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: METHOD FOR PRODUCING AN OXIDATION-STABILIZED BIOMASS OIL technical field

[0001] The present invention relates to the field of biomass oils, obtained from biomass pyrolysis or from hydrothermal treatment of biomass, and more particularly to their stabilization, notably either for their use as is or separated into usable streams for the preparation of fuels and / or for the preparation of lubricants, or for their use in a hydroconversion or cracking process, notably for the manufacture of 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 containing lignin. These bio-oils represent an attractive alternative for the production of hydrocarbons from renewable resources and for reducing greenhouse gas emissions.

[0003] Bio-oils, however, are complex liquids, consisting of water and a complex mixture of oxygenated compounds (such as aldehydes, ketones, furans, carboxylic acids, sugar-like compounds, lignin-derived compounds, etc.). Their elemental composition is close to that of the starting biomass, with, in particular, a high oxygen content. Table 1 gives orders of magnitude for 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, lignocellulose biomass) Elemental Composition (%w) Carbon >70 10-70 Hydrogen 5-15 5-10 Oxygen 8-20 20-55 Nitrogen 0-10 0-2 Sulfur <2 <1 Water Content (%w) <15 15-30 Viscosity (mPa.s) (50 °C) 60 to 1500 or more 10-100 Acid value (mgKOH per g bio-oil) 5-200 50-250 Carbonyl content (mol / kg) ND 3-8

[0005] The presence of carbonyl compounds such as aldehydes and ketones makes the bio-oil thermally unstable, as temperature promotes polymerization / condensation reactions. This thermal instability results in a very rapid change in their properties when 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, especially organic acids. They are also immiscible with fossil hydrocarbons. Furthermore, they contain many temperature-sensitive molecules, such as sugars.

[0008] In order to be used in refineries for the production of renewable (or partially renewable if blended with fossil fuels) fuels or liquid fuels, bio-oils must therefore be treated to improve their properties and enable their use in conventional refining processes and / or for fuel production. It is known to subject bio-oils to hydrocracking or hydrotreating treatments, including hydrodeoxygenation (HDO). The hydrotreating 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 involved, these processes lead to coke formation. Furthermore, HDO requires high hydrogen consumption and is difficult to industrialize because of its high exothermicity. Finally, it has been observed that even at relatively low temperatures, where hydrogenation reactions primarily occur, coking phenomena can occur, causing deactivation of the supported catalyst and even leading to blockage of the fixed-bed reactor. It is then necessary to shut down the reactor for cleaning.

[0009] It is also known to subject bio-oils to esterification and acetalization reactions in the presence of an alcohol and an acid catalyst, enabling the conversion of organic acids into esters and aldehydes into acetals, and thus improving the Product properties. However, since bio-oils are thermally unstable, optimizing the reaction can be difficult when maintaining them at a temperature below their instability point. Furthermore, because the reactions are balanced, the conversion of all aldehydes to acetals is not guaranteed.

[0010] Document WO2016 / 207609 describes a process for fractionating pyrolysis oil to produce a hydrophobic aromatic fraction and an aqueous phase. This process includes an oxidation step of the aldehydes and ketones contained in the biomass oil, producing an effluent containing carboxylic acids and water. This effluent is then entirely subjected to an esterification reaction under conditions that allow the formation of two distinct phases: an organic phase containing the hydrophobic aromatic fraction (molecules derived from lignin and phenolic species) and an aqueous phase containing pyrolytic sugars, organic acids, and phenolic species. However, some of the recoverable carbon ends up in the aqueous phase, so the overall yield is not optimal. Furthermore, it is then necessary to treat the aqueous phase, which generates significant additional costs.

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

[0012] The invention aims to provide a process for treating a bio-oil that enables its thermal stabilization. This bio-oil is selected from an oil resulting from biomass pyrolysis, an oil resulting from the hydrothermal liquefaction of biomass, a lignin oil, and mixtures thereof. In particular, oxidation of the bio-oil followed by distillation under reduced pressure yields a thermally stable product that can then be used as is, directly blended in a fuel pool, or that can subsequently undergo one or more treatments in a refining unit.

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

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

[0015] (b) an oxidation step of 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,

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

[0017] During step (b), at least some of the carbonyl compounds, namely aldehydes and / or ketones, initially present in the biomass oil are oxidized. In particular, the aldehydes are oxidized to carboxylic acids, which significantly reduces the oil's thermal instability. Distillation of the water naturally formed during the oxidation reaction yields a stabilized product that can be used immediately without further processing. Due to its low water content, the stabilized biomass oil can be used as is, for example, blended in fuel pools, with or without additives. These additives can stabilize the medium (e.g., emulsifiers), neutralize the medium, and / or reduce its acidity. The oil can also be processed alone or in blends 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 from 15 °C to 80 °C or from 20 °C to 60 °C, - Step (b) is carried out at an absolute pressure of 0.01 to 10 bar, optionally from 0.1 to 5 bar or from 0.5 to 2 bar, advantageously at atmospheric pressure, - The reaction time for 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 0.1 to 2, advantageously 0.5 to 1.5.

[0019] The 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 residue under vacuum contains at most 10% water by mass, advantageously at plus 5% by mass of water, optionally at most 3% by mass. - the vacuum-sealed 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 carbonyl compound content, and in particular aldehydes and / or ketones, reduced by at least 20%, preferably by at least 30%, advantageously by at least 50%, compared to the carbonyl compound content, 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%, compared 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 lead to undesirable corrosion phenomena during subsequent treatments.

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

[0022] (d) a vacuum esterification step of the residue from step (c) in the presence of a excess alcohol and an acid catalyst under conditions efficient for forming esters and producing an effluent containing 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 stabilized biomass oil at least partially esterified.

[0024] These additional steps allow at least part of the carboxylic acids to be esterified and thus reduce the acidity of the stabilized oil, facilitating its further processing in refining processes, in particular when it is processed alone, or in coprocessing with fossil feedstocks.

[0025] In this embodiment, the method may include one or more of the following features: - the alcohol has a carbon chain in the C1-C20 range, preferably in the C1-C3 range, - step (d) is carried out at a temperature of 50 to 120 °C, preferably from 50 to 100 °C, 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 residue under vacuum from step (c), - a carboxylic acid content of the reduced organic phase of at least 20%, preferably at least 30% more, preferably at least 50%, compared 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 hydrotreating unit, and / or

[0031] j) processed 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 usable streams for fuel preparation and fuels such as LPG, petrol, 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) can be subjected to treatments f) to 1) alone or in mixture with a hydrocarbon feedstock of fossil origin, with or without additives, in particular of the type mentioned above, optionally after having been fractionated according to distillation temperature ranges adapted to these units. Definitions

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

[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 obtained from the pyrolysis of biomass and / or an oil obtained from the hydrothermal liquefaction of biomass.

[0038] The term "pyrolysis oil" herein means 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 various modes of pyrolysis, such as, for example, rapid pyrolysis, vacuum pyrolysis, catalytic pyrolysis, pyrolysis in the presence of hydrogen, and slow pyrolysis or carbonization, etc... In particular, pyrolysis can be a rapid pyrolysis consisting of a rapid increase (<2 seconds) of temperature to 300°C-750°C, leading to depolymerization and fragmentation of the constituent elements of biomass (holocelluloses (cellulose, hemicellulose), lignin), followed by rapid quenching of the degradation products.

[0040] Hydrothermal liquefaction (HTL) is a thermochemical process for converting biomass using water as a solvent, reactant, and catalyst for the degradation reactions of organic matter, with the water typically in a subcritical or supercritical state. This process generally takes place at temperatures of 250 to 500 °C and 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 ASTM D 482 and represents for those skilled in the art a well-known assessment of the amount of carbon residue produced after pyrolysis under standard temperature and pressure conditions.

[0044] The total acidity index (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 Honeywell Hydranal Coulomat AK® (CAS: 101023-55-6) as the reagent. Specifically, the samples to be tested were prepared at a concentration of 0.05 gd in dry tetrahydrofuran (THF).

[0048] In the present description, "carbonyls" or "carbonyl compounds" means ketones and aldehydes exclusively; "carbonyl group" means the Rl(C=0)R2 group, where RI 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 this description, "carboxylated compound" or "compounds comprising a carboxylated group" means 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, notably according to the method described below. Detailed description of the invention

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

[0053] The biomass oil supplied in step a) may be an oil from biomass pyrolysis, an oil 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 biomass selected 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 in mixture.

[0055] Step (a) of supplying biomass oil may therefore include the mixing of one or more of the aforementioned oils.

[0056] Step (a) may further include:

[0057] (al) a step of biomass liquefaction 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 include a pyrolysis step, a hydrothermal liquefaction step, a solvolysis step or any other treatment enabling the production of biomass oil, in particular from lignocellulosic and / or lignin-rich biomass.

[0060] When step (a1a) includes a pyrolysis or hydrothermal liquefaction step, the product comprises a liquid phase, a gaseous phase, and a solid phase. The liquefaction step (a1a) may include a pyrolysis step, typically carried out at a temperature of 300 to 1000 °C or 400 to 700 °C, this pyrolysis being, for example, rapid pyrolysis, flash pyrolysis, catalytic pyrolysis, or hydropyrolysis. In particular, the pyrolysis may be rapid 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 (al) may include 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) allows the gaseous phase, essentially C1-C4 hydrocarbons and the solid phase (typically char) to be removed in order to recover only the liquid organic phase forming a biomass oil.

[0063] When step (al) includes a solvolysis step in the presence of a solvent, the product formed comprises a liquid phase and a solid phase. The solvent can be water (this is called 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 in this solvolysis step is typically lignin-rich biomass (e.g., lignocellulosic biomass, herbaceous biomass, black liquor from the paper industry, or any other biomass or waste containing lignin). Step (a1a) releases the lignin contained in the biomass from other compounds, such as hemicelluloses and their derivatives.

[0068] The separation step (a2) allows the solvent used during hydrolysis or solvolysis to be removed 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 include 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, or ethyl acetate. Distillation may be used to remove the solvent(s) used.

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

[0071] Step (al) may also include any processing step enabling the production of 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 acidic reducing medium (e.g. the bisulfite process in the presence of Na2SO3, at 140-170°C).

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

[0073] The biomass can be chosen from lignocellulosic biomass, herbaceous biomass (biomass of plants having a non-woody stem), aquifer biomass (plants growing in or under water 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 from surplus agricultural land, preferably not used for human or animal consumption: dedicated crops, called energy crops (short-rotation coppice (SRC), very short-rotation coppice (VSRC); (ii) biomass produced by deforestation (forest maintenance) or the clearing of agricultural land, etc.; (iii) agricultural residues from crops, in particular cereal crops, vines, orchards, olive trees, fruits and vegetables including nuts, agri-food residues, etc.; (iv) forestry residues from silviculture and wood processing; (v) agricultural residues from livestock farming (manure, slurry, bedding, 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 microalgae (algal biomass can be an algal suspension obtained by harvesting algae from, for example, a bioreactor, or an algal residue obtained by dehydrating an algal suspension) or macroalgae; (ix) herbaceous biomass; (x) vegetable oils contained in certain waste (cashew nut shells or other); (xi) industrial waste (type B wood), (xii) sewage sludge, (xiii) digestate from methanizers; (xiv) vinasse from the production of alcohols by fermentation.

[0075] The biomass oil obtained may contain from 8 to 55% oxygen by mass. 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, and phenols. Oxidation step (b)

[0076] 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. Biomass oil typically contains at least aldehydes and / or ketones.

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

[0078] In one embodiment, the biomass oil supplied 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 no more than 90 °C, for example at a temperature of 15 °C to 90 °C, optionally from 15 °C to 80 °C or from 20 °C to 60 °C, or in any range defined by two of these limits.

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

[0081] In step (b), the biomass oil supplied in step (a) is brought into contact with an oxidizing agent. The reaction time can 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 within any range defined by two of its limits.

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

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

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

[0085] For example, an amount of oxidant can be added such that 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, or in any range defined by two of these limits.

[0086] Step (b) produces an effluent containing 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 water added with the oxidizing agent. This water content can therefore 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 can advantageously be reduced by at least 20%, preferably by at least 30%, 40%, 50%, 60%, 70% or at least 80% compared to the content of carbonyl compounds of the biomass oil at the inlet of step (b) supplied 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%, compared to the carboxylic acid content of the biomass oil supplied in step (a). Step (c) of vacuum distillation

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

[0090] This step c) of vacuum distillation allows to separate a distillate containing water and a residue under vacuum, 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 efficient conditions to remove a desired quantity of water, particularly depending on the subsequent use of the stabilized biomass oil. It can advantageously be implemented at low temperatures. 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 the stabilized biomass oil. This oil can be obtained as is in fuel pools, or it can be subjected to refining treatments and / or a subsequent esterification reaction. In the latter case, the reduced water content of the stabilized biomass oil allows the equilibrium of a subsequent esterification reaction to shift towards ester formation. This vacuum distillation step can also remove some of the most 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 residue under vacuum may thus exhibit 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 ASTM E3146-20, 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%, compared to the carboxylic acid content of the biomass oil supplied in step (a) Optional esterification step

[0095] This esterification step reduces the acidity of the stabilized biomass oil. It can also eliminate remaining carbonyl compounds, particularly aldehydes and / or ketones, as well as hydroxylated compounds. Indeed, under the esterification conditions of carboxyl groups, acetalization of carbonyl groups and etherification of hydroxylated groups can also be observed.

[0096] The vacuum residue obtained during the vacuum distillation step typically contains many 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 a part of these groups into esters and / or acetals and / or ethers, This 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 carbon chain in C1-C20. However, in a preferred embodiment, the alcohol has a carbon chain in C1-C3 (i.e. e.g. methanol, ethanol, propanol).

[0100] The quantity of alcohol added can be determined based on the carbonyl and / or hydroxyl content of the stabilized biomass oil so as to add the alcohol with an excess of approximately 50% w / w. For example, a mass ratio of stabilized biomass oil / alcohol of 1 / 0.5 to 1 / 10 may 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 suitable homogeneous acid catalysts include sulfuric acid, p-toluenesulfonic 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®), and oxide-based acid catalysts such as silica, zeolites, alumina, silica-alumina, titanium dioxide, and zirconia.

[0102] The catalyst can 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 residue under vacuum.

[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 suitable pressure to shift 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 referred to as removal by reactive distillation. However, the water can also be removed discontinuously, for example by a reflux apparatus. Reflux makes it possible, in particular, to carry out a light distillation sufficient to extract the water or a water-alcohol mixture depending on the conditions, especially when a purge with an inert gas is performed. The use of an azeotropic solvent can also be implemented.Thus, in some embodiments, steps (d) esterification and (e) separation by distillation can be carried out simultaneously.

[0104] In other embodiments, the 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] A person skilled in the art will know how to adapt the conditions to obtain the desired esterification rate.

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

[0107] By way of example, when the alcohol used is C1-C3, step (d) can be carried out at a temperature of no more than 80 °C, for example at a temperature of 60 to 80 °C.

[0108] The reaction time can 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) can 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 stabilized biomass oil, at least partially esterified, water, and unreacted alcohol. This effluent is entirely and directly subjected to the separation step (e), in particular without an intermediate step such as phase separation.

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

[0112] This separation step (e) can thus allow the excess alcohol to be separated, 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) allows the separation of (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] The distillation separation step (e) can be carried out under atmospheric pressure or under reduced pressure, under temperature and / or pressure conditions enabling the removal of water, and optionally excess alcohol, from the effluent of step (d).

[0115] The separation step (e) by distillation can be carried out at a temperature of 15 to 80 °C, preferably 20 to 70 °C, more preferably 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 stabilized biomass oil at least partially esterified.

[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 by at least 30%, more preferably by at least 50%, compared to the total acidity index of the vacuum residue from step (c), - a carboxylic acid content reduced by at least 20%, preferably by at least 30%, more preferably by at least 50% compared to the carboxylic acid content of the vacuum residue of step (c). Optional follow-up treatments

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

[0120] The vacuum residue / organic phase can thus be treated in the aforementioned units (catalytic fluidized bed cracker, hydrocracker, catalytic hydrogenation unit, and / or hydrotreating unit) while limiting or eliminating the deactivation of the catalysts used and / or the formation of coke, despite the high temperatures implemented in these units, typically 500 to 550°C in a catalytic fluidized bed cracker, 100 to 500°C in a hydrotreating or hydrogenation unit, and above 230°C, often 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 for treatment alone or mixed with a fossil feedstock, with or without additives. Description of the figure

[0121] The [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 line 1. The oxidation zone 10 is further supplied with an oxidizing agent via a line 2. The oxidation zone 10 may comprise, or consist of, one (or more) continuously operating reactor, in which product flows continuously through the various lines, or one (or more) batch reactors supplied with reactants at the beginning of the reaction and whose effluents are discharged and treated at the end of the reaction. The different phases may be brought into contact by means of agitation, turbulent flow, or any other means.

[0123] The feed line 1 may originate from a biomass liquefaction zone 3 fed 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 enabling the production of 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 entirely via a line 4 to a reduced-pressure distillation zone 20, for example, a vacuum distillation column or any other device enabling distillation under reduced pressure. This distillation zone 20 separates a distillate, discharged via a line 5, which consists mainly of water, from a vacuum residue, discharged via a line 6, which consists mainly of 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 processing units 30, 50. The further processing unit(s) 50 can be a fluidized bed catalytic cracker, a hydrocracker, a catalytic hydrogenation unit, a hydrotreating 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 line 7 and with catalyst via a line 8. The esterification zone 30 can comprise, or consist of, one (or more) continuously operating reactor, with product flows circulating continuously in the different lines, or one (or more) batch operating reactor supplied with reactants at the beginning of the reaction and whose effluents are discharged and treated at the end of the reaction.

[0127] All of the effluent exiting the esterification zone via pipe 9 is then sent to a new separation zone 40 to separate the water discharged via a line 11, and possibly excess alcohol, mixed or not with water. The separation zone 40 can be a distillation column, a reflux device or other, possibly integrated into the esterification zone 30 to implement reactive distillation, or 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 discharged 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 further processing units 50.

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

[0130] Method for determining 31P NMR content of carboxylic acids: 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-norbomene-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 shaken plate for 1 minute. When homogenized, 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 described below is carried out.

[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 solvent solution.

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

[0138] The sample is then prepared in a bottle by adding the bio-oil sample to the various 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 shaken 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: 32K

[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 composite-pulse decoupling sequence (CPD). Spectrum processing conditions

[0150] The NMR signal is processed using Topspin® software. The 31P NMR spectrum is obtained by Fourier transform on 32K points after exponential multiplication (line broadening factor = 4). The spectrum is manually phase-matched, and 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 Carboxyl CO OH 133.7 - 136.0 Internal standard (NHND) 150.6- 153.0

[0152] The NHND peak area 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

Demands

1. A process for treating a biomass oil comprising: (a) a step of supplying 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 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 the biomass oil at least partially oxidized and water, (c) a step of distilling under reduced pressure the effluent from step (b) separating a distillate containing the water and a residue under vacuum forming a stabilized biomass oil having a reduced water content.

2. A treatment process 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 from 15°C to 80°C or from 20°C to 60°C, - step (b) is carried out at an absolute pressure of 0.01 to 10 bar, optionally from 0.1 to 5 bar or from 0.5 to 2 bar or at atmospheric pressure, - the reaction time of step (b) is from 15 minutes to 5 hours, optionally from 30 minutes to 2 hours, - the oxidizing agent is selected 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) the number of moles of oxidizing agent present is 0.1 to 2, advantageously 0.5 to 1.

5.

3. A treatment process 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-sealed 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-sealed residue has a carbonyl compound content reduced by at least 20%, preferably by at least 30%, advantageously by at least 50%, compared 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%, compared 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) an esterification step of the residue under vacuum from step (c) in the presence of excess alcohol and an acid catalyst under conditions efficient for forming esters and producing an effluent containing 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 stabilized biomass oil at least partially esterified.

5. A treatment method according to claim 4, characterized in that it comprises at least one of the following features: - the alcohol has a carbon chain in the C1-C20 range, preferably in the C1-C3 range, - 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%, compared to the total acidity index of the vacuum residue from step (c). - a carboxylic acid content of the reduced organic phase of at least 20%, preferably at least 30%, more preferably at least 50%, compared to the carboxylic acid content of the vacuum residue of step (c).

6. Processing method according to any one of the preceding claims, wherein the biomass oil supplied in step a) is derived from biomass selected 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 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 of 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 hydrotreating unit, and / or (j) treated in a steam cracking unit, and / or (k) treated in a partial oxidation unit, and / or (1) used as is or separated into usable streams 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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