FR3135986A1 - PROCESS FOR MANUFACTURING HYDROCARBON FLUIDS FROM FEEDS OF RENEWABLE ORIGIN - Google Patents

Abstract

METHOD FOR MANUFACTURING HYDROCARBON FLUIDS FROM FEEDS OF RENEWABLE ORIGIN The invention relates to a process for manufacturing renewable hydrocarbon fluids comprising at least: a) a step of supplying a first oil of natural origin and a second oil of natural origin, b) a step of producing ethyl esters of fatty acids by reaction of the triglycerides contained in the first oil of natural origin with ethanol of renewable origin in a transesterification reactor, c) a step of preparing a hydrocarbon filler containing the ethyl esters of fatty acids of step b) and the second oil of natural origin of step a), the hydrocarbon filler having a content of ethyl esters of fatty acids from 5 to 95% by mass, d) a deoxygenation step by hydrotreatment, in which the hydrocarbon feed prepared in step c) is subjected to a deoxygenation reaction in the presence of at least one catalyst under conditions suitable for transform the fatty acid esters and the free fatty acids contained in said hydrocarbon feed into paraffins, e) a hydroisomerization step during which the effluent from step d) is subjected to a hydroisomerization reaction in the presence of dihydrogen and at least one catalyst, f) a separation step in which the effluent from step e) is separated into at least one fraction chosen from a naphtha fraction, a gas oil fraction and a kerosene fraction. Abstract figure: without

Description

PROCESS FOR MANUFACTURING HYDROCARBON FLUIDS FROM FEEDS OF RENEWABLE ORIGIN

The present invention relates to the manufacture of hydrocarbon fluids from complex mixtures of hydrocarbons of renewable origin. In particular, the present invention relates to a process for converting a biological raw material comprising fatty acid esters (FAE), free fatty acids (FFA) into oxygen-free paraffinic compounds, which can be used as fuels.

Background of the invention

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. In particular, some countries such as France are implementing taxes on aviation fuels. Thus, from 2022, 1% of the jet used in France must be of renewable origin. Thus, the preparation of jet fuel, or other hydrocarbon fuels or fluids, from molecules derived from biomass constitutes a real economic, environmental and strategic challenge.

Prior art

Today, there are numerous processes for manufacturing a renewable fuel, or one comprising a component of biological origin.

A well-known process consists of carrying out a transesterification of the triglycerides contained in vegetable or animal fats or oils with an alcohol, generally methanol or ethanol, in the presence of a catalyst. The resulting renewable fuel is called biodiesel or fatty acid methyl ester and is currently incorporated into the diesel pool. The alcohols used to carry out this transesterification reaction are, however, produced by synthesis processes using products that are harmful to the environment and raw materials (olefins) of fossil origin. Thus, synthetic ethanol is often manufactured by the sulfuric process based on the absorption of ethylene in sulfuric acid, followed by the hydrolysis of the ethyl sulfates formed. The use of sulfuric acid requires specific materials for the equipment used. Another commonly used process involves directly hydrating ethylene using water vapor in the presence of a catalyst. Although simpler, this process requires high temperatures and pressures and also uses ethylene of fossil origin. Thus, although considered as components of renewable origin, ethyl or methyl esters of fatty acids are obtained by processes which are expensive in energy and/or which use compounds harmful to the environment, and most often use raw materials that are not of renewable origin.

Another well-known process for manufacturing a renewable fuel and other hydrocarbon fluids consists of subjecting a vegetable or animal fat or oil to deoxygenation in the presence of dihydrogen and a catalyst, generally followed by isomerization in order to obtain the required cold properties. In this case, we are not talking about biodiesel, a term reserved for fuels resulting from transesterification, but rather fuel of renewable origin. The filler used is entirely of renewable origin, the latter typically including animal fats and oils and various seed-based oils, soya, rapeseed, palm, seed oils which have been collected after being used to prepare food, commonly called used cooking oils (UCO), or even algal oils. Crops used to produce oils for fuel, however, can compete with food crops and have a negative impact on the environment. Among the loads of renewable origin available today, loads with waste status, such as animal fats or used oils (also referred to by the acronym UCO for “Used Cooking Oil” in English), are interesting in order to 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 waste requires respecting the time/temperature and pressure conditions as recommended in European Regulation 1069/2009.

The invention aims to propose a process for manufacturing hydrocarbon fluids, and in particular renewable fuels, whose impact on the environment is as low as possible.

Description of the invention

The invention proposes a process for manufacturing renewable hydrocarbon fluids comprising at least the steps consisting of:

a) a step of supplying a first oil of natural origin and a second oil of natural origin,

b) a step of producing ethyl esters of fatty acids by reaction of the triglycerides contained in the first oil of natural origin with ethanol of renewable origin in a transesterification reactor,

c) a step of preparing a hydrocarbon feed containing the ethyl esters of fatty acids from step b) and the second oil of natural origin from step a), the hydrocarbon feed having a content of ethyl esters d fatty acids from 5 to 95% by mass,

d) a deoxygenation step by hydrotreatment, in which the hydrocarbon feedstock prepared in step c) is subjected to a deoxygenation reaction in the presence of at least one catalyst under conditions suitable for transforming the fatty acid esters and the free fatty acids contained in said hydrocarbon filler in paraffins,

e) a hydroisomerization step during which the effluent from step d) is subjected to a hydroisomerization reaction in the presence of dihydrogen and at least one catalyst,

f) a separation step in which the effluent from step e) is separated into at least one fraction chosen from a naphtha fraction, a kerosene fraction and a gas oil fraction.

Detailed description of the invention

The terms "comprising" and "comprises" as used herein are synonymous with "including", "includes" or "contains", "containing", and are inclusive or unlimited and do not exclude additional features, unspecified elements or method steps.

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 for measuring the points d boiling of petroleum fractions by gas chromatography, ASTM D7169 for heavy hydrocarbons, ASTM D7500, D86 or D1160 for distillates.

Step a) supply of an oil of natural origin

Each of the first and second oils of natural origin provided in step a) of the process of the present invention may be a mixture of one or more oils of natural origin.

The first oil of natural origin and the second oil of natural origin provided in step a) may or may not be identical.

In a preferred embodiment, the first oil of natural origin is chosen from animal fat, used oil, animal fats and used cooking oils which are animal by-products, and mixtures thereof, preferably animal fats and used cooking oils which are animal by-products.

This makes it possible to reduce the environmental impact of the fluids produced by the present invention.

In a preferred embodiment, the second oil of natural origin used in step c) is chosen from a vegetable oil, an animal oil or fat, an oil produced by microorganisms and their mixtures. Preferably, the second oil of natural origin is not a used oil and/or is not an animal by-product.

An oil of natural origin is defined as an oil that does not contain mineral oil of fossil origin.

Typically, an oil of natural origin may contain 50%m or more, preferably 60%m or more, preferably 70%m or more, fatty acid esters (mono-, di- or triglycerides) and/or of fatty acids.

In one embodiment, an oil of natural origin may contain fatty acid esters (mono-, di- or triglycerides) and/or free fatty acids, containing one to three C8-C24 acyl groups, saturated or unsaturated. When multiple acyl groups are present, they may be the same or different.

The oil of natural origin can be chosen from a vegetable oil, an animal oil or fat, a used oil, an oil produced by microorganisms, animal fats and used cooking oils which are animal by-products, as well as their mixtures.

The vegetable oil can be chosen from pine oil, rapeseed oil, sunflower oil, castor oil, peanut oil, linseed oil, babasu oil , hemp oil, linola oil, jatropha oil, peanut oil, rice bran oil, mustard oil, carinata oil, walnut oil coconut oil, copra oil, olive oil, palm oil, cottonseed oil, corn oil, palm kernel oil, soybean oil, coconut oil squash, grapeseed oil, argan oil, jojoba oil, sesame oil, walnut oil, hazelnut oil, Chinese wood oil, rice oil, safflower oil, and any combination thereof.

Used oil includes used cooking oils or used food oils and oils recovered from waste water, such as trap and drain greases/oils, gutter oils, sewer oils, e.g. water treatment plants, and used fats from the food industry.

Animal fat can be chosen from tallow, lard, grease (yellow and brown fat), fish oil/fat, milk fat, animal fats which are animal by-products.

In particular, animal fats and used cooking oils which are animal by-products have the status of animal by-products within the meaning of Regulation (EC) No. 1069/2009 of the European Parliament and of the Council of October 21, 2009 and Regulation (EU) No. 142/2011 of the Commission (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.

The oil of natural origin can also be an oil produced by microorganisms, natural or genetically modified, such as bacteria, yeasts, in particular oleaginous yeasts, algae, prokaryotes or eukaryotes. In particular, these oils can be recovered by well-known mechanical or chemical extraction methods.

The aforementioned oils, rich in triglycerides, additionally contain varying amounts of non-triglyceride components such as free fatty acids, mono- and diglycerides, and many other organic and inorganic components, including phosphatides, sterols, tocopherols, tocotrienols, hydrocarbons, pigments (gossypol, chlorophyll), vitamins (carotenoids), sterol glucosides, glycolipids, protein fragments, traces of pesticides and traces of metals, as well as resinous and mucilaginous materials.

Such oils are obtained by chemical and physical treatments well known to those skilled in the art, similar to those used for the treatment of edible oils, such as degumming, neutralization with an alkaline solution ( generally NaOH), bleaching, finishing or polishing, steam treatment, cavitation, etc.

Step b)

The ethyl esters of fatty acids produced in step b) come from the reaction of the triglycerides contained in the first oil of natural origin with ethanol of renewable origin in a transesterification reactor.

In particular, this step a) can thus include a step of transesterification of oil of natural origin with ethanol to obtain ethyl esters of the fatty acids initially contained in the oil of natural origin and glycerin, followed by a step of separation by distillation of the ethyl esters produced.

The transesterification reaction is well known to those skilled in the art. It 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 to 90°C and a reaction time from 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 is 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 of 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 transesterification reaction can also be carried out under supercritical conditions can also be used, the reaction being carried out at high pressures of 15-35MPa, and, in some cases, at high temperatures of 250 to 280°C, or even higher. Under these supercritical conditions, the reaction can be carried out in the absence or presence of catalyst. Examples of usable conditions and catalysts are described in “Transesterification in Supercritical Conditions” Somkiat Ngamprasertsith et al, Biodiesel - Feedstocks and Processing Technologies, November 2011, chapter 12, pages 247-268. In the absence of a catalyst, we can for example operate at temperatures of 280-350°C, pressures of 19 to 35 MPa, an alcohol/oil molar ratio of 24:1 to 42-1 and a reaction time of 5 to 30 min.

The ethyl esters of fatty acids used in the present invention are advantageously 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).

The oil of natural origin may be as previously described. In a preferred embodiment, this oil of natural origin is chosen from an animal fat and/or a used oil, and in particular from an animal fat and/or a used oil having the status of waste, which makes it possible to reduce further the environmental impact of the fluids produced by the process according to the invention. Advantageously, this oil of natural origin has a content of compounds other than glycerides and free fatty acids, and in particular other than triglycerides and free fatty acids, less than or equal to 1% by mass.

Advantageously, particularly when they are produced from animal fats and/or used cooking oils which are animal by-products, the ethyl esters of 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 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 by-products which are animal fats, the fatty acid ethyl esters provided in step a) may include 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.

Step b) of supplying ethyl esters of fatty acids may further comprise (i) obtaining ethanol of renewable origin, (ii) followed by the reaction of the first oil of natural origin 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, during step (i), a substrate is subjected to ethanolic fermentation in a bioreactor containing a culture of one or more microorganisms and the ethanol of renewable origin produced is recovered.

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 is essentially made up 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 H ₂ SO ₄ , CO ₂ or SO ₂ 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, 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 resulting gas typically comprises primarily CO and _H2 , with minor 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 volume percent, may also be suitable, particularly when H ₂ and CO ₂ 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 CO ₂ , 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 into a fermentation medium. 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, O ₂ 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, under 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 anaerobic fermentation of a substrate comprising CO are detailed in WO2007/117157, WO2008/115080, WO2009/022925 and WO02/08438.

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.

Recovery 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 microorganism cells in 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 results in 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/H ₂ , this synthetic gas being derived from biomass.

Biomass can for example be gasified to produce a synthesis gas (or “syngas” in English) rich in CO/H ₂ , this synthetic gas then being converted into methanol in the presence of a catalyst. A process of this type is for example described in 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 c)

The hydrocarbon feed prepared in step c) contains the ethyl esters of fatty acids produced in step b) and the second oil of natural origin provided by step a). This hydrocarbon filler has a fatty acid ethyl ester content of 5 to 95% by mass, advantageously 20 to 80% by mass, preferably 30 to 70% by mass, for example 50% is included in any range. defined by two of the aforementioned values.

This preparation step can be carried out by simply mixing the components of 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 components of the hydrocarbon feed of steps a) and b) upstream of a hydrotreatment reactor in which step d), or inside this reactor.

In a preferred embodiment, the hydrocarbon feed consists solely of the components of steps a) and b). No charge of fossil origin is added to the charge.

The hydrocarbon filler of the present invention therefore comprises, or even consists solely of, ethyl esters of fatty acids, free fatty acids, and glycerides (mono-, di-, triglycerides) originating from the components of steps a) and b). .

Hydrotreatment step d)

Different reactions can take place in the transformation of fatty acid esters and free fatty acids contained in the hydrocarbon feed into paraffins:

• hydrodeoxygenation (HDO), which eliminates oxygen from treated oils and leads to the formation of linear paraffins while preserving the number of carbons of the initial fatty chains and is accompanied by the formation of water and propane, this reaction can be carried out on fatty acid esters, free fatty acids or mixtures thereof;
• decarboxylation and/or decarbonylation (COD _x ), which leads to the formation of paraffins containing one less carbon atom than the initial fatty chain and is accompanied by the formation of carbon oxides (CO and CO ₂ ) and of propane, this reaction can be carried out on glycerides, any esters or with free fatty acids.

This hydrotreatment step d) can thus comprise one or more steps chosen from hydrodeoxygenation, decarboxylation and decarbonylation.

This hydrotreatment step is typically carried out in the presence of dihydrogen and at least one catalyst suitable for transforming the fatty acid esters and the free fatty acids contained in the hydrocarbon feed into paraffins, in particular into linear or substantially linear paraffins.

The catalyst can be chosen from (i) oxides or sulphides of Ni, Mo, W, Co or mixtures of NiW, NiMo, CoMo, NiCoW, NiCoMo, NiMoW and CoMoW, (ii) metals or mixtures of alloys. of metals from group 10 and group 11 of the periodic table, (iii) basic oxides such as alkali metal oxides, alkaline earth oxides, lanthanide oxides, zinc oxide, spinels, perovskites, calcium silicates.

The catalyst may have a supported or unsupported catalytic active phase.

When the catalyst comprises a support for the catalytic active phase, it is preferable for the support to have a high specific surface area. In one embodiment, the specific surface area must be at least 5 m ² /g, preferably at least 50 m ² /g and more preferably at least 75 m ² /g, this specific surface area can be measured by methods known in the art such as the BET method where nitrogen adsorption makes it possible to estimate the specific surface area of the solid material.

It is also preferable that the support of the catalytic active phase has a low acidity, preferably neutral or basic, in order to avoid hydroisomerization reactions which would give rise to branched paraffins and cracking at high temperature and pressure. in the presence of dihydrogen.

The hydrotreatment can be carried out at a temperature of 100 to 550°C in the presence of dihydrogen at pressures ranging from 0.01 to 10 MPa. The ratio between dihydrogen and feedstock can be 100 to 2000 Nl/l.

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 stirred tank reactor, a bubbling bed reactor, a slurry type reactor, etc., preferably a bed reactor. fixed.

Advantageously, the effluent from step d) can be subjected, before being sent to step e) or f), to a separation of non-condensable components such as propane, CO ₂ , CO, methane, dihydrogen and vaporized water. This separation can be a flash separation or be carried out in a stripping section. Depending on operating conditions, some of the remaining water may be condensed and removed in this optional step by settling or drainage. Flash separation and liquid water discharge can be carried out simultaneously. The dihydrogen can in particular be separated and returned to the inlet of step d).

Hydrodeoxygenation

Several reactions occur under hydrodeoxygenation conditions. The easiest is the hydrogenation of the double bonds in the alkyl chain. The more difficult reaction is the removal of oxygen atoms from CO bonds. The carboxyl group of the fatty acid and the hydroxyl group of the glycerol moiety are hydrodeoxygenated. This results in the production of linear paraffin, from the acyl fraction, and propane, from glycerol. Depending on the conditions (catalyst, temperature, dihydrogen, etc.), the carboxyl group can also be broken down into CO/CO ₂ (decarboxylation or decarbonylation), which in turn can be hydrogenated into methane. These hydrodeoxygenation reactions consume a lot of hydrogen.

As an example, we give the equation for the hydrodeoxygenation of triolein:

[C ₁₈ H ₃₃ O] ₃ C ₃ H ₅ O ₃ + 15 H ₂ 3 C ₁₈ H ₃₈ + C ₃ H ₈ + 6 H ₂ O

Hydrodeoxygenation of fatty acids:

R-CH ₂ -CH ₂ -COOH + 3 H ₂ R-CH ₂ -CH ₂ -CH ₃ + 2 H ₂ O

The catalyst is typically a solid catalyst which can be chosen from oxides or sulphides of Ni, Mo, W, Co or mixtures such as NiW, NiMo, CoMo, NiCoW, NiCoMo, NiMoW and CoMoW as catalytic phase, preferably supported on carbon, alumina, silica, titanium oxide or zirconia.

The hydrodeoxygenation can be carried out at a temperature of 200 to 500°C, preferably 220 to 400°C, under a pressure of 1 MPa to 10 MPa (10 to 100 bars), for example 6 MPa, and with a ratio of dihydrogen/hydrocarbon filler from 100 to 2000, but preferably from 350 to 1500, for example 800 Nl H ₂ /l of hydrocarbon filler.

For optimal performance and stable continuous operation, it is preferable that the active metal component of the catalyst in the case of Ni, Mo, W, Co or mixtures thereof, be in the form of sulphides. It is therefore preferable that traces of decomposable sulfur compounds (thermally or catalytically) are present or voluntarily added to the charge in order to maintain the metal sulfide in its sulfide state. For example, these sulfur compounds can be H ₂ S, COS, CS ₂ , mercaptans (for example, methylsulfide), thioethers (for example, DiMethylSulfide), disulfides (for example, DiMethyldiSulfide), thiophene and tetrahydrothiophene compounds.

Hydrodeoxygenation is preferably carried out in continuous fixed bed reactors, continuous stirred tank reactors or slurry type reactors, particularly in the presence of a solid catalyst.

Decarboxylation and/or decarbonylation

Under the conditions of decarboxylation and/or decarbonylation, the following reactions can occur:

Decarboxylation:

R-CH ₂ -CH ₂ -COOH R-CH ₂ -CH ₃ + CO ₂

[C ₁₈ H ₃₃ O] ₃ C ₃ H ₅ O ₃ + 6 H ₂ 3 C ₁₇ H ₃₆ + 3 CO ₂ + C ₃ H ₈

Decarbonylation:

R-CH ₂ -CH ₂ -COOH R-CH=CH ₂ + CO + H ₂ O

Other reactions that can occur under decarboxylation and/or decarbonylation conditions are:

- hydrogenation of unsaturated bonds:

R-CH=CH ₂ + H ₂ R-CH ₂ -CH ₃

- hydrodeoxygenation of fatty acids:

R-CH ₂ -CH ₂ -COOH + 3 H ₂ R-CH ₂ -CH ₂ -CH ₃ + 2 H ₂ O

Additional hydrogenation of the CO/CO ₂ product can occur depending on the amount of dihydrogen available, the catalyst and the reaction conditions:

CO + 3 H ₂ CH ₄ + H ₂ O

CO ₂ + 4 H ₂ CH ₄ + 2 H ₂ O

Decarboxylation and/or decarbonylation is preferably carried out in the presence of a solid catalyst, generally in batch tank reactors, continuous fixed bed reactors, continuously stirred tank reactors or slurry type reactors.

The catalyst can be chosen from:

- the oxides or sulphides of Ni, Mo, W, Co, NiW, NiMo, CoMo, NiCoW, NiCoMo, NiMoW and CoMoW as catalytic phase, preferably supported on carbon, alumina, silica, titanium oxide or zirconia, or

- metals or mixtures of alloys from group 10 (Ni, Pt and Pd) and group 11 (Cu and Ag) supported by carbon, magnesia, zinc oxide, spinels (Mg ₂ Al ₂ O ₄ , ZnAl ₂ O ₄ ), perovskites (BaTiO ₃ , ZnTiO ₃ ), calciumsilicates (such as xonotlite), alumina, silica or silica-aluminas or mixtures thereof, or

- basic oxides, such as alkali metal oxides (MgO, ZnO), alkaline earth oxides, lanthanide oxides, zinc oxide, spinels (Mg ₂ Al ₂ O ₄ , ZnAl ₂ O ₄ ), perovskites (BaTiO ₃ , ZnTiO ₃ ), calcium silicates (such as xonotlite), either in bulk or dispersed on neutral or basic supports, on basic zeolites (such as alkaline or alkaline earth zeolites at low silica/alumina content obtained by exchange or impregnation).

For optimal performance and stable continuous operation, it is preferable that the active metal component of a catalyst containing Ni, Mo, W, Co or their mixtures, be in the form of sulfides. It is then preferable that traces of decomposable sulfur compounds (thermally or catalytically) are present or voluntarily added to the charge in order to maintain the metal sulfide in its sulfide state. We can use the same compounds as those mentioned above.

Generally, decarboxylation and/or decarbonylation is carried out in the presence of dihydrogen which will stabilize the catalytic activity by removing highly adsorbed unsaturated species (e.g. when decarbonylation is the predominant reaction pathway) from the catalyst surface by reaction reactions. addition of hydrogen. The presence of dihydrogen can also hydrogenate the double bonds present in the acyl portion of the fatty acid to obtain paraffinic reaction products from the decarboxylation process.

The decarboxylation and/or decarbonylation step can be carried out at a temperature of 100 to 550°C in the presence of dihydrogen at pressures ranging from 0.01 to 10 MPa. The ratio between dihydrogen and feedstock can be 100 to 2000 Nl/l.

Hydroisomerization step e)

All or part of the effluent from step c) can be subjected, in particular directly, to a hydroisomerization reaction in the presence of dihydrogen and at least one catalyst to obtain an effluent which can then be fractionated into at least one fraction chosen from a naphtha fraction, a gas oil fraction and a kerosene fraction.

The liquid part obtained from the hydrotreatment step comprises a hydrocarbon fraction consisting essentially of n-paraffins having approximately 9 to approximately 24 carbon atoms.

A part of this hydrocarbon fraction, after separation, can be used as recycling of hydrocarbons towards the deoxygenation section in order to absorb the heat of reaction, to dilute the deteriorating effect of the remaining impurities or to provide more dihydrogen in the form dissolved in the deoxygenation section.

This hydrocarbon fraction is useful as a diesel fuel because it includes high cetane n-paraffins and exhibits good cold flow properties following isomerization of a portion of the n-paraffins to isoparaffins. ..

Suitable hydroisomerization catalysts used in hydroisomerization processes are all of the bifunctional type combining an acidic function with a (de)hydrogenating function.

The acid function is provided by a support (amorphous or crystalline) whose specific surface areas are generally between 100 and 700 m ² /g and which has surface acidity, such as halogenated aluminas (in particular sulfated, phosphated, chlorinated or fluorinated ), aluminas (possibly containing boron), amorphous silicas-aluminas, amorphous silicas-aluminas-titaniums, sulfated zirconias, tungsten zirconias and zeolites or their mixtures. Acidity can be measured by methods well known to those skilled in the art. It can, for example, be measured by temperature-programmed desorption (TPD) with ammonia, by infrared measurement of absorbed molecules (pyridine, CO...), by a catalytic cracking test or by hydroconversion using a molecule model.

The (de)hydrogenation function is provided either by one or more metals from group 6 of the periodic table of elements, or by a combination of at least one metal from group 6 of the periodic table and at least one metal from groups 8 , 9, 10.

The distance between the two functions, acidic and (de)hydrogenating, is one of the key parameters governing the activity and selectivity of the catalyst.

A weak acid function and a strong (de)hydrogenating function give catalysts of low activity, generally requiring a high temperature (greater than or equal to 390-400°C), and long residence times or at low hourly space velocity (the VSLH expressed in liquid volume of feed to be treated per unit volume of catalyst and per hour is generally less than or equal to 2), but has very good selectivity for middle distillates (jet fuels and gas oils). Generally speaking, the term "middle distillates" as used in the present invention applies to one or more fractions whose initial boiling point is at least 150°C and whose end point is generally less than about 350°C, preferably less than 370°C.

Conversely, a strong acid function and a weak (de)hydrogenating function result in catalysts that are active, but have lower selectivity for middle distillates and the result is more cracked hydrocarbons in the range of naphthas and jet fuels.

One type of conventional hydroisomerization catalyst is based on amorphous supports that are moderately acidic, such as silica-aluminas for example. These systems are used to maximize middle distillates with good cold flow properties.

The catalysts and conditions for hydroisomerization are well known in the art.

Hydrocarbons from the deoxygenation section are contacted with an isomerization catalyst in the presence of dihydrogen under isomerization conditions to isomerize normal paraffins into branched paraffins. Isomerization of the paraffinic product may be accomplished in any manner known in the art or using any suitable catalyst known in the art.

The acidic support material may be amorphous or crystalline. Suitable support materials include amorphous alumina, amorphous silica-alumina, amorphous silica borate, amorphous silica-alumina-titanium, zeolites or modified zeolites having the following structures: ferrierite, zeolite beta, zeolite Y, Mordenite zeolite and molecular sieves of the type ALPO-31, SAPO-11, SAPO-31, SAPO-37, SAPO-41, SM-3, MgAPSO-31, FU-9, NU-10, NU-23, ZSM-12 , ZSM-22, ZSM-23, ZSM-35, ZSM-38, ZSM-48, ZSM-50, ZSM-57, theta-1, EU-1, EU-13, ISI-1, KZ-2, ISI -4 and KZ-1, MeAPO-11, MeAPO-31, MeAPO-41, MeAPSO-11, MeAPSO-31, MeAPSO-41, MeAPSO-46, ELAPO-11, ELAPO-31, ELAPO-41, ELAPSO-11 , ELAPSO-31, ELAPSO-41, each of which can be used alone or in combination.

The production of the bifunctional hydroisomerization catalyst can be carried out by any method known in the art. The (de)hydrogenation function can be added to the acidic support by impregnation of metal-containing solutions, by ion exchange and by mixing.

The hydroisomerization step can be carried out using one or more types of catalysts in a plurality (one or more) of catalyst beds in the same reactor or in a plurality of different reactors. The feed intended for hydroisomerization may be sent to the catalyst simultaneously with the dihydrogen-containing gases in a downward flow mode, in an upward flow mode or the liquid feed may flow in a downward flow while the Gases containing dihydrogens flow in an upward flow mode through the catalyst beds.

The hydroisomerization conditions include a temperature of 150°C to 500°C or more preferably 220°C to 450°C and more preferably 250 to 420°C and a pressure of 1 MPa to 15 MPa or more preferably 1, 5 MPa to 9 MPa and more preferably from 2 MPa to 6 MPa. The hourly space velocity is about 0.1 to 20 h ^-1 , more preferably 0.2 to 10 h ^-1 and most preferably 0.3 to 4 h ^-1 . The supplied dihydrogen-containing gases are introduced simultaneously with the feedstock at a ratio of 75 to 2500 Nl (H ₂ )/l feed, more preferably 150 to 1500 Nl or more preferably 250 to 1000 Nl.

During the hydroisomerization reaction, secondary hydrocracking reactions can occur. Those skilled in the art will know how to choose appropriate conditions for treating the effluent from step d) under hydroisomerization conditions, namely conditions in which hydroisomerization reactions mainly occur.

Step f) separation

The effluent leaving step e) undergoes fractionation, for example carried out by adding a separation column, for example a distillation column, or by lateral withdrawal.

This fractionation makes it possible to recover at least one fraction chosen from a naphtha fraction, a gas oil fraction and a kerosene fraction. This fractionation step can also make it possible to separate non-condensable fractions and/or unreacted dihydrogen, which can optionally be sent to the inlet of step d) or e).

The recovered naphtha fraction preferably has an initial boiling point of 30°C and a final boiling point of 80°C to 180°C.

The recovered gas oil fraction preferably has an initial boiling point of 80 to 180°C and a final boiling point less than or equal to 360°C. This fraction can be used as diesel engine fuel.

The recovered kerosene fraction preferably has a final boiling point below 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 kerosene fraction can be used as jet fuel.

In particular, it will be possible to adapt the cutting points of the recovered fractions in order to obtain products meeting particular specifications.

Claims (11)

Process for manufacturing renewable hydrocarbon fluids comprising at least:
a) a step of supplying a first oil of natural origin and a second oil of natural origin,
b) a step of producing ethyl esters of fatty acids by reaction of the triglycerides contained in the first oil of natural origin with ethanol of renewable origin in a transesterification reactor,
c) a step of preparing a hydrocarbon feed containing the ethyl esters of fatty acids from step b) and the second oil of natural origin from step a), the hydrocarbon feed having a content of ethyl esters d fatty acids from 5 to 95% by mass,
d) a deoxygenation step by hydrotreatment, in which the hydrocarbon feedstock prepared in step c) is subjected to a deoxygenation reaction in the presence of at least one catalyst under conditions suitable for transforming the fatty acid esters and the free fatty acids contained in said hydrocarbon filler in paraffins,
e) a hydroisomerization step during which the effluent from step d) is subjected to a hydroisomerization reaction in the presence of dihydrogen and at least one catalyst,
f) a separation step in which the effluent from step e) is separated into at least one fraction chosen from a naphtha fraction, a gas oil fraction and a kerosene fraction. Manufacturing process according to claim 1, in which, in step a) the first oil of natural origin and the second oil of natural origin are each independently chosen from a vegetable oil, an animal oil or fat, used oil, oil produced by microorganisms, animal fats and/or used cooking oils which are animal by-products, as well as mixtures thereof. Manufacturing process according to claim 2, in which the first oil of natural origin is chosen from animal fat, used oil, and mixtures thereof, preferably animal fats and used cooking oils which are by-products animals. Manufacturing process according to claim 2 or 3, in which the second oil of natural origin used in step c) is chosen from a vegetable oil, an animal oil or fat, an oil produced by microorganisms and their mixtures. Manufacturing process according to any one of claims 1 to 4, in which step b) comprises:
(i) obtaining ethanol from renewable sources,
(ii) followed by the reaction of the first oil of natural origin with the ethanol obtained in step (i) in a transesterification reactor. Manufacturing process according to claim 5, in which, during step (i), a substrate is subjected to ethanolic fermentation in a bioreactor containing a culture of one or more microorganisms and the original ethanol is recovered renewable product. Manufacturing method according to claim 6, in which, during step (i),

• a substrate rich in sugars and/or starch derived from biomass is subjected to aerobic fermentation, or
• a gaseous substrate comprising CO is subjected to anaerobic fermentation.

Manufacturing process according to claim 5, in which, during step (i), a synthesis gas rich in CO/H ₂ derived from biomass is converted into ethanol of renewable origin. Process according to any one of claims 1 to 8, in which step d) of deoxygenation by hydrotreatment is carried out at a temperature of 100 to 550°C in the presence of dihydrogen at pressures ranging from 0.01 to 10 MPa. Process according to any one of claims 1 to 9, in which step d) of deoxygenation by hydrotreatment is carried out in the presence of a catalyst chosen from (i) the oxides or sulphides of Ni, Mo, W, Co or mixtures of NiW, NiMo, CoMo, NiCoW, NiCoMo, NiMoW and CoMoW, (ii) metals or mixtures of metal alloys from group 10 and group 11 of the periodic table, (iii) basic oxides such as oxides of alkali metals, alkaline earth oxides, lanthanide oxides, zinc oxide, spinels, perovskites, calcium silicates. Process according to any one of claims 1 to 10, in which step e) of hydroisomerization is carried out at a temperature of 150°C to 500°C, at a pressure of 1 MPa to 15 MPa.