Isophorone dimer prepared from biomass, method for preparing same, and alternative aviation fuel comprising same

Abstract

The present invention relates to an isophorone dimer prepared from biomass, a method for preparing same, and an alternative aviation fuel comprising same. Specifically, the present invention relates to: an isophorone dimer prepared by forming isophorone using carboxylic acid obtained from biomass and subjecting the isophorone to dimerization, hydrogenation, and deoxygenation; a method for preparing same; and an alternative aviation fuel comprising same.

Description

Isophorone dimer produced from biomass, method for producing the same, and alternative aviation fuel comprising the same

[0001] The present invention relates to an isophorone dimer produced from biomass, a method for producing the same, and an alternative aviation fuel comprising the same. Specifically, the present invention relates to an isophorone dimer produced by forming isophorone using a carboxylic acid obtained from biomass, and then undergoing dimerization-hydrogenation-deoxygenation from the isophorone, a method for producing the same, and an alternative aviation fuel comprising the same.

[0002]

[0003] Fossil fuel reserves are limited, and problems such as declining profitability and high carbon emissions persist. Furthermore, with the Paris Climate Agreement coming into effect, there is a growing global movement to reduce carbon emissions.

[0004] Accordingly, the importance of research developing fuels from renewable biomass sources is increasing, and attempts are being made to develop alternative fuels. Specifically, there is a fuel characterized by branched saturated hydrocarbons from cellulosic butanol (Biojet) and a saturated linear fuel manufactured from synthesis gas. However, the volumetric calorific value of these fuels is approximately 34.3 MJ / L, which is lower than the volumetric calorific value (39.6 MJ / L) of JP-10, which is currently used as aviation fuel. This is because the mass density of these fuels is low, at approximately 0.75 to 0.78 g / ml. Because both the mass density and volumetric calorific value are low, they have the disadvantage of being somewhat inefficient when applied as an alternative to aviation fuel.

[0005] Furthermore, when producing fuel (bio-oil) from biomass, the fuel contains significant amounts of carboxylic acids, such as acetic acid and formic acid, which increases fuel instability and corrosiveness. To address this, research is being conducted on methods for removing acids and improving fuel stability through esterification reactions between carboxylic acids and alcohols. However, compounds synthesized through esterification reactions pose a challenge for use as standalone fuels.

[0006] Therefore, there is a need to develop a new compound that has properties that can be used as an alternative to aviation fuel, can be manufactured from biomass, and can be applied as a standalone fuel.

[0007]

[0008] The technical problem to be solved by the present invention is to provide an isophorone dimer produced from biomass.

[0009] Another technical problem to be solved by the present invention is to provide a method for producing isophorone dimer from biomass.

[0010] Another technical problem to be solved by the present invention is to provide an alternative aviation fuel comprising the above-described isophorone dimer.

[0011]

[0012] An isophorone dimer according to one embodiment of the present invention may be represented by the following structural formula 1.

[0013] [Structural formula 1]

[0014]

[0015] (However, in structural formula 1, the above R 1 Inland R 5 are each independently an alkyl group having 1 to 30 carbon atoms.)

[0016] An isophorone dimer according to one embodiment of the present invention may include a compound represented by the following structural formula 1a.

[0017] [Structural formula 1a]

[0018]

[0019] The isophorone dimer according to one embodiment of the present invention may have a freezing point of 100 K or more and less than 226 K.

[0020] The isophorone dimer according to one embodiment of the present invention may have a mass density of 0.79 g / ml to 1.00 g / ml under room temperature and pressure conditions.

[0021] An isophorone dimer according to one embodiment of the present invention may have an energy density of 34.0 MJ / L to 45.0 MJ / L.

[0022] The isophorone dimer according to one embodiment of the present invention may have a heat of combustion of 40.0 MJ / kg to 50.0 MJ / kg.

[0023] A method for producing an isophorone dimer according to another embodiment of the present invention may include synthesizing an isophorone dimer represented by the following structural formula 1 through a hydrodeoxygenation (HDO) reaction from isophorone.

[0024] [Structural formula 1]

[0025]

[0026] (However, in structural formula 1, the above R 1 Inland R 5 are each independently an alkyl group having 1 to 30 carbon atoms.)

[0027] A method for producing an isophorone dimer according to another embodiment of the present invention may include the steps of: preparing isophorone; dimerizing the isophorone to form a first intermediate; hydrogenating the first intermediate to form a second intermediate; and deoxygenating the second intermediate to finally obtain the isophorone dimer.

[0028] In a method for producing an isophorone dimer according to another embodiment of the present invention, the isophorone dimer may include a compound represented by the following structural formula 1a.

[0029] [Structural formula 1a]

[0030]

[0031] The isophorone preparation step of the method for producing an isophorone dimer according to another embodiment of the present invention may be to form isophorone by ketonizing a carboxylic acid contained in biomass and then performing a catalytic reaction.

[0032] The first intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention may be a step of mixing and reacting isophorone and sodium hydroxide and then neutralizing the mixture to form a first intermediate represented by the following structural formula 2.

[0033] [Structural formula 2]

[0034]

[0035] In the first intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention, the reaction temperature may be 75 to 90°C.

[0036] The first intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention may have a reaction time of 12 to 24 hours.

[0037] In the first intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention, the mixing equivalent ratio of the isophorone and sodium hydroxide may be 1:1 to 3:1.

[0038] The second intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention may be forming a second intermediate expressed by the following structural formula 3.

[0039] [Structural formula 3]

[0040]

[0041] The second intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention is performed in a hydrogen (H2) gas atmosphere, and the hydrogen gas pressure in the reactor may be 50 to 100 bar.

[0042] In the second intermediate forming step of the method for producing an isophorone dimer according to another embodiment of the present invention, the method includes mixing the first intermediate and the catalyst in an equivalent ratio of 1:0.05 to 1:0.5, wherein the catalyst is at least one selected from among metals and metal compounds including Pt, Pd, Ru, and Rh, and the metal compound may include a metal oxide, a metal carbide, or a metal hydroxide.

[0043] In the second intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention, the reaction temperature may be 25 to 50°C.

[0044] The step of obtaining the isophorone dimer in the method for producing the isophorone dimer according to another embodiment of the present invention may include obtaining the isophorone dimer represented by the following structural formula 1a by performing a deoxygenation reaction by mixing trifluoroacetic acid (TFA) and triethylsilane (Et3SiH) with the second intermediate.

[0045] [Structural formula 1a]

[0046]

[0047] The step of obtaining the isophorone dimer in the method for producing the isophorone dimer according to another embodiment of the present invention may include mixing trifluoroacetic acid in an equivalent ratio of 6 to 7 based on 1 equivalent of the entire second intermediate, and may include mixing triethylsilane in an equivalent ratio of 1 to 2 based on 1 equivalent of the entire second intermediate.

[0048] In a method for producing an isophorone dimer according to another embodiment of the present invention, the reaction temperature of the isophorone dimer obtaining step may be 20 to 30°C.

[0049] In a method for producing an isophorone dimer according to another embodiment of the present invention, the reaction time of the isophorone dimer obtaining step may be 3 to 10 hours.

[0050] In the first intermediate formation step and the second intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention, the method may include producing an isophorone dimer from the isophorone without purifying and separating the first intermediate and the second intermediate.

[0051] An alternative aviation fuel according to another embodiment of the present invention may include an isophorone dimer according to one embodiment of the present invention.

[0052]

[0053] The isophorone dimer according to one embodiment of the present invention has a low freezing point and properties such as mass density, energy density, and heat of combustion that are similar to those of JP-10, which is currently used as aviation fuel, and thus can be used as an alternative fuel to aviation fuel, and can be produced from biomass, making it environmentally friendly and economical.

[0054] A method for producing an isophorone dimer according to another embodiment of the present invention can produce an isophorone dimer having the above-described advantages.

[0055] According to another embodiment of the present invention, an alternative aviation fuel may be easily used as an alternative aviation fuel by including an isophorone dimer having similar physical properties, such as freezing point, mass density, energy density, and heat of combustion, compared to existing JP-10 aviation fuel.

[0056]

[0057] Figure 1 illustrates the structural formula of an isophorone dimer according to one embodiment of the present invention.

[0058] Figure 2 illustrates (a) a process of performing an esterification reaction and a hydrogenation reaction from carboxylic acid contained in biomass, (b) a process of synthesizing isophorone from a ketoneization and catalytic reaction of acetic acid contained in biomass, and (c) a process of synthesizing an isophorone dimer from the isophorone, respectively.

[0059] FIG. 3 illustrates a process for synthesizing a first intermediate and a second intermediate in a method for producing an isophorone dimer according to another embodiment of the present invention.

[0060] FIG. 4 illustrates a process of synthesizing a second intermediate by hydrogenating a first intermediate in a method for producing an isophorone dimer according to another embodiment of the present invention.

[0061] FIG. 5 illustrates a process of synthesizing an isophorone dimer by deoxygenating a second intermediate in a method for producing an isophorone dimer according to another embodiment of the present invention.

[0062]

[0063] The terms first, second, and third, etc., are used to describe, but are not limited to, various parts, components, regions, layers, and / or sections. These terms are used only to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Accordingly, a first part, component, region, layer, or section described below may be referred to as a second part, component, region, layer, or section without departing from the scope of the present invention.

[0064] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used herein, the singular forms "a," "an," and "the" include plural forms as well, unless the context clearly dictates otherwise. The word "comprising," as used herein, specifies particular features, regions, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of other features, regions, integers, steps, operations, elements, and / or components.

[0065] When a part is referred to as being "on" or "over" another part, it can be directly on or over the other part, or there may be other parts intervening. Conversely, when a part is referred to as being "directly on" another part, there are no other parts intervening.

[0066] Although not defined otherwise, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or overly formal unless otherwise defined.

[0067] Also, unless otherwise stated, % means weight%, and 1 ppm is 0.0001 weight%.

[0068] In FIGS. 1 to 5 of this specification, “Me” expressed in the chemical structural formula means a methyl group expressed as -CH3.

[0069] R expressed in structural formula 1 of this specification 1 Inland R 5 Each independently represents an alkyl group having 1 to 30 carbon atoms.

[0070] In this specification, the term "combination(s) thereof" described in the expression in the Makushi format means one or more mixtures or combinations selected from the group consisting of the components described in the expression in the Makushi format, and means including any one or more selected from the group consisting of said components.

[0071] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0072]

[0073] Hereinafter, an isophorone dimer according to one embodiment of the present invention will be described.

[0074] 1. Isophorone dimer

[0075] An isophorone dimer according to one embodiment of the present invention may be represented by the following structural formula 1.

[0076] [Structural formula 1]

[0077]

[0078] (However, in structural formula 1, the above R 1 Inland R 5 are each independently an alkyl group having 1 to 30 carbon atoms.)

[0079] An isophorone dimer according to one embodiment of the present invention may include a compound represented by the following structural formula 1a.

[0080] The compound (2,2,7,7,9-pentamethyl-1,2,3,4,5,6,7,8,9,10-decahydro-5,9-methanobenzo[8]annulene) represented by the following structural formula 1a may be included in the above-mentioned structural formula 1.

[0081] Figure 1 illustrates the structural formula of an isophorone dimer according to one embodiment of the present invention.

[0082] The structural formula of Fig. 1 means the same as the structural formula 1a below.

[0083] [Structural formula 1a]

[0084]

[0085] The isophorone dimer according to one embodiment of the present invention may have a freezing point of 100 K or more and less than 226 K.

[0086] If the freezing point is within the above-mentioned range, it can be used as a substitute for the existing aviation fuel, JP-10.

[0087] On the other hand, if the freezing point is below the lower limit of the aforementioned range, combustibility may be excellent, but there may be problems such as high calorific value and high volatility, resulting in low stability. Furthermore, if the freezing point exceeds the upper limit of the aforementioned range, combustibility may be reduced, resulting in reduced fuel efficiency.

[0088] The isophorone dimer according to one embodiment of the present invention may have a mass density of 0.79 g / ml to 1.00 g / ml under room temperature and pressure conditions.

[0089] If the mass density is within the aforementioned range, it can be used as a substitute for the existing aviation fuel, JP-10.

[0090] On the other hand, if the mass density is below the lower limit of the aforementioned range, the energy density per volume may decrease, resulting in reduced fuel efficiency. Furthermore, if the mass density exceeds the upper limit of the aforementioned range, while the energy density per volume may improve, the fuel combustion rate may decrease somewhat, resulting in reduced efficiency.

[0091] An isophorone dimer according to one embodiment of the present invention may have an energy density of 34.0 MJ / L to 45.0 MJ / L.

[0092] If the energy density is within the aforementioned range, it can be used as a substitute for the existing aviation fuel, JP-10.

[0093] On the other hand, if the energy density is below the lower limit of the aforementioned range, the amount of energy generated per volume is low, which creates a burden of having to load more to generate the same amount of energy. In other words, there is a problem of low fuel efficiency as aviation fuel. In addition, if the energy density exceeds the upper limit of the aforementioned range, the amount of energy generated per volume is high, which theoretically may have the advantage of being able to generate high energy with relatively small weight. However, since the molecular weight of the isophorone dimer is significantly large, there is a problem of difficulty in rapid combustion or incomplete combustion occurring, so in reality, the fuel efficiency may not be high.

[0094] The isophorone dimer according to one embodiment of the present invention may have a heat of combustion of 40.0 MJ / kg to 50.0 MJ / kg.

[0095] If the above combustion heat is within the above-mentioned range, it can be used as a substitute for the existing aviation fuel, JP-10.

[0096] On the other hand, if the heat of combustion is below the lower limit of the aforementioned range, the amount of energy generated relative to the fuel weight may be low, and the burden of fuel weight that the aircraft must load may increase relative to fuel efficiency. If the heat of combustion exceeds the upper limit of the aforementioned range, the amount of energy generated relative to the fuel weight may be high, and thus fuel efficiency may be high, but thermal stability may be somewhat reduced.

[0097]

[0098] Hereinafter, a method for producing an isophorone dimer according to another embodiment of the present invention will be described.

[0099] 2. Method for producing isophorone dimer

[0100] A method for producing an isophorone dimer according to another embodiment of the present invention may include synthesizing an isophorone dimer represented by the following structural formula 1 through a hydrodeoxygenation (HDO) reaction from isophorone.

[0101] [Structural formula 1]

[0102]

[0103] (However, in structural formula 1, the above R 1 Inland R 5 are each independently an alkyl group having 1 to 30 carbon atoms.)

[0104] Figure 2 illustrates a process for synthesizing isophorone from ketoneization and catalytic reaction of acetic acid contained in biomass and a process for synthesizing isophorone dimer from said isophorone.

[0105] Referring to the above drawing 2, the above hydrodeoxygenation (HDO) reaction means the reaction disclosed in (c).

[0106] A method for producing an isophorone dimer according to another embodiment of the present invention may include the steps of: preparing isophorone; dimerizing the isophorone to form a first intermediate; hydrogenating the first intermediate to form a second intermediate; and deoxygenating the second intermediate to finally obtain the isophorone dimer.

[0107] FIG. 3 illustrates a process for synthesizing a first intermediate and a second intermediate in a method for producing an isophorone dimer according to another embodiment of the present invention.

[0108] In a method for producing an isophorone dimer according to another embodiment of the present invention, the process of forming a first intermediate by dimerizing isophorone can follow the above-described Figure 3.

[0109] FIG. 4 illustrates a process of synthesizing a second intermediate by hydrogenating a first intermediate in a method for producing an isophorone dimer according to another embodiment of the present invention.

[0110] In a method for producing an isophorone dimer according to another embodiment of the present invention, the process of hydrogenating the first intermediate to form a second intermediate may follow the above-described Figure 4.

[0111] The above hydrogenation means reduction by reacting the first intermediate with hydrogen gas (H2) above a certain pressure.

[0112] FIG. 5 illustrates a process of synthesizing an isophorone dimer by deoxygenating a second intermediate in a method for producing an isophorone dimer according to another embodiment of the present invention.

[0113] In a method for producing an isophorone dimer according to another embodiment of the present invention, the process of forming an isophorone dimer by deoxygenating the second intermediate may follow the above-described Figure 5.

[0114] In a method for producing an isophorone dimer according to another embodiment of the present invention, the isophorone dimer may include a compound represented by the following structural formula 1a.

[0115] The compound (2,2,7,7,9-pentamethyl-1,2,3,4,5,6,7,8,9,10-decahydro-5,9-methanobenzo[8]annulene) represented by the following structural formula 1a may be included in the above-mentioned structural formula 1.

[0116] [Structural formula 1a]

[0117]

[0118] The isophorone preparation step of the method for producing an isophorone dimer according to another embodiment of the present invention may be to form isophorone by ketoneizing a carboxylic acid contained in biomass and then performing a catalytic reaction. Preferably, the carboxylic acid may be acetic acid.

[0119] The isophorone dimer single substance manufactured according to the method for manufacturing the isophorone dimer of the present invention can be independently applied as an alternative fuel for aviation fuel. Conversely, efforts have been made to synthesize compounds by performing an esterification reaction on acetic acid in biomass and apply them as fuels. However, it has been difficult to independently use compounds synthesized through the esterification reaction as an alternative fuel for aviation fuel. The method for manufacturing the isophorone dimer of the present invention is technically significant in that it can produce an alternative fuel for aviation fuel with higher utility than conventional techniques.

[0120] The first intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention may be a step of mixing and reacting isophorone and sodium hydroxide and then neutralizing the mixture to form a first intermediate represented by the following structural formula 2.

[0121] [Structural formula 2]

[0122]

[0123] (However, in structural formula 2, the above R 1 Inland R 5 are each independently an alkyl group having 1 to 30 carbon atoms.)

[0124] Preferably, the first intermediate represented by the above structural formula 2 may be a compound (5-hydroxy-2,2,7,7,9-pentamethyl-2,3,5,6,7,8,9,10-octahydro-5,9-methanobenzo[8]annulen-4(1H)-one) represented by the following structural formula 2a.

[0125] [Structural formula 2a]

[0126]

[0127] In the first intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention, the reaction temperature may be 75 to 90°C.

[0128] When the above reaction temperature is within the above-mentioned range, dimerization of isophorone can easily occur.

[0129] On the other hand, if the reaction temperature is below the lower limit of the aforementioned range, the dimerization reaction rate of isophorone may be significantly slow or the reaction may not occur properly. In addition, if the reaction temperature exceeds the upper limit of the aforementioned range, side reactions may occur in addition to the dimerization reaction of isophorone, resulting in the formation of unexpected compounds.

[0130] The first intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention may have a reaction time of 12 to 24 hours.

[0131] When the above reaction time is within the above-mentioned range, the dimerization reaction of isophorone can occur appropriately.

[0132] On the other hand, if the reaction time is below the lower limit of the aforementioned range, the dimerization reaction of isophorone may not occur sufficiently, so that the isophorone monomer may remain and the yield of the first intermediate may be low. In addition, if the reaction time exceeds the upper limit of the aforementioned range, the dimerization reaction of isophorone may occur sufficiently, but the reaction time may be unnecessarily long, which may cause a problem of reduced process efficiency.

[0133] In the first intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention, the mixing equivalent ratio of the isophorone and sodium hydroxide may be 1:1 to 3:1.

[0134] When the mixing equivalent ratio of the above isophorone and sodium hydroxide is within the above-mentioned range, the dimerization reaction of isophorone can proceed sufficiently and the yield of the first intermediate can be maximized.

[0135] On the other hand, if the mixing equivalence ratio of the isophorone and sodium hydroxide is less than the lower limit of the aforementioned range, the amount of sodium hydroxide is excessive compared to the reaction amount of isophorone, so that the amount of acid solution input during neutralization increases, which may cause an increase in process costs. In addition, the possibility of side reactions occurring may increase due to the increase in the generation of neutralization heat. If the mixing equivalence ratio of the isophorone and sodium hydroxide exceeds the upper limit of the aforementioned range, the amount of sodium hydroxide is small compared to the reaction amount of isophorone, so that a significant amount of isophorone monomer that has not been dimerized may remain. This may cause a problem of a decrease in the yield of the first intermediate.

[0136] The second intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention may be forming a second intermediate expressed by the following structural formula 3.

[0137] [Structural formula 3]

[0138]

[0139] (However, in structural formula 3, the above R 1 Inland R 5 are each independently an alkyl group having 1 to 30 carbon atoms.)

[0140] Preferably, the second intermediate represented by the above structural formula 3 may be a compound (2,2,7,7,9-pentamethyl-2,3,4,6,7,8,9,10-octahydro-5,9-methanobenzo[8]annulen-5(1H)-ol) represented by the following structural formula 3a.

[0141] [Structural formula 3a]

[0142]

[0143] The second intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention is performed in a hydrogen (H2) gas atmosphere, and the hydrogen gas pressure in the reactor may be 50 to 100 bar.

[0144] When the hydrogen gas pressure is within the above-mentioned range, the yield and production rate of the second intermediate can be improved.

[0145] When the hydrogen gas pressure is below the lower limit of the aforementioned range, a second intermediate may be formed, but the formation rate may be slow and the yield may be low, less than 50%. When the hydrogen gas pressure exceeds the upper limit of the aforementioned range, the formation rate of the second intermediate may be fast and the yield may be improved, but the risk of explosion in the process may be high.

[0146] In the second intermediate forming step of the method for producing an isophorone dimer according to another embodiment of the present invention, the method includes mixing the first intermediate and the catalyst in an equivalent ratio of 1:0.05 to 1:0.5, wherein the catalyst is at least one selected from among metals and metal compounds including Pt, Pd, Ru, and Rh, and the metal compound may include a metal oxide, a metal carbide, or a metal hydroxide.

[0147] Preferably, the mixing ratio of the first intermediate and the catalyst may be an equivalent ratio of 1:0.1 to 1:0.3. More preferably, the mixing ratio of the first intermediate and the catalyst may be an equivalent ratio of 1:0.3.

[0148] Preferably, the catalyst may be at least one selected from PtO2 and PtO2hydrate.

[0149] When the mixing ratio of the first intermediate and the catalyst is within the above-mentioned range, the second intermediate can be easily formed.

[0150] On the other hand, if the mixing ratio of the first intermediate and the catalyst is below the lower limit of the aforementioned range, the reaction may occur quickly, but there may be problems such as high process costs and low production efficiency due to excessive catalyst amounts compared to the amount of reactants. In addition, if the mixing ratio of the first intermediate and the catalyst exceeds the upper limit of the aforementioned range, the reaction rate may be somewhat lowered due to insufficient catalyst amounts compared to the reactants, which may lead to problems such as long process times.

[0151] In the second intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention, the reaction temperature may be 25 to 50°C.

[0152] When the above reaction temperature is within the above-mentioned range, the production reaction of the second intermediate can occur appropriately.

[0153] On the other hand, if the reaction temperature is below the lower limit of the aforementioned range, there may be a problem in that the rate of production of the second intermediate is slowed. In addition, if the reaction temperature exceeds the upper limit of the aforementioned range, the second intermediate may be produced quickly, but side reactions may also occur, resulting in the problem of impurities being mixed in.

[0154] The step of obtaining the isophorone dimer in the method for producing the isophorone dimer according to another embodiment of the present invention may include obtaining the isophorone dimer represented by the following structural formula 1a by performing a deoxygenation reaction by mixing trifluoroacetic acid (TFA) and triethylsilane (Et3SiH) with the second intermediate.

[0155] [Structural formula 1a]

[0156]

[0157] The step of obtaining the isophorone dimer in the method for producing the isophorone dimer according to another embodiment of the present invention may include mixing trifluoroacetic acid in an equivalent ratio of 6 to 7 based on 1 equivalent of the entire second intermediate, and may include mixing triethylsilane in an equivalent ratio of 1 to 2 based on 1 equivalent of the entire second intermediate.

[0158] When the mixing equivalent ratio of the trifluoroacetic acid and triethylsilane is within the above-mentioned range, the isophorone dimer can be easily produced.

[0159] On the other hand, if the mixed equivalent ratio of trifluoroacetic acid and triethylsilane is below the lower limit of the aforementioned range, the deoxygenation reaction may not sufficiently occur from the second intermediate, and there may be a problem of low yield of isophorone dimer. In addition, if the mixed equivalent ratio of trifluoroacetic acid and triethylsilane exceeds the upper limit of the aforementioned range, the formation of isophorone dimer may occur easily, but there may be a problem of containing a large amount of impurities in the final product.

[0160] In a method for producing an isophorone dimer according to another embodiment of the present invention, the reaction temperature of the isophorone dimer obtaining step may be 20 to 30°C.

[0161] When the above reaction temperature is within the above-mentioned range, the formation reaction of the isophorone dimer can occur appropriately.

[0162] On the other hand, if the reaction temperature is below the lower limit of the aforementioned range, there may be a problem in that the production rate of isophorone dimers decreases. In addition, if the reaction temperature exceeds the upper limit of the aforementioned range, isophorone dimers may be produced quickly, but side reactions may also occur, resulting in the problem of impurities being mixed in.

[0163] In a method for producing an isophorone dimer according to another embodiment of the present invention, the reaction time of the isophorone dimer obtaining step may be 3 to 10 hours.

[0164] When the above reaction time is within the above-mentioned range, the isophorone dimer can be sufficiently formed.

[0165] On the other hand, if the reaction time is below the lower limit of the aforementioned range, the deoxygenation of the second intermediate may not proceed sufficiently, resulting in a low yield of isophorone dimer. Furthermore, if the reaction time exceeds the upper limit of the aforementioned range, the deoxygenation reaction may sufficiently occur, but the reaction time may become unnecessarily long, resulting in a decrease in process efficiency.

[0166] In the first intermediate formation step and the second intermediate formation step of the method for producing an isophorone dimer according to another embodiment of the present invention, the method may include producing an isophorone dimer from the isophorone without purifying and separating the first intermediate and the second intermediate.

[0167] However, the method for producing an isophorone dimer according to another embodiment of the present invention is not limited to the above-described method. In the method for producing an isophorone dimer, if necessary, whether or not to perform a purification and separation process in the first intermediate and / or second intermediate formation step can be appropriately selected. Specifically, in order to improve the yield of the final material, the isophorone dimer, the purification and separation process can be excluded in the first intermediate and / or second intermediate formation step, and the isophorone dimer can be produced by performing a one-pot, one-step reaction from isophorone. Alternatively, in order to prevent side reactions during the process and further improve the purity of the isophorone finally obtained, the method may include performing a purification and separation process in each of the first intermediate and / or second intermediate formation steps. Therefore, the method for producing an isophorone dimer of the present invention can encompass both a production method including a purification and separation process in the first intermediate and / or second intermediate formation step and a production method not including the purification and separation process, and the present invention is not limited to either one.

[0168] Hereinafter, an alternative aviation fuel according to another embodiment of the present invention will be described.

[0169] 3. Alternative fuels for aviation fuel

[0170] An alternative aviation fuel according to another embodiment of the present invention may include an isophorone dimer according to one embodiment of the present invention.

[0171]

[0172] Hereinafter, examples, comparative examples, and experimental examples of the present invention will be described. However, the following examples are merely preferred embodiments of the present invention, and the present invention is not limited to these examples. Furthermore, various modifications and variations are possible within the scope of the claims, the detailed description of the invention, and the accompanying drawings, and such modifications may also fall within the scope of the present invention.

[0173] Example 1

[0174] (1) Dimerization - first intermediate formation stage

[0175] Isophorone was prepared by ketonization and catalytic reaction of acetic acid contained in biomass. The isophorone (2.00 equivalents) and sodium hydroxide (1.00 equivalents) were dissolved in benzene (6.00 M) to form a reaction mixture. The reaction mixture was stirred at 82°C for 16 hours, and then neutralized by adding 3N HCl aqueous solution. After the neutralization reaction was completed, the first intermediate formed in the mixture was extracted with CH2Cl2. The extracted organic layer was then washed with brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was then purified by flash column chromatography on silica gel to obtain the first intermediate in a yield of 80 mol%. (However, the yield of the first intermediate refers to the molar ratio (mol%) of the first intermediate obtained based on the total number of moles of isophorone introduced as a reaction raw material in the dimerization step.) At this time, the obtained first intermediate is 5-hydroxy-2,2,7,7,9-pentamethyl-2,3,5,6,7,8,9,10-octahydro-5,9-methanobenzo[8]annulen-4(1H)-one.

[0176] (2) Hydrogenation - Second intermediate formation stage

[0177] The hydrogenation reaction was carried out in a 160 mL stainless steel batch reactor. The first intermediate obtained in the dimerization step (1.00 eq), a PtO2 catalyst (0.300 eq), and acetic acid (0.720 M) were added to the reactor. The atmosphere in the reactor was maintained at 25°C and H2 (70 bar). The reaction mixture was then stirred at 500 rpm for 2 h and filtered through Celite. A saturated aqueous solution of NaHCO3 was added to the filtrate and extracted with CH2Cl2. The extracted organic layer was then washed with brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel to give the second intermediate in a yield of 69 mol%. (However, the yield of the second intermediate refers to the molar ratio (mol%) of the second intermediate obtained based on the total number of moles of the first intermediate introduced as a reactant in the hydrogenation step.) At this time, the obtained second intermediate is 2,2,7,7,9-pentamethyl-2,3,4,6,7,8,9,10-octahydro-5,9-methanobenzo[8]annulen-5(1H)-ol.

[0178] (3) Deoxygenation - isophorone dimer formation step

[0179] Trifluoroacetic acid (6.60 eq) was added to a solution of the second intermediate (1.00 eq) dissolved in CH2Cl2 (0.250 M). Triethylsilane (1.20 eq) was then rapidly added to the mixture to form a reaction mixture. The reaction mixture was stirred at 25°C for 6 h, and monitored by TLC after staining with KMnO4. A saturated aqueous solution of NaHCO3 was added to the reaction mixture and extracted with CH2Cl2. The extracted organic layer was washed with brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel. The collected fractions were distilled under vacuum to finally obtain the isophorone dimer in a yield of 74 mol%. (However, the yield of the above isophorone dimer refers to the molar ratio (mol%) of the isophorone dimer obtained based on the total number of moles of the second intermediate introduced as a reactant in the deoxygenation step.) At this time, the obtained isophorone dimer is 2,2,7,7,9-pentamethyl-1,2,3,4,5,6,7,8,9,10-decahydro-5,9-methanobenzo[8]annulene.

[0180] Comparative Example 1

[0181] (2) An isophorone dimer was prepared in the same manner as in Example 1, except that the catalyst PtO2 was mixed at a 0.1 equivalent ratio, the pressure of hydrogen gas was maintained at 1 bar, and stirring and reaction were performed for 72 hours.

[0182] Comparative Example 2

[0183] (2) An isophorone dimer was prepared in the same manner as in Comparative Example 1, except that tetrahydrofuran (THF) was used instead of acetic acid as the solvent.

[0184] Comparative Example 3

[0185] (2) An isophorone dimer was prepared in the same manner as in Comparative Example 1, except that methanol (MeOH) was used instead of acetic acid as a solvent.

[0186] Comparative Example 4

[0187] (2) An isophorone dimer was prepared in the same manner as in Comparative Example 2, except that a 50% Pd / C catalyst was mixed at a 1.0 equivalent ratio instead of a 0.1 equivalent ratio of PtO as a catalyst.

[0188] Comparative Example 5

[0189] (2) An isophorone dimer was prepared in the same manner as in Comparative Example 3, except that a 50% Pd / C catalyst was mixed at a 1.0 equivalent ratio instead of a 0.1 equivalent ratio of PtO as a catalyst.

[0190] Comparative Example 6

[0191] (2) An isophorone dimer was prepared in the same manner as in Comparative Example 3, except that Pd(OH)2 was mixed instead of PtO20.1 as a catalyst.

[0192] Example 2

[0193] (2) An isophorone dimer was prepared in the same manner as in Example 1, except that the catalyst PtO2 was mixed in an equivalent ratio of 0.1 and the reaction temperature was 50°C, stirring was performed for 4 hours, and the reaction was conducted.

[0194] Example 3

[0195] (2) An isophorone dimer was prepared in the same manner as in Example 1, except that the catalyst PtO2 was mixed in an equivalent ratio of 0.1 and stirred and reacted for 4 hours.

[0196] Example 4

[0197] An isophorone dimer was prepared in the same manner as in Example 1, except that the reaction was carried out in one pot without performing the purification and separation processes in (1) and (2).

[0198]

[0199] Classification Hydrogenation Conditions Catalyst Type Catalyst Equivalent Non-solvent Type Reaction Temperature Hydrogen Gas Pressure Reaction Time Yield of Second Intermediate (Yield of Hydrogenation Step) [equiv] [℃] [bar] [hr] [mol%] Example 1 PtO 2 0.3 AcOH 2 5 70 269 Comparative Example 1 PtO 2 0.1 AcOH 2 5 17 247 Comparative Example 2 PtO 2 0.1 THF 2 5 17 20 Comparative Example 3 PtO 2 0.1 MeOH 2 5 17 20 Comparative Example 450% Pd / C 1.0 THF 2 5 17 20 Comparative Example 550% Pd / C 1.0 MeOH 2 5 17 20 Comparative Example 6 Pd(OH) 2 0.8 MeOH 2 5 17 20 Example 2 PtO 2 0.1 AcOH 5 0 70 453 Example 3PtO20.1AcOH2570450

[0200] Table 1 above shows the yield of the second intermediate according to the hydrogenation conditions. According to Table 1 above, Comparative Examples 4 to 6, which used 50% Pd / C or Pd(OH)2 as a catalyst instead of PtO2, showed no formation of the second intermediate or a very low yield. In addition, judging from the fact that Comparative Examples 4 to 6 did not form the second intermediate or showed a very low yield despite using a significantly larger amount of catalyst than Examples 1 to 3, it was confirmed that the Pt-based catalyst, particularly the PtO2 catalyst, was highly effective in producing the isophorone dimer of the present invention. In addition, even when the PtO2 catalyst was used, the second intermediate was not formed in Comparative Examples 2 and 3, which used a solvent such as methanol or tetrahydrofuran instead of acetic acid (AcOH). That is, it was found that the yield may vary depending on the solvent in producing the isophorone dimer of the present invention, and that introducing acetic acid as a solvent is preferable. In addition, when comparing Comparative Example 1 with Examples 2 and 3, it was confirmed that the yields of Examples 2 to 4, in which the hydrogen gas pressure was maintained high at 70 bar even though the reaction time was short at 2 to 4 hours, were higher than that of Comparative Example 1, in which the hydrogen pressure was low at 1 bar and the reaction time was long at 72 hours. From this, it was found that a large amount of hydrogen was required to form the second intermediate, and it was confirmed that the step of forming the second intermediate corresponds to the hydrogenation process. When comparing Examples 2 and 3, it was confirmed that the yield of the second intermediate of Example 2, which had a shorter reaction time, was higher than that of Example 3. This can be inferred to be because, since the reactivity of the second intermediate is high, if the reaction time is longer than necessary, the second intermediate produced easily reacts with the surrounding excess oxygen, thereby reducing the yield.

[0201] Whether to perform purification and separation in the dimerization step Whether to perform purification and separation in the hydrogenation step Whether to perform purification and separation in the deoxygenation step Final yield of isophorone dimer [mol%] Example 100041 Example 4XX053

[0202] Table 2 above is a table showing the yield of the isophorone dimer finally obtained after the completion of the reaction, depending on whether the purification and separation processes of the dimerization and hydrogenation steps are performed. Specifically, the yield of the isophorone dimer finally obtained is based on the total mole number of isophorone prepared before the dimerization reaction, and means the yield of the isophorone dimer obtained after the completion of the final reaction (deoxygenation).

[0203] The final yield of the above isophorone dimer can be calculated according to the following equation 1.

[0204] [Formula 1] Final yield of isophorone dimer = (number of moles of isophorone dimer finally obtained after completion of deoxygenation reaction) / (total number of moles of isophorone added in the dimerization step)

[0205] According to Table 2 above, Example 1, in which purification and separation were performed in the dimerization and hydrogenation steps, which are the first and second intermediate formation steps, respectively, the final yield of the isophorone dimer was confirmed to be 41 mol%. On the other hand, Example 4, in which the reaction was performed in one pot without purification and separation in both the dimerization and hydrogenation steps, the final yield of the isophorone dimer was confirmed to be 53 mol%. It was confirmed that the yield was further improved when the final compound, isophorone dimer, was synthesized in one pot from isophorone, the starting material for the reaction, without purification and separation in each intermediate formation step. It can be inferred that the final yield is lowered because purification and separation of each intermediate may result in the loss of some of the first intermediate and / or second intermediate, which are the starting materials for the next reaction step. That is, in order to improve the production rate of the final isophorone dimer, it may be advantageous to improve the yield by not performing a purification separation process at each stage of dimerization and hydrogenation, and it may also be desirable from the perspective of improving the economic efficiency of the process.

[0206]

[0207] Experimental Example 1 - NMR Spectra

[0208] The substances produced after each step of dimerization, hydrogenation, and deoxygenation were analyzed through NMR spectra, and the results of NMR spectra analysis of the first intermediate, second intermediate, and isophorone dimer are presented.

[0209] First intermediate

[0210] 1H NMR (400 MHz, DMSO) δ 5.19 (s, 1H), 2.28 - 1.97 (m, 6H), 1.70 (d,J= 12.9 Hz, 1H), 1.47 (d,J= 11.6 Hz, 1H), 1.36 - 1.22 (m, 2H), 1.14 (dd,J= 19.7, 12.7 Hz, 2H), 0.98 (s, 3H), 0.96 (s, 6H), 0.87 (s, 3H), 0.70 (s, 3H); 13 C NMR (101 MHz, DMSO) δ 200.8, 158.4, 134.8, 71.0, 51.7, 51.4, 50.4, 46.8, 45.0, 43.8, 37.0, 32.4, 32.3, 31.9, 31.2, 29.1, 28.2, 26.7.

[0211] Second intermediate

[0212] 1 H NMR (400 MHz, DMSO) δ 4.27 (s, 1H), 2.21 - 2.04 (m, 1H), 1.85 (d,J= 17.9 Hz, 1H), 1.74 (d,J= 17.8 Hz, 1H), 1.58 - 1.38 (m, 4H), 1.34 - 0.98 (m, 7H), 0.88 (s, 3H), 0.87 (s, 3H), 0.84 (s, 3H), 0.82 (s, 3H), 0.77 (s, 3H); 13 C NMR (101 MHz, DMSO) δ 133.5, 126.9, 70.8, 52.8, 48.9, 47.9, 44.0, 43.7, 37.3, 35.5, 33.1, 32.7, 31.3, 30.8, 28.6, 28.0, 25.9, 20.6.

[0213] isophorone dimer

[0214] 1H NMR (400 MHz, CDCl3) δ 2.03 (dtd,J= 21.0, 4.1, 1.9 Hz, 2H), 1.94 - 1.73 (m, 2H), 1.68 - 1.59 (m, 1H), 1.51 - 1.11 (m, 10H), 0.90 (s, 6H), 0.86 (s, 3H), 0.85 (s, 3H), 0.84 (s, 3H); 13 C NMR (101 MHz, CDCl3) δ 130.5, 127.9, 54.1, 44.6, 44.2, 40.5, 40.1, 37.8, 36.4, 36.2, 34.0, 30.7, 30.5, 30.2, 29.3, 29.2, 26.7.

[0215] Experimental Example 2 - GC-MS

[0216] The structural and chemical properties of the substances produced after each step of dimerization, hydrogenation, and deoxygenation were measured and identified using GC-MS. The GC-MS measurement results were confirmed as follows.

[0217] First intermediate

[0218] GC-MS (EI)m / z([M] + ) calcd for C 18 H 28 O2: 276, found:276.

[0219] Second intermediate

[0220] GC-MS (EI)m / z([M] + ) calcd for C 18 H 30 O:262, found:262.

[0221] isophorone dimer

[0222] GC-MS (EI)m / z([M] + ) calcd for C 18 H 30 :246, found:246.

[0223] The present invention was able to derive the structure of each compound of the first intermediate, the second intermediate, and the isophorone dimer from the NMR spectra and GC-MS results derived from the above experimental examples 1 and 2, and to elucidate the reaction mechanism.

Claims

1. Expressed by the following structural formula 1, Isophorone dimer. [Structural formula 1] (However, in structural formula 1, the above R 1 Inland R 5 are each independently an alkyl group having 1 to 30 carbon atoms.) 2. In paragraph 1, The above isophorone dimer comprises a compound represented by the following structural formula 1a: Isophorone dimer. [Structural formula 1a] 3. In paragraph 1, A freezing point of 100 K or more and less than 226 K, Isophorone dimer.

4. In paragraph 1, Having a mass density of 0.79 g / ml to 1.00 g / ml under room temperature and pressure conditions, Isophorone dimer.

5. In paragraph 1, Energy density is 34.0 MJ / L to 45.0 MJ / L, Isophorone dimer.

6. In paragraph 1, The heat of combustion is 40.0 MJ / kg to 50.0 MJ / kg, Isophorone dimer.

7. Synthesizing an isophorone dimer represented by the structural formula 1 below through a hydrodeoxygenation (HDO) reaction from isophorone. Method for producing isophorone dimer. [Structural formula 1] (However, in structural formula 1, the above R 1 Inland R 5 are each independently an alkyl group having 1 to 30 carbon atoms.) 8. In paragraph 7, Steps to prepare isophorone; A step of forming a first intermediate by dimerizing the above isophorone; A step of forming a second intermediate by hydrogenating the first intermediate; and A step of deoxygenating the second intermediate to finally obtain an isophorone dimer; Method for producing isophorone dimer.

9. In paragraph 8, The above isophorone dimer comprises a compound represented by the following structural formula 1a: Method for producing isophorone dimer. [Structural formula 1a] 10. In paragraph 8, The above isophorone preparation step is to form isophorone by ketoneizing the carboxylic acid contained in the biomass and then performing a catalytic reaction. Method for producing isophorone dimer.

11. In paragraph 8, The above first intermediate formation step is to form a first intermediate expressed by the following structural formula 2 by mixing and reacting isophorone and sodium hydroxide and then neutralizing them. Method for producing isophorone dimer. [Structural formula 2] (However, in structural formula 2, the above R 1 Inland R 5 are each independently an alkyl group having 1 to 30 carbon atoms.) 12. In paragraph 8, In the first intermediate formation step, the reaction temperature is 75 to 90°C. Method for producing isophorone dimer.

13. In paragraph 8, The above first intermediate formation step has a reaction time of 12 to 24 hours. Method for producing isophorone dimer.

14. In paragraph 11, In the first intermediate formation step, the mixing equivalent ratio of the isophorone and sodium hydroxide is 1:1 to 3:

1. Method for producing isophorone dimer.

15. In paragraph 8, The above second intermediate formation step forms a second intermediate expressed by the following structural formula 3. Method for producing isophorone dimer. [Structural formula 3] (However, in structural formula 3, the above R 1 Inland R 5 are each independently an alkyl group having 1 to 30 carbon atoms.) 16. In paragraph 8, The above second intermediate formation step is performed in a hydrogen (H2) gas atmosphere, The hydrogen gas pressure inside the reactor is 50 to 100 bar. Method for producing isophorone dimer.

17. In paragraph 8, In the second intermediate formation step, the first intermediate and the catalyst are mixed in an equivalent ratio of 1:0.05 to 1:0.5, The above catalyst is at least one selected from metals and metal compounds including Pt, Pd, Ru, and Rh, The above metal compound includes a metal oxide, a metal carbide, and a metal hydroxide. Method for producing isophorone dimer.

18. In paragraph 8, In the second intermediate formation step, the reaction temperature is 25 to 50 ℃, Method for producing isophorone dimer.

19. In paragraph 8, The above isophorone dimer obtaining step includes obtaining an isophorone dimer represented by the following structural formula 1a by performing a deoxygenation reaction by mixing trifluoroacetic acid (TFA) and triethylsilane (Et3SiH) with the second intermediate, Based on 1 equivalent of the entire second intermediate, trifluoroacetic acid is mixed in a ratio of 6 to 7 equivalents, Including mixing triethylsilane in an equivalent ratio of 1 to 2 based on 1 equivalent of the entire second intermediate. Method for producing isophorone dimer. [Structural formula 1a] 20. In paragraph 8, The reaction temperature of the above isophorone dimer obtaining step is 20 to 30°C. Method for producing isophorone dimer.

21. In paragraph 8, The reaction time of the above isophorone dimer obtaining step is 3 to 10 hours. Method for producing isophorone dimer.

22. In paragraph 8, In the first intermediate formation step and the second intermediate formation step, the isophorone dimer is generated from the isophorone without purifying and separating the first intermediate and the second intermediate. Method for producing isophorone dimer.

23. Comprising an isophorone dimer according to any one of clauses 1 to 6, Alternative fuel to aviation fuel.

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