Synthesis of fatty acid methyl esters and fatty acid ethyl esters

Abstract

In the present invention, a novel synthesis method for fatty acid methyl esters and fatty acid ethyl esters is provided. More specifically, a fatty oil composition obtained from dry insects by mechanical treatment is reacted with an aliphatic alcohol in the presence of an alkali metal alkoxide, such as methoxide or ethoxide, to obtain fatty acid methyl esters (FAME) or fatty acid ethyl esters (FAEE).

Description

Technical Field

[0001] In this invention, a novel synthetic method for fatty acid methyl esters and fatty acid ethyl esters is provided. More specifically, a fatty oil composition obtained by mechanical treatment from dried insects is reacted with an alkali metal alkoxide such as a methanol salt or an ethanol salt to obtain fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE). Background Technology

[0002] Fatty acid methyl esters (FAMEs), also known as biodiesel, are a renewable and environmentally friendly liquid fuel. However, the feedstocks (primarily crop oils) are valuable resources mainly used in food and feed, which to some extent limits some of the larger-scale chemical applications of biodiesel. Therefore, there is a need to develop non-food feedstocks or feedstocks that can be used in both food and biodiesel applications to fully realize the potential of biodiesel.

[0003] Production costs are a major obstacle preventing biodiesel from being used as a primary fuel. Cost analysis shows that 75% of biodiesel costs come from feedstocks, primarily crop oils such as soybean oil, rapeseed oil, and sunflower oil. Besides their economic limitations, crop oils are also a finite food resource. To overcome these challenges, non-food feedstocks such as jatropha, Chinese tallow tree, and microalgae are being used in biodiesel production. However, these alternative feedstocks face their own challenges, such as long life cycles, competition for crop land, and competition for limited water resources.

[0004] In addition, large amounts of organic waste are generated, such as animal waste, residential waste (e.g., household waste), commercial waste (e.g., from shops, markets, stores, hotels, etc.), and institutional waste (e.g., from schools, hospitals, etc.). This organic waste can be used to feed high-fat insects, which can then be used for biodiesel production.

[0005] One insect species of particular interest in this field is the black soldier fly (Hermetia illucens) (BSF). BSF larvae have high levels of both protein and fatty acids. While the protein can be used in the food and feed industries, such as in the production of dog food, the fatty acids can be further converted into biodiesel.

[0006] Therefore, there is interest in methods for preparing fatty acid methyl esters and fatty acid ethyl esters from insect feedstocks, which allow for subsequent processing of protein fractions and can be used for large-scale industrial applications.

[0007] Against this backdrop, Mohan et al. (Mohan, K. et al., Science of the Total Environment 859 (2023) 160235) disclosed various possibilities for producing biodiesel from black water worms. However, all of these methods involve chemical extraction steps to separate fatty acids and other parts of the larvae, such as proteins. Typically, extraction involves hexane or petroleum ether. The use of such chemicals interferes with further processing of the protein fraction. Furthermore, Mohan et al. highlighted a two-step method for producing biodiesel from BSF larvae, comprising acid-catalyzed esterification and base-catalyzed transesterification.

[0008] Following this line of thought, Li et al. (Li, Q. et al., Fuel [Fuel] 90 (2011) 1545-1548) disclosed a method for producing biodiesel from black waterworm larvae (BSFL), which involves a chemical extraction step using petroleum ether and a two-step process of acid-catalyzed esterification and base-catalyzed transesterification to convert fatty acids into FAME.

[0009] On the other hand, some literature discloses the conversion of fatty acids into fatty acid methyl esters for analytical purposes. However, these methods involve significantly smaller amounts of reactants, and it is unclear whether such reactions can be scaled up, especially for reactions involving fatty acids derived from insects without any chemical extraction steps. For example, Christie (WW Journal of Lipid Research, Vol. 23, pp. 1072-1075, 1982) disclosed the conversion of 1-10 mg of glycerides into FAME for gas-liquid chromatography (GLC) analysis. Other analytical studies of fatty acids describe the preparation of FAME involving boron trifluoride (BF3) dissolved in methanol. However, BF3 is a highly toxic gas and should therefore be avoided for large-scale industrial applications.

[0010] Therefore, there is a need in the art for methods to prepare fatty acid methyl esters and fatty acid ethyl esters from insect raw materials, which allow for further processing of protein fractions from insect larvae and can be scaled up for industrial applications.

[0011] Surprisingly, the inventors of this invention have discovered that fatty oil compositions obtained solely from insect larvae through mechanical processing (such as cold pressing) and without exposure to further chemical extraction can be directly used in transesterification reactions using alkali metal alkoxides (such as methanol or ethanol). The resulting products are glycerol and fatty acid methyl esters (FAME) or fatty acid ethyl esters (FAEE). This type of reaction is a one-step reaction, which can be scaled up for industrial applications. Furthermore, the mild treatment of the larvae will allow for the use of protein fractions in a variety of applications, including in the food and feed industries. Summary of the Invention

[0012] In a first aspect, the present invention relates to a method for preparing, and preferably processing, fatty acid methyl esters (FAME) or fatty acid ethyl esters (FAEE), the method comprising:

[0013] i) Obtaining a fatty oil composition by mechanically treating dried insects, provided that the treatment does not involve a chemical extraction step;

[0014] iia) The fatty oil composition of step i) is reacted in methanol containing at least 0.5% by weight of sodium methoxide, potassium methoxide or lithium methoxide at a pressure of at least 2.5 bar under a N2 atmosphere at a temperature of at least 60°C for at least 30 minutes.

[0015] In order to obtain fatty acid methyl esters (FAME).

[0016] or

[0017] iib) The fatty oil composition of step i) is reacted in ethanol containing at least 0.5% by weight of sodium ethoxide, potassium ethoxide or lithium ethoxide at a pressure of at least 2.5 bar under a N2 atmosphere at a temperature of at least 60°C for at least 30 minutes.

[0018] In order to obtain fatty acid ethyl esters (FAEE).

[0019] In a preferred embodiment, the fatty oil composition has a protein content of at least 0.1%, preferably at least 0.25%, and more preferably at least 1%, relative to the total weight of the composition.

[0020] In other preferred embodiments, the amount of the fatty oil composition reacted in step iia) or iib) is at least 10 grams, preferably at least 20 grams, and more preferably at least 25 grams.

[0021] In another preferred embodiment, the mechanical processing is pressing, and more preferably cold pressing.

[0022] In a preferred embodiment, the alkali metal methoxide is sodium methoxide.

[0023] In other preferred embodiments, in the reaction of step iia) or iib)

[0024] - The reaction time is between 20 and 120 minutes, preferably between 30 and 90 minutes, and more preferably between 45 and 75 minutes;

[0025] - The reaction temperature is between 65°C and 100°C, preferably between 75°C and 95°C, and more preferably between 80°C and 90°C;

[0026] - The methanol contains 0.25% to 2% by weight, and preferably 0.5% to 1.5% by weight, of an alkali metal methanol salt;

[0027] - The ethanol contains 0.25% to 2% by weight, and preferably 0.5% to 1.5% by weight, an alkali metal ethanol salt; and / or

[0028] - The partial pressure of N2 is between 2 and 10 bar, preferably between 3.5 and 7.5 bar, and more preferably between 4 and 5 bar.

[0029] Furthermore, in a preferred embodiment, the reaction in step iia) or iib) does not include the addition of boron trifluoride.

[0030] In another embodiment, insects

[0031] - It is dried during its larval stage; and / or

[0032] - It is a holometabolous insect.

[0033] In a preferred embodiment, the insect is from the genus Diptera, preferably the suborder Brachycera, and more preferably the black soldier fly.

[0034] In other preferred embodiments, fatty acid methyl esters (FAME) or fatty acid ethyl esters (FAEE) are purified by phase separation and / or distillation.

[0035] In other preferred embodiments, fatty acid methyl esters (FAME) or fatty acid ethyl esters (FAEE) are processed into fatty alcohols, fatty amines, fatty amides, fatty acid carboxylate, fatty methyl ketones, dimer fatty acids, terminal fatty olefins, polyols, and FAME-based surfactants or polyesters or FAEE-based surfactants or polyesters.

[0036] In another preferred embodiment, fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is processed into fatty alcohol by reacting FAME or FAEE with hydrogen at a pressure of at least 200 bar, in an H2 atmosphere, and at a temperature of at least 150°C for at least 12 hours in the presence of at least 3% by weight of a catalyst applied to a support. The catalyst is selected from the group consisting of CuO, Cu2O, and combinations thereof, and the support is selected from the group consisting of Al2O3, ZrO2, TiO2, and SiO2.

[0037] In a preferred embodiment,

[0038] - The reaction time is between 16 and 40 hours, and preferably between 24 and 36 hours;

[0039] - The reaction temperature is between 160°C and 300°C, preferably between 175°C and 265°C, and more preferably between 190°C and 230°C;

[0040] - The reaction mixture contains 2% to 8% by weight, and preferably 4% to 6% by weight, of a catalyst; and / or

[0041] - The partial pressure of H2 is between 170 and 380 bar, and preferably between 250 and 300 bar.

[0042] In other preferred embodiments, fatty alcohols are purified by rotary evaporation and / or distillation.

[0043] In a preferred embodiment, step iia is performed. Detailed Implementation

[0044] In this invention, the inventors unexpectedly discovered that a fatty oil composition obtained by cold-pressing and drying insect larvae, containing significant amounts of impurities, can be directly used in reactions using alkali metal alkoxides such as methanol or ethanol salts. The reaction products are glycerol and fatty acid methyl esters (FAME) or fatty acid ethyl esters (FAEE). This one-step reaction can be scaled up for industrial applications. On the other hand, the proteins remaining in the dried larvae can be used in various applications, such as products for the food and feed industries.

[0045] In a first aspect, the present invention relates to a method for preparing, and preferably processing, fatty acid methyl esters (FAME) or fatty acid ethyl esters (FAEE), the method comprising:

[0046] i) Obtaining a fatty oil composition by mechanically treating dried insects, provided that the treatment does not involve a chemical extraction step;

[0047] iia) The fatty oil composition of step i) is reacted in methanol containing at least 0.5% by weight of sodium methoxide, potassium methoxide or lithium methoxide at a pressure of at least 2.5 bar under a N2 atmosphere at a temperature of at least 60°C for at least 30 minutes.

[0048] In order to obtain fatty acid methyl esters (FAME).

[0049] or

[0050] iib) The fatty oil composition of step i) is reacted in ethanol containing at least 0.5% by weight of sodium ethoxide, potassium ethoxide or lithium ethoxide at a pressure of at least 2.5 bar under a N2 atmosphere at a temperature of at least 60°C for at least 30 minutes.

[0051] In order to obtain fatty acid ethyl esters (FAEE).

[0052] As may be used interchangeably herein, the terms "fatty acid methyl ester," "FAME," or "biodiesel" refer to compounds having between 9 and 31 carbon atoms. Therefore, the fatty acid methyl ester prepared by the method of the present invention is according to formula (I):

[0053] Formula (I)

[0054] R1 is a C7 to C29 alkyl or C7 to C29 alkenyl.

[0055] Preferably, the fatty acid methyl ester has between 11 and 21 carbon atoms. In these compounds, R1 is a C9 to C19 alkyl or alkenyl group.

[0056] As may be used interchangeably herein, the term "fatty acid ethyl ester" or "FAEE" refers to a compound having between 10 and 32 carbon atoms. Therefore, the fatty acid methyl ester prepared by the method of the present invention is according to formula (II):

[0057] Equation (II)

[0058] R2 is a C7 to C29 alkyl or C7 to C29 alkenyl.

[0059] Preferably, the fatty acid ethyl ester has between 12 and 22 carbon atoms. In these compounds, R2 is a C10 to C20 alkyl or alkenyl group.

[0060] In a preferred embodiment, the alkenyl groups of R1 and R2 have one, two, or three double bonds, more preferably one double bond.

[0061] As used herein, the term "fatty oil composition" refers to a liquid fraction following mechanical treatment of insect larvae. In a preferred embodiment, the fatty oil composition may comprise at least 50% fatty acids, monoglycerides, diglycerides, and triglycerides. In other embodiments, the fatty oil composition comprises at least 60%, at least 70%, at least 80%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% fatty acids, monoglycerides, diglycerides, and triglycerides by weight. Molecules in the fatty oil composition that are not fatty acids, monoglycerides, diglycerides, and triglycerides include proteins, but may also include steroids, nucleic acids (such as DNA and RNA), phospholipids, glycolipids and sphingolipids, water, and sugars (including chitin). Fatty acids are defined as carboxylic acids having saturated or unsaturated aliphatic chains. Fatty acids primarily consist of unbranched chains with an even number of carbon atoms ranging from 8 to 30.

[0062] Monoglycerides are a class of glycerol esters composed of glycerol molecules linked to fatty acids via ester bonds. Because glycerol contains both primary and secondary alcohol groups, two different types of monoglycerides can be formed: 1-monoacylglycerol, in which a fatty acid is attached to a primary alcohol, and 2-monoacylglycerol, in which a fatty acid is attached to a secondary alcohol. Diglycerides, or diacylglycerols (DAGs), are glycerol esters composed of two fatty acid chains covalently bonded to a glycerol molecule via ester bonds. Two possible forms exist: 1,2-diacylglycerols and 1,3-diacylglycerols. Triglycerides (TG, triacylglycerols, TAGs, or triacylglycerol esters) are esters derived from glycerol and three fatty acids.

[0063] As used herein, the term "mechanical treatment" refers to the treatment of dried insects, particularly dried insect larvae, and how to obtain fatty oil compositions. This treatment does not involve "chemical treatment" as defined below. Mechanical treatment includes, but is not limited to, pressing (particularly cold pressing), centrifugation, rotary filtration (particularly rotary vacuum drum filtration), clarification decantation, and homogenization. Preferably, mechanical treatment involves cold pressing of the insects using a screw press.

[0064] As used herein, the term "chemical extraction step" refers to the preparation of fatty oil compositions from dried insects. This method does not include a chemical extraction step. Chemical extraction in the sense of this invention means treating dried insects with compounds that support or enhance the extraction of fatty acids, monoglycerides, diglycerides, and triglycerides from insects. This includes surfactants or hydrophobic compounds or liquids, including diethyl ether, petroleum ether, or other unipolar solvents. It also includes enzymatic extraction, including the use of proteases and / or lipases, or microbial extraction. Furthermore, the term "chemical extraction step" also includes methods using chemical compounds in combination with other processes, such as the use of microwaves or ultrasound. Therefore, the methods of this invention do not include the use of chemical compounds, enzymes, or even whole microorganisms, alone or in combination with processes such as microwave treatment or ultrasonic baths.

[0065] In another embodiment, the fatty oil composition may be filtered or refined between steps i) and iia) or iib). In a more preferred embodiment, insoluble particles are separated from the fatty oil composition.

[0066] As used in this article, “dry” means that the insect has a water content of less than 50%, less than 40%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, less than 5%, or less than 1% by weight.

[0067] As used in this article, the term "insect" refers to a specific class of arthropods. They are the largest group within the phylum Arthropoda. Insects possess a chitinous exoskeleton, a three-part body (head, thorax, and abdomen), three pairs of articulated legs, compound eyes, and a pair of antennae.

[0068] The reaction steps iia) and iib) of the method of the present invention involve the reaction of a fatty oil composition with methanol or ethanol in the presence of an alkali metal alkoxide such as a methanol salt or an ethanol salt. This reaction includes the solvation or transesterification of monoglycerides, diglycerides, and triglycerides to directly form glycerol and the corresponding fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE). Therefore, the product of the method of the present invention includes not only FAME or FAEE, but also glycerol as a byproduct.

[0069] As used in this article, the term "methanol salt" refers to the anion CH3O - As used herein, the term "ethanol salt" refers to the anion CH3CH2O - .

[0070] As used herein, the term "processing" is intended to be interpreted broadly. This means that the term covers the processing of all components that are part of the method of the present invention. Furthermore, this means that FAME and FAEE can be further reacted to form fatty alcohols or other compounds, as described in more detail below. However, such processing can also refer to further processing of the dried insects following mechanical treatment. Therefore, in a preferred embodiment, the method of the present invention further includes one or more steps to recover protein fractions from the dried and mechanically treated insects.

[0071] In a preferred embodiment, the fatty oil composition has a protein content of at least 0.1%, at least 0.25%, at least 1%, at least 3%, at least 5%, at least 7%, or at least 10% relative to the total weight of the composition.

[0072] In other preferred embodiments, the amount of the fatty oil composition reacted in step iia) or iib) is at least 10 grams, preferably at least 20 grams, and more preferably at least 25 grams. It should be noted that the method of the present invention can be scaled up for industrial applications, therefore the amount of the fatty oil composition reacted in step iia) or iib) can be at least 500 grams, at least 1 kilogram, at least 10 kilograms, at least 50 kilograms, or at least 100 kilograms.

[0073] In another preferred embodiment, the mechanical processing is pressing, and more preferably cold pressing. In a more preferred embodiment, a screw press is used to apply cold pressing.

[0074] In a preferred embodiment, the alkali metal methoxide is sodium methoxide (CH3NaO).

[0075] In other preferred embodiments, in the reaction of step iia) or iib)

[0076] - The reaction time is between 20 and 120 minutes, preferably between 30 and 90 minutes, and more preferably between 45 and 75 minutes;

[0077] - The reaction temperature is between 65°C and 100°C, preferably between 75°C and 95°C, and more preferably between 80°C and 90°C;

[0078] - The methanol contains 0.25% to 2% by weight, and preferably 0.5% to 1.5% by weight, of an alkali metal methanol salt;

[0079] - The ethanol contains 0.25% to 2% by weight, and preferably 0.5% to 1.5% by weight, an alkali metal ethanol salt; and / or

[0080] - The partial pressure of N2 is between 2 and 10 bar, preferably between 3.5 and 7.5 bar, and more preferably between 4 and 5 bar.

[0081] Furthermore, in a preferred embodiment, the reaction in step iia) or iib) does not include the addition of boron trifluoride (BF3).

[0082] In another embodiment, insects

[0083] - It is dried during its larval stage; and / or

[0084] - It is a holometabolous insect.

[0085] Holometabolous insects exhibit complete metamorphosis, meaning that insect development includes all four life stages: egg, larva, pupa, and imago (or adult). The larva is a unique juvenile form of an insect before it undergoes metamorphosis into an adult. The appearance of larvae is often very different from that of the adult form (e.g., caterpillars and butterflies), including distinct structures and organs not present in the adult form. Their diets can also be quite different. The larvae used in the methods of this invention can have a high fat content. In some embodiments, the larvae contain at least 60%, at least 70%, at least 80%, or at least 90% by weight of fatty acids, monoglycerides, diglycerides, and triglycerides.

[0086] As used in this article, the term "holometabolous insects" refers to the following orders: Diptera, Megaptera, Scorpionidae, Neuroptera, Coleoptera, Trichoptera, Hymenoptera, Trichoptera, Lepidoptera, Longiptera, and Saurischia.

[0087] In a preferred embodiment, the insect is from the genus Diptera, preferably the suborder Brachycera, and more preferably the black soldier fly.

[0088] In other preferred embodiments, fatty acid methyl esters (FAME) or fatty acid ethyl esters (FAEE) are purified by phase separation and / or distillation. As used herein, “phase separation” refers to the conversion of a homogeneous system (e.g., a doped formulation) into two or more phases. In this invention, phase separation can be based on the mechanism of vapor-induced phase separation (VIPS). As used herein, the term “distillation” refers to a method of heating a solution containing FAME, FAEE, or the corresponding fatty alcohol to its boiling point and separating the volatile components contained therein.

[0089] In a more preferred embodiment, the above phase separation is performed without the need for additives / additional solvents (such as glycerol, n-hexane, or petroleum ether).

[0090] In other preferred embodiments, fatty acid methyl esters (FAME) or fatty acid ethyl esters (FAEE) are processed into fatty alcohols, fatty amines, fatty amides, fatty acid carboxylic esters, fatty methyl ketones, dimer fatty acids, terminal fatty olefins, polyols, and FAME-based surfactants or polyesters, or FAEE-based surfactants or polyesters. The compounds may contain 8 to 30 carbon atoms and may have a linear structure. Preferably, functional groups such as alcohol, amine, amide, and carboxylic ester groups are located at the ends. This processing step of converting fatty acid methyl esters (FAME) or fatty acid ethyl esters (FAEE) into fatty alcohols, fatty amines, fatty amides, fatty acid carboxylic esters, fatty methyl ketones, dimer fatty acids, terminal fatty olefins, polyols, and FAME-based surfactants or polyesters, or FAEE-based surfactants or polyesters, particularly fatty alcohols, can be considered step iii) of the method of the present invention.

[0091] As used herein, the term "fatty methyl ketone" refers to a compound according to formula (3),

[0092] Equation (3),

[0093] R3 is a C7 to C29 alkyl or C7 to C29 alkenyl, preferably a C10 to C20 alkyl or alkenyl.

[0094] As used herein, the term “terminal aliphatic olefin” refers to a compound having 7 to 29, preferably 10 to 20, carbon atoms in a straight chain, wherein at one end the first two carbon atoms are connected by a double bond.

[0095] In another preferred embodiment, fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is processed into fatty alcohol by reacting FAME or FAEE with hydrogen at a pressure of at least 200 bar, in an H2 atmosphere, and at a temperature of at least 150°C for at least 12 hours in the presence of a catalyst, comprising at least 3% by weight of a catalyst applied to a support. The catalyst is selected from the group consisting of CuO, Cu2O, and combinations thereof, and the support is selected from the group consisting of Al2O3, ZrO2, TiO2, and SiO2.

[0096] Therefore, the catalyst includes CuO on an Al2O3 support, CuO on a ZrO2 support, CuO on a TiO2 support, and CuO on a SiO2 support. Alternatively, the catalyst includes Cu2O on an Al2O3 support, Cu2O on a ZrO2 support, Cu2O on a TiO2 support, and Cu2O on a SiO2 support.

[0097] In a preferred embodiment,

[0098] - The reaction time is between 16 and 40 hours, and preferably between 24 and 36 hours;

[0099] - The reaction temperature is between 160°C and 300°C, preferably between 175°C and 265°C, and more preferably between 190°C and 230°C;

[0100] - The reaction mixture contains 2% to 8% by weight, and preferably 4% to 6% by weight, of a catalyst; and / or

[0101] - The partial pressure of H2 is between 170 and 380 bar, and preferably between 250 and 300 bar.

[0102] In other preferred embodiments, fatty alcohols are purified by rotary evaporation and / or distillation.

[0103] As used in this article, the term "rotary evaporation" refers to methods that include the use of a rotary evaporator (rotary evaporator).

[0104] In a preferred embodiment, step iia is performed. Example

[0105] I. General Information

[0106] Typically, experiments for the transesterification step (transesterification of triacylglycerol (TAG) to FAME) are conducted in a 300 mL or 9 L autoclave (one-pot reaction vessel) at a nitrogen pressure of 4 bar and a temperature range of 85°C. The reaction time is preferably 1 h.

[0107] This method is characterized by the use of three main components: fats / triglycerides as starting materials, methanol as a solvent, and sodium methoxide as a catalyst. The product is FAME, and the byproduct is glycerol.

[0108] Phase separation can then be performed. The lower phase (glycerol) can be discarded. In cases where phase separation is difficult, the addition of glycerol and / or heptane can be considered. On a larger scale, this solvent addition is usually unnecessary.

[0109] Typically, subsequent distillation of the obtained crude FAME (upper phase) is carried out in a temperature range of 175°C–250°C and a vacuum pressure of 2–12 mbar. First, residual methanol and other volatile “low-boiling substances” (boiling points up to the FAME boiling point) are removed. Second, a mixture of FAMEs can be distilled off. Third, a storage tank contains all “high-boiling substances,” such as byproducts and impurities from residual proteins and DNA.

[0110] The obtained FAME was analyzed by elemental analysis and quantitative GC (with internal standard).

[0111] Typically, experiments for the hydrogenation step (hydrogenating FAME to fatty alcohols) are conducted in a 300 mL or 9 L autoclave (one-pot reaction vessel) at a temperature of 210°C and a hydrogen pressure of 270 bar.

[0112] The method is characterized by the use of three main components: distilled FAME, hydrogen, and a heterogeneous catalyst.

[0113] The following reaction parameters were used in the experiment:

[0114] - The reaction time is 30-40 h, preferably 36 h.

[0115] Typically, copper-based catalysts must be activated in an autoclave under a hydrogen atmosphere before they can be used for hydrogenation. In the case of this invention, the catalyst is typically activated.

[0116] Analysis was performed using gas chromatography (GC) and measurements of chemical values ​​(OH value and iodine value).

[0117] Insect lipids / triglycerides were commercially available from Hermetia Baruth GmbH (Baruth / Mark, Germany). Insect lipids / fat / triglycerides / triacylglycerides were obtained by cold pressing dried *Burmese gall midge* larvae without the use of chemical additives. The insect lipids were used in their filtered form (Examples 1, 2, and 3) or directly without further purification steps (Example 4) for further synthesis. All other chemicals used were purchased from chemical wholesalers.

[0118] II. Representative Procedure

[0119] Example 1: Transesterification and FAME Distillation (Small Scale)

[0120] Sodium methoxide (1 g) was added to a mixture of insect lipids (103 g; filtered) and methanol (24 g) in an autoclave. The reaction vessel was closed and then purged with nitrogen (three times at 5 bar). Stirring (700 U / min) was applied at atmospheric pressure (1 bar) and 60°C. The reaction mixture was heated to 85°C and the nitrogen pressure was maintained at 4 bar.

[0121] The reaction mixture was stirred under these conditions for 1 h and then cooled to room temperature. Afterward, the phases were separated and the upper phase was distilled (at 175°C–225°C, 2–4 mbar). Distillation yielded a liquid sample (84 g) of FAME.

[0122] Example 2: Transesterification and FAME Distillation (Large Scale)

[0123] Sodium methoxide (40 g) was added to a mixture of insect lipids (4033 g; filtered) and methanol (866 g) in an autoclave. The reaction vessel was closed and then purged with nitrogen (three times at 5 bar). Stirring (700 U / min) was applied at atmospheric pressure (1 bar) and 60°C. The reaction mixture was heated to 85°C and the nitrogen pressure was maintained at 4 bar.

[0124] The reaction mixture was stirred under these conditions for 1 h and then cooled to room temperature. Afterwards, the phases were separated and the upper phase was distilled (at 200°C–240°C, 2–11 mbar). Distillation yielded a liquid sample of FAME (3307 g).

[0125] Example 3: Transesterification and FAME distillation using unfiltered insect fat

[0126] Sodium methoxide (0.8 g) was added to a mixture of insect lipids (79 g; unpurified) and methanol (19 g) in an autoclave. The reaction vessel was closed and then purged with nitrogen (three times at 5 bar). Stirring (700 U / min) was applied at atmospheric pressure (1 bar) and 60°C. The reaction mixture was heated to 85°C and the nitrogen pressure was maintained at 4 bar.

[0127] The reaction mixture was stirred under these conditions for 1 h and then cooled to room temperature. Glycerol (21 g) and heptane (80 mL) were then added, and the phases were separated. The lower phase was extracted once with heptane (40 mL), and the upper phases were combined. The solvent was removed by evaporation, and the crude material was distilled (at 130°C–175°C, 2–7 mbar). Distillation yielded a liquid sample (72 g) of FAME.

[0128] Example 4: Transesterification and FAME distillation under additional insect protein contamination

[0129] Sodium methoxide (1.0 g) was added to a mixture of insect lipids (100 g; filtered), insect protein (10 g), and methanol (24 g) in an autoclave. The reaction vessel was closed and subsequently purged with nitrogen (three times at 5 bar). Stirring (700 U / min) was applied at atmospheric pressure (1 bar) and 60°C. The reaction mixture was heated to 85°C and the nitrogen pressure was maintained at 4 bar.

[0130] The reaction mixture was stirred under these conditions for 1 h and then cooled to room temperature. Afterward, the phases were separated and the upper phase was distilled (at 150°C–280°C and 2 mbar). Distillation yielded a liquid sample (80 g) of FAME.

[0131] Example 5: Analysis of the FAMEs synthesized in Examples 1-4

[0132] Table 1 below shows the quantitative content of different fatty acid methyl esters ordered by their chain length, as determined by GC (using a standard mixture of fatty acid methyl esters as a reference).

[0133] Table 1

[0134]

[0135] Table 1 (continued)

[0136]

[0137] Table 1 (continued)

[0138]

[0139] Example 6: Catalyst Activation

[0140] The catalyst used for the hydrogenation reaction, namely a catalyst containing CuO, Al2O3, and La2O3, is placed in an autoclave. The reaction vessel is closed and then purged with nitrogen (three times at 20 bar) and then hydrogen is introduced. The reaction vessel is heated to 200°C (heating rate of 100°C / h) at an initial hydrogen pressure of 50 bar.

[0141] The reaction vessel was then cooled to room temperature and the pressure reduced to atmospheric pressure (1 bar). The starting material was then loaded into the reaction vessel via an HPLC pump.

[0142] Example 7: Hydrogenation and evaporation of FAME (small scale)

[0143] FAME (100 g) was added to the activated catalyst (5.0 g) in the autoclave. The reaction vessel was then purged with nitrogen (once at 20 bar). Stirring was applied at an initial hydrogen pressure of 50 bar (700 U / min). The reaction mixture was heated to 210°C and the hydrogen pressure was increased and maintained at 270 bar.

[0144] The reaction mixture was stirred under these conditions for 36 h, then cooled to room temperature and purged with nitrogen (three times at 20 bar). The catalyst was then separated and the filter cake was washed three times with methanol. The solvent was removed by evaporation (at 60°C and 9 mbar) to produce a liquid mixture of fatty alcohols, which solidified (69 g) during storage.

[0145] Example 8: Hydrogenation and Evaporation of FAME (Large Scale)

[0146] FAME (3200 g) was added to the activated catalyst (160 g) in the autoclave. The reaction vessel was then purged with nitrogen (once at 20 bar). Stirring was applied at an initial hydrogen pressure of 50 bar (700 U / min). The reaction mixture was heated to 210°C and the hydrogen pressure was increased and maintained at 270 bar.

[0147] The reaction mixture was stirred under these conditions for 36 h, then cooled to room temperature and purged with nitrogen (three times at 20 bar). The catalyst was then separated and the filter cake was washed three times with methanol. The solvent was removed by evaporation (at 60°C and 9 mbar), yielding a liquid mixture of fatty alcohols that solidified upon storage (2166 g).

[0148] Example 9: Analysis of the fatty alcohols synthesized in Examples 7 and 8

[0149] Table 2 below shows the quantitative content of different fatty alcohols sorted by their chain length, as determined by GC (using a mixture of fatty alcohol standard mixtures as a reference).

[0150] Table 2

[0151]

[0152] Example 10: Comparison of the composition of fats from different natural sources

[0153] Table 3 below shows the quantitative heteroatom content of different fat samples as determined by elemental analysis.

[0154] Table 3

[0155]

Claims

1. A method for preparing, and preferably processing, fatty acid methyl esters (FAME) or fatty acid ethyl esters (FAEE), the method comprising: i) Obtaining a fatty oil composition by mechanically treating dried insects, provided that the treatment does not involve a chemical extraction step; iia) The fatty oil composition of step i) is reacted in methanol containing at least 0.5% by weight of sodium methoxide, potassium methoxide or lithium methoxide at a pressure of at least 2.5 bar under a N2 atmosphere at a temperature of at least 60°C for at least 30 minutes. In order to obtain the fatty acid methyl ester (FAME) or iib) The fatty oil composition of step i) is reacted in ethanol containing at least 0.5% by weight of sodium ethoxide, potassium ethoxide or lithium ethoxide at a pressure of at least 2.5 bar under a N2 atmosphere at a temperature of at least 60°C for at least 30 minutes. In order to obtain the fatty acid ethyl ester (FAEE).

2. The method according to claim 1, wherein, The fatty oil composition has a protein content of at least 0.1%, preferably at least 0.25%, and more preferably at least 1% relative to the total weight of the composition.

3. The method according to claim 1 or 2, wherein, The amount of the fatty oil composition reacted in step iia) or iib) is at least 10 grams, preferably at least 20 grams, and more preferably at least 25 grams.

4. The method according to any one of claims 1 to 3, wherein, The mechanical process is pressing, and more preferably cold pressing.

5. The method according to any one of claims 1 to 4, wherein, The alkali metal methanol salt is sodium methoxide.

6. The method according to any one of claims 1 to 5, wherein, In the reaction in step iia) or iib) - The reaction time is between 20 and 120 minutes, preferably between 30 and 90 minutes, and more preferably between 45 and 75 minutes; - The reaction temperature is between 65°C and 100°C, preferably between 75°C and 95°C, and more preferably between 80°C and 90°C; - The methanol contains 0.25% to 2% by weight, and preferably 0.5% to 1.5% by weight, of the alkali metal methanol salt; - The ethanol contains 0.25% to 2% by weight, and preferably 0.5% to 1.5% by weight, of an alkali metal ethanol salt; and / or - The partial pressure of N2 is between 2 and 10 bar, preferably between 3.5 and 7.5 bar, and more preferably between 4 and 5 bar.

7. The method according to any one of claims 1 to 6, wherein, The reaction in step iia) or iib) does not include the addition of boron trifluoride.

8. The method according to any one of claims 1 to 7, wherein, The insect - It is dried during its larval stage; and / or - It is a holometabolous insect.

9. The method according to any one of claims 1 to 8, wherein, The insect belongs to the genus Diptera, preferably the suborder Brachycera, and more preferably the black soldier fly.

10. The method according to any one of claims 1 to 9, wherein, The fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is purified by phase separation and / or distillation.

11. The method according to any one of claims 1 to 10, wherein, The fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is processed into fatty alcohols, fatty amines, fatty amides, fatty acid carboxylic esters, polyols, and FAME-based surfactants or polyesters, or FAEE-based surfactants or polyesters.

12. The method according to claim 11, wherein, The fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is processed into a fatty alcohol by reacting FAME or FAEE with hydrogen at a pressure of at least 200 bar, under an H2 atmosphere, and at a temperature of at least 150°C for at least 12 hours in the presence of at least 3% by weight of a catalyst applied to a support. The catalyst is selected from the group consisting of CuO, Cu2O, and combinations thereof, and the support is selected from the group consisting of Al2O3, ZrO2, TiO2, and SiO2.

13. The method according to claim 12, wherein, - The reaction time is between 16 and 40 hours, and preferably between 24 and 36 hours; - The reaction temperature is between 160°C and 300°C, preferably between 175°C and 265°C, and more preferably between 190°C and 230°C; - The reaction mixture contains 2% to 8% by weight, and preferably 4% to 6% by weight, of the catalyst; and / or - The partial pressure of H2 is between 170 and 380 bar, and preferably between 250 and 300 bar.

14. The method according to claim 12 or 13, wherein, The fatty alcohol was purified by rotary evaporation and / or distillation.

15. The method according to any one of claims 1 to 15, wherein, Proceed to step iia).

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