Method for preparing sustainable aviation fuel component oil from biomass-based derivative

Abstract

The invention discloses a method for preparing sustainable aviation fuel component oil by using a biomass-based derivative, and belongs to the technical field of biological aviation fuel preparation. The method comprises the following steps: carrying out aldol condensation on furfural and 2, 5-hexanedione to increase a carbon chain so as to obtain an oxygen-containing aviation oil precursor; performing pre-hydrogenation on the oxygen-containing aviation oil precursor by using an M1 catalyst to obtain a pre-hydrogenation product; carrying out catalytic hydrodeoxygenation, catalytic hydrocracking and catalytic isomerization on the pre-hydrogenation product by using an M2 catalyst, and fractionating to obtain aviation fuel component oil, the M1 catalyst is characterized in that Ni metal is loaded on a metal oxide carrier; the M2 catalyst is prepared by loading Ni metal on an acidic hierarchical pore molecular sieve carrier. The carbon number of the prepared aviation fuel component is in continuous normal distribution, and the sustainable aviation fuel component oil is prepared by taking common biomass-based platform derivatives as raw materials, so that the method has important significance on promoting green development of the aviation field.

Description

Technical Field

[0001] The invention belongs to the technical field of bio-aviation fuel preparation, and in particular relates to a method for preparing sustainable aviation fuel component oil by using biomass-based derivatives. Background Art

[0002] Most biomass platform molecules are short-chain oxygenated compounds, which are not suitable for direct use as fuels. Long-chain hydrocarbon fuels can be efficiently prepared through CC coupling reactions (such as aldol condensation, ketonization, oligomerization, hydroxyalkylation, etc.) and then deoxygenation (i.e. dehydration, hydrogenolysis, hydrogenation, decarbonization / decarboxylation, etc.).

[0003] In the early stage, Dumesic's team used acetone (C 3 ) with biomass-derived furan aldehydes (such as 5-hydroxymethylfurfural and furfural) to extend the carbon chain, followed by hydrodeoxygenation to obtain C 8 The above straight-chain alkanes (Science, 2005, 308, 1446-1450). However, the final product of this technical route is mainly short-chain normal alkanes. In addition, the generated aviation fuel precursors such as furfural acetone and difurfuryl acetone are prone to self-condensation reaction at high temperature, resulting in many side reactions and low yields during the hydrodeoxygenation process. Hydrodeoxygenation of aviation fuel precursors after low-temperature hydrogenation saturation can effectively avoid side reactions and catalyst carbon deposition, thereby improving catalytic efficiency.

[0004] Patent CN117866673B proposes a method of using a cellulose derivative 2,5-hexanedione (C 6 ) to provide α-H, and C 11 The long-chain aviation fuel precursor of propylene is further hydrodeoxygenated to synthesize alkane products. Patents CN103805224B, CN104711007A, and CN102850157B use an equal volume impregnation method to load the metal on a solid acid carrier, and directly hydrodeoxygenate the aldol condensation product to obtain an alkane product with the corresponding carbon number. However, this route has the following problems: (1) The metal particles obtained by the catalyst prepared by the traditional impregnation method are large in size, resulting in a decrease in the utilization rate of the active metal. In addition, the interaction between larger metal particles and the acid carrier is weak, and the metal particles are prone to migration and agglomeration during high temperature, which reduces the catalytic activity. (2) The carbon chain length of the ideal sustainable aviation fuel should be between C 8 ~C 16 and presents a normally distributed characteristic. However, the alkane component obtained through this route is single and needs to be further regulated by catalytic cracking, catalytic isomerization and other reactions. Summary of the invention

[0005] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a method for preparing sustainable aviation fuel using biomass-based derivatives, which solves the problems in the prior art.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing a sustainable aviation fuel component oil comprises the following steps:

[0008] The furfural and 2,5-hexanedione are subjected to aldol condensation to extend the carbon chain to obtain an oxygenated jet fuel precursor;

[0009] Pre-hydrogenating the oxygenated aviation fuel precursor using an M1 catalyst to obtain a pre-hydrogenated product;

[0010] The pre-hydrogenated product is subjected to catalytic hydrodeoxygenation, catalytic hydrocracking and catalytic isomerization using an M2 catalyst, and a sustainable aviation fuel component oil is obtained after fractionation;

[0011] The M1 catalyst is: Ni metal loaded on a metal oxide carrier; the M2 catalyst is: Ni metal loaded on an acidic multi-level pore molecular sieve carrier.

[0012] Furthermore, the molar ratio of furfural to 2,5-hexanedione is 1:5 to 5:1.

[0013] Furthermore, the step of preparing the oxygenated aviation fuel precursor includes: adding a mixed solution of furfural and 2,5-hexanedione to a NaOH aqueous solution for aldol condensation; after the reaction is completed, quenching the reaction in an ice water bath, adding acid for neutralization, centrifuging, washing, and drying to obtain the oxygenated aviation fuel precursor.

[0014] Furthermore, the process of pre-hydrogenation of the oxygenated jet fuel precursor is as follows: the oxygenated jet fuel precursor and the solvent are dissolved and mixed in a mixer; thereafter, the oxygenated jet fuel precursor is pushed into a gasifier together with hydrogen for preheating, and then flows into a pre-hydrogenation reactor, where the C=C and C=O in the oxygenated jet fuel precursor are saturated under the action of an M1 catalyst to obtain a pre-hydrogenation product.

[0015] Furthermore, the solvent is isopropanol or acetone.

[0016] Furthermore, the process of obtaining the sustainable aviation fuel component oil is as follows:

[0017] The pre-hydrogenated product flows to the hydrodeoxygenation, hydrocracking and isomerization reactors, where it undergoes hydrodeoxygenation, hydrocracking and isomerization treatments under the action of the M2 catalyst;

[0018] After the reaction is completed, the materials enter the first separator, where they are condensed to separate the gas phase and the liquid phase. The hydrogen is separated, purified and pressurized before being recycled and enters the hydrodeoxygenation, hydrocracking and isomerization reactors for hydrogen supplementation, while the liquid phase alkanes flow into the second separator.

[0019] The solvent and the product are separated in the second separator, and the vaporized solvent is condensed and liquefied by the condenser and then enters the mixer for recycling. The liquid phase material flowing out of the second separator is the sustainable aviation fuel component oil.

[0020] Furthermore, in the M1 catalyst, the metal oxide is Al 2 O 3 、CeO 2 Or ZrO; the loading amount of Ni metal is 5 to 30wt%.

[0021] Furthermore, in the M2 catalyst, the acidic multi-level porous molecular sieve carrier is HZSM-5, Hβ or HY; and the loading amount of Ni metal is 5 to 30 wt%.

[0022] Furthermore, the preparation process of the M2 catalyst includes:

[0023] After the molecular sieve is treated with alkali, it is passed through NH 4 The acidic multi-level pore molecular sieve carrier is obtained by calcining after ion exchange of Cl aqueous solution;

[0024] Will Ni(NO 3 ) 2 6H 2 O is dissolved in deionized water, ethylene glycol is added to continue ultrasonic dissolution, and then it is dropped onto the acidic multi-level porous molecular sieve carrier for loading, and the M2 catalyst is obtained after drying and calcination.

[0025] Application of the above-mentioned method for preparing a sustainable aviation fuel component oil in the preparation of sustainable aviation fuel.

[0026] Beneficial effects of the present invention:

[0027] 1. The present invention designs a highly dispersed Ni-based multi-level porous catalyst and develops a new catalyst. On the one hand, the active metal is loaded on the carrier by the ethylene glycol-assisted impregnation method, which effectively reduces the size of the metal particles and improves the metal activity and stability; on the other hand, a "top-down" strategy is adopted to construct a multi-level porous molecular sieve carrier. The multi-level pores can not only overcome the diffusion limitation of the reactants, but also the Ni active metal particles can be distributed in the pores, thereby improving the reaction efficiency.

[0028] 2. The present invention proposes a new process for directly obtaining high-quality aviation fuel by dual-stage bed continuous hydrogenation, that is, the aviation fuel precursor is first pre-hydrogenated on a Ni-based catalyst to saturate the C=C and C=O bonds in the aviation fuel precursor raw material; the pre-hydrogenated material is efficiently hydrogenated and CO bonds are broken on highly dispersed Ni active sites, and hydrocracking and isomerization reactions are carried out on a multi-level pore molecular sieve carrier with abundant acid sites to obtain a highly isoparaffinized aviation fuel product with continuous normal distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 is the XRD spectrum of M2 catalyst;

[0031] Figure 2 TEM image of Ni / HZSM-5-m;

[0032] Figure 3 This is the GC-MS spectrum of the oxygenated jet fuel precursor obtained after aldol condensation in Example 1;

[0033] Figure 4 It is a process flow chart of pre-hydrogenation, hydrodeoxygenation, hydrocracking and isomerization reactions of the present invention;

[0034] Figure 5 This is the GC spectrum of the sustainable aviation fuel component oil obtained in Example 24;

[0035] Figure 6 This is the product distribution diagram of the sustainable aviation fuel component oil obtained in Example 24;

[0036] Figure 7 It is a synthetic route map of the sustainable aviation fuel component oil of the present invention.

[0037] In the figure: 1-mixer, 2-gasifier, 3-pre-hydrogenation reactor, 4-hydrogenation deoxygenation, hydrocracking, isomerization reactor, 5-first separator, 6-second separator, 7-hydrogen separation and purification booster, 8-condenser. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] like Figure 7 As shown, a method for preparing a sustainable aviation fuel component oil from a biomass-based derivative comprises the following steps:

[0040] S1, biomass derivative furfural and 2,5-hexanedione undergo aldol condensation to extend the carbon chain to obtain C 11 ~C 16 oxygenated jet fuel precursors;

[0041] S2, pre-hydrogenating the oxygenated aviation fuel precursor using M1 catalyst (pre-hydrogenation catalyst) to obtain a pre-hydrogenation product;

[0042] S3, using M2 catalyst (hydrodeoxygenation, hydrocracking, isomerization catalyst) to catalytically perform hydrodeoxygenation, catalytic hydrocracking and catalytic isomerization on the pre-hydrogenated product, and obtain sustainable bio-sustainable aviation fuel component oil after fractionation.

[0043] In S1, an inorganic base is used to catalyze the aldol condensation of furfural and 2,5-hexanedione, wherein the inorganic base is NaOH, and the molar concentration of the alkaline solution is 0.01 to 2 mol / L, such as 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.5 mol / L, 1 mol / L, 2 mol / L. In some embodiments, the molar ratio of furfural to 2,5-hexanedione is 1:5 to 5:1, such as 1:5, 1:2, 1:1, 2:1, 5:1, etc.

[0044] The aldol condensation reaction is carried out in a thick-walled pressure-resistant tube at normal pressure. After furfural and 2,5-hexanedione are mixed evenly, they are added to an inorganic alkali solution and continuously and rapidly stirred. The reaction temperature is 25 to 80°C, for example, 25°C, 40°C, 60°C, 80°C, etc.; the reaction time is 1 to 8h, for example, 1h, 3h, 5h, 8h, etc.

[0045] After the reaction was completed, the condensation product was obtained by centrifugation, washed with deionized water and dried to obtain C 11 ~C 16 Long-chain oxygen-containing compounds (jet fuel precursors) are mainly single condensation and double condensation mixed products, and their corresponding molecular structures are as follows:

[0046]

[0047] The jet fuel precursor product obtained after aldol condensation is a viscous dark brown substance. Due to its high viscosity, it is necessary to C 11 ~C 16 The oxygenated jet fuel precursor is dissolved in an organic solvent, which is one or more of C1-3 alcohols, acetone, and cycloalkanes; the jet fuel precursor solution is pumped into a fixed bed front-end reactor for low-temperature pre-hydrogenation reaction to saturate the C=C and C=O bonds in the jet fuel precursor, in order to avoid serious side reactions and catalyst deactivation during high-temperature hydrodeoxygenation.

[0048] The pre-hydrogenation catalyst (M1 catalyst) is Ni / Al 2 O 3 、Ni / CeO 2 、Ni / ZrO 2 One of the above, wherein the Ni metal loading is 5 to 30 wt%, such as 5 wt%, 10 wt%, 15 wt%, 20 wt%, 30 wt%; the pre-hydrogenation reaction temperature is 100 to 180°C, such as 100°C, 120°C, 150°C, 180°C, etc.; the reaction hydrogen pressure is 2 to 6 MPa, such as 2 MPa, 4 MPa, 6 MPa, etc.; the mass space velocity is 0.2 to 4 h -1 , for example, 0.2h -1 , 0.5h -1 , 1h -1 , 2h -1 , 3h -1 , 4h -1 wait.

[0049] After pre-hydrogenation treatment, the reaction liquid flows directly into the fixed bed rear reactor for hydrodeoxygenation, hydrocracking and isomerization reaction. After pre-hydrogenation, the hydrogenation and CO bond breaking steps are usually carried out at the metal site, and the acid site of the zeolite can dehydrate the alcohol intermediate, isomerize and hydrocracking the long-chain alkanes. The present invention realizes the preparation of a catalyst (M2 catalyst) with high metal dispersion under the condition of high metal loading, using a multi-level porous molecular sieve as an acid carrier, and exhibits high activity and stability in the hydrodeoxygenation reaction.

[0050] The hydrogenation active metal of the reaction catalyst (M2 catalyst) is Ni, and the metal precursor is one of nickel nitrate, nickel chloride, nickel acetylacetonate, and nickel citrate; the molar ratio of ethylene glycol to Ni species in the precursor solution is 0.5 to 3, for example, 1:2, 1:1, 2:1, 3:1; the metal loading is 5 to 30wt%, for example, 5wt%, 10wt%, 15wt%, 20wt%, 30wt%, etc.

[0051] The acidic carrier of the M2 catalyst is a multi-level porous molecular sieve, such as HZSM-5, Hβ, HY, etc.; the concentration of the alkali solution for treating the molecular sieve is 0.05-2mol / L, such as 0.05mol / L, 0.2mol / L, 0.4mol / L, 1mol / L, 2mol / L, etc.; the treatment temperature is 50-100℃, such as 50℃, 80℃, 100℃, etc.; the treatment time is 40-80min, such as 40min, 60min, 80min, etc. The molecular sieve treated with alkali is washed, dried, calcined, and then NH 4 Cl aqueous solution ion exchange, in which NH 4 The concentration of Cl aqueous solution is 0.5-2 mol / L, for example, 0.5 mol / L, 1 mol / L, 2 mol / L, etc.; the ion exchange temperature is 50-100°C, for example, 50°C, 80°C, 100°C, etc.; the ion exchange time is 2-6h, for example, 2h, 4h, 6h, etc.; the number of ion exchanges is 2-5 times, for example, 2 times, 3 times.

[0052] The reaction temperature of catalytic hydrodeoxygenation, catalytic hydrocracking and catalytic isomerization is 220-320°C, for example, 220°C, 240°C, 260°C, 280°C, 300°C, 320°C, etc.; the reaction hydrogen pressure is 2-6MPa, for example, 2MPa, 4MPa, 6MPa, etc.; the mass space velocity is 0.5-10h -1 , for example, 1h -1 , 1.25h -1 , 2.5h -1 , 5h -1 , 7.5h -1 , 10h -1 .

[0053] Preparation of M1 catalyst

[0054] The preparation method of the pre-hydrogenation catalyst (M1 catalyst) used in the example is as follows:

[0055] Weigh Al(NO 3 ) 3 6H 2 O was dissolved in deionized water, and urea was added under magnetic stirring. Transferred to the polytetrafluoroethylene liner of a 100 mL stainless steel hydrothermal kettle, kept at 150 °C for 12 h, cooled to room temperature, centrifuged and washed thoroughly. After vacuum drying at 80 °C for 12 h, Al(OH) 3 Precursor, Al(OH) 3 The precursor was calcined in a muffle furnace at 500 °C for 6 h to obtain Al 2 O 3 carrier.

[0056] Will Ce(NO 3 )3 6H 2 O and NaOH were dissolved in deionized water, respectively. Then, the solutions were mixed and stirred for 30 min. The resulting mixture was transferred to a 100 mL stainless steel hydrothermal kettle lined with polytetrafluoroethylene, kept at 100 °C for 24 h, cooled to room temperature, centrifuged and washed thoroughly. Ce(OH) was obtained after vacuum drying at 80 °C for 12 h. 3 Precursor, Al(OH) 3 The precursor was calcined in a muffle furnace at 500 °C for 4 h to obtain CeO 2 carrier.

[0057] Cl 2 OZr was dissolved in deionized water, and 25% ammonia and PEG-600 were mixed in deionized water. After the two solutions were heated to 55°C, the 25% ammonia and PEG-600 mixed solution was quickly added to the Cl 2 The resulting mixture was stirred at 55°C for 30 min and aged at room temperature for 12 h. After centrifugation, it was fully washed, dried at 110°C for 1 h, and calcined at 400°C for 3 h in a muffle furnace to obtain a ZrO2 carrier.

[0058] Weigh Ni(NO 3 ) 2 6H 2 O was dissolved in deionized water and ultrasonicated for 30 min to completely dissolve, and then slowly added to Al 2 O 3 、CeO 2 and ZrO 2 The catalyst was stirred at 60 °C for 12 h, dried at 105 °C in a forced air drying oven for 12 h, and then calcined at 450 °C in a muffle furnace for 4 h at a heating rate of 5 °C / min to obtain the pre-hydrogenation catalyst Ni / Al 2 O 3 、Ni / CeO 2 and Ni / ZrO 2 .

[0059] Preparation of M2 catalyst

[0060] The preparation method of the hydrodeoxygenation, hydrocracking and isomerization catalyst (M2 catalyst) used in the examples is as follows:

[0061] Weigh HZSM-5, Hβ, and HY molecular sieves with MFI, BEA, and FAU topological structures respectively and add them to 0.4 mol / L NaOH solution. Stir at 70°C for 60 min and filter. Wash thoroughly with deionized water until the filtrate is neutral. Dry in a forced air drying oven at 105°C for 12 h to obtain multi-level pore NaZSM-5, denoted as NaZSM-5-m (multi-level pore Naβ is denoted as Naβ-m; multi-level pore NaY is denoted as NaY-m). 10 g NaZSM-5-m, Naβ-m, and NaY-m were respectively added to 200 mL of 1.0 mol / L NH 4 Cl solution at 80 °C for 3 h, the treatment was repeated 3 times, and after drying in a 105 °C forced air drying oven for 12 h, it was calcined at 550 °C in a muffle furnace for 4 h to obtain multi-level porous HZSM-5, Hβ, and HY, which were denoted as HZSM-5-m, Hβ-m, and HY-m.

[0062] Weigh Ni(NO 3 ) 2 6H 2 O was dissolved in deionized water, ultrasonicated for 30 minutes to completely dissolve, and then ethylene glycol was added at a molar ratio of Ni:ethylene glycol of 1:1, and ultrasonicated for 30 minutes. It was slowly added dropwise to the multi-level porous molecular sieve support for equal volume impregnation, stirred at 60°C for 12 hours, dried at 105°C in a blast drying oven for 12 hours, and calcined at 400°C in a muffle furnace for 2 hours to obtain hydrodeoxygenation, hydrocracking, and isomerization catalysts Ni / HZSM-5-m, Ni / Hβ-m, and Ni / HY-m.

[0063] Figure 1 XRD spectra of 15% Ni / HZSM-5-m, original HZSM-5 and HZSM-5-m for hydrodeoxygenation, hydrocracking and isomerization catalysts. The stability of the carrier is closely related to the topological structure of the molecular sieve. High framework density zeolites such as MFI are relatively stable in high temperature hydrothermal environments. Figure 1 It can be seen that the synthesized Ni / HZSM-5-m maintains the MFI topological structure. A weaker and broader NiO diffraction peak was detected in the XRD spectrum of Ni / HZSM-5-m, and the NiO grain size was calculated to be ~7.8nm using the Fourier formula. Figure 2 The TEM image of Ni / HZSM-5-m shows that Ni is evenly distributed on the support without obvious agglomeration.

[0064] The method for preparing the sustainable aviation fuel component oil of the present invention is introduced below through the following examples and comparative examples.

[0065] Examples 1-9

[0066] Examples 1 to 9 are used to illustrate the preparation of C by condensation of furfural and 2,5-hexanedione in the process for preparing sustainable aviation fuel component oil of the present invention. 11 ~C 16 Oxygenated jet fuel precursors:

[0067] The mixed solution of furfural and 2,5-hexanedione was added to 25 mL of NaOH aqueous solution for aldol condensation. After the reaction was completed, the reaction was quenched in an ice water bath, and hydrochloric acid was added for neutralization, centrifugation, washing, and drying to obtain the oxygenated jet fuel precursor. The specific reaction parameters and the total carbon yield of the product are shown in Table 1. Figure 3 The GC-MS spectrum of the condensation product of Example 1 shows that C 11 ~C 16 Condensation products.

[0068] Table 1 Condensation reaction of furfural and 2,5-hexanedione under different process parameters

[0069]

[0070]

[0071] It can be concluded from Examples 1 to 3 in Table 1 that a higher product carbon yield can be obtained when the molar ratio of furfural to 2,5-hexanedione is 2:1; it can be concluded from Examples 1, 4, and 5 that the NaOH concentration is 0.05 mol / L; it can be concluded from Examples 1, 6, and 7 that the aldol condensation reaction temperature is 40°C; it can be concluded from Examples 1, 8, and 9 that the reaction time is 5 hours. When the NaOH concentration is low, the reaction temperature is low, and the reaction time is short, the condensation efficiency is low, and furfural and 2,5-hexanedione are not completely converted. When the NaOH concentration is high, the reaction temperature is high, and the reaction time is long, a large number of macromolecular tri-condensation and tetra-condensation products will be formed, and the carbon number length is not within the sustainable aviation fuel range, and it is not conducive to the subsequent hydrodeoxygenation and upgrading process.

[0072] Examples 10-23

[0073] Examples 10 to 23 are used to illustrate the pre-hydrogenation reaction in the process for preparing sustainable aviation fuel component oil of the present invention to saturate C=C and C=O;

[0074] like Figure 4 As shown, according to Figure 4As shown in the process flow chart, the oxygenated jet fuel precursor obtained by aldol condensation prepared in Example 1 and the solvent are added to the mixer 1, stirred and fully dissolved as the pre-hydrogenation reaction raw materials, the raw materials are pushed into the gasifier 2 together with hydrogen for preheating, and then flow into the pre-hydrogenation reactor 3, under the action of the pre-hydrogenation catalyst (M1 catalyst), the C=C and C=O in the oxygenated jet fuel precursor are saturated, and the solubility of the pre-hydrogenated raw materials in the solvent is higher, which is conducive to the next step of the hydrodeoxygenation reaction. The reaction conditions and results are shown in Table 2.

[0075] Table 2 Catalytic pre-hydrogenation reaction of furfural and 2,5-hexanedione aldol condensation products

[0076]

[0077] From the pre-hydrogenation experiment in Table 2, Example 10 was selected as the optimal reaction condition, and the subsequent hydrodeoxygenation, hydrocracking, and isomerization reactions were carried out under the pre-hydrogenation conditions of Example 10.

[0078] Examples 24-36

[0079] Examples 24 to 36 are used to illustrate the hydrodeoxygenation, hydrocracking and isomerization reactions in the process for preparing sustainable aviation fuel component oil of the present invention.

[0080] according to Figure 4 As shown in the process flow chart, the pre-hydrogenated material continues to flow to the lower hydrodeoxygenation reactor 4, and is subjected to quality improvement treatments such as hydrodeoxygenation, hydrocracking, and isomerization in the reactor under the action of the M2 catalyst. The material after the reaction is completed enters the first separator 5, and the gas phase and liquid phase materials are separated after condensation. The hydrogen is separated, purified and pressurized by the hydrogen separation and purification booster 7 and recycled, and enters the hydrodeoxygenation, hydrocracking, and isomerization reactor 4 for hydrogen supplementation, and the liquid phase alkane flows into the second separator 6. The solvent and the product are separated in the second separator, and the vaporized solvent is condensed and liquefied by the condenser 8 and can be recycled in the mixer 1. The liquid phase material flowing out of the second separator is the sustainable aviation fuel component oil.

[0081] Figure 5 is the GC spectrum of the product of Example 24, Figure 6 The product distribution of Example 24 is shown in the figure. As can be seen from the figure, the alkane component after hydrodeoxygenation has a continuous carbon number distribution and a normal distribution characteristic, showing a high isoalkane ratio. The experimental results show that under the action of the M2 multifunctional catalyst, hydrodeoxygenation, hydrocracking and isomerization reactions occur, realizing the integration of multiple reactions and improving product quality and preparation efficiency.

[0082] The reaction conditions and results are shown in Table 3.

[0083] Table 3 Preparation of sustainable aviation fuel component oil by hydrodeoxygenation

[0084]

[0085]

[0086] As can be seen from Table 3, after post-treatment, HZSM-5 molecular sieve has strong acidity and suitable pore structure, and shows excellent performance in the subsequent hydrodeoxygenation, hydrocracking and isomerization reactions of the pre-hydrogenation products of long-chain aviation fuel precursors. The ability to remove oxygen is insufficient when the carrier acidity is weak or the loading amount of hydrogenation active metal Ni is low. The catalyst in Example 24 can achieve continuous reaction for 500 hours. The sustainable aviation fuel obtained after fractionation of the product of Example 24 has a density of 0.82 g / mL and a freezing point of <-50°C. It can be mixed with traditional aviation fuel without changing the existing aircraft and engine design, while providing better performance.

[0087] Comparative Example 1

[0088] The oxygenated jet fuel precursor prepared by aldol condensation in Example 1 was directly subjected to hydrodeoxygenation, and the reaction conditions were the same as those in Example 24. After 48 hours of reaction, the catalyst was completely deactivated. It was calculated that the oxygen content of the product was 13%. 8+ The alkane yield was 46%.

[0089] Comparative Example 2

[0090] The reaction was carried out under the same conditions as in Example 24, except that the catalyst used in the hydrodeoxygenation, hydrocracking and isomerization reactions was 15% Ni / HZSM-5 synthesized using the original HZSM-5 as a carrier. 1 ~C 7 The alkane content is 47%, C 8 ~C 16 The alkane yield was 31%, and the catalyst was completely deactivated after 96 hours of reaction.

[0091] It can be seen from Examples 1 to 36 and Comparative Examples 1 to 2 that the method and process for preparing sustainable aviation fuel of the present invention have significant advantages. The step of pre-hydrogenating the aldol condensation product can effectively reduce the side reactions (such as condensation and polymerization reactions) in the hydrodeoxygenation process, slow down the deactivation of the catalyst, and extend the service life of the catalyst. HZSM-5 molecular sieve is a zeolite material with an MFI structure. Due to its unique catalytic properties, it is widely used in a variety of chemical reactions. The Ni-based hydrodeoxygenation catalyst synthesized with the multi-level pore HZSM-5 molecular sieve as a carrier not only improves the mass transfer efficiency of macromolecular reactants and products, but also improves the catalyst's anti-carbon deposition performance. In a two-stage continuous flow fixed bed reactor, pre-hydrogenation, hydrodeoxygenation, hydrocracking and isomerization reactions are carried out continuously, forming a compact process flow, simplifying the sustainable aviation fuel production process, and being suitable for a continuous production process.

[0092] In summary, the method and process of sustainable aviation fuel proposed in the present invention optimizes the preparation route. After obtaining the oxygenated aviation fuel precursor through aldol condensation, pre-hydrogenation saturation of double bonds is first performed, and then hydrodeoxygenation, hydrocracking and isomerization reactions are carried out. In each reaction, a suitable specific catalyst is used to reduce the occurrence of side reactions in the whole process and improve the reaction conversion rate and yield. The present invention uses biomass platform compounds as raw materials, uses non-precious metal-based catalysts for quality improvement, reduces production costs, improves economic benefits, and is conducive to promoting the commercialization and large-scale development of biomass aviation fuel.

[0093] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0094] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for preparing a sustainable aviation fuel component oil, characterized in that: The following steps are involved: The furfural and 2,5-hexanedione are subjected to aldol condensation to extend the carbon chain to obtain an oxygenated jet fuel precursor; Pre-hydrogenating the oxygenated aviation fuel precursor using an M1 catalyst to obtain a pre-hydrogenated product; Using M2 catalyst to perform catalytic hydrodeoxygenation, catalytic hydrocracking and catalytic isomerization on the pre-hydrogenated product, and obtain sustainable aviation fuel component oil after fractionation; The M1 catalyst is: Ni metal loaded on a metal oxide carrier; the M2 catalyst is: Ni metal loaded on an acidic multi-level pore molecular sieve carrier.

2. The method for preparing a sustainable aviation fuel component oil according to claim 1, characterized in that: The molar ratio of furfural to 2,5-hexanedione is 1:5 to 5:

1.

3. The method for preparing a sustainable aviation fuel component oil according to claim 1 or 2, characterized in that: The steps of preparing the oxygenated aviation fuel precursor include: adding a mixed solution of furfural and 2,5-hexanedione into a NaOH aqueous solution for aldol condensation; after the reaction is completed, quenching the reaction in an ice water bath, adding acid for neutralization, centrifuging, washing, and drying to obtain the oxygenated aviation fuel precursor.

4. The method for preparing a sustainable aviation fuel component oil according to claim 1, characterized in that: The process of pre-hydrogenation of oxygenated jet fuel precursor is as follows: the oxygenated jet fuel precursor and the solvent are dissolved and mixed in a mixer; then the oxygenated jet fuel precursor is pushed into a gasifier together with hydrogen for preheating, and then flows into a pre-hydrogenation reactor, where the C=C and C=O in the oxygenated jet fuel precursor are saturated under the action of the M1 catalyst to obtain a pre-hydrogenated product.

5. The method for preparing a sustainable aviation fuel component oil according to claim 4, characterized in that: The solvent is isopropyl alcohol or acetone.

6. The method for preparing a sustainable aviation fuel component oil according to claim 4, characterized in that: The process of obtaining sustainable aviation fuel component oil is as follows: The pre-hydrogenated product flows to the hydrodeoxygenation, hydrocracking and isomerization reactors, where it undergoes hydrodeoxygenation, hydrocracking and isomerization treatments under the action of the M2 catalyst; The materials after the reaction are completed enter the first separator, where the gas phase and liquid phase materials are separated after condensation; The hydrogen is recycled after separation, purification and pressurization, and enters the hydrodeoxygenation, hydrocracking and isomerization reactors for hydrogen supplementation, and the liquid alkane flows into the second separator; The solvent and the product are separated in the second separator, and the vaporized solvent is condensed and liquefied by the condenser and then enters the mixer for recycling. The liquid phase material flowing out of the second separator is the sustainable aviation fuel component oil.

7. The method for preparing a sustainable aviation fuel component oil according to claim 1, characterized in that: In the M1 catalyst, the metal oxide is Al2O3, CeO2 or ZrO; and the loading amount of Ni metal is 5 to 30 wt%.

8. The method for preparing a sustainable aviation fuel component oil according to claim 1, characterized in that: In the M2 catalyst, the acidic multi-level porous molecular sieve carrier is HZSM-5, Hβ or HY; the loading amount of Ni metal is 5 to 30 wt%.

9. The method for preparing a sustainable aviation fuel component oil according to claim 8, characterized in that: The preparation process of M2 catalyst includes: The molecular sieve is treated with alkali, and then calcined by ion exchange with an NH4Cl aqueous solution to obtain the acidic multi-level porous molecular sieve carrier; Ni(NO3)2·6H2O was dissolved in deionized water, ethylene glycol was added to continue ultrasonic dissolution, and then added dropwise to the acidic multi-level porous molecular sieve carrier for loading, and the M2 catalyst was obtained after drying and calcination.

10. Use of the method for preparing a sustainable aviation fuel component oil according to any one of claims 1 to 9 in preparing sustainable aviation fuel.

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