CN108097325B

CN108097325B - Catalyst for preparing acrylic acid and methyl acrylate and preparation method thereof

Info

Publication number: CN108097325B
Application number: CN201611055147.6A
Authority: CN
Inventors: 石磊; 倪友明; 朱文良; 刘勇; 刘红超; 刘中民
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2016-11-25
Filing date: 2016-11-25
Publication date: 2020-03-27
Anticipated expiration: 2036-11-25
Also published as: CN108097325A

Abstract

The invention relates to a catalyst for preparing acrylic acid and methyl acrylate and a preparation method thereof. The method comprises the following steps: (1) treating the molecular sieve with MOR configuration by using acid, drying and roasting to obtain the acid-modified molecular sieve with MOR configuration; (2) washing the acid-modified molecular sieve with MOR configuration to neutrality, adding a binder, molding and roasting; (3) treating the acid-modified MOR configuration molecular sieve of step (2) in an atmosphere containing pyridine and/or pyridine substitutes to produce a catalyst comprising the acid-modified MOR molecular sieve.

Description

Catalyst for preparing acrylic acid and methyl acrylate and preparation method thereof

Technical Field

The invention relates to a catalyst for preparing acrylic acid and methyl acrylate and a preparation method thereof.

Background

Acrylic acid and methyl acrylate are important chemical raw materials, can be used as coatings, flocculating agents, dispersing agents, binding agents and the like, are widely applied to the industries of buildings, water treatment, daily chemical industry, soil treatment, leather and the like, and are closely related to the daily life of people. The most common process for the preparation of acrylic acid and methyl acrylate in the industry today is the two-stage oxidation of propylene, i.e. the first oxidation of propylene to acrolein, which is further oxidized to give acrylic acid. However, the raw material propylene is derived from petroleum, belongs to non-renewable resources and is not in accordance with the sustainable development concept.

With the rapid development of C1 chemistry, acetic acid and methyl acetate production capacity became excessive. The method for preparing acrylic acid and methyl acrylate by using cheap raw materials of acetic acid and methyl acetate as raw materials provides a feasible route for continuously preparing acrylic acid and methyl acrylate.

The catalysts adopted in the research are mostly alkaline catalysts or acid-base bifunctional catalysts, and the preparation process generally adopts methods such as impregnation, ion exchange and coprecipitation to load active components on a carrier, so that the defects of complex preparation, complex influencing factors, low repeatability, easy loss of active components and the like exist, and the requirement of industrial large-scale production cannot be met.

Disclosure of Invention

One of the objects of the present invention is to provide a catalyst for the production of acrylic acid and/or methyl acrylate from a feedstock comprising carbon monoxide and a formaldehyde-based compound, said catalyst comprising an acid-modified molecular sieve having MOR configuration, said formaldehyde-based compound being at least one of formaldehyde, methylal, trioxymethylene.

In one embodiment, the acid-modified molecular sieve having the MOR configuration has a silicon to aluminum atomic ratio of from 1 to 100.

In one embodiment, it is preferred that the atomic ratio of silicon to aluminum in the acid-modified molecular sieve having the MOR configuration is from 2 to 50.

In one embodiment, the catalyst comprises a pyridine compound, or the acid-modified molecular sieve having the MOR configuration comprises a pyridine compound.

Preferably, in one embodiment, the catalyst contains pyridine compound with mass content of 0.01-15%, or the acid modified molecular sieve with MOR configuration contains pyridine compound with mass content of 0.01-15%.

In one embodiment, the catalyst contains 3 to 10% by mass of the pyridine compound, or the acid-modified molecular sieve with MOR configuration contains 3 to 10% by mass of the pyridine compound.

Further preferably, in a specific embodiment, the catalyst contains pyridine compound with mass content of 4% to 6%, or the acid modified molecular sieve with MOR configuration contains pyridine compound with mass content of 4% to 6%.

In one embodiment, the pyridines comprise pyridine and/or substituted pyridine, and the substituted pyridine is selected from the group consisting ofFrom one to three H of five H in the pyridine ring are independently selected from F, Cl, Br, I, CH₃、CF₃、CH₃CH₂、NO₂At least one of the compounds substituted with the substituent(s) in (1).

In one embodiment, the pyridine compound comprises monomethyl pyridine, dimethyl pyridine, trimethyl pyridine, ethyl pyridine, nitro pyridine, fluoro pyridine, chloro pyridine, bromo pyridine, and iodo pyridine.

A second object of the present invention provides a process for preparing a catalyst according to the first object of the present invention, which process comprises the steps of: (1) treating the molecular sieve with MOR configuration by using acid, washing, drying and roasting to obtain the acid-modified molecular sieve with MOR configuration; (2) adding a binder into the acid-modified molecular sieve with MOR configuration, molding and roasting; (3) treating the acid-modified MOR-configuration molecular sieve obtained in the step (2) in an atmosphere containing pyridine compounds to obtain the catalyst containing the acid-modified MOR molecular sieve.

In one embodiment, in step (1), the molecular sieve having MOR configuration is treated in an acid solution at 30 ℃ to 100 ℃ for 1h to 10 h.

In one embodiment, in step (1), the molecular sieve having MOR configuration is treated in an alkaline solution at 40 ℃ to 90 ℃ for 2h to 5 h.

In a specific embodiment, the acid is at least one of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, oxalic acid, and citric acid. The acid is preferably at least one of hydrochloric acid, nitric acid, acetic acid, oxalic acid and citric acid.

In one embodiment, the concentration of the acid in the solution is from 0.05mol/L to 1 mol/L; preferably, the concentration of the acid in the solution is 0.1mol/L to 0.7 mol/L.

In one embodiment, the binder is selected from at least one of silica, zirconia, alumina, magnesia, titania, pseudo-boehmite, kaolin, montmorillonite;

in one embodiment, it is preferable that the binder is contained in the catalyst in an amount of 1 to 70% by mass. (ii) a

In one embodiment, it is more preferable that the binder is contained in the catalyst in an amount of 10 to 50% by mass.

In one embodiment, in step (3), the pyridine compound-containing atmosphere has a volume percentage of 0.01% to 15%.

In one embodiment, in step (3), the volume percentage of the pyridine compound in the atmosphere containing the pyridine compound is 1% to 10%.

In one embodiment, the pyridines comprise pyridine and/or substituted pyridine selected from one to three of the five H in the pyridine ring independently selected from F, Cl, Br, I, CH₃、CF₃、CH₃CH₂、NO₂At least one of the compounds substituted with the substituent(s) in (1).

In one embodiment, the conditions of the calcination in steps (1) and (2) are independently: air atmosphere, 350-680 ℃, 1-10 h.

In one embodiment, it is preferred that the conditions of the calcination in steps (1) and (2) are independently: air atmosphere, 400 to 600 ℃ and 2 to 6 hours.

In one embodiment, in step (3), the treatment conditions are: 240 ℃ to 400 ℃, 0.5 hour to 24 hours.

In one embodiment, preferably in step (3), the treatment conditions are: 250 to 350 ℃ for 2 to 10 hours.

In one embodiment, the reaction conditions for the preparation of acrylic acid and/or methyl acrylate are as follows: the temperature is 180-400 ℃, the pressure is 0.2-15.0 Mpa, and the total feed gasThe space velocity of the material is 0.05h^-1To 10.0h^-1。

In one embodiment, the method further comprises the steps of exchanging the formed acid-modified molecular sieve with MOR configuration with ammonium, washing, drying and calcining between the step (2) and the step (3). The roasting condition is air atmosphere, the temperature is 350-680 ℃, and the time is 1-10 hours; preferably an air atmosphere, from 400 ℃ to 600 ℃ for 2h to 6 h.

In one embodiment, the reaction conditions for the preparation of acrylic acid and/or methyl acrylate are preferably as follows: the temperature is 300-350 ℃, the pressure is 0.2-5.0 Mpa, and the total feed space velocity of the raw material gas is 0.3h^-1To 2h^-1。

In one embodiment, the ratio of the molar amount of carbon monoxide to the total molar amount of formaldehydes is from 1:1 to 200: 1.

In one embodiment, the ratio of the molar amount of carbon monoxide to the total molar amount of formaldehydes is from 10:1 to 100: 1.

In one embodiment, the ratio of the molar amount of carbon monoxide to the total molar amount of formaldehydes is from 20:1 to 50: 1.

In a specific embodiment, the formaldehyde-based compound is at least one of formaldehyde, methylal and trioxymethylene.

In a specific embodiment, the reactor of the reaction zone is selected from one of a tank reactor, a fixed bed reactor, a moving bed reactor, and a fluidized bed reactor.

In one embodiment, there may be one reactor, or a plurality of reactors connected in series or parallel.

The beneficial effects of the invention include but are not limited to:

(1) the catalyst for producing acrylic acid and methyl acrylate based on methylal and carbon monoxide has the advantages of simple industrial preparation, high selectivity of target products, good catalyst stability and the like. The activity and the stability of the catalyst are effectively improved, the regeneration times of the catalyst are reduced, the production process of acrylic acid and methyl acrylate by methylal and the production cost of the catalyst are simplified, and the production operation cost is reduced.

(2) The catalyst consumption of unit product is reduced, and the investment is reduced.

(3) The regeneration, activation and loading and unloading frequency of the catalyst are reduced, the emission of waste gas in the regeneration process of the catalyst is reduced, and the production and maintenance cost is reduced.

Detailed Description

The present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

The raw materials in the examples of the present invention were all purchased from commercial sources unless otherwise specified.

In the present invention, methylal is reacted with carbon monoxide to produce compounds such as dimethyl ether, acetic acid, methyl acetate, acrylic acid and methyl acrylate. The generation of the product can be directionally controlled by controlling reaction conditions of different temperatures and pressures, raw material compositions in different proportions and other conditions through thermodynamic and kinetic factors, and the method is carried out according to the following equation. Ideally, the total carbon selectivity of acrylic acid in the product is 60% and the total carbon selectivity of acetic acid is 40%, with no other by-products being formed. If the product selectivity is calculated by taking methylal as a single reaction raw material, the carbon mole selectivity of acrylic acid is 50 percent, and the carbon mole selectivity of acetic acid is 50 percent.

The raw materials and products of the invention are detected by an Aligent 7890A gas chromatography of Agilent and an FFAP capillary column of Agilent. According to one embodiment of the present invention, a fixed bed reactor is used, the catalyst packing mass is 0.5 to 3.0g, the reaction temperature is 180 to 350 ℃, and the reaction pressure is 0.1 to 10 MPa. The raw material methylal is prepared by introducing carbon monoxide into a fixed bed reactor under different water bath temperatures (0-50 ℃) to carry saturated vapor of methylal, so as to obtain methylal raw material gases with different volume contents. The saturated vapor pressure of the starting methylal under different temperature conditions is calculated as shown in the following formula:

ln(p1*/p2*)＝-ΔvapHm/8.3145×(1/T1-1/T2)

wherein p1 and p2 represent the saturated vapor pressures of the acetal at different temperatures (T1, T2), respectively. The molar evaporation enthalpy Δ vapHm is known to be 43.99KJ/mol, boiling point 42.3 ℃, so that the saturated vapor pressure of methylal at any temperature can be calculated. The amount of starting methylal material entering the reactor per unit time can be calculated from the saturated vapor pressure.

The conversion and selectivity in the examples of the invention were calculated as follows:

methylal conversion [ (moles of methylal in feed) - (moles of methylal in discharge) ]/(moles of methylal in feed) × (100%)

Acrylic acid selectivity 2/3 (moles of acrylic acid in output) ÷ [ (moles of methylal carbon in input) - (moles of methylal carbon in output) ] × (100%)

Methyl acrylate selectivity 3/4 (moles of methyl acrylate carbon on discharge) ÷ [ (moles of methylal carbon on feed) - (moles of methylal carbon on discharge) ] × (100%)

Acetic acid selectivity 1/2 (moles of acetic acid in the output) ÷ [ (moles of methylal carbon in the input) - (moles of methylal carbon in the output) ] × (100%)

Methyl acetate selectivity is 2/3 (moles of methyl acetate carbon in the output) ÷ [ (moles of methylal carbon in the input) - (moles of methylal carbon in the output) ] × (100%).

The analysis of organic matter (pyridine compound) in the catalyst/molecular sieve comprises the following operation processes:

weighing 100mg of catalyst sample, and filling the catalyst sample into a polytetrafluoroethylene bottle with a cover; adding 1ml of 20% hydrofluoric acid aqueous solution, shaking uniformly, standing for 1h to completely dissolve the molecular sieve catalyst; to the dissolved solution was added 1ml of methylene Chloride (CH)₂Cl₂) Extracting an organic phase, shaking uniformly, transferring to a separating funnel of a polytetrafluoroethylene piston, standing for layering, and discharging lower-layer oily liquid; the analysis was carried out using an Agilent gas chromatograph-mass spectrometer (Agilent 7890A/5975C GC/MSD). Chlorobenzene or hexachloroethane was added as an internal standard to the dichloromethane solution (1. mu. l C)₆H₅Cl/100ml CH₂Cl₂Or 10ppm of C₂Cl₆). The analysis was performed using an HP-5MS column with an initial column box temperature of 35 deg.C, 5 deg.C/min ramp to 300 deg.C and hold for 10 min.

Example 1

100 g of H-MOR (Si/Al ═ 6.5) molecular sieve was treated in 1000mL of 0.5mol/L acetic acid solution at 80 ℃ for 2 hours, filtered and washed to neutrality, then dried at 120 ℃ and calcined at 550 ℃ for 4 hours under an air atmosphere. 80g of sample subjected to acid treatment, 28g of pseudo-boehmite (containing 29 wt% of water) and 10% of dilute nitric acid are uniformly mixed, extruded and formed, dried at 120 ℃, roasted at 550 ℃ for 4 hours, and the prepared sample is treated at 300 ℃ for 2 hours in an atmosphere containing 7.5% of pyridine in gas phase to prepare the methylal conversion catalyst No. 1. The pyridine content in catalyst # 1 was analyzed to be 6.0%.

Example 2

100 g of H-MOR molecular sieve with Si/Al of 5, 25, 50 and 100 respectively is respectively put into 1000mL of 0.5mol/L hydrochloric acid, nitric acid, oxalic acid and citric acid solution to be treated for 2 hours at 80 ℃, filtered and washed to be neutral, and then roasted for 4 hours at 120 ℃ and 550 ℃ under an air atmosphere. 80g of sample subjected to acid treatment, 28g of pseudo-boehmite (containing 29 percent of water) and 10 percent of dilute nitric acid are uniformly mixed, extruded and formed, dried at 120 ℃, roasted at 550 ℃ for 4 hours, and the prepared sample is treated at 300 ℃ for 2 hours in the atmosphere of pyridine with 7.5 percent of volume in gas phase to prepare methylal conversion catalysts No. 2, No. 3, No. 4 and No. 5. The pyridine content in analyzed catalyst 2# was 4.3%; the pyridine content in catalyst 3# was 4.2%; the pyridine content in catalyst # 4 was 4.1 percent; the pyridine content in catalyst # 5 was 4.1%.

Example 3

100 g of H-MOR molecular sieve is put into 1000mL of nitric acid solution with the concentration of 0.05mol/L, 0.1mol/L, 0.7mol/L and 1mol/L respectively to be treated for 2 hours at the temperature of 80 ℃, and the other conditions are consistent with the example 1, thus preparing methylal conversion catalysts 6#, 7#, 8#, and 9 #. The pyridine content in analyzed catalyst 6# was 4.2%; the pyridine content in catalyst 7# was 4.2%; the pyridine content in catalyst 8# was 4.2%; the pyridine content in catalyst # 9 was 4.2%.

Example 4

100 g of H-MOR molecular sieve is put into 1000mL of nitric acid solution with the concentration of 0.5mol/L respectively to be treated for 2 hours at 30 ℃, 40 ℃, 70 ℃, 90 ℃ and 100 ℃, and other conditions are consistent with those of the example 1, so that methylal conversion catalysts 10#, 11#, 12#, 13#, and 14# are prepared. The pyridine content in analyzed catalyst 10# was 4.1%; the pyridine content in catalyst 11# was 4.1%; the pyridine content in catalyst 12# was 4.1%; the pyridine content in catalyst 13# was 4.1%; the pyridine content in catalyst # 14 was 4.1%.

Example 5

The binder pseudo-boehmite is 10%, 30% and 50% by weight, and the catalyst is prepared according to the other conditions in the same way as in the examples, and the methylal conversion catalysts No. 15, No. 16 and No. 17 are prepared. The pyridine content in analyzed catalyst 15# was 5.2%; the pyridine content in catalyst 16# was 3.6%; the pyridine content in catalyst 17# was 2.9%.

The binding agent pseudo-boehmite is respectively replaced by silicon dioxide, titanium oxide, silicon dioxide and aluminum oxide, silicon dioxide and titanium oxide, aluminum oxide and titanium oxide, the weight content of the binding agent is 20 percent, and other conditions are the same as those in the example 1, and the methylal conversion catalysts 18#, 19#, 20#, 21#, and 22# are prepared. The pyridine content in analyzed catalyst 18# was 4.8%; the pyridine content in catalyst 19# was 4.8%; the pyridine content in catalyst 20# was 4.8%; the pyridine content in catalyst 21# was 4.8%; the pyridine content in catalyst 22# was 4.8%.

Example 6

100 g of H-MOR molecular sieve is put into 1000mL of nitric acid solution with the concentration of 0.5mol/L to be respectively treated for 1, 6 and 10 hours at the temperature of 80 ℃, and the other conditions are consistent with the example 1, thus preparing the methylal conversion catalysts 23#, 24#, and 25 #. The pyridine content in analyzed catalyst # 23 was 4.0%; the pyridine content in catalyst No. 24 was 4.0%; the pyridine content in catalyst # 25 was 4.0%.

Example 7

80g of H-MOR (Si/Al ═ 6.5) molecular sieve is put into 1000mL of 0.5mol/L acetic acid solution and treated at 80 ℃ for 2 hours, filtered and washed to be neutral, then dried at 120 ℃, a sample after being roasted at 550 ℃ for 4 hours under the air atmosphere is mixed with 28g of pseudo-boehmite and 10% of dilute nitric acid evenly and then extruded into strips for forming, after being roasted, the sample is exchanged for three times (2 hours/time) by 0.5mol/L ammonium nitrate, washed by deionized water and dried, and then roasted at 400 ℃, 500 ℃ and 650 ℃ for 4 hours respectively, and the obtained sample is treated at 300 ℃ for 2 hours under the atmosphere containing 7.5% of pyridine by volume in gas phase to prepare the methylal conversion catalysts 26#, 27#, and 28 #. The pyridine content in analyzed catalyst 26# was 4.0%; the pyridine content in catalyst 27# was 4.0%; the pyridine content in catalyst 28# was 4.1%.

Example 8

80g of H-MOR (Si/Al ═ 6.5) molecular sieve is put into 1000mL of 0.5mol/L acetic acid solution and treated at 80 ℃ for 2 hours, filtered and washed to be neutral, then dried at 120 ℃, a sample after being roasted at 550 ℃ for 4 hours under the air atmosphere is mixed with 28g of pseudo-boehmite and 10% of dilute nitric acid evenly and then extruded into strips for forming, after being roasted, the sample is exchanged for three times (2 hours/time) by 0.5mol/L ammonium nitrate, washed by deionized water and dried, and then roasted at 550 ℃ for 2, 6 and 10 hours respectively, and the obtained sample is treated at 300 ℃ for 2 hours under the atmosphere containing 7.5% of pyridine by volume in gas phase, thus obtaining the methylal conversion catalysts 29#, 30#, and 31 #. The pyridine content in analyzed catalyst 29# was 4.1%; the pyridine content in catalyst # 30 was 4.1%; the pyridine content in catalyst # 31 was 4.1%.

Example 9

80g of H-MOR (Si/Al ═ 6.5) molecular sieve is put into 1000mL of 0.5mol/L acetic acid solution and treated at 80 ℃ for 2 hours, filtered and washed to be neutral, then dried at 120 ℃, a sample after being roasted at 550 ℃ for 4 hours under the air atmosphere is mixed with 28g of pseudo-boehmite and 10% dilute nitric acid evenly and extruded to be shaped, after being roasted, the sample is exchanged for three times (2 hours/time) by 0.5mol/L ammonium nitrate, washed by deionized water and dried, and then roasted at 550 ℃ for 4 hours, and the obtained sample is respectively treated at 240 ℃, 280 ℃, 350 and 400 ℃ under the atmosphere containing 7.5% of volume of pyridine in gas phase for 2 hours to prepare the methylal conversion catalyst 32#, 33#, 34#, 35 #. The pyridine content in analyzed catalyst 32# was 4.1%; the pyridine content in catalyst # 33 was 4.1%; the pyridine content in catalyst 34# was 4.1%; the pyridine content in catalyst # 35 was 4.1%.

Example 10

80g of H-MOR (Si/Al is 6.5) molecular sieve is put into 1000mL of acetic acid solution with the concentration of 0.5mol/L to be treated for 2 hours at 80 ℃, filtered and washed to be neutral, then dried at 120 ℃, a sample after being roasted for 4 hours at 550 ℃ in air atmosphere is evenly mixed with 28g of pseudo-boehmite and 10% of dilute nitric acid and then extruded into strips for forming, after being roasted, the mixture is exchanged for three times (2 hours/time) by 0.5mol/L of ammonium nitrate, washed by deionized water and dried, after being roasted for 4 hours at 550 ℃, the obtained sample respectively contains 7.5% by volume of methylpyridine, dimethylpyridine, trimethylpyridine, ethylpyridine, nitropyridine, fluoropyridine, chloro-pyridine, bromo-pyridine and iodo-pyridine in gas phase at 300 ℃ for 2 hours, and the methylal conversion catalysts 36#, 37#, 38#, 39#, 40#, 41#, 42#, and the like are prepared, 43#, 44 #. The content of pyridine compound in the analyzed catalyst 36# was 4.1%; the content of the pyridine compound in the catalyst 37# is 4.1%; the content of the pyridine compound in the catalyst 38# was 4.1%; the content of the pyridine compound in the catalyst 39# was 4.1%; the content of the pyridine compound in the catalyst 40# is 4.1%; the content of the pyridine compound in the catalyst 41# was 4.1%; the content of the pyridine compound in the catalyst 42# was 4.1%; the content of the pyridine compound in the catalyst 43# was 4.1%; the pyridine compound content in catalyst 44# was 4.1%.

Example 11

80g of H-MOR (Si/Al ═ 6.5) molecular sieve is put into 1000mL of 0.5mol/L acetic acid solution and treated at 80 ℃ for 2 hours, filtered and washed to be neutral, then dried at 120 ℃, a sample after being roasted at 550 ℃ for 4 hours under the air atmosphere is uniformly mixed with pseudo-boehmite and 10% dilute nitric acid and then extruded into strips for forming, after roasting, the sample is exchanged for three times (2 hours/time) by 0.5mol/L ammonium nitrate, washed by deionized water and dried, after being roasted at 550 ℃ for 4 hours respectively, the obtained sample is treated at 300 ℃ for 2 hours under the atmosphere of pyridine containing 0.01%, 2.0%, 8.0% and 15% of volume in gas phase respectively, and then methylal conversion catalysts 45#, 46#, 47#, and 48#, are prepared. The pyridine content in analyzed catalyst 45# was 0.1%; the pyridine content in catalyst 46# was 1.5%; the pyridine content in catalyst 47# was 4.9%; the pyridine content in catalyst 48# was 10.1%.

Example 11

80g of H-MOR (Si/Al ═ 6.5) molecular sieve is put into 1000mL of 0.5mol/L acetic acid solution and treated at 80 ℃ for 2 hours, filtered and washed to be neutral, then dried at 120 ℃, a sample after being roasted at 550 ℃ for 4 hours under the air atmosphere is evenly mixed with pseudo-boehmite and 10% diluted nitric acid and then extruded into strips for forming, after being roasted, the sample is exchanged for three times (2 hours/time) by 0.5mol/L ammonium nitrate, washed by deionized water and dried, and then the samples are respectively roasted at 550 ℃ for 4 hours, 10 and 20 hours, and the obtained samples are respectively treated at 300 ℃ under the atmosphere containing 7.5% of pyridine by volume in gas phase for 4, 10 and 20 hours, thus obtaining the methylal conversion catalysts 49#, 50#, 51 #. The pyridine content in analyzed catalyst 49# was 5.2%; the pyridine content in catalyst 50# was 6.2%; the pyridine content in catalyst 51# was 6.6%.

Comparative example 1 preparation of Cs-based catalyst

(1) Weighing 82.9g of cesium acetate, 5.5g of zirconium nitrate and 5.0g of cerium nitrate, and adding 120mL of deionized water for dissolving to prepare an aqueous solution;

(2) weighing 170g of silicon dioxide and 28g of magnesium oxide, uniformly mixing, adding the solution prepared in the step (1), kneading, extruding into strips, forming, drying at 120 ℃ for 4 hours, and roasting at 400 ℃ for 4 hours to obtain a metal oxide catalyst, wherein the sample is marked as D0^#。

Comparative example 2

Unmodified H-MOR molecular sieve having an atomic silica to alumina ratio of 6.5 in example 1, and catalyst number D1^#。

Unmodified H-MOR molecular sieves with atomic Si/Al ratios of 5, 25, 50, 100 in example 2, respectively, the catalysts being numbered D2^#、D3^#、D4^#、D5^#。

Example 12 catalyst evaluation

10g of each prepared catalyst sample was placed in a stainless steel fixed bed reaction tube having an inner diameter of 8.5mm, carbon monoxide was introduced, and the pressure of the reaction system was increased to 5MPa(ii) a Then according to the reaction space velocity WHSV of 3000h^-1And the reaction is carried out at a reaction temperature of 240 ℃. The starting materials and the products obtained were analyzed on-line by Agilent 7890A gas chromatography (column: HP-PLOT-Q capillary column, Porapak-Q packed column; detector: FID, TCD) and the results are given in Table 1.

TABLE 1

As can be seen from the data in Table 1, compared with the technical scheme of the comparative example, the selectivity of acrylic acid and methyl acrylate is obviously improved; in particular, test No. 1 in Table 1 compares with test Nos. 52 and 54, catalyst D1 of the comparative example^#With the prolonging of the reaction time, the conversion rate and the selectivity are reduced rapidly, while the conversion rate and the selectivity of the catalyst 1 prepared by the technical scheme of the invention are still very high after 1500h of reaction, and the service life is far longer than that of the catalyst D1 of the comparative example 2^#Also much larger than catalyst D0 of comparative example 1^#。

The above description is only for the purpose of illustrating the present invention and is not intended to limit the present invention in any way, and the present invention is not limited to the above description, but rather should be construed as being limited to the scope of the present invention.

Claims

1. A process for the preparation of a catalyst for the production of acrylic acid and/or methyl acrylate from a feedstock comprising carbon monoxide and a formaldehyde-based compound, the process comprising the steps of:

(1) treating the molecular sieve with MOR configuration by using acid, washing, drying and roasting to obtain the acid-modified molecular sieve with MOR configuration;

(2) adding a binder into the acid-modified molecular sieve with MOR configuration, molding and roasting;

(3) treating the acid-modified MOR-configuration molecular sieve treated in the step (2) in an atmosphere containing pyridine compounds to prepare a catalyst containing the acid-modified MOR molecular sieve;

in the step (3), the treatment conditions under the atmosphere containing the pyridine compound are as follows: 240 ℃ to 400 ℃, 0.5 hour to 24 hours;

the acid-modified molecular sieve with MOR configuration contains pyridine compounds with the mass content of 0.01-15% after the pyridine compounds are treated; the pyridine compound comprises pyridine and/or substituted pyridine, wherein one to three H in five H selected from pyridine rings are independently selected from F, Cl, Br, I and CH₃、CF₃、CH₃CH₂、NO₂At least one of the compounds substituted with the substituent(s) in (b);

the formaldehyde compound is at least one of formaldehyde, methylal and trioxymethylene.

2. The process of claim 1, wherein the acid-modified molecular sieve having the MOR configuration comprises from 4% to 6% by weight of pyridine compound after pyridine compound treatment.

3. The method according to claim 1, wherein in step (3), the treatment conditions under the atmosphere containing the pyridine compound are as follows: 250 to 350 ℃ for 2 to 10 hours.

4. The process of claim 1, wherein the acid-modified molecular sieve having the MOR configuration has a silicon to aluminum atomic ratio of from 1 to 100.

5. The process of claim 1, wherein the acid-modified molecular sieve having the MOR configuration has a silicon to aluminum atomic ratio of from 2 to 50.

6. The process according to claim 1, characterized in that in step (1), the molecular sieve having MOR configuration is treated in acid solution at 30 to 100 ℃ for 1 to 10 h.

7. The process according to claim 1, characterized in that in step (1), the molecular sieve having MOR configuration is treated in acid solution at 40 to 90 ℃ for 2 to 5 h.

8. The method of claim 1, wherein the acid is at least one of hydrochloric acid, nitric acid, sulfuric acid, acetic acid, oxalic acid, and citric acid.

9. The method of claim 1, wherein the concentration of the acid in the solution is 0.05mol/L to 1 mol/L.

10. The method of claim 1, wherein the concentration of the acid in the solution is 0.1mol/L to 0.7 mol/L.

11. The method of claim 1, wherein the binder is selected from at least one of silica, zirconia, alumina, magnesia, titania, pseudoboehmite, kaolin, and montmorillonite.

12. The method of claim 1, wherein the binder is present in the catalyst in an amount of 1 to 70% by mass.

13. The method of claim 1, wherein the binder is present in the catalyst in an amount of 10 to 50% by mass.

14. The method of claim 1, wherein in step (3), the pyridine compound is contained in the atmosphere containing the pyridine compound in an amount of 0.01 to 15 vol%.

15. The method according to claim 1, wherein in step (3), the pyridine compound-containing atmosphere contains 1 to 10 vol% of pyridine compound.

16. The method of claim 1, wherein the firing conditions in steps (1) and (2) are independently: air atmosphere, 350-680 ℃, 1-10 h.

17. The method of claim 1, wherein the firing conditions in steps (1) and (2) are independently: air atmosphere, 400 to 600 ℃ and 2 to 6 hours.

18. The process according to claim 1, characterized in that the reaction conditions for the preparation of acrylic acid and/or methyl acrylate are as follows:

the temperature is 180 ℃ to 400 ℃, the pressure is 0.2MPa to 15.0MPa, and the total feeding space velocity of the raw material gas is 0.05h^-1To 10.0h^-1。

19. The process according to claim 1, characterized in that the reaction conditions for the preparation of acrylic acid and/or methyl acrylate are as follows:

the temperature is 300-350 ℃, the pressure is 0.2-5.0 Mpa, and the total feed space velocity of the raw material gas is 0.3h^-1To 2h^-1。