PROCESS FOR PRODUCING AN OXIDATION-STABILIZED BIOMASS OIL

Abstract

The invention relates to a process for treating biomass oil comprising: (a) a step of supplying biomass oil selected from biomass pyrolysis oil, biomass hydrothermal liquefaction oil, lignin oil, and mixtures thereof; (b) a step of oxidizing the biomass oil supplied in step (a) in the presence of an oxidizing agent at a temperature of 90 °C or lower, this step producing an effluent containing at least partially oxidized biomass oil and water; (c) a step of distilling the effluent from step (b) under reduced pressure, separating a distillate containing water from a residue under vacuum to form a stabilized biomass oil with a reduced water content. Figure 1

Description

Title of the invention: PROCESS FOR PRODUCING A BIOMASS OIL STABILIZED BY OXIDATION Technical field

[0001] The present invention relates to the field of biomass oils, resulting from biomass pyrolysis or from a hydrothermal treatment of biomass, and more particularly their stabilization, in particular either with a view to their use as such or separated into streams usable for the preparation of fuels and combustibles and / or for the preparation of lubricants, or with a view to their use in a hydroconversion or cracking process, in particular for manufacturing fuels. Prior art

[0002] Biomass oils, also called "bio-oils" can be obtained by pyrolysis or hydrothermal liquefaction of biomass or by depolymerization of compounds comprising lignin. These bio-oils constitute an interesting alternative for the production of hydrocarbons from renewable resources and reducing greenhouse gas emissions.

[0003] Bio-oils are, however, complex liquids, consisting of water and a complex mixture of oxygenated compounds (such as aldehydes, ketones, furans, carboxylic acids, sugar-type compounds, lignin-derived compounds, etc.). Their elemental composition is close to the composition of the starting biomass, with in particular a significant oxygen content. Table 1 gives orders of magnitude of several characteristics of pyrolysis and hydrothermal liquefaction bio-oils.

[0004] [Table 1] Properties of hydrothermal liquefaction and pyrolysis bio-oils Hydrothermal liquefaction oil Pyrolysis oil (wood, lignocellulosic biomass) Elemental composition (%m) Carbon >70 10-70 Hydrogen 5-15 5-10 Oxygen 8-20 20-55 Nitrogen 0-10 0-2 Sulphur <2 <1 Water content (%m) <15 15-30 Viscosity (mPa.s) (50 °C) from 60 to 1500 or more 10-100 Acid number (mgKOH per gbio-oil) 5-200 50-250 Carbonyl content (mol / kg) ND 3-8

[0005] The presence of carbonyl compounds such as aldehydes and ketones makes bio-oil thermally unstable, with the temperature promoting polymerization / condensation reactions. Thermal instability thus results in a very rapid evolution of their properties when they are heated to temperatures above 80°C. These polymerization / condensation reactions are also observed during prolonged storage at room temperature.

[0006] Due to their particular properties stated above, the use of bio-oils raises many problems.

[0007] In particular, bio-oils cannot be used as fuel due to their high content of oxygenated molecules, and in particular organic acids. They are also immiscible with fossil hydrocarbons. In addition, they contain many temperature-sensitive molecules, such as sugars.

[0008] In order to be used in refineries for the production of renewable liquid fuels or combustibles (or partially renewable if they are mixed with fossil fuels or combustibles), bio-oils must therefore be treated to improve their properties and allow their recovery in conventional refining processes and / or to produce fuels. It is thus known to subject bio-oils to hydrocracking or hydrotreatment treatments, including hydrodeoxygenation (HDO). The hydrotreatment of a bio-oil is generally carried out in a fixed-bed reactor, typically at a temperature ranging from 80°C to 450°C and a pressure of 8 to 20 MPa in the presence of a supported catalyst. Typically, hydrogenation stabilization is carried out at temperatures of 80°C to 250°C and hydrodeoxygenation is carried out at temperatures of 250°C to 450°C.Due to the high temperatures used, these treatments lead to the formation of coke. In addition, HDO requires a high consumption of hydrogen and is difficult to industrialize due to its high exothermicity. Finally, it is noted that even at relatively low temperatures where mainly hydrogenation reactions take place, coking phenomena occur causing deactivation of the supported catalyst and even clogging of the fixed bed reactor. It is then necessary to stop the reactor to clean it.

[0009] It is also known to subject bio-oils to esterification and acetalization reactions in the presence of an alcohol and an acid catalyst to convert organic acids into esters and aldehydes into acetals and thus to improve the product properties. However, since bio-oils are thermally unstable, optimizing the reaction can be difficult when the bio-oils need to be kept at a temperature below a temperature at which they are unstable. In addition, since the reactions carried out are balanced, the conversion of all aldehydes to acetals is not guaranteed.

[0010] Document WO2016 / 207609 describes a process for fractionating a pyrolysis oil to produce a hydrophobic aromatic fraction and an aqueous phase. This process comprises a step of oxidation of the aldehydes and ketones contained in the biomass oil producing an effluent containing carboxylic acids and water, this effluent being subjected in its entirety to an esterification reaction under conditions making it possible to form two distinct phases: an organic phase containing the hydrophobic aromatic fraction (molecules originating from lignin and phenolic species) and an aqueous phase containing pyrolytic sugars, organic acids and phenolic species. However, some of the carbons that can be recovered are found in the aqueous phase, so that the overall yield is not optimum. Furthermore, it is then necessary to treat the aqueous phase, which generates significant additional costs.

[0011] There is thus a need to improve the methods for treating a bio-oil making it possible to obtain a stabilized bio-oil and, in particular, its subsequent treatment in a refining unit without the risk of coke formation. Summary of the invention

[0012] The invention aims to provide a method for treating a bio-oil allowing it to be thermally stabilized. This bio-oil is chosen from an oil resulting from the pyrolysis of biomass, an oil resulting from a hydrothermal liquefaction of biomass, a lignin oil, and mixtures thereof. In particular, an oxidation of the bio-oil followed by distillation under reduced pressure makes it possible to obtain a thermally stable product which can then be used as is, directly as a mixture in a fuel pool, or which can then undergo one or more treatments in a refining unit.

[0013] An object of the invention thus relates to a method for treating a biomass oil, comprising:

[0014] (a) a step of providing a biomass oil selected from a biomass oil biomass pyrolysis, biomass hydrothermal liquefaction oil, lignin oil, and mixtures thereof,

[0015] (b) a step of oxidizing the biomass oil provided in step (a) in the presence of an oxidizing agent at a temperature less than or equal to 90°C, this step producing an effluent containing the at least partially oxidized biomass oil and water,

[0016] (c) a step of distillation under reduced pressure of the effluent from step (b) separating a distillate containing water and a vacuum residue forming a stabilized biomass oil having a reduced water content.

[0017] During step (b), at least a portion of the carbonyl compounds, namely aldehydes and / or ketones, initially contained in the biomass oil are oxidized. In particular, oxidation of the aldehydes to carboxylic acids is observed, which makes it possible to significantly reduce the thermal instability of the oil. The removal by distillation of the water formed naturally during the oxidation reaction makes it possible to obtain a stabilized product that can be used immediately without further treatment. The biomass oil thus stabilized, due to its low water content, can in fact be used as is, for example as a mixture in fuel pools, with or without additives. The additives can be additives for stabilizing the medium (e.g. emulsifiers) and / or for neutralizing the medium and / or for reducing the acidity of the medium. It can also be treated alone or as a mixture in refining processes to produce fuels.

[0018] The oxidation step (b) may have one or more of the following characteristics: - step (b) is carried out at a temperature of 15°C to 90°C, optionally 15°C to 80°C or 20°C to 60°C, - step (b) is carried out at an absolute pressure of 0.01 to 10 bar, optionally 0.1 to 5 bar or 0.5 to 2 bar, advantageously at atmospheric pressure, - the reaction time of step (b) is 15 minutes to 5 hours, optionally 30 minutes to 2 hours, - the oxidizing agent is chosen from ozone, dioxygen, hydrogen peroxide, nitric acid, hexavalent chromium compounds, heptavalent manganese compounds, - the ratio of the number of moles of carbonyl compounds contained in the biomass oil supplied in step (a) to the number of moles of oxidizing agent present is from 0.1 to 2, advantageously from 0.5 to 1.5.

[0019] Distillation step (c) may have one or more of the following characteristics: - step (c) is carried out at an absolute pressure of 0.1 to 400 mbar, preferably 1 to 200 mbar, more preferably 70 to 120 mbar, - step (c) is carried out at a temperature of 15 to 80°C, preferably 20 to 75°C, more preferably 20 to 70°C, - the vacuum residue contains at most 10% by mass of water, advantageously at most plus 5% by mass of water, optionally at most 3% by mass. - the vacuum residue has a total acidity index (TAN) increased by at least 20%, preferably by at least 30%, advantageously by at least 50%, compared to the total acidity index of the biomass oil supplied in step (a), - the vacuum residue has a content of carbonyl compounds, and in particular aldehydes and / or ketones, reduced by at least 20%, preferably at least 30%, advantageously at least 50% relative to the content of carbonyl compounds, and in particular aldehydes and / or ketones, of the biomass oil supplied in step (a), - the vacuum residue has a carboxylic acid content increased by at least 20%, preferably by at least 30%, advantageously by at least 50%, relative to the carboxylic acid content of the biomass oil supplied in step (a).

[0020] The stabilized biomass oil from step (c) contains carboxylic acids resulting from the oxidation of aldehydes and / or ketones. This acidity can cause unwanted corrosion phenomena during subsequent treatments.

[0021] Thus, in one embodiment, the method may further comprise:

[0022] (d) a step of esterification of the residue under vacuum from step (c) in the presence of a excess alcohol and an acid catalyst under conditions effective to form esters and producing an effluent containing the at least partially esterified stabilized biomass oil, water and unreacted alcohol,

[0023] (e) a step of separating the effluent produced in step (d) separating (i) a phase containing water, and optionally excess alcohol, and (ii) an organic phase containing the at least partially esterified stabilized biomass oil.

[0024] These additional steps make it possible to at least partially esterify the carboxylic acids and thus reduce the acidity of the stabilized oil, facilitating its subsequent treatment in refining processes, in particular when it is treated alone, or in coprocessing with fossil feedstocks.

[0025] In this embodiment, the method may comprise one or more of the following features: - the alcohol has a C1-C20 carbon chain, preferably C1-C3, - step (d) is carried out at a temperature of 50 to 120°C, preferably from 50 to 100°C, more preferably from 60 to 80°C, - the water content of the organic phase is at most 10% by mass, advantageously at most 5% by mass, - the total acidity index of the organic phase is reduced by at least 20%, preferably by at least 30%, advantageously by at least 50%, compared to the total acidity index of the vacuum residue from step (c), - a carboxylic acid content of the organic phase reduced by at least 20%, preferably at least 30%, more preferably at least 50% relative to the carboxylic acid content of the vacuum residue from step (c).

[0026] At least a portion of the vacuum residue from step (c) or of the organic phase from step (e) may further be:

[0027] f) treated in a fluidized bed catalytic cracker, and / or

[0028] g) treated in a hydrocracker, and / or,

[0029] h) treated in a catalytic hydrogenation unit, and / or

[0030] i) treated in a hydrotreatment unit, and / or

[0031] j) treated in a steam cracking unit, and / or

[0032] k) treated in a partial oxidation unit, and / or

[0033] 1) used as is or separated into streams usable for the preparation of fuels and fuels such as LPG, gasoline, diesel, heavy fuel oil, for the preparation of lubricants and / or for the preparation of special fluids.

[0034] The vacuum residue from step (c) or the organic phase from step (e) may be subjected to treatments f) to 1) alone or in a mixture with a hydrocarbon feedstock of fossil origin, with or without additives, in particular of the aforementioned type, optionally after having been fractionated according to distillation temperature ranges adapted to these units. Definitions

[0035] The terms "comprising" and "comprises" as used herein are synonymous with "including," "includes," or "contains," "containing," and are inclusive or unbounded and do not exclude additional features, elements, or method steps not specified.

[0036] The expressions % by weight and % by mass have an equivalent meaning and refer to the proportion of the mass of a product relative to 100g of a composition comprising it.

[0037] By “bio-oil” or “biomass oil” is meant an oil resulting from the pyrolysis of biomass and / or an oil resulting from the hydrothermal liquefaction of biomass.

[0038] By "pyrolysis oil" is meant here a crude oil resulting from the pyrolysis of biomass, optionally pretreated, for example by vacuum distillation (to remove water) and / or filtration / adsorption and / or liquid / liquid extraction. Pyrolysis is a thermochemical decomposition of biomass at high temperature in the absence of oxygen.

[0039] The term "pyrolysis" includes different modes of pyrolysis, such as, for example, fast pyrolysis, vacuum pyrolysis, catalytic pyrolysis, pyrolysis in the presence of hydrogen, and slow pyrolysis or carbonization, etc. In particular, pyrolysis can be fast pyrolysis consisting of a rapid increase (<2 seconds) in temperature to 300°C-750°C, leading to depolymerization and fragmentation of the constituent elements of the biomass (holocelluloses (cellulose, hemicellulose), lignin), followed by rapid quenching of the degradation products.

[0040] By "hydrothermal liquefaction" (or HTL for "Hydrothermal Liquefaction" in English), we mean a thermochemical conversion process of biomass using water as a solvent, reagent and catalyst for the degradation reactions of organic matter, the water typically being in a subcritical or supercritical state. This process generally takes place at temperatures of 250 to 500 °C and at pressures of 10 to 25-40 MPa. Reaction times vary from a few seconds to several tens of minutes.

[0041] By “fossil feedstock” is meant a hydrocarbon compound resulting from the processing of crude oil.

[0042] Atmospheric pressure is the actual measured pressure. It therefore varies around normal atmospheric pressure (1013.25 mbar).

[0043] The Conradson carbon content (denoted CCR) is defined by the ASTM D 482 standard and represents for those skilled in the art a well-known evaluation of the quantity of carbon residues produced after pyrolysis under standard conditions of temperature and pressure.

[0044] The total acid number (TAN) can be determined according to ASTM D664-18e2 by potentiometric titration.

[0045] The carbon, hydrogen and nitrogen content can be measured according to ASTM D5291-21.

[0046] Oxygen content can be measured according to ASTM D5622-17.

[0047] The water content can be determined according to ASTM D6304-20 by the Karl Fischer coulometric titration method using Hydranal Coulomat AK® from Honeywell (CAS: 101023-55-6) as reagent. In particular, the test samples were prepared at a concentration of 0.05 (gd) in dry tetrahydrofuran (THF).

[0048] In the present description, by "carbonyls" or "carbonyl compounds" is meant ketones and aldehydes exclusively; by "carbonyl group" is meant the group R1(C=O)R2, where R1 and R2, which may be identical or different, are chosen from the following groups: H, an alkyl, aryl, arylalkyl, alkylaryl or cycloalkyl group, comprising or not heteroatoms.

[0049] In the present description, by “carboxylated compound” or “compounds comprising a carboxylated group” is meant carboxylic acids and esters.

[0050] The carbonyl content, measured in mol / kg, can be determined using the ASTM E3146-20 standard.

[0051] The carboxylic acid content can be determined by NMR, in particular by phosphorus (31P) NMR, in particular according to the method described below. Detailed description of the invention

[0052] The present invention relates to methods of treating biomass oil by oxygenation and distillation. Step (a) of supplying biomass oil

[0053] The biomass oil provided in step a) may be an oil resulting from the pyrolysis of biomass, an oil resulting from the hydrothermal liquefaction of biomass, a lignin oil, or a mixture of one or more of these oils.

[0054] In one embodiment, the biomass oil may advantageously be derived from a biomass chosen from lignocellulosic biomass, herbaceous biomass, aquifer biomass, paper and cardboard, organic waste (forestry, agricultural, industrial and / or household waste), or any other material composed of at least one of these constituents (wood B for example), alone or as a mixture.

[0055] Step (a) of providing biomass oil may thus comprise mixing one or more of the aforementioned oils.

[0056] Step (a) may further comprise:

[0057] (al) a step of liquefying biomass and obtaining a hydrocarbon product comprising a liquid phase and a solid phase, and optionally a gaseous phase,

[0058] (a2) a step of separating the liquid phase of said product, said liquid phase forming a biomass oil.

[0059] The liquefaction step (al) may comprise a pyrolysis step, a hydrothermal liquefaction step, a solvolysis step or any other treatment making it possible to obtain a biomass oil, in particular from lignocellulosic and / or lignin-rich biomass.

[0060] When step (a1) comprises a pyrolysis or hydrothermal liquefaction step, the product comprises a liquid phase, a gaseous phase and a solid phase. The liquefaction step (a1) may comprise a pyrolysis step, typically carried out at a temperature of 300 to 1000°C or 400 to 700°C, this pyrolysis being, for example, a fast pyrolysis or a flash pyrolysis or a catalytic pyrolysis or a hydropyrolysis. In particular, the pyrolysis may be a fast pyrolysis consisting of a rapid increase (<2 seconds) in temperature to 300°C-750°C, leading to depolymerization and fragmentation of the constituent elements of the biomass (holocelluloses (cellulose, hemicellulose), lignin), followed by rapid quenching of the degradation products.

[0061] Alternatively or in combination, the liquefaction step (a1) may comprise a hydrothermal liquefaction step, typically carried out at a temperature of 250 to 500°C and at pressures of 10 to 25-40 MPa. Reaction times typically vary from a few seconds to several tens of minutes.

[0062] The separation step (a2) makes it possible to eliminate the gaseous phase, essentially the C1-C4 hydrocarbons and the solid phase (typically char) to recover only the liquid organic phase forming a biomass oil.

[0063] When step (a1) comprises a solvolysis step in the presence of a solvent, the product formed comprises a liquid phase and a solid phase. The solvent may be water (this is then referred to as hydrolysis), water mixed with an alcohol, or a polar organic solvent, containing for example at least one oxygen atom, generally ethanol and / or methanol.

[0064] The solvolysis step can be carried out in the presence of a catalyst or not, and / or in the presence of dihydrogen.

[0065] In the presence of dihydrogen, and optionally a catalyst, this step can be carried out at a temperature of 150 to 350°C, a dihydrogen pressure of 0.2 to 150 bar, and a residence time of up to 240 min.

[0066] In the absence of dihydrogen, this step can be carried out at a temperature of 150 to 350°C, a pressure of 2 to 50 bar and a residence time of up to 240 minutes. An acid catalyst can optionally be used, such as for example a mineral acid or an organic acid, for example formic acid or carbonic acid.

[0067] The biomass treated during this solvolysis step is typically a lignin-rich biomass (e.g. lignocellulosic biomass, herbaceous biomass, black liquor from the paper industry or any other biomass or waste containing lignin). Step (a1) allows the lignin contained in the biomass to be released from other compounds, such as hemicelluloses and their derivatives.

[0068] The separation step (a2) makes it possible to eliminate the solvent used during the hydrolysis or solvolysis in order to recover only the liquid organic phase forming a biomass oil, and in particular a lignin oil.

[0069] The separation step (a2) may then comprise a solid / liquid separation step and / or a liquid-liquid extraction step, optionally followed by distillation. The liquid-liquid extraction step may be carried out using a solvent such as water, methanol, ethanol, propanols, butanols, dioxane, acetone, ethyl acetate. Distillation may make it possible to remove the solvent(s) used.

[0070] These steps (a1) and (a2) can for example be implemented as described in documents WO2023020752, EP3741828, WO2022 / 090364, EP3371279.

[0071] Step (a1) may also comprise any treatment step making it possible to obtain a biomass oil, in particular from lignin-rich biomass, such as high-temperature treatments in a strongly basic medium (e.g. the Kraft or Soda process in the presence of NaOH, with or without Na2S, at 160-170°C), or treatments in an acid reducing medium (e.g. bisulfite process in the presence of Na2SO3, at 140-170°C).

[0072] The biomass treated during step a1) can be defined as an organic plant product, namely a product composed of, or derived from, agricultural or forestry plant material.

[0073] The biomass may be chosen from lignocellulosic biomass, herbaceous biomass (biomass of plants having a non-woody stem), aquifer biomass (plants growing in water or underwater such as algae), paper, cardboard, organic waste (forestry, industrial, agricultural and / or household waste), or any other material composed of at least one of these constituents, alone or in mixtures.

[0074] Biomass can thus include (i) biomass produced by surplus agricultural land, preferably not used for human or animal food: dedicated crops, called energy crops (short rotation coppice (SRC), very short rotation coppice (VRC); (ii) biomass produced by deforestation (forest maintenance) or clearing of agricultural land, etc.; (iii) agricultural residues from crops, in particular cereal crops, vines, orchards, olive trees, fruits and vegetables including nuts, residues from the agri-food industry, etc.; (iv) forest residues from forestry and wood processing; (v) agricultural residues from livestock farming (manure, slurry, litter, droppings, etc.); (vi) household organic waste (paper, cardboard, green waste, etc.); (vii) industrial organic waste, with or without additives (paper, cardboard, wood, waste putrescible,...); (viii) algal biomass, namely biomass formed from algae, for example micro-algae (algal biomass may be an algae suspension obtained by harvesting algae from, for example, a bioreactor, or an algae residue obtained by dehydrating an algae suspension) or macro-algae; (ix) herbaceous biomass; (x) vegetable oils contained in certain waste (cashew nut shells or other); (xi) industrial waste (wood type B), (xii) sludge from sewage treatment plants, (xiii) digestates from methanizers; (xiv) vinasses from the production of alcohol by fermentation.

[0075] The biomass oil obtained may contain from 8 to 55% by mass of oxygen. This oxygen is present in oxygenated compounds containing at least one hydroxyl group (-OH) and / or at least one carbonyl group (>C=O). A biomass oil may in particular contain carboxylic acids, ketones, aldehydes, phenols. Step (b) of oxidation

[0076] A biomass oil typically contains numerous oxygenated compounds containing one or more hydroxyl groups (phenols, polyalcohols) and / or one or more carbonyl groups (aldehydes and / or ketones) and / or one or more carboxyl groups (carboxylic acids, esters), which make the biomass oil corrosive, viscous, immiscible with other hydrocarbons and unstable. The biomass oil typically contains at least aldehydes and / or ketones.

[0077] The oxidation step b) of the present invention makes it possible to transform these oxygenated compounds, and in particular the aldehydes and possibly the ketones, into carboxylic acids, and possibly into esters, which has the effect of reducing its instability.

[0078] In one embodiment, the biomass oil provided in step (a) can be sent directly, without an intermediate step, to the oxidation step (b).

[0079] This step is carried out at a temperature of at most 90°C, for example at a temperature of 15°C to 90°C, optionally 15°C to 80°C or 20°C to 60°C, or in any interval defined by two of these limits.

[0080] Step (b) can be carried out at atmospheric pressure or under moderate pressure. The pressure may in particular be chosen according to the nature of the selected oxidizing agent. A moderate pressure can advantageously be applied when the oxidizing agent is in the gaseous state. Step (b) can thus be carried out at an absolute pressure of 0.01 to 10 bar, optionally of 0.1 to 5 bar or of 0.5 to 2 bar, preferably at atmospheric pressure. Typically, an absolute pressure of 0.01 to 1 bar can be applied in the presence of a liquid oxidizing agent and an absolute pressure of 1 to 10 bar can be applied in the presence of a gaseous oxidizing agent.

[0081] In step (b), the biomass oil provided in step (a) is contacted with an oxidizing agent. The reaction time may be from 15 minutes to 5 hours, optionally from 15 minutes to 2 hours or from 30 minutes to 2 hours or from 15 minutes to 1 hour or in any interval defined by two of its limits.

[0082] The oxidizing agent may be chosen from ozone, dioxygen, nitric acid, hydrogen peroxide, hexavalent chromium compounds (for example: chromium trioxide, potassium or sodium dichromate), hep-tavalent manganese compounds (for example potassium permanganate). Hydrogen peroxide is preferred.

[0083] The oxidizing agent may be added in aqueous solution to the biomass oil or directly added to the biomass oil.

[0084] In step (b) a quantity of oxidizing agent sufficient to oxidize the carbonyl compounds, namely the aldehydes and / or ketones, present in the biomass oil provided in step (b) may typically be added. This quantity may be determined based on the number of moles of carbonyl compounds present in biomass oil, for example determined by ASTM E3146-20.

[0085] For example, it is possible to add an amount of oxidant such that the ratio of the number of moles of carbonyl compounds contained in the biomass oil provided in step (a) to the number of moles of oxidizing agent present is from 0.1 to 2, advantageously from 0.5 to 1.5, or in any interval defined by two of these limits.

[0086] Step (b) produces an effluent containing the at least partially oxidized biomass oil and water. The water comes from the oxidation reaction (water formed during dehydration leading to the formation of carboxylic acid), from the water initially contained in the biomass oil, and optionally from the water added with the oxidizing agent. This water content can thus be relatively high, typically from 20 to 70% by mass.

[0087] The at least partially oxidized biomass oil has a reduced content of carbonyl compounds, and in particular of aldehydes and / or ketones, advantageously of aldehydes. At the outlet of step (b), the content of carbonyl compounds, and in particular of aldehydes and / or ketones, advantageously of aldehydes, of the biomass oil may advantageously be reduced by at least 20%, preferably by at least 30%, 40%, 50%, 60%, 70% or at least 80% relative to the content of carbonyl compounds of the biomass oil at the inlet of step (b) provided by step (a).

[0088] The at least partially oxidized biomass oil has a carboxylic acid content increased by at least 20%, preferably by at least 30%, advantageously by at least 50%, relative to the carboxylic acid content of the biomass oil supplied in step (a). Vacuum distillation step (c)

[0089] The effluent produced during oxidation step (b) is subjected, in particular directly without an intermediate step, to step (c).

[0090] This vacuum distillation step c) makes it possible to separate a distillate containing water and a vacuum residue, the latter having a low water content, typically less than 10% by mass, advantageously less than 5% by mass, or 3% by mass.

[0091] Vacuum distillation can advantageously be carried out under conditions effective to remove a desired amount of water, in particular depending on the subsequent use of the stabilized biomass oil. It can advantageously be carried out at low temperature. Typically, this vacuum distillation can be carried out at a temperature of 15 to 80 °C, preferably 20 to 75 °C, more preferably 20 to 70 °C, at an absolute pressure of 0.1 to 400 mbar, preferably 1 to 200 mbar, more preferably 70 to 120 mbar.

[0092] Distillation can remove 60 to 90% by mass of the water initially present in the effluent, allowing the use of stabilized biomass oil. thus obtained as such in fuel pools, or to subject this stabilized biomass oil to refining treatments and / or to a subsequent esterification reaction. In the latter case, the reduced water content of the stabilized biomass oil makes it possible to shift the equilibrium of a subsequent esterification reaction towards the formation of the ester. This vacuum distillation step can also make it possible to eliminate some of the more volatile short-chain acids.

[0093] The vacuum residue thus contains almost all of the hydrocarbon compounds initially present in the biomass oil supplied in step (a).

[0094] Advantageously, the vacuum residue can thus have one or more of the following characteristics: - a water content of at most 10% by mass, advantageously at most 5% by mass of water, optionally at most 3% by mass, - a total acidity index (TAN) increased by at least 20%, preferably by at least 30%, advantageously by at least 50%, compared to the total acidity index of the biomass oil supplied in step (a), - a content of carbonyl compounds, and in particular of aldehydes and / or ketones, in particular measured according to the ASTM E3146-20 standard, reduced by at least 20%, preferably by at least 30%, advantageously by at least 50%, or even more, compared to the content of carbonyl compounds of the biomass oil supplied in step (a), - a carboxylic acid content increased by at least 20%, preferably by at least 30%, advantageously by at least 50%, relative to the carboxylic acid content of the biomass oil supplied in step (a) Optional esterification step

[0095] This esterification step makes it possible to reduce the acidity of the stabilized biomass oil. It can also make it possible to eliminate the remaining carbonyl compounds, in particular the remaining aldehydes and / or ketones, as well as the hydroxyl compounds. Indeed, under the conditions of esterification of the carboxyl groups, acetalization of the carbonyl groups and etherification of the hydroxyl groups can also be observed.

[0096] The vacuum residue obtained during the vacuum distillation step typically contains numerous oxygenated compounds containing one or more hydroxyl groups (phenols, polyalcohols) and / or one or more carbonyl and carboxyl groups (mostly carboxylic acids, optionally esters, and possibly unoxidized aldehydes and / or ketones), which make the biomass oil polar, corrosive, viscous.

[0097] The optional esterification step (d) of the present invention makes it possible to transform at least part of these groups into esters and / or acetals and / or ethers, which has the effect of reducing the viscosity of the stabilized biomass oil, reducing its acidity and improving its miscibility with other hydrocarbons.

[0098] This step is carried out in the presence of an alcohol, in excess, and an acid catalyst.

[0099] The alcohol used may have a C1-C20 carbon chain. However, in a preferred embodiment, the alcohol has a C1-C3 carbon chain (i.e., methanol, ethanol, propanol).

[0100] The quantity of alcohol added can be determined according to the content of the stabilized biomass oil in carbonyl and / or hydroxyl groups so as to add the alcohol with an excess of the order of 50% m. For example, a stabilized biomass oil / alcohol mass ratio of 1 / 0.5 to 1 / 10 can be used.

[0101] The acid catalyst may be a solid or liquid catalyst (heterogeneous or homogeneous catalysis), of the type commonly used in esterification reactions. Examples of homogeneous acid catalysts that can be used include sulfuric acid, p-toluene sulfonic acid, 4-methylbenzenesulfonic acid, benzenesulfonic acid, methylsulfonic acid, nitric acid, acetic acid, phosphoric acid, preferably sulfuric acid. Examples of heterogeneous acid catalysts include ion exchange resins (e.g. Amberlyst®15, Amberlyst®36, Dowex50WX2®), acid catalysts based on oxides such as silica, zeolites, alumina, silica-alumina, titanium oxide, zirconia oxide.

[0102] The catalyst may typically be present in a content ranging from 0.01% to 5% by mass, preferably from 0.05% to 4% by mass relative to the mass of vacuum residue.

[0103] Depending on the nature of the alcohol used, the water formed during step (d) can advantageously be removed continuously, in particular extracted continuously, typically by distillation, by applying a pressure suitable for shifting the equilibria of the esterification and / or acetalization and / or etherification reactions towards the formation of esters and / or acetals and / or ethers. This is then removal by reactive distillation. However, the water can also be removed discontinuously, for example by a reflux device. Reflux makes it possible in particular to carry out light distillation sufficient to extract the water or a water-alcohol mixture depending on the conditions, in particular when flushing with an inert gas is carried out. The use of an azeotropic solvent can also be implemented.Thus, in certain embodiments, steps (d) of esterification and (e) of separation by distillation can be carried out simultaneously.

[0104] In other embodiments, steps (d) of esterification and (e) of separation (by distillation or by another process) can be carried out successively, in particular when the alcohol used is C1-C3.

[0105] Those skilled in the art will know how to adapt the conditions to obtain the desired esterification rate.

[0106] Esterification step (d) can be carried out at temperatures of 50 to 120°C, preferably 50 to 100°C, more preferably 60 to 80°C. The temperature may in particular be chosen according to the nature of the alcohol used.

[0107] For example, when the alcohol used is C1-C3, step (d) can be carried out at a temperature of at most 80°C, for example at a temperature of 60 to 80°C.

[0108] The reaction time may be from 15 minutes to 5 hours, advantageously from 30 minutes to 4 hours, in particular from 1 hour to 2 hours or in any interval defined by two of these limits.

[0109] Step (d) may be carried out at atmospheric pressure or under reduced pressure under reactive distillation conditions (steps (d) and (e) by simultaneous distillation).

[0110] Step (d) produces an effluent containing the at least partially esterified stabilized biomass oil, water and unreacted alcohol. This effluent is entirely and directly subjected to separation step (e), in particular without an intermediate step such as phase separation.

[0111] This separation step (e) may be a distillation step, a liquid-liquid separation step, an adsorption separation step, a membrane filtration separation step.

[0112] This separation step (e) can thus make it possible to separate the excess alcohol, which can then be reused during the esterification step (d), optionally after purification.

[0113] In a preferred embodiment, the separation step (e) is a distillation step. In this case, the separation step (e) makes it possible to separate (i) a distillate containing water, and optionally excess alcohol, and (ii) a residue consisting of the organic phase forming the at least partially esterified stabilized biomass oil.

[0114] Step (e) of separation by distillation can be carried out under atmospheric pressure or under reduced pressure, under temperature and / or pressure conditions allowing the removal of water, and optionally excess alcohol, from the effluent of step (d).

[0115] Step (e) of separation by distillation may be carried out at a temperature of 15 to 80°C, preferably 20 to 70°C, more preferably at a temperature of 25 to 60°C, and at an absolute pressure of 0.1 to 500 mbar, preferably 1 to 400 mbar, more preferably 2 to 200 mbar.

[0116] Step (e) thus produces (i) a phase containing water, and optionally alcohol in excess, and (ii) an organic phase forming the at least partially esterified stabilized biomass oil.

[0117] The organic phase may have one or more of the following characteristics: - a water content of at most 10% by mass, preferably at most 5% by mass, more preferably at most 3% by mass, - a total acidity index reduced by at least 20%, preferably at least 30%, more preferably at least 50% compared to the total acidity index of the vacuum residue from step (c), - a reduced carboxylic acid content of at least 20%, preferably at least 30%, more preferably at least 50% relative to the carboxylic acid content of the vacuum residue from step (c). Optional further processing

[0118] At least a portion of the vacuum residue from step (c), or of the organic phase from step (e) can then be treated, alone or in a mixture with a hydrocarbon feedstock of fossil origin, in one or more refining units such as a fluidized bed catalytic cracker, a hydrocracker, a catalytic hydrogenation unit, a hydrotreatment unit, a partial oxidation unit (or POX unit), or a sequence of two or more of these units, or even be used as is or separated into streams usable for the preparation of fuels and combustibles such as LPG, gasoline, diesel, heavy fuel oil, for the preparation of lubricants and / or for the preparation of special fluids.

[0119] In most cases, the vacuum residue from step (c), or the organic phase from step (e) will be sent as is or fractionated according to distillation temperature ranges to feed a fluidized bed catalytic cracker, a hydrocracker, a catalytic hydrogenation unit, a hydrotreatment unit, a POX unit, a pool of fuels or combustibles such as LPG, gasoline, jet, diesel, fuel (including marine fuels), or even a pool of lubricants and / or for the preparation of special fluids.

[0120] The vacuum residue / organic phase can thus be treated in the aforementioned units (fluidized bed catalytic cracker, hydrocracker, catalytic hydrogenation unit, and / or hydrotreatment unit) by limiting or eliminating the deactivation of the catalysts used and / or the formation of coke, despite the high temperatures used in these units, typically from 500 to 550°C in a fluidized bed catalytic cracker, from 100 to 500°C in a hydrotreatment or hydrogenation unit, above 230°C, often from 300 to 430°C in a hydrocracker. The vacuum residue from step (c), or the organic phase from step (e) can be sent in part or in whole to one or more of these units to be treated alone or in a mixture with a fossil feedstock, with or without additives. Description of the figure

[0121] [Fig. 1] is a schematic representation of one embodiment of the present invention.

[0122] In [Fig. 1], the bio-oil to be stabilized is introduced into the oxidation zone 10 via a feed pipe 1. The oxidation zone 10 is further supplied with an oxidizing agent via a pipe 2. The oxidation zone 10 may comprise, or consist of, one (or more) reactors operating continuously, product streams then circulating continuously in the different pipes, or one (or more) reactors operating in batch mode supplied with reactants at the start of the reaction and whose effluents are evacuated and treated at the end of the reaction. The different phases may be brought into contact using stirring, a turbulent regime or any other means.

[0123] The feed line 1 may come from a biomass liquefaction zone 3 supplied with biomass, and optionally with steam 4'. This liquefaction zone 3 may be a pyrolysis reactor or a hydrothermal liquefaction reactor or a solvolysis reactor or any other reactor making it possible to produce a biomass oil, typically including an effluent separation zone in order to select only the liquid organic phase which forms a biomass oil.

[0124] The effluent produced by the oxidation zone 10 is then sent via a pipe 4 in its entirety into a reduced pressure distillation zone 20, for example a vacuum distillation column or any other device making it possible to carry out distillation under reduced pressure. This distillation zone 20 makes it possible to separate a distillate discharged via a pipe 5, which mainly comprises water, and a vacuum residue, discharged via a pipe 6, which mainly comprises at least partially oxidized biomass oil.

[0125] The vacuum residue can then be used as is, fractionated or not into usable streams, or sent to one or more further treatment units 30, 50. The further treatment unit(s) 50 can be a fluidized bed catalytic cracker, a hydrocracker, a catalytic hydrogenation unit, a hydrotreatment unit, a steam cracking unit, a POX unit.

[0126] Thus, in one embodiment, the vacuum residue can be sent to an esterification zone 30 further supplied with alcohol via a pipe 7 and with catalyst via a pipe 8. The esterification zone 30 can comprise, or consist of, one (or more) reactors operating continuously, product streams then circulating continuously in the different pipes, or one (or more) reactors operating in batch mode supplied with reactants at the start of the reaction and the effluents of which are evacuated and treated at the end of the reaction.

[0127] All of the effluent leaving the esterification zone via line 9 is then sent to a new separation zone 40 to separate the water discharged via a line 11, and possibly the excess alcohol, mixed or not with water. The separation zone 40 may be a distillation column, a reflux device or other, possibly integrated into the esterification zone 30 to implement a reactive distillation, or even a liquid-liquid separation column, a membrane separation system, or an adsorption separation device.

[0128] The organic phase produced by the separation zone 40 is evacuated via a pipe 12, and can either be used as is, with or without additives, fractionated or not into usable streams, or sent to one or more subsequent treatment units 50.

[0129] When the water discharged via line 11 contains alcohols, it can be returned to line 7 in order to recycle the unreacted alcohol, possibly after having undergone an intermediate treatment to remove the water.

[0130] 31P NMR method for determining carboxylic acid content: Sample preparation

[0131] A. A solvent solution is prepared by mixing 10g + / - 1g of CDC13 with 10g + / - 1g of Pyridine + 70mg of Cr(AcAc)3 + 80mg of N-hydroxy-5-norbornene-2,3-dicarboximide (NHND).

[0132] The sample is prepared in a vial by adding the bio-oil sample to the solvent solution in the following proportions: • Sample: (6-20) mg, • solvent solution: 600 mg + / - 50 mg, • 2-chloro-4,4,5,5-tetramethyl-1,3-2-dioxaphospholane (TMDP): 150 mg + / -50 mg.

[0133] The preparation is homogenized on a stirred plate for 1 minute. When homogeneous, the preparation is transferred using a glass pipette into a 5 mm NMR tube.

[0134] B. In the event that precipitation is observed during the procedure described in A, the procedure is as described below.

[0135] A solvent solution is prepared by mixing 10g + / - 1g of CDC13 with 10g + / - 1g of Pyridine.

[0136] A standard solution is prepared by putting 85 mg of NHND with 2.4 g of the solvent solution.

[0137] A solution of Cr(AcAc)3 is prepared by putting 10 mg of Cr(AcAc)3 with 2.4 g of the solvent solution.

[0138] The sample is then prepared in a flask by adding the bio-oil sample to the different solutions above in the following proportions: • Sample: (20-30) mg; • Dimethylformamide (DMF): 500 mg + / - 50 mg; • Solvent solution: 350 mg + / - 50 mg; • Standard solution: 150 mg + / - 50 mg; • Cr(AcAc)3 solution: 150mg + / - 50mg; • TMDP: 150 mg + / - 50 mg.

[0139] The preparation is homogenized on a stirred plate for 1 min. The preparation is then sonicated for 15 minutes. When homogeneous, the preparation is transferred using a glass pipette into a 5 mm NMR tube. Spectrum Recording Conditions

[0140] The 31P NMR signal is recorded on a Bruker 400 MHz with a 5 mm BBFO (“Broad Band Fluoride Observation”) probe under the following conditions:

[0141] Pulse angle: 90°

[0142] Pulse repetition time: 25 s

[0143] Spectral width: 234 ppm centered on 110 ppm

[0144] Number of points: 32 K

[0145] Acquisition time: 0.47 s

[0146] Temperature: 298 K

[0147] Rotation: 0 Hz

[0148] Number of scans: 200

[0149] Decoupling sequence: inverse-gated decoupling sequence to avoid the nuclear Overhauser effect (NOE), with the Waltz-16 pulse decoupling sequence (or CPD sequence for Composite-Pulse Decoupling). Spectrum processing conditions

[0150] The NMR signal is processed with Topspin® software. The 31P NMR spectrum is obtained by Fourier transformation on 32K points after exponential multiplication (line broadening factor = 4). The spectrum is manually phased, the baseline is corrected. The chemical shift scale is referenced to the TMDP anhydride signal at 132.2 ppm.

[0151] The peak regions are integrated with the following limits: Chemical Shift Range (ppm) Aliphatic OH 144.2 - 150.6 Phenolic OH 137.3 - 144.2 Carboxylic CO OH 133.7 - 136.0 Internal Standard (NHND) 150.6- 153.0

[0152] The area of ​​the NHND peak is normalized to 1. The measured areas are directly related to the relative abundance of each type of phosphorus.

[0153]

[0154]

[0155]

[0156]

[0157]

[0158] The number of moles of the internal standard is then calculated: nEA mol ) = - ■ purny 7 M[EI) 1 J Ef With nEi the number of moles of the internal standard (mol), CEI the concentration of the internal standard in the stock solution of the solvent, mss the mass of stored solvent added to the analyzed NMR tube, M(EI) the molecular mass of the NHND and purity the purity of the NHND. With this value, the number of moles for each functional group per gram of sample can be calculated as follows: _ SCFnEl ^scmiple With nGF the number of moles of the functional group, >SGF the normalized peak area of ​​the functional group and Msample the mass of the sample added to the analyzed NMR tube.

Claims

Claims

1. A method for treating a biomass oil comprising: (a) a step of providing a biomass oil selected from a biomass pyrolysis oil, a biomass hydrothermal liquefaction oil, a lignin oil, and mixtures thereof, (b) a step of oxidizing the biomass oil provided in step (a) in the presence of an oxidizing agent at a temperature of less than or equal to 90°C, this step producing an effluent containing the at least partially oxidized biomass oil and water, (c) a step of distilling under reduced pressure the effluent of step (b) separating a distillate containing water and a vacuum residue forming a stabilized biomass oil having a reduced water content.

2. Treatment method according to claim 1, wherein the oxidation step (b) has one or more of the following characteristics: - step (b) is carried out at a temperature of 15°C to 90°C, optionally 15°C to 80°C or 20°C to 60°C, - step (b) is carried out at an absolute pressure of 0.01 to 10 bar, optionally 0.1 to 5 bar or 0.5 to 2 bar or at atmospheric pressure, - the reaction time of step (b) is 15 minutes to 5 hours, optionally 30 minutes to 2 hours, - the oxidizing agent is chosen from ozone, dioxygen, hydrogen peroxide, nitric acid, hexavalent chromium compounds, heptavalent manganese compounds, - the ratio of the number of moles of compounds carbonyls contained in the biomass oil provided in step (a) the number of moles of oxidizing agent present is from 0.1 to 2, advantageously from 0.5 to 1.

5.

3. A treatment method according to any one of claims 1 or 2, wherein the distillation step (c) comprises at least one of the following features: - step (c) is carried out at an absolute pressure of 0.1 to 400 mbar, preferably 1 to 200 mbar, more preferably 70 to 120 mbar, - step (c) is carried out at a temperature of 15 to 80°C, preferably 20 to 75°C, more preferably 20 to 70°C, - the vacuum residue contains at most 10% by mass of water, optionally at most 5% or at most 3% by mass, - the vacuum residue has a total acidity index (TAN) increased by at least 20%, preferably by at least 30%, advantageously by at least 50%, compared to the total acidity index of the biomass oil supplied in step (a), - the vacuum residue has a reduced carbonyl compound content of at least 20%, preferably at least 30%, advantageously at least 50% relative to the carbonyl compound content of the biomass oil supplied in step (a), - the vacuum residue has a carboxylic acid content increased by at least 20%, preferably by at least 30%, advantageously by at least 50%, relative to the carboxylic acid content of the biomass oil supplied in step (a).

4. A treatment method according to any one of claims 1 to 3, further comprising: (d) a step of esterifying the vacuum residue of step (c) in the presence of an excess alcohol and an acid catalyst under conditions effective to form esters and producing an effluent containing the at least partially esterified stabilized biomass oil, water and unreacted alcohol, (e) a step of separating the effluent produced in step (d) separating (i) a phase containing water, and optionally excess alcohol, and (ii) an organic phase forming the at least partially esterified stabilized biomass oil.

5. Treatment method according to claim 4, characterized in that it comprises at least one of the following characteristics: - the alcohol has a C1-C20 carbon chain, preferably C1-C3, - step (d) is carried out at a temperature of 50 to 120°C, preferably 50 to 100°C, more preferably 60 to 80°C, - the water content of the organic phase is at most 10% by mass. - the total acidity index of the organic phase is reduced by at least 20%, advantageously by at least 30%, advantageously by at least 50%, relative to the total acidity index of the vacuum residue from step (c), - a carboxylic acid content of the organic phase reduced by at least 20%, preferably at least 30%, more preferably at least 50% relative to the carboxylic acid content of the vacuum residue from step (c).

6. A treatment method according to any one of the preceding claims, wherein the biomass oil provided in step a) is derived from a biomass chosen from lignocellulosic biomass, herbaceous biomass, aquifer biomass, paper and cardboard, organic waste, or any other material composed of at least one of these constituents, alone or in a mixture.

7. A treatment process according to any one of claims 1 to 6, wherein at least a portion of the vacuum residue from step (c) or the organic phase from step (e) is: (f) treated in a fluidized bed catalytic cracker, and / or (g) treated in a hydrocracker, and / or, (h) treated in a catalytic hydrogenation unit, and / or (i) treated in a hydrotreatment unit, and / or (j) treated in a steam cracking unit, and / or (k) treated in a partial oxidation unit, and / or (1) used as such or separated into streams usable for the preparation of fuels and combustibles such as LPG, gasoline, diesel, heavy fuel oil, for the preparation of lubricants and / or for the preparation of special fluids.

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