrothermal treatment of a mixture is carried out containing, as a source of aluminum, the product of centrifugal thermal activation of gibbsite, Ni and/or Cu and/or Co salts, or mixtures thereof, Mg or Ca salts, or Sr, or Ba, or Zn and urea, to obtain precursors - layered mixed hydroxides with a hydrotalcite structure or their mixtures with individual hydroxides, and the resulting catalyst precursor is calcined and activated, and the hydrothermal treatment of the mixture is carried out at a temperature not exceeding 150 ° C, followed by stage of drying, the calcination of the precursor is carried out in air at a temperature of 200-900°C, and subsequent activation in hydrogen at a temperature of 200-700°C. 2. The method according to claim 1, characterized in that the hydrothermal treatment of a mixture containing the product of centrifugal thermal activation of gibbsite, individual Ni and/or Cu and/or Co salts, or mixtures thereof, as well as Mg or Ca or Sr salts, or Ba or Zn and urea are carried out at a molar ratio (sum of metals): urea = 2-10, preferably 3-5. 3. The method according to p. oxides of Mg or Ca, or Sr, or Ba, or Zn, in the amount of 60-90 wt.%, mainly 70-80 wt.%.