Method for catalytically depolymerizing lignin derivative and lignin depolymerized oil

Abstract

The invention discloses a method for catalytically depolymerizing a lignin derivative and lignin depolymerized oil. The invention relates to a method for preparing lignin depolymerized oil rich in 1, 2-diphenylethyl structure bisphenol and lignin oligomer by a lignin derivative containing a 1, 1-diphenylmethyl structure under the synergistic catalysis of a transition metal catalyst, a hydrogen donor and an acid catalyst in a liquid medium. Directional depolymerization of lignin is realized by catalyzing aryl migration reaction of a 1, 1-benzhydryl structure, and different from traditional reaction taking lignin monophenol as a target product, one-step directional preparation of a bisphenol product and co-production of a lignin oligomer can be realized. According to the method disclosed by the invention, the product type of lignin-based bisphenol is expanded, and the application of catalytic depolymerization of lignin to preparation of high-value chemicals, fuels and polymer materials is promoted.

Description

Technical Field

[0001] The invention relates to a method for catalytically depolymerizing lignin derivatives and lignin depolymerized oil, in particular to lignin derivatives with a 1,1-diphenylmethyl structure, and to a technology for catalytically depolymerizing lignin with a transition metal catalyst and high-value utilization of biomass. Background Art

[0002] Lignin is a natural aromatic polymer with great application potential. It is an important potential raw material for the preparation of green aromatic chemicals due to its wide source and low price. Lignin is mainly composed of structural units such as p-hydroxyphenyl, guaiacyl, and syringyl. Although the connection forms between the structural units are diverse, the main connection is C-O bonds such as β-O-4 aromatic ether bonds. By catalytically breaking the C-O bonds of lignin, lignin can be depolymerized into monophenolic compounds such as phenol, guaiacol, propyl guaiacol, syringol, propyl syringol, vanillin, syringaldehyde, etc. There is no direct utilization route for lignin monophenols. After subsequent catalytic refining processes, it can be converted into high-value-added pharmaceutical intermediates, lignin fuels, etc.

[0003] Bisphenol A (BPA) and other bisphenol polymerization monomers are the main forms of petrochemical-based phenols, which are mainly prepared by the condensation reaction of two molecules of phenol and one molecule of acetone. At present, lignin monophenols can also be cross-linked with formaldehyde or condensed between monophenols to prepare lignin-based bisphenols (US11414519B2; Green Chem., 2018, 20, 1050-1058; Green Chem., 2019, 21, 6622-6633). This type of lignin-based bisphenol can meet the synthesis requirements of thermoplastic polymers and thermosetting polymers, and at the same time, compared with petrochemical-based BPA, the endocrine disrupting toxicity is significantly reduced. It can be considered that lignin-based bisphenols are expected to become an important structural monomer for the synthesis of green renewable polymer materials.

[0004] At present, lignin bisphenols are difficult to prepare directly by catalytic depolymerization of lignin. Taking natural lignin as an example, the content of β-O-4 aromatic ether bonds between its structural units is higher than 50%, while the relative content of β-β, β-5, β-5 and other C-C bonds between structural units is low and the reaction activity is poor (Nat. Chem., 2021, 13, 1118-1125). Therefore, after catalytic depolymerization of natural lignin, the yield of bisphenol is low (less than 5%), and the product structure is complex, which makes it difficult to produce practical utilization value. Taking industrial lignin as an example, during the chemical treatment process, random condensation and cross-linking reactions are prone to occur between and within lignin molecular chains, forming a large number of low-activity C-C bond connections. Therefore, after catalytic depolymerization of industrial lignin, the C-C bonds generated by lignin self-condensation are difficult to break, and the products are mainly oligomers, which makes it difficult to generate monophenol or bisphenol products (CN202111477348.6). Summary of the invention

[0005] The purpose of the present invention is to break through the limitation that the existing lignin depolymerization products are mainly monophenol compounds, and to provide a technical route for preparing lignin bisphenols by catalytic depolymerization of lignin derivatives with a 1,1-diphenylmethyl structure.

[0006] The specific technical scheme of the present invention is: a lignin derivative having a 1,1-diphenylmethyl structure, a transition metal catalyst, a liquid solvent, an acid catalyst and a hydrogen donor are added to a high-temperature and high-pressure reactor in a certain proportion. After the reactor is sealed, the temperature is raised to the reaction temperature under the condition of uniform stirring at 600 rpm, and after the reaction temperature is reached and the reaction is carried out for a certain time, the reactor is cooled, and the reaction mixture is filtered, concentrated by vacuum distillation, and extracted to obtain lignin depolymerized oil rich in lignin bisphenol and oligomers.

[0007] In the present invention, the lignin derivative with a 1,1-diphenylmethyl structure is prepared by directing the substitution of phenol and its derivatives for the benzyl hydroxyl group of the β-O-4 aromatic ether bond structure in the lignin raw material; the aromatic ring of the arylating agent contains 0, 1 or 2 substituents in addition to the hydroxyl group, and the substituent is any one of methyl, ethyl, propyl, isopropyl, methoxy, phenoxy, and phenolic hydroxyl groups or a mixture of two or more thereof, and the preferred arylating agent is phenol, p-cresol, guaiacol, and syringol.

[0008] In the present invention, the preparation process of the lignin derivative having a 1,1-diphenylmethyl structure is as follows:

[0009] 40g of lignocellulose, 16g-32g of arylation agent, and 400mL of 88wt% organic acid aqueous solution were weighed and added into a reactor; after the reactor was sealed, the temperature was raised to 100°C with stirring and the reaction was carried out for 120min; after cooling, the reaction mixture was filtered, the filtrate was collected and concentrated, and the concentrate was mixed with a reverse solvent (water or ethanol aqueous solution, the volume fraction of ethanol in the reverse solvent was 0%-20%) to perform reverse solvent precipitation of arylation lignin, and the arylation lignin was filtered and dried to obtain arylation lignin powder; the lignocellulose was any one of poplar, birch, pine, bamboo, crop straw, and reed, or a mixture of two or more thereof; the arylation agent was any one of phenol, p-cresol, guaiacol, and eugenol, or a mixture of two or more thereof; the organic acid was any one of formic acid, acetic acid, maleic acid, oxalic acid, and p-toluenesulfonic acid, or a mixture of two or more thereof.

[0010] In the present invention, the lignin solvent system is any one of methanol, ethanol, propanol, butanol, isopropanol, dioxane, tetrahydrofuran and water, or a mixture of two or more thereof. The preferred lignin solvent is a methanol / water mixture with a volume ratio of 4:1 to 1:4, and a more preferred volume ratio of 3:1 to 1:1. The mass of the liquid medium is 5-500 times the mass of the lignin derivative, the preferred addition amount is 10-100 times the mass of the lignin derivative, and the more preferred addition amount is 20-50 times the mass of the lignin derivative.

[0011] In the present invention, the acid catalyst of the lignin solvent system is any one of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, p-hydroxybenzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, phosphotungstic acid, phosphomolybdic acid, trifluoroacetic acid, zinc chloride, ferric chloride, cupric chloride, aluminum chloride and lithium chloride, or a mixture of two or more thereof, and the concentration of the acid catalyst is 0.5-20 g / L, and the preferred acid catalyst is any one of sulfuric acid, p-toluenesulfonic acid and methanesulfonic acid, or a mixture of two or more thereof, and the preferred acid concentration is 1-10 g / L, and the more preferred acid concentration is 2-5 g / L.

[0012] In the present invention, the transition metal selected from the transition metal catalyst is any one of palladium, platinum, ruthenium, nickel, rhodium and iridium, or a mixture of two or more thereof, and the preferred transition metals are palladium and platinum; the carrier selected from the transition metal catalyst is any one of activated carbon, aluminum oxide, silicon dioxide, titanium dioxide, zirconium oxide, cerium oxide, molybdenum oxide, molybdenum sulfide, tungsten oxide, hydrotalcite, hydroxyapatite and molecular sieve (H-ZSM-5) or a mixture of two or more thereof, and the preferred catalyst carrier is activated carbon, titanium dioxide, molybdenum oxide and molybdenum sulfide; the loading amount of the transition metal on the carrier is 0.1-15wt%, the preferred loading range is 0.5-10wt%, and the more preferred loading range is 2-5wt%; the addition amount of the transition metal catalyst is 2-200wt% of the weight of the lignin, the preferred addition amount of the transition metal catalyst is 10-80wt%, and the more preferred addition amount of the transition metal catalyst is 20-50wt%.

[0013] In the present invention, the hydrogen donor for the catalytic reduction depolymerization is any one of formic acid, methanol, ethanol, isopropanol, glucose, xylose, ethylene glycol, propylene glycol, and hydrogen, or a mixture of two or more thereof. The preferred hydrogen donors are formic acid, isopropanol, and hydrogen. The preferred formic acid addition amount (based on the mass of lignin) is 50-400wt%, the preferred propanol addition amount (based on the mass of lignin) is 100-500wt%, and the preferred hydrogen pressure is 0.2-5MPa; the more preferred formic acid addition amount (based on the mass of lignin) is 100-300wt%.

[0014] In the present invention, the catalytic depolymerization reaction conditions of the lignin derivative are reaction temperature of 120-300°C and reaction time of 0.2-48.0h; the optimal reaction temperature is 160-260°C and the optimal reaction time is 0.5-24h; the more optimal reaction temperature is 180-240°C and the more optimal reaction time is 1-12h.

[0015] The lignin depolymerization oil after catalytic depolymerization is prepared by filtering the reaction mixture after the reaction, distilling under reduced pressure and separating by liquid-liquid extraction.

[0016] In the present invention, after the catalytic depolymerization is completed and the reactor is cooled to room temperature, the reaction mixture is filtered through filter paper to remove the transition metal catalyst, the volatile solvent in the filtrate is removed by reduced pressure rotary evaporation, and the filtrate is concentrated and subjected to liquid-liquid extraction (dichloromethane: water, 1:1, v / v) for 3 times, the dichloromethane phase is passed through anhydrous sodium sulfate to remove residual water, and the organic solvent is removed by reduced pressure rotary evaporation to prepare bisphenol-rich lignin depolymerization oil.

[0017] The method involves a lignin derivative containing a 1,1-diphenylmethyl structure, and utilizes the synergistic catalytic effect of a transition metal catalyst and an acid catalyst in a liquid medium to selectively prepare a lignin-based bisphenol compound having a 1,2-diphenylethyl structure. The method achieves directional depolymerization of lignin by catalyzing the aromatic migration reaction of the 1,1-diphenylmethyl structure, which is different from the traditional reaction with lignin monophenol as the target product, and can achieve directional preparation of bisphenol products in one step, while co-producing lignin oligomers, effectively promoting the high-value utilization of lignin.

[0018] The method involved in the present invention expands the product types of lignin-based bisphenols and promotes the application of catalytic depolymerization of lignin to prepare high-value chemicals, fuels and polymer materials.

[0019] Mechanism of the present invention:

[0020] Compared with natural lignin (lignin containing a large amount of benzyl hydroxyl groups), the lignin involved in the present invention (lignin benzyl hydroxyl groups are arylated and replaced by phenol or phenol derivatives to generate 1,1-diphenylmethyl structures) has a greatly reduced activity during the catalytic cleavage reaction of β-O-4 aromatic ether bonds. Therefore, lignin with a 1,1-diphenylmethyl structure (such as industrial lignin with a self-condensation structure) is usually difficult to achieve high-value catalytic conversion. The present invention utilizes the synergistic effect of acid catalysis and hydrogenation catalysts to achieve the directional catalytic conversion of the 1,1-diphenylmethyl structure in lignin, and highly selectively prepares lignin bisphenol products while co-producing lignin oligomers. In this process, the acidic additive first catalyzes the 1,2-aryl migration of the lignin aromatic group, and breaks the β-O-4 aromatic ether connected to the 1,1-diphenylmethyl structure to generate a stilbene structure intermediate. Since the stilbene structure intermediate is unstable under high temperature and acidic conditions and is prone to double bond coupling reaction, the present invention uses a hydrogenation catalyst to reduce the stilbene structure to stable 1,2-diphenylethyl bisphenol, thereby improving the selectivity and yield of the bisphenol product. The benzyl carbon in the lignin structural unit involved in the present invention has undergone an arylation reaction, and the benzyl hydroxyl content is greatly reduced. Therefore, the monophenol yield in the catalytic depolymerization process is significantly lower than the monophenol yield in the traditional catalytic reduction depolymerization process of natural lignin. The structural units of the arylated lignin involved in the invention contain a small amount of β-β, β-5, β-5 and other C-C bonds. Under the catalytic depolymerization conditions involved in the present invention, the related chemical bonds are relatively stable and do not break, so lignin oligomers rich in C-C bonds can be co-produced. The present invention involves the coordinated depolymerization of arylated lignin by an acidic additive and a transition metal catalyst to achieve the selective preparation of lignin bisphenol products and the co-production of lignin oligomers.

[0021] Compared with the prior art, the present invention has the following innovations and beneficial effects:

[0022] 1. Based on the 1,1-diphenylmethyl structural characteristics of arylated lignin, the present invention designs acid-catalyzed and hydrogenation-catalyzed directional depolymerization pathways, develops a one-pot aromatic migration and stilbene reduction two-step tandem reaction, and prepares bisphenol with a 1,2-diphenylethyl structure. The catalytic conversion route and the 1,2-diphenylethyl bisphenol product are original.

[0023] 2. The present invention realizes the synergistic catalytic depolymerization of arylated lignin by an acidic auxiliary agent and a transition metal catalyst, and the yield of lignin-based bisphenol products is significantly higher than that reported previously. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Aromatization of lignin with phenol, guaiacol, syringol and p-cresol 1 H– 13 C HSQC NMR spectrum;

[0025] Figure 2Gas chromatogram of catalytic depolymerization of syringol to arylate lignin to produce monophenols and bisphenols;

[0026] Figure 3 Catalytic depolymerization of syringol to arylate lignin to produce four major bisphenols 1 H– 13 C HSQC NMR spectrum;

[0027] Figure 4 The oligomer components in the lignin depolymerization oil 1 H– 13 C HSQC NMR spectrum;

[0028] Figure 5 Gas chromatogram of catalytic decomposition of polyphenol arylation to produce monophenol and bisphenol;

[0029] Figure 6 Catalytic decomposition of polyphenols to arylate lignin to produce two main bisphenols 1 H– 13 C HSQC NMR spectrum. DETAILED DESCRIPTION

[0030] In order to further elaborate and illustrate the present invention, several specific implementation cases are listed below, but the present invention is not limited to the following embodiments.

[0031] In the following examples, Pd / C (5% and 10% loading), Pt / C catalyst (5% and 10% loading), and Ru / C (5% loading) were purchased from Aladdin Biotech;

[0032] Pd / ZrO2 (1% loading), Pd / WO3 (1% loading), Pd / MoO3 (1% loading), Pd / TiO2 (2% loading), Pd / HZSM-5 (2% loading), Pt / TiO2 (2% loading) were prepared by impregnation method. Taking Pd / TiO2 (2% loading) as an example, 1g TiO2 (P25) was dispersed in 20mL of hydrochloric acid aqueous solution dissolved with PdCl2 (palladium chloride) (pH = 1, PdCl2 concentration of 9.6mmol / L, calculated based on 2% Pd mass loading in the catalyst), stirred at room temperature for 12 hours, heated to 110°C and evaporated to dryness, and the obtained solid was reduced with hydrogen at 300°C for 4 hours to obtain the catalyst Pd / TiO2 (2% loading). The preparation process of the remaining catalysts is the same as above, except that different PdCl2 concentrations (e.g., 4.8 mmol / L) and / or different carriers are used, or HPtCl6 is used instead of PdCl2;

[0033] The lignin derivatives (rich in 1,1-diphenylmethyl structure) in the following examples are prepared by directing the substitution of phenol and its derivatives for the benzyl hydroxyl groups of the β-O-4 aryl ether bond structure in the lignin raw materials to prepare the corresponding arylated lignin. Figure 1 It can be proved that in the chemical structure of the arylated lignin prepared by the following method, the β-O-4 aromatic ether bond signal containing benzyl hydroxyl group originally present in natural lignin basically disappears, and is replaced by an aromatic ether bond signal with a 1,1-diphenylmethyl structure generated by replacing the benzyl hydroxyl group with an aromatic group.

[0034] The extraction conditions of phenol aryl lignin are as follows: 40g birch powder (20-80 mesh), 32g phenol, 400mL 88wt% formic acid aqueous solution are weighed and added to a high-temperature reactor. After the reactor is sealed, it is stirred at a constant speed of 500 rpm, heated to 100°C, and reacted for 120min. After the reactor is cooled to room temperature, the reaction mixture is filtered through filter paper, the filtrate is collected and concentrated to 150mL by rotary evaporation, and the concentrated solution is dropped into 1000mL water, and the aryl lignin is precipitated. After the aryl lignin is filtered through filter paper, it is dried in an oven at 60°C to collect the phenol aryl lignin powder.

[0035] The extraction conditions of p-cresol arylated lignin are as follows: 40g bamboo powder (4-40 mesh), 32g p-cresol, 400mL 88wt% formic acid aqueous solution are weighed and added to a high-temperature reactor. After the reactor is sealed, it is stirred at a constant speed of 500 rpm, heated to 120°C, and reacted for 40 minutes. After the reactor is cooled to room temperature, the reaction mixture is filtered through filter paper, the filtrate is collected and concentrated to 150mL by rotary evaporation, and the concentrated solution is dripped into 1000mL of reverse solvent (water / ethanol, 9:1, v / v), and the arylated lignin is precipitated. After the arylated lignin is filtered through filter paper, it is dried in an oven at 60°C, and the p-cresol arylated lignin powder is collected.

[0036] The extraction conditions of guaiacol aryl lignin are as follows: 40g poplar wood (4-40 mesh), 32g guaiacol, 400mL 88wt% formic acid aqueous solution are weighed and added to a high-temperature reactor. After the reactor is sealed, it is stirred at a constant speed of 500 rpm, heated to 120°C, and reacted for 40 minutes. After the reactor is cooled to room temperature, the reaction mixture is filtered through filter paper, and the filtrate is collected and concentrated to ~150mL by rotary evaporation. The concentrated solution is dripped into 1000mL of reverse solvent (water / ethanol, 9:1, v / v), and the aryl lignin is precipitated. After the aryl lignin is filtered through filter paper, it is dried in an oven at 60°C, and the guaiacol aryl lignin powder is collected.

[0037] The preparation conditions of eugenol arylated lignin are as follows: 40g of poplar wood (20-80 mesh), 16g of eugenol, and 400mL of 88wt% formic acid aqueous solution are weighed and added to a high-temperature reactor. After the reactor is sealed, it is stirred at a constant speed of 500 rpm, heated to 120°C, and reacted for 30 minutes. After the reactor is cooled to room temperature, the reaction mixture is filtered through filter paper, and the filtrate is collected and concentrated to ~150mL by rotary evaporation. The concentrated solution is dripped into 1000mL of water, and the arylated lignin is precipitated. After the arylated lignin is filtered through filter paper, it is dried in an oven at 60°C, and the eugenol arylated lignin powder is collected.

[0038] The extraction conditions of kraft lignin are as follows: the raw material is poplar wood powder (4-40 mesh), the solution is an aqueous solution containing a final concentration of 10wt% NaOH and 3wt% Na2S, the material-liquid mass ratio is 4:1, the cooking temperature is 160℃, and the cooking time is 3h.

[0039] The extraction conditions of enzymatic lignin are as follows: after the poplar wood powder (4-40 mesh) is treated with a planetary ball mill (ball-to-material ratio of 50:1, rotation speed of 460rpm) for 24h, it is treated with commercial cellulase (CTec 3, 50FPU / g wood powder) in an acetic acid / sodium acetate buffer solution (20mL / g wood powder) at pH = 4.8 for 48h, the enzymatic hydrolysis temperature is 50℃, and the shaking rate is 100rpm. After the undissolved residue is collected by filtration, it is purified with a 90wt% acetic acid solution (20mL / g residue) at room temperature, and the obtained lignin is precipitated in water (the volume is 10 times the volume of the purified acetic acid solution).

[0040] Example 1

[0041] Weigh 1g of syringol arylated lignin, 0.5g of Pd / C (Pd in ​​Pd / C is 5wt% loading, the same below), 50g of methanol: water (7:3, v / v) mixed solution (containing 1g / L p-toluenesulfonic acid) and 200wt% (added amount, based on lignin mass) of formic acid, and add them into a high temperature and high pressure reactor. After the reactor is sealed, argon gas is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 24h. After the reactor was cooled (to room temperature, the same below), the reaction mixture was filtered through filter paper, the filtrate was concentrated by rotary evaporation under reduced pressure (~40°C), and then extracted three times using a 250mL separatory funnel (extraction agent, dichloromethane: water, 1:1, v / v, each time with 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the organic solvent in the dichloromethane phase was removed by rotary evaporation under reduced pressure (~40°C) to prepare bisphenol-rich lignin depolymerization oil.

[0042] The yields of monophenols (mainly including phenol, guaiacol, 4-alkylguaiacol, syringol, 4-alkylsyringol, etc., wherein the carbon number of the alkyl group is not higher than 3) and bisphenols (mainly including 3-(4-hydroxy-3-methoxyphenethyl)-2,6-dimethoxyphenol, 4-(4-hydroxy-3-methoxyphenethyl)-2,6-dimethoxyphenol, 3-(4-hydroxy-3,5-dimethoxyphenethyl)-2,6-dimethoxyphenol, 3-(4-hydroxy-3,5-dimethoxyphenethyl)-2,6-dimethoxyphenol, 4-(4-hydroxy-3,5-dimethoxyphenethyl)-2,6-dimethoxyphenol, etc.) in the lignin depolymerization oil were quantitatively analyzed by Agilent 7890A gas chromatograph. The gas chromatogram is shown in FIG. Figure 2 The yield of lignin depolymerization oil is the percentage of lignin depolymerization oil mass to the mass of aromatic lignin (raw material). The yield of lignin oligomers (mainly oligomeric lignin products with a molecular weight of ~400–900 g / mol, with the aromatic units of lignin oligomers mainly connected by C–C bonds) is calculated by the difference method, which is equal to the yield of lignin depolymerization oil minus the total yield of monophenols and bisphenols.

[0043] Example 2

[0044] 1g of syringol arylated lignin, 0.5g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 2g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 180°C and the reaction was carried out for 12h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0045] The lignin depolymerized oil samples were separated by preparative chromatography (the stationary phase was 200–300 mesh silica gel, and the eluent was a mixture of ethyl acetate and petroleum ether in a volume ratio of 1:4). The 2D NMR spectra of the four main bisphenols are shown in Figure 2. Figure 3 As shown, the results show that lignin bisphenol has a 1,2-diphenylethyl bridge structure. BP2 bisphenol crystals and terephthaloyl chloride can be synthesized into polyarylate plastics according to the method described in the literature (Green Chem., 2018, 20, 1050-1058). The weight average molecular weight of the polymer is about 30 kg / mol, and it has good thermal stability (T d5％ 390℃, Tdmax is 425°C).

[0046] The lignin depolymerized oil sample was extracted by solvent reflux to separate the monophenol and bisphenol components from the lignin oligomer components. The solvent reflux extraction used a Soxhlet extraction apparatus, the solvent was n-hexane, and the reflux temperature was 100°C. The 2D NMR spectrum of the lignin oligomer component is shown in Figure 4 As shown, the results show that the aromatic structural units in the lignin oligomer component are mainly linked by C-C bonds, and the chemical structure has good rigidity. Epoxy resins with rigid skeleton structures can be prepared by epoxidation reaction.

[0047] Example 3

[0048] Weigh 1g of syringol arylated lignin, 0.5g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 5g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 6h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0049] Example 4

[0050] Weigh 1g of syringol arylated lignin, 0.5g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 8g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 4h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by vacuum rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by vacuum rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0051] Example 5

[0052] 1g of syringol arylated lignin, 0.5g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 10g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 200℃ and the reaction was carried out for 4h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by vacuum rotary evaporation (~40℃), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by vacuum rotary evaporation (~40℃) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0053] Example 6

[0054] 1g of syringol arylated lignin, 0.5g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 10g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 160°C and reacted for 24h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0055] Example 7

[0056] 2g of p-cresol aromatized lignin, 1g of Pd / ZrO2 (Pd in ​​Pd / ZrO2 is 1wt% loading), 50g of methanol: water (2:1, v / v) mixed solution (containing 5g / L p-toluenesulfonic acid) and 200wt% (added amount, based on lignin mass) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 200℃ and the reaction was carried out for 4h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by reduced pressure rotary evaporation (~40℃), and then extracted 3 times with a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by reduced pressure rotary evaporation (~40℃) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0057] Example 8

[0058] Weigh 2g of p-cresol aromatized lignin, 1g of Pd / WO3 (1wt% loading), 50g of methanol: water (2:1, v / v) mixed solution (containing 10g / L hydrochloric acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high-temperature and high-pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 220°C and the reaction is carried out for 8h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0059] Example 9

[0060] 1g of phenol arylated lignin, 0.5g of Pd / MoO3 (Pd in ​​Pd / MoO3 is 1wt% loading), 50g of methanol: water (2:1, v / v) mixed solution (containing 10g / L phosphoric acid) and 200wt% (added amount, based on lignin mass) of formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 240℃ and reacted for 2h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by reduced pressure rotary evaporation (~40℃), and then extracted 3 times with a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by reduced pressure rotary evaporation (~40℃) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0061] Example 10

[0062] Weigh 1g of phenol arylated lignin, 0.5g of Pd / TiO2 (2wt% loading), 50g of methanol: water (2:1, v / v) mixed solution (containing 5g / L sulfuric acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 4h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0063] Embodiment 11

[0064] 1g of phenol arylated lignin, 0.5g of Pd / H-ZSM-5 (Pd in ​​Pd / H-ZSM-5 is 2wt% loading), 50g of methanol: water (2:1, v / v) mixed solution (containing 1g / L hydrochloric acid) and 200wt% (added amount, based on lignin mass) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 240℃ and the reaction was carried out for 4h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by vacuum rotary evaporation (~40℃), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by vacuum rotary evaporation (~40℃) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0065] Example 12

[0066] Weigh 1g of phenol arylated lignin, 0.5g of Ru / C (5wt% loading), 50g of methanol: water (2:1, v / v) mixed solution (containing 10g / L hydrochloric acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 220°C and the reaction is carried out for 8h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0067] Embodiment 13

[0068] 2g of phenol arylated lignin, 1g of Pt / C (5wt% loading), 50g of methanol: water (4:1, v / v) mixed solution (containing 5g / L sulfuric acid) and 200wt% (added amount, based on the mass of lignin) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 180°C and reacted for 4h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0069] Embodiment 14

[0070] Weigh 1g of phenol arylated lignin, 0.5g of Pt / C (5wt% loading), 50g of methanol: water (3:1, v / v) mixed solution (containing 5g / L sulfuric acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 8h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0071] Embodiment 15

[0072] 1g of phenol arylated lignin, 0.5g of Pt / TiO2 (Pd in ​​Pd / TiO2 is 2wt% loading), 50g of methanol: water (1:1, v / v) mixed solution (containing 5g / L sulfuric acid) and 200wt% (added amount, based on lignin mass) of formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 220℃ and reacted for 1h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by vacuum rotary evaporation (~40℃), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by vacuum rotary evaporation (~40℃) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of the lignin depolymerization oil is the same as in Example 1. The quantitative analysis of the lignin depolymerization oil is the same as in Example 1.

[0073] Example 16

[0074] Weigh 1g of phenol arylated lignin, 0.5g of Pd / C (5wt% loading), 50g of methanol: water (1:3, v / v) mixed solution (containing 5g / L sulfuric acid) and 50wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 4h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0075] Embodiment 17

[0076] Weigh 1g of phenol arylated lignin, 0.5g of Pd / C (5wt% loading), 50g of methanol: water (1:4, v / v) mixed solution (containing 5g / L sulfuric acid) and 100wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 160°C and the reaction is carried out for 12h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0077] Embodiment 18

[0078] 1g of phenol arylated lignin, 0.5g of Pd / C (Pd in ​​Pd / C is 10wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 5g / L methylsulfonic acid) and 200wt% (added amount, based on lignin mass) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 200℃ and the reaction was carried out for 4h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by vacuum rotary evaporation (~40℃), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by vacuum rotary evaporation (~40℃) to prepare bisphenol-rich lignin depolymerization oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0079] Embodiment 19

[0080] 5g of phenol arylated lignin, 2.5g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 2g / L p-toluenesulfonic acid) and 400wt% (added amount, based on the mass of lignin) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 200°C and the reaction was carried out for 4h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0081] Embodiment 20

[0082] Weigh 2g of phenol arylated lignin, 1g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 2g / L p-toluenesulfonic acid) and 300wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 4h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0083] Embodiment 21

[0084] 1.5g of phenol arylated lignin, 0.75g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 2g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 200℃ and the reaction was carried out for 4h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by vacuum rotary evaporation (~40℃), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by vacuum rotary evaporation (~40℃) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0085] Embodiment 22

[0086] Weigh 1g of phenol arylated lignin, 0.5g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 2g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 6h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1. The quantitative analysis of lignin depolymerized oil is the same as in Example 1. The gas chromatogram of monophenol and bisphenol in lignin depolymerized oil is as follows: Figure 5 The 2D NMR spectra of two main bisphenols (4-(4-hydroxyphenethyl)-2-methoxyphenol and 4-(4-hydroxyphenethyl)-2,6-dimethoxyphenol) are shown in Figure 6 As shown, the results indicate that lignin bisphenol has a 1,2-diphenylethyl bridging structure.

[0087] Embodiment 23

[0088] 0.5g of phenol arylated lignin, 0.25g of Pd / C (5wt% loading), 50g of methanol: water (3:1, v / v) mixed solution (containing 5g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 200℃ and the reaction was carried out for 4h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by reduced pressure rotary evaporation (~40℃), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by reduced pressure rotary evaporation (~40℃) to prepare bisphenol-rich lignin depolymerization oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0089] Embodiment 24

[0090] 1g of phenol arylated lignin, 0.1g of Pd / C (Pd in ​​Pd / C is 10wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 5g / L p-toluenesulfonic acid) and 200wt% (added amount, based on lignin mass) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 200℃ and the reaction was carried out for 4h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by vacuum rotary evaporation (~40℃), and then extracted 3 times with a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by vacuum rotary evaporation (~40℃) to prepare bisphenol-rich lignin depolymerized oil.

[0091] Embodiment 25

[0092] Weigh 1g of phenol arylated lignin, 0.25g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 5g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 4h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0093] Embodiment 26

[0094] Weigh 1g of phenol arylated lignin, 0.8g of Pd / C (10wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 5g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 4h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by vacuum rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by vacuum rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0095] Embodiment 27

[0096] 2g of guaiacol arylated lignin, 1g of Pt / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 5g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid were weighed and added to a high temperature and high pressure reactor. After the reactor was sealed, argon was passed through the reactor headspace, and after uniform stirring (600rpm) was turned on, the temperature was raised to 200°C and the reaction was carried out for 4h. After the reactor was cooled, the reaction mixture was filtered through filter paper, and the filtrate was concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase was dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent was removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0097] Embodiment 28

[0098] Weigh 2g of guaiacol arylated lignin, 1g of Pt / C (10wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 5g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) isopropanol and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 4h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by vacuum rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by vacuum rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0099] Embodiment 29

[0100] Weigh 2g of guaiacol arylated lignin, 1g of Pt / C (10wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 5g / L p-toluenesulfonic acid) and 400wt% (added amount, based on the mass of lignin) isopropanol and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon gas is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 4h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0101] Embodiment 30

[0102] Weigh 1g of guaiacol arylated lignin, 0.5g of Pt / C (5wt% loading), and 50g of a methanol: water (7:3, v / v) mixture (containing 5g / L p-toluenesulfonic acid) and add it to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, 0.5MPa of hydrogen is filled at room temperature, and after uniform stirring (600rpm), the temperature is raised to 220°C and the reaction is carried out for 4h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare bisphenol-rich lignin depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0103] Embodiment 31

[0104] Weigh 1g of guaiacol arylated lignin, 0.5g of Pt / C (5wt% loading), and 50g of a mixture of methanol: water (7:3, v / v) (containing 5g / L p-toluenesulfonic acid) and add them to a high-temperature and high-pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, 2MPa of hydrogen is filled at room temperature, and uniform stirring (600rpm) is turned on, and the temperature is raised to 220°C for 4h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), followed by extraction 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare lignin depolymerized oil rich in bisphenol. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0105] Comparative Example 1

[0106] Weigh 1g of kraft lignin, 0.5g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 2g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high-temperature and high-pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 6h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare lignin depolymerization oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0107] Comparative Example 2

[0108] Weigh 1g of enzymatic lignin, 0.5g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution (containing 2g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high-temperature and high-pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 6h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare lignin depolymerization oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0109] Comparative Example 3

[0110] Weigh 1g of phenol arylated lignin, 50g of methanol: water (7:3, v / v) mixed solution (containing 2g / L p-toluenesulfonic acid) and 200wt% (added amount, based on the mass of lignin) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 6h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare lignin-rich depolymerized oil. The quantitative analysis of lignin depolymerized oil is the same as in Example 1.

[0111] Comparative Example 4

[0112] Weigh 1g of phenol arylated lignin, 0.5g of Pd / C (5wt% loading), 50g of methanol: water (7:3, v / v) mixed solution, 200wt% (added amount, based on lignin mass) formic acid, and add them to a high temperature and high pressure reactor. After the reactor is sealed, argon is passed through the reactor headspace, and after uniform stirring (600rpm) is turned on, the temperature is raised to 200°C and the reaction is carried out for 6h. After the reactor is cooled, the reaction mixture is filtered through filter paper, and the filtrate is concentrated by reduced pressure rotary evaporation (~40°C), and then extracted 3 times using a 250mL separatory funnel (extractant, dichloromethane: water, 1:1, v / v, each time 100mL), the dichloromethane phase is dried over anhydrous sodium sulfate, and the dichloromethane phase organic solvent is removed by reduced pressure rotary evaporation (~40°C) to prepare lignin depolymerization oil. The quantitative analysis of lignin depolymerization oil is the same as in Example 1.

[0113] Table 1. Preparation of monophenols, bisphenols and lignin oligomers by catalytic depolymerization of lignin samples

[0114]

[0115]

[0116] Note: The yield calculations are based on the mass of the aromatized lignin sample or the extracted lignin sample.

[0117] As can be seen from Table 1, the method for catalytic depolymerization of 1,1-diphenylmethyl structure lignin derivatives of the present invention can effectively reduce the yield of monophenol, selectively prepare lignin bisphenol, and co-produce lignin oligomers. Aromatic lignin prepared from syringol, p-cresol, phenol, and guaiacol can be depolymerized under the catalytic depolymerization conditions of the present invention, and bisphenol containing 1,2-diphenylethyl structure can be efficiently generated. Compared with Comparative Example 1 (kraft lignin) and Comparative Example 2 (enzymatic lignin), Example 2 (syringol aryl lignin) has a 910%-6400% increase in lignin bisphenol yield under the same catalytic depolymerization conditions; Example 22 (phenol aryl lignin) has a 1100%-8000% increase in lignin bisphenol yield under the same catalytic depolymerization conditions.

[0118] In the catalytic depolymerization process involved in the present invention, the acid catalyst and the transition metal catalyst are the key factors affecting the catalytic depolymerization of 1,1-diphenylmethyl structure lignin derivatives to generate lignin bisphenol. As shown in Comparative Example 3, when there is no transition metal catalyst in the catalytic depolymerization process, the lignin monophenol yield does not change significantly, but the lignin bisphenol yield drops to 1.5%, the main reason is that the bisphenol depolymerization product (because it contains double bonds) generated under acidic conditions is unstable, and the lignin yield is significantly reduced due to the condensation reaction. As shown in Comparative Example 4, when there is no acid catalyst in the catalytic depolymerization process, the lignin monophenol yield, lignin bisphenol yield and lignin oligomer yield are significantly reduced, the main reason is that the transition metal catalyst cannot depolymerize the lignin derivative with 1,1-diphenylmethyl structure under neutral conditions. The above results show that the method for catalytic depolymerization of lignin derivatives can realize the one-step method to prepare bisphenol compounds, and co-produce lignin oligomers at the same time, which can promote the industrial application of catalytic depolymerization of lignin to prepare high-value chemicals, fuels and polymer materials.

[0119] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the basic principles of the chemical reactions involved in the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for catalytic depolymerization of lignin derivatives, characterized in that: The lignin derivative with a 1,1-diphenylmethyl structure is used in a liquid medium to prepare lignin depolymerized oil rich in 1,2-diphenylethyl structure bisphenol and lignin oligomers through the synergistic catalytic action of a transition metal catalyst, a hydrogen donor and an acid catalyst.

2. The method according to claim 1, characterized in that: The lignin derivative with a 1,1-diphenylmethyl structure is a selectively α-arylated modified lignin (as shown in the raw material structural formula on the left side of Formula 1); in the structure of the lignin derivative (as shown in the raw material structural formula on the left side of Formula 1), Ar1 is an aromatic ring originally present in the lignin, and contains 0, 1 or 2 methoxy groups at the ortho position of the aromatic ring hydroxyl group on the aromatic ring; Ar2 is an aromatic ring of an arylating agent, and in addition to a hydroxyl group, the aromatic ring also contains 0, 1 or 2 substituents, and the substituents are any one or a mixture of two or more of methyl, ethyl, propyl, isopropyl, methoxy, phenoxy, and phenolic hydroxyl groups, and the preferred arylating agent is any one or more of phenol, p-methylphenol, guaiacol, and syringol; R1 is a hydroxyl group or an acyl group; Formula 1. Schematic diagram of the reaction of catalytic depolymerization of lignin derivatives with 1,1-diphenylmethyl structure to produce 1,2-diphenylethyl structure bisphenol products 1,2-diphenylethyl structure bisphenol product (as shown in the product structure on the right side of Formula 1), wherein there is an ethyl bridge structure between the aromatic ring Ar1 and the aromatic ring Ar2, and the substituents R2 and R3 of the ethyl are independently hydrogen, methyl and hydroxymethyl respectively; Ar1 ​​is an aromatic ring originally present in lignin, and the ortho position of the aromatic ring hydroxyl contains 0 or 1 or 2 methoxy groups; Ar2 is an aromatic ring of an arylating agent, which contains 0 or 1 or 2 substituents in addition to a hydroxyl group, and the substituents are any one or a mixture of two or more of methyl, ethyl, propyl, isopropyl, methoxy, phenoxy, and phenolic hydroxyl groups, and the preferred arylating agent is any one or more of phenol, p-methylphenol, guaiacol, and eugenol; R1 is a hydroxyl group or an acyl group.

3. The method according to claim 1, characterized in that: The lignin derivative with a 1,1-diphenylmethyl structure is a selectively α-arylated modified lignin (as shown in the raw material structure on the left side of Formula 1), which is prepared by directing the substitution of the benzyl hydroxyl group in the β-O-4 aryl ether bond structure in the lignin raw material by an arylation agent, and retains the β-O-4 aryl ether bond structure of the natural lignin (as shown in Formula 2); In the structure of the lignin derivative (the raw material structure on the left side as shown in Formula 1), Ar1 is an aromatic ring originally present in the lignin, and contains 0, 1 or 2 methoxy groups at the ortho position of the aromatic ring hydroxyl group on the aromatic ring; Ar2 is an aromatic ring of an arylating agent, and contains 0, 1 or 2 substituents on the aromatic ring in addition to the hydroxyl group, and the substituents are any one or a mixture of two or more of methyl, ethyl, propyl, isopropyl, methoxy, phenoxy, and phenolic hydroxyl groups, and the preferred arylating agent is any one or more of phenol, p-methylphenol, guaiacol, and eugenol; R1 is a hydroxyl group or an acyl group (the acyl group is derived from an organic acid solvent such as formic acid, acetic acid, etc., in the preparation process of the lignin derivative); Formula 2. Schematic diagram of the reaction for preparing lignin derivatives with 1,1-benzhydryl structure by selective α-arylation.

4. The method according to claim 1, 2 or 3, characterized in that: The preparation process of the lignin derivative having a 1,1-diphenylmethyl structure is as follows: Weigh 40-80g of cellulose, 16g-40g of arylation agent, and 400mL of 60-95wt% organic acid aqueous solution, and add them into a reactor; after the reactor is sealed, heat it to 80-140°C while stirring, and react for 30-180min; after cooling, the reaction mixture is filtered, the filtrate is collected and concentrated, and the concentrate is mixed with a reverse solvent (water or ethanol aqueous solution, the volume fraction of ethanol in the reverse solvent is 0%-20%) to perform reverse solvent precipitation of aryl lignin, and the aryl lignin is filtered and dried to obtain aryl lignin powder; The wood cellulose is any one of poplar, birch, pine, bamboo, crop straw, and reed, or a mixture of two or more thereof; The arylation agent is any one of phenol, cresol, guaiacol, eugenol, and catechol, or a mixture of two or more thereof; The organic acid is any one of formic acid, acetic acid, maleic acid, oxalic acid and p-toluenesulfonic acid or a mixture of two or more thereof.

5. The method according to claim 1, characterized in that: The liquid medium for catalytic depolymerization reaction is any one of dioxane, tetrahydrofuran, methanol, ethanol, propanol, butanol, isopropanol, glycerol, toluene and water, or a mixture of two or more thereof; the preferred lignin solvent is a methanol / water mixture with a volume ratio of 4:1 to 1:4, and a more preferred volume ratio of 3:1 to 1:1; The mass of the liquid medium is 5-500 times the mass of the lignin derivative, the optimal amount is 10-100 times the mass of the lignin derivative, and the more optimal amount is 20-50 times the mass of the lignin derivative.

6. The method according to claim 1, characterized in that: The acid catalyst is any one of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, p-hydroxybenzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, phosphotungstic acid, phosphomolybdic acid, trifluoroacetic acid, zinc chloride, ferric chloride, cupric chloride, aluminum chloride and lithium chloride, or a mixture of two or more thereof; the concentration of the acid catalyst in the liquid medium is 0.5-20 g / L, the preferred acid catalyst is any one of sulfuric acid, p-toluenesulfonic acid and methanesulfonic acid, or a mixture of two or more thereof, the preferred acid catalyst concentration is 1-10 g / L, and the more preferred acid concentration is 2-5 g / L.

7. The method according to claim 1, characterized in that: The transition metal selected as the transition metal catalyst in the catalytic depolymerization reaction is any one of palladium, platinum, ruthenium, nickel, rhodium and iridium, or a mixture of two or more thereof; the transition metal catalyst is a supported catalyst, and the carrier selected as the transition metal catalyst is any one of activated carbon, aluminum oxide, silicon dioxide, titanium dioxide, zirconium oxide, cerium oxide, molybdenum oxide, molybdenum sulfide, tungsten oxide, hydrotalcite, hydroxyapatite and molecular sieve (H-ZSM-5) or a mixture of two or more thereof; the loading amount of the active component transition metal on the carrier is 0.1-15wt%, the preferred loading range is 0.5-10wt%, and the more preferred loading range is 2-5wt%; The amount of the transition metal catalyst used is 2-100wt% of the mass of the lignin derivative, the preferred amount of the transition metal catalyst used is 10-80wt%, and the more preferred amount of the transition metal catalyst used is 20-50wt% of the mass of the lignin derivative.

8. The method according to claim 1, characterized in that: The hydrogen donor for the catalytic depolymerization reaction is any one of formic acid, methanol, ethanol, isopropanol, glucose, xylose, ethylene glycol, glycerol, and hydrogen, or a mixture of two or more thereof; when the hydrogen donor is not hydrogen, the amount of the hydrogen donor (based on the mass of lignin) is 50-400wt%; when the hydrogen donor is hydrogen, the hydrogen pressure during the reaction is 0.1-8MPa; The preferred hydrogen donor is any one or more of formic acid, isopropanol and hydrogen, the preferred formic acid dosage (based on the mass of lignin) is 50-400wt%, the preferred propanol dosage (based on the mass of lignin) is 100-500wt%, the preferred hydrogen pressure during the reaction process is 0.2-5MPa; the more preferred formic acid addition amount (based on the mass of lignin) is 100-300wt%.

9. The method according to any one of claims 1 to 8, characterized in that: The reaction conditions for the catalytic depolymerization of the lignin derivative are as follows: a reaction temperature of 120-300°C and a reaction time of 0.1-48h; a preferred reaction temperature of 160-260°C and a preferred reaction time of 0.5-24h; and a more preferred reaction temperature of 180-240°C and a more preferred reaction time of 1-12h.

10. The lignin depolymerized oil rich in 1,2-diphenylethyl structure bisphenol and lignin oligomers obtained by the method according to any one of claims 1 to 9.

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