Preparation method of sustainable aviation fuel

Abstract

The present disclosure provides a method for preparing a Sustainable Aviation Fuel (SAF), the method comprising: a step of preparing a renewable feedstock, a step of preparing a renewable feedstock, a step of preparing a renewable feedstock, a step of preparing a renewable feedstock, a step of preparing a renewable feedstock, a step of preparing a renewable feedstock, a step of preparing a renewable feedstock, and a step of preparing the SAF, and a step of preparing the SAF. And a step for introducing the renewable feedstock as a reactant into a hydrogenation reaction in the presence of a catalyst comprising a metal and a zeolite, the zeolite being a 1D (dimensional) 10MR (membered-rns) zeolite, the conversion rate of the hydrogenation reaction of a fraction exceeding the boiling point of the SAF being 50% or less. The process enables the production of aviation fuels from environmentally friendly feedstocks. In addition, the SAF prepared by the method can replace aviation fuels previously prepared from fossil raw materials. In addition, the emission of carbon dioxide into the atmosphere can be reduced, and therefore it is expected that global warming caused by the emission of carbon dioxide can be suppressed.

Description

Technical Field

[0001] The present disclosure relates to a method for preparing sustainable aviation fuel (SAF). Background Art

[0002] Jet fuel is the fuel used in aircraft engines. Jet fuel is not significantly different in composition from kerosene and is generally prepared by mixing various additives into kerosene fractions. Specifically, jet fuel is prepared by processing low-volatility kerosene.

[0003] Carbon dioxide emitted by humans causes rapid climate change with rising temperatures through the greenhouse effect. Therefore, in order to prevent the increase in carbon dioxide concentration in the atmosphere, the so-called "carbon neutrality" that reduces emissions from human activities and increases absorption to make actual emissions zero (zero) has recently attracted attention.

[0004] SAF refers to aviation fuel made from sustainable and renewable raw materials, which can be biological materials such as seaweed, plants and animals, edible oil, or synthetic materials made from carbon dioxide in the air, hydrogen from water, etc.

[0005] SAF can replace existing aviation fuel without modifying existing aircraft. The advantage of SAF is that it can reduce carbon emissions by up to 80% compared to conventional aviation fuels made from fossil resources such as oil and coal. SAF has attracted much attention from the perspectives of the depletion of existing fossil resources, rising crude oil prices, and from the perspectives of preventing global warming and reducing carbon dioxide emissions.

[0006] [Prior art literature]

[0007] [Patent Literature]

[0008] (Patent Document 1) KR 10-2015-0046398A Summary of the invention

[0009] Technical issues

[0010] The present disclosure may provide a method for preparing SAF.

[0011] Technical Solution

[0012] One aspect of the present disclosure is a method for preparing SAF, comprising: a step of preparing a renewable feedstock; and a step of introducing the renewable feedstock as a reactant into a hydrogenation reaction in the presence of a catalyst, wherein the catalyst comprises a metal and a zeolite, and the zeolite is a 1D (dimensional) 10MR (membered-rings) zeolite, wherein the hydrogenation reaction conversion rate of the fraction exceeding the boiling point of SAF is less than 50%.

[0013] According to one embodiment, the renewable supply feedstock has a paraffin content of at least 50 wt%, comprising hydrocarbons having a carbon number of at least C16.

[0014] According to one embodiment, the hydrogenation reaction includes a hydroisomerization reaction and a hydrocracking reaction.

[0015] According to one embodiment, the metal includes at least one of Group VIB metals and Group VIII metals of the Periodic Table.

[0016] According to one embodiment, the zeolite includes at least one of a zeolite having a TON structure, a zeolite having an MTT structure, a zeolite having an AEL structure, and a zeolite having an MRE structure.

[0017] According to one embodiment, the hydrogenation reaction is carried out at a temperature of 200 to 500°C; a hydrogen partial pressure of 1 to 200 bar; and a reaction time of 0.1 to 10 hours. -1 Liquid hourly space velocity (LHSV); and 40 to 1800 Nm 3 / m 3 The hydrogen / reactant ratio is controlled.

[0018] According to one embodiment, the method includes the step of recovering a fraction below the SAF boiling point in the product of the hydrogenation reaction, and the step of recovering the fraction below the SAF boiling point in the product of the hydrogenation reaction includes the step of separating a fraction below the SAF boiling point and a fraction in the SAF boiling point range.

[0019] According to one embodiment, in the product of the hydrogenation reaction, the fraction in the SAF boiling point range and the fraction below the SAF boiling point satisfy the relationship ΔM / ΔL≥100, wherein ΔM is the change in the content of the fraction in the SAF boiling point range before and after the hydrogenation reaction, and ΔL is the change in the content of the fraction below the SAF boiling point before and after the hydrogenation reaction.

[0020] According to one embodiment, the method includes the step of recovering a fraction below the SAF boiling point in the product of the hydrogenation reaction, and the step of recovering the fraction below the SAF boiling point in the product of the hydrogenation reaction includes the step of introducing the fraction below the SAF boiling point into a hydroisomerization reaction.

[0021] According to one embodiment, the method includes the step of recycling a fraction exceeding the boiling point of SAF in the product of the hydrogenation reaction as a reactant for the hydrogenation reaction.

[0022] According to one embodiment, the SAF has a freezing point below -40°C.

[0023] Technical Effects

[0024] The present disclosure provides a method for preparing SAF. The method enables the preparation of aviation fuel from environmentally friendly raw materials. In addition, the SAF prepared by the method can replace aviation fuel previously prepared from fossil raw materials. In addition, the amount of carbon dioxide emissions into the atmosphere can be reduced, so it can be expected to suppress global warming caused by carbon dioxide emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a simplified process diagram of a SAF preparation method according to an embodiment;

[0026] Figure 2 is a simplified process diagram of a SAF preparation method according to another embodiment;

[0027] Figure 3 and Figure 4 is a graph showing conversion rate and selectivity under each catalyst according to an experimental result of using n-hexadecane as a raw material according to an experimental example;

[0028] Figure 5 1 is a graph showing conversion rate versus ΔM / ΔL according to an experimental result using FT synthetic oil as a raw material according to an experimental example. DETAILED DESCRIPTION

[0029] The present disclosure is described in detail below with reference to the accompanying drawings, but this is only an example, and the present disclosure is not limited to the specific embodiments described exemplarily.

[0030] The present disclosure provides a method for preparing SAF. Figure 1 and Figure 2 The following are brief process diagrams of the SAF preparation method according to some embodiments of the present disclosure. For reference, Figure 1 and Figure 2 The reported values ​​are drawn assuming that the hydrogenation reaction conversion rate of the fraction exceeding the boiling point of SAF is 40%. Figure 1 and / or Figure 2To understand the SAF preparation method of the present disclosure, it should be noted that the method of the present disclosure is not limited to the drawings described. Figure 1 and Figure 2 HDW is an abbreviation for hydro-dewaxing reaction, which can be used interchangeably with hydrogenation reactions including hydrocracking reaction and hydroisomerization reaction in the present disclosure. Also, HDF is an abbreviation for hydro-finishing reaction, which can be performed to reduce the olefin content in the fraction and improve stability. Also, Dist. is an abbreviation for distillation, which can be performed to separate based on the difference in boiling points of the fractions.

[0031] The method includes the step of preparing a renewable supply raw material. In the present disclosure, a 'renewable supply raw material' is carbon dioxide in the air, exhaust gas from factories, or biological raw materials derived from vegetable oils, fats, grains, sugars, wood, etc., and refers to raw materials other than existing fossil fuels and raw materials derived therefrom. Such raw materials have no or little impact on the environment. Renewable supply raw materials are expected to replace limited resources such as fossil raw materials and become long-term, sustainable resources.

[0032] The renewable supply raw materials disclosed in the present invention may include, for example, biomass-derived fatty acids, vegetable oils, animal oils, waste cooking oils, Fischer-Tropsch (FT) process-derived synthetic crude oil (syncrude), Fischer-Tropsch wax (FT-wax), etc., but are not limited thereto.

[0033] The reactant of the FT process is synthesis gas (syngas). In some embodiments, the synthesis gas can be derived from water and carbon dioxide. Specifically, the synthesis gas can be prepared from hydrogen and carbon dioxide derived from water. More specifically, the hydrogen can be green hydrogen. Green hydrogen refers to hydrogen obtained by water electrolysis using renewable energy such as geothermal, wind power, and hydropower. Green hydrogen does not emit carbon dioxide during the production process, so it is rated as environmentally friendly hydrogen.

[0034] In addition, from the perspective of carbon neutrality, the carbon dioxide may be carbon dioxide produced as a by-product of human production activities, etc. As an example, the carbon dioxide may be captured carbon dioxide. Specifically, the carbon dioxide may be carbon dioxide captured by direct air capture (DAC) and / or carbon dioxide captured by point emission. Direct air capture is a method of separating and capturing carbon dioxide from the air. Direct air capture has the advantage of not being restricted by site. Point source carbon capture is a method used in factories that produce carbon dioxide by-products, such as thermal power plants. Since the concentration of carbon dioxide is high in such factories, the capture efficiency of carbon dioxide is excellent, and it also has the advantage of directly reducing the emission of carbon dioxide into the atmosphere from the place where carbon dioxide is produced.

[0035] The synthesis gas prepared from the hydrogen and carbon dioxide obtained as above is used as a reactant of the FT process, and the product of the FT process can be used as a renewable supply raw material of the present disclosure.

[0036] Compared with existing petrochemical fractions, the renewable supply raw material has a relatively high paraffin content. In some embodiments, the renewable supply raw material may have a paraffin content of at least 50 wt % based on the total weight of the renewable supply raw material.

[0037] Specifically, the renewable supply feedstock may have a paraffin content of at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%. Also, the paraffin content may be 50 wt% to 100 wt%, 55 wt% to 100 wt%, 60 wt% to 100 wt%, 65 wt% to 100 wt%, 70 wt% to 100 wt%, 80 wt% to 100 wt%, 50 wt% to 95 wt%, 55 wt% to 90 wt%, or any lower range between the endpoints.

[0038] In the present disclosure, the SAF boiling point range may vary slightly depending on the properties of the desired product. In one embodiment of the present disclosure, the SAF boiling point range may be about 150 to 300° C. The SAF includes hydrocarbons of a corresponding boiling point range. As an example, the boiling point range of the fraction in the present disclosure may be measured by the ASTM D7500 method.

[0039] The SAF of the present disclosure may include hydrocarbons having a carbon number of C8 to C16. The carbon number range of the SAF may also vary slightly depending on the desired product properties. For example, the SAF may include hydrocarbons having a carbon number range equivalent to C8 to C14, C9 to C16, C10 to C15, and the like.

[0040] In one embodiment, the SAF may contain hydrocarbons having a carbon number of C9 to C15. Specifically, the SAF may contain at least 90 wt% of hydrocarbons having a carbon number of C9 to C15. More specifically, the SAF may contain at least 95 wt%, more specifically at least 98 wt%, more specifically at least 99 wt% of hydrocarbons having a carbon number of C9 to C15. Most specifically, the SAF may consist of hydrocarbons having a carbon number of C9 to C15.

[0041] In the preparation method of the present disclosure, a variety of renewable supply raw materials with a wide range of carbon numbers can be used. The renewable supply raw materials may include: hydrocarbons below the above-mentioned SAF boiling point range; hydrocarbons within the SAF boiling point range; or hydrocarbons exceeding the SAF boiling point range. Specifically, in some embodiments, the renewable supply raw materials may include a small amount of hydrocarbons below C9. In another embodiment, the renewable supply raw materials may include hydrocarbons in the SAF boiling point range. In yet another embodiment, the renewable supply raw materials may include hydrocarbons above the SAF boiling point range.

[0042] As an example, the renewable supply feedstock may contain hydrocarbons with a carbon number of at least C16. Specifically, the renewable supply feedstock may contain at least 90 wt% hydrocarbons with a carbon number of at least C16 relative to the total weight of the renewable supply feedstock. More specifically, the renewable supply feedstock may contain at least 95 wt%, at least 96 wt%, at least 97 wt%, or at least 98 wt% hydrocarbons with a carbon number of at least C16.

[0043] In addition, in some embodiments, the renewable supply raw material may contain at least 90 wt% of hydrocarbons having a boiling point of at least 300° C. More specifically, the renewable supply raw material may contain at least 95 wt%, at least 96 wt%, at least 97 wt%, or at least 98 wt% of hydrocarbons having a boiling point of at least 300° C.

[0044] The method of the present disclosure includes the step of introducing the above-mentioned renewable supply raw material as a reactant into a hydrogenation reaction in the presence of a catalyst. Wherein 'reactant' refers to the reactant of the hydrogenation reaction. The above-mentioned renewable supply raw material, which may contain hydrocarbons with a higher carbon number than SAF, can be converted into hydrocarbons with a carbon number corresponding to SAF through the hydrogenation reaction, and in addition, can be upgraded to meet the specifications required for use as aviation fuel.

[0045] In the present disclosure, the hydrogenation reaction may include a hydroisomerization reaction and a hydrocracking reaction. The hydroisomerization reaction converts normal paraffins (n-paraffin) into isoparaffins (iso-paraffin). Due to the characteristics of aircraft operating at low temperatures and high altitudes, aviation fuel needs to have a low freezing point. Converting normal paraffins into isoparaffins by hydroisomerization can help improve the low-temperature performance of the final product.

[0046] In addition, the hydrocracking reaction decomposes hydrocarbon molecules into hydrocarbon molecules with a smaller carbon number. In some embodiments, the carbon number range of hydrocarbons in the renewable supply feedstock may be C5 to C120 or more. In order to achieve a SAF with a distribution ranging from C9 to C15 from the renewable supply feedstock, not only the hydroisomerization reaction but also the hydrocracking reaction is required.

[0047] In some other embodiments, the renewable supply feedstock may contain hydrocarbons having a carbon number distribution of C16 to C20. In order to achieve SAF from the renewable supply feedstock, a hydrocracking reaction is required. In addition, decomposing C16 to C20 hydrocarbons into C9 to C15 hydrocarbons requires a more delicate hydrocracking reaction than decomposing C100 hydrocarbons into C9 to C15 hydrocarbons.

[0048] The hydrogenation reaction is performed in the presence of a catalyst. Specifically, the catalyst may be a bi-functional catalyst. The catalyst may include a support having an acid site for hydrogenation / dehydrogenation reactions and for metal and skeletal isomerization reactions. The catalyst may include a metal and a zeolite.

[0049] Specifically, the metal may include at least one of Group VIB metals and Group VIII metals of the periodic table. More specifically, the metal may include at least one of Fe, Ni, Mo, Co, W, Ru, Pt and Pd. More specifically, the metal may include at least one of Pt and Pd.

[0050] In addition, in one embodiment, the zeolite may be a 1D (1 dimensional) 10MR (10 membered-rings) zeolite. The 10MR zeolite has a pore size suitable for isomerizing and / or cracking paraffin. In addition, the zeolite with a 1D pore structure in the 10MR zeolite is suitable for the isomerization of normal paraffins. More specifically, the zeolite may include at least one of a zeolite with a TON structure, a zeolite with an MTT structure, a zeolite with an AEL structure, and a zeolite with an MRE structure. More specifically, the zeolite may be at least one of a zeolite with a TON structure, a zeolite with an MTT structure, a zeolite with an AEL structure, and a zeolite with an MRE structure. As an example, the zeolite may include ZSM-22, ZSM-23, SAPO-11, EU-2, and ZSM-48, but is not limited thereto.

[0051] Therefore, the selectivity of the catalyst of the present disclosure for the hydroisomerization reaction can be higher than the selectivity for the hydrocracking reaction. In some embodiments, the selectivity for the hydroisomerization reaction in the hydrogenation reaction can be, for example, greater than 0.5 and less than 1.0, such as greater than or equal to 0.6 and less than 1.0, greater than or equal to 0.7 and less than 1.0, greater than or equal to 0.75 and less than 1.0, greater than or equal to 0.8 and less than 1.0, greater than or equal to 0.9 and less than 1.0, or can be any lower range between the endpoints. The relatively high selectivity for this hydroisomerization reaction can help to increase the yield of SAF and reduce the yield of fractions lighter than SAF, such as renewable naphtha (RN).

[0052] By using the catalyst as described above, the method of the present disclosure does not require additional hydrocracking reaction with additional catalyst. It does not require additional reactor for hydrocracking reaction, thus also having a positive impact on reducing process equipment costs.

[0053] In the present disclosure, the hydrogenation reaction is performed under the reaction conditions that the conversion rate of the fraction exceeding the boiling point of SAF reaches 50% or less. The 'conversion rate of the fraction exceeding the boiling point of SAF' described in the present disclosure is defined as the percentage of (the change in the content of the fraction exceeding the boiling point of SAF before and after the hydrogenation reaction) / (the content of the fraction exceeding the boiling point of SAF in the reactants introduced into the hydrogenation reaction). The unit of the content is wt%. Specifically, the conversion rate is defined as follows.

[0054]

[0055] As described above, in one embodiment, the SAF boiling point range may be about 150 to 300° C. Therefore, the boiling point of the fraction exceeding the SAF boiling point may exceed about 300° C. And, the boiling point of the fraction below the SAF boiling point may be below about 150° C.

[0056] In one embodiment, the conversion rate of the fraction exceeding the boiling point of the SAF can be greater than 0% and below 50%. Specifically, the conversion rate can be 1% to 50%, 5% to 50%, 10% to 50%, 20% to 50%, 30% to 50%, 40% to 50%, 1% to 40%, 5% to 40%, 10% to 40%, 20% to 40%, 30% to 40%, 1% to 30%, 5% to 30%, 10% to 30%, 20% to 30%, or any lower range between the endpoints. As described below, in the method of the present disclosure, the fraction exceeding the boiling point of the SAF is reintroduced into the hydrogenation reaction as a reactant by recycling, and the lower the conversion rate, the lower the yield of the fraction below the boiling point of the SAF can be reduced.

[0057] The hydrogenation reaction can be performed under conditions that can achieve high hydroisomerization reaction selectivity and low conversion rate of fractions exceeding the boiling point of SAF. Using a catalyst with high hydroisomerization reaction selectivity under low conversion rate conditions of fractions exceeding the boiling point of SAF can inhibit the fractions above the boiling point of SAF from being cracked into fractions below the boiling point of SAF. In some embodiments, the hydrogenation reaction can be performed at a temperature of 200 to 500°C; a hydrogen partial pressure of 1 to 200 bar; and a reaction time of 0.1 to 10 hours. -1 Liquid hourly space velocity (LHSV); and 40 to 1800 Nm 3 / m 3 The hydrogen / reactant ratio is controlled.

[0058] Specifically, the temperature may be 200 to 500° C., 250 to 500° C., 300 to 500° C., 200 to 450° C., 250 to 450° C., 300 to 450° C., 200 to 400° C., 250 to 400° C., 300 to 400° C. More specifically, the temperature may be 300 to 380° C. More specifically, the temperature may be 300 to 360° C.

[0059] And, specifically, the hydrogen partial pressure may be 1 to 200 bar, 5 to 200 bar, 10 to 200 bar, 30 to 200 bar, 1 to 150 bar, 5 to 150 bar, 10 to 150 bar, 30 to 150 bar, 1 to 120 bar, 5 to 120 bar, 10 to 120 bar, 30 to 120 bar, 1 to 100 bar, 5 to 100 bar, 10 to 100 bar, 30 to 100 bar. More specifically, the hydrogen partial pressure may be 30 to 90 bar. More specifically, the hydrogen partial pressure may be 30 to 80 bar.

[0060] And, specifically, the LHSV may be 0.1 to 10 hr -1 , 0.1 to 8.0 hr -1 , 0.1 to 6.0 hr -1 or 0.1 to 4.0 hr -1 More specifically, the LHSV may be 0.1 to 3.0 hr -1 More specifically, the LHSV may be 0.5 to 2.0 hr -1 .

[0061] And, specifically, the hydrogen / reactant ratio can be 40 to 1800 Nm 3 / m 3 , 50 to 1600 Nm 3 / m 3 , 60 to 1500 Nm 3 / m 3 , 80 to 1500 Nm 3 / m 3 More specifically, the hydrogen / reactant ratio may be 100 to 1500 Nm 3 / m 3 It should be noted that the hydrogenation reaction conditions may vary depending on the type of catalyst used and the type of renewable supply feedstock.

[0062] The method disclosed herein comprises the step of recovering a fraction below the SAF boiling point in the product of the hydrogenation reaction, wherein the fraction below the SAF boiling point may include a fraction within the SAF boiling point range and a fraction below the SAF boiling point.

[0063] In some embodiments, in the product of the hydrogenation reaction, the fraction in the SAF boiling point range and the fraction below the SAF boiling point may satisfy the following relationship.

[0064] △M / △L≥100

[0065] Among them, ΔM is the change in the content of the fraction in the SAF boiling point range before and after the hydrogenation reaction. That is, ΔM refers to the amount of fraction generated in the SAF boiling point range after the hydrogenation reaction. And ΔL is the change in the content of the fraction below the SAF boiling point before and after the hydrogenation reaction. That is, ΔL refers to the amount of fraction generated below the SAF boiling point after the hydrogenation reaction.

[0066] Specifically, the ΔM / ΔL ratio may be 100 to 500, such as 100 to 110, 100 to 120, 100 to 130, 100 to 140, 100 to 150, 100 to 160, 100 to 170, 100 to 180, 100 to 190, 100 to 200, 100 to 300, 100 to 400, or any lower range between the endpoints. More specifically, the ΔM / ΔL ratio may be 200 to 500. More specifically, the ΔM / ΔL ratio may be 300 to 500. The greater the value of the ΔM / ΔL ratio, the lower the yield of the fraction below the SAF boiling point. Therefore, the method of the present disclosure may be performed to achieve the above-mentioned low conversion rate of the fraction above the SAF boiling point and the value of the high ΔM / ΔL ratio.

[0067] In some embodiments, the step of recovering the fraction below the SAF boiling point in the product of the hydrogenation reaction may include the step of separating the fraction below the SAF boiling point and the fraction in the SAF boiling point range. The fraction below the SAF boiling point may include an RN fraction. The RN fraction may be recovered separately as needed. The recovered RN fraction may be used as a raw material for preparing known petrochemical products through subsequent processes. In addition, the separated SAF boiling point fraction may be obtained through subsequent processes as needed as the SAF of the present disclosure.

[0068] In one embodiment, the step of recovering the fraction below the SAF boiling point in the product of the hydrogenation reaction may further include the step of introducing the fraction below the SAF boiling point into a hydroisomerization reaction. The hydroisomerization reaction is carried out separately from the above-mentioned hydrogenation reaction. The normal paraffins remaining in the fraction can be removed by the hydroisomerization reaction to further improve the low temperature performance of the fraction. The hydroisomerization reaction can be performed under known hydroisomerization reaction conditions without particular limitation. As an example, the hydroisomerization reaction can also be performed under the above-mentioned hydrogenation reaction conditions of the present disclosure.

[0069] In another embodiment, the fraction below the SAF boiling point in the product of the hydrogenation reaction is separated into a fraction below the SAF boiling point and a fraction in the SAF boiling point range, and only the separated fraction in the SAF boiling point range can be introduced into the hydroisomerization reaction.

[0070] In addition, further, in some embodiments, the recovery step may further include the step of introducing the fraction in the boiling point range of SAF into a hydrofining reaction. In the hydrofining reaction, the fraction may be hydrogenated to remove aromatics in the fraction and saturate olefins, thereby improving the oxidation, thermal, UV and other stability of the fuel product. The hydrofining reaction may be performed under known reaction conditions.

[0071] As an example, the hydrofining reaction can be performed in the presence of a catalyst. The catalyst used for the hydrofining reaction includes one or more metals selected from Group 6, Group 8, Group 9, Group 10, and Group 11 elements having a hydrogenation function, and specifically, sulfides of Ni-Mo, Co-Mo, and Ni-W metals or precious metals such as Pt and Pd can be used.

[0072] As the carrier, silica, alumina, silica-alumina, titania, zirconia, or zeolite can be used, and specifically, alumina and silica-alumina can be used.

[0073] In addition, the method of the present disclosure includes the step of recycling the fraction exceeding the SAF boiling point in the product of the hydrogenation reaction as a reactant for the hydrogenation reaction. In one embodiment, the fraction exceeding the SAF boiling point can be mixed with a renewable supply feedstock before being introduced into the hydrogenation reaction. In another embodiment, the fraction exceeding the SAF boiling point and the renewable supply feedstock can be introduced into the hydrogenation reaction separately. It should be noted that, in any case, the fraction exceeding the SAF boiling point in the reactant introduced into the hydrogenation reaction described in the above description of the conversion rate is the sum of the fraction exceeding the SAF boiling point in the renewable supply feedstock and the fraction exceeding the SAF boiling point recycled in the hydrogenation reaction product.

[0074] See also Figure 2 In some embodiments, the preparation method may include the step of separating the renewable supply raw material into a fraction exceeding the SAF boiling point and a fraction below the SAF boiling point before the hydrogenation reaction. In the embodiment, only the fraction exceeding the SAF boiling point may be introduced into the hydrogenation reaction. Thereafter, the hydrogenation reaction product may be mixed with the renewable supply raw material and introduced into the separation step.

[0075] SAF may be prepared by the method described above. In one embodiment, the SAF may have a freezing point below -40°C. The SAF boiling point range fraction obtained by the method of the present disclosure may be mixed with additional additives as needed to meet the specifications of commercial aviation fuel.

[0076] The embodiments of the present disclosure are further described below with reference to specific experimental examples. The embodiments and comparative examples included in the experimental examples are merely illustrative of the present disclosure and do not limit the scope of the appended claims. It is obvious to those skilled in the art that various changes and modifications to the embodiments can be implemented within the scope of the present disclosure and the technical concept, and it is also natural that such changes and modifications belong to the scope of the appended claims.

[0077] Example

[0078] 1. Prepare a highly selective catalyst for hydroisomerization reaction

[0079] 1-1. Preparation of catalyst for hydrogenation reaction

[0080] A variety of catalysts for hydrogenation reactions including zeolite carriers were prepared. The catalysts were prepared using the same type and content of metal and the same preparation method, except that the type of zeolite was different. As the metal, Pt metal in a 1wt% aqueous solution state was used. As the metal impregnation method for preparing the catalyst, the incipient wetness impregnation method was used. BETA, ZSM-5, FER, MOR, ZSM-23 and EU-2 zeolites were used as zeolite carriers. Zeolite catalysts each having a Pt content of 0.6wt% were prepared.

[0081] 1-2. Experiment to confirm the selectivity of hydrogenation reaction

[0082] n-hexadecane (C16) is used as a model sample of a renewable supply raw material with a high proportion of paraffin content as a reaction raw material for this experiment. n-hexadecane is isomerized into branched hexadecane (iso-C16) having the same carbon number of C16 as n-hexadecane as the reaction raw material through a hydrogenation reaction, or cracked into low molecular hydrocarbons having a carbon number of less than C15. Isomerized C16 can generally be classified into products with a single methyl group (mono-C16), products with a dimethyl group (di-C16), and products with a trimethyl group (tri-C16) according to the number of methyl groups. Among them, mono-C16 generally has the highest yield.

[0083] 1 g of the previously prepared catalyst was placed in a continuous fixed bed reactor, and the selectivity of the product under each catalyst was confirmed under the reaction conditions shown below while n-hexadecane and hydrogen were simultaneously supplied to the reactor.

[0084]

Table 1

[0085] Reaction conditions scope Reaction temperature (℃) 260-350 <![CDATA[H 2 Partial pressure (bar)]]> 30-80 <![CDATA[LHSV(hr -1 )]]> 1-2

[0086] The experimental results are shown in terms of the relationship between the conversion rate and the selectivity according to the temperature change, as shown in FIG. Figure 3 and Figure 4 In this experiment, the conversion rate refers to the change in the amount of n-hexadecane as the reaction raw material before and after the reaction. As the reaction time goes by, n-hexadecane is converted into the reaction product, and only a part of it remains after the reaction is completed.

[0087] Figure 3 The result is shown with the selectivity of mono-C16 as the y-axis. The selectivity of mono-C16 refers to the weight ratio of mono-C16 relative to the total reaction product of n-hexadecane conversion (including hexadecane branched by hydroisomerization reaction and low molecular weight hydrocarbons with carbon numbers below C15 by hydrocracking reaction).

[0088] Figure 4 The results are shown with the selectivity of isomeric C16 including mono-, di- and tri-C16 as the y-axis. The selectivity of isomeric C16 refers to the weight ratio of isomeric C16 relative to the total reaction product.

[0089] exist Figure 3 and Figure 4 The more it is located to the right and the upper side, the more it corresponds to a catalyst having a higher selectivity for hydroisomerization than for hydrocracking. The experimental results show that ZSM-23 and EU-2 zeolite catalysts having 1-D and 10MR structures are catalysts suitable for the hydroisomerization reaction of normal paraffins.

[0090] 2. Hydrogenation reaction experiment of renewable raw materials

[0091] 2-1. Hydrogenation reaction experiments of various catalyst types

[0092] The FT synthetic oil prepared by the FT synthesis reaction of synthetic gas is used as the reaction raw material, and the previously prepared catalyst is used for hydrogenation reaction. The main component of the FT synthetic oil is paraffin hydrocarbons, and the boiling point of the FT synthetic oil is about 150-710°C. 5 -C 120 Wide range of carbon number distribution)

[0093] After injecting the reaction raw materials and catalyst into the autoclave reactor, hydrogen was supplied to the autoclave reactor until the hydrogen partial pressure reached 30 bar. Then, the temperature of the reactor was raised to 200° C., and the temperature was raised to the reaction temperature while stirring at 500 rpm and maintained for a certain reaction time.

[0094] The experimental conditions and results are shown in Table 2 below.

[0095]

Table 2

[0096] raw material Experiment 1 Experiment 2 Experiment 3 catalyst Pt / EU-2 Pt / ZSM-5 Ni / Y zeolite Pore ​​structure 1D 3D 3D Raw material / catalyst (g / g) / h 7.5 7.5 7.5 Reaction temperature (℃) 350 350 350 Reaction time (h) 2 2 2 Light fraction content (wt%) 0 8.4 40.7 45.2 Middle distillate content (wt%) 1.9 22.9 37.8 45.2 Heavy fraction content (wt%) 98.1 68.7 21.5 9.6 Heavy fraction conversion rate (%) 30.0 78.1 87.4 △M / △L 250 88 51

[0097] The contents of each fraction of the reaction raw materials and reaction products were analyzed by the SIMDIS analysis method using the ASTM D7500 method. The same analysis method was also used in the following experiment. Among them, the light fraction refers to the fraction with a boiling point below 150°C, the middle fraction refers to the fraction with a boiling point of 150 to 300°C, and the heavy fraction refers to the fraction with a boiling point exceeding 300°C. The heavy fraction conversion rate refers to the value of the change in the content of the heavy fraction before and after the reaction divided by the content of the heavy fraction in the raw material. △M / △L refers to the value of the change in the middle fraction before and after the reaction divided by the change in the light fraction before and after the reaction.

[0098] Referring to Table 2, the raw material before the reaction contained 98.1 wt% of a heavy fraction having a boiling point range of 300 to 710° C. Through the reaction, the heavy fraction in the raw material was cracked, thereby reducing its content, and increasing the contents of the light fraction and the middle fraction.

[0099] From Experiment 1, it can be seen that by satisfying a heavy fraction conversion rate of 50% or less and a ΔM / ΔL of 100 or more, the production of light fractions can be suppressed and the production of middle fractions that can be used to prepare SAF can be increased. By separating and recycling the heavy fraction from the reaction product while maintaining the heavy fraction conversion rate and ΔM / ΔL within the numerical range and reintroducing the heavy fraction into the hydrogenation reaction, the production of light fractions can be suppressed, and at the same time, it is expected that the middle fraction can be obtained at a higher yield.

[0100] 2-2. Hydrogenation reaction experiment in a continuous fixed bed reactor

[0101] A hydrogenation reaction experiment was conducted in a continuous fixed bed reactor using the catalyst and reaction raw materials of Experiment 1. Hydrogen was first supplied to the continuous fixed bed reactor loaded with the catalyst, and then FT synthetic oil was supplied.

[0102] The experimental conditions and results are shown in Table 3 below.

[0103]

Table 3

[0104] raw material Experiment 4 catalyst Pt / EU-2 Pore ​​structure 1D Reaction temperature (℃) 330 Reaction pressure (bar) 30 <![CDATA[LHSV(h -1 )]]> 0.5 <![CDATA[Gas to oil ratio (GOR, nm 3 / m 3 )]]> 500 Light fraction content (wt%) 0 4.6 Middle distillate content (wt%) 1.9 26.7 Heavy fraction content (wt%) 98.1 68.7 Heavy fraction conversion rate (%) 30.0 △M / △L 539

[0105] The contents of each fraction in the reaction raw material and the reaction product were analyzed by SIMDIS analysis using the ASTM D7500 method. As shown in Table 3, similar to the results of Experiment 1, in Experiment 4, the heavy fraction conversion rate of 50% or less and ΔM / ΔL of 100 or more were satisfied at the same time, thereby suppressing the production of light fractions and increasing the production of middle fractions that can be used to prepare SAF.

[0106] 2-3. Hydrogenation reaction experiments under various reaction conditions

[0107] Experiments were conducted using the catalyst used in Experiment 1 above but changing the content ratio of the raw material and the catalyst; the reaction temperature; and the reaction time.

[0108] The experimental conditions and results are shown in Table 4 below.

[0109]

Table 4

[0110]

[0111] As shown in Table 4, in Experiment D, when the catalyst content is increased and the reaction time is increased to improve the conversion rate of the heavy fraction, the production of the light fraction is increased compared to the production of the middle fraction. On the contrary, in Experiment E, when the conversion rate of the heavy fraction is reduced to nearly 10%, the production of the light fraction is further suppressed and the production of the middle fraction is increased. Figure 1 and / or Figure 2 As shown in the figure, by reintroducing the heavy fraction in the reaction product into the reaction under the condition of lower heavy fraction conversion rate, it is expected that SAF can be prepared with higher yield.

[0112] 2-4. Experiment to confirm the change of ΔM / ΔL according to the conversion rate of heavy fraction

[0113] Hydrogenation reactions were carried out using the catalysts used in Experiments 1 to 3, and the changing trend of ΔM / ΔL according to the change in the heavy fraction conversion rate was confirmed under various reaction conditions. The results are shown in Figure 5 .

[0114] See also Figure 5 It can be seen that ΔM / ΔL tends to decrease as the conversion rate of the heavy fraction increases. In addition, when a zeolite catalyst having a 1D structure such as the catalyst used in Experiment 1 is used, the ΔM / ΔL value is higher at a heavy fraction conversion rate of 50% or less than when a 3D structure catalyst used in Experiments 2 and 3 is used, so SAF can be produced at a higher yield.

[0115] The contents described above are merely examples of the principles of the present disclosure, and other configurations may be further included without departing from the scope of the present disclosure.

Claims

1. A method for preparing sustainable aviation fuel, for preparing sustainable aviation fuel, comprising: Steps to prepare renewable supply feedstocks; as well as The step of introducing the renewable supply raw material as a reactant into a hydrogenation reaction in the presence of a catalyst, wherein the catalyst comprises a metal and a zeolite, and the zeolite is a one-dimensional 10-membered ring zeolite, The conversion rate of the hydrogenation reaction of the fraction exceeding the boiling point of the sustainable aviation fuel is 50% or less.

2. The method for preparing sustainable aviation fuel according to claim 1, wherein: The renewable supply feedstock has a paraffin content of at least 50 wt%, comprising hydrocarbons having a carbon number of at least C16.

3. The method for preparing sustainable aviation fuel according to claim 1, wherein: The hydrogenation reaction includes a hydroisomerization reaction and a hydrocracking reaction.

4. The method for preparing sustainable aviation fuel according to claim 1, wherein: The metal includes at least one of Group VIB metals and Group VIII metals of the periodic table.

5. The method for preparing sustainable aviation fuel according to claim 1, wherein: The zeolite includes at least one of a zeolite having a TON structure, a zeolite having an MTT structure, a zeolite having an AEL structure, and a zeolite having an MRE structure.

6. The method for preparing sustainable aviation fuel according to claim 1, wherein: The hydrogenation reaction is carried out at a temperature of 200 to 500°C; a hydrogen partial pressure of 1 to 200 bar; and a time of 0.1 to 10 hours. -1 Liquid hourly space velocity; and 40 to 1800 Nm 3 / m 3 The hydrogen / reactant ratio is controlled.

7. The method for preparing sustainable aviation fuel according to claim 1, wherein: The method for preparing sustainable aviation fuel comprises the steps of recovering a fraction below the boiling point of the sustainable aviation fuel in the product of the hydrogenation reaction, The step of recovering the fraction below the boiling point of sustainable aviation fuel in the product of the hydrogenation reaction comprises the step of separating the fraction below the boiling point of sustainable aviation fuel and the fraction within the boiling point range of sustainable aviation fuel.

8. The method for preparing sustainable aviation fuel according to claim 1, wherein: In the product of the hydrogenation reaction, the fraction in the boiling point range of the sustainable aviation fuel and the fraction below the boiling point of the sustainable aviation fuel satisfy the following relationship: △M / △L≥100, Where △M is the change in the fraction content of the boiling point range of sustainable aviation fuel before and after the hydrogenation reaction. ΔL is the change in the content of the fraction below the boiling point of sustainable aviation fuel before and after the hydrogenation reaction.

9. The method for preparing sustainable aviation fuel according to claim 1, wherein: The method for preparing sustainable aviation fuel comprises the steps of recovering a fraction below the boiling point of the sustainable aviation fuel in the product of the hydrogenation reaction, The step of recovering the fraction below the boiling point of sustainable aviation fuel in the product of the hydrogenation reaction comprises the step of introducing the fraction below the boiling point of sustainable aviation fuel into a hydroisomerization reaction.

10. The method for preparing sustainable aviation fuel according to claim 1, wherein: The method for preparing sustainable aviation fuel comprises the step of recycling a fraction exceeding the boiling point of the sustainable aviation fuel in the product of the hydrogenation reaction as a reactant for the hydrogenation reaction.

11. The method for preparing sustainable aviation fuel according to claim 1, wherein: The sustainable aviation fuel has a freezing point below -40°C.

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