A method for the production of sustainable aviation kerosene from biomass-based ethylene glycol

Abstract

The application discloses a method for preparing sustainable aviation kerosene (isomeric paraffin) by a two-step method of bio-based ethylene glycol, and belongs to the technical field of biomass fuel preparation. The bio-based ethylene glycol is used as raw material, a condensation carbonation reaction is carried out under the condition of high-pressure nitrogen atmosphere and 250-350 DEG C to prepare C4-C6 isomeric alcohol intermediates; and the obtained isomeric alcohol is catalyzed by a solid acid hydrogenation bifunctional catalyst, and C8-C16 isomeric paraffin, i.e. sustainable aviation kerosene components, is obtained through dehydration condensation and hydrogenation conversion. The application opens up a brand-new process route for preparing sustainable aviation fuel from biomass-based dihydric alcohol, the intermediates do not need additional isomerization treatment, the process is green and does not produce three wastes, and thus a feasible technical scheme is provided for low-carbon emission reduction and diversified supply of sustainable aviation fuel for the aviation industry.

Description

Technical Field

[0001] This method relates to a green fuel synthesis technology, specifically a method for preparing sustainable aviation fuel from biomass-based diols. Background Technology

[0002] The air transport industry is a significant source of carbon emissions in the global transportation sector. Promoting sustainable aviation fuel (SAF) to replace traditional petroleum-based jet fuel has become a core technological path for the aviation industry to achieve deep emission reductions. Traditional petroleum-based jet fuel relies on fossil crude oil refining, is non-renewable, and has high carbon emission intensity throughout its entire life cycle, making it difficult to meet the mandatory targets for low-carbon development in the medium and long term.

[0003] Currently, the mainstream industrialized production routes for sustainable aviation fuel include several technologies such as hydrogenated oil and fat fuel (HEFA), Fischer-Tropsch synthesis (FT-SPK), alcohol-to-jet fuel (ATJ), and electro-liquid fuel (PtL). Conventional ATJ processes mostly use single low-carbon alcohols such as ethanol and butanol as raw materials. The carbon chain growth steps are cumbersome, and the generated straight-chain alkanes require an additional independent isomerization process to meet the low-temperature flowability requirements of aviation fuel. The superimposed processes lead to problems such as increased equipment investment, multiple separation and purification of materials, and decreased overall yield.

[0004] Bio-based ethylene glycol is a large-scale industrial biomass platform compound that can be produced on a large scale from lignocellulosic biomass such as straw and agricultural and forestry waste through hydrolysis and hydrogenolysis. It boasts a wide range of raw material sources, stable prices, and sustainable supply, making it a highly promising renewable oxygen-containing feedstock. Currently, few technologies offer complete processes for the targeted synthesis of jet fuel components from bio-based ethylene glycol as a starting material. The few existing polyol conversion routes suffer from problems such as poor catalytic system compatibility, the need for multiple rounds of purification of intermediate products, the requirement for subsequent separate isomerization modification, numerous process byproducts, and the generation of wastewater and waste residue. These issues result in insufficient greenness and make it difficult to achieve continuous and stable production of C8–C16 isoparaffinic jet fuel products.

[0005] In summary, existing SAF preparation technologies are constrained by multiple factors such as raw material supply, process complexity, process matching, and environmental emissions. There is an urgent need to develop a new sustainable aviation kerosene preparation process that uses readily available bio-based ethylene glycol as raw material, has a simplified process, does not require secondary isomerization, and is clean and free of waste emissions throughout the entire process. Summary of the Invention

[0006] This invention, building upon existing monohydric alcohol-to-jet (ATJ) technology, innovatively proposes a novel process route (Ethylene glycol to Jet, EGTJ) for producing sustainable aviation kerosene using ethylene glycol as a raw material. The aim is to establish a new, environmentally friendly, and biomass-resource-based sustainable aviation kerosene production technology. The complete process route is shown in Figure 1, consisting of two core steps: Step 1, ethylene glycol undergoes catalytic condensation and carbon enrichment to generate C4-C6 fatty alcohol intermediates; Step 2, the aforementioned C4-C6 fatty alcohols undergo dehydration condensation and hydrogenation conversion sequentially to finally obtain C8-C16 alkane products with a carbon number distribution within the aviation kerosene fraction.

[0007] The present invention is implemented by the following technical solution: Step (1) Condensation carbonization reaction: Ethylene glycol, solvent and catalyst are added together to a high-pressure reactor and sealed; nitrogen is used to replace the air in the reactor, and the replacement operation is repeated 3 times. Then, high-pressure nitrogen is introduced into the reactor to establish the reaction pressure; the temperature is raised to the preset reaction temperature and the reaction is kept at the temperature for a predetermined time to obtain a mixed reaction solution containing solvent and C4-C6 fatty alcohol.

[0008] Step (2) Dehydration condensation-hydrogenation conversion and product purification: The mixed reaction liquid obtained in step (1) is subjected to ordinary distillation to remove the solvent and separate C4-C6 isoalcohols; the intermediate is subjected to dehydration condensation reaction and hydrogenation reaction in sequence under high temperature reaction conditions in a solid acid hydrogenation bifunctional catalyst system to convert it into crude isoalkanes from aviation kerosene fraction; after the reaction is completed, the solid catalyst is removed by filtration, and the filtrate is then finely separated by distillation to finally obtain multi-component aviation kerosene fraction isoalkanes.

[0009] In the above method, the reaction solvent in step (1) is one or more combinations of water, methanol, and ethanol.

[0010] In the above method, the catalyst in step (1) is: the main active center of the metal center is Cu and Ni, and the additive is one or more combinations of bimetallic catalysts of Mg, Al, Co and Fe; In the above method, the catalyst support in step (1) is one or more combinations of activated carbon, silicon dioxide, aluminum oxide, zirconium oxide, cerium oxide, and magnesium oxide.

[0011] In the above method, the volume ratio of the reaction raw material to the solvent in step (1) is 1:5 to 1:10.

[0012] In the above method, the reaction time in step (1) is 0.5-10 h.

[0013] In the above method, the reaction temperature in step (1) is 250-350 ℃ and the nitrogen pressure is 1 MPa.

[0014] In the above method, the dehydration / hydrogenation catalyst in step (2) is one or more combinations of Pt, Ni, Ru, Pd, Co, Fe, and Mn as the main active center. The catalyst support is any one of solid acids such as H-ZSM-5, HY, H-MCM, H-MOR, Amberlyst, solid phosphoric acid, and zirconium sulfonate.

[0015] In the above method, the reaction temperature in step (2) is 200-300 ℃ and the hydrogen pressure is 3-6 MPa.

[0016] In summary, this invention constructs a novel, efficient, and green process for the directional conversion of ethylene glycol to produce sustainable aviation kerosene. Unlike existing traditional ATJ (Metal-to-Jet) technologies that use monohydric alcohols such as ethanol as core raw materials, this invention achieves for the first time the precise directional conversion of a dihydric alcohol system into alkanes in aviation kerosene fractions, breaking through the industry barrier of existing alcohol-to-jet kerosene technologies being limited to monohydric alcohol feedstocks. This invention prepares C4-C6 fatty alcohol intermediates through biomass-based ethylene glycol catalytic condensation and carbon enrichment, then couples this with an integrated process of dehydration condensation and hydrogenation modification, ultimately obtaining isoparaffin products with a carbon number distribution of C8-C16. The aviation kerosene fraction yield reaches 72.8% C, demonstrating excellent conversion efficiency. This invention effectively improves and enriches the alcohol-to-jet kerosene (MTJ) technology system, fills the technological gap in the production of sustainable aviation fuel from biomass-based ethylene glycol, and provides a reliable and feasible new technical solution for low-carbon reduction, diversified sustainable aviation kerosene production, and green industrialization in the aviation industry, possessing extremely high engineering application value and industrialization prospects. Attached Figure Description

[0017] Figure 1 A roadmap for the two-step preparation of sustainable aviation kerosene from ethylene glycol. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] Example 1

[0020] The catalyst used in this embodiment is prepared by the following method: The CuNi / MgAl2O4 catalyst was synthesized via a coprecipitation method, with the following steps: First, 0.02 mol copper nitrate, 0.02 mol nickel nitrate, 0.02 mol aluminum nitrate, and 0.02 mol magnesium nitrate were dissolved in 100 mL of deionized water to prepare solution A. Separately, 0.02 mol Na2CO3 and 0.04 mol NaOH were dissolved in 100 mL of deionized water to prepare mixed solution B. Under continuous vigorous stirring, solutions A and B were simultaneously added dropwise to a three-necked flask, and stirring was continued for 1 hour. The mixture was then transferred to an 80°C oil bath and aged for 12 hours to obtain the catalyst precursor. After cooling to room temperature, the precursor was filtered and thoroughly washed until the filtrate was neutral. The resulting solid product was dried overnight in an oven, ground uniformly, and then calcined in a muffle furnace at 600°C for 6 hours under air atmosphere to finally obtain the CuNi / MgAl2O4 catalyst.

[0021] The 1% Ru / ZSM-5 catalyst was prepared by impregnation. An appropriate amount of ruthenium chloride was dissolved in 2.5 mL of water, and 1 g of ZSM-5 (Si / Al=25) support was added to the solution. The mixture was stirred and impregnated at room temperature for 12 h, followed by drying at 80 °C for 4 h. The mixture was placed in a quartz reaction tube, and under a hydrogen atmosphere, the flow rate was controlled at 50 mL / min. The temperature was then increased from room temperature to 300 °C at a rate of 5 °C / min and maintained at 300 °C for 4 h. After cooling to room temperature, the catalyst was passivated with 5 wt% O2 / N2 for 4 h to obtain the 1% Ru / ZSM-5 catalyst.

[0022] This invention provides a specific embodiment for the efficient preparation of sustainable aviation kerosene isoparaffins from bio-based ethylene glycol, such as... Figure 1 As shown, the detailed process steps are as follows: (1) Preparation of C4-C6 isomeric alcohol intermediates by catalytic carbonization of ethylene glycol 1 mL of ethylene glycol, 10 mL of methanol solvent, and 0.2 g of CuNi / MgAl2O4 bimetallic composite catalyst were added to a 50 mL high-pressure reactor, which was then sealed. The reactor was purged with high-purity nitrogen three times to completely remove oxygen and impurities. High-purity nitrogen was then continuously introduced until the initial pressure reached 1 MPa. The reactor was heated to 280 °C and reacted under constant temperature for 2 h. After the reaction, the mixture was allowed to cool naturally to room temperature. The pressure was slowly released, and the reactor was opened to obtain the mixed reaction solution. The reaction solution was subjected to simple distillation at atmospheric pressure to remove the methanol solvent, ultimately yielding a high-purity C4–C6 isomeric alcohol mixed intermediate.

[0023] (2) Preparation of aviation kerosene fraction isoparaffins by dehydration and hydrogenation of C4-C6 isomeric alcohols

[0024] The C4–C6 isomeric alcohol mixed solution prepared above was added to a high-pressure reactor along with 1 g of Ru / ZSM-5 solid acid hydrogenation bifunctional catalyst with a loading of 1 wt%. After purging the reactor with high-purity nitrogen, high-purity hydrogen was introduced until the system pressure reached 4 MPa. The stirring speed was set to 400 rpm, the reaction temperature to 230 °C, and the reaction was carried out continuously at this temperature for 6 h. After the reaction was completed, the reactor was cooled and depressurized, the solid catalyst was separated by filtration, and the filtrate was purified by distillation to finally obtain aviation kerosene-based isomeric alkanes with a carbon number distribution in the C8–C16 range.

[0025] Gas chromatography analysis showed that the ethylene glycol conversion rate in this embodiment reached 100%, the yield of C4-C6 isomeric alcohol intermediates was 86.1%, and the final yield of isomeric alkanes in aviation kerosene fraction was stable at over 70%, with the product composition meeting the standards for sustainable aviation fuel fractions.

[0026] Example 2

[0027] The catalyst used in this embodiment is prepared by the following method: CuMgAlO x The catalyst was synthesized using a coprecipitation method, with the following steps: First, 0.02 mol copper nitrate, 0.02 mol aluminum nitrate, and 0.02 mol magnesium nitrate were dissolved in 100 mL of deionized water to prepare solution A; separately, 0.02 mol Na₂CO₃ and 0.04 mol NaOH were dissolved in 100 mL of deionized water to prepare mixed solution B. Under continuous vigorous stirring, solutions A and B were simultaneously added dropwise to a three-necked flask, and stirring was continued for 1 hour. The mixture was then transferred to an 80°C oil bath and aged for 12 hours to obtain the catalyst precursor. After cooling to room temperature, the precursor was filtered and thoroughly washed until the filtrate was neutral. The resulting solid product was dried overnight in an oven, ground uniformly, and then calcined in a muffle furnace at 600°C for 6 hours in air to finally obtain CuMgAlO₂. x catalyst.

[0028] The 10% Ni / H-MOR catalyst was prepared by impregnation. An appropriate amount of nickel nitrate was dissolved in 2.5 mL of water, and 1 g of H-MOR (Si / Al=25) support was added to the solution. The mixture was stirred and impregnated at room temperature for 12 h, followed by drying at 80 °C for 4 h. The mixture was placed in a quartz reaction tube, and under a hydrogen atmosphere, the flow rate was controlled at 50 mL / min. The temperature was then increased from room temperature to 300 °C at a rate of 5 °C / min, and maintained at 600 °C for 5 h. After cooling to room temperature, the catalyst was passivated with 5 wt% O2 / N2 for 4 h to obtain the 10% Ni / H-MOR catalyst.

[0029] This invention provides a specific embodiment for the efficient preparation of sustainable aviation kerosene isoparaffins from bio-based ethylene glycol, and the detailed process steps are as follows: (1) Preparation of C4-C6 isomeric alcohol intermediates by catalytic carbonization of ethylene glycol 2 mL of ethylene glycol, 15 mL of methanol solvent, and 0.2 g of CuMgAlOx solid catalyst were added to a 50 mL high-pressure reactor, which was then sealed. The reactor was purged with high-purity nitrogen three times to completely remove residual air and impurities. Then, high-purity nitrogen was introduced into the reactor at room temperature, setting the initial pressure to 1 MPa. The stirring device was turned on, and the reactor was heated to 280 °C at a constant rate, and the reaction was maintained at this temperature for 4 h. After the reaction was complete, the heating was turned off, and the reactor was allowed to cool naturally to room temperature. The residual gas was slowly released, and the reactor was opened to collect the complete reaction mixture. The resulting reaction mixture was subjected to simple distillation at atmospheric pressure to remove the methanol solvent, ultimately yielding a mixed intermediate solution rich in C4–C6 isomeric alcohols.

[0030] (2) Preparation of aviation kerosene fraction isoalkanes from C4-C6 isoalcohols via a series of dehydration-oligomerization-hydrogenation reactions.

[0031] The C4–C6 isomeric alcohol mixed solution prepared above was added to a high-pressure reactor along with 1 g of Ni / H-MOR solid acid catalyst with a loading of 10 wt%. The reactor was purged three times with high-purity nitrogen to remove air, and then high-purity hydrogen was introduced until the system pressure reached 4 MPa. The stirring speed was set to 400 rpm, the reaction temperature to 260 ℃, and the reaction was carried out continuously at this temperature for 6 h. Dehydration, oligomerization, and hydrogenation reactions occurred sequentially in a series coupled reaction within the system. After the reaction was completed, the system was cooled and depressurized, the solid catalyst was separated by filtration, and the filtrate was purified by distillation to ultimately obtain isomeric alkanes with a carbon number distribution between the aviation kerosene distillation zone.

[0032] Gas chromatography (GC) analysis showed that the ethylene glycol (EG) conversion rate in this example reached 100%, and the C4-C6 alcohol carbon yield was 80.3%. The aviation kerosene isoparaffin products prepared by the tandem reaction had a freezing point below -47 ℃, fully meeting the national standard requirements for low-temperature performance and distillation fractionation of sustainable aviation fuel, and the product quality was excellent.

[0033] Example 3

[0034] The catalyst used in this embodiment is prepared by the following method: (1) CuMgAlO x Preparation of SiO2 catalyst. The preparation method of CuMgAl precursor catalyst is described in Example-2. xThe SiO2 catalyst was synthesized via an impregnation method. An appropriate amount of silicon source (silica) was weighed and added to 50 mL of deionized water, and the above-mentioned CuMgAlO2 catalyst was then added. x The precursor was added and impregnated with stirring at room temperature for 12 hours. Excess moisture was then removed by rotary evaporation, and the mixture was dried at 80 °C for 4 hours. The dried solid was placed in a muffle furnace and calcined at 600 °C for 6 hours in air to finally obtain CuMgAlO. x @SiO2 catalyst.

[0035] (2) The PdNi / H-Beta catalyst was prepared by impregnation, and the specific steps are as follows: An appropriate amount of palladium chloride (or palladium nitrate) and nickel nitrate pentahydrate were dissolved together in 2.5 mL of deionized water. 1 g of H-Beta (Si / Al=25) support was added to the solution, and the mixture was stirred and impregnated at room temperature for 12 hours, then dried at 80 °C for 4 hours. The mixture was placed in a quartz reaction tube, and under a hydrogen atmosphere, the flow rate was controlled at 50 mL / min. The temperature was then increased from room temperature to 500 °C at a rate of 5 °C / min, and maintained at 500 °C for 5 hours for reduction. After cooling to room temperature, the mixture was passivated with a 5 wt% O2 / N2 mixed gas for 4 hours to obtain the PdNi / H-Beta catalyst.

[0036] This invention provides a specific embodiment for the efficient preparation of sustainable aviation kerosene isoparaffins from bio-based ethylene glycol, and the detailed process steps are as follows: (1) Preparation of C4-C6 isomeric alcohol intermediates by catalytic carbonization of ethylene glycol 2 mL of ethylene glycol, 20 mL of methanol solvent, and 0.2 g of CuMgAl@SiO2 solid catalyst were added to a 50 mL high-pressure reactor, which was then sealed. The reactor was purged with high-purity nitrogen three times to completely remove residual air and impurities. Then, high-purity nitrogen was introduced into the reactor at room temperature, setting the initial pressure to 1 MPa. The stirring device was turned on, and the reactor was heated to 290 °C at a constant rate, and the reaction was maintained at this temperature for 4 h. After the reaction was complete, the heating was turned off, and the reactor was allowed to cool naturally to room temperature. The residual gas was slowly released, and the reactor was opened to collect the reaction mixture. The resulting reaction mixture was subjected to simple distillation at atmospheric pressure to remove unreacted methanol solvent, ultimately yielding a mixed intermediate solution rich in C4–C6 isomeric alcohols.

[0037] (2) Preparation of aviation kerosene fraction isoalkanes from C4-C6 isoalcohols via a series of dehydration-oligomerization-hydrogenation reactions.

[0038] The C4-C6 isomeric alcohol mixed solution prepared above was added to a high-pressure reactor along with 1 g of PdNi / H-Beta solid acid catalyst. The reactor was purged three times with high-purity nitrogen to remove air, and then high-purity hydrogen was introduced until the system pressure reached 5 MPa. The stirring speed was set to 400 rpm, the reaction temperature to 280 ℃, and the reaction was carried out continuously at this temperature for 6 h. The dehydration, oligomerization, and hydrogenation processes were sequentially completed within the system. After the reaction, the system was cooled and depressurized, the solid catalyst was separated by filtration, and then purified by simple distillation to finally obtain isomeric alkanes with a carbon number distribution between the aviation kerosene distillation zone.

[0039] Gas chromatography (GC) analysis showed that the ethylene glycol (EG) conversion rate in this example reached 100%, and the C4-C6 alcohol carbon yield was 81.5%. The final C8-C16 isoparaffin aviation kerosene fraction yield reached over 70%, and the obtained aviation kerosene isoparaffin product had a freezing point below -47 ℃. All indicators were excellent, fully meeting the national standard requirements for low-temperature performance and fractionation of sustainable aviation fuel. The product had excellent purity and performance.

[0040] Example 4

[0041] The catalyst used in this embodiment is prepared by the following method: (1) Preparation of CuZnAl@SiO2 composite catalyst: It was prepared by co-precipitation-coating modification process. A mixed metal nitrate solution was prepared according to the molar ratio of copper, zinc and aluminum. Sodium carbonate aqueous solution was used as precipitant. The co-precipitation reaction was completed under constant temperature stirring. After static aging, it was filtered, washed with deionized water until neutral, and dried to obtain CuZnAl layered precursor. Then, SiO2 was uniformly coated on the surface of the precursor by tetraethyl orthosilicate hydrolysis process. After high temperature calcination crystallization treatment, a highly dispersed and sintering-resistant CuZnAl@SiO2 composite solid catalyst was finally obtained.

[0042] (2) Preparation of NiCo / H-Beta bifunctional catalyst: acidic H-Beta molecular sieve was selected as the support, and the nickel-cobalt active components were uniformly loaded on the surface and inside the pores of the molecular sieve by the equal volume impregnation method. After impregnation, the catalyst was aged at room temperature, dried at constant temperature to remove residual solvent, and then calcined by programmed temperature rise and in-situ hydrogen reduction to obtain a highly active and highly selective NiCo / H-Beta bifunctional solid acid hydrogenation catalyst.

[0043] This invention provides a specific embodiment for the efficient preparation of sustainable aviation kerosene isoparaffins from bio-based ethylene glycol, and the detailed process steps are as follows: (1) Preparation of C4-C6 isomeric alcohol intermediates by catalytic carbonization of ethylene glycol 2 mL of ethylene glycol, 20 mL of methanol solvent, and 0.2 g of the prepared CuZnAl@SiO2 solid catalyst were added to a 50 mL high-pressure reactor, which was then sealed. The reactor was purged with high-purity nitrogen three times to completely remove residual air and impurities. Then, high-purity nitrogen was introduced into the reactor at room temperature, setting the initial pressure to 1.2 MPa. The stirring device was turned on, and the reactor was heated to 285 °C at a constant rate, and the reaction was maintained at this temperature for 4 hours. After the reaction was complete, the heating was turned off, and the reactor was allowed to cool naturally to room temperature. The residual gas was slowly released, and the reactor was opened to collect the reaction mixture. The resulting reaction mixture was subjected to simple distillation at atmospheric pressure to remove unreacted methanol solvent, ultimately yielding a mixed intermediate solution rich in C4–C6 isomeric alcohols.

[0044] (2) Preparation of aviation kerosene fraction isoalkanes from C4-C6 isoalcohols via a series of dehydration-oligomerization-hydrogenation reactions.

[0045] The C4–C6 isomeric alcohol mixture prepared above was added to a high-pressure reactor along with 1 g of the prepared NiCo / H-Beta bifunctional catalyst. The reactor was purged three times with high-purity nitrogen to remove air, and then high-purity hydrogen was introduced until the system pressure reached 4.5 MPa. The stirring speed was set to 400 rpm, the reaction temperature to 270 °C, and the reaction was carried out continuously at this temperature for 6 h. The dehydration, oligomerization, and hydrogenation processes were sequentially completed within the system. After the reaction, the system was cooled and depressurized, the solid catalyst was separated by filtration, and then purified by simple distillation to finally obtain isomeric alkanes with a carbon number distribution between C8 and C16 in the aviation kerosene distillation zone.

[0046] Gas chromatography (GC) analysis showed that the ethylene glycol (EG) conversion rate in this example reached 100%, and the C4-C6 alcohol carbon yield was 78.6%. The final C8-C16 isoparaffin aviation kerosene fraction yield reached 68.5%. The obtained aviation kerosene isoparaffin product had a freezing point below -48 ℃, excellent low-temperature flow properties, and a pure fraction composition, fully meeting the national standard requirements for sustainable aviation fuel. It can be directly used as a basic component of aviation kerosene.

[0047] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A method for preparing sustainable aviation kerosene from biomass-based ethylene glycol, characterized in that, Step (1) Condensation and carbon enrichment reaction: Bio-based ethylene glycol, solvent and solid catalyst are put into a high-pressure reactor and sealed; the air inside the reactor is replaced with nitrogen three times, and then high-pressure nitrogen is introduced to establish a reaction pressure system; the temperature is raised to the set reaction temperature and the reaction is kept at a constant temperature for a set time to obtain a reaction solution containing C4 to C6 fatty alcohols; Step (2) Dehydration condensation-hydrogenation conversion: The reaction solution obtained in step (1) is subjected to simple distillation to remove the solvent, and a C4-C6 isomeric alcohol intermediate is obtained. The intermediate is placed in a solid acid-hydrogenation bifunctional catalyst system, and dehydration condensation reaction and hydrogenation reaction are carried out sequentially under high temperature conditions. After the reaction is completed, the solid catalyst is filtered to separate it, and the filtrate is purified by distillation to finally obtain a multi-component isomeric alkane product with carbon number falling in the aviation kerosene fraction.

2. The method according to claim 1, characterized in that, The reaction solvent in step (1) is one or more combinations of water, methanol, and ethanol.

3. The method according to claim 1, characterized in that, The catalyst in step (1) is: the main active centers of the metal center are Cu and Ni, and the additives are one or more combinations of bimetallic catalysts of Mg, Al, Co and Fe.

4. The method according to claim 3, characterized in that, The catalyst support in step (1) is one or more combinations of activated carbon, silicon dioxide, alumina, zirconium oxide, and cerium oxide.

5. The method according to claim 1, characterized in that, The volume ratio of the reaction raw materials to the solvent in step (1) is 1:5 to 1:

10.

6. The method according to claim 1, characterized in that, The reaction temperature in step (1) is 250-350℃ and the nitrogen pressure is 1MPa.

7. The method according to claim 1, characterized in that, The solvent reaction time in step (1) is 0.5-10 seconds.

8. The method according to claim 1, characterized in that, The reaction raw materials in step (1) are one or more combinations of ethylene glycol, 1,2-propanediol and 1,2-butanediol.

9. The method according to claim 1, characterized in that, The dehydration / hydrogenation catalyst in step (2) is one or more combinations of Pt, Ni, Ru, Pd, Co, Fe, and Mn as the main active center, and the catalyst support is any one of solid acids such as H-ZSM-5, HY, H-MCM, H-MOR, Amberlyst, solid phosphoric acid, and zirconium sulfonate.

10. The method according to claim 1, characterized in that, Step (2) The hydrogen pressure is 0.5-8.0 MPa.

11. The method according to claim 1, characterized in that, The reaction temperature in step (2) is 200-300℃.

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