Fuel precursor, fuel and preparation method thereof

Abstract

The invention provides a fuel precursor, a fuel and a preparation method thereof. The preparation method of the fuel precursor comprises the following steps: mixing furanol, an organic extractant, water and an acidic molecular sieve catalyst to obtain a mixture; and heating the mixture in an inert atmosphere to obtain the fuel precursor. Along with the proceeding of the reaction, furanol continuously diffuses to the water phase and reacts, and meanwhile, the organic extractant can timely extract the target product fuel precursor into the organic phase, so that further polymerization reaction is avoided, and the yield of the fuel precursor is improved; and the two-phase system enables the separation and purification of the fuel precursor to be easier.

Description

Technical Field

[0001] The present application relates to the field of chemical technology, and in particular to a fuel precursor, a fuel and a preparation method thereof. Background Art

[0002] The main sources of traditional aviation kerosene are fossil fuels such as oil and coal. In order to optimize the energy structure, using biomass energy such as lignocellulose to replace traditional fossil energy is a feasible path. At present, hydrocarbon fuels in the range of C9 to C15 are regarded as excellent aviation fuel components. However, due to the limitations of relevant technologies, the yield of hydrocarbon fuels in the range of C9 to C15 obtained from biomass energy such as lignocellulose is low, with the highest yield being only about 10% to 15%. Summary of the invention

[0003] In view of this, embodiments of the present application provide a fuel precursor, a fuel, and a method for preparing the same.

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

[0005] mixing furanol, an organic extractant, water and an acidic molecular sieve catalyst to obtain a mixture;

[0006] The mixture is heated under an inert atmosphere to obtain the fuel precursor.

[0007] In one embodiment, the furanol includes at least one of furfuryl alcohol, furfuryl alcohol derivatives, 5-methylfurfuryl alcohol, 5-methylfurfuryl alcohol derivatives, 5-hydroxymethylfurfural and 5-hydroxymethylfurfural derivatives.

[0008] In one embodiment, the organic extractant includes at least one of toluene and p-xylene.

[0009] In one embodiment, the silicon-aluminum ratio of the acidic molecular sieve catalyst is 20 to 100;

[0010] Preferably, the acidic molecular sieve catalyst includes at least one of Hβ, HY, Al-MCM-41, Al-SBA-15 and Al-SBA-16.

[0011] In one embodiment, the mass of the acidic molecular sieve catalyst is 5wt% to 16wt% of the mass of the raw material furanol;

[0012] Preferably, the mass ratio of the furanol, water and the organic extractant is 1:1:(0.2-2).

[0013] In one embodiment, the mixture is heated at a temperature of 80°C to 110°C for a time of 6 to 12 hours;

[0014] Preferably, the mixture is heated under stirring conditions;

[0015] Preferably, the stirring speed is 500-1000 rpm.

[0016] In one embodiment, after heating the mixture, the fuel precursor is dispersed in the organic extractant, and water and the organic extractant are separated to obtain the fuel precursor containing the organic extractant;

[0017] The fuel precursor containing the organic extractant is separated and purified to obtain the fuel precursor.

[0018] The second aspect of the present application provides a fuel precursor, which is prepared by the aforementioned preparation method and includes at least one of the structural formulas shown in formula (1) to formula (3):

[0019]

[0020] Where m is equal to 0 or 1, and n is equal to 1 or 2.

[0021] A third aspect of the present application provides a method for preparing a fuel, wherein the aforementioned fuel precursor or the fuel precursor prepared by the aforementioned preparation method is subjected to hydrogenation and deoxygenation to obtain the fuel.

[0022] In one embodiment, a method for preparing a fuel comprises:

[0023] The fuel precursor, the solvent and the first hydrodeoxygenation catalyst are mixed and then subjected to a first reaction;

[0024] The product obtained after the first reaction is mixed with the first hydrodeoxygenation catalyst and the second hydrodeoxygenation catalyst, and then subjected to a second reaction to obtain the fuel;

[0025] Preferably, the first hydrodeoxygenation catalyst comprises Pd / C, and the second hydrodeoxygenation catalyst comprises HZSM-5 molecular sieve;

[0026] Preferably, the conditions of the first reaction include at least one of the following conditions: temperature of 140-160°C; pressure of 3-5 MPa; hydrogen atmosphere; and time of 5-8 h;

[0027] Preferably, the conditions of the second reaction include at least one of the following conditions: temperature of 240-260° C.; pressure of 3-5 MPa; hydrogen atmosphere; and time of 10-14 h.

[0028] According to the preparation method of the fuel precursor provided by the embodiment of the present application, the mixture contains water, an organic extractant and furanol. In the initial stage, furanol is distributed in both the aqueous phase and the organic phase. The mixture is heated, and the reaction mainly occurs in the aqueous phase. The selected acidic molecular sieve catalyst has good hydrophilicity; as the reaction proceeds, furanol continues to diffuse into the aqueous phase and react, and the organic extractant can extract the target product fuel precursor into the organic phase in time, avoiding further polymerization reaction, and improving the yield of the fuel precursor; and the two-phase system makes it easier to separate and purify the fuel precursor. The present application can achieve efficient conversion of furanol to C9-C15 aviation fuel precursor. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic flow chart of a method for preparing a fuel precursor in one embodiment of the present application.

[0030] Figure 2 Graph showing the furanol conversion rate and fuel precursor selectivity in Examples 1-3 and Comparative Examples 1-3. DETAILED DESCRIPTION

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The first aspect of the present application provides a method for preparing the aforementioned fuel precursor, referring to Figure 1 The schematic flow chart of the method for preparing a fuel precursor is shown, and the method for preparing a fuel precursor includes the following steps.

[0036] S100: mixing furanol, an organic extractant, water and an acidic molecular sieve catalyst to obtain a mixture.

[0037] It can be understood that the present application uses a solid acidic molecular sieve as a catalyst and a two-phase system comprising an organic extractant and water for reaction extraction. Due to the use of a two-phase system, the product is distributed in the organic phase, which is easy to separate, thereby solving the problem of low yield of the target product fuel precursor synthesized by the oligomerization reaction of furanol; and the acidic molecular sieve as a catalyst can be recycled and reused, which is conducive to reducing production costs.

[0038] In one embodiment, the silicon-aluminum ratio of the acidic molecular sieve catalyst is 20 to 100, for example, 20, 30, 40, 50, 60, 70, 80, 90 or 100. It should be noted that the silicon-aluminum ratio of the acidic molecular sieve catalyst refers to the molar ratio of SiO2 and Al2O3 of the acidic molecular sieve catalyst. Therefore, the above acidic molecular sieve catalyst is conducive to improving the selectivity of the fuel precursor.

[0039] In one embodiment, the acidic molecular sieve catalyst includes at least one of Hβ, HY, Al-MCM-41, Al-SBA-15 and Al-SBA-16. By using a molecular sieve with good hydrophilicity, the conversion rate of furanol is improved; by using a molecular sieve with relatively low acid content, the selectivity of the fuel precursor is improved.

[0040] In one embodiment, the furanol includes at least one of furfuryl alcohol derivatives, 5-methylfurfuryl alcohol, 5-methylfurfuryl alcohol derivatives, 5-hydroxymethylfurfural and 5-hydroxymethylfurfural derivatives.

[0041] In one embodiment, the organic extractant includes at least one of toluene and p-xylene.

[0042] In one embodiment, the mass of the acidic molecular sieve catalyst is 5wt% to 16wt% of the mass of the raw material furanol, for example, it can be 5wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt% or 16wt%, etc. Relative to the above dosage range, when the dosage of the acidic molecular sieve catalyst is less than 5wt%, the conversion rate of furanol is low; when the dosage of the acidic molecular sieve catalyst is higher than 16wt%, the fuel precursor undergoes further condensation to generate macromolecular substances, and the selectivity is reduced.

[0043] In one embodiment, the mass ratio of the furanol, water and the organic extractant is 1:1:(0.2-2), for example, 1:1:0.2, 1:1:0.5, 1:1:1, 1:1:1.5 or 1:1:2, etc. Relative to the above ratio range, when the amount of the organic extractant is small, the fuel precursor cannot be extracted into the extraction phase in time, and when the amount of the organic extractant is large, the improvement of the furanol conversion rate and the fuel precursor selectivity is not obvious.

[0044] S200: heating the mixture under an inert atmosphere to obtain the fuel precursor.

[0045] In one embodiment, the mixture is heated to a temperature of 80°C to 110°C (eg, 80°C, 90°C, 100°C, or 110°C, etc.) for 6 to 12 hours (eg, 6 hours, 8 hours, 10 hours, or 12 hours, etc.).

[0046] In one embodiment, the mixture is heated under stirring conditions. Thus, the organic extractant can extract the target product fuel precursor into the organic phase in a timely manner, avoiding further polymerization reaction and improving the yield of the fuel precursor.

[0047] In one embodiment, the stirring speed is 500-1000 rpm, for example, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm or 1000 rpm.

[0048] In one embodiment, after heating the mixture, the fuel precursor is dispersed in the organic extractant, and water and the organic extractant are separated to obtain the fuel precursor containing the organic extractant; the fuel precursor containing the organic extractant is separated and purified to obtain the fuel precursor.

[0049] According to the preparation method of the fuel precursor provided by the embodiment of the present application, the mixture contains water, an organic extractant and furanol. In the initial stage, furanol is distributed in both the aqueous phase and the organic phase. The mixture is heated, and the reaction mainly occurs in the aqueous phase. The selected acidic molecular sieve catalyst has good hydrophilicity; as the reaction proceeds, furanol continues to diffuse into the aqueous phase and react, and the organic extractant can extract the target product fuel precursor into the organic phase in time, avoiding further polymerization reaction, and improving the yield of the fuel precursor; and the two-phase system makes it easier to separate and purify the fuel precursor. The present application can achieve efficient conversion of furanol to C9-C15 aviation fuel precursor.

[0050] The second aspect of the present application provides a fuel precursor, which is prepared by the aforementioned preparation method and includes at least one of the structural formulas shown in formula (1) to formula (3):

[0051]

[0052] Where m is equal to 0 or 1, and n is equal to 1 or 2.

[0053] The third aspect of the present application provides a fuel, wherein the fuel comprises the structural formula (4):

[0054]

[0055] Here, x is an integer greater than or equal to 7 and less than or equal to 13, for example, it can be 7, 8, 9, 10, 11, 12 or 13.

[0056] A fourth aspect of the present application provides a method for preparing a fuel, wherein the aforementioned fuel precursor or the fuel precursor prepared by the aforementioned preparation method is subjected to hydrogenation and deoxygenation to obtain the fuel.

[0057] In one embodiment, the method for preparing the fuel includes: mixing the fuel precursor, the solvent and the first hydrodeoxygenation catalyst and performing a first reaction; mixing the product obtained after the first reaction with the first hydrodeoxygenation catalyst and the second hydrodeoxygenation catalyst and performing a second reaction to obtain the fuel.

[0058] In one embodiment, the first hydrodeoxygenation catalyst comprises Pd / C, and the second hydrodeoxygenation catalyst comprises HZSM-5 molecular sieve.

[0059] In one embodiment, the conditions of the first reaction include at least one of the following conditions: temperature of 140-160° C.; pressure of 3-5 MPa; hydrogen atmosphere; and time of 5-8 h.

[0060] In one embodiment, the conditions of the second reaction include at least one of the following conditions: temperature of 240-260° C.; pressure of 3-5 MPa; hydrogen atmosphere; and time of 10-14 h.

[0061] Exemplarily, the step of hydrodeoxygenating the fuel precursor includes: mixing the fuel precursor, solvent (such as cyclohexane, etc.), and Pd / C catalyst, and reacting for 5 to 8 hours at 140 to 160° C., 3 to 5 MPa, and hydrogen atmosphere. After the reaction is completed, the old catalyst is separated by centrifugation, and fresh Pd / C catalyst and HZSM-5 molecular sieve catalyst are added again, and the reaction is carried out for 10 to 14 hours at 240 to 260° C., 3 to 5 MPa, and hydrogen atmosphere.

[0062] 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.

[0063] Example 1

[0064] The method for preparing the fuel precursor comprises the following steps:

[0065] (1) Al-MCM-41 molecular sieve was first calcined at 580 °C for 3 h to remove the adsorbed impurities.

[0066] (2) At 100°C and N2 atmosphere, add 5 g of furfuryl alcohol, 5 g of toluene and 5 g of water into a 25 mL reactor.

[0067] (3) Weigh 0.6 g of calcined Al-MCM-41 molecular sieve and add it to the solution of step (2) under magnetic stirring at 600 rpm, and react for 8 h.

[0068] (4) After the reaction is completed, the organic phase and the aqueous phase are separated; the organic phase is collected and the product components are analyzed using a gas chromatograph-mass spectrometer and a gas chromatograph.

[0069] In this embodiment, the furfuryl alcohol conversion rate is 81%, and the fuel precursor yield is 34.1%.

[0070] Example 2-21

[0071] The preparation method of the fuel precursor of Example 2-21 is basically the same as that of Example 1, except that: the type of furanol, heating temperature, heating time, amount of acidic molecular sieve catalyst, type of acidic molecular sieve catalyst, type of organic extractant, mass ratio of furanol, water and organic extractant, etc. are shown in Table 1. The conversion rate of furanol and the yield of the fuel precursor are also shown in Table 1 below.

[0072] Table 1

[0073]

[0074]

[0075] From the above results, it can be seen that the use of acidic molecular sieves as catalysts for the oligomerization of furanol in combination with the reaction extraction method has high catalyst activity, high furanol conversion rate and target product yield, and the yield of C9-C15 compounds can reach up to 71.56%.

[0076] Comparative Example 1

[0077] The preparation method of the fuel precursor in this comparative example is basically the same as that in Example 1, except that the catalyst Al-MCM-41 is replaced by HY-5.3. In this comparative example, the conversion rate of furfuryl alcohol is 83.4%, and the yield of C9-C15 compounds is 13.6%.

[0078] Comparative Example 2

[0079] The preparation method of the aviation fuel precursor in this comparative example is basically the same as that in Example 1, except that the heating temperature is increased to 150° C. In this comparative example, the conversion rate of furfuryl alcohol is 100%, and the yield of C9-C15 compounds is 16.8%.

[0080] Comparative Example 3

[0081] The preparation method of the aviation fuel precursor in this comparative example is basically the same as that in Example 1, except that the organic extractant is replaced by dioxane. In this comparative example, the conversion rate of furfuryl alcohol is 91.30%, and the yield of C9-C15 compounds is 3.68%.

[0082] The results of furanol conversion and fuel precursor selectivity in Examples 1-3 and Comparative Examples 1-3 are shown in Table 1. Figure 2 In the preparation method of the embodiment of the present application, the furanol conversion rate and the fuel precursor selectivity are both high.

[0083] 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.

[0084] 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 precursor, characterized in that: include: mixing furanol, an organic extractant, water and an acidic molecular sieve catalyst to obtain a mixture; The mixture is heated under an inert atmosphere to obtain the fuel precursor.

2. The preparation method according to claim 1, characterized in that: The furan alcohol includes at least one of furfuryl alcohol, furfuryl alcohol derivatives, 5-methylfurfuryl alcohol, 5-methylfurfuryl alcohol derivatives, 5-hydroxymethylfurfural and 5-hydroxymethylfurfural derivatives.

3. The preparation method according to claim 1, characterized in that: The organic extractant includes at least one of toluene and p-xylene.

4. The preparation method according to claim 1, characterized in that: The silicon-aluminum ratio of the acidic molecular sieve catalyst is 20 to 100; Preferably, the acidic molecular sieve catalyst includes at least one of Hβ, HY, Al-MCM-41, Al-SBA-15 and Al-SBA-16.

5. The preparation method according to claim 1, characterized in that: The mass of the acidic molecular sieve catalyst is 5wt% to 16wt% of the mass of the raw material furanol; Preferably, the mass ratio of the furanol, water and the organic extractant is 1:1:(0.2-2).

6. The preparation method according to claim 1, characterized in that: The mixture is heated to a temperature of 80° C. to 110° C. for a time of 6 to 12 hours; Preferably, the mixture is heated under stirring conditions; Preferably, the stirring speed is 500-1000 rpm.

7. The preparation method according to claim 1, characterized in that: After heating the mixture, the fuel precursor is dispersed in the organic extractant, and water and the organic extractant are separated to obtain the fuel precursor containing the organic extractant; The fuel precursor containing the organic extractant is separated and purified to obtain the fuel precursor.

8. A fuel precursor, characterized in that: It is prepared by the preparation method according to any one of claims 1 to 7, and comprises at least one of the structural formulas shown in formula (1) to formula (3): Where m is equal to 0 or 1, and n is equal to 1 or 2.

9. A method for preparing fuel, characterized in that: The fuel is obtained by hydrodeoxygenating the fuel precursor according to claim 8 or the fuel precursor prepared by the preparation method according to any one of claims 1 to 7.

10. The preparation method according to claim 9, characterized in that: include: The fuel precursor, the solvent and the first hydrodeoxygenation catalyst are mixed and then subjected to a first reaction; The product obtained after the first reaction is mixed with the first hydrodeoxygenation catalyst and the second hydrodeoxygenation catalyst, and then subjected to a second reaction to obtain the fuel; Preferably, the first hydrodeoxygenation catalyst comprises Pd / C, and the second hydrodeoxygenation catalyst comprises HZSM-5 molecular sieve; Preferably, the conditions of the first reaction include at least one of the following conditions: temperature of 140-160°C; pressure of 3-5 MPa; hydrogen atmosphere; and time of 5-8 h; Preferably, the conditions of the second reaction include at least one of the following conditions: temperature of 240-260° C.; pressure of 3-5 MPa; hydrogen atmosphere; and time of 10-14 h.

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