CN112547044B - Catalyst for acrylic acid synthesis and preparation method and application thereof - Google Patents
Catalyst for acrylic acid synthesis and preparation method and application thereof Download PDFInfo
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- CN112547044B CN112547044B CN201910918136.3A CN201910918136A CN112547044B CN 112547044 B CN112547044 B CN 112547044B CN 201910918136 A CN201910918136 A CN 201910918136A CN 112547044 B CN112547044 B CN 112547044B
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- 239000003054 catalyst Substances 0.000 title claims abstract description 102
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 title claims abstract description 38
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 title claims abstract description 38
- 230000015572 biosynthetic process Effects 0.000 title claims abstract description 24
- 238000002360 preparation method Methods 0.000 title claims abstract description 24
- 238000001308 synthesis method Methods 0.000 title description 3
- 238000003786 synthesis reaction Methods 0.000 claims abstract description 22
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 20
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 19
- 239000001301 oxygen Substances 0.000 claims abstract description 19
- 239000006185 dispersion Substances 0.000 claims abstract description 16
- 238000000034 method Methods 0.000 claims abstract description 15
- 239000007788 liquid Substances 0.000 claims abstract description 6
- UNTBPXHCXVWYOI-UHFFFAOYSA-O azanium;oxido(dioxo)vanadium Chemical compound [NH4+].[O-][V](=O)=O UNTBPXHCXVWYOI-UHFFFAOYSA-O 0.000 claims description 40
- HGINCPLSRVDWNT-UHFFFAOYSA-N Acrolein Chemical compound C=CC=O HGINCPLSRVDWNT-UHFFFAOYSA-N 0.000 claims description 32
- 239000013078 crystal Substances 0.000 claims description 31
- 238000002425 crystallisation Methods 0.000 claims description 21
- 230000008025 crystallization Effects 0.000 claims description 21
- 238000006243 chemical reaction Methods 0.000 claims description 18
- QGAVSDVURUSLQK-UHFFFAOYSA-N ammonium heptamolybdate Chemical compound N.N.N.N.N.N.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.O.[Mo].[Mo].[Mo].[Mo].[Mo].[Mo].[Mo] QGAVSDVURUSLQK-UHFFFAOYSA-N 0.000 claims description 17
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 12
- 239000012298 atmosphere Substances 0.000 claims description 10
- 238000002156 mixing Methods 0.000 claims description 10
- 239000002994 raw material Substances 0.000 claims description 10
- 150000001875 compounds Chemical class 0.000 claims description 7
- 238000001354 calcination Methods 0.000 claims description 6
- 238000000465 moulding Methods 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 4
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 3
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 3
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 3
- 239000002243 precursor Substances 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims 13
- VHUUQVKOLVNVRT-UHFFFAOYSA-O azanium;hydron;hydroxide Chemical compound [NH4+].O VHUUQVKOLVNVRT-UHFFFAOYSA-O 0.000 claims 1
- 150000003839 salts Chemical class 0.000 abstract description 13
- 230000008569 process Effects 0.000 abstract description 8
- 229910052787 antimony Inorganic materials 0.000 abstract description 2
- 229910052802 copper Inorganic materials 0.000 abstract description 2
- 229910052721 tungsten Inorganic materials 0.000 abstract description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 20
- 239000000843 powder Substances 0.000 description 18
- 239000008367 deionised water Substances 0.000 description 17
- 229910021641 deionized water Inorganic materials 0.000 description 17
- 239000002002 slurry Substances 0.000 description 15
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 14
- 230000000052 comparative effect Effects 0.000 description 14
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 12
- 238000011156 evaluation Methods 0.000 description 12
- 239000007864 aqueous solution Substances 0.000 description 10
- 229910002804 graphite Inorganic materials 0.000 description 10
- 239000010439 graphite Substances 0.000 description 10
- 241000276425 Xiphophorus maculatus Species 0.000 description 9
- 238000010438 heat treatment Methods 0.000 description 9
- 238000001035 drying Methods 0.000 description 8
- 229910052757 nitrogen Inorganic materials 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- 230000003197 catalytic effect Effects 0.000 description 5
- 239000002905 metal composite material Substances 0.000 description 4
- 230000001590 oxidative effect Effects 0.000 description 4
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 4
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 4
- 238000001878 scanning electron micrograph Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 230000002194 synthesizing effect Effects 0.000 description 4
- 238000005054 agglomeration Methods 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000002253 acid Substances 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 239000012876 carrier material Substances 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- WUJISAYEUPRJOG-UHFFFAOYSA-N molybdenum vanadium Chemical compound [V].[Mo] WUJISAYEUPRJOG-UHFFFAOYSA-N 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- BYUANIDVEAKBHT-UHFFFAOYSA-N [Mo].[Bi] Chemical compound [Mo].[Bi] BYUANIDVEAKBHT-UHFFFAOYSA-N 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000004817 gas chromatography Methods 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
- B01J23/24—Chromium, molybdenum or tungsten
- B01J23/30—Tungsten
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/002—Mixed oxides other than spinels, e.g. perovskite
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/40—Catalysts, in general, characterised by their form or physical properties characterised by dimensions, e.g. grain size
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
- C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
- C07C51/23—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of oxygen-containing groups to carboxyl groups
- C07C51/235—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of oxygen-containing groups to carboxyl groups of —CHO groups or primary alcohol groups
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Catalysts (AREA)
Abstract
The invention discloses a catalyst for acrylic acid synthesis, which comprises a catalyst with a general formula Mo 12 V a O g Wherein a=0.5 to 10.0. The invention also discloses a preparation method of the catalyst, which comprises the process of crystallizing the dispersion liquid of the oxygen-containing salt containing the V element, the oxygen-containing salt of one or more elements selected from Cu, W and Sb and the oxygen-containing salt of the Mo element.
Description
Technical Field
The invention belongs to the technical field of acrylic acid synthesis methods, and particularly relates to a catalyst for propylene synthesis, a preparation method and application of the catalyst for propylene synthesis.
Background
Acrylic acid and its esters are widely used, wherein crude acrylic acid is mainly used for producing water-soluble coatings and adhesives, and high-purity acid is mainly used for producing SAP (super absorbent resin). With the development of building, electronics and automobile industries, the worldwide acrylic acid demand and yield are continuously increased, and particularly, the domestic acrylic acid yield is greatly increased in recent years, and the domestic yield is increased from 14 ten thousand tons to 300 ten thousand tons in 2000 by 2018.
The current method for preparing acrylic acid industrially is a two-step oxidation method of propylene, which is to oxidize propylene into acrolein under the action of a catalyst and then oxidize acrolein into acrylic acid. One type of catalyst commonly used in the two-step oxidation method is a metal composite oxide catalyst, such as molybdenum-vanadium (Mo-V) composite oxide, molybdenum-bismuth (Mo-Bi) composite oxide, and the like, and the activities of the different types of metal composite oxide catalysts and the yields of obtained acrylic acid are greatly different.
The conventional method for preparing the metal composite oxide catalyst mostly adopts the processes of preparing a metal compound into a solution, adding an insoluble oxide into the solution for heating and evaporating, and then calcining, crushing and forming, and the catalyst obtained by the preparation method usually lacks stable crystal form, has short service life, low conversion rate and selectivity of the catalyst and low product yield.
Disclosure of Invention
One of the technical problems to be solved by the invention is that the catalyst used in the reaction of synthesizing the acrylic acid by oxidizing the acrolein in the prior art has short service life and low product yield, and the catalyst with long service life and high acrylic acid yield is provided.
The second technical problem to be solved by the invention is that the catalyst for synthesizing the acrylic acid by oxidizing the acrolein with uniform and stable crystal morphology and high product yield is difficult to prepare by the preparation method in the prior art, and the preparation method of the catalyst with stable rod-shaped crystal structure, long service life and high product yield is provided.
The third technical problem to be solved by the present invention is to provide a method for synthesizing acrylic acid by using the catalyst as one of the above technical problems.
In order to solve one of the above technical problems, the present invention firstly provides the following technical solutions:
a catalyst for synthesizing acrylic acid is composed of Mo 12 V a O g Wherein, the rod-shaped crystal of (C) is formed,
a＝0.5～10.0；
g is a number determined by the total valence of the elements other than oxygen in the formula.
In the above scheme, mo, V, and O represent the elements molybdenum, vanadium, and oxygen, respectively, and a and g represent their respective atomic ratios.
Mo in the present invention relative to the metal composite catalyst commonly used in the prior art 12 V a O g Stable rod-like crystal structure can be obtained under certain preparation conditions, and the structure can be kept stable in long-term repeated application. In the catalytic reaction, mo 12 V a O g The rod-shaped crystals have larger specific surface area and are difficult to agglomerate, so that the catalyst has higher catalytic efficiency and longer service life compared with the amorphous or other crystal forms.
In some embodiments of the catalyst of the present invention, the Mo 12 V a O g Where a=4.
In some embodiments of the catalyst of the present invention, the rod-like crystals have a diameter of 0.1 to 5 microns.
In some embodiments of the catalyst of the present invention, the rod-like crystals have a length of 1 to 50 microns.
In some embodiments of the catalysts of the present invention, the rod-shaped crystals have an aspect ratio of 3 to 100.
In some embodiments of the catalyst of the present invention, it further comprises a carrier on which the rod-like crystals described above are supported.
In some embodiments of the catalyst of the present invention, it comprises 20 to 90 parts by mass of rod-like crystals and 10 to 80 parts by mass of a carrier.
The person skilled in the art can choose carriers of different morphology, size and composition in the prior art according to the actual need, for example the carriers can be chosen from SiO 2 、Al 2 O 3 、ZrO 2 And TiO 2 But is not limited to the above-described selection.
In order to solve the second technical problem, the invention provides the following technical scheme:
a process for producing a catalyst for acrylic acid synthesis, which comprises a step of crystallizing a dispersion of a raw material compound comprising an oxygen-containing salt of V element, an oxygen-containing salt of one or more elements selected from Cu, W and Sb and an oxygen-containing salt of Mo element, wherein the ratio of the amounts of the substances of Mo element and V element in the raw material compound is 12 (0.5 to 10.0), and preferably the dispersion is an aqueous dispersion. Preferably, the oxygen-containing salt of Mo element is added to the dispersion after the oxygen-containing salt of V element.
In the above scheme, the crystallization refers to a process of converting amorphous substances into crystals.
In the above embodiment, the aqueous dispersion is a dispersion in which the solvent is water, and is obtained by adding an oxygen-containing salt of V element, an oxygen-containing salt of W element, and an oxygen-containing salt of Mo element to water.
The inventors have unexpectedly found that Mo having a rod-like crystal structure can be obtained by controlling the order of addition of the raw material compounds, specifically by controlling the manner in which an oxygen-containing salt of Mo element is added to a solvent after an oxygen-containing salt of V element, and then crystallizing under an inert atmosphere 12 V a O g A compound.
In some embodiments of the preparation process of the present invention, the crystallization temperature is 80 to 250 ℃, preferably 90 to 150 ℃, such as, but not limited to, 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 140 ℃, or 145 ℃. In some embodiments of the preparation methods of the present invention, the crystallization time is 2 to 168 hours, preferably, the crystallization time is 10 to 160 hours, for example, but not limited to, 10 hours, 20 hours, 30 hours, 50 hours, 100 hours, or 150 hours.
In some embodiments of the preparation methods of the present invention, the crystallization is performed in a closed container in an inert atmosphere, which may be provided by an atmosphere of nitrogen, argon, helium, or the like.
In some embodiments of the preparation methods of the present invention, the starting compounds include ammonium heptamolybdate and/or a hydrate thereof, ammonium metavanadate and/or a hydrate thereof, and ammonium tungstate and/or a hydrate thereof.
In some embodiments of the preparation process of the present invention, the dispersion contains 1 to 50wt% of ammonium heptamolybdate and/or a hydrate thereof, more preferably 2 to 15wt%. In a specific embodiment, the ammonium heptamolybdate and/or the hydrate thereof is added to the mixed aqueous solution of ammonium metavanadate and ammonium tungstate in the form of an aqueous ammonium heptamolybdate solution.
In some embodiments of the preparation method of the present invention, the crystallized crystals or crystallized dispersion liquid is mixed with a carrier raw material and then calcined and molded to obtain the catalyst for acrylic acid synthesis, wherein the calcination temperature is 200-1000 ℃ and/or the calcination time is 0.5-100 hours.
In some embodiments of the preparation methods of the present invention, the firing temperature is 400 to 700 ℃, such as, but not limited to, 450 ℃, 500 ℃, 550 ℃, 600 ℃, 650 ℃.
In some embodiments of the preparation methods of the present invention, the calcination time is 3 to 10 hours.
In some embodiments of the methods of preparation of the present invention, the firing time may be selected from, but is not limited to, the following values: 1 hour, 1.5 hour, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, 8.5 hours, 9 hours, 10 hours, 20 hours or 30 hours.
In some embodiments of the preparation methods of the present invention, what isThe calcination may be performed in an oxidizing atmosphere, preferably an oxygen-containing atmosphere such as, but not limited to, steam, oxygen, air, an oxygen-containing gas, and N, or an inert atmosphere 2 (and/or inert gas) mixtures; the inert atmosphere is preferably nitrogen and/or an inert gas such as, but not limited to, he, ne, and/or Ar.
Preferably, the firing is performed in an air atmosphere.
In some embodiments of the preparation methods of the present invention, the carrier material is SiO 2 、Al 2 O 3 、ZrO 2 、TiO 2 And at least one of their precursors.
Wherein the precursor refers to a substance which can be converted into a corresponding oxide through simple dehydration, oxidation and other reactions, such as a hydrate and the like.
Preferably, the catalyst for acrylic acid synthesis contains 20 to 90 parts by mass of crystals and 10 to 80 parts by mass of a carrier.
Preferably, the carrier material further comprises graphite.
In some embodiments of the preparation method of the present invention, the molding may be selected according to actual requirements, such as but not limited to rolling balls, extruding bars or tabletting, and during the molding process, a molding auxiliary agent may be optionally added according to requirements.
The shape of the molded catalyst can be in various forms such as a sphere, a Raschig ring or a cylinder, wherein the diameter of the sphere can be preferably 3-5 mm; the outer diameter of the Raschig ring can be preferably 4-7 mm, the inner diameter is preferably 1.5-3 mm, and the length is preferably 3-5 mm; the outer diameter of the cylinder may preferably be 4 to 7mm, and the length thereof may preferably be 3 to 5mm.
In order to solve the third technical problem, the present invention further provides the following technical scheme:
the catalyst for acrylic acid synthesis and/or the catalyst prepared by the method are applied to acrylic acid synthesis, and particularly applied to the process of preparing acrylic acid by oxidizing acrolein.
In some embodiments of the use of the present invention, the catalyst is contacted with acrolein at 240 to 320 ℃.
In some embodiments of the use of the present invention, the acrolein has a volumetric space velocity of from 100 to 150 mL-h -1 ·g -1 。
In some embodiments of the use of the present invention, the catalyst has a reaction temperature with acrolein of 270 ℃ and a volumetric space velocity of 110ml·h -1 ·g -1 Under the embodiment, the conversion rate of the acrolein can reach 99.5%, the yield of the acrylic acid product can reach 93.2%, and the catalytic effect of the catalyst is not obviously reduced in the 500-hour life test.
The invention has the following beneficial effects:
(1) The catalyst for acrylic acid synthesis of the present invention contains Mo having a rod-like crystal structure 12 V a O g The catalyst has high catalytic activity, high product yield and long service life, and the catalytic effect is not obviously reduced after 500 hours of use;
(2) The preparation method disclosed by the invention is simple in process and convenient to operate, the active component in the obtained catalyst is a stable and uniform rod-shaped crystal, and compared with the catalyst with an amorphous or other crystal structure as the active component, the catalyst has the advantages of higher catalytic efficiency, longer service life and better selectivity;
(3) The application of the invention can efficiently convert the acrolein into the acrylic acid at 240-320 ℃, the product yield is more than 90%, and the acrolein conversion rate is more than 99%.
Drawings
FIG. 1 is an SEM image of a catalyst for acrylic acid synthesis obtained in example 1 of the present invention;
FIG. 2 is an SEM image of a catalyst for acrylic acid synthesis obtained in example 2 of the present invention;
FIG. 3 is an SEM image of the catalyst of comparative example 1 of the present invention;
fig. 4 is an SEM image of the catalyst obtained in comparative example 2 of the present invention.
Detailed Description
The present invention will be described in detail with reference to examples. It should be understood that the embodiments and examples described herein are for the purpose of illustration and explanation only and are not intended to limit the present invention.
The catalyst evaluation methods used in the following examples were:
introducing the reactant acrolein into a fixed bed reactor filled with a catalyst to be detected, absorbing the reacted product by using dilute acid at 0 ℃, analyzing by using gas chromatography, calculating carbon balance in the analysis process, and selecting data when the carbon balance is 95-105% as effective data, wherein the reaction conditions are as follows:
the reactor comprises: a fixed bed reactor with an inner diameter of 25.4 mm and a length of 750 mm;
catalyst loading: 150 g;
reaction temperature: 270 ℃;
reaction time: 500 hours;
the volume ratio of the raw materials is as follows: acrolein to air to water vapor = 1:3.2:2.1;
acrolein volume space velocity: 110 mL.h -1 ·g -1 。
[ example 1 ]
43.9 g of ammonium metavanadate (NH) 4 VO 3 ) 38.2 g ammonium tungstate ((NH) 4 ) 5 H 5 [H 2 (WO 4 ) 6 ]·H 2 O) was dissolved in 1000ml of deionized water, to which 20wt% ammonium heptamolybdate ((NH) was added 4 ) 6 Mo 7 O 24 ·4H 2 And O) 1000g of aqueous solution, transferring the obtained slurry into a closed reaction kettle, introducing high-purity nitrogen (99.9%) for replacement for 5 times, heating to 150 ℃ for crystallization for 24 hours, transferring the slurry into a flat chassis, putting the flat chassis into an oven for drying at 130 ℃ for 24 hours, and crushing to obtain powder.
160 g of the obtained powder and 160 g of Al are taken 2 O 3 Uniformly mixing 1.6g of graphite and 3.2g of deionized water, setting a tabletting pressure of 3kN by a tablet press, tabletting and forming to obtain a round platy formed catalyst with a diameter of 5mm and a tablet thickness of 4mm, and finally roasting at 395 ℃ for 4 hours to obtain the catalyst for acrylic acid synthesis.
The microstructure of the obtained catalyst is observed by a scanning electron microscope SEM, and as shown in the attached figure 1, the active component in the obtained catalyst is in a regular rod-shaped crystal structure, the crystal diameter is about 1 mu m, the length is about 5 mu m, and the length diameter is 5.
The obtained catalyst was evaluated by the catalyst evaluation method, and the results are shown in table 1.
[ example 2 ]
43.9 g of ammonium metavanadate (NH) 4 VO 3 ) 38.2 g ammonium tungstate ((NH) 4 ) 5 H 5 [H 2 (WO 4 ) 6 ]·H 2 O) was dissolved in 1000ml of deionized water, to which 20wt% ammonium heptamolybdate ((NH) was added 4 ) 6 Mo 7 O 24 ·4H 2 And O) 1000g of aqueous solution, transferring the obtained slurry into a closed reaction kettle, introducing high-purity nitrogen (99.9%) for replacement for 5 times, heating to 130 ℃ for crystallization for 24 hours, transferring the slurry into a flat chassis, putting into an oven for drying at 130 ℃ for 24 hours, and crushing to obtain powder.
160 g of the obtained powder and 160 g of Al are taken 2 O 3 Uniformly mixing 1.6g of graphite and 3.2g of deionized water, setting a tabletting pressure of 3kN by a tablet press, tabletting and forming to obtain a round platy formed catalyst with a diameter of 5mm and a tablet thickness of 4mm, and finally roasting at 395 ℃ for 4 hours to obtain the catalyst for acrylic acid synthesis.
The microstructure of the obtained catalyst was observed by SEM, and as shown in fig. 2, it was found that the active component of the obtained catalyst had a regular rod-like crystal structure with a crystal diameter of 0.5 μm, a length of 6 μm and an aspect ratio of 12.
The obtained catalyst was evaluated by the catalyst evaluation method, and the results are shown in table 1.
[ example 3 ]
43.9 g of ammonium metavanadate (NH) 4 VO 3 ) 38.2 g ammonium tungstate ((NH) 4 ) 5 H 5 [H 2 (WO 4 ) 6 ]·H 2 O) was dissolved in 1000ml of deionized water, to which 20wt% ammonium heptamolybdate ((NH) was added 4 ) 6 Mo 7 O 24 ·4H 2 O) 1000g of aqueous solution, will giveTransferring the slurry into a closed reaction kettle, introducing high-purity nitrogen (99.9%) for replacement for 5 times, heating to 110 ℃ for crystallization for 24 hours, transferring the slurry into a flat chassis, putting into an oven for drying at 130 ℃ for 24 hours, and crushing to obtain powder.
160 g of the obtained powder and 160 g of Al are taken 2 O 3 Uniformly mixing 1.6g of graphite and 3.2g of deionized water, setting a tabletting pressure of 3kN by a tablet press, tabletting and forming to obtain a round platy formed catalyst with a diameter of 5mm and a tablet thickness of 4mm, and finally roasting at 395 ℃ for 4 hours to obtain the catalyst for acrylic acid synthesis.
The obtained catalyst was evaluated by the catalyst evaluation method, and the results are shown in table 1.
[ example 4 ]
43.9 g of ammonium metavanadate (NH) 4 VO 3 ) 38.2 g ammonium tungstate ((NH) 4 ) 5 H 5 [H 2 (WO 4 ) 6 ]·H 2 O) was dissolved in 1000ml of deionized water, to which 20wt% ammonium heptamolybdate ((NH) was added 4 ) 6 Mo 7 O 24 ·4H 2 And O) 1000g of aqueous solution, transferring the obtained slurry into a closed reaction kettle, introducing high-purity nitrogen (99.9%) for replacement for 5 times, heating to 90 ℃ for crystallization for 24 hours, transferring the slurry into a flat chassis, putting the flat chassis into an oven for drying at 130 ℃ for 24 hours, and crushing to obtain powder.
160 g of the obtained powder and 160 g of Al are taken 2 O 3 Uniformly mixing 1.6g of graphite and 3.2g of deionized water, setting a tabletting pressure of 3kN by a tablet press, tabletting and forming to obtain a round platy formed catalyst with a diameter of 5mm and a tablet thickness of 4mm, and finally roasting at 395 ℃ for 4 hours to obtain the catalyst for acrylic acid synthesis.
The obtained catalyst was evaluated by the catalyst evaluation method, and the results are shown in table 1.
[ example 5 ]
43.9 g of ammonium metavanadate (NH) 4 VO 3 ) 38.2 g ammonium tungstate ((NH) 4 ) 5 H 5 [H 2 (WO 4 ) 6 ]·H 2 O) dissolved in 1000ml deionized waterTo this was added 20% by weight of ammonium heptamolybdate ((NH) 4 ) 6 Mo 7 O 24 ·4H 2 And O) 1000g of aqueous solution, transferring the obtained slurry into a closed reaction kettle, introducing high-purity argon (99.9%) for replacement for 5 times, heating to 130 ℃ for crystallization for 24 hours, transferring the slurry into a flat chassis, putting into an oven for drying at 130 ℃ for 24 hours, and crushing to obtain powder.
160 g of the obtained powder and 160 g of Al are taken 2 O 3 Uniformly mixing 1.6g of graphite and 3.2g of deionized water, setting a tabletting pressure of 3kN by a tablet press, tabletting and forming to obtain a round platy formed catalyst with a diameter of 5mm and a tablet thickness of 4mm, and finally roasting at 395 ℃ for 4 hours to obtain the catalyst for acrylic acid synthesis.
The obtained catalyst was evaluated by the catalyst evaluation method, and the results are shown in table 1.
[ example 6 ]
43.9 g of ammonium metavanadate (NH) 4 VO 3 ) 38.2 g ammonium tungstate ((NH) 4 ) 5 H 5 [H 2 (WO 4 ) 6 ]·H 2 O) was dissolved in 1000ml of deionized water, to which 20wt% ammonium heptamolybdate ((NH) was added 4 ) 6 Mo 7 O 24 ·4H 2 And O) 1000g of aqueous solution, transferring the obtained slurry into a closed reaction kettle, introducing high-purity argon (99.9%) for replacement for 5 times, heating to 130 ℃ for crystallization for 72 hours, transferring the slurry into a flat chassis, putting into an oven for drying at 130 ℃ for 24 hours, and crushing to obtain powder.
160 g of the obtained powder and 160 g of Al are taken 2 O 3 Uniformly mixing 1.6g of graphite and 3.2g of deionized water, setting a tabletting pressure of 3kN by a tablet press, tabletting and forming to obtain a round platy formed catalyst with a diameter of 5mm and a tablet thickness of 4mm, and finally roasting at 395 ℃ for 4 hours to obtain the catalyst for acrylic acid synthesis.
The obtained catalyst was evaluated by the catalyst evaluation method, and the results are shown in table 1.
Comparative example 1
43.9 g of ammonium metavanadate (NH) 4 VO 3 ) 38.2 g ammonium tungstate ((NH) 4 ) 5 H 5 [H 2 (WO 4 ) 6 ]·H 2 O) was dissolved in 1000ml of deionized water, to which 20wt% ammonium heptamolybdate ((NH) was added 4 ) 6 Mo 7 O 24 ·4H 2 O) 1000g of aqueous solution, and transferring the slurry into an oven to dry for 24 hours at 130 ℃, and then crushing to obtain powder.
160 g of the obtained powder and 160 g of Al are taken 2 O 3 Uniformly mixing 1.6g of graphite and 3.2g of deionized water, setting a tabletting pressure of 3kN by a tablet press, tabletting and forming to obtain a round platy formed catalyst with a diameter of 5mm and a tablet thickness of 4mm, and finally roasting at 395 ℃ for 4 hours to obtain a comparative catalyst.
The microstructure of the comparative catalyst is observed by scanning electron microscope SEM, as shown in figure 3, it can be seen that the active components in the obtained catalyst are powdery, have no uniform and stable crystal structure, and have agglomeration phenomenon.
The comparative catalysts were evaluated by the catalyst evaluation methods described above, and the results are shown in table 1.
Comparative example 2
43.9 g of ammonium metavanadate (NH) 4 VO 3 ) 38.2 g ammonium tungstate ((NH) 4 ) 5 H 5 [H 2 (WO 4 ) 6 ]·H 2 O) was dissolved in 1000ml of deionized water, to which 20wt% ammonium heptamolybdate ((NH) was added 4 ) 6 Mo 7 O 24 ·4H 2 And O) 1000g of aqueous solution, transferring the obtained slurry into a closed reaction kettle, heating to 200 ℃ for crystallization for 24 hours, transferring into an oven for drying at 130 ℃ for 24 hours, and crushing to obtain powder.
160 g of the obtained powder and 160 g of Al are taken 2 O 3 Uniformly mixing 1.6g of graphite and 3.2g of deionized water, setting tabletting pressure to 3kN through a tablet press, tabletting and forming to obtain a round platy formed catalyst with the diameter of 5mm and the thickness of 4mm, and finally roasting at 395 ℃ for 4 hours to obtain the required catalyst to obtain the comparative catalyst.
The microstructure of the comparative catalyst is observed by scanning electron microscope SEM, as shown in figure 4, it can be seen that the active components in the obtained catalyst have no uniform and stable crystal structure, and agglomeration phenomenon exists.
The results of the evaluation of the comparative catalyst by the foregoing evaluation method are shown in table 1.
[ comparative example 3 ]
200 g of ammonium heptamolybdate ((NH) 4 ) 6 Mo 7 O 24 ·4H 2 O) and 38.2 g of ammonium tungstate ((NH) 4 ) 5 H 5 [H 2 (WO 4 ) 6 ]·H 2 O) was dissolved in 1000ml of deionized water, to which 4.39% by weight of ammonium metavanadate (NH) 4 VO 3 ) 1000g of aqueous solution, transferring the obtained slurry into a closed reaction kettle, introducing high-purity nitrogen (99.9%) for 5 times, heating to 200 ℃ for crystallization for 24 hours, transferring into an oven for drying at 130 ℃ for 24 hours, and crushing to obtain powder.
160 g of the obtained powder and 160 g of Al are taken 2 O 3 Uniformly mixing 1.6g of graphite and 3.2g of deionized water, setting tabletting pressure to 3kN through a tablet press, tabletting and forming to obtain a round platy formed catalyst with the diameter of 5mm and the thickness of 4mm, and finally roasting at 395 ℃ for 4 hours to obtain the required catalyst to obtain the comparative catalyst.
The microstructure of the comparative catalyst is observed by a scanning electron microscope SEM, so that the catalyst has a non-uniform and stable crystal structure and obvious agglomeration phenomenon.
The results of the evaluation of the comparative catalyst by the foregoing evaluation method are shown in table 1.
TABLE 1
The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.
Claims (18)
1. A preparation method of a catalyst for acrylic acid synthesis is characterized by comprising the following steps: the method comprises crystallizing a dispersion of a raw material compound, wherein the raw material compound comprises ammonium heptamolybdate and/or a hydrate thereof, ammonium metavanadate and/or a hydrate thereof, and ammonium tungstate and/or a hydrate thereof, and the ratio of the amounts of substances of Mo element and V element in the raw material compound is 12 (0.5-10.0); ammonium heptamolybdate and/or a hydrate thereof is added to the dispersion liquid after ammonium metavanadate and/or a hydrate thereof, and the dispersion liquid is an aqueous dispersion liquid;
the crystallization is performed in an inert atmosphere;
the catalyst for acrylic acid synthesis comprises Mo having the general formula 12 V a O g Wherein a=0.5 to 10.0; g is a number determined by the total valence of the elements other than oxygen in the formula.
2. The method of manufacturing according to claim 1, characterized in that: the crystallization temperature is 80-250 ℃, and/or the crystallization time is 2-168 hours.
3. The preparation method according to claim 2, characterized in that: the crystallization temperature is 90-150 ℃ and/or the crystallization time is 10-160 hours.
4. A production method according to any one of claims 1 to 3, characterized in that: the crystallization is carried out in a closed container in an inert atmosphere.
5. A production method according to any one of claims 1 to 3, characterized in that: the crystallization temperature is selected from 95 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 140 ℃ or 145 ℃; and/or the time of crystallization is selected from 10 hours, 20 hours, 30 hours, 50 hours, 100 hours or 150 hours.
6. A production method according to any one of claims 1 to 3, characterized in that: the dispersion contains 1-50wt% of ammonium heptamolybdate and/or a hydrate thereof.
7. The method of manufacturing according to claim 6, wherein: the dispersion contains 2-15wt% of ammonium heptamolybdate and/or hydrate thereof.
8. A production method according to any one of claims 1 to 3, characterized in that: and mixing the crystallized crystals or crystallized dispersion liquid with a carrier raw material, and roasting and molding to obtain the catalyst for acrylic acid synthesis, wherein the roasting temperature is 200-1000 ℃ and/or the roasting time is 0.5-100 hours.
9. The method of manufacturing according to claim 8, wherein: the carrier raw material is SiO 2 、Al 2 O 3 、ZrO 2 、TiO 2 And one or more of their precursors.
10. The method of manufacturing according to claim 8, wherein: the catalyst for acrylic acid synthesis contains 20-90 parts by mass of crystals and 10-80 parts by mass of a carrier.
11. The method of manufacturing according to claim 8, wherein: the roasting temperature is 400-700 ℃.
12. The method of manufacturing according to claim 11, wherein: the roasting temperature is 450 ℃, 500 ℃, 550 ℃, 600 ℃ and 650 ℃.
13. The method of manufacturing according to claim 8, wherein: and the roasting time is 3-10 hours.
14. The method of manufacturing according to claim 8, wherein: the calcination time was 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, 8.5 hours, 9 hours, 10 hours, 20 hours, 30 hours.
15. A production method according to any one of claims 1 to 3, characterized in that: the diameter of the rod-shaped crystal is 0.1-5 microns, and/or the length of the rod-shaped crystal is 1-50 microns, and/or the length-diameter ratio of the rod-shaped crystal is 3-100.
16. Use of a catalyst prepared by the preparation method according to any one of claims 1 to 15 in the synthesis of acrylic acid.
17. The use according to claim 16, characterized in that the use comprises contacting the catalyst with acrolein at a reaction temperature of 240-320 ℃ and/or contacting the catalyst with a volume space velocity of 100-150 ml/h -1 •g -1 Is contacted with acrolein.
18. The use according to claim 17, wherein the reaction temperature is 270 ℃ and the volumetric space velocity is 110 ml/h -1 •g -1 。
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