WO2023170360A1

WO2023170360A1 - Process for manufacturing a jet fuel from loads of renewable origin

Info

Publication number: WO2023170360A1
Application number: PCT/FR2023/050296
Authority: WO
Inventors: Sophie LOYAN; Jérémy MINEAU
Original assignee: Totalenergies Onetech
Priority date: 2022-03-07
Filing date: 2023-03-03
Publication date: 2023-09-14
Also published as: FR3133196A1

Abstract

The invention relates to a method for manufacturing a jet fuel comprising at least the steps of: a) providing ethyl esters of fatty acids resulting from the reaction of animal fats and/or used oils with methanol in a transesterification reactor, b) providing hydrocarbons of fossil origin, c) preparing a hydrocarbon load containing the hydrocarbons of fossil origin provided by step b) and the ethyl esters of fatty acids provided by step a) in a content of at most 5 vol.% relative to the hydrocarbon load, d) subjecting the hydrocarbon load prepared in step c) to a hydrotreatment and obtaining a treated hydrocarbon load, e) fractionating the treated hydrocarbon load obtained in step d) and recovering a kerosene fraction as a jet fuel.

Description

Title: PROCESS FOR MANUFACTURING A JET FUEL FROM FEEDS OF RENEWABLE ORIGIN

Technical area

The present invention relates to the technical field of refining petroleum feedstocks of fossil origin and feedstocks of biological origin, particularly for the manufacture of jet fuel. More particularly, the invention relates to a process for obtaining a jet fuel having a component of biological (or renewable) origin.

Background of the invention

Conventional jet fuels, also called jet fuel, jet fuel or kerosene, are produced from crude oil and contain a complex mixture of hydrocarbons that typically have 6 to 18 carbon atoms. These hydrocarbons include linear and branched alkanes, cycloalkanes and aromatic hydrocarbons. The cut points of the jet-fuel fraction typically vary between 140°C and 240°C.

Commercial jet fuel is typically obtained by mixing different fuel bases. These fuel bases can be crude oil distillation cuts, possibly hydrotreated or sometimes subjected to a softening treatment (MEROX process for example). These bases can also be cuts from a hydrocracker effluent or an effluent from a catalytic cracker (often after hydrotreatment). Other fuel bases can be prepared by other routes such as Fischer Tropsch synthesis followed by a cracking step. The choice of fuel bases as well as their relative proportions are made so that the final properties of the mixture meet the desired specifications.

Due to the increasing scarcity of fossil resources and increasingly significant environmental concerns, the use of molecules from biomass is increasingly sought after to replace molecules of fossil origin. However, the preparation of jet fuel from molecules derived from biomass directly usable in the formulation of jet fuel constitutes a real economic and environmental challenge. In particular, certain countries like France put in place incentive taxes relating to the incorporation of renewable energy in transport and in particular for the aviation sector.

Prior art

A solution for obtaining a jet fuel with a component of biological origin consists of mixing a conventional jet with a paraffin base derived from renewable feedstocks as provided for by standard D7566-21, thus allowing the production of alternative aviation fuels. Bases for aviation fuel derived from renewable feedstocks that can be incorporated into fossil fuels are

• Synthetic paraffinic kerosenes [SPK], resulting from processes such as the Fischer-Tropsch process, the hydrotreatment of esters and fatty acids [HEFA-SPK] or produced by the Alcohol-to-jet route (transformation of alcohol into kerosene) [ATJ-SPK],

• Synthetic isoparaffins produced by hydrotreatment from fermented sugars [SIP-HFS],

• Synthetic aromatic kerosenes obtained by alkylation of light aromatics from non-petroleum sources [SPK/A],

• Synthetic kerosenes obtained from the hydrothermal conversion of fatty acid esters and fatty acids,

• Synthetic paraffinic kerosenes [SPK] obtained from hydrocarbons, esters and hydrotreated fatty acids.

This solution, however, requires specific processing facilities to produce the paraffinic bases which will be mixed with the conventional jet.

Another solution consists of co-treating a hydrocarbon of fossil origin with a feed of renewable origin, as provided in particular in standard ASTM D1655-21 c.

Thus, document EP2346962 describes a process making it possible to obtain a kerosene cut, part of which is of biological origin. For this purpose, a feed of petroleum origin mixed with a feed of biological origin is subjected to a hydrotreatment step, then fractionated in order to recover a kerosene cut. The filler of biological origin used is an animal oil and/or fat, or a mixture of these oils/fats. The oils and/or fats used are not transesterified.

Document EP2533895 describes a specific catalyst for producing biodiesel. It describes in particular the use of this catalyst to treat a load which is a mixture of a hydrocarbon of fossil origin (kerosene, diesel, etc.) and a biomass chosen from vegetable or animal oils and fats. The oils and/or fats used are not trans-esterified. Jet production is not mentioned.

Furthermore, document EP3813539 describes a process for producing a purified biodiesel from renewable raw materials (such as fats and oils) containing unsaponifiable materials. The process involves the esterification of vegetable oils or fats to obtain a crude biodiesel which is then subjected to distillation to produce a purified biodiesel and a distillation base. The latter contains more than 2% by mass of unsaponifiables as well as soaps, phospholipids, proteins, colored compounds, sulfur compounds, high boiling point compounds containing acidic or basic groups, and mono-, di- and triglycerides. This distillation bottom is then diluted with a filler of fossil origin of the middle distillate type, before being subjected to a hydrodeoxygenation step in order to produce hydrocarbons of the diesel type. Jet production is not mentioned.

Among the charges of renewable origin available today, charges having the status of animal by-products within the meaning of European Regulation 1069/2009 and its implementing acts (EU) 142/2011, such as animal fats or Used cooking oils (also referred to by the acronym UCO for “Used Cooking Oil” in English), are interesting in order to limit the environmental impact of the fuel produced. These charges are, however, subject to restrictive health regulations. The use of these fillers leads to traceability constraints and health controls associated in particular with the management of aqueous effluents. Furthermore, the use of these fillers having the status of animal by-products requires respecting the time/temperature and pressure conditions as recommended in European Regulation 1069/2009, these conditions not being met by a step of hydrotreatment alone. There is therefore a need for a process for manufacturing a jet fuel by unit co-processing. hydrotreatment, in particular from feedstocks of renewable origin having the status of animal by-products, which makes it possible to overcome the aforementioned problems.

Description of the invention

The invention proposes a process for manufacturing a jet fuel comprising at least the steps consisting of: a) providing ethyl esters of fatty acids resulting from the reaction of animal fats and/or used oils with ethanol in a transesterification reactor, b) supplying hydrocarbons of fossil origin, c) preparing a hydrocarbon feed containing the hydrocarbons of fossil origin supplied by step b) and the fatty acid ethyl esters supplied by step a ) in a content of at most 5% vol relative to the hydrocarbon feedstock, d) subjecting the hydrocarbon feedstock prepared in step c) to hydrotreatment and obtaining a treated hydrocarbon feedstock, e) fractionating the treated hydrocarbon feedstock obtained in step d) and recover a kerosene fraction as jet fuel, said kerosene fraction preferably having a final boiling point below 300°C, measured in particular according to standard ASTM D86-12.

The process according to the invention thus makes it possible to obtain an aviation fuel, part of which is of renewable origin, this type of fuel also being called SAF for “Sustainable Aviation Fuel” in English. In particular, the kerosene fraction obtained meets the specifications of an A1 jet according to standard ASTM D1655-21, in particular when the ethyl esters are obtained from animal fats which are animal by-products. This makes it possible to increase the production of kerosene by using this type of fat.

In particular, the process according to the invention can be implemented in existing hydrotreatment units.

Detailed description of the invention

The terms "comprising" and "includes" as used herein are synonymous with "including", "includes" or "contains", "containing", and are inclusive or without limitation and do not exclude additional features, elements or steps of unspecified methods.

The expressions % by weight and % by mass have an equivalent meaning and refer to the proportion of the mass of a product compared to 100g of a composition comprising it.

Boiling points as mentioned here are measured at atmospheric pressure unless otherwise noted. An initial boiling point is defined as the temperature value at which a first vapor bubble is formed. A final boiling point is the highest temperature achievable during distillation. At this temperature, no more vapor can be transported to a condenser. The determination of the initial and final points uses techniques known in the trade and several methods adapted depending on the range of distillation temperatures are applicable, for example NF EN 15199-1 (version 2020) or ASTM D2887-19 for the measurement of boiling points of petroleum fractions by gas chromatography, ASTM D7169-05 for heavy hydrocarbons, ASTM D7500-15(2019), D86-12 or D1160-18 for distillates.

Animal fats and used oils

The animal fats and used cooking oils, from which the ethyl esters used in the present invention are derived, are advantageously animal fats and used cooking oils having the status of animal by-products, in particular within the meaning of Regulation (EC) No. °1069/2009 of the European Parliament and of the Council of October 21, 2009 and Commission Regulation (EU) No. 142/2011 (Regulation implementing EC Regulation No. 1069/2009).

Animal fats with the status of animal by-product are fatty residues of animal origin, other than used cooking oils, for example from the food industries or rendering installations.

Used cooking oils having the status of animal by-products are used cooking oils (used cooking oils or UCO), namely residues of fats of plant or animal origin used for human food, in food industry, collective or commercial catering. Step a)

The ethyl esters of fatty acids supplied in step a) come from the reaction of animal fats and/or used oils with ethanol in a transesterification reactor.

In particular, this step a) may thus include, or consist of, a step of transesterification of animal fats and/or used oils with ethanol to obtain ethyl esters of the fatty acids initially contained in the animal fats and/or used oils, and glycerin, followed by a separation step by distillation, decantation or centrifugation of the ethyl esters produced.

During the transesterification step, the triglycerides contained in animal fats and/or used cooking oils react with ethanol to obtain ethyl esters of fatty acids in a transesterification reactor. This reaction, well known to those skilled in the art, is usually carried out in the presence of a catalyst, by an acid or basic, homogeneous or heterogeneous catalysis process, typically at a temperature of 25°C to 110°C or 35°C. °C to 90°C and a reaction time of 30 minutes to 50 hours. For example, we could use a catalyst/oil mass ratio of 0.25 to 8% and an ethanol/oil molar ratio of 3:1 to 15:1.

This reaction is for example carried out in the presence of acid catalysts (hydrochloric acid, sulfuric acid, sulfonic acid, boron trifloride, zinc chloride, acid ion exchangers, aluminum trioxide, iron trioxide, etc.) or in the presence basic catalysts such as alkali metal alkoxides and hydroxides as well as sodium or potassium carbonates (sodium hydroxide, potassium hydroxide, sodium ethanolate, potassium ethanolate, etc.).

The ethyl esters of fatty acids used in the present invention are therefore free of impurities such as unsaponifiable compounds, soaps, or other compounds originating from animal fats or used oils used as raw material. In particular, their unsaponifiable content is less than or equal to 1% m/m (measured according to standard ISO 3596:2001).

Advantageously, particularly when they are produced from animal fats and/or used cooking oils which are animal by-products, the esters ethyl fatty acids provided in step a) may comprise at least one of the following characteristics:

- at least 9%m, typically from 9%m to 64%m, of ethyl esters of fatty acids whose carbon chain contains from 12 to 16 carbon atoms,

- at least 25%m, typically from 30%m to 98%m, of ethyl esters of fatty acids whose carbon chain contains 18 carbon atoms,

- at most 4%m, typically from 0%m to 2%m, of ethyl esters of fatty acids whose carbon chain contains 20 to 22 carbon atoms.

When these esters are produced from animal fats (other than cooking oils) which are animal by-products (in particular within the meaning of European Regulation 1069/2009 and its implementing acts (EU) 142/2011), the ethyl esters of fatty acids provided in step a) may comprise at least one of the following characteristics:

- at least 20%m, typically from 20%m to 64%m,

- ethyl esters of fatty acids whose carbon chain contains 12 to 16 carbon atoms,

- at least 25%m, typically from 25%m to 65%m, of ethyl esters of fatty acids whose carbon chain contains 18 carbon atoms,

- at most 4%m, typically from 0%m to 2%m, of ethyl esters of fatty acids whose carbon chain contains 20 carbon atoms,

- at most 1%m, typically from 0%m to 1%m, of ethyl esters of fatty acids whose carbon chain contains 22 carbon atoms.

Preferably, the content of ethyl esters of fatty acids whose carbon chain contains 20 to 22 carbon atoms will be as low as possible, preferably zero, in order to improve the cold properties and in particular the freezing point.

In a preferred embodiment, the esters produced from animal fats which are animal by-products and having one or more of the characteristics mentioned above, are produced from animal fats originating from category 1 materials and/or from materials of category 2, category 1 and 2 materials being defined in articles 8 and 9 respectively of European Regulation 1069/2009. Step a) of supplying ethyl esters of fatty acids may in particular comprise (i) obtaining ethanol of renewable origin, (ii) followed by the reaction of animal fats and/or used oils with the ethanol obtained in step (i) in a transesterification reactor.

By ethanol of renewable origin, we mean ethanol obtained from biomass and/or by fermentation.

A. Obtaining ethanol of renewable origin by fermentation

In one embodiment, ethanol can be obtained by ethanolic fermentation in a bioreactor containing a culture of one or more microorganisms.

Ethanol of renewable origin can then advantageously be obtained by: aerobic fermentation of a substrate rich in sugars and/or starch derived from biomass, or anaerobic fermentation of a gas comprising CO, which may or may not come from biomass .

Aerobic fermentation

Ethanol can thus be produced by aerobic fermentation of a substrate rich in sugars and/or starch derived from biomass.

This substrate can for example include, or come from, sugar cane, sugar beet, sugar sorghum, corn, wheat, barley, rye, sorghum, triticale, potato , sweet potato, cassava, and/or lignocellulosic biomass.

The sugar-rich substrate can also be derived from lignocellullosic biomass by a treatment comprising (i) a step of separating the lignin, cellulose and hemicellulose contained in the lignocellullosic biomass, followed (ii) by a step of conversion of cellulose and/or hemicellulose into sugars.

Obtaining this type of substrate from lignocellulosic biomass is well known to those skilled in the art. Lignocellulosic biomass consists essentially of cellulose, hemicellulose and lignin. This biomass comes from agricultural and forestry residues or by-products from wood processing or crops, whether woody plants or herbaceous plants. This Lignocellulosic biomass can also include distillers' grains and allow the manufacture of ethanol as described in document EP2675778.

The first step (i) is a pretreatment step which makes it possible to separate the lignocellulosic matrix and to release the cellulose and hemicellulose from the complex formed with the lignin by means of one or more pretreatments. As pretreatment, we know steam pretreatment (or steam explosion), hot water pretreatment (hydrothermal), ammonia explosion (AFEX), pretreatment in an acid medium or pretreatment alkaline. Steam explosion treatment involves treating biomass, preferably previously shredded or ground, with high-pressure saturated steam at temperatures of approximately 160 to 240°C and pressures of 0.7 to 4.8MPa. The efficiency of steam treatment can be improved by adding H2SO4, CO2 or SO2 as a catalyst. In AFEX pretreatment, the biomass is contacted with a charge of anhydrous liquid ammonia in a ratio of 1:1 to 2:1 (1 to 2kg ammonia/kg dry biomass) for 10 to 60 min at 60 -90°C and at pressures above 3MPa. Hydrothermal pretreatment is similar to steam explosion, but uses liquid water at elevated temperatures instead of steam. In the case of pretreatment in an acid medium, typically in the presence of dilute acid, an aqueous suspension of the cellulose substrate is heated to the desired temperature and pretreated with preheated sulfuric acid (concentrations <4% mass) in a steel reactor stainless steel, the treatment is carried out at a temperature of 140 to 215°C. The residence time varies from a few seconds to a few minutes depending on the processing temperature. Lime pretreatment is an inexpensive physicochemical alkaline treatment that improves the digestibility of cellulosic biomass. By using 0.1g of Ca(OH)2/g of biomass, the treatment can be carried out over a wide temperature range from 25 to 130°C. The Organosolv process which is a process for the delignification and/or saccharification of cellulosic materials and plant crops can also be used. In general, the Organosolv process involves the use of a mixture of water and a solvent such as alcohols or ketones and sometimes other solvents of a non-polar nature, as well as an acidic compound to facilitate hydrolysis. A process of this type is described for example in document US4470851A. Step (ii) is a step of converting cellulose and/or hemicellulose into sugars. It is also well known to those skilled in the art. This is typically a hydrolysis which can be catalyzed by acid or by enzymes such as cellulases, for example the Trichoderma reesei strain, xylanases and xylosidases and arabinofuranosidases.

The substrate rich in sugars and/or starch is then subjected to fermentation.

For example, this fermentation can be carried out using microorganisms, and in particular yeasts, specialized which make it possible to optimize the profitability of the production process, in particular the following yeasts: Ethanol Red® (Fermentie), Thermosacc® (Lallemand )), Angel Super Alcohol® (Angel®) and Fali® (AB Mauric)), the Saccharomyces cerevisiae yeast strains described in document FR3015985, the Candida Shehatae or Pichia stipitis yeast strains, or any other suitable microorganism.

Anaerobic fermentation

Ethanol can also be produced by anaerobic fermentation of a gas comprising CO. The substrate is then a gaseous substrate (a gas) containing CO. This gaseous substrate can be a by-product of an industrial process or automobile exhaust. In some embodiments, the industrial process is selected from the group consisting of manufacturing of ferrous metal products, including steel mills, manufacturing of non-ferrous products, petroleum refining processes, coal gasification, production of electric power, carbon black production, ammonia production, methanol production, coke manufacturing and methane reforming. In these embodiments, the gaseous substrate can be captured from the industrial process before it is emitted into the atmosphere, using any suitable method. Depending on the composition of the gas thus captured, it may also be desirable to treat it to remove any unwanted impurities, such as dust particles, before introducing it into the fermentation. For example, the gas can be filtered or purified by known methods.

In other embodiments of the invention, the gaseous substrate can come from the gasification of biomass. The gasification process involves partial combustion of biomass in a restricted supply of air or oxygen. THE The resulting gas typically comprises primarily CO and H2, with minimal volumes of CO2, methane, ethylene, and ethane. For example, biomass by-products obtained during the extraction and processing of food products, such as sugar from sugar cane or starch from corn or cereals, or non-food biomass waste generated by the forestry industry, can be gasified to produce a CO-containing gas which can be used in the present invention.

The gaseous substrate used typically has a significant proportion of CO. The CO content of the gaseous substrate is typically 15% to 100% by volume, 15% to 95% by volume, 40% to 95% by volume, 40% to 60% by volume, and 45% to 95% by volume. 55% by volume or is in any interval defined by two of these limits. Advantageously, the gas containing CO can comprise 25%, 30%, 35%, 40%, 45%, 50%, 55% or 60% CO by volume. Gases with lower CO contents, such as 6 vol%, may also be suitable, particularly when hh and CO2 are also present.

It is not necessary for the gas substrate to contain hydrogen, but this is not considered detrimental to ethanol production. The gaseous substrate may also contain CO2, for example, in a proportion of 1% to 80% by volume, or 1% to 30% by volume or 5% to 10% by volume or in any interval defined by two of these limits.

Typically, carbon monoxide will be added to the fermentation reaction in the gaseous state, or in the liquid state. For example, carbon monoxide can be supplied in a liquid. For example, a liquid can be saturated with a gas containing carbon monoxide, and then this liquid can be added to a bioreactor. This can be achieved using a standard methodology. As an example, a microbubble dispersion generator (Hensirisak et. al. Scale-up of microbubble dispersion generator for aerobic fermentation; Applied Biochemistry and Biotechnolo RV Volume 101, Number 3 / October, 2002) could be used.

Furthermore, it is often desirable to increase the CO concentration of the gas (or the partial pressure of CO in the gas) and thus increase the efficiency of fermentation reactions using CO as a substrate. Increasing the partial pressure of CO in the gas increases the mass transfer of CO in a medium of fermentation. The composition of the gas streams used to fuel a fermentation reaction can have a significant impact on the efficiency and/or costs of this reaction. For example, 1'02 can reduce the efficiency of an anaerobic fermentation process. Dealing with unwanted or unnecessary gases in the steps of a fermentation process before or after fermentation can increase the load on those steps (e.g., when the gas stream is compressed before entering a bioreactor, unnecessary energy can be used to compress gases that are not necessary for fermentation). Therefore, it may be desirable to treat substrate streams, particularly substrate streams derived from industrial sources, to remove undesirable components and increase the concentration of desirable components.

Any microorganism capable of fermenting a gaseous substrate comprising CO to produce ethanol can be used in the present invention. As an example, microorganisms of the genus Moorella, Clostridia, Ruminococcus, Acetobacterium, Eubacterium, Butyribacterium, Oxobacter, Methanosarcina, Methanosarcina, and Desulfotomaculum can be used.

As an example, one may use the microorganism(s) of the genus Clostridium, including the strains of Clostridium ljungdahlii, Clostridium carboxydivorans, Clostridium ragsdalei and Clostridium autoethanogenum, of the genus Moorella, including Moorella sp HUC22-1, of the genus Carboxydothermus,, Moorella thermoacetica, Moorella thermoautotrophica, Ruminococcus productus, Acetobacterium woodii, Eubacterium limosum, Butyribacterium methylotrophicum, Oxobacter pfennigii, Methanosarcina barkeri, Methanosarcina acetivorans, or Desulfotomaculum kuznetsovii. Other specific examples of microorganisms are anaerobic carboxydotrophic bacteria. Examples of usable strains are described in document WO201226833.

It should be noted that the invention can be applied to a mixed culture of two or more microorganisms.

Fermentation environment and conditions

Whatever the nature of the substrate (gaseous or not) used, for the fermentation of ethanol to occur by growth of one or more microorganisms, an appropriate nutrient medium must be introduced into the bioreactor in addition to a substrate, in appropriate conditions. A nutrient medium will contain components, such as vitamins and minerals, sufficient to support the growth of the microorganism used. The reaction conditions to take into account are the temperature, the flow rate of the medium, the pH, the redox potential of the medium, the stirring speed (if using a continuously stirring reactor), the level of inoculum, maximum substrate concentrations and substrate introduction rates into the bioreactor to ensure that the substrate level does not become limiting, and maximum product concentrations to avoid product inhibition. Optimal reaction conditions will depend in part on the particular microorganism used. The methods for cultivating microorganisms are known in the art and those skilled in the art know how to optimize the culture conditions for each microorganism, depending on its nature. Examples of fermentation conditions suitable for the anaerobic fermentation of a substrate comprising CO are detailed in W02007/117157, W02008/115080, W02009/022925 and W002/08438.

Bioreactor

Fermentation reactions can be carried out in any suitable bioreactor. In some embodiments of the invention, the bioreactor may comprise a first growth reactor in which the microorganisms are cultivated, and a second fermentation reactor, into which the broth from the growth reactor is introduced and into which the Most of the fermentation product (e.g. ethanol) is produced.

of the fermentation product

The fermentation will result in a fermentation broth comprising a desirable product (ethanol) and/or one or more by-products (such as acetate and butyrate when the substrate is a gas containing CO) as well as microorganism cells, in a nutrient medium.

Ethanol recovery may include continuously removing a portion of the broth and recovering ethanol from the removed portion of the broth.

For example, the removed part of the broth containing ethanol can be passed through a separation unit to separate, for example by filtration, the bacterial cells from the broth and produce a permeate containing ethanol without cells, and the return of the microorganism cells to the bioreactor. The cell-free ethanol-containing permeate can then be used for the subsequent transesterification reaction.

In some embodiments, recovery of the ethanol and/or one or more other products or by-products produced in the fermentation reaction comprises continuously removing a portion of the broth and separately recovering the ethanol and one or more other products from the portion removed from the broth.

As an example, ethanol can be recovered from the fermentation broth using methods such as filtration, distillation or fractional evaporation, pervaporation and extractive fermentation. Distillation of ethanol from a fermentation broth gives an azeotropic mixture of ethanol and water (i.e. 95% ethanol and 5% water). Anhydrous ethanol can then be obtained by the use of molecular sieve ethanol dehydration technology, which is also well known in the art.

Extractive fermentation procedures involve the use of a water-miscible solvent that poses a low risk of toxicity to the fermentation organism, to recover ethanol from the diluted fermentation broth. For example, oleyl alcohol is a solvent that can be used in this type of extraction process. The oleyl alcohol is continuously introduced into a fermenter, whereupon this solvent rises forming a layer at the top of the fermenter which is continuously extracted and passed through a centrifuge. The water and cells are then easily separated from the oleyl alcohol and returned to the bioreactor, while the ethanol-laden solvent is fed into a rapid vaporization unit. Most ethanol is vaporized and condensed, while oleyl alcohol is non-volatile and is recovered for reuse in fermentation.

B. Obtaining ethanol of renewable origin from biomass

Ethanol of renewable origin can also be obtained from biomass by conversion of a synthesis gas rich in CO/H2, this synthetic gas coming from biomass.

Biomass can for example be gasified to produce a synthesis gas (or “syngas” in English) rich in CO/H2, this synthetic gas then being converted into methanol in the presence of a catalyst. A process of this type is for example described in the document WO2012003901.

Synthesis gas suitable for further conversion to ethanol can also be obtained by pyrolysis of biomass.

Biomass used to produce syngas may include wood fuels from natural forests and woodlands (e.g. sawdust), agricultural residues (e.g. rice husk, straw manure) , energy crops that are grown exclusively for energy production (e.g. corn and oil palm), urban waste (e.g. wood waste, rice, straw manure), energy crops that are grown exclusively for energy production (e.g., corn and oil palm), urban waste (e.g., municipal solid waste and sewage), and waste-derived biomass fuel (e.g., wood pellets).

Step b)

The fossil hydrocarbons which can be used in the present invention can be chosen from kerosene cuts.

A kerosene cut of fossil origin has boiling points ranging from 130°C to 300°C. It typically has an initial boiling point according to the ASTM D86-12 standard of 130 to 160°C and a final boiling point according to the ASTM D86-12 standard of 220°C to 300°C. These kerosene cuts can be :

- a kerosene cut from the direct distillation of crude oil,

- a kerosene cut from different conversion processes such as catalytic cracking, hydrocracking and/or visbreaking.

In the context of hydrotreatment, the hydrocarbons of fossil origin are advantageously a kerosene cut or a mixture of kerosene cuts, preferably coming from the direct distillation of crude oil or from hydrocracking.

Step c)

The hydrocarbon feed prepared in step c) contains the hydrocarbons of fossil origin provided by step b) and the ethyl esters of fatty acids provided by step a) in a content of at most 5% vol relative to the hydrocarbon filler, advantageously at most 0.9% or 0.6% or 0.5% or 0.4% or 0.3% by volume .

Advantageously, the content of fatty acid ethyl esters in the hydrocarbon feedstock can be from 0.1% by volume to 1% by volume, preferably from 0.1% by volume to 0.9% by volume, or from 0 .1% to 0.6% by volume, more preferably 0.1% to 0.5% by volume or 0.1 to 0.4% by volume or 0.1 to 0.3% by volume , or in any inclusive interval defined by two of these limits.

This preparation step can be carried out by simply mixing the constituents of the hydrocarbon feed supplied in steps a) and b), in particular upstream of the hydrotreatment step of step d), or during step d. ).

We can thus plan to mix the constituents of the hydrocarbon feedstock supplied in steps a) and b) upstream of a hydrotreatment reactor in which step d), or inside this reactor.

Step d)

Step d) of hydrotreatment of the hydrocarbon feed can be implemented in one or more reactors. Any type of reactor usually used for this type of reaction can be used, for example a fixed bed reactor, a bubbling bed reactor, a slurry reactor, etc., preferably a fixed bed reactor.

In particular, it is possible to use a reactor of the type usually used for the hydrotreatment of hydrocarbons of fossil origin.

Advantageously, step d) is carried out under a pressure of 15 to 130 bars and at a temperature of 250 to 380°C, preferably 280 to 340°C, in the presence of a hydrotreatment catalyst and dihydrogen. .

Typically we can provide an hourly space velocity of the liquid (WH in French, LHSV in English - Liquid Hourly Space Velocity): from 0.2 to 9 hr ¹ , preferably 0.5 to 7, and more preferably 0.8 to 1 .8, and a dihydrogen ratio: 50 to 1500 Nm ³ /m ³ of charge, preferably 120 to 250 Nm ³ /m ³ and more preferably 120 to 200 Nm ³ /m ³ .

Step d) is typically carried out in a fixed bed reactor, comprising one or more catalyst beds. More specifically, step d) can be carried out under a pressure of 15 to 50 bars and at a temperature of 280°C to 340°C, in the presence of a hydrotreatment catalyst and dihydrogen, typically with a dihydrogen rate from 120 to 180 Nm ³ /m ³ of charge. Typically we can predict an hourly space velocity of the liquid of l to 1.6 h ^-1 .

The hydrotreatment catalyst is a conventional hydrotreatment catalyst. Conventional hydrotreatment catalysts include in particular an active metal compound such as nickel, platinum, palladium, rhenium, rhodium, nickel tungstate, nickel molybdenate, molybdenum, cobalt molybdenate, nickel molybdenate, nickel, this metallic compound may or may not be deposited on a support. This support can generally comprise oxides such as silicas, aluminas, aluminosilicates (in particular zeolites), oxides of titanium, or even carbon, molecular sieves, salts or alkaline earth metals. When a support is present, it advantageously has a specific surface area varying from 100 to 250 m ² /g, preferably from 150 to 200 m ² /g.

Advantageously, the catalyst comprises at least two metals from groups 6, 9, 10, 11 of the periodic table of elements, preferably at least two metals such as NiMo, CoMo, or even CoNiMo, preferably on an alumina support.

When supported, conventional hydroprocessing catalysts typically comprise a metal content of 0.01 to 25% by mass relative to the total mass of the catalyst, preferably 15 to 20% by mass, for example 20 % by mass relative to the total mass of the catalyst.

In a preferred embodiment, the catalyst used does not have an isomerizing function or has negligible isomerizing activity under the reaction conditions. In other words, the catalyst does not promote the isomerization of the hydrocarbon compounds present in the feed. When a support is present, it is preferably slightly or not acidic.

Thus, a catalyst not having an isomerizing function can comprise at least one metal from groups 6, 9, 10, 11 of the periodic table of elements, optionally on a support chosen from alumina, silica alumina, phosphated alumina, borated alumina, phosphated alumina silica, alone or in a mixture. The hydrotreatment step d) produces an effluent containing a liquid fraction containing the kerosene fraction, and a gaseous fraction.

Step e)

The hydrotreated feedstock obtained at the outlet of step d) undergoes fractionation. This fractionation can be carried out by distillation or stripping, in particular by adding a separation column, for example a distillation column, or even a stripping column.

After the hydrotreatment stage, the effluent leaving the reactor is fractionated, typically by stripping, in order to recover a kerosene cut. This fractionation can be implemented so that the kerosene cut forms a jet fuel, respecting in particular the desired specifications.

The recovered kerosene fraction has a final boiling point less than or equal to 300°C, in particular measured according to the ASTM D86-12 standard.

The initial boiling point according to ASTM D86-12 can be 120 to 185°C. The final boiling point according to ASTM D86-12 can be 220 to 300°C.

The recovered kerosene fraction advantageously has one or more of the following properties:

- a kinematic viscosity at -20°C of 1.2 to 8.0 mm ² /s (NF EN ISO 3104-August 1996),

- a density at 15°C of 775 to 840 kg/m ³ (ASTM D4052-18 or IP 365),

- a freezing point of at most -47°C (ASTM D5972-16 or IP435),

- a flash point of at least 38°C (IP170-21 or ASTM D56-21A).

In particular, it will be possible to adapt the cutting points of the recovered kerosene fraction in order to obtain a kerosene fraction respecting the desired specifications, for example those of an A1 jet according to the ASTM D1655-21 standard, in particular at least with regard to the point final distillation and/or freezing point and/or flash point.

Thus, step e) makes it possible to obtain a kerosene fraction meeting one or more of the required specifications, in particular those of an A1 jet according to the ASTM standard. D1655-21, in particular at the incorporation levels of the ethyl esters in the hydrocarbon feed prepared in step c) above.

The fractionation step also makes it possible to recover the gas produced, in particular methane, during the hydrotreatment step.

Description of figures

Fig. 1: simplified diagram of a hydrotreatment unit making it possible to implement the process according to one embodiment of the invention.

Figure 1 represents a simplified diagram of a hydrotreatment unit 1 making it possible to implement the process according to the invention.

This unit 1 comprises a reactor 2 into which the feed to be treated is introduced by means of a line 3. This reactor contains one or more beds of hydrotreatment catalysts.

The filler (C), in the present invention, is a mixture of a kerosene filler of fossil origin and ethyl esters of fatty acids of renewable origin.

A line 4 recovers the effluent leaving reactor 2 and leads it to a separation section 5.

A heat exchanger 6 is placed downstream of the reactor on line 4 in order to heat the charge circulating in line 3, upstream of the reactor.

Upstream of this heat exchanger 6, a line 7, connected to line 3, supplies a gas rich in H2 to the load to be treated.

Downstream of the heat exchanger 6, and upstream of the reactor 2, the feed mixed with the H2-rich gas circulating in line 3 is heated by a furnace 8.

Thus, the feed is mixed with the hydrogen-rich gas, then brought to the reaction temperature by the heat exchanger 6 and the oven 8 before entering reactor 2. It then passes into reactor 2.

At the outlet of the reactor, the mixture obtained is cooled, then separated in the separation section 5, for example by stripping, which makes it possible to obtain: - a gaseous fraction (G), containing in particular water from stripping, gaseous hydrocarbons, an acid gas rich in H2S, part of which is reinjected into the gas rich in H2 mixed with the load, by means of a line 9,

- a kerosene cup (K).

Claims

1. Process for manufacturing a jet fuel comprising at least the steps consisting of: a) providing ethyl esters of fatty acids resulting from the reaction of animal fats which are animal by-products with ethanol in a transesterification reactor, step a) comprising:

(i) obtaining ethanol from renewable sources,

(ii) followed by the reaction of animal fats with the ethanol obtained in step

(i) in a transesterification reactor, and the fatty acid ethyl esters supplied include:

- from 20%m to 64%m of ethyl esters of fatty acids whose carbon chain contains 12 to 16 carbon atoms,

- from 25%m to 65%m of ethyl esters of fatty acids whose carbon chain contains 18 carbon atoms, b) supply hydrocarbons of fossil origin, c) prepare a hydrocarbon feed containing hydrocarbons of fossil origin provided by step b) and the ethyl esters of fatty acids provided by step a) in a content of at most 5% by volume relative to the hydrocarbon feed, d) subjecting the hydrocarbon feed prepared during the step c) to a hydrotreatment and obtain a treated hydrocarbon feedstock, e) fractionate the treated hydrocarbon feedstock obtained in step d) and recover a kerosene fraction as jet fuel, said kerosene fraction preferably having a lower final boiling point at 300°C.

2. Manufacturing process according to claim 1, in which during step e) the cutting points of the recovered kerosene fraction are adapted in order to obtain a kerosene fraction meeting the specifications of an A1 jet according to standard ASTM D1655 -21. Manufacturing process according to claim 1 or 2, in which the fatty acid ethyl esters provided in step a) comprise at least one of the following characteristics:

- at most 4%m of ethyl esters of fatty acids whose carbon chain contains 20 carbon atoms,

- at most 1%m of ethyl esters of fatty acids whose carbon chain contains 22 carbon atoms. Manufacturing process according to any one of claims 1 to 3, in which the hydrocarbons of fossil origin supplied in step b) are chosen from kerosene cuts. Manufacturing process according to any one of claims 1 to 4, in which, during step (i), the ethanol of renewable origin is obtained by ethanolic fermentation in a bioreactor containing a culture of one or more microorganisms. Manufacturing process according to claim 5, in which, during step (i), the ethanol is obtained by:

- aerobic fermentation of a substrate rich in sugars and/or starch derived from biomass, or

- anaerobic fermentation of a gaseous substrate comprising CO. Manufacturing process according to any one of claims 1 to 4, in which, during step (i), the ethanol of renewable origin is obtained by conversion of a synthesis gas rich in CO/H2, this synthesis gas comes from biomass. Manufacturing process according to any one of claims 1 to 7, in which step d) is carried out under a pressure of 15 to 130 bars and at a temperature of 250 and 380°C, in the presence of a catalyst hydrotreatment and dihydrogen. Manufacturing process according to any one of claims 1 to 8, in which the hydrotreatment catalyst comprises at least one metal of the groups 6, 9, 10, 11 of the periodic table of elements, optionally on a support chosen from alumina, silica alumina, phosphated alumina, borated alumina, phosphated silica alumina, alone or as a mixture.