Compositions, methods and uses

Abstract

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

Description

[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 comprising waste rubber pyrolysis oil or waste plastic pyrolysis oil.

[0002] Pyrolysis oil is the liquid produced by the pyrolysis of waste, waste such as plastic waste, waste tire, waste rubber, biomass (such as agricultural waste, forestry waste, waste cooking oil and algae waste). The example of the waste plastics that can produce plastic pyrolysis oil through pyrolysis includes polyethylene, polypropylene, polystyrene, polyethylene terephthalate (PET) and its mixture. The oil obtained from the pyrolysis of plastics is commonly referred to as waste plastic pyrolysis oil (WPPO). The oil obtained from the pyrolysis of rubber (such as from tire) is commonly referred to as waste rubber pyrolysis oil (WRPO). The organic liquid produced by the pyrolysis of rubber, plastics and other waste materials has very dark color, unpleasant smell, and is unstable. However, there is a strong hope to find the purposes of these oils to avoid these wastes from being sent to landfills or polluting the ocean.

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

[0004] The application of pyrolysis oils is limited due to their poor oxidation stability. This is believed to be due to oxidation of oxygen- or nitrogen-containing species present in the oil. The nature of these oils and their production methods mean that they generally contain a greater proportion of components that are susceptible to oxidation than mineral-derived middle distillate fuels.

[0005] Pyrolysis oils may optionally be hydrotreated or cracked before subsequent use. These processes may increase their oxidative stability. Alternatively, they may be treated with chemical additives to improve their stability.

[0006] The inventors have found that certain compounds are effective in improving the oxidative stability of compositions comprising pyrolysis oil. In addition, the inventors have found that such compounds are effective in improving the storage stability of compositions comprising pyrolysis oil.

[0007] According to a first aspect of the present invention, there is provided a composition comprising pyrolysis oil and the following substances as additives:

[0008] (a) One or more nitrogen-containing antioxidants.

[0009] A first aspect of the present invention relates to a composition comprising pyrolysis oil. Pyrolysis oil can be obtained by pyrolysis of any type of waste. The components of the oil and its characteristics will depend on the type of pyrolysis waste and the pyrolysis conditions. For example, pyrolysis oil can be obtained by pyrolysis of plastic waste, rubber waste, agricultural waste, forestry waste, waste cooking oil and algae waste.

[0010] Preferably, the pyrolysis oil comprises plastic pyrolysis oil.Plastic pyrolysis oil can be obtained by pyrolysis of any type of plastic.

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

[0012] Preferred plastic pyrolysis oils are obtained by further pyrolysis of one or more polymers selected from polyethylene, polypropylene, PET, rubber, waste tires and mixtures thereof.

[0013] In a particularly preferred embodiment, the pyrolysis oil is obtained by pyrolysis of rubber. For example, the pyrolysis oil can be obtained by pyrolysis of waste tires.

[0014] In some embodiments, the pyrolysis oil in the composition of the first aspect may be a hydrotreated pyrolysis oil.

[0015] In some embodiments, the pyrolysis oil in the composition of the first aspect has been treated using a cracking process.

[0016] In a preferred embodiment, the composition of the first aspect comprises pyrolysis oil obtained directly from a pyrolysis plant without purification or further treatment.

[0017] In some embodiments, the pyrolysis oil has a normal paraffin content of less than 15 wt%, preferably less than 10 wt%, such as less than 6 wt%.

[0018] In some embodiments, the pyrolysis oil has an asphaltene content of less than 5 wt%, preferably less than 2 wt%, such as less than 1 wt%.

[0019] In some embodiments, the composition of the first aspect may include a mixed 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).

[0020] Throughout this specification, the term "comprising" or "including" means including the specified (one or more) components, but does not exclude the presence of other components. The term "essentially consisting of" or "essentially composed of" means including the specified components, but excluding other components except for the components added for purposes other than achieving the technical effects of the present invention. The term "consisting of" or "consisting of" means including the specified components, but excluding other components.

[0021] Where appropriate, depending on the context, the use of the terms "comprising" or "including" may also be understood to include the meaning of "consisting essentially of" or "consisting essentially of," and may also be understood to include the meaning of "consisting of" or "consisting of."

[0022] 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.

[0023] Middle distillate fuel oils may include petroleum-based fuel oils, especially middle distillate fuel oils. Such distillate fuel oils typically boil in the range of 110° C. to 500° C., such as 150° C. to 400° C. Middle distillate fuel oils may include atmospheric or vacuum distillates, cracked gas oils, or a mixture of any proportion of straight run and refinery streams (e.g., thermal and / or catalytic cracking and hydrocracking fractions).

[0024] Middle distillate fuel oils may include non-renewable Fischer-Tropsch fuels such as those described as GTL (gas-to-liquids) fuels, CTL (coal-to-liquids) fuels and OTL (oil sands-to-liquids) fuels.

[0025] The middle distillate fuel oil may comprise a renewable fuel, such as a biofuel composition or a biodiesel composition.

[0026] Middle distillate fuel oil can comprise first generation biodiesel.First generation biodiesel contains esters of for example vegetable oil, animal fat and waste edible fat.This form of biodiesel can be obtained by transesterifying oil, for example rapeseed oil, soybean oil, safflower oil, palm oil, palm kernel oil, corn oil, peanut oil, cottonseed oil, tallow, coconut oil, medicinal nut oil (jatropha oil), sunflower oil, waste edible oil, hydrogenated vegetable oil or any mixture thereof with alcohol (normally monohydric alcohol) in the presence of a catalyst.

[0027] Middle distillate fuel oils may include second generation biodiesel. Second generation biodiesel is derived from renewable resources such as vegetable oils and animal fats, and is typically processed in refineries, typically using hydroprocessing (e.g., the H-Bio process developed by Petrobras). Second generation biodiesel may be similar in properties and quality to petroleum-based fuel oil streams, such as renewable diesel produced from vegetable oils, animal fats, etc., and is sold by ConocoPhillips as Renewable Diesel and by Neste as NExBTL.

[0028] The middle distillate fuel oil used in the present invention may include third generation biodiesel. Third generation biodiesel utilizes gasification and Fischer-Tropsch technology, including those described as BTL (biomass to liquid) fuels. Third generation biodiesel is not much different from some second generation biodiesel, but is intended to utilize whole plants (biomass), thereby expanding the feedstock base.

[0029] Middle distillate fuel oils may contain mixtures of any or all of the above diesel fuel oils.

[0030] In some embodiments, the middle distillate fuel oil can be a mixed diesel fuel comprising biodiesel. In such mixtures, biodiesel can exist 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%.

[0031] In some embodiments, the middle distillate fuel oil may contain a secondary fuel, such as ethanol. Preferably however the diesel fuel composition does not contain ethanol.

[0032] Middle distillate fuel oils may contain a relatively high sulphur content, for example greater than 0.05 wt%, such as 0.1 wt% or 0.2 wt%.

[0033] In a preferred embodiment, however, the middle distillate fuel oil has a sulfur 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 sulfur contents are also suitable, for example fuels containing less than 50 wt.-ppm, preferably less than 20 wt.-ppm, for example 10 wt.-ppm or less sulfur.

[0034] Various metal species may be present in middle distillate fuel oils. This may be due to contamination of the fuel during manufacture, storage, transport or use, or due to contamination of fuel additives. Metal species may also be added to the fuel intentionally. For example, transition metals are sometimes added as fuel-borne catalysts, for example to improve the performance of diesel particulate filters.

[0035] In a preferred embodiment, the middle distillate fuel oil used in the present invention contains sodium and / or calcium. Preferably, they contain sodium. Sodium and / or calcium are generally present in an amount totaling 0.01 to 50 ppm, preferably 0.05 to 5 ppm, preferably 0.1 to 2 ppm, for example 0.1 to 1 ppm.

[0036] Other metal-containing species may also be present as contaminants, for example, by corrosion of metal and metal oxide surfaces by acidic species present in the fuel or from lubricating oils. During use, fuels (e.g., diesel fuels) often come into contact with metal surfaces, for example, in vehicle refueling systems, fuel tanks, fuel transportation devices, 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, such as lead.

[0037] In addition to the metal-containing contaminants that may be present in middle distillate fuel oils, there are also situations where metal-containing materials may be intentionally added to the fuel. For example, as is known in the art, a metal-containing fuel-borne catalyst material may be added to aid in the regeneration of a particulate filter.

[0038] Metal-containing contaminants may be in the form of insoluble particulate matter or soluble compounds or complexes, depending on their source. Metal-containing fuel-borne catalysts are generally soluble compounds or complexes or colloidal substances.

[0039] In some embodiments, the middle distillate fuel oil may contain a metal-containing substance including a fuel-borne catalyst. Preferably, the fuel-borne catalyst comprises one or more metals selected from iron, cerium, platinum, manganese, Group I and Group II metals (e.g., calcium and strontium). Most preferably, the fuel-borne catalyst comprises a metal selected from iron and cerium.

[0040] In some embodiments, the middle distillate fuel oil may contain metal-containing species including zinc. Zinc may be present in an amount of 0.01 to 50 ppm, preferably 0.05 to 5 ppm, more preferably 0.1 to 1.5 ppm.

[0041] The composition of the first aspect comprises (a) one or more nitrogen-containing antioxidants.

[0042] Any suitable nitrogen-containing antioxidant may be used.

[0043] Suitable nitrogen-containing antioxidants will be known to those skilled in the art.

[0044] Suitable amino antioxidants include aromatic amines, hindered amines, N-oxides, substituted hydroxylamines and acylated nitrogen compounds.

[0045] Suitable aromatic amines include diaminobenzenes and alkylated diaminobenzenes, especially 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; diphenylamines and alkylated diphenylamines, such as N,N-diphenyl-1,4-phenylenediamine; and naphthylamines, such as N-phenyl-1-naphthylamine and N-phenyl-2-naphthylamine.

[0046] Suitable hindered amines include secondary and tertiary aliphatic amines, such as dimethylcyclohexylamine.

[0047] Suitable N-oxides include TEMPO and its derivatives.

[0048] Preferably, the one or more nitrogen-containing antioxidants (a) are selected from:

[0049] (i) acylated nitrogen compounds;

[0050] (ii) phenylenediamine;

[0051] (iii) substituted hydroxylamine;

[0052] (iv) and mixtures thereof.

[0053] Suitable acylated nitrogen compounds (i) can be prepared by reacting carboxylic acid acylating agents with amines and are known to those skilled in the art. In such compounds, the acylating agent is linked to the amino compound via an imide, amide, amidine or acyloxyammonium bond.

[0054] Preferred acylated nitrogen compounds are hydrocarbyl substituted. The hydrocarbyl substituent may be located in the carboxylic acid acylating agent derived portion of the molecule, or in the amine derived portion of the molecule, or both. However, it is preferably located in the acylating agent portion. One class of preferred acylated nitrogen 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.

[0055] The acylating agent may be a mono- or polycarboxylic acid (or a reactive equivalent thereof), such as a substituted succinic, phthalic or propionic acid or anhydride.

[0056] Suitable hydrocarbyl-substituted acylating agents and methods for their preparation are well known in the art.

[0057] Examples of hydrocarbyl substituents containing at least eight carbon atoms are n-octyl, n-decyl, n-dodecyl, tetrapropenyl, n-octadecyl, oleyl, chlorooctadecyl, triacontyl, etc. The hydrocarbyl substituents may be made from homopolymers or interpolymers (e.g., copolymers, terpolymers) of monoolefins and diolefins having 2 to 10 carbon atoms (e.g., ethylene, propylene, butane-1, isobutylene, butadiene, isoprene, 1-hexene, 1-octene, etc.). Preferably, these olefins are 1-monoolefins.

[0058] As used herein, the term "hydrocarbyl" refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly aliphatic hydrocarbon character.

[0059] The hydrocarbyl substituents are preferably predominantly saturated, that is, they contain no more than one carbon-carbon unsaturated bond for every ten 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.

[0060] The hydrocarbyl substituent in such acylating agents preferably contains at least 10 carbon atoms, more preferably at least 12 carbon atoms, 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. Mn of 700 to 1300 is particularly preferred. In a particularly preferred embodiment, the hydrocarbyl substituent has a number average molecular weight of 700-1000, preferably 700-850, for example 750.

[0061] The acylating agent derived from a carboxylic acid may include a mixture of compounds. For example, a mixture of compounds having different hydrocarbyl substituents may be used. In some embodiments, the acylating agent may have more than one hydrocarbyl substituent. In such embodiments, each hydrocarbyl substituent may be the same or different.

[0062] A preferred hydrocarbyl substituent is polyisobutylene. Such compounds are known to those skilled in the art.

[0063] The preferred hydrocarbyl substituted acylating agent is polyisobutenyl succinic anhydride.These compounds are commonly referred to as "PIBSA" and are well known to those skilled in the art.

[0064] Conventional polyisobutylenes and so-called "highly reactive" polyisobutylenes are suitable for use in the present invention. Highly reactive polyisobutylenes are defined herein as polyisobutylenes 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 polyisobutylenes are those having greater than 80 mol % and up to 100 mol % of terminal vinylidene groups, such as those described in US Pat. No. 7291758. Preferred polyisobutylenes have the preferred molecular weight ranges as generally described above for the hydrocarbyl substituents.

[0065] Other preferred hydrocarbyl groups include hydrocarbyl groups having internal olefins, for example as described in applicant's published application WO2007 / 015080.

[0066] As used herein, internal olefins refer to any olefins containing primarily non-alpha double bonds, i.e., beta or higher olefins. Preferably, such materials are substantially entirely beta olefins or higher olefins, e.g., containing less than 10% by weight of alpha olefins, more preferably less than 5% by weight or less than 2% by weight. Typical internal olefins include Neodene 1518IO available from Shell.

[0067] Internal olefins are sometimes referred to as isomerized olefins and can be prepared from alpha olefins by isomerization processes known in the art, or can be obtained from other sources. The fact that they are also referred to as internal olefins reflects that they do not necessarily have to be prepared by isomerization.

[0068] The preferred carboxylic acid derived acylating agent is a polyisobutenyl substituted succinic anhydride or PIBSA. Particularly preferred PIBSAs are those having a PIB molecular weight (Mn) of 300 to 2800, preferably 450 to 2300, more preferably 500 to 1300.

[0069] The carboxylic acid derived acylating agent reacts with an amine. Suitably, it reacts with a primary or secondary amine. Some examples of suitable amines will now be described.

[0070] Amine compounds useful for reaction with the acylating agent include polyalkylene polyamines having the following general formula:

[0071] (R 3 )2N[UN(R 3 )] n R 3

[0072] Each R 3 independently selected from hydrogen atoms, hydrocarbon groups, or hydroxy-substituted hydrocarbon groups containing up to about 30 carbon atoms, provided that at least one R 3 is a hydrogen atom, n is an integer from 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 U is preferably C1-4 alkylene, and most preferably ethylene.

[0073] Other useful amines include heterocyclic substituted polyamines, including hydroxyalkyl substituted polyamines, wherein the polyamine is as described above and the heterocyclic substituent is selected from nitrogen-containing aliphatic and aromatic heterocycles such as piperazine, imidazoline, pyrimidine, morpholine and derivatives thereof.

[0074] Other useful amines that can be reacted with the acylating agent include aromatic polyamines having the general formula:

[0075] Ar(NR 3 2) y

[0076] wherein Ar is an aromatic nucleus having 6 to 20 carbon atoms, each R 3 As defined above and y is 2 to 8.

[0077] Specific examples of polyalkylene polyamines include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, tris(trimethylene)tetramine, pentaethylenehexamine, hexaethyleneheptamine, 1,2-propylenediamine, and mixtures thereof. Other commercially available materials containing composite mixtures of polyamines may also be used. For example, in addition to the higher boiling fractions containing 8 or more nitrogen atoms, higher ethylene polyamines may optionally contain all or some of the above. Specific examples of hydroxyalkyl substituted polyamines include N-(2-hydroxyethyl)ethylenediamine, N,N'-bis(2-hydroxyethyl)ethylenediamine, N-(3-hydroxybutyl)tetramethylenediamine, etc. 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-heptadecanyl-1-(2-hydroxyethyl)-imidazoline, etc. Specific examples of aromatic polyamines (3) are various isomeric phenylenediamines, various isomeric naphthalenediamines, etc.

[0078] Preferred amines are polyethylene polyamines including ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, and mixtures and isomers thereof.

[0079] In a preferred embodiment, the reaction product of a carboxylic acid derived acylating agent and an amine includes at least one primary or secondary amine group.

[0080] Preferred acylated nitrogen compounds for use in the present invention are prepared by reacting a polyisobutylene-substituted succinic acid derived acylating agent (e.g., anhydrides, acids, esters, etc.) 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, wherein the polyisobutylene substituent has a number average molecular weight (Mn) of from 170 to 2800. These acylated nitrogen compounds are suitably formed by reacting an acylating agent:amino compound molar ratio 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 reacting an acylating agent to an amino compound in a molar ratio of from 1.8:1 to 1:1.2, preferably from 1.6:1 to 1:1.2, more preferably from 1.4:1 to 1:1.1, and most preferably from 1.2:1 to 1:1. Acylated amino compounds of this type and their preparation are well known to the person skilled in the art and are described, for example, in EP 0 565 285 and US Pat. No. 5,925,151.

[0081] In a particularly preferred embodiment the acylated nitrogen-containing additive (i) comprises the reaction product of a polyisobutylene-substituted succinic acid or succinic anhydride and a polyethylene polyamine to form a succinimide detergent. Preferred polyethylene polyamines include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine and mixtures and isomers thereof. Suitable polyisobutylene substituents of the polyisobutylene-substituted succinic acid or succinic anhydride have a number average molecular weight of 500 to 2000, preferably 500 to 1500, more preferably 500 to 1100, suitably 600 to 1000, preferably 700 to 800, for example about 750.

[0082] Component (i) may comprise a mixture of two or more acylated nitrogen compounds.

[0083] Of the additives used in the present invention, preferably at least 50% by weight of the additives have a number average molecular weight greater than 400, preferably at least 70% of the molecules, more preferably at least 90%, preferably at least 95%, suitably at least 97% have a number average molecular weight greater than 400.

[0084] A suitable method for measuring the molecular weight distribution of an additive is GPC using polystyrene standards.

[0085] Those skilled in the art will appreciate that polyisobutylene-substituted succinimide detergent additives typically contain a complex mixture of compounds. Such compounds are typically prepared by reacting polyisobutylene (PIB) with maleic anhydride (MA) to form polyisobutylene-substituted succinic anhydride (PIBSA), which is then reacted with a polyamine (PAM) to form polyisobutylene-substituted succinimide (PIBSI). In the reaction of PIB and MA, more than one MA can react with each PIB, and some unreacted PIB may remain. Each PIBSA molecule can react with one or more PAM molecules, as described above. Changing the ratios of the different starting materials and including intermediate purification steps can affect the ratios of the various components in the final additive material.

[0086] Some preferred phenylenediamine antioxidants (ii) suitable for use in the present invention include those of the formula:

[0087]

[0088] Where R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 R is independently selected from hydrogen, optionally substituted alkyl, alkenyl, aryl, alkaryl or aralkyl, ester, carboxylic acid, aldehyde, ketone, ether, alcohol, amine or amide. 1 Preferably, R 3 Preferably, R 2 is an alkyl group, preferably having 1 to 10 carbon atoms. More preferably, R 2 is an alkyl group having 1 to 5 carbon atoms. 2 is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl. 2 is isopropyl or sec-butyl. 4 is an alkyl group, preferably having 1 to 10 carbon atoms. More preferably, R 4 is an alkyl group having 1 to 5 carbon atoms. 4 Preferably, R is selected from methyl, ethyl, propyl, isopropyl, sec-butyl, butyl, tert-butyl and isobutyl. Most preferably, R 4 is isopropyl or sec-butyl.

[0089] R 5 , R 6 and R 7 Preferably, R is selected from hydrogen or an alkyl group, more preferably selected from hydrogen and an alkyl group having 1 to 10 carbon atoms, more preferably selected from hydrogen and an alkyl group having 1 to 5 carbon atoms. 5 , R6 and R 7 is independently selected from hydrogen, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl and isobutyl. 5 is hydrogen. Most preferably, R 6 is hydrogen. Most preferably, R 7 For hydrogen.

[0090] In a particularly preferred embodiment, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 Each is hydrogen, and component (ii) comprises p-phenylenediamine.

[0091] Component (ii) may comprise a mixture of compounds and / or a mixture of isomers.

[0092] The preferred substituted hydroxylamine compound (iii) used herein is a compound of formula R2NOH, wherein each R is independently hydrogen or an optionally substituted hydrocarbon group. Preferably, each R is an optionally substituted hydrocarbon group. Each R may be the same or different. Preferably, each R is the same.

[0093] 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 carbon atoms, 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 an ethyl group.

[0094] Preferably, component (iii) comprises diethylhydroxylamine.

[0095] Component (iii) may comprise a mixture of compounds and / or a mixture of isomers.

[0096] The composition of the first aspect of the present invention comprises 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.

[0097] In some embodiments, component (a) of the composition of the first aspect includes (i) an acylated nitrogen compound.

[0098] In some embodiments, component (a) of the composition of the first aspect includes (ii) phenylenediamine.

[0099] In some embodiments, component (a) of the composition of the first aspect comprises (iii) a substituted hydroxylamine.

[0100] In some embodiments, component (a) of the composition of the first aspect comprises (i) an acylated nitrogen compound and (ii) a phenylenediamine.

[0101] In some embodiments, component (a) of the composition of the first aspect comprises (i) an acylated nitrogen compound and (iii) a substituted hydroxylamine.

[0102] In some embodiments, component (a) of the composition of the first aspect comprises (ii) a phenylenediamine and (iii) a substituted hydroxylamine.

[0103] 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.

[0104] 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.

[0105] Copolymer (b) is suitably an alternating copolymer and is prepared by reacting maleic anhydride with an alpha-olefin. Methods for carrying out such reactions will be well known to those skilled in the art and are described, for example, in US4240916, US3560456 and US4151069.

[0106] The copolymer additive of the present invention is suitably prepared by reacting maleic anhydride with an alpha-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.

[0107] Preferably, the alpha-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 alpha-olefin has 18 to 30 carbon atoms, for example 20 to 28 carbon atoms.

[0108] To form the copolymer additives of the present invention, mixtures of alpha-olefins may be used.

[0109] In a preferred embodiment, mixtures of α-olefins having 20 to 24 carbon atoms are used.

[0110] In one embodiment, a mixture of alpha-olefins having from 24 to 28 carbon atoms is used, for example a mixture having from 26 to 28 carbon atoms.

[0111] The present invention relates to copolymers comprising maleic anhydride derived units and alpha-olefin derived units.

[0112] The copolymers obtained directly from the reaction of α-olefins with maleic anhydride contain alkyl chains and anhydride functional groups.

[0113] In some embodiments, the anhydride groups can be further reacted. For example, in some embodiments, the anhydride groups can be hydrolyzed to provide carboxylic acid functional groups.

[0114] In some embodiments, the anhydride and / or hydrolysis acid product may be further functionalized in part or in whole, for example by reaction with an amine and / or alcohol to incorporate ester and / or amide and / or imide functional groups into the copolymer.

[0115] In a preferred embodiment, the copolymer is not further functionalized in this manner and the maleic anhydride derived units are present as underivatized anhydride moieties and / or carboxylic acid moieties.

[0116] Most preferably, the maleic anhydride derived units of the copolymer contain anhydride groups.Suitably, the additive comprises a copolymer obtained directly from the reaction of an alpha-olefin with maleic anhydride.

[0117] Preferred copolymers for use herein have a number average molecular weight of from 1000 to 50000 Da, preferably from 2000 to 40000 Da, suitably from 2500 to 30000 Da, for example from 3000 to 25000 Da.

[0118] Preferably, the copolymer has a number average molecular weight of 5000 to 20000 Da, in one embodiment, the copolymer has a number average molecular weight of 5000 to 10000 Da. In one embodiment, the copolymer has a number average molecular weight of 8000 to 17000 Da.

[0119] In some embodiments, the composition of the first aspect may further comprise (c) a reaction product of a carboxylic acid and a polyamine.

[0120] Preferably, the carboxylic acid reacts with the polyamine to form a heterocyclic moiety, such as an imidazoline or tetrahydropyridine moiety. Preferably, the polyamine comprises an optionally substituted ethylenediamine moiety and the reaction product with the carboxylic acid results in the production of an imidazoline.

[0121] Preferably, the reaction product of component (c) is a substituted imidazoline compound. Such compounds are known in the art of fuel and lubricant additives.

[0122] Preferred compounds are formed from the reaction of fatty acids with polyamines and suitable compounds of this type are described, for example, in USRE23227, US3193454 and US7857871.

[0123] Suitable polyamines include hydroxy substituted polyamines such as described in US2007193110.

[0124] Suitable acids that may be used to prepare the additive for component (c) include ether carboxylic acids (such as described in US6372918) and terpene-derived carboxylic acids (such as described in US4994575).

[0125] In some embodiments, component (c) may include an imidazoline that has been further reacted. The further reaction may be with an alkylene oxide (see, for example, US2713582), an aryl sulfonic acid (see, for example, US4247300A), or a sulfonating agent such as SO3 (see, for example, US2917376).

[0126] Preferably, component (c) comprises the reaction product of one or more fatty acids having from 10 to 36 carbon atoms and polyethylene polyamines having from 2 to 8 nitrogen atoms.

[0127] Preferred fatty acids are compounds of the formula RCOOH wherein R is an alkyl or alkenyl group having 10 to 36 carbon atoms, preferably 12 to 30 carbon atoms, more preferably 12 to 24 carbon atoms, suitably 14 to 22 carbon atoms, more preferably 16 to 20 carbon atoms.

[0128] The fatty acid may be a naturally occurring fatty acid comprising a mixture of compounds. Preferably, the fatty acid comprises a C18 component.

[0129] A preferred fatty acid is tall oil fatty acid.

[0130] Polyethylene polyamines suitable for reaction with fatty acids include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, and mixtures and isomers thereof.

[0131] Most preferably, component (c) comprises an imidazoline comprising the reaction product of tall oil fatty acid and diethylenetriamine.

[0132] In some embodiments, the composition of the first aspect comprises (d) a metal deactivator compound.

[0133] In some embodiments, the diesel fuel composition used in the present invention further comprises a metal deactivation compound. Any metal deactivation compound known to those skilled in the art may be used, and includes, for example, the substituted triazole compounds of Figure (A), wherein R and R' are independently selected from optionally substituted alkyl or hydrogen.

[0134]

[0135] Preferred metal deactivating compounds are compounds having formula (B):

[0136]

[0137] Where R 1 , R 2 and R 3 R is independently selected from optionally substituted alkyl or hydrogen, preferably alkyl or hydrogen of 1 to 4 carbon atoms. 1 Preferably, hydrogen, R 2 Preferably, hydrogen, and R 3 Preferably, it is methyl. n is an integer from 0 to 5, and most preferably 1.

[0138] A particularly preferred metal deactivator is N,N'-disalicyclidene-1,2-diaminopropane and has the following formula, as shown in Figure (C);

[0139]

[0140] Another preferred metal deactivation compound is shown in Figure (D):

[0141]

[0142] Components (a), (b) and (c) are suitably included in the composition of the first aspect in amounts based on the proportion of pyrolysis oil present in the composition. By this is meant that for a blended fuel, the treat rate of the additive will be adjusted according to the amount of pyrolysis oil present in the blend. Thus, if a component is added to neat pyrolysis oil in an amount of 500 ppm, the treat rate used for a blended fuel comprising 50% pyrolysis oil would be 250 ppm.

[0143] The nitrogen-containing antioxidant component (a) is preferably comprised 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.

[0144] The nitrogen-containing antioxidant component (a) 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 2000 ppm, for example up to 1000 ppm, in each case based on the proportion of pyrolysis oil present in the composition.

[0145] Preferably, the nitrogen-containing antioxidant component (a) is present in the composition of the first aspect in an amount of 1 to 10000 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.

[0146] In some embodiments, the nitrogen-containing antioxidant component (a) is present in the composition of the first aspect in an amount of 10 to 500 ppm, preferably 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.

[0147] In a preferred embodiment, component (a) comprises a mixture of (i) an acylated nitrogen compound, (ii) a phenylenediamine and (iii) a substituted hydroxylamine, which are suitably present in a ratio of 1 to 4 parts (i): 1 to 4 parts (ii): 2 to 6 parts (iii) (by weight).

[0148] In a preferred embodiment, the composition of the first aspect comprises 1 to 250 ppm, preferably 10 to 150 ppm, for example 50 to 100 ppm of (i) an acylated nitrogen compound; 1 to 250 ppm, preferably 10 to 150 ppm, for example 50 to 100 ppm of (ii) a phenylenediamine; and optionally 1 to 500 ppm, preferably 50 to 250 ppm, for example 100 to 150 ppm of (iii) a substituted hydroxylamine, in each case based on the proportion of the pyrolysis oil present in the composition.

[0149] When copolymer component (b) is present, it is preferably comprised 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.

[0150] When copolymer component (b) is present, it 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.

[0151] Preferably, when copolymer component (b) is present, it 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.

[0152] When component (c) is present, it is preferably comprised 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.

[0153] When component (c) is present, it 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.

[0154] Preferably, when component (c) is present, it 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.

[0155] Metal deactivators (d) may optionally be included in the composition in an amount of 1 to 1000 ppm, preferably 5 to 500 ppm, for example 10 to 100 ppm.

[0156] In this specification, any reference to ppm refers to parts per million by weight.

[0157] In a preferred embodiment, the first aspect of the present invention provides a composition comprising: pyrolysis oil; 100 to 500 ppm, preferably 200 to 400 ppm of (a) one or more nitrogen-containing antioxidants; and optionally 10 to 400 ppm, preferably 50 to 200 ppm 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.

[0158] In some embodiments, the composition of the first aspect can be used as middle distillate fuel oil.Therefore, said composition can include one or more other additives, for example common additives in diesel oil.These additives include for example antioxidants, dispersants, detergents, metal deactivation compounds, wax anti-settling agents, cold flow improvers, cetane number improvers, demisters, stabilizers, demulsifiers, defoamers, corrosion inhibitors, lubricity improvers, dyes, markers, combustion improvers, metal deactivators, odor masking agents, drag reducers and conductivity improvers.The examples of the respective suitable amounts of these types of additives will be known to those skilled in the art.

[0159] According to a second aspect of the present invention, there is provided an additive composition for pyrolysis oil, comprising:

[0160] (a) one or more nitrogen-containing antioxidants; and optionally:

[0161] (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units; and / or

[0162] (c) Reaction products of carboxylic acids and polyamines.

[0163] Preferred features of the second aspect are as defined in relation to the first aspect.

[0164] Preferably, the additive composition comprises a diluent or solvent. Suitable diluents and solvents will be known to those skilled in the art.

[0165] Preferred solvents include mixtures of aromatic solvents such as xylene, Aromatic 150 or Aromatic 100.

[0166] In a particularly preferred embodiment, the additive composition of the second aspect comprises:

[0167] (a) a nitrogen-containing antioxidant comprising (i) an acylated nitrogen compound, (ii) a phenylenediamine, and (iii) a substituted hydroxylamine;

[0168] (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units; and / or

[0169] (c) the reaction product of a carboxylic acid and a polyamine; and

[0170] Aromatic solvents.

[0171] It has been found that the use of additive component (a), optionally in combination with additives (b) and / or (c), can improve the oxidation stability of the pyrolysis oil.

[0172] There are a number of standard tests used to evaluate the stability of diesel fuel, including ASTM D4625, ASTM D6468 and ASTM D2274.

[0173] The inventors have measured the oxidative stability of the compositions of the present invention using the Rancimat test. This test is commonly used to evaluate the oxidative stability of biodiesel compositions. Like pyrolysis oil, biodiesel contains high levels of components that can be easily oxidized by atmospheric oxidation.

[0174] The Rancimat test is an accelerated oxidation test in which the sample is heated under full air bubbling. The volatile decomposition products enter deionized water and the conductivity of the water is measured. The time required for the fuel to begin to decompose is measured by recording the time when an increase in conductivity is observed. This is called the induction period.

[0175] To evaluate the oxidation stability of the pyrolysis oil composition of the present invention, the inventors followed the Rancimat test method specified in the European standard EN 14112, with the only difference being the nature of the fuel.

[0176] It has been found that the use of additive component (a), optionally in combination with additives (b) and / or (c), can improve the storage stability of pyrolysis oils.The storage stability of oils can be assessed using standard tests such as ASTM D4625.

[0177] According to a third aspect of the present invention, there is provided a method of improving the oxidative stability of a composition comprising pyrolysis oil, the method comprising adding to the composition (a) one or more nitrogen-containing antioxidants.

[0178] The method may also optionally include adding to the composition:

[0179] (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units; and / or

[0180] (c) Reaction products of carboxylic acids and polyamines.

[0181] According to a fourth aspect of the present invention, there is provided (a) use of one or more nitrogen-containing antioxidants for improving the oxidative stability of a composition containing pyrolysis oil.

[0182] A fourth aspect of the present invention may relate to the use of (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units in combination with (a) one or more nitrogen-containing antioxidants; and / or (c) a reaction product of a carboxylic acid and a polyamine to improve the oxidative stability of a composition containing pyrolysis oil.

[0183] Preferred features of the third and fourth aspects include the properties of the composition as defined in relation to the first aspect, and the properties of components (a), (b) and (c) and suitable treat rates thereof.

[0184] The method and use of the invention suitably improves the oxidative stability of a composition comprising pyrolysis oil, as measured by the Rancimat test.

[0185] Preferably, use of (a) a nitrogen-containing dispersant increases the induction time measured by the Rancimat test of a composition containing pyrolysis oil by at least 50%, preferably at least 100%, more preferably at least 150%, for example at least 200% or at least 300%.

[0186] The use of (a) a nitrogen-containing dispersant may increase the induction time of a composition containing pyrolysis oil as measured by the Rancimat test by at least 2 hours, preferably at least 4 hours, suitably at least 6 hours.

[0187] In some embodiments, the use of (a) a nitrogen-containing dispersant can increase the induction time measured by the Rancimat test of a composition containing pyrolysis oil by at least 8 hours, preferably at least 10 hours, suitably at least 12 hours.

[0188] Suitably, the use of (b) a copolymer comprising maleic anhydride derived units and alpha-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 will increase the oxidation induction time measured by the Rancimat test of a composition comprising pyrolysis oil by at least 50%, preferably at least 100%, more preferably at least 150%, for example at least 200% or at least 300%.

[0189] Suitably, the use of (b) a copolymer comprising maleic anhydride derived units and alpha-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 measured by the Rancimat test of a composition comprising pyrolysis oil by at least 2 hours, preferably at least 4 hours, suitably at least 6 hours.

[0190] In some embodiments, 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 oxidative 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.

[0191] In a fifth aspect, the present invention provides a method for improving the oxidative stability of a composition comprising a pyrolysis oil and one or more nitrogen-containing antioxidants, the method comprising adding to the composition:

[0192] (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units; and / or

[0193] (c) Reaction products of carboxylic acids and polyamines.

[0194] In a sixth aspect, the present invention provides 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 for improving the oxidative stability of a composition comprising pyrolysis oil and one or more nitrogen-containing antioxidants.

[0195] Preferred features of the fifth and sixth aspects include the properties of the composition as defined in relation to the first aspect, and the properties of components (a), (b) and (c) and suitable treat rates thereof.

[0196] 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 (a) one or more nitrogen-containing antioxidants to the composition.

[0197] The method may also optionally include adding to the composition:

[0198] (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units; and / or

[0199] (c) Reaction products of carboxylic acids and polyamines.

[0200] According to an eighth aspect of the present invention, there is provided (a) use of one or more nitrogen-containing antioxidants for improving the storage stability of a composition containing pyrolysis oil.

[0201] The eighth aspect of the present invention may relate to (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units in combination with (a) one or more nitrogen-containing antioxidants; and / or (c) a reaction product of a carboxylic acid and a polyamine for improving the storage stability of a composition containing pyrolysis oil.

[0202] 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, the method comprising adding to the composition:

[0203] (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units; and / or

[0204] (c) Reaction products of carboxylic acids and polyamines.

[0205] In a tenth aspect, the present invention provides 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 for improving the storage stability of a composition comprising pyrolysis oil and one or more nitrogen-containing antioxidants.

[0206] The methods and uses of the seventh, eighth, ninth and tenth aspects of the invention suitably improve the storage stability of a composition comprising pyrolysis oil, as measured by the standard method of ASTM D4625 and / or by said standard method modified to be performed using a 200 ml sample of pyrolysis oil at ambient temperature. Said improvement in storage stability suitably results in / is provided by a reduction in the amount of adherent insoluble matter produced by the pyrolysis oil during storage (compared to a similar pyrolysis oil to which no additives are added), and / or a reduction in the total amount of insoluble matter produced by the pyrolysis oil during storage, suitably as measured by reference to the above method.

[0207] In some embodiments, the methods and uses of the seventh, eighth, ninth and tenth aspects reduce the amount of adhering insoluble matter produced by the pyrolysis oil during storage by at least 30% compared to a similar pyrolysis oil without added additives, suitably reducing the amount of said adhering insoluble matter by at least 70%, by at least 80%, or by at least 90%, suitably as measured by ASTM D4625 and / or by said standard method modified as described herein.

[0208] In some embodiments, the methods and uses of the seventh, eighth, ninth and tenth aspects reduce the amount of total insoluble matter produced by the pyrolysis oil during storage by at least 30% compared to a similar pyrolysis oil without added additives, suitably reducing the amount of total insoluble matter by at least 40%, by at least 50% or by at least 60%, suitably as measured by ASTM D4625 and / or by the standard method modified as described herein.

[0209] Preferred features of the seventh, eighth, ninth and tenth aspects include the properties of the composition defined in relation to the first aspect, and the properties of components (a), (b) and (c) and suitable treat rates thereof.

[0210] Any feature of any aspect of the invention may be combined with any other aspect as appropriate.

[0211] The invention will now be further described by way of the following non-limiting examples.

[0212] Embodiment 1:

[0213] An additive composition was prepared comprising the following components:

[0214] Table 1.

[0215]

[0216]

[0217] PIBSI A is a polyisobutenyl succinimide obtained from the condensation reaction of polyisobutenyl succinic anhydride derived from polyisobutylene having an Mn of about 750 and a mixture of polyethylene polyamines having an average composition close to tetraethylene pentamine.

[0218] The metal deactivator B is N,N'-disalicylidene-1,2-diaminopropane.

[0219] 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.

[0220] Imidazolidine D is the reaction product of diethylenetriamine and tall oil fatty acid.

[0221] Embodiment 2:

[0222] Compositions 1, 2 and 3 in Example 1 were metered into waste rubber (waste tire) pyrolysis oil having the following specifications:

[0223] Table 2.

[0224]

[0225]

[0226] The induction period of the basic waste rubber pyrolysis oil was measured using the method specified in EN 14112. 500 ppm of compositions 1, 2 and 3 were each metered into three further samples of waste rubber pyrolysis oil and the Rancimat test was repeated.

[0227] The results are shown in Table 3:

[0228] Table 3.

[0229]

[0230]

[0231] Embodiment 2:

[0232] Additive compositions 1, 2 and 3 in Example 1 were metered at 500 mg / l into waste tire pyrolysis oil having the above specifications to obtain oil pyrolysis oil compositions 1, 2 and 3, respectively. These samples were tested for storage stability relative to waste rubber pyrolysis oil samples without additives using a modified ASTM D4625 standard method. The standard method was modified by testing at ambient temperature instead of 43°C and using 200 ml of pyrolysis oil sample instead of 400 ml of sample. The method provides the amount of filtered insoluble matter, adhered insoluble matter and total insoluble matter in each sample.

[0233] The amount of insoluble matter recovered (filtered and adhered) for each composition, including the total amount, is shown in Table 4:

[0234] Table 4.

[0235]

[0236] These results show that when the additives of the present invention are used, the amount of adherent insoluble matter produced during storage of plastic pyrolysis oil is significantly reduced. The results of samples 1, 2 and 3 (at a treatment rate of 500 mg / l) also show that the total amount of insoluble matter produced during storage is significantly reduced. Therefore, these additives can effectively improve the storage stability of pyrolysis oil.

Claims

1. A composition comprising pyrolysis oil and as an additive: (a) One or more nitrogen-containing antioxidants.

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

3. The composition according to claim 1 or claim 2, comprising a mixed fuel oil, wherein the mixed fuel oil comprises pyrolysis oil (preferably waste plastic pyrolysis oil or waste rubber pyrolysis oil) and middle distillate fuel oil.

4. A composition according to any one of the preceding claims, wherein component (a) comprises (i) an acylated nitrogen compound.

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

6. A composition according to any preceding claim wherein component (a) comprises (ii) a phenylenediamine.

7. A composition according to any one of the preceding claims, wherein component (a) comprises (iii) a substituted hydroxylamine.

8. The composition of any one of the preceding claims further comprising (b) a copolymer comprising maleic anhydride derived units and alpha-olefin derived units.

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

10. The composition of any preceding claim further comprising (c) a reaction product of a carboxylic acid and a polyamine.

11. The composition of claim 9 comprising the reaction product of one or more fatty acids having from 10 to 36 carbon atoms and polyethylene polyamines having from 2 to 8 nitrogen atoms.

12. An additive composition for pyrolysis oil, comprising: (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) Reaction products of carboxylic acids and polyamines.

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

14. The method of claim 13, further comprising adding to the composition: (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units; and / or (c) Reaction products of carboxylic acids and polyamines.

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

16. Use of (a) one or more nitrogen-containing antioxidants and (b) a copolymer comprising maleic anhydride derived units and alpha-olefin derived units to improve the oxidative stability of a composition containing pyrolysis oil.

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

18. A method for improving the oxidative stability of a composition comprising pyrolysis oil and one or more nitrogen-containing antioxidants, the method comprising adding to the composition: (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units; and / or (c) Reaction products of carboxylic acids and polyamines.

19. Use of (b) a copolymer comprising maleic anhydride derived units and alpha-olefin derived units and / or (c) a reaction product of a carboxylic acid and a polyamine for improving the oxidative stability of a composition comprising pyrolysis oil and one or more nitrogen-containing antioxidants.

20. 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.

21. (a) Use of one or more nitrogen-containing antioxidants for improving the storage stability of a composition containing pyrolysis oil.

22. A method for improving the storage stability of a composition comprising pyrolysis oil and optionally one or more nitrogen-containing antioxidants, the method comprising adding to the composition: (b) a copolymer comprising maleic anhydride derived units and α-olefin derived units; and / or (c) Reaction products of carboxylic acids and polyamines.

23. Use of (b) a copolymer comprising maleic anhydride derived units and alpha-olefin derived units and / or (c) a reaction product of a carboxylic acid and a polyamine for improving the storage stability of a composition comprising pyrolysis oil and optionally one or more nitrogen-containing antioxidants.