Preparation method of one-step hydrodeoxygenation heterogeneous supported bifunctional catalyst for biolipid

Abstract

The invention discloses a preparation method of a one-step hydrodeoxygenation heterogeneous supported bifunctional catalyst for biological oil and fat. Adding tetraethyl silicate and ethanol into a beaker, stirring at room temperature to obtain a solution I, adding ammonia water and ethanol into the beaker, and stirring at room temperature to obtain a solution II; adding the solution II into the solution I in a room-temperature stirring state, then continuously stirring to form transparent sol, aging, carrying out suction filtration, washing with water, drying and grinding to obtain a silicon dioxide carrier; and dissolving the silicon dioxide and phosphomolybdic acid in deionized water, and carrying out rotary evaporation and vacuum drying to obtain the one-step hydrodeoxygenation heterogeneous supported bifunctional catalyst for the biological oil. The prepared one-step hydrodeoxygenation heterogeneous supported bifunctional catalyst for the biological oil and fat can realize one-step hydrodeoxygenation reaction of the biological oil and fat, the problem that an intermediate product in conventional reaction is easy to crack and the like is avoided, and the catalyst is simple in preparation method and has relatively high industrial application potential.

Description

Technical Field

[0001] The invention relates to a method for preparing a one-step hydrogenation, deoxygenation and isomerization supported bifunctional catalyst for bio-oil, and belongs to the technical field of petrochemical industry. Background Art

[0002] Energy is the basis of human survival. However, due to excessive development and utilization by humans, fossil energy is being depleted. Therefore, the development of renewable clean energy is urgent. Solar energy, biomass energy, wind energy, etc. are all common renewable energy sources. Among them, biomass energy comes from the photosynthesis of plants and is stored in biomass. Biodiesel and bio-jet fuel, as a renewable and sustainable energy source, can effectively reduce carbon dioxide emissions, reduce the greenhouse effect, and meet the requirements of green and low-carbon. Therefore, the processing of bio-oils and fats into bio-fuels is one of the current research hotspots in the field of petrochemicals.

[0003] The development of bio-oil conversion has gone through two major stages: the first generation and the second generation. The first generation of biodiesel is a fatty acid methyl ester obtained by esterification of vegetable oil or animal fat with methanol. This technology is quite mature and has been mass-produced worldwide. Compared with traditional petrochemical diesel, the first generation of biodiesel has the advantages of environmental protection, high cetane number and renewability, but it still has shortcomings in low-temperature fluidity, oxygen content, stability and calorific value. Therefore, it can usually only be used as an additive for petrochemical diesel, and the addition ratio is generally not more than 5%. The second generation preparation method is to convert oil into a hydrocarbon mixture similar to petrochemical diesel through hydrodeoxygenation reaction, namely biodiesel and biojet fuel. Compared with the first generation of biodiesel, the second generation of biofuel not only maintains the advantages of environmental protection, high cetane number and renewability, but also has better fluidity, lower oxygen content, higher stability and higher calorific value, and can be mixed with petrochemical diesel in any proportion. The core of the production process of the second generation of biofuel lies in the catalyst, among which heteropolyacids are widely used in the catalytic field due to their unique acidity, redox properties and stability, and show high activity in isomerization reactions. The dispersion of active metals has a great influence on the activity of catalysts, and anchoring active metals on carriers is a strategy to improve dispersion. Silica (SiO2) has the advantages of high specific surface area, strong structural controllability, and stable chemical properties, which can provide more active sites. Summary of the invention

[0004] The present invention aims to solve the problem that existing catalysts are easily deactivated by combining with free carboxylic acids in waste oils and fats, and provides a method for preparing a one-step hydrodeoxygenation isomerization supported bifunctional catalyst for bio-oils and fats, thereby realizing a one-step hydrodeoxygenation reaction of bio-oils and fats, while avoiding the problem that intermediate products are easily cracked in conventional reactions, and the catalyst preparation method is simple, and has high potential for industrial application.

[0005] The technical solution adopted by the present invention is as follows: A method for preparing a one-step hydrodeoxygenation isomerization supported bifunctional catalyst for bio-oil, comprising the following steps: S1: tetraethyl silicate and an organic solvent are added to a beaker, stirred at room temperature for 30 to 60 minutes to obtain solution I; ammonia water and an organic solvent are added to a beaker, stirred at room temperature for 30 to 60 minutes to obtain solution II; the obtained solution II is added to solution I under stirring at room temperature, and stirring is continued after the addition is completed to form a transparent sol, and then the solution is allowed to stand at room temperature for 24 to 48 hours, filtered, the filter cake is washed with deionized water, and the filter cake is vacuum dried for 12 hours, and ground to obtain a SiO2 carrier; S2: SiO2 carrier and phosphomolybdic acid are added to a beaker, deionized water is added, stirred and dissolved at room temperature for 1 to 4 hours, rotary evaporated to dryness, and vacuum dried for 12 to 24 hours to obtain a one-step hydrodeoxygenation isomerization supported bifunctional catalyst for bio-oil; In step S1, the volume ratio of tetraethyl silicate to the organic solvent in the solution I is 3:40; the volume ratio of ammonia water to the organic solvent in the solution II is 1:20; the volume ratio of tetraethyl silicate to ammonia water in the transparent sol is 3:2; the organic solvent is selected from any one of ethanol, acetone, and isopropanol; the concentration of ammonia water is 25 vol%; the temperature of the vacuum drying is 50-70°C; In step S2, the molar ratio of the SiO2 carrier to phosphomolybdic acid is 1:0.01-0.2; the temperature of the rotary evaporation is 80°C; and the temperature of the vacuum drying is 150-250°C.

[0006] A one-step hydrogenation, deoxygenation and isomerization supported bifunctional catalyst for bio-oil is prepared by the above-mentioned preparation method.

[0007] Application of the above-mentioned one-step hydrodeoxygenation isomerization supported bifunctional catalyst in catalyzing the hydrodeoxygenation isomerization of bio-oil; The biological oil is any one of methyl palmitate, waste oil and palm oil.

[0008] The use of the above-mentioned one-step bio-oil hydrodeoxygenation isomerization supported bifunctional catalyst in catalyzing the hydrodeoxygenation isomerization of bio-oil comprises the following steps: S1: adding bio-oil to a suspended bed reactor, and then sequentially adding a supported bifunctional catalyst for one-step hydrodeoxygenation isomerization of bio-oil and sublimated sulfur powder, sealing the reactor, and starting stirring to fully mix the raw materials to obtain a mixture; S2: replacing the air in the reactor containing the mixture with hydrogen, and filling it with hydrogen to a certain pressure, starting the temperature increase program, with a temperature increase rate of 4-6°C / min, first increasing the temperature to the sulfidation temperature for sulfidation reaction, and then increasing the temperature to the cracking reaction temperature for cracking reaction; In step S1, the mass ratio of the bio-oil and the bio-oil one-step hydrodeoxygenation isomerization supported bifunctional catalyst is 100:1-10; the S / Mo atomic ratio of the bio-oil one-step hydrodeoxygenation isomerization supported bifunctional catalyst and sublimated sulfur powder is 8-12:1; In step S2, the certain pressure is 6-20 MPa; the vulcanization temperature is 200-300°C, and the vulcanization reaction time is 40-60 min; the cracking reaction temperature is 350-450°C, and the cracking reaction time is 3-6 h.

[0009] The significant advantages of the present invention are: (1) The present invention provides a one-step hydrodeoxygenation isomerization supported bifunctional catalyst for bio-oil, wherein the phosphomolybdic acid is sulfided under the action of a sulfiding agent to generate molybdenum sulfide for hydrodeoxygenation reaction, and the catalyst can be recovered. The generated phosphoric acid continues to undergo an isomerization reaction in a suspended bed reactor, thereby achieving one-step hydrodeoxygenation isomerization and avoiding cracking of intermediate products; (2) The one-step hydrodeoxygenation isomerization supported bifunctional catalyst for bio-oil provided by the present invention has a simple preparation method, and the carrier used has a nanosphere structure, which greatly increases its specific surface area so that more active sites are in contact with the bio-oil, thereby greatly improving the conversion rate of the bio-oil; (3) The bio-oil one-step hydrodeoxygenation isomerization supported bifunctional catalyst provided by the present invention can be used for the one-step hydrodeoxygenation isomerization reaction of various waste oils in a suspended bed, and has the characteristics of high conversion rate, low coking rate and good impurity removal effect. DETAILED DESCRIPTION

[0010] In order to make the contents of the present invention easier to understand, the technical solution of the present invention is further described below in conjunction with specific implementation methods, but the present invention is not limited thereto.

[0011] Embodiment 1: Take 6mL tetraethyl silicate (TEOS) and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution I; take 4mL 25vol% ammonia water and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution II; add the obtained solution II to solution I under stirring at 800rpm, continue stirring for 1h to form a transparent sol, then stand at room temperature for 24h, filter, wash the filter cake with deionized water, and then vacuum dry the filter cake at 80℃ for 12h, grind to 60 mesh, and obtain SiO2 carrier. Take 2g SiO2 carrier and 3.0378g phosphomolybdic acid and add them to a beaker, add 50mL deionized water, stir at 800rpm for 1h to dissolve, and evaporate on a rotary evaporator at 80℃ and 30r / min for 120min to dry the water, and then vacuum dry at 150℃ for 12h to obtain catalyst A.

[0012] Embodiment 2: Take 6mL tetraethyl silicate (TEOS) and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution I; take 4mL 25vol% ammonia water and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution II; add the obtained solution II to solution I under stirring at 800rpm, continue stirring for 1h to form a transparent sol, then stand at room temperature for 24h, filter, wash the filter cake with deionized water, and then vacuum dry the filter cake at 80℃ for 12h, grind to 60 mesh, and obtain SiO2 carrier. Take 2g SiO2 carrier and 6.0781g phosphomolybdic acid and add them to a beaker, add 50mL deionized water, stir at 800rpm for 1h to dissolve, and evaporate on a rotary evaporator at 80℃ and 30r / min for 120min to dry the water, and then vacuum dry at 150℃ for 12h to obtain catalyst B.

[0013] Embodiment 3: Take 6mL tetraethyl silicate (TEOS) and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution I; take 4mL 25vol% ammonia water and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution II; add the obtained solution II to solution I under stirring at 800rpm, continue stirring for 1h to form a transparent sol, then stand at room temperature for 24h, filter, wash the filter cake with deionized water, and then vacuum dry the filter cake at 80℃ for 12h, grind to 60 mesh, and obtain SiO2 carrier. Take 2g SiO2 carrier and 9.1171g phosphomolybdic acid and add them to a beaker, add 50mL deionized water, stir at 800rpm for 1h to dissolve, and evaporate on a rotary evaporator at 80℃ and 30r / min for 120min to dry the water, and then vacuum dry at 150℃ for 12h to obtain catalyst C.

[0014] Embodiment 4: Take 6mL tetraethyl silicate (TEOS) and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution I; take 4mL 25vol% ammonia water and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution II; add the obtained solution II to solution I under stirring at 800rpm, continue stirring for 1h to form a transparent sol, then stand at room temperature for 24h, filter, wash the filter cake with deionized water, and then vacuum dry the filter cake at 80℃ for 12h, grind to 60 mesh, and obtain SiO2 carrier. Take 2g SiO2 carrier and 12.1562g phosphomolybdic acid and add them to a beaker, add 50mL deionized water, stir at 800rpm for 1h to dissolve, and evaporate on a rotary evaporator at 80℃ and 30r / min for 120min to dry the water, and then vacuum dry at 150℃ for 12h to obtain catalyst D.

[0015] Embodiment 5: Take 6mL tetraethyl silicate (TEOS) and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution I; take 4mL 25vol% ammonia water and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution II; add the obtained solution II to solution I under stirring at 800rpm, continue stirring for 1h to form a transparent sol, then stand at room temperature for 24h, filter, wash the filter cake with deionized water, and then vacuum dry the filter cake at 80℃ for 12h, grind to 60 mesh, and obtain SiO2 carrier. Take 2g SiO2 carrier and 15.1952g phosphomolybdic acid and add them to a beaker, add 50mL deionized water, stir at 800rpm for 1h to dissolve, and evaporate on a rotary evaporator at 80℃ and 30r / min for 120min to dry the water, and then vacuum dry at 150℃ for 12h to obtain catalyst E. Embodiment 6: Take 6mL tetraethyl silicate (TEOS) and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution I; take 4mL 25vol% ammonia water and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution II; add the obtained solution II to solution I under stirring at 800rpm, continue stirring for 2h to form a transparent sol, then stand at room temperature for 24h, filter, wash the filter cake with deionized water, and then vacuum dry the filter cake at 80℃ for 12h, grind to 60 mesh, and obtain SiO2 carrier. Take 2g SiO2 carrier and 9.1171g phosphomolybdic acid and add them to a beaker, add 50mL deionized water, stir at 800rpm for 1h to dissolve, and evaporate on a rotary evaporator at 80℃ and 30r / min for 120min to dry the water, and then vacuum dry at 200℃ for 12h to obtain catalyst F.

[0016] Embodiment 7: Take 6mL tetraethyl silicate (TEOS) and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution I; take 4mL 25vol% ammonia water and 80mL ethanol and add them to a beaker, stir at 800rpm for 30min to obtain solution II; add the obtained solution II to solution I under stirring at 800rpm, continue stirring for 1h to form a transparent sol, then stand at room temperature for 24h, filter, wash the filter cake with deionized water, and then vacuum dry the filter cake at 80℃ for 12h, grind to 60 mesh, and obtain SiO2 carrier. Take 2g SiO2 carrier and 9.1171g phosphomolybdic acid and add them to a beaker, add 50mL deionized water, stir at 800rpm for 1h to dissolve, and evaporate on a rotary evaporator at 80℃ and 30r / min for 120min to dry the water, and then vacuum dry at 150℃ for 24h to obtain catalyst G.

[0017] Embodiment 8: 6 mL of tetraethyl silicate (TEOS) and 80 mL of ethanol were added to a beaker, stirred at 800 rpm for 30 min at room temperature to obtain solution I; 4 mL of 25 vol% ammonia water and 80 mL of ethanol were added to a beaker, stirred at 800 rpm for 30 min at room temperature to obtain solution II; the obtained solution II was added to solution I under stirring at 800 rpm at room temperature, and continued to stir for 2 h after the addition was completed to form a transparent sol, and then aged at room temperature for 48 h, filtered, the filter cake was washed with deionized water, and then the filter cake was vacuum dried at 80 ° C for 12 h, and ground to 60 mesh to obtain SiO2 carrier. 2 g of SiO2 carrier and 9.1171 g of phosphomolybdic acid were added to a beaker, 50 mL of deionized water was added, and the solution was stirred at 800 rpm for 1 h at room temperature to dissolve, and the water was evaporated to dryness on a rotary evaporator at 80 ° C and 30 r / min for 120 min, and then vacuum dried at 150 ° C for 12 h to obtain catalyst H.

[0018] Application Examples The one-step hydrodeoxygenation isomerization supported bifunctional catalysts prepared in Examples 2, 3, 4, and 6 were used for the evaluation of suspended bed catalytic hydrodeoxygenation isomerization of methyl palmitate. The experimental steps are as follows: 40g of methyl palmitate was weighed and added to a 300mL suspended bed reactor, and then 2g of catalyst and 0.4172g of sublimated sulfur powder were added in sequence. The reactor was sealed and stirred to fully mix, and the stirring rate was 550r / min. The air in the reactor was replaced with hydrogen, and then hydrogen was filled to a pressure of 20MPa; the heating program was started, and the heating rate was 5℃ / min. The temperature was first raised to 250℃ for sulfurization reaction for 40min, and then raised to 400℃ for cracking reaction for 5h. After the reaction was completed, the reactor was cooled to room temperature, the product was collected for vacuum distillation, the distillation residue was washed with toluene, centrifuged, and dried, and then weighed, and the conversion rate and coking rate were calculated respectively.

[0019] As a comparison, the results of the hydrodeoxygenation isomerization of methyl palmitate without any catalyst and with molybdenum isooctanoate developed by Eni, Italy as a catalyst were also determined.

[0020] The results are shown in Table 1 below. The one-step hydrodeoxygenation isomerization supported bifunctional catalyst provided by the present invention has excellent catalytic activity. When applied to the suspended bed hydrodeoxygenation isomerization of methyl palmitate, the conversion rate of methyl palmitate is significantly higher than that without a catalyst, and the coking rate is significantly lower than that without a catalyst. Compared with the molybdenum isooctanoate developed by Eni, Italy, the one-step hydrodeoxygenation isomerization supported bifunctional catalyst provided by the present invention has basically the same activity, but the preparation process is simple and the reagents used are non-toxic, and the cost has a great advantage.

[0021] Table 1 Hydrodeoxygenation isomerization results of methyl palmitate Example 2 Example 3 Example 4 Example 6 Comparative Example 1 Comparative Example 2 catalyst B C D F none Molybdenum 2-ethylhexanoate Cracking reaction temperature (℃) 400 400 400 400 400 400 Pressure(MPa) 20 20 20 20 20 20 Mo equivalent (ppm) 600 600 600 600 600 600 Conversion rate (%) 75.24 82.36 69.78 81.96 41.27 85.27 Coking rate (%) 3.58 1.86 4.79 1.26 30.37 3.58 Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. However, the obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for preparing a one-step hydrodeoxygenation isomerization supported bifunctional catalyst for bio-oil, characterized in that: The following steps are involved: S1: Take tetraethyl silicate and an organic solvent and add them to a beaker, stir at room temperature for 30-60 minutes to obtain solution I; take ammonia water and an organic solvent and add them to a beaker, stir at room temperature for 30-60 minutes to obtain solution II; add the obtained solution II to solution I under stirring at room temperature, continue stirring after the addition is completed to form a transparent sol, and then stand at room temperature for aging for 24-48 hours, filter, wash the filter cake with deionized water, and then vacuum dry the filter cake for 12 hours, grind, and obtain SiO2 carrier; S2: Take SiO2 carrier and phosphomolybdic acid and add them to a beaker, add deionized water, stir and dissolve at room temperature for 1-4 hours, rotary evaporate until the water is dry, and vacuum dry for 12-24 hours to obtain a one-step hydrodeoxygenation isomerization supported bifunctional catalyst for bio-oil.

2. The preparation method according to claim 1, characterized in that: In step S1, the volume ratio of tetraethyl silicate to the organic solvent in the solution I is 3:40; the volume ratio of ammonia water to the organic solvent in the solution II is 1:20; the volume ratio of tetraethyl silicate to ammonia water in the transparent sol is 3:2; the organic solvent is selected from any one of ethanol, acetone, and isopropanol; the concentration of ammonia water is 25 vol%; and the temperature of the vacuum drying is 50-70°C.

3. The preparation method according to claim 1, characterized in that: In step S2, the molar ratio of the SiO2 carrier to phosphomolybdic acid is 1:0.01-0.2; the temperature of the rotary evaporation is 80°C; and the temperature of the vacuum drying is 150-250°C.

4. A one-step hydrodeoxygenation isomerization supported bifunctional catalyst for bio-oil, characterized in that: The product is prepared by the preparation method described in any one of claims 1 to 3.

5. Use of the supported bifunctional catalyst for one-step hydrodeoxygenation isomerization of bio-oil as claimed in claim 4 in catalyzing the hydrodeoxygenation isomerization of bio-oil.

6. The use according to claim 5, characterized in that: The biological oil is any one of methyl palmitate, waste oil and palm oil.

7. The use according to claim 6, characterized in that: The following steps are involved: S1: adding bio-oil to a suspended bed reactor, and then sequentially adding a supported bifunctional catalyst for one-step hydrodeoxygenation isomerization of bio-oil and sublimated sulfur powder, sealing the reactor, and starting stirring to fully mix the raw materials to obtain a mixture; S2: Replace the air in the reactor containing the mixture with hydrogen, and fill it with hydrogen to a certain pressure, start the heating program, and the heating rate is 4~6℃ / min. First, heat it to the sulfiding temperature for sulfiding reaction, and then heat it to the cracking reaction temperature for cracking reaction.

8. The use according to claim 7, characterized in that: In step S1, the mass ratio of the bio-oil and the bio-oil one-step hydrodeoxygenation isomerization supported bifunctional catalyst is 100:1-10; the S / Mo atomic ratio of the bio-oil one-step hydrodeoxygenation isomerization supported bifunctional catalyst and sublimated sulfur powder is 8-12:

1.

9. The use according to claim 7, characterized in that: In step S2, the certain pressure is 6-20 MPa; the vulcanization temperature is 200-300°C, and the vulcanization reaction time is 40-60 min; the cracking reaction temperature is 350-450°C, and the cracking reaction time is 3-6 h.