Preparation method of sustainable aviation fuel

Abstract

The invention discloses a sustainable aviation fuel preparation method, which comprises: filling a fixed bed reactor with a CoMn-coated ZSM-11 catalyst, filling nitrogen, removing air, and introducing H2 and COX to carry out a reaction to obtain the sustainable aviation fuel, the CoMn-coated ZSM-11 catalyst is used for catalyzing one-step hydrogenation of COX to directly synthesize the sustainable aviation fuel, the production path of the traditional biomass-based sustainable aviation fuel can be remarkably simplified, the cost is low, CO, CO2 and mixed gas of the CO and the CO2 can be treated, when raw material gas containing CO2 is treated, reverse water-gas reaction is not needed, cyclic utilization of carbon is achieved, and the method is suitable for industrial production. Large-scale development of green aviation energy is promoted; the method is simple in process, mild in reaction condition and short in period, and strong acid, organic acid and any precious metal component are not needed in the whole preparation process.

Description

Technical Field

[0001] This invention belongs to the field of sustainable aviation fuel synthesis catalyst technology, specifically relating to a method for preparing sustainable aviation fuel. Background Technology

[0002] With the continued development of the global economy, the demand for liquid fuels in the air transport sector is increasing. Currently, aviation fuel still mainly relies on traditional fossil fuels, which emit significant carbon, placing increasing pressure on the aviation industry to reduce carbon emissions. Sustainable aviation fuel (SAF), produced using renewable resources or waste materials, can directly replace traditional fossil-based aviation kerosene. Promoting the research and application of SAF preparation technology can build a more stable and sustainable energy supply system through diversified raw material pathways such as waste oils, agricultural and forestry waste, and algal biomass. This will not only help significantly reduce the aviation industry's dependence on fossil fuels but also significantly reduce carbon emissions throughout its entire life cycle. It is a key path to promote the green and low-carbon transformation of the aviation industry and has profound significance for ensuring energy security and promoting sustainable socio-economic development.

[0003] Carbon monoxide and carbon dioxide, as typical non-petroleum-based carbon resources, are widely available and inexpensive, making them highly promising carriers for carbon recycling. They can be directly converted into aromatic hydrocarbons via catalytic conversion. However, in the Fischer-Tropsch synthesis route, the hydrocarbons generated in the Fischer-Tropsch reaction consistently follow an ASF distribution, resulting in a wide hydrocarbon spectrum and limited aromatic hydrocarbon yield. Furthermore, due to the thermodynamic stability and chemical inertness of CO2, as well as the kinetic barriers to C-C bond formation, directly converting CO2 into aromatic hydrocarbons via hydrogenation remains a significant challenge. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing sustainable aviation fuel.

[0005] The technical solution of the present invention is as follows: The preparation method of CoMn@ZSM-11 catalyst includes the following steps: (1) According to the proportion, put 3-9g of glucose and 5-15g of urea into a container, heat in an oil bath at 110-150℃, and stir at 350-550rpm to obtain the first mixture; add 3-6g of Co(NO3)2·6H2O and 2-5g of 50wt% Mn(NO3)2 aqueous solution to the first mixture, stir evenly, then add 0.2-0.4g of anhydrous Na2CO3, heat to 140-200℃, react for 4-8 hours to obtain a purple-red liquid, dry the purple-red liquid, calcine in a tube furnace at 350-450℃ under a nitrogen atmosphere for 2-4 hours, and then calcine in a muffle furnace at 250-350℃ for 2-4 hours. The product obtained is denoted as CoMn. (2) Add 0.5-1g NaAlO2 and 35-45g tetrabutylammonium hydroxide (TBAOH) to 32-35mL of 1.79wt% NaOH aqueous solution, stir for 1-3 h, add 60-70g tetraethyl orthosilicate, stir evenly to obtain a second mixture, heat to 150-200℃, react for 3 days, a precipitate is formed, filter, wash the solid with ultrapure water, dry, and calcine at 520-560℃ for 4-6 hours; (3) Mix the product obtained in step (2) with 1M NH4NO3 aqueous solution at 60-100℃ in a mass ratio of 1:50, let stand for 6 hours for ammonium ion exchange; filter, wash with ultrapure water, and dry. (4) Repeat step (3) twice; to obtain H-type ZSM-11 molecular sieve; (5) CoMn and H-type ZSM-11 molecular sieve were ground for 30 min at a mass ratio of 1:1 to obtain CoMn@ZSM-11 catalyst.

[0006] Step (1) is preferably as follows: 6g of glucose and 10g of urea are placed in a container according to the proportion, heated in an oil bath at 120°C, and stirred at 400 rpm to obtain a first mixture; 4.4g of Co(NO3)2·6H2O and 2.7g of 50wt% Mn(NO3)2 aqueous solution are added to the first mixture, stirred evenly, and then 0.2g of anhydrous Na2CO3 is added, heated to 180°C, and reacted for 5 hours to obtain a purple-red liquid. The purple-red liquid is dried, calcined in a tube furnace at 400°C under a nitrogen atmosphere for 3 hours, and then calcined in a muffle furnace at 300°C for 3 hours. The product obtained is denoted as CoMn.

[0007] Step (2) is preferably as follows: 0.82g NaAlO2 and 38.92g tetrabutylammonium hydroxide (TBAOH) are added sequentially to 32mL of 1.79wt% NaOH aqueous solution, stirred for 2 h, 64.37g tetraethyl orthosilicate is added, stirred evenly to obtain a second mixture, heated to 170℃, reacted for 3 days, a precipitate is formed, filtered, the solid is washed with ultrapure water, dried, and calcined at 550℃ for 6 hours.

[0008] Step (3) is preferably performed by mixing the product obtained in step (2) with 1M NH4NO3 aqueous solution at 80°C in a mass ratio of 1:50, letting it stand for 6 hours for ammonium ion exchange, filtering, washing with ultrapure water, and drying at 80°C for 12 hours.

[0009] The CoMn@ZSM-11 catalyst prepared by the above method.

[0010] A method for preparing sustainable aviation fuel includes the following steps: The CoMn@ZSM-11 catalyst was packed into a fixed-bed reactor, purged with nitrogen, and air was removed. H2 and CO were then introduced. X At 280-360℃, 2-4MPa, and 600-3000mL•g -1 •h -1 Under certain conditions, a reaction occurs to produce sustainable aviation fuel; H2 and CO. X The molar ratio is 1-3:1; CO X It is at least one of CO and CO2.

[0011] Preferably, H2 and CO X The molar ratio is 3:1.

[0012] Preferably, the reaction temperature is 300℃, the pressure is 3.5MPa, and the space velocity is 1800mL•g. -1 •h -1 .

[0013] The beneficial effects of this invention are: 1. Catalysis of CO using CoMn@ZSM-11 catalyst X A one-step hydrogenation synthesis of aromatic-rich sustainable aviation fuel significantly simplifies the traditional biomass-based sustainable aviation fuel production pathway and effectively reduces preparation costs. This catalyst can process CO, CO2, and mixtures of both, and when processing feedstock gas containing CO2, it eliminates the need for a reverse-flow gasification reaction. The feedstock gas can be CO2 from air capture or industrial point sources, or syngas obtained through biomass gasification, achieving carbon recycling and promoting the large-scale development of green aviation energy.

[0014] 2. This invention features a simple process, mild reaction conditions, and a short cycle. The entire preparation process requires no strong acids, organic acids, or any precious metals, making it environmentally friendly and in line with green chemistry principles. The catalyst exhibits high stability and is easy to store, demonstrating significant technical feasibility and environmental friendliness.

[0015] 3. The catalyst used in this invention is a highly efficient bifunctional catalytic system. In the process of hydrogenating carbon dioxide to produce aromatics, the catalyst is equivalent to a miniature reactor. X The H2 reactants are first activated at the CoMn sites on the surface of the CoMn@ZSM-11 catalyst, transforming into low-carbon olefins. These olefins then immediately enter the porous structure of the ZSM-11 catalyst and undergo polymerization and aromatization at the acidic sites of the H-type ZSM-11, ultimately generating a sustainable aviation fuel rich in aromatics. The entire chain reaction occurs on a single CoMn@ZSM-11 catalyst. This relay catalyst approach eliminates the need for traditional multi-unit reactors in series, reducing energy consumption and simplifying the reaction unit. This process not only significantly improves feedstock conversion efficiency but also strongly promotes carbon chain growth, resulting in a high aromatic content and a correspondingly high calorific value in the synthesized sustainable aviation fuel. Attached Figure Description

[0016] Figure 1 The image shows the XRD pattern of the CoMn@ZSM-11 catalyst prepared in this invention. Detailed Implementation

[0017] The present invention will be further described below through specific embodiments.

[0018] Example 1 The preparation method of CoMn@ZSM-11 catalyst includes the following steps: (1) 6g of glucose and 10g of urea were placed in a 250mL beaker and heated in an oil bath at 120℃. The mixture was stirred at 400rpm to obtain the first mixture. 4.4g of Co(NO3)2·6H2O and 2.7g of 50wt% Mn(NO3)2 aqueous solution were added to the first mixture and stirred evenly. Then 0.2g of anhydrous Na2CO3 was added and heated to 180℃. The reaction was carried out for 5 hours to obtain a purple-red liquid. The purple-red liquid was dried and calcined in a tube furnace at 400℃ under a nitrogen atmosphere for 3 hours. Then it was calcined in a muffle furnace at 300℃ for 3 hours. The product obtained was denoted as CoMn. (2) 0.82 g NaAlO2 and 38.92 g tetrabutylammonium hydroxide (TBAOH) were added to 32 mL of 1.79 wt% NaOH aqueous solution and stirred for 2 h. 64.37 g tetraethyl orthosilicate was added and stirred evenly to obtain a second mixture. The mixture was heated to 170 °C and reacted for 3 days. A precipitate was formed. The mixture was filtered, and the solid was washed with ultrapure water, dried, and calcined at 550 °C for 6 hours. (3) Mix the product obtained in step (2) with 1M NH4NO3 aqueous solution at 80°C at a mass ratio of 1:50, let stand for 6 hours for ammonium ion exchange; filter, wash with ultrapure water, and dry at 80°C for 12 hours. (4) Repeat step (3) twice; to obtain H-type ZSM-11 molecular sieve; (5) CoMn and H-type ZSM-11 molecular sieve were ground for 30 min at a mass ratio of 1:1 to obtain CoMn@ZSM-11 catalyst, see [link to catalyst]. Figure 1 .

[0019] from Figure 1 As can be seen, the CoMn@ZSM-11 catalyst exhibits characteristic diffraction peaks of H-type ZSM-11 molecular sieves at 2θ = 7.9°, 8.8°, 23.1°, 23.9°, and 24.4°, indicating that the prepared catalyst possesses a typical MFI topology. Furthermore, the characteristic diffraction peaks at 2θ = 44.9° and 45.5° belong to Co₂C, indicating that it is the active phase of the Co species.

[0020] Example 2 The preparation method of CoMn@ZSM-11 catalyst includes the following steps: (1) According to the proportion, 3g of glucose and 5g of urea were placed in a container and heated in an oil bath at 110°C. The mixture was stirred at 350 rpm to obtain the first mixture. 3g of Co(NO3)2·6H2O and 2g of 50wt% Mn(NO3)2 aqueous solution were added to the first mixture and stirred evenly. Then 0.2g of anhydrous Na2CO3 was added and heated to 140°C. The reaction was carried out for 8 hours to obtain a purple-red liquid. The purple-red liquid was dried and calcined in a tube furnace at 350°C under a nitrogen atmosphere for 4 hours. Then it was calcined in a muffle furnace at 250°C for 4 hours. The product obtained was denoted as CoMn. (2) 0.5g NaAlO2 and 35g tetrabutylammonium hydroxide (TBAOH) were added to 32mL of 1.79wt% NaOH aqueous solution and stirred for 1h. 60g tetraethyl orthosilicate was added and stirred evenly to obtain a second mixture. The mixture was heated to 150℃ and reacted for 3 days. A precipitate was formed. The mixture was filtered, and the solid was washed with ultrapure water, dried, and calcined at 520℃ for 6 hours. (3) Mix the product obtained in step (2) with 1M NH4NO3 aqueous solution at 60°C at a mass ratio of 1:50, let stand for 6 hours for ammonium ion exchange; filter, wash with ultrapure water, and dry at 80°C for 12 hours. (4) Repeat step (3) twice; to obtain H-type ZSM-11 molecular sieve; (5) CoMn and H-type ZSM-11 molecular sieve were ground for 30 min at a mass ratio of 1:1 to obtain CoMn@ZSM-11 catalyst.

[0021] Example 3 The preparation method of CoMn@ZSM-11 catalyst includes the following steps: (1) According to the proportion, 9g of glucose and 15g of urea were placed in a container and heated in an oil bath at 150°C. The mixture was stirred at 550 rpm to obtain the first mixture. 6g of Co(NO3)2·6H2O and 5g of 50wt% Mn(NO3)2 aqueous solution were added to the first mixture and stirred evenly. Then 0.4g of anhydrous Na2CO3 was added and heated to 200°C. The reaction was carried out for 4 hours to obtain a purple-red liquid. The purple-red liquid was dried and calcined in a tube furnace at 450°C under a nitrogen atmosphere for 2 hours. Then it was calcined in a muffle furnace at 350°C for 2 hours. The product obtained was denoted as CoMn. (2) 1g NaAlO2 and 45g tetrabutylammonium hydroxide (TBAOH) were added to 35mL of 1.79wt% NaOH aqueous solution and stirred for 3 h. 70g tetraethyl orthosilicate was added and stirred evenly to obtain a second mixture. The mixture was heated to 200℃ and reacted for 3 days. A precipitate was formed. The solid was filtered, washed with ultrapure water, dried, and calcined at 560℃ for 4 hours. (3) Mix the product obtained in step (2) with 1M NH4NO3 aqueous solution at 100°C at a mass ratio of 1:50, let stand for 6 hours for ammonium ion exchange; filter, wash with ultrapure water, and dry at 80°C for 12 hours; (4) Repeat step (3) twice; to obtain H-type ZSM-11 molecular sieve; (5) CoMn and H-type ZSM-11 molecular sieve were ground for 30 min at a mass ratio of 1:1 to obtain CoMn@ZSM-11 catalyst.

[0022] Example 4 A method for preparing sustainable aviation fuel includes the following steps: 1.0 g of the CoMn@ZSM-11 catalyst prepared in Example 1 (40 mesh) was packed into a fixed-bed reactor, purged with nitrogen, and H2 and CO2 were introduced. The reactor was then subjected to a reaction at 300 °C, 3.5 MPa, and 1800 mL•g.-1 •h -1 Under certain conditions, the reaction yields sustainable aviation fuel; the molar ratio of H2 to CO2 is 3:1.

[0023] CO2 conversion rate and sustainable aviation fuel (C8-C) 16 The selectivity of aromatics is shown in Table 1.

[0024] Experiments have shown that replacing the CoMn@ZSM-11 catalyst prepared in this example with the CoMn@ZSM-11 catalyst prepared in Example 2 or Example 3, while maintaining the same other parameters as in this example, results in a sustainable aviation fuel with higher CO2 conversion rate and a higher C8-C9 content. 16 The selectivity of aromatics and the CO2 conversion rate and the content of C8-C in sustainable aviation fuel in this embodiment. 16 Aromatic hydrocarbons have similar selectivity.

[0025] Example 5 A method for preparing sustainable aviation fuel includes the following steps: 1.0 g of the CoMn@ZSM-11 catalyst prepared in Example 1 (40 mesh) was packed into a fixed-bed reactor, purged with nitrogen, and air was removed. H2 and CO2 were then introduced, and the reactor was subjected to a reaction at 280 °C, 2 MPa, and 3000 mL•g. -1 •h -1 Under certain conditions, the reaction yields sustainable aviation fuel; the molar ratio of H2 to CO2 is 3:1.

[0026] CO2 conversion rate and sustainable aviation fuel (C8-C) 16 The selectivity of aromatics is shown in Table 1.

[0027] Example 6 A method for preparing sustainable aviation fuel, characterized by comprising the following steps: 1.0 g of the CoMn@ZSM-11 catalyst prepared in Example 1 (40 mesh) was packed into a fixed-bed reactor, purged with nitrogen, and H2 and CO2 were introduced. The reactor was then subjected to a reaction at 360 °C, 4 MPa, and 600 mL•g. -1 •h -1 Under certain conditions, the reaction yields sustainable aviation fuel; the molar ratio of H2 to CO2 is 1:1.

[0028] CO2 conversion rate and sustainable aviation fuel (C8-C) 16 The selectivity of aromatics is shown in Table 1.

[0029] Example 7 A method for preparing sustainable aviation fuel includes the following steps: 1.0 g of the CoMn@ZSM-11 catalyst prepared in Example 1 (40 mesh) was packed into a fixed-bed reactor, purged with nitrogen, and air was removed. H2 and CO were then introduced, and the reactor was subjected to a reaction at 300 °C, 3.5 MPa, and 1800 mL•g. -1 •h -1 Under certain conditions, the reaction yields sustainable aviation fuel; the molar ratio of H2 to CO is 3:1.

[0030] CO conversion rate and sustainable aviation fuel (C8-C) 16 The selectivity of aromatics is shown in Table 1.

[0031] Example 8 A method for preparing sustainable aviation fuel includes the following steps: 1.0 g of the CoMn@ZSM-11 catalyst prepared in Example 1 (40 mesh) was packed into a fixed-bed reactor, purged with nitrogen, and air was removed. H2 and CO were then introduced. X At 300℃, 3.5MPa, and 1800mL•g -1 •h -1 Under certain conditions, a reaction occurs to produce sustainable aviation fuel; H2 and CO. X The molar ratio is 3:1; CO X The molar ratio of CO and CO2 is 5:1.

[0032] CO X Conversion rate and sustainable aviation fuel (C8-C) 16 The selectivity of aromatics is shown in Table 1.

[0033] Table 1. Evaluation results of the catalytic performance of the catalyst in Example 1.

[0034] .

Claims

1. A method for preparing CoMn@ZSM-11 catalyst, comprising the following steps: (1) According to the proportion, put 3-9g of glucose and 5-15g of urea into a container, heat in an oil bath at 110-150℃, and stir at 350-550rpm to obtain the first mixture; add 3-6g of Co(NO3)2·6H2O and 2-5g of 50wt% Mn(NO3)2 aqueous solution to the first mixture, stir evenly, then add 0.2-0.4g of anhydrous Na2CO3, heat to 140-200℃, react for 4-8 hours to obtain a purple-red liquid, dry the purple-red liquid, calcine in a tube furnace at 350-450℃ under a nitrogen atmosphere for 2-4h, and then calcine in a muffle furnace at 250-350℃ for 2-4h. The product obtained is denoted as CoMn. (2) Add 0.5-1g NaAlO2 and 35-45g tetrabutylammonium hydroxide to 32-35mL of 1.79wt% NaOH aqueous solution, stir for 1-3 h, add 60-70g tetraethyl orthosilicate, stir evenly to obtain a second mixture, heat to 150-200℃, react for 3 days, a precipitate is formed, filter, wash the solid with ultrapure water, dry, and calcine at 520-560℃ for 4-6 hours; (3) Mix the product obtained in step (2) with 1M NH4NO3 aqueous solution at 60-100℃ in a mass ratio of 1:50, let stand for 6 hours for ammonium ion exchange; filter, wash with ultrapure water, and dry. (4) Repeat step (3) twice; to obtain H-type ZSM-11 molecular sieve; (5) CoMn and H-type ZSM-11 molecular sieve were ground for 30 min at a mass ratio of 1:1 to obtain CoMn@ZSM-11 catalyst.

2. The preparation method according to claim 1, characterized in that: Step (1) is as follows: 6g of glucose and 10g of urea are placed in a container according to the proportion, heated in an oil bath at 120°C, and stirred at 400 rpm to obtain a first mixture; 4.4g of Co(NO3)2·6H2O and 2.7g of 50wt% Mn(NO3)2 aqueous solution are added to the first mixture, stirred evenly, and then 0.2g of anhydrous Na2CO3 is added, heated to 180°C, and reacted for 5 hours to obtain a purple-red liquid. The purple-red liquid is dried, calcined in a tube furnace at 400°C under a nitrogen atmosphere for 3 hours, and then calcined in a muffle furnace at 300°C for 3 hours. The product obtained is denoted as CoMn.

3. The preparation method according to claim 1, characterized in that: Step (2) is as follows: 0.82g NaAlO2 and 38.92g tetrabutylammonium hydroxide are added to 32mL of 1.79wt% NaOH aqueous solution and stirred for 2 h. Then, 64.37g tetraethyl orthosilicate is added and stirred evenly to obtain a second mixture. The mixture is heated to 170℃ and reacted for 3 days. A precipitate is formed. The mixture is filtered, and the solid is washed with ultrapure water, dried, and calcined at 550℃ for 6 hours.

4. The preparation method according to claim 1, characterized in that: Step (3) is as follows: the product obtained in step (2) is mixed with 1M NH4NO3 aqueous solution at 80°C at a mass ratio of 1:50, and allowed to stand for 6 hours for ammonium ion exchange; then filtered, washed with ultrapure water, and dried at 80°C for 12 hours.

5. The CoMn@ZSM-11 catalyst prepared by any one of claims 1-4.

6. A method for preparing sustainable aviation fuel, characterized in that: Includes the following steps: The CoMn@ZSM-11 catalyst of claim 5 was loaded into a fixed-bed reactor, nitrogen was introduced, air was removed, and H2 and CO were introduced. X At 280-360℃, 2-4MPa, and 600-3000mL•g -1 •h -1 Under certain conditions, a reaction occurs to produce sustainable aviation fuel; H2 and CO. X The molar ratio is 1-3:1; CO X It is at least one of CO and CO2.

7. The preparation method according to claim 6, characterized in that: The H2 and CO X The molar ratio is 3:

1.

8. The preparation method according to claim 6, characterized in that: The reaction temperature was 300℃, the pressure was 3.5 MPa, and the space velocity was 1800 mL•g. -1 •h -1 .

Images