CN112608218A

CN112608218A - Synthetic method of pentanediol and synthetic method for preparing biomass-based piperylene by converting levulinic acid and derivatives thereof

Info

Publication number: CN112608218A
Application number: CN202011608874.7A
Authority: CN
Inventors: 白晨曦; 祁彦龙; 刘士俊; 代全权; 崔龙
Original assignee: Changchun Institute of Applied Chemistry of CAS
Current assignee: Changchun Institute of Applied Chemistry of CAS
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2021-04-06

Abstract

The invention provides a synthesis method of pentanediol, which comprises the following steps of carrying out conversion reaction on mixed liquid obtained by mixing levulinic acid and/or levulinic acid derivatives, a catalyst and an organic solvent in an atmosphere containing hydrogen to obtain pentanediol. The invention can utilize bulk biological chemical levulinic acid or derivatives thereof which are cheap and easy to obtain pentanediol through catalytic conversion, and further obtain piperylene. The raw materials in the invention are derived from renewable resources, and are hydrogenated and dehydrated to prepare the piperylene, particularly, a dehydration reaction route and a dehydration catalyst are constructed, and finally, a green sustainable technological route for synthesizing the piperylene is obtained. The invention provides a method for green and sustainable synthesis of linear pentadiene based on bio-based chemical conversion, which has the advantages of simple operation, short flow, no need of harsh experimental conditions, easy preparation of raw materials and catalysts, and large-scale synthesis prospect.

Description

Synthetic method of pentanediol and synthetic method for preparing biomass-based piperylene by converting levulinic acid and derivatives thereof

Technical Field

The invention belongs to the technical field of conversion and synthesis of bio-based chemicals, and relates to a synthesis method of pentanediol and a synthesis method of piperylene, in particular to a synthesis method of pentanediol and a synthesis method of preparing bio-based piperylene by conversion of levulinic acid and derivatives thereof.

Background

Piperylene is mainly used for producing petroleum resin, terpene resin, cyclic hydrogen resin curing agent, coating ink, adhesive and the like. The C5 fraction is extracted for industrial preparation of piperylene, C5 is a byproduct of cracking ethylene production, generally about 10-20% of the ethylene yield, and C5 fraction contains 15-20% of isoprene, 15-17% of cyclopentadiene and 10-20% of piperylene, so the industrial production capacity and economy of piperylene depend on the ethylene equipment scale. Although the total yield of ethylene is large in China, the devices are scattered, so that C5 resources are scattered, and the transportation cost is high. In recent years, the development of the U.S. shale gas technology will impact the traditional ethylene industry, resulting in C5 resource shortages. In addition, the fossil resource reserves are limited, the harm of the refining industry to the environment is not suspected, and with the prominent environmental problems and the increasing exhaustion of fossil resources, more and more researchers are dedicated to the directional conversion of renewable resources such as biomass and the like, and a green method for preparing piperylene is sought. Originally in 1944, Valderrama et al used biofermentation to convert sorbic acid to piperylene. The biological fermentation method relates to bioengineering (metabolism and fermentation process), gene technology (gene modification) and the like, and although the conditions are mild, the process is complex, the efficiency is low, and the process flexibility is poor. In the field of biomass catalytic conversion, only three routes can prepare piperylene so far: (1) converting furfural into methyltetrahydrofuran through methylfuran, and finally dehydrating to obtain piperylene (Rubber chemistry Technology,1945,18, 284-285; ACS Catalysis,2017,7,5248-5256), wherein the method has long route, low yield (< 30%), and high material and energy consumption; (2) the Otsumadman subject group in Otsumadagaku, Zhang, takes xylitol as a raw material, firstly deoxidizes and dehydrates (DODH) under the action of formic acid, then deeply deoxidizes to obtain piperylene, the yield is not more than 51.8 percent, the DODH is the key of the route, the formic acid is a catalyst and a reactant, the formic acid catalyzes the dehydration of the xylitol and is in competition relation with the DODH, so the catalytic efficiency is not high, and the DODH system is lack of a reducing agent, so the yield is low (Green Chemistry,2017,19,638 and 642); (3) the subject group uses butanone/formaldehyde as a raw material, linear hydroxy ketone is obtained by condensation, 1, 3-pentanediol is synthesized by hydrogenation, and then the linear hydroxy ketone is dehydrated and converted into piperylene, however, as the chemical environments of hydrogen on two adjacent carbons of carbonyl in a butanone structure are different, hydrogen on methylene is more active under reaction conditions, so that the reaction tends to generate nonlinear hydroxy ketone, and finally isoprene is generated, the industrial value of the route for preparing piperylene is not great (CN 201910044174).

Therefore, continuously designing and developing a novel synthetic route, enriching and optimizing a synthetic technology, developing a catalyst with low cost and long service life, catalyzing biomass chemicals which are cheap and easy to obtain, directionally and efficiently converting the biomass chemicals, still being the development direction of a piperylene preparation technology, having important significance for green environmental protection and sustainable development, being the first task of current scientific and technological workers, and also being one of the focuses of prospective researchers in the industry.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide an application of an acidic catalyst and a solid catalyst in the synthesis of piperylene, and a synthetic method of piperylene, in particular a synthetic method of converting levulinic acid or a derivative thereof into biomass-based piperylene. The invention can utilize cheap and easily obtained levulinic acid and/or levulinic acid derivatives as reaction raw materials, and can utilize cheap and easily obtained bulk biological-based chemicals of the levulinic acid to obtain the m-pentadiene.

The invention provides a synthesis method of pentanediol, which comprises the following steps:

1) and (2) carrying out conversion reaction on a mixed solution obtained by mixing levulinic acid and/or levulinic acid derivatives, a catalyst and an organic solvent in an atmosphere containing hydrogen to obtain pentanediol.

Preferably, the levulinic acid derivative comprises one or more of methyl levulinate, ethyl levulinate, n-propyl levulinate and gamma valerolactone;

the organic solvent comprises one or more of ethanol, isopropanol and formic acid;

the concentration of the levulinic acid and/or the levulinic acid derivative in the mixed solution is 100-400 mg/ml;

the pressure of the hydrogen-containing atmosphere is 2-10 MPa;

the hydrogen-containing atmosphere comprises hydrogen or a hydrogen-containing mixed gas.

Preferably, the time of the conversion reaction is 1-6 h;

the temperature of the conversion reaction is 120-200 ℃;

the concentration of the catalyst in the mixed solution is 5-50 mg/ml;

the catalyst comprises a supported Cu-based catalyst.

Preferably, the supported Cu-based catalyst includes a carrier and a Cu element and a promoter element supported on the carrier;

the carrier comprises modified activated carbon, modified carbon nanotubes and porous resin;

the promoter element comprises one or more of Co, Ni, Fe, Mo and W;

the loading capacity of the Cu element is 5-30%;

the loading amount of the catalytic promoter element is 0.05-25%;

the preparation method of the supported Cu-based catalyst comprises an equal-volume impregnation method.

Preferably, the modification comprises acid modification;

the supported Cu-based catalyst also comprises a step of reducing atmosphere heat treatment before conversion reaction;

the temperature of the heat treatment is 200-500 ℃;

the heat treatment time is 2-8 h;

the porous resin includes a P-containing porous resin.

The invention provides a synthetic method of piperylene, which comprises the following steps:

under the action of a solid acid catalyst, carrying out dehydration reaction on the raw material to obtain the m-pentadiene.

Preferably, the temperature of the dehydration reaction is 250-600 ℃;

the solid acid catalyst comprises a supported solid acid catalyst;

the supported solid acid catalyst comprises a carrier and a metal element and a rare earth element which are supported on the carrier;

the loading capacity of the supported solid acid catalyst is 0.1-30%;

the feedstock comprises pentanediol;

the piperylene comprises biomass-based piperylene.

Preferably, the metal element includes one or more of Na, K, Mg, Ca, Ag, Cu, Ni, V, Nb, W, Mo and Cr;

the rare earth elements comprise one or more of La, Ce, Pr, Nd, Pm, Sm, Eu and Gd;

the carrier comprises Zr-Si, Ti-Zr, Al-Mg and ZrO₂、SiO₂、Al₂O₃And MgO;

the loading comprises loading the metal element and the rare earth element on the carrier simultaneously, or loading the rare earth element on the carrier first and then loading the metal element on the carrier;

the loading capacity of the supported solid acid catalyst which simultaneously loads the metal element and the rare earth element on the carrier is 0.1-20%;

the loading capacity of the supported solid acid catalyst is 5-30% when the rare earth element is loaded on the carrier and the metal element is loaded on the carrier.

Preferably, the reaction mode of the dehydration reaction comprises a continuous reaction in a fixed bed reactor;

the feeding rate of the dehydration reaction is 0.01-0.1 ml/min;

the loading amount of the solid catalyst of the fixed bed reactor is 0.1-3.0 g;

the flow rate of the carrier gas of the fixed bed reactor is 10-80 ml/min;

the preparation method of the solid acid catalyst comprises an impregnation method.

Preferably, the solid acid catalyst further comprises a protective atmosphere heat treatment step before the dehydration reaction;

the temperature of the heat treatment is 600-800 ℃;

the heat treatment time is 2-5 h;

the protective atmosphere comprises nitrogen and/or an inert gas;

the raw material comprises pentanediol synthesized by the synthesis method in any one of the technical schemes.

The invention provides a synthesis method of pentanediol, which comprises the following steps of carrying out conversion reaction on mixed liquid obtained by mixing levulinic acid and/or levulinic acid derivatives, a catalyst and an organic solvent in an atmosphere containing hydrogen to obtain pentanediol. Compared with the prior art, the invention can utilize cheap and easily-obtained levulinic acid or the derivative thereof as a reaction raw material, and can utilize cheap and easily-obtained bulk bio-based chemicals to obtain pentanediol and further obtain piperylene through catalytic conversion. The raw materials in the invention can be bulk bio-based chemicals which are cheap and easy to obtain, are derived from renewable resources, and are catalytically converted and synthesized into pentanediol through (1) levulinic acid and derivatives thereof; (2) and dehydrating pentanediol to prepare piperylene. The invention takes levulinic acid and derivatives thereof as raw materials, prepares the m-pentadiene through hydrogenation and dehydration, and particularly obtains a green and sustainable process route for synthesizing the m-pentadiene through a dehydration reaction route and a dehydration catalyst construction. The invention provides a method for green and sustainable synthesis of linear pentadiene based on bio-based chemical conversion, which takes a biomass-based platform compound levulinic acid and derivatives thereof as raw materials, prepares 1, 4-pentanediol through hydrogenation, and prepares m-pentadiene through dehydration.

Experimental results show that the method for preparing 1, 3-pentadiene has good conversion effect, the raw materials are cheap and easy to obtain, the yield is higher than the technical level (less than or equal to 55%) of the existing biomass conversion preparation, the product is easy to separate, the catalyst is high in activity and long in service life, and carbon deposition is not easy to occur.

Drawings

FIG. 1 is a comparison of a process route for preparing piperylene by catalytic conversion according to the present invention and a conventional process route;

FIG. 2 is a mass spectrum of pentanediol prepared in example 1 of the present invention;

FIG. 3 is a product distribution diagram (GC graph) of the pentanediol synthesis provided in example 1 of the present invention;

FIG. 4 is a mass spectrum of piperylene prepared in example 1 of the present invention;

FIG. 5 is a drawing showing the nitrogen adsorption stripping of the Zr-Si carrier prepared in example 1 of the present invention.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

All of the starting materials of the present invention, without particular limitation as to their source, may be purchased commercially or prepared according to conventional methods well known to those skilled in the art.

All the raw materials of the present invention are not particularly limited in their purity, and the present invention preferably employs purity requirements that are conventional in the field of analytical purification or piperylene preparation.

All the raw materials and the process of the invention belong to the conventional trade marks or the abbreviation, each trade mark or the abbreviation is clear and definite in the field of related application, and the technical personnel in the field can purchase the raw materials or prepare the raw materials or the abbreviation from the market or prepare the raw materials or the abbreviation by a conventional method or adopt corresponding equipment to realize the raw materials or the abbreviation according to the trade marks, the abbreviation and the corresponding application.

The invention adopts a process route for synthesizing the pentanediol by catalytic conversion of the levulinic acid and/or the derivative thereof, and particularly, the levulinic acid and/or the derivative thereof is converted into the pentanediol by hydrogenation on a Cu-based catalyst.

The invention is a complete and refined integral preparation process, better ensures the green synthesis of products, and improves the reaction efficiency, and the levulinic acid and/or levulinic acid derivatives preferably comprise biomass-based levulinic acid and/or levulinic acid derivatives.

The specific selection of the levulinic acid derivative is not particularly limited in principle, and can be selected and adjusted by those skilled in the art according to the needs of practical application, product requirements and quality requirements, and the invention is to better ensure green synthesis of products and improve reaction efficiency, wherein the levulinic acid derivative preferably comprises one or more of methyl levulinate, ethyl levulinate, n-propyl levulinate and gamma valerolactone, more preferably methyl levulinate, ethyl levulinate, n-propyl levulinate or gamma valerolactone, more preferably methyl levulinate, ethyl levulinate or gamma valerolactone, and more preferably methyl levulinate and gamma valerolactone.

The specific selection of the organic solvent is not particularly limited in principle, and can be selected and adjusted by those skilled in the art according to the actual application requirements, product requirements and quality requirements.

In the invention, the concentration of levulinic acid and/or levulinic acid derivatives in the mixed solution is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual application needs, product requirements and quality requirements, in order to better ensure green synthesis of products and improve reaction efficiency, the concentration of levulinic acid and/or levulinic acid derivatives in the mixed solution is preferably 100-400 mg/ml, more preferably 150-350 mg/ml, and more preferably 200-300 mg/ml.

The pressure of the hydrogen-containing atmosphere is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual application requirements, product requirements and quality requirements, in order to better ensure green synthesis of products and improve reaction efficiency, the pressure of the hydrogen-containing atmosphere is preferably 2-10 MPa, more preferably 3-9 MPa, more preferably 4-8 MPa, and more preferably 5-7 MPa.

The selection of the hydrogen-containing atmosphere is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application requirements, product requirements and quality requirements.

The time of the conversion reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application needs, product requirements and quality requirements, the green synthesis of the product is better ensured, the reaction efficiency is improved, and the time of the conversion reaction is preferably 1-6 hours, more preferably 2-5 hours, and more preferably 3-4 hours.

The temperature of the conversion reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual application requirements, product requirements and quality requirements, the green synthesis of the product is better ensured, the reaction efficiency is improved, and the temperature of the conversion reaction is preferably 120-200 ℃, more preferably 130-190 ℃, more preferably 140-180 ℃, and more preferably 150-170 ℃.

In the invention, the concentration of the catalyst in the mixed solution is not particularly limited in principle, and a person skilled in the art can select and adjust the catalyst according to the actual application needs, product requirements and quality requirements, in order to better ensure the green synthesis of the product and improve the reaction efficiency, the concentration of the catalyst in the mixed solution is preferably 5-50 mg/ml, more preferably 15-40 mg/ml, and more preferably 25-30 mg/ml.

The invention is a complete and refined integral preparation process, better ensures the green synthesis of products, and improves the reaction efficiency, and the synthesis method of the pentanediol specifically comprises the following steps:

the conversion reaction is carried out in a stainless steel reaction kettle, the filling volume is controlled to be 50ml, the concentration of the catalyst is controlled to be 5-50 mg/ml, the solvent is one of ethanol, isopropanol and formic acid, the concentration of the raw material is 100-400 mg/ml, and the raw material is put into the reaction kettle and is filled with H₂Replacing 5 times, and recharging 2-10 MPaH₂The reaction temperature is 120-200 ℃, and the reaction time is 1-6 h.

More specifically, the present invention is to provide a novel,

the conversion reaction (hydrogenation reaction) is carried out in a stainless steel high-pressure reaction kettle, the filling volume is controlled to be 50ml, the concentration of the catalyst is 5-50 mg/ml, the concentration is preferably 8-45 mg/ml, the solvent is one of ethanol, isopropanol and formic acid, the solvent is preferably one of ethanol and isobutanol, the concentration of the raw material is 100-400 mg/ml, the concentration is preferably 120-280 mg/ml, the raw material is filled in the reaction kettle, and H is used for feeding the raw material into the reaction kettle₂Replacing 5 times, and recharging 2-10 MPaH₂The pressure is preferably 3-8 MPa, the reaction temperature is 120-200 ℃, the temperature is preferably 120-180 ℃, the reaction time is 1-6 hours, and the time is preferably 2-5 hours.

In a still more particular aspect,

the hydrogenation reaction (conversion reaction) is preferably carried out in a stainless steel high-pressure reaction kettle, the filling volume is controlled to be 50ml, the concentration of the catalyst is 5-50 mg/ml, the concentration is preferably 8-45 mg/ml, more preferably 10-40 mg/ml, the solvent is one of ethanol, isopropanol and formic acid, the solvent is preferably one of ethanol and isopropanol, more preferably isopropanol, the concentration of the raw material is 100-400 mg/ml, preferably 120-280 mg/ml, more preferably 150-260 mg/ml, the raw material is filled into the reaction kettle, and H is used for reaction₂Replacing 5 times, and recharging 2-10 MPaH₂The pressure is preferably 3-8 MPa, the reaction temperature is preferably 4.5-8 MPa and is 120-200 ℃, the temperature is preferably 120-180 ℃, the reaction time is preferably 130-175 ℃, the reaction time is 1-6 h, and the time is preferablyIs 2 to 5 hours, and more preferably 3 to 4.5 hours.

The type of the catalyst is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application requirements, product requirements and quality requirements.

The specific selection of the supported Cu-based catalyst is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application needs, product requirements and quality requirements.

The specific selection of the carrier is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application needs, product requirements and quality requirements.

The specific mode of modification is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application needs, product requirements and quality requirements.

The specific selection of the porous resin is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application requirements, product requirements and quality requirements.

The specific selection of the promoter element is not particularly limited in principle, and can be selected and adjusted by those skilled in the art according to the actual application requirements, product requirements and quality requirements.

The loading of the Cu element is not particularly limited in principle, and a person skilled in the art can select and adjust the loading according to the actual application requirements, the product requirements and the quality requirements, and in order to better ensure the green synthesis of the product and improve the reaction efficiency, the loading of the Cu element is preferably 5% to 30%, more preferably 10% to 25%, and more preferably 15% to 20%.

The loading of the promoter element is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application requirements, product requirements and quality requirements, and in order to better ensure the green synthesis of the product and improve the reaction efficiency, the loading of the promoter element is preferably 0.05-25%, more preferably 5-20%, and still more preferably 10-15%.

The preparation method of the supported Cu-based catalyst is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application needs, product requirements and quality requirements.

The invention is a complete and refined integral preparation process, better ensures the green synthesis of products, improves the reaction efficiency, and preferably comprises the step of carrying out heat treatment in reducing atmosphere before the conversion reaction of the supported Cu-based catalyst.

The heat treatment temperature is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual application needs, product requirements and quality requirements, so that the green synthesis of the product is better ensured, the reaction efficiency is improved, and the heat treatment temperature is preferably 200-500 ℃, more preferably 250-450 ℃, and more preferably 300-400 ℃.

The heat treatment time is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual application needs, product requirements and quality requirements, so that the green synthesis of the product is better ensured, the reaction efficiency is improved, and the heat treatment time is preferably 2-8 hours, more preferably 3-7 hours, and more preferably 4-6 hours.

The invention is a complete and refined integral preparation process, better ensures the green synthesis of products, improves the reaction efficiency, and particularly,

the catalyst is preferably a supported Cu-based catalyst. The support is preferably modified activated carbon, carbon nanotubes, synthetic multi (staged) porous resins, and the like. The promoter is preferably one or more of Co, Ni, Fe, Mo, W, etc.

Among them, the preparation of the multi (stage) pore resin is preferably: uniformly mixing trivinylphenylphosphine, 4-tert-butylstyrene, divinylbenzene, Span 80 and a small amount of chlorobenzene to obtain an oil phase, controlling the mass ratio of the 4-tert-butylstyrene to the divinylbenzene to be 0.5-3.0/1, controlling the content of P by regulating and controlling the addition amount of the trivinylphenylphosphine, wherein the mass ratio of the trivinylphenylphosphine to the 4-tert-butylstyrene to the divinylbenzene is (0.02-0.08): 1; CaCl₂And K₂S₂O₈Dissolving in water to form an aqueous phase, CaCl₂And K₂S₂O₈The mass ratio of (A) is 5-10/1, and the concentration of the solution is 10-20 mg/ml; controlling the volume ratio of oil to water to be 0.2-2/9, adding the water phase into the oil phase under vigorous stirring, and then reacting for 3-10 h at 50-100 ℃ to obtain the multi (level) pore polymer.

The active carbon and the carbon nano tube are preferably common commercial brands and adopt HCl and HNO₃、H₂SO₄Or modifying with mixed acid, treating at 100-180 ℃ for 3-24 h, then washing with water to neutrality, and drying for later use.

The preparation of the catalyst preferably adopts an isometric impregnation method, metal salt containing Cu and a cocatalyst is dissolved in water, added into a culture dish containing a carrier, the load of Cu is controlled to be 5-30% (calculated according to Cu), the load of the cocatalyst is controlled to be 0.05-25% (calculated according to the total amount of the metal), standing is carried out for 12h at room temperature, and after drying at 120 ℃, the catalyst is treated for 2-8 h in a nitrogen atmosphere at 300-650 ℃. Before use, the mixture is treated for 2-8 hours at 200-500 ℃ in a hydrogen atmosphere.

More specifically, the present invention is to provide a novel,

the Cu-based catalyst is preferably a supported Cu-based catalyst, the carrier is preferably modified activated carbon, carbon nanotubes, synthetic multi (stage) hole resin and the like, and is preferably modified activated carbon, carbon nanotubes and synthetic multi (stage) hole resin; the cocatalyst is one or more of Co, Ni, Fe, Mo, W and the like, and preferably one or two of Co, Ni, Mo and W.

Wherein HCl and HNO are preferably adopted as the modified activated carbon and the carbon nano tubes₃、H₂SO₄Or the modified activated carbon and the carbon nano-tube (the activated carbon and the carbon nano-tube are selected from common trademarks sold on the market) are modified by mixed acid to prepare the modified activated carbon and the carbon nano-tube, the treatment temperature is 100-180 ℃, the preferred treatment temperature is 120-160 ℃, the treatment time is 3-24 h, the preferred treatment time is 5-18 h, then the modified activated carbon and the carbon nano-tube are washed to be neutral by water, and the modified activated carbon and the carbon nano-tube are dried.

The multi (stage) pore resin is preferably prepared in water-oil two phases by adopting trivinylphenylphosphine, 4-tert-butylstyrene, divinylbenzene and the like; uniformly mixing trivinylphenylphosphine, 4-tert-butylstyrene, divinylbenzene, Span 80 and a small amount of chlorobenzene to obtain an oil phase, wherein the mass ratio of the 4-tert-butylstyrene to the divinylbenzene is controlled to be 0.5-3.0/1, the preferred mass ratio is 0.6-2.8/1, the mass ratio of the trivinylphenylphosphine to the 4-tert-butylstyrene to the divinylbenzene is 0.02-0.08/1, and the preferred mass ratio is 0.03-0.06/1; on the other hand, CaCl₂And K₂S₂O₈Dissolving in water to form an aqueous phase, CaCl₂And K₂S₂O₈The mass ratio of (A) is 5-10/1, the mass ratio is preferably 6-8/1, the concentration of the solution is 10-20 mg/ml, and the concentration is preferably 12-18 mg/ml. Adding the water phase into the oil phase under vigorous stirring, and reacting for 3-10 h at 50-100 ℃ to obtain the multi (stage) hole polymer, wherein the reaction temperature is preferably 60-90 ℃, and the reaction time is preferably 5-9 h. In addition, the water phase and the oil phase are mixedThe volume ratio of oil to water is controlled to be 0.2-2/9, and the preferred volume ratio is 0.3-1.8/9.

The supported Cu-based catalyst preferably adopts an isometric impregnation method, metal salt containing Cu and a cocatalyst is dissolved in water and added into a culture dish containing a carrier, the load of Cu is controlled to be 5-30% (calculated according to Cu), the preferred load is 8-28%, the load of the cocatalyst is 0.05-25% (calculated according to the total amount of the metal), the preferred load is 0.08-20%, the supported Cu-based catalyst is kept stand for 12 hours at room temperature, after being dried at 120 ℃, the supported Cu-based catalyst is treated for 2-8 hours in a nitrogen atmosphere at 300-650 ℃, the treatment temperature is preferably 350-650 ℃, and the treatment time is preferably 4-8 hours. Before use, the mixture is treated for 2-8 hours at 200-500 ℃ in a hydrogen atmosphere, the treatment temperature is preferably 300-450 ℃, and the treatment time is preferably 3-7 hours. Among them, the metal salts of Cu and the promoter are preferably easily soluble compounds such as nitrates, carbonates, halides, and the like.

In a still more particular aspect,

the Cu-based catalyst is preferably a supported Cu-based catalyst, the carrier is preferably modified activated carbon, carbon nanotubes, synthetic multi (stage) hole resin and the like, and is preferably modified activated carbon, carbon nanotubes and synthetic multi (stage) hole resin; the cocatalyst is preferably one or more of Co, Ni, Fe, Mo, W, etc., preferably one or two of Co, Ni, Mo, W, more preferably one or two of Co, Ni, W.

HCl and HNO are preferably adopted as the modified activated carbon and the carbon nano tube₃、H₂SO₄Or the modified activated carbon and the carbon nano-tube (the activated carbon and the carbon nano-tube are selected from common trademarks sold on the market) are subjected to mixed acid modification treatment to obtain the modified activated carbon and the carbon nano-tube, the treatment temperature is 100-180 ℃, the treatment temperature is preferably 120-160 ℃, the treatment time is preferably 130-155 ℃, the treatment time is 3-24 hours, the treatment time is preferably 5-18 hours, and the treatment time is preferably 8-12 hours, then the modified activated carbon and the carbon nano-tube are washed to be neutral by water, and the modified activated carbon and the.

The multi (stage) pore resin is preferably prepared in water-oil two phases by adopting trivinylphenylphosphine, 4-tert-butylstyrene, divinylbenzene and the like; wherein, trivinylphenyl phosphine, 4-tert-butylstyrene, divinyl benzene, Span 80 and a small amount of chlorobenzene are uniformly mixed to obtain an oil phase, and the 4-tert-butylstyrene and the di-chlorobenzene are controlledThe mass ratio of the vinylbenzene is 0.5-3.0/1, the mass ratio is preferably 0.6-2.8/1, more preferably 0.8-2.4/1, the mass ratio of the trivinylphenylphosphine to the 4-tert-butylstyrene and the divinylbenzene is 0.02-0.08/1, the mass ratio is preferably 0.03-0.06/1, and more preferably 0.04-0.06/1; on the other hand, CaCl₂And K₂S₂O₈Dissolving in water to form an aqueous phase, CaCl₂And K₂S₂O₈The mass ratio of (A) is 5-10/1, the mass ratio is preferably 6-8/1, the concentration of the solution is 10-20 mg/ml, the concentration is preferably 12-18 mg/ml, and the concentration is more preferably 13-16 mg/ml. Adding the water phase into the oil phase under vigorous stirring, and reacting for 3-10 h at 50-100 ℃ to obtain the multi (stage) hole polymer, wherein the reaction temperature is preferably 60-90 ℃, more preferably 70-85 ℃, and the reaction time is preferably 5-9 h, more preferably 6-8 h. In addition, the volume ratio of oil to water is controlled to be 0.2-2/9, and the volume ratio is preferably 0.3-1.8/9, and more preferably 0.5-1.5/9.

The supported Cu-based catalyst is preferably prepared by an isometric impregnation method, metal salt containing Cu and a cocatalyst is dissolved in water and added into a culture dish containing a carrier, the load of Cu is controlled to be 5-30% (calculated as Cu), preferably 8-28%, more preferably 9-26%, the load of the cocatalyst is 0.05-25% (calculated as total amount of metal), preferably 0.08-20%, more preferably 0.09-18%, the supported Cu-based catalyst is kept stand at room temperature for 12h, and after being dried at 120 ℃, the supported Cu-based catalyst is treated in a nitrogen atmosphere at 300-650 ℃ for 2-8 h, the treatment temperature is preferably 350-650 ℃, more preferably 400-600 ℃, and the treatment time is preferably 4-8 h, more preferably 5-7 h. Before use, the mixture is treated for 2-8 hours at 200-500 ℃ in a hydrogen atmosphere, the treatment temperature is preferably 300-450 ℃, more preferably 320-410 ℃, and the treatment time is preferably 3-7 hours, more preferably 4-6 hours. Among them, the metal salts of Cu and the promoter are preferably easily soluble compounds such as nitrates, carbonates, halides, and the like.

The invention also provides a synthetic method of piperylene, which comprises the following steps:

The invention adopts a process route for preparing piperylene by dehydrating pentanediol, in particular to a process route for preparing piperylene by dehydrating pentanediol on a supported solid acid catalyst.

The invention is a complete and refined integral preparation process, better ensures the green synthesis of products, and improves the reaction efficiency, and the raw material preferably comprises pentanediol, and more preferably comprises pentanediol synthesized by the synthesis method in any one of the technical schemes.

The invention is a complete and refined integral preparation process, better ensures the green synthesis of products, and improves the reaction efficiency, and the m-pentadiene preferably comprises biomass-based m-pentadiene.

The temperature of the dehydration reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual application requirements, product requirements and quality requirements, so that the green synthesis of the product is better ensured, the reaction efficiency is improved, and the temperature of the dehydration reaction is preferably 250-600 ℃, more preferably 300-550 ℃, more preferably 350-500 ℃, and more preferably 400-450 ℃.

The method for the dehydration reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application needs, product requirements and quality requirements.

The feeding rate of the dehydration reaction is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application requirements, product requirements and quality requirements, in order to better ensure the green synthesis of the product and improve the reaction efficiency, the feeding rate of the dehydration reaction is preferably 0.01-0.1 ml/min, more preferably 0.03-0.08 ml/min, and more preferably 0.05-0.06 ml/min.

The loading amount of the solid catalyst of the fixed bed reactor is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual application requirements, product requirements and quality requirements, in order to better ensure green synthesis of products and improve reaction efficiency, the loading amount of the solid catalyst of the fixed bed reactor is preferably 0.1-3.0 g, more preferably 0.5-2.5 g, and more preferably 1.0-2.0 g.

The flow rate of the carrier gas of the fixed bed reactor is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application requirements, product requirements and quality requirements, in order to better ensure the green synthesis of products and improve the reaction efficiency, the flow rate of the carrier gas of the fixed bed reactor is preferably 10-80 ml/min, more preferably 20-70 ml/min, more preferably 30-60 ml/min, and more preferably 40-50 ml/min.

The invention is a complete and refined integral preparation process, better ensures the green synthesis of products, improves the reaction efficiency, and the synthetic method of the piperylene can specifically comprise the following steps:

the dehydration reaction is preferably carried out on a fixed bed, the loading capacity of the catalyst is 0.5-3 g, the catalyst is treated for 2-5 hours at 600-800 ℃ in a nitrogen atmosphere before the reaction, the raw material feeding rate is 0.01-0.1 ml/min, the nitrogen flow rate is 10-80 ml/min, and the reaction temperature is 250-600 ℃.

More specifically, the present invention is to provide a novel,

the dehydration reaction is preferably carried out on a fixed bed, the loading amount of the catalyst is 0.5-3 g, preferably 0.8-2.8 g, before the reaction, the catalyst is treated for 2-5 hours at the temperature of 600-800 ℃ in a nitrogen atmosphere, the treatment temperature is preferably 650-750 ℃, and the treatment time is preferably 3-4 hours; during reaction, the raw material feeding rate is 0.01-0.1 ml/min, preferably 0.03-0.08 ml/min, the nitrogen flow rate is 10-80 ml/min, preferably 15-70 ml/min, the reaction temperature is 250-600 ℃, and preferably 260-580 ℃.

In a still more particular aspect,

the dehydration reaction is preferably carried out on a fixed bed, and the loading amount of the catalyst is 0.5-3 g, preferably 0.8-2.8 g, and more preferably 0.9-2.6 g; before reaction, treating the catalyst for 2-5 h at 600-800 ℃ in a nitrogen atmosphere, wherein the treatment temperature is preferably 650-750 ℃, more preferably 660-720 ℃, and the treatment time is preferably 3-4 h, more preferably 3.5-4 h; during reaction, the raw material feeding rate is 0.01-0.1 ml/min, preferably 0.03-0.08 ml/min, more preferably 0.04-0.06 ml/min, the nitrogen flow rate is 10-80 ml/min, preferably 15-70 ml/min, more preferably 20-65 ml/min, the reaction temperature is 250-600 ℃, preferably 260-580 ℃, more preferably 280-550 DEG C

The type of the solid acid catalyst is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application requirements, product requirements and quality requirements.

The composition of the solid acid catalyst is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application requirements, product requirements and quality requirements.

The loading amount of the supported solid acid catalyst is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application needs, product requirements and quality requirements, and in order to better ensure the green synthesis of the product and improve the reaction efficiency, the loading amount of the supported solid acid catalyst is preferably 0.1-30%, more preferably 5-25%, and still more preferably 10-20%.

The selection of the metal element is not particularly limited in principle, and can be selected and adjusted by those skilled in the art according to the actual application requirements, product requirements and quality requirements, and in order to better ensure green synthesis of the product and improve reaction efficiency, the metal element preferably comprises one or more of Na, K, Mg, Ca, Ag, Cu, Ni, V, Nb, W, Mo and Cr, and more preferably Na, K, Mg, Ca, Ag, Cu, Ni, V, Nb, W, Mo or Cr.

The selection of the rare earth elements is not particularly limited in principle, and a person skilled in the art can select and adjust the rare earth elements according to the actual application requirements, the product requirements and the quality requirements.

The selection of the carrier is not particularly limited in principle, and the carrier can be selected and adjusted by a person skilled in the art according to the actual application requirements, the product requirements and the quality requirements₂、SiO₂、Al₂O₃And MgO, more preferably Zr-Si, Ti-Zr, Al-Mg, ZrO₂、SiO₂、Al₂O₃Or MgO.

The invention is a complete and refined integral preparation process, better ensures the green synthesis of products, and improves the reaction efficiency, and the loading preferably comprises loading the metal elements and the rare earth elements on the carrier simultaneously, or loading the rare earth elements on the carrier first and then loading the metal elements on the carrier.

The invention is a complete and refined integral preparation process, better ensures the green synthesis of products, and improves the reaction efficiency, and the loading capacity of the supported solid acid catalyst which simultaneously loads the metal elements and the rare earth elements on the carrier is preferably 0.1-20%, more preferably 4-16%, and more preferably 8-12%.

The invention is a complete and refined integral preparation process, better ensures the green synthesis of products and improves the reaction efficiency, the rare earth element is loaded on the carrier, and then the load capacity of the supported solid acid catalyst loaded on the carrier by the metal element is preferably 5-30%, more preferably 10-25%, and more preferably 15-20%.

In the present invention, the amount of the element supported is preferably an amount obtained by conversion of the element oxide, and can be understood as a mass content of the element oxide or an amount of the element oxide supported.

The preparation method of the solid acid catalyst is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application needs, product requirements and quality requirements.

The invention is a complete and refined integral preparation process, better ensures the green synthesis of products, improves the reaction efficiency, and preferably comprises the step of protective atmosphere heat treatment before the dehydration reaction of the solid acid catalyst.

The temperature of the heat treatment is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual application requirements, product requirements and quality requirements, so that the green synthesis of the product is better ensured, the reaction efficiency is improved, and the temperature of the heat treatment is preferably 600-800 ℃, more preferably 640-760 ℃, and more preferably 680-720 ℃.

The heat treatment time is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to actual application needs, product requirements and quality requirements, so that the green synthesis of the product is better ensured, the reaction efficiency is improved, and the heat treatment time is preferably 2-5 hours, more preferably 2.5-4.5 hours, and more preferably 3-4 hours.

The specific selection of the protective atmosphere is not particularly limited in principle, and can be selected and adjusted by a person skilled in the art according to the actual application requirements, product requirements and quality requirements.

the solid acid catalyst is preferably a supported catalyst, which can be described in the form of A-BA is one of Na, K, Mg, Ca, Ag, Cu, Ni, V, Nb, W, Mo, Cr, etc., B is one of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, etc., C is Zr-Si, Ti-Zr, Al-Mg, ZrO, etc₂、SiO₂、Al₂O₃And MgO, etc.

Wherein the content of the first and second substances,

(1) A-B/C is that A and B are simultaneously loaded on a C carrier by an impregnation method, and A/B/C is that B, A is sequentially loaded on the C carrier by the impregnation method.

(2) A is a water-soluble compound containing Na, K, Mg, Ca, Ag, Cu, Ni, V, Nb, W, Mo, Cr, etc., B is a water-soluble compound containing La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, etc.,

(3) pseudo-boehmite and hydrated alumina are used as an Al source, TEOS, water glass and silica sol are used as an Si source, zirconyl nitrate is used as a Zr source, magnesium nitrate is used as an Mg source, titanium tetrachloride is used as a Ti source, and the materials are mixed according to a certain proportion to synthesize Zr-Si (Zr/Si is 0.2-3/1), Ti-Si (Ti/Si is 0.2-3/1), Ti-Zr (Ti/Zr is 0.2-3/1), Al-Mg (Al/Mg is 0.2-3/1), ZrO by a gel method or a precipitation method₂、SiO₂、Al₂O₃And MgO, and the like, then mixing the mixture with ethanol, treating at 180-350 ℃, and preparing the porous carrier by a supercritical drying method.

(4) Preparation of catalyst type A-B/C: dissolving a water-soluble compound containing A and B in water to form an impregnation liquid, weighing a certain amount of C, adding the C into the A-B impregnation liquid, standing for 12 hours, drying at 120 ℃, and roasting at 400-600 ℃ for 3-8 hours to obtain A-B/C; preparation of catalyst type A/B/C: and (2) impregnating the carrier C with an aqueous solution containing a certain amount of B, standing for 12h, drying at 120 ℃, roasting at 400-600 ℃ for 3-8 h to obtain B/C, then impregnating the carrier B/C with an aqueous solution containing a certain amount of A, standing for 12h, drying at 120 ℃, and roasting at 400-600 ℃ for 3-8 h to obtain A/B/C. The A-B/C type and A/B/C type catalysts respectively have the A and B loading amounts of 0.1-20% and 5-30%.

More specifically, the present invention is to provide a novel,

the solid acid catalyst is preferably a supported solid acid catalyst, and the form of the supported solid acid catalyst can be expressed as A-B/C or A/B/C, A is Na, K, Mg, Ca, Ag, Cu, Ni, or Cu,One of V, Nb, W, Mo, Cr and the like is preferably one of Na, K, Mg, Ag, Cu, V, W and Mo, B is one of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd and other rare earth elements, preferably one of La, Ce, Pr, Nd, Pm and Gd, and C is Zr-Si, Ti-Zr, Al-Mg, ZrO₂、SiO₂、Al₂O₃One of the carriers such as MgO, preferably Zr-Si, Ti-Zr, Al-Mg, ZrO₂、SiO₂、Al₂O₃One kind of (1). Wherein A is a water-soluble compound containing Na, K, Mg, Ca, Ag, Cu, Ni, V, Nb, W, Mo, Cr, etc., and B is a water-soluble compound containing La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, etc.

Preferably, the carrier C of the supported solid acid catalyst adopts pseudo-boehmite and hydrated alumina as Al sources, TEOS, water glass and silica sol as Si sources, zirconyl nitrate as Zr sources, magnesium nitrate as Mg sources and titanium tetrachloride as Ti sources, which are mixed according to a certain proportion to synthesize Zr-Si (Zr/Si ═ 0.2-3/1), Ti-Si (Ti/Si ═ 0.2-3/1), Ti-Zr (Ti/Zr ═ 0.2-3/1), Al-Mg (Al/Mg ═ 0.2-3/1), ZrO-Mg₂、SiO₂、Al₂O₃MgO and the like, the synthesis method is preferably a precipitation method, the Zr/Si ratio in Zr-Si is preferably 0.3-2.8/1, the Ti/Si ratio in Ti-Si is preferably 0.3-2.8/1, the Ti/Zr ratio in Ti-Zr is preferably 0.3-2.8/1, and the Al/Mg ratio in Al-Mg is preferably 0.3-2.8/1. And finally, mixing the obtained sample with ethanol, and treating at 180-350 ℃ for 3-10 h, wherein the treatment temperature is preferably 200-300 ℃, and the treatment time is preferably 5-8 h.

The supported solid acid catalyst is prepared by adopting an impregnation method, wherein the A-B/C type catalyst is prepared by the steps of dissolving a water-soluble compound containing A and B in water to form an impregnation liquid, weighing a certain amount of C, adding the C into the A-B impregnation liquid, standing for 12 hours, drying at 120 ℃, and roasting at 400-600 ℃ for 3-8 hours to obtain A-B/C; the A/B/C type catalyst is prepared by the steps of impregnating carrier C with an aqueous solution containing a certain amount of B, standing for 12 hours, drying at 120 ℃, roasting at 400-600 ℃ for 3-8 hours to obtain B/C, then impregnating carrier B/C with an aqueous solution containing a certain amount of A, standing for 12 hours, drying at 120 ℃, and roasting at 400-600 ℃ for 3-8 hours to obtain A/B/C. The load amounts of A and B in the prepared A-B/C type and A/B/C type catalysts are 0.1-20% and 5-30% respectively, and the load amounts are preferably 0.2-16% and 6-26% respectively; the roasting temperature of the catalyst is preferably 450-600 ℃, and the roasting time is preferably 4-6 h.

In a still more particular aspect,

the supported solid acid catalyst can be expressed as A-B/C or A/B/C, A is one of Na, K, Mg, Ca, Ag, Cu, Ni, V, Nb, W, Mo, Cr and the like, preferably one of Na, K, Mg, Ag, Cu, V, W and Mo, more preferably one of Na, K, Ag, Cu, W and Mo, B is one of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd and other rare earth elements, preferably one of La, Ce, Pr, Nd, Pm and Gd, more preferably one of La, Ce, Pr, Nd and Gd, and C is Zr-Si, Ti-Zr, Al-Mg, ZrO₂、SiO₂、Al₂O₃One of the carriers such as MgO, preferably Zr-Si, Ti-Zr, Al-Mg, ZrO₂、SiO₂、Al₂O₃More preferably Zr-Si, Ti-Si, ZrO₂、Al₂O₃One kind of (1). Wherein A and B are both water-soluble compounds.

Preferably, the carrier C of the supported solid acid catalyst adopts pseudo-boehmite and hydrated alumina as Al sources, TEOS, water glass and silica sol as Si sources, zirconyl nitrate as Zr sources, magnesium nitrate as Mg sources and titanium tetrachloride as Ti sources, which are mixed according to a certain proportion to synthesize Zr-Si (Zr/Si ═ 0.2-3/1), Ti-Si (Ti/Si ═ 0.2-3/1), Ti-Zr (Ti/Zr ═ 0.2-3/1), Al-Mg (Al/Mg ═ 0.2-3/1), ZrO-Mg₂、SiO₂、Al₂O₃MgO, etc.; wherein, the synthesis method is preferably a precipitation method, the Al source is preferably pseudo-boehmite, and the Si source is preferably TEOS or water glass; the Zr/Si ratio in the synthesized Zr-Si is preferably 0.3-2.8/1, the Ti/Si ratio in the Ti-Si is preferably 0.3-2.8/1, the Ti/Zr ratio in the Ti-Zr is preferably 0.3-2.8/1, and the Al/Mg ratio in the Al-Mg is preferably 0.3-2.8/1; finally, mixing the obtained sample with ethanol, and treating at 180-350 ℃ for 3-10 h, wherein the treatment temperature is preferably 200-300 ℃, more preferably 220-280 ℃, and the treatment time is preferably5 to 8 hours, more preferably 6 to 8 hours.

The supported solid acid catalyst is preferably prepared by an impregnation method, wherein the A-B/C type catalyst is prepared by the steps of dissolving a water-soluble compound containing A and B in water to form an impregnation liquid, weighing a certain amount of C, adding the C into the A-B impregnation liquid, standing for 12 hours, drying at 120 ℃, and roasting at 400-600 ℃ for 3-8 hours to obtain A-B/C; the A/B/C type catalyst is prepared by the steps of impregnating carrier C with an aqueous solution containing a certain amount of B, standing for 12 hours, drying at 120 ℃, roasting at 400-600 ℃ for 3-8 hours to obtain B/C, then impregnating carrier B/C with an aqueous solution containing a certain amount of A, standing for 12 hours, drying at 120 ℃, and roasting at 400-600 ℃ for 3-8 hours to obtain A/B/C. The prepared A-B/C type and A/B/C type catalysts respectively have the A and B loading amounts of 0.1-20% and 5-30%, the loading amounts are respectively preferably 0.2-16% and 6-26%, and more preferably 0.4-15.3% and 8-25%; the roasting temperature of the catalyst is preferably 450-600 ℃, more preferably 465-590 ℃, and the roasting time is preferably 4-6 hours, more preferably 4.5-5.5 hours.

Referring to fig. 1, fig. 1 is a comparison diagram of a process route for preparing piperylene by catalytic conversion according to the present invention and a conventional process route.

The invention provides a method for synthesizing pentanediol and a method for synthesizing biomass-based piperylene by using levulinic acid or biotransformation of levulinic acid. The invention can utilize cheap and easily obtained levulinic acid or derivatives thereof as reaction raw materials, and can utilize cheap and easily obtained bulk bio-based chemicals to obtain pentanediol and further obtain piperylene through catalytic conversion. The raw materials in the invention can be bulk bio-based chemicals which are cheap and easy to obtain, are derived from renewable resources, and are catalytically converted and synthesized into pentanediol through (1) levulinic acid and derivatives thereof; (2) and dehydrating pentanediol to prepare piperylene. The invention takes levulinic acid and derivatives thereof as raw materials, prepares the m-pentadiene through hydrogenation and dehydration, and particularly obtains a green and sustainable process route for synthesizing the m-pentadiene through a dehydration reaction route and a dehydration catalyst construction. The invention provides a method for green and sustainable synthesis of linear pentadiene based on bio-based chemical conversion, which takes a biomass-based platform compound levulinic acid and derivatives thereof as raw materials, prepares 1, 4-pentanediol through hydrogenation, and prepares m-pentadiene through dehydration.

For further illustration of the present invention, the method for synthesizing pentanediol and the method for synthesizing piperylene provided by the present invention are described in detail with reference to the following examples, but it should be understood that the examples are implemented on the premise of the technical scheme of the present invention, and the detailed embodiments and specific procedures are given, only for further illustration of the features and advantages of the present invention, but not for limitation of the claims of the present invention, and the scope of protection of the present invention is not limited to the following examples.

Example 1

(1) Conversion of methyl levulinate to pentanediol

Preparing a carbon nanotube-loaded Cu catalyst: weighing 2g of carbon nano tube, dispersing in a 1000ml round bottom flask, adding 1MHNO₃Then adding a reflux pipe, placing in an oil bath, heating to 140 ℃, stirring for reaction for 16h, cooling to room temperature, repeatedly filtering and washing with water until the pH value of the water is about 7, and drying. Weighing a certain amount of copper nitrate and cobalt nitrate to prepare an aqueous solution, adding the aqueous solution into a culture dish containing 1.5g of modified carbon nanotubes to ensure that the contents of Cu and Co are 15 percent and 2 percent respectively, standing the solution at room temperature for 12 hours, drying the solution at 120 ℃, and treating the solution at 400 ℃ for 5 hours in a nitrogen atmosphere. And then treating for 5.5h in a hydrogen atmosphere at 350 ℃ to obtain the carbon nanotube supported Cu catalyst.

Adding 7.5g methyl levulinate into a stainless steel high-pressure reaction kettle with a tetrafluoro lining, adding isopropanol to reach the volume of 50ml, weighing 0.8g catalyst, and filling 2MPa H₂After 5 times of replacement, 8MPaH was charged₂Heating to 170 ℃ and reactingAfter 4h, the yield of pentanediol was 73% and the conversion of methyl levulinate was 86%.

(2) Preparation of piperylene by dehydrating pentanediol

Weighing 52g of zirconyl nitrate and TEOS in total according to the Zr/Si ratio of 0.8/1, adding a water/ethanol solvent into a 500ml round-bottom flask, dropwise adding ammonia water to adjust the pH value of the system, stopping dropwise adding ammonia water when the pH value is about 10, continuing stirring for 30min, filtering, washing with water, filtering again, drying at 120 ℃, finally mixing the obtained sample and ethanol according to the solid-liquid mass ratio of 1:3, placing the mixture into a stainless steel reaction kettle, and treating the mixture at 200 ℃ for 6h to obtain the fluffy Zr-Si carrier.

Weighing 3g of Zr-Si carrier, adding the Zr-Si carrier into a beaker filled with 5.5ml of praseodymium nitrate and silver nitrate aqueous solution, wherein the concentrations of the silver nitrate and the praseodymium nitrate are 0.05g/ml and 0.14g/ml respectively, stirring, standing for 12h, drying at 120 ℃, and roasting at 475 ℃ for 5.5h to obtain the Ag-Pr/Zr-Si catalyst.

Weighing 2g of Ag-Pr/Zr-Si catalyst, loading the catalyst into a fixed bed reactor, heating the reactor to 600 ℃, treating the catalyst in a nitrogen atmosphere for 3.6 hours, and then starting to react, wherein the feeding rate of pentanediol is 0.04ml/min, the flow rate of nitrogen is 50ml/min, the reaction temperature is 450 ℃, the conversion rate of pentanediol is 90%, and the yield of piperylene is 56%.

The intermediate products pentanediol and piperylene prepared in example 1 of the present invention were characterized.

Referring to fig. 2, fig. 2 is a mass spectrum of pentanediol prepared in example 1 of the present invention.

Referring to fig. 3, fig. 3 is a product distribution diagram (GC plot) of the pentanediol synthesis provided in example 1 of the present invention.

Referring to fig. 4, fig. 4 is a mass spectrum of piperylene prepared in example 1 of the present invention.

Referring to fig. 5, fig. 5 is a drawing illustrating nitrogen adsorption and desorption of the Zr — Si carrier prepared in example 1 of the present invention.

Example 2

(1) Conversion of methyl levulinate to pentanediol

Weighing 2.5g of trivinylphenylphosphine, 53g of 4-tert-butylstyrene, 21g of divinylbenzene, 30ml of Span 80 and 200ml of chlorobenzene, and uniformly mixing to obtain an oil phase;on the other hand, 18g of CaCl was weighed₂And 2.6g K₂S₂O₈Dissolved in 1000ml of water to form an aqueous phase. Adding the water phase into the oil phase under vigorous stirring, reacting at 80 ℃ for 8h, and filtering to obtain the multi (level) pore polymer. Weighing a certain amount of copper nitrate and nickel nitrate to prepare an aqueous solution, adding the aqueous solution into a culture dish containing 2.5g of porous polymer to ensure that the contents of Cu and Ni are 23 percent and 2 percent respectively, standing the solution at room temperature for 12 hours, drying the solution at 120 ℃, and treating the solution at 400 ℃ for 5 hours in a nitrogen atmosphere. And then treating for 5h in a hydrogen atmosphere at 400 ℃ to obtain the porous polymer supported Cu catalyst.

Adding 10g methyl levulinate into a stainless steel high-pressure reaction kettle with a tetrafluoro lining, adding isopropanol to 50ml, weighing 1.2g catalyst, and filling 2MPa H₂After 5 times of replacement, 8MPaH was charged₂And heating to 155 ℃ for reaction for 4h to obtain the pentanediol yield of 65% and the methyl levulinate conversion rate of 81%.

(2) Preparation of piperylene by dehydrating pentanediol

Weighing 50g of pseudo-boehmite and magnesium nitrate in a 500ml round-bottom flask according to the Al/Mg ratio of 1.5/1, adding a water/ethanol solvent, dropwise adding ammonia water to adjust the pH value of the system, stopping dropwise adding ammonia water when the pH value is about 10, continuing stirring for 30min, filtering, washing with water, filtering again, drying at 120 ℃, finally mixing the obtained sample and ethanol according to the solid-liquid mass ratio of 1:2, placing in a stainless steel reaction kettle, and treating at 250 ℃ for 8h to obtain the fluffy Al-Mg carrier.

Weighing 3g of Al-Mg carrier, adding the Al-Mg carrier into a beaker filled with 5.5ml of aqueous solution of lanthanum nitrate and sodium carbonate, wherein the concentration of the lanthanum nitrate and the concentration of the sodium carbonate are respectively 0.08g/ml and 0.21g/ml, stirring, standing for 12h, drying at 120 ℃, and roasting at 500 ℃ for 5h to obtain the Na-La/Al-Mg catalyst.

Weighing 1.8g of Na-La/Al-Mg catalyst, loading the Na-La/Al-Mg catalyst into a fixed bed reactor, heating to 560 ℃, treating for 4 hours in a nitrogen atmosphere, and starting to react, wherein the feeding rate of pentanediol is 0.05ml/min, the flow rate of nitrogen is 50ml/min, the reaction temperature is 421 ℃, the conversion rate of pentanediol is 86%, and the yield of piperylene is 63%.

Example 3

(1) Conversion of gamma-valerolactone to pentanediol

Preparing a carbon nanotube-loaded Cu catalyst: weighing 2g of carbon nano tube, dispersing in a 1000ml round bottom flask, adding 1MHNO₃Then adding a reflux pipe, placing in an oil bath, heating to 160 ℃, stirring for reaction 10, cooling to room temperature, repeatedly filtering and washing with water until the pH value of the water is about 7, and drying. Weighing a certain amount of copper nitrate and nickel nitrate to prepare an aqueous solution, adding the aqueous solution into a culture dish containing 1.5g of modified carbon nanotubes to ensure that the contents of Cu and Ni are 15 percent and 10 percent respectively, standing the solution at room temperature for 12 hours, drying the solution at 120 ℃, and treating the solution at 400 ℃ for 5 hours in a nitrogen atmosphere. And then treating for 6h in a hydrogen atmosphere at 400 ℃ to obtain the carbon nanotube supported Cu catalyst.

Adding 7.5g of gamma-valerolactone into a stainless steel high-pressure reaction kettle with a tetrafluoro lining, adding isopropanol until the volume is 50ml, weighing 1.2g of catalyst, and filling 2MPa H₂After 5 times of replacement, 6MPa H is filled₂And heating to 150 ℃ for reaction for 4h to obtain the pentanediol yield of 53% and the gamma-valerolactone conversion rate of 72%.

(2) Preparation of piperylene by dehydrating pentanediol

Weighing 3g of Zr-Si carrier, adding the Zr-Si carrier into a beaker filled with 5.5ml of praseodymium nitrate aqueous solution (the concentration of the praseodymium nitrate is 0.14g/ml), stirring, standing for 12h, drying at 120 ℃, roasting at 500 ℃ for 5h to obtain Pr/Zr-Si, then adding the Zr-Si carrier into the beaker filled with 5.5ml of silver nitrate aqueous solution (the concentration of the silver nitrate is 0.08g/ml), stirring, standing for 12h, drying at 120 ℃, and roasting at 500 ℃ for 5h to obtain the Ag/Pr/Zr-Si catalyst.

Weighing 2g of Ag/Pr/Zr-Si catalyst, loading the Ag/Pr/Zr-Si catalyst into a fixed bed reactor, heating the fixed bed reactor to 600 ℃, treating the catalyst for 3.5 hours in a nitrogen atmosphere, starting to react, wherein the feeding rate of pentanediol is 0.04ml/min, the flow rate of nitrogen is 50ml/min, the reaction temperature is 460 ℃, the conversion rate of pentanediol is 93%, and the yield of piperylene is 76%.

Example 4

(1) Conversion of gamma-valerolactone to pentanediol

Weighing 2.5g of trivinylphenylphosphine, 53g of 4-tert-butylstyrene, 21g of divinylbenzene, 30ml of Span 80 and 200ml of chlorobenzene, and uniformly mixing to obtain an oil phase; on the other hand, 18g of CaCl was weighed₂And 2.6g K₂S₂O₈Dissolved in 1000ml of water to form an aqueous phase. Adding the water phase into the oil phase under vigorous stirring, reacting at 80 ℃ for 8h, and filtering to obtain the multi (level) pore polymer. Weighing a certain amount of copper nitrate and nickel nitrate to prepare an aqueous solution, adding the aqueous solution into a culture dish containing 2.5g of porous polymer to ensure that the contents of Cu and Ni are respectively 18 percent and 8 percent, standing the solution at room temperature for 12 hours, drying the solution at 120 ℃, and treating the solution at 380 ℃ in a nitrogen atmosphere for 5 hours. And then treating for 5h in a hydrogen atmosphere at 400 ℃ to obtain the porous polymer supported Cu catalyst.

Adding 10g of gamma-valerolactone into a stainless steel high-pressure reaction kettle with a tetrafluoro lining, adding isopropanol until the volume is 50ml, weighing 2.0g of catalyst, and filling 2MPa H₂After 5 times of replacement, 8MPa H is filled₂And heating to 175 ℃ for reaction for 4h to obtain the pentanediol yield of 65% and the gamma-valerolactone conversion rate of 82%.

(2) Preparation of piperylene by dehydrating pentanediol

Weighing 50g of zirconyl nitrate into a 500ml round-bottom flask, adding water, dropwise adding ammonia water to adjust the pH of the system, stopping dropwise adding ammonia water when the pH is about 10, continuing stirring for 30min, filtering, washing with water, filtering again, drying at 120 ℃, mixing the obtained sample with ethanol according to the solid-liquid mass ratio of 1:3, placing the mixture into a stainless steel reaction kettle, and treating at 180 ℃ for 6 hours to obtain fluffy ZrO₂And (3) a carrier.

3g of ZrO were weighed₂Adding the carrier into a beaker filled with 5.5ml of cerium nitrate aqueous solution (the concentration of the cerium nitrate is 0.14g/ml), stirring, standing for 12h, drying at 120 ℃, and roasting at 500 ℃ for 5h to obtain Ce/ZrO₂Then, it was added to a beaker containing 5.5ml of an aqueous silver nitrate solution (nitric acid)Silver concentration of 0.08g/ml), stirring, standing for 12h, drying at 120 ℃, and roasting at 500 ℃ for 5h to obtain Ag/Ce/ZrO₂A catalyst.

Weighing 2g of Ag/Ce/ZrO₂The catalyst is loaded into a fixed bed reactor, the temperature is raised to 550 ℃, the reaction is started after the catalyst is treated for 3.5 hours in nitrogen atmosphere, the feeding rate of the pentanediol is 0.04ml/min, the flow rate of the nitrogen is 50ml/min, the reaction temperature is 400 ℃, the conversion rate of the pentanediol is 89%, and the yield of the piperylene is 68%.

Example 5

(1) Conversion of methyl levulinate to pentanediol

Preparing a carbon nanotube-loaded Cu catalyst: weighing 2g of carbon nano tube, dispersing in a 1000ml round bottom flask, adding 1MHNO₃Then adding a reflux pipe, placing in an oil bath, heating to 150 ℃, stirring for reaction for 10h, cooling to room temperature, repeatedly filtering and washing with water until the pH value of the water is about 7, and drying. Weighing a certain amount of copper nitrate and cobalt nitrate to prepare an aqueous solution, adding the aqueous solution into a culture dish containing 1.5g of modified carbon nanotubes to ensure that the contents of Cu and Co are respectively 20% and 8%, standing the solution at room temperature for 12 hours, drying the solution at 120 ℃, and treating the solution at 400 ℃ for 5 hours in a nitrogen atmosphere. And then treating for 5h in a hydrogen atmosphere at 400 ℃ to obtain the carbon nanotube supported Cu catalyst.

Adding 10g methyl levulinate into a stainless steel high-pressure reaction kettle with a tetrafluoro lining, adding isopropanol to 50ml, weighing 2.8g catalyst, and filling 2MPa H₂After 5 times of replacement, 8MPa H is filled₂And heating to 160 ℃ for reaction for 4h to obtain the pentanediol yield of 79% and the methyl levulinate conversion rate of 91%.

(2) Preparation of piperylene by dehydrating pentanediol

Weighing 50g of zirconyl nitrate into a 500ml round-bottom flask, adding water to prepare a solution, dropwise adding ammonia water to adjust the pH of the system, stopping dropwise adding ammonia water when the pH is about 10 to generate a large amount of precipitate, continuously stirring for 30min, filtering, washing with water, filtering again, drying at 120 ℃, finally mixing the obtained sample with ethanol according to the solid-liquid mass ratio of 1:3, placing the mixture into a stainless steel reaction kettle, and treating at 180 ℃ for 6 hours to obtain fluffy ZrO₂And (3) a carrier.

3g of ZrO were weighed₂Adding the carrier into a beaker filled with 5.5ml of neodymium nitrate aqueous solution (the concentration of the neodymium nitrate is 0.14g/ml), stirring, standing for 12h, drying at 120 ℃, and roasting at 500 ℃ for 5h to obtain Nd/ZrO₂Then, the mixture was added into a beaker containing 5.5ml of an aqueous solution of copper nitrate (concentration of copper nitrate: 0.08g/ml), stirred, allowed to stand for 12 hours, dried at 120 ℃ and baked at 500 ℃ for 5 hours to obtain Cu/Nd/ZrO₂A catalyst.

Weighing 2g of Cu/Nd/ZrO₂The catalyst is loaded into a fixed bed reactor, the temperature is raised to 500 ℃, the reaction is started after the catalyst is treated for 3.5 hours in the nitrogen atmosphere, the pentanediol feeding rate is 0.04ml/min, the nitrogen flow rate is 50ml/min, the reaction temperature is 380 ℃, the pentanediol conversion rate is 88%, and the piperylene yield is 60%.

Example 6

(1) Conversion of gamma-valerolactone to pentanediol

Weighing 1.5g of trivinylphenylphosphine, 46g of 4-tert-butylstyrene, 30g of divinylbenzene, 30ml of Span 80 and 200ml of chlorobenzene, and uniformly mixing to obtain an oil phase; on the other hand, 15g of CaCl was weighed₂And 3.0g K₂S₂O₈Dissolved in 900ml of water to form an aqueous phase. Adding the water phase into the oil phase under vigorous stirring, reacting at 70 ℃ for 8h, and filtering to obtain the multi (level) pore polymer. Weighing a certain amount of copper nitrate and cobalt nitrate to prepare an aqueous solution, adding the aqueous solution into a culture dish containing 2.5g of porous polymer to ensure that the contents of Cu and Co are respectively 20% and 5%, standing the solution at room temperature for 12 hours, drying the solution at 120 ℃, and treating the solution at 400 ℃ for 5 hours in a nitrogen atmosphere. And then treated in a hydrogen atmosphere at 430 ℃ for 5h to obtain the porous polymer supported Cu catalyst.

Adding 8g of gamma-valerolactone into a stainless steel high-pressure reaction kettle with a tetrafluoro lining, adding isopropanol until the volume is 50ml, weighing 1.2g of catalyst, and filling 2MPa H₂After 5 times of replacement, 8MPa H is filled₂And heating to 160 ℃ for reaction for 3h to obtain the product with the pentanediol yield of 46% and the gamma-valerolactone conversion rate of 63%.

(2) Preparation of piperylene by dehydrating pentanediol

Weighing 50g of zirconyl nitrate and TEOS in total according to the Zr/Si ratio of 1.2/1, putting the zirconyl nitrate and the TEOS in a 500ml round bottom flask, adding a water/ethanol solvent, dropwise adding ammonia water to adjust the pH of the system, stopping dropwise adding ammonia water when the pH is about 10, continuing stirring for 30min, filtering, washing with water, filtering again, drying at 120 ℃, finally, mixing the obtained sample and ethanol according to the solid-liquid mass ratio of 1:3, putting the mixture in a stainless steel reaction kettle, and treating the mixture at 180 ℃ for 6h to obtain the fluffy Zr-Si carrier.

Weighing 3g of Zr-Si carrier, adding the Zr-Si carrier into a beaker filled with 5.5ml of cerium nitrate aqueous solution (the concentration of the cerium nitrate is 0.09g/ml), stirring, standing for 12h, drying at 120 ℃, roasting at 500 ℃ for 5h to obtain Ce/Zr-Si, subsequently adding the Zr-Si carrier into the beaker filled with 5.5ml of potassium carbonate aqueous solution (the concentration of the potassium carbonate is 0.02g/ml), stirring, standing for 12h, drying at 120 ℃, and roasting at 500 ℃ for 5h to obtain the K/Ce/Zr-Si catalyst.

Weighing 1.5g K/Ce/Zr-Si catalyst, loading the catalyst into a fixed bed reactor, heating to 560 ℃, treating for 3.5h in nitrogen atmosphere, starting to react, wherein the feeding rate of pentanediol is 0.05ml/min, the flow rate of nitrogen is 50ml/min, the reaction temperature is 400 ℃, the conversion rate of pentanediol is 89%, and the yield of piperylene is 63%.

The above detailed description of a method for synthesizing pentanediol and a method for converting levulinic acid or a derivative thereof into biomass-based piperylene provided by the present invention, and the principles and embodiments of the present invention are described herein using specific examples, which are provided only to help understand the method and the core ideas thereof, including the best mode, and also to enable any person skilled in the art to practice the present invention, including making and using any devices or systems and performing any combination of the methods. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention. The scope of the invention is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A method for synthesizing pentanediol is characterized by comprising the following steps:

2. The synthetic method of claim 1 wherein the levulinic acid derivative comprises one or more of methyl levulinate, ethyl levulinate, n-propyl levulinate, and gamma valerolactone;

the pressure of the hydrogen-containing atmosphere is 2-10 MPa;

3. The synthesis method according to claim 1, wherein the conversion reaction time is 1-6 h;

the temperature of the conversion reaction is 120-200 ℃;

the concentration of the catalyst in the mixed solution is 5-50 mg/ml;

the catalyst comprises a supported Cu-based catalyst.

4. The synthesis method according to claim 3, wherein the supported Cu-based catalyst comprises a carrier and Cu element and a promoter element supported on the carrier;

the promoter element comprises one or more of Co, Ni, Fe, Mo and W;

the loading capacity of the Cu element is 5-30%;

the loading amount of the catalytic promoter element is 0.05-25%;

5. The method of synthesis of claim 4, wherein the modification comprises acid modification;

the temperature of the heat treatment is 200-500 ℃;

the heat treatment time is 2-8 h;

the porous resin includes a P-containing porous resin.

6. A synthetic method of piperylene is characterized by comprising the following steps:

7. The synthesis method according to claim 6, wherein the temperature of the dehydration reaction is 250-600 ℃;

the solid acid catalyst comprises a supported solid acid catalyst;

the loading capacity of the supported solid acid catalyst is 0.1-30%;

the feedstock comprises pentanediol;

the piperylene comprises biomass-based piperylene.

8. The synthesis method according to claim 7, wherein the metal elements comprise one or more of Na, K, Mg, Ca, Ag, Cu, Ni, V, Nb, W, Mo and Cr;

9. The synthesis method according to claim 6, wherein the dehydration reaction is carried out in a reaction mode comprising a continuous reaction in a fixed bed reactor;

the feeding rate of the dehydration reaction is 0.01-0.1 ml/min;

the loading amount of the solid catalyst of the fixed bed reactor is 0.1-3.0 g;

the flow rate of the carrier gas of the fixed bed reactor is 10-80 ml/min;

10. The synthesis method according to any one of claims 6 to 9, characterized in that the solid acid catalyst further comprises a protective atmosphere heat treatment step before the dehydration reaction;

the temperature of the heat treatment is 600-800 ℃;

the heat treatment time is 2-5 h;

the protective atmosphere comprises nitrogen and/or an inert gas;

the raw material comprises pentanediol synthesized by the synthesis method of any one of claims 1 to 5.