NL2008794C2

NL2008794C2 - Process for hydrotreating vegetal materials.

Info

Publication number: NL2008794C2
Application number: NL2008794A
Authority: NL
Inventors: Robertus Hendrikus Venderbosch
Original assignee: Btg Biomass Technology Group B V
Priority date: 2012-05-10
Filing date: 2012-05-10
Publication date: 2013-11-12
Also published as: EP2847299A1; WO2013169112A1

Description

PROCESS FOR HYDROTREATING VEGETAL MATERIALS

The present invention relates to a process for treating vegetal biomasses.

5 Being the only sustainable product containing carbon, vegetal biomasses are the only alternative for fossil derived crude oil derivatives. Research on the use of biomass, particularly from vegetal sources, for first generation biofuels is rapidly expanding (e.g. bio-ethanol 10 from sugar sources and starches and bio-diesel from pure plant oils). Biomass, in particular the one consisting of ligno-cellulosic materials, is difficult to convert into transportation fuels. Conventional refinery scales (up to 100 t/hr crude oil equivalence) are preferable for economic 15 reason, but problematic for biomass, as these are usually scattered and collection is expensive and difficult. In addition, various types of biomass are different in structure and composition (accordingly the handling procedures have continuously to be adapted), have a low 20 energy density compared to many fossil resources, and often contain significant amounts of water and ash.

Such disadvantages can be overcome if the biomass is first de-centrally restructured, densified at a smaller scale (say 2 to 10 t/hr) while the intermediate product can 25 be transported to a large central processing unit where it is transformed to a more stable product (at a scale of say 50 to 200 t/hr). A potentially attractive technology for this purpose is fast pyrolysis. Fast pyrolysis is a process in which organic materials are heated to 450 - 600 °C with a 30 short temperature/time ramp, in absence of air. The meaning of a short temperature/time ramp depends on the type of material to be fast pyrolysed. Under these conditions, organic vapours, permanent gases and charcoal are produced.

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The vapours are condensed to pyrolysis oil. Typically, 50 -75 wt. % of the feedstock is converted into pyrolysis oil. Fast pyrolysis transforms difficult-to-handle biomass of different nature into a clean and uniform liquid, called 5 pyrolysis oil. Pyrolysis oil (obtained by fast pyrolysis) can be used for the production of renewable/sustainable energy and chemicals. Its energy density is four to five times higher than wood, and more than tenfold for fluffy agricultural residues. This offers important logistic 10 advantages. Pyrolysis liquids contain negligible amounts of ash, and have a volumetric energetic density 5 to 20 times higher than the original biomass.

Pyrolysis oils are rather unstable. An indicator to assess the degree of stability is its tendency to produce 15 coke, via the residue retained upon distillation, for example the 'Conradson Carbon Residue', or the 'Micron Carbon Residue Testing' (abbreviated CCR and MCRT, respectively). The CCR and the MCRT both can be measured via a Standard Test Method for Conradson Carbon Residue (for 20 example from the American National Standard Institute). Both of these carbon residues are given via a standard industrial coking test for characterizing the coke forming tendency. A similar analysis can be carried out using thermogravimetric analysis (or thermal gravimetric analysis, 'TGA'), in which 25 a sample of material is heated up to a temperature of 900°C under nitrogen in the absence of air while the weight of the remaining sample is continuously measured. The weight of the residue remaining is referred to as the 'TGA residue'. In general, pyrolysis-oils show CCR values around 10 to 50 %, 30 while CCR-values for feed for refinery applications such as Fluid Catalytic Cracking (FCC) generally < 5 wt. %. Pure pyrolysis oils are immiscible with conventional crude oil derivatives, and cannot be processed in FCC units due to the 3 large CCR value. Pyrolysis oils can be hydrotreated to lower the CCR-value. Products from mild hydrotreatment (treatment with hydrogen) are reportedly distillable, with no significant coke formation, and co-processing in a 5 laboratory FCC facility (designated as 'Micro Activity Testing' or MAT) is demonstrated.

Several processes for upgrading the pyrolysis oil have been proposed up to date. Examples include hydrogenation under hydrogen pressures, Catalytic Cracking and a High 10 Pressure Thermal Treatment (HPTT). These upgrading processes for the pyrolysis oil may involve, for instance, removal of the oxygen (usually >95%), decarboxylation, viscosity reduction, sulphur removal, nitrogen removal, and the like. Existing processes include the hydrodeoxygenation of bio-15 oil, (HDO), in which a simultaneous hydrogenation, deoxygenation and cracking takes place. These processes apparently require high pressures of hydrogen, for instance, in the range of 50 bar to 350 bar and temperatures ranging from 50 up to 450°C, for the removal of oxygen from the 20 pyrolysis oil in the form of water, CO or CO2 (COx) , with a long multi-step hydrodeoxygenation to achieve significant (-95%) oxygen removal, whereas significant methanation due to the presence of C0X also leads to high hydrogen consumption. However, these processes entail very high 25 hydrogen consumption, which makes them uneconomical and difficult to carry out.

Further, pure pyrolysis oils are immiscible with conventional crude oil derivatives, acidic, and cannot easily be processed in FCC units, also because of the high 30 CCR value. After some hydrotreatment, however (up to 25 wt. % oxygen), co-processing in a small FCC (MAT) facility with aromatic hydrocarbonaceous feedstocks is successfully demonstrated, producing bio-gasoline with high RON value.

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Fluid Catalytic Cracking of hydrogenated oils affects the way the oxygen is removed, viz. by decarboxylation rather than dehydration, while coke is formed together with additional water.

5 In known methods for the conversion of pyrolysis oils to hydrocarbon products, a first partial hydrotreatment of the pyrolysis oil is carried out using catalysts such as Nickel or Nickel/Molybdenum catalysts on a high surface area support or Pt and/or Pd dispersed on gamma-alumina or 10 activated carbon, followed by separation of the partially deoxygenated oil stream to separate a hydrocarbon stream, and finally by full hydrotreating of the hydrocarbon stream in the presence of a hydrocracking catalyst. Other methods include the use of Re-containing catalysts used for the 15 hydrogenolysis, or palladium-catalyzed hydrogenations of bio-oils and certain organic compounds. Re, Ru or Pd or any other noble metal as active material, though, renders the catalyst very expensive. Additionally, a problem with catalysts known from the conventional refinery processes, 20 such as Nickel/Molybdenum or Cobalt/Molybdenum on alumina supports, is that they are not meant to handle high water contents, however high water content are common in pyrolysis oils. Experiments indeed showed that porous catalysts, prepared by impregnation of active metals on a porous 25 support material, are quickly deactivated, as the catalyst support disintegrates, leaching of active components into the water takes place, catalyst pores are clogged, and finally a pressure build-up in the reactor. Lower temperatures for a first mild hydrogenation reaction appears 30 profitable, as deactivation of the catalyst is less pronounced at lower temperatures.

US20110119994 A1 discloses a process for catalytic hydrotreatment of a pyrolysis oil wherein pyrolysis oil was 5 hydrodeoxygenated, producing a partially deoxygenated pyrolysis oil with an oxygen content in between 10 and 30 wt.%, to be separated from the product stream, and to be hydrogenated in the presence of a hydrocarbon feed derived 5 from a mineral crude oil where after at least one product fraction from the hydrogenated product stream is separated: a partially deoxygenated stream was thus mixed with a mineral crude oil stream.

There is a need for further process and catalyst 10 improvements for conversion of pyrolysis oils into useful and more stable (intermediate) products. Such products will have lower CCR-values, lower water content (and reasonable viscosity to allow pumping), but also allowing high carbon yields (from biomass to final products).

15 Accordingly, it is a goal of the present invention, amongst other goals, to provide an improved process for the treatment of biomasses coming from vegetal sources which are technically easier to carry out. Further, it also a goal of the present invention to provide a process for the treatment 20 vegetal biomasses that can be in a short amount of time and/or that can be carried out at mild conditions compared to known methods. Furthermore, it is a goal of the present invention to provide an improved process for treating vegetal biomasses, which does not present the above-25 mentioned drawbacks and additionally manufactures a product that is better suited for further processing because it is more stable, specifically because the product comprises a low water content, low coking tendency, low viscosity and low amounts of acids. Additionally, high overall carbon 30 yield (from biomass to final products) can be obtained with the process of the present invention.

The above-mentioned goals are achieved by the process according to the present invention. Specifically, the above- 6 mentioned goals are achieved by a process for the treatment of a vegetal biomass comprising: a) hydrotreating a vegetal biomass in the presence of a catalyst to obtain a hydrotreated product; 5 b) separating the hydrotreated product into an aqueous fraction and an organic fraction; c) concentrating the aqueous fraction obtained in step b) to obtain a concentrate ; d) adding the concentrate obtained in c) to the organic 10 fraction obtained in b); and e) further treating the mixture obtained in d); .

In the context of the present invention, the vegetal biomass in step a) is contacted with a catalyst suitable for the hydrotreatment carried out. The hydrotreatment is a 15 treatment with hydrogen. Specifically, the vegetal biomass is contacted with at least one catalyst and is hydrotreated until a pre-determined level of hydrotreatment of said biomass is obtained. The catalyst can be one catalyst or the combination of more than one catalyst, such as two catalysts 20 or more, three catalysts or more, four catalysts or more, five catalysts or more. The catalyst can comprise more than one metal, also designated by a mixed metal catalyst. In the context of the present invention, a catalyst is a reagent that participates in the chemical reaction, but is not 25 consumed by the reaction itself. The catalyst used in the method of the present invention, can be any commercially known catalyst, such as a catalyst comprising copper, or copper, zinc oxide, or copper zinc oxide and alumina or a catalyst comprising chrome oxide and zinc oxide. The 30 catalyst can advantageously be chosen from a metallic oxide, a metallic hydride, or a metallic oxysalt comprising at least one of the metals chosen from the group Al, Cu, Cr,

Cs, Fe, Ir, La, Mo, Mn, Ni, Pd, Rh, Si, Sm, Ti, Zn.

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The predetermined level of hydrotreatment is a desired level of hydrotreatment that is to be achieved. The predetermined level of hydrotreatment defines the completion of the conversion of hydrogen and the vegetal biomass. It is 5 to be understood as the moment in time, wherein the desired yield of conversion is achieved, such as at least 80%, at least 85%, at least 90%, at least 95%, 100%. Accordingly, the process according to the present invention comprises performing the reaction until the predetermined level of 10 conversion is reached.

In the context of the present invention, the pretreated vegetal biomass obtained in step a) is separated into two fractions, an aqueous fraction and an organic fraction. By "fraction" is to be understood a part of the 15 vegetal biomass. "Fraction" can also be designated as a phase. An aqueous fraction is to be understood as a fraction comprising water. Particularly, the aqueous fraction comprises a mixture of water and of an alcoholic component, also designated as one or a mixture of more than one 20 hydrocarbon comprising the hydroxyl functional group -OH, also known as an alcohol. Accordingly, the alcoholic component comprises at least one alcohol. Advantageously, the alcoholic component is a mixture of different alcohols. By alcoholic components is to be understood organic 25 compounds, in particular hydrocarbons having one or more hydroxyl functional groups (-OH), such as mono-ol, di-ols, tri-ols. The alcohol component can be any alcohol or mixture of alcohols, such as linear, branched, or cyclic alkyls, linear, branched, or cyclic alkenyls, or linear, branched, 30 or cyclic alkynyls of any length, as well as aromatic alcohols. Examples of are methanol, ethanol, propyl alcohols, butyl alcohols, pentyl alcohols, hexyl alcohols, phenol, cresol. An organic fraction can be understood as a 8 fraction made of hydrocarbons. The hydrocarbons may also contain oxygen, or functional groups comprising one or more oxygen. The composition of the organic fraction, therefore the nature of the organic components, varies according to 5 the origin of the biomass. Optionally after the separation, the organic fraction can be further treated in conventional processing.

Step c) of the process of the present invention, relates to concentrating the aqueous fraction obtained in 10 step b) to obtain a concentrate as well as a diluate.

Accordingly, step c) relates to concentrating the aqueous fraction obtained in step b) to obtain a concentrate and a diluate. The diluate can be further treated in a step f). Accordingly, step f) comprises further treating of the 15 diluate obtained in phase c). The diluate can also be designated as "distillate" in distillation or "extract" in extraction, or "permeate" in membrane filtration, and is to be understood as being comprised in the water-rich fraction and is the fraction removed from the aqueous fractions other 20 than the concentrate. The amount of water in the diluate is more than 50% by weight, preferably equal to or more than 60% by weight, more preferably equal to or less than 70% by weight, even more preferably equal to or less than 80% by weight, and most preferably equal to or less than 90% by 25 weight. It can contain smaller concentrations of low-weight oxygen containing components such as acetic acid, methanol, ethanol, propanol, and so on. The treatments of the diluate can be any process to recover low alkyls (Ci-C6-alkyls) comprising a functional group, such as a carboxylic acid -30 COOH, an ester -C00-, an aldehyde -CHO, a ketone -C0-, an alcohol -OH. Examples of such treatments would be process for the recovery of acetic acid, or methanol, or ethanol, or propanol.

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In the context of the present invention, step c) is a step wherein the concentration of the aqueous fraction is carried out. Accordingly, a concentrate is obtained in step c). This concentrating step can also be designated as 5 dewatering step. Accordingly, a dewatering step is carried out in step c). By dewatering is to be understood that the aqueous fraction, or phase comprising water, will be further treated to remove the water (together with some other smaller weight components as acidic acid, methanol and so 10 on) from said fraction to produce the so-called "diluate" and isolate the alcoholic component. Step c) therefore allows concentrating (concentrating can also be defined as "removing" water from) the alcoholic component, or dewatering the alcoholic component, therefore obtaining a 15 concentrate. The aqueous fraction subjected to the concentrating, or dewatering, step yields in additional organic matter: a water-free alcoholic component, also designated as a water-lean alcoholic fraction that is then added to the organic fraction obtained in step b) , such as 20 recited in step c). Concentrating the aqueous fraction is carried out by at least one step selected from distillation, condensation, phase separation, sedimentation, filtration and chromatography. The concentrating (or dewatering) of the aqueous fraction can also be carried out by more than one 25 successive step selected from distillation, condensation, phase separation, sedimentation, filtration and chromatography. In the context of the present invention, "more than one" is to be understood as two, three, four, five, six, seven, eight, nine, or ten.

30 In the context of the present invention, the mixture comprising the concentrated (or dewatered) alcoholic component and the organic fraction after step d) is then suitable for further treatment. In step e), the mixture can 10 be used in different application, such as in combustion, in gasification, via conventional distillation for chemical, but also in a further hydrotreating to arrive at products containing almost no more oxygen.

5 The dewatering of vegetal biomass derived oils can be carried out with the water soluble fraction of a pyrolysis oil derived from biomass. Distillation of pyrolysis oil fractions yield (very) viscous organic components (> 500 cST) with high charring tendency (MCRT > 15 % by weight).

10 Surprisingly, the aqueous fraction derived from a first hydrotreatment step, where oxygen is removed down to levels of 10 to 20% in the remaining organic phase, can be distilled to yield a water-lean fraction, with water content of equal to or less than 5% by weight, that is still fluid 15 (viscosity of equal to or less than 250 cSt) and has low charring tendency (of equal to or less than 10% by weight). More surprisingly, during the concentrating, or dewatering, step also part of the acids, and mainly acetic acid, can be removed, substantially improving the performance of the 20 catalysts required in a further treating step, preferably a hydrotreating step over more conventional catalysts.

The combination of the organic phase with the concentrate, can be designated as stabilized pyrolysis oil ("SPO"), because it presents the advantage that it is 25 stabilized and that the overall carbon yield is increased significantly. Additionally, the coke formation of the mixture surprisingly appears more limited. One reason for this could be the effect of the dilution of the low MCRT yielding alcoholic components. Further, the alcoholic phase 30 yields to a significant better type of product oil (as it mainly contains alcohols) and the combustion characteristics are better due to the lower weight alcoholic components. Furthermore, a reduction in viscosity of the vegetal biomass 11 is observed, making the processes carried out in step e) realized more efficiently, or more easily. Accordingly, the present invention presents a process with the above-mentioned advantages, in that the hydrotreating process of 5 vegetal biomasses, or vegetal materials, is optimized. In other words, the process according to the present invention provides a higher efficiency and a higher reliability.

In the context of the present invention, a biomass is to be understood as being a carbohydrate such as a lipid 10 material (such as oil or fat), or such as a material containing lignitic hemicellulose and/or lignitic cellulose (‘lignocellulosic materials') and can contain sugars or starch. The biomass has a vegetal, or vegetal, origin (any type of plant) and can accordingly be a triglyceride, a 15 vegetal fats, a vegetal oil. They can also contain free fatty acids, mono- and di- glycerides, and unsaponifiable lipids .

The aqueous fraction can be any suitable aqueous medium extracted from the vegetal biomass and/or added to the 20 vegetal biomass (such as, but not limited by, distilled water, de-ionised water, de-gazed water). Accordingly, the aqueous fraction can have any water content and may be at least partly provided by the vegetal biomass.

The organic fraction is to be understood the water 25 insoluble fraction remaining after hydrotreating the biomass to a predetermined hydrotreatment level and after separation from the aqueous fraction. The organic fraction with a water content of equal to or less than 15% by weight, preferably a 12.5% by weight, more preferably 10% by weight, even more 30 preferably 9% by weight, most preferably 8% by weight.

Further, the organic fraction has a density of at least 1.0 kg/1 and an oxygen content on basis of the dry material of less than 30% by weight, preferably less than 27.5% by 12 weight, more preferably less than 25% by weight, most preferably less than 20% by weight.

The aqueous fraction is to be understood the water soluble fraction after hydrotreating the biomass in step a) 5 (also designated as pretreatment step) to a predetermined hydrotreatment level, with a water content equal to or of at least 25% by weight, preferably at least 30% by weight, more preferably at least 50% by weight, even more preferably at least 55% by weight, most preferably at least 60% by weight, 10 even most preferably at least 65% by weight relative to the total weight of the aqueous fraction. The water content of the aqueous fraction can have any value equal to or above 30% by weight of the total weight of the aqueous fraction, such as at least any of the following value: 30%, 35%, 40%, 15 45%, 50%, 55%, 60%, 65%, 70, 75%, 80%, 85%, 90%, 95% by weight.

The concentrate can also be designated as "alcoholic component" and is to be understood as being comprised in the aqueous fraction (also designated as the water soluble 20 fraction). The concentrate is obtained after step c): by concentrating, or dewatering, the aqueous fraction. The amount of alcoholic component in the aqueous fraction is equal to or less than 30% by weight, preferably equal to or less than 25% by weight, more preferably equal to or less 25 than 15% by weight, even more preferably equal to or less than 10% by weight, and most preferably equal to or less than 5% by weight.

When the organic fraction obtained in step b) is mixed with the concentrate obtained in step c), the mixture formed 30 such as described in step d) can be designated as stabilized oil. The stabilized oil is to be understood as the mixture of the organic phase obtained in step d) after hydrotreatment of the material in step a) and the 13 concentrate, or alcoholic phase, remaining after concentrating/dewatering the aqueous phase in step c).

In the context of the present invention, "at least once" is to be understood as one time, two times, three 5 times, four times, five times or six times, successively or not. The definitions, preferences and advantages described for the process of the present invention are applicable to all the embodiments of the present invention. The temperature and pressure of the mixing step d) is 10 advantageously the same pressure and the same temperature as in step b) and/or c), namely at a pressure equal to, or below 100 bar and a temperature equal to, or below 150°C. Preferably, the pressure is equal to, or below 80 bar, more preferably equal to, or below 50 bar. The temperature is 15 preferably equal to, or below 150°C, more preferably equal to, or below 120°C.

According to the present invention, the product obtained in d) can also be submitted to at least one separation process in order to remove water before carrying 20 out step e). Accordingly, in this step, even more water is removed from the product obtained in d). The at least one additional separation can be one separation, two separations, three separations, four separations. The separation process can be any separation process or a 25 combination of more than one process. Advantageously, the separation is chosen from the group distillation, condensation, evaporation. According to the present invention, the product obtained in any of the steps b), c) and d) is supplied to step a) to be hydrotreated in the 30 presence of a catalyst with the biomass as defined in step a). Accordingly, any of the products obtained in steps b) to d) can be added to the biomass in step a) and treated with the succession of steps a) to d) such as recited in the 14 process of the present invention. This presents the advantage of better completion of the process steps.

According to the present invention, the diluate obtained in step c) can produce hydrogen in step f).

5 Specifically, the diluate obtained in step c) is gasified and produces hydrogen in step f). Accordingly, in the context of the present invention, the hydrogen from the diluate phase can be obtained at conditions wherein the water is in the supercritical phase. Supercritical water is 10 water at conditions above its critical temperature (Tc = 374°C) and critical pressure (Pc = 220 bar).

Hydrogen could be produced by any known method for producing hydrogen, such as a specific thermochemical processes (gasification).

15 Advantageously, the process of the present invention presents the advantage that the hydrogen is produced in step f) and can directly be used in step a). The advantage of using the hydrogen directly in step a) is technically practical.

20 The hydrogen produced in the process of the present invention can also be isolated for use in a different process where hydrogen is needed.

According to the present invention, the treatment in step e) is selected from a cracking reaction (fluid 25 catalytic cracking or steam cracking), a further hydrogenation (such as a further hydrodeoxygenation or hydrocracking) and a gasification.

According to the process of the present invention, the treatment in step e) can be a hydrotreatment. Specifically, 30 the hydrotreatment is the hydrogenation of the mixture obtained in d) in the presence of at least one catalyst to yield a hydrogenated vegetal biomass.

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According to the present invention, the treatment in step e) is a hydrotreatment such as a hydrodeoxygenation. Specifically, the hydrodeoxygenation is the hydrogenation, deoxygenation and possibly hydrocracking of the mixture 5 obtained in d) in the presence of at least one catalyst to yield a hydrodeoxygenated vegetal biomass.

By hydrogenation is to be understood a treatment with hydrogen, i.e. chemical reaction between molecular hydrogen (H2) and another compound present in the vegetal biomass, 10 usually in the presence of a catalyst. Catalysts are required for the reaction to be usable; non-catalytic hydrogenation takes place only at very high temperatures. Hydrogen adds to double and triple bonds in hydrocarbons (such as alkenes or alkynes).

15 By deoxygenation is to be understood a chemical reaction involving the removal of oxygen atoms from a molecule, such as the replacement of a hydroxyl group by hydrogen or the replacement of an oxo group by two hydrogen atoms. The term hydrodeoxygenated means that a compound 20 underwent a hydrodeoxygenation (HDO) which is a hydrogenolysis process for removing oxygen from compounds. The term hydrocracking means that a compound is further cracked to produce a lower weight materials. It is of interest for biofuels, which are derived from oxygen-rich 25 precursors like sugars. Typical HDO catalysts commonly are nickel-molybdenum or cobalt-molybdenum on gamma alumina.

According to the processes of the present invention, the hydrotreatment is to be understood a treatment with hydrogen (H2) . It can be a hydrogenation or a 30 hydrodeoxygenation (also designated by the abbreviation HDO). In the processes according to the present invention, the contacting between the catalyst and the biomass and/or the gaseous hydrogen can be done, for example by stirring in 16 well-known stirred tank reactors. In the process of the present invention, the stirring can be carried out by mechanical stirring or magnetical stirring, or by passing the oil over the catalyst bed in a packed bed mode. The 5 reactors used in the process according to the present invention can be any suitable reactor, such as an autoclave.

The gaseous hydrogen can be designated by H2. It can be pure or mixed with another gas such as CO or C02 or CH4, or recycle gas from the process, in which gaseous products 10 derived from the process (CO, C02 and CH4) can be concentrated. The feed of gaseous hydrogen can be for example continuous until completion of the treatment. Maintaining the gaseous hydrogen feed continuous is to be understood as keeping the feed of gaseous hydrogen in order 15 to continuously feed the reactor with hydrogen and accordingly keep the pressure of hydrogen constant in the reactor, until the end of the treatment.

The conditions of the hydrotreatment are a certain temperature and a certain pressure, depending on the 20 material to be hydrotreated. In the present invention, the hydrotreatment in step a) and/or in step e) is carried out at a temperature in the range of 50°C to 800°C, such as any temperature above 50°C, such as any temperature below 800°C. Preferably, the hydrotreatment in step a) and/or in step e) 25 is carried out at a temperature in the range of 50°C to 500°C, such as equal to, or below 450°C. The pressure is in the range of 10 bar to 400 bar, such as any pressure above 10 bar, such as any pressure below 350 bar or below 300 bar. The hydrotreatment is carried out until a predetermined 30 level of conversion is reached. The predetermined level of hydrotreatment defines the completion of the hydrotreatment reaction. It is to be understood as the moment in time, wherein the desired yield of hydrogenation is achieved 17 determined by favorable product characteristics here defined by the value for the CCR (and/or MCRT, and/or residue) below 10%.

According to the present invention, the treatment of 5 the diluate phase from step c) in step f) is a gasification, such as in the reforming in supercritical water.

Gasification converts the biomass into carbon monoxide, hydrogen and carbon dioxide, by reacting the biomass at high temperatures (>700 °C), without combustion, with a 10 controlled amount of oxygen and/or steam. The resulting gas mixture of carbon monoxide, hydrogen and carbon dioxide is called syngas (synthesis gas or synthetic gas) and is itself a fuel.

The treated biomass after step e) can be obtained at 15 the end of the treatment by a subsequent isolation step and/or a purification step, for example by distillation, and /or by phase separation, and/or sedimentation and/or filtration and/or chromatography.

According to the present invention, the hydrotreatment 20 of the vegetal biomass in step a) is carried out at a temperature ranging 50 °C to 800 °C substantially in oxygen-free environment. Oxygen-free environment can be achieved by removing the air of the reactor in which the process is carried out and thus the process would be carried out 25 substantially in absence of air. The term "in absence of air" means that the reaction is carried out in absence of air, that the oxygen of the air has been removed. Step a) can also be carried out in inert atmosphere.

According to the present invention, step b) and/or step 30 c) is carried out by at least one process selected from the group consisting of a distillation, a condensation, a phase separation, a sedimentation, a filtration and a chromatography. Specifically, step b) and/or step c) is 18 carried out by at least one process, such as one process, two processes, three processes, four processes. In the context of the present invention, step b) and/or step c) being carried out in at least one process is to be 5 understood in that the separation in step b) and/or the concentration in step c) is carried out in one distillation or more, and/or in one condensation or more, and/or in one phase separation or more, and/or in one sedimentation or more, and/or in one filtration or more, and/or in one 10 chromatography or more.

According to the present invention, after the concentration in step c), the water content of the concentrate is at most 30% by weight of water with respect to the total weight of the aqueous fraction. To this extent, 15 step c) is a dewatering step. According to the present invention, the concentration or dewatering step is a step in which the water content of the aqueous phase is reduced from by at least 50% by weight making the total amount of water of at most 30% by weight, preferably at most 25% by weight, 20 more preferably at most 15% by weight, even more preferably at most 10% by weight, and most preferably at most 5% by weight. The dewatering can be done in-situ, i.e. at the pressure and/or temperature applied in the hydrotreatment step a), or after depressurization and cooling of the 25 product phases. Examples for the latter here are by a subsequent isolation step and/or a purification step, for example by (atmospheric or vacuum) distillation, and /or by phase separation, and/or sedimentation and/or filtration and/or chromatography. Preferentially, dewatering takes 30 place by distillation at reduced pressures and temperatures, such as below 150°C and below 1.5 bar, more preferential at temperatures below 150°C and below 1 bar, and most preferentially below 100°C and below 0.15 bar.

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According to the present invention, step c) is carried out at the same pressure and the same temperature range than in step a) and/or in step e). Specifically, according to the present invention, concentrating the aqueous fraction in 5 step c) is carried out at the same pressure and temperature range than in the hydrotreatment step a). According to the present invention, step a) is carried out at a temperature in the range 50°C to 1000°C, preferably 50°C to 800°C and at a pressure in the range 5 bar to 350 bar, preferably 10 to 350 10 bar. Step a) is carried out in a substantially oxygen-free environment. A substantially oxygen-free environment is to be understood an environment in which oxygen has been at least partially removed by pumping, purging with a different gas (such as argon, or any other inert gas).

15 According to the present invention, step c) is carried out at the same pressure and temperature range than in step e). According to the present invention, step e) is carried out at a temperature in the range 50 °C to 1000 °C, and at a pressure in the range 5 bar to 350 bar. Step e) can be 20 carried out in a substantially oxygen-free environment.

According to the present invention, in step c), the concentration of the aqueous phase is carried out at a pressure equal to, or below 1.5 bar and at a temperature equal to, or below 150°C. Advantageously, the concentration 25 is carried out at a pressure below 1 bar, preferably below 0.5 bar, more preferably 0.15 bar. Advantageously, step c) is carried out at a temperature equal to, or below 120 °C, preferably equal to, or below 100 °C. Step c) can be carried out at any combination of pressure and temperature mentioned 30 above. Preferably, step c) is carried out by distillation.

According to the process of the present invention, the biomass can be submitted to pyrolysis before step a). Accordingly, the vegetal biomass is advantageously submitted 20 to a thermal treatment, called pyrolysis, before carrying out the process of the present invention. The thermal treatment is carried out at a temperature ranging 200 °C to 800 °C, preferably 300°C to 700°C, more preferably 450°C to 5 650°C, such as below 650°C, such as above 450°C, in absence of air. This thermal treatment, or thermal process carried out before step a) is also designated as pyrolysis. It can be a fast pyrolysis. The resulting product is also designated as pyrolysis oil.

10 According to the present invention, the pressure in step a) is advantageously in the range 10 bar to 350 bar.

The pressure of step a) is more advantageously a pressure in the range of 10 bar to 250 bar, preferably 100 to 250 bar, more preferably 150 to 220 bar. According to another 15 preferred embodiment, the temperature applied in step a) is a temperature in the range of 50°C to 400°C, such as 50°C, 6 0 °C, 70 °C, 80 °C, 90 °C, 100°C, 110°C, 120°C, 130°C, 140°C, 150 °C, 16 0 °C, 170 °C, 180 °C, 190°C, 200°C, 210°C, 220°C, 230 °C, 240 °C, 250 °C, °C, 270°C, 280°C, 290°C, 300°C, 310°C, 20 320 °C, 330 °C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400 °C.

According to the present invention, the separation of the aqueous and organic fraction in step b) is carried out at pressures below 100 bar, and temperatures below 250°C, 25 preferably below 200°C, more preferably below 150°C.

The catalysts used in the hydrotreatment step of step a) and/or e) can comprise any type of catalysts applied in the hydrotreating of pyrolysis oils, for example those comprising noble metal and non-noble metal derived catalysts 30 on support material, with noble metal include (but not restricted to platinum, rhodium, ruthenium, palladium, gold, iridium or combinations thereof, and non-noble metal catalysts selected from nickel, cobalt, molybdenum, 21 tungsten, copper, iron, manganese, osmium, tin and combinations thereof, such as NiMo, CoMo, NiCu, Ni/Cu/Co, Ni/Co/Mo and so on. Support materials include (but are not restricted to) Group IV metal oxides, Group V metal oxides 5 and Group IIIA metal oxides, and can be selected from for example (and not restricted to) Ti02, Zr02, Nb205, quartz, silicon carbide, A1203, silicon oxide an alike, but also carbon. Furthermore, the active metals may be adhered to nano-porous support, such as zeolites, nano-porous carbon, 10 nanotubes and fullerenes. Ni-Cu catalysts produced by a so-called sol-gel method as described in W02012030215A1 were found to be particularly effective, as they substantially promote hydrogenation of carbonyl groups in bio-oil already at temperatures below 150°C. According to another aspect, 15 the present invention thus relates to the use of a hydrotreating or hydrodeoxygenation or hydrocracking catalyst prepared by a so-called sol-gel method. The sol-gel process is understood to be a catalyst production process that involves the use of metal alkoxides as catalysts 20 precursors, which undergo hydrolysis and condensation polymerization reactions to give gels under relative mild temperatures. The preparation of a silica glass begins with an appropriate alkoxide which is mixed with water and a mutual solvent to form a solution. Hydrolysis leads to the 25 formation of silanol groups (Si—OH). Subsequent condensation reactions produce siloxane bonds (Si—0—Si). During the drying process (at ambient pressure), the solvent liquid is removed and substantial shrinkage occurs. Heat treatment of the latter at elevated temperature produces viscous 30 sintering and effectively transforms the porous gel into a dense glass. The catalysts prepared by the sol-gel process include materials that have specific properties than if prepared by another method, such as ferroelectricity, 22 electrochromism, or superconductivity, but also composition control, microstructure control, purity, and uniformity of the method combined with the ability to form various shapes at low temperatures.

5 According to a specific process layout of the present invention, recycling of the oxygen containing organic phase from the stabilization step back to the reactor, (i) to effectively reduce the concentration of reactive groups to reduce polymerization, (ii) reducing the local water 10 concentration and (iii) reducing the polarity of the bio-oil thus promoting the local hydrogen solubility. As an important economic advantage, the organic and / or alcoholic phases thus produced are not substantially deoxygenated, allowing complete mixing with the original vegetal material 15 and thus avoiding the need for expensive emulsifiers.

According to the present invention, the vegetal biomass treated in the process according to the present invention can be used for the preparation of biofuels. Biofuels are a wide range of energy source derived from biomass. The term 20 designates solid or liquid fuels (e.g. bioethanol, biodiesel) and various biogases. Bioethanol is an alcohol made by fermenting the sugar components of plant materials and it is made mostly from sugar and starch crops. With advanced technology being developed, cellulosic biomass, 25 such as trees and grasses, are also used as feedstocks for ethanol production. Biodiesel is made from vegetal oils, animal fats or recycled greases. Biodiesel can be used as a fuel for vehicles in its pure form, but it is usually used as a diesel additive to reduce levels of particulates, 30 carbon monoxide, and hydrocarbons from diesel-powered vehicles .

23

According to the present invention, the biomass is a vegetal biomass that is a material containing lignitic and/or hemi-cellulosic and/or cellulosic materials.

5 The present invention is further illustrated, without being limited, by the following Figure 1 and Examples 1-8.

Figure 1: Process for the hydrotreatment of a vegetal material 10

Figure 1 illustrates the process for the hydrotreatment and further deoxygenation of the pyrolysis oil. Examples 1 provides the information on the catalyst specifically suited for the process depicted in Figure 1, while examples 2-5 15 provide details on the mass balance of the process aimed at, examples 6-9 specification of de-water samples and on the feed stock used in example 2-9.

Figure 1 shows the overall process lay-out in case vegetal material (1) is treated in a reactor ('stabiliser', 2) at 20 elevated pressures and temperatures using hydrogen (4), yielding an upgraded mixture (4) that can be separated in an organic rich phase (5)and an aqueous phase (6)in a separator (7) . The aqueous phase is transferred to a dewatering unit (8) , where water-rich phase (also designated by diluate) (9) 25 can be separated from the alcoholic phase (10). The alcohol phase is mixed with the organic phase to yield the SPO stabilized pyrolysis oil (11). The stabilized oil can be further used as a product, f.i. in a (co-) refining concept, where it is (co-)treated with a.o. vacuum gas oil in fluid 30 catalytic cracking, in a conventional hydrotreater, or as (co-)feed to a steam cracking unit). In a preferential scheme the SPO is further hydrogenated to remove virtually all oxygen in a second hydrotreater (12) to yield a mixture 24 of a second aqueous phase and organic oil (13), from which in a second separator (14) the oxygen-lean product (15) and hydrotreater water (16) is obtained. In a preferential setup the oxygen-lean product can be further refined (such as 5 in a distillation tower 17). The hydrogen used in hydrotreaters 2 and 12 is in excess, and several process combinations known to those skilled in the art are possible. One option presented here for illustration is to transfer the gas used in hydrotreater (2) and slightly enriched by 10 contaminants as CO2 and CH4 (18) directly to the hydrotreater (12)and vent part of the remaining gas effluent (19), recirculating the remaining back to the stabilizer (2) as recycle gas (20). In another option, through a distillation tower (17) various fraction can be derived from 15 the carbonaceous phase (15), for example fractions (21), (22) and (23) derived thereof.

Examples 20 Example 1.

For the preparation of NiCu/Si02 catalyst, the appropriate amounts of commercial NiC03 »mNi (OH2 *nH20) , CuC03 *mCu (OH2) , and 25% NH3 solution were dissolved in water and stirred for 4 h. Subsequently a solution of ethyl silicate in ethyl alcohol 25 was added to the suspension and the obtained solution was stirred for 4 h. Then, during stirring, the solution was 0

heated to 80 C until a viscous mixture was formed. This mixture was dried at 120 °C for 4 h during which a solid was obtained. Next, the resulting catalyst is calcined, while 30 increasing the temperature from room temperature to 400°C

with the heating rate of 5 C/min, and keeping it at 400°C for a further 2 h. After that the material is cooled down to the room temperature. Finally the catalyst is pressed into 25 tablets, with size 10 x 4 mm. The pressure applied was approx 3000 kg for each tablet, yielding the unsupported catalyst being referred to in the latter examples. Then the catalyst was activated by reduction in Ar and H2 mixture (Ar 5 : H2 = 1:1 vol.) at pressures up to 5 bar, and temperatures of 300°C.

Examples 2-5.

The catalyst prepared in Example 1 were applied to treat 10 pine wood derived oil in a packed bed system, consisting of four reactor segments that can individually be regulated in temperature, and a ratio of hydrogen gas flow over the oil flow of approx. 750 L/kg0n fed- In total 110 g of this catalyst was applied, at pressure of 200 bar.

15 The weight hourly space velocity, or WHSV is in the range of 0.2 to 0.6 hf1.

Table 1. Yields of hydrotreated oil fractions: the aqueous fraction and the organic fraction in % by weight of the 20 total product flow.

Examples Example 2 Example 3 Example 5 WHSV (hT1) 0.28 0.29 0.53

Temperature reactors 150/150/15 150/250/250 150/250/350 (°C) 0/150 /250 /400

Organic oil yield 0.45 0.47 0.38 ( 9^/ q oil fed)

Aqueous Oil yield 0.52 0.46 0.52 (g/g oil fed)

Distillate (g/gaqueous 0.46 0.68 0.86 oil)

Alcoholic phase 0.54 0.28 0.14 (g/gaqueous oil) 26

Carbon yield Organic 0.88 0.85 0.78 + Alcohol ( gc, organic+alcohol /gc, feed)

Carbon yield Organic 0.54 0.59 0.64 (9c, organic /9b, feed)

Carbon yield 0.05 0.05 0.10

Diluate (gc,product/gc,fee d)

Table 1 shows the yields for the hydrotreated oil fractions derived at different temperatures. Temperatures indicated are those set on the heaters for the four separate, down-5 flow operated reactor segments, increasing the temperature from start to end and as further detailed by Venderbosch et al. in (J. Chem. Techn. Biotechn., 85, 674-686). It can be noted that if the organic and alcohol phases are combined, a significant increase in the carbon yield (defined by carbon 10 fed over carbon retained in products), and as in example 2, it increases from 0.54 to 0.88 gc,product/gc,feed (where gc,product and gc,feed represent the weight of carbon in grams recovered in products and fed as feed, and where products are only the organic phase and organic and alcoholic phase respectively). 15 Especially at the lower temperature applied in example 2 the increase compared to just the organic phase is more substantial, indicating that the invention is specifically applicable in such a low-temperature stabilisation step.

20 Example 6-9.

Pyrolysis oil (see Table 2) derived from the pyrolysis of pine is dewatered by first addition of water to the oil in a 1:1 ratio by weight, separating the aqueous phase from the organic phase, where after the aqueous phase is distilled 25 under vacuum conditions (down to 0.1 bara) at temperatures 27 up to 90°C. The dewatered phase is further analysed and results are shown in Table 2. It shows that de-watered oil, comprising a merely sugar phase, shows high charring tendencies of near 15 to 25 wt.%, suggesting that reactive 5 components are present here.

Upon a hydrotreatment of the oil, these reactive components are (partially) transformed to components forming the so-called organic phase, but also to the alcoholic components, having a much lower charring tendency of 5 - 10% by weight. 10 Examples 8 and 9 show the range of data determined for the alcoholic and diluate (=distillate) phases, as retrieved from the experiments further detailed in examples 2-5.

Table 2. Characteristic of pyrolysis oils derived from pine 15 wood, dewatered pyrolysis oils and dewatered hydrotreated oil aqueous phase fraction.

Examples Example 6 Example 7 Example 8 Example 9

Pyrolysis Dewatered Alcoholic Distillate oil pyrolysis phase fraction @ oil @ 0.1 fraction 0.1 bara

bara and @ 0.1 and 90°C

90°C bara and

90°C

Elemental composition (0 by balance) C (% by 40 - 45 40 - 47 45 - 55 5-15 weight) H (% by 6.5 - 8 6.5 - 7.5 7 - 8.5 10 - 12 weight) N (% by 0.01 - 0.1 <0.1 - 1 weight) 28

Water 18 - 30 0 - 10 0 - 10 70 - 95 content (% by weight) MCRT (% by 15 - 25 15 - 25 5-10 Ö weight)

Viscosity 10 - 30 >300 100 1-10 (cSt) 250

Carbonyl 120 - 200 250 - 400 10 -30 10 - 50 content (mgBuo/l)

Acid number 50 - 80 50 - 80 35 - 70 10 - 50 (mgK0H/l)

Claims

A method for treating a vegetable biomass comprising: a) hydrotreating a vegetable biomass in the presence of a catalyst; b) separating the resulting hydrotreated product into an aqueous fraction and an organic fraction; c) concentrating the aqueous fraction; D) mixing the concentrate with the organic fraction; and e) further treating the resulting mixture.

2. Method according to claim 1, wherein step c) is carried out at the same pressure and at the same temperature range as in step a) and / or in step e).

3. A method according to claim 1, wherein step c) is carried out at a pressure equal to, or lower than, 1.5 bar and at a temperature equal to or lower than 150 ° C.

4. A method according to any one of claims 1 to 3, wherein the treatment in step e) is selected from a cracking reaction, a hydrogenation and a gasification.

The method of any one of claims 1 to 4, wherein the product obtained in d) is subjected to at least one separation process to remove the water prior to performing step e).

The method of any one of claims 1 to 5, wherein the method comprises a step c) consisting of concentrating the aqueous fraction obtained in step b) to obtain a concentrate and a diluate and a step f ) which comprises further treating the diluate obtained in step c). 5

The method of claim 6, wherein the diluate obtained in step c) is gasified and produces hydrogen in step f).

The method of claim 7, wherein the produced hydrogen is used in step a).

9. Method according to any of claims 1 to 8, wherein step b) and / or step c) is carried out by at least one process selected from the group consisting of a distillation, a condensation, a phase separation, a sedimentation , a filtration and chromatography.

10. A method according to any one of claims 1 to 9, wherein the amount of water of the concentrate after step c) is at most 30% by weight of water relative to the total weight of the aqueous fraction.

11. A method according to any of claims 1 to 10, wherein the temperature in step a) is the range of 50 ° C to 1000 ° C, preferably 50 ° C to 800 ° C, in a substantially oxygen-free environment and wherein the pressure in step a) is in the range of 5 bar to 350 bar, preferably 10 bar to 350 bar.

The method of any one of claims 1 to 11, wherein the temperature in step e) is in the range of 50 ° C to 1000 ° C and wherein the pressure in step e) is in the range of 5 bar up to 350 bar.

The method of any one of claims 1 to 12, wherein the biomass is subjected to a pyrolysis prior to step a).

14. A method according to any one of claims 1 to 13, wherein the separation of the aqueous fraction and organic fraction in step b) is carried out at pressures lower than 100 bar and at temperatures lower than 150 ° C.

15. A method according to any one of claims 1 to 14, wherein the biomass is wood material and / or hemi-cellulosic material and / or cellulosic material.