Method for producing ethylene glycol and 1, 2-propylene glycol by using cellulose and carbohydrate biomass as raw materials

Abstract

The invention discloses a method for producing ethylene glycol and 1, 2-propylene glycol by using one or more of cellulose, cellobiose, hexose (such as glucose and fructose), pentose (such as xylose, ribose and arabinose) and sorbitol as raw materials. According to the method, a cerium oxide compound is used as a carrier to load metal to serve as a catalyst, cellulose, hexose, pentose and the like are used as reaction raw materials, the reaction raw materials are directly converted into ethylene glycol and 1, 2-propylene glycol in water at the temperature of 160-250 DEG C under certain hydrogen pressure, and the total selectivity of the ethylene glycol and the 1, 2-propylene glycol reaches 68%. The catalyst has the advantages of simple structure, simple synthesis method, good repeatability, cheap and easily available raw materials, and green and environment-friendly reaction system. An effective and feasible path is provided for efficient catalytic conversion and utilization of biomass such as cellulose and saccharides, and the method is low in equipment requirement, free of corrosion to equipment, small in investment and capable of producing ethylene glycol and 1, 2-propylene glycol at the same time and has important value.

Description

Technical Field

[0001] The present application relates to the technical field of cellulose-based biomass conversion applications, and in particular to a method for catalytically converting one or more of cellulose, cellobiose, hexose (such as glucose, fructose), pentose (such as xylose, ribose, arabinose), and sorbitol to produce ethylene glycol and propylene glycol. Background Art

[0002] Biomass is the largest non-food resource on the planet. The rich carbon content in biomass makes it an ideal material to replace the increasingly scarce and non-renewable fossil resources. Lignocellulose is a type of biomass, mainly composed of three parts: cellulose, hemicellulose, and lignin. Cellulose is the main component of lignocellulose, which is widely found in agricultural waste, such as wheat straw, corn stalks, etc. Cellulose is made of glucose as a monomer, and the monomers are connected by 1,4-β glycosidic bonds. Its molecular formula (C 6 H 10 O 5 )n, usually n contains thousands of glucose units, equivalent to 300 to 15,000 glucose groups, and a molecular weight of 50,000 to 2,500,000. Cellulose is a polysaccharide biomass macromolecule with glycosidic bonds and hydrogen bonds in the molecule, so its structure is very stable. The sugar mixture produced by cellulose hydrolysis or fermentation mainly includes pentose and hexose. The current conversion of pentose and hexose has the problems of low raw material utilization, low total product yield, and high separation cost. Therefore, the conversion of biomass-derived sugars and sugar mixtures to generate chemicals has important research and application prospects. Catalytic conversion of polysaccharides can produce a variety of useful chemicals, such as diols (including ethylene glycol, propylene glycol, butanediol and pentanediol, etc.), 2,5-furandicarboxylic acid, cellulose-based carbon aerogels, and 5-hydroxymethylfurfur. Ethylene glycol is an important chemical raw material, widely used in the polyester industry. It can be used to make a variety of compounds such as polyether, polyester and coatings. It is also used as a solvent, reaction intermediate and plasticizer, and plays an important role in the manufacture of synthetic fibers, resins, pigments and dyes. Propylene glycol is an important chemical intermediate, which is widely used in many fields such as plastics, clothing, synthetic resins, cosmetics, food, etc. It can also be used as antifreeze, deicing agent, heat transfer medium, liquid detergent, etc. At present, ethylene glycol is mainly produced by cracking petroleum and coal in industry, but this will cause a series of problems, such as global environmental deterioration and rising temperatures. Producing ethylene glycol through biomass resources is environmentally friendly, green and sustainable, and can achieve a win-win situation in social and economic benefits. Summary of the invention

[0003] The present application provides a method for catalytically converting biomass such as cellulose, cellobiose, hexose (glucose, fructose), pentose (xylose, ribose, arabinose) and mixed sugars to produce ethylene glycol and propylene glycol.

[0004] This application adopts the following technical solutions:

[0005] A method for producing ethylene glycol and propylene glycol comprises the following steps: reacting raw materials in a reaction solvent under the action of a catalyst, and obtaining ethylene glycol and propylene glycol after the reaction is completed.

[0006] Optionally, the catalyst is a composite catalyst composed of component A and component B, wherein component A is a hydrogenation metal, and component A is one of Cu, Ni, Ru, and Pd; component B is a carrier, and component B is CeO 2 or Ce(OH) 3 .

[0007] Optionally, the reaction raw materials are one or more of cellulose, cellobiose, hexose (such as glucose, fructose), pentose (such as xylose, ribose, arabinose), and sorbitol.

[0008] Optionally, the loading amount of Cu and Ni is 1wt%-30wt%, the loading amount of Ru is 0.1wt%-5wt%, and the loading amount of Pd is 0.01wt%-1wt%. Preferably, the loading amount of Cu and Ni is 3wt%-15wt%, the loading amount of Ru is 0.3wt%-1wt%, and the loading amount of Pd is 0.1wt%-0.5wt%.

[0009] Optionally, component A is Ru and component B is Ce(OH) 3 The catalyst is prepared by reducing Ru / CeO in aqueous solution. 2 generate.

[0010] Optionally, the amount of the catalyst is 4%-400% of the mass of the reaction raw materials.

[0011] Optionally, the initial reaction pressure is 10 bar-80 bar.

[0012] Optionally, the reaction solvent is water or a mixed solution containing alcohol. The alcohol includes ethylene glycol and propylene glycol, and the mass fraction of the alcohol is 0-30wt%.

[0013] Optionally, the reaction temperature is 160°C-250°C. Preferably, the reaction temperature is 180°C-230°C.

[0014] Optionally, when cellulose is used as the reaction raw material, the reaction time is 0.5h-24h; when glucose, fructose, cellobiose or sorbitol is used as the reaction raw material, the reaction time is 5min-1000min.

[0015] The beneficial effects of this application are as follows:

[0016] The method uses cerium oxide compounds as carriers to load metals as catalysts, and uses cellulose, cellobiose, hexose, pentose, sorbitol and mixed sugars as reaction raw materials. In water at 160-250°C and under a certain hydrogen pressure, the direct conversion generates ethylene glycol and 1,2-propylene glycol, and the overall selectivity of the two reaches 68%. The catalyst has a simple structure, a simple synthesis method with good repeatability, the raw materials used are cheap and easy to obtain, and the reaction system is green and environmentally friendly. The present invention provides an effective and feasible path for the efficient catalytic conversion and utilization of biomass such as cellulose and sugars. The method has low equipment requirements, no corrosion to equipment, low investment, and can produce ethylene glycol and 1,2-propylene glycol at the same time, which is of great value. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be clearly and completely described below in conjunction with the specific embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0018] The methods mentioned in the following examples are conventional methods unless otherwise specified, and the sources of the drugs are shown in the following table.

[0019] Source of medicine

[0020]

[0021]

[0022] Example 1. Preparation of Catalyst

[0023] The carrier cerium oxide was synthesized by hydrothermal method or purchased from Maclean manufacturer, and the cerium oxide supported metal catalyst was synthesized by impregnation method. The catalysts used in the following examples were synthesized according to the following method unless otherwise specified. 2 Take the synthesis as an example: weigh a certain amount of nickel nitrate hexahydrate, add a little water to dissolve it, add cerium oxide to the dissolved nickel nitrate hexahydrate, stir it at room temperature for a period of time and then place it in an oven at 110°C for drying. The dried catalyst is first calcined at 350°C in an air atmosphere for 3 hours, and finally calcined at 400°C in a hydrogen atmosphere for 4 hours.

[0024] Example 2: Ni / CeO 2 Catalytic conversion of glucose into ethylene glycol and 1,2-propylene glycol

[0025] Add 0.4 g 1% Ni / CeO to each of the five reactors. 2 , 0.4g 3%Ni / CeO 2 , 0.2g 5%Ni / CeO 2 , 0.2g15%Ni / CeO 2 , 0.2g 30%Ni / CeO 2 0.1 g of glucose and 40 ml of water were added to the reactor. The initial hydrogen pressure of the reaction was 5 MPa, and the reaction was carried out at 205°C for 10 min.

[0026] After the reaction, the generated liquid product was filtered, fixed to volume, and detected by Shimadzu liquid chromatography. The detector was a differential detector, the chromatographic column was Aminex HPX-87C, the chromatographic column temperature was 70°C, and the mobile phase was water: acetonitrile = 3:2. The product detection and quantitative method in the following examples was carried out according to this method unless otherwise specified.

[0027] Calculation of reactant conversion and product selectivity:

[0028]

[0029] In the following examples, the reactant conversion rate and product selectivity are calculated according to the above formula unless otherwise specified.

[0030] The product after the reaction was detected and quantified by liquid chromatography, and the results are shown in the following table:

[0031]

[0032] Other products in the table include four-carbon alcohols (erythritol and threitol), five-carbon alcohols (xylitol, ribitol and arabitol), and six-carbon alcohols (mannitol and sorbitol).

[0033] Example 3, Cu / CeO 2 Catalytic conversion of glucose into ethylene glycol and 1,2-propylene glycol

[0034] Add 0.1 g glucose and 0.4 g 1% Cu / CeO to each of the four reactors. 2 , 0.4g 3%Cu / CeO 2 , 0.2g15%Cu / CeO 2 , 0.2g 30%Cu / CeO 2 , 40ml water, the initial hydrogen pressure of the reaction was 5MPa, the reaction temperature was 205℃, and the reaction time was 10min.

[0035] The product after the reaction was detected and quantified by liquid chromatography, and the results are shown in the following table:

[0036]

[0037] Other products in the table include lactic acid and hydroxyacetone.

[0038] Example 4: Ni / CeO 2 Catalyze the conversion of pentose to ethylene glycol and 1,2-propylene glycol

[0039] 0.1 g ribose, 0.1 g arabinose, 0.1 g D-xylose, 0.1 g L-xylose were added to the four reactors respectively, and 0.2 g 5% Ni / CeO 2 , 40mL of water, the initial hydrogen pressure of the reaction was 5MPa, the reaction temperature was 205℃, and the reaction time was 10min.

[0040] The filtrate after the reaction was detected and quantified by liquid chromatography, and the results are shown in the following table:

[0041]

[0042] Other products in the table include four-carbon alcohols (erythritol and threitol), and five-carbon alcohols (xylitol, ribitol, and arabitol).

[0043] Example 5: Ni / CeO 2 Catalytic conversion of mixed sugars into ethylene glycol and 1,2-propylene glycol

[0044] Mixed sugars were added to the three groups of reactors. The specific sugars are shown in the table below, and 0.05g of each sugar was added. 0.2g of 5% Ni / CeO was added to the three groups of reactors. 2 , 40mL water, the initial hydrogen pressure of the reaction is 5MPa, the reaction temperature is 205℃, and the reaction time is 10min.

[0045] The filtrate after the reaction was detected and quantified by liquid chromatography, and the results are shown in the following table:

[0046]

[0047] Other products in the table include four-carbon alcohols (erythritol and threitol), five-carbon alcohols (xylitol, ribitol and arabitol), and six-carbon alcohols (mannitol and sorbitol).

[0048] Example 6: Ru / CeO 2 、Ru / Ce(OH) 3 Catalytic conversion of cellobiose to ethylene glycol and 1,2-propylene glycol

[0049] To each of the five reactors, 0.1 g of cellobiose and 0.2 g of 0.1% Ru / CeO were added. 2 , 0.2g

[0050] 0.3%Ru / CeO 2 , 0.2g 1%Ru / CeO 2 , 0.2g 3%Ru / Ce(OH) 3 ,0.2g 5%Ru / Ce(OH) 3 , 40 ml of water, the initial hydrogen pressure of the reaction was 5 MPa, and the reaction was carried out at 205°C for different times.

[0051] The product after the reaction was detected and quantified by liquid chromatography, and the results are shown in the following table:

[0052]

[0053] Other products in the table include cellobiol, tetraols (erythritol, threitol), pentaols (ribitol, arabitol), and hexaols (mannitol, sorbitol).

[0054] Example 7, Pd / CeO 2 Catalytic conversion of glucose into ethylene glycol and 1,2-propylene glycol

[0055] Add 0.1 g glucose, 0.4 g 0.01% Pd / CeO to each of the four reactors. 2 , 0.2g 0.1% Pd / CeO 2 , 0.2g 0.5% Pd / CeO 2 , 0.2g 1% Pd / CeO 2 ,, 40mL water, initial hydrogen pressure 5MPa, reaction at 205℃ for different time. .

[0056] The product after the reaction was detected and quantified by liquid chromatography, and the results are shown in the following table:

[0057]

[0058] Other products in the table include four-carbon alcohols (erythritol and threitol), five-carbon alcohols (xylitol, ribitol and arabitol), and six-carbon alcohols (mannitol and sorbitol).

[0059] Example 8, Ni / CeO 2 Catalytic conversion of sorbitol to ethylene glycol and 1,2-propylene glycol

[0060] Add 1g of sorbitol and 0.2g of 5% Ni / CeO to each of the three reactors. 2 , 40ml of water, the initial hydrogen pressure of the reaction was 1MPa, and the reaction was carried out at 220℃ for 2h, 4h, and 8h respectively.

[0061] The product after the reaction was detected and quantified by liquid chromatography, and the results are shown in the following table:

[0062]

[0063] Other products in the table include four-carbon alcohols (erythritol, threitol), five-carbon alcohols (ribitol, arabitol) and mannitol.

[0064] Example 9, Ni / CeO 2 Catalytic conversion of sorbitol to ethylene glycol and 1,2-propylene glycol

[0065] Add 1g of sorbitol and 0.2g of 5% Ni / CeO to each of the three reactors. 2 , 40ml of water, the initial hydrogen pressure of the reaction was 1MPa, 3MPa, and 8MPa respectively, and the reaction was carried out at 220℃ for 10min.

[0066] The product after the reaction was detected and quantified by liquid chromatography, and the results are shown in the following table:

[0067]

[0068] Other products in the table include four-carbon alcohols (erythritol, threitol), five-carbon alcohols (ribitol, arabitol) and mannitol.

[0069] Example 10: 5% Ni / CeO 2 Catalytic conversion of high concentration glucose into ethylene glycol and 1,2-propylene glycol

[0070] Add 0.2 g 5% Ni / CeO to each of the three reactors. 2 , 2g 5%Ni / CeO 2 , 2g 5%Ni / CeO 2 , 40ml water, the initial hydrogen pressure of the reaction is 5MPa, when the reactor temperature reaches 205℃, turn on the plunger pump, set the glucose injection rates to 0.01mL / min, 0.05mL / min, 0.05mL / min, the glucose concentration is 500g / L, the injection times are 1000min, 200min and 410min, and the continuous injection masses of glucose are 5g, 5g, 10g respectively.

[0071] The products after the reaction were detected and quantified by liquid chromatography. The results showed that the conversion rate of glucose reached 100%, and the selectivity of the products ethylene glycol and propylene glycol were shown in the following table:

[0072]

[0073] Other products are four-carbon alcohols (erythritol and threitol), five-carbon alcohols (xylitol, ribitol and arabitol), and six-carbon alcohols (mannitol and sorbitol), with overall selectivities of 1%, 3%, and 1.1%, respectively.

[0074] Example 11: Ni / CeO 2 Catalytic conversion of glucose into ethylene glycol and 1,2-propylene glycol

[0075] Add 2g 5% Ni / CeO into the reactor 2 , 40ml water, the initial hydrogen pressure of the reaction is 5MPa, the plunger pump injection rate is set to 0.05mL / min, the glucose concentration is 500g / L, the plunger pump is turned on when the reactor temperature reaches 250℃, 230℃, 200℃, 180℃, and 160℃, and the injection is performed for 30min at different reaction temperatures, that is, 0.75g of glucose is injected each time.

[0076] The product after the reaction was detected and quantified by liquid chromatography, and the results are shown in the following table:

[0077]

[0078] Other products are four-carbon alcohols (erythritol, threitol), five-carbon alcohols (ribitol, arabitol), and six-carbon alcohols (sorbitol and mannitol).

[0079] Example 12: 5% Ni / CeO 2 Catalytic conversion of cellulose to ethylene glycol and 1,2-propylene glycol

[0080] Add 1g cellulose, 0.2g 5% Ni / CeO 2 , 40 mL of water, the reaction temperature, reaction time and initial hydrogen pressure are shown in the following table.

[0081] The unreacted cellulose was weighed on a balance, and the mass of the remaining solid was measured, that is, the conversion rate of the cellulose was measured, as shown in the following table. The reaction product was detected and quantified by liquid chromatography, and the product distribution results were shown in the following table:

[0082]

[0083] Other products are four-carbon alcohols (erythritol, threitol), five-carbon alcohols (ribitol, arabitol), and six-carbon alcohols (sorbitol and mannitol).

[0084] The invention discloses a method of using M / CeO 2 (M=Cu, Ni, Pd, Ru), Ru / Ce(OH) 3The method of using a catalyst to catalyze the conversion of biomass such as cellulose, cellobiose, hexose (such as glucose, fructose), pentose (such as xylose, ribose, arabinose), sorbitol and mixed sugars to produce ethylene glycol and 1,2-propylene glycol has a low catalyst raw material price, a simple synthesis process and a certain economic value. Under given reaction conditions, the selectivity of catalytic conversion of cellulose to ethylene glycol and 1,2-propylene glycol (ethylene glycol, 1,2-propylene glycol) reaches 45%, and the selectivity of catalytic conversion of glucose to ethylene glycol and 1,2-propylene glycol reaches 68%. The catalyst and solvent used in the method are non-corrosive, the experimental operation is simple, and the reaction is rapid. The method can be used to catalytically convert cellulose and sugar biomass to produce useful chemicals, which has a certain practical value.

[0085] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A method for producing ethylene glycol and propylene glycol, characterized in that: The method comprises: under the action of a catalyst, the reaction raw materials are placed in a reaction solvent for reaction, and ethylene glycol and propylene glycol are obtained after the reaction is completed; The catalyst is a composite catalyst composed of component A and component B, wherein component A is a hydrogenation metal and is one of Cu, Ni, Ru and Pd; component B is a carrier and is CeO2 or Ce(OH)3; The reaction raw materials are one or more of cellulose, cellobiose, hexose, pentose and sorbitol.

2. The method according to claim 1, characterized in that The loading amount of Cu and Ni is 1wt%-30wt%, the loading amount of Ru is 0.1wt%-5wt%, and the loading amount of Pd is 0.01wt%-1%wt%.

3. The method according to claim 2, characterized in that The loading amount of Cu and Ni is 3wt%-15wt%, the loading amount of Ru is 0.3wt%-1wt%, and the loading amount of Pd is 0.1wt%-0.5wt%.

4. The method according to claim 3, characterized in that Component A is Ru, component B is Ce(OH)3, and the catalyst is generated by reducing Ru / CeO2 in an aqueous solution.

5. The method according to claim 1, characterized in that The amount of the catalyst is 4%-400% of the mass of the reaction raw materials, and the initial reaction pressure is 10 bar-80 bar.

6. The method according to claim 1, characterized in that The reaction solvent is water or a mixed solution containing alcohol.

7. The method according to claim 6, characterized in that The alcohol mainly includes ethylene glycol and propylene glycol, and the mass fraction of the alcohol is 0-30wt%.

8. The method according to claim 1, characterized in that The reaction temperature is 160°C-250°C.

9. The method according to claim 8, characterized in that The reaction temperature is 180°C-230°C.

10. The method according to claim 1, characterized in that When cellulose is used as the reaction raw material, the reaction time is 0.5h-24h; when hexose, pentose, cellobiose, sorbitol or mixed sugars are used as the reaction raw materials, the reaction time is 5min-1000min.

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