Method for producing aviation fuel component

Abstract

The present disclosure describes a process for producing a renewable aviation fuel component wherein the process comprises providing a renewable feedstock and subjecting the feedstock to a decarboxylation and / or decarbonylation (DCO) reaction (20) in a DCO zone, thereby obtaining a DCO effluent (21); subjecting at least a portion of the DCO effluent to a hydrotreating (HT) reaction (30) in the HT zone to obtain a hydrotreated effluent (31); subjecting the hydrotreated effluent to gas-liquid separation (40) to obtain a degassed hydrotreated effluent (41); subjecting at least a portion of the degassed hydrotreated effluent to hydroisomerization (H-ISO) (50), thereby obtaining a hydroisomerized effluent (51); and subjecting at least a portion of the hydroisomerized effluent (51) to fractionation (60) and recovering at least renewable aviation fuel components.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method for producing renewable aviation fuel components. The present disclosure particularly relates to, but is not limited to, a method for producing renewable aviation fuel components, including subjecting a renewable feedstock to decarboxylation and / or decarbonylation (DCO) reactions, hydrotreating, and hydroisomerization. BACKGROUND ART

[0002] This section illustrates useful background information and does not admit that any of the techniques described herein represents the state of the art.

[0003] Currently, there is a continuing need in transportation, particularly in the aviation sector, to reduce greenhouse gas emissions and / or carbon footprint. Accordingly, the interest in renewable aviation fuels and aviation fuel components is growing and has been growing.

[0004] Methods for producing aviation fuel components from renewable raw materials have been proposed. However, in such methods, the carbon and hydrogen efficiency of the aviation fuel components and the yield of the aviation fuel are relatively low. Accordingly, there is a continuing need to improve the yield of renewable aviation fuel components in methods for producing renewable aviation fuel components useful for aviation fuels.

[0005] Renewable feedstocks from a variety of biological sources contain C18 and heavier fatty acids, which limits their effective use in the production of renewable aviation fuels because the properties of the resulting n-alkanes and iso-alkanes affect, for example, the boiling point range, low temperature flow properties, density, and cold soak viscosity of the final aviation fuel components. Accordingly, there is a continuing need to use renewable feedstocks containing C18 and heavier fatty acids in the production of renewable aviation fuels without incurring an undue loss in yield. SUMMARY OF THE INVENTION

[0006] This application relates to the invention defined in the appended independent claims and to its embodiments disclosed hereinafter. The appended claims define the invention. Any examples and technical descriptions of devices, products, and / or methods not covered by the claims in the specification and / or drawings are presented not as embodiments of the invention but as background art or examples for understanding the invention.

[0007] In view of the above, an object of the present invention is to provide a method for producing renewable aviation fuel components from renewable raw materials. An object is to improve the carbon and hydrogen efficiency of renewable aviation fuel components and to be able to increase the yield of aviation fuel components in the method for producing the aviation fuel components. Another object is to increase the utilization rate of carboxylic acids of renewable raw materials having 18 or more carbon atoms in the production of aviation fuel components. Another object is to minimize the hydrogen consumption in the method for producing renewable aviation fuel components. Another object is to minimize the production of C1-C7 hydrocarbons (hydrocarbon) that are not suitable for aviation fuel components. However, in practice, this means that the content of C1-C4 hydrocarbons is reduced the most due to the trailing of the lower and / or upper ends of the fractionation cut point. Another object of the present invention is to provide a method for producing other hydrocarbon fractions from renewable resources.

[0008] According to a first exemplary aspect, there is provided a method for producing renewable aviation fuel components, the method comprising:

[0009] i) providing a renewable raw material comprising free carboxylic acid (FCA), carboxylic acid ester, triglyceride, or a combination thereof;

[0010] ii) in the presence of a DCO catalyst, subjecting the raw material to a decarboxylation and / or decarbonylation (DCO) reaction in a DCO zone for removing one carbon from the carbon chain of the carboxylic acid moiety of the renewable raw material, wherein the DCO zone:

[0011] - the DCO deoxygenation selectivity is at least 75 wt-% of the total weight of the deoxygenated hydrocarbons, and

[0012] - the deoxygenation conversion rate is at least 50 wt-% of the total weight of the raw material,

[0013] thereby obtaining a DCO effluent;

[0014] iii) in the presence of hydrogen and a hydrotreating catalyst, subjecting at least a portion of the DCO effluent from step ii) to a hydrotreating (HT) reaction in an HT zone to obtain a hydrotreated effluent;

[0015] iv) subjecting the hydrotreated effluent from step iii) to gas-liquid separation to obtain a degassed hydrotreated effluent;

[0016] v) subjecting at least a portion of the degassed hydrotreated effluent from step iv) to hydroisomerization (H-ISO), thereby obtaining a hydroisomerized effluent; and

[0017] vi) subjecting at least a portion of the hydroisomerized effluent from step v) to fractionation and recovering at least renewable aviation fuel components.

[0018] According to a second exemplary aspect, there is provided a use of a renewable aviation fuel component obtainable from the method of the first aspect as a renewable aviation fuel blend component in an aviation fuel blend, wherein the aviation fuel blend further comprises a fossil aviation fuel blend component.

[0019] The different non-limiting exemplary aspects and embodiments have been described above. The embodiments in the foregoing are only used to explain the selected aspects or steps that can be used in different implementations. Some embodiments may be presented by referring only to certain exemplary aspects. It should be understood that the corresponding embodiments may also be applicable to other exemplary aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Some exemplary embodiments are described with reference to the accompanying drawings, in which:

[0021] Figure 1 Schematically shows a method for producing a renewable aviation fuel component according to a first exemplary embodiment of the present invention;

[0022] Figure 2 Schematically shows a method for producing a renewable aviation fuel component according to a second exemplary embodiment of the present invention;

[0023] Figure 3 Schematically shows a method for producing a renewable aviation fuel component according to a third exemplary embodiment of the present invention;

[0024] Figure 4 Schematically shows a method for producing a renewable aviation fuel component according to a fourth exemplary embodiment of the present invention;

[0025] Figure 5 Schematically shows a method for producing a renewable aviation fuel component according to a fifth exemplary embodiment of the present invention; and

[0026] Figure 6 Schematically shows a method for producing a renewable aviation fuel component according to a sixth exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0027] DEFINITIONS

[0028] The present invention relates to a method for producing a renewable aviation fuel component. The present disclosure relates to a method comprising subjecting a renewable feedstock to a decarboxylation and / or decarbonylation (DCO) reaction to remove one carbon from the carbon chain of the carboxylic acid of the renewable feedstock. As used herein, the term "decarboxylation / decarbonylation" refers to the removal of CO 2(Decarboxylation) or removal of a carbon atom and the covalently bound carboxyl oxygen from a carboxyl group by CO (decarbonylation). Decarboxylation / decarbonylation can occur completely unaffected by molecular hydrogen. Decarboxylation and decarbonylation reactions together or individually are referred to as decarbonization reactions (decarb-reaction, DCO). A liquid product mainly containing normal alkanes with an odd or uneven number of carbon atoms can be recovered from the DCO reaction.

[0029] In the following description, the same reference numerals denote the same elements or steps.

[0030] Unless otherwise specified, all standards cited herein are the latest revised versions available as of the filing date.

[0031] As used in the context of the present disclosure, the performance of the renewable aviation fuel component complies with the specifications set forth in Appendix A2 of ASTM D7566-22. In one embodiment, the renewable aviation fuel component obtained from the method comprises C8-C17 alkanes.

[0032] Unless otherwise specified, for distillation characteristics and boiling range, reference is made to EN ISO 3405:2019. For boiling point distribution, reference can also be made to gas chromatography-based methods such as ASTM D2887-19e1. The fatty acid distribution of the feed can be determined according to ISO 12966-4:2015 or measured using known analytical methods based on, for example, GC-FID or GC-AED.

[0033] As used herein, the term "feed" or "feedstock" refers to any raw material supplied to a specific reaction. As used herein, the term "renewable" refers to compounds or compositions that can be obtained from, derived from, or sourced from plants and / or animals, including compounds or compositions that can be obtained from, derived from, or sourced from fungi and / or algae, in whole or in part. As used herein, renewable compounds or compositions can include genetically engineered compounds or compositions. Renewable feeds, components, compounds, or compositions can also be referred to as biocompounds or compositions, or as biogenic (biologically originated) compounds or compositions.

[0034] Renewable organic compounds can be chemically distinguished from compounds of fossil origin (including hydrocarbons) by suitable methods for analyzing the carbon content of renewable resources, such as DIN51637 (2014), ASTM D6866 (2020), and EN 16640 (2017). The methods are based on the fact that, compared to carbon atoms of fossil origin, renewable or biologically sourced carbon atoms contain a greater number of unstable radiocarbon ( 14 C) atoms. Therefore, by analyzing 12 C and 14The ratio of C isotopes can distinguish carbon compounds derived from renewable sources or biological sources or raw materials from carbon compounds derived from fossil sources or raw materials. Thus, the specific ratio of said isotopes can be used as a "tag" to identify renewable carbon compounds and distinguish them from non-renewable carbon compounds. The isotope ratio does not change during a chemical reaction. Thus, the isotope ratio can be used to identify renewable compounds, components, and compositions and distinguish them from non-renewable fossil materials in reactor feeds, reactor effluents, separated product fractions, and their various blends.

[0035] Numerically, the biogenic carbon content can be expressed as the amount of biogenic carbon in the material as a weight percentage of the total carbon (TC) in the material (in accordance with ASTM D6866 (2020) or EN 16640 (2017)). In this context, the term renewable preferably refers to a material having a biogenic carbon content of greater than 95 wt-% and even more preferably about 100 wt-% based on the total weight of carbon in the material (EN 16640 (2017)).

[0036] As used herein, the term "hydrocarbons" refers to compounds containing carbon and hydrogen, particularly alkanes, normal alkanes, isoparaffins, mono-branched isoparaffins, multi-branched isoparaffins, olefins, cycloalkanes, and aromatic hydrocarbons. Oxygenated hydrocarbons are specifically referred to herein as hydrocarbons containing covalently bonded oxygen.

[0037] As used herein, alkanes refer to non-cycloalkanes, i.e., non-cyclic open-chain saturated hydrocarbons that are straight-chain (normal paraffins) or branched-chain (isoparaffins). In other words, alkanes herein are normal paraffins and / or isoparaffins. In the context of the present disclosure, isoparaffins refer to branched-chain open-chain alkanes, i.e., non-cyclic open-chain saturated hydrocarbons having one or more alkyl side chains. An isoparaffin having one alkyl side chain or branch is referred to herein as a mono-branched isoparaffin, while an isoparaffin having two or more alkyl side chains or branches is referred to herein as a multi-branched isoparaffin.

[0038] In the context of the present disclosure, CX+ carboxylic acids, CX+ fatty acids, CX+ hydrocarbons, CX+ alkanes, or CX+ isoparaffins refer to carboxylic acids, fatty acids, hydrocarbons, alkanes, or isoparaffins having at least X carbon atoms, where X is any viable integer.

[0039] As used herein, the term "free carboxylic acid (FCA)" refers to an organic acid containing a carboxyl group (-COOH) attached to an R-alkyl group having one or more carbons. As used herein, the term "carboxylic acid ester" refers to a carboxylic acid derivative in which the hydrogen atom of the hydroxyl group has been replaced by an alkyl group R', and the carboxylic acid ester has the structure R-COO-R', where R' is an alkyl chain containing one or more carbons. As used herein, the term "triglyceride" refers to an ester derived from glycerol and three fatty acids.

[0040] In the context of the present disclosure, weight-% abbreviated as wt-%, refers to the indicated weight of the liquid stream or effluent under discussion obtained by gas-liquid separation relative to the (total) weight of the feed, stream, effluent, product, component, or sample under discussion. Any known method can be used for analysis. An example of an available method includes the PIONA method (a method for determining normal paraffins, isoparaffins, olefins, naphthenes, and aromatics), which is a GCxGC analysis method, such as described for GCxGC by Pyl et al. in Journal of Chromatography A, 1218 (2011) 3217-3223. For example, the weight percentages of fatty acids, fatty acid methyl esters, and trans-fatty acid isomers in liquid animal and / or vegetable fats and oils can be analyzed according to ISO 12966-1:2014.

[0041] As used herein, the term "hydrotreating (HT)" or "hydroprocessing" refers to a catalytic method for treating organic materials with molecular hydrogen. In the context of the present disclosure, hydrotreating can at least include removing oxygen from organic oxygenates in the form of water, i.e., hydrodeoxygenation (HDO); removing sulfur from organic sulfur compounds in the form of hydrogen sulfide (H 2 S), i.e., hydrodesulfurization (HDS); removing nitrogen from organic nitrogen compounds in the form of ammonia (NH 3 ), i.e., hydrodenitrogenation (HDN); removing halogens, e.g., removing chlorine from organic chloride compounds in the form of hydrochloric acid (HCl), i.e., hydrodechlorination (HDCl); removing metals by demetallization; removing phosphorus by dephosphorization; hydroisomerization (H-ISO) of the feed; hydrodearomatization of the feed; and / or hydrogenation of olefin bonds (if olefin bonds are present in the feed).

[0042] As used herein, the term "hydrodeoxygenation (HDO)" refers to the use of hydrogen to remove covalently bound oxygen from the carboxylic acids of a feedstock in the form of water. A liquid product mainly containing normal paraffins with an even number of carbon atoms is recovered from the HDO reaction.

[0043] As used herein, the term "hydroisomerization" or "H-ISO" refers to an isomerization process in the presence of hydrogen, in which the properties of a feedstock are improved by converting normal / straight-chain hydrocarbons into branched-chain hydrocarbons having the same number of carbon atoms.

[0044] As used herein, the term "hydrocracking" refers to the catalytic decomposition of organic hydrocarbon materials using molecular hydrogen under high pressure. In hydrocracking, the feedstock is catalytically converted into compounds of lower molecular weight (i.e., lower Mw than the compounds of the initial feedstock). The cracking to lower molecular weight compounds is relatively non-selective, and thus carbon chains of various chain lengths can be obtained through hydrocracking reactions.

[0045] As used herein, the term "deoxygenation conversion" refers to the weight percentage of the feedstock under discussion that has undergone removal of oxygen from the total weight of the initial feedstock. For example, for C18 carboxylic acid, a deoxygenation conversion of 85 wt-% indicates that 85 wt-% of the C18 carboxylic acid in the feedstock has undergone deoxygenation. The term "deoxygenation conversion" does not specify by what reaction the oxygen is removed. Thus, in the context of the DCO reaction, such as step ii) of the present method, the deoxygenation conversion can theoretically occur through DCO and / or HDO reactions. On the other hand, the DCO selectivity is calculated from the deoxygenated products and thus quantifies the amount of the desired DCO reaction that has occurred, excluding the unreacted feed (i.e., the non-deoxygenated feed) from the calculation compared to other deoxygenation reactions.

[0046] As used herein, in the context of the DCO reaction, the term "selectivity" or "DCO deoxygenation selectivity" refers to the weight percentage of the deoxygenated products that have undergone deoxygenation through the DCO reaction out of the total amount of the deoxygenated products. In practice, this means that the remaining weight percentage of the deoxygenated products / hydrocarbons has undergone deoxygenation through the HDO reaction. For example, the specific DCO selectivity weight percentage for C18 carboxylic acid can be calculated from the weight percentages of the C17 and C18 hydrocarbon components (i.e., HC17 and HC18) in the deoxygenated products using the formula HC17 / (HC17 + HC18)*100, thus representing the weight percentage portion of the C18 carboxylic acid that has undergone the DCO reaction and been converted into C17 hydrocarbons. The total DCO selectivity for both C18 and C16 carboxylic acids can be calculated from the weight percentages of the C15 - C18 hydrocarbon components in the deoxygenated products using the formula (HC15 + HC17) / (HC15 + HC16 + HC17 + HC18)*100.

[0047] The yield of components (such as aviation fuel intermediate components) that can be recovered from the DCO reaction in step ii) of the current method can be calculated by multiplying the conversion rate under discussion by the selectivity of the method. The yield of aviation fuel intermediate components from the DCO reaction provides the potential for the yield of aviation fuel components. The isomerized C17 alkanes boil within the aviation fuel boiling range of 100 - 300 °C (about C8 - C17 fraction), while the C18 alkanes boil at 317 °C and should not be used as aviation fuel components.

[0048] As used herein, "degassed" refers to an effluent that has undergone gas - liquid separation, in which at least substances that are gaseous at NTP (normal temperature and pressure) have been separated or removed. For example, such degassed effluent includes degassed hydrotreated effluent. Additionally, for the purpose of analysis, any stream, effluent, product, or sample for which any physicochemical or compositional characteristic is analyzed is degassed, actually before any analysis is carried out. In practical language, they are respectively understood as "liquid" streams, effluents, products, or samples. The fraction separated from the degassed effluent, typically C1 - C4, such as propane, can be referred to as the "gas phase" or "gaseous fraction" of the corresponding effluent. Further, in cases where any stream, effluent, product, or sample is characterized by corresponding parameters, the numbers given are relative to the degassed weight or volume.

[0049] As used herein, the term "catalyst deactivation" refers to, at a given point in time, a decrease in the activity of the catalyst (reflected by the amount of unreacted feed in the reactor effluent) and / or a decrease in the selectivity of the catalyst (reflected by the amount of desired reaction product reduced in the reactor effluent) compared to the catalyst activity and / or selectivity at the start of the method of the present disclosure. As used herein, the term catalyst deactivation is not limited to any specific type or mechanism of deactivation, although the catalyst deactivation observed in the method of the present disclosure is generally considered to be attributed to poisoning and fouling phenomena and includes both reversible and irreversible deactivation.

[0050] As used herein, the term "ASA" refers to "amorphous silica - alumina". In one embodiment, the terms "ASA" and "amorphous silica - alumina" are synonymous with each other.

[0051] As used herein, the term "noble metal" refers to a metallic chemical element that can resist corrosion and is typically present in its elemental form, such as Au, Pt, Ru, Rh, Pd, Os, and Ir.

[0052] As used herein, the term "DCO zone" or "HT zone" refers to the DCO / HT reaction space in which the DCO / HT reactions occur respectively. The DCO / HT zone is a region or space defined by process conditions and / or by process equipment, or the DCO / HT zone is a separate reactor dedicated respectively to the DCO / HT reaction. The DCO / HT zone can also be a separate catalyst bed within a reactor dedicated respectively to the DCO / HT reaction, in which other catalyst beds are also placed, or a separate catalyst bed section within a catalyst bed dedicated to the DCO / RT reaction, in which other reactions also occur.

[0053] As used herein, "naphtha (volatile oil)" refers to a hydrocarbon component suitable for a fuel component conforming to gasoline fuel standard specifications, such as the specifications defined in EN 228:2012+A1:2017. Generally, such gasoline fuel components have a boiling point (i.e., having an IBP and an FBP) in the range of about 25°C to about 210°C, such as determined according to EN ISO3405:2019.

[0054] As used herein, "diesel component" refers to a hydrocarbon composition suitable for a fuel composition conforming to diesel fuel standard specifications, such as the specifications defined in EN 590:2022 or EN 15940:2016+A1:2018+AC:2019. Generally, such diesel fuel components have a boiling point (i.e., having an IBP and an FBP) in the range of about 160°C to about 380°C, such as determined according to EN ISO 3405:2019.

[0055] Overall method

[0056] The present disclosure provides a method for producing renewable aviation fuel components.

[0057] In one embodiment, step i) of the method for producing renewable aviation fuel components includes providing a renewable feedstock comprising free carboxylic acids (FCA), carboxylic acid esters, triglycerides, or combinations thereof.

[0058] In this method, renewable feedstocks or biooils and / or fats derived from renewable resources are used, such as oils and fats from plants and / or animals and / or fish and compounds derived therefrom. Typical vegetable oils or animal oils or fats used as feedstocks have structural units comprising free fatty acids (FFA) and / or free carboxylic acids (FCA), and / or carboxylic acid esters (such as triglycerides (triglycerides are carboxylic acid esters of glycerol, such as triesters of glycerol with three fatty acid moieties), diglycerides, and monoglycerides).

[0059] In one embodiment, the renewable raw materials include free carboxylic acids, carboxylic acid esters, triglycerides, free fatty acids, derivatives of said fatty acids (such as fatty acid esters and triglycerides of fatty acids), metal salts of said fatty acids, or combinations thereof.

[0060] In one embodiment, the renewable raw materials contain at least 70 wt-%, preferably at least 80 wt-%, more preferably at least 90 wt-% of free carboxylic acids (FCA), carboxylic acid esters, triglycerides, or combinations thereof, based on the total weight of the renewable raw materials.

[0061] In one embodiment, the renewable raw materials include natural fats or their derivatives. In one embodiment, the renewable raw materials are selected from the group consisting of vegetable fats, vegetable oils, vegetable waxes, animal fats, animal oils, animal waxes, fish fats, fish oils, fish waxes, animal and / or fish and / or plant waste and residual materials such as waste cooking oil, or any combination thereof.

[0062] The raw materials may include, but are not limited to, vegetable oils, vegetable oils, microbial oils such as babassu oil, palm oil, carinata oil, olive oil, coconut fat, soybean oil, canola oil, coconut oil, illipe butter, rapeseed oil, peanut oil, sesame oil, corn oil, sunflower oil, poppy seed oil, cottonseed oil, soybean oil, laurel oil, crude tall oil, tall oil, tall oil fatty acids, tall oil pitch, crude palm oil, palm oil, palm oil fatty acid distillate, jatropha oil, palm kernel oil, camelina oil, archaebacterial oil, bacterial oil, fungal oil, protozoal oil, algae-based oil, illipe butter, seaweed oil, mustard seed oil, oil from halophiles, lauric-myristic groups (C12-C14) including milk fat, palmitic groups (C16) including land animal fats, stearic groups (C18) including land animal fats, linoleic groups (unsaturated C18) including whale oil and fish oil, erucic acid groups (monounsaturated carboxylic acid, C22:1) including whale oil and fish oil, oleo stearic acid groups (conjugated unsaturated C18) including whale oil and fish oil, fats with substituted fatty acids (ricinoleic acid, C18) such as castor oil, or mixtures of any two or more thereof.

[0063] In one embodiment, the renewable raw materials are selected from the suitable raw materials listed in Appendix IX, Part A or Appendix IX, Part B of the Renewable Energy Directive (EU) 2018 / 2001, preferably waste and residues, and mixtures thereof.

[0064] Exemplary renewable feedstocks preferably include waste and residual materials derived from animal fats / oils, vegetable fats / oils, and / or fish fats / oils. These can include sludge palm oil such as palm effluent sludge (PES) or palm oil mill effluent (POME), used cooking oil (UCO), acid oil (ASK), brown grease (BG), sludge palm oil, spent bleaching earth oil (SBEO), technical corn oil (TCO), or lignocellulosic-based oil, municipal solid waste-based oil, and / or algae-based oil. Most preferably, the feedstock includes UCO, sludge palm oil, TCO, and / or algae-based oil.

[0065] The carboxylic acids present in natural triglycerides are almost entirely fatty acids with an even number of carbon atoms. Thus, renewable feedstocks generally contain C8-C24 carboxylic acids, mainly C16-C22 carboxylic acids, more commonly C16-C18 carboxylic acids, and most commonly C18 carboxylic acid.

[0066] Renewable feedstocks can contain compounds with carbon-carbon double bonds and can thus be saturated, unsaturated, or polyunsaturated. In one embodiment, at least 40 wt-%, at least 50 wt-%, at least 60 wt-%, or at least 80 wt-% of the free carboxylic acids, carboxylic acid esters, and triglycerides of the renewable feedstock are unsaturated.

[0067] In one embodiment, the aviation fuel component according to the present disclosure includes C8-C17 hydrocarbons. C18 hydrocarbons do not truly meet the required boiling range set for aviation fuels according to Appendix A2 of ASTM D7566-2022, and thus, depending on their desired properties, the aviation fuel component may contain only a very limited amount of C18 hydrocarbons. Nevertheless, the aviation fuel component meets the requirements of Appendix A2 of ASTM D7566-2022 in terms of performance. Decarboxylation / decarbonylation (DCO) is a selective reaction that can reduce the carbon number of a carboxylic acid by one, such as from C18 to C17, and thus the DCO reaction enables the use of C18 carboxylic acids in the aviation fuel component.

[0068] In one embodiment, the renewable feedstock includes free carboxylic acids, carboxylic acid esters, and triglycerides with a carbon number of C18 or more. In one embodiment, the renewable feedstock contains at least 40 wt-%, preferably at least 50 wt-%, more preferably at least 60 wt-%, further preferably at least 70 wt-%, even more preferably at least 80 wt-%, and most preferably at least 90 wt-% of FCA and carboxylic acid esters having a carbon number of at least C18 based on the total weight of the renewable feedstock.

[0069] In one embodiment, at least 40 wt-%, preferably at least 50 wt-%, more preferably at least 70 wt-%, and even more preferably at least 80 wt-% of the carbon of the renewable feedstock is contained in C18 FCA and carboxylic acid esters.

[0070] In one embodiment, the renewable feedstock is of plant or animal origin, or a combination thereof.

[0071] In one embodiment, step ii) of the method for producing a renewable aviation fuel component comprises subjecting the feedstock to a decarboxylation and / or decarbonylation (DCO) reaction in a DCO zone in the presence of a DCO catalyst to remove one carbon from the carbon chain of the carboxylic acid moiety of the renewable feedstock, thereby obtaining a DCO effluent 21.

[0072] Figure 1 An exemplary embodiment of the method sequence is schematically presented, which presents the current method for producing a renewable aviation fuel component. In Figure 1 the method, the renewable feedstock 10 undergoes a DCO reaction 20 in step ii), the DCO effluent 21 obtained therefrom undergoes a hydrotreating (HT) reaction 30 in step iii), the hydrotreated effluent 31 obtained therefrom undergoes a gas-liquid separation 40 in step iv), the degassed hydrotreated effluent 41 obtained therefrom undergoes a hydroisomerization (H-ISO) 50 in step v), the degassed hydroisomerized effluent 51 obtained therefrom undergoes a fractionation 60 in step vi), and at least a renewable aviation fuel component is recovered therefrom.

[0073] The DCO reaction 20 of step ii) is carried out in the liquid phase. Thus, free carboxylic acids (FCA) and carboxylic acid esters having 18 carbon atoms in the renewable feedstock can be converted into C17 hydrocarbons by the DCO reaction 20 without further reducing the carbon number of the C17 hydrocarbons, such as by a less controllable cracking reaction, thereby losing yield. Therefore, compared with a method of converting C18 hydrocarbons into C17 hydrocarbons or smaller hydrocarbons by hydrocracking, the current method is beneficial because the current method produces a surprisingly low yield loss and a low hydrogen consumption. Therefore, the current method is also beneficial because it produces a renewable aviation fuel component without an additional hydrocracking step and without exposing the entire reaction effluent to hydrocracking, thereby enabling a higher yield of the renewable aviation fuel component to be obtained.

[0074] In one embodiment, the renewable feedstock 10 undergoing the DCO reaction 20 in step ii) contains less than 50 wt-ppm, preferably less than 10 wt-ppm, more preferably less than 5 wt-ppm of sulfur. In one embodiment, where the renewable feedstock is at least partially of animal origin, the feedstock 10 undergoing the DCO reaction 20 in step ii) may contain more than 5 wt-ppm or more than 50 wt-ppm of sulfur. In such embodiments, catalyst deactivation can be avoided by catalyst selection, for example, by selecting a non-noble metal catalyst.

[0075] In one embodiment, the renewable feedstock 10 for the DCO reaction 20 in step ii) contains less than 50 wt-ppm, preferably less than 10 wt-ppm, more preferably less than 5 wt-ppm of nitrogen. In one embodiment, where the renewable feedstock is at least partially of animal origin, the feedstock 10 for the DCO reaction 20 in step ii) may contain more than 5 wt-ppm or more than 50 wt-ppm of nitrogen. In such embodiments, catalyst deactivation can be avoided by catalyst selection, for example by selecting a non-noble metal catalyst.

[0076] In one embodiment, the renewable feedstock 10 entering the DCO reaction 20 in step ii) contains 8 - 12 wt-% oxygen based on the total weight of the renewable feedstock.

[0077] In one embodiment, the feedstock undergoes a decarboxylation and / or decarbonylation (DCO) reaction 20 in the DCO zone, where the DCO deoxygenation selectivity is at least 75 wt-% of the total weight of the deoxygenated hydrocarbons and the deoxygenation conversion rate is at least 50 wt-% of the total weight of the feedstock.

[0078] In one embodiment, the feedstock is supplied to the DCO zone to prevent backflow of the feedstock stream. In one embodiment, the process conditions in the DCO zone, such as the H 2 flow rate and weight hourly space velocity (WHSV), can be adjusted independently of the process conditions in any other catalyst bed within the same reactor.

[0079] The deoxygenation conversion rate of the feedstock is an adjustable process parameter that can be adjusted by modifying one or more of the operating conditions selected from the following of the method steps discussed: temperature, pressure, WHSV, or a combination thereof. For example, the deoxygenation conversion rate of the feedstock can be increased by increasing the temperature or decreasing the WHSV and reducing the diluent recycle (increasing the residence time) entering the method step. For example, the WHSV of the process can be increased by increasing the flow rate of the feed or reducing the amount of catalyst. An increase in WHSV increases the ratio of the DCO / HDO reaction.

[0080] In one embodiment, the DCO deoxygenation selectivity in step ii) is at least 80 wt-%, preferably at least 85 wt-%, more preferably at least 90 wt-%, even more preferably at least 95 wt-%, and most preferably at least 97 wt-% of the total weight of the deoxygenated hydrocarbons. In one embodiment, the DCO reaction in step ii) includes a DCO deoxygenation selectivity of at least 90 wt-%, at least 91 wt-%, at least 92 wt-%, at least 93 wt-%, at least 94 wt-%, at least 95 wt-%, at least 96 wt-%, at least 97 wt-%, at least 98 wt-%, at least 99 wt-% or 100 wt-% of the total weight of the deoxygenated hydrocarbons in the DCO effluent 21.

[0081] In one embodiment, the renewable feedstock mainly comprises C16 and C18 carboxylic acids. Thus, the DCO deoxygenation selectivity in step ii) actually refers to the selectivity for C18 and C16 carboxylic acids. In one embodiment, the DCO deoxygenation selectivity for C18 and C16 carboxylic acids is at least 75 wt-%, preferably at least 80 wt-% of the total weight of the deoxygenated hydrocarbons and / or deoxygenated C18 and C16 hydrocarbons. In one embodiment, the DCO deoxygenation selectivity for C18 and C16 carboxylic acids in step ii) is at least 85 wt-%, preferably at least 90 wt-%, more preferably at least 95 wt-%, and most preferably at least 97 wt-% of the total weight of the deoxygenated hydrocarbons.

[0082] In one embodiment, the deoxygenation conversion rate in step ii) is at least 55 wt-%, preferably at least 60 wt-%, more preferably at least 70 wt-%, more preferably at least 80 wt-%, at least 90 wt-%, at least 95%, or at least 99 wt-% of the total weight of the feedstock.

[0083] In one embodiment, the DCO reaction 20 in step ii) includes a deoxygenation conversion rate of at least 55 wt-%, at least 60 wt-%, at least 65 wt-%, at least 70 wt-%, at least 75 wt-%, at least 80 wt-%, at least 85 wt-%, at least 90 wt-%, or at least 95 wt-%, or at least 99 wt-% of the total weight of the feed.

[0084] In one embodiment, the DCO reaction 20 in step ii) includes a deoxygenation conversion rate of C18 and C16 carboxylic acids of at least 50 wt-% of the total weight of the feed. In one embodiment, the deoxygenation conversion rate of C18 and C16 carboxylic acids is at least 55 wt-%, at least 60 wt-%, at least 70 wt-%, at least 80 wt-%, at least 90 wt-%, at least 95%, or at least 99 wt-% of the total weight of the feed.

[0085] The deoxygenation conversion rate can be adjusted by, for example, changing the processing temperature and / or the feed inlet flow rate.

[0086] However, in one embodiment, it is preferred not to adjust the deoxygenation conversion of the DCO reaction in step ii) to 100 wt-% of the total weight of the feedstock, as this would impair the DCO deoxygenation selectivity of the process. In some embodiments, the deoxygenation conversion of the DCO reaction in step ii) is still adjusted to up to 99.5 wt-% of the total weight of the feed.

[0087] In one embodiment, at least 50 wt-%, preferably at least 70 wt-%, more preferably at least 85 wt-%, even more preferably at least 95 wt-% of the total weight of the free carboxylic acids, carboxylic acid esters, triglycerides, or combinations thereof contained in the renewable feedstock 10 is deoxygenated in the DCO reaction 20 of step ii).

[0088] In one embodiment, before directing the DCO effluent to step iii), the DCO effluent from step ii) is at least partially subjected to at least the separation of CO and / or CO 2 gases. In one embodiment, the DCO effluent 21 from step ii) is directed to at least the separation 25 of CO and / or CO 2 gases, where most of the carbon oxides present in the DCO effluent are removed, thereby obtaining a carbon-oxide-deprived DCO effluent 22( Figure 2 ). In another embodiment, CO and / or CO 2 gases are completely removed from the DCO effluent, thereby obtaining a carbon-oxide-depleted DCO effluent 22. In one embodiment, subjecting the DCO effluent to gas-liquid separation 25 includes removing the gaseous CO 2 and CO. In one embodiment, the DCO effluent 21 from step ii) is degassed 25 of all gaseous components, thereby obtaining a degassed DCO effluent 22. In the context of the present application, the term DCO effluent may refer to a DCO effluent from which carbon oxides have or have not been separated. In a preferred embodiment, carbon oxides are separated from the DCO effluent.

[0089] In one embodiment, the DCO effluent 22 from which carbon oxides are separated (e.g., Figure 2 ) contains at least 85 wt-%, preferably at least 90 wt-% of hydrocarbons with non-even carbon numbers, based on the total weight of the DCO effluent 22, provided that the DCO deoxygenation selectivity and deoxygenation conversion are set to 100 wt-%.

[0090] Before the hydrotreating (HT) in the continuous step iii), at least CO and / or CO are separated from the DCO effluent 2The gas is beneficial as it prevents / minimizes the occurrence of methanation reactions during the hydrotreating reaction 30 of the DCO effluent in step iii). Reverse water-gas shift reaction (rWGS) and / or the Boudouard reaction The occurrence of methanation reactions and rWGS is harmful as they increase the hydrogen consumption required for the reaction. The occurrence of the Boudouard reaction in the DCO effluent is harmful as it may increase coking of the HT / HDO catalyst.

[0091] In another embodiment, the DCO effluent 21 from step ii) does not undergo CO / CO 2 separation of the gas before step iii).

[0092] In one embodiment, carbon oxides are separated from the DCO effluent 21 by flash distillation or stripping, preferably by reducing the pressure in the DCO effluent (i.e., by flash distillation) to separate the carbon oxides. In one embodiment, by reducing the pressure of the effluent by 0.2 - 1 MPa after leaving the DCO reaction zone, CO and / or CO 2 gas is separated from the DCO effluent 21.

[0093] In one embodiment, carbon oxides containing CO and / or CO 2 gas are separated from the DCO effluent 21, and a gas stream containing inert gases such as steam, methane, nitrogen, or a combination thereof can be used to remove the gaseous products. In such embodiments, the gas stream containing inert gases can be combined with the DCO effluent 21, or it can be directed to the DCO catalyst bed, or it can also be directed to other parts of the reactor. In one embodiment, the resulting gas stream containing the stripped CO and / or CO 2 gas is fed to an amine wash and then released to the atmosphere or burned.

[0094] The separation of carbon oxides and other gases can be carried out between reactors, between zones, or between catalyst beds within the same reactor system. The separation of carbon oxides and other gases can also be carried out at the bottom of the reactor, even if the reactor includes other catalyst beds in addition to the DCO catalyst bed.

[0095] In a preferred embodiment, the gas concentration in the DCO effluent 21 is reduced by degassing. In one embodiment, at least part of the DCO effluent 21 is stripped of all gaseous elements, except for carbon oxides, and also includes the excess gaseous hydrogen required in the subsequent steps of the process. However, the amount of hydrogen in the DCO effluent 21 is small because the amount of hydrogen added to the DCO reaction 20 is typically low. In some embodiments, some of the post-condensed gaseous components removed from the DCO effluent can be returned to the DCO effluent during the hydrotreating (HT) in step iii).

[0096] In one embodiment, the total oxygen content of the carbon-oxide-lean DCO effluent 22 is less than 5 wt-%, preferably less than 3 wt-%, more preferably less than 2 wt-% of the total weight of the carbon-oxide-lean DCO effluent 22.

[0097] For example, the weight percentage of decarboxylated / decarbonylated hydrocarbons in the DCO effluent can be calculated as the sum of the weight percentages of odd-carbon-number hydrocarbons. In one embodiment, at least 55 wt-%, preferably at least 70 wt-%, more preferably at least 80 wt-%, more preferably at least 85 wt-%, even more preferably at least 90 wt-%, most preferably at least 95 wt-% or at least 99 wt-% of the free carboxylic acids (FCA), carboxylic acid esters, and triglycerides contained in the renewable feedstock are deoxygenated by the DCO reaction 20 in step ii).

[0098] In one embodiment, in the DCO reaction 20 of step ii), at least 55 wt-%, preferably at least 70 wt-%, more preferably at least 80 wt-%, even more preferably at least 90 wt-%, most preferably at least 95 wt-% or at least 99 wt-% of the FCA and carboxylic acid esters constituting the renewable feedstock are converted into odd-carbon-number hydrocarbons. For example, natural vegetable oils mainly contain even-carbon-number carboxylic acids.

[0099] In one embodiment, the DCO catalyst for the DCO reaction 20 of step ii) is a heterogeneous catalyst comprising at least a metal and a catalyst support. In one embodiment, the DCO catalyst is a heterogeneous catalyst comprising at least one transition metal or a combination of transition metals. In one embodiment, the DCO catalyst comprises at least one metal from Groups 7 to 11 of the Periodic Table of the Elements, or any combination thereof.

[0100] In one embodiment, the metal of the heterogeneous DCO catalyst is an elemental metal or a metal compound, depending on the metal contained in the DCO catalyst. In one embodiment, the DCO reaction 20 of step ii) is carried out in the presence of a metal catalyst, such as an elemental metal catalyst. In one embodiment, the DCO reaction of step ii) is carried out in the presence of an elemental noble metal catalyst. In an alternative embodiment, the DCO reaction of step ii) is carried out in the presence of a metal compound catalyst.

[0101] In one embodiment, the DCO catalyst of step ii) is a heterogeneous catalyst that contains a metal selected from nickel, cobalt, copper, zinc, molybdenum, manganese, ruthenium, rhodium, rhenium, iridium, palladium, platinum, and any combination thereof.

[0102] In one embodiment, the heterogeneous DCO catalyst is a monometallic catalyst. In one embodiment, the heterogeneous DCO catalyst is a bimetallic catalyst. In one embodiment, the heterogeneous DCO catalyst is a trimetallic catalyst. In one embodiment, the DCO catalyst is a metal compound.

[0103] In one embodiment, the heterogeneous DCO catalyst contains a noble metal selected from ruthenium, rhodium, platinum, palladium, rhenium, iridium, and any combination thereof. More preferably, the heterogeneous DCO catalyst is a non-sulfided catalyst that contains a noble metal selected from ruthenium, rhodium, platinum, palladium, and any combination thereof. In one embodiment, the heterogeneous DCO catalyst containing at least one noble metal preferably contains platinum and / or palladium.

[0104] In one embodiment, the heterogeneous DCO catalyst contains nickel, platinum, and / or palladium because these catalysts are selective for deoxygenation via the DCO reaction. In one embodiment, the selectivity of the catalyst for the DCO reaction decreases in the following order: Pd > Pt > Ni > Rh > Ir > Ru.

[0105] Renewable feedstocks, such as various vegetable oils, generally do not contain large amounts of sulfur components, except for, for example, tall oil feeds derived from Kraft processing and selected animal fats. Therefore, noble metal catalysts can be used in such feedstocks. In one embodiment, the heterogeneous DCO catalyst is preferably a non-sulfided catalyst. Non-sulfided catalysts are preferred because they do not require sulfiding before or during operation, and thus do not require additional method steps to sulfide the catalyst or add sulfur to the feed to maintain catalyst activity. In addition, the sulfur content of various process streams can be kept low, and H from various process streams 2The efficiency requirements for S separation and recovery are low, so no additional equipment such as amine washing or sulfur units is needed. In particular, compared with sulfided catalysts, non-sulfided catalysts containing noble metals may be active at lower temperatures and show higher selectivity for isomerization reactions, but are sensitive to deactivation caused by H 2 S. The sulfur content of the feed can be determined from the liquid according to ISO 20846-2011 or from the gas fraction according to ASTM-D6667. Non-sulfided noble metal DCO catalysts are beneficial because they can effectively catalyze specific DCO reactions.

[0106] In one embodiment, in the presence of sulfur, the catalyst function containing noble metals such as Pt and / or Pd is impaired. In such embodiments, sulfur acts as a catalyst inhibitor and shortens the catalyst life, requiring more frequent catalyst regeneration or replacement. In one embodiment, the feedstock for the DCO reaction 20 in step ii) contains less than 50 wt-ppm, preferably less than 10 wt-ppm, more preferably less than 5 wt-ppm of sulfur based on the total weight of the feedstock. In one embodiment, any sulfur present in the feedstock in the DCO reaction is not added sulfur, but sulfur initially present in the renewable feedstock 10. In one embodiment, where the renewable feedstock 10 contains more than 50 wt-ppm of sulfur, the sulfur in the feedstock is removed in a pretreatment 80 before the DCO reaction (e.g., Figure 2 ). In one embodiment, the sulfur in the feedstock is removed in a pretreatment 80 before the DCO reaction, where the DCO catalyst contains noble metals such as Pt and / or Pd.

[0107] In one embodiment, the DCO catalyst contains nickel, preferably oxidized Ni. In one embodiment, the DCO catalyst contains cobalt. In one embodiment, the DCO catalyst contains copper. In one embodiment, the DCO catalyst contains zinc. In one embodiment, the DCO catalyst contains molybdenum. In one embodiment, the DCO catalyst contains manganese.

[0108] DCO catalysts containing nickel (Ni) are beneficial because, in the presence of hydrogen, such catalysts effectively hydrogenate the double bonds of fatty acids and catalyze specific DCO reactions. In one embodiment, the nickel-containing catalyst can function in the presence of sulfur. Thus, when the DCO reaction is carried out in the presence of a heterogeneous catalyst containing Ni, the feedstock can contain a higher amount of sulfur without impairing the catalyst function or the conversion rate and / or selectivity of the DCO reaction 20. In one embodiment, the DCO reaction 20 of step ii) is carried out in the presence of a heterogeneous catalyst containing Ni, and the feedstock for carrying out the DCO reaction contains at most 100 wt-ppm, preferably at most 50 wt-ppm, more preferably at most 25 wt-ppm of sulfur based on the total weight of the feedstock. The DCO reaction containing these small amounts of sulfur is beneficial because the low sulfur content of the feedstock helps to improve the hydrogenation of double bonds.

[0109] In one embodiment, where the DCO catalyst contains a noble metal, such as platinum or palladium, it is beneficial to pre-treat the noble metal catalyst with hydrogen, and the catalyst hydrogenation pre-treatment is carried out before the DCO reaction 20 of the renewable feedstock 10 in the DCO zone.

[0110] In one embodiment, the loading amount of the active catalyst metal varies in the range of 0.1 - 20 wt% of the total catalyst weight. When nickel is used as the active catalyst metal, the beneficial loading amount varies in the range of 2 - 55 wt-%, preferably 10 - 30 wt-% of the total catalyst weight. When Pt and / or Pd are used as the active catalyst metal, the beneficial loading amount varies in the range of 0.1 - 0.4 wt-% of the total catalyst weight, preferably 0.2 wt-%.

[0111] In one embodiment, the DCO catalyst further comprises at least one support selected from alumina; silica; zirconia; titania; carbon, such as activated carbon or graphite; molecular sieves; and any combination thereof.

[0112] In a preferred embodiment, the DCO catalyst support is a renewable catalyst support, such as alumina, silica or zeolite. Renewable catalyst supports are beneficial because such supports have a long lifespan. Alumina is beneficial as a catalyst support because it is a stable support and is well tolerated to the carbon oxides present in the DCO reaction. Zeolite is beneficial as a catalyst support because it has a high surface area, high porosity, high adsorption capacity, and is easily separated from the reactants and products.

[0113] In one embodiment, the DCO catalyst is loaded on an oxide and / or mesoporous material.

[0114] In one embodiment, the DCO catalyst support is a carbonaceous support such as activated carbon, carbon fiber, carbon nanotubes attached to a monolithic material, or carbon cloth. In one embodiment, the carbonaceous catalyst support is beneficial because it enhances the adsorption of acidic CO 2 onto the basic sites on the catalyst support surface, thereby suppressing carbon deposition on the catalyst and thus enhancing the catalytic stability.

[0115] In one embodiment, the DCO reaction 20 of step ii) is carried out in the presence of an elemental noble metal catalyst containing at least one noble metal selected from platinum, palladium, ruthenium, and rhodium, and the catalyst is supported on a renewable support, preferably the support is alumina and / or silica.

[0116] In one embodiment, the DCO catalyst is a heterogeneous catalyst comprising a metal selected from Ni, Co, Cu, Zn, Mo, Mn, Ru, Rh, Re, Ir, Pd, Pt, or any combination thereof, and a support selected from alumina, silica, zirconia, titania, carbon (such as activated carbon or graphite), molecular sieves, or any combination thereof.

[0117] In one embodiment, the DCO catalyst metal is impregnated or deposited on the catalyst support and optionally converted into its sulfide.

[0118] The DCO reaction 20 can be carried out in a batch, semi-batch, or continuous reaction mode in a reactor such as a trickle bed reactor, a continuous tubular reactor, or a continuous stirred tank reactor, and it is also possible to separate gaseous CO / CO 2 and any light hydrocarbons having a carbon number of <C4.

[0119] In one embodiment, the DCO reaction of step ii) is carried out in H 2 with a feed ratio of less than 300 nl H 2 / L of the feedstock or with no addition of H 2 at all. The note "nl H 2 / L feedstock" herein refers to the normal liters of hydrogen per liter of the feedstock. In one embodiment, the DCO reaction 20 is carried out in H 2 with a feed ratio of less than 250 nl H 2 / L of the feedstock, less than 200 nl H 2 / L of the feedstock, less than 150 nl H 2 / L of the feedstock, less than 100 nl H 2 / L of the feedstock, less than 50 nl H 2 / L of the feedstock or with no addition of H 2 at all.

[0120] The DCO reaction does not require any added hydrogen, and the absence of hydrogen in the DCO reaction ensures that the feedstock undergoes deoxygenation through the DCO reaction rather than hydrodeoxygenation (HDO). Thus, in one embodiment, no external H 2 is added to the DCO reaction 20 of step ii). In the DCO reaction of step ii), neither side reactions nor the direct reduction of carboxyl groups consume hydrogen.

[0121] In one embodiment, the DCO reaction of step ii) is carried out in the presence of steam, nitrogen, and / or methane (CH 4 ), and preferably the DCO reaction of step ii) is carried out in the presence of methane (CH 4 ). In such embodiments, no external H 2 needs to be added to the DCO reaction of step ii).

[0122] In one embodiment, the DCO reaction 20 is carried out in the presence of a very small amount of hydrogen, i.e., an H 2 feed ratio of 0.01 - 300 nl H 2 / L of feedstock, such as 0.01 - 150 nl H 2 / L of feedstock, such as 0.01 - 100 nl H 2 / L of feedstock, such as 0.01 - 50 nl H 2 / L of feedstock, such as 0.01 - 20 nl H 2 / L of feedstock, or even 0.01 - 10 nl H 2 / L of feedstock.

[0123] The very small amount or absence of H 2 in the DCO step is beneficial because it minimizes the hydrogen consumption throughout the process. In addition, the very small amount or no addition of hydrogen in the DCO reaction inhibits possible methanation reactions, i.e., the conversion of carbon oxides to methane. In one embodiment, only a very small amount of hydrogen is required for the DCO reaction 20 to reduce the DCO catalyst. However, the DCO catalyst can optionally be pretreated with hydrogen before introducing the renewable feedstock into contact with the catalyst. Pretreatment of the DCO catalyst is preferred because it ensures the activity of the catalyst. Thus, hydrogen is not necessarily required for the reduction of the DCO catalyst in the DCO reaction 20.

[0124] However, in some embodiments, it is beneficial to carry out the DCO reaction of step ii) in the presence of a slightly higher amount of H 2 because the hydrogenation of the feedstock 10 allows for the hydrogenation of possible double bonds present in the feedstock, which also releases heat that can be used for the endothermic DCO reaction 20. Thus, in certain embodiments, the DCO reaction 20 of step ii) is carried out in H 2The feed ratio is 50 - 300 nl H 2 / L of raw material, or 50 - 200 nl H 2 / L of raw material or 50 - 150 nl H 2 / L of raw material, which means the amount of H 2 is still very low. However, advantageously, the DCO reaction 20 is carried out in the presence of said very small amount of hydrogen, and the hydrogenation of the double bonds present in the raw material mainly takes place in step iii) the HT reaction 30.

[0125] In one embodiment, wherein the DCO reaction 20 of step ii) is carried out in H 2 The feed ratio is 0.01 - 300 nl H 2 / L of raw material, preferably 0.01 - 150 nl H 2 / L of raw material, the DCO deoxygenation selectivity is at least 75 wt-% of the total weight of the deoxygenated hydrocarbons, preferably at least 80 wt-%, and the deoxygenation conversion rate is at least 50 wt-% of the total weight of the feed, preferably at least 55 wt-%.

[0126] In one embodiment, it is beneficial to carry out the deoxygenation of the renewable raw material 10 by the DCO reaction 20, because the hydrogen consumption in the deoxygenation of the raw material and thus the whole process of producing renewable aviation fuel is reduced. In one embodiment, the deoxygenation of the raw material by the DCO reaction 20 reduces the amount of hydrogen required in any continuous deoxygenation step using hydrogen (such as hydrodeoxygenation (HDO)), because the need for further deoxygenation of the feed after the DCO reaction of step ii) is reduced or eliminated.

[0127] In one embodiment, the DCO reaction 20 of step ii) is carried out under the following conditions: at a temperature of 50 - 450 °C, preferably at a temperature of 200 - 450 °C, more preferably at a temperature of 250 - 400 °C; and / or at a pressure of 0.1 - 10 MPa, preferably at a pressure of 0.1 - 2 MPa. In one embodiment, the DCO reaction 20 of step ii) is carried out at a temperature of 350 - 400 °C and / or at a pressure of 0.1 - 2 MPa or 0.1 - 0.5 MPa.

[0128] In one embodiment, the upper limit of the reaction temperature of the DCO reaction is set low enough, i.e., below 400 °C, so that no undesired decomposition of the raw material occurs. In one embodiment, the reaction temperature of the DCO reaction is high enough and the pressure of the DCO reaction is low enough so that deoxygenation is carried out by the DCO reaction rather than the HDO reaction.

[0129] In one embodiment, the DCO reaction 20 of step ii) is carried out for 0.1 - 15 h -1The weight hourly space velocity (WHSV) is preferably 0.25 - 5 h -1 The DCO reaction 20 of step ii) is carried out at a WHSV of. In one embodiment, the DCO reaction 20 of step ii) includes 0.1 - 15 h -1 The weight hourly space velocity (WHSV), preferably the WHSV is 0.1 - 1 h -1 . In one embodiment, the upper limit of the WHSV of the DCO reaction is set low enough to achieve the desired deoxygenation conversion rate wt-%, and to avoid non-specific side reactions, especially if the DCO reaction temperature is high.

[0130] In one embodiment, the DCO reaction 20 of step ii) is carried out under the following conditions:

[0131] - In the presence of a heterogeneous DCO catalyst comprising a metal selected from nickel, cobalt, copper, zinc, molybdenum, manganese, ruthenium, rhodium, rhenium, iridium, palladium, platinum and any combination thereof, wherein the DCO catalyst comprises at least one support selected from alumina, silica, zirconia, titanium dioxide, carbon such as activated carbon or graphite, molecular sieves, and any combination thereof;

[0132] - In H 2 The feed ratio is less than 300 nl H 2 / L of the raw material or no H 2 is present;

[0133] - At a temperature of 50 - 450 °C, preferably at a temperature of 200 - 450 °C, more preferably at a temperature of 250 - 400 °C;

[0134] - At a pressure of 0.1 - 10 Mpa, preferably at a pressure of 0.1 - 2 MPa;

[0135] - At a weight hourly space velocity (WHSV) of 0.1 - 15 h -1 The weight hourly space velocity (WHSV) is preferably 0.25 - 5 h -1 ;

[0136] Or any combination thereof.

[0137] In one embodiment, step iii) of the method includes subjecting at least a portion of the DCO effluent from step ii) to a hydrotreating (HT) reaction in the HT zone in the presence of hydrogen and a hydrotreating catalyst to obtain a hydrotreated effluent.

[0138] The DCO reaction 20 of step ii) and the HT reaction 30 of step iii) are two separate reactions that occur in their respective reaction zones. Thus, the feed entering the HT reaction zone for the HT reaction 30 is the DCO effluent 21, which has undergone the DCO reaction 20 in the DCO zone.

[0139] In one embodiment, the HT zone is the HT reaction space where the HT reaction 30 takes place. In one embodiment, feed is provided to the HT zone so as to prevent backflow of the feed stream. In one embodiment, the process conditions in the HT zone, such as H 2 flow rate and WHSV can be adjusted independently of the process conditions in any other catalyst bed located within the same reactor.

[0140] In one embodiment, the hydrotreating (HT) reaction of step iii) is selected from hydrodeoxygenation (HDO), double bond hydrogenation, hydrodenitrogenation (HDN), hydrodesulfurization (HDS), and any combination thereof, preferably the hydrotreating reaction of step iii) comprises HDN.

[0141] In one embodiment, the hydrotreating (HT) reaction 30 of step iii) is configured to remove any heteroatoms present in the DCO effluent.

[0142] In one embodiment, the HT reaction 30 of step iii) comprises removing heteroatoms and other impurities by hydrotreating, such impurities being selected from halogens, metals, phosphorus, aromatic hydrocarbons, or any combination thereof. In one embodiment, the removal of said impurities is selected from the group consisting of hydrodehalogenation (HDH), demetallization, dephosphorization, hydrodearomatization (HDA), or any combination thereof. In one embodiment, the HT reaction 30 comprises hydrogenating double bonds in the DCO effluent. In one embodiment, subjecting the DCO effluent to the HT reaction 30 hydrogenates any remaining double bonds and removes impurities, preferably the HT reaction 30 comprises HDN and / or HDS. Embodiments where the HT reaction 30 comprises double bond hydrogenation are beneficial because the presence of olefinic bonds in the feed to H-ISO 50 in step v) can lead to the formation of aromatic hydrocarbons (even polyaromatic hydrocarbons), oligomerization of olefins into high molecular weight compounds (i.e., compounds not included in the boiling range of aviation fuel and / or diesel fuel), and can increase the temperature of H-ISO 50. In one embodiment, the HT reaction 30 of step iii) further comprises hydroisomerization.

[0143] In one embodiment, the HT reaction 30 is advantageously carried out by avoiding hydrocracking (HC) because this would unnecessarily reduce the final yield of aviation fuel components.

[0144] In a preferred embodiment, the HT reaction 30 of step iii) at least comprises HDN because the catalyst used in H-ISO in step v) may be sensitive to the presence of nitrogen, and thus it is most suitable to remove nitrogen from the feed before step v).

[0145] In one embodiment, the HT reaction 30 of step iii) includes HDO. In one embodiment, where the hydrotreating includes HDO, at least a portion of the DCO effluent is subjected to the HT reaction to remove any residual oxygen in the DCO effluent. Embodiments where the HT reaction includes HDO are beneficial because the overall process thus includes separate DCO and HDO reactions, which can be optimized separately by process conditions.

[0146] All reactions that may occur during the hydrotreating of step iii) can be carried out in the same reactor in different catalyst beds, or even simultaneously or successively in the same catalyst bed.

[0147] In one embodiment, the HT reaction 30 of step iii) is carried out in the presence of an HT catalyst comprising at least one Group VIII and / or Group VIB metal of the Periodic Table of the Elements, preferably selected from nickel, molybdenum, tungsten, cobalt, and any combination thereof, preferably selected from NiMo, CoMo, or NiW.

[0148] In one embodiment, the hydrotreating of step iii) includes HDO and / or HDN and / or HDS, and the reaction of step iii) is carried out in the presence of a hydrotreating catalyst comprising Ni, NiMo, CoMo, or NiW.

[0149] In one embodiment, the hydrotreating reaction of step iii) is carried out in the presence of a sulfided hydrotreating catalyst. The sulfided catalyst is beneficial for maintaining the activity of the catalyst.

[0150] In one embodiment, the hydrotreating of step iii) includes HDO and / or HDN and / or HDS, and the reaction of step iii) is carried out in the presence of a sulfided hydrotreating catalyst. The sulfided catalyst is beneficial for catalyzing the deoxygenation reaction.

[0151] In one embodiment, the HT catalyst of step iii) further comprises at least one support selected from zeolite, silica, alumina, amorphous silica alumina (ASA), and any combination thereof.

[0152] In one embodiment, the hydrotreating of step iii) is carried out in the presence of a sulfided hydrogenation catalyst containing at least one supported Ni, NiMo, CoMo, and / or NiW catalyst, with the support being zeolite, silica, alumina, and / or ASA, or a combination thereof. In one embodiment, the hydrogenation catalyst is sulfided NiMo supported on ASA and / or alumina.

[0153] In one embodiment, the hydrotreating in step iii) includes HDN, and the HT reaction 30 in step iii) is preferably carried out in the presence of a hydrotreating catalyst comprising NiMo supported on alumina.

[0154] In one embodiment, less than 50 wt-%, preferably less than 40 wt-%, more preferably less than 30 wt-%, even more preferably less than 20 wt-%, even more preferably less than 15 wt-%, even more preferably less than 10 wt-%, and most preferably less than 5 wt-% of the total weight of the free carboxylic acids, carboxylic acid esters, triglycerides or combinations thereof contained in the initial renewable feedstock 10 are deoxygenated in the HT reaction 30 of step iii).

[0155] Most or all of the oxygen in the renewable feedstock is removed in the DCO reaction 20 of step ii), so HDO in the hydrotreating of step iii) may not be necessary. In some embodiments, where the deoxygenation conversion of the DCO reaction 20 at step ii) is not 100 wt-% of the total weight of the renewable feedstock, but for example 70 wt-%, 80 wt-%, 90 wt-% or 95 wt-%, a low concentration of oxygen remains in the DCO effluent. In such embodiments, when the hydrotreating in step iii) includes HDO, it is beneficial to remove the residual oxygen from the DCO effluent. However, in such embodiments, the amount of hydrogen required for HDO of the DCO effluent is significantly lower compared to the deoxygenation of a renewable feedstock based only on HDO. Therefore, even if the HT reaction 30 in step iii) includes HDO, the process is beneficial because it uses very little hydrogen. Thus, in the present process, it is beneficial for the DCO reaction 20 to be carried out before the HT reaction 30 because the total amount of hydrogen required for both the DCO and HT reactions is minimized. For example, in other processes, where the HT reaction (such as the HDO reaction) is before the DCO reaction, or where the DCO and HDO reactions occur simultaneously, the hydrogen consumption may be much higher when hydrogen is available (for reference, see reaction 5 in Example 2).

[0156] Furthermore, by feeding only a small amount of H to the HT reaction 30 in step iii) 2 and the process conditions allow, the absence of hydrogen will favor deoxygenation by the DCO reaction. In one embodiment, the process conditions that favor the DCO reaction to occur at the HT reaction 30 in step iii) include a pressure below 10 Mpa, a H below 300 nl 2 / L feed of H 2A feed ratio and a temperature of about 350 °C. In one embodiment, during the HT reaction 30 in step iii), at least 30%, preferably at least 40%, more preferably at least 50% of the deoxygenation reaction occurs via the DCO reaction. In one embodiment, about 30% of the deoxygenation in the HT reaction consists of DCO.

[0157] In one embodiment, the HT reaction 30 in step iii) is carried out in H 2 The feed ratio is 50 - 2000 nl H 2 / L of feed, preferably 100 - 1000 nl H 2 / L of feed, more preferably 150 - 500 nl H 2 / L of feed. In one embodiment, the HT reaction 30 in step iii) is carried out in H 2 The feed ratio is at least 200 nl H 2 / L of feed, at least 250 nl H 2 / L of feed, at least 300 nl H 2 / L of feed, at least 350 nl H 2 / L of feed, at least 400 nl H 2 / L of feed, at least 450 nl H 2 / L of feed, or at least 500 nl H 2 / L of feed. The amount of H 2 required at the HT reaction in step iii) mainly depends on the deoxygenation conversion rate wt-% of the DCO reaction 20 at step ii). For example, if the deoxygenation conversion rate wt-% at the DCO reaction is 50 wt-%, then the amount of H 2 required at the HT reaction is relatively higher than the case where the deoxygenation conversion rate wt-% at the DCO reaction is 90 wt-% to completely remove oxygen from the feed. Compared with the HDO reaction, other hydrotreating reactions such as the HDN and HDS reactions do not consume a large amount of H 2 since the concentrations of S and N compounds in the feed are lower compared to the oxygenates in the renewable feedstock. In one embodiment, the HT reaction 30 in step iii) is carried out at a H 2 feed ratio of 300 - 500 nl H 2 / L of feed, preferably 400 - 500 nl H 2 / L of feed.

[0158] To ensure a sufficient amount of H 2 at the HT reaction 30 in step iii), an amount of H 2 3 - 4 times in excess of the theoretical consumption is fed into the reaction. In one embodiment, the HT reaction 30 in step iii) mainly comprises HDN and / or HDS and is carried out at 50 - 500 nl H2 / L feed, preferably 50 - 200 nl H 2 / L feed of H 2 at a feed ratio.

[0159] For the HDO reaction, H 2 feed ratio of at least 250 nl H 2 / L feed is preferred. Thus, in one embodiment, the HT reaction 30 of step iii) comprises at least HDO, and at an H 2 feed ratio of 250 - 2000 nl H 2 / L feed, preferably 300 - 500 nl H 2 / L feed.

[0160] In one embodiment, the HT reaction 30 of step ii) is carried out under the following conditions: its H 2 feed ratio is at least 1.5 times or 2 times higher than the H 2 feed ratio used in the DCO reaction 20 of step ii) of the method. In one embodiment, the DCO reaction of step ii) is carried out at 50 - 150 nl H 2 / L feed of H 2 feed ratio, and the HT reaction of step iii) is carried out at 250 - 500 nl H 2 / L feed of H 2 feed ratio. In one embodiment, where at least 80 wt-% of the oxygen contained in the renewable raw material is removed under the DCO reaction 20 of step ii), the HT reaction 30 of step iii) can be carried out at 250 - 500 nl H 2 / L feed of H 2 feed ratio.

[0161] In one embodiment, the HT reaction 30 of step iii) is carried out at a temperature of 250 - 450 °C, preferably at a temperature of 280 - 350 °C; and / or at a pressure of 0.1 - 20 MPa, preferably at a pressure of 2 - 10 MPa. In one embodiment, the HT reaction of step iii) is carried out at a pressure of 2 - 20 MPa, 4 - 10 MPa, or 4 - 5 MPa.

[0162] In one embodiment, the HT reaction 30 of step iii) is carried out at a weight hourly space velocity (WHSV) of 0.25 - 5 h -1 preferably with a WHSV of 0.5 - 2 h -1 .

[0163] In one embodiment, the HT reaction 30 of step iii) is carried out under the following conditions:

[0164] - In the presence of an HT catalyst, which comprises at least one Group VIII and / or Group VIB metal of the Periodic Table of the Elements, preferably selected from nickel, molybdenum, tungsten, cobalt, and any combination thereof, preferably selected from NiMo, CoMo, and NiW; the HT catalyst further comprises at least one support selected from zeolite, silica, alumina, amorphous silica-alumina (ASA), and any combination thereof;

[0165] - At an H 2 / L feed of 50 - 2000 nl, preferably 100 - 1000 nl H 2 / L feed, more preferably 150 - 500 nl H 2 / L feed of H 2 feed ratio;

[0166] - At a temperature of 250 - 450 °C, preferably a temperature of 280 - 350 °C;

[0167] - At a pressure of 1 - 20 MPa, preferably a pressure of 2 - 10 MPa;

[0168] - At a weight hourly space velocity (WHSV) of 0.25 - 5 h -1 , preferably a WHSV of 0.5 - 2 h -1 ;

[0169] or any combination thereof.

[0170] In one embodiment, 50 - 5000 wt-ppm, preferably 100 - 2000 wt-ppm of sulfur is added to the DCO effluent 21 directed to step iii). In one embodiment, 50 - 5000 wt-ppm, preferably 100 - 2000 wt-ppm of sulfur is added to the carbon-oxide-lean DCO effluent 22, i.e., at least partially removing carbon oxides from the DCO effluent. Adding sulfur to the DCO effluent prior to step iii) is beneficial for the function of the hydrotreating catalyst.

[0171] In one embodiment, the hydrotreating 30 of step iii) is preferably carried out in the presence of a sulfided catalyst. In one embodiment, the hydrotreating catalyst is sulfided on the hydrotreating catalyst bed before step iii) of the hydrotreating and before contacting at least a portion of the DCO effluent from step ii) with the catalyst. In such embodiments, no additional sulfur needs to be added to the hydrotreated DCO effluent.

[0172] Even though the reaction conditions for the DCO and HDO reactions may seem similar, at least the combination of the catalyst used and the suitable DCO or HDO reaction conditions are different from each other, and the DCO reaction 20 meets the required DCO deoxygenation selectivity and conversion criteria.

[0173] In one embodiment, step iv) of the method comprises subjecting the hydrotreated effluent 31 from step iii) to a gas-liquid separation 40 to obtain a degassed hydrotreated effluent 41.

[0174] In one embodiment, the gas-liquid separation 40 of step iv) comprises removing at least gaseous sulfur and nitrogen from the hydrotreated effluent 31. In one embodiment, in step iv), the gaseous sulfur and nitrogen are removed in the form of gaseous H 2 S and NH 3 In one embodiment, the gas-liquid separation 40 of step iv) comprises removing at least CO and / or CO 2 gas. This is especially the case if the DCO effluent 21 from step ii) is not subjected to a separation of CO / CO 2 gas 25 before step iii). In one embodiment, the gas-liquid separation 40 of step iv) further comprises removing other gaseous components selected from steam, hydrogen, methane, and combinations thereof.

[0175] In one embodiment, the degassed hydrotreated effluent 41 contains less than 30 wt-ppm, preferably less than 20 wt-ppm, more preferably less than 10 wt-ppm, even more preferably less than 5 wt-ppm, and most preferably less than 2 wt-ppm of sulfur (ppm by weight, calculated as elemental S) in the total corresponding effluent.

[0176] The very low sulfur content in the degassed hydrotreated effluent 41 entering the hydroisomerization (H-ISO) 50 of step v), such as less than 2 wt-ppm, is beneficial because there is only a very small amount or no H 2 S present in the H-ISO 50. This is especially beneficial in embodiments where the H-ISO of step v) contains a noble metal catalyst because the function of the noble metal catalyst is impaired in the presence of sulfur. Furthermore, due to the presence of less H 2 S, less corrosion of the equipment is expected in the long run, and for certain equipment materials, even less stringent corrosion resistance requirements may be applicable.

[0177] It is important to remove nitrogen (N) from the feed before hydroisomerization 50 because nitrogen is harmful to the isomerization catalyst, and catalyst passivation and / or deactivation will accelerate in the case of increasing nitrogen concentration. Therefore, a very low nitrogen content in the stream of H-ISO 50 entering step v) is beneficial because passivation and / or deactivation of the H-ISO catalyst can be delayed and / or avoided.

[0178] In one embodiment, the degassed hydrotreated effluent 41 from step iv) contains 10 wt-ppm or less, preferably 8 wt-ppm or less, more preferably 5 wt-ppm or less, even more preferably 2 wt-ppm or less, most preferably 1 wt-ppm or less, such as even 0.5 wt-ppm of nitrogen (calculated as elemental N) based on the total weight of the degassed hydrotreated effluent 41.

[0179] In one embodiment, the gas-liquid separation 40 of step iv) is carried out as an integral step inside the reactor in which the HT reaction 30 of step iii) takes place, even if the reactor includes other catalyst beds in addition to the HT catalyst bed. In one embodiment, the gas-liquid separation 40 of step iv) is carried out between reactors.

[0180] In one embodiment, the method includes:

[0181] a. Subjecting at least a portion of the following

[0182] - the DCO effluent 21 from step ii), or

[0183] - the hydrotreated effluent 31 from step iii), or

[0184] - the degassed hydrotreated effluent 41 from step iv), or

[0185] - the hydroisomerization effluent 51 from step v)

[0186] to fractional distillation (FRAC) 70 and at least recovering a first fraction 71 containing hydrocarbons with carbon number > C17 and a second fraction 72 containing hydrocarbons with carbon number ≤ C17;

[0187] b. Directing the hydrocarbons with carbon number > C17 (71) to hydrocracking (HC) 75 in the presence of a hydrocracking catalyst to obtain a hydrocracked effluent 76;

[0188] c. Combining the hydrocracked effluent 76 with the second fraction 72; and

[0189] d. Directing the combined hydrocracked effluent 76 and the second fraction 72 to step iii), iv), v) or vi) respectively.

[0190] Figure 2 An exemplary embodiment is shown, where some possible alternative locations of the fractionation (FRAC) 70 and hydrocracking (HC) 75 steps are included in the current method sequence. In one embodiment, the method includes the FRAC and HC steps 70, 75 after the DCO reaction 20 in step ii) and before the HT reaction 30 in step iii), or after the HT reaction 30 in step iii) and before the gas-liquid separation 40 in step iv), or after the gas-liquid separation 40 in step iv) and before the hydroisomerization (H-ISO) 50 in step v). In one embodiment, the HC reaction 75 is carried out simultaneously with the H-ISO 50 in step v). In an alternative embodiment, the method includes the FRAC and HC steps 70, 75 after the H-ISO 50 in step v). Preferably, the method includes the FRAC and HC steps 70, 75 before the H-ISO 50 in step v).

[0191] In one embodiment, the hydrocracking 75 in step b. is carried out in the presence of a bifunctional hydrocracking catalyst comprising metal sites and acid sites. In one embodiment, the bifunctional hydrocracking catalyst is selected from one or more of platinum, palladium, nickel, molybdenum, cobalt, tungsten, or any combination thereof. In one embodiment, the bifunctional hydrocracking catalyst comprises a noble metal or a Group VIA metal such as molybdenum or tungsten, and a Group VIIIA metal such as cobalt or nickel. In one embodiment, the hydrocracking catalyst is Ni / W, Ni / Mo, Co / Mo, Pt or Pd.

[0192] In one embodiment, the HC 75 in step b. is carried out in the presence of an acidic hydrocracking catalyst support. The acidity of the hydrocracking catalyst support is important for the function of the HC 75 process. In one embodiment, the acidic support is selected from one or more of alumina, amorphous silica-alumina, zeolite and binder. In one embodiment, the acidic support is selected from SiO 2 and Al 2 O 3 in one or more of.

[0193] Some renewable feedstocks can contain a relatively large proportion of carboxylic acids with carbon numbers > C18, such as rapeseed oil, Brassica Carinata, and some fish oils. In such cases, hydrocarbons suitable for aviation fuel components cannot be obtained solely through the DCO reaction. Therefore, by including the FRAC and HC steps 70, 75 in the method after the DCO reaction 20, deoxygenated hydrocarbons with carbon numbers ≥ C18 (i.e., the first fraction 71) can also be used for the aviation fuel fraction, while the lighter second fraction 72 containing deoxygenated ≤ C17 hydrocarbons does not need to be unnecessarily reduced and exposed to hydrocracking ( Figure 3 ).

[0194] In Figure 3 an exemplary embodiment, a more detailed exemplary embodiment is provided, in which the fractionation (FRAC) step 70 is carried out after the gas-liquid separation 40 in step iv). A first fraction 71 containing hydrocarbons with carbon numbers > C17 and a second fraction 72 containing hydrocarbons with carbon numbers ≤ C17 are obtained, but only the first fraction 71 is exposed to the HC step 75 to obtain a hydrocracked effluent 76. The second fraction 72 must not be exposed to hydrocracking, resulting in an unnecessary loss of yield.

[0195] For example, rapeseed oil fatty acids (95% C18FA and 5% C16FA) can be introduced into a pretreatment step 80 in which impurities in the feedstock are removed. The removed impurities can include alkali metals such as sodium, potassium, and / or alkaline earth metals such as magnesium and calcium. The pretreatment step also removes impurities such as sulfur-containing, phosphorus-containing, silicon-containing, and chloride-containing compounds and / or polyethylene waxes. The pretreatment step 80 can include filtration, degumming, heat treatment, solvent extraction, distillation / evaporation, and / or bleaching procedures.

[0196] The pretreated effluent 85, such as purified rapeseed oil fatty acids (FFA and TRIG), can be directed to the DCO reaction 20 in step ii), where oxygen is removed without adding hydrogen or using a minimal amount of hydrogen. The selected DCO catalyst can be, for example, Pd / C, and the DCO reaction 20 is carried out at a temperature of about 350 °C, a pressure of about 5 bar, a weight hourly space velocity (WHSV) of about 0.25 h -1 and a H 2 / L feedstock H 2 feed ratio reaction conditions. Using the catalyst and reaction conditions, the DCO reaction 20 (removing deoxygenation through CO 2 / CO to produce odd-numbered normal alkanes) is superior to hydrodeoxygenation (HDO, consuming hydrogen through H 2O is removed for deoxidation to produce even-numbered n-alkanes). Similarly, in such DCO reactions 20, the deoxygenation conversion rate of fatty acids is about 85 wt-% of the total weight of the pretreated effluent 85, and the deoxygenation selectivity of DCO for C15 and C17 n-alkanes is about 95 wt-% of the total weight of the deoxygenated hydrocarbons. During step ii) DCO reaction 20, it is preferred to avoid a complete deoxygenation conversion rate of the feedstock (i.e., 100 wt-%), because this results in a higher DCO deoxygenation selectivity of the DCO reaction 20 for the DCO product. Most of the double bonds present in the fatty acids of the renewable feedstock can also be hydrogenated at the indicated low H 2 The double bonds are hydrogenated at a feed ratio. The hydrogenation of double bonds is an exothermic reaction that generates heat energy, which can be used in the endothermic DCO reaction 20. In addition, since the endothermic DCO reaction 20 absorbs heat energy, the exothermic hydrogenation reaction of double bonds is still well controlled. The DCO reaction 20 in step ii) not only reduces the hydrogen consumption of the entire process, but also converts C18 fatty acids into hydrocarbons within the boiling range set for aviation fuel components.

[0197] Carbon oxides are removed from the DCO effluent 21 at the gas-liquid separation step 25. After that, the carbon-oxide-lean DCO effluent 22 formed can be introduced into the hydrotreating (HT) reaction 30 in step iii), where all remaining oxygenates can be deoxygenated. The hydrotreating reaction 30 optionally mainly consists of hydrodeoxygenation (HDO) reactions and can be carried out at a pressure of about 40 - 50 bar, a temperature of about 300 - 330 °C, a weight hourly space velocity (WHSV) of about 1 h -1 and a H 2 / L feed H 2 feed ratio. Generally, a certain amount of DCO reaction also occurs during the HT reaction 30. Different from the HT reaction 30 in step iii) which mainly consists of HDO reactions, during the HT reaction 30 in step iii), conditions favorable for the DCO reaction can be selected. This results in an even lower hydrogen consumption of the entire process and an increase in the C17 alkane content of the hydrotreating effluent 31, thereby increasing the potential yield of aviation fuel components. At steps iii) and iv), it is also important to convert and remove nitrogen- and sulfur-containing compounds in the feed to prevent the neutralization / deactivation of hydrocracking catalysts and also potentially H-ISO catalysts, thus achieving efficient catalyst performance.

[0198] As Figure 3As shown, the hydrotreated effluent 31 can then be fractionated at the fractionation (FRAC) step 70. Prior to fractionation, the gas is separated from the hydrotreated effluent 31 using the gas / liquid separation 40 of step iv) to obtain a degassed hydrotreated effluent 41, which can be introduced into a fractionation unit that separates the effluent 41 into at least two fractions, namely a first fraction 71 containing normal paraffins with 18 or more carbon atoms and a second fraction 72 containing normal paraffins with 17 or fewer carbon atoms. Cracking is not required for the second fraction 72 as it already has the boiling range of renewable aviation fuel components. Thus, by not exposing the second fraction 72 to a cracking reaction, the yield loss of aviation fuel components is minimized. The first fraction 71 containing paraffins heavier than C17 (C18 and heavier) can be introduced into hydrocracking (HC) 75, where mild hydrocracking of the heavier paraffin feed is carried out using a bifunctional HC catalyst. The bifunctional HC catalyst contains metals such as Pd, Pt, Ni, W, Mo, and acidic functional groups such as amorphous silica alumina (ASA), zeolites, alumina / chlorinated alumina. The HC reaction of the paraffins 75 can be carried out under mild HC reaction conditions, such as at a pressure of about 35 - 70 bar, a temperature of about 325 - 375 °C, a WHSV of about 0.5 - 3.0 h -1 and a H 2 / L feed H 2 feed ratio. The hydrocracking conversion can be set to about 95 wt-% of the total weight of the feed to be hydrocracked. The hydrocracking selectivity for the aviation fuel boiling range is set to about 75 wt-% of the total weight of the converted hydrocracking effluent. In addition, the converted hydrocracking effluent can contain about 7 wt-% naphtha and about 18 wt-% liquefied petroleum gas (LPG, containing C3 and C4 hydrocarbons) (where about 2 wt-% is light gas such as C1, C2 hydrocarbons) based on the total weight of the converted hydrocracking effluent.

[0199] Before the hydroisomerization (H-ISO) step 50, the hydrocracked effluent 76 is treated by gas-liquid separation 90 to separate the gas from the hydrocracked effluent 76, thereby obtaining a degassed liquid effluent 91 (e.g., Figure 3 ). The degassed liquid effluent 91 can be combined with the lighter second fraction 72 (which bypasses the hydrocracking reaction 75) and introduced together into the hydroisomerization (H-ISO) 50. The hydroisomerization 50 can be carried out at a pressure of about 30 - 50 bar, a temperature of about 320 - 340 °C, a WHSV of about 0.5 - 3.0, and a H 2 / L feed H 2It is carried out at a feed ratio. In the H-ISO 50 reaction, up to 99 wt-% of the normal paraffins present in the liquid effluent 91 are converted to isoparaffins, while cracking to naphtha and LPG fractions may occur in only up to 5 wt-% of the paraffins in the liquid effluent 91. The boiling point of the isomerized C17 paraffin is below 300 °C, while the boiling point of the n-C18 paraffin is 317 °C and that of n-C17 is 302 °C. In addition, the n-C18 paraffin has a higher melting point of 28 °C compared to the n-C17 paraffin (22 °C), indicating that the isomerization of the n-C17 paraffin contained in the degassed liquid effluent 91 is somewhat more prone to isomerization than the n-C18 paraffin.

[0200] In one embodiment, the reaction conditions for HC 75 in step b. are selected from one or more of the following: a temperature of 300 - 450 °C, preferably 350 - 400 °C; a pressure of 5 MPa - 25 MPa, preferably 6 MPa - 15 MPa; a H 2 / L feed, preferably 500 - 850 nl H 2 / L feed of H 2 feed ratio; and a WHSV of 0.25 - 5 h -1 、preferably 0.5 - 2 h -1 .

[0201] In one embodiment, HC 75 in step b. is mild hydrocracking (MHC), resulting in an MHC conversion of the hydrocracked effluent 76 of less than 50 wt-%, preferably less than 30 wt-% of the total weight of the first fraction 71.

[0202] Some C17 hydrocarbons in the aviation fuel component are restricted by the boiling range set by the ASTM D7566-22 standard for aviation fuel components. Therefore, in some embodiments, the carbon number of at least some of the C17 hydrocarbons (including hydrocarbons with a carbon number ≤ C17) contained in the deoxygenated second fraction 72 is further reduced by hydrocracking.

[0203] To make the hydrotreated effluent meet the requirements of the aviation fuel fraction, the freezing point must be adjusted. By isomerizing normal paraffins to isoparaffins, the effluent 41 from step iv) or the effluent 91 from the gas-liquid separation 90 (depending on Figure 3 ) is directed into contact with a material having catalytic activity in hydroisomerization to adjust the freezing point.

[0204] In one embodiment, step v) of the method comprises subjecting at least a portion of the degassed hydrotreated effluent 41 from step iv) to hydroisomerization (H-ISO) 50 to obtain a hydroisomerized effluent 51. In one embodiment, step v) of the method comprises subjecting at least a portion of the degassed hydrotreated effluent 91 to hydroisomerization (H-ISO) 50 to obtain a hydroisomerized effluent 51.

[0205] In one embodiment, H-ISO 50 can be carried out in a conventional hydroisomerization unit. In one embodiment, H-ISO 50 of step v) comprises 100 - 800 nl H 2 / L of feed of H 2 flow, preferably the H 2 flow is 200 - 650 nl H 2 / L of feed. In one embodiment, H-ISO 50 of step v) comprises a WHSV of 0.5 - 3 h -1 and preferably the WHSV is 0.5 - 2 h -1 .

[0206] In one embodiment, in H-ISO 50 of step v), a hydroisomerization catalyst known in the art can be used. In one embodiment, the hydroisomerization (H-ISO) 50 of step v) is carried out in the presence of a hydroisomerization catalyst comprising:

[0207] - at least one metal selected from Group VIII of the Periodic Table, preferably selected from nickel, platinum and palladium, more preferably selected from platinum and palladium; and / or

[0208] - a support, preferably selected from Al 2 O 3 or SiO 2 , and / or

[0209] - a molecular sieve, preferably selected from SAPO-11, SAPO-41, ZSM-22, ZSM-23 and ferrierite.

[0210] Bifunctional hydrocracking catalysts and hydroisomerization catalysts have similarities. In a sense, both contain metal sites that can catalyze the (de)hydrogenation of n-alkanes / i-alkanes to the corresponding n-olefins / i-olefins, and acid sites that can catalyze the protonation of n-olefins / i-olefins to n-carbonium ions / i-carbonium ions, further catalyze the isomerization of n-carbonium ions or i-carbonium ions, and / or catalyze the cracking of n-carbonium ions / i-carbonium ions into lighter n-olefins / i-olefins and lighter n-carbonium ions / i-carbonium ions, and catalyze the deprotonation of n-carbonium ions / i-carbonium ions to n-olefins / i-olefins. And the hydrogenation reactions of various n-olefins / i-olefins are again catalyzed by the metal sites of these bifunctional catalysts to form n-alkanes / i-alkanes. At H-ISO 50 in step v), whether the hydroisomerization or cracking reaction prevails under given operating conditions and a given feed composition is particularly affected by the characteristics of the hydroisomerization catalyst. These characteristics of the catalyst include, for example, the total acidity of the catalyst, the number of acid sites, the strength and / or density of the acid sites, and the metal content in the catalyst.

[0211] In one embodiment, H-ISO 50 in step v) is carried out in the presence of a hydroisomerization catalyst comprising at least one noble metal, preferably platinum and / or palladium. The hydroisomerization catalyst comprising at least one noble metal is beneficial because it can provide higher selectivity for the isomerization reaction and is highly active at lower operating temperatures compared to catalysts containing only non-noble metals.

[0212] In one embodiment, the hydroisomerization catalyst is supported on a catalyst support comprising one or more porous acidic materials having microporous, mesoporous or hierarchical (micro-mesoporous) structures that act as molecular sieves. The various available SAPOs and zeolites provide the required acidity and porosity characteristics. The mentioned SAPOs and zeolites are commercially available, and their acidity and porosity characteristics can enable hydroisomerization, including the multi-branching of n-alkanes, even long-chain n-alkanes such as C16+ alkanes.

[0213] In one embodiment, the hydroisomerization catalyst in step v) is a non-sulfided catalyst. In one embodiment, the hydroisomerization catalyst is selected from Pt / SAPO-11 / Al 2 O 3 、Pt / ZSM-22 / Al 2 O 3 、Pt / ZSM-23 / Al 2 O 3and Pt / SAPO-11 / SiO 2 . In one embodiment, the hydroisomerization catalyst requires the presence of hydrogen to maintain the stability of the catalyst.

[0214] . In one embodiment, H-ISO 50 in step v) is carried out under the following conditions: a hydroisomerization temperature of 200 - 500 °C, preferably 230 - 500 °C, more preferably 250 - 450 °C, even more preferably 280 - 400 °C; and a pressure of 2 - 15 MPa, preferably 1 - 10 MPa, more preferably 3 - 10 MPa.

[0215] . In one embodiment, the renewable feedstock 10 is pretreated 80 before step ii), wherein the pretreatment includes:

[0216] a. Removing impurities from the renewable feedstock, such as alkaline earth metals and non-alkaline earth metals, and / or phosphorus;

[0217] b. Hydrolysis of the renewable feedstock;

[0218] c. Fractionation of the renewable feedstock;

[0219] d. Hydrogenation of the renewable feedstock, or

[0220] e. Any combination thereof.

[0221] . In one embodiment, the renewable feedstock 10 is pretreated 80 before step ii), wherein the pretreatment includes:

[0222] a. Removing impurities from the renewable feedstock, such as metals and / or sulfur and / or phosphorus;

[0223] b. Hydrolysis of the renewable feedstock;

[0224] c. Fractionation of the renewable feedstock;

[0225] d. Hydrogenation of the renewable feedstock, or

[0226] e. Any combination thereof.

[0227] For example, in Figure 2 and Figure 3 , the renewable feedstock 10 is exposed to the pretreatment 80 before the DCO reaction 20 in step ii), and the effluent 85 of the pretreatment is then directed to the DCO reaction 20.

[0228] . In one embodiment, the pretreatment 80 includes removing elemental metals and / or metal compounds. In one embodiment, the pretreatment 80 includes removing alkali metals and / or alkaline earth metals. In one embodiment, the pretreatment 80 includes removing non-alkaline earth metals.

[0229] In one embodiment, the pretreated renewable effluent 85 comprises one or more of the following:

[0230] - alkali metals and alkaline earth metals in an amount less than 10 wt-ppm, preferably less than 5 wt-ppm, more preferably less than 1 wt-ppm, calculated as elemental alkali metals and rare earth metals;

[0231] - other metals other than alkali metals and alkaline earth metals in an amount less than 10 wt-ppm, preferably less than 5 wt-ppm, more preferably less than 1 wt-ppm, calculated as elemental metals; and / or

[0232] - phosphorus in an amount less than 30 wt-ppm, preferably less than 15 wt-ppm, more preferably less than 5 wt-ppm, calculated as elemental phosphorus,

[0233] all based on the total weight of the pretreated effluent 85.

[0234] In one embodiment, the pretreated renewable effluent 85 comprises one or more of the following:

[0235] - alkali metals and / or alkaline earth metals in an amount less than 10 wt-ppm, preferably less than 5 wt-ppm, more preferably less than 1 wt-ppm, calculated as elemental metals;

[0236] - other metals other than alkali metals and alkaline earth metals in an amount less than 10 wt-ppm, preferably less than 5 wt-ppm, more preferably less than 1 wt-ppm, calculated as elemental metals; and / or

[0237] - phosphorus in an amount less than 30 wt-ppm, preferably less than 15 wt-ppm, more preferably less than 5 wt-ppm, calculated as elemental phosphorus,

[0238] all based on the total weight of the pretreated effluent 85.

[0239] In one embodiment, the pretreated effluent 85 contains less than 1 wt-ppm of metals or metal-containing compounds. In one embodiment, the pretreated effluent 85 contains less than 1 wt-ppm of alkali metals and alkaline earth metals, as well as other metals other than alkali metals and rare earth metals, and less than 5 wt-ppm of phosphorus. In one embodiment, the pretreatment 80 of the renewable feedstock includes removing sulfur from the feed, and the pretreated effluent 85 contains 50 wt-ppm or less, preferably 10 wt-ppm or less, more preferably 5 wt-ppm or less of sulfur.

[0240] In one embodiment, the pretreatment 80 includes:

[0241] a. hydrolyzing the renewable feedstock; and

[0242] b. Fractionate at least a portion of the hydrolyzed effluent from step a), and recover a first fraction 82 comprising free fatty acids (FFAs) having a carbon number > C17 and a second fraction 83 comprising FFAs having a carbon number of C17 or less;

[0243] wherein the FFAs having a carbon number > C17 (82) are introduced into the DCO reaction 20 of step ii), and the FFAs 83 having a carbon number of C17 or less are introduced into the hydrotreating reaction 30 of step iii).

[0244] Figure 4 An exemplary embodiment of a method including the pretreatment steps a. (hydrolysis) and b. (fractionation) is shown. In one embodiment, it is advantageous to hydrolyze and fractionate the renewable feedstock into the first fraction 82 and the second fraction 83 because in the DCO reaction 20, only the carbon number of the free fatty acids having a carbon number > C17 is reduced (while the shorter ≤ C17 FFAs 83 are not reduced). In one embodiment, it is advantageous to hydrolyze and fractionate the renewable feedstock into the first fraction 82 and the second fraction 83 because the pretreatment 80 avoids unnecessary reduction of the carbon number of carboxylic acids already within the aviation fuel fraction limits, thereby improving the carbon efficiency of the initial renewable feedstock 10 and thus increasing the final yield of at least the renewable aviation fuel fraction.

[0245] In one embodiment, wherein the method includes a pretreatment 80 that includes hydrolyzing and fractionating the feedstock into a first fraction 82 and a second fraction 83, the HT reaction 30 of step iii) includes HDO. This is because all the FFAs contained in the first fraction 82 (including FFAs having a carbon number of C17 or less) bypass the DCO reaction 20 step and are only deoxygenated in the HDO reaction 30 of step iii).

[0246] In one embodiment, wherein the method includes a pretreatment 80 that includes fractionating the feedstock into a first fraction 82 and a second fraction 83, the feed entering the HT reaction 30 of step iii) preferably contains only compounds having a carbon number of 17 or less.

[0247] In one embodiment, the pretreatment 80 of the renewable feedstock 10 includes hydrogenation of the feedstock. In one embodiment, the pretreatment hydrogenation of the renewable feedstock is beneficial for removing double bonds from free carboxylic acids, carboxylic acid esters, and / or triglycerides of the renewable feedstock.

[0248] As Figure 5 shown, the different effluents obtained from the method steps can be recycled back to upstream method steps.

[0249] In one embodiment, the method includes:

[0250] a. Recycle at least a portion of the DCO effluent 21 back to the DCO reaction 20 of step ii),

[0251] b. Recycle at least a portion of the hydrotreated effluent 31 back to the HT reaction 30 of step iii),

[0252] c. Recycle at least a portion of the hydrotreated effluent 31 back to the DCO reaction 20 of step ii); or

[0253] d. Any combination thereof.

[0254] In Figure 5 exemplary embodiments, various alternative and / or parallel routes for recycling feed during the process are shown.

[0255] In one embodiment, the method includes recycling at least a portion of the pretreated effluent 85 back to the pretreatment 80 ( Figure 5 ). Recycling the pretreated effluent 85 back to the pretreatment 80 is beneficial because it ensures the effective removal of impurities from the feedstock. When the renewable feedstock 10 contains a large number of olefinic bonds, recycling at least a portion of the pretreated effluent back to the pretreatment 80 is also beneficial. The olefinic bonds can dimerize / oligomerize during the acid treatment procedure of the pretreatment 80 step to form heavier compounds that are not suitable for aviation fuel or diesel fuel.

[0256] In one embodiment, the DCO effluent 21 or the hydrotreated effluent 31 can be recycled back into the feed entering the pretreatment 80 ( Figure 5 not shown in). This is beneficial because when the DCO effluent 21 and / or the hydrotreated effluent 31 are recycled into the feed entering the pretreatment 80, for example, it can reduce the viscosity of the renewable feedstock 10, thereby facilitating the mixing and filtration of the chemicals during the bleaching process, thereby improving the efficiency of the pretreatment purification.

[0257] In one embodiment, the DCO effluent 21 and / or the hydrotreated effluent 31 can be recycled back to the DCO reaction 20, optionally recycled back to the pretreated effluent 85 ( Figure 5 ). In one embodiment, at least a portion of the DCO effluent 21 is recycled back into the pretreated effluent 85 and thus recycled into the DCO reaction 20 of step ii) to improve the DCO conversion efficiency by deoxygenating any remaining oxygenates in the DCO effluent, thereby increasing the conversion rate of the unconverted oxygen components.

[0258] In one embodiment, the DCO effluent 21 and / or the hydrotreated effluent 31 are recycled back to the endothermic DCO reaction 20 to provide additional thermal energy to the DCO reaction 20 of step ii). Diluting the reaction feed entering the DCO reaction 20 with an inert (converted) feed also controls the DCO reaction temperature and makes it more stable. In one embodiment, recycling at least a portion of the hydrotreated effluent 31 back to the DCO reaction 20 of step ii) is beneficial because the hydrotreated effluent also dilutes the concentrations of impurities such as nitrogen and sulfur present in the renewable feedstock 10.

[0259] In one embodiment, the hydrotreated effluent 31 can be recycled into the DCO effluent 21 or the carbon-oxide-lean DCO effluent 22 ( Figure 5 ). The hydrotreating reaction 30 is highly exothermic, so recycling the hydrotreated effluent 31 back into 21 or 22 stabilizes the reaction temperature of the HT reaction 30. The n-alkanes produced during the HT process in step iii) are nearly inert under HT conditions. The stabilization of the HT reaction temperature and the dilution of the DCO effluent 21 or 22 (HT feed) also prevent side reactions such as the oligomerization of double bonds and the ketonization of free fatty acids. However, since the deoxygenation and at least partial hydrogenation of double bonds have already occurred in the DCO in step ii), reducing the reactions required during the HT process in step iii), and thus reducing the exothermic heat generated, the reaction temperature control during the HT process in step iii) is easier. Where the first HT reaction 30 is insufficient, for example when the heteroatom level in the hydrotreated effluent 31 is too high, recycling at least a portion of the hydrotreated effluent 31 back to the HT reaction 30 of step iii) is also beneficial.

[0260] In one embodiment, step vi) of the method includes fractionating 60 at least a portion of the hydroisomerized effluent 51 from step v) and recovering at least the renewable aviation fuel components.

[0261] In one embodiment, the renewable aviation fuel components meet the specifications set forth in Appendix A2 of ASTM D7566-22. In one embodiment, the renewable aviation fuel components obtained from the method contain C8-C17 alkanes.

[0262] In one embodiment, compared to a method without the DCO reaction 20 in step ii), the present method is capable of recovering renewable aviation fuel components with increased yields from the fractionation 60 in step iv), and the increase in yield depends on the fatty acid distribution of the renewable feedstock 10. In some embodiments, the overall increase in the yield of renewable aviation fuel components is believed to be due to the higher C18 fatty acid content in the renewable feedstock that undergoes the DCO reaction 20 in step ii).

[0263] The method for producing renewable aviation fuel components of the present invention provides renewable aviation fuel components with increased yields without the need for cracking or only mild hydrocracking conditions. Since there are no harsh cracking conditions, unpredictable cracking of hydrocarbons does not occur, and a relatively larger portion of the initial liquid renewable feedstock can be obtained as the final renewable components (including renewable aviation fuel components).

[0264] In one embodiment, the renewable aviation fuel component is mixed with a fossil aviation fuel component for use as an aviation fuel blend.

[0265] In one embodiment, the renewable aviation fuel component obtained from the method according to the present disclosure can be used as a renewable aviation fuel blend component in an aviation fuel blend, where the aviation fuel blend further includes a fossil aviation fuel blend component.

[0266] In one embodiment, according to the current regulatory requirements at a given time or requirements of, for example, an aviation original equipment manufacturer (OEM), the renewable aviation fuel component of the present disclosure can also be used as is, i.e., 100% as an aviation fuel product.

[0267] In one embodiment, the fractionation 60 in step vi) further includes recovering a renewable diesel component and / or a renewable naphtha component.

[0268] In one embodiment, the present method for producing renewable aviation fuel components similarly provides a method for producing a renewable diesel component and / or a renewable naphtha component.

[0269] In one embodiment, the fractionation 60 in step vi) includes recovering at least one other component containing hydrocarbons with 18 or more carbon atoms and recycling the at least one other component back to the DCO reaction 20, the HC step 75 in step ii), or any combination thereof, as Figure 6 shown.

[0270] In one embodiment, at least one other component containing hydrocarbons with 18 or more carbon atoms is recycled from the fractionation 60 in step vi) back to the DCO reaction 20 in step ii) to be used as a solvent that provides heat energy for the DCO reaction. Since all hydrocarbons have been deoxygenated at step vi) of the method, no more carbon can be removed from the hydrocarbons of the at least one other component through the DCO reaction in step ii). However, in the HC step 75 after the DCO step later in the method, hydrocarbons with ≥C18 can be shortened. According to some embodiments, at least one other component is recycled from step vi) back to the HC step 75 to further reduce the carbon number of the hydrocarbons present in the at least one other component.

[0271] Examples

[0272] Example 1. Decarboxylation / Decarbonylation (DCO) of Renewable Feedstock

[0273] Background and Equipment

[0274] The test runs were carried out in a conventional catalytic test unit, which had a feed tank, a feed pump, a catalytic fixed-bed reactor, and a pressure control unit according to certain standards. All reactions were carried out in a continuous reaction mode. The products were collected in a product tank, which also served as a gas / liquid separator. The gas volume was measured with measuring equipment, and samples were taken and analyzed from the gas stream separately. The hydrogen consumption was measured from the GC results, and the hydrocarbon products (liquids) and water were manually separated and analyzed with a GC device. The GC analysis of hydrocarbons is a well-known method.

[0275] Renewable Feedstock

[0276] According to the present disclosure, the renewable liquid feedstock used as a renewable feedstock in all DCO reactions is raffinated rapeseed oil (although other feedstocks with a suitable fatty acid distribution can also be used). The feedstock contains about 95 wt-% C18 fatty acids and 5 wt-% C16 fatty acids of the total weight of the feedstock fatty acids. Thus, the rapeseed oil contains a considerable portion of C18 fatty acids, which can be used in the renewable aviation fuel components prepared according to the present method. The initial rapeseed oil feedstock contains about 5 wt-ppm of sulfur and 10 wt-ppm of nitrogen.

[0277] Pretreatment of Feedstock

[0278] The rapeseed oil fatty acids (95% C18FA and 5% C16FA) were introduced into a pretreatment step, in which the impurities of the renewable feedstock were removed. The renewable feedstock was first filtered, then heat-treated at 280 °C, and finally bleached with a conventional bleaching method. The removed impurities include alkali metals such as sodium and potassium, and / or alkaline earth metals such as magnesium and calcium. This pretreatment step also removed most of the phosphorus, silicon, chloride components, and polyethylene wax.

[0279] DCO Catalyst

[0280] The catalyst used in the DCO reaction is palladium supported on carbon (Pd / C) (Reactions 1 - 3), or sulfided NiMo supported on alumina (sulfided NiMo / Al 2 O 3)(Reaction 4). In Reaction 4, sulfur is added to the DCO feedstock at a concentration of 1000 wt-ppm. The NiMo catalyst is sulfided before the DCO reaction to contain approximately 6 - 7 wt-% sulfur (calculated on the total weight of the catalyst). In all Reactions 1 - 4, 10 - 25 g of the catalyst is loaded into the reactor and then reduced (for Pd catalyst) or sulfided (for NiMo catalyst) under a hydrogen stream at 200 °C.

[0281] However, the DCO catalyst used in the DCO reaction can be different from the Pd and NiMo catalysts disclosed above. For example, Patent EP168133781B1 lists other possible DCO catalysts in Table 1, and these catalysts can also be used in the DCO reaction of this method. The catalysts shown in Table 1 of EP168133781B1 are not optimized for the current DCO method, so Table 1 does not give optimized percentage values for DCO conversion and selectivity. However, other catalysts can also be used in this method, and the DCO reaction and the catalysts shown in Example 1 of EP168133781B1 are incorporated herein by reference.

[0282] DCO reaction

[0283] The DCO reaction proceeds as parallel Reactions 1 - 4. In Reactions 1 - 3, the effect of changing the weight hourly space velocity (WHSV) value using a Pd / C catalyst on the resulting DCO product distribution was observed. Thus, except for adjusting the WHSV of the feedstock to different levels in each of Reactions 1 - 3 (adjusted to 0.25 h -1 in Reaction 1, adjusted to 0.5 h -1 in Reaction 2, and adjusted to 1 h -1 in Reaction 3), the reaction conditions for Reactions 1 to 3 are the same in other respects. In each parallel DCO Reaction 1 - 3, the hydrogen (H 2 ) / oil feed ratio is set to 150 nl H 2 / L feed, and DCO Reactions 1 - 3 are carried out at a temperature of 350 °C and a reactor pressure of 0.5 MPa. Reaction 4 is catalyzed by a sulfided NiMo / Al 2 O 3 catalyst, and the reaction conditions include a hydrogen (H 2 ) feed ratio of 150 nl H 2 / L feed, a temperature of 350 °C, a reactor pressure of 0.5 MPa, and a WHSV of 1 h -1 . In all Reactions 1 - 4, hydrogen is added to the feed at a relatively low concentration because it is only needed for the hydrogenation of the double bonds present in the feedstock carboxylic acid.

[0284] Results

[0285] The gaseous products contained in the DCO effluent after the DCO reaction mainly include carbon oxides (CO / CO 2 ) and light hydrocarbons with carbon number <C4. After the DCO reaction, the gaseous fraction is removed from the liquid fraction by gas-liquid separation. The liquid product distributions of DCO reactions 1-4 are shown in Table 1. Table 1 shows the individual components contained in the liquid fraction of the DCO reaction product (i.e., the liquid DCO effluent). All reactions 1-4 produce high wt-% of deoxygenated C17 and C15 hydrocarbons (HC). Since the amount of odd-numbered carboxylic acids in natural raw materials is usually very low or completely absent, the C17 and C15 HC present in the liquid DCO effluent are mainly formed by the deoxygenation of C18 and C16 carboxylic acids, and the resulting HC has one less carbon atom than the original carboxylic acids in the starting material. Among reactions 1-4, the DCO effluent of reaction 1 contains the highest wt-% of C17-HC (74.93 wt%). The DCO effluents of each of reactions 1-3 contain a large proportion of deoxygenated C17 HC, which can be used as aviation fuel components (as opposed to C18 HC). Therefore, the weight percentage of C17 hydrocarbons directly reflects the potential increase in the yield of intermediate aviation fuel components. Not all deoxygenation reactions of the raw material occur through the DCO reaction, as evidenced by the small amounts of C18 and C16 hydrocarbons present in the DCO effluent. This is because there is at least a small amount of hydrogen present in all reactions, and the catalyst used also catalyzes the HDO reaction. However, most of the deoxygenation occurs through the DCO reaction, as can be seen when comparing the product distributions of reactions 1-4 with those of a sample deoxygenated only by HDO (see Table 5, reaction 5). However, due to the presence of double bonds in the fatty acids of the renewable feedstock, a low hydrogen concentration is beneficial. The noble metal DCO catalyst can effectively hydrogenate double bonds, and during the DCO reaction, the removal of double bonds occurs more readily than the HDO reaction.

[0286] Table 1. Liquid product distributions of DCO reactions 1-4, expressed as weight percentages of the total weight of the liquid DCO reaction products.

[0287] Reaction 1 Reaction 2 Reaction 3 Reaction 4 C18FA 14.22 33.18 52.00 47.27 C16FA 0.75 1.75 2.74 2.49 C18-HC 5.64 3.70 2.13 11.82 C17-HC 74.93 57.92 40.42 35.45 C16HC 0.30 0.19 0.11 0.62 C15HC 3.94 3.05 2.40 2.14 <C15HC 0.10 0.10 0.10 0.10 >C18HC / FA 0.12 0.12 0.11 0.11

[0288] The total sulfur and nitrogen contents in the DCO effluents produced by reactions 1-3 are only slightly lower than those of the initial raw material because the DCO catalyst used is not designed to catalyze HDS / HDN. Therefore, an HT reaction step is required after the DCO reaction step to ensure the effective removal of nitrogen and sulfur components before the hydrocracking or hydroisomerization step using a bifunctional catalyst (including metal active sites and acidic active sites). In reaction 4 with a sulfided feedstock, sulfur is also removed more effectively, but since the conditions are favorable for DCO, HDN / HDS is incomplete and an HT step is still required (Table 2).

[0289] Table 2. Concentrations of sulfur (S) and nitrogen (N) in the DCO effluent, expressed in wt-ppm.

[0290]

[0291] DCO reactions 1 - 4 do not completely deoxygenate the initial feedstock (i.e., 100%), which is evidenced by the presence of C18 and C16 fatty acids (FA) in the liquid DCO effluent (Table 1). From reactions 1 - 4, the highest deoxygenation conversion is in reaction 1, where 85 wt-% of the C18 and C16 carboxylic acids in the initial DCO feedstock have been deoxygenated. For reaction 2, the conversion is 65 wt-% for both C16 and C18, for reaction 3, the conversion is the lowest, 45 wt-% for both C16 and C18, and for reaction 4, the conversion is 50 wt-% for both C16 and C18. Therefore, from the deoxygenation conversion, it can be concluded that the WHSV combined with the Pd / C catalyst is at least 0.25 h -1 (longer residence time) for reaction 1, which results in the highest deoxygenation conversion, while reactions 2 - 3 with higher WHSV values using the same catalyst, or reaction 4 with a WHSV of 1 h combined with a sulfided NiMo catalyst have much lower deoxygenation conversions. -1

[0292] The deoxygenation selectivity rates of reactions 1 - 3 are inversely correlated with their respective conversions, indicating that the DCO deoxygenation selectivity decreases when the deoxygenation conversion approaches 100 wt-%. To maintain a high DCO deoxygenation selectivity, the deoxygenation conversion is preferably set below 100 wt-%. Therefore, after the DCO reaction step 20, the HT reaction step 30 is necessary to complete deoxygenation and remove sulfur and nitrogen from the feed. From reactions 1 - 4, the highest DCO deoxygenation selectivity is in reaction 3, where a DCO selectivity of 95 wt-% is obtained for both C17 and C15 hydrocarbons that are deoxygenated through the DCO reaction from the total amount of C18 and C17, or C16 and C15 hydrocarbons deoxygenated from the DCO effluent. For reaction 2, the selectivity is 94 wt-% for both C17 and C15 HC, and for reaction 1, the selectivity is 93 wt-% for both C17 and C15 HC. Therefore, it can be concluded that by increasing the residence time of the feedstock (decreasing the WHSV), the DCO deoxygenation selectivity of the reaction decreases, although the rate of decrease is different from the rate of increase in the total deoxygenation conversion. For reaction 4, the selectivity is 75 wt-% for both C17 and C15 HC from the total amount of C18 and C17, or C16 and C15 hydrocarbons deoxygenated from the DCO effluent.

[0293] When considering the sum of hydrocarbons with odd carbon numbers in the DCO effluent in Table 1 and the total deoxygenation rate of the DCO effluent obtained from Reactions 1-4 shown in Table 3, it can be concluded that most deoxygenation reactions occur via the DCO reaction.

[0294] Table 3. Total deoxygenation rate of the DCO effluent, calculated using the formula "weight percentage of deoxygenated DCO effluent = 1 - (sum of un-deoxygenated FAs in the DCO effluent)".

[0295]

[0296] In Reactions 1-3, the total deoxygenation rate and DCO conversion in Table 3 are related to the amount of carbon oxides in the gaseous products contained in the DCO effluent after the DCO reaction. In Reaction 4, due to the lower DCO conversion, the deoxygenated DCO effluent contains a proportionally smaller amount of carbon oxides (although the total deoxygenation rate is higher due to HDO). After the DCO reaction, the gaseous products are removed from the liquid fraction by gas-liquid separation. The weight percentage of carbon oxide compounds (including at least CO 2 and CO) in the gaseous products is shown in Table 4.

[0297] Table 4. Gaseous carbon oxide content of the DCO effluent from Reactions 1-4, expressed as a weight percentage of the total weight of the corresponding DCO effluent (DCO reaction product).

[0298]

[0299] Example 2. Hydrotreating of the DCO effluent

[0300] Feed used in the hydrotreating (HT) reaction

[0301] The liquid fractions obtained from DCO Reactions 1-4 shown in Table 1 are respectively further used in hydrotreating (HT) Reactions 1-4. In addition, Comparative Reaction 5 is also included, in which the soda-extracted rapeseed oil is exposed to the HT reaction without first exposing the feedstock to the DCO reaction. Each of the liquid products 1-4 from the DCO reaction is introduced into the same reactor setup for the hydrotreating (HT) step using a hydrotreating catalyst.

[0302] Pretreatment of the feedstock / catalyst

[0303] In all of Reactions 1-5, the catalyst used in the HT reaction is a commercially available sulfided NiMo supported on alumina (sulfided NiMo / Al 2 O 3) Sulfur is added to the HT feedstock at a concentration of 500 wt-ppm (Reactions 1-5) to keep the catalyst in a sulfided state. In all reactions, 25 g of the catalyst was loaded into the reactor and then dried and sulfided using the DMDS procedure well-known in the refining industry. Based on the total weight of the catalyst, the sulfided NiMo catalyst has approximately 6-7 wt-% sulfur.

[0304] HT reaction conditions

[0305] The HT reaction was carried out in parallel Reactions 1-5. HT Reactions 1-3 were carried out at a temperature of 350 °C and a reactor pressure of 4 MPa, and the WHSV of the feedstock was adjusted to 1 h -1 . In Reaction 1, the hydrogen (H 2 ) feed ratio was set to 250 nl H 2 / L of feedstock, while in Reaction 2, the hydrogen (H 2 ) feed ratio was set to 300 nl H 2 / L of feedstock, and in Reaction 3, the hydrogen (H 2 ) feed ratio was set to 350 nl H 2 / L of feedstock. Thus, the reaction conditions for Reactions 1-3 were the same in other respects. Due to the larger number of oxygenates in the hydrotreating feed (DCO effluent), the hydrogen (H 2 ) feed ratio was set higher in Reactions 2 and 3. Reaction 4 was carried out at a temperature of 330 °C and a reactor pressure of 4 MPa, and the WHSV of the feedstock was adjusted to 1 h -1 , and the hydrogen (H 2 ) feed ratio was set to 500 nl H 2 / L of feedstock to ensure effective deoxygenation and HDS / HDN reactions.

[0306] Reaction 5 (a comparative example of single-step deoxygenation of rapeseed oil fatty acids) was carried out under conventional hydrotreating reaction conditions: the temperature was 310 °C, and the reactor pressure was 5 MPa, and the WHSV of the feedstock was adjusted to 1 h -1 , and the hydrogen (H 2 ) feed ratio was set to 1000 nlH 2 / L of feedstock. Since the feedstock for Reaction 5 contains all the oxygenates present in the initial alkali-extracted rapeseed oil, hydrogen was added to the feed at a high concentration. In this case, hydrotreating requires 2-3 times the excess H 2 (calculated based on the theoretical hydrogen consumption for 100% HDO + double bond hydrogenation).

[0307] Results

[0308] The gaseous products of the HT effluent after the HT reaction include carbon oxides (CO / CO 2) and light hydrocarbons with a carbon number <C4, and also includes H released in the HDO reaction 2 O. After the HT reaction, the gaseous fraction is removed from the liquid fraction by gas-liquid separation. 100% deoxygenation conversion was achieved in all reactions 1-5, so there is no residual oxygenated fatty acid in the HT effluent.

[0309] The analysis of the liquid HT reaction products from reactions 1-5 is shown in Table 5. In each of reactions 1-4, the weight percentage of C17 HC increased significantly relative to the amount present in the corresponding DCO effluent, indicating that the HT reaction also includes a significant portion of deoxygenation via the DCO reaction pathway. Table 5 of the liquid product distribution shows that the HT reactions of reactions 1-3 include the largest portion of deoxygenation via DCO, while reactions 5 and 4 mainly include deoxygenation via HDO. The DCO selectivity rates (C15 and C17 selectivity rates) of the HT reactions 1-5 also confirm this. The DCO deoxygenation selectivity rates for reactions 1, 2, 3, 4, and 5 are 50 wt%, 50 wt-%, 47 wt-%, 35 wt-%, and 30 wt-% respectively (calculated as the weight percentage of deoxygenated C17 or C15 hydrocarbons that are deoxygenated via DCO based on the total amount of deoxygenated C18 and C17, or C16 and C15 hydrocarbons in the HT effluent). From the DCO deoxygenation selectivity rates of C15 and C17 hydrocarbons, it can be concluded that in the HT reactions 1-3, approximately half of the deoxygenation reactions of the unreacted FAs occur via the DCO reaction (50 / 50 / 47 wt-% respectively). Each effluent from reactions 1-5 also contains a significant weight percentage of deoxygenated C18 HC, indicating that all HT reactions 1-5 include deoxygenation via HDO. Reactions 4 and 5 show the highest HDO deoxygenation rates (Table 5), and the lowest DCO selectivity rates of the HT reactions.

[0310] The HT effluent of reaction 1 has the lowest amount of C18 HC (12.45 wt-%), indicating that the HT effluent of reaction 1 only requires very mild hydrocracking, or only a small portion of the HT effluent (after fractionation) requires hydrocracking, and the entire effluent meets the boiling range set for aviation fuel components. Therefore, the HT effluent of reaction 1 has the highest amount (highest amount, maximum content) of ≤C17 HC (82.54 wt-%), indicating that the HT effluent from reaction 1 contains the largest portion of hydrocarbons that can be used as intermediate aviation fuel components without hydrocracking after fractionation. Thus, reaction 1 provides the highest potential yield. Table 6 further clarifies this, showing the weight percentages of renewable aviation fuel component intermediates (HC <C18) obtained from the initial rapeseed oil feedstock.

[0311] Table 5. Liquid product distribution after the HT step (Reactions 1-5), expressed as weight percentages of the total weight of the liquid HT reaction products.

[0312]

[0313] Table 6. Weight percentages of the renewable aviation fuel component middle hydrocarbon yield (<C18) obtained from the initial alkali raffinate rapeseed oil feedstock after the DCO and HT steps.

[0314]

[0315] The total sulfur and nitrogen contents of the HT effluent from all Reactions 1-5 were below the detection limit of the analysis, i.e., <1 wt-ppm, indicating that the HT reaction also actually included complete HDN and HDS reactions.

[0316] Table 7. Shows the total hydrogen consumption of Reactions 1-5 during the DCO reaction (Example 1) and the hydrotreating (HT) reaction (Example 2). The amount of H 2 consumed in Reactions 1-4 was significantly lower than the hydrogen consumption of Comparative Reaction 5 (a single-step HT reaction under conventional HT reaction conditions without the DCO reaction). The amount of hydrogen required in Reactions 1-5 was inversely proportional to the amount of deoxygenation reaction occurring through the DCO reaction (DCO selectivity).

[0317] Table 7. Combined total hydrogen consumption of the DCO and hydrotreating (HT) Reactions 1-5.

[0318]

[0319] Thereafter, the hydrotreated liquid product is optionally introduced into a hydrocracking step. Prior to this, the hydrotreated liquid product can be obtained by gas-liquid separation and then distilled into two fractions, namely hydrocarbons C17 and lower, and hydrocarbons C18 and heavier, and only the latter is introduced into the hydrocracking step. Before introducing the liquid into the isomerization step, the hydrocracked product effluent is then introduced into gas / liquid separation together with the lighter fraction from the distillation step. Experimental studies of these steps can be carried out using conventional catalytic reactor systems and distillation / evaporation units, respectively.

[0320] Various embodiments have been shown. It should be understood that in this document, the words "comprise", "include", and "contain" are each used as open-ended expressions and are not intended to be exclusive.

[0321] The foregoing description has provided a complete and informative description of the best mode contemplated by the inventors for carrying out the present invention by way of specific implementations and non-limiting examples of embodiments. However, it will be apparent to those skilled in the art that the present invention is not limited to the details of the embodiments provided above, but rather can be implemented in other embodiments or in different combinations of embodiments using equivalent means without departing from the features of the present invention.

[0322] In addition, some features of the exemplary embodiments disclosed above can be advantageously used without correspondingly using other features. Accordingly, the foregoing description should be considered as illustrative only of the principles of the present invention and not as limiting thereof. Thus, the scope of the present invention is limited only by the appended patent claims.

Claims

1. A method for producing renewable aviation fuel components, the method comprising: i) providing a renewable feedstock (10) comprising free carboxylic acids (FCA), carboxylic acid esters, triglycerides, or combinations thereof; ii) in the presence of a DCO catalyst, subjecting the feedstock to a decarboxylation and / or decarbonylation (DCO) reaction (20) in a DCO zone to remove one carbon from the carbon chain of the carboxylic acid moiety of the renewable feedstock, wherein the DCO zone: - the DCO deoxygenation selectivity is at least 75 wt-% of the total weight of the deoxygenated hydrocarbons, and - the deoxygenation conversion rate is at least 50 wt-% of the total weight of the feedstock, thereby obtaining a DCO effluent (21); iii) in the presence of hydrogen and a hydrotreating catalyst, subjecting at least a portion of the DCO effluent from step ii) to a hydrotreating (HT) reaction (30) in an HT zone to obtain a hydrotreated effluent (31); iv) subjecting the hydrotreated effluent from step iii) to gas-liquid separation (40) to obtain a degassed hydrotreated effluent (41); v) subjecting at least a portion of the degassed hydrotreated effluent from step iv) to hydroisomerization (H-ISO) (50), thereby obtaining a hydroisomerized effluent (51); and vi) subjecting at least a portion of the hydroisomerized effluent (51) from step v) to fractionation (60) and at least recovering the renewable aviation fuel components.

2. The method according to claim 1, wherein the DCO deoxygenation selectivity in step ii) is at least 80 wt-%, preferably at least 85 wt-%, more preferably at least 90 wt-%, even more preferably at least 95 wt-%, most preferably at least 97 wt-% of the total weight of the deoxygenated hydrocarbons.

3. The method according to claim 1 or 2, wherein the deoxygenation conversion rate of step ii) is at least 55 wt-%, preferably at least 60 wt-%, more preferably at least 70 wt-%, more preferably at least 80 wt-%, at least 90 wt-%, at least 95 wt-%, or at least 99 wt-% of the total weight of the feedstock.

4. The method according to any one of the preceding claims, wherein before directing the DCO effluent to step iii), the DCO effluent (21) from step ii) is at least partially subjected to separation of at least CO and / or CO 2 gas (25).

5. The method according to any one of the preceding claims, wherein the DCO catalyst in step ii) is a heterogeneous catalyst comprising a metal selected from nickel, cobalt, copper, zinc, molybdenum, manganese, ruthenium, rhodium, rhenium, iridium, palladium, platinum, and any combination thereof.

6. The method according to any one of the preceding claims, wherein the DCO catalyst further comprises at least one support selected from alumina; silica; zirconia; titanium dioxide; carbon, such as activated carbon or graphite; molecular sieves; and any combination thereof.

7. The method according to any one of the preceding claims, wherein the DCO reaction (20) of step ii) is carried out at an H 2 feed ratio of less than 300 nl H 2 / L of feedstock, or without adding H 2 at all.

8. The method according to any one of the preceding claims, wherein the DCO reaction (20) in step ii) is carried out at a temperature of 50 - 450 °C, preferably the temperature is 200 - 450 °C, more preferably the temperature is 250 - 400 °C; and / or is carried out at a pressure of 0.1 - 10 MPa, preferably the pressure is 0.1 - 2 MPa.

9. The method according to any one of the preceding claims, wherein the DCO reaction (20) in step ii) is carried out at a weight hourly space velocity (WHSV) of 0.1 - 15 h -1 , preferably 0.25 - 5 h -1 of WHSV.

10. The method according to any one of the preceding claims, wherein the HT reaction (30) in step iii) is selected from hydrodeoxygenation (HDO), hydrogenation of double bonds, hydrodenitrogenation (HDN), hydrodesulfurization (HDS), and any combination thereof, preferably the hydrotreating reaction in step iii) comprises HDN.

11. The method according to any one of the preceding claims, wherein the HT reaction (30) in step iii) is carried out in the presence of the HT catalyst, the HT catalyst comprising at least one metal of Group VIII and / or Group VIB of the Periodic Table of the Elements, preferably selected from nickel, molybdenum, tungsten, cobalt, and any combination thereof, preferably selected from NiMo, CoMo, and NiW.

12. The method according to any one of the preceding claims, wherein the HT catalyst in step iii) further comprises at least one support selected from zeolite, silica, alumina, amorphous silica alumina (ASA), and any combination thereof.

13. The method according to any one of the preceding claims, wherein the HT reaction (30) of step iii) is carried out at an H 2 feed of 50 - 2000 nlH 2 / L, preferably 100 - 1000 nlH 2 / L, more preferably 150 - 500 nl H 2 feed ratio.

14. The method according to any one of the preceding claims, wherein the HT reaction (30) in step iii) is carried out under the following conditions: a temperature of 250 - 450 °C, preferably the temperature is 280 - 350 °C; and / or a pressure of 1 - 20 MPa, preferably the pressure is 2 - 10 MPa.

15. The method according to any one of the preceding claims, wherein 50 - 5000 wt-ppm, preferably 100 - 2000 wt-ppm of sulfur is added to the DCO effluent (21) led to step iii).

16. The method according to any one of the preceding claims, comprising: a. subjecting at least a portion of: - the DCO effluent (21) from step ii), or - the hydrotreating effluent (31) from step iii), - the degassed hydrotreating effluent (41) from step iv), or - the hydroisomerization effluent (51) from step v) to fractionation (FRAC) (70) and recovering at least a first fraction (71) comprising hydrocarbons having a carbon number > C17 and a second fraction (72) comprising hydrocarbons having a carbon number ≤ C17; b. leading the hydrocarbons having a carbon number > C17 (71) to hydrocracking (HC) (75) in the presence of a hydrocracking catalyst to obtain a hydrocracked effluent (76); c. combining the hydrocracked effluent (76) with the second fraction (72); and d. leading the combined hydrocracked effluent (76) and the second fraction (72) to step iii), step iv), step v), or step vi) respectively.

17. The method according to any one of the preceding claims, wherein the H-ISO (50) in step v) is carried out in the presence of a hydroisomerization catalyst, the catalyst comprising: - at least one metal selected from Group VIII of the Periodic Table of the Elements, preferably selected from nickel, platinum, and palladium, more preferably selected from platinum and palladium; and / or - A carrier, preferably selected from Al 2 O 3 or SiO 2 ; and / or - Molecular sieves, preferably selected from SAPO-11, SAPO-41, ZSM-22, ZSM-23 and ferrierite.

18. The method according to any one of the preceding claims, wherein said H-ISO in step v) is carried out under the following conditions: A hydroisomerization temperature of 200 - 500 °C, preferably 230 - 500 °C, more preferably 250 - 450 °C, even more preferably 280 - 400 °C; and A pressure of 2 - 15 MPa, preferably 1 - 10 MPa, more preferably 3 - 10 MPa.

19. The method according to any one of the preceding claims, wherein said renewable feedstock (10) is pretreated (80) before step ii), wherein said pretreatment comprises: a. Removing impurities from said renewable feedstock, such as metals and / or sulfur and / or phosphorus; b. Hydrolysis of said renewable feedstock; c. Fractionation of said renewable feedstock; d. Hydrogenation of said renewable feedstock, or e. Any combination thereof.

20. Use of the renewable aviation fuel component obtainable from the method according to any one of claims 1 - 19 as a renewable aviation fuel blend component in an aviation fuel blend, wherein said aviation fuel blend further comprises a fossil aviation fuel blend component.

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