Patent Application
20240271053
The present invention relates to pyrolysis oils and to methods and uses relating thereto. In particular the invention relates to additives for improving the physical properties, especially flowability, of compositions comprising plastic pyrolysis oils. The present invention specifically relates to lowering the pour point of compositions comprising pyrolysis oils.
Pyrolysis oils are the fluids generated directly from the pyrolysis of waste, for example plastic waste, biomass for example agricultural waste, forestry waste, waste cooking oils, algae waste, used tyres or waste rubber. Examples of waste plastic which may be pyrolysed to produce plastic pyrolysis oils include low density polyethylene, high density polyethylene, ultra-high density polyethylene, polypropylene, polystyrene, polyethylene terephthalates (PET), rubber (e.g. from tyres), polyacrylate and polynitrile.
The organic liquid produced by the pyrolysis of plastics and other waste materials has a very dark colour, an unpleasant odour and is unstable. Such liquids may also have a tendency to gel at low or moderate temperatures and therefore be impractical to handle and process.
Pyrolysis oils can be used as a feedstock for chemical processing, for example in the production of polymers such as polyethylene. Pyrolysis oils can also be used as a feedstock to a fractionator from which distillate cuts can be produced, and can be used as a feedstock to secondary refinery process units such as a fluid catalysed cracking unit (FCCU). Pyrolysis oils may also be used in fuel oils. The use of pyrolysis oils to produce polymers represents a more sustainable alternative to the use of crude oil feedstocks in polymer production.
The utility of pyrolysis oils can be limited due to their poor stability and poor handling properties, particularly on cooling for example during transport or storage.
Pyrolysis oils, particularly those derived from plastics, may also have a relatively high pour point which impairs their flow properties and use at low to moderate or even high temperatures. Such pyrolysis oils contain saturated, paraffinic, wax-like molecules produced during pyrolysis. These wax-like molecules start to crystallize and precipitate as the temperature of the pyrolysis oil is decreased, for example during storage, and eventually form a three-dimensional network of agglomerated wax crystals which impairs the free flow of the oil. At a certain temperature, the pyrolysis oil will completely gel and no longer flow as a liquid. This temperature is known as the gelation or freeze point of the oil. The temperature of the oil just before it completely gels, where it still exhibits surface movement is known as the pour point of the oil. If the pour point of a liquid can be lowered, then this would provide an improvement in the handling and processing of said liquid even at moderate to relatively low temperatures. This can be important from a safety perspective when handling and storing in the field. Pyrolysis oils tend to have relatively low flashpoints (100° F. for example). If the oil has poor handling near its flash point, then applying external heat in order to improve flowability poses a safety risk. Therefore, due to the relatively high pour points of pyrolysis oils, it would be desirable to lower the pour points of such pyrolysis oils to facilitate their handling, storage and safety in order to enhance their value and use as a blend component, in fuel oils and as feedstocks for chemical processes, for example.
The present inventors have found that certain compounds having a C30 (or higher) group as defined herein, when used by themselves, are effective at reducing the pour point of compositions comprising pyrolysis oils. The inventors have further found that such additives can improve the ability of similar polymeric additives that do not have a C30 group to reduce the pour point of compositions comprising pyrolysis oils.
According to a first aspect of the present invention there is provided a composition comprising a pyrolysis oil and, as an additive, one or more of:
Suitably the additives (a) and/or (b) act as pour point depressants in the compositions of this first aspect. By pour point depressant we mean to refer to an additive that can lower the pour point of a composition (i.e. the compositions referred to above comprising pyrolysis oil) to maintain the fluidity of the composition at lower temperatures. The “pour point” of a liquid is defined as the lowest temperature at which said liquid will pour, flow or exhibit surface movement under a specific set of conditions. Standard methods for measuring the pour point of a liquid composition include ASTM D97, D5853-11, D5950-14 and D5949-10. Preferably the pour point of the compositions of the present invention are determined using a modified method according to ASTM D97.
The first aspect of the present invention relates to a composition comprising a pyrolysis oil. The pyrolysis oil may be obtained from the pyrolysis of any type of waste. The components of the oil and the properties thereof will depend on the types of waste pyrolysed and on the pyrolysis conditions. For example, the pyrolysis oil may be obtained from the pyrolysis of waste, for example plastic waste, agricultural waste, forestry waste, waste cooking oils, algal waste, used tyres or waste rubber.
Preferably, the pyrolysis oil comprises a plastic pyrolysis oil. Suitable plastic pyrolysis oil may be obtained from the pyrolysis of any type of plastic. Preferred plastic pyrolysis oils are obtained from the pyrolysis of one or polymers selected from polyethylene, polypropylene, PET, rubber, polyacrylate, polynitrile and mixtures thereof.
In some embodiments, the pyrolysis oil of the composition of the first aspect may be a hydrotreated pyrolysis oil.
In some embodiments, the pyrolysis oil of the composition of the first aspect has been through a cracking process.
In preferred embodiments, the composition of the first aspect comprises a pyrolysis oil directly obtained from a pyrolysis plant without purification or further treatment.
Suitably the pyrolysis oil (when unadditised) has a baseline pour point of at least 30° C., suitably at least 40° C.
Suitably the n-paraffin content of the pyrolysis oil is from 3 to 30 wt %. In some embodiments the n-paraffin content of the pyrolysis oil is from 15 to 30 wt %, suitably from 20 to 27 wt %.
Suitably at least 30 wt % of the n-paraffin compounds in the pyrolysis oil are C9-C18 n-paraffins. Suitably from 30 to 50 wt % of the n-paraffin compounds in the pyrolysis oil are C9-C18 n-paraffins.
Suitably at least 25 wt % of the n-paraffin compounds in the pyrolysis oil are C20-C30 n-paraffins. Suitably from 25 to 35 wt % of the n-paraffin compounds in the pyrolysis oil are C20-C30 n-paraffins. Suitably at least 10 wt % of the n-paraffin compounds in the pyrolysis oil are C30-C40 n-paraffins. Suitably from 10 to 20 wt % of the n-paraffin compounds in the pyrolysis oil are C30-C40 n-paraffins. Suitably at least 5 wt % of the n-paraffin compounds in the pyrolysis oil are C40+n-paraffins. Suitably from 5 to 10 wt % of the n-paraffin compounds in the pyrolysis oil are C40+n-paraffins.
Suitably the n-paraffin compounds in the pyrolysis oil comprise from 30 to 50 wt % C9-C18 n-paraffins, from 25 to 35 wt % C20-C30 n-paraffins, from 10 to 20 wt % C30-C40 n-paraffins and from 5 to 10 wt % C40+n-paraffins, based on the total weight of n-paraffins present in the pyrolysis oil.
In some embodiments, the composition of the first aspect may comprise a blended fuel oil comprising a plastic pyrolysis oil and one or more fuel oils from hydrocarbon and/or renewable sources.
In some embodiments the composition of the first aspect comprises a blended fuel oil comprising a plastic pyrolysis oil and a middle distillate fuel oil.
The middle distillate fuel oil may comprise a petroleum-based fuel oil, especially a middle distillate fuel oil. Such middle distillate fuel oils generally boil within the range of from 110° C. to 500° C., e.g. 150° C. to 400° C. The middle distillate fuel oil may comprise atmospheric distillate or vacuum distillate, cracked gas oil, or a blend in any proportion of straight run and refinery streams such as thermally and/or catalytically cracked and hydro-cracked distillates.
The middle distillate fuel oil may comprise non-renewable Fischer-Tropsch fuels such as those described as GTL (gas-to-liquid) fuels, CTL (coal-to-liquid) fuels and OTL (oil sands-to-liquid).
The middle distillate fuel oil may comprise a renewable fuel such as a biofuel composition or biodiesel composition.
The middle distillate fuel oil may comprise first generation biodiesel. First generation biodiesel contains esters of, for example, vegetable oils, animal fats and used cooking fats. This form of biodiesel may be obtained by transesterification of oils, for example rapeseed oil, soybean oil, safflower oil, palm oil, palm kernel oil, corn oil, peanut oil, cotton seed oil, tallow, coconut oil, physic nut oil (Jatropha), sunflower seed oil, used cooking oils, hydrogenated vegetable oils or any mixture thereof, with an alcohol, usually a monoalcohol, in the presence of a catalyst.
The middle distillate fuel oil may comprise second generation biodiesel. Second generation biodiesel is derived from renewable resources such as vegetable oils and animal fats and processed, often in the refinery, often using hydroprocessing such as the H-Bio process developed by Petrobras. Second generation biodiesel may be similar in properties and quality to petroleum-based fuel oil streams, for example renewable diesel produced from vegetable oils, animal fats etc. and marketed by ConocoPhillips as Renewable Diesel and by Neste as NExBTL.
The middle distillate fuel oil used in the present invention may comprise third generation biodiesel. Third generation biodiesel utilises gasification and Fischer-Tropsch technology including those described as BTL (biomass-to-liquid) fuels. Third generation biodiesel does not differ widely from some second generation biodiesel, but aims to exploit the whole plant (biomass) and thereby widens the feedstock base.
The middle distillate fuel oil may contain blends of any or all of the above diesel fuel oils.
In some embodiments the middle distillate fuel oil may be a blended diesel fuel comprising bio-diesel. In such blends the bio-diesel may 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%.
In some embodiments the middle distillate fuel oil may comprise a secondary fuel, for example ethanol. However, the middle distillate fuel oil composition preferably does not contain ethanol.
The middle distillate fuel oil may contain a relatively high sulphur content, for example greater than 0.05% by weight, such as 0.1% or 0.2%.
However in preferred embodiments, the middle distillate fuel oil has a sulphur content of at most 0.05% by weight, more preferably of at most 0.035% by weight, especially of at most 0.015%. Fuels with even lower levels of sulphur are also suitable, such as fuels with less than 50 ppm sulphur by weight, preferably less than 20 ppm, for example 10 ppm or less.
Various metal species may be present in the middle distillate fuel oil. 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 fuels deliberately. For example, transition metals are sometimes added as fuel-borne catalysts, for example to improve the performance of diesel particulate filters.
In preferred embodiments the middle distillate fuel oil used in the present invention comprises sodium and/or calcium. Preferably middle distillate fuel oil comprises sodium. The sodium and/or calcium is typically present in a total amount of from 0.01 to 50 ppm, preferably from 0.05 to 5 ppm preferably 0.1 to 2 ppm, such as 0.1 to 1 ppm.
Other metal-containing species may also be present as a contaminant, for example through the corrosion of metal and metal oxide surfaces by acidic species present in the fuel or from lubricating oil. In use, fuels such as diesel fuels routinely come into contact with metal surfaces for example, in vehicle fuelling systems, fuel tanks, fuel transportation means etc. Typically, metal-containing contamination may comprise transition metals such as zinc, iron and copper; other group I or group II metals and other metals such as lead.
In addition to metal-containing contamination which may be present in middle distillate fuel oils there are circumstances where metal-containing species may deliberately be added to the fuel. For example, as is known in the art, metal-containing fuel-borne catalyst species may be added to aid with the regeneration of particulate traps.
Metal-containing contamination, depending on its source, may be in the form of insoluble particulates or soluble compounds or complexes. Metal-containing fuel-borne catalysts are often soluble compounds or complexes or colloidal species.
In some embodiments, the middle distillate fuel oil may comprise metal-containing species comprising 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.
In some embodiments, the middle distillate fuel oil may comprise metal-containing species comprising zinc. Zinc may be present in an amount of from 0.01 to 50 ppm, preferably from 0.05 to 5 ppm, more preferably 0.1 to 1.5 ppm.
The composition of the first aspect comprises one or more of:
In some embodiments, the composition of the first aspect comprises (a) as an additive.
In some embodiments, the composition of the first aspect comprises (b) as an additive.
In some embodiments, the composition of the first aspect comprises (a) and (b) as additives.
In some embodiments, the composition of the first aspect comprises additive (a) an aldehyde-alkylphenol and/or an aldehyde-alkylphenol-polyamine copolymer, wherein the alkylphenol of the copolymer comprises an alkyl group having at least 30 carbon atoms.
The inventors have surprisingly found that such copolymers comprising alkylphenols, wherein the alkyl group of the alkylphenol has at least 30 carbons, can advantageously lower the pour point of liquid compositions comprising pyrolysis oil. By way of comparison, such copolymers wherein the alkylphenols of the copolymer comprise an alkyl group having less than 30 carbon atoms were found to be ineffective at significantly lowering the pour point of said compositions comprising pyrolysis oil.
In embodiments wherein the additive (a) is an aldehyde-alkylphenol copolymer, said copolymers are suitably the reaction product of, as monomers, an aldehyde and an alkylphenol, wherein the alkyl group of the alkylphenol has at least 30 carbon atoms. The aldehyde-alkylphenol copolymer may be considered to comprise alkylphenol-derived sub-units and aldehyde-derived sub-units.
In embodiments wherein the additive (a) is an aldehyde-alkylphenol-polyamine copolymer, said copolymers are suitably the reaction product of, as monomers, an aldehyde, an alkylphenol and a polyamine, wherein the alkyl group of the alkylphenol has at least 30 carbon atoms. The aldehyde-alkylphenol-polyamine copolymer may be considered to comprise alkylphenol-derived sub-units, aldehyde-derived sub-units and polyamine-derived sub-units. Such copolymers may be referred to as Mannich resins, being formed by a Mannich polymerisation reaction.
Preferably the aldehyde used to prepare the aldehyde-alkylphenol or aldehyde-alkylphenol-polyamine copolymers is selected from formaldehyde or a reactive equivalent thereof, for example paraformaldehyde, C2 to C10 aldehydes and aromatic aldehydes, for example benzaldehyde. Preferably, formaldehyde or a reactive equivalent thereof is used as the aldehyde component to prepare the aldehyde-alkylphenol or aldehyde-alkylphenol-polyamine copolymers. Therefore, preferred aldehyde-alkylphenol copolymers are copolymers of formaldehyde and an alkylphenol. Such aldehyde-alkylphenol copolymers may be prepared by the methods disclosed in U.S. Pat. Nos. 9,518,184 and 9,068,128, which are incorporated herein by reference.
Suitable aldehyde-alkylphenol-polyamine copolymers of additive (a) are copolymers of formaldehyde, an alkylphenol and a polyamine. Such aldehyde-alkylphenol-polyamine copolymers may be formed by the methods disclosed in EP2197991A2 and U.S. Pat. No. 9,528,074B2, which are incorporated herein by reference.
Preferably the alkylphenol is mono-substituted with the alkyl group, preferably at the para position. Preferred alkyl groups have 30 to 50 carbon atoms, preferably 30 to 40 carbon atoms. Such alkylphenols may be prepared by the reaction of phenol with an olefin comprising the number of carbon atoms referred to above.
It will be appreciated that such alkylphenols may contain a mixture of compounds having alkyl groups with a range of chain lengths. Therefore, the alkylphenol monomer from which the aldehyde-alkylphenol copolymer is formed (and so the alkylphenol sub-unit of the aldehyde-alkylphenol copolymer), may contain some alkyl groups with fewer than 30 carbon atoms. However, the majority of said alkyl groups contain at least 30 carbon atoms. For example, preferably at least 50 wt % of the alkyl groups of the alkylphenol monomer (and preferably at least 50 wt % of the alkylphenol-derived sub-units of the aldehyde-alkylphenol or aldehyde-alkylphenol-polyamine copolymer) have alkyl groups with at least 30 carbon atoms, suitably at least 75 wt %, at least 80 wt % or at least 82 wt %.
Suitably at least 50 wt % of the alkylphenol monomer (and suitably at least 50 wt % of the alkylphenol-derived sub-units of the aldehyde-alkylphenol or aldehyde-alkylphenol-polyamine copolymer) have alkyl groups with 30 to 40 carbon atoms, suitably at least 75 wt %, at least 80 wt % or at least 82 wt %.
Preferably the alkyl group of the alkylphenol monomer (and suitably of the alkylphenol-derived sub-units of the aldehyde-alkylphenol or aldehyde-alkylphenol-polyamine copolymer) has a number average molecular weight of from 400 to 1,000, suitably from 400 to 600.
In some embodiments the alkyl phenol monomer (and therefore the alkylphenol sub-unit of the aldehyde-alkylphenol or aldehyde-alkylphenol-polyamine copolymer) is a polyisobutenyl (PIB) substituted phenol. Therefore the alkyl group referred to above is a PIB, in such embodiments.
Polyisobutenyl (PIB) substituted phenols include a hydrocarbyl chain having the repeating unit:
Poly(isobutenes) are prepared by the addition polymerisation of isobutene, (CH3)2C═CH2. Each molecule of the resulting polymer will include a single alkene moiety.
Conventional polyisobutenes and so-called “highly-reactive” polyisobutenes are suitable for use in preparing additive (a) of the present invention. Highly reactive polyisobutenes in this context are defined as polyisobutenes wherein at least 50%, preferably 70% or more, of the terminal olefinic double bonds are of the vinylidene type as described in EP0565285. Particularly preferred polyisobutenes are those having more than 80 mol % and up to 100% of terminal vinylidene groups such as those described in EP1344785, which is incorporated herein by reference.
Methods of preparing polyalkylene substituted phenols, for example polyisobutene substituted phenols are known to the person skilled in the art, and include the methods described in EP831141, which is incorporated herein by reference.
The PIB substituent preferably has a number average molecular weight of from 400 to 1,000, suitably from 400 to 600 or from 420 to 560.
In some preferred embodiments, the additive (a) is an aldehyde-alkylphenol copolymer having the structures (I) or (II):
wherein R is an alkyl group having at least 30 carbon atoms and n is at least 1.
Preferably n is from 2 to 12, preferably from 5 to 10 or from 5 to 7.
Preferably R is a C30-C60 alkyl group, preferably a C30-C50 alkyl group or a C30-C40 alkyl group.
As mentioned above, the alkylphenols may contain a mixture of compounds having alkyl groups with a range of chain lengths and also may contain some alkyl groups with fewer than 30 carbon atoms. However, suitably at least 50 wt % of the R groups present in the additive have at least 30 carbon atoms, suitably at least 75 wt %, at least 80 wt % or at least 82 wt %.
Preferably at least 50 wt % of the R groups present in the additive are C30-C50 alkyl groups, preferably C30-C40 alkyl groups. Preferably at least 75 wt %, at least 80 wt % or at least 82 wt % of the R groups additive are C30-C50 alkyl groups, preferably C30-C40 alkyl groups.
Preferably the aldehyde-alkylphenol copolymer of additive (a) has a molecular weight in the range 3,000 to 20,000, suitably from 4,000 to 10,000, preferably from 5,000 to 7,000.
Further suitable aldehyde-alkyl phenol copolymers for use herein include compounds of formula (I) in which the terminal phenol groups are further functionalised, for example by reaction with a fatty acid or an amine and an aldehyde via a Mannich reaction. Compounds of this type are described, for example, in US2007/221539, which is incorporated herein by reference.
In embodiments wherein the additive (a) is an aldehyde-alkylphenol-polyamine copolymer, the polyamine is suitably an amine having at least two amino groups and from 2 to 22 carbon atoms. In such embodiments, the polyamine may be a polyalkylene polyamine. Preferably the polyamine is a polyalkylene polyamine in which the alkylene component has 1 to 6, preferably 1 to 4, most preferably 2 to 3 carbon atoms. Most preferably the polyamine is a polyethylene polyamine.
Preferably the polyamine has 2 to 15 nitrogen atoms, preferably 2 to 10 nitrogen atoms, more preferably 2 to 8 nitrogen atoms.
In especially preferred embodiments, polyamine has the formula R1R2NCHR3CHR4NR5R6 wherein each of R1, R2, R3, R4, R5 and R6 is independently selected from hydrogen, and an optionally substituted alkyl, alkenyl, alkynyl, aryl, alkylaryl or arylalkyl substituent. Therefore the polyamine used to form the additive preferably includes an optionally substituted ethylene diamine residue.
Preferably at least one of R1 and R2 is hydrogen. Preferably both of R1 and R2 are hydrogen.
Preferably at least two of R1, R2, R5 and R6 are hydrogen.
Preferably at least one of R3 and R4 is hydrogen. In some preferred embodiments each of R3 and R4 is hydrogen. In some embodiments R3 is hydrogen and R4 is alkyl, for example a C1 to C4 alkyl group, especially methyl.
Preferably at least one of R5 and R6 is an optionally substituted alkyl, alkenyl, alkynyl, aryl, alkylaryl or arylalkyl substituent.
In embodiments in which at least one of R1, R2, R3, R4, R5 and R6 is not hydrogen, each is independently selected from an optionally substituted alkyl, alkenyl, alkynyl, aryl, alkylaryl or arylalkyl moiety. Preferably each is independently selected from hydrogen and an optionally substituted C(1-6) alkyl moiety.
In particularly preferred compounds each of R1, R2, R3, R4 and R5 is hydrogen and R6 is an optionally substituted alkyl, alkenyl, alkynyl, aryl, alkylaryl or arylalkyl substituent. Preferably R6 is an optionally substituted C(1-6) alkyl moiety.
Such an alkyl moiety may be substituted with one or more groups selected from hydroxyl, amino (especially unsubstituted amino; —NH—, —NH2), sulpho, sulphoxy, C(1-4) alkoxy, nitro, halo (especially chloro or fluoro) and mercapto.
There may be one or more heteroatoms incorporated into the alkyl chain, for example O, N or S, to provide an ether, amine or thioether.
In some embodiments, substituents R1, R2, R3, R4, R5 or R6 are hydroxy-C(1-4)alkyl and amino-(C(1-4)alkyl, especially HO—CH2—CH2— and H2N—CH2—CH2—.
Suitably the polyamine includes only amine functionality, or amine and alcohol functionalities.
The polyamine may, for example, be selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctamine, propane-1,2-diamine, 2(2-amino-ethylamino)ethanol, and N1,N1-bis (2-aminoethyl) ethylenediamine (N(CH2CH2NH2)3). Most preferably the polyamine comprises tetraethylenepentamine or especially ethylenediamine.
Commercially available sources of polyamines typically contain mixtures of isomers and/or oligomers, and products prepared from these commercially available mixtures fall within the scope of the present invention.
In such embodiments wherein the additive (a) is an aldehyde-alkylphenol-polyamine copolymer, said copolymers are suitably the reaction product of, as monomers, formaldehyde; an alkylphenol wherein the alkyl group of the alkylphenol has at least 30 carbon atoms; and polyamine selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctamine, propane-1,2-diamine, 2(2-amino-ethylamino)ethanol, and N1,N1-bis (2-aminoethyl) ethylenediamine (N(CH2CH2NH2)3).
(b) The Reaction Product of an Alcohol and/or Amine with α-Olefin-Ethylenically Unsaturated Carboxylate Copolymers
In some embodiments, the composition of the first aspect comprises additive (b) the reaction product of an alcohol and/or amine with a copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound, wherein the alpha-olefin and/or the alcohol and/or amine has at least 30 carbon atoms.
The copolymers of additive (b) therefore comprise groups having at least 30 carbon atoms, either derived the alpha-olefin or from the alcohol and/or amine.
The additive (b) can be considered to comprise alpha-olefin-derived sub-units, ethylenically unsaturated carboxylate compound-derived sub-units and moieties derived from the alcohol and/or amine and the unsaturated carboxylate compound-derived sub-units. Such moieties derived from the alcohol and/or amine and the unsaturated carboxylate compound-derived sub-units may be any group resulting from the reaction of the alcohol and/or amine with the carboxylate group of the ethylenically unsaturated carboxylate compound-derived sub-units. For example, the moieties derived from the alcohol and/or amine and the unsaturated carboxylate compound-derived sub-units may be ester, amide, imide or amine salt groups, or mixtures thereof. Suitably the moieties derived from the alcohol and/or amine are ester and/or amide groups.
The inventors have surprisingly found that such copolymers wherein the alpha-olefin group used to form the copolymer has at least 30 carbons, can advantageously lower the pour point of liquid compositions comprising pyrolysis oil. By way of comparison, such copolymers which comprise alkyl sub-units having less than 30 carbon atoms or comprise a low proportion of alkyl sub-units having at least 30 carbons, were found to be ineffective at significantly lowering the pour point of said compositions comprising pyrolysis oil.
The same advantages may be obtained by embodiments wherein the group having at least 30 carbons is provided by the alcohol or amine which is reacted with the copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound.
Suitably the copolymers of additive (b) are the reaction product of, as monomers, an alpha-olefin and an ethylenically unsaturated carboxylate compound; wherein said reaction product has been further reacted to form an ester or amide derivative.
In embodiments wherein the alpha-olefin has at least 30 carbon atoms, the alpha-olefin suitably has 30 to 50 carbon atoms, preferably 30 to 40 carbon atoms.
It will be appreciated that such alpha-olefins may contain a mixture of compounds having a range of different chain lengths/number of carbon atoms. Therefore, the alpha-olefin monomer from which the copolymer of additive (b) is formed, and so the alpha-olefin-derived sub-units of the copolymer, may contain some alpha-olefins with fewer than 30 carbon atoms.
In some embodiments, the alpha-olefin is a mixture of alpha-olefin compounds wherein 10 to 90 wt % of the alpha-olefin compounds have at least 30 carbon atoms, suitably wherein from 20 to 50 wt % of the alpha-olefin compounds have at least 30 carbon atoms.
The alpha-olefin used to form the copolymer of additive (b) may be provided by a commercially available alpha-olefin product, for example a commercially available alpha-olefin mixture comprising alpha-olefin compounds having at least 30 carbon atoms, suitably a majority of alpha-olefin compounds having at least 30 carbon atoms. The alpha-olefin may be provided by a mixture of more than one commercially available alpha-olefin product, for example a mixture of a first commercially available alpha-olefin mixture comprising alpha-olefin compounds having at least 30 carbon atoms and a second commercially available alpha-olefin mixture comprising alpha-olefin compounds having fewer than 30 carbon atoms. Such a second commercially available alpha-olefin mixture may comprise or consist of C24-28, C20-24 or C26-28 alpha-olefin compounds, or a mixture thereof.
In such embodiments, said first and second commercially available alpha-olefin products may be mixed in a suitable ratio to provide a mixture of alpha-olefin compounds wherein 10 to 90 wt % of the alpha-olefin compounds have at least 30 carbon atoms, suitably wherein from 20 to 50 wt % of the alpha-olefin compounds have at least 30 carbon atoms.
In some embodiments, the majority of said alpha-olefins contain at least 30 carbon atoms. For example, preferably at least 50 wt % of the alpha-olefin monomers (and preferably the alpha-olefin-derived sub-units of the copolymer of additive (b)) have at least 30 carbon atoms, suitably at least 75 wt %, at least 80 wt % or at least 82 wt %.
Suitably at least 50 wt % of the alpha-olefin monomers (and suitably the alpha-olefin-derived sub-units of the copolymer) have 30 to 40 carbon atoms, suitably at least 75 wt %, at least 80 wt % or at least 82 wt %.
Preferably the alpha-olefin monomers (and suitably the alpha-olefin-derived sub-units of the copolymer) have a number average molecular weight of from 400 to 1,000, suitably from 400 to 600 or from 420 to 560.
In some embodiments the alpha-olefin monomer (and therefore the alpha-olefin-derived sub-unit of the copolymer) is a polyisobutenylene (PIB). Therefore, the alpha-olefin-derived sub-unit referred to above is a PIB sub-unit in such embodiments. Suitable PIBs are as described above for additive (a).
The PIB monomer (and sub-unit) preferably has a number average molecular weight of from 400 to 1,000, suitably from 400 to 600 or from 420 to 560.
In embodiments wherein the alcohol and/or amine has at least 30 carbon atoms, the alpha-olefin may also comprise at least 30 carbon atoms and may be as defined above. Alternatively, the alpha-olefin may have 12 to 28 carbon atoms, preferably from 16 to 28 carbon atoms, from 18 to 26 carbon atoms or most preferably from 20 to 24 carbon atoms. The alpha-olefin may be linear or branched.
The ethylenically unsaturated carboxylate compound used to prepare copolymers of additive (b) may be selected from fumaric acid, maleic anhydride, maleic acid, (meth)acrylic acid, itaconic anhydride or itaconic acid, maleimide and N-alkyl, N-aryl, and N-alkaryl maleimides, phthalic anhydride, citraconic anhydride, citraconimide and N-alkyl, N-aryl, and N-alkaryl citraconimides or combinations thereof.
Preferably the ethylenically unsaturated carboxylate compound is maleic anhydride. Therefore, the copolymer of additive (b) suitably comprises maleic acid-derived sub-units and alpha-olefin-derived sub-units. In such embodiments, the copolymer of additive (b) may be referred to as an ester or amide derivative of an alpha-olefin maleic anhydride copolymer (which may be referred to as an OMAC ester or amide). Preferably additive (b) is an ester derivative of an alpha-olefin maleic anhydride copolymer (which may be referred to as an OMAC ester).
The copolymer of additive (b) is suitably an alternating copolymer and is firstly prepared by reacting maleic anhydride with an alpha-olefin, to form the OMAC which is subsequently derivatized by reacting with an alcohol and/or amine forming an ester, amide, imide or amine salt from the maleic anhydride moieties. Means for carrying out such reactions will be 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, which are incorporated herein by reference.
The OMAC is suitably prepared by reacting maleic anhydride with an alpha-olefin as defined above in a molar ratio of from 3:1 to 1:3, preferably 2:1 to 1:2, more preferably from 1.5:1 to 1:1.5, for example about 1:1.
Preferably the alpha-olefin has the number of carbon atoms referred to above. A mixture of alpha-olefins may be used.
Suitable ester, amide, imide or amine salt derivatives of the copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound are formed by reacting the carboxylate moiety of the ethylenically unsaturated carboxylate sub-units of the copolymer with a suitable alcohol or amine. Such alcohols and amines are suitably C12-C50 alcohols and amines, C12-C40 alcohols or amines, C12-C28 alcohols or amines, suitably C16-C24 alcohols or amines, preferably C18-C22 alcohols or amines. Therefore, the copolymer of additive (b) suitably comprises C12-C50 ester, amide, imide or amine salt moieties, preferably C16-C24 or C18-C22 ester, amide, imide or amine salt moieties. The alcohols or amines may be branched or linear. Suitably the alcohols or amines are linear. The alcohols or amines may be saturated, unsaturated, or a mixture of both.
In embodiments wherein additive (b) is the reaction product of an amine with a copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound, the amine may be a monoamine, diamine or a polyamine. The polyamine may be as defined above.
In some embodiments, the copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound is reacted with alcohols or amines having at least 30 carbon atoms, suitably 30 to 50 carbon atoms or 30 to 40 carbon atoms.
Such alcohols or amines may contain a mixture of compounds having different numbers of carbon atoms. The alcohols or amines may comprise compounds with fewer than 30 carbon atoms. However, suitably at least 50 wt % of the alcohols or amines used to prepare the additive have at least 30 carbon atoms, suitably at least 75 wt %, at least 80 wt % or at least 82 wt %.
Preferably the alcohols or amines have a number average molecular weight of from 400 to 1,000, suitably from 400 to 600 or from 420 to 560.
Preferably the carboxylate moiety of the ethylenically unsaturated carboxylate compound is reacted with C12-C50 alcohols, C12-C40 alcohols, C12-C28 alcohols, suitably C16-C24 alcohols, preferably C18-C22 alcohols. Therefore, the copolymer of additive (b) suitably comprises C12-C28 ester moieties, preferably C16-C24 or C18-C22 ester moieties.
In embodiments wherein the alpha-olefin has at least 30 carbon atoms, the alcohol and/or amines are suitably C12-C28 alcohols or amines, suitably C16-C24 alcohols or amines, preferably C18-C22 alcohols or amines.
In some embodiments wherein the alpha-olefin comprises alpha-olefin compounds having at least 30 carbon atoms, the alcohol and/or amine may be a mixture of alcohol compounds having at least 20 carbon atoms (which may be termed a “C20+ alcohol”). Such C20+ alcohols are commercially available as Alfol® and Nafol®.
In some embodiments wherein the alpha-olefin comprises alpha-olefin compounds having at least 30 carbon atoms, the alcohol and/or amine may be a mixture of alcohol compounds comprising predominantly alcohol compounds having 20 carbon atoms. For example, such a mixture of alcohols may comprise at least 40 wt % of alcohol compounds having 20 carbon atoms, suitably approximately 50 wt %.
In embodiments wherein the alpha-olefin has fewer than 30 carbon atoms, for example 12 to 28 carbon atoms, the alcohols or amines have at least 30 carbon atoms, suitably 30 to 50 carbon atoms or 30 to 40 carbon atoms, as defined above.
In some embodiments, the alpha-olefin has at least 30 carbon atoms as defined above and the alcohols or amines have at least 30 carbon atoms, as defined above.
The reaction product of an alcohol and/or amine with a copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound is suitably prepared by reacting the copolymer with the alcohol and/or amine as defined above in a molar ratio of from 0.1:1 to 1:2, from 0.5:1 to 1:1.5, preferably from 1.1:1 to 1:1.1.
Suitably, the reaction product of an alcohol and/or amine with a copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound is prepared by reacting the copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound with from 0.5 to 1.5 molar equivalents of the alcohol and/or amine, based on the amount of ethylenically unsaturated carboxylate monomer used to form the copolymer. In some embodiments, from 0.5 to 1.0 molar equivalents of the alcohol and/or amine, based on the amount of ethylenically unsaturated carboxylate monomer used, are reacted with the copolymer.
In some embodiments, the copolymer of additive (b) is a C12-C28 ester or amide of an alpha-olefin maleic anhydride copolymer, wherein the alpha-olefin-derived sub-unit has at least 30 carbon atoms. Preferably the copolymer of additive (b) is a C12-C28 ester of an alpha-olefin maleic anhydride copolymer, wherein the alpha-olefin maleic anhydride copolymer comprises alpha-olefin-derived sub-units having at least 30 carbon atoms. Suitably, at least 30 wt %, at least 40 wt % or at least 50 wt % of the alpha-olefin compounds used to form the copolymer are C30-C40 alpha-olefins. Therefore, at least 30 wt %, at least 40 wt % or at least 50 wt % of the alpha-olefin-derived sub-units of the copolymer have from 30 to 40 carbon atoms.
In some embodiments, the copolymer of additive (b) is the reaction product of an alpha-olefin maleic anhydride copolymer and from 0.5 to 1.5 molar equivalents of an alcohol, based on the amount of maleic anhydride monomer used to form the copolymer, suitably from 0.5 to 1.0 molar equivalents.
Suitably the copolymer of additive (b) is the reaction product of an alpha-olefin maleic anhydride copolymer and from 0.5 to 1.5 molar equivalents, based on the amount of maleic anhydride monomer used to form the copolymer, of a C12-C28 alcohol, wherein the alpha-olefin maleic anhydride copolymer is formed by the reaction of maleic anhydride and an alpha-olefin comprising at least 30 wt %, at least 40 wt % or at least 50 wt % of alpha-olefins having at least 30 carbon atoms, suitably from 30 to 40 carbon atoms.
Preferably the additive (b) has a molecular weight in the range of from 4,000 to 30,000, from 6,000 to 20,000 or from 6,000 to 12,000.
The additives (a) and/or (b) are preferably included in the composition of the first aspect, when present, in an amount of at least 10 ppm, preferably at least 20 ppm, more preferably at least 50 ppm, for example at least 100 ppm. Suitably the additives (a) and/or (b) are present in an amount of at least 200 ppm, at least 300 ppm, at least 400 ppm or at least 500 ppm.
Suitably, the additives (a) and/or (b) are preferably included in the composition of the first aspect, when present, in an amount of up to 10,000 ppm, preferably up to 5,000 ppm, more preferably up to 3,000 ppm, up to 2,500 ppm or up to 2,000 ppm.
The additives (a) and/or (b) are preferably included in the composition of the first aspect, when present, in an amount of from 100 to 10,000 ppm, from 200 to 3,000 ppm, from 350 to 3,000 ppm or from 400 ppm to 2,500 ppm.
In embodiments wherein both (a) and (b) are present, the combined amounts of additives (a) and (b) present in the composition are suitably as described above.
In this specification any reference to ppm is to parts per million by volume.
The additive may also comprise a carrier or diluent. Therefore, the additive may be added to the composition as an additive composition comprising the additive(s) and said carrier or diluent.
Preferred carriers and diluents are aromatic hydrocarbon compounds, especially C10 alkyl naphthalene.
In some embodiments the composition of the first aspect may be used as a middle distillate fuel oil. Thus, the composition may include one or more further additives such as those which are commonly found in diesel fuels. These include, for example, antioxidants, dispersants, detergents, metal deactivating compounds, wax anti-settling agents, cold flow improvers, cetane improvers, dehazers, stabilisers, demulsifiers, antifoams, corrosion inhibitors, lubricity improvers, dyes, markers, combustion improvers, metal deactivators, odour masks, drag reducers and conductivity improvers. Examples of suitable amounts of each of these types of additives will be known to the person skilled in the art.
The inclusion of additives (a) and/or (b) has surprisingly been found to decrease the pour point of compositions comprising pyrolysis oils. The decrease in the pour points of such compositions is suitably at least 5° C., at least 10° C., at least 15° C. or at least 20° C., compared to a similar composition comprising pyrolysis oil lacking additives (a) and (b) (i.e. an unadditised composition comprising pyrolysis oil). Such an unadditised composition comprising pyrolysis oil suitably does not comprise other pour point depressants. Such an unadditised composition comprising pyrolysis oil may contain other additives, for example antioxidants such as component (d) defined below.
In some embodiments, the composition of this first aspect comprises a further additive (c) selected from one or more of:
The inventors have found that the combination of further additive (c), which does not comprise the groups having at least 30 carbon atoms discussed above, with the additives (a) or (b), which do comprise groups having at least 30 carbon atoms, may provide a further lowering of the pour point in the compositions of this first aspect of the present invention comprising pyrolysis oil. This combination may provide a synergistic effect in the reduction of the pour point of said compositions comprising pyrolysis oil.
For the avoidance of doubt, suitably neither additive (c1) nor additive (c2) comprise significant amounts of compounds comprising alkyl groups or alkyl chains having 30 carbon atoms or more. Such additives are often obtained as mixtures and may contain some compounds with alkyl groups or alkyl chains having at least 30 carbon atoms. However, suitably less than 50 wt % of the alkyl groups or alkyl chains present in the additive have at least 30 carbon atoms, suitably less than 25 wt %, less than 10 wt % or less than 5 wt %. Suitably additive (c1) and/or additive (c2) are substantially free of alkyl groups or alkyl chains having 30 carbon atoms or more.
In embodiments wherein additive (c) is additive (c1) an aldehyde-alkylphenol copolymer and/or an aldehyde-alkylphenol-polyamine copolymer, said copolymers are suitably the reaction product of, as monomers, an aldehyde, an alkylphenol and optionally a polyamine, wherein the alkyl group of the alkylphenol has fewer than 30 carbon atoms.
The alkyl group of the alkylphenol of additive (c1) suitably has from 12 to 28 carbon atoms, preferably from 16 to 28 carbon atoms, from 18 to 26 carbon atoms or most preferably from 20 to 24 carbon atoms. The alkyl group may be linear or branched.
In embodiments wherein additive (c) is additive (c2), the additive is suitably an ester, amide, imide or amine salt derivative of the copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound. Additive (c2) is suitably formed by reacting the carboxylate moiety of the ethylenically unsaturated carboxylate sub-units of the copolymer with a suitable alcohol or amine.
The alpha-olefin used to form additive (c2) suitably has from 12 to 28 carbon atoms, preferably from 16 to 28 carbon atoms, from 18 to 26 carbon atoms or most preferably from 20 to 24 carbon atoms. The alpha-olefin may be linear or branched.
The ethylenically unsaturated carboxylate compound used to form additive (c2) is suitably as defined above for additive (b).
The alcohol and/or amine used to form additive (c2) is suitably a C12-C28 alcohol or amine, or a mixture thereof, suitably a C16-C24 alcohol or amine, preferably a C18-C22 alcohol or amine. Therefore, the copolymer of additive (c2) suitably comprises C12-C28 ester, amide, imide or amine salt moieties, preferably C16-C24 or C18-C22 ester, amide, imide or amine salt moieties. The alcohols or amines may be branched or linear. Suitably the alcohols or amines are linear. The alcohols or amines may be saturated, unsaturated, or a mixture of both.
In such embodiments comprising further additive (c), the ratio of the total amount of additive (a) and/or (b) present in the composition to the amount of additive (c) present is suitably from 2:1 to 1:3, suitably from 1.5:1 to 1:2, suitably from 1:1 to 1:1.6.
In some embodiments the composition of the first aspect comprises (d) an antioxidant. Mixtures of two or more antioxidants may be present.
Suitable antioxidants for use herein include phenolic antioxidants, and amino based antioxidants.
Suitable amino based antioxidants include aromatic amines, hindered amines, N-oxides, polyalkylene polyamines; and polyisobutenyl substituted succinimides.
Suitable aromatic amines include diaminobenzene and alkylated diamino benzenes, especially dialkylated and trialkylated diaminobenzenes, for example p-phenylenediamine, 3,5-diethyltoluene-2,4-diamine; 3,5-diethyltoluene-2,2-diamine; 2,4,6-triethylbenzene-2,6-diamine alkylated diphenyl amines; diphenylamines and alkylated diphenylamines, for example N,N-diphenyl-1,4-phenylenediamines; and naphthylamines, for example N-phenyl-1-napthylamine and N-phenyl-2-naphthylamine.
Suitable hindered amines include secondary and tertiary aliphatic amines, for example dimethyl cyclohexylamine and diethylhydroxylamine.
Suitable N-oxides include TEMPO and derivatives thereof.
Polyisobutenyl substituted succinimides are known to those skilled in the art and their use as antioxidants is described in WO2009/016400, for example.
In some embodiments, (d) is a phenolic antioxidant.
In some embodiments the composition of the first aspect comprises an amino based and a phenolic antioxidant.
Any suitable phenolic antioxidant may be used. Suitable antioxidants will be known to the person skilled in the art.
By phenolic antioxidant compound we mean to include any compound which contains a phenol moiety i.e., a benzene ring which is substituted with a hydroxyl group. This may be a very simple compound, for example a benzene diol, alkyl substituted phenol or a benzene triol. Alternatively, the phenolic antioxidant may be part of a more complex molecule. It may include two phenol moieties, for example, see the compounds disclosed in US 2006/0219979.
Suitable phenolic antioxidant compounds for use in the present invention include those of formula (III):
wherein R1 is selected from an optionally substituted alkyl or alkenyl group, an aryl group, an aralkyl group; an ester, a carboxylic acid, an aldehyde, a ketone, an ether, an alcohol, an amine or an amide; R2 and R3 are independently selected from hydrogen, an optionally substituted alkyl or alkenyl group, an aryl group, an ester group, a ketone, an aldehyde, a carboxylic acid, an ether, an alcohol, an amine or an amide; and n is an integer from 1 to 5.
Preferably R1 is an alkyl group, preferably having 1 to 9 carbon atoms, and may be straight chained or branched. Preferably R1 is selected from methyl, ethyl, isopropyl, and tertiary butyl. R1 and R2 may together form a cyclic substituent, either alkyl or aryl. R2 and R3 are preferably hydrogen or an alkyl group having 1 to 9 carbon atoms. Preferably R2 and R3 are independently selected from hydrogen, methyl, ethyl, tertiary butyl and isopropyl. Preferably n is 1, 2 or 3.
Preferred phenolic antioxidant compounds for use in the present invention are substituted benzene compounds having 1 or more hydroxy substituents. Examples include tertiarybutylhydroquinone (TBHQ or MTBHQ), 2,5-di-tertiarybutylhydroquinone (DTBHQ), pyrogallol, pyrocatechol 2,6-di-tert-butyl-4-methylphenol (BHT), 2,6-ditertiary-butyl-phenol, propylgallate and tertiarybutylcatechol.
One especially preferred phenolic antioxidant for use herein is 2,6-ditertiary-butyl-phenol. However, as the skilled person will appreciate, commercial sources of this compound often comprise mixtures including mono-, tertiary- and tritertiary-butyl-phenols.
The antioxidant (d), when 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 50 ppm, for example at least 70 ppm.
The antioxidant (d), when present, may be included in the composition of the first aspect in an amount of up to 10,000 ppm, preferably up to 5,000 ppm, more preferably up to 2,000 ppm, for example up to 1,000 ppm.
In a preferred embodiment, the composition of the first aspect comprises from 100 to 1,000 ppm, preferably 250 to 750 ppm of (d) an antioxidant and 100 to 10,000 ppm, preferably from 400 ppm to 2,500 ppm of the additive (a) and/or (b).
According to a second aspect of the present invention there is provided a method of reducing the pour point of a composition comprising a pyrolysis oil, the method comprising adding to the composition one or more additives selected from:
The additives (a) and (b) used in the method of this second aspect may have any of the suitable features and advantages described in relation to the first aspect.
The composition comprising a pyrolysis oil used in the method of this second aspect may have any of the suitable features and advantages described in relation to the first aspect.
The composition comprising a pyrolysis oil used in the method of this second aspect may comprise component (d) an antioxidant as defined in relation to the first aspect.
According to a third aspect of the present invention there is provided a use of one or more additives to reduce the pour point of a composition comprising a pyrolysis oil, wherein the one or more additives are selected from:
The additives (a) and (b) used in this third aspect may have any of the suitable features and advantages described in relation to the first aspect.
The composition comprising a pyrolysis oil used in this third aspect may have any of the suitable features and advantages described in relation to the first aspect.
The composition comprising a pyrolysis oil used in this third aspect may comprise component (d) an antioxidant as defined in relation to the first aspect.
The method of the second aspect or the use of the third aspect suitably provides a reduction in the pour point of the composition is of at least 5° C., at least 10° C., at least 15° C. or at least 20° C. Such reductions are suitably relative to a similar composition comprising pyrolysis oil lacking additives (a) and (b) (i.e. an unadditised composition comprising pyrolysis oil). Such an unadditised composition comprising pyrolysis oil suitably does not comprise other pour point depressants. Such an unadditised composition comprising pyrolysis oil may contain other additives, for example antioxidants such as component (d) defined above.
The method of the second aspect or the use of the third aspect may also provide one or more of the following to the composition:
Such improvements in further low temperature properties may be an decrease in the cloud point, mitigation of viscosity change with temperature change and/or lowering the viscosity of the composition at or near the pour point of the unadditised fluid.
In the method of the second aspect or the use of the third aspect, additive (a) and/or (b) may be added to the composition comprising the pyrolysis oil at any time, including during the process itself. It is preferred that the additive(s) are added as soon as possible after synthesis of the oil, preferably before the oil cools.
The method and use of the present invention decreases the pour point of a composition comprising a pyrolysis oil.
Preferably the method and use of the present invention decreases the pour point of a composition comprising a plastic pyrolysis oil.
The method and use of the present invention may also improve the stability of a composition comprising a pyrolysis oil.
The method and use of the present invention may improve the stability of a composition comprising a plastic pyrolysis oil.
The method and use of the present invention may improve the storage stability of compositions comprising a pyrolysis oil.
The method and use of the present invention may improve the storage stability of composition comprising a plastic pyrolysis oil.
An improvement in storage stability suitably results in a reduction in degradation of the oil in storage. This may be observed in a number of ways.
In some embodiments the improvement in stability may provide reduced sedimentation.
In some embodiments the improvement in stability may reduce or prevent increases in viscosity.
In some embodiments the improvement in stability may provide improved filterability, particularly after storage.
In some embodiments the improvement in stability may provide an improvement in low temperature properties of the composition comprising the pyrolysis oil.
In some embodiments, the use of this third aspect is to reduce the pour point of a composition comprising a pyrolysis oil and an additive (c), wherein additive (c) is as defined in relation to the first aspect.
In such embodiments, additive (c) is suitably selected from one or more of: (c1) an aldehyde-alkylphenol copolymer and/or an aldehyde-alkylphenol-polyamine copolymer, wherein the alkylphenol of the copolymer comprises an alkyl group having fewer than 30 carbon atoms; and (c2) the reaction product of an alcohol and/or amine with a copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound, wherein the alpha-olefin, the alcohol and the amine, when present, have fewer than 30 carbon atoms.
In such embodiments additive (c) is suitably additive (c2) as defined above.
Therefore this third aspect of the invention may provide a use of one or more of additives (a) and (b) in combination with one or more of additives (c1) and (c2) to reduce the pour point of a composition comprising a pyrolysis oil. Suitably the use involves one or more of additives (a) and (b) in combination with one or more of additives (c2) to reduce the pour point of a composition comprising a pyrolysis oil.
In such embodiments, the use may involve a synergistic reduction of the pour point of the composition comprising a pyrolysis oil, provided by the combination of additive (a) and/or additive (b) with additive (c1) and/or additive (c2). Suitably the use involves a synergistic reduction of the pour point of the composition comprising a pyrolysis oil, provided by the combination of additive (a) and/or additive (b) with additive (c2).
According to a fourth aspect of the present invention there is provided a use of one or more additives selected from:
In such embodiments, additive (c) is selected from one or more of:
Suitably additive (c) is (c2) the reaction product of an alcohol and/or amine with a copolymer of an alpha-olefin and an ethylenically unsaturated carboxylate compound, wherein the alpha-olefin, the alcohol and the amine, when present, have fewer than 30 carbon atoms.
The additives (a) and (b) used in this third aspect may have any of the suitable features and advantages described in relation to the first aspect.
Additive (c) is suitably as defined in relation to the first aspect.
The composition comprising a pyrolysis oil used in this fourth aspect may have any of the suitable features and advantages described in relation to the first aspect.
The composition comprising a pyrolysis oil used in this fourth aspect may comprise component (d) an antioxidant as defined in relation to the first aspect.
The use of the fourth aspect suitably provides a reduction in the pour point of the composition is of at least 5° C., at least 10° C., at least 15° C. or at least 20° C. Such reductions are suitably relative to a similar composition comprising pyrolysis oil and an additive (c) but lacking additives (a) and (b). Such a composition comprising pyrolysis oil and additive (c) may contain other additives, for example antioxidants such as component (d) as defined above.
The invention will now be further described with reference to the following non-limiting examples.
Additive Composition A is a commercially available composition comprising an aldehyde-alkylphenol copolymer according to the definition of additive (a) described above and a solvent, Solvesso 150. This additive is formed from formaldehyde and an alkylphenol wherein the alkylphenol is a mixture of compounds having alkyl groups with at least 30 carbon atoms. The additive is a linear polymer having a relatively high number average molecular weight of from 5,000 to 7,000. The amount of the aldehyde-alkylphenol copolymer present in Additive Composition A (wt % of active) was 48-52 wt %.
Additive Composition B comprises an OMAC ester according to the definition of additive (b) described above. This additive is formed by reacting an alpha olefin comprising at least 82 wt % of alpha olefin compounds having at least 30 carbon atoms with maleic anhydride to form an alpha-olefin maleic anhydride copolymer. This copolymer is then esterified with 1.0 mole equivalents of a C18-C22 alcohol, with respect to the maleic anhydride monomer used, to provide the additive. The amount of the OMAC ester present in Additive Composition B (wt % of active) was 70-75 wt %.
Additive Composition C comprises an OMAC ester according to the definition of additive (b) described above. Additive Composition C is formed by reacting an alpha olefin comprising approximately 50 wt % of a commercially sold ‘C30+’ alpha olefin compound and approximately 50 wt % of C24-C28 alpha olefins with maleic anhydride to form an alpha-olefin maleic anhydride copolymer. This copolymer is then esterified with 1.0 mole equivalents of a C18-C22 alcohol, with respect to the maleic anhydride monomer used, to provide the additive. The amount of OMAC ester present in Additive Composition C (wt % of active) was 75-80 wt %.
Comparative Additive Composition D is a commercially available composition comprising an aldehyde-alkylphenol copolymer and a solvent, Solvesso 150. The copolymer is formed from formaldehyde and an alkylphenol wherein the alkylphenol is a mixture of compounds having C24-C28 alkyl groups. The amount of the aldehyde-alkylphenol copolymer present in the composition (wt % of active) was 48-52 wt %.
Comparative Additive Composition E is an OMAC ester formed by reacting C24-C28 alpha olefins with maleic anhydride to form an alpha-olefin maleic anhydride copolymer. This copolymer is then esterified with 1.0 mole equivalents of a C18-C22 alcohol, with respect to the maleic anhydride monomer used, to provide the additive. The amount of OMAC ester present in the composition (wt % of active) was 75-80 wt %.
Comparative Additive Composition F is a commercially available OMAC ester formed by reacting C24-28 alpha-olefins with maleic anhydride and then esterifying with 0.5-1.0 moles C18-22 fatty alcohol (with respect to the maleic anhydride monomer). The amount of OMAC ester present in the composition (wt % of active) was 75-80 wt %.
Comparative Additive Composition G is a commercially available OMAC ester formed by reacting C20-24 alpha-olefins with maleic anhydride and then esterifying with 0.5-1.0 moles C18-22 fatty alcohol (with respect to the maleic anhydride monomer). The amount of OMAC ester present in the composition (wt % of active) was 70-75 wt %.
Comparative Additive Composition H is a commercially available polyalkylated phenol additive. The amount of the additive present in the composition (wt % of active) was approximately 50 wt %.
Additive Composition I comprises an OMAC ester according to the definition of additive (b) described above. Additive Composition I is formed by reacting an alpha olefin comprising approximately 30 wt % of a commercially sold ‘C30+’ alpha olefin product and approximately 70 wt % of a C24-C28 alpha olefin product with maleic anhydride to form an alpha-olefin maleic anhydride copolymer. This copolymer is then esterified with 0.5-1.0 mole equivalents of an alcohol with respect to the maleic anhydride monomer used, to provide the additive. The alcohol is a mixture of C16-C26 linear fatty alcohols comprising approximately 50 wt % of C20 alcohols. The amount of OMAC ester present in Additive Composition I (wt % of active) was 70-75 wt %.
In the following example and comparative compositions, the additives were added to a plastic-derived pyrolysis oil having the following specification.
The following example and comparative compositions were formed by admixing the stated additive into the pyrolysis oil defined above, at the stated dosage.
Example 1 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Additive A.
Example 1b comprised the pyrolysis oil described above and 1,000 ppm (by volume) of Additive A.
Example 1c comprised the pyrolysis oil described above and 500 ppm (by volume) of Additive A.
Example 2 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Additive B.
Example 2b comprised the pyrolysis oil described above and 1,000 ppm (by volume) of Additive B.
Example 3 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Additive C.
Example 4 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of a 1:1 weight ratio of Additive A and Comparative Additive Composition E.
Example 5 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of a 1:1 weight ratio of Additive A and Comparative Additive Composition F.
Example 6 comprised the pyrolysis oil described above 2,000 ppm (by volume) of a 1:1 weight ratio of Additive B and Comparative Additive Composition E.
Comparative Example 1 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Comparative Additive D.
Comparative Example 2 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Comparative Additive E.
Comparative Example 3 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Comparative Additive Composition F.
Comparative Example 4 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Comparative Additive Composition G.
Comparative Example 5 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Comparative Additive Composition H.
The pour points of the example compositions comprising additive types (a) or (b) were determined alongside an unadditised control and comparative compositions comprising different additives, using the method of ASTM D97. In a minor modification to the method of ASTM D97, 20 ml samples of the base pyrolysis oil were used in these tests.
The pour points of the compositions are shown below in Table 1.
The change in pour point of the composition compared to the control is provided in parenthesis after the pour point.
Additives A and B were also tested at different dosage levels—500 ppm (Example 1c), 1,000 ppm (Example 1b/2b) and 2,000 ppm (Example 1/2) in the pyrolysis oils, in separate tests. The results are shown in Table 2 below.
The results show that the compositions of the present invention (Examples 1, 1b, 1c, 2, 2b, 3, 4, 5 and 6) comprising additives of type (a) and (b) as defined herein (Additives Compositions A, B and C) have significantly lower pour points than the unadditised control composition comprising only the pyrolysis oil and the comparative compositions comprising additives which do not comprise significant amounts of C30+ alkyl chains. The pour points of the compositions of Examples 1-6 were between 14 and 31° C. lower than the control and comparative compositions. The results of Examples 4-6 also show a synergistic effect of combining additives of type (a) and (b) with OMAC ester additives which do not comprise groups having greater than 30 carbon atoms and which have no pour depressant activity when used on their own.
Such decreases in the pour points of these compositions of the present invention are expected to provide significant advantages in the handling and use of such pyrolysis oils, for example plastic waste-derived pyrolysis oils. This may facilitate the utilization of such pyrolysis oils in the production of fuels and chemical feedstocks and therefore provide beneficial uses for plastic waste to reduce the amount of such waste entering landfill or polluting the oceans. Therefore such potential improvements to pyrolysis oils are expected to provide significant overall environmental benefits.
The following example and comparative compositions were formed by admixing the stated additive into a waste plastic pyrolysis oil at the stated dosage. The waste plastic pyrolysis oil was a different commercially produced waste plastic pyrolysis oil sourced in the USA, and was conditioned at 160° F.
Example 2.1 comprised the pyrolysis oil described above and 1,000 ppm (by volume) of Additive I.
Example 2.2 comprised the pyrolysis oil described above and 1,000 ppm (by volume) of Additive A.
Example 2.3 comprised the pyrolysis oil described above and 1,500 ppm (by volume) of Additive A.
Example 2.4 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Additive I.
Example 2.5 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Additive C.
Example 2.6 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Additive A.
Comparative Example 2.1 comprised the pyrolysis oil described above and 1,000 ppm (by volume) of Comparative Additive E.
Comparative Example 2.2 comprised the pyrolysis oil described above and 1,000 ppm (by volume) of Comparative Additive F.
Comparative Example 2.3 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Comparative Additive E.
Comparative Example 2.4 comprised the pyrolysis oil described above and 2,000 ppm (by volume) of Comparative Additive F.
The pour points of the set 2 example compositions comprising additive types (a) or (b) were determined alongside an unadditised control and comparative compositions comprising different additives, using the modified method of ASTM D97 described above.
The pour points of the compositions are shown below in Table 3.
The change in pour point of the composition compared to the control is provided in parenthesis after the pour point.
These results show that the compositions of the present invention (Examples 2.1-2.6) comprising additives of type (a) and (b) as defined herein (Additives Compositions A, C and I) have significantly lower pour points than both the unadditised control composition comprising only the pyrolysis oil and the comparative compositions comprising additives which do not comprise significant amounts of C30+ alkyl chains. The pour points of the compositions of Examples 2.1-2.6 were between 13 and 25° C. lower than the control and comparative compositions.
As noted above for example set 1, such decreases in the pour points of these compositions of the present invention of example set 2 are expected to provide significant advantages in the handling and use of such pyrolysis oils, for example plastic waste-derived pyrolysis oils. This may facilitate the utilization of such pyrolysis oils in the production of fuels and chemical feedstocks and therefore provide beneficial uses for plastic waste to reduce the amount of such waste entering landfill or polluting the oceans. Therefore such potential improvements to pyrolysis oils are expected to provide significant overall environmental benefits.
Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.
Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of other components. The term “consisting essentially of” or “consists essentially of” means including the components specified but excluding other components except for materials present as impurities, unavoidable materials present as a result of processes used to provide the components, and components added for a purpose other than achieving the technical effect of the invention. Typically, when referring to compositions, a composition consisting essentially of a set of components will comprise less than 5% by weight, typically less than 3% by weight, more typically less than 1% by weight of non-specified components.
The term “consisting of” or “consists of” means including the components specified but excluding addition of other components.
Whenever appropriate, depending upon the context, the use of the term “comprises” or “comprising” may also be taken to encompass or include the meaning “consists essentially of” or “consisting essentially of”, and may also be taken to include the meaning “consists of” or “consisting of”.
For the avoidance of doubt, wherein amounts of components in a composition are described in wt %, this means the weight percentage of the specified component in relation to the whole composition referred to.
The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each aspect or exemplary embodiment of the invention as set out herein are also to be read as applicable to any other aspect or exemplary embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each exemplary embodiment of the invention as interchangeable and combinable between different exemplary embodiments.
Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
All of the features disclosed in this specification (including any accompanying claims, and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
Each feature disclosed in this specification (including any accompanying claims, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
| Number | Date | Country | |
|---|---|---|---|
| 63445380 | Feb 2023 | US |
