Method for producing sustainable aviation fuel and biodiesel fuel

Abstract

The present invention relates to a method for producing a sustainable aviation fuel and a biodiesel fuel.

Description

Sustainable Aviation Fuel and Biodiesel Production Methods

[0001] The present invention relates to a method for producing sustainable aviation fuel (SAF) and biodiesel fuel (BDF®).

[0002] SAF is a jet fuel made from renewable or waste materials that meets sustainability standards. In recent years, there has been an international movement to introduce SAF from the perspectives of preventing global warming and recycling resources. Furthermore, from an environmental perspective, attempts are being made to use biomass resources as aviation fuel.

[0003] Biomass resources are used as raw materials for SAF, such as waste wood, waste cooking oil, vegetable oil, etc. Known methods for producing SAF using biomass resources as raw materials include the Fischer-Tropsch method, which synthesizes SAF from CO and H using a catalytic reaction of Co, Fe, etc., and a method for producing SAF using hydrocracking (Non-Patent Document 1).

[0004] However, both methods require a large amount of energy for fuel production and are not effective measures to mitigate climate change.Furthermore, there are problems such as high costs due to the rising price of waste cooking oil, which is the raw material, and the low yield of SAF from biomass feedstock, which is 10% or less in the Fischer-Tropsch process and 2-30% in the method using hydrocracking (Non-Patent Document 2).

[0005] NG, Kok Siew; FAROOQ, Danial; YANG, Aidong. Global biorenewable development strategies for sustainable aviation fuel production. Renewable and Sustainable Energy Reviews, 2021, 150: 111502.VERMA, Vikas, et al. Catalytic hydroprocessing of waste cooking oil for the production of drop-in aviation fuel and optimization for improving jet biofuel quality in a fixed bed reactor. Fuel, 2023, 333: 126348.

[0006] The problem to be solved by the present invention is to provide a novel method for producing sustainable aviation fuel (SAF) and biodiesel fuel (BDF), and the SAF and BDF obtained by said method.

[0007] As a result of extensive research, the inventors discovered that SAF and BDF can be obtained using a novel method using coconut oil as a raw material, and thus completed the present invention.

[0008] That is, the present invention includes the following embodiments. [1] A method for producing sustainable aviation fuel using coconut oil as a raw material, comprising: producing a mixture of fatty acid alkyl esters by reacting fatty acid triglycerides and / or fatty acids that are degradation products thereof with a lower alcohol; and distilling the mixture of fatty acid alkyl esters under reduced pressure to separate a C8 fatty acid alkyl ester fraction and / or a C10 fatty acid alkyl ester fraction. [2] The production method according to [1], further comprising distilling the mixture after separating the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction under reduced pressure to separate a C12 fatty acid alkyl ester fraction. [3] The production method according to [1], wherein the mixture of fatty acid alkyl esters is produced by a transesterification reaction using fatty acid triglycerides derived from coconut oil and a lower alkyl alcohol. [4] The production method according to [1], wherein the mixture of fatty acid alkyl esters is produced by an esterification reaction using fatty acids that are degradation products of fatty acid triglycerides derived from coconut oil and a lower alkyl alcohol. [5] A method for producing a biodiesel fuel, comprising: using coconut oil as a raw material, reacting fatty acid triglycerides and / or fatty acids that are degradation products thereof with a lower alcohol to produce a mixture of fatty acid alkyl esters; vacuum distilling the mixture of fatty acid alkyl esters to remove a C8 fatty acid alkyl ester fraction and / or a C10 fatty acid alkyl ester fraction; and obtaining a mixture after removing the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction. [6] The production method according to [5], wherein the mixture of fatty acid alkyl esters is produced by a transesterification reaction using fatty acid triglycerides derived from coconut oil and a lower alkyl alcohol.[7] The method according to [5], wherein the production of the mixture of fatty acid alkyl esters is carried out by an esterification reaction using a fatty acid that is a decomposition product of fatty acid triglycerides derived from coconut oil and a lower alkyl alcohol. [8] The method according to any one of [1] to [7], wherein the mixture to which water has been added is distilled under reduced pressure. [9] The method according to any one of [1] to [7], wherein the lower alkyl alcohol is methanol, ethanol, propanol, isopropanol, or butanol.

[10] The method according to any one of [1] to [7], wherein the vacuum distillation in separating or distilling off the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction is carried out at a temperature of 110°C or higher and 130°C or lower.

[11] The method according to any one of [1] to [7], wherein a transesterification reaction is carried out in the presence of coconut oil, a lower alkyl alcohol, a catalyst, and an organic solvent.

[12] The method according to any one of [1] to [7], wherein the organic solvent is acetone.

[13] A sustainable aviation fuel produced by the method according to any one of [1] to [4].

[14] A biodiesel fuel produced by the method according to any one of [5] to [7].

[15] The sustainable aviation fuel according to

[13] , which consumes 0.5 L / LSAF or less of energy in terms of petroleum equivalent during production.

[16] The biodiesel fuel according to

[14] , which consumes 0.5 L / LSAF or less of energy in terms of petroleum equivalent during production.

[0009] According to the present invention, it is possible to provide a novel method for producing SAF and BDF, and SAF and BDF obtained by the method.

[0010] FIG. 1 is a diagram showing an overview of the present invention. FIG. 1 is a diagram showing a GC / FID chromatogram of fatty acid esters made from virgin coconut oil as a raw material in Example 1. FIG. 1 is a diagram showing a GC / FID chromatogram of fatty acid esters made from waste edible coconut oil as a raw material in Example 1. FIG. 2 is a diagram showing a GC / FID chromatogram of C8 and C10 fatty acid methyl esters in Example 1. FIG. 3 is a diagram showing a GC / FID chromatogram of C8 and C10 fatty acid ethyl esters in Example 1. FIG. 4 is a diagram showing a GC / FID chromatogram of C8 and C10 fatty acid isopropyl esters in Example 3. FIG. 5 is a diagram showing the results of HPLC analysis of C8 and C10 fatty acid methyl esters in Example 1. FIG. 6 is a diagram showing the results of HPLC analysis of C8 and C10 fatty acid ethyl esters in Example 1. FIG. 7 is a diagram showing the results of HPLC analysis of C8 and C10 fatty acid isopropyl esters in Example 3.

[0011] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described, but the present invention is not limited to the following examples.

[0012] (Coconut Oil) In this specification, "coconut oil" is not particularly limited as long as it is coconut oil extracted from the endosperm of coconut fruit. Known coconut oils include coconut oil extracted by pressing the solid endosperm of coconut without heating (so-called virgin coconut oil), and coconut oil extracted by adding water to the solid endosperm of coconut and heating it (so-called refined coconut oil). As the coconut oil, commercially available coconut oil may be used, or coconut oil extracted as coconut oil may be used.

[0013] Coconut oil may contain, but is not limited to, C6, C8, C10, C12, C14, C16, and / or C18 fatty acid triglycerides. An example of the fatty acid composition in the triglycerides contained in coconut oil is shown in Table 1.

[0014]

[0015] The coconut oil may be virgin coconut oil or used, waste coconut oil. Examples of fatty acid compositions of virgin coconut oil and waste coconut oil are shown in Table 2.

[0016]

[0017] (Method for Producing SAF) In a first aspect, a method for producing an SAF is provided.

[0018] Producing a Mixture of Fatty Acid Alkyl Esters The method of this embodiment involves producing a mixture of fatty acid alkyl esters using coconut oil as a raw material. The fatty acid composition in the mixture of fatty acid alkyl esters is derived from the coconut oil used as a raw material. The mixture of fatty acid alkyl esters is produced, for example, by the following method. In producing the mixture of fatty acid alkyl esters, coconut oil is used as a raw material. In the production reaction, coconut oil itself may be used as a raw material, or fatty acid triglycerides extracted from coconut oil may be used as a raw material. In either case, fatty acid triglycerides derived from fatty acid alkyl esters serve as the starting material in the production reaction. Examples of the production reaction include a transesterification reaction using fatty acid triglycerides derived from coconut oil and a lower alkyl alcohol, or an ester formation reaction using fatty acids obtained by hydrolyzing fatty acid triglycerides derived from coconut oil and a lower alkyl alcohol.

[0019] The mixing may be carried out to the extent that the reaction system becomes a homogeneous phase. A homogeneous phase refers to a state in which the fatty acid triglyceride or fatty acid, catalyst, organic solvent, and lower alkyl alcohol form a single phase. The catalyst may be a catalyst commonly used in transesterification reactions. Examples include alkaline catalysts such as sodium hydroxide and potassium hydroxide, acid catalysts such as hydrochloric acid, sulfuric acid, and hydrofluoric acid, enzymes such as lipase, inorganic substances such as calcium oxide, and solid catalysts such as ion exchange resins such as cation exchange resins and anion exchange resins. An alkaline catalyst or an acid catalyst is preferably used. A single catalyst may be used, or multiple catalysts may be used in combination. The alkaline catalyst or acid catalyst may be used in the form of an aqueous solution or the like according to a known method.

[0020] The organic solvent may be at least one selected from the group consisting of acetone, isopropanol, and acetonitrile. The organic solvent may be added in an amount of 10% by weight or more relative to the coconut oil. Preferably, the organic solvent may be added in an amount of 10% by weight to 50% by weight relative to the coconut oil.

[0021] Isopropanol reacts with fatty acids produced by hydrolysis of fatty acid triglycerides, so when isopropanol is used, it is preferable to use fatty acids produced by hydrolysis of fatty acid triglycerides as the raw material.

[0022] The lower alkyl alcohol may be at least one selected from the group consisting of methanol, ethanol, propanol, isopropanol, and butanol. The stoichiometric ratio of the lower alkyl alcohol to the fatty acid is suitably 1 to 1.6 times, preferably 1 to 1.2 times, and more preferably 1 to 1.17 times. The stoichiometric ratio for transesterification of the fatty acid and the alcohol is 3 moles of alcohol per mole of fatty acid.

[0023] The amount of catalyst may be adjusted as appropriate depending on the type of catalyst used, the amount of fatty acids in the raw materials, the scale of the reaction system, etc. Specifically, an amount that allows the transesterification reaction to proceed sufficiently without decreasing the rate of transesterification and that allows the catalyst to be separated during refining may be appropriately determined. For example, when an alkaline catalyst is used, the amount of alkaline catalyst used is 0.03 to 1.0 wt. % of the coconut oil, preferably 0.3 to 0.8 wt. %.

[0024] The transesterification reaction after mixing may be carried out at room temperature, preferably 5° C. to 35° C., more preferably 10° C. to 30° C., and even more preferably 15° C. to 25° C. The reaction time is not particularly limited as it is adjusted appropriately depending on the reaction, but is set to a reaction time of 1 minute to 3 hours, preferably 5 minutes to 2 hours, and more preferably 10 minutes to 1 hour.

[0025] The transesterification reaction involves mixing fatty acid triglycerides derived from coconut oil or fatty acids produced by decomposition of fatty acid triglycerides derived from coconut oil, a catalyst, an organic solvent, and a lower alkyl alcohol.

[0026] The mixing may be carried out in a vessel equipped with a stirring means. The fatty acid triglyceride or fatty acid, catalyst, organic solvent, and lower alkyl alcohol are placed in the vessel and mixed. The stirring may be performed manually or by using a device, and any known stirring means may be used.

[0027] Recovery of Acetone, Alcohol, and Glycerin The method of this embodiment further includes recovering acetone, alcohol, and glycerin. The recovery of acetone and alcohol may be carried out by distilling or vacuum distilling the reaction solution containing the fatty acid alkyl ester obtained by the above reaction. The distillation or vacuum distillation may be carried out according to a known method. For example, the distillation or vacuum distillation may be carried out at a temperature of 100°C or less, preferably 60°C to 80°C, and more preferably 65°C to 75°C. The distillation or vacuum distillation may also be carried out at a pressure of 1 atmosphere or less, preferably 0.9 atmospheres or less, and more preferably 0.8 atmospheres or less. The reaction time is adjusted appropriately depending on the reaction, so is not particularly limited, but is set to a reaction time of 1 minute to 3 hours, preferably 5 minutes to 2 hours, and more preferably 10 minutes to 1 hour.

[0028] The recovery of glycerin may be carried out by allowing the reaction solution to stand to separate into a fatty acid alkyl ester layer (upper layer) and a glycerin layer (lower layer), and then recovering the lower glycerin layer.

[0029] The method of this embodiment may include washing the reaction solution after glycerin recovery. The washing may be performed by adding water to the reaction solution after glycerin recovery, allowing the solution to stand to separate into an alkyl ester layer and a water layer, and then recovering the water in the lower layer. The washing may be performed multiple times until the pH of the washed water becomes neutral.

[0030] Separating the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction The method of this embodiment further includes separating the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction. Separating the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction may be carried out by adding water to the fatty acid alkyl esters after the washing and distilling under reduced pressure. The reduced pressure distillation may be carried out according to a known method. For example, distillation or reduced pressure distillation may be carried out at a temperature of 150°C or less, preferably 110°C to 130°C, more preferably 115°C to 120°C. Alternatively, distillation or reduced pressure distillation may be carried out at a pressure of 1 atmosphere or less, preferably 0.9 atmospheres or less, more preferably 0.8 atmospheres or less. The reaction time is adjusted appropriately depending on the reaction and is not particularly limited, but is set to 1 minute to 3 hours, preferably 5 minutes to 2 hours, and more preferably 10 minutes to 1 hour. When the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction are separated, they may be separated under conditions for separating both fractions simultaneously, or separately, or a portion may be separated simultaneously and the remainder separately. As the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction, fractions containing C8 fatty acid alkyl esters and / or C10 fatty acid alkyl esters may be mixed.

[0031] The C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction obtained by the vacuum distillation may be heated under reduced pressure to remove water. For example, water may be removed at a pressure of 1 atmosphere or less, preferably 0.9 atmospheres or less, more preferably 0.8 atmospheres or less, and at a temperature of 100° C. or less, preferably 90° C. or less, more preferably 80° C. or less. The C8 fatty acid alkyl ester and / or the C10 fatty acid alkyl ester obtained as described above can be used as an SAF.

[0032] Separating the C12 fatty acid alkyl ester fraction The method of this embodiment further includes separating the C12 fatty acid alkyl ester fraction. Separating the C12 fatty acid alkyl ester fraction may be carried out by adding water to the fatty acid alkyl ester remaining after separating the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction, followed by vacuum distillation. The vacuum distillation may be carried out according to a known method. For example, distillation or vacuum distillation may be carried out at a temperature of 170°C or lower, preferably 130°C to 150°C, more preferably 135°C to 145°C. Alternatively, distillation or vacuum distillation may be carried out at a pressure of 1 atmosphere or lower, preferably 0.9 atmospheres or lower, more preferably 0.8 atmospheres or lower. The reaction time is adjusted appropriately depending on the reaction and is not particularly limited, but is set to 1 minute to 3 hours, preferably 5 minutes to 2 hours, and more preferably 10 minutes to 1 hour.

[0033] The C12 fatty acid alkyl ester fraction separated by the vacuum distillation may be subjected to a known hydrodecarboxylation reaction to produce C12 isoparaffins. For example, the C12 fatty acid alkyl ester may be subjected to a sulfide treatment by a known method, and after the sulfide treatment, hydrogen may be added and the reaction may be carried out at 200°C to 300°C, preferably 230°C to 270°C, more preferably 240°C to 260°C, for 30 minutes to 4 hours, preferably 1 hour to 3 hours. The C12 isoparaffins obtained as described above can be used as SAF.

[0034] The method of the present embodiment includes producing isopropyl esters by an esterification reaction, which may be carried out by reacting a C8 fatty acid and / or a C10 fatty acid with a catalyst, an organic solvent, and isopropanol.

[0035] The catalyst used in the ester production reaction may be an acid catalyst, preferably sulfuric acid. In the present invention, the amount of catalyst used in the ester production reaction may be appropriately adjusted depending on the amount of fatty acid in the raw material, the scale of the reaction system, etc. Specifically, the amount may be appropriately determined so that the rate of the ester production reaction does not decrease, the reaction can be carried out sufficiently, and the catalyst can be separated by purification.

[0036] The organic solvent used in the ester production reaction may be isopropanol, acetone, or acetonitrile. The organic solvent may be added in an amount of 10% by weight or more based on the fatty acid. Preferably, the organic solvent may be added in an amount of 10% by weight to 50% by weight based on the fatty acid.

[0037] The ester production reaction involves heating a solution containing a mixture of a C8 fatty acid and / or a C10 fatty acid, a catalyst, an organic solvent, and isopropanol. The heating is carried out at a temperature of 30°C to 90°C, preferably 40°C to 80°C, more preferably 50°C to 70°C, and even more preferably 55°C to 65°C. The reaction time is not particularly limited and is adjusted appropriately depending on the reaction, but is set to 1 to 12 hours, preferably 2 to 8 hours, and more preferably 4 to 6 hours.

[0038] After the ester production reaction, the reaction solution may be allowed to stand to separate into a fatty acid alkyl ester layer (upper layer) and a water layer (lower layer), and then the lower water layer may be recovered to recover water containing the catalyst.

[0039] The method of this embodiment may include washing the reaction solution after catalyst recovery. The washing may be performed by adding water to the reaction solution after catalyst recovery, allowing it to stand to separate into an alkyl ester layer and a water layer, and then recovering the water in the lower layer. The washing may be performed multiple times until the pH of the washed water becomes neutral.

[0040] The method of this embodiment may include drying the reaction solution after washing. The drying may be performed according to a known method. For example, drying may be performed at a temperature of 100°C or less, preferably 60°C to 90°C, and more preferably 75°C to 85°C. Drying may also be performed at a pressure of 1 atmosphere or less, preferably 0.9 atmospheres or less, and more preferably 0.8 atmospheres or less. The C8 fatty acid isopropyl ester and / or C10 fatty acid isopropyl ester obtained as described above can be used as an SAF.

[0041] (Method for Producing BDF) In a second aspect, a method for producing BDF is provided.

[0042] The method of this embodiment includes producing a mixture of fatty acid alkyl esters, recovering acetone, alcohol, and glycerin, and distilling off the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction, but these steps may be similar to the steps of producing a mixture of fatty acid alkyl esters, recovering acetone, alcohol, and glycerin, and separating off the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction described in the above-mentioned method for producing SAF, and therefore further explanation will be omitted. The method of this embodiment may also include obtaining the reaction solution after distilling off the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction as BDF.

[0043] The method of this embodiment may further include distilling off the C12 fatty acid alkyl ester fraction, which may be the same as the separation of the C12 fatty acid alkyl ester fraction described in the above-mentioned method for producing SAF. The method of this embodiment may include obtaining the reaction solution after distilling off the C12 fatty acid alkyl ester fraction as BDF.

[0044] The properties of the fatty acid esters produced by the above method are shown in Table 3.

[0045]

[0046] In this embodiment, C6, C8, and C10 methyl esters, C6, C8, C10, and C12 ethyl esters, C6, C8, C10, and C12 propyl esters, C6, C8, C10, and C12 isopropyl esters, and C6, C8, and C10 butyl esters may be used as SAFs. C12, C14, C16, and C18 methyl esters, C14, C16, and C18 ethyl esters, C14, C16, and C18 propyl esters, C14, C16, and C18 isopropyl esters, and C12, C14, C16, and C18 butyl esters may be used as BDFs.

[0047] (Use of SAF) The SAF produced by the above-mentioned method may be mixed with conventional aviation fuel and used as aviation fuel. The conventional aviation fuel may be kerosene. Kerosene is one of the fractional distillation components of petroleum and is a C10 to C15 hydrocarbon.

[0048] The SAF produced by the above-described method may be added to kerosene in an amount of 10% or more, preferably 30% or more, and more preferably 50% or more. When the SAF is C8, C10, and C12 fatty acid ethyl esters, fatty acid propyl esters, and isopropyl esters, the SAF may be added to kerosene in an amount of 30% or more. When the SAF is C8 and C10 fatty acid methyl esters, the SAF may be added to kerosene in an amount of 10% or more. When the SAF is C8 and C10 fatty acid ethyl esters and fatty acid propyl esters, the SAF may be added to kerosene in an amount of up to 50%.

[0049] (Energy consumption in oil equivalent) "L / LSAF" refers to a numerical unit that converts the amount of energy consumed for heating a solution, etc., when producing 1 L of SAF into the amount of oil. The numerical value expressed in this unit serves as an evaluation index for the amount of energy consumed during SAF production. The energy consumption in oil equivalent during production is preferably 1 L / LSAF or less, more preferably 0.7 L / LSAF or less, more preferably 0.5 L / LSAF or less, and even more preferably 0.2 L / LSAF.

[0050] The present invention will be described in more detail below with reference to specific examples, but the present invention is not limited to the following examples. In the description of the examples, "%" means "% by mass."

[0051] (Example 1) (1-1) Preparation of reaction solution 1000 mL of coconut oil (LUNAS coconut oil (virgin coconut oil) or Philippine waste edible coconut oil; analytical results by GC / FID (Agilent Technologies, GC systems HP 6890 series) are shown in Figures 2 and 3), 100 mL of acetone (Wako Pure Chemical Industries, 10% based on oil), and 8.9 g of potassium hydroxide (KOH, Wako Pure Chemical Industries, 1.0% based on coconut oil) were dissolved in methanol (Wako Pure Chemical Industries) or ethanol (Wako Pure Chemical Industries) in a reaction vessel (Yashiro Scientific Instruments). The amount of alcohol was 4 to 5 times the molar ratio of the triglyceride.

[0052] (1-2) Transesterification reaction and recovery of acetone, alcohol, and glycerin The reaction solution prepared in (1-1) above was subjected to a transesterification reaction at room temperature for 30 minutes. After the reaction, the reaction solution was heated to 70°C under reduced pressure (approximately 0.8 atmospheres), and the co-solvent acetone and the remaining unreacted alcohol were recovered. The recovery time was 30 minutes, and approximately 80% of the acetone and approximately 90% of the alcohol were recovered. After allowing to stand for 10 minutes, the mixture was separated into an alkyl ester layer and a by-product glycerin layer, and the glycerin was recovered from the bottom of the reactor.

[0053] (1-3) Washing of Alkyl Esters and Recovery of C8 and C10 Alkyl Esters After glycerin recovery, the crude alkyl esters produced were mixed with water at a volume ratio of 30% to the alkyl ester. After separation into the alkyl ester and water layers, water was recovered from the bottom of the reactor. This washing process was repeated three times. Approximately 30% water, by volume, was added to the washed alkyl esters and heated to 115-120°C under vacuum. This operation removed the C8 (alkyl caprylate) and C10 (alkyl caprate) components from the coconut oil, along with the water vapor present in this temperature range, from the system and liquefied and recovered using a chiller (heat exchanger). This yielded pure C8 and C10 alkyl esters containing water. The water was removed from the mixture of water and C8 and C10 alkyl esters at 80°C under reduced pressure. The resulting C8 and C10 alkyl esters were used as SAF.

[0054] When C8 and C10 alkyl esters were converted into SAF in the process (1-3), 15 to 20% by weight of the raw material could be used as SAF and 80 to 85% as BDF.

[0055] Example 2 The same steps as in the processes (1-1) to (1-3) of Example 1 were carried out, except that the dried C12 to C18 fatty acid alkyl component remaining in the reactor was not recovered.

[0056] (2-1) Recovery of C12 alkyl esters After recovering C8 and C10 alkyl esters with steam in the process (1-3) of Example 1, about 30% water was added to the reactor again, and the mixture was heated to 140° C. under reduced pressure. As a result, C12 alkyl esters were recovered together with steam.

[0057] A high-pressure reactor (manufactured by Yashiro Scientific Instruments) was used for the hydrodecarboxylation reaction. A Ni-Mo catalyst (manufactured by Ketjen Corporation) and methyl sulfide (manufactured by Wako Pure Chemical Industries, Ltd.) were added and sulfide treatment was performed. Hydrogen (2 atmospheres) and a C12 alkyl ester were added, and the reaction was carried out at 250°C for 2 hours. The dodecane yield obtained was approximately 65-70%, and the proportion of isoparaffins was approximately 15-20%. Adding Co and Fe as promoters to the Ni-Mo catalyst increased the proportion of isoparaffins by approximately 5%.

[0058] When C8 and C10 alkyl esters were converted to SAF using Process (1-3) in Example 1, 15-20% of the raw material weight could be used as SAF and 80-85% as BDF. When Process (2-1) was carried out in Example 2, 60-65% of the coconut oil could be used as SAF and 35-40% as BDF.

[0059] Example 3 The same steps as in (1-1) to (1-3) of Example 1 were carried out to obtain C8 and C10 alkyl esters.

[0060] (3-1) Production of isopropyl ester by ester formation reaction 200 mL of acetonitrile as a co-solvent, 2.0 moles of isopropanol (total amount = 23 moles) in a molar ratio to the alkyl ester, and 20 mL of concentrated sulfuric acid as an acid catalyst were added to 1000 mL of C8 caprylic acid and 1000 mL of C10 capric acid (total amount = 2000 mL = caprylic acid = 6.3 moles, capric acid = 5.18 moles, total amount = 11.5 moles), and the ester formation reaction was carried out at 60°C for approximately 5 hours. The by-product of the ester formation reaction was water. After the reaction, the mixture was separated into an alkyl ester layer and a water layer, and then the water mixed with the sulfuric acid catalyst was recovered from the bottom of the reactor.

[0061] Water was added at a volume ratio of 30% to the alkyl ester. After separation into an alkyl ester layer and a water layer, water was recovered from the bottom of the reactor. This washing process was repeated three times. The washed alkyl ester was then washed three times in the same manner as above and then dried at 80°C under reduced pressure.

[0062] The results of analysis of the C8 and C10 fatty acid methyl esters and ethyl esters produced in Example 1 (1-3) and the isopropyl ester produced in (3-1) above by GC / FID (GC systems HP 6890 series, manufactured by Agilent Technologies) are shown in Figures 3 to 5.

[0063] The HPLC analysis results of the C8 and C10 fatty acid methyl esters and ethyl esters produced in Example 1 (1-3) and the isopropyl esters produced in the above (3-1) are shown in Figures 6 to 8.

[0064] 2 to 9 show that the yields of SAF and BDF in the examples were all within the range of 97% to 99%. The yield of BDF in the examples exceeded the 96.5% fatty acid ester content standard specified in JIS K2390.

Claims

1. A method for producing sustainable aviation fuel, comprising: using coconut oil as a raw material, producing a mixture of fatty acid alkyl esters by reacting fatty acid triglycerides and / or fatty acids that are degradation products thereof with a lower alcohol; and vacuum distilling the mixture of fatty acid alkyl esters to separate a C8 fatty acid alkyl ester fraction and / or a C10 fatty acid alkyl ester fraction.

2. The production method according to claim 1, further comprising subjecting the mixture obtained after separating the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction to vacuum distillation to separate the C12 fatty acid alkyl ester fraction.

3. The method of claim 1, wherein the step of producing the mixture of fatty acid alkyl esters is to produce the mixture of fatty acid alkyl esters by a transesterification reaction using fatty acid triglycerides derived from coconut oil and a lower alkyl alcohol.

4. The method of claim 1, wherein the step of producing the mixture of fatty acid alkyl esters is carried out by an esterification reaction using fatty acids that are the degradation products of fatty acid triglycerides derived from coconut oil and lower alkyl alcohols.

5. A method for producing biodiesel fuel, comprising: using coconut oil as a raw material, producing a mixture of fatty acid alkyl esters by reacting fatty acid triglycerides and / or fatty acids that are decomposition products thereof with a lower alcohol; vacuum distilling the mixture of fatty acid alkyl esters to remove a C8 fatty acid alkyl ester fraction and / or a C10 fatty acid alkyl ester fraction; and obtaining a mixture after removing the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction.

6. The method according to claim 5, wherein the step of producing the mixture of fatty acid alkyl esters is to produce the mixture of fatty acid alkyl esters by a transesterification reaction using fatty acid triglycerides derived from coconut oil and a lower alkyl alcohol.

7. The method of claim 5, wherein the step of producing the mixture of fatty acid alkyl esters is carried out by an ester-producing reaction using a fatty acid that is a decomposition product of fatty acid triglycerides derived from coconut oil and a lower alkyl alcohol.

8. The method according to any one of claims 1 to 7, wherein the mixture to which water has been added is distilled under reduced pressure.

9. The method according to any one of claims 1 to 7, wherein the lower alkyl alcohol is methanol, ethanol, propanol, isopropanol, or butanol.

10. The method according to any one of claims 1 to 7, wherein in separating or distilling off the C8 fatty acid alkyl ester fraction and / or the C10 fatty acid alkyl ester fraction, vacuum distillation is carried out at a temperature of 110°C or higher and 130°C or lower.

11. The method according to any one of claims 1 to 7, wherein the transesterification reaction is carried out in the presence of coconut oil, a lower alkyl alcohol, a catalyst, and an organic solvent.

12. The method according to any one of claims 1 to 7, wherein the organic solvent is acetone.

13. A sustainable aviation fuel produced by the method of any one of claims 1 to 4.

14. A biodiesel fuel produced by the method according to any one of claims 5 to 7.

15. The sustainable aviation fuel according to claim 13, wherein the energy consumption in oil equivalent during production is 0.5 L / LSAF or less.

16. The biodiesel fuel according to claim 14, wherein the energy consumption during production is 0.5 L / LSAF or less in terms of petroleum equivalent.

Images