Catalyst for preparing acetone by oxidation of isoparaffin and preparation method thereof

Abstract

A catalyst for preparing acetone from isoparaffins, comprising an active component and a carrier, wherein the active component is a metal element, and the metal element comprises one or a mixture of two or more of Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, Ni, Zn and Ag elements; or, the active component is a mixture of a metal element and a zeolite molecular sieve, and the metal element comprises one or a mixture of two or more of Mn, Co, Cu, Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, Ni, Zn and Ag elements; wherein the content of the metal element is 0.1-40wt%. Under the catalytic action of the above catalyst, isoparaffins are oxidized to acetone, the selectivity of acetone is high, and the by-products are reduced relative to other reaction systems.

Description

Technical Field

[0001] The present application relates to a catalyst in the chemical industry, and in particular, to a catalyst for preparing acetone by isomerization oxidation and a preparation method thereof. Background Art

[0002] Acetone is the simplest saturated ketone and an important organic chemical raw material. It is mainly used in the production of organic glass, medicine, pesticides, epoxy resin, polycarbonate, etc., or directly used as a solvent and in the production of other solvents.

[0003] The main methods for producing acetone include fermentation, organic matter hydration, propylene oxidation, isobutyraldehyde oxidation, etc.

[0004] Among them, the earliest method of producing acetone is the fermentation method. The fermentation method uses grains or other sugars as raw materials, and obtains a sterile fermentation base liquid after high-temperature boiling and sterilization, and then adds specific bacteria for fermentation. The liquid obtained after fermentation is distilled to obtain acetone. However, the fermentation method is relatively backward in technology, with high production costs and low efficiency. Now the fermentation method has been basically eliminated.

[0005] Another method is propylene oxidation, which uses oxygen as an oxidant to oxidize propylene to acetone. The catalyst with copper chloride-palladium chloride as the active component catalyzes the oxidation of propylene to acetone, and the catalyst can be recycled through the following reaction. The mechanism of action includes: the raw material propylene converts the PdCl in the catalyst to 2 Reduced to Pd, acetone and HCl are produced simultaneously. Another component on the catalyst is CuCl 2 Pd is oxidized again to PdCl 2 , while CuCl 2 is reduced to CuCl. Finally, CuCl is reacted with HCl and O 2 Under the action of 2 , thus completing the cycle.

[0006]

[0007] Pd+2CuCl 2 →PdCl 2 +2CuCl

[0008] 2CuCl+1 / 2O 2 +2HCl→2CuCl 2 +H 2 O

[0009] Although the propylene oxidation method has a high yield of acetone, it is difficult to apply in industry due to the price of the reaction raw material isobutyraldehyde.

[0010] Chinese patent application publication No. CN104193606A discloses a process for synthesizing acetone using synthesis gas as raw materials. The raw materials of the method are CO and H in the synthesis gas. 2 , firstly synthesize methanol, obtain methanol and CO for carbonylation reaction to produce acetone. This method has low efficiency in producing acetone and is not conducive to the continuous production of acetone.

[0011] Chinese patent application publication Nos. CN106946639A, CN106883107A and CN106883088A disclose that ethanol generates ethylene, acetaldehyde and acetone through a photocatalytic reaction under the action of a loaded Au or Ag-based catalyst. This method has a low acetone yield, high cost and low efficiency.

[0012] US Patent Publication US6933414B1 discloses that formaldehyde and methyl chloride are used as raw materials to generate acetone, and the reaction products are acetone and hydrochloric acid. This method has high production costs and is prone to environmental pollution.

[0013] At present, the main production method of acetone is the cumene oxidation method, and the main production steps of this method are the synthesis of cumene, the peroxidation of cumene, the concentration, decomposition and neutralization of cumene peroxide, and the refining of products. The prior art discloses the following technology, the raw materials are cumene peroxide and cumene, under the catalytic action of organic acid, dicumyl peroxide and cumene are first generated under the condition of a reaction temperature of 40 to 75°C, and the organic acid catalyst includes: 2-hydroxy-5-methyl-benzenesulfonic acid, 4-hydroxybenzene-1,3-disulfonic acid, 2-hydroxy-5-methoxybenzenesulfonic acid, etc.; further, under the condition of a reaction temperature of 110 to 140°C, acetone and phenol are generated, and then acetone can be obtained through subsequent treatments such as distillation and purification. This method requires a large amount of acid, and the mixed solution after the reaction needs to be added to neutralize the excess acid before refining. Alternatively, the above raw materials of cumene peroxide and cumene can also use only cumene as the raw material, and part of the cumene is oxidized to cumene peroxide, and the above mixture of cumene hydroperoxide and cumene is obtained. Alternatively, cumene peroxide is used as the raw material, and as the temperature of the reactor gradually increases, cumene peroxide generates cumene peroxide and dicumyl peroxide under the catalytic action of concentrated sulfuric acid; the reaction temperature is then increased, and dicumyl peroxide is decomposed into acetone and phenol, and the products phenol and acetone are obtained through distillation and other methods. In the reaction of the existing cumene oxidation method, non-acidic catalysts are used, and a part of the cumene peroxide and unreacted cumene in the mixed solution generate dimethylbenzyl alcohol. A solution containing dimethylbenzyl alcohol is contacted with an acidic catalyst to generate α-methylstyrene, acetone and phenol. This method effectively avoids the use of concentrated sulfuric acid and alkaline substances, reduces equipment corrosion, and reduces production costs.

[0014] Chinese patent publication No. CN102186799A discloses producing acetone by cumene hydroperoxide under the action of an acidic catalyst, wherein the acidic catalyst is a 2-hydroxybenzenesulfonic acid catalyst, wherein X in the 2-hydroxybenzenesulfonic acid catalyst is independently an alkyl, an aromatic hydrocarbon group, a halogen, or a combination thereof, Y is hydrogen, an alkyl, an aromatic hydrocarbon group, a hydroxyalkyl, a sulfonic acid, or a combination thereof, and n is 0 to 3. Summary of the invention

[0015] One object of the present application is to provide a catalyst for directly preparing acetone, which simplifies the reaction steps when the catalyst is used to prepare acetone. The preparation method of the catalyst is simple.

[0016] Another object of the present application is to improve the selectivity of acetone in the reaction system of preparing acetone from isoparaffin by using the catalyst.

[0017] A catalyst for preparing acetone from isoparaffin, comprising an active component and a carrier, wherein:

[0018] The active component is a metal element, and the metal element includes one or a mixture of two or more of Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, Ni, Zn and Ag; or

[0019] The active component is a mixture of metal elements and zeolite molecular sieves, wherein the metal elements include one or a mixture of two or more of Mn, Co, Cu, Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, Ni, Zn and Ag elements;

[0020] Wherein, the content of the metal element is 0.1-40wt%.

[0021] Under the catalytic action of the above catalyst, isoparaffin is oxidized to acetone, the selectivity of acetone is high, and the by-products are reduced compared with other reaction systems. DETAILED DESCRIPTION

[0022] The catalyst for preparing acetone from isoparaffins of the present application is further described in detail below. The protection scope of the present application is not limited, and its protection scope is defined by the claims. Certain disclosed specific details provide a comprehensive understanding of each disclosed embodiment. However, those skilled in the relevant art know that the embodiment can be implemented without using one or more of these specific details and using other materials, etc.

[0023] Unless the context requires otherwise, in the specification and claims, the terms "include" and "comprising" should be construed as having an open-ended, inclusive meaning, that is, "including, but not limited to".

[0024] The "embodiment", "one embodiment", "another embodiment" or "certain embodiments" mentioned in the specification means that the specific features, structures or characteristics described in connection with the embodiment are included in at least one embodiment. Therefore, "embodiment", "one embodiment", "another embodiment" or "certain embodiments" do not necessarily all refer to the same embodiment. Moreover, specific features, structures or characteristics may be combined in any manner in one or more embodiments. Each feature disclosed in the specification may be replaced by any alternative feature that can provide the same, equal or similar purpose. Therefore, unless otherwise specified, the disclosed features are only general examples of equal or similar features.

[0025] The isoalkane in the present application refers to a branched alkane relative to a normal alkane, for example, an alkane having a methyl substituent at the 2- or 3-position, 2-methylalkane, 3-methylalkane, and the like.

[0026] The zeolite molecular sieves of the present application include natural or artificially synthesized crystalline aluminosilicates or silicates having molecular sieve effects.

[0027] The catalyst of the present application can directly catalyze the oxidation of isoparaffins into acetone, and the selectivity of acetone is high.

[0028] A catalyst for preparing acetone from isoparaffin, comprising an active component and a carrier, wherein the active component is a metal element, and the metal element comprises one or a mixture of two or more of Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, Ni, Zn and Ag; or

[0029] The active component is a mixture of metal elements and zeolite molecular sieves, wherein the metal elements include one or a mixture of two or more of Ce, Ti, Zr, Nb, W, V, Cr, Mo, Mn, Co, Fe, Cu, Ni, Zn and Ag elements;

[0030] Wherein, the content of the metal element in the catalyst is 0.1-40wt%.

[0031] In the catalyst, the content of the metal element is the ratio of the mass of the metal oxide to the mass of the catalyst, and the metal oxide is calculated as the oxide in a stable state.

[0032] In certain embodiments, the content of the metal element in the catalyst is 0.3-20 wt %.

[0033] The above-mentioned metal elements may exist in the form of metal or metal oxide, preferably metal oxide.

[0034] In certain embodiments, the active metal element in the catalyst is present in the form of a metal oxide, preferably WO3 、TiO 2 、MnO x 、MoO x 、CoO x ,FeO x , CuO x One or more of the .

[0035] In certain embodiments, the support comprises Al 2 O 3 、SiO 2 , kaolin, diatomaceous earth, MgO, CaO and La 2 O 3 One or more of the following. Preferably Al 2 O 3 、SiO 2 and kaolin or a mixture of both.

[0036] In certain embodiments, the active element is selected from one or a combination of multiple metal elements including Co, Mo, Cu, Mn, Ti, and Fe.

[0037] In the catalyst, the content of the active component metal element is 5.0-15wt%.

[0038] The active component metal element is loaded on the carrier, and the selectivity of acetone is high in the reaction of directly preparing acetone from isoalkane.

[0039] In certain embodiments, the content of the zeolite molecular sieve in the catalyst is 5%-80wt%, preferably 20-50wt%.

[0040] In certain embodiments, the zeolite molecular sieve includes one or a mixture of two or more of Y-type molecular sieve, USY-type molecular sieve, ZSM-5-type molecular sieve, β-type molecular sieve, mordenite and offretite.

[0041] In certain embodiments, the zeolite molecular sieve is selected from one or a mixture of two or more of USY, ZSM-5 and β-type molecular sieves.

[0042] The active component metal and the zeolite molecular sieve are both active as catalysts, and have better catalytic performance in the reaction system of preparing acetone from isoparaffins, and the selectivity of acetone in the obtained product is higher.

[0043] In some embodiments, the active components are metal elements and zeolite molecular sieves, wherein the metal elements include one or a mixture of two or more of Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, Ni, Zn and Ag elements, and the content of zeolite molecular sieve is preferably 20-40wt%.

[0044] In some embodiments, the active component is the metallic element Mo.

[0045] In certain embodiments, the active components are metal elements and zeolite molecular sieves, wherein the metal elements include one or a mixture of two or more of Mn, Co, and Cu elements, and the content of the zeolite molecular sieve is preferably 20-50 wt%.

[0046] The Si / Al ratio in the zeolite molecular sieve is 1-500, preferably 3-200; more preferably 3-50.

[0047] Here, Si / Al refers to the molar ratio or atomic ratio of Si element to Al element in the zeolite molecular sieve.

[0048] Active elements such as Co, Mo, and Mn metals work together with molecular sieves. The metal elements reduce the isoalkane oxides to alcohols, and then the molecular sieves can further oxidize acetone and alcohols. In particular, when the Si / Al in the molecular sieve is 3-200, a better catalytic effect can be obtained.

[0049] In the catalyst, in addition to the above-mentioned active component metal element, or the content of the metal element and the zeolite molecular sieve, the rest is the carrier.

[0050] By using the catalyst of the present application, the conversion rate of isomerized alkanes directly converted into oxygen is above 90%, and the conversion rate of acetone is above 40%.

[0051] Under the action of catalyst, the main by-products of the reaction system of isomerizing alkanes to prepare acetone are tert-butyl alcohol, methanol and isobutylene, which are the raw materials for producing MTBE. 2 There are very few by-products such as methane and water.

[0052] The catalyst preparation method can adopt the common preparation method in the prior art. The catalyst can be manufactured by a method of first beating the pulp and then spraying the granules; it can also be manufactured by a method of kneading and then extruding strips; it can also be manufactured by a rolling ball method.

[0053] On the other hand, in the preparation method of the catalyst for preparing acetone from isoparaffin, a substance containing metal elements and / or molecular sieves is mixed with a sol containing a carrier component, and the mixture is dried and calcined to obtain a catalyst.

[0054] The substance containing metal elements is an oxide containing metal elements.

[0055] In certain embodiments, the calcination temperature is controlled at 550-750°C.

[0056] On the other hand, the preparation method of the above-mentioned catalyst for preparing acetone from isoparaffin includes first loading the metal element on the zeolite molecular sieve by impregnation method, mixing the loaded zeolite molecular sieve with a sol containing a carrier component, and obtaining the catalyst after drying and calcining.

[0057] The substance containing metal elements is a water-soluble salt containing metal elements.

[0058] The mass concentration of the water-soluble salt containing the metal element is 1-60%, preferably 10-40%.

[0059] The performance of the catalyst of the present application is further described below in conjunction with specific examples.

[0060] All materials used in the following examples are commercially available. In all examples, the values ​​in front of each material represent the mass content of the catalyst. For example, the 10Mn-30ZSM / SiO 2 Catalyst, 10Cu-30ZSM / SiO 2 , 10 means the content of CuO in the catalyst is 10%, 30 means the content of molecular sieve ZSM-5 in the catalyst is 30%, and the rest is carrier SiO 2 .

[0061] Example 1

[0062] Take a certain amount of silica sol (in the form of SiO 2 A certain amount of ZSM-5 molecular sieve (making the mass fraction of ZSM-5 in the final catalyst to be 30%, wherein the Si / Al ratio of the ZSM-5 molecular sieve is 38) and a certain amount of CuO powder (making the mass fraction of CuO in the final catalyst to be 10%) were added to a stirring kettle, and the mixture was stirred for 2 hours, dried at 120°C, and calcined at 700°C for 2 hours to obtain 10Cu-30ZSM / SiO 2 catalyst.

[0063] Example 2

[0064] Take a certain amount of silica sol (in the form of SiO 2 The mass fraction of ZSM-5 molecular sieve is 30%, wherein the Si / Al of ZSM-5 molecular sieve is 38) and the mixture is stirred in a stirred tank. Then a certain amount of ZSM-5 molecular sieve (so that the mass fraction of ZSM in the final catalyst is 30%) and a certain amount of MnO are added. 2 powder (so that the final catalyst contains MnO 2 The mass fraction of 10% was obtained by continuing to stir for 2 hours, drying at 120°C, and calcining at 700°C for 2 hours. 2catalyst.

[0065] Example 3

[0066] Take a certain amount of aluminum sol (in Al 2 O 3 The catalyst was stirred in a stirred tank, and then a certain amount of USY molecular sieve (so that the mass fraction of USY in the final catalyst is 30%, wherein the Si / Al of USY molecular sieve is 6) and a certain amount of CoO powder (so that the mass fraction of CoO in the final catalyst is 10%) were added. After stirring for 2 hours, the catalyst was dried at 120°C and calcined at 700°C for 2 hours to obtain 10Co-30USY / Al 2 O 3 catalyst.

[0067] Example 4

[0068] Take a certain amount of aluminum sol (in Al 2 O 3 The catalyst was stirred in a stirred tank, and then a certain amount of Hβ molecular sieve (so that the mass fraction of Hβ in the final catalyst was 30%, and the Si / Al of Hβ molecular sieve was 21) and a certain amount of TiO 2 powder (so that the final catalyst contains TiO 2 The mass fraction is 10%), and then the mixture is stirred for 2 hours, dried at 120°C, and calcined at 700°C for 2 hours to obtain 10Ti-30Hβ / Al 2 O 3 catalyst.

[0069] Example 5

[0070] Take a certain amount of aluminum sol (in Al 2 O 3 , mass fraction is 30%) in a stirred tank, and then a certain amount of Fe 2 O 3 (so that the Fe 2 O 3 The mass fraction of 10% was obtained by stirring for 2 hours, drying at 120°C, and calcining at 700°C for 2 hours. 2 O 3 catalyst.

[0071] Example 6

[0072] Take a certain amount of silica sol (in the form of SiO 2 The mass fraction is 30%) and placed in a stirring kettle for stirring, and then a certain amount of MoO 3 (so that the MoO3 The mass fraction of 10% was obtained by stirring for 2 hours, drying at 120°C, and calcining at 700°C for 2 hours. 2 catalyst.

[0073] Example 7

[0074] Take a certain amount of silica sol (in the form of SiO 2 The mass fraction is 30%) and placed in a stirring tank for stirring, and then a certain amount of TiO 2 (so that the final catalyst contains TiO 2 The mass fraction of 10% was obtained by continuing to stir for 2 hours, drying at 120°C, and calcining at 700°C for 2 hours. 2 O 3 catalyst.

[0075] Example 8

[0076] Take a certain amount of silica sol (in the form of SiO 2 The catalyst was placed in a stirred tank and stirred, and then a certain amount of CuO was added (so that the mass fraction of CuO in the final catalyst was 10%). After stirring for 2 hours, it was dried at 120°C and calcined at 700°C for 2 hours to obtain 10Cu / Al 2 O 3 catalyst.

[0077] Example 9

[0078] Take a certain amount of USY molecular sieve and impregnate 30% manganese nitrate on the molecular sieve (so that the final catalyst contains MnO 2 The mass fraction of USY molecular sieve is 10%, wherein Si / Al=6), and after drying, MnO is obtained by calcining at 550℃ for 2h. 2 -USY, will MnO 2 -USY and aluminum sol (with Al 2 O 3 The catalyst was placed in a stirred tank and stirred for 2 h, dried at 120 °C, and calcined at 700 °C for 2 h, so that the mass content of USY in the final catalyst was 30%, and 10MnO 2 -30USY / Al 2 O 3 catalyst.

[0079] Examples 10-13

[0080] The process steps and process parameters for preparing the catalysts in Examples 10-13 are the same as those in Example 1, except that ZMS-5 with different silicon-to-aluminum ratios is selected. The silicon-to-aluminum ratio in Example 10 is 26; the silicon-to-aluminum ratio in Example 11 is 100; the silicon-to-aluminum ratio in Example 12 is 200; and the silicon-to-aluminum ratio in Example 13 is 500. The corresponding 10Cu-30ZSM / SiO 2 catalyst.

[0081] Experimental example

[0082] In this example, isobutane is used as the raw material, and the catalysts prepared in the above examples 1-13 are respectively in a fixed bed reactor. Reaction conditions: temperature 170°C, 3Mpa, residence time 60min; the proportion of oxygen in the raw gas is 20%, and the reaction results are shown in Table 1. The calculation of the conversion rate and selectivity involved in the reaction results are calculated by mass fraction. Among them, the selectivity in the table is the content of each substance in all products.

[0083] Table 1

[0084]

[0085]

Claims

1. Application of a catalyst in the preparation of acetone from isoparaffins, It is characterized in that The catalyst comprises an active component and a carrier, wherein: The active component is a metal oxide, wherein the metal element in the metal oxide includes one or a mixture of two or more of Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, Ni, Zn and Ag; or, The active component is a mixture of metal oxides and zeolite molecular sieves, wherein the metal elements in the metal oxides include one or a mixture of two or more of Mn, Co, Cu, Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, Ni, Zn and Ag, and the zeolite molecular sieve includes one or a mixture of two or more of Y-type molecular sieve, USY-type molecular sieve, ZSM-5-type molecular sieve, β-type molecular sieve, mordenite and offretite; Wherein, the content of the metal oxide in the catalyst is 0.1-40wt%, and the Si / Al in the zeolite molecular sieve is 1-500.

2. The use according to claim 1, It is characterized in that The Si / Al ratio in zeolite molecular sieve is 3-200.

3. The use according to claim 1, It is characterized in that In the catalyst, the content of zeolite molecular sieve is 5wt%-80wt%.

4. The use according to claim 1, It is characterized in that In the catalyst, the content of zeolite molecular sieve is 20wt%-50wt%.

5. The use according to any one of claims 1 to 4, It is characterized in that The content of the metal oxide in the catalyst is between 0.3wt% and 20wt%.

6. The use according to any one of claims 1 to 4, It is characterized in that The content of the active component metal oxide is 5.0wt%-15wt%.

7. The use according to any one of claims 1 to 4, It is characterized in that The active component in the catalyst is selected from WO 3 、TiO 2 One or a mixture of both.

8. The use according to any one of claims 1 to 4, It is characterized in that The support includes Al 2 O 3 、SiO 2 , kaolin, diatomaceous earth, MgO, CaO and La 2 O 3 One or more of the .

9. The use according to any one of claims 1 to 4, It is characterized in that The support includes Al 2 O 3 、SiO 2 and kaolin or a mixture of both.

10. The use according to any one of claims 1 to 4, It is characterized in that In the catalyst, the content of zeolite molecular sieve is 20wt%-40wt%.

11. The use according to any one of claims 1 to 3, It is characterized in that The active components are metal oxide and zeolite molecular sieve. The metal elements in the metal oxide include one or a mixture of two or more of Mn, Co and Cu elements. The content of the zeolite molecular sieve is 20wt%-50wt%.

12. The use according to any one of claims 1 to 4, It is characterized in that The zeolite molecular sieve is one or a mixture of two or more of USY, ZSM-5 and β-type molecular sieves.

13. The use according to any one of claims 1 to 4, It is characterized in that The method for preparing a catalyst comprises: mixing a sol containing a metal oxide and a carrier component, and drying and calcining the mixture to obtain a catalyst; or The catalyst is obtained by mixing a sol containing metal oxides, zeolite molecular sieves and a carrier component, and drying and calcining the mixture.

14. The use according to claim 13, It is characterized in that The calcination temperature is controlled at 550-750°C.

15. The use according to any one of claims 1 to 4, It is characterized in that The preparation method of the catalyst comprises: firstly loading the metal element on the zeolite molecular sieve by impregnation method, mixing the obtained zeolite molecular sieve loaded with metal oxide with a sol containing carrier components, and obtaining the catalyst after drying and calcining.

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