Fuel and preparation method thereof

Abstract

The invention provides a fuel and a preparation method thereof. The preparation method of the fuel comprises the following steps: mixing a phenolic compound, furanol, an acidic molecular sieve catalyst and a solvent, and carrying out an alkylation reaction in an inert atmosphere to obtain an alkylation product; and carrying out hydrodeoxygenation on the alkylated product to obtain the fuel. The acidic molecular sieve is a heterogeneous acidic catalyst, can be easily separated from a reaction system, and has no corrosion to equipment.

Description

Technical Field

[0001] The present application relates to the field of chemical technology, and in particular to fuel and a method for preparing the same. Background Art

[0002] As the global aviation transport market expands, the demand for aviation fuel will continue to grow in the future. Traditional petroleum-based hydrocarbon fuels inevitably have environmental pollution problems, so the development of green energy is urgent. At present, alkylation reactions are mostly used to prepare fuels. In alkylation reactions, homogeneous acid catalysts are most commonly used. The presence of homogeneous catalysts inevitably leads to problems such as difficulty in separation and recovery, severe equipment corrosion and environmental pollution. Therefore, environmentally friendly heterogeneous acid catalysts have attracted people's attention. Summary of the invention

[0003] In view of this, an embodiment of the present application provides a fuel and a method for preparing the same.

[0004] The first aspect of the present application provides a method for preparing a fuel, the method comprising:

[0005] A phenolic compound, furanol, an acidic molecular sieve catalyst and a solvent are mixed and an alkylation reaction is carried out in an inert atmosphere to obtain an alkylation product;

[0006] The alkylation product is subjected to hydrodeoxygenation to obtain the fuel.

[0007] In one embodiment, the phenolic compound comprises a structural formula as shown in formula (1) and / or formula (2):

[0008]

[0009] Wherein, R1 includes H and / or OCH3; R2 includes at least one of CH3, C2H5, C3H7, C2H3O2, C3H5O, C3H5 and C4H7O.

[0010] In one embodiment, the furanol comprises a structural formula as shown in formula (3) and / or formula (4):

[0011]

[0012] In one embodiment, the molar ratio of the phenolic compound to the furanol is 5:0.5-2.5;

[0013] Preferably, the alkylation product comprises the structural formula shown in formula (5) and / or formula (6):

[0014]

[0015] Wherein, R1 includes H and / or OCH3; R2 includes at least one of CH3, C2H5, C3H7, C2H3O2, C3H5O, C3H5 and C4H7O; R3 includes H and / or CHO.

[0016] In one embodiment, the silicon-to-aluminum ratio of the acidic molecular sieve is 20 to 80;

[0017] Preferably, the acidic molecular sieve includes at least one of Hβ, HY and Al-MCM-41.

[0018] In one embodiment, the mass of the acidic molecular sieve catalyst is 5-20 wt % of the total mass of the phenolic compound and the furanol.

[0019] In one embodiment, the temperature range of the alkylation reaction is 60-140° C., and the time of the alkylation reaction is 0.5-3 h.

[0020] In one embodiment, the hydrodeoxygenation comprises:

[0021] Using water as solvent and Pd / C and HZSM-5 as catalysts, the alkylation product is subjected to the hydrodeoxygenation in a hydrogen atmosphere;

[0022] Preferably, the hydrodeoxygenation temperature is 180-220° C., the pressure is 5-7 MPa, and the time is 10-14 h.

[0023] In one embodiment, the inert atmosphere includes nitrogen and / or argon.

[0024] The second aspect of the present application provides a fuel prepared using the above-mentioned preparation method.

[0025] According to the fuel preparation method provided in the embodiment of the present application, phenolic compounds and furanol are used as raw materials, and the molecular sieve constructs a regularly arranged pore and cavity system through aluminum oxide tetrahedrons and silicon oxide tetrahedrons. Acid and Lewis acid are distributed in the framework and non-framework coordination of the crystal, and the shape selectivity and The rich distribution of acid and Lewis acid increases the activity of the catalyst. Furanol can better form carbon cations under the catalysis of acidic molecular sieves, attack the benzene ring to undergo electrophilic substitution reactions, and phenolic compounds carry hydroxyl and methoxy groups, which are electron-donating groups and can increase the electron cloud density of the benzene ring, making it easy to undergo electrophilic addition reactions with carbon cations, thereby achieving a high conversion rate of furanol and a high selectivity of alkylated products. Acidic molecular sieves are heterogeneous acidic catalysts, which are easy to separate from the reaction system and can be recycled, and are non-corrosive to equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a graph showing the conversion rate and alkylation selectivity of furanol under different conditions in Example 1, Example 2, Example 5 and Comparative Examples 7-9 of the present application. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the 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 creative work are within the scope of protection of this application.

[0028] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods and means well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0030] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0031] The first aspect of the present application provides a method for preparing a fuel, the method comprising:

[0032] A phenolic compound, furanol, an acidic molecular sieve catalyst and a solvent are mixed and an alkylation reaction is carried out in an inert atmosphere to obtain an alkylation product;

[0033] The alkylation product is subjected to hydrodeoxygenation to obtain the fuel.

[0034] According to the fuel preparation method provided in the embodiment of the present application, phenolic compounds and furanol are used as raw materials, and the molecular sieve constructs a regularly arranged pore and cavity system through aluminum oxide tetrahedrons and silicon oxide tetrahedrons. Acid and Lewis acid are distributed in the framework and non-framework coordination of the crystal, and the shape selectivity and The rich distribution of acid and Lewis acid increases the activity of the catalyst. Furanol can better form carbon cations under the catalysis of acidic molecular sieves, attack the benzene ring to undergo electrophilic substitution reactions, and phenolic compounds carry hydroxyl and methoxy groups, which are electron-donating groups and can increase the electron cloud density of the benzene ring, making it easy to undergo electrophilic addition reactions with carbon cations, thereby achieving a high conversion rate of furanol and a high selectivity of alkylated products. Acidic molecular sieves are heterogeneous acidic catalysts, which are easy to separate from the reaction system and can be recycled, and are non-corrosive to equipment.

[0035] Lignin and holocellulose are the main components of lignocellulose. Both are macromolecular polymers and cannot be used directly. They need to be depolymerized into small molecular compounds. The most commonly used depolymerization method is catalytic hydrogenolysis. The main product of catalytic hydrogenolysis of lignin is phenolic compounds, and the main product of catalytic hydrogenolysis of holocellulose is furan alcohol. Therefore, the phenolic compound selected in one embodiment of the present application is a phenolic compound obtained by catalytic hydrogenolysis of lignin, and furan alcohol is furan alcohol obtained by catalytic hydrogenolysis of holocellulose.

[0036] Compared with benzene, which is a raw material for traditional alkylation reactions, the phenolic compounds in the embodiments of the present application have hydroxyl and methoxy groups. The hydroxyl and methoxy electron-donating groups increase the electron cloud of the benzene ring, making it easier to undergo electrophilic addition reactions with the carbon cation obtained from furanol.

[0037] In one embodiment, the phenolic compound comprises a structural formula as shown in formula (1) and / or formula (2):

[0038]

[0039] Wherein, R1 includes H and / or OCH3; R2 includes at least one of CH3, C2H5, C3H7, C2H3O2, C3H5O, C3H5 and C4H7O.

[0040] In one embodiment, the furanol comprises a structural formula as shown in formula (3) and / or formula (4):

[0041]

[0042] Exemplarily, the phenolic compound includes at least one of phenol, guaiacol, 2,6-dimethoxyphenol, 4-ethylphenol, 4-methylguaiacol, 4-ethylguaiacol, 4-acetoneguaiacol, ginger ketone, 4-methyl-2,6-dimethoxyphenol, 4-hydroxy-3,5-dimethoxyphenylacetic acid, isoeugenol, eugenol, etc.; the furanol includes at least one of furfuryl alcohol, 5-hydroxymethylfurfural, and furfuryl alcohol.

[0043] In one embodiment, the molar ratio of the phenolic compound to the furanol is 5:0.5-2.5, for example, 5:0.5, 5:1, 5:1.5, 5:2, 5:2.5, etc. Relative to the above molar ratio range, when the molar ratio of the phenolic compound to the furanol is greater than 5:0.5, the excess phenolic compound will occupy the active sites of the catalyst and reduce the reaction activity; when the molar ratio of the phenolic compound to the furanol is less than 5:2.5, the carbon cation will preferentially undergo (transition) polymerization reaction with the excess furanol to generate linear byproducts, reducing the selectivity of the alkylation product.

[0044] In one embodiment, the alkylation product comprises a structural formula as shown in formula (5) and / or formula (6):

[0045]

[0046] Wherein, R1 includes H and / or OCH3; R2 includes at least one of CH3, C2H5, C3H7, C2H3O2, C3H5O, C3H5 and C4H7O; R3 includes H and / or CHO.

[0047] In one embodiment, the silicon-aluminum ratio of the acidic molecular sieve is 20 to 80, for example, 20, 30, 40, 50, 60, 70, 80, etc. Relative to the above silicon-aluminum ratio range, when the silicon-aluminum ratio of the acidic molecular sieve is less than 20, the total acid content of the molecular sieve is too high, which will increase the degree of furanol polymerization and reduce the selectivity of the alkylation reaction; when the silicon-aluminum ratio of the acidic molecular sieve is greater than 80, the total acid content of the molecular sieve is low, the number of acidic sites is insufficient, and the generation of carbon cations cannot be well promoted, and the selectivity of the alkylation product is reduced.

[0048] In one embodiment, the acidic molecular sieve includes at least one of Hβ, HY and Al-MCM-41. The alkylation reaction requires a molecular sieve with moderate pore size and acid content for catalysis. Hβ and HY have a large acid content, wherein Hβ has a three-dimensional twelve-membered ring channel structure, and HY has a supercage structure and a three-dimensional twelve-membered ring channel structure; although Al-MCM-41 has a moderate acid content, it has a two-dimensional structure of ten-membered ring channels, and the larger channel structure is conducive to better entry of reactants into the catalyst for subsequent reactions.

[0049] In one embodiment, the mass of the acidic molecular sieve catalyst is 5-20wt% of the total mass of the phenolic compound and the furanol, for example, 5wt%, 10wt%, 15wt%, 20wt%, etc. Relative to the above content range, when the relative amount of the acidic molecular sieve catalyst is less than 5wt%, the total acid amount of the catalyst is low, and only a part of the furanol raw material can be converted into carbon cations under the catalysis of the acid, and the subsequent electrophilic addition alkylation reaction of the carbon cations is greatly limited; when the relative amount of the acidic molecular sieve catalyst is higher than 20wt%, the excess acid can better promote the generation of carbon cations, and also increase the possibility of polymerization reaction between the carbon cations and the furanol raw material, which will lead to a decrease in the selectivity of the alkylation product.

[0050] In one embodiment, the temperature range of the alkylation reaction is 60-140° C., and the time of the alkylation reaction is 0.5-3 h.

[0051] In one embodiment, the hydrodeoxygenation comprises: using water as solvent, Pd / C and HZSM-5 as catalysts, and subjecting the alkylation product to the hydrodeoxygenation in a hydrogen atmosphere.

[0052] In one embodiment, the hydrodeoxygenation temperature is 180-220° C., the pressure is 5-7 MPa, and the time is 10-14 hours.

[0053] In a specific embodiment, the hydrodeoxygenation includes: 1 g of the alkylation product, 0.2 g of Pd / C and 4.5 g of HZSM-5 as catalysts, 20 mL of H2O as solvent, and reacting at 200°C and 6 MPa H2 for 12 hours.

[0054] In one embodiment, the inert atmosphere includes nitrogen and / or argon.

[0055] The second aspect of the present application provides a fuel having a structure of formula (7) and is prepared using the above-mentioned preparation method.

[0056]

[0057] Wherein, R4 includes at least one of CH3, C2H5, C3H7, and C4H9, and R5 includes C5H 11 and / or C6H 13 .

[0058] The present application is further described below in conjunction with specific embodiments. It should be noted that the following embodiments are only used to explain the present application and cannot be understood as limiting the present application.

[0059] Example 1

[0060] The method for preparing the fuel comprises the following steps:

[0061] (1) Before using HY (SiAl ratio of 20) molecular sieve, it was calcined at 550°C for 5 hours to remove the adsorbed impurities.

[0062] (2) 0.0625 mol (5.875 g) of phenol, 0.0125 mol (1.225 g) of furfuryl alcohol, 1.42 g (20 wt%) of HY catalyst and 10 g of dichloroethane solvent were weighed into a 50 mL high pressure batch reactor and reacted for 1 h under 0.5 MPa N2 atmosphere, 60°C and 700 r / min.

[0063] (3) After the reaction is completed, the product is centrifuged, the upper organic phase is recovered, and samples are taken for qualitative and quantitative analysis. The product is qualitatively analyzed by gas chromatography, and the product is quantitatively analyzed by gas chromatography-mass spectrometry.

[0064] The conversion rate of furfuryl alcohol was 100%, and the selectivity of the alkylated product was 92%. The alkylated product can be purified by vacuum distillation.

[0065] (4) 1.0 g of alkylation product, 0.2 g of Pd / C, 4.5 g of HZSM-5 and 20 mL of H2O were added to a high-pressure batch reactor and reacted for 12 h under 6 MPa H2 atmosphere, 200 °C and 700 r / min. After the reaction, the organic phase product was collected and the fuel properties were tested. The density of the fuel was 0.807 g / cm 3 , the freezing point is below -60℃.

[0066] Examples 2-13 and Comparative Examples 1-4

[0067] The preparation methods of the fuels in Examples 2-13 and Comparative Examples 1-4 are basically the same as those in Example 1, except for the reaction raw materials (including the type and amount of phenolic compounds and furanol), the type of acidic molecular sieve catalyst, the relative amount of the acidic molecular sieve catalyst (referring to the ratio of the mass of the acidic molecular sieve catalyst to the total mass of the phenolic compounds and furanol) and the alkylation reaction conditions, as shown in Table 1.

[0068] Table 1

[0069]

[0070]

[0071] Examples 14-15

[0072] The phenolic compounds in Examples 14-15 are a mixture, the composition of the phenolic compounds in Example 14 is raw material pool A, and the composition of the phenolic compounds in Example 15 is raw material pool B. The composition of the mixture is shown in Table 2:

[0073] Table 2

[0074]

[0075]

[0076] Using a preparation method substantially the same as that in Example 1, a phenolic mixed raw material pool constructed with real lignin oil was used as a reaction substrate, and the results of the alkylation reaction are shown in Table 3 below.

[0077] Table 3

[0078]

[0079] From the above results, it can be seen that for the alkylation reaction of different phenolic compounds and furanol, by selecting a suitable acidic molecular sieve catalyst and appropriate reaction conditions, the furanol conversion rate can reach 100% and the selectivity of the alkylation product exceeds 95%. Even if a complex phenolic mixture is used to simulate real lignin oil for reaction, the yield of the alkylation product can still reach more than 85%.

[0080] Comparative Example 5

[0081] The preparation method of the alkylation product in this comparative example is basically the same as that in Example 1, except that the amount of the acidic catalyst used is 2 wt %. In this comparative example, the furanol conversion rate is 36%, and the alkylation product selectivity is 43%.

[0082] Comparative Example 6

[0083] The preparation method of the alkylation product in this comparative example is basically the same as that in Example 2, except that the acidic catalyst used is HZSM-5. In this comparative example, the furanol conversion rate is 9% and the alkylation product selectivity is 15%.

[0084] Comparative Example 7

[0085] The preparation method of the alkylation product in this comparative example is basically the same as that in Example 5, except that the acidic catalyst used is HY with a silicon-aluminum ratio of 5.3. In this comparative example, the furanol conversion rate is 25% and the alkylation product selectivity is 31%.

[0086] Comparative Example 8

[0087] The preparation method before fuel in Comparative Example 8 is basically the same as that in Example 1, except that the acidic molecular sieve catalyst is replaced by AlCl3.

[0088] The selectivity of the alkylation product of Comparative Example 8 and the conversion rate of furanol are shown in Table 4 below.

[0089] Table 4

[0090]

[0091] After the acidic molecular sieve catalyst of Example 1 was reused, the recovered acidic molecular sieve catalyst was used as a catalyst to prepare fuel according to the same preparation method as Example 1. The selectivity of the alkylation product and the conversion rate of furanol are shown in Table 5 below.

[0092] Table 5

[0093]

[0094] The catalyst AlCl3 in Comparative Example 8 cannot be recovered and causes serious corrosion to the equipment.

[0095] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0096] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for preparing a fuel, characterized in that: include: A phenolic compound, furanol, an acidic molecular sieve catalyst and a solvent are mixed and an alkylation reaction is carried out in an inert atmosphere to obtain an alkylation product; The alkylation product is subjected to hydrodeoxygenation to obtain the fuel.

2. The preparation method according to claim 1, characterized in that: The phenolic compound includes the structural formula shown in formula (1) and / or formula (2): Wherein, R1 includes H and / or OCH3; R2 includes at least one of CH3, C2H5, C3H7, C2H3O2, C3H5O, C3H5 and C4H7O.

3. The preparation method according to claim 1, characterized in that: The furanol includes the structural formula shown in formula (3) and / or formula (4):

4. The preparation method according to any one of claims 1 to 3, characterized in that: The molar ratio of the phenolic compound to the furanol is 5:0.5-2.5; Preferably, the alkylation product comprises the structural formula shown in formula (5) and / or formula (6): Wherein, R1 includes H and / or OCH3; R2 includes at least one of CH3, C2H5, C3H7, C2H3O2, C3H5O, C3H5 and C4H7O; R3 includes H and / or CHO.

5. The preparation method according to claim 1, characterized in that: The silicon-aluminum ratio of the acidic molecular sieve is 20 to 80; Preferably, the acidic molecular sieve includes at least one of Hβ, HY and Al-MCM-41.

6. The preparation method according to claim 1 or 5, characterized in that: The mass of the acidic molecular sieve catalyst is 5-20 wt % of the total mass of the phenolic compound and the furanol.

7. The preparation method according to claim 1, characterized in that: The temperature range of the alkylation reaction is 60 to 140° C., and the time of the alkylation reaction is 0.5 to 3 hours.

8. The preparation method according to claim 1, characterized in that: The hydrodeoxygenation comprises: Using water as solvent and Pd / C and HZSM-5 as catalysts, the alkylation product is subjected to the hydrodeoxygenation in a hydrogen atmosphere; Preferably, the hydrodeoxygenation temperature is 180-220° C., the pressure is 5-7 MPa, and the time is 10-14 h.

9. The preparation method according to claim 1, characterized in that: The inert atmosphere includes nitrogen and / or argon.

10. A fuel, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 9.

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