CN117258787A - Catalyst for preparing acetone by oxidation of isoparaffin and preparation method thereof - Google Patents

Abstract

The catalyst for preparing acetone from isoparaffin comprises an active component and a carrier, wherein the active component is a metal element, and the metal element comprises one or more than two of Ce, ti, zr, nb, W, V, cr, mo, fe, ni, zn and Ag elements; or the active component is a mixture of metal elements and zeolite molecular sieves, wherein the metal elements comprise one or more than two 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 catalysis of the catalyst, isoparaffin is oxidized into acetone, the selectivity of the acetone is high, and byproducts are reduced relative to other reaction systems.

Description

Catalyst for oxidation of isoparaffins to acetone and preparation method thereof

Technical field

The present application relates to a catalyst in the field of chemical industry, specifically, to a catalyst for preparing acetone by isomerization oxidation and a preparation method thereof.

Background technique

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 as a solvent and used in the production of other solvents.

The main production methods of acetone include fermentation method, organic matter hydration method, propylene oxidation method, isobutyraldehyde oxidation method, etc.

Among them, the earliest way to produce acetone was the fermentation method. The fermentation method uses grains or other sugars as raw materials. After high-temperature cooking and sterilization, a sterile fermentation bottom liquid is obtained, and then specific strains of bacteria are added for fermentation. The liquid obtained after fermentation is distilled to obtain acetone. However, fermentation technology is relatively backward, production cost is high, and efficiency is low. Now the fermentation method has been basically eliminated.

Another method, the propylene oxidation method, uses oxygen as the 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 and regenerated through the following reaction. The mechanism of action includes: the raw material propylene reduces the _PdCl2 in the catalyst to Pd, and simultaneously generates acetone and HCl. Another component on the catalyst, CuCl ₂ , oxidizes Pd to PdCl ₂ again, while CuCl ₂ is reduced to CuCl. Finally, CuCl is re-oxidized to CuCl ₂ under the action of HCl and O ₂ , thus completing the cycle.

Pd+2CuCl ₂ →PdCl ₂ +2CuCl

2CuCl+1/2O ₂ +2HCl→2CuCl ₂ +H ₂ O

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

Chinese Patent Application Publication No. CN104193606A discloses a process for synthesizing acetone using synthesis gas as raw material. The raw materials of this method are CO and H ₂ in the synthesis gas. Methanol is first synthesized, and the methanol and CO are carbonylated to generate acetone. This method has low efficiency in generating acetone and is not conducive to the continuous production of acetone.

Chinese Patent Application Publication No. CN106946639A, CN106883107A, and CN106883088A disclose that under the action of a supported Au or Ag-based catalyst, ethanol undergoes a photocatalytic reaction to generate ethylene, acetaldehyde, and acetone. This method has low acetone yield, high cost, and low efficiency.

US Patent Publication US6933414B1 discloses using formaldehyde and methyl chloride 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.

At present, the main production method of acetone is the cumene oxidation method. 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 product refining. . The prior art discloses the following technology. The raw materials are cumene peroxide and cumene. Under the catalysis of organic acid, dicumyl peroxide and cumene are first generated under the condition of a reaction temperature of 40 to 75°C. , organic acid catalysts include: 2-hydroxy-5-methyl-benzenesulfonic acid, 4-hydroxybenzyl-1,3-disulfonic acid, 2-hydroxy-5-methoxybenzenesulfonic acid, etc.; further, in When the reaction temperature reaches 110 to 140°C, acetone and phenol are generated, and acetone can be obtained through subsequent treatments such as distillation and purification. This method requires a large amount of acid, and the reaction mixture needs to be added to neutralize the excess acid before being purified. Alternatively, the above-mentioned raw materials cumene peroxide and cumene can also only use cumene as the raw material, and part of the cumene is oxidized into cumene peroxide. The above-mentioned cumene hydroperoxide and cumene are obtained. mixture of propylbenzene. Alternatively, cumene peroxide is used as raw material. As the temperature of the reactor gradually increases, cumene peroxide generates cumene peroxide and dicumyl peroxide under the catalytic action of concentrated sulfuric acid; and then increases At the reaction temperature, dicumyl peroxide decomposes 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, a non-acidic catalyst is used, and part of the peroxidized cumene and unreacted cumene in the mixed liquid generate dimethylbenzylmethanol. Contacting a solution containing dimethylbenzylcarbinol with an acidic catalyst produces 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.

Chinese Patent Publication No. CN102186799A discloses the production of acetone through cumene hydroperoxide under the action of an acidic catalyst. The acidic catalyst is a 2-hydroxybenzenesulfonic acid catalyst. X in the 2-hydroxybenzenesulfonic acid catalyst is independently an alkyl group or an aromatic hydrocarbon group. , halogen, its combination, Y is hydrogen, alkyl, aromatic hydrocarbon group, hydroxyalkyl, sulfonic acid, its combination, n is 0 to 3.

Contents of the invention

One object of this application is a catalyst for directly preparing acetone. Using the catalyst to prepare acetone simplifies the reaction steps. The preparation method of the catalyst is simple.

Another object of the present application is to use the catalyst to improve the selectivity of acetone in the reaction system for preparing acetone from isoparaffins.

A catalyst for producing acetone from isoparaffins, including an active component and a carrier, wherein,

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

The active component is a mixture of metal elements and zeolite molecular sieves. The metal elements include Mn, Co, Cu, Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, Ni, Zn and One or a mixture of two or more 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 amount of by-products is reduced compared with other reaction systems.

Detailed ways

The catalyst for producing acetone from isoparaffins of the present application will be described in further detail below. The scope of protection of this application is not limited, and the scope of protection is defined by the claims. Certain disclosed specific details are provided to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that embodiments may be practiced without one or more of these specific details, using other materials, etc.

Unless the context requires otherwise, in the specification and claims, the terms "include" and "include" shall be understood to have an open-ended, inclusive meaning, that is, "including, but not limited to."

The "embodiment", "an embodiment", "another embodiment" or "certain embodiments" mentioned in the specification refer to the specifically described features and structures related to the embodiment. or properties included in at least one embodiment. Thus, "embodiment," "an embodiment," "another embodiment," or "certain embodiments" are not necessarily all referring 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 serving the same, equivalent or similar purpose. Therefore, unless otherwise stated, the features disclosed are only general examples of equivalent or similar features.

Iso-alkanes in this application refer to branched-chain alkanes relative to normal alkanes, such as alkanes with a methyl substituent at the 2- or 3-position, 2-methylalkanes, 3-methylalkanes, etc.

Zeolite molecular sieves in this application include those natural or synthetic crystalline aluminosilicates or silicates that function as molecular sieves.

The catalyst of the present application can directly catalytically oxidize isoparaffins into acetone, and the selectivity of acetone is high.

A catalyst for producing acetone from isoparaffins, including an active component and a carrier, wherein the active component is a metal element, and the metal element includes Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, One or a mixture of more than two elements Ni, Zn and Ag; or

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

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

In the catalyst, the content of metal elements is the ratio of the mass of metal oxides to the mass of the catalyst, and the metal oxides are calculated as stable oxides.

In certain embodiments, the content of metal elements in the catalyst is 0.3-20 wt%.

The above-mentioned metal elements may exist in the form of metals or metal oxides, preferably metal oxides.

In some embodiments, the active component metal element in the catalyst exists in the form of metal oxide, preferably one or more of WO ₃ , TiO ₂ , MnO _x , MoO _x , CoO _x , FeO _x , and CuO _x .

In certain embodiments, the carrier includes one or more of Al ₂ O ₃ , SiO ₂ , kaolin, diatomaceous earth, MgO, CaO, and La ₂ O ₃ . One or a mixture of two of Al ₂ O ₃ , SiO ₂ and kaolin is preferred.

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

In the catalyst, the content of active component metal elements is 5.0-15wt%.

The above-mentioned active component metal element is loaded on the carrier, and the selectivity of acetone is high in the reaction of isoparaffin directly preparing acetone.

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

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 rhosite.

In some embodiments, the zeolite molecules are selected from one or a mixture of two or more of USY, ZSM-5, and β-type molecular sieves.

The active component metal and zeolite molecular sieve act as catalysts at the same time, and have better catalytic performance in the reaction system for preparing acetone from isoparaffins, and the selectivity of acetone in the obtained product is higher.

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

In some ways, the active component is the metallic element Mo.

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

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

Si/Al here refers to the mass ratio, or atomic ratio, of the Si element to the Al element in the zeolite molecular sieve.

Active elements such as Co, Mo, and Mn metals work together with molecular sieves. The metal elements reduce isoparaffin oxides to alcohols, and then acetone and alcohols can be further oxidized under the action of molecular sieves. In particular, Si/Al in molecular sieves is in 3 When -200, better catalytic effect can be obtained.

In the catalyst, in addition to the above-mentioned active component metal elements, or the content of metal elements and zeolite molecular sieves, the remainder is the carrier.

Using the catalyst of the present application, the conversion rate of isomerized alkanes directly into oxygen is over 90%, and the conversion rate of acetone reaches over 40%.

Under the action of a catalyst, the main by-products of the reaction system of isomerizing alkanes to prepare acetone are tert-butyl alcohol, methanol and isobutylene. These by-products are all raw materials for the production of MTBE. There are very few by-products such as XO, XO ₂ , methane and water.

The above-mentioned catalyst preparation method can be prepared by commonly used methods in the prior art. The catalyst can be manufactured by first beating and then spraying and granulating; it can also be manufactured by kneading and then extruding; or it can also be manufactured by rolling balls.

On the other hand, the above-mentioned preparation method of the catalyst for producing acetone from isoparaffins involves mixing the metal element-containing material and/or molecular sieve with the sol containing the carrier component, and then drying and roasting to obtain the catalyst.

The substance containing metal elements is an oxide containing metal elements.

In some embodiments, the calcining temperature is controlled at 550-750°C.

On the other hand, the preparation method of the above-mentioned catalyst for producing acetone from isoparaffins includes first loading metal elements on zeolite molecular sieves through an impregnation method, mixing the obtained loaded zeolite molecular sieves with a sol containing carrier components, and drying and roasting. Catalyst is obtained.

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

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

The performance of the catalyst of the present application will be further described below with reference to specific examples.

All substances used in the following examples are commercially available. From the products obtained in all examples, the previous numerical value of each substance indicates the mass content of the catalyst, for example, the 10Mn-30ZSM/SiO ₂ catalyst in Example 1, 10Cu-30ZSM/SiO ₂ , 10 indicates the content of CuO in the catalyst is 10%, 30 means that the content of molecular sieve ZSM-5 in the catalyst is 30%, and the rest is carrier SiO ₂ .

Example 1

Take a certain amount of silica sol (based on _SiO2 , the mass fraction is 30%) and place it in a stirring tank for stirring, then add a certain amount of ZSM-5 molecular sieve (so that the mass fraction of ZSM-5 in the final catalyst is 30%) , among which, ZSM-5 molecular sieve (Si/Al = 38), and a certain amount of CuO powder (so that the mass fraction of CuO in the final catalyst is 10%), continue stirring for 2 hours, dry at 120°C, and roast at 700°C In 2h, the 10Cu-30ZSM/SiO ₂ catalyst can be obtained.

Example 2

Take a certain amount of silica sol (calculated as _SiO2 , the mass fraction is 30%, in which the Si/Al of ZSM-5 molecular sieve = 38) is placed in a stirring tank and stirred, and then a certain amount of ZSM-5 molecular sieve is added (so that the final The mass fraction of ZSM in the obtained catalyst is 30%), and a certain amount of MnO ₂ powder (so that the mass fraction of MnO ₂ in the final catalyst is 10%). After continuing to stir for 2 hours, it is dried at 120°C and roasted at 700°C. In 2h, the 10Mn-30ZSM/SiO ₂ catalyst can be obtained.

Example 3

Take a certain amount of aluminum sol (based on Al ₂ O ₃ , the mass fraction is 30%), place it in a stirring tank and stir, and then add a certain amount of USY molecular sieve (so that the mass fraction of USY in the final catalyst is 30%, where , Si/Al=6 of USY molecular sieve), and a certain amount of CoO powder (so that the mass fraction of CoO in the final catalyst is 10%), continue stirring for 2 hours, dry at 120°C, and roast at 700°C for 2 hours. 10Co-30USY/Al ₂ O ₃ catalyst was obtained.

Example 4

Take a certain amount of aluminum sol (based on Al ₂ O ₃ , the mass fraction is 30%), place it in a stirring tank and stir, and then add a certain amount of Hβ molecular sieve (so that the mass fraction of Hβ in the final catalyst is 30%, Hβ Si/Al of the molecular sieve = 21), and a certain amount of TiO ₂ powder (so that the mass fraction of TiO ₂ in the final catalyst is 10%), continue stirring for 2 hours, dry at 120°C, and roast at 700°C for 2 hours. 10Ti-30Hβ/Al ₂ O ₃ catalyst was obtained.

Example 5

Take a certain amount of aluminum sol (based on Al ₂ O ₃ , the mass fraction is 30%), place it in a stirring tank and stir, then add a certain amount of Fe ₂ O ₃ (so that the mass fraction of Fe ₂ O ₃ in the final catalyst is (10%), continue stirring for 2 hours, dry at 120°C, and calcine at 700°C for 2 hours to obtain the 10Fe/Al ₂ O ₃ catalyst.

Example 6

Take a certain amount of silica sol (based on _SiO2 , the mass fraction is 30%), place it in a stirring tank and stir, then add a certain amount of _MoO3 (so that the mass fraction of _MoO3 in the final catalyst is 10%), continue After stirring for 2 hours, drying at 120°C and calcining at 700°C for 2 hours, the 10Mo/SiO ₂ catalyst can be obtained.

Example 7

Take a certain amount of silica sol (based on _SiO2 , the mass fraction is 30%), place it in a stirring tank and stir, then add a certain amount of _TiO2 (so that the mass fraction of _TiO2 in the final catalyst is 10%), continue After stirring for 2 hours, drying at 120°C and calcining at 700°C for 2 hours, the 10Ti/Al ₂ O ₃ catalyst can be obtained.

Example 8

Take a certain amount of silica sol (based on _SiO2 , the mass fraction is 30%) and place it in a stirring tank for stirring, then add a certain amount of CuO (so that the mass fraction of CuO in the final catalyst is 10%), and continue stirring for 2 hours. Afterwards, dry at 120°C and calcine at 700°C for 2 hours to obtain the 10Cu/Al ₂ O ₃ catalyst.

Example 9

Take a certain amount of USY molecular sieve, impregnate manganese nitrate with a mass concentration of 30% on the molecular sieve (so that the mass fraction of _MnO2 in the final catalyst is 10%, where the Si/Al of USY molecular sieve = 6), dry it and bake it at 550°C After 2h, MnO ₂ -USY was obtained. MnO ₂ -USY and aluminum sol (based on Al ₂ O ₃ , the mass fraction was 30%) were placed in a stirring tank and stirred for 2h, dried at 120°C, and roasted at 700°C for 2h, so that the final If the mass content of USY in the catalyst is 30%, a 10MnO ₂ -30USY/Al ₂ O ₃ catalyst can be obtained.

Example 10-13

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

Experimental example

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

Table 1

Claims (10)

1. A catalyst for producing acetone from isoparaffins, including an active component and a carrier, wherein, The active component is a metal element, and the metal element includes one or a mixture of two or more elements among Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, Ni, Zn and Ag; or, The active component is a mixture of metal elements and zeolite molecular sieves. The metal elements include Mn, Co, Cu, Ce, Ti, Zr, Nb, W, V, Cr, Mo, Fe, Ni, Zn and One or a mixture of two or more Ag elements; Wherein, the content of the metal element is 0.1-40wt%; Preferably, Si/Al in the zeolite molecular sieve is 1-500, preferably 3-200; More preferably, the content of zeolite molecular sieve in the catalyst is 5%-80wt%, preferably 20-50wt%. 2. The preparation method according to claim 1, characterized in that the content of metal elements in the catalyst is 0.3-20wt%; Preferably, the content of the active component metal element is 5.0-15wt%. 3. The preparation method according to claim 1 or 2, characterized in that the active component metal element in the catalyst is selected from WO ₃ , TiO ₂ , MnO _x , MoO _x , CoO _x , FeO _x , and CuO _x One or a mixture of several. 4. The preparation method according to claim 1 or 2, characterized in that the active element is selected from one or a combination of multiple metal elements including Co, Mo, Mn, Ti, and Fe. 5. The preparation method according to any one of claims 1 to 4, characterized in that the carrier includes one of Al ₂ O ₃ , SiO ₂ , kaolin, diatomite, MgO, CaO and La ₂ O ₃ or Several kinds; One or a mixture of two of Al ₂ O ₃ , SiO ₂ and kaolin is preferred. 6. The preparation method according to any one of claims 1 to 5, characterized in that the active components are metal elements and zeolite molecular sieves, and the metal elements include Ce, Ti, Zr, Nb, W, V, Cr , Mo, Fe, Ni, Zn and Ag elements, or a mixture of two or more, and the content of zeolite molecular sieve is preferably 20-40wt%. 7. The preparation method according to any one of claims 1 to 5, characterized in that the active components are metal elements and zeolite molecular sieves, and the metal elements include one or two of Mn, Co, and Cu elements. In the above mixing, the content of zeolite molecular sieve is preferably 20-50wt%. 8. The preparation method according to any one of claims 1 to 7, wherein the zeolite molecular sieve includes Y-type molecular sieve, USY-type molecular sieve, ZSM-5-type molecular sieve, β-type molecular sieve, mordenite and rhosite zeolite. One or a mixture of two or more; Preferably, the zeolite molecules are selected from one or a mixture of two or more of USY, ZSM-5 and β-type molecular sieves. 9. A method for preparing the catalyst according to any one of claims 1 to 8, comprising: mixing the metal element-containing material and/or the molecular sieve with the sol containing the carrier component, and obtaining the catalyst after drying and roasting; Preferably, the roasting temperature is controlled at 550-750°C. 10. A method for preparing the catalyst according to any one of claims 1 to 8, comprising: first loading the metal elements on the zeolite molecular sieve through an impregnation method, mixing the obtained loaded zeolite molecular sieve with a sol containing the carrier component, and After drying and roasting, the catalyst is obtained.