CN114213222A - Method for catalytic depolymerization of lignin into phenol compound - Google Patents

Method for catalytic depolymerization of lignin into phenol compound Download PDF

Info

Publication number
CN114213222A
CN114213222A CN202111460783.8A CN202111460783A CN114213222A CN 114213222 A CN114213222 A CN 114213222A CN 202111460783 A CN202111460783 A CN 202111460783A CN 114213222 A CN114213222 A CN 114213222A
Authority
CN
China
Prior art keywords
lignin
catalyst
poplar
ethanol
reaction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202111460783.8A
Other languages
Chinese (zh)
Inventor
沈德魁
迂文兵
程崇博
王�琦
董楠航
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Southeast University
Original Assignee
Southeast University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Southeast University filed Critical Southeast University
Priority to CN202111460783.8A priority Critical patent/CN114213222A/en
Publication of CN114213222A publication Critical patent/CN114213222A/en
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
    • C07C41/01—Preparation of ethers
    • C07C41/18—Preparation of ethers by reactions not forming ether-oxygen bonds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B01J23/755—Nickel
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
    • C07C41/01—Preparation of ethers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/584—Recycling of catalysts

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Catalysts (AREA)

Abstract

The invention relates to a method for catalytic depolymerization of lignin into phenol compounds, which takes ethanol/isopropanol mixed solvent as a hydrogen supply solvent system, NiCu/C as a catalyst and N2In the environment, lignin is subjected to a hydrogenation depolymerization reaction to generate a phenol compound. The lignin is organic soluble poplar lignin. In the NiCu/C catalyst, C is a carrier and adopts activated carbon; ni is an active component; cu is taken as an auxiliary agent; wherein the Ni content is 10wt%, and the Cu content is 3-7 wt%. The invention has the advantages of mild reaction condition, low reaction cost and no need of using exogenous H2And high reaction efficiency.

Description

Method for catalytic depolymerization of lignin into phenol compound
Technical Field
The invention belongs to the technical field of biomass conversion, and particularly relates to a method for catalytic depolymerization of lignin into a phenol compound.
Background
Today, with the continuous growth of the global population, the world faces huge resource challenges, especially the energy crisis caused by the huge consumption of fossil fuels and the environmental impact brought by the energy crisis. Biomass is an abundant, only renewable resource that can be used to produce fuels, chemicals, and energy.
The lignin is one of three main components of biomass, is the only natural resource containing a benzene ring structure which exists in large quantity in the nature, and is a naturally-occurring aromatic ring library. Therefore, the renewable lignin is used as a raw material to replace non-renewable fossil resources such as petroleum and the like to prepare high-value aromatic chemicals, and the high dependence of the fossil resources on the outside in China can be relieved.
At present, the methods used for depolymerizing lignin are generally two: 1) the catalytic depolymerization with hydrogen as a hydrogen donor and nickel boron as a catalyst under a reaction condition of 20MPa has problems of severe reaction conditions and high reaction risk coefficient, and 2) the catalytic depolymerization with an alcohol solvent such as methanol or ethanol as a hydrogen donor and a carbon-supported metal ion as a catalyst has problems of low yield of benzene ring monomer compounds although the reaction conditions are mild and the operation is safe.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide the method for catalyzing and depolymerizing the lignin into the phenol compounds, which has the advantages of mild reaction conditions, safe operation and high yield of the phenol compounds.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a method for catalytic depolymerization of lignin to phenol compound uses the mixed solvent of alcohol/isopropanol as hydrogen-supplying solvent system, NiCu/C as catalyst and N2In the environment, lignin is subjected to a hydrogenation depolymerization reaction to generate a phenol compound.
Further, the mass ratio of ethanol to isopropanol in the ethanol/isopropanol mixed solvent is 1: 1.
Furthermore, in the NiCu/C catalyst, C is a carrier and adopts activated carbon; ni is an active component; cu is taken as an auxiliary agent; wherein, the content of Ni is 9-11wt%, and the content of Cu is 3-7 wt%.
Further, the preparation method of the NiCu/C catalyst comprises the following steps:
according to activated carbon, Ni (NO)3)2·6H2O、Cu(NO3)2·3H2And the mass volume ratio of O to deionized water is 1 g: 0.4955 g: 0.1141-0.2661 g: 1.6mL, adding Ni (NO) to deionized water3)2·6H2O and Cu (NO)3)2·3H2O, stirring for 30min until the metal ions are completely dissolved to obtain a metal ion solution;
slowly dripping the metal ion solution on the activated carbon, stirring until the metal ions are highly dispersed on the activated carbon, air-drying overnight, and drying at 120 ℃ to obtain a catalyst precursor;
placing the catalyst precursor in H2/N2Reducing the mixed gas for 2 hours at 450 ℃, and cooling to obtain the NiCu/C catalyst.
Further, the lignin is organic soluble poplar lignin.
Further, the preparation method of the organic soluble poplar lignin comprises the following steps:
step 1, extracting poplar biomass by using a mixed solution of ethanol and toluene, and separating lignin;
step 2, mixing poplar biomass, methanol and hydrochloric acid according to the mass-volume ratio of 1 g: 7.5 mL: 0.02mL, adding methanol and concentrated hydrochloric acid into the extracted poplar biomass, then carrying out sealed stirring reaction in a high-pressure reaction kettle at 110 ℃ for 12 days, and filtering to obtain a filtrate;
step 3, according to the mass volume ratio of the poplar biomass to the ice of 6 g: 1cm3Adding ice blocks into the filtrate to precipitate lignin into lignin solid, then filtering, collecting the lignin solid, then washing with cold water until the pH value of the washing liquor is 7, and carrying out vacuum drying to obtain the organic soluble poplar lignin.
Further, the volume ratio of the ethanol to the toluene in the mixed solution of the ethanol and the toluene is 1: 1.
Further, the reaction temperature of the depolymerization reaction is: 210-290 ℃; n is a radical of2The pressure of (A) is 1-10 MPa; stirring operation is carried out in the reaction process, and the reaction time is 2-8 h.
Further, during the hydro-depolymerization reaction, the mass-volume ratio of the lignin to the ethanol/isopropanol mixed solvent is 10mg:1 mL;
the mass ratio of the lignin to the catalyst is 10: 1.
Further, the lignin was dried overnight at 60 ℃ before use.
Further, the phenolic compound comprises one or more of 2-methoxy-4-propylphenol, 2, 6-dimethoxy-4-propylphenol, 4- (3-hydroxypropyl) -2-methoxyphenol, 4- (3-hydroxypropyl) -2, 6-dimethoxyphenol, 4-ethylguaiacol, 2-methoxy-4-methylphenol and 2-methoxy-4-vinylphenol.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, by improving the hydrogenolysis method of lignin in an alcohol solvent, the method for preparing the lignin hydrogenation depolymerization by taking the glycol solvent as a hydrogen supply system and the supported transition metal as a catalyst, which is environment-friendly, low in price and high in stability, is prepared, so that the high-efficiency hydrogenolysis of the lignin is realized, and two types of high-value monophenol compounds with high yield are prepared: 2-methoxy-4-propyl Phenol (PG) and 2, 6-dimethoxy-4-propyl Phenol (PS) have great significance for realizing high-value utilization of lignin. In addition, the catalyst prepared by the method can be recycled, and the service life is long. The invention has the advantages of mild reaction condition, low reaction cost and no need of using exogenous H2And high reaction efficiency.
Detailed Description
In the present invention, methanol: analytically pure, 99.9%; concentrated hydrochloric acid: the mass concentration is 37%.
Example 1
A method for catalytic depolymerization of lignin to monophenolic compounds comprising the steps of: drying the organic soluble poplar lignin at 60 ℃ overnight, and mixing the organic poplar lignin, an ethanol/isopropanol mixed solvent (the mass ratio of ethanol to isopropanol is 1:1) and Ni10Cu5The mass-volume ratio of the catalyst/C is 10mg:1mL:1mg, 300mg of organic soluble poplar lignin is firstly addedAdding 30mL of ethanol/isopropanol mixed solvent into a high-pressure reaction kettle, and then adding Ni10Cu5catalyst/C30 mg, and 20. mu.L of n-decane added as internal standard; then using N2Purging the autoclave to vent air and pressurizing the reaction vessel to 1MPa N at room temperature2Stirring and reacting at 270 ℃ and 700rpm for 4h, cooling in a water bath to room temperature, and filtering to obtain a filtrate, namely the phenolic compound.
The filtrate was sampled and analyzed and measured by GC-MS and GC-FID, and the results were shown in Effect example 1.
The preparation method of the organic poplar lignin comprises the following steps:
step 1, extracting 600g of poplar biomass by using a mixed solution of ethanol and toluene, and separating lignin; the volume ratio of the ethanol to the toluene in the mixed solution of the ethanol and the toluene is 1: 1.
Step 2, mixing poplar biomass, methanol and concentrated hydrochloric acid according to the mass-to-volume ratio of 1 g: 7.5 mL: 0.02 mL; weighing 600g of poplar biomass, adding 4500mL of methanol and 12mL of concentrated hydrochloric acid into the extracted poplar biomass, then carrying out sealed stirring reaction in a high-pressure reaction kettle at 110 ℃ for 12 days, and filtering to obtain a filtrate;
step 3, according to the mass volume ratio of the poplar biomass to the ice of 6 g: 1cm3Adding 100cm of the filtrate3Precipitating lignin into lignin solid by using an ice block, filtering, collecting the lignin solid, washing with cold water until the pH value of a washing liquid is 7, and drying in vacuum to obtain the organic soluble poplar lignin.
The Ni10Cu5The carrier of the/C catalyst is activated carbon, the loading of Ni is about 10wt%, and the loading of Cu is about 5%.
The Ni10Cu5The preparation method of the/C catalyst comprises the following steps:
according to the proportion of active carbon: ni (NO)3)2·6H2O、Cu(NO3)2·3H2The mass ratio of O to deionized water is 1 g: 0.4955 g: 0.1901 g: 1.6mL, 2.48g of Ni (NO) was added to 8mL of deionized water3)2·6H2O and 0.95g of Cu (NO)3)2·3H2O, stirring for 30min until the metal ions are completely dissolved to obtain a metal ion solution;
then, 5g of activated carbon is weighed, the metal ion solution is slowly dripped on the activated carbon (the dripping operation is completed within 1 hour), then the mixture is stirred for 1 hour until the metal ions are highly dispersed on the activated carbon, and then the mixture is air-dried overnight and dried at 120 ℃ to obtain a catalyst precursor;
placing the catalyst precursor in H2/N2Mixed gas (H) of (2)2The gas flow is 10mL/min, N2Gas flow of 20mL/min) at 450 ℃ for 2h, and cooling to obtain Ni10Cu5catalyst/C (Ni in this example)10Cu5The actual loading of Ni in the/C catalyst was 9.76 wt% and the actual loading of Cu was 4.84%), and was stored in a vacuum desiccator for future use.
Example 2
A method for the catalytic depolymerization of lignin to phenolic compounds comprising the steps of: drying the organic soluble poplar lignin at 60 ℃ overnight, and mixing the organic poplar lignin, an ethanol/isopropanol mixed solvent (the mass ratio of ethanol to isopropanol is 1:1) and Ni10Cu5The mass-volume ratio of the catalyst/C is 10mg:1mL:1mg, 300mg of organic soluble poplar lignin and 30mL of ethanol/isopropanol mixed solvent are firstly added into a high-pressure reaction kettle, and then Ni is added10Cu7catalyst/C30 mg, and 20. mu.L of n-decane added as internal standard; then using N2Purging the high-pressure reaction kettle to discharge air, pressurizing the reaction vessel to 1MPa N2 at room temperature, stirring and reacting at 270 ℃ and 700rpm for 4 hours, cooling in a water bath to room temperature, and filtering to obtain a filtrate, namely the phenol compound.
The filtrate was sampled and analyzed and measured by GC-MS and GC-FID, and the results were shown in Effect example 1.
The preparation method of the organic poplar lignin comprises the following steps: the same as example 1;
the Ni10Cu7The carrier of the/C catalyst is activated carbon, the loading of Ni is about 10wt%, and the loading of Cu is about 7%.
The Ni10Cu7Preparation method of/C catalyst：
According to the proportion of active carbon: ni (NO)3)2·6H2O、Cu(NO3)2·3H2The mass ratio of O to deionized water is 1 g: 0.4955 g: 0.2661 g: 1.6mL), 2.48g of Ni (NO) was added to 8mL of deionized water3)2·6H2O and 1.33g of Cu (NO)3)2·3H2O, stirring for 30min until the metal ions are completely dissolved to obtain a metal ion solution;
then, 5g of activated carbon is weighed, the metal ion solution is slowly dripped on the activated carbon (the dripping operation is completed within 1 hour), then the mixture is stirred for 1 hour until the metal ions are highly dispersed on the activated carbon, and then the mixture is air-dried overnight and dried at 120 ℃ to obtain a catalyst precursor;
placing the catalyst precursor in H2/N2The flow rate of the H2 gas was 10mL/min, N2Gas flow of 20mL/min) at 450 ℃ for 2h, and cooling to obtain Ni10Cu5catalyst/C (Ni in this example)10Cu5In the/C catalyst, the actual loading of Ni was 9.72 wt% and the actual loading of Cu was 6.87%), and then stored in a vacuum desiccator for later use.
Example 3
A method for the catalytic depolymerization of lignin to phenolic compounds comprising the steps of: drying the organic soluble poplar lignin at 60 ℃ overnight, and mixing the organic poplar lignin, an ethanol/isopropanol mixed solvent (the mass ratio of ethanol to isopropanol is 1:1) and Ni10Cu3The mass-volume ratio of the catalyst/C is 10mg:1mL:1mg, 300mg of organic soluble poplar lignin and 30mL of ethanol/isopropanol mixed solvent are firstly added into a high-pressure reaction kettle, and then Ni is added10Cu3catalyst/C30 mg, and 20. mu.L of n-decane added as internal standard; then using N2Purging the autoclave to vent air and pressurizing the reaction vessel to 1MPa N at room temperature2Stirring and reacting at 270 ℃ and 700rpm for 4h, cooling in a water bath to room temperature, and filtering to obtain a filtrate, namely the phenol compound.
The filtrate was sampled and analyzed and measured by GC-MS and GC-FID, and the results were shown in Effect example 1.
The preparation method of the organic poplar lignin comprises the following steps: the same as example 1;
the Ni10Cu3The carrier of the/C catalyst is activated carbon, the loading of Ni is about 10wt%, and the loading of Cu is about 3%.
The Ni10Cu3The preparation method of the/C catalyst comprises the following steps:
according to the proportion of active carbon: ni (NO)3)2·6H2O、Cu(NO3)2·3H2The mass ratio of O to deionized water is 1 g: 0.4955 g: 0.1141 g: 1.6mL, 2.48g of Ni (NO) was added to 8mL of deionized water3)2·6H2O and 0.57g of Cu (NO)3)2·3H2O, stirring for 30min until the metal ions are completely dissolved to obtain a metal ion solution;
then, 5g of activated carbon is weighed, the metal ion solution is slowly dripped on the activated carbon (the dripping operation is completed within 1 hour), then the mixture is stirred for 1 hour until the metal ions are highly dispersed on the activated carbon, and then the mixture is air-dried overnight and dried at 120 ℃ to obtain a catalyst precursor;
placing the catalyst precursor in H2/N2Mixed gas (H) of (2)2The gas flow is 10mL/min, N2Gas flow of 20mL/min) at 450 ℃ for 2h, and cooling to obtain Ni10Cu5catalyst/C (Ni in this example)10Cu5In the/C catalyst, the actual loading of Ni was 9.81 wt% and the actual loading of Cu was 2.79%), and then stored in a vacuum desiccator for further use.
Comparative example 1
The same as example 1, except that: the catalyst used was different from the catalyst used in this comparative example, Ni10Catalyst of/C, said Ni10The carrier of the/C catalyst is activated carbon, and the loading amount of Ni is about 10 wt%.
The comparative sample was analyzed and measured by GC-MS and GC-FID, and the results were shown in Effect example 1.
The Ni10The preparation method of the/C catalyst comprises the following steps:
according to the proportion of active carbon: ni (NO)3)2·6H2The mass ratio of O to deionized water is 1 g: 0.4955 g: 1.6mL, 2.48g of Ni (NO) was added to 8mL of deionized water3)2·6H2O, stirring for 30min until the metal ions are completely dissolved to obtain a metal ion solution;
then, 5g of activated carbon is weighed, the metal ion solution is slowly dripped on the activated carbon (the dripping operation is completed within 1 hour), then the mixture is stirred for 1 hour until the metal ions are highly dispersed on the activated carbon, and then the mixture is air-dried overnight and dried at 120 ℃ to obtain a catalyst precursor;
placing the catalyst precursor in H2/N2Mixed gas (H) of (2)2The gas flow is 10mL/min, N2Gas flow of 20mL/min) at 450 ℃ for 2h, and cooling to obtain Ni10catalyst/C (Ni in this example)10Actual Ni loading in the/C catalyst was 9.72 wt%), and then stored in a vacuum desiccator for later use.
Comparative example 2
The same as example 1, except that: the catalyst used was different from the catalyst used in this comparative example, Cu was used as the catalyst10A catalyst of/C, said Cu10The carrier of the/C catalyst is activated carbon, and the loading amount of Cu is about 10 wt%.
The comparative sample was analyzed and measured by GC-MS and GC-FID, and the results were shown in Effect example 1.
The Cu10The preparation method of the/C catalyst comprises the following steps:
according to the proportion of active carbon: cu (NO)3)2·3H2The mass ratio of O to deionized water is 1 g: 0.3802 g: 1.6mL, 0.95g of Cu (NO) was added to 8mL of deionized water3)2·3H2O, stirring for 30min until the metal ions are completely dissolved to obtain a metal ion solution;
then, 5g of activated carbon is weighed, the metal ion solution is slowly dripped on the activated carbon (the dripping operation is completed within 1 hour), then the mixture is stirred for 1 hour until the metal ions are highly dispersed on the activated carbon, and then the mixture is air-dried overnight and dried at 120 ℃ to obtain a catalyst precursor;
placing the catalyst precursor in H2/N2Mixed gas (H) of (2)2The gas flow is 10mL/min,N2the gas flow of 20mL/min) at 450 ℃ for 2h, and cooling to obtain Cu10catalyst/C (Cu in this example)10Actual Cu loading in the/C catalyst was 9.72 wt%), and then stored in a vacuum desiccator for later use.
Comparative example 3
The same as example 1, except that: the catalyst used was different from the catalyst used in this comparative example, Ni10W5Catalyst of/C, said Ni10W5The carrier of the/C catalyst is active carbon, and the loading amount of Ni is about 10 wt%; the loading of W was about 5 wt%.
The comparative sample was analyzed and measured by GC-MS and GC-FID, and the results were shown in Effect example 1.
The Ni10W5The preparation method of the/C catalyst comprises the following steps:
according to the proportion of active carbon: ni (NO)3)2·6H2The mass ratio of O, ammonium metatungstate to deionized water is 1 g: 0.4955 g: 0.8094 g: 1.6mL, 2.48g of Ni (NO) was added to 8mL of deionized water3)2·6H2Stirring O and 4.05g of ammonium metatungstate for 30min until the O and the ammonium metatungstate are completely dissolved to obtain a metal ion solution;
then, 5g of activated carbon is weighed, the metal ion solution is slowly dripped on the activated carbon (the dripping operation is completed within 1 hour), then the mixture is stirred for 1 hour until the metal ions are highly dispersed on the activated carbon, and then the mixture is air-dried overnight and dried at 120 ℃ to obtain a catalyst precursor;
placing the catalyst precursor in H2/N2Mixed gas (H) of (2)2The gas flow is 10mL/min, N2Gas flow of 20mL/min) at 450 ℃ for 2h, and cooling to obtain Ni10W5catalyst/C (Ni in this example)10W5In the/C catalyst, the actual loading of Ni was 9.65 wt%; actual loading of W was 4.90 wt%), then stored in a vacuum desiccator for use.
Comparative example 4
The same as example 1, except that: no catalyst was used.
The comparative sample was analyzed and measured by GC-MS and GC-FID, and the results were shown in Effect example 1.
Comparative example 5
The same as example 1, except that: the hydrogen donor solvent system adopts not an ethanol/isopropanol mixed solvent but an ethanol single solvent;
the samples of this example were analyzed and measured by GC-MS and GC-FID, and the results are shown in Effect example 1.
Comparative example 6
The same as example 1, except that: the hydrogen donor solvent system adopts an isopropanol single solvent instead of an ethanol/isopropanol mixed solvent;
the samples of this example were analyzed and measured by GC-MS and GC-FID, and the results are shown in Effect example 1.
Comparative example 7
The same as example 1, except that: the adopted lignin is not organic soluble poplar lignin, but alkali lignin;
the alkali lignin was purchased from: shanghai Aladdin Biotechnology Ltd.
The comparative sample is analyzed and determined by GC-MS and GC-FID, and the result shows an effect example.
Comparative example 8
The same as example 1, except that: the adopted lignin is not organic soluble poplar lignin, but Clarsen corn lignin;
the Clarsen corn lignin is purchased from environmental protection materials, Inc. of Yanghai, Jinan.
The comparative sample is analyzed and determined by GC-MS and GC-FID, and the result shows an effect example.
Effect example 1
In order to analytically determine the phenolic compound samples prepared in each example and comparative examples 1-8 by using GC-MS and GC-FID, an internal standard reagent n-decane was added during depolymerization of lignin, and the determination results of each effect example and comparative example are shown in tables 1 and 2:
TABLE 1
Figure BDA0003389811760000081
Note: PG: 2-methoxy-4-propylphenol, PS: 2, 6-dimethoxy-4-propylphenol, PG-OH: 4- (3-hydroxypropyl) -2-methoxyphenol, PS-OH: 4- (3-hydroxypropyl) -2, 6-dimethoxyphenol, others: comprises 4-ethylguaiacol, 2-methoxy-4-methylphenol and 2-methoxy-4-vinylphenol.
TABLE 2
Figure BDA0003389811760000082
Figure BDA0003389811760000091
The following conclusions can be drawn from the data in table 1:
1) no significant monophenol compounds were detected in the hydrogenolysis products of organosolv lignin catalyzed by NiW/C (comparative example 3), and the addition of W to the catalyst may promote the adsorption of ethanol and isopropanol on the surface of the catalyst, thereby preventing the lignin from contacting the catalyst, resulting in many side reactions between ethanol and isopropanol. The Ni110/C (comparative 1), NiCu/C (examples 1-3) and Cu10/C (comparative 2) catalysts significantly improved the yield of depolymerized monomer product compared to the non-catalyzed experiment (comparative 4), and the NiCu/C catalyst showed the best catalytic activity, Ni10Cu5the/C catalyst achieved a yield of 63.4 wt% of phenolic monomer. And Ni10Compared to the/C catalyst, the NiCu/C catalyst has a higher monomer yield due to its higher catalytic activity for the cleavage of lignin bonds with the aid of Cu.
2) The hydrogenolysis bio-oil yield of organosolv wood lignin without catalyst was 67.1 wt% (comparative example 4), while the coke formation on the Ni/C catalyst (comparative example 1) and the NiCu/C catalyst (examples 1-3) was significantly reduced, indicating the positive effect of the catalyst.
3) Examples 1-3 of the present invention the main monomer products obtained from organosolv poplar lignin were 2-methoxy-4-Propylphenol (PG), 2, 6-dimethoxy-4-Propylphenol (PS), 4- (3-hydroxypropyl) -2-methoxyphenol (PG-OH), 4- (3-hydroxypropyl) -2, 6-dimethoxyphenol (PS-OH), and other monomer products also contained 4-ethylguaiacol, 2-methoxy-4-methylphenol and 2-methoxy-4-vinylphenol.
4)、Ni10the/C catalyst showed good activity in lignin depolymerization with total yield of phenol monomers exceeding 50 wt%. When Cu is introduced, the NiCu/C catalyst exhibits a specific Ni10/C catalyst is more reactive. For the NiCu/C catalyst, as the Cu addition increases, the monomer yield first increases and then decreases. And Ni10Cu5the/C catalyst showed the best catalytic performance and achieved a total phenolic monomer yield of 63.4 wt%, with a suitable Cu content of 3-7wt% and the best Cu addition of 5 wt%. While when the loading of Cu in the catalyst increases, the yield of phenolic monomers decreases, probably because of the formation of massive Cu particles on the NiCu/C catalyst, which block the mesopores of the catalyst and inhibit the access of lignin to the active sites of the catalyst.
5) When alkali lignin was used as the substrate (comparative example 7), in Ni10Cu5No significant depolymerization occurred with the/C catalysis. This may be attributed to the fact that the hydrogen donating ability of the ethanol/isopropanol mixed solvent is greatly affected by the alkaline environment, since the PH of the alkali lignin is about 10 and the side reactions between ethanol and isopropanol inhibit the hydrogenolysis of lignin. When Clarsen corn lignin is used as the substrate (comparative example 8), in Ni10Cu5The yield of phenolic monomers was 23.3 wt.% under the catalysis of/C.
In conclusion, it can be obtained that: the ethanol/isopropanol mixed solvent, the NiCu/C catalyst and the lignin can act synergistically to promote the lignin depolymerization reaction, so that the yield of the phenolic monomer compound is obviously improved, and the optimal effect cannot be obtained by the lack of the ethanol/isopropanol mixed solvent, the NiCu/C catalyst and the lignin.
Effect example 2: ni10Cu5Cyclic stability test of the/C catalyst
Pressing to realThe method described in example 1, continuous use of Ni10Cu5The catalyst/C was used for three times the depolymerization of lignin by hydrogenation, and the total yield of phenolic compounds obtained each time was determined, the results are shown in Table 3
TABLE 3
Number of catalytic cycles Bio-oil yield (wt%) Total yield (wt%) of phenol compounds
1 st time 77.2 63.4
2 nd time 74.5 60.5
3 rd time 75.8 61.8
From the data in table 3 it can be found that: in depolymerizing the organosolv poplar lignin, Ni10Cu5The second use and the third use of the/C catalyst, the bio-oil yield is always kept above 70 wt%, the yield of depolymerized monomer products is always kept about 60 wt%, and no significant reduction phenomenon is found in the bio-oil yield and the monomer product yield, so that the Ni prepared by the method is used for preparing the Ni-based catalyst10Cu5the/C catalyst can be reused at least 3 times in succession.
The embodiments described above are only preferred embodiments of the invention and are not exhaustive of the possible implementations of the invention. Any obvious modifications to the above would be obvious to those of ordinary skill in the art, but would not bring the invention so modified beyond the spirit and scope of the present invention.

Claims (10)

1. A method for catalyzing and depolymerizing lignin into phenol compounds is characterized in that,
using ethanol/isopropanol mixed solvent as hydrogen supply solvent system, using NiCu/C as catalyst, and adding N2In the environment, lignin is subjected to catalytic hydrogenation depolymerization reaction to generate phenol compounds.
2. The method of claim 1, wherein the lignin is depolymerized to phenolic compounds,
the mass ratio of ethanol to isopropanol in the ethanol/isopropanol mixed solvent is 1: 1.
3. The method of claim 1, wherein the lignin is depolymerized to phenolic compounds,
in the NiCu/C catalyst, C is a carrier and adopts activated carbon; ni is an active component; cu is taken as an auxiliary agent; wherein, the content of Ni is 9-11wt%, and the content of Cu is 3-7 wt%.
4. The method of claim 3, wherein the step of depolymerizing lignin to phenol compounds is carried out by a catalyst,
the preparation method of the NiCu/C catalyst comprises the following steps:
according to activated carbon, Ni (NO)3）2·6H2O、Cu（NO3）2·3H2And the mass volume ratio of O to deionized water is 1 g: 0.4955 g: 0.1141-0.2661 g: 1.6mL, adding Ni (NO) to deionized water3）2•6H2O and Cu (NO)3）2•3H2O, stirring for 30min until the metal ions are completely dissolved to obtain a metal ion solution;
slowly dripping the metal ion solution on the activated carbon, stirring until the metal ions are highly dispersed on the activated carbon, air-drying overnight, and drying at 120 ℃ to obtain a catalyst precursor;
placing the catalyst precursor in H2/N2Reducing the mixed gas at 450 ℃ for 2h, and cooling to obtain the NiCu/C catalyst.
5. The method of claim 1, wherein the lignin is depolymerized to phenolic compounds,
the lignin is organic soluble poplar lignin.
6. The method of claim 5, wherein the lignin is depolymerized to phenolic compounds,
the preparation method of the organic soluble poplar lignin comprises the following steps:
step 1, extracting poplar biomass by using a mixed solution of ethanol and toluene, and separating lignin;
step 2, mixing poplar biomass, methanol and hydrochloric acid according to the mass-volume ratio of 1 g: 7.5 mL: 0.02mL, adding methanol and concentrated hydrochloric acid into the extracted poplar biomass, then carrying out sealed stirring reaction in a high-pressure reaction kettle at 110 ℃ for 12 days, and filtering to obtain a filtrate;
step 3, according to the mass volume ratio of the poplar biomass to the ice of 6 g: 1cm3Adding ice blocks into the filtrate to precipitate lignin into lignin solid, then filtering, collecting the lignin solid, then washing with cold water until the pH value of the washing liquor is 7, and carrying out vacuum drying to obtain the organic soluble poplar lignin.
7. The method of claim 1, wherein the lignin is depolymerized to phenolic compounds,
the reaction temperature of the catalytic depolymerization reaction is as follows: 210-290 ℃; n is a radical of2The pressure of (A) is 1-10 MPa; stirring operation is carried out in the reaction process, and the reaction time is 2-8 h.
8. The method of claim 1, wherein the lignin is depolymerized to phenolic compounds,
when the catalytic hydrogenation depolymerization reaction is carried out, the mass volume ratio of the lignin to the ethanol/isopropanol mixed solvent is 10mg:1 mL;
the mass ratio of the lignin to the catalyst is 10: 1.
9. The method of claim 1, wherein the lignin is depolymerized to phenolic compounds,
the lignin was dried overnight at 60 ℃ before use.
10. The method of claim 1, wherein the phenolic compound comprises one or more of 2-methoxy-4-propylphenol, 2, 6-dimethoxy-4-propylphenol, 4- (3-hydroxypropyl) -2-methoxyphenol, 4- (3-hydroxypropyl) -2, 6-dimethoxyphenol, 4-ethylguaiacol, 2-methoxy-4-methylphenol, and 2-methoxy-4-vinylphenol.
CN202111460783.8A 2021-12-03 2021-12-03 Method for catalytic depolymerization of lignin into phenol compound Pending CN114213222A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111460783.8A CN114213222A (en) 2021-12-03 2021-12-03 Method for catalytic depolymerization of lignin into phenol compound

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111460783.8A CN114213222A (en) 2021-12-03 2021-12-03 Method for catalytic depolymerization of lignin into phenol compound

Publications (1)

Publication Number Publication Date
CN114213222A true CN114213222A (en) 2022-03-22

Family

ID=80699453

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111460783.8A Pending CN114213222A (en) 2021-12-03 2021-12-03 Method for catalytic depolymerization of lignin into phenol compound

Country Status (1)

Country Link
CN (1) CN114213222A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112844379A (en) * 2020-12-31 2021-05-28 华南理工大学 Method for preparing monophenol chemicals by catalyzing lignin depolymerization through ruthenium loaded on metal organic framework material derivative

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112844379A (en) * 2020-12-31 2021-05-28 华南理工大学 Method for preparing monophenol chemicals by catalyzing lignin depolymerization through ruthenium loaded on metal organic framework material derivative

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
CHONGBO CHENG等: "Catalytic hydrogenolysis of lignin in ethanol/isopropanol over an activated carbon supported nickel-copper catalyst", 《BIORESOURCE TECHNOLOGY》, no. 319, pages 1 - 8 *

Similar Documents

Publication Publication Date Title
CN101116816B (en) Method for preparing load type rhodium catalyst for making high-carbon aldehyde using hydroformylation of higher olefins
CN110743544B (en) Palladium-carbon catalyst for preparing alpha-phenylethyl alcohol by selective hydrogenation of acetophenone and preparation method and application thereof
CN108048125B (en) Method for preparing aromatic hydrocarbon by high-selectivity catalytic transfer hydrogenation of lignin derivatives
CN103508857A (en) Method for depolymerizing lignin into aromatic compounds under conditions of no additional hydrogen
CN113117688A (en) MOF precursor molybdenum-nickel catalyst, preparation method thereof and application thereof in lignin degradation
CN108218673B (en) Method for catalyzing selective depolymerization of lignin by non-noble metal
CN112973718B (en) Kerosene co-hydrogenation catalyst and preparation method thereof
CN112521353B (en) Method for preparing 2, 5-dimethylfuran by catalytic hydrogenation of 5-hydroxymethylfurfural
CN104388110B (en) Method for preparing chain alkane from lignin
CN109701654A (en) A kind of method of Non-precious Metal Catalysts lignin selection depolymerization
CN113522333A (en) Preparation method and application of carbon-nitrogen co-doped iron-cobalt-based catalyst
CN114272932B (en) Nickel-cerium biochar catalyst and preparation method and application thereof
WO2019062286A1 (en) Lignin depolymerization method
CN111138248A (en) Application of recyclable palladium-based catalyst in lignin hydrogenation degradation
CN113856718A (en) Preparation method of molybdenum carbide hydrogenolysis lignin catalyst
CN103483597A (en) Method for modifying enzymatic hydrolysis lignin by alkali activation
CN113880888A (en) Method for efficiently catalyzing, transferring and hydro-depolymerizing lignin under mild conditions
CN111215090A (en) Application of oxygen-rich vacancy tungsten oxide supported catalyst in lignin depolymerization
CN114213222A (en) Method for catalytic depolymerization of lignin into phenol compound
KR20120094555A (en) Novel metal catalyst supported on activated carbon aerogel, production method thereof and decomposition method of lignin compound using said catalyst
CN110129084B (en) Biomass hydrogen supply-catalytic liquefaction coupling method and supported biomass liquefaction catalyst
CN109535108B (en) Preparation method of 2, 5-dimethylfuran
CN111545202A (en) Cheap metal catalyst for lignin oligomer hydrogenation depolymerization synchronous quality improvement and preparation method and application thereof
CN113908856B (en) Method for preparing sulfur-doped bimetallic catalyst by using MOF as carrier and application
CN112295571B (en) PtNi cage catalyst and application thereof in furfuryl alcohol preparation by catalyzing selective hydrogenation of furfural

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination