Compositions, methods and uses

Abstract

A composition is disclosed that comprises a pyrolysis oil and, as an additive: (a) one or more nitrogen-containing antioxidants. An additive composition for pyrolysis oil is also disclosed, which comprises: (a) one or more nitrogen-containing antioxidants; and optionally: (b) a copolymer comprising maleic anhydride-derived units and α-olefin-derived units; and / or (c) a reaction product of a carboxylic acid and a polyamine. A method for improving the oxidative stability of a composition comprising pyrolysis oil, comprising adding (a) one or more nitrogen-containing antioxidants to the composition, and related uses of said nitrogen-containing antioxidants, is also disclosed. Such methods and uses are also disclosed for the improvement in storage stability of a composition comprising pyrolysis oil.

Description

[Technical field]

[0001] The present invention relates to pyrolysis oil and methods and uses thereof. In particular, the present invention relates to an additive for improving the stability of a composition containing waste rubber pyrolysis oil or waste plastic pyrolysis oil. [Background technology]

[0002] Pyrolysis oil is a fluid produced from the pyrolysis of waste materials such as plastic waste, used tires, waste rubber, biomass such as agricultural waste, forestry waste, waste cooking oil and algae waste. Examples of waste plastics that can be pyrolyzed to produce plastic pyrolysis oil include polyethylene, polypropylene, polystyrene, polyethylene terephthalates (PET) and mixtures thereof. Oils obtained from the pyrolysis of plastics are commonly referred to as waste plastic pyrolysis oils (WPPO). Oils obtained from the pyrolysis of rubber (e.g., from tires) are commonly referred to as waste rubber pyrolysis oils (WRPO). Organic liquids produced by the pyrolysis of rubber, plastic and other waste materials have a very dark color, an unpleasant odor and are unstable. However, there is a strong desire to find uses for such oils to avoid such wastes being sent to landfills or polluting the oceans.

[0003] Pyrolysis oil can be used as a feedstock for chemical processing, for example in the production of polymers such as polyethylene. Pyrolysis oil can also be used in fuel oil. The use of pyrolysis oil to produce polymers provides a sustainable alternative to the use of crude oil feedstocks.

[0004] The usefulness of pyrolysis oils is limited due to their low oxidative stability, believed to be due to oxidation of oxygen- or nitrogen-containing species present in the oil. The nature of these oils and the method of their production means that they typically contain a greater proportion of components that are sensitive to oxidation than mineral-derived middle distillate fuels.

[0005] Pyrolysis oils may be hydrotreated or cracked prior to further use, which may improve their oxidative stability, or may be treated with chemical additives to improve their stability. Summary of the Invention [Means for solving the problem]

[0006] The inventors have found that certain compounds are effective in improving the oxidative stability of compositions containing pyrolysis oils, and further, that such compounds are effective in improving the storage stability of compositions containing pyrolysis oils.

[0007] According to a first aspect of the present invention, a pyrolysis oil and, as an additive: (a) one or more nitrogen-containing antioxidants A composition comprising:

[0008] A first aspect of the present invention relates to a composition comprising pyrolysis oil. Pyrolysis oil can be obtained by pyrolysis of any waste. The components and properties of the oil vary depending on the type of waste pyrolyzed and the pyrolysis conditions. For example, pyrolysis oil can be obtained from the pyrolysis of plastic waste, rubber waste, agricultural waste, forestry waste, used cooking oil and algae waste.

[0009] Preferably, the pyrolysis oil comprises plastic pyrolysis oil, which can also be obtained from the pyrolysis of any type of plastic.

[0010] Preferred plastic pyrolysis oils are obtained from further pyrolysis of one or more polymers selected from polyethylene, polypropylene, PET, rubber and mixtures thereof.

[0011] Preferred plastic pyrolysis oils are obtained from further pyrolysis of one or more polymers selected from polyethylene, polypropylene, PET, rubber, used tires and mixtures thereof.

[0012] In a particularly preferred embodiment, the pyrolysis oil is obtained from the pyrolysis of rubber, for example, the pyrolysis oil can be obtained from the pyrolysis of used tires.

[0013] In some embodiments, the pyrolysis oil in the composition of the first aspect may be a hydrotreated pyrolysis oil.

[0014] In some embodiments, the pyrolysis oil in the composition of the first aspect has been processed using a cracking process.

[0015] In a preferred embodiment, the composition of the first aspect comprises pyrolysis oil obtained directly from a pyrolysis plant without any refining or further processing.

[0016] In some embodiments, the pyrolysis oil has an n-paraffin content of less than 15 wt%, preferably less than 10 wt%, for example less than 6 wt%.

[0017] In some embodiments, the pyrolysis oil has an asphaltene content of less than 5 wt%, preferably less than 2 wt%, for example less than 1 wt%.

[0018] In some embodiments, the composition of the first aspect may comprise a blended fuel oil comprising pyrolysis oil and one or more fuel oils from hydrocarbon and / or renewable sources. Preferably, the pyrolysis oil is waste plastic pyrolysis oil (WPPO) or waste rubber pyrolysis oil (WRPO).

[0019] Throughout this specification, the term "comprising" or "comprises" means including the specified component(s) but does not exclude the presence of other components. The term "consisting essentially of" or "consists essentially of" means including the specified components but excluding other components, except for components that are added for purposes other than achieving the technical effect of the invention. The term "consisting of" or "consists of" means including the specified components but excluding other components.

[0020] Wherever appropriate and depending on the context, use of the words "comprises" or "comprising" can be interpreted to include meaning "consists essentially of" or "consisting essentially of" and can be interpreted to include meaning "consists of" or "consisting of." DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] In some embodiments, the composition of the first aspect comprises a blended fuel oil comprising a pyrolysis oil (preferably WPPO or WRPO) and a middle distillate fuel oil.

[0022] The middle distillate fuel oil may comprise a petroleum-based fuel oil, in particular a middle distillate fuel oil. Such distillate fuel oils usually boil within the range of 110° C. to 500° C., for example 150° C. to 400° C. The middle distillate fuel oil may comprise atmospheric or vacuum distillates, cracked gas oils, or blends of straight run and product streams in any proportion, for example thermally cracked and / or catalytically cracked fractions and hydrocracked fractions.

[0023] Middle distillate fuel oils may include non-renewable Fischer-Tropsch fuels, such as those referred to as gas-to-liquids (GTL), coal-to-liquids (CTL), and oil sands-to-liquids (OTL).

[0024] Middle distillate fuel oils may include renewable fuels, such as biofuel or biodiesel compositions.

[0025] The middle distillate fuel oil may comprise first generation biodiesel. First generation biodiesel contains, for example, esters of vegetable oils, animal fats and used cooking fats. This form of biodiesel can be obtained by transesterification of oils, such as rapeseed oil, soybean oil, safflower oil, palm oil, palm kernel oil, corn oil, peanut oil, cottonseed oil, tallow, coconut oil, Jatropha oil, sunflower seed oil, used cooking oil, hydrogenated vegetable oil or any mixture thereof, with alcohols, usually monoalcohols, in the presence of a catalyst.

[0026] Middle distillate fuel oils may include second generation biodiesel, which is derived from renewable resources such as vegetable oils and animal fats, and is often processed in refineries using hydroprocessing, such as the H-Bio process developed by Petrobras. Second generation biodiesel may be similar in properties and quality to renewable diesel produced from petroleum-based fuel oil fractions, such as vegetable oils, animal fats, etc., and is marketed as renewable diesel by ConocoPhillips and NExBTL by Neste.

[0027] The middle distillate fuel oil used in the present invention may include third generation biodiesel, which includes what is referred to as biomass-to-liquid (BTL) and utilizes gasification and Fischer-Tropsch technology. Third generation biodiesel is not significantly different from some second generation biodiesel, but is intended to utilize whole plants (biomass), thereby expanding the feedstock base.

[0028] The middle distillate fuel oil may contain blends of any or all of the above diesel fuel oils.

[0029] In some embodiments, the middle distillate fuel oil can be a blended diesel fuel containing biodiesel. In such a blend, the biodiesel can be present in an amount of, for example, up to 0.5%, up to 1%, up to 2%, up to 3%, up to 4%, up to 5%, up to 10%, up to 20%, up to 30%, up to 40%, up to 50%, up to 60%, up to 70%, up to 80%, up to 90%, up to 95%, or up to 99%.

[0030] In some embodiments, the middle distillate fuel oil may include a secondary fuel, such as ethanol, however, preferably the diesel fuel composition does not contain ethanol.

[0031] Middle distillate fuel oils may contain a relatively high sulphur content, for example greater than 0.05% by weight, such as 0.1% or 0.2% by weight.

[0032] However, in a preferred embodiment, the middle distillate fuel oil has a sulphur content of at most 0.05 wt%, more preferably at most 0.035 wt%, in particular at most 0.015 wt%. Fuels with even lower levels of sulphur are also suitable, for example fuels having less than 50 ppm sulphur by weight, preferably less than 20 ppm sulphur by weight, for example 10 ppm or less by weight.

[0033] Various metal species may be present in middle distillate fuel oils. This may be due to contamination of the fuel during production, storage, transportation or use, or due to contamination of fuel additives. Metal species may also be intentionally added to the fuel. For example, transition metals are sometimes added as fuel borne catalysts, for example to improve the performance of diesel particulate filters.

[0034] In a preferred embodiment, the middle distillate fuel oil used in the present invention contains sodium and / or calcium, preferably sodium. The sodium and / or calcium are typically present in a total amount of 0.01 to 50 ppm, preferably 0.05 to 5 ppm, preferably 0.1 to 2 ppm, for example 0.1 to 1 ppm.

[0035] Other metal-containing species may also be present as contaminants, for example, through corrosion of metal and metal oxide surfaces by acidic species present in the fuel or from the lubricating oil. During use, fuels such as diesel fuels are constantly in contact with metal surfaces, for example, in vehicle fuel delivery systems, fuel tanks, fuel vehicles, etc. Typically, metal-containing contaminants may include transition metals such as zinc, iron, and copper; other Group I or Group II metals, and other metals, for example, lead.

[0036] In addition to metal-containing contaminants that may be present in middle distillate fuel oils, metal-containing species may be intentionally added to the fuel in some cases. For example, as is known in the art, metal-containing fuel-generated catalytic species may be added to aid in the regeneration of particulate traps.

[0037] Metal-containing contaminants can be in the form of insoluble particles or soluble compounds or complexes depending on their source. Metal-containing fuel-generated catalysts are often soluble compounds or complexes or colloidal species.

[0038] In some embodiments, the middle distillate fuel oil may contain a metal-containing species including an in-fuel generated catalyst. Preferably, the in-fuel generated catalyst contains one or more metals selected from iron, cerium, platinum, manganese, Group I and Group II metals, such as calcium and strontium. Most preferably, the in-fuel generated catalyst contains a metal selected from iron and cerium.

[0039] In some embodiments, the middle distillate fuel oil may include metal-containing species including zinc, which may be present in an amount of from 0.01 to 50 ppm, preferably from 0.05 to 5 ppm, more preferably from 0.1 to 1.5 ppm.

[0040] The composition of the first embodiment includes (a) one or more nitrogen-containing antioxidants.

[0041] Any suitable nitrogen-containing antioxidant may be used.

[0042] Suitable nitrogen-containing antioxidants are known to those skilled in the art.

[0043] Suitable amino-based antioxidants include aromatic amines, hindered amines, N-oxides, substituted hydroxylamines, and acylated nitrogen compounds.

[0044] Suitable aromatic amines include diaminobenzenes and alkylated diaminobenzenes, particularly dialkylated and trialkylated diaminobenzenes, such as p-phenylenediamine, 3,5-diethyltoluene-2,4-diamine; 3,5-diethyltoluene-2,2-diamine; 2,4,6-triethylbenzene-2,6-diamine alkylated diphenylamines; diphenylamine and alkylated diphenylamines, such as N,N-diphenyl-1,4-phenylenediamine; and naphthylamines, such as N-phenyl-1-naphthylamine and N-phenyl-2-naphthylamine.

[0045] Suitable hindered amines include secondary and tertiary aliphatic amines, such as dimethylcyclohexylamine.

[0046] Suitable N-oxides include TEMPO and its derivatives.

[0047] Preferably, the one or more nitrogen-containing antioxidants (a) are selected from: (i) acylated nitrogen compounds; (ii) phenylenediamine; (iii) substituted hydroxylamines; and (iv) Mixtures thereof.

[0048] Suitable acylated nitrogen compounds (i) can be prepared by reacting a carboxylic acid acylating agent with an amine and are known to those skilled in the art, in which the acylating agent is linked to the amino compound via an imide, amide, amidine or acyloxyammonium linkage.

[0049] The preferred acylated nitrogen-containing compounds are hydrocarbyl-substituted. The hydrocarbyl substituent may be on either the carboxylic acid acylating agent-derived portion of the molecule or the amine-derived portion of the molecule, or both. Preferably, however, it is on the acylating agent portion. A preferred class of acylated nitrogen-containing compounds suitable for use in the present invention are those formed by the reaction of an acylating agent having a hydrocarbyl substituent of at least 8 carbon atoms with a compound containing at least one primary or secondary amine group.

[0050] The acylating agent may be a mono- or polycarboxylic acid (or reactive equivalents thereof), such as a substituted succinic, phthalic or propionic acid or anhydride.

[0051] Suitable hydrocarbyl-substituted acylating agents and means for their preparation are well known in the art.

[0052] Illustrative examples of hydrocarbyl-based substituent groups containing at least 8 carbon atoms are n-octyl, n-decyl, n-dodecyl, tetrapropenyl, n-octadecyl, oleyl, chlorooctadecyl, triacontanyl, etc. Hydrocarbyl-based substituents can be prepared from homo- or interpolymers (e.g., copolymers, terpolymers) of mono- and di-olefins having 2 to 10 carbon atoms, such as, for example, ethylene, propylene, butane-1, isobutene, butadiene, isoprene, 1-hexene, 1-octene, etc. Preferably, these olefins are 1-monoolefins.

[0053] The term "hydrocarbyl," as used herein, denotes a group having a carbon atom directly attached to the remainder of the molecule and having predominantly aliphatic hydrocarbon character.

[0054] The hydrocarbyl substituents are preferably predominantly saturated, i.e., they contain no more than one carbon-carbon unsaturated bond for every 10 carbon-carbon single bonds present. Most preferably, they contain no more than one carbon-carbon non-aromatic unsaturated bond for every 50 carbon-carbon bonds present.

[0055] The hydrocarbyl substituent in such acylating agents preferably contains at least 10, more preferably at least 12, for example at least 30 or at least 40 carbon atoms. It may contain up to about 200 carbon atoms. Preferably, the hydrocarbyl substituent of the acylating agent has a number average molecular weight (Mn) of 170 to 2800, for example 250 to 1500, preferably 500 to 1500 and more preferably 500 to 1100. An Mn of 700 to 1300 is especially preferred. In a particularly preferred embodiment, the hydrocarbyl substituent has a number average molecular weight of 700 to 1000, preferably 700 to 850, for example 750.

[0056] The carboxylic acid derived acylating agent may comprise a mixture of compounds. For example, a mixture of compounds with different hydrocarbyl substituents may be used. In some embodiments, the acylating agent may have one or more hydrocarbyl substituents. In such embodiments, each hydrocarbyl substituent may be the same or different.

[0057] A preferred hydrocarbyl substituent is polyisobutene. Such compounds are known to those skilled in the art.

[0058] A preferred hydrocarbyl-substituted acylating agent is polyisobutenyl succinic anhydride. These compounds are commonly referred to as "PIBSA" and are known to those skilled in the art.

[0059] Conventional polyisobutenes and so-called "highly reactive" polyisobutenes are suitable for use in the present invention. Highly reactive polyisobutenes in this context are defined as polyisobutenes in which at least 50%, preferably 70% or more of the terminal olefinic double bonds are of the vinylidene type, as described in EP 0565285. Particularly preferred polyisobutenes are those with more than 80 mol% and up to 100 mol% terminal vinylidene groups, such as those described in US Pat. No. 7,291,758. Preferred polyisobutenes generally have the preferred molecular weight ranges as described above for the hydrocarbyl substituents.

[0060] Other preferred hydrocarbyl groups include those having internal olefins, for example as described in the Applicant's published application WO 2007 / 015080.

[0061] Internal olefins, as used herein, refers to any olefin that contains primarily non-alpha double bonds, which are beta or higher olefins. Preferably, such materials are substantially entirely beta or higher olefins, e.g., containing less than 10 wt.% alpha olefins, more preferably less than 5 wt.% or less than 2 wt.%. Exemplary internal olefins include Neodene 1518IO available from Shell.

[0062] Internal olefins, sometimes known as isomerized olefins, can be prepared from alpha olefins by processes of isomerization known in the art or are available from other sources. The fact that they are also known as internal olefins reflects the fact that they do not necessarily have to be prepared by isomerization.

[0063] A preferred carboxylic acid derived acylating agent is polyisobutenyl-substituted succinic anhydride or PIBSA. Particularly preferred PIBSA has a PIB molecular weight (Mn) of 300-2800, preferably 450-2300, more preferably 500-1300.

[0064] The carboxylic acid derived acylating agent is reacted with an amine. Preferably, it is reacted with a primary or secondary amine. Examples of some suitable amines are described herein.

[0065] Amine compounds useful for reaction with an acylating agent include those having the general formula: (R 3 ) 2 N[UN(R 3 )] n R 3 (In the formula, each R 3 are independently selected from a hydrogen atom, a hydrocarbyl group, or a hydroxy-substituted hydrocarbyl group containing up to about 30 carbon atoms, provided that at least one R 3is a hydrogen atom, n is an integer of 1 to 10, and U is a C1-18 alkylene group. 3 is independently selected from hydrogen, methyl, ethyl, propyl, isopropyl, butyl, and isomers thereof. Most preferably, each R 3 is ethyl or hydrogen. U is preferably a C1-4 alkylene group, most preferably ethylene.

[0066] Other useful amines include heterocycle-substituted polyamines, including hydroxyalkyl-substituted polyamines, where the polyamines are as described above and the heterocycle substituents are selected from nitrogen-containing aliphatic and aromatic heterocycles, such as piperazine, imidazoline, pyrimidine, morpholine, and derivatives thereof.

[0067] Other useful amines for reaction with the acylating agent include amines of the general formula: Ar(NR 3 2 ) y (wherein Ar is an aromatic nucleus of 6 to 20 carbon atoms, and each R 3 is as defined above, and y is 2 to 8).

[0068] Specific examples of polyalkylene polyamines include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, tri(tri-methylene)tetraamine, pentaethylenehexamine, hexaethylene-heptamine, 1,2-propylenediamine, and mixtures thereof. Other commercially available materials, including complex mixtures of polyamines, can also be used, such as higher ethylene polyamines that may contain all or some of the above, in addition to higher boiling fractions containing 8 or more nitrogen atoms. Specific examples of hydroxyalkyl-substituted polyamines include N-(2-hydroxyethyl)ethylenediamine, N,N'-bis(2-hydroxyethyl)ethylenediamine, N-(3-hydroxybutyl)tetramethylenediamine, and the like. Specific examples of heterocyclic substituted polyamines (2) are N-2-aminoethylpiperazine, N-2 and N-3 aminopropylmorpholine, N-3 (dimethylamino)propylpiperazine, 2-heptyl-3-(2-aminopropyl)imidazoline, 1,4-bis(2-aminoethyl)piperazine, 1-(2-hydroxyethyl)piperazine, and 2-heptadecyl-1-(2-hydroxyethyl)-imidazoline, etc. Specific examples of aromatic polyamines (3) are the various isomeric phenylenediamines, the various isomeric naphthalenediamines, etc.

[0069] Preferred amines include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethylene-heptamine, and mixtures and isomers thereof, and polyethylenepolyamines.

[0070] In a preferred embodiment, the reaction product of the carboxylic acid derived acylating agent and the amine contains at least one primary or secondary amine group.

[0071] Preferred acylated nitrogen-containing compounds for use in the present invention are prepared by reacting a poly(isobutene)-substituted succinic acid derived acylating agent (e.g., anhydride, acid, ester, etc.) in which the poly(isobutene) substituent has a number average molecular weight (Mn) of 170 to 2800 with a mixture of ethylene polyamines having from 2 to about 9 amino nitrogen atoms, preferably from about 2 to about 8 nitrogen atoms, and from about 1 to about 8 ethylene groups per ethylene polyamine. These acylated nitrogen compounds are suitably formed by reaction of a molar ratio of acylating agent:amino compound of from 10:1 to 1:10, preferably from 5:1 to 1:5, more preferably from 2:1 to 1:2, and most preferably from 2:1 to 1:1. In a particularly preferred embodiment, the acylated nitrogen compound is formed by reaction of an acylating agent with an amino compound in a molar ratio of 1.8:1 to 1:1.2, preferably 1.6:1 to 1:1.2, more preferably 1.4:1 to 1:1.1, and most preferably 1.2:1 to 1: 1. Acylated amino compounds of this type and their preparation are well known to those skilled in the art and are described, for example, in EP 0 565 285 and US 5 925 151.

[0072] In a particularly preferred embodiment, the acylated nitrogen-containing additive (i) comprises the reaction product of a polyisobutene-substituted succinic acid or anhydride with a polyethylene polyamine to form a succinimide detergent. Preferred polyethylene polyamines include ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, hexaethylene-heptamine, and mixtures and isomers thereof. Suitably, the polyisobutene substituent of the polyisobutene-substituted succinic acid or anhydride has a number average molecular weight of 500-2000, preferably 500-1500, more preferably 500-1100, suitably 600-1000, preferably 700-800, for example about 750.

[0073] Component (i) may comprise a mixture of two or more acylated nitrogen compounds.

[0074] In the additives used in the present invention, preferably at least 50 wt% of the additive, preferably at least 70%, more preferably at least 90%, preferably at least 95%, suitably at least 97% of the molecules have a number average molecular weight of greater than 400.

[0075] A suitable method for determining the molecular weight distribution of the additive is GPC using polystyrene standards.

[0076] Those skilled in the art will appreciate that polyisobutene-substituted succinimide detergent additives typically contain a complex mixture of compounds. Such compounds are usually prepared by reacting polyisobutene (PIB) with maleic anhydride (MA) to form polyisobutene-substituted succinic anhydride (PIBSA), which is then reacted with a polyamine (PAM) to form polyisobutene-substituted succinimide (PIBSI). In the reaction of PIB with MA, more than one MA can react with each PIB, leaving some unreacted PIB. Each PIBSA molecule can react with one or more PAM molecules as described above. Varying the ratio of different starting materials and including intermediate purification steps can affect the ratio of the various components of the final additive material.

[0077] Some preferred phenylenediamine antioxidants (ii) suitable for use in the present invention include those having the formula: [ka] (In the formula, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7are independently selected from hydrogen, optionally substituted alkyl, alkenyl, aryl, alkaryl or aralkyl groups, esters, carboxylic acids, aldehydes, ketones, ethers, alcohols, amines or amides. Preferably, R 1 is hydrogen. Preferably, R 3 is hydrogen. Preferably, R 2 is preferably an alkyl group having 1 to 10 carbon atoms. More preferably, R 2 is an alkyl group having 1 to 5 carbon atoms. 2 is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl. Most preferably, R 2 is isopropyl or sec-butyl. 4 is preferably an alkyl group having 1 to 10 carbon atoms. More preferably, R 4 is an alkyl group having 1 to 5 carbon atoms. 4 is preferably selected from methyl, ethyl, propyl, isopropyl, sec-butyl, butyl, tert-butyl and isobutyl. Most preferably, R 4 is isopropyl or sec-butyl.

[0078] R 5 , R 6 and R 7 is preferably selected from hydrogen or an alkyl group, more preferably from hydrogen and an alkyl group having 1 to 10 carbon atoms, more preferably from hydrogen and an alkyl group having 1 to 5 carbon atoms. 5 , R 6 and R 7 is independently selected from hydrogen, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl and isobutyl. Most preferably, R 5 is hydrogen. Most preferably, R 6 is hydrogen. Most preferably, R 7 is hydrogen.

[0079] In a particularly preferred embodiment, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 is hydrogen and component (ii) comprises p-phenylenediamine.

[0080] Component (ii) may comprise a mixture of compounds and / or a mixture of isomers.

[0081] Preferred substituted hydroxylamine compounds (iii) for use in the present invention have the formula R 2 NOH. Preferably, each R is an optionally substituted hydrocarbyl group. Each R may be the same or different. Preferably, each R is the same.

[0082] Preferably, each R is an optionally substituted alkyl or alkenyl group, preferably having 1 to 12 carbon atoms, suitably 1 to 10 or 1 to 8 carbon atoms, for example 1 to 6, preferably 1 to 4 carbon atoms. Preferably, each R is an alkyl group. Each R may be a substituted alkyl group, for example a hydroxy-substituted alkyl group. Preferably, each R is an unsubstituted alkyl group or a hydroxyalkyl group. More preferably, each R is an unsubstituted alkyl group. The alkyl chain may be linear or branched. Preferably, each R is selected from methyl, ethyl, propyl and butyl, including isomers thereof. Most preferably, each R is ethyl.

[0083] Preferably, component (iii) comprises diethylhydroxylamine.

[0084] Component (iii) may comprise a mixture of compounds and / or a mixture of isomers.

[0085] The composition of the first aspect of the invention comprises a pyrolysis oil and (a) one or more nitrogen-containing antioxidants. The nitrogen-containing additives are preferably selected from (i) acylated nitrogen compounds, (ii) phenylenediamines, and (iii) substituted hydroxylamines.

[0086] In some embodiments, component (a) of the composition of the first aspect comprises (i) an acylated nitrogen compound.

[0087] In some embodiments, component (a) of the composition of the first aspect comprises (ii) a phenylenediamine.

[0088] In some embodiments, component (a) of the composition of the first aspect comprises (iii) a substituted hydroxylamine.

[0089] In some embodiments, component (a) of the composition of the first aspect comprises (i) an acylated nitrogen compound and (ii) a phenylenediamine.

[0090] In some embodiments, component (a) of the composition of the first aspect comprises (i) an acylated nitrogen compound and (iii) a substituted hydroxylamine.

[0091] In some embodiments, component (a) of the composition of the first aspect comprises (ii) a phenylenediamine and (iii) a substituted hydroxylamine.

[0092] In some embodiments, component (a) of the composition of the first aspect comprises (i) an acylated nitrogen compound, (ii) a phenylenediamine, and (iii) a substituted hydroxylamine.

[0093] In some embodiments, the composition of the first aspect may further comprise (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units.

[0094] Copolymer (b) is preferably an alternative copolymer prepared by reacting maleic anhydride with an α-olefin. Means for carrying out such reactions are well known to those skilled in the art and are described, for example, in U.S. Pat. Nos. 4,240,916, 3,560,456 and 4,151,069.

[0095] The copolymer additive of the present invention is suitably prepared by reacting maleic anhydride with an α-olefin in a molar ratio of from 3:1 to 1:3, preferably from 2:1 to 1:2, more preferably from 1.5:1 to 1:1.5, for example about 1:1.

[0096] Preferably, the α-olefin has 6 to 40 carbon atoms, preferably 10 to 36 carbon atoms, preferably 12 to 36 carbon atoms, for example, 16 to 32 carbon atoms. Most preferably, the α-olefin has 18 to 30 carbon atoms, for example, 20 to 28 carbon atoms.

[0097] Mixtures of α-olefins may be used to form the copolymer additives of the present invention.

[0098] In one preferred embodiment, a mixture of α-olefins having 20 to 24 carbon atoms is used.

[0099] In one embodiment, a mixture of α-olefins having from 24 to 28 carbon atoms is used, for example, a mixture having from 26 to 28 carbon atoms.

[0100] The present invention relates to copolymers containing maleic anhydride derived units and α-olefin derived units.

[0101] The copolymers obtained directly from the reaction of α-olefins with maleic anhydride contain alkyl chains and anhydride functional groups.

[0102] In some embodiments, the anhydride group can be further reacted, for example, in some embodiments, the anhydride group can be hydrolyzed to provide a carboxylic acid functional group.

[0103] In some embodiments, the anhydride and / or hydrolysis acid product can be further functionalized, partially or fully, for example by reaction with an amine and / or alcohol to incorporate ester and / or amide and / or imide functional groups into the copolymer.

[0104] In a preferred embodiment, the copolymer is not further functionalized in this manner and the maleic anhydride derived units are present as underived anhydride moieties and / or as carboxylic acid moieties.

[0105] Most preferably, the maleic anhydride derived units of the copolymer contain an anhydride group.Suitably, the additive comprises a copolymer obtained directly from the reaction of an alpha-olefin with maleic anhydride.

[0106] Preferred copolymers for use in the present invention have a number average molecular weight of from 1000 Da to 50000 Da, preferably from 2000 Da to 40000 Da, suitably from 2500 Da to 30000 Da, for example from 3000 Da to 25000 Da.

[0107] Preferably, the copolymer has a number average molecular weight of from 5,000 Da to 20,000 Da, and in one embodiment, the copolymer has a number average molecular weight of from 5,000 Da to 10,000 Da. In one embodiment, the copolymer has a number average molecular weight of from 8,000 Da to 17,000 Da.

[0108] In some embodiments, the composition of the first aspect may further comprise (c) a reaction product of a carboxylic acid and a polyamine.

[0109] Preferably, the carboxylic acid and the polyamine react to form a heterocyclic moiety, such as an imidazoline or tetrahydropyrimidine moiety. Preferably, the polyamine comprises an optionally substituted ethylenediamine moiety, and the reaction product with the carboxylic acid leads to an imidazoline.

[0110] Preferably, the reaction product of component (c) is a substituted imidazoline compound. Such compounds are known in the fuel and lubricant additive art.

[0111] Preferred compounds are formed by the reaction of fatty acids with polyamines, suitable compounds of this type are described, for example, in USRE23227, US Pat. No. 3,193,454 and US Pat. No. 7,857,871.

[0112] Suitable polyamines include hydroxy-substituted polyamines, for example, as described in U.S. Patent Application Publication No. 2007193110.

[0113] Suitable acids that can be used to prepare the additive of component (c) include ether carboxylic acids (e.g., as described in U.S. Pat. No. 6,372,918) and terpine-derived carboxylic acids (e.g., as described in U.S. Pat. No. 4,994,575).

[0114] In some embodiments, component (c) may comprise a further reacted imidazoline, which may be further reacted with an alkylene oxide (see, e.g., U.S. Pat. No. 2,713,582), an arylsulfonic acid (see, e.g., U.S. Pat. No. 4,247,300A), or a sulfonating agent such as SO 3 (See, for example, U.S. Pat. No. 2,917,376).

[0115] Preferably, component (c) comprises the reaction product of one or more fatty acids having from 10 to 36 carbon atoms and a polyethylene polyamine having from 2 to 8 nitrogen atoms.

[0116] Preferred fatty acids are compounds of formula RCOOH, where R is an alkyl or alkenyl group having from 10 to 36 carbon atoms, preferably from 12 to 30 carbon atoms, more preferably from 12 to 24 carbon atoms, suitably from 14 to 22 carbon atoms, more preferably from 16 to 20 carbon atoms.

[0117] The fatty acid may be a naturally occurring fatty acid comprising a mixture of compounds. Preferably, the fatty acid comprises a C18 component.

[0118] A preferred fatty acid is tall oil fatty acid.

[0119] Suitable polyethylene polyamines for reacting with fatty acids include ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, hexaethylene heptamine and mixtures and isomers thereof.

[0120] Most preferably, component (c) comprises an imidazoline containing the reaction product of tall oil fatty acid and diethylenetriamine.

[0121] In some embodiments, the composition of the first aspect comprises (d) a metal deactivator compound.

[0122] In some embodiments, the diesel fuel composition used in the present invention further comprises a metal deactivating compound. Any metal deactivating compound known to one of ordinary skill in the art may be used, and may include, for example, the substituted triazole compounds of Figure (A), where R and R' are independently selected from an optionally substituted alkyl group or hydrogen. [ka] (A)

[0123] Preferred metal deactivating compounds have the formula (B): [ka] (B) (In the formula, R 1 , R 2 and R 3 R is independently selected from an optionally substituted alkyl group or hydrogen, preferably an alkyl group having 1 to 4 carbon atoms or hydrogen. 1 is preferably hydrogen, R 2 is preferably hydrogen, R 3 is preferably methyl. n is an integer of 0 to 5, most preferably 1.

[0124] A particularly preferred metal deactivator is N,N'-disallicyclidene-1,2-diaminopropane, shown in Figure (C); [ka] (C) It has the formula shown in:

[0125] Another preferred metal deactivating compound is shown in Figure (D): [ka] (D) As shown in.

[0126] Components (a), (b) and (c) suitably comprise the composition of the first aspect in amounts based on the proportion of pyrolysis oil present in the composition. By this we mean that for blended fuels, the treat rate of the additive is adjusted to take into account the amount of pyrolysis oil present in the blend. Thus, if the components are added in an amount of 500 ppm to neat pyrolysis oil, a treat rate of 250 ppm is used for a blended fuel containing 50% pyrolysis oil.

[0127] The nitrogen-containing antioxidant component (a) is preferably contained in the composition of the first aspect in an amount of at least 10 ppm, preferably at least 20 ppm, more preferably at least 50 ppm, for example at least 70 ppm, in each case based on the proportion of pyrolysis oil present in the composition.

[0128] The nitrogen-containing antioxidant component (a) may be included in the composition of the first aspect in an amount of up to 10000 ppm, preferably up to 5000 ppm, more preferably up to 2000 ppm, for example up to 1000 ppm, in each case based on the proportion of pyrolysis oil present in the composition.

[0129] Preferably, the nitrogen-containing antioxidant component (a) is present in the composition of the first aspect in an amount of 1 to 10 000 ppm, preferably 10 to 1000 ppm, preferably 50 to 750 ppm, more preferably 100 to 500 ppm, for example 150 to 400 ppm or 200 to 350 ppm, in each case based on the proportion of pyrolysis oil present in the composition.

[0130] In some embodiments, the nitrogen-containing antioxidant component (a) is present in the composition of the first aspect in an amount of from 10 to 500 ppm, preferably from 20 to 300 ppm, 50 to 200 ppm, or 50 to 175 ppm, in each case based on the proportion of pyrolysis oil present in the composition.

[0131] In a preferred embodiment, component (a) comprises a mixture of (i) an acylated nitrogen compound, (ii) a phenylenediamine, and (iii) a substituted hydroxylamine, suitably present in the ratio of 1-4 parts by weight (i):1-4 parts by weight (ii):2-6 parts by weight (iii).

[0132] In a preferred embodiment, the composition of the first aspect comprises, in each case based on the proportion of pyrolysis oil present in the composition, from 1 to 250 ppm, preferably from 10 to 150 ppm, for example from 50 to 100 ppm of (i) an acylated nitrogen compound; from 1 to 250 ppm, preferably from 10 to 150 ppm, for example from 50 to 100 ppm of (ii) a phenylenediamine; and optionally from 1 to 500 ppm, preferably from 50 to 250 ppm, for example from 100 to 150 ppm of (iii) a substituted hydroxylamine.

[0133] The copolymer component (b), if present, is preferably contained in the composition of the first aspect in an amount of at least 10 ppm, preferably at least 20 ppm, more preferably at least 40 ppm, for example at least 50 ppm, in each case based on the proportion of pyrolysis oil present in the composition.

[0134] The copolymer component (b), if present, may be contained in the composition of the first aspect in an amount of up to 10000 ppm, preferably up to 5000 ppm, more preferably up to 1000 ppm, for example up to 500 ppm, in each case based on the proportion of pyrolysis oil present in the composition.

[0135] Preferably, the copolymer component (b), if present, is contained in the composition of the first aspect in an amount of 1 to 5000 ppm, preferably 5 to 1000 ppm, preferably 10 to 500 ppm, more preferably 20 to 300 ppm, for example 30 to 200 ppm or 50 to 150 ppm, in each case based on the proportion of pyrolysis oil present in the composition.

[0136] Component (c), if present, is preferably included in the composition of the first aspect in an amount of at least 10 ppm, preferably at least 20 ppm, more preferably at least 40 ppm, for example at least 50 ppm, in each case based on the proportion of pyrolysis oil present in the composition.

[0137] Component (c), if present, may be included in the composition of the first aspect in an amount of up to 10000 ppm, preferably up to 5000 ppm, more preferably up to 1000 ppm, for example up to 500 ppm, in each case based on the proportion of pyrolysis oil present in the composition.

[0138] Preferably, component (c), if present, is contained in the composition of the first aspect in an amount of 1 to 5000 ppm, preferably 5 to 1000 ppm, preferably 10 to 500 ppm, more preferably 20 to 300 ppm, for example 30 to 200 ppm or 50 to 150 ppm, in each case based on the proportion of pyrolysis oil present in the composition.

[0139] The metal deactivator (d) may optionally be included in the composition in an amount of from 1 to 1000 ppm, preferably from 5 to 500 ppm, for example from 10 to 100 ppm.

[0140] In this specification, all references to ppm are to parts per million by weight.

[0141] In a preferred embodiment, a first aspect of the present invention provides a composition comprising: a pyrolysis oil; 100-500 ppm, preferably 200-400 ppm of (a) one or more nitrogen-containing antioxidants; and optionally 10-400 ppm, preferably 50-200 ppm of (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin, and / or (c) a reaction product of a carboxylic acid and a polyamine.

[0142] In some embodiments, the composition of the first aspect can be used as a middle distillate fuel oil. Thus, the composition may contain one or more additional additives, such as those commonly found in diesel fuel. These include, for example, antioxidants, dispersants, detergents, metal deactivating compounds, wax anti-settling agents, cold flow improvers, cetane improvers, anti-clouding agents, stabilizers, demulsifiers, anti-foaming agents, corrosion inhibitors, lubrication performance improvers, dyes, markers, combustion improvers, metal deactivators, odor masks, drag reducers, and conductivity improvers. Examples of suitable amounts of each of these types of additives are known to those skilled in the art.

[0143] According to a second aspect of the present invention, there is provided an additive composition for pyrolysis oil comprising: (a) one or more nitrogen-containing antioxidants; and optionally: (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin; and / or (c) Reaction products of carboxylic acids and polyamines An additive composition is provided comprising:

[0144] Preferred features of the second aspect are as defined in relation to the first aspect.

[0145] Preferably, the additive composition includes a diluent or solvent. Suitable diluents and solvents are known to those skilled in the art.

[0146] Preferred solvents include mixtures of aromatic solvents such as xylene, aromatic 150 or aromatic 100.

[0147] In one particularly preferred embodiment, the additive composition of the second aspect comprises: (a) nitrogen-containing antioxidants, including (i) acylated nitrogen compounds, (ii) phenylenediamines, and (iii) substituted hydroxylanes; (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin; and / or (c) reaction products of carboxylic acids and polyamines; and Aromatic Solvents Includes.

[0148] The use of additive component (a), optionally in combination with additives (b) and / or (c), has been found to improve the oxidative stability of the pyrolysis oil.

[0149] There are several standard tests available for determining diesel fuel stability, including ASTM D4625, ASTM D6468, and ASTM D2274.

[0150] The inventors have measured the oxidative stability of the compositions of the present invention using the Rancimat test, a test commonly used to determine the oxidative stability of biodiesel compositions. Like pyrolysis oils, biodiesel contains high levels of components that can be easily oxidized by atmospheric oxidation.

[0151] The Rancimat test is an accelerated oxidation test in which a sample is heated while air is bubbled through it. The volatile decomposition products are passed through deionized water and the conductivity of the water is measured. The time it takes for the fuel to decompose is measured by recording the time at which an increase in conductivity is observed. This is known as the induction period.

[0152] To determine the oxidative stability of the pyrolysis oil compositions of the present invention, the inventors followed the Rancimat test method set out in the European standard EN 14112, the only difference being the nature of the fuel.

[0153] The use of additive component (a), optionally in combination with additives (b) and / or (c), has been found to improve the storage stability of pyrolysis oil. Storage stability of the oil can be determined using standard tests such as ASTM D4625.

[0154] According to a third aspect of the present invention, there is provided a method for improving the oxidative stability of a composition comprising a pyrolysis oil, the method comprising adding to the composition (a) one or more nitrogen-containing antioxidants.

[0155] The method optionally comprises adding to the composition: (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin; and / or (c) Reaction products of carboxylic acids and polyamines The method may further include adding

[0156] According to a fourth aspect of the present invention, there is provided the use of (a) one or more nitrogen-containing antioxidants to improve the oxidative stability of a composition containing pyrolysis oil.

[0157] A fourth aspect of the invention may involve the use of (a) in combination with one or more nitrogen-containing antioxidants; (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin; and / or (c) a reaction product of a carboxylic acid and a polyamine to improve the oxidative stability of compositions containing pyrolysis oil.

[0158] Preferred features of the third and fourth aspects include the nature of the composition and the nature of components (a), (b) and (c) and the appropriate treat rates thereof, as defined in relation to the first aspect.

[0159] The methods and uses of the present invention suitably increase the oxidative stability of compositions comprising pyrolysis oil, as measured by the Rancimat test.

[0160] Preferably, the use of (a) the nitrogen-containing dispersant increases the induction time of the composition containing the pyrolysis oil as measured by the Rancimat test by at least 50%, preferably at least 100%, more preferably at least 150%, such as at least 200% or at least 300%.

[0161] (a) The use of a nitrogen-containing dispersant may increase the induction time, as measured by the Rancimat test, of a composition containing pyrolysis oil by at least 2 hours, preferably at least 4 hours, suitably at least 6 hours.

[0162] In some embodiments, the use of (a) a nitrogen-containing dispersant can increase the induction time, as measured by the Rancimat test, of a composition containing pyrolysis oil by at least 8 hours, preferably at least 10 hours, and suitably at least 12 hours.

[0163] Suitably, the use of (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin, and / or (c) a reaction product of a carboxylic acid and a polyamine in combination with (a) one or more nitrogen-containing antioxidants increases the oxidation induction time of a composition comprising pyrolysis oil as measured by the Rancimat test by at least 50%, preferably at least 100%, more preferably at least 150%, such as at least 200% or at least 300%.

[0164] Suitably, the use of (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units and / or (c) a reaction product of a carboxylic acid and a polyamine in combination with (a) one or more nitrogen-containing antioxidants increases the oxidation induction time of a composition comprising pyrolysis oil by at least 2 hours, preferably at least 4 hours, suitably at least 6 hours, as measured by the Rancimat test.

[0165] In some embodiments, the use of (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units and / or (c) a reaction product of a carboxylic acid and a polyamine in combination with (a) one or more nitrogen-containing antioxidants increases the oxidation induction time of a composition comprising pyrolysis oil, as measured by the Rancimat test, by more than 8 hours, e.g., more than 10 hours or more than 12 hours.

[0166] In a fifth aspect, the present invention provides a method for improving the oxidative stability of a composition comprising pyrolysis oil and one or more nitrogen-containing antioxidants, the method comprising: (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin; and / or (c) Reaction products of carboxylic acids and polyamines The method includes adding

[0167] In a sixth aspect, the present invention provides the use of (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin and / or (c) a reaction product of a carboxylic acid and a polyamine for improving the oxidative stability of a composition comprising a pyrolysis oil and one or more nitrogen-containing antioxidants.

[0168] Preferred features of the fifth and sixth aspects include the nature of the composition, and the nature of components (a), (b) and (c) and suitable treat rates thereof, as defined in relation to the first aspect.

[0169] According to a seventh aspect of the present invention, there is provided a method for improving the storage stability of a composition comprising pyrolysis oil, the method comprising adding to the composition (a) one or more nitrogen-containing antioxidants.

[0170] The method optionally comprises adding to the composition: (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin; and / or (c) Reaction products of carboxylic acids and polyamines The method may further include adding

[0171] According to an eighth aspect of the present invention, there is provided the use of (a) one or more nitrogen-containing antioxidants to improve the storage stability of a composition containing pyrolysis oil.

[0172] This eighth aspect of the invention may involve the use of (a) in combination with one or more nitrogen-containing antioxidants; (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin; and / or (c) a reaction product of a carboxylic acid and a polyamine to improve the storage stability of compositions containing pyrolysis oil.

[0173] In a ninth aspect, the present invention provides a method for improving the storage stability of a composition comprising pyrolysis oil and one or more nitrogen-containing antioxidants, comprising: (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin; and / or (c) Reaction products of carboxylic acids and polyamines The method includes adding

[0174] In a tenth aspect, the present invention provides the use of (b) a copolymer comprising units derived from maleic anhydride and units derived from an α-olefin and / or (c) a reaction product of a carboxylic acid and a polyamine to improve the storage stability of a composition comprising a pyrolysis oil and one or more nitrogen-containing antioxidants.

[0175] The methods and uses of the seventh, eighth, ninth and tenth aspects of the invention preferably improve the storage stability of compositions comprising pyrolysis oil, as measured by the standard method of ASTM D4625 and / or by said standard method as modified to be carried out at ambient temperature using a 200 ml sample of pyrolysis oil. Said improvement in storage stability preferably results / is provided by a reduction in the amount of adherent insoluble material produced by the pyrolysis oil on storage and / or a reduction in the total amount of insoluble material produced by the pyrolysis oil on storage, as measured by the suitable methods mentioned above, compared to a comparable unadditized pyrolysis oil.

[0176] In some embodiments, the methods and uses of the seventh, eighth, ninth and tenth aspects provide at least a 30% reduction in the amount of adherent insoluble material produced by the pyrolysis oil upon storage, preferably at least a 70% reduction, at least an 80% reduction or at least a 90% reduction in the amount of adherent insoluble material, as measured suitably by ASTM D4625 and / or said standard method modified as described herein, compared to a comparable unadditized pyrolysis oil.

[0177] In some embodiments, the methods and uses of the seventh, eighth, ninth and tenth aspects provide at least a 30% reduction in the amount of total insoluble material produced by the pyrolysis oil upon storage, preferably at least a 40% reduction, at least a 50% reduction or at least a 60% reduction in the amount of total insoluble material, as measured suitably by ASTM D4625 and / or said standard method modified as described herein, compared to a comparable unadditized pyrolysis oil.

[0178] Preferred features of the seventh, eighth, ninth and tenth aspects include the nature of the composition and the nature of components (a), (b) and (c) and the appropriate treat rates thereof, as defined in relation to the first aspect.

[0179] Any feature of any aspect of the invention may be combined with any other aspect where appropriate.

[0180] The invention will now be further described by way of the following non-limiting examples.

[0181] Example 1 An additive composition was prepared containing the following components: [Table 1] JPEG2025510115000007.jpg117170

[0182] PIBSI A is a polyisobutenyl succinimide obtained from the condensation reaction of polyisobutenyl succinic anhydride derived from polyisobutene of approximately 750 Mn with a mixture of polyethylene polyamines of average composition approximating that of tetraethylenepentamine.

[0183] Metal deactivator B is N,N'-disalicyclidene-1,2-diaminopropane.

[0184] Copolymer C is an alternating copolymer of maleic anhydride and a mixture of α-olefins having 20 to 24 carbon atoms. The number average molecular weight is 15000 Da.

[0185] Imidazoline D is the reaction product of diethylenetriamine and tall oil fatty acid.

[0186] Example 2 Compositions 1, 2 and 3 from Example 1 were dosed into waste rubber (waste tire) pyrolysis oil having the following specifications: [Table 2]

[0187] The induction period of the base waste rubber pyrolysis oil was measured using the method set out in EN 14112. 500 ppm of compositions 1, 2 and 3 were separately dosed into three further samples of waste rubber pyrolysis oil and the Rancimat test was repeated.

[0188] The results are shown in Table 3: [Table 3] JPEG2025510115000010.jpg35170

[0189] Example 2 Additive compositions 1, 2 and 3 from Example 1 were dosed at 500 mg / l into waste tire pyrolysis oil with the specifications listed above to provide pyrolysis oil compositions 1, 2 and 3, respectively. Using a modification of the ASTM D4625 standard method, these samples were tested for storage stability against an unadditized sample of waste rubber pyrolysis oil. The standard method was modified by running the test at ambient temperature instead of 43°C and by using a 200 ml sample of pyrolysis oil instead of a 400 ml sample. The method provides the amount of filterable insoluble material, adherent insoluble material and total insoluble material in each sample.

[0190] The amount of insoluble material (filterable and adherent) recovered for each composition, including the total amount, is shown in Table 4: [Table 4] JPEG2025510115000012.jpg42170

[0191] These results show a significant reduction in the amount of adhesive insoluble material produced by plastic pyrolysis oils upon storage when the additives of the present invention are used. The results for samples 1, 2 and 3 (500 mg / l treatment rate) also show a significant reduction in the total amount of insoluble material produced upon storage. These additives may therefore be effective in improving the storage stability of pyrolysis oils.

Claims

1. As a pyrolysis oil and additive: (a) One or more nitrogen-containing antioxidants A composition containing the following:

2. The composition according to claim 1, wherein the pyrolysis oil is obtained from the pyrolysis of one or more polymers selected from polyethylene, polypropylene, PET, rubber and mixtures thereof.

3. The composition according to claim 1, comprising a blend of fuel oil containing pyrolysis oil (preferably waste plastic pyrolysis oil or waste rubber pyrolysis oil) and middle distillate fuel oil.

4. The composition according to claim 1, wherein component (a) comprises (i) an acylated nitrogen compound.

5. The composition according to claim 4, wherein component (i) comprises a reaction product of polyisobutene-substituted succinic acid or succinic anhydride and polyethylene polyamine.

6. The composition according to claim 1, wherein component (a) comprises (ii) phenylenediamine.

7. The composition according to claim 1, wherein component (a) comprises a (iii)-substituted hydroxylamine.

8. (b) The composition according to claim 1, further comprising a copolymer containing units derived from maleic anhydride and units derived from α-olefins.

9. The composition according to claim 8, comprising a copolymer of maleic anhydride and a mixture of α-olefins having 20 to 24 carbon atoms.

10. (c) The composition according to claim 1, further comprising a reaction product of a carboxylic acid and a polyamine.

11. The composition according to claim 10, comprising a reaction product of one or more fatty acids having 10 to 36 carbon atoms and polyethylene polyamine having 2 to 8 nitrogen atoms.

12. Additive composition for pyrolysis oil: (a) One or more nitrogen-containing antioxidants; and optionally: (b) Copolymers comprising units derived from maleic anhydride and units derived from α-olefins; and / or (c) Reaction product of carboxylic acid and polyamine The additive composition comprising the above.

13. A method for improving the oxidative stability of a composition containing pyrolysis oil, comprising the step of adding (a) one or more nitrogen-containing antioxidants to the composition.

14. In the composition: (b) Copolymers comprising units derived from maleic anhydride and units derived from α-olefins; and / or (c) The method according to claim 13, further comprising the step of adding a reaction product of a carboxylic acid and a polyamine.

15. (a) Use of one or more nitrogen-containing antioxidants to improve the oxidative stability of a composition containing pyrolysis oil.

16. To improve the oxidative stability of a composition containing pyrolysis oil, (a) use of one or more nitrogen-containing antioxidants and (b) use of a copolymer containing maleic anhydride-derived units and α-olefin-derived units.

17. To improve the oxidative stability of a composition containing pyrolysis oil, (a) use of one or more nitrogen-containing antioxidants and (c) use of a reaction product of a carboxylic acid and a polyamine.

18. A method for improving the oxidative stability of a composition comprising a pyrolysis oil and one or more nitrogen-containing antioxidants, wherein the composition comprises: (b) Copolymers comprising units derived from maleic anhydride and units derived from α-olefins; and / or (c) Reaction product of carboxylic acid and polyamine The method comprising the step of adding.

19. (b) Use of copolymers comprising maleic anhydride-derived units and α-olefin-derived units and / or (c) reaction products of carboxylic acids and polyamines to improve the oxidative stability of compositions comprising pyrolysis oil and one or more nitrogen-containing antioxidants.

20. A method for improving the storage stability of a composition containing pyrolysis oil, comprising the step of adding (a) one or more nitrogen-containing antioxidants to the composition.

21. (a) Use of one or more nitrogen-containing antioxidants to improve the storage stability of compositions containing pyrolysis oil.

22. A method for improving the storage stability of a composition comprising a pyrolysis oil and, optionally, one or more nitrogen-containing antioxidants, wherein the composition comprises: (b) Copolymers comprising units derived from maleic anhydride and units derived from α-olefins; and / or (c) Reaction product of carboxylic acid and polyamine The method comprising the step of adding.

23. (b) Use of copolymers containing maleic anhydride-derived units and α-olefin-derived units and / or (c) reaction products of carboxylic acids and polyamines to improve the storage stability of a composition comprising a pyrolysis oil and optionally one or more nitrogen-containing antioxidants.