A process for the continuous production of carbonyl compounds using a heterogeneous catalyst and a catalyst therefor

Abstract

The application discloses a method for continuously preparing carbonyl compounds by using heterogeneous catalysts and the heterogeneous catalysts used in the method. The method comprises the following steps: step 1, mixing reaction of a reaction raw material solution and ozone gas in a reactor 1; and step 2, respectively introducing the product obtained in the step 1 and a reducing agent / oxidizing agent into a reactor 2 provided with a catalyst to carry out reaction, wherein the gas is controlled by using a flow controller, so as to obtain a carbonyl product. According to the method, various raw materials can be used, and the method can be continuously carried out due to the use of the heterogeneous catalysts. The heterogeneous catalysts have a wide source and are easy to prepare. The method is safe in process, the catalyst has good stability and long service life, and the method can be continuously produced and has high efficiency.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis, and more particularly to a method for the continuous preparation of carbonyl compounds using a heterogeneous catalyst and the heterogeneous catalyst used in the method. Background Technology

[0002] Carbonyl compounds such as aldehydes, carboxylic acids, and ketones are widely used synthetic intermediates. For example, aldehydes can be hydrogenated to synthesize alcohols and oxidized to synthesize acids; carboxylic acids can be esterified to synthesize esters and decarboxylated to synthesize ketones; ketones can be hydrogenated to synthesize alcohols, reacted with amines to synthesize imines, and further hydrogenated to synthesize amines.

[0003] There are various methods for synthesizing carbonyl compounds. For example, aldehydes can be synthesized through dihalohydrolysis, alcohol oxidation, and carboxylic acid reduction; carboxylic acids can be synthesized through aldehyde oxidation and cyano hydrolysis; and ketones can be synthesized through secondary alcohol oxidation and carboxylic acid decarboxylation. However, in the oxygen oxidation of alcohols to aldehydes, it is generally difficult to control the reaction to a high selectivity because the generated aldehyde is very prone to further oxidation to carboxylic acids. In recent years, the ozone oxidation method for synthesizing carbonyl compounds such as aldehydes, ketones, and carboxylic acids has gradually attracted more attention from researchers. Ozone has extremely strong oxidizing properties and has wide applications in the field of synthesis. However, ozone has poor reaction selectivity, high risk, difficulty in temperature control, and is prone to explosion. Moreover, the ozonation intermediates are unstable and often undergo rearrangement or decomposition reactions before being reduced to carbonyl compounds. For example, in the ozonation of olefins, when ozone is introduced into the olefin, ozone reacts quantitatively with the olefin to generate viscous ozonides. However, these ozonides are very unstable and prone to explosion, posing a safety hazard. CN1537087A discloses a method for converting ozonation intermediates into products via catalytic reduction. However, the catalysts used are all precious metals, and the reaction process is discontinuous, still presenting challenges in controlling the reaction process and safety issues related to intermittent reactions. Therefore, whether a continuous, heterogeneous catalytic, highly selective ozonation reaction can be achieved, and whether the ozonide can be continuously converted into aldehydes, ketones, and acids via reduction or oxidation, are crucial factors affecting the industrialization of ozonation reactions.

[0004] Biomass resources are the most abundant renewable resources on Earth. From them, green energy and green materials can be continuously synthesized to replace the dwindling fossil resources. Biochar synthesized using biomass materials as precursors, due to its rich and tunable surface functional groups, often strongly promotes the catalytic activity of catalysts, and is receiving increasing attention in the field of catalysis. Catalysts synthesized based on these materials can achieve high activity and high selectivity, and to some extent replace traditional precious metal catalysts. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention aims to provide a method for the continuous preparation of carbonyl compounds using a heterogeneous catalyst and the heterogeneous catalyst used in the method. According to the present invention, the method can use a variety of raw materials, and since a heterogeneous catalyst is used, the method can be carried out continuously. The heterogeneous catalyst is widely available and easy to prepare.

[0006] According to one aspect of the present invention, an object of the present invention is to provide a method for the continuous preparation of carbonyl compounds using a heterogeneous catalyst, the method comprising the following steps:

[0007] Step 1. The reaction raw material solution and ozone gas are introduced into reactor 1 for mixing and reaction;

[0008] Step 2. The product obtained in Step 1 and the reducing agent / oxidizing agent are respectively introduced into reactor 2 containing a catalyst for reaction, wherein the gas flow is controlled by a flow controller to obtain carbonylated products;

[0009] In step 1 above, the reactor 1 is selected from a series stirred tank reactor, a tubular reactor, a loop reactor, and a tower reactor;

[0010] In step 1 above, the reaction raw material is an unsaturated organic compound containing one or more alkenyl or aryl double bonds that can be cracked by ozone.

[0011] Preferably, the reactants are alkenyl compounds represented by Formula 1:

[0012]

[0013] R1, R2, R3, and R4 are each independently selected from hydrogen, C1-6 alkyl, halogen-substituted C1-6 alkyl, hydroxyl-substituted C1-6 alkyl, and amino-substituted C1-6 alkyl. Alternatively, R1 and R3 can be linked to form unsaturated C6-C14 cycloalkyl, C6-C14 aryl, 5-15 membered heterocyclic group containing 1-3 heteroatoms selected from N, O, and S, or 5-15 membered heteroaryl group containing 1-3 heteroatoms selected from N, O, and S. R2 and R4 can be linked to form unsaturated C6-C14 cycloalkyl, C6-C14 aryl, 5-15 membered heterocyclic group containing 1-3 heteroatoms selected from N, O, and S, or 5-15 membered heteroaryl group containing 1-3 heteroatoms selected from N, O, and S.

[0014] Preferably, R1, R2, R3, and R4 are each independently selected from hydrogen, C1-3 alkyl, halogen-substituted C1-3 alkyl, hydroxyl-substituted C1-3 alkyl, and amino-substituted C1-3 alkyl. Alternatively, R1 and R3 can be linked to form an unsaturated C6-C10 cycloalkyl, a C6-C10 aryl, a 5-10 membered heterocyclic group containing 1-3 heteroatoms selected from N, O, and S, or a 5-10 membered heteroaryl containing 1-3 heteroatoms selected from N, O, and S. R2 and R4 can be linked to form an unsaturated C6-C10 cycloalkyl, a C6-C10 aryl, a 5-10 membered heterocyclic group containing 1-3 heteroatoms selected from N, O, and S, or a 5-10 membered heteroaryl containing 1-3 heteroatoms selected from N, O, and S.

[0015] Preferably, the halogen is selected from F, Cl, Br and I.

[0016] Preferably, the reactants are selected from C6-14 aryl groups or 5-15 heteroaryl compounds containing 1-3 heteroatoms selected from N, O and S, and more preferably from C6-10 aryl groups or 5-10 heteroaryl compounds containing 1-3 heteroatoms selected from N, O and S.

[0017] Preferably, the reaction raw materials are selected from naphthalene, quinoline, methyl methacrylate, ethyl methacrylate, maleic anhydride, maleic acid, cyclohexene, cyclopentene, 2,5-dihydrofuran, and 2,3-dihydrofuran.

[0018] In step 1 above, the reaction temperature can be -70℃ to 50℃;

[0019] In step 1 above, the reaction pressure is 0.1-0.5 MPa;

[0020] In step 1 above, the reaction residence time is 0.5s-10min.

[0021] In step 1 above, the solvent of the reaction raw material solution includes one or more of methanol, ethanol, isopropanol, tert-butanol, formic acid, acetic acid, propionic acid, water, dichloromethane, and dichloroethane.

[0022] In step 1 above, the mass concentration of the reaction raw material solution is 3%-100%.

[0023] In step 1 above, the molar ratio of ozone to the double bond in the reactant molecules is 1.0-4.0, preferably 1.05-2.0, and more preferably 1.05-1.5.

[0024] In step 2 above, the reactor 2 can be a fixed bed reactor, a fluidized bed reactor, a slurry bed reactor, a stirred reactor, a tubular reactor, or a loop reactor;

[0025] In step 2 above, the reaction temperature can be -20℃ to 120℃;

[0026] In step 2 above, the reaction pressure is 0.1-1.0 MPa;

[0027] In step 2 above, the reaction residence time is 5s-10min;

[0028] In step 2 above, the reaction space velocity is 0.05-1.0 h⁻¹. -1 .

[0029] In step 2 above, the oxidant is one or more of oxygen and air, and the reducing agent is hydrogen.

[0030] In step 2 above, the molar ratio of the product from step 1 to the reducing agent / oxidizing agent is 1:2-1:10.

[0031] According to another aspect of the present invention, another object of the present invention is to provide a catalyst for the above-described continuous preparation method of carbonyl compounds, said catalyst being prepared by a method comprising the following steps:

[0032] 1. After the dried biomass raw material is crushed by a pulverizer, it is added together with the solid acid catalyst and ball-milled into a fine powder of 200-400 mesh. The powder is then added to a reaction vessel, distilled water is added, the reaction vessel is sealed, and the mixture is heated to 150-250℃ for hydrolysis reaction for 4-10 hours. After the reaction is completed, the temperature is lowered, the pressure is released, and the mixture is filtered under reduced pressure. The filtrate is then distilled and concentrated to 20% of its original volume to obtain a concentrated solution.

[0033] 2. Add the acid solution to the concentrated solution described in step 1 under vigorous stirring. After mixing evenly, add chitosan and transfer to a hydrothermal reactor. Perform hydrothermal treatment at 160-220℃ for 4-20 hours. After cooling and depressurization, wash the obtained product three times with anhydrous ethanol and deionized water respectively, and then dry it at 110℃ for 12 hours to obtain the doped carbon material.

[0034] 3. Add alkali to the doped carbon material obtained in step 2, stir and mix evenly, place it in a tube furnace, heat to 300-700℃ under an inert gas atmosphere for carbonization treatment for 4-20 hours. After carbonization, cool down, wash the obtained material with distilled water until the filtrate is neutral, and dry at 110℃ for 12 hours.

[0035] 4. Prepare a metal precursor solution, add the doped carbon material obtained in step 3 to it, mix evenly, let stand for 12 hours, then evaporate the solvent, dry in an oven at 120°C for 12 hours, and then heat in a tube furnace at 200-500°C in a hydrogen atmosphere for 4-12 hours to obtain the intermediate product.

[0036] 5. Add an alkaline solution to the intermediate catalyst obtained in step 4 above, mix well, add tetraethyl orthosilicate, stir and react at 30-70℃ for 4-20h, filter, dry at 120℃ for 10h, and then calcine in a tube furnace at 400-600℃ for 4-8h in an air atmosphere to obtain the catalyst.

[0037] Preferably, the filter cake obtained after filtration in step 1 contains the solid acid catalyst. The filter cake is calcined in air at 350-550°C for 3-6 hours to remove organic matter, thereby obtaining the solid acid catalyst. The obtained solid acid catalyst can be recycled.

[0038] In step 1 above, the biomass material includes one or more of the following: corn cobs, corn stalks, sawdust, peanut shells, and bamboo shoots.

[0039] Preferably, the biomass material includes one or more of corn cobs, corn stalks, and peanut shells.

[0040] More preferably, the biomass material includes one or more of corn cobs and corn stalks.

[0041] In step 1 above, the solid acid catalyst includes one or more of the following: silicon dioxide, γ-alumina, zirconium dioxide, cerium dioxide, tungsten trioxide, niobium pentoxide, zeolite molecular sieve, and ion exchange resin.

[0042] Preferably, the solid acid catalyst comprises one or more of the following: silicon dioxide, γ-alumina, tungsten trioxide, niobium pentoxide, zeolite molecular sieve, and ion exchange resin.

[0043] More preferably, the solid acid catalyst includes one or more of γ-alumina, zeolite molecular sieves, and ion exchange resins.

[0044] Preferably, the zeolite molecular sieve includes one or more of HZSM5, HZSM11, HY, Hβ, HMOR, and SAPO-34.

[0045] In step 1 above, the mass ratio of distilled water to biomass raw material is 50:1-2:1.

[0046] Preferably, in step 1 above, the mass ratio of distilled water to biomass raw material is 20:1-5:1.

[0047] In step 1 above, the hydrolysis reaction temperature is 120-250℃.

[0048] Preferably, in step 1 above, the hydrolysis reaction temperature is 150-220℃.

[0049] More preferably, in step 1 above, the hydrolysis reaction temperature is 160-210℃.

[0050] In step 1 above, the hydrolysis reaction time is 4-10 hours.

[0051] Preferably, in step 1 above, the hydrolysis reaction time is 4-6 hours.

[0052] In step 1 above, the mass concentration of the concentrated solution is 10%-30%.

[0053] Preferably, in step 1 above, the mass concentration of the concentrated solution is 10%-20%.

[0054] In step 2 above, the acid is selected from one or more of formic acid, acetic acid, propionic acid, and hydrochloric acid.

[0055] In step 2 above, the mass concentration of the acid solution is 1%-30%.

[0056] Preferably, in step 2 above, the mass concentration of the acid solution is 3%-10%.

[0057] In step 2 above, the mass ratio of the acid solution to the concentrated solution is 1:1 to 10:1.

[0058] Preferably, in step 2 above, the mass ratio of the acid solution to the concentrated solution is 1:1 to 5:1.

[0059] In step 2 above, the mass ratio of chitosan to concentrated solution is 1:10 to 1:100.

[0060] In step 2 above, the hydrothermal treatment temperature is 160-220℃.

[0061] Preferably, in step 2 above, the hydrothermal treatment temperature is 180-210℃.

[0062] In step 2 above, the hydrothermal treatment time is 4-20 hours.

[0063] Preferably, in step 2 above, the hydrothermal treatment time is 5-10 hours.

[0064] In step 3 above, the alkali is selected from one or more of sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, and potassium ethoxide.

[0065] In step 3 above, the mass ratio of the alkali to the doped carbon material is 1:1 to 10:1.

[0066] Preferably, in step 3 above, the mass ratio of the alkali to the doped carbon material is 1:1 to 5:1.

[0067] More preferably, in step 3 above, the mass ratio of the alkali to the doped carbon material is 1:1 to 3:1.

[0068] In step 3 above, the inert gas used in the carbonization process includes one or more of nitrogen, helium, and argon.

[0069] Preferably, in step 3 above, the inert gas used in the carbonization process includes one or more of nitrogen and argon.

[0070] In step 4 above, the metal precursor is a nitrate or hydrochloride of Ni, Cu, Co, or Fe.

[0071] In step 4 above, the mass concentration of the metal precursor solution is 5-25 wt%.

[0072] In step 4 above, the mass ratio of the metal precursor to the carbon material is 1:100-1:5.

[0073] Preferably, in step 4 above, the mass ratio of the metal precursor to the carbon material is 1:50 to 1:5.

[0074] More preferably, in step 4 above, the mass ratio of the metal precursor to the carbon material is 1:30 to 1:8.

[0075] In step 5 above, the alkali is selected from one or more of sodium hydroxide, potassium hydroxide, ammonia, urea, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0076] In step 5 above, the mass ratio of the alkaline solution to the doped carbon material is 2:1 to 20:1.

[0077] Preferably, in step 5 above, the mass ratio of the alkaline solution to the doped carbon material is 5:1-20:1.

[0078] In step 5 above, the mass concentration of the alkaline solution is 5%-30%.

[0079] In step 5 above, the mass ratio of tetraethyl orthosilicate to the doped carbon material is 1.5:1-50:1.

[0080] Preferably, in step 5 above, the mass ratio of tetraethyl orthosilicate to the doped carbon material is 2:1-50:1.

[0081] Beneficial effects

[0082] The catalyst and method for synthesizing carbonyl compounds provided by this invention are safe, have good catalyst stability, long lifespan, can be used for continuous production, and are highly efficient. Attached Figure Description

[0083] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0084] Figure 1 A transmission electron microscope (TEM) image of catalyst 1 obtained according to preparation example 1 of the present invention;

[0085] Figure 2 This is a physisorption test diagram of catalyst 1 obtained according to preparation example 1 of the present invention.

[0086] Figure 3 The image shows the X-ray diffraction (XRD) pattern of catalyst 1 obtained according to Preparation Example 1 of the present invention.

[0087] Figure 4 This is a schematic diagram of the reaction according to Reaction Example 1 of the present invention. Detailed Implementation

[0088] The present invention will now be described in detail. Before proceeding with the description, it should be understood that the terminology used in this specification and the appended claims should not be construed as limited to its general or dictionary meaning, but rather should be interpreted according to the meaning and concept corresponding to the technical aspects of the invention, based on the principle that the inventors are allowed to appropriately define the terms for the best interpretation. Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the invention. It should be understood that other equivalents or modifications can be obtained from it without departing from the spirit and scope of the invention.

[0089] The following embodiments are merely examples illustrating implementations of the present invention and do not constitute any limitation on the present invention. Those skilled in the art will understand that modifications made without departing from the spirit and concept of the present invention fall within the protection scope of the present invention. Unless otherwise specified, the reagents and instruments used in the following embodiments are commercially available products.

[0090] In this document, the terms “comprising,” “including,” “having,” “containing,” or any other similar terms are open-ended conjunctions intended to cover non-exclusive inclusions. For example, a composition or article containing a plurality of elements is not limited to those listed herein, but may also include other elements not explicitly listed but typically inherent to the composition or article. Furthermore, unless explicitly stated to the contrary, the term “or” is inclusive, not exclusive. For example, the condition “A or B” is satisfied in any of the following cases: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); A and B are both true (or exist). Moreover, in this document, the terms “comprising,” “including,” “having,” and “containing” should be interpreted as specifically disclosed and simultaneously cover closed or semi-closed conjunctions such as “composed of” and “substantially composed of.”

[0091] In this document, all features or conditions defined in the form of numerical ranges or percentage ranges are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible secondary ranges and individual values ​​within those ranges, particularly integer values. For example, a range description of "1 to 8" should be considered as specifically disclosing all secondary ranges such as 1 to 7, 2 to 8, 2 to 6, 3 to 6, 4 to 8, 3 to 8, etc., particularly secondary ranges defined by all integer values, and should be considered as specifically disclosing individual values ​​within those ranges such as 1, 2, 3, 4, 5, 6, 7, 8, etc. Unless otherwise specified, the foregoing interpretation applies to all content throughout this invention, regardless of its scope.

[0092] If a quantity or other numerical value or parameter is expressed as a range, a preferred range, or a series of upper and lower limits, it should be understood that this document has specifically disclosed all ranges consisting of any upper or preferred value of that range and the lower or preferred value of that range, regardless of whether such ranges are separately disclosed. Furthermore, when a range of numerical values ​​is mentioned herein, unless otherwise stated, the range shall include its endpoints and all integers and fractions within the range.

[0093] In this document, numerical values ​​are to be understood as having a precision with significant digits, provided that the purpose of the invention can be achieved. For example, the number 40.0 should be understood to cover a range from 39.50 to 40.49.

[0094] In step 2 of the method for continuous preparation of carbonyl compounds using a heterogeneous catalyst according to the present invention, the reaction temperature can be -20℃ to 120℃;

[0095] In the reduction reaction, if the temperature is higher than the above range, most of the products obtained will be carbonyl reduction products, and the yield will decrease. If the reaction temperature is lower than the above range, the reduction reaction will be incomplete, and the yield will decrease.

[0096] In oxidation reactions, if the temperature is higher than the above range, it will cause an increase in by-products and affect the yield. If the temperature is lower than the above range, the oxidation reaction will be incomplete and the yield will decrease.

[0097] In step 2 above, the reaction pressure is 0.1-1.0 MPa;

[0098] In the reduction reaction, if the pressure is higher than the above range, most of the products obtained will be carbonyl reduction products, and the yield will decrease. If the reaction pressure is lower than the above range, the reduction reaction will be incomplete, and the yield will decrease.

[0099] In the oxidation reaction, if the pressure is higher than the above range, it will lead to an increase in by-products, affecting the yield and increasing equipment costs. If the pressure is lower than the above range, the oxidation reaction will be incomplete, resulting in a lower yield. In step 2 above, the reaction residence time is 5s-10min.

[0100] In the reduction reaction, if the product is above the above range, most of the product obtained will be carbonyl reduction products, and the yield will decrease. If the product is below the above range, the reduction reaction will be incomplete, and the yield will decrease.

[0101] In oxidation reactions, if the reaction rate exceeds the above range, it will result in an increase in byproducts and affect the yield. If the reaction rate is below the above range, the oxidation reaction will be incomplete and the yield will decrease.

[0102] In step 2 above, the reaction space velocity is 0.05-1.0 h⁻¹. -1 .

[0103] In the reduction reaction, if the value is above the above range, the reduction reaction will be incomplete and the yield will decrease. If the value is below the above range, most of the products obtained will be carbonyl reduction products, and the yield will also decrease.

[0104] In oxidation reactions, if the reaction rate is above the above range, the oxidation reaction will be incomplete and the yield will decrease. If the reaction rate is below the above range, it will result in an increase in by-products and affect the yield.

[0105] In step 2 above, the molar ratio of the product from step 1 to the reducing agent / oxidizing agent is 1:2-1:10;

[0106] In the reduction reaction, if the product is above the above range, most of the product obtained will be carbonyl reduction products, and the yield will decrease. If the product is below the above range, the reduction reaction will be incomplete, and the yield will decrease.

[0107] In oxidation reactions, if the reaction rate exceeds the above range, it will result in an increase in byproducts and affect the yield. If the reaction rate is below the above range, the oxidation reaction will be incomplete and the yield will decrease.

[0108] Unless otherwise specified, all raw materials used in this invention are commercially available, and all methods and equipment used are conventional methods and equipment in the field.

[0109] In the following examples, naphthalene, quinoline, methyl methacrylate, ethyl methacrylate, cyclohexene, methanol, and dichloromethane were purchased from Sinopharm Chemical Reagent Co., Ltd.; high-purity nitrogen and high-purity hydrogen were purchased from Qingdao Dehai Weiye Technology Co., Ltd.; and corn cobs, corn stalks, and peanut shells were purchased locally.

[0110] In the continuous preparation method of carbonyl compounds according to the present invention, the product obtained in step 2 is filtered through a 0.22 μm filter membrane and analyzed by gas chromatography (GC). Qualitative analysis of the low-boiling-point product is performed by GC-MS and comparison with the GC retention time of a standard, confirming that the reaction product is mainly a carbonyl compound. Quantitative determination of the product is performed using a Shimadzu-GC 2020 gas chromatograph, with quantitative analysis based on comparison with the retention time and peak area of ​​a standard. The relevant calculation formulas are as follows:

[0111]

[0112]

[0113]

[0114] Example

[0115] Preparation Example 1

[0116] 1. After crushing 150g of dried corn cob in a pulverizer, add it together with 15g of HZSM5 catalyst to a ball mill and ball mill it into a fine powder of 200-400 mesh. Add the powder to a reaction vessel, add 800ml of distilled water, seal the reaction vessel, heat to 200℃, and carry out the hydrolysis reaction for 6 hours. After the reaction is completed, cool down, depressurize, filter under reduced pressure, and distill and concentrate the filtrate to obtain 143ml of concentrated solution.

[0117] 2. Add 200 ml of 10% acetic acid solution to the concentrated solution described in step 1 under vigorous stirring, then add 5 g of chitosan and mix well. Add the mixture to a hydrothermal reactor and hydrothermally treat at 180°C for 10 h. After cooling and depressurization, wash the obtained product three times with anhydrous ethanol and deionized water respectively, and then dry at 110°C for 12 h to obtain the doped carbon material.

[0118] 3. Take 20g of the doped carbon material obtained in step 2, add 60g of potassium hydroxide, stir and mix evenly, place in a tube furnace, heat to 500℃ under an inert gas atmosphere for carbonization treatment for 5h. After carbonization, cool down, wash the obtained material with distilled water until the filtrate is neutral, and dry at 110℃ for 12h.

[0119] 4. Prepare 20 ml of ferric nitrate solution with a mass percentage concentration of 5 wt%, add 10 g of the doped carbon material obtained in step 3 to it, mix well, let stand for 12 h, then evaporate the solvent, dry in an oven at 120 °C for 12 h, and then heat to 250 °C in a tube furnace in a hydrogen atmosphere for 4 h.

[0120] 5. Add 20 ml of 5% ammonia water to 10 g of the above catalyst, mix well, add 15 g of tetraethyl orthosilicate, stir and react at 40 °C for 10 h, filter, dry the resulting solid at 120 °C for 8 h, and then calcine at 450 °C for 6 h in an air atmosphere in a tube furnace to obtain catalyst 1.

[0121] Figure 1 The image shows a transmission electron microscope (TEM) image of catalyst 1 obtained in this embodiment. As can be seen from the image, the silica generated by the hydrolysis of tetraethyl orthosilicate can encapsulate the metal particles to form a core-shell catalyst with a size of about 20-40 nm and a metal core size of about 5-8 nm.

[0122] Figure 2 This is a physisorption test diagram of catalyst 1 obtained in this embodiment. The diagram shows that the specific surface area of ​​catalyst 1 is 10⁶ m². 2 / g.

[0123] Figure 3 The X-ray diffraction (XRD) pattern of catalyst 1 obtained according to Example 1 of the present invention shows that no diffraction peaks of silica were observed in catalyst 1. This may be because the generated silica is coated on the surface of the iron oxide and does not form a clear crystal structure, thus no diffraction occurs. Diffraction peaks of magnetite (Fe3O4) are clearly visible, indicating that metallic iron exists in catalyst 1 in the form of magnetite. The XRD results show that the catalyst particle size distribution is relatively uniform.

[0124] Preparation Example 2

[0125] Replace the corn cob in step 1 with bamboo shoot powder, replace the ferric nitrate solution in step 4 with copper nitrate, and keep the rest the same as catalyst 1 to obtain catalyst 2.

[0126] Preparation Example 3

[0127] Replace the corn cob in step 1 with peanut shell powder, replace the ferric nitrate solution in step 4 with cobalt nitrate, and keep the rest the same as catalyst 1 to obtain catalyst 3.

[0128] Preparation Example 4

[0129] Replace the corn cob in step 1 with peanut shell powder, replace the ferric nitrate solution in step 4 with nickel nitrate, and keep the rest the same as catalyst 1 to obtain catalyst 4.

[0130] Preparation Example 5

[0131] Replace the corn cob in step 1 with peanut shell powder, replace the acetic acid solution in step 2 with formic acid solution, and keep the rest the same as catalyst 1 to obtain catalyst 5.

[0132] Preparation of catalyst 6

[0133] Replace the ammonia in step 5 with sodium hydroxide solution, and keep the rest the same as catalyst 1 to obtain catalyst 6.

[0134] Reaction Example 1

[0135] 1. Add 100g of naphthalene to 1000ml of a mixed solvent of tert-butanol and water (the volume ratio of tert-butanol to water is 3:1), stir to dissolve, and pump the mixed solvent into a tower reactor (the tower reactor has an inner diameter of 4cm, a length of 40cm, and is filled with glass fiber packing) from the top at a rate of 0.2ml / min using a plunger pump. At the same time, oxygen containing ozone (ozone concentration of 100mg / L) is introduced from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at 20°C, the mixture flows out of the reactor from the bottom.

[0136] 2. The product obtained in step 1 is passed through a plunger pump at a rate of 0.3 h. -1 The gas was pumped into a fixed-bed reactor containing catalyst 1 prepared in Preparation Example 1, while hydrogen gas (molar ratio of hydrogen to naphthalene 5:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 20°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was o-phthalaldehyde, with a product yield of 91%. Figure 4 This is a schematic diagram of the reaction in Example 1.

[0137] Reaction Example 2

[0138] 1. Add 100g of naphthalene to 1000ml of a mixed solvent of tert-butanol and water (the volume ratio of tert-butanol to water is 3:1), stir to dissolve, and pump the mixed solvent into a tower reactor (the tower reactor has an inner diameter of 4cm, a length of 40cm, and is filled with glass fiber packing) from the top at a rate of 0.2ml / min using a plunger pump. At the same time, oxygen containing ozone (ozone concentration of 100mg / L) is introduced from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at 20°C, the mixture flows out of the reactor from the bottom.

[0139] 2. The product obtained in step 1 is passed through a plunger pump at a flow rate of 0.1 h. -1 The air velocity was pumped into a fixed-bed reactor containing catalyst 2 prepared in Preparation Example 2, while air (molar ratio of oxygen to naphthalene of 10:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 40°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was phthalic acid, with a product yield of 96%.

[0140] Reaction Example 3

[0141] 1. Add 100g of quinoline to 500ml of a mixed solvent of acetic acid and water (the volume ratio of acetic acid to water is 4:1), stir to dissolve, and pump the above mixed solvent into a tower reactor (the tower reactor has an inner diameter of 4cm, a length of 40cm, and is filled with glass fiber packing) from the top through a plunger pump at a rate of 0.3ml / min. At the same time, oxygen containing ozone (ozone concentration of 100mg / L) is introduced from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at 20°C, the raw material flows out of the reactor from the bottom.

[0142] 2. The product obtained in step 1 is passed through a plunger pump at a flow rate of 0.1 h. -1 The air velocity was pumped into a fixed-bed reactor containing catalyst 3 prepared in Preparation Example 3, while air (molar ratio of oxygen to quinoline was 15:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 35°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was 2,3-pyridinedicarboxylic acid, with a product yield of 93%.

[0143] Reaction Example 4

[0144] 1. Add 100g of quinoline to a mixed solvent of 500ml formic acid (88%) and water (the volume ratio of formic acid to water is 4:1), stir to dissolve, and pump the above mixed solvent into a tower reactor (the tower reactor has an inner diameter of 4cm, a length of 40cm, and is filled with glass fiber packing) from the top through a plunger pump at a rate of 0.3ml / min. At the same time, oxygen containing ozone (ozone concentration of 100mg / L) is introduced from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at 20°C, the raw material flows out of the reactor from the bottom.

[0145] 2. The product obtained in step 1 is passed through a plunger pump at a flow rate of 0.1 h. -1 The catalyst 3 prepared in Preparation Example 3 was pumped into a fixed-bed reactor at a high air velocity, while oxygen (molar ratio of oxygen to quinoline was 15:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 50°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was 2,3-pyridinedicarboxylic acid, with a product yield of 95%.

[0146] Reaction Example 5

[0147] 1. Add 100g of quinoline to a mixed solvent of 500ml formic acid (88%) and water (the volume ratio of formic acid to water is 4:1), stir to dissolve, and pump the above mixed solvent into a tower reactor (the tower reactor has an inner diameter of 4cm, a length of 40cm, and is filled with glass fiber packing) from the top through a plunger pump at a rate of 0.3ml / min. At the same time, oxygen containing ozone (ozone concentration of 100mg / L) is introduced from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at 20°C, the raw material flows out of the reactor from the bottom.

[0148] 2. The product obtained in step 1 is passed through a plunger pump at a flow rate of 0.1 h. -1 The gas was pumped into a fixed-bed reactor containing catalyst 4 prepared in Preparation Example 4, and hydrogen gas (molar ratio of hydrogen to quinoline was 15:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 10°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was 2,3-pyridinedicarboxaldehyde, with a product yield of 89%.

[0149] Reaction Example 6

[0150] 1. Add 100g of methyl methacrylate to 400ml of methanol and stir to dissolve. Pump the above mixed solvent into the tower reactor (the tower reactor has an inner diameter of 4cm, a length of 40cm, and is filled with glass fiber packing) from the top through a plunger pump at a rate of 0.3ml / min. At the same time, introduce ozone-containing oxygen (ozone concentration of 100mg / L) from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at 10°C, the raw material flows out of the reactor from the bottom.

[0151] 2. The product obtained in step 1 is passed through a plunger pump at a flow rate of 0.1 h. -1 The gas was pumped into a fixed-bed reactor containing catalyst 4 at a high air velocity, while air (molar ratio of oxygen to methyl methacrylate 10:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 20°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was methyl pyruvate, with a product yield of 98%.

[0152] Reaction Example 7

[0153] 1. Add 100g of ethyl methacrylate to 400ml of ethanol and stir to dissolve. Pump the above mixed solvent into the tower reactor (the tower reactor has an inner diameter of 4cm, a length of 40cm, and is filled with glass fiber packing) from the top through a plunger pump at a rate of 0.5ml / min. At the same time, introduce ozone-containing oxygen (ozone concentration of 100mg / L) from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at 10°C, the raw material flows out of the reactor from the bottom.

[0154] 2. The product obtained in step 1 is passed through a plunger pump at a rate of 0.4 h. -1 The catalyst 4 was pumped into a fixed-bed reactor containing the catalyst at a high air velocity, while air (with a molar ratio of oxygen to ethyl methacrylate of 10:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 30°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was ethyl pyruvate, with a product yield of 96%.

[0155] Reaction Example 8

[0156] 1. Add 100g of methyl methacrylate to 400ml of methanol and stir to dissolve. Pump the above mixed solvent into the tower reactor (the tower reactor has an inner diameter of 4cm, a length of 40cm, and is filled with glass fiber packing) from the top through a plunger pump at a rate of 0.5ml / min. At the same time, introduce ozone-containing oxygen (ozone concentration of 100mg / L) from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at 10°C, the raw material flows out of the reactor from the bottom.

[0157] 2. The product obtained in step 1 is passed through a plunger pump at a rate of 0.4 h. -1 The catalyst 4 was pumped into a fixed-bed reactor containing catalyst 4 via a space velocity pump, while hydrogen gas (molar ratio of hydrogen to methyl methacrylate 10:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 80°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was methyl lactate, with a product yield of 90%.

[0158] Reaction Example 9

[0159] 1. Add 100g maleic acid to a mixed solvent of 500ml formic acid (88%) and water (volume ratio of formic acid to water is 4:1), stir to dissolve, and pump the above mixed solvent into a tower reactor (the tower reactor has an inner diameter of 4cm, a length of 40cm, and is filled with glass fiber packing) from the top through a plunger pump at a rate of 0.5ml / min. At the same time, oxygen containing ozone (ozone concentration of 100mg / L) is introduced from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at 10℃, the raw material flows out of the reactor from the bottom.

[0160] 2. The product obtained in step 1 is passed through a plunger pump at a flow rate of 0.1 h. -1 The gas was pumped into a fixed-bed reactor containing catalyst 4 at a high air velocity, while hydrogen gas (molar ratio of hydrogen to maleic acid 10:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 40°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was glyoxylic acid, with a product yield of 87%.

[0161] Reaction Example 10

[0162] 1. Add 100g maleic acid to a mixed solvent of 500ml formic acid (88%) and water (volume ratio of formic acid to water is 4:1), stir to dissolve, and pump the above mixed solvent into a tower reactor (the tower reactor has an inner diameter of 4cm, a length of 40cm, and is filled with glass fiber packing) from the top through a plunger pump at a rate of 0.5ml / min. At the same time, oxygen containing ozone (ozone concentration of 100mg / L) is introduced from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at 10℃, the raw material flows out of the reactor from the bottom.

[0163] 2. The product obtained in step 1 is passed through a plunger pump at a flow rate of 0.1 h. -1 The catalyst 6 was pumped into a fixed-bed reactor containing the catalyst at a high air velocity, while air (with a molar ratio of oxygen to maleic acid of 10:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 40°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was oxalic acid, with a product yield of 86%.

[0164] Reaction Example 11

[0165] 1. Add 100g of cyclohexene to 500ml of a mixed solvent of methanol and dichloromethane (volume ratio of methanol to dichloromethane is 5:1), stir and mix to dissolve. Pump the mixed solvent into a tower reactor (4cm inner diameter, 40cm long, filled with glass fiber packing) from the top using a plunger pump at a rate of 0.5ml / min. At the same time, introduce ozone-containing oxygen (ozone concentration of 100mg / L) from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at -10℃, the mixture flows out of the reactor from the bottom.

[0166] 2. The product obtained in step 1 is passed through a plunger pump at a flow rate of 0.1 h. -1 The catalyst 6 was pumped into a fixed-bed reactor containing catalyst 6 via a space velocity pump, while air (with a molar ratio of oxygen to cyclohexene of 10:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 40°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was adipic acid, with a product yield of 93%.

[0167] Reaction Example 12

[0168] 1. Add 100g of cyclopentene to 500ml of a mixed solvent of methanol and dichloromethane (volume ratio of methanol to dichloromethane is 5:1), stir and mix to dissolve. Pump the mixed solvent into a tower reactor (4cm inner diameter, 40cm long, filled with glass fiber packing) from the top using a plunger pump at a rate of 0.5ml / min. At the same time, introduce ozone-containing oxygen (ozone concentration of 100mg / L) from the bottom of the reactor at a rate of 1L / min. After the raw material and ozone react in the reactor at -10℃, the mixture flows out of the reactor from the bottom.

[0169] 2. The product obtained in step 1 is passed through a plunger pump at a flow rate of 0.1 h. -1 The catalyst 4 was pumped into a fixed-bed reactor at a high air velocity, while hydrogen gas (molar ratio of hydrogen to cyclohexene 10:1) was simultaneously introduced into the reactor through a mass flow controller. The reaction was carried out at 40°C, and the carbonylated product was obtained after gas-liquid separation. The mixture was subjected to chromatographic analysis, and the main product was glutaraldehyde, with a product yield of 90%.

[0170] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for the continuous preparation of carbonyl compounds using a heterogeneous catalyst, the method comprising the following steps: Step 1. The reactant solution and ozone gas are introduced into reactor 1 for mixing and reaction; Step 2. The product obtained in Step 1 and the reducing agent are respectively introduced into reactor 2 containing a catalyst for reaction, wherein the gas flow is controlled by a flow controller to obtain carbonylated products; In step 1 above, the reaction raw materials are selected from naphthalene, quinoline, maleic acid, and cyclopentene; the corresponding carbonylation products are selected from o-phthalaldehyde, 2,3-pyridinedicarboxaldehyde, glyoxylic acid, and glutaraldehyde. In step 1 above, the reaction pressure is 0.1-0.5 MPa; In step 1 above, the reaction residence time is 0.5s-10min; In step 1 above, the solvent of the reaction raw material solution includes one or more of methanol, ethanol, isopropanol, tert-butanol, formic acid, acetic acid, propionic acid, water, dichloromethane, and dichloroethane. In step 1 above, the mass concentration of the reaction raw material solution is 3%-100%; In step 1 above, the molar ratio of ozone to the double bonds in the reactant molecules is 1.0-4.0; In step 2 above, the reaction temperature is -20℃ to 120℃; In step 2 above, the reaction pressure is 0.1-1.0 MPa; In step 2 above, the reaction residence time is 5s-10min; In step 2 above, the reaction space velocity is 0.05-1.0 h⁻¹. -1 ; In step 2 above, the reducing agent is hydrogen gas; In step 2 above, the molar ratio of the product to the reducing agent in step 1 is 1:2 to 1:10; In step 2 above, the catalyst is prepared by a method including the following steps: 1) After the dried biomass raw material is crushed by a pulverizer, it is added together with the solid acid catalyst and ball-milled into a fine powder of 200-400 mesh. The powder is then added to a reaction vessel, distilled water is added, the reaction vessel is sealed, and the mixture is heated to 150-250℃ for hydrolysis reaction for 4-10 h. After the reaction is completed, the temperature is lowered, the pressure is released, and the mixture is filtered under reduced pressure. The filtrate is then distilled and concentrated to 20% of its original volume to obtain a concentrated solution. The biomass material is selected from one or more of corn cobs, corn stalks, sawdust, peanut shells, and bamboo shoots. 2) Add the acid solution to the concentrated solution described in step 1) under vigorous stirring. After mixing evenly, add chitosan and transfer to a hydrothermal reactor. Perform hydrothermal treatment at 160-220℃ for 4-20 h. After cooling and depressurization, wash the obtained product three times with anhydrous ethanol and deionized water respectively, and then dry at 110℃ for 12 h to obtain the doped carbon material. 3) Add alkali to the doped carbon material obtained in step 2), stir and mix evenly, place it in a tube furnace, heat to 300-700℃ under an inert gas atmosphere for carbonization treatment for 4-20 h, cool down after carbonization, wash the obtained material with distilled water until the filtrate is neutral, and dry at 110℃ for 12 h. 4) Prepare a metal precursor solution, add the doped carbon material obtained in step 3), mix evenly, let stand for 12 hours, then evaporate the solvent, dry in an oven at 120°C for 12 hours, and then heat to 200-500°C in a tube furnace under a hydrogen atmosphere for 4-12 hours to obtain an intermediate product, wherein the metal precursor is a nitrate or hydrochloride of Ni, Cu, Co, or Fe. 5) Add an alkaline solution to the intermediate catalyst obtained in step 4) above, mix well, add tetraethyl orthosilicate, stir and react at 30-70℃ for 4-20 h, filter, dry at 120℃ for 10 h, and then calcine in a tube furnace at 400-600℃ for 4-8 h in an air atmosphere to obtain the catalyst.

2. A method for the continuous preparation of carbonyl compounds using a heterogeneous catalyst, the method comprising the following steps: Step 1. The reactant solution and ozone gas are introduced into reactor 1 for mixing and reaction; Step 2. The product obtained in Step 1 and the oxidant are respectively fed into reactor 2 containing a catalyst for reaction, wherein the gas flow is controlled by a flow controller to obtain the carbonylated product; In step 1 above, the reaction raw materials are selected from naphthalene, quinoline, methyl methacrylate, ethyl methacrylate, maleic acid, and cyclohexene; the corresponding carbonylation products are selected from phthalic acid, 2,3-pyridinedicarboxylic acid, methyl pyruvate, ethyl pyruvate, oxalic acid, and adipic acid. In step 1 above, the reaction pressure is 0.1-0.5 MPa; In step 1 above, the reaction residence time is 0.5s-10min; In step 1 above, the solvent of the reaction raw material solution includes one or more of methanol, ethanol, isopropanol, tert-butanol, formic acid, acetic acid, propionic acid, water, dichloromethane, and dichloroethane. In step 1 above, the mass concentration of the reaction raw material solution is 3%-100%; In step 1 above, the molar ratio of ozone to the double bonds in the reactant molecules is 1.0-4.0; In step 2 above, the reaction temperature is -20℃ to 120℃; In step 2 above, the reaction pressure is 0.1-1.0 MPa; In step 2 above, the reaction residence time is 5s-10min; In step 2 above, the reaction space velocity is 0.05-1.0 h⁻¹. -1 ; In step 2 above, the oxidant is one or more of oxygen and air; In step 2 above, the molar ratio of the product to the oxidant in step 1 is 1:2 to 1:10; In step 2 above, the catalyst is prepared by a method including the following steps: 1) After the dried biomass raw material is crushed by a pulverizer, it is added together with the solid acid catalyst and ball-milled into a fine powder of 200-400 mesh. The powder is then added to a reaction vessel, distilled water is added, the reaction vessel is sealed, and the mixture is heated to 150-250℃ for hydrolysis reaction for 4-10 h. After the reaction is completed, the temperature is lowered, the pressure is released, and the mixture is filtered under reduced pressure. The filtrate is then distilled and concentrated to 20% of its original volume to obtain a concentrated solution. The biomass material is selected from one or more of corn cobs, corn stalks, sawdust, peanut shells, and bamboo shoots. 2) Add the acid solution to the concentrated solution described in step 1) under vigorous stirring. After mixing evenly, add chitosan and transfer to a hydrothermal reactor. Perform hydrothermal treatment at 160-220℃ for 4-20 h. After cooling and depressurization, wash the obtained product three times with anhydrous ethanol and deionized water respectively, and then dry at 110℃ for 12 h to obtain the doped carbon material. 3) Add alkali to the doped carbon material obtained in step 2), stir and mix evenly, place it in a tube furnace, heat to 300-700℃ under an inert gas atmosphere for carbonization treatment for 4-20 h, cool down after carbonization, wash the obtained material with distilled water until the filtrate is neutral, and dry at 110℃ for 12 h. 4) Prepare a metal precursor solution, add the doped carbon material obtained in step 3), mix evenly, let stand for 12 hours, then evaporate the solvent, dry in an oven at 120°C for 12 hours, and then heat to 200-500°C in a tube furnace under a hydrogen atmosphere for 4-12 hours to obtain an intermediate product, wherein the metal precursor is a nitrate or hydrochloride of Ni, Cu, Co, or Fe. 5) Add an alkaline solution to the intermediate catalyst obtained in step 4) above, mix well, add tetraethyl orthosilicate, stir and react at 30-70℃ for 4-20 h, filter, dry at 120℃ for 10 h, and then calcine in a tube furnace at 400-600℃ for 4-8 h in an air atmosphere to obtain the catalyst.

3. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 1 above, the reactor 1 is selected from a series of batch reactors, tubular reactors, loop reactors, and tower reactors.

4. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 1 above, the molar ratio of ozone to the double bonds in the reactant molecules is 1.05-2.

0.

5. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 1 above, the molar ratio of ozone to the double bonds in the reactant molecules is 1.05-1.

5.

6. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 2 above, the reactor 2 is selected from fixed bed reactor, fluidized bed reactor, slurry bed reactor, stirred reactor, tubular reactor, and loop reactor.

7. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 1 of the catalyst preparation method, after the reaction is completed, the filter cake obtained by filtration contains the solid acid catalyst. The filter cake is calcined in air at 350-550°C for 3-6 hours to remove organic matter and obtain the solid acid catalyst. The obtained solid acid catalyst can be recycled. In step 1 above, the solid acid catalyst is selected from one or more of the following: silicon dioxide, γ-alumina, zirconium dioxide, cerium dioxide, tungsten trioxide, niobium pentoxide, zeolite molecular sieve, and ion exchange resin. In step 1 above, the mass ratio of distilled water to biomass raw material is 50:1-2:1; In step 1 above, the hydrolysis reaction temperature is 120-250℃; In step 1 above, the hydrolysis reaction time is 4-10 hours; In step 1 above, the mass concentration of the concentrated solution is 10%-30%.

8. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 1 of the catalyst preparation method, the biomass material is selected from one or more of corn cobs, corn stalks, and peanut shells.

9. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 1 of the catalyst preparation method, the biomass material is selected from one or more of corn cobs and corn stalks.

10. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 1 of the method for preparing the catalyst, the solid acid catalyst is selected from one or more of silicon dioxide, γ-alumina, tungsten trioxide, niobium pentoxide, zeolite molecular sieve, and ion exchange resin.

11. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 1 of the method for preparing the catalyst, the solid acid catalyst is selected from one or more of γ-alumina, zeolite molecular sieves, and ion exchange resins.

12. The method for continuous preparation of carbonyl compounds according to claim 7, characterized in that, In step 1 of the catalyst preparation method, the zeolite molecules are selected from one or more of HZSM5, HZSM11, HY, Hβ, HMOR, and SAPO-34.

13. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 1 of the catalyst preparation method, the mass ratio of distilled water to biomass raw material is 20:1-5:

1. In step 1 above, the hydrolysis reaction temperature is 160-210℃; In step 1 above, the hydrolysis reaction time is 4-6 hours; In step 1 above, the mass concentration of the concentrated solution is 10%-20%.

14. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 2 of the catalyst preparation method, the acid is selected from one or more of formic acid, acetic acid, propionic acid, and hydrochloric acid. In step 2 above, the mass concentration of the acid solution is 1%-30%; In step 2 above, the mass ratio of the acid solution to the concentrated solution is 1:1 to 10:1; In step 2 above, the mass ratio of chitosan to concentrated solution is 1:10 to 1:100; In step 2 above, the hydrothermal treatment temperature is 160-220℃; In step 2 above, the hydrothermal treatment time is 4-20 hours.

15. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 2 of the catalyst preparation method described above, the mass concentration of the acid solution is 3%-10%. In step 2 above, the mass ratio of the acid solution to the concentrated solution is 1:1 to 5:1; In step 2 above, the hydrothermal treatment temperature is 180-210℃; In step 2 above, the hydrothermal treatment time is 5-10 hours.

16. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 3 of the catalyst preparation method, the base is selected from one or more of sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide, and potassium ethoxide. In step 3 above, the mass ratio of the alkali to the doped carbon material is 1:1 to 10:1; In step 3 above, the inert gas used in the carbonization process includes one or more of nitrogen, helium, and argon.

17. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 3 of the catalyst preparation method, the mass ratio of the alkali to the doped carbon material is 1:1-5:

1. In step 3 above, the inert gas used in the carbonization process includes one or more of nitrogen and argon.

18. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 3 of the catalyst preparation method, the mass ratio of the alkali to the doped carbon material is 1:1 to 3:

1.

19. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 4 of the catalyst preparation method described above, the mass concentration of the metal precursor solution is 5-25 wt%. In step 4 above, the mass ratio of the metal precursor to the carbon material is 1:100-1:

5.

20. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 4 of the catalyst preparation method, the mass ratio of the metal precursor to the carbon material is 1:50-1:

5.

21. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 4 of the catalyst preparation method, the mass ratio of the metal precursor to the carbon material is 1:30-1:

8.

22. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 5 of the catalyst preparation method, the alkali is selected from one or more of sodium hydroxide, potassium hydroxide, ammonia, urea, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate. In step 5 above, the mass ratio of the alkaline solution to the doped carbon material is 2:1-20:1; In step 5 above, the mass concentration of the alkaline solution is 5%-30%; In step 5 above, the mass ratio of tetraethyl orthosilicate to the doped carbon material is 1.5:1-50:

1.

23. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 5 of the catalyst preparation method, the mass ratio of the alkaline solution to the doped carbon material is 5:1-20:

1.

24. The method for continuous preparation of carbonyl compounds according to claim 1 or 2, characterized in that, In step 5 of the catalyst preparation method, the mass ratio of tetraethyl orthosilicate to the doped carbon material is 2:1-50:1.

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