Method for producing a stabilised biomass oil

Abstract

The invention relates to a method for producing a stabilised biomass oil, comprising: (a) providing a biomass oil chosen from a biomass pyrolysis oil, a biomass hydrothermal liquefaction oil and mixtures thereof, and an unsupported hydrotreating catalyst or a precursor of an unsupported hydrotreating catalyst, (b) hydrotreating the biomass oil provided in step a) in the presence of dihydrogen and the unsupported hydrotreating catalyst or its precursor provided in step (a) at a temperature less than or equal to 250°C and obtaining an effluent containing biomass oil that is at least partially hydrogenated, thereby forming a stabilised biomass oil and the unsupported hydrotreating catalyst. The resulting stabilised biomass oil can be used as is or separated into streams that can be used for the preparation of fuels and combustibles and / or for the preparation of lubricants, or in a hydroconversion or cracking process, especially for the manufacture of fuels.

Description

[0001] TITLE: PROCESS FOR PRODUCING STABILIZED BIOMASS OIL

[0002] Technical field

[0003] The present invention relates to the field of biomass oils, resulting from biomass pyrolysis or 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.

[0004] Background to the invention

[0005] Biomass oils, also known as "bio-oils," can be obtained through pyrolysis or hydrothermal liquefaction of biomass. These bio-oils represent an attractive alternative for producing hydrocarbons from renewable resources and reducing greenhouse gas emissions.

[0006] Bio-oils are, however, 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 a particularly high oxygen content. Table 1 gives orders of magnitude of several characteristics of pyrolysis and hydrothermal liquefaction bio-oils.

[0007] Table 1 Properties of hydrothermal liquefaction and pyrolysis bio-oils

[0008] These bio-oils are also chemically and thermally unstable. Chemical instability is reflected in the evolution over time of their physicochemical properties (viscosity, water content, solids content, etc.) which can lead to a separation into two phases. Thermal instability results in a very rapid evolution of their properties when they are heated to temperatures above 80°C. Chemical instability is not a disadvantage for usual subsequent treatments, particularly in a fluidized bed catalytic cracker, a hydrocracker, a hydrotreatment or hydrogenation unit. Since these treatments are carried out at temperatures often well above 80°C, thermal instability is, however, problematic.

[0009] Due to their special properties stated above, the use of bio-oils raises many problems.

[0010] Currently, the main ways of recovering these bio-oils are combustion in boilers or gas turbines to produce heat and / or electricity, or the production of bases for chemistry.

[0011] To be used in refineries for the production of renewable (or partially renewable if blended with fossil fuels), bio-oils must undergo pretreatment. Such pretreatment may be a hydrotreatment step, for example hydrogenation to stabilize the bio-oils, and / or hydrodeoxygenation (HDO). 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 from 80°C to 250°C and hydrodeoxygenation is carried out at temperatures from 250°C to 450°C. HDO reactions are favored by high temperatures and pressures.The use of high pressures promotes the HDO reaction and allows the rate of bio-oil polymerization reactions to be reduced compared to HDO reactions. However, it is observed that even at relatively low temperatures where mainly hydrogenation reactions take place, coking phenomena cause deactivation of the supported catalyst and even clog the fixed bed reactor. It is then necessary to stop the reactor to clean it.

[0012] Prior art

[0013] Thus, in order to limit coking phenomena, it is known to carry out, before HDO, a stabilization step of a pyrolysis oil consisting of a low-temperature hydrogenation in a fixed-bed reactor (“Bio-oil Stabilization by Hydrogenation over Reduced Metal Catalysts at Low Temperatures”, Huamin Wang et al, ACS Sustainable Chem. Eng. 2016, 4, 5533-5545). The stabilization is carried out by a hydrogenation treatment of the pyrolysis oil at a temperature of 80 to 200°C, under 10.3 MPa with a dihydrogen-oil ratio of 2500 L / L, in the presence of a supported catalyst Ru / TiC>2. However, a deactivation of the catalyst is still observed. The publication “Technology advancements in hydroprocessing of bio-oils”, Alan H.Zacher, et al, Biomass and Bioenergy 125 (2019) 151-168 also describes a low-temperature (140°C) stabilization treatment of pyrolysis oil in the presence of dihydrogen and various catalysts, including a Ru / TiO2 catalyst, in a fixed-bed reactor. It is also explained that pyrolysis oil cannot be treated at high temperatures in an ebullated-bed reactor.

[0014] In order to avoid reactor plugging problems, document WO2021156436A1 also teaches introducing a pyrolysis oil into a slurry-type reactor at a temperature below 100°C. Once inside the reactor, the pyrolysis oil is subjected, in a mixture with another feedstock and in the presence of a catalyst, to a hydrocracking reaction at 300-600°C under a pressure of 100-200 bars. This document does not mention any pretreatment of the pyrolysis oil.

[0015] WO2009146225A1 also describes a process for hydroconversion of renewable feedstocks such as pyrolysis oil. The renewable feedstocks (solid or liquid) are co-treated with other liquid feedstocks in a fluidized bed reactor, an ebullated bed reactor, or in the presence of a slurry phase catalyst. WO2010005625A2 describes a process for hydroconversion of a renewable feedstock such as pyrolysis oil in the presence of an unsupported catalytic system. The reaction is carried out at a temperature of 300-600°C under pressures of 1000 to 3000 psi gauge to deoxygenate and crack the renewable feedstock. No pretreatment of the pyrolysis oil is described in these two documents.

[0016] Document EP2404982A1 describes a process for the recovery of heavy feedstocks by hydroconversion in the presence of unsupported catalysts. The feedstock may comprise oils from pyrolysis or hydrothermal treatment of biomass. The hydroconversion is carried out at temperatures of 360°C to 480°C. The catalysts described make it possible to improve the hydroconversion without modifying the operating conditions usually used.

[0017] Document W02014001633A1 teaches reducing coke formation during hydrotreatment by co-treating biomass pyrolysis oil and crude tall oil, the pyrolysis oil having previously been subjected to pretreatment. The co-treatment is carried out in the presence of dihydrogen and a supported catalyst at temperatures of 100 to 450°C, but temperatures of 300 to 350°C are required to completely remove oxygen. The pyrolysis oil can be pretreated by various processes including prehydrogenation in the presence of a supported catalyst at a temperature of 50 to 350°C.

[0018] However, there is a need to stabilize bio-oil by limiting catalyst deactivation problems and in particular to allow its subsequent treatment in a refining unit without the risk of coke formation.

[0019] Summary of the invention

[0020] The invention aims to provide a method for stabilizing a bio-oil selected from an oil resulting from the pyrolysis of biomass and an oil resulting from a hydrothermal liquefaction of biomass. In particular, hydrogenation at temperatures less than or equal to 250°C in the presence of an unsupported hydrotreatment catalyst makes it possible to significantly limit the problems of catalyst deactivation. An object of the invention relates to a method for producing a stabilized biomass oil, comprising:

[0021] (a) the provision of a biomass oil selected from a biomass pyrolysis oil, a biomass hydrothermal liquefaction oil and mixtures thereof, and an unsupported hydrotreatment catalyst or a precursor of an unsupported hydrotreatment catalyst,

[0022] (b) hydrotreating the biomass oil provided in step (a) in the presence of dihydrogen and the unsupported hydrotreating catalyst or its precursor provided in step (a) at a temperature less than or equal to 250°C and obtaining an effluent containing the at least partially hydrogenated biomass oil forming a stabilized biomass oil and the unsupported hydrotreating catalyst.

[0023] In one embodiment, the hydrotreatment step (b) is carried out at a temperature of 50°C to 250°C, optionally 80°C to 200°C, or 100°C to 200°C or 120°C to 180°C or in any range defined by two of these limits.

[0024] In one embodiment, the hydrotreatment step (b) is carried out under a dihydrogen pressure of 5 to 30 MPa, optionally 7 to 25 MPa or 7 to 15 MPa, 8 to 20 MPa or 8 to 15 MPa or in any interval defined by two of these limits.

[0025] In one embodiment, the unsupported hydrotreatment catalyst contains, or consists of, at least one metal selected from metals of groups 3 to 14. The hydrotreatment catalyst may thus be a compound containing at least one metal. The hydrotreatment catalyst may also be a metal or a metal alloy, for example in powder form.

[0026] In one embodiment, step (a) comprises a step of providing a precursor of the unsupported hydrotreatment catalyst. The catalyst precursor may in particular be a compound containing at least one metal selected from groups 3 to 14, this compound being selected from ammonium salts, sulfates, nitrates, chlorides, naphthenates, oxyhydroxides, carbamates, dithioates, oxides, octoates, metallocenes or any other organometallic compound. The unsupported hydrotreatment catalyst is typically a metal catalyst, containing a metal active center, which may be a solid, soluble or not in the biomass oil, or a liquid, soluble or not in the biomass oil.

[0027] The catalyst may in particular be solubilized or dispersed in different organic bases, derived from biomass or petroleum products or in an aqueous solution, in particular in water. These organic and aqueous bases serve, in particular only, to form and / or transport the active metal center to the reactor containing the biomass oil.

[0028] In one embodiment, during hydrotreatment step (b), the unsupported hydrotreatment catalyst is dispersed in the biomass oil, forming therewith a suspension phase or an emulsion phase. A suspension phase (suspension of a solid in a liquid), also called "slurry", is formed when the catalyst is a solid insoluble in the biomass oil. An emulsion phase is formed when the catalyst is a liquid insoluble (immiscible) in the biomass oil.

[0029] When the unsupported hydrotreatment catalyst can be dispersed in the bio-oil, the hydrogenation can then be carried out in particular in a "slurry" type reactor.

[0030] In one embodiment, the method according to the invention further comprises:

[0031] (c) recovering the effluent produced in step (b) and separating the stabilized bio-oil produced in step (b) from the unsupported hydrotreatment catalyst, and optionally returning the unsupported hydrotreatment catalyst to step (b), or

[0032] (c') recovering the effluent produced in step (b) and returning a portion of the effluent produced in step (b) to the inlet of step (b), or

[0033] (c”) recovering the effluent produced in step (b) and separating the effluent into a heavy fraction optionally containing the unsupported catalyst and a fraction lighter than the heavy fraction containing the stabilized bio-oil. In one embodiment, at least a portion of the effluent from step (b) or (c') or of the stabilized bio-oil from step (c) or of the fraction containing the stabilized bio-oil from step (c”) is:

[0034] (e) treated in a fluidized bed catalytic cracker, and / or

[0035] (f) treated in a hydrocracker, and / or,

[0036] (g) treated in a catalytic hydrogenation unit, and / or

[0037] (h) treated in a hydrotreatment unit, and / or

[0038] (i) used as such or separated into streams suitable for the preparation of fuels and combustibles such as LPG, gasoline, diesel, heavy fuel oil and / or for the preparation of lubricants.

[0039] The effluent from step (b) or (c') or from the stabilized bio-oil from step (c) or from the fraction containing the stabilized bio-oil from step (c”) may in particular be treated, in part or in full, in units (e) to (h) alone or in a mixture with a fossil feedstock usually used in these units, in particular without the addition of another feedstock of non-fossil origin. Similarly, this effluent may be used as is or separated into usable streams, alone or in a mixture with a fuel, combustible or lubricant of fossil origin, in particular without the addition of another fuel, combustible or lubricant of non-fossil origin.

[0040] Description of the figure

[0041] Figure 1 is a schematic representation of one embodiment of the present invention.

[0042] Definitions

[0043] 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.

[0044] 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. 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.

[0045] By "biomass" we mean an organic material such as wood (hardwood, softwood), straw, energy crops (short rotation coppice (SRC), very short rotation coppice (VRC), miscanthus, switchgrass, sorghum, etc.) and forest or agricultural biomass residues such as bark, shavings, sawdust, bagasse, household organic waste, etc. Biomass can in particular be chosen from lignocellulosic biomass, herbaceous biomass (biomass of plants with a non-woody stem), aquifer biomass (plants growing in or underwater such as algae), paper, cardboard, household organic waste, alone or in mixtures.

[0046] Biomass can thus include (i) biomass produced by surplus agricultural land, preferably not used for human or animal food: dedicated crops, called energy crops; (ii) biomass produced by deforestation (forest maintenance) or the clearing of agricultural land; (iii) agricultural residues from crops, in particular cereal crops, vines, orchards, olive trees, fruits and vegetables, agri-food residues, etc.; (iv) forest residues from forestry 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 (paper, cardboard, wood, putrescible waste, etc.)); (viii) algal biomass, namely biomass formed from algae, for example microalgae (the algal biomass may 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.

[0047] The resulting biomass oil may contain 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.

[0048] Pyrolysis oil herein means 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 elevated temperature in the absence of oxygen.

[0049] 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 may be fast pyrolysis consisting of a rapid (<2 seconds) increase 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.

[0050] Hydrothermal liquefaction (HTL) is a thermochemical biomass conversion process using water as a solvent, reactant, and catalyst for organic matter degradation reactions, 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.

[0051] “Fossil feedstock” means a hydrocarbon compound derived from the processing of crude oil.

[0052] A "hydroprocessing catalyst" means a catalyst that promotes the incorporation of hydrogen into the products. This type of catalyst is typically a metal catalyst comprising one or more metals from groups 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 and 14 of the periodic table.

[0053] Detailed description of the invention

[0054] The present invention relates to methods for producing a stabilized biomass oil by hydrogenation using an unsupported metal catalyst. The present invention is generally described below with reference to Figure 1.

[0055] Figure 1 is a schematic of one embodiment of a method for producing a stabilized bio-oil of the present invention. In Figure 1, the bio-oil to be stabilized is introduced into the hydrotreatment zone 20 via a feed line 10. The hydrotreatment zone 20 is further supplied with a metal-containing compound via a line 12, optionally with a sulfur-containing compound via a line 14 and with gas containing dihydrogen via a line 15.

[0056] In one embodiment, as will be seen later, the metal-containing compound forms (optionally combined with the sulfur-containing compound) in the hydrotreatment zone 20 an unsupported metal catalyst.

[0057] In another embodiment, also illustrated in FIG. 1, an unsupported metal catalyst is formed and / or activated in the presence of dihydrogen in a container 16 into which a metal-containing compound, mixed or not with a carrier fluid and / or a solvent, optionally a sulfur-containing compound, is introduced via a line 12', the container 16 being heated to temperatures sufficient to form the catalyst from the precursor(s). The unsupported metal catalyst (sulfurized or not) thus formed is then brought into the hydrotreatment zone 20 via a line 18. In yet another embodiment, the bio-oil to be stabilized can be introduced into the container 16 via a line 10', the line 18 then brings to the hydrotreatment zone a mixture formed of the bio-oil and the unsupported metal catalyst.

[0058] In another embodiment, an unsupported hydrotreatment catalyst may be directly introduced into the hydrotreatment zone 20 via a dedicated conduit, whether or not mixed with a carrier fluid and / or a solvent as described below.

[0059] In one embodiment, an optional promoter may optionally be introduced into the hydrotreatment zone 20 via the line 17.

[0060] The bio-oil to be treated is a liquid resulting from the pyrolysis or hydrothermal liquefaction of biomass.

[0061] When the catalyst or its precursor is a solid or liquid, insoluble in the biomass oil, in order to improve the dispersion of the catalyst in the hydrotreatment reaction zone, the catalyst precursor(s) or the unsupported catalyst may be combined with a carrier fluid to form a catalyst suspension (slurry) or a catalyst emulsion before the catalyst is added to the hydrotreatment zone. This suspension or emulsion may be made in the container 16 or in any other capacity. Typically, this suspension or emulsion contains from a few hundred to a few thousand ppm of catalyst or catalyst precursor diluted in the carrier fluid, the volume of carrier fluid is thus small compared to the volume of bio-oil to be treated. The carrier fluid may be any type of product known in the art for creating a catalyst suspension or emulsion.In one embodiment, this carrier fluid is a bio-oil as used as feed to the hydrotreatment zone 20, including the same bio-oil. In one embodiment, the carrier fluid may be a portion of the effluent exiting the hydrotreatment zone, a by-product, or a portion of the stabilized bio-oil obtained in the present invention. In one embodiment, the carrier fluid may be a low-cost light oil such as mineral oil. Aqueous solutions of catalyst precursor materials may also be used. These aqueous precursors are typically added to the feedstock (bio-oil) or a carrier fluid to form an emulsion in which the metal catalyst is formed.

[0062] Alternatively, a solution of a catalyst or catalyst precursor may be produced in a solvent, for example in the container 16 or in any other capacity. The solvent may be any type of product known in the art for solubilizing a catalyst or catalyst precursor. The solvent may in particular be water or an oil or bio-oil, in particular of the same nature as that described for the carrier fluid.

[0063] The catalysts used in the present invention are unsupported catalysts. By "unsupported" is meant that the catalyst does not comprise, and is not associated with, inert support materials such as aluminas, silicas, MgO, carbons, zeolites, oxides, including cerium, zirconium or titanium oxides, etc.

[0064] The catalyst used in the process of the present invention may be any catalyst known to be useful in a process for hydrotreating and hydrogenating petroleum hydrocarbons, particularly in a process in which the catalyst is in suspension (in "slurry") or in emulsion.

[0065] For purposes of the present invention, the hydroprocessing zone comprises an active hydroprocessing catalyst. However, the catalyst feed may comprise an active catalyst and / or catalyst precursors. In other words, the catalyst feed need not comprise an active catalyst. Instead, the catalyst feed may include one or more precursors that react together or react with ingredients present in the bio-oil or in the hydroprocessing zone to form an active hydroprocessing catalyst in the hydroprocessing zone.

[0066] Examples of unsupported catalysts that can be used include, but are not limited to, solid catalysts, whether soluble or not in the bio-oil to be treated, or liquid catalysts, including liquid metal catalysts that are insoluble in the bio-oil to be treated. The unsupported catalysts may be in sulfurized or non-sulfurized form.

[0067] Catalysts can in particular be metals such as cobalt, molybdenum, nickel, iron, vanadium, tin, copper, ruthenium, platinum and other catalysts containing metals from groups 3 to 14. Fine catalyst powders such as powdered carbons, geotite, bauxite and limonite can also be used without, however, serving as a support for a possible metal catalyst phase. Metals can be added to the reaction zone of the reactor in many forms, including as metal salts such as ammonium heptamolybdate and iron sulfate. Metals can be added as bio-oil-soluble or water-soluble species.

[0068] The catalysts used in the present invention may in particular be microparticulate solid metal catalysts prepared from catalyst precursor materials such as precursor materials, optionally water-soluble, oil-soluble or gaseous. When the catalyst precursor materials are mixed in the presence of heat, the precursor materials form a very small solid particulate metal catalyst, which may or may not be sulfurized. The solid particulate metal catalyst will generally be formed of nano- or micro-sized particles having, for example, an average size of less than 100 microns and preferably less than 20 microns. The formation of very small metal catalyst particles can facilitate the dispersion of the catalyst throughout the hydrotreatment zone and improve the contact of the catalyst with the bio-oil.The catalyst precursor materials used in the present method comprise a metal-containing compound, optionally a sulfur-containing compound, and an optional promoter. The metal-containing compound will generally be an oil- or water-soluble or insoluble compound comprising one or more metals selected from metals such as cobalt, molybdenum, nickel, iron, vanadium, tin, copper, ruthenium, platinum, and other metals of Groups 3 to 14. For example, a water- or oil-soluble metal-containing compound comprising one or more metals selected from the group consisting of molybdenum, cobalt, iron, nickel, ruthenium, tin, copper, and combinations thereof may be used.

[0069] The metal-containing compound or catalyst will be added to the hydrotreatment zone in a weight amount that is based on the weight of the metal in the compound / catalyst and is also based on the feed rate of the bio-oil. Typically, the feed rate of the metal-containing compound / catalyst will be between 50 ppm and up to 5% by weight of metal based on the mass feed rate of the bio-oil to the hydrotreatment zone. For example, the metal level may be between 100 ppm and 3% by weight of metal. The feed rate by weight of metal in the metal-containing compound or catalyst added to the hydrotreatment zone will largely depend on the catalytic activity and activity profile of the metal catalyst.

[0070] Suitable metal compounds (oil-soluble or insoluble) include compounds produced by the combination of an oxide or oxyhydroxide or salt of a metal selected from Group 3 to 14, including metal catalysts derived from an organic acid salt or organometallic compounds of vanadium, tungsten, chromium, iron, molybdenum, etc. Some examples of suitable metal compounds include metal ammonium salts, metal sulfates, metal nitrates, metal chlorides, including metal di- and tri-chlorides, metal naphthenates, metal oxyhydroxides, metal carbamates, metal dithioates, metal oxides, metal octoates, metallocenes or other organometallic compounds, etc.

[0071] For example, Mo-containing precursors may be naphthenates or octoates, Ni-containing precursors may be octoates, such as 2-ethyl hexanoate, and V-containing precursors may be acetylacetonate or acetoacetonate. Another example of such a metal compound is the reaction product of a vanadium catalyst precursor, V2O5, and ammonium sulfide to form an ammonium salt of vanadium sulfide as described in US 4,194,967 B1. Other non-limiting examples of usable metal compounds dispersed in the oil include molybdenum naphthenate, nickel di-2-ethylhexanoate, molybdenum dithiocarboxylate, nickel naphthenate, molybdenum hexacarbonyl, molybdenum 2-ethylhexanoate (also known as molybdenum octoate), ammonium molybdates, iron naphthenate, molybdenum lithiocarboxylate (MoDTC), molybdenum lithiophosphate (MoDTP).The various examples of precursors may be used alone or in mixtures. Other useful oil-soluble dispersed catalysts include aliphatic alicyclic carboxylic acids of molybdenum and the oil-soluble metal compound of molybdenum naphthene as described in US 4,226,742 B1. Other useful oil-soluble dispersed catalysts are disclosed, for example, in US 4,824,821 B1, 4,740,925 B1, 5,578,197 B1 and 6,139,723 B1. Other useful catalysts comprising FeSO4 are disclosed in US 4,299,685 B1.

[0072] Examples of organometallic coordination compounds suitable as precursors are compounds of formula CiC2MLn (I), where

[0073] - M is a metal chosen from group 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14,

[0074] -Ci and -C2 are monocyclic or polycyclic aryl hydrocarbon ligands which are each linked by at least one pi bond (typically two pi bonds and one sigma bond) to M, -Ci and -C2 being the same or different, each of -Ci or -C2 comprising from 0 to 5 substituents R, -Ci and -C2 being independent or linked by at least one substituent R, each substituent R being the same or different, R being selected from (i) a substituted or unsubstituted, C3-C8, partially unsaturated, unsaturated or aromatic monocyclic or polycyclic ring structure, fused or not to the ligand -Ci or -C2, (ii) a substituted or unsubstituted, partially unsaturated or unsaturated, linear or branched C3-C8 alicyclic hydrocarbyl radical, (iii) a substituted or unsubstituted, linear or branched C1-C8 saturated hydrocarbyl radical, (iv) a radical SiR'2, with R' identical or different, R' being chosen from a C1-C8 alkyl group, a C3-C8 cycloalkyl group,a C3-C8 aryl group or a C1-C8 alkoxy group,

[0075] -L is a ligand that is linked to M by a sigma bond, n is an integer between 0 and 3, each -L is, independently, a univalent ligand.

[0076] A fused ring is a ring having two carbon atoms and a bond in common with another ring.

[0077] An example of an organometallic coordination compound is a metallocene compound having the general formula (C2Rs)2MLn (II), where the substituted or unsubstituted cyclopentadienyl ligands (C2R5) (R representing the hydrogen atom or being defined as in formula (I)) are each linked to M by at least one pi bond (typically two pi bonds and one sigma bond), and the ligands L are linked to M by a sigma bond, and where M, L and n are defined as in formula (I).

[0078] In formulas (I) or (II), M may be selected from group 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 of the periodic table of elements, preferably M is selected from Fe, V or Mo.

[0079] In formulas (I) or (II), the ligand -L may be chosen from hydrides (-L = -H), halides (-L = -F, -Cl, -Br, -I), "Pseudo-halides" (-L = -CN (cyanide)), alkoxides (-L = -OR), thiolates (-L = -SR), amides (-L = -NR2), phosphides (-L = -PR2), alkyls (-L = -CH2R or other), alkenyls (-L = - CHCHR), alkynyls (-L = -CCR), acyls (-L = -COR), isocyanides (-L = - CNR), nitrosyl (-L = -NO), diazenides (-L = -NNR), imides (-L = =NR), -L = -ER3 or -EX3 (with E = Si, Ge, Sn), -L = -PR3, -PX3, -AsRs, -SbRs and amines, - L = ER2 (with E = O, S, Se, Te), where X is a halogen atom and R is a C1-C8, preferably C1-C6, linear or branched alkyl or alkenyl group, or a C3-C8 alicyclic or aromatic group.

[0080] Examples of useful organometallic coordination compounds include metallocenes, including dicyclopentadienyls of a metal selected from Group 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 such as iron dicyclopentadienyl (ferrocene, Fe(CsH5)2), molybdenum dicyclopentadienyl (Mo(CsH5)2), bis(cyclopentadienyl)molybdenum dichloride ((CsHs^MoC^). Examples of water-soluble dispersed metal-containing compounds useful as catalyst precursors of this invention include, but are not limited to, sodium molybdate, nickel nitrate, iron nitrate, water-soluble multi-metal composite catalyst precursors, heptamolybdate ammonium tetrathiomolybdate (AHM), ammonium paramolybdate (APM) and ammonium tetrathiomolybdate (ATM) soluble in water.

[0081] One or more metal-containing compounds may be combined with one or more sulfur-containing compounds at a temperature above 250°C, for example, from 250°C to 350°C, in the absence of bio-oil, or at a temperature of 150°C to 250°C when the bio-oil to be treated is present, to form the sulfurized metal catalysts useful in this invention. Some examples of useful sulfur-containing compounds include, but are not limited to, gaseous hydrogen sulfide, organic sulfides such as DMDS, polysulfides, elemental sulfur, sodium sulfide, thiophene, and so on. One or more metal-containing compounds may then be combined with one or more sulfur-containing compounds at molar ratios of metal to sulfur ranging from at least 1:1.5 to 1:10 or greater and preferably from at least 1:2 to 1:5 or greater.For example, sulfur in sulfur-containing compounds may combine with metals in a 2:1 molar ratio to form a metal sulfide catalyst. It may be preferable for an excess molar amount of sulfur to combine with the metal-containing compound to form the sulfide catalysts.

[0082] As stated above, temperatures of 150°C to 350°C are used to initiate the formation of metal sulfide catalysts from the catalyst precursor materials. In addition, hydrogen must be present before the catalysts can form. Therefore, the location in the hydrotreating process where the metal sulfide catalyst is formed can be controlled by controlling the point at which hydrogen is added into the process.

[0083] For example, hydrogen may be added to vessel 16 to promote catalyst formation outside of hydroprocessing zone 20 of Figure 1. Alternatively, catalyst precursor materials may be combined in the absence of hydrogen and directed into hydroprocessing zone 20 where, in the presence of hydrogen, they react to form a metal catalyst. The metal catalysts may be used alone or they may be further enhanced by adding small amounts of promoters and / or they may be used with other well-known catalyst additives. In one embodiment, small percentages of at least one active metal such as palladium, platinum, nickel, tungsten, cobalt, molybdenum, or mixtures thereof are incorporated into the catalysts. It is preferred that a Group 4 - Group 8-10 metal be combined with the catalyst precursors to form a metal catalyst.More preferably, a promoter metal selected from the group consisting of nickel, cobalt, or mixtures thereof is incorporated into the unsupported catalyst of this invention. The promoter metal may be added to the catalyst in the form of water- or oil-soluble or insoluble metal compounds. If a promoter metal is used, it is preferred that the promoter metal compound be of the same compound class as the metal-containing compound to minimize the number of by-products in the hydrotreating zone effluent. For example, if the metal-containing compound is an ammonium compound, then it is preferred, but not required, that the promoter metal also be an ammonium compound. The optional promoter metal compound may be combined with the other catalyst precursor materials before the catalyst is formed.The promoter metal compound may be added to the other catalyst precursor materials in an amount based on the weight of the metal in the promoter metal compound. Generally, the promoter metal may be combined with the other catalyst promoter materials in an amount by weight of promoter metal ranging from 0.5% by mass to 15% by mass of the amount by weight of the metal in the metal-containing compound added to the hydrotreating zone and more preferably at a weight ranging from 1% by mass to 10% by mass.

[0084] During low temperature hydroprocessing (250°C or below), the oxygenates in the bio-oil are primarily converted to alcohols. The resulting hydroprocessing reaction products may be used as feedstocks in conventional downstream fuel manufacturing processes, including but not limited to deoxygenation treatments, hydrocracking, etc., and / or may be used as such to prepare fuels, combustibles, and / or lubricants. The hydroprocessing zone will include an effective amount of unsupported catalyst. An effective amount of unsupported catalyst is an amount sufficient to convert at least a portion of the combined feedstock to hydrogenated products. The actual amount of catalyst that may reside in the hydroprocessing zone varies depending on the type and activity of the catalyst selected.For example, the amount of catalyst can be as low as 100 ppm (based on the weight of the catalyst metal). It is also possible for the hydrotreating reaction to include up to 5% by weight of a low-activity metal. For example, a large amount of iron sulfide would likely be required to be effective in a hydrotreating zone due to its low activity. The final choice of catalyst and the amount used will depend on one or more factors, including, but not limited to, cost, activity, susceptibility to fouling and poisoning, and so on.

[0085] Additional additives may be added to or combined with the unsupported catalyst to improve the conversion of the combined feedstock. For example, it may be useful to combine the catalyst with non-metallic refractory materials such as carbon absorbents, silica, alumina, clays, and similar materials, as long as the unsupported catalyst does not deposit on the surface of the refractory material. The unsupported catalysts may be mixed with the refractory materials by well-known methods such as dry mixing, adding the catalyst and refractory materials separately to the reaction zone, etc. Other known additives that improve catalytic activity or inhibit deactivation of the unsupported catalyst may also be added to the catalyst or hydrotreating zone.

[0086] Since water is present in the bio-oil feedstock, additives that bind to the water or control the pH of the reaction may optionally be added to the reaction zone. Ultimately, any additive known to those skilled in the art to be useful in conjunction with the types of unsupported catalysts or the types of processes used in the present invention may be added to the hydroprocessing zone or combined with the bio-oil or catalysts introduced into the hydroprocessing zone. A gas stream containing hydrogen is added to the hydroprocessing zone via line 15 to maintain the hydroprocessing pressure within the desired range. The gas stream containing hydrogen may be essentially pure hydrogen (H2) or may include additives such as hydrogen sulfide impurities or recycle gases such as light hydrocarbons.Reactive or non-reactive gases can be combined with dihydrogen and introduced into the hydrotreating zone to maintain the reaction zone at the desired pressure.

[0087] The hydrotreatment zone of this invention may be selected from any type of hydrotreatment reactor that is useful for carrying out hydrogenation of hydrocarbon products in which the unsupported catalyst is mixed with the feedstock, for example in suspension or emulsion in the feedstock. In particular, an ebullated bed or slurry reactor may be used. The hydrotreatment zone may comprise two or more reactors operating at different reaction degrees or may be a single reactor. A single reactor is preferred in current methods because the inventors have surprisingly discovered that hydrotreatment at a temperature of 250°C or less in the presence of unsupported catalyst makes it possible to limit catalyst deactivation and coke formation while allowing stabilization, and possibly partial hydrodeoxygenation, of the bio-oil.The reactor(s) in the hydrotreatment zone can operate in batch or continuous mode.

[0088] The hydrotreatment zone will comprise a dynamic catalytic bed. One or more ebullated bed or slurry reactors may be used for this purpose, for example a continuously stirred reactor such as a continuous stirred tank reactor (CSTR). Such reactors are known to those skilled in the art. Agitation may be achieved by means of a stirring system or a pump.

[0089] The hydrotreating reaction takes place under hydrotreating reaction conditions sufficient to obtain the desired yield of hydrogenated organic compounds, including alcohols, from the bio-oil, including to obtain a stabilized bio-oil. A bio-oil includes numerous oxygenated compounds such as sugars, ketones, aldehydes, and carboxylic acids, as well as unsaturated compounds such as alkenes and aromatics. A bio-oil can be considered stabilized when the compounds such as sugars, ketones, aldehydes, and carboxylic acids are converted, at least partially, into alcohols. It may happen that the unsaturated compounds (alkenes and aromatics) are also partially hydrogenated during stabilization.For example, a bio-oil may be considered stabilized when its carbonyl content is reduced by at least 20%, preferably at least 30%, 40%, 50%, 60% or at least 80% compared to the carbonyl content of the biomass oil before stabilization. This carbonyl content, measured in mol / kg, can be determined using the ASTM E3146-20 standard, or by nuclear magnetic resonance (NMR). 13 C as described in the examples.

[0090] The reaction conditions generally include temperatures ranging from 50 to 250°C, preferably from 80°C to 200°C, more preferably from 100°C to 200°C and even more preferably from 120°C to 180°C or any range defined by two of these limits.

[0091] The hydrogen pressures, in particular at the inlet to the hydrotreatment zone, typically range from 5 to 30 MPa, preferably from 7 to 25 MPa, more preferably from 8 to 20 MPa and even more preferably from 7 to 15 MPa or from 8 to 15 MPa, or in any interval defined by two of these limits.

[0092] The reaction time is typically 15 minutes to 10 hours, preferably 30 minutes to 5 hours, more preferably 30 minutes to 3 hours or 1 hour to 3 hours, or any interval defined by two of these limits.

[0093] Under these conditions, the hydrocarbon compounds in the bio-oil are hydrogenated without being completely deoxygenated or cracked to form a stabilized bio-oil which can then undergo high temperature treatments (300°C or more) to form fuels or high value-added products.

[0094] Referring again to the figure, the reactor / hydrotreatment zone 20 will generally include a gaseous product discharge line 22 and an effluent discharge line 24 containing the at least partially hydrogenated biomass oil forming a stabilized biomass oil and the unsupported hydrotreatment catalyst. When the unsupported catalyst is a solid insoluble in the biomass oil, the effluent exiting the hydrotreatment zone 20 forms a slurry phase that may be directed to a device 30 that effectively separates at least some of the solid material in the slurry from the liquid material. The device 30 may be a filter, sludge separators, centrifuges, distillation to remove solids, or any other device or apparatus used in hydrocarbon processing to separate or concentrate solids.The liquid effluent can then be recovered via the pipe 32 and subsequently treated in downstream processes to produce fuels in particular. Such a device 30 can also be provided when the unsupported catalyst is a soluble solid or a liquid, to separate any solid impurities and / or sediments possibly present in the effluent and / or the heavy part of the effluent.

[0095] In most cases, the liquid effluent leaving the hydrotreatment zone or device 30 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 pool of fuels or combustibles such as LPG, gasoline, jet, diesel, fuel (including marine fuels), or even a pool of lubricants.

[0096] The liquid effluent thus stabilized 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. This stabilized liquid effluent can be sent in part or in full to one or more of these units to be treated alone or in a mixture with a fossil feedstock.

[0097] The residual gas discharged from the hydrotreatment zone 20 via line 22, which may also contain high-value light hydrocarbons, may be processed in conventional refining processes to convert and / or recover high-value materials such as light hydrocarbons, dihydrogen, and so on. The residual gas and liquid effluent discharged via lines 22 and 32, respectively, may also be processed in downstream processes to remove unwanted contaminants such as water, sulfur, oxygen, etc. When present, the device 30 also produces concentrated sludge discharged via line 34, which may include the unsupported catalyst and / or impurities and / or sediment and / or the heavy portion of the effluent.All or part of the concentrated sludge formed in the device 30, possibly containing the unsupported catalyst and / or impurities and / or sediments, may be returned to the hydrotreatment zone 20 via the line 35. Alternatively or in combination, all or part of this concentrated sludge may be removed via the line 36 for separation, treatment and / or disposal.

[0098] The embodiment of the method according to the invention and its various variants described with reference to Figure 1 can be implemented in one (or more) reactors operating continuously, product flows then circulating continuously in the various pipes, or in 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.

[0099] EXAMPLES

[0100] Method for determining the content of aldehydes / ketones and sugars by NMR

[0101] Sample preparation:

[0102] A 5 ml solution of DMSO-d6 + Cr(AcAc)s is prepared by placing 41 + / - 2 mg of Cr(AcAc)s in a 5 ml volumetric flask brought to the 5 ml mark with DMSO-d6.

[0103] The sample is prepared in a flask by adding the bio-oil sample to the DMSO-d6 + Cr(AcAc) 3 solution in the following proportions:

[0104] • Sample: 230 mg + / - 10 mg

[0105] • DMSO-d6 + Cr(AcAc)s: 480 mg + / - 10 mg

[0106] The preparation is homogenized on a stirred plate and then transferred with a glass pipette into a 5 mm NMR tube. A maximum of 8 samples are prepared at the same time to record the spectra within a time interval of 72 hours.

[0107] Spectrum recording conditions: The NMR signal 13 C{ 1H} is recorded on a Bruker 500 MHz with a 5 mm BBFO (“Broad Band Fluoride Observation”) probe under the following conditions:

[0108] Pulse angle: 90°.

[0109] Pulse repetition time: 3s

[0110] Spectral width: 36232 Hz centered at 120 ppm

[0111] Number of points: 64K

[0112] Acquisition time: 0.9s

[0113] Temperature: 25°C

[0114] Rotation: 20 Hz

[0115] Number of scans: 6000

[0116] Decoupling sequence: inverse-gated decoupling sequence to avoid the nuclear Overhauser effect (NOE), with the Waltz-16 Composite-Pulse Decoupling sequence (CPD).

[0117] Spectrum processing conditions:

[0118] The NMR signal is processed with Mestre-Nova® software. The NMR spectrum 13 C{ 1 H} is obtained by Fourier transformation on 64K points after exponential multiplication (line broadening factor = 1). The spectrum is manually phased, the baseline is automatically corrected with the Whittaker smoothing procedure and the chemical shift scale is referenced to the DMSO signal at 39.52 ppm.

[0119] The peak regions are integrated with the following limits:

[0120] The sum of the peak areas is normalized to 100% and the measured peak areas are directly related to the relative abundance of each carbon type. Example of stabilization of wood pyrolysis oil

[0121] A pine pyrolysis oil obtained by a fast pyrolysis process (FPBO for “Fast Pyrolysis Bio-oil”) having the properties shown in Table 2 was subjected to stabilization by hydrotreatment in the presence of several unsupported catalysts.

[0122] Table 2: Properties of the FPBO used in the tests

[0123] Stabilization tests were carried out in the presence of several catalysts.

[0124] The commercial catalysts used are as follows: -Molybdenum Octoate: CAS 94232-43-6

[0125] -Goethite a-FeOOH: CAS 51274-00-1

[0126] -Ni powder: CAS 7440-02-0

[0127] Table 3 lists the conditions for the synthesis of the M0S2 catalyst from molybdenum octoate. Table 3: Synthesis of M0S2

[0128] The tests were carried out in a 100 mL semi-batch reactor with an internal diameter of 4.1 mm. This is a stainless steel reactor that can reach reaction temperatures up to 500°C and pressures up to 170 barg, allowing continuous injection of dihydrogen.

[0129] The tests were carried out at temperatures between 120 and 150°C (Table 4) under a pressure and hydrogen flow rate of 120 bar (12 MPa) and 50 NL / h respectively. The stirring speed was 1300 rpm. The reaction time ranged from 30 min to 2 h (see Table 4). 60 g of feedstock were treated for each test. DMDS (0.2 mL) was added to the molybdenum octoate to activate it.

[0130] The tests were carried out as follows. First, heating is initiated manually to reach 50°C. Then, the pressure increase, stirring, and injection of dihydrogen are initiated in turn at this temperature. The temperature increase to reach the final temperature, 120°C or 150°C, lasts 15 minutes. Then, it is kept stable for 30 minutes to 2 hours depending on the tests to promote the catalytic reaction. Finally, stopping the heating allows the temperature to decrease to reach 50°C in 15 minutes.

[0131] Table 4: Operating conditions of the tests

[0132] The liquid effluent produced by each test is formed of two liquid phases of different viscosities, a first phase (phase 1) containing a significant quantity of water (approximately 50% vol), less viscous than a second phase (phase 2), containing essentially organic compounds. In order to facilitate the analysis of the aldehyde / ketone and sugar contents of the effluent, the two phases were separated and then analyzed by NMR of the 13 C, according to the method previously described. The yields of each phase are presented in Table 5.

[0133] Table 5: Liquid phase yield

[0134] Table 6 shows the aldehyde and ketone and sugar contents of the feed before treatment and after treatment measured by NMR of the 13 C, according to the method previously described. The contents after treatment correspond to the contents of the two phases recovered, namely of the entire effluent produced.

[0135] These results show that a low-temperature hydrogenation treatment in the presence of an unsupported catalyst can reduce the aldehyde / ketone and sugar contents of the feedstock and therefore stabilize it. The effluent thus stabilized can then be sent for further treatment (alone or mixed with a fossil feedstock), for example to produce a fuel, combustible, lubricant, etc. Table 6 analysis of the feedstock before treatment and the liquid effluent produced.

Claims

DEMANDS 1. A process for producing a stabilized biomass oil, comprising: (a) the supply of a biomass oil selected from a biomass pyrolysis oil, a biomass hydrothermal liquefaction oil and mixtures thereof, and an unsupported hydrotreating catalyst or a precursor of an unsupported hydrotreating catalyst, (b) hydrotreating the biomass oil supplied in step (a) in the presence of dihydrogen and the unsupported hydrotreating catalyst or its precursor supplied in step (a) at a temperature of 250°C or less and obtaining an effluent containing the biomass oil at least partially hydrogenated forming a stabilized biomass oil and the unsupported hydrotreating catalyst.

2. A process according to claim 1, wherein the hydrotreating step (b) is carried out at a temperature of 50°C to 250°C, optionally from 80°C to 200°C or from 100°C to 200°C or from 120°C to 180°C.

3. A process according to claim 1 or 2, wherein the hydrotreating step (b) is carried out under a dihydrogen pressure of 5 to 30 MPa, optionally of 7 to 25 MPa or of 7 to 15 MPa.

4. A process according to any one of claims 1 to 3, wherein the unsupported hydrotreating catalyst contains, or is made up of, at least one metal selected from the metals of groups 3 to 14.

5. A process according to any one of claims 1 to 4, wherein the precursor of the unsupported hydrotreating catalyst is a compound containing at least one metal selected from groups 3 to 14, such compound being selected from ammonium salts, sulfates, nitrates, chlorides, naphthenates, oxyhydroxides, carbamates, dithiates, oxides, octoates, metallocenes, or any other organometallic compound.

6. A process according to any one of claims 1 to 5, wherein in the hydrotreating step (b), the unsupported hydrotreating catalyst is in a dispersed state in the biomass oil, and forms with it a suspended or emulsified phase. A method according to any one of claims 1 to 6, further comprising: (c) the recovery of the effluent produced in step (b) and the separation of the stabilized bio-oil produced in step (b) from the unsupported hydrotreating catalyst, and optionally the return of the unsupported hydrotreating catalyst to step (b). A process according to any one of claims 1 to 6 further comprising: (c') the recovery of the effluent produced in step (b) and the return of a portion of the effluent produced in step (b) to the inlet of step (b). A process according to any one of claims 1 to 6 further comprising: (c) the recovery of the effluent produced in step (b) and the separation of the effluent into a heavy fraction optionally containing the unsupported catalyst and a lighter fraction containing the stabilized bio-oil. A process according to any one of claims 1 to 9, wherein at least a portion of the effluent from step (b) or (c') or of the stabilized bio-oil from step (c) or of the fraction containing the stabilized bio-oil from step (c") is: (e) treated in a fluidized bed catalytic cracker, and / or (f) treated in a hydrocracker, and / or, (g) treated in a catalytic hydrogenation unit, and / or (h) treated in a hydrotreating unit, and / or (i) used as is or separated into usable streams for the preparation of fuels and combustibles such as LPG, petrol, diesel, heavy fuel oil and / or for the preparation of lubricants.

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