Process for the treatment of a pyrolysis oil

Abstract

The invention relates to a slurry process for reducing the content of halogen and / or nitrogen compounds of a pyrolysis oil, wherein the process comprises: (i) treating in continuous the pyrolysis oil with a solid material comprising Cu, Zn, CuO, ZnO or a mixture thereof, in the presence of hydrogen at a temperature of from 150 °C to 300 °C; and (ii) recovering the pyrolysis oil resulting from step (i); wherein the solid material of step (i) is a spent catalyst or sorbent from refining or chemistry processes. The invention also relates to the use of said solid material for reducing the content of halogen and / or nitrogen compounds of a pyrolysis oil, and to a pyrolysis oil obtainable by the process of the invention.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a slurry process for reducing or removing halogen and / or nitrogen from a pyrolysis oil, said process comprising contacting said pyrolysis oil with a solid material comprising copper, zinc or an oxide thereof and a support that is a spent or waste catalyst or sorbent from other industrial processes. The invention also relates to the use of said solid material for reducing or removing halogen and / or nitrogen from a pyrolysis oil and to a pyrolysis oil obtainable by the process of the invention.BACKGROUND

[0002] The management of plastic waste currently represents one of the major challenges faced by our societies. 353 million metric tons of plastic waste were generated worldwide in 2019, of which 33 million metric tons, were recycled. Almost half of global plastic waste was landfilled that year, while 82 million metric tons were mismanaged and littered. Landfilled plastic waste represents a loss of valuable material resource, leading to increase necessity of fossil raw materials, depleting earth resources and impacting ecosystems where those raw materials are extracted from the earth. Mismanaged plastic waste typically leaks into rivers, oceans, and other waterways, devastating marine life and ecosystems. A way to avoid landfilling of plastic waste is to reintroduce such waste in the plastic lifecycle. Mismanagement of plastic waste is of public concern and responsibility, requiring social policies and education for its solution. Improving ways of reintroduction of plastic waste into industrial manufacturing processes, so to consider it as a valuable resource instead of waste, will also promote the reduction of plastic waste pollution. One known method is to convert plastic waste into a pyrolysis oil that can be further refined as monomers and used in the production of fresh polymers. This process has the advantage of providing freshly-made polymers with a full control on the properties of the polymer, by selection of appropriate monomers and process conditions.

[0003] Processes for the upgrading of plastic pyrolysis oil are known in the art. For instance, patent applications WO 2022 / 023262 A1, WO 2022 / 023263 A1, WO 2022 / 144235 A1 describe processes allowing for the production of refined pyrolysis oil suitable for being fed to a steam cracker.

[0004] Since downstream processing of pyrolysis oil typically requires the use of catalysts that are easily poisoned or deactivated by the presence of chlorinated and / or nitrogenated species, processes of pyrolysis oil refining typically comprise a step whereby the pyrolysis oil is submitted to a treatment aiming at removing or reducing halogen and nitrogen species.

[0005] On the other hand, several industrial processes require the use of catalyst materials comprising copper, zinc or oxides thereof. These solid materials need to be replaced for fresh materials after a certain period of time, in particular when the catalytic activity of the material no longer meets the requirements of the process for which the catalyst was designed, specifically in terms of conversion of the starting materials and / or selectivity towards the formation of desired products or secondary by-products. In some cases, the activity loss can be compensated within certain limits by increasing reaction temperature. However, if such compensation is not efficient enough, the catalyst must be regenerated or replaced.

[0006] Several reasons are known in the art for catalyst deactivation. The most common reason for catalyst deactivation is poisoning of the catalyst, whereby active sites of the catalyst get blocked or occupied by certain elements present in the feedstock by chemisorption or formation of superficial complexes. Such elements typically include sulfur, phosphorus and heavy metals. In such cases, a deactivated catalyst may comprise sulfur, phosphorus and / or heavy metals deposits. Another cause of catalyst deactivation is the fouling of the catalyst whereby the pores of the catalyst materials get blocked by polymeric compounds or carbonaceous deposits such as coke, which are formed at elevated temperature. Such blockage of the pores of the catalyst hampers mass transfer and / or access at the active sites of the catalyst, which reduces the activity of the catalyst. When the catalyst is exposed to high temperatures, the agglomeration of small metal crystallites below the melting point, called sintering, may also occur, which also reduces the porosity and active surface of the catalyst. Another cause of thermal degradation of catalyst relates to solid-solid reactions taking place between metals, such as Cu, Ni, Co, and alumina carriers which result in the formation of inactive metal aluminates. Thus, phase changes caused by thermal degradation of the catalyst is an additional cause of catalyst deactivation. Further to the above, catalysts may get deactivated by the volatilization of metals comprised in the catalytic active site. In particular, Cu, Ni, Fe and noble metals can escape from catalysts after conversion to volatile chlorides if traces of chlorine are present in the feed.

[0007] Once catalysts are considered spent, there exist different ways of managing the discarded catalyst for said process. A first option relates to the regeneration of the catalyst, especially when catalyst deactivation is reversible. However, catalysts deactivated by thermal degradation (e.g. sintering, phase changes, etc.) or mechanical stress are very difficult to fully regenerate. In this regard, examples of full catalyst regeneration are still rare. A further alternative strategy for the management of waste catalysts is the recovery of precious metal components from said catalysts by leaching. Such strategy is common for catalysts comprising nickel, cobalt or molybdenum but are rarer in cases where the recovery costs are higher than the price of recovered components. Thus, typically copper and / or zinc catalysts are often disposed of. Before disposal, spent catalysts containing various contaminants need to be encapsulated to avoid their release into water. The disposal of encapsulated catalysts is not only expensive but is becoming increasingly difficult.

[0008] Several catalysts comprising copper and / or zinc are known in the art. Those include catalysts for the CO-shift or water gas shift reaction, which catalysts typically comprise CuO and ZnO supported on a solid support such as aluminium oxide. These catalysts typically suffer from sintering and / or poisoning during the reaction, for instance by S and Cl species. Methanol synthesis catalysts are ones comprising copper and / or zinc. The catalyst activity of a methanol synthesis catalyst depends on the delicate balance between copper surface area, the number of active copper sites and copper crystallite size. To achieve long-term performance, it is also important to prevent sintering and poisoning as far as possible. Undesired by-products formation, such as higher alcohols, esters, ethers and ketones occur through the same intermediate species on the active copper site of the catalyst and must be reduced. In these processes, catalyst poisoning is generally prevented by treating the feedstock material (e.g. synthesis gas) with sulfur traps, which generally use sorbent materials rich in zinc oxide. The repurposing of these catalysts or sorbents in the dehalogenation or denitrogenation of pyrolysis oil has however not been reported in the art.

[0009] From what is disclosed in the art, it derives that there is still a need for improved processes for the dehalogenation and / or denitrogenation of pyrolysis oil, in particular pyrolysis oil derived from plastic waste, specifically there is a need for more sustainable processes.SUMMARY OF THE INVENTION

[0010] The inventors have found that it is unexpectedly possible to employ spent or waste catalyst materials comprising one or more of Cu, Zn, CuO and ZnO from several industrial processes in a slurry process for the dehalogenation and / or denitrogenation of a pyrolysis oil, in particular of a pyrolysis oil deriving from waste plastic.

[0011] Despite said spent catalyst materials have been discarded for their intended use, the inventors have found that they can be used for reducing the content of halogen and / or nitrogen compounds in a pyrolysis oil without the need of a prior activation step.

[0012] The invention thus relates in a first aspect to a slurry process for reducing the content of halogen and / or nitrogen compounds, such as organohalogen and / or organonitrogen compounds, of a pyrolysis oil, the process comprising: (i) treating in continuous the pyrolysis oil with a solid material comprising Cu, Zn, CuO, ZnO or a mixture thereof, in the presence of hydrogen at a temperature of from 150 °C to 300 °C; and (ii) recovering the pyrolysis oil resulting from step (i); wherein the solid material of step (i) is a spent catalyst or sorbent from refining or chemistry processes.

[0013] In a second aspect, the invention relates to the use of a solid material as defined in the first aspect of the invention for reducing the content of halogen and / or nitrogen compounds, such as organohalogen and / or organonitrogen compounds, of a pyrolysis oil.

[0014] In a third aspect, the invention relates to a pyrolysis oil obtainable by the process according to the first aspect of the invention.

[0015] The invention thus provides a second life to waste catalysts, which would otherwise be disposed of, and thus addresses the long-felt need of extending the useful lifetime of such catalysts or sorbents. The invention thus allows reducing the consumption of metals, as waste catalysts or sorbents are being used for the treatment of the pyrolysis oil. In this regard, as waste catalyst or sorbent is being used for dehalogenating and / or denitrogenating a pyrolysis oil which may derive from waste plastic, the process of the invention is particularly sustainable, as it only requires a very limited number of fresh raw materials.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Fig. 1 describes the boiling range distribution of the pyrolysis oil of the Examples, expressed as the temperature at which pyrolysis oil is distilled (in °C) in function of the percentage of the pyrolysis oil distilled, as simulated by ASTM D2887. Fig. 2 describes the distribution of particle size of spent catalysts LSK2, LK819 and LK813 after milling the solid spent catalysts as described in the Examples (expressed as volume percentage of particles over average particle size). DETAILED DESCRIPTION

[0017] All terms as used herein in this document, unless otherwise stated, shall be understood in their ordinary meaning as known in the art. Other more specific definitions for certain terms as used in the present document are as set forth below and are intended to apply uniformly throughout the specification and claims unless an otherwise expressly set out definition provides a broader definition.

[0018] For the purposes of the invention, any ranges given include both the lower and the upper end-points of the range. Ranges given, such as temperatures, times, molar ratio, volume ratio and the like, should be considered approximate (i.e. with a 5% margin of variation around indicated point), unless specifically stated.

[0019] Throughout the description and claims the word "comprises" and variations of the word, are not intended to exclude other technical features, additives, components or steps. Furthermore, the word "comprise" encompasses the cases of "consist essentially of" and "consist of".

[0020] In the context of the invention, a "slurry process" refers to a chemical process whereby a reagent comprised in a solid phase reacts with another reagent comprised in a liquid phase, said solid phase being suspended in said liquid phase. Slurry reactor configurations are well-known in the art and will become apparent to the skilled person on the basis of common general knowledge. Such reactor configurations are disclosed for instance in Beenackers, A.A.C.M., van Swaaij, W.P.M. (1986). Slurry Reactors, Fundamentals and Applications. In: de Lasa, H.I. (eds) Chemical Reactor Design and Technology. NATO ASI Series, vol 110. Springer, Dordrecht, the content of which is incorporated herein by reference.

[0021] In the context of the invention, the term "organohalogen" refers to an organic compound comprising in its molecular formula a halogen group. In preferred embodiments, said halogen is a chlorine group. In further embodiments, the term "organohalogen" refers to one or more of alkanes (e.g. paraffins), naphthenes, olefins, aromatic compounds, alcohols, ketones, aldehydes, acids, and waxes, wherein at least one hydrogen atom is replaced by a halogen group, in particular by a chlorine group. In particular embodiments, the term "organohalogen" refers to halogenated hydrocarbons, that is to compounds containing only carbon and hydrogen, whether saturated or unsaturated, with one or more halogen atoms replacing an equivalent number of hydrogen atoms in the hydrocarbon. In an embodiment, the term "organohalogen" refers to (poly)chlorinated hydrocarbons, such as those deriving from the pyrolysis of poly(vinyl chloride) or additives commonly used to improve the performance of polymers, such as stabilizers and plasticizers, which comprise halogen containing compounds. Non-limiting examples of hydrocarbons include alkanes (linear, branched, and cyclic), alkenes (olefins), and aromatics, among other compounds. Non-limiting examples of "organohalogens" include chloroform, dichloromethane, 1,2-dichloroethane, trichloroethylene, chlorobenzene, dichlorobenzenes, polychlorinated biphenyl compounds, vinyl chloride, chloroacetone, chloroacetic acid and mixtures thereof.

[0022] In the context of the invention, the term "organonitrogen" refers to an organic compound comprising in its molecular formula a nitrogen group, such as a nitrogen group comprised in a urethane group, a cyano group, a nitrile group, a nitro group, an amine group (including an aromatic amine group) or an amide group. In further embodiments, the term "organonitrogen" refers to one or more of alkanes (e.g. paraffins), naphthenes, olefins, aromatic compounds, alcohols, ketones, aldehydes, acids, and waxes comprising a nitrogen group, such as a nitrogen group comprised in a urethane group, a cyano group, a nitrile group, a nitro group, an amine group (including an aromatic amine group) or an amide group either in their skeleton or as a substituent. In further embodiments, the term "organonitrogen" refers to one or more of amines (primary, secondary and tertiary amines, e.g. methylamine, dimethylamine), amides (e.g. formamide, acetamide), nitrogen-containing heterocycles (e.g. pyridine, pyrrolidine, indole, quinoline, quinoline derivatives), nitriles (e.g. acetonitrile, benzonitrile), nitro compounds (e.g. nitrobenzene, 4-nitrophenol) and isocyanates (e.g., methyl isocyanate).

[0023] Aside from the organohalogen and organonitrogen compounds, other halogen and nitrogen compounds in the pyrolysis oil than can be removed or reduced according to the invention are inorganic halogen (e.g. inorganic chlorides) and inorganic nitrogen compounds. Examples of inorganic halogen compounds include halohydric acids and metal halide salts, such as sodium halides, potassium halides and magnesium halides. Examples of inorganic chlorides include hydrochloric acid and metal chloride salts, such as sodium chloride, potassium chloride and magnesium chloride. Examples of inorganic nitrogen compounds include ammonium salts (e.g. ammonium chloride), ammonia and nitrate salts (e.g. alkali metal nitrates, such as sodium nitrate and potassium nitrate).

[0024] Pyrolysis oils are known in the art and typically comprise alkanes (e.g. paraffins), naphthenes, olefins, aromatic compounds, alcohols, ketones, aldehydes, acids, amines, nitriles, N-heteroaromatic compounds, (poly)chlorinated hydrocarbons, thiols, sulfides, waxes. Pyrolysis oil may be obtained by thermal decomposition in an oxygen poor environment of any feedstock comprising organic matter, such as biomass (wood and wood waste, agricultural residues, energy crops, manure), plastics (e.g. polyolefins, mixed plastic waste), or waste (municipal waste, sewage sludge, industrial waste). Said organic matter may comprise nitrogen and / or halogen atoms. When the pyrolysis oil is a plastic pyrolysis oil (e.g. an oil obtained by pyrolysis of mixed plastic waste), nitrogen atoms may come from polyamides and polyurethanes and / or halogen atoms may come from halogenated polymers, such as polyvinyl chloride and / or additives commonly used to improve the performance of polymers, such as stabilizers and plasticizers which comprise nitrogen, halogen and sulfur containing compounds.

[0025] In the context of the present invention, the terms "spent catalyst or sorbent" and "waste catalyst or sorbent" are interchangeable and refer to a catalyst or sorbent that can no longer perform its original duty. Typically, a catalyst or sorbent is considered "spent" when it no longer exhibits the necessary activity or specificity required by the user including a catalyst or sorbent that is no longer suitable for being reactivated or regenerated for further use in the process for which it was originally designed. Spent or waste catalysts or sorbents useful in the context of the invention may be those comprising Cu, Zn, CuO, ZnO or a mixture thereof and a solid support whereby their activity, expressed by conversion, catalytic turnover and / or selectivity, is no longer sufficient for the purposes of the process for which the catalyst or sorbent material was initially designed, such that the catalyst or sorbent needs to be substituted by a fresh one. The diverse causes of catalyst and sorbent deactivation are known in the art and include, among others, poisoning of active sites by chemisorption (e.g. of sulfurized species or halogenated species), fouling (blockage of pores by coking), thermal degradation (e.g. formation of crystallites, sintering) or volatilization of active sites.

[0026] A first aspect of the invention relates to a slurry process for reducing the content of halogen and / or nitrogen compounds, such as organohalogen and / or organonitrogen compounds, of a pyrolysis oil, the process comprising: (i) treating in continuous the pyrolysis oil with a solid material comprising Cu, Zn, CuO, ZnO or a mixture thereof, in the presence of hydrogen at a temperature of from 150 °C to 300 °C; and (ii) recovering the pyrolysis oil resulting from step (i); wherein the solid material of step (i) is a spent catalyst or sorbent from refining or chemistry processes.

[0027] In a second aspect, the invention relates to the use of a solid material as defined in the first aspect of the invention for reducing the content of halogen and / or nitrogen compounds, such as organohalogen and / or organonitrogen compounds, of a pyrolysis oil.

[0028] In a third aspect, the invention relates to a pyrolysis oil obtainable by the process according to the first aspect of the invention.Pyrolysis oil

[0029] The invention does not particularly limit the type of pyrolysis oil that can be used as starting material in the slurry process and use of the invention. In some embodiments, the (crude) pyrolysis oil used as starting material in the first and second aspects of the invention has the characteristics or properties defined below.

[0030] The pyrolysis oil according to the invention is an oil originating from the pyrolysis of a feedstock, advantageously in liquid form at ambient temperature.

[0031] In a particular embodiment, the pyrolysis oil is a plastic pyrolysis oil, that is, it is an oil obtained from the pyrolysis of plastics, such as the pyrolysis of plastic waste.

[0032] The pyrolysis oil comprises a mixture of hydrocarbon-based compounds, notably paraffins, olefins, naphthenes and aromatics, said compounds having each a boiling temperature from 25 °C to 600 °C.

[0033] In an embodiment, the content of paraffins, olefins, naphthenes and aromatics represents at least 95 wt%, or even at least 98 wt%, of the total weight of the pyrolysis oil.

[0034] In an embodiment, the pyrolysis oil comprises 40-80 wt% of paraffins, such as 50-70 wt%, with respect to the weight of the pyrolysis oil. Such paraffins include n-paraffins and iso-paraffins.

[0035] In an embodiment, the pyrolysis oil comprises 10-50 wt% of naphthenes, such as 10-40 wt%, with respect to the weight of the pyrolysis oil.

[0036] In an embodiment, the pyrolysis oil comprises 10-50 wt% of olefins, such as 10-40 wt%, with respect to the weight of the pyrolysis oil.

[0037] In an embodiment, the pyrolysis oil comprises 10-50 wt% of naphthenes+olefins, such as 20-40 wt%, with respect to the weight of the pyrolysis oil.

[0038] In an embodiment, the pyrolysis oil comprises 2-20 wt% of aromatics, such as 4-15 wt%, with respect to the weight of the pyrolysis oil.

[0039] In a particular embodiment, the pyrolysis oil comprises: a paraffin content of 40-80 wt% with respect to the weight of the pyrolysis oil, a naphthene+olefin content of 10-50 wt% with respect to the weight of the pyrolysis oil, and an aromatic content of 2-20 wt% with respect to the weight of the pyrolysis oil.

[0040] In a further embodiment, the pyrolysis oil comprises: a paraffin content of 50-70 wt% with respect to the weight of the pyrolysis oil, a naphthene+olefin content of 20-40 wt% with respect to the weight of the pyrolysis oil, and an aromatic content of 4-15 wt% with respect to the weight of the pyrolysis oil.

[0041] The content of paraffins, olefins, naphthenes and aromatics in the pyrolysis oil can be determined by gas chromatography coupled to mass spectrometry.

[0042] In addition to the hydrocarbons, the pyrolysis oil can comprise impurities, including inorganic compounds, such as metals or metal ions, and / or organic compounds containing heteroatoms, such as halogen, oxygen, nitrogen, sulfur and / or silicon. In an embodiment, the content of impurities is less than 2 wt%, or even less than 1 wt%, with respect to the weight of the pyrolysis oil.

[0043] In an embodiment, the pyrolysis oil has a content in halogen atoms of 10-2500 ppm, or even 100-1000 ppm, as measured according to ASTM D7359. In a particular embodiment, the content of halogen atoms is 150-500 ppm.

[0044] In an embodiment, the pyrolysis oil has a content in chlorine atoms comprised in organohalogen compounds of 10-2000 ppm, or even 100-1000 ppm, measured according to ASTM D7536. Said content can be determined, for example, after removal of water soluble chlorides (e.g. inorganic chlorides) by means of extraction of one volume part of pyrolysis oil with three volume parts of ultrapure water (milli-Q ®< ) at ambient temperature and, measured according to ASTM D7536. In a particular embodiment, the content of chlorine atoms in the form of organohalogen compounds in the pyrolysis oil is 100-500 ppm.

[0045] In an embodiment, the pyrolysis oil has a content in nitrogen atoms of 10-5000 ppm, or even 100-3000 ppm, as measured according to ASTM D4629. In a particular embodiment, the content of nitrogen atoms is 200-2500 ppm.

[0046] In an embodiment, the pyrolysis oil has a content in sulfur atoms of 0-3000 ppm, or even 0-1000, as measured according to ASTM D5453. In a particular embodiment, the content of sulfur atoms is 0-500 ppm.

[0047] In an embodiment, the pyrolysis oil has a water content lower than 0.1 wt%.

[0048] In an embodiment, the pyrolysis oil has a Total Acidity Number (TAN) lower than 5 mgKOH per gram of pyrolysis oil, as measured according to ASTM D664, or even lower than 3 mgKOH per gram of pyrolysis oil.

[0049] In an embodiment, the pyrolysis oil has a bromine number lower than 150 g of bromine per 100 g of pyrolysis oil, as measured according to ASTM D1159.

[0050] The pyrolysis oil can have a density of 0.70-0.99 g / cc measured at 15°C according to ASTM D4052. In an embodiment the pyrolysis oil has a density of 0.75-0.90 g / cc measured at 15°C according to ASTM D4052.

[0051] In an embodiment, the pyrolysis oil has a boiling point in the range of from 30 to 600 °C as determined by ASTM D2887.

[0052] In an embodiment, at least 80 wt% of the components in the pyrolysis oil have a boiling point of less 400 °C. In an embodiment, at least 90 wt% of the components in the pyrolysis oil have a boiling point of less 400 °C.

[0053] In an embodiment, at least 50 wt% of the components in the pyrolysis oil have a boiling point of less than 300 °C. In an embodiment, at least 60 wt% of the components in the pyrolysis oil have a boiling point of less 300 °C.

[0054] After the process of the first aspect of the invention or the use of the second aspect of the invention, the resulting pyrolysis oil has a lower content of halogen and / or nitrogen compounds, such as organohalogen and / or organonitrogen compounds, than the crude pyrolysis oil used as starting material.

[0055] In a particular embodiment, the content of halogen atoms in the pyrolysis oil is reduced by at least 25%, or even by at least 35%. In an embodiment, the content of halogen atoms is reduced by at least 40%.

[0056] In an embodiment, the content of chlorine atoms in organic compounds in the pyrolysis oil is reduced by at least 20%, or even by at least 30%.

[0057] In a particular embodiment, the content of nitrogen atoms in the pyrolysis oil is reduced by at least 35%, or even by at least 45%. In an embodiment, the content of nitrogen atoms is reduced by at least 45%.Solid material

[0058] The solid material according to step (i) of the first aspect of the invention and according to the second aspect of the invention is a spent catalyst or sorbent from other processes, such as refining or chemistry processes, that comprises a metal selected from Cu andZn in the form of Cu (i.e. elemental copper), Zn (i.e. elemental zinc), CuO, ZnO or a mixture thereof.

[0059] In an embodiment, the solid material comprises at least 10 wt% of the metal selected from Cu and / or Zn, which can be in the form of Cu (i.e. elemental copper), Zn (i.e. elemental zinc), CuO, ZnO or a mixture thereof. In a further embodiment, the solid material comprises at least 20 wt% of said metal. In the present document the weight percent of a metal M in the form of M and / or MO refers to the weight amount of the metal M comprised in the solid material, said weight amount not including any weight contribution of O in the form MO of the metal M (i.e. the weight amount of M atoms).

[0060] According to an embodiment, the solid material comprises at least 30 wt% of the metal selected from Cu and / or Zn in the form of Cu, Zn, CuO, ZnO or a mixture thereof. In a further embodiment, it comprises at least 50 wt% of said metal, such as at least 60 wt%.

[0061] In a particular embodiment, the solid material comprises 10-90 wt%, or even 30-80 wt% of the metal selected from Cu and / or Zn in the form of Cu, Zn, CuO, ZnO or a mixture thereof. According to a further embodiment, the solid material comprises 60-95 wt% of said metal.

[0062] In an embodiment, the solid material comprises 10-40 wt% of copper in the form of copper or copper oxide and 30-60 wt% of zinc in the form of zinc or zinc oxide.

[0063] The support in the solid material may be selected from alumina, silica, graphite, chromium oxide, molybdenum oxide, titania, magnesia or a mixture thereof. In an embodiment, the support comprises alumina.

[0064] The solid material according to step (i) may further comprise a support. The support may contain dopant compounds or promoters, such as molybdenum oxide, boron oxide, zirconia, ceria, titanium oxide, phosphorous pentoxide or mixtures thereof.

[0065] In an embodiment, the solid material comprises an alumina support that is optionally doped.

[0066] In an embodiment, the solid material comprises 1-40 wt%, or even 5-30 wt% of the support. In a particular embodiment, the solid material comprises 5-20 wt% of the support.

[0067] In an embodiment, the solid material comprises 50-98 wt% of the metal selected from Cu and / or Zn in the form of Cu, Zn, CuO, or ZnO and 1-40 wt% of the support.

[0068] In a further embodiment, the solid material comprises 60-95 wt% of the metal selected from Cu and / or Zn in the form of Cu, Zn, CuO, or ZnO and 1-40 wt% of the support.

[0069] In an embodiment, the solid material comprises at least 60 wt%, or even at least 70 wt%, of the metal selected from Cu and / or Zn in the form of Cu, Zn, CuO, or ZnO and the support.

[0070] According to an embodiment, the solid material is a porous material.

[0071] Since the solid material is a spent catalyst or sorbent, it may comprise one or more of carbonaceous deposits, metallic deposits, sulfurous deposits, phosphorous deposits and combinations thereof.

[0072] In an embodiment, the solid material is a porous material wherein at least a portion of the pores is partially or totally blocked.

[0073] In an embodiment, the solid material comprises sintered copper and / or zinc crystals.

[0074] As mentioned above, the presence of one or more of sintered crystals, carbonaceous deposits, sulfur deposits and blocked pores is responsible for material deactivation, which leads to the material having the consideration of "spent or waste".

[0075] In an embodiment, the solid material is selected from the group consisting of: spent catalyst from a water-gas shift process; spent catalyst from a methanol synthesis process by hydrogenation of carbon oxide; spent sorbent from sulfur traps for syngas reforming and processing; spent catalyst from an ethylene or propylene purification process; spent catalyst from hydrogenation of aldehydes to produce oxo alcohols; spent catalyst from hydrogenolysis of glycerol to produce 1,2-propanediol; spent catalyst from hydrogenation of nitrobenzene to produce aniline; spent catalyst from hydrogenation of fatty acid or fatty acid methyl esters to fatty alcohols; spent catalyst from the hydrogenation of dimethyl maleate to 1,4-butanediol, gamma-butyrolactone and tetrahydrofuran; spent catalyst from the hydrogenation of methyl-phenyl ketone to alpha-methyl benzyl alcohol; and mixtures thereof.

[0076] The above reactions and suitable catalysts or sorbent therefor are known for the person of skill in the art. For example, US8252962B2 relates to a process for the hydrogenolysis of glycerol to produce 1,2-propanediol; a process for the hydrogenation of nitrobenzene to produce aniline is disclosed in Chemistry of petrochemical processes, Gulf publishing Company, 2nd Ed, p.279; a process for the hydrogenation of fatty acid or fatty acid methyl esters to fatty alcohols is disclosed in Ullmann's encyclopedia of industrial chemistry; 2012. Wiley-VCH.

[0077] In a further embodiment, the solid material is selected from the group consisting of: spent catalyst from a water-gas shift process; spent catalyst from a methanol synthesis process by hydrogenation of carbon oxides; and mixtures thereof.

[0078] A spent catalyst or sorbent from the above mentioned processes refers to a catalyst or sorbent that has been used in one of said processes and has been discarded for further use in said process.

[0079] A catalyst or sorbent is considered spent when certain conditions are not satisfied, such as those related to the performance of the catalyst in terms of conversion of reagents and / or selectivity towards targeted products. The catalyst or sorbent is considered spent when it no longer meets the requirements of the process. The skilled person will readily identify for each one of the above processes conditions at which the catalyst or sorbent is considered spent on the basis of common general knowledge upon reduction to practice of the invention.

[0080] For instance, catalysts for water-gas shift reactions are typically used to convert CO from synthesis gas by reaction with water to produce hydrogen and carbon dioxide. In particular embodiments, a catalyst for water-gas shift reaction is considered spent when a concentration equal to or higher than 0.3% vol / vol of CO in the exit stream of the shift reactor is measured. In further particular embodiments, suitable catalysts from a water-gas shift process are those employed for low or medium temperature shift steps of the water-gas shift process. Such catalysts may comprise 10-70 wt% of copper in the form of Cu and / or CuO and / or 10-50 wt% of zinc in the form of Zn and / or ZnO. In some embodiments, these catalysts typically further comprise a support that is alumina in an amount of 1-50 wt%, or even of 1-20 wt% of the catalyst.

[0081] In some embodiments, the solid material is a spent catalyst from a water-gas shift process, the corresponding non-spent catalyst (fresh catalyst) consisting essentially of 64 wt% of copper in the form of Cu and / or CuO, 24 wt% of zinc in the form of Zn and / or ZnO, 1.4 wt% of promotor and balance of alumina as support. Said catalyst can be in the form of pellets. Such catalyst is for instance KATALCO ®< 83-6 (Johnson Matthey).

[0082] In some embodiments, the solid material is a spent catalyst from a water-gas shift process, the corresponding non-spent catalyst consisting essentially of at least 34 wt% of copper in the form of Cu and / or CuO, at least 19 wt% of zinc in the form of Zn and / or ZnO, and at least 4 wt% of alumina as support. Said catalyst can be in the form of cylinders. Such catalyst is for instance LK-813 ®< (Haldor Topsoe).

[0083] In some embodiments, the solid material is a spent catalyst from a water-gas shift process, the corresponding non-spent catalyst consisting essentially of at least 24 wt% of copper in the form of Cu and / or CuO, at least 30 wt% of zinc in the form of Zn and / or ZnO, and at least 6 wt% of alumina as support. Said catalyst can be in the form of cylinders. Such catalyst is for instance LK-819 ®< (Haldor Topsoe).

[0084] In some embodiments, the solid material is a spent catalyst from a water-gas shift process, the corresponding non-spent catalyst consisting essentially of at least 15 wt% of copper in the form of Cu and / or CuO, at least 16 wt% of zinc in the form of Zn and / or ZnO, and at least 14 wt% of alumina as support. Said catalyst can be in the form of cylinders. Such catalyst is for instance LSK-2 ®< (Haldor Topsoe).

[0085] In some embodiments, the solid material is a spent catalyst from a water-gas shift process, the corresponding non-spent catalyst consisting essentially of 45 wt% of copper in the form of Cu and / or CuO, 44 wt% of zinc in the form of Zn and / or ZnO, and balance of alumina as support. Said catalyst can be in the form of tablets. Such catalyst is for instance Shiftmax 217 ®< (Clariant).

[0086] In other embodiments, the solid material is a mixture of one or more spent catalysts from a water-gas shift reaction, the corresponding non-spent catalysts being as defined above.

[0087] In an embodiment, said non-spent catalyst from a water-gas shift reaction is selected from KATALCO ®< 83-6, KATALCO ®< 83-3, LK-823 ®< , LK-813 ®< , LK-819 ®< , LSK-2 ®< , Shiftmax 217 ®< (Clariant), Shiftmax 300 ®< (Clariant) and mixtures thereof. In a further embodiment, said non-spent catalyst from a water-gas shift reaction is selected from LK-813 ®< , LK-819 ®< , LSK-2 ®< , and a mixture thereof.

[0088] In an embodiment, the solid material is a spent catalyst from a water-gas shift reaction as described above.

[0089] In other embodiments, the solid material is a spent catalyst from a methanol synthesis process, the corresponding non-spent catalyst comprising Cu, CuO, Zn, ZnO and, optionally, alumina as a support. This includes Clariant Megamax ®< catalysts, such as Clariant Megamax 800 ®< and Clariant Megamax 900 ®< . These catalysts are generally considered spent catalysts when undesired by-products such as higher alcohols, esters, ethers and ethers start forming in amounts beyond the tolerated threshold amount in the product.

[0090] In other embodiments, the solid material is a spent sorbent material for sulfur traps, the corresponding non spent sorbent for sulfur trap comprising 90 wt% of Zn in the form of Zn and / or ZnO and alumina.

[0091] In other embodiments, the solid material is a spent sorbent material for sulfur traps, the corresponding non spent sorbent for sulfur trap being suitable for the purification of synthesis gas and comprising at least 85 wt%, or even at least 90 wt% of Zn in the form of Zn and / or ZnO and alumina. Said non-spent sorbent material for sulfur traps may further comprise CuO in an amount of up to 3 wt%.

[0092] In other embodiments, the solid material is a spent sorbent material for sulfur traps, the corresponding non spent sorbent for sulfur trap being selected from the group consisting of Actisorb ®< S2, Actisorb ®< G1 ML, Katalco ®< 32-4, Katalaco ®< 35-2, Puraspec ®< 2084, HTZ-51, ST-201 and a mixture thereof.

[0093] In other embodiments, the solid material is a spent sorbent material for arsine and / or sulfur traps, the corresponding non spent sorbent for arsine and / or sulfur trap being suitable for the purification of ethylene and comprising 20-60 wt% of Cu in the form of Cu and / or CuO and 20-75 wt% of Zn in the form of Zn and / or ZnO.

[0094] In other embodiments, the solid material is a spent sorbent material for arsine and / or sulfur traps, the corresponding non spent sorbent for arsine and / or sulfur trap being suitable for the purification of ethylene and comprising 30-50 wt% of Cu in the form of Cu and / or CuO and 50-70 wt% of Zn in the form of Zn and / or ZnO. Such sorbent materials are for instance Polymax ®< 300 and Polymax ®< 301.

[0095] In other embodiments, the solid material is a spent sorbent material for arsine and / or sulfur traps, the corresponding non spent sorbent for arsine and / or sulfur trap being suitable for the purification of ethylene and comprising 25-50 wt% of Cu in the form of Cu and / or CuO and 25-50 wt% of Zn in the form of Zn and / or ZnO. Such sorbent materials are for instance Puristar ®< R3-16 and Puristar ®< R3-12.

[0096] In other embodiments, the solid material is a spent sorbent material for arsine and / or sulfur traps, the corresponding non spent sorbent for arsine and / or sulfur trap being suitable for the purification of ethylene and consisting essentially of copper oxide. Such material is for instance AxTrap ™< 192.

[0097] There is no specific preference regarding the shape of the spent solid material, which may be provided in any known form, including tablets, rings, stars, wagon wheels, and extrudates such as cylinders or pellets. In an embodiment, the spent catalyst or sorbent is in the form of extrudates.

[0098] In some embodiments, before the solid material is employed in step (i) of the first aspect of the invention and / or in the use of the second aspect of the invention, it is milled or grinded to produce a solid material with an average particle size by volume lower than 100 µm; or even lower than 80 µm. In a further embodiment, the volume average particle size is higher than 1 µm; or even higher than 5 µm. According to an embodiment, the volume average particle size by volume is 5-80 µm. According to a further embodiment, the volume average particle size by volume is 10-50 µm, or even 20-40 µm. It may be milled or grinded, and subsequently sieved to produce such solid material.

[0099] It has been found that the spent catalyst or sorbent can be used in the present invention without the need of a prior activation step.

[0100] The solid material can be used in the dehalogenation and / or denitrogenation of a pyrolysis oil as a catalyst, or as a reagent or as a sorbent.

[0101] Since the solid material is a spent catalyst or sorbent that has been disposed of, it is very cheap or even free. Therefore, it can be used in any amount until the desired level of halogen and / or nitrogen compounds is achieved with no significant increase in the production cost.Treatment of the pyrolysis oil with the solid material

[0102] Before the solid material is used in the dehalogenation and / or denitrogenation of the pyrolysis oil, it can be treated to remove components coming from its previous use, such as water, hydrocarbons or other organic compounds.

[0103] Therefore, in an embodiment, the process of the invention comprises a step previous to step (i) of drying the solid material.

[0104] Optionally, the process may further comprise extracting organic compounds (e.g. hydrocarbons) from the solid material, for example via solid-liquid extraction techniques (e.g. Soxhlet extraction). Said extraction can be performed using an organic solvent, such as hydrocarbon solvents, for instance pentanes, hexanes, heptanes, octanes, and mixtures thereof. Alternatively, said extraction may be carried out in the slurry reactor, using the pyrolysis oil as extraction solvent.

[0105] In alternative or additional embodiments, the process of the invention comprises a step previous to step (i) of grinding or milling the solid material and optionally subsequent sieving to produce a solid material with an average particle size by volume of 5 to 80 µm; in particular with an average particle size by volume of 10 to 50 µm. In a further embodiment, the average particle size by volume is 20 to 40 µm.

[0106] In an embodiment, the process of the first aspect of the invention comprises: (i) optionally, drying a solid material comprising Cu, Zn, CuO, ZnO or a mixture thereof and a support, (i") grinding and optionally sieving the solid material to produce a solid material with an average particle size by volume of 5 to 80 µm, particularly of an average particle size by volume of 10-50 µm, or even 20-40 µm; (i‴) treating in continuous the pyrolysis oil with the solid material from (i"), in the presence of hydrogen at a temperature of from 150 °C to 300 °C; and (ii) recovering the pyrolysis oil resulting from step (i‴); wherein the solid material is a spent catalyst or sorbent from refining or chemistry processes.

[0107] In an embodiment, the weight ratio of pyrolysis oil to solid material is from 100:1 to 10:1; or even from 30:1 to 20:1.

[0108] In further embodiments, the solid material represents 1-20 wt% of the slurry of pyrolysis oil and solid material. In an embodiment, the solid material represents 1-15 wt% of the slurry of pyrolysis oil and solid material. In a further embodiment, the solid material represents 2-10 wt% of the slurry of pyrolysis oil and solid material.

[0109] In further embodiments, the Cu and / or Zn in the form of Cu, CuO, Zn or ZnO in the solid material represents 0.5-15 wt% of the slurry of pyrolysis oil and solid material. In an embodiment, the Cu and / or Zn in the form of Cu, CuO, Zn or ZnO in the solid material represents 1-10 wt%, or even 2-10 wt%, of the slurry of pyrolysis oil and solid material.

[0110] In further embodiments, the Cu in the form of Cu or CuO in the solid material represents 0.2-10 wt% of the slurry of pyrolysis oil and solid material. In an embodiment, the Cu in the form of Cu or CuO in the solid material represents 0.5-5 wt% of the slurry of pyrolysis oil and solid material.

[0111] In further embodiments, the Zn in the form of Zn or ZnO in the solid material represents 0.3-15 wt% of the slurry of pyrolysis oil and solid material. In an embodiment, the Zn in the form of Zn or ZnO in the solid material represents 1-10 wt% of the slurry of pyrolysis oil and solid material.

[0112] The process of the invention may be carried out in the absence of a solvent.

[0113] In an embodiment, the pressure of hydrogen in the process of the invention is 10-50 kg / cm 2< . In a particular embodiment the pressure of hydrogen is 20-30 kg / cm 2< .

[0114] In an embodiment, the step of treating the pyrolysis oil with the solid material is carried out at a temperature of 150-250 °C. In a further embodiment, said temperature is 180-250 °C.

[0115] The step of treating the pyrolysis oil with the solid material can be carried out for a period of time of at least 1 hour, or even at least 2 hours. In a particular embodiment, said step is carried out for 1-10 hours, or from 2-5 hours.

[0116] The process of the invention comprises a step (ii) of recovering the pyrolysis oil resulting from the step of treating the (crude) pyrolysis oil with the solid material. Said step of recovering the resulting pyrolysis oil may comprise separating the pyrolysis oil from the solid material, for example by filtration, centrifugation or decantation.

[0117] The solid material separated in step (ii) can be recycled to the step of treatment of the pyrolysis oil (steps (i) or (i‴) above), either as such or in combination with additional solid material according to the invention that has not been used in a process according to the first aspect ("fresh" solid material),. Therefore, in a further embodiment, the solid material separated in step (ii) is provided as solid material or as a portion thereof in step (i) or (i‴).

[0118] In an embodiment, step (ii) can comprise a step of washing the pyrolysis oil with an aqueous solution, for example by injection of an aqueous solution. This washing step allows removal of salts or other water-soluble components from the pyrolysis oil.

[0119] In an embodiment, step (ii) can comprise a step of separating or removing the gaseous components or phase (e.g. hydrogen), for example by stripping or flashing.

[0120] In a particular embodiment, step (ii) of recovering the pyrolysis oil, comprises: (ii') removing the gaseous phase, for example by stripping or flashing, (ii") separating the pyrolysis oil from the solid material, for example by filtration, centrifugation or decantation, and (ii‴) washing the pyrolysis oil with an aqueous solution.

[0121] In an embodiment, steps (ii')-(ii‴) are carried out in the above-indicated order.

[0122] Additional objects, advantages and features of the invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention. The following examples are provided by way of illustration, and they are not intended to be limiting of the present invention.EXAMPLES Pyrolysis oil

[0123] A commercial pyrolysis oil obtained from mixed plastic waste of polyolefinic origin was used. Tables 1 and 2 below show the PIONA (paraffins, isoparaffins, olefins, naphthenes and aromatics) and analytical characterizations of said sample, respectively. Piona analysis was carried out by GCxGC-TOFMS, under the conditions listed below: 1D Column:HP-5 (30 m x 0.25 mm x 0.25 µm)2D Column:ZB-50 (1.5 m x 0.10 mm x 0.10 µm)Injection:0.5 µL split 1:100 at 350 °CFlow rate of He Carrier gas:Constant flow: 1.0 mL. min-1Oven T program:40 °C (hold 0.2 min) to 340 °C at 5 °C·min-1Modulator T:5°C above the first oven TModulation period:8s. hot pulse 0.8s Table 1. PIONA characterization of sample Component Weight % Paraffins61.1Naphtenes / Olefins32Aromatics6.6Diaromatics0.3 Table 2 Analytical characterization of sample Value Unit Measurement method sulfur29.3wppmASTM D5453density0.7944g / ccat 15°CNitrogen1945wppmASTM D4629Water<0.05%wtKarl-fisherTAN1.87mgKOH / gASTM D664Total CI273.9wppmATSM D7536Organic CI175.4wppmASTM D7536*Inorganic CI98.5wppmFluorine< 10wppmASTM D7359Bromine< 10wppmASTM D7359Chlorine206wppmASTM D7359Bromine number37.39g / 100gASTM D1159 * measured after removal of water soluble chlorides by extraction of one volume part of pyrolysis oil with three volume parts of ultrapure water (milli-Q ®< ) at ambient temperature.

[0124] Figure 1 shows the evolution of temperature at which a determined volume fraction of the pyrolysis oil is distilled, as determined by ASTM D2887.Solid material

[0125] Three samples of waste catalysts from the Water gas Shift plant of Repsol, Cartagena, Spain, have been provided as wet samples. These samples were considered waste catalyst as soon as the selectivity of CO in the water gas shift process reached 0.3%. Three samples of waste catalyst were used: 1) LSK-2 is a catalyst employed as chlorine guard in medium and low temperature shift reactions. A fresh, non spent sample of LSK-2 typically has the following features: CatalystLSK-2DescriptionShapeCylindersSize, nominal, ODxH, mm4.5x4.5Chemical composition, wt%Cu>15Zn>16Al>14Graphite and oxygen as metallic oxidesBalance 2) LK-813 is a catalyst for medium temperature shift, typically used in the intermediate catalyst bed for the conversion of CO. A fresh, non spent sample of LK-813 typically has the following features: CatalystLK-813DescriptionShapeCylindersSize, nominal, ODxH, mm4.5x3.4 Chemical composition, wt%Cu>34Zn>19Al>4Graphite and oxygen as metallic oxidesBalance 3) LK-819 is a catalyst for medium temperature shift, typically used in the intermediate catalyst bed for the conversion of CO. A fresh, non spent sample of LK-819 typically has the following features: CatalystLK-819DescriptionShapeCylindersSize, nominal, ODxH, mm4.5x3.4 Chemical composition, wt%Cu>24Zn>30Al>6Graphite and oxygen as metallic oxidesBalance

[0126] The as-received samples were dried and submitted to a step of removal of hydrocarbons that was carried out by Soxhlet extraction performed on the extruded catalyst using pentanes as solvent.

[0127] Each of the three solids obtained from step (ii) was independently submitted to a step of ball milling employing a milling intensity suitable for providing particle size of between 5 µm and 100 µm. The milling step was carried out in the absence of a solvent. Obtained solids were kept under air atmosphere. The three samples presented similar distributions of particle size (as shown in Figure 2), with a population of particles having an average particle size by volume of between 20-40 µm. Table 3 below shows the elemental characterization, as carried out by X-ray fluorescence of the milled products. Table 3LK-819LSK-2LK-813%wt%wt%wtNa0.938Al4.595.177.69Si0.0150.0150.024P0.0180.020.016Cl0.0180.0240.043K0.0380.0350.054Ca0.012Fe0.0150.0140.014Ni0.0240.021Cu25.722.720.7Zn47.448.547.7

[0128] The resulting catalyst powders were used as obtained.Slurry treatment of pyrolysis oil

[0129] A 1 L autoclave reactor was charged with 500 g of the pyrolysis oil and with a solid material consisting of a blend of the three spent catalysts having 7 g of each one of the aforementioned catalysts at room temperature. After the charging phase, the autoclave was closed, stirred and purged with nitrogen until leaving an internal pressure of 1.3 bar with a minimal amount of oxygen in the purge gas. The reactor was then pressurized with hydrogen until reaching a pressure of 25 kg / cm 2< . From this point, the outlet of the reactor was closed and hydrogen was supplied in order to maintain the pressure constant inside the reactor. The reaction mixture was then heated progressively till a temperature of 200 °C After reaching this temperature, pressure and temperature were maintained constant in the reactor for a period of 3 hours. After this time, hydrogen supply was closed and the reactor was slowly depressurized, purged with nitrogen gas and cooled down to ambient conditions. Reactor was discharged from the mixture of liquid and solid, said solid being afterwards isolated by decantation and removal of supernatant while leaving the solid within a liquid phase so as to prevent its oxidation. The thus recovered solid material was used in subsequent tests of the reaction with the addition of 6 g of fresh solid material (2 g of each of the spent catalysts in the blend).

[0130] Three tests of the process were carried out using: (i) the initial charge of the solid material (test 1), (ii) recovered solid material from (i) + 6 g of fresh solid material (test 2), (iii) recovered solid material from (ii) + 6 g of fresh solid material (test 3). The composition of the liquid product resulting from each one of the three runs is shown in Table 4. Table 4Parameter Method Unit Test 1 Test 2 Test 3 SulfurASTM D5453wppm45.845.242.1Total CIASTM D7536wppm133.2161.1159.5Organic CIASTM D7536wppm92.05 109.5 115.35 Inorganic Clwppm41.1551.644.15Bromine numberASTM D1159g / 100g42.1141.7240.65waterKarl-fisher%wt0.0660.05< 0.05TANASTM D664mgKOH / g1.791.771.83NitrogenASTM D4269wppm844840813

[0131] ASTM D7536 allows determining the amount of chloride compounds, including both organochlorinated compounds and inorganic chlorides. This method thus allows determining the total amount of chloride ions in a sample. Also, the amount of organochlorinated compounds may be determined by ASTM D7536 after removal of inorganic chlorides, e.g. by washing the sample with water. The amount of inorganic chlorides can be obtained by substracting the amount of organochlorinated compounds in the sample to the total amount of chlorides in the sample.

[0132] The results of the analysis indicate that the acidity and water content of the pyrolysis oil before and after treatment with the spent catalyst is maintained while the bromine number is reduced very slightly, which indicates a low degree of hydrogenation of unsaturated compounds. Table 5 below shows the relative reduction in chlorine and nitrogen, expressed as a percentage of the composition, for each test, of the pyrolysis oil obtained after treatment with the spent catalyst, if compared to the composition of the crude pyrolysis oil. Table 5Test 1Test 2Test 3Total CI51.441.241.8Organic CI47.537.634.2Inorganic CI58.247.655.2Nitrogen56.656.858.2

[0133] A reduction of about 40% of organic chloride and more than 50% of total nitrogen and inorganic chloride was observed.

[0134] In view of the finding by the inventors that spent catalysts from other industrial processes can be used in a very efficient, simple and economical method to reduce the content of halogen and nitrogen components of a pyrolysis oil, similar results could be expected for other spent catalysts comprising Cu and / or Zn in the form of Cu, Zn, CuO, ZnO or mixtures thereof.

Claims

1. Slurry process for reducing the content of halogen and / or nitrogen compounds, such as organohalogen and / or organonitrogen compounds, of a pyrolysis oil, the process comprising: (i) treating in continuous the pyrolysis oil with a solid material comprising Cu, Zn, CuO, ZnO or a mixture thereof, in the presence of hydrogen at a temperature of from 150 °C to 300 °C; and (ii) recovering the pyrolysis oil resulting from step (i); wherein the solid material of step (i) is a spent catalyst or sorbent from refining or chemistry processes.

2. Process according to claim 1, wherein the solid material of step (i) further comprises a support.

3. Process according to any one of claims 1 to 2, wherein the solid material of step (i) is selected from the group consisting of: - spent catalyst from a water-gas shift process; - spent catalyst from a methanol synthesis process by hydrogenation of carbon oxides; - spent sorbent from sulfur traps for syngas reforming and processing; - spent catalyst from an ethylene or propylene purification process; - spent catalyst from hydrogenation of aldehydes to produce oxo alcohols; - spent catalyst from hydrogenolysis of glycerol to produce 1,2-propanediol; - spent catalyst from hydrogenation of nitrobenzene to produce aniline; - spent catalyst from hydrogenation of fatty acid or fatty acid methyl esters to fatty alcohols; - spent catalyst from the hydrogenation of dimethyl maleate to 1,4-butanediol, gamma-butyrolactone and tetrahydrofuran; - spent catalyst from the hydrogenation of methyl-phenyl ketone to alpha-methyl benzyl alcohol; and - mixtures thereof.

4. Process according to any one of claims 1 to 3, wherein the solid material of step (i) comprises at least 10 wt% of metal selected from Cu and / or Zn in the form of the Cu, Zn, CuO, ZnO or a mixture thereof.

5. Process according to any one of claims 1 to 4, wherein the solid material of step (i) comprises at least 30 wt% of metal selected from Cu and / or Zn in the form of the Cu, Zn, CuO, ZnO or a mixture thereof, such as at least 50 wt%.; such as wherein the solid material of step (i) comprises from 10 wt% to 40 wt% of copper in the form of Cu, CuO a mixture thereof and from 30 wt% to 60 wt% of zinc in the form of Zn, ZnO or a mixture thereof.

6. Process according to any one of claims 2 to 5, wherein the support is selected from alumina, silica, graphite, chromium oxide, molybdenum oxide, titania, magnesia or a mixture thereof.

7. Process according to any one of claims 2 to 6, wherein the solid material of step (i) comprises at least 60 wt%, or even at least 70 wt%, of metal selected from Cu and / or Zn in the form of Cu, Zn, CuO, ZnO or a mixture thereof and the support.

8. Process according to any one of claims 1 to 7 wherein the solid material of step (i) is a spent catalyst from a water-gas shift process.

9. Process according to any one of claims 1 to 8 comprising a step previous to step (i) of grinding the solid material to produce a solid material with an average particle size by volume of 1-100 µm, such as 5-80 µm.

10. Process according to any one of claims 1 to 9 wherein the weight ratio of pyrolysis oil to solid material in step (i) is from 100:1 to 10:1; such as from 30:1 to 20:1.

11. Process according to any one of claims 1 to 10 wherein the pressure of hydrogen in step (i) is from 20 to 30 kg / cm2.

12. Process according to any one of claims 1 to 11, wherein step (ii) comprises separating the pyrolysis oil from the solid material, for example by filtration, centrifugation or decantation.

13. Process according to claim 12 wherein the solid material separated in step (ii) is provided as solid material or as a portion thereof in step (i).

14. Process according to any one of claims 1 to 13, wherein the pyrolysis is a plastic pyrolysis oil.

15. Use of a solid material as defined in any one of claims 1 to 8 for reducing the content of halogen and / or nitrogen compounds, such as organohalogen and / or organonitrogen compounds, of a pyrolysis oil.

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