GB2507675A

GB2507675A - Fuel additive composition

Info

Publication number: GB2507675A
Application number: GB1400705.8A
Authority: GB
Inventors: Robert Leslie Hall; Julia Mansfield; Neil Ryding
Original assignee: FUEL ADDITIVE SCIENCE TECHNOLOGIES Ltd
Current assignee: FUEL ADDITIVE SCIENCE TECHNOLOGIES Ltd
Priority date: 2012-12-13
Filing date: 2013-12-12
Publication date: 2014-05-07
Anticipated expiration: 2033-12-12
Also published as: GB2507675B; GB201400705D0

Abstract

The present invention relates to fuel additive compositions and additised fuels. In particular, the invention relates to additives for kerosene used in domestic oil-fired pressure-jet boilers. The fuel additive compositions of the invention include a dispersant; a demulsifier; a metal deactivator; and an antioxidant. Specifically, the additive compositions contain 9-14 parts polyisobutylene succinimide, 4-7 parts alkoxylated phenol-formaldehyde resin-containing demulsifier composition, 1-16 parts N,N-disalicylidene1,2-diaminopropane, 7-10.5 parts 2,6-di-tert-butylphenol and 7-10.5 parts amine-aldehyde condensate antioxidant. Together these ingredients bring a range of instantaneous benefits, including enhanced fuel performance, reduced deposits, improved fuel economy/fuel consumption and reduced emissions.

Description

FUEL ADDITIVE COMPOSITION

HELD OF THE INVENTION

[0001] The present invention relates to a fuel additive composition for use in fuels, particularly fuels such as kerosene used in domestic oil-fired boilers. The present invention also relates to fuel compositions comprising the fuel additive compositions of the invention or comprising the respective ingredients thereof, a fuel combustion system for combusting said fuel compositions, a method of combusting said fuel compositions, and uses of the fuel additive compositions of the invention or respective ingredients thereof to achieve a wide range of benefits, including inter a/ia improved fuel performance, reduced deposits, and reduced emissions.

BACKGROUND OF THE INVENTION

[0002] Combustion systems, such as burners (e.g. boilers), engines (e.g. internal combustion engine of motor vehicles), and furnaces, are typically fuelled by hydrocarbon fuels. Combustible liquid hydrocarbon fuels are particularly widely used, owing to their ease of manufacture (e.g. via fractional distillation of crude petroleum), and their ease of use, storability and transportability. For instance, petrol (gasoline), typically comprising C5 to C10 hydrocarbons, is widely used as a fuel for the internal combustion engines of cars. Diesel fuels, typically comprising C14 to C20 hydrocarbons, are also widely used as a fuel in cars, trucks and trains.

Kerosene (paraffin oils), typically comprising C10 to C16 hydrocarbons, is widely used as a jet fuel in aeroplanes, but is also used as fuel in domestic heating boilers.

[0003] Fuels such as these, especially the heavier fractions, upon combustion can yield deposits which contaminate the combustion systems in which they burn. In particular, fuel injectors and burner nozzles can become blocked by deposits left by the combusted fuels, which can compromise the ongoing efficiency and functioning of the combustion system.

[0004] In recent times, various fuel additives have been identified and developed for use in hydrocarbon fuels to address some of the problems of dirty-burning fuels. In fact, legislation in the United States requires that all gasolines are treated with deposit control additives (DCAs, which are generally detergents), in order that fuel lines and fuel injectors are suitably cleansed to allow optimal air/fuel mixing and therefore efficient combustion.

[0005] Deposit control can be a particular problem in pressure-jet oil-fired heating boilers.

Pressure-jet oil-fired heating boilers operate by burning a fine spray liquid fuel (e.g. kerosene) that is pumped, from a fuel storage tank, through a burner nozzle. Heat from the resulting flame is transferred, via a suitable heat-exchanger, to water circulated within a central heating system (e.g. through radiators and such like) in order to heat the surrounding environment. Typically, such boilers are thermostatically controlled in order to achieve a desired temperature in the surrounding environment.

[0006] Most domestic heating boilers lose efficiency during the period between services without the home occupants knowing about it, because the boiler still runs. Efficiency losses tend to arise due to poor air/fuel mixing resulting from nozzle deposits/blockages. This can lead to incomplete combustion of the relevant fuel. Moreover, deposits that build up on heat transfer surfaces reduce heat transfer efficiency, thereby compromising the overall operating efficiency of the boiler.

[0007] Other problems associated with pressure-jet oil-fired boilers, and their respective fuels, include poor fuel performance and fuel consumption; poor boiler efficiency; incomplete combustion of fuels; high emissions of carbon dioxide and carbon monoxide; poor air-fuel mixing; poor water-handling (e.g. where water can collect and mix with fuel in a fuel storage tank); deposit build-ups (e.g. on nozzles and heat exchangers); system breakdowns (e.g. where luminosity sensors are masked by deposits); corrosion of internal parts; frequent servicing requirements; precipitation of fuels on storage (e.g. in storage tanks); pre-filtration requirements with respect to the fuel (e.g. to remove precipitates and/or sediment); the requirement that fuels must be relatively clean.

[0008] It is therefore an object of the present invention to solve at least one of the problems

inherent with the prior art.

[0009] Another object of the present invention is to improve fuel performance.

[0010] Another object of the invention is to improve fuel consumption.

[0011] Another object of the invention isto improve the efficiency of fuel combustion systems.

[0012] Another object of the invention is to improve the completeness of combustion of a fuel within a fuel combustion system.

[0013] Another object of the invention is to instantaneously reduce emissions from a fuel combustion system.

[0014] Another object of the invention is to improve air-fuel mixing within a fuel combustion system.

[0015] Another object of the invention is to improve water handling within a fuel combustion system.

[0016] Another object of the invention is to reduce the build up of deposits within a fuel combustion system.

[0017] Another object of the invention is to reduce the risk of breakdown of a fuel combustion system.

[0018] Another object of the invention is to protect component parts of a fuel combustion system.

[0019] Another object is to improve corrosion inhibition within a fuel combustion system.

[0020] Another object is to reduce the amount of servicing required of the relevant combustion system.

[0021] Another object is to reduce precipitate of the relevant fuels on storage.

[0022] Another object is to achieve any of the benefits described herein instantaneously.

[0023] Another object is to achieve two or more, or all of the aforementioned objectives.

SUMMARY OF THE INVENTION

[0024] According to a first aspect of the present invention, there is provided a fuel additive composition (suitably for pressure-jet boilers), comprising: i) a dispersant; U) a demulsifier; Hi) a metal deactivator; and iv) an antioxidant.

[0025] According to a second aspect of the present invention, there is provided a fuel composition (suitably for pressure-jet boilers) comprising a base fuel and a fuel additive composition of the first aspect.

[0026] According to a third aspect of the present invention, there is provided a fuel composition (suitably for pressure-jet boilers) comprising a base fuel and: i) a dispersant; U) a demulsifier; Ui) a metal deactivator; and iv) an antioxidant.

[0027] According to a third aspect of the present invention, there is provided a fuel composition (suitably for pressure-jet boilers) comprising a base fuel and: i) a dispersant; U) a demulsifier; iii) a metal deactivator; and iv) an antioxidant; wherein the fuel composition comprises at most 45 ppm of both dispersant and demulsifier combined (i.e. the sum of the individual treat rate for each ingredient).

[0028] According to a fourth aspect of the present invention, there is provided a fuel combustion system (e.g. pressure-jet boiler) for combusting a fuel composition as defined herein, comprising: a) a fuel storage unit comprising a fuel composition as defined herein; b) a combustion unit fluidly connectable to the fuel storage unit and operable to combust the fuel composition provided to the combustion unit from the fuel storage unit.

[0029] According to a fifth aspect of the present invention, there is provided a method of combusting a fuel composition, comprising providing a fuel composition as defined herein and combusting the fuel composition.

[0030] According to a sixth aspect of the present invention, there is provided a use, in a fuel combustion system, of: i) a dispersant; U) a demulsifier; Ui) a metal deactivator; and iv) an antioxidant; for one or more or all of the following: a) improving fuel performance; b) improving fuel consumption; c) improving the efficiency of the fuel combustion system; d) improving the completeness of combustion of a fuel composition by the fuel combustion system; e) reducing emissions from the fuel combustion system; f) improving air-fuel mixing within the fuel combustion system; g) improving water handling within the fuel combustion system; h) reducing the build up of deposits within the fuel combustion system; i) reducing the risk of breakdown of the fuel combustion system; j) protecting component parts of the fuel combustion system; k) improving corrosion inhibition within the fuel combustion system; I) reducing the amount of servicing required of the combustion system; m) reducing precipitation on storage of the fuel; n) reducing or eliminating pro-filtration of fuels prior to combustion of said fuels; and o) enhancing the beneficial impact of replacing one or more dirty components within the combustion system with corresponding clean components.

[0031] According to a seventh aspect of the present invention, there is provided a use, in a fuel combustion system, of: i) a dispersant; ii) a demulsifier; iii) a metal deactivator; and iv) an antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for achieving one or more or all of the following benefits: a) improving fuel performance; b) improving fuel consumption; c) improving the efficiency of the fuel combustion system; d) improving the completeness of combustion of a fuel composition by the fuel combustion system: e) reducing emissions from the fuel combustion system; f) improving air-fuel mixing within the fuel combustion system; g) improving water handling within the fuel combustion system; h) reducing the build up of deposits within the fuel combustion system; i) reducing the risk of breakdown of the fuel combustion system; j) protecting component parts of the fuel combustion system; k) improving corrosion inhibition within the fuel combustion system; I) reducing the amount of servicing required of the combustion system; m) reducing precipitation on storage of the fuel; n) reducing or eliminating pro-filtration of fuels prior to combustion of said fuels; and a) enhancing the beneficial impact of replacing one or more dirty components within the combustion system with corresponding clean components; wherein one or more of the benefit(s) are instantaneous (e.g. any one or more of benefits a)-g) and o)).

[0032] According to an eighth aspect of the present invention, there is provided a use, in a fuel combustion system, of: i) a dispersant; ii) a demulsifier; iii) a metal deactivator; and iv) an antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for achieving one or more or all of the following benefits: a) improving fuel consumption; b) improving the efficiency of the fuel combustion system; c) reducing emissions from the fuel combustion system; d) improving water handling within the fuel combustion system; e) reducing the risk of breakdown of the fuel combustion system; and f) enhancing the beneficial impact of replacing one or more dirty components (e.g. a burner nozzle) within the combustion system with corresponding clean components; wherein one or more of the benefit(s) are instantaneous.

[0033] According to a ninth aspect of the present invention, there is provided a use, in a fuel combustion system, of: i) a dispersant; ii) a demulsifier; iii) a metal deactivator; and iv) an antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for achieving all of the following benefits: a) improving fuel consumption; b) improving the efficiency of the fuel combustion system; c) reducing emissions from the fuel combustion system; wherein all of the benefits are instantaneous.

[0034] According to a tenth aspect of the present invention, there is provided a use, in a fuel combustion system, of: i) a dispersant; U) a demulsifier; Ui) a metal deactivator; and iv) an antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for achieving one or more or all of the following benefits: a) reducing emissions from the fuel combustion system; b) improving water handling within the fuel combustion system; c) reducing the risk of breakdown of the fuel combustion system; and d) enhancing the beneficial impact of replacing one or more dirty components (e.g. a burner nozzle) within the combustion system with corresponding clean components; wherein one or more of the benefit(s) are instantaneous.

[0035] According to an eleventh aspect of the present invention, there is provided a use, in a fuel combustion system, of: i) a dispersant; U) a demulsifier; Ui) a metal deactivator; and iv) an antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for achieving all of the following benefits: a) reducing emissions from the fuel combustion system; b) improving the efficiency of the fuel combustion system; and c) reducing the risk of breakdown of the fuel combustion system; wherein one or more of the benefit(s) are instantaneous.

[0036] According to a twelfth aspect of the present invention, there is provided a use, in a fuel combustion system, of:

S

i) a dispersant; U) a demulsifier; iii) a metal deactivator; and iv) an antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for both: reducing emissions from the fuel combustion system; and reducing the risk of breakdown of the fuel combustion system; wherein the reduction in emissions from the fuel combustion system is instantaneous.

[0037] According to a thirteenth aspect of the present invention, there is provided a use, in a fuel combustion system, of: i) a dispersant; ii) a demulsifier; iii) a metal deactivator; and iv) an antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for achieving one or more or all of the following benefits: a) reducing emissions from the fuel combustion system; b) reducing the risk of breakdown of the fuel combustion system; and wherein one or more of the benefit(s) are instantaneous.

[0038] According to a fourteenth aspect of the present invention, there is provided a use, in a fuel combustion system, of: i) a dispersant; U) a demulsifier; Ui) a metal deactivator; and iv) an antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for reducing emissions from the fuel combustion system; wherein the reduction in emissions from the fuel combustion system is instantaneous.

[0039] According to a fifteenth aspect of the present invention, there is provided a use, in a fuel combustion system, of: i) a dispersant; ii) a demulsifier; iii) a metal deactivator; and iv) an antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for improving the efficiency of the fuel combustion system; wherein the improvement in the efficiency of the fuel combustion system is instantaneous.

[0040] According to a sixteenth aspect of the present invention, there is provided a method of obtaining any one or more of the abovementioned benefits (or groups of benefits as defined herein in relation to a use) in a fuel combustion system, the method comprising operating the fuel combustion system with a fuel composition as defined herein (e.g. the third aspect).

[0041] According to a seventeenth aspect of the present invention, there is provided a kit of parts, comprising all of the components of a fuel additive composition as defined herein (whether the components are provided separately or with any combination of one or more of said components mixed together), for example: i) a dispersant; ii) a demulsifier; iii) a metal deactivator; and iv) an antioxidant.

[0042] According to a eighteenth aspect of the present invention, there is provided a fuel additive composition, a kit of parts, a fuel composition, or a fuel combustion system as defined herein, for obtaining any one or more of the abovementioned benefits (or groups of benefits as defined herein in relation to a use) when used in a fuel combustion system.

[0043] Features, including optional, suitable, and preferred features in relation to one aspect of the invention may also be features, including optional, suitable and preferred features in relation to any other aspect of the invention, except where the particular context renders this undesirable or impossible.

BRIEF DESCRIPTION OF THE DRA WINGS

[0044] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which: [0045] Figure 1 is a photograph showing water separation in a measuring cylinder between kerosene and 10% water with no additives; [0046] Figure 2 is a photograph showing water separation in a measuring cylinder between kerosene and 10% water with an additive of the invention (of Example 1) and a dye; [0047] Figure 3 is a photograph showing water separation in a measuring cylinder between kerosene and 10% water with anadditive of the invention (of Example 1) without any dye; [0048] Figure 4 is a photograph showing water separation in a measuring cylinder between kerosene and 10% water with an older-technology additive (of Example 1 A) without any dye; [0049] Figure 5 is a bar chart showing the correlation between the thickness of soot deposits within a boiler system and the % fuel energy loss; [0050] Figure 6 shows the impact of mechanically cleaning a boiler light cell by monitoring the light cell "current draw" (micro amps) with time (in days); [0051] Figure 7 shows how light cell current draw" (micro amps) varies with time (in days) for regular kerosene (Base Fuel" -blue line) and the inventive fuels (red line); [0052] Figure 8 is a graph showing how the differential between the flue gas temperature (Fl) and air intake temperature (AT) (i.e. FT-AT) varies with time; [0053] Figure 9 is a graph showing how combustion efficiency varies with time. Figure 9 can be correlated with Figure 8 to observe how FT-AT correlates with combustion efficiency.

[0054] Figure 10 is a graph showing a typical plot of combustion efficiency (%) against time (minutes) for neat kerosene (coded Base 19) and kerosenes dosed with two different combustion improvers, coded Additive A and Additive B respectively.

DETAILED DESCRIPTION OF THE INVENTION

Definitions [0055] Unless otherwise stated, the following terms used in the specification and claims have the following meanings set out below.

[0056] Herein, amounts stipulated for components and ingredients, whether specified in terms of "parts", ppm (parts per million), percentages (%, e.g. wt%), or ratios, are intended to be by weight, unless stated otherwise. However, since many of the components have a density of approximately 1, alternative embodiments of the invention provide that all weight amounts, weight proportions, and weight ratios may instead be volume amounts, volume proportions, and volume ratios. As such, in alternative embodiments, wherever an amount, proportion, or ratio is given by weight, this may be converted to a volume amount, proportion, or ratio of the same value (i.e. x wt% may be translated to x vol%).

[0057] Herein, unless stated otherwise, the term "parts" (e.g. parts by weight, pbw) when used in relation to multiple ingredients/components, refers to relative ratios between said multiple ingredients/components. Though in many embodiments the amounts of individual components within a composition may be given as a "wt%" value, in alternative embodiments any or all such wt% values may be converted to parts by weight to define a multi-component composition. This is so because the relative ratios between components is often more important than the absolute concentrations thereof in either the fuel additive composition or fuel composition itself. Where a composition comprising multiple ingredients is described in terms of parts by weight alone (i.e. to indicate only relative ratios of ingredients), it is not necessary to stipulate the absolute amounts or concentrations of said ingredients (whether in toto or individually) because the advantages of the invention stem from the relative ratios of the respective ingredients rather than their absolute quantities or concentrations. For instance, the dilution level of an additive composition is usually unimportant, since a preprepared additive composition merely provides a convenient means to achieve particular concentrations of the stipulated ingredients (in a stipulated relative ratio) within a fuel composition by simply adding an appropriate quantity of said additive composition to a fuel. The actual amount of additive composition to be added to a given amount of fuel can be judiciously selected based on the concentration of the ingredients within the additive composition and the desired final concentration desired within the fuel composition. However, in certain embodiments, such compositions consists essentially of or consist of the stipulated ingredients and a diluent.

[0058] Herein, the term "hydrocarbyl" may include either aromatic or aliphatic hydrocarbons. In a particular embodiment, "hydrocarbyl" refers to aliphatics.

[0059] In this specification the term "alkyl" includes both straight and branched chain alkyl groups. References to individual alkyl groups such as "propyl" are specific for the straight chain version only and references to individual branched chain alkyl groups such as isopropyl" are specific for the branched chain version only. For example, (1-6C)alkyl" includes (1-4C)alkyl, (1- 3C)alkyl, propyl, isopropyl and t-butyl. A similar convention applies to other radicals, for example "phenyl( 1 -6C)alkyl" includes phenyl(1 -4C)alkyl, benzyl, 1 -phenylethyl and 2-phenylethyl.

[0060] The term "(m-nC)" or "(m-nC) group" used alone or as a prefix, refers to any group having m to n carbon atoms.

[0061] Herein, where a compound is described as "soluble" in a particular medium (e.g. solvent, or fuel, etc.), said compound is suitably soluble in said medium within one or more of the concentration limits proposed in relation to said compound.

[0062] Herein, the term "dispersant" is intended to include deposit control additives and may be used interchangeably therewith.

[0063] Herein, the term "clean", when used herein to describe the state of the relevant combustion system, generally refers to the state of the "nozzle" (i.e. burner nozzle) within the combustion system (especially a boiler), though it may optionally additionally refer also to other components of the combustion system, for example, a heat-exchanger and/or luminosity sensor Clean combustion systems and/or components, such as clean nozzles, are generally characterised by the absence of deposit build-ups and/or blockages, which suitably affects the performance and/or emissions of the combustion system (as measurable by a change in performance and/or emissions relative to a dirty combustion system, for example, with a dirty nozzle). Clean combustion systems (or clean components thereof) may be defined as combustion systems that have been in operation (e.g. suitably at least 50% of the time, suitably at least 80% of the time, suitably continuous operation) for at most 3 months, suitably at most 6 weeks, suitably at most 1 month, suitably at most 1 week, suitably at most 1 day, suitably at most 1 hour, suitably no more than 30 minutes, whether or not the system is continuously fired or otherwise intermittently fired on demand).

[0064] A suitable comparative testing protocol for "clean" systems (e.g. for comparing clean combustion systems running on fuels addised in accordance with the invention with clean combustion systems running on fuels not additised in accordance with the invention), includes: i. Mechanically cleaning the combustion system (e.g. boiler) and fitting a new burner nozzle; ii. Obtaining start test measurement(s) by running the combustion system on a fuel composition that is not additised with a fuel additive composition (or the components thereof) of the invention, e.g. a base fuel (e.g. kerosene), and measuring one or more desired parameters (e.g. emissions); Ui. Optionally obtaining end test measurement(s) by running the combustion system (e.g. boiler) for a predetermined time period (e.g. 6 to 26 weeks) on the fuel composition not additised with a fuel additive composition (or the components thereof) of the invention, e.g. a base fuel (e.g. kerosene); and thereafter remeasuring the one or more desired parameters (e.g. emissions) and optionally also any deposit quantities (e.g. surface scrapings) after the predetermined time period (e.g. 6 to 26 weeks); iv. Mechanically cleaning said combustion system (e.g. boiler) and fitting a new burner nozzle (suitably the same size as previously); v. Obtaining further start test measurement(s), this time by running the combustion system on a fuel composition that is additised with a fuel additive composition (or the components thereof) of the invention, and measuring the one or more desired parameters (e.g. emissions); vi. Optionally obtaining end test measurement(s) by running the combustion system (e.g. boiler) for a predetermined time period (e.g. 6 to 26 weeks; suitably the same amount of time as per the above tests) on the fuel composition additised with a fuel additive composition (or the components thereof) of the invention; and thereafter remeasuring the one or more desired parameters (e.g. emissions) and optionally also any deposit quantities (e.g. surface scrapings) after the predetermined time period (6 to 26 weeks); vii. Comparing the relevant measurements of the one or more parameters (e.g. emissions) and/or deposit quantities.

[The optional" end test measurements allow time-course performance and deposits to be compared. When testing for instantaneous effects, these optional end test measurements may be dispensed with, and instead just the start test measurements may be compared -i.e. steps iH) and vi) may be excluded.] [Measurements, whether start test or end test or both, are suitably only taken after a "conditioning"/equilibriation period -e.g. running the combustion system for at least 30 minutes, suitably at least 1 hour, and suitably between 1-4 hours].

[Suitably sufficient measurements are taken to achieve a statistically significant sample of measurements, e.g. typically at least 3, and preferably 6 measurements may be taken, wherein the measurements are suitably taken every 10-60 minutes] [The above test protocol may, in an alternative embodiment, be performed without the cleaning and nozzle replacement step in between tests on the non-addised fuel and tests on the additised fuel, i.e. without step iv).] [The skilled person will appreciate that the above test protocol may, in some embodiments, be adapted to increase and thereby exaggerate deposit deposition rates by firing the combustion system constantly and/or adding fuel components that increase deposition rates] [0065] Herein, the term "dirty", when used herein to describe the state of the relevant combustion system, generally refers to the state of the "nozzle" (i.e. burner nozzle) within the combustion system (especially a boiler), though it may optionally additionally refer also to other components of the combustion system, for example, a heat-exchanger and/or luminosity sensor Dirty combustion systems and/or components, such as dirty nozzles, are generally characterised by the presence of deposit build-ups and/or blockages, suitably which affect the performance and/or emissions of the combustion system (as measurable by a change in performance and/or emissions relative to a clean combustion system, for example, with a clean nozzle). Dirty combustion systems (or dirty components thereof) may be defined as combustion systems that have been in operation (e.g. suitably at least 50% of the time, suitably at least 80% of the time, suitably continuous operation, whether or not the system is continuously fired or otherwise intermittently fired on demand) for at least 1 month, suitably at least 3 months, more suitably at least 6 months (or at least 26 weeks), most suitably at least 12 months. In particular embodiments, dirtiness is defined by a combustion system that has been fired for at least 20% of any of the aforementioned times.

[0066] A suitable comparative testing protocol for dirty" systems (e.g. for comparing dirty combustion systems running on fuels addised in accordance with the invention with dirty combustion systems running on fuels not additised in accordance with the invention), includes: i. Mechanically cleaning the combustion system (e.g. boiler) and fitting a field fouled dirty burner nozzle (i.e. a used burner nozzle with deposit build ups which adversely affect nozzle performance); ii. Obtaining start test measurement(s) by running the combustion system on a fuel composition that is not additised with a fuel additive composition (or the components thereof) of the invention, e.g. a base fuel (e.g. kerosene), and measuring one or more desired parameters (e.g. emissions); iü. Optionally obtaining end test measurement(s) by running the combustion system (e.g. boiler) for a predetermined time period (e.g. 6 to 26 weeks) on the fuel composition not additised with a fuel additive composition (or the components thereof) of the invention, e.g. a base fuel (e.g. kerosene); and thereafter remeasuring the one or more desired parameters (e.g. emissions) and optionally also any deposit quantities (e.g. surface scrapings) after the predetermined time period (e.g. 6 to 26 weeks); iv. Obtaining further start test measurement(s), this time by running the combustion system on a fuel composition that is additised with a fuel additive composition (or the components thereof) of the invention, and measuring the one or more desired parameters (e.g. emissions); v. Optionally obtaining end test measurement(s) by running the combustion system (e.g. boiler) for a predetermined time period (e.g. 6 to 26 weeks; suitably the same amount of time as per the above tests) on the fuel composition additised with a fuel additive composition (or the components thereof) of the invention; and thereafter remeasuring the one or more desired parameters (e.g. emissions) and optionally also any deposit quantities (e.g. surface scrapings) after the predetermined time period (6 to 26 weeks); vi. Comparing the relevant measurements of the one or more parameters (e.g. emissions) and/or deposit quantities.

[The "optional" end test measurements allow time-course performance and deposits to be compared. When testing for instantaneous effects, these optional end test measurements may be dispensed with, and instead just the start test measurements may be compared -i.e. steps iH) and v) may be excluded.] [Measurements, whether start test or end test or both, are suitably only taken after a "conditioning"/equilibriation period -e.g. running the combustion system for at least 30 minutes, suitably at least 1 hour, and suitably between 1-4 hours].

[Suitably sufficient measurements are taken to achieve a statistically significant sample of measurements, e.g. typically at least 3, and preferably 6 measurements may be taken, wherein the measurements are suitably taken every 10-60 minutes] [The skilled person will appreciate that the above test protocol may, in some embodiments, be adapted to increase and thereby exaggerate deposit deposition rates by firing the combustion system constantly and/or adding fuel components that increase deposition rates] [In alternative embodiments, instead of using a mechanically cleaned combustion system fitted with a field fouled dirty burner nozzle, the combustion system (e.g. boiler) may be a combustion system that has been running for at least 26 weeks.] [0067] Herein, the term "instantaneous", when used herein to describe any benefits (e.g. improved fuel performance, reduced emissions, etc.) afforded by the fuel additives of the present invention, is intended to mean that said benefits are instantaneously realised (i.e. without substantial delay, suitably without any delay) once a combustion system begins to run on a fuel comprising a fuel additive (or the component parts thereof) of the present invention.

Any instantaneous benefits are suitably relative to a combustion system running on a fuel not treated with a fuel additive (or the component parts thereof) of the invention. Instantaneous realisation of the benefits suitably means said benefits are realised within 12 hours of continuous operation of the relevant combustion system (whether said operation involves continuous tiring or intermittent firing on demand, though suitably such benefits are achieved whore said operation involves continuous firing), more suitably within 4 hours of continuous operation, more suitably within 1 hour. "Instantaneous" may mean after the combustion system has reached "equilibrium" (see below), for instance when the heat produced by a boiler balances the heat transterred to the circulating water and heate lost by the system. As such, "instantaneous" realisation of the benetits may suitably mean said benetits are realised within 12 hours ot continuous operation ot the relevant combustion system after equilibrium has been reached (whether said operation involves continuous firing or intermittent firing on demand, though suitably such benefits are achieved where said operation involves continuous firing), more suitably within 4 hours of continuous operation, more suitably within 1 hour. Such instantaneous benefits are readily measurable by comparing a combustion system running on a fuel not additised with a fuel additive of the invention (i.e. non-additised fuel) with the same combustion system running on a fuel that is additised in accordance with the invention (i.e. additised fuel). Suitably such measurements may involve assessing the combustion system running on the non-additised fuel betore assessing said system running on the additised fuel.

Benef its, such as reduced emissions, improved etticiency, improved tuel consumption, etc., are readily discernable using the analytical techniques outlined in the Example section or techniques otherwise well known to those skilled in the art.

[0068] An example ot a suitable comparative testing protocol tor instantaneous benefits includes: o Comparative measurements of instantaneous benefits in a clean system "Instant Clean": i. Mechanically cleaning the combustion system (e.g. boiler) and fitting a new burner nozzle; ii. Obtaining test measurement(s) by running the combustion system on a fuel composition that is not additised with a tuel additive composition (or the components thereof) of the invention, e.g. a base fuel (e.g. kerosene), and measuring one or more desired parameters (e.g. emissions) atter a 1 to 4 hours "conditioning'Yequilibration period -suitably measurements are taken every 10 to minutes to achieve statistical signiticance, suitably with 6 tests; Ui. Optionally mechanically cleaning said combustion system (e.g. boiler) and fitting a new burner nozzle (suitably the same size as previously); iv. Obtaining further test measurement(s), this time by running the combustion system on a tuel composition that is additised with a fuel additive composition (or the components thereof) ot the invention, and measuring the one or more desired parameters (e.g. emissions) after a 1 to 4 hours "conditioning'Jequilibration period -suitably measurements are taken every 10 to 60 minutes to achieve statistical significance, suitably with 6 tests; v. Comparing the relevant measurements of the one or more parameters (e.g. emissions).

o Comparative measurements of Instantaneous benefits in a dirty system "Instant Dirty": i. Mechanically cleaning the combustion system (e.g. boiler) and fitting a field fouled dirty burner nozzle; ii. Obtaining test measurement(s) by running the combustion system on a fuel composition that is not additised with a fuel additive composition (or the components thereof) of the invention, e.g. a base fuel (e.g. kerosene), and measuring one or more desired parameters (e.g. emissions) after a 1 to 4 hours "conditioning'Yequilibration period -suitably measurements are taken every 10 to minutes to achieve statistical significance, suitably with 6 tests; iü. Obtaining further test measurement(s), this time by running the combustion system on a fuel composition that is additised with a fuel additive composition (or the components thereof) of the invention, and measuring the one or more desired parameters (e.g. emissions) after a ito 4 hours "conditioning'Vequilibration period -suitably measurements are taken every 10 to 60 minutes to achieve statistical significance, suitably with 6 tests; iv. Comparing the relevant measurements of the one or more parameters (e.g. emissions).

[The skilled person will appreciate that the above test protocol may, in some embodiments, be adapted to increase and thereby exaggerate deposit deposition rates by firing the combustion system constantly and/or adding fuel components that increase deposition rates] [In alternative embodiments, instead of using a mechanically cleaned combustion system fitted with a field fouled dirty burner nozzle, the combustion system (e.g. boiler) may be a combustion system that has been running for at least 26 weeks.] [0069] Herein, a combustion system is said to have reached "equilibrium" when the combustion system is in a balanced state. For instance, equilibrium may include where the energy produced by the combustion system balances the energy delivered for work and energy lost from the system. In the case of a boiler, equilibrium may suitably be when the heat produced by the boiler balances the heat transferred to the circulating fluid (e.g. water) and heat lost by the system. Another indication of equilibrium, particularly for a boiler system, may be where the inlet and outlet water temperatures are substantially stabilised, at least relative to each other (i.e. the difference between them is substantially stabilised). Another indication of equilibrium, particularly for a boiler system, may be where the inlet air temperature (e.g. measured on entry into the boiler or just before a burner nozzle) and outlet flue gas temperature (e.g. measured on exit from the boiler or just after passing through the heat exchanger) are stabilised, at least relative to each other (i.e. the difference between them is substantially stabilised). Typically a combustion system may need to be continuously fired for a period of time (e.g. suitably at least 10 minutes, suitably at least 30 minutes, suitably at least 1 hour) before equilibrium is reached.

[0070] Discerning the "benefits" described herein suitably involves taking measurements using techniques described herein (for instance, in the Example Section) or techniques otherwise well known in the art. For instance, instruments and procedures are given herein to allow the efficiency of a combustion system to be ascertained by reference to the chemical composition of flue gases and the temperatures before (AT) and after combustion (FT). Emissions may be measured using a conventional boiler engineer's equipment (e.g. Testo 327 Flue Gas Analyser) to thereby demonstrate that an end user's engineer will be able to measure the difference made by the fuel additives of the present invention. As such, efficiency improvements, emission reductions, fuel economy improvements, etc. can be discerned accordingly.

[0071] Herein, where a composition is said to "consist essential of" one or more given components, said composition suitably comprises at least 80 wt% of the one or more given components, suitably at least 90 wt% thereof, suitably at least 95% thereof, suitably at least 99% thereof.

General Methodology [0072] The present invention provides a novel additive composition and a novel combination of additive ingredients for a fuel composition. The inventors have found that additising fuel in accordance with the present invention achieves a range of beneficial effects not previously attained in the art, especially in the field of pressure-jet oil-fired domestic central heating boilers, which has its own unique issues. In particular. additised fuels according to the invention benefit from improved fuel performance, improved fuel consumption, improved efficiency for the corresponding fuel combustion system, improved combustion completeness, reduced emissions (especially carbon dioxide and carbon monoxide), improved fuel consumption/fuel economy, improved air-fuel mixing, improved water handling, reduced build up of deposits within the fuel combustion system (especially pressure-jet boilers), reduced breakdowns of the corresponding fuel combustion system (especially pressure-jet boilers), improved protection for component parts of the relevant fuel combustion system; and improve corrosion inhibition.

[0073] Another surprising advantage associated with additised fuels of the invention, over corresponding fuels without the fuel additives of the invention (e.g. unadditised kerosene), is the instantaneous combustion benefits (as per the above, but especially reduced CO2 and/or CO emissions, and reduced fuel consumption) they afford to combustion systems having either clean or dirty components (e.g. a clean or dirty nozzle, for instance, where the combustion system is a pressure-jet boiler). The extent to which additised fuels of the present invention instantaneously benefit combustion systems having clean components (especially a clean nozzle within a pressure-jet boiler) is particularly surprising. For instance, additising the fuel (e.g. kerosene) burnt within a pressure-jet boiler instantaneously improves fuel performance, fuel consumption and, in particular, reduces emissions (e,g. CO2 and/or CO emissions), where the boiler is fitted with a clean and/or new burner nozzle. Additionally, the beneficial impact (e,g, reduced CO2 and/or CO emissions) of replacing dirty components of a combustion system (e.g. a dirty nozzle within a pressure-jet boiler) with corresponding clean components is dramatically increased in combustion systems running on addised fuels of the invention compared with those running on fuels not addised in accordance with the invention.

[0074] As such, the additives and additised fuels of the invention represent a significant contribution to the art, and in particular reduce the amount of servicing required of combustion systems, such as pressure-jet boilers.

Individual Fuel Additive Ingredients [0075] Particular additive ingredients that are either features or optional features in relation to the present invention are now described. References herein to a single generic ingredient (e.g. dispersant, demulsifier, metal deactivator, antioxidant, corrosion inhibitor, diluents) may, unless stated otherwise, encompass one or more specific ingredients falling within that generic class of ingredient. As such, any specified quantities (e.g. wt%, parts, ppm, etc.) given herein in relation to a single generic ingredient may, unless stated otherwise, refer to the total quantity (i.e. the sum) of all specific ingredients falling within said generic class of ingredient. In some embodiments, references to a single generic ingredient encompass only one specific ingredient falling with that generic class of ingredient.

DisDersant [0076] The dispersant, in suitable admixture with the other ingredients of the fuel additive compositions of the invention, suitably controls the surface tension of the additised fuel such that smaller droplet sizes (i.e. better atomisation) and greater spray angles are achievable when the additised fuel is sprayed from a burner nozzle within the relevant combustion system. This in turn facilitates great combustion efficiency. The dispersant, again in suitable admixture with the other ingredients, also reduces the build-up of deposits upon key components within a combustion system, such as a burner nozzle (i.e. nozzle blockage) and/or heat exchanger, thereby improving the long term performance of the combustion system. The deposit-reducing power of the additive compositions of the invention also reduces combustion system breakdowns and lock outs" caused by dirty sensors (e.g. safety sensors such as flame luminosity sensors).

[0077] The dispersant is suitably a surface active agent.

[0078] The fuel additive composition suitably comprises one or more dispersants. In a particular embodiment, the fuel additive composition comprises just a single dispersant.

[0079] The dispersant(s) may be any suitable dispersant known in the art for use in fuels.

Suitably the dispersant is soluble in fuel compositions of the present invention (especially the base fuel thereof). Suitably, the dispersant(s) is an ashless dispersant.

[0080] Suitably the disperant(s) is or includes a nitrogenous dispersant and/or a surface-active hydrocarbon (e.g. a polymeric hydrocarbon, such as polyisobutylene (RIB)), or a suitable mixture of two or more thereof. In some embodiments, a surface-active hydrocarbon dispersant (especially a RIB) may be used alongside a nitrogenous dispersant (e.g. RIBSI), for instance, to adjust or fine tune the surface tension properties of the fuels with which the additive composition is intended to be mixed.

[0081] Suitably the dispersant(s) is or includes a nitrogenous dispersant. Suitably the nitrogenous dispersant comprises moieties selected from amine, ammonium, hydrazine, hydrazone, hydrazido, amide, ureido, carbamate, imine, enamine, and succinimide moieties.

[0082] In a particular embodiment, the nitrogenous dispersant is an amine or amide.

[0083] Suitably the nitrogenous dispersant(s) is or includes the reaction product of an amine (including ammonia, a primary amine, or a secondary amine) with a suitably amine-derivatising compound such as a carboxylic acid, polyacid (or appropriate acyl-activated derivative thereof, e.g. anhydride, acid chloride, etc.), aldehyde, ketone, succinimide, or other appropriate amine-derivatising group. Suitably the nitrogenous dispersant comprises one or more hydrocarbyl moieties, suitably one or more (4-SOC)hydrocarbyl substituents, suitably one or more (6- 30C)hydrocarbyl substituents. Suitably the one or more hydrocarbyl moieties are linear or branched aliphatic hydrocarbyl. The one or more hydrocarbyl moieties may be suitably present on the amine, the amine-derivatising group, or both.

[0084] Suitably the nitrogenous dispersant(s) is or includes a polyisobutylene succinimide (RIBSI), a polyetheramine (REA), or a suitable mixture of two or more thereof.

[0085] In a particular embodiment, the amine-derivatising compound is hydrocarbyl-substituted succinic acid or acyl-activated derivative thereof (e.g. anhydride). Again, suitably the hydrocarbyl substituent is suitably (4-500)hydrocarbyl, suitably (6-30C)hydrocarbyl. In a particular embodiment, the hydrocarbyl-substituent is a polyisobutylene group. Most suitably, the polyisobutylene group has a molecular weight from 500-2800, suitably between 700 and 1300. In a particular embodiment, the dispersant is polyisobutylene succinimide, wherein the polyisobutylene is optionally defined as herein.

[0086] Suitably, the nitrogenous dispersant(s) is or includes a polyisobutylenesuccinimide (RIBSI) of formula I: P1 B N P I B) (Formula I) wherein RIB is a polyisobutylene group with an MW between 500 and 2800; wherein n is an integer between 1 and 10; and wherein m is either 0 or 1, such that if m is 0 the polyisobutylenesuccinimide of formula I terminates at an amino moiety.

[0087] The polyisobutylenesuccinimide of formula I is suitably formed by reaction of polyisobutylene anhydride with an appropriate polyethylene polyamine.

[0088] Suitably, the RIB group(s) have a molecular weight between 950 and 2500.

[0089] In a particular embodiment, n is an integer between 5 and 10. In a particular embodiment, n is an integer between 1 and 4.

[0090] Suitably, the nitrogenous dispersant(s) is or includes a polyetheramine. The polyetheramine suitably has a molecular weight between 150 and 300, suitably 200 to 250.

[0091] Suitably, the nitrogenous dispersant(s) is or includes a polyetheramine (PEA) of formula II: H2 N NH2 (Formula II) wherein Ri is a hydrocarbyl group; and wherein p is an integer between 2 and 10.

[0092] Suitably, in the polyetheramine of formula II, R1 and p are selected so that the polyether amine has a molecular weight between 150 and 300, suitably between 200 and 250. Suitably Ri is hydrogen or (1 -80)alkyl, most suitably hydrogen or methyl, most suitably methyl.

[0093] The disperant(s) may be or include a surface-active hydrocarbon, most suitably a polyisobutylene (RIB). Such a polyisobutylene may be a RIB defined as hereinabove. For instance, the polyisobutylene suitably has a molecular weight from 500-2800, suitably between 700 and 1300.

[0094] In a particular embodiment, the dispersant(s) is selected from PIBSI, PEA, and RIB, or a suitable mixture of two or more thereof.

[0095] The dispersant is suitably present within the fuel additive composition at 5-25 wt%, suitably at 10-20 wt%, suitably at 12-18 wt%. In an embodiment, the fuel additive composition comprises 7-17 wt% dispersant, suitably 5-15 wt%, suitably 9-16 wt%, suitably 9-14 wt%, suitably 11-13 wt%, suitably 8-12 wt%, suitably 9-11 wt% dispersant. Suitably, these amounts include the combined total of dispersants where two or more dispersants are present. The dispersant is suitably present in the fuel composition in an amount calculated by multiplying the aforementioned wt% proportions, given in relation to the additive composition, by the treat rates disclosed herein in relation to the fuel additive composition in the fuel composition.

[0096] In some embodiments, one or more dispersants (e.g. PIBSI) may exhibit anti-corrosion properties. As such, the additive composition or corresponding fuel compositions may or may not comprise an additional corrosion inhibitor.

Dem u/sifter [0097] The demulsifier serves as an emulsion preventative", especially with respect to water dispersed with a fuel composition. The demulsifier, in suitable admixture with the other ingredients of the fuel additive composition, facilitates separation of water from a fuel composition, thereby improving water handling in a water-contaminated combustion system.

[0098] The fuel additive composition suitably comprises one or more demulsifiers. In a particular embodiment, the fuel additive composition comprises just a single demulsifier.

[0099] The demulsifier(s) may be any suitable demulsifier known in the art.

[00100] Suitably the demulsifier(s) is selected from the group including polyglycols, acylated polyglycols, alkoxylated phenol-fornialdehyde, alkoxylated alkylphenol-formaldehyde resins, alkylated phenols, alkoxylated polyamines, alkoxylated polyols, epoxy resins, oxiranes, methyloxiranes, or a suitable mixture of two or more thereof. Alkoxylated compounds suitably include ethoxylated or propoxylated compounds, most suitably ethoxylated.

[00101] Suitably the demulsifier(s) is selected from the group including acylated polyglycols, alkoxylated phenol-formaldehyde, alkoxylated alkylphenol-formaldehyde resins, alkylated phenols, alkoxylated polyamines, alkoxylated polyols, epoxy resins, oxiranes, methyloxiranes, or a suitable mixture of two or more thereof. Alkoxylated compounds suitably include ethoxylated or propoxylated compounds, most suitably ethoxylated.

[00102] In a particular embodiment, the demulsifier comprises an alkoxylated (especially ethoxylated) phenol-formaldehyde resin and optionally one or more polyglycols. In such embodiments, the demulsifier may be provided in aromatic solvent along with petroleum sulphonate and aliphatic alcohol.

[00103] Demulsifiers are suitably commonly available as alkoxylated phenol-formaldehyde resin-containing demulsifiers.

[00104] In a particular embodiment, the demulsifier is an alkoxylated phenol-formaldehyde resin-containing demulsifier, which may suitably additionally comprise one or more or all of a polyglycol. petroleum sulphonate and aliphatic alcohol in aromatic solvent.

[00105] The demulsifier is suitably present within the fuel additive composition at 0.05-10 wt%, suitably at 0.1-5 wt%, suitably at 0.5-5 Nt%. In a particular embodiment, the emulsifier is present in the fuel additive composition at 1-5 wt%. In an embodiment, the fuel additive composition comprises 3-9 wt% demulsifier, suitably 4-S wt%, suitably 5-7 wt% demulsifier. In an embodiment, the fuel additive composition comprises 4-7 wt% demulsifier, suitably 4.5-6 wt%. Suitably, these amounts include the combined total of demulsifiers where two or more demulsifiers are present. The demulsifier is suitably present in the fuel composition in an amount calculated by multiplying the aforementioned wt% proportions, given in relation to the additive composition, by the treat rates disclosed herein in relation to the fuel additive composition in the fuel composition.

Metal Deactivator [00106] The metal deactivator, in suitable admixture with the other ingredients of the fuel composition, suitably serves to stabilise both the fuel additive composition and fuel composition, by deactivating and/or sequestering (e.g. via chelation) metal ions which may be present therein. Such metal ions may have been introduced during production processes (e.g. by copper desulfurization treatments and such like), may be naturally occurring in fuels or additive ingredients, or may have become a part of the fuel upon reaction thereof with metallic parts of combustion systems and the like (e.g. via oxidative processes). Suitably the metal deactivator limits any catalytic effects of such metal ions, which may otherwise catalyse the formation of waxy/gummy residues and other deposits which may compromise the performance of combustion systems within which the relevant fuel compositions are combusted.

[00107] The fuel additive composition suitably comprises one or more metal deactivators.

In a particular embodiment, the fuel additive composition comprises two or more metal deactivators, most suitably only two metal deactivators.

[00108] The metal deactivator (s) may be any suitable metal deactivator (s) known in the art for use in fuel compositions. The metal deactivators are suitably soluble within the fuel compositions of the invention (especially the base fuel thereof).

[00109] The metal deactivator(s) are suitably metal-chelating compounds, suitably non-ionic metal-chelating compounds. Suitably the metal deactivator(s) are metal-chelating compounds whose corresponding metal-chelates are soluble within the relevant fuel composition (or base fuel thereof).

[00110] The metal deactivator(s) are suitably selected from the group including N,N'- Disalicylidene-1,2-diaminopropane and benzotriazole derivatives (such as N-N'-bis(2-ethylhexyl)-ar-methyl 1 H-benzotriazol-1 -methanamine), or a suitable mixture of two or more thereof.

[00111] In a particular embodiment, the metal deactivator is a mixture of N,N'- Disalicylidene-1,2-diaminopropane and N-N'-bis(2-ethylhexyl)-ar-methyl 1 H-benzotriazol-1 -methanamine), suitably a mixture thereof in a respective weight ratio between 10:1 and 1:10, suitably 5:1 and 1:5, most suitably between 5:1 and 1:1. In a particular embodiment, the metal deactivator is disalicylidene-1,2-diaminopropane.

[00112] The metal deactivator is suitably present within the fuel additive composition at 3-wt%, suitably at 5-15 wt%, suitably at 5-12 wt%. In an embodiment, the fuel additive composition comprises 0.05-20 wt% metal deactivator, suitably 0.5-16 wt%, suitably 1-5 wt%, suitably 1-3 wt%, suitably 1.5-2.5 wt% metal deactivator. In an embodiment, the fuel additive composition comprises 5-30 wt% metal deactivator, suitably 10-25 wt%, suitably 12-20 wt%.

Suitably, these amounts include the combined total of metal deactivators where two or more metal deactivators are present. The metal deactivator is suitably present in the fuel composition in an amount calculated by multiplying the aforementioned wt% proportions, given in relation to the additive composition, by the treat rates disclosed herein in relation to the fuel additive composition in the fuel composition.

[00113] In some embodiments, one or more metal deactivators may exhibit anti-corrosion properties. As such, the additive composition or corresponding fuel compositions may or may not comprise an additional corrosion inhibitor.

Antioxidants [00114] The antioxidant, in suitable admixture with the other ingredients of the fuel composition, suitably serves to stabilise a fuel composition, particularly with respect to oxidation.

[00115] The fuel additive composition suitably comprises one or more antioxidants. In a particular embodiment, the fuel additive composition comprises two or more antioxidants, most suitably only two antioxidants.

[00116] The antioxidant(s) may be any suitable antioxidant(s) known in the art for use in fuel compositions. The antioxidants are suitably soluble within the fuel compositions of the invention (especially the base fuel thereof).

[00117] The antioxidant(s) is suitably selected from phenolic antioxidants, phenylamine antioxidants, phenylenediamine antioxidants, and phenylamide antioxidants, or a suitable mixture of two or more thereof.

[00118] Suitably, the antioxidant(s) is selected from phenolic antioxidants and phenylenediamine antioxidants, or a suitable mixture of two or more thereof.

[00119] The antioxidant(s) is suitably selected from phenolic antioxidants, phenylamine antioxidants, phenylenediamine antioxidants, amine-aldehyde condensate antioxidants, and phenylamide antioxidants, or a suitable mixture of two or more thereof.

[00120] Most suitably, the antioxidant(s) is selected from phenolic antioxidants, amine-aldehyde condensate antioxidants and phenylenediamine antioxidants, or a suitable mixture of two or more thereof.

[00121] In a particular embodiment, the antioxidant(s) is a mixture of a phenolic antioxidant and an amine-aldehyde condensate antioxidant.

[00122] Where the antioxidant is or comprises a phenylenediamine antioxidant, the phenylenediamine antioxidant is of the Formula Ill: N HR2 \:J NH R3 (Formula Ill) wherein R2 and R3 are each independently selected from the group including hydrogen and a (1 -8C)hydrocarbyl group.

[00123] The NHR2 and NHR3 substituents of the phenylenediamine antioxidant of Formula Ill are suitably juxtaposed in a meta-or para-relationship to one another, most suitably a para-relationship.

[00124] Suitably, R2 and H3 are each independently selected from the group including hydrogen, and a (1-6C)alkyl. Suitably, R2 and ft are each independently selected from (1-4C) alkyl. In a particular embodiment, both R2 and R3 are the same. In a particular embodiment, both R2 and R3 are scc-butyl groups.

[00125] In a particular embodiment, the phenylenediamine antioxidant is N,N'-di-sec-butyl-p-phenylenediamine.

[00126] Where the antioxidant is or comprises a phenolic antioxidant, the phenolic antioxidant is of the Formula IV: (Formula IV) wherein R4 and R6are each independently selected from hydrogen and (1-8C)hydrocarbyl; and wherein R5 is selected from hydrogen and (1-8C)hydrocarbyl.

[00127] Suitably, R4 and R6 are each independently selected from a (1-8C)hydrocarbyl, most suitably from a (1-6C)alkyl, most suitably from a (1-4C)alkyl. In a particular embodiment, both R4 and H6 are the same, suitably both being tert-butyl. In a particular embodiment, each of R4 and H6 are different, suitably one being tert-butyl and the other being methyl.

[00128] Suitably R5 is selected from hydrogen and (1-4C)alkyl. Suitably H5 is selected from hydrogen or methyl.

[00129] Suitably, the phenolic antioxidant is selected from 2,6-di-tert.-butylphenol, 2,6-di-tert.-4-methylphenol, and 2,4-dimethyl-6-tert.butylphenol.

[00130] In a particular embodiment, the antioxidant(s) is selected from 2,6-di-tert.- butylphenol, 2,6-di-tert.-4-methylphenol, 2,4-dimethyl-6-tert.butylphenol, and N,N'-di-sec-butyl-p-phenylenediamine, or a suitable mixture of two or more thereof.

[00131] In a particular embodiment, the antioxidant(s) is selected from 2,6-di-tert.-butylphenol and N,N'-di-sec-butyl-p-phenylenediamine, or a suitable mixture of two or more thereof.

[00132] In a particular embodiment, the antioxidant(s) is selected from any of the abovementioned groups of antioxidants (or mixtures thereof) and in addition an amine-aldehyde condensate antioxidant.

[00133] In a particular embodiment, the antioxidant(s) is a mixture of 2,6-di-tert.- butylphenol and an amine-aldehyde condensate antioxidant. In a particular embodiment, 2,6-di-tert.-butylphenol and an amine-aldehyde condensate antioxidant are mixed in a weight ratio of between 1:3 and 3:1, most suitably between 1:2 and 2:1.

[00134] In a particular embodiment, the antioxidant(s) is a mixture of 2,6-di-tert.-butylphenol and N,N'-di-sec-butyl-p-phenylenediamine, suitably mixed in a weight ratio of between 1:3 and 3:1 most suitably between 1:2 and 2:1.

[00135] The antioxidant is suitably present within the fuel additive composition at 1-25 wt%, suitably at 2-20 wt%, suitably at 6-14 wt%. In an embodiment, the fuel additive composition comprises 8-32 wt% antioxidant, suitably 15-25 wt%, suitably 16-19 wt%, suitably 18-22 wt%, suitably 5-20 wt%. Suitably, these amounts include the combined total of antioxidants where two or more antioxidants are present. The antioxidant is suitably present in the fuel composition in an amount calculated by multiplying the aforementioned wt% proportions, given in relation to the additive composition, by the treat rates disclosed herein in relation to the fuel additive composition in the fuel composition.

Corrosion Inhibitor [00136] Though one or more of the dispersants and/or metal deactivators used with the present invention may exhibit anti-corrosion properties, the fuel additive composition may suitably comprise a corrosion inhibitor, suitably inhibiting corrosion of metal parts of a combustion systems within which the fuel additive and corresponding fuel compositions are intended for use. Suitably, the corrosion inhibitor is distinct from any of the other classes of ingredients described herein. Suitably, the primary function of the corrosion inhibitor is corrosion inhibition, whereas the primary functions of any of the aforementioned ingredients (e.g. dispersant and/or metal deactivator) are as described in relation to said ingredients.

Suitably, the corrosion inhibitor is not a dispersant or metal deactivator.

[00137] The fuel additive composition may comprise one or more corrosion inhibitors. In a particular embodiment, the fuel additive composition comprises just a single corrosion inhibitor.

[00138] The corrosion inhibitor(s) may be any suitable corrosion inhibitor(s) known in the art for use in fuel compositions. The corrosion inhibitors are suitably soluble within the fuel compositions of the invention (especially the base fuel thereof).

[00139] The corrosion inhibitor(s) are suitably non-ionic, and may include organic amines and the like. Suitably, the corrosion inhibitor is a volatile amine corrosion inhibitor. In a particular embodiment, the corrosion inhibitor is dicyclohexylamine.

[00140] The corrosion inhibitor may be present within the fuel additive composition at 0-wt%, suitably 2-10 wt%. In an embodiment, the fuel additive composition comprises 5-15 wt% corrosion inhibitor, suitably 8-12 wt% corrosion inhibitor. Suitably, these amounts include the combined total of corrosion inhibitors where two or more corrosion inhibitors are present.

The corrosion inhibitor is suitably present in the fuel composition in an amount calculated by multiplying the aforementioned wt% proportions, given in relation to the additive composition, by the treat rates disclosed herein in relation to the fuel additive composition in the fuel composition. In a particular embodiment, the fuel additive composition is free of additional corrosion inhibitors. Where the fuel additive composition is free of corrosion inhibitors, suitably one or more of the other ingredients (e.g. dispersant(s) and/or metal deactivator(s)) exhibits anti-corrosion properties.

Optional Additive Ingredients [00141] The fuel additive compositions and/or fuel compositions of the present invention may comprise one or more additional additives, for instance, which enhance performance.

Further additives may include corrosion inhibitors, rust inhibitors, gum inhibitors, lubricants, solvents, anti-static agents, anti-icing agents, further dispersants, stabilisers, cold-flow improvers, anti-waxing agents, combustion promoters such as organo-metallics, further antioxidants, dyes, fragrances. Such additional additives may be added to fuel compositions of the invention separately to the fuel additive compositions (or ingredients thereof) of the invention. In some embodiments, no further additives are included.

[00142] Suitably, the fuel additive compositions (and corresponding additised fuel compositions) of the invention may additionally comprise a dye which may, for instance, enable a manufacturer, distributor, or consumer to visually discern and identify fuel compositions of the present invention from other fuel compositions.

[00143] Suitably, the fuel additive compositions (and corresponding additised fuel compositions) of the invention may additionally comprise a fragrance which may, for instance, enable a manufacturer, distributor, or consumer to discern fuel compositions of the present invention from other fuel compositions merely by smell. Such a fragrance may also improve the smell of fuel compositions of the invention, which may be particularly important where such fuel compositions are to be used in domestic boiler systems, where it would be a significant advantage to mask unpleasant fuel smells which may otherwise impinge on the domestic environment.

Fuel Additive ComDosition [00144] The fuel additive composition may be suitable for use in boilers, suitably pressure-jet boiler.

[00145] The present invention provides a fuel additive composition, comprising: i) a dispersant; U) a demulsifier; Ui) a metal deactivator; and iv) an antioxidant.

[00146] The additive composition may be provided in kit form as separate ingredients or separate combinations of ingredients. As such, the present invention provides a fuel additive kit comprising: i) a dispersant; ii) a demulsifier; Ui) a metal deactivator; and iv) an antioxidant; optionally with one or more of the ingredients in combination with one another.

[00147] However, preferably the fuel additive composition is provided as a single additive composition comprising all ingredients in combination.

[00148] Suitably, the fuel additive composition (or the individual ingredients thereof, if additised separately) is compatible for use in the relevant base fuel and fuel composition, is suitably soluble therein (especially at the optimal concentration), and is preferably safe and stable upon storage, especially prolonged storage (e.g. over a period of one month, suitably six months, suitably a year, more suitably two years). Moreover, the fuel additive composition (or combination of individual ingredients thereof), when added to a fuel, produce a solution that is safe and stable upon storage, especially prolonged storage (e.g. over a period of one month, suitably six months, suitably a year, more suitably two years).

[00149] Herein, references to any particular ingredient of the additive composition (e.g. a dispersant, a demulsifier, a metal deactivator, an antioxidant, a diluent) may be construed as a reference to a particular class or category of said ingredient, especially where said ingredient is described in terms of a general classification or function. As such, a reference to a particular ingredient (or ingredient class) may suitably be a reference to one or more such ingredients falling within said class. Unless stated otherwise, any amounts or proportions given in relation to such an ingredient (or ingredient class) may be construed as the combined amounts or proportions of all ingredients falling within said ingredient class. Therefore, where an additive composition is described as comprising a certain amount or proportion of a "metal deactivator", the additive composition may suitably comprise one or more metal activators which, in combination, are present in the amount or proportion stated. However, as and where stated, reference to a particular ingredient! ingredient class may relate to only a single ingredient within that class, in which case all amounts and proportions relating to said ingredient should be construed accordingly.

[00150] Where an additive composition is described as comprising multiple ingredients, and the amounts of said ingredients are given as parts by weight alone (i.e. to indicate only relative ratios of ingredients), it is not necessary to stipulate the absolute amounts or concentrations of said ingredients (whether in toto or individually) because the advantages of the invention stem from the relative ratios of the respective ingredients rather than their absolute quantities or concentrations. For instance, the dilution level of such an additive composition is typically irrelevant, since the purpose of the additive composition is to provide a convenient means to produce a fuel composition comprising particular concentrations of the stipulated ingredients (in a stipulated relative ratio) simply by adding an appropriate quantity of said additive composition to a fuel. The actual amount of additive composition to be added to a given amount of fuel can be judiciously selected based on the known concentrations of the stipulated ingredients within the additive composition and the desired final concentrations thereof desired within the fuel composition. However, suitably, the additive composition comprises at least 10 wt% of all the stipulated ingredients combined (excluding any diluent), suitably at least 20 wt%, suitably at least 25 wt%, suitably at least 30 wt%. The balance (i.e. the remainder of the additive composition not constituted by the stipulated ingredients) may consist essentially of a diluent.

[00151] In a particular embodiment, the additive composition comprises: -5-25 parts of dispersant; to -0.05-10 parts of demulsifier; to -3-20 parts of metal deactivator; to -1-25 parts of antioxidant.

[00152] In a particular embodiment, the additive composition comprises: -10-20 parts of dispersant; to -0.1-5 parts of demulsifier; to -5-15 parts of metal deactivator; to -2-20 parts of antioxidant.

[00153] In a particular embodiment, the additive composition comprises: -12-18 parts of dispersant; to -0.5-3 parts of demulsitier; to -5-12 parts of metal deactivator; to -6-14 parts of antioxidant.

[00154] In a particular embodiment, the additive composition comprises: -14-16 parts of dispersant; to -1-3 parts of demulsifier; to -6-10 parts of metal deactivator; to -8-12 parts of antioxidant.

[00155] In a particular embodiment, the additive composition comprises: -14-16 parts of dispersant; to -1.5-2.5 parts of demulsifier; to -7-9 parts of metal deactivator; to -9-1 1 parts of antioxidant.

[00156] In a particular embodiment, the additive composition comprises: -5-25 parts of dispersant; to -1-15 parts of demulsifier; to -a metal deactivator; to -1-35 parts of antioxidant.

[00157] In a particular embodiment, the additive composition comprises: -7-17 parts of dispersant; to -3-9 parts of demulsitier; to -a metal deactivator; to -15-25 parts of antioxidant.

[00158] In a particular embodiment, the additive composition comprises: -8-12 parts of dispersant; to -4-8 parts of demulsifier; to -a metal deactivator; to -18-22 parts of antioxidant.

[00159] In a particular embodiment, the additive composition comprises: -9-1 1 parts of dispersant; to -5-7 parts of demulsitier; to -a metal deactivator; to -19-21 parts of antioxidant.

[00160] In a particular embodiment, the additive composition comprises: -5-25 parts of dispersant; to -1-15 parts of demulsifier; to -0.05-20 parts metal deactivator; to -1-35 parts of antioxidant.

[00161] In a particular embodiment, the additive composition comprises: -7-17 parts of dispersant; to -3-9 parts of demulsitier; to -0.05-20 parts metal deactivator; to -15-25 parts of antioxidant.

[00162] In a particular embodiment, the additive composition comprises: -8-12 parts of dispersant; to -4-8 parts of demulsifier; to -0.5-16 parts metal deactivator; to -18-22 parts of antioxidant.

[00163] In a particular embodiment, the additive composition comprises: -9-11 parts of dispersant; to -5-7 parts of demulsifier; to -1-3 parts metal deactivator; to -19-21 parts of antioxidant.

[00164] In a particular embodiment, the additive composition comprises: -8-15 parts of dispersant; to -3-8 parts of demulsifier; to -a metal deactivator; to -13-22 parts of antioxidant.

[00165] In a particular embodiment, the additive composition comprises: -8-15 parts of dispersant; to -3-8 parts of demulsifier; to -0.5-18 parts metal deactivator; to -13-22 parts of antioxidant.

[00166] In a particular embodiment, the additive composition comprises: -8-15 parts of dispersant; to -3-8 parts of demulsifier; to -10-18 parts metal deactivator; to -13-22 parts of antioxidant.

[00167] In a particular embodiment, the additive composition comprises: -9-14 parts of dispersant; to -4-7 parts of demulsifier; to -a metal deactivator; to -14-21 parts of antioxidant.

[00168] In a particular embodiment, the additive composition comprises: -9-14 parts of dispersant; to -4-7 parts of demulsitier; to -1-16 parts metal deactivator; to -14-21 parts of antioxidant.

[00169] In a particular embodiment, the additive composition comprises: -9-14 parts of dispersant; to -4-7 parts of demulsitier; to -12-16 parts metal deactivator; to -14-21 parts of antioxidant.

[00170] In a particular embodiment, the additive composition comprises: -11-13 parts of dispersant; to -4.5-6 parts of demulsitier; to -a metal deactivator; to -16-19 parts of antioxidant.

[00171] In a particular embodiment, the additive composition comprises: -11-13 parts of dispersant; to -4.5-6 parts of demulsifier; to -12-15 parts metal deactivator; to -16-19 parts of antioxidant.

[00172] In a particular embodiment, the additive composition comprises: -5-25 wt% dispersant; -0.05-10 wt% demulsitier; -3-20 wt% metal deactivator; -1-25 wt% antioxidant.

[00173] In a particular embodiment, the additive composition comprises: -10-20 wt% dispersant; -0.1-5 wt% demulsitier; -5-15 wt% metal deactivator; -2-20 wt% antioxidant.

[00174] In a particular embodiment, the additive composition comprises: -12-18 wt% dispersant; -0.5-3 wt% demulsifier; -5-l2wt% metal deactivator; -6-l4wt% antioxidant.

[00175] In a particular embodiment, the additive composition comprises: -14-16 wt% dispersant; -1-3wt%demulsifier; -6-10 wt% metal deactivator; -8-12 wt% antioxidant.

[00176] In a particular embodiment, the additive composition comprises: -14-16 wt% dispersant; -1.5-2.5 wt% demulsitier; -7-9 wt% metal deactivator; -9-11 wt% antioxidant.

[00177] In a particular embodiment, the additive composition comprises: -5-25 wt% dispersant; to -1-lSwt%demulsifier;to -a metal deactivator; to -1-35 wt% antioxidant.

[00178] In a particular embodiment, the additive composition comprises: -7-17 wt% dispersant; to -3-9 wt% demulsifier; to -a metal deactivator; to -15-25 wt% antioxidant.

[00179] In a particular embodiment, the additive composition comprises: -8-12 wt% dispersant; to -4-8 wt% demulsifier; to -a metal deactivator; to -18-22 wt% antioxidant.

[00180] In a particular embodiment, the additive composition comprises: -9-1 1 wt% dispersant; to -5-7 wt% demulsifier; to -a metal deactivator; to -19-21 wt% antioxidant.

[00181] In a particular embodiment, the additive composition comprises: -5-25 wt% dispersant; to -1-15 wt% demulsifier; to -0.05-20 wt% metal deactivator; to -1-35 wt% antioxidant.

[00182] In a particular embodiment, the additive composition comprises: -7-17 wt% dispersant; to -3-9 wt% demulsifier; to -0.05-20 wt% metal deactivator; to -15-25 wt% antioxidant.

[00183] In a particular embodiment, the additive composition comprises: -8-12 wt% dispersant; to -4-8 wt% demulsifier; to -0.5-lSwt% metal deactivator; to -18-22 wt% antioxidant.

[00184] In a particular embodiment, the additive composition comprises: -9-1 1 wt% dispersant; to -5-7 wt% demulsifier; to -1-3 wt% metal deactivator; to -19-21 wt% antioxidant.

[00185] In a particular embodiment, the additive composition comprises: -5-25 wt% dispersant; to -1-lOwt% demulsifier; to -5-25 wt% metal deactivator; to -5-35 wt% antioxidant.

[00186] In a particular embodiment, the additive composition comprises: -10-20 wt% dispersant; to -3-10 wt% demulsifier; to -10-20 wt% metal deactivator; to -15-30 wt% antioxidant.

[00187] In a particular embodiment, the additive composition comprises: -13-16 wt% dispersant; to -5-8 wt% demulsifier; to -14-18 wt% metal deactivator; to -18-22 wt% antioxidant.

[00188] Suitably, the dispersant, demulsifier, metal deactivator, and antioxidant in any of the abovementioned compositions are defined as follows: -the dispersant(s) is selected from a polyisobutylene succinimide, a polyetheramine, a polyisobutylene, or a combination of two or more thereof (suitably no more than two thereof); -the demulsifier(s) is selected from the group including polyglycols, acylated polyglycols, alkoxylated phenol-formaldehyde, alkoxylated alkylphenol-formaldehyde resins, alkylated phenols, alkoxylated polyamines, alkoxylated polyols, epoxy resins, oxiranes, methyloxiranes, or a combination of two or more thereof (suitably no more than two thereof); -the metal deactivator(s) is selected from the group including N,N'-Disalicylidene-l 2- diaminopropane and benzotriazole derivatives (such as N-N'-bis(2-ethylhexyl)-ar-methyl 1H-benzotriazol-1-methanamine). or a combination of two or more thereof (suitably no more than two thereof); -the antioxidant(s) is selected from 2,6-di-tert.-butylphenol, 2,6-di-tert.-4- methylphenol, 2,4-dimethyl-6-tert.butylphenol, and N,N'-di-sec-butyl-p-phenylenediamine, or a combination of two or more thereof (suitably no more than two thereof).

[00189] Suitably, the dispersant, demulsifier, metal deactivator, and antioxidant in any of the abovementioned compositions are defined as follows: -the dispersant(s) is selected from a polyisobutylene succinimide, a polyetheramine, a polyisobutylene, or a combination of two or more thereof (suitably no more than two thereof); -the demulsifier(s) is selected from the group including polyglycols, acylated polyglycols, alkoxylated phenol-formaldehyde, alkoxylated alkylphenol-formaldehyde resins, alkylated phenols, alkoxylated polyamines, alkoxylated polyols, epoxy resins, oxiranes, methyloxiranes, or a combination of two or more thereof (suitably no more than two thereof); -the metal deactivator(s) is selected from the group including N,N'-Disalicylidene-l 2- diaminopropane and benzotriazole derivatives (such as N-N'-bis(2-ethylhexyl)-ar-methyl 1H-benzotriazol-1-methanamine), or a combination of two or more thereof (suitably no more than two thereof); -the antioxidant(s) is selected from 2,6-di-tert.-butylphenol, 2,6-di-tert.-4-methylphenol, 2,4-dimethyl-6-tert.butylphenol, an amine-aldehyde condensate, and N,N'-di-sec-butyl-p-phenylenediamine, or a combination of two or more thereof (suitably no more than two thereof).

[00190] In a particular embodiment, the additive composition comprises: -5-25 parts polyisobutylene succinimide; to -0.5-10 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -2-10 parts N,N'-disalicylidene-1,2-diaminopropane; to -1-10 parts N-N'-bis(2-ethylhexyl)-ar-methyl 1 H-benzotriazol-1 -methanamine; to -1-10 parts 2,6-di-tert-butylphenol; to -1-10 parts N,N'-di-sec-butyl-p-phenylenediamine.

[00191] In a particular embodiment, the additive composition comprises: -10-20 parts polyisobutylene succinimide; to -1-5 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -2-5 parts N,N'-disalicylidene-l,2-diaminopropane; to -3-10 parts N-N'-bis(2-ethylhexyl)-ar-methyl 1 H-benzotriazol-1 -methanamine; to -1-10 wt% 2,6-di-tert-butylphenol; to -1-10 parts N,N'-di-sec-butyl-p-phenylenediamine.

[00192] In a particular embodiment, the additive composition comprises: -12-18 parts polyisobutylene succinimide; to -1-3 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -3-7 parts N,N'-disalicylidene-1,2-diaminopropane; to -2-5 parts N-N'-bis(2-ethylhexy-ar-methyl 1 H-benzotriazol-1 -methanamine; to -3-7 parts 2,6-di-tert-butylphenol; to -3-7 parts N,N-di-sec-butyl-p-phenylenediamine.

[00193] In a particular embodiment, the additive composition comprises: -14-16 parts polyisobutylene succinimide; to -1-3 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -4-6 parts N,N-disalicylidene-1,2-diaminopropane; to -2-4 parts N-N'-bis(2-ethylhexy-ar-methyl 1 H-benzotriazol-1 -methanamine; to -4-6 parts 2,6-di-tert-butylphenol; to -4-6 parts N,N'-di-sec-butyl-p-phenylenediamine.

[00194] In a particular embodiment, the additive composition comprises: -14-16 parts polyisobutylene succinimide; to -1.5-2.5 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -4-6 parts N,N'-disalicylidene-l,2-diaminopropane; to -2.5-3.5 parts N-N'-bis(2-ethylhexy-ar-methyl 1 H-benzotriazol-1 -methanamine; to -4-6 parts 2,6-di-tert-butyiphenol; to -4-6 parts N,N'-di-sec-butyl-p-phenylenediamine.

[00195] In a particular embodiment, the additive composition comprises: -polyisobutylene succinimide; -demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); -N,N'-disalicylidene-l,2-diaminopropane; -2,6-di-tert-butylphenol; and -amine-aldehyde condensate antioxidant.

[00196] In a particular embodiment, the additive composition comprises: -5-25 parts polyisobutylene succinimide; to -1-15 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.05-20 pads N,N'-disalicylidene-1,2-diaminopropane; to -1-20 parts 2,6-di-tert-butylphenol; to -1-20 parts amine-aldehyde condensate antioxidant.

[00197] In a particular embodiment, the additive composition comprises: -7-17 parts polyisobutylene succinimide; to -3-9 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.05-20 pads N,N'-disalicylidene-1,2-diaminopropane; to -5-15 parts 2,6-di-tert-butylphenol; to -5-15 parts amine-aldehyde condensate antioxidant.

[00198] In a particular embodiment, the additive composition comprises: -8-12 parts polyisobutylene succinimide; to -4-8 pads demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.05-20 parts N,N'-disalicylidene-1,2-diaminopropane; to -8-12 parts 2,6-di-tert-butylphenol; to -8-12 parts amine-aldehyde condensate antioxidant.

[00199] In a particular embodiment, the additive composition comprises: -9-11 parts polyisobutylene succinimide; to -5-7 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.05-20 pads N,N'-disalicylidene-1,2-diaminopropane; to -9-11 parts 2,6-di-tert-butylphenol; to -9-11 parts amine-aldehyde condensate antioxidant.

[00200] In a particular embodiment, the additive composition comprises: -7-17 parts polyisobutylene succinimide; to -3-9 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.5-16 parts N,N'-disalicylidene-1,2-diaminopropane; to -5-15 parts 2,6-di-tert-butylphenol; to -5-15 parts amine-aldehyde condensate antioxidant.

[00201] In a particular embodiment, the additive composition comprises: -8-12 parts polyisobutylene succinimide; to -4-8 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -1-5 parts N,N-disalicylidene-1,2-diaminopropane; to -8-12 parts 2,6-di-tcrt-butylphenol; to -8-12 parts amine-aldehyde condensate antioxidant.

[00202] In a particular embodiment, the additive composition comprises: -9-11 parts polyisobutylene succinimide; to -5-7 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -1-3 parts N,N'-disalicylidene-l,2-diaminopropane; to -9-11 parts 2,6-di-tert-butylphenol; to -9-1 1 parts amine-aldehyde condensate antioxidant.

[00203] In a particular embodiment, the additive composition comprises: -8-15 parts of polyisobutylene succinimide; to -3-8 parts of demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -N,N'-disalicylidene-l,2-diaminopropane; to -6.5-11 parts 2,6-di-tcrt-butylphenol; to -6.5-11 parts amine-aldehyde condensate antioxidant.

[00204] In a particular embodiment, the additive composition comprises: -8-15 parts of polyisobutylene succinimide; to -3-8 parts of demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.5-18 parts N,N'-disalicylidene-l,2-diaminopropane; to -6.5-11 parts 2,6-di-tert-butylphenol; to -6.5-11 parts amine-aldehyde condensate antioxidant.

[00205] In a particular embodiment, the additive composition comprises: -8-15 parts of polyisobutylene succinimide; to -3-8 parts of demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -10-18 parts N,N'-disalicylidene-1,2-diaminopropane; to -6.5-11 parts 2,6-di-tert-butylphenol; to -6.5-11 parts amine-aldehyde condensate antioxidant.

[00206] In a particular embodiment, the additive composition comprises: -9-14 parts of polyisobutylene succinimide; to -4-7 parts of demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -N,N'-disalicylidene-l,2-diaminopropane; to -7-10.5 parts 2,6-di-tert-butylphenol; to -7-10.5 parts amine-aldehyde condensate antioxidant.

[00207] In a particular embodiment, the additive composition comprises: -9-14 parts of polyisobutylene succinimide; to -4-7 parts of demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -1-16 parts N,N-disalicylidene-1,2-diaminopropane; to -7-10.5 parts 2,6-di-tert-butylphenol; to -7-10.5 parts amine-aldehyde condensate antioxidant.

[00208] In a particular embodiment, the additive composition comprises: -9-14 parts of polyisobutylene succinimide; to -4-7 parts of demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -12-16 parts N,N-disalicylidene-1,2-diaminopropane;to -7-10.5 parts 2,6-di-tert-butylphenol; to -7-10.5 parts amine-aldehyde condensate antioxidant.

[00209] In a particular embodiment, the additive composition comprises: -11-13 parts of polyisobutylene succinimide;to -4.5-6 parts of demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -N,N'-disalicylidene-l,2-diaminopropane; to -8-9.5 parts 2,6-di-tert-butylphenol; to -8-9.5 parts amine-aldehyde condensate antioxidant.

[00210] In a particular embodiment, the additive composition comprises: -11-13 parts of polyisobutylene succinimide;to -4.5-6 parts of demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -12-15 parts N,N-disalicylidene-1,2-diaminopropane;to -8-9.5 parts 2,6-di-tert-butylphenol; to -8-9.5 parts amine-aldehyde condensate antioxidant.

[00211] In a particular embodiment, the additive composition comprises: -5-25 wt% polyisobutylene succinimide; -0.5-10 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); -2-10 wt% N,N'-disalicylidene-1,2-diaminopropane; -1-10 wt% N-N'-bis(2-ethylhexy-ar-methyl 1 H-benzotriazol-1 -methanamine; -1-10 wt% 2,8-di-tert-butylphenol; and -1-10 wt% N,N-di-sec-butyl-p-phenylenediamine.

[00212] In a particular embodiment, the additive composition comprises: -10-20 wt% polyisobutylene succinimide; -1-5 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); -2-5 wt% N,N'-disalicylidene-l,2-diaminopropane; -3-10 wt% N-N'-bis(2-ethylhexy-ar-methyl 1 H-benzotriazol-1 -methanamine; -1-lOwt% 2,8-di-tert-butylphenol; and -1-10 wt% N,N-di-sec-butyl-p-phenylenediamine.

[00213] In a particular embodiment, the additive composition comprises: -12-18 wt% polyisobutylene succinimide; -1-3 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); -3-7 wt% N,N-disalicylidene-1,2-diaminopropane; -2-5 wt% N-N'-bis(2-ethylhexyl)-ar-methyl 1 H-benzotriazol-1 -methanamine; -3-7 wt% 2.6-di-tert-butylphenol; and -3-7 wt% N,N'-di-sec-butyl-p-phenylenediamine.

[00214] In a particular embodiment, the additive composition comprises: -14-16 wt% polyisobutylene succinimide; -1-3 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); -4-6 wt% N,N'-disalicylidene-l,2-diaminopropane; -2-4 wt% N-N'-bis(2-ethylhexyQ-ar-methyl 1 H-benzotriazol-1 -methanamine; -4-6 wt% 2,6-di-tert-butylphenol; and -4-6 wt% N,N'-di-sec-butyl-p-phenylenediamine.

[00215] In a particular embodiment, the additive composition comprises: -14-16 wt% polyisobutylene succinimide; -1.5-2.5 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); -4-6 wt% N,N-disalicylidene-1,2-diaminopropane; -2.5-3.5 wt% N-N'-bis(2-ethylhexyl)-ar-methyl 1H-benzotriazol-1-methanamine; -4-6 wt% 2,6-di-tert-butylphenol; and -4-6 wt% N,N'-di-sec-butyl-p-phenylenediamine.

[00216] In a particular embodiment, the additive composition comprises: -5-25 wt% polyisobutylene succinimide; to -1-15 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.05-20 wt% N,N'-disalicylidene-l,2-diaminopropane; to -1-20 wt% 2,6-di-tert-butylphenol; to -1-20 wt% amine-aldehyde condensate antioxidant.

[00217] In a particular embodiment, the additive composition comprises: -7-17 wt% polyisobutylene succinimide; to -3-9 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.05-20 wt% N,N'-disalicylidene-l,2-diaminopropane; to -5-lSwt% 2,6-di-tert-butylphenol; to -5-15 wt% amine-aldehyde condensate antioxidant.

[00218] In a particular embodiment, the additive composition comprises: -8-12 wt% polyisobutylene succinimide; to -4-8 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.05-20 wt% N,N'-disalicylidene-l,2-diaminopropane; to -8-l2wt% 2,6-di-tert-butylphenol; to -8-12 wt% amine-aldehyde condensate antioxidant.

[00219] In a particular embodiment, the additive composition comprises: -9-11 wt% polyisobutylene succinimide; to -5-7 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.05-20 wt% N,N'-disalicylidene-l,2-diaminopropane; to -9-11 wt% 2,6-di-tert-butylphenol; to -9-1 1 wt% amine-aldehyde condensate antioxidant.

[00220] In a particular embodiment, the additive composition comprises: -7-17 wt% polyisobutylene succinimide; to -3-9 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.5-16 wt% N,N'-disalicylidene-l,2-diaminopropane; to -5-lSwt% 2,6-di-tert-butylphenol; to -5-15 wt% amine-aldehyde condensate antioxidant.

[00221] In a particular embodiment, the additive composition comprises: -8-12 wt% polyisobutylene succinimide; to -4-8 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -1-5 wt% N,N-disalicylidene-1,2-diaminopropane; to -8-l2wt% 2,6-di-tcrt-butylphenol; to -8-12 wt% amine-aldehyde condensate antioxidant.

[00222] In a particular embodiment, the additive composition comprises: -9-11 wt% polyisobutylene succinimide; to -5-7 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -1-3 wt% N,N'-disalicylidene-l,2-diaminopropane; to -9-11 wt% 2,6-di-tert-butylphenol; to -9-1 1 wt% amine-aldehyde condensate antioxidant.

[00223] In a particular embodiment, the additive composition comprises: -5-25 wt% polyisobutylene succinimide; to -1-10 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -5-25 wt% N,N'-disalicylidene-l,2-diaminopropane; to -2.5-17.5 wt% 2,6-di-tcrt-butylphenol; to -2.5-1 7.5 wt% amine-aldehyde condensate antioxidant.

[00224] In a particular embodiment, the additive composition comprises: -10-20 wt% polyisobutylene succinimide; to -3-10 wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -10-20 wt% N,N'-disalicylidene-l,2-diaminopropane; to -7.5-lSwt% 2,6-di-tert-butylphenol; to -7.5-15 wt% amine-aldehyde condensate antioxidant.

[00225] In a particular embodiment, the additive composition comprises: -13-16 wt% polyisobutylene succinimide; to -5-S wt% demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -14-18 wt% N,N'-disalicylidene-1,2-diaminopropane; to -9-1 1 wt% 2,6-di-tert-butylphenol; to -9-1 1 wt% amine-aldehyde condensate antioxidant.

[00226] Suitably, the fuel additive composition is a liquid. The additive composition may comprise a diluent, for instance, to ensure the additive is of a suitable viscosity for introduction into, or injection into a fuel. Alternatively the additive composition may be a concentrate intended for dilution with said prior to its introduction or injection into a fuel.

[00227] The diluent may comprise one or more specific diluents, though in preferred embodiments the diluents consists essentially of (or even consists of) one diluent.

[00228] Suitably, the abovementioned formulations of fuel additive compositions comprise a diluent, suitably 50-80 parts (relative to the other ingredients listed) or 50-80 wt%, more suitably 55-75 parts (relative to the other ingredients listed) or 55-75 wt%, most suitably 60-70 parts (relative to the other ingredients listed) or 60-70 wt%. In an embodiment, the fuel additive composition comprises 20-75 parts diluent, suitably 25-70 parts, suitably 30-60 parts, suitably 35-55 parts diluent. Where a composition is defined, without mention of a diluent, in terms of proportions and/or ratios of various ingredients (such as those abovementioned and adaptations thereof which account for additional optional ingredients described elsewhere herein), the balance (i.e. up to 100%) may be suitably made up of at least 90% diluent, suitably at least 95% diluent, suitably 100% diluent.

[00229] In a particular embodiment, the additive composition comprises at least 30 wt% of the stipulated ingredients (i.e. of the additive composition, at 30 wt% is constituted by the combined total of all the stipulated ingredients), suitably at least 50 wt%, suitably at least 70 wt%. Suitably, of the balance (the remainder) of the additive composition, at least 70 wt% is constituted by a diluent, suitably at least 80 wt%, suitably at least 90 wt%, suitably at least 95 wt%, suitably about 100%. Any remaining balance may suitably comprise other additional ingredients, or impurities.

[00230] The diluent is suitably selected from an aromatic compound, a hydrocarbon compound, and/or mixtures thereof. Suitably the diluent is derived from crude oil distillation, and may be selected from kerosene, cracked gas oil, vacuum gas oil, long residue, short residue, heavy naphtha, light gas oil, medium gas oil, heavy gas oil, cycle oil, gasoline, diesel and/or mixtures thereof.

[00231] Suitably the diluent has a boiling point between 80 and 230 C. The diluent is suitably insoluble and/or immiscible with water.

[00232] In a particular embodiment, the diluent is or comprises heavy naphtha. The heavy naphtha suitably comprises (6-12C)hydrocarbons and/or (6-12C)aromatic compounds and suitably has a boiling point between 90 and 200°C. Suitably the heavy naphtha is a complex mixture, suitably comprising alkylbenzenes, suitably (3-4C)alkylbenzenes.

[00233] The fuel additive composition of the invention may suitably further comprise a corrosion inhibitor, such as dicyclohexylamine. In particular embodiments, the fuel additive composition comprises 0-15 parts (relative to the other ingredients listed above) or 0-15 wt% corrosion inhibitor (or one or more corrosion inhibitors), suitably 2-10 parts (relative to the other ingredients listed above) or 2-10 wt% corrosion inhibitor. In particular embodiments, the fuel additive composition comprises 5-15 parts (relative to the other ingredients listed above) or 5-15 wt% corrosion inhibitor (or one or more corrosion inhibitors), suitably 8-12 parts (relative to the other ingredients listed above) or 8-12 wt% corrosion inhibitor.

[00234] The fuel additive composition may suitably further comprise a dye. In particular embodiments, the fuel additive composition comprises 0-10 parts (relative to the other ingredients listed above) or 0-10 wt% dye (or one or more dyes).

[00235] The fuel additive composition may suitably further comprise a fragrance. In particular embodiments, the fuel additive composition comprises 0-20 parts (relative to the other ingredients listed above) or 0-20 wt% fragrance (or one or more fragrances).

[00236] Though a fuel composition of the invention may be produced through adding the ingredients of the additive composition to the fuel either separately or in various combinations (e.g. (i) + (U) + (iii) + (iv); or (i)/(ii) + (iii)/(iv)), it is clearly preferably to add all the relevant ingredients as a single additive composition (i.e. (i)/(ii)/(iU)/(iv)) as defined above. However, where the ingredients are added separately or in various combinations to the fuel, their relative proportions and concentrations within the resulting fuel compositions suitably reflect the proportions and concentrations of those as if they were added to the fuel as part of an additive composition as defined herein.

Base Fuel [00237] The base fuel of the fuel compositions of the present invention is suitably a hydrocarbon-based fuel. The base fuel may be a mixture of hydrocarbon-based fuels. The base fuel may comprise one or more hydrocarbon-based fuels derived (by distillation) from hydrocarbon mixture, whether naturally occurring, synthetic, or partially synthetic (e.g. crude oil, biofuels, synthetic oil/hydrocarbons). For instance, the base fuel may be obtained by fractional distillation of crude petroleum between about 150°C and 275°C.

[00238] Suitably, the base fuel is a combustible hydrocarbon liquid. Suitably the base fuel has a flash point above 35°C. Suitably the base fuel has an autoignition temperature greater than 200°C.

[00239] Suitably, the base fuel is or comprises C6 to C16 hydrocarbons. Suitably the base fuel comprises at least 80 wt% C6 to C16 hydrocarbons, suitably at least 90 wt% C6 to C16 hydrocarbons, suitably at least 95 wt% C6 to C16 hydrocarbons.

[00240] Suitably, the base fuel is or comprises 010 to 016 hydrocarbons. Suitably the base fuel comprises at least 80 wt% 010 to C16 hydrocarbons, suitably at least 90 wt% 010 to C16 hydrocarbons, suitably at least 95 wt% Cio to 016 hydrocarbons.

[00241] In a particular embodiment, the base fuel is or comprises kerosene. Suitably the base fuel comprises at least 80 wt% kerosene, suitably at least 90 wt% kerosene, suitably at least 95 wt% kerosene. In a particular embodiment, the base fuel is kerosene.

[00242] The base fuel is suitably fuel for oil-fired boilers, for instance, domestic oil-fired boilers. The base fuel is suitably fuel for pressure-jet boilers. Most suitably, the base fuel is suitably fuel for domestic oil-tired pressure-jet boilers.

[00243] Suitably the base fuel is immiscible with water.

Fuel Composition [00244] The present invention provides a fuel composition comprising a base fuel and a fuel additive composition as defined herein.

[00245] The tuel composition may be suitably formed by simply adding/mixing a fuel additive composition ot the invention to/with a base fuel (or pre-additised form thereof, i.e. with different additives to those of the invention). Once said fuel additive composition is added to the base fuel, mixing suitably ensues to substantially homogenise the fuel composition.

[00246] The fuel composition of the present invention suitably comprises at least loppm ot the tuel additive composition, suitably at least SOppm, most suitably at least 75 ppm. The fuel composition of the present invention suitably comprises at most 300 ppm of the fuel additive composition, suitably at most 200 ppm, most suitably at most 150 ppm. In a particular embodiment, the fuel composition comprises 75-lSOppm fuel additive composition. In a particular embodiment, the fuel composition comprises 75-1 25ppm fuel additive composition.

[00247] The aforementioned fuel additive composition concentrations within the fuel composition reflect the "treat rate" of the tuel with respect to the fuel additive composition as a whole (i.e. the tuel additive composition treat rate). As such, the "fuel additive composition treat rate" is the combined concentrations of all ingredients of the fuel additive composition. Suitably, therefore, the fuel composition may be said to comprise the ingredients of the fuel additive composition (or the additive ingredients otherwise stipulated in relation to the tuel composition) so that the combined total of all these ingredients satisfies any one of the optional conditions set forth herein in relation to the treat rate ot the tuel additive composition (e.g. at least 50 ppm, at most 200ppm as described above).

[00248] "ppm" values given in relation to the fuel composition are ppm by weight unless specifically stated otherwise.

[00249] Since, elsewhere in this specitication, optional weight percentage proportions are given tor individual ingredients of the fuel additive composition, it is straight forward to derive individual "treat rates" for each individual ingredient or class of ingredient (i.e. "individual ingredient treat rates") by multiplying the percentage proportion of each individual ingredient or ingredient class, stipulated in relation to the additive composition, by the optional "tuel additive composition treat rates" mentioned above. The tuel composition may theretore also be defined by reterence to the specific ingredients of the additive composition rather than by reterence to an additive composition itself. Such ingredients may be added together (e.g. as part of a fuel additive composition of the invention) or be added separately or in various combinations as mentioned above (e.g. (i) + (ii) + (iU) + (iv); or (i)/(ii) + (iH)/(iv)). As such, the present invention also provides a fuel composition comprising a base fuel and: i) a dispersant; ii) a demulsifier; iii) a metal deactivator; and iv) an antioxidant.

[00250] The relative ratios of the individual additive components D-iv), or any other optional ingredients defined herein in relation to the fuel additive compositions, within the fuel composition may be suitably defined in the same manner as per the fuel additive composition (i.e. in parts by weight). For instance, the fuel composition may comprise: -5-25 parts of dispersant; to -1-15 parts of demulsifier; to -a metal deactivator; to -1-35 parts of antioxidant; and may optionally comprise these ingredients in any of the aforementioned ratios described in relation to the additive composition. Furthermore, the fuel composition may be restricted by any one or more of the features defined herein in relation to the fuel composition.

[00251] Moreover, wt% concentrations of the individual additive components i)-iv), or any other optional ingredients defined herein in relation to the fuel additive compositions, within the fuel composition may be suitably calculated and defined by reference to treat rates and the wt% of the individual additive components as defined in relation to the relative additive composition.

[00252] The fuel composition suitably comprises at least 0.5 ppm, suitably at least Sppm, suitably at least 9ppm dispersant. The fuel composition suitably comprises at most 75ppm, suitably at most 4Oppm, suitably at most 27 ppm dispersant. The fuel composition suitably has at most 45ppm dispersant, suitably at most 25 ppm dispersant. Suitably, the fuel composition has between 5 and 25 ppm dispersant, suitably between 10 and 20 ppm.

[00253] The fuel composition suitably comprises at least 0.005 ppm, suitably at least 0.01 ppm, suitably at least 0.05 ppm demulsifier. The fuel composition suitably comprises at least 2ppm demulsifier, suitably at least 4ppm. The fuel composition suitably comprises at most 30 ppm, suitably at most lOppm, suitably at most 4.5 ppm demulsifier. Suitably, the fuel composition has between 1 and 15 ppm demulsifier, suitably between 2 and 12 ppm, suitably between 3 and 10 ppm, suitably between 5 and 9ppm.

[00254] Suitably, the fuel composition comprises at least 5 ppm of both dispersant and demulsifier combined (i.e. the sum of the individual treat rate for each ingredient), suitably at least 7 ppm, suitably at least 9 ppm, suitably at least 15 ppm. Suitably, the fuel composition comprises at most 50 ppm of both dispersant and demulsifier combined (i.e. the sum of the individual treat rate for each ingredient), suitably at most 45 ppm, suitably at most 40 ppm, suitably at most 30 ppm, suitably at most 25 ppm, suitably at most 20 ppm. In a particular embodiment, the fuel composition comprises between 5 and 45 ppm of both dispersant and demulsifier combined, suitably between 10 and 30 ppm, most suitably between 15 and 25 ppm.

[00255] The fuel composition suitably comprises at least 0.3 ppm, suitably at least 2.5 ppm, suitably at least 3.75 ppm metal deactivator. Suitably the fuel composition comprises at least 1 Oppm metal deactivator, suitably at least 15 ppm. The fuel composition suitably comprises at most 60 ppm, suitably at most 30 ppm, suitably at most 18 ppm metal deactivator.

Suitably the fuel composition comprises between 10 and 30 ppm metal deactivator, suitably between 15 and 25 ppm.

[00256] The fuel composition suitably comprises at least 0.1 ppm, suitably at least 1 ppm, suitably at least 4.5 ppm antioxidant. Suitably the fuel composition comprises at least 10 ppm antioxidant, suitably at least 15 ppm, suitably at least 20 ppm. The fuel composition suitably comprises at most 75 ppm, suitably at most 40 ppm, suitably at most 30 ppm, suitably at most 21 ppm antioxidant. Suitably the fuel composition comprises between 12 and 32 ppm antioxidant, suitably between 18 and 28 ppm.

[00257] In a particular embodiment, the fuel composition comprises: i) 5 ppm -25 ppm dispersant; ii) 1 -15 ppm demulsifier; Ui) 5 -30 ppm metal deactivator; and iv) 10 -32 ppm antioxidant.

[00258] In a particular embodiment, the fuel composition comprises: i) 5 ppm -25 ppm dispersant; U) 1 -15 ppm demulsifier; Ui) 5 -30 ppm metal deactivator; and iv) 10 -32 ppm antioxidant; wherein the fuel composition comprises between 5 and 45 ppm of both dispersant and demulsifier combined.

[00259] In a particular embodiment, the fuel composition comprises: i) 10 ppm -20 ppm dispersant; U) 2 -12 ppm demulsifier; Ui) 12 -25 ppm metal deactivator; and iv) 18 -28 ppm antioxidant.

[00260] In a particular embodiment, the fuel composition comprises: i) 10 ppm -20 ppm dispersant; ii) 2 -12 ppm demulsifier; iii) 12 -25 ppm metal deactivator; and iv) 18 -28 ppm antioxidant.

wherein the fuel composition comprises between 15 and 30 ppm of both dispersant and demulsifier combined.

[00261] In a particular embodiment, the fuel composition comprises: -5-25 parts of dispersant; to -1-15 parts of demulsifier; to -a metal deactivator; to -1-35 parts of antioxidant; (or any of the aforementioned ratios of these ingredients defined in relation to the additive composition) wherein the fuel composition comprises at most 45 ppm of both dispersant and demulsifier combined (i.e. the sum of the individual treat rate for each ingredient).

[00262] In a particular embodiment, the fuel composition comprises: i) 5 ppm -25 ppm polyisobutylene succinimide; ii) 1 -15 ppm demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); iii) 5 -30 ppm N,N'-disalicylidene-l,2-diaminopropane; and iv) 5-16 ppm 2,6-di-tert-butylphenol; to v) 5-16 ppm amine-aldehyde condensate antioxidant.

[00263] In a particular embodiment, the fuel composition comprises: i) 5 ppm -25 ppm polyisobutylene succinimide; ii) 1 -15 ppm demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); iii) 5 -30 ppm N,N'-disalicylidene-l,2-diaminopropane; and iv) 5-16 ppm 2,6-di-tert-butylphenol; to v) 5 -16 ppm amine-aldehyde condensate antioxidant.

wherein the fuel composition comprises between 5 and 45 ppm of both dispersant and demulsifier combined.

[00264] In a particular embodiment, the fuel composition comprises: i) 10 ppm -20 ppm polyisobutylene succinimide; ii) 2 -12 ppm demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); iii) 12-25 ppm N,N'-disalicylidene-1,2-diaminopropane; and iv) 9 -14 ppm 2,6-di-tert-butylphenol; to v) 9 -14 ppm amine-aldehyde condensate antioxidant.

[00265] In a particular embodiment, the fuel composition comprises: i) 10 ppm -20 ppm polyisobutylene succinimide; ii) 2 -12 ppm demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); üi) 12-25 ppm N,N-disalicylidene-1,2-diaminopropane; and iv) 9 -14 ppm 2,6-di-tert-butylphenol; to v) 9 -14 ppm amine-aldehyde condensate antioxidant.

[00266] In a particular embodiment, the fuel composition comprises: -5-25 parts of dispersant; to -1-15 parts of demulsifier; to -a metal deactivator; to -1-35 parts of antioxidant; (or any of the aforementioned ratios of these ingredients defined in relation to the additive composition) wherein the fuel composition comprises at most 45 ppm of both dispersant and demulsifier combined (i.e. the sum of the individual treat rate for each ingredient).

[00267] According to a further aspect of the invention there is provided a fuel composition comprising: i) 0.5 ppm -75 ppm dispersant; ii) 0.005 ppm -30 ppm demulsifier; iii) 0.3 ppm -60 ppm metal deactivator; and iv) 0.1 ppm -75 ppm antioxidant.

[00268] Of course, the fuel composition may comprise any of the other ingredients described in relation to the fuel additive composition (e.g. corrosion inhibitor, diluent, dye, fragrance), optionally in corresponding amounts.

[00269] Suitably, the fuel additive composition of the present invention (or the ingredients thereof) are added to the fuel prior to or at point of combustion (e.g. via in situ dosing, for example, in boiler). In principle, the additives may be added to the fuel at any point in fuel supply chain, including to a fuel storage tank of a domestic boiler, though addition with mixing is preferable. As such, in preferred embodiments, pre-additised fuel compositions are provided to the domestic user.

Combustion System [00270] The present invention provides a fuel combustion system, comprising: a) a fuel storage unit comprising a fuel composition as defined herein; b) a combustion unit fluidly connectable to the fuel storage unit and operable to combust the fuel composition provided to the combustion unit from the fuel storage unit.

[00271] The fuel storage unit is suitably a fuel tank for safely storing fuel. The combustion unit may be any suitable combustion unit known in the art for combusting the fuel compositions of the present invention. The fuel combustion system suitably comprises a fuel line (e.g. relevant pipework) connecting the fuel storage unit to the combustion unit such that fuel in the fuel storage unit can be drawn (or fed/pumped) into the combustion unit for combustion. The fuel combustion system may comprise a fuel pump for pumping fuel from the fuel storage unit into the combustion unit, optionally via a fuel filter.

[00272] Accordingly, the present invention additionally provide a method of combusting a fuel composition, comprising providing a fuel composition as defined herein and combusting the fuel composition.

[00273] The combustion system may be a burner, engine, or furnace. In preferred embodiments, the combustion system is a burner, more particularly a boiler (e.g. a domestic heating boiler). Suitably the burner burns fuel compositions of the present invention, suitably burning fuel sprayed from a burner nozzle (suitably under pressure). The combustion system is suitably an oil-tired boiler, suitably a pressure-jet boiler. The combustion system is most suitably a pressure-jet oil-fired domestic heating boiler, which most suitably uses kerosene as a base fuel. Suitably, the burners of the invention comprise burner nozzles, and optionally other components, which typically require regular servicing or replacement to remove combustion-derived deposits. In particular embodiments, burners of the present invention comprise burner nozzles which are vulnerable to blockage after prolonged usage, suitably as a result of deposits made by combusted fuels.

[00274] According to a fifth aspect of the present invention, there is provided a method of combusting a fuel composition, comprising providing a fuel composition as defined herein and combusting the fuel composition.

Advantages 01 the Invention and Uses of the Additives [00275] The combination of ingredients characterising the fuel additive and fuel compositions of the invention afford a variety of surprising improvements in the combustion of fuels, such as kerosene, in domestic oil-fired boiler systems. It is reasonable to expect such benefits to be equally apparent in alternative fuels and combustion systems. The unique and unexpected advantages of the invention improves fuel performance and combustion efficiency, improves protection for the relevant combustion system and its component parts (e.g. better deposit control) thereby reducing servicing and breakdowns, and significantly improves water handling, which can be a particular problem, especially in domestic oil-fired boiler systems, where water can build up in the fuel storage tank and thereby compromise combustion efficiency.

[00276] In particular, using the combination of ingredients of the invention within a fuel composition reduces CO2 emissions (suitably instantaneously, regardless of the condition of the combustion system within which it is combusted) suitably by at least 0.5%, suitably by at least 0.9%, in comparison to fuels without the combination of ingredients of the invention. The present invention suitably reduces CO2 emissions by at least 0.5%, suitably by at least 0.9%, even with a clean nozzle (i.e. newly replaced nozzle, e.g. without deposit build-ups or blockages) on the burner of the relevant combustion system. The present invention suitably reduces 002 emissions by at least 1%, suitably by at least 2%, suitably by at least 3%, with a dirty nozzle (e.g. a nozzle that is ready to be replaced in accordance with standard servicing) on the burner of the relevant combustion system, as compared to standard fuels without the additive ingredients of the present invention. Using the combination of ingredients of the invention within a fuel composition suitably reduces 002 emissions instantaneously without increasing emissions of particulate matter (e.g. carbon, soot, etc.). Suitably, combustion efficiency increases. The impact on the reduction of 002 emissions of using fuels containing additive ingredients of the invention is suitably greater than the impact of replacing a dirty burner nozzle with a clean burner nozzle. Since 002 emissions are a recognised measure of boiler performance and combustion efficiency, it is clear that the additive ingredients of the present invention enhance performance of a combustion system more than would replacing or servicing the relevant parts thereof. Moreover, using fuel additive ingredients of the present invention prolongs time periods between services of a combustion system, and reduces the risk of breakdown thereof. Furthermore, the use of fuel additives of the present invention would permit the usage of lower/dirtier grades of fuels within the relevant combustion systems, but with reduced servicing requirements.

[00277] A further benefit provided by the additive compositions of the invention, is that the relevant additised fuels, when sprayed through a nozzle, produce smaller atomised droplets at a larger spray angle. Both the smaller droplet size and greater spray angle increases air/fuel mixing and improves overall combustion.

[00278] The inventors have found that fuel consumption can be reduced, through the use of the additive ingredients of the present invention, by up to 10%. As such, the additives and/or combination of additive ingredients of the invention represent a significant contribution to the art, and help to significantly reduce any adverse environmental impacts of combustion systems.

[00279] The present invention provides a use, in a fuel combustion system, of: i) a dispersant; U) a demulsifier; Ui) a metal deactivator; and iv) an antioxidant; for one or more or all of the following: a) improving fuel performance; b) improving fuel consumption; c) improving the efficiency of the fuel combustion system; d) improving the completeness of combustion of a fuel composition by the fuel combustion system; e) reducing emissions from the fuel combustion system; f) improving air-fuel mixing within the fuel combustion system; g) improving water handling within the fuel combustion system; h) reducing the build up of deposits within the fuel combustion system; i) reducing the risk of breakdown of the fuel combustion system; j) protecting component parts of the fuel combustion system; k) improving corrosion inhibition within the fuel combustion system; I) reducing the amount of servicing required of the combustion system; m) reducing precipitation on storage of the fuel; n) reducing or eliminating pre-filtration of fuels prior to combustion of said fuels; and a) enhancing the beneficial impact of replacing one or more dirty components within the combustion system with corresponding clean components.

[00280] The present invention also provides a use, in a fuel combustion system, of a fuel additive composition as defined herein, for any of the abovementioned uses a)-o).

[00281] Suitably, the uses described herein reduce 002 emissions from the fuel combustion system, suitably without increasing emissions of particular matter (e.g. carbon, soot, etc.), and suitably without decreasing combustion efficiency.

[00282] The additised fuels of the invention also impart instantaneous combustion benefits (as per the above, but especially reduced 002 and/or CO emissions) to combustion systems having either clean or dirty components. The extent to which additised fuels of the present invention instantaneously benefit combustion systems having clean components is particularly surprising. For instance, additising kerosene burnt within a pressure-jet boiler instantaneously improves fuel performance and, in particular, reduces emissions (e,g. CO2 and/or CO emissions), where the boiler is fitted with a clean and/or new burner nozzle.

Moreover, though there is always a beneficial impact (e,g, reduced 002 and/or CO emissions) in replacing dirty components within a combustion system with corresponding clean components, this beneficial impact is dramatically increased for combustion systems running on addised fuels of the invention.

[00283] In a particular embodiment, improvements in fuel performance (as per use (a) above) includes instantaneously reducing 002 and/or CO emissions from clean and/or dirty burner nozzles, and may suitably include improving the benefits of switching from a dirty to a clean burner nozzle.

[00284] The present invention provides a use, in a fuel combustion system, of a fuel additive composition (or the component parts thereof as defined herein, whether provided via a kit or otherwise) and/or a fuel composition as defined herein for achieving one or more or all of the following benefits: a) improving fuel performance; b) improving fuel consumption; c) improving the efficiency of the fuel combustion system; d) improving the completeness of combustion of a fuel composition by the fuel combustion system; e) reducing emissions from the fuel combustion system; f) improving air-fuel mixing within the fuel combustion system; g) improving water handling within the fuel combustion system; h) reducing the build up of deposits within the fuel combustion system; i) reducing the risk of breakdown of the fuel combustion system; j) protecting component parts of the fuel combustion system; k) improving corrosion inhibition within the fuel combustion system; I) reducing the amount of servicing required of the combustion system; m) reducing precipitation on storage of the fuel; n) reducing or eliminating pre-filtration of fuels prior to combustion of said fuels; and o) enhancing the beneficial impact of replacing one or more dirty components within the combustion system with corresponding clean components; wherein one or more of the benefit(s) are instantaneous benefit(s).

[00285] In a particular embodiment, any, some or all of benefits a)-f) and o) listed above are instantaneous benefits.

[00286] In a particular embodiment the use is for achieving one or more or all of the following benefits: a) improving fuel consumption; b) improving the efficiency of the fuel combustion system; c) reducing emissions from the fuel combustion system; d) improving water handling within the fuel combustion system; e) reducing the risk of breakdown of the fuel combustion system; and f) enhancing the beneficial impact of replacing one or more dirty components (e.g. a burner nozzle) within the combustion system with corresponding clean components; wherein one or more of the benefit(s) are instantaneous.

[00287] In an embodiment, the use is for achieving all of the following benefits: a) improving fuel consumption; b) improving the efficiency of the fuel combustion system; c) reducing emissions from the fuel combustion system; wherein all of the benefits are instantaneous.

[00288] In a particular embodiment the use is for achieving one or more or all of the following benefits: a) reducing emissions from the fuel combustion system; b) improving water handling within the fuel combustion system; c) reducing the risk of breakdown of the fuel combustion system; and d) enhancing the beneficial impact of replacing one or more dirty components (e.g. a burner nozzle) within the combustion system with corresponding clean components; wherein one or more of the benefit(s) are instantaneous.

[00289] In a particular embodiment the use is for achieving all of the following benefits: a) reducing emissions from the fuel combustion system; b) improving the efficiency of the fuel combustion system; and c) reducing the risk of breakdown of the fuel combustion system; wherein one or more of the benefit(s) are instantaneous.

[00290] In a particular embodiment the use is for both: reducing emissions from the fuel combustion system; and reducing the risk of breakdown of the fuel combustion system; wherein the reduction in emissions from the fuel combustion system is instantaneous.

[00291] In a particular embodiment the use is for achieving one or more or all of the following benefits: a) reducing emissions from the fuel combustion system; b) reducing the risk of breakdown of the fuel combustion system; and wherein one or more of the benefit(s) are instantaneous.

[00292] In a particular embodiment the use is for reducing emissions from the fuel combustion system; wherein the reduction in emissions from the fuel combustion system is instantaneous.

[00293] In a particular embodiment the use is for improving the efficiency of the fuel combustion system; wherein the improvement in the efficiency of the fuel combustion system is instantaneous.

[00294] In a particular embodiment the use is for improving the fuel consumption or fuel economy of the fuel combustion system; wherein suitably the improvement in the fuel consumption or fuel economy of the fuel combustion system is instantaneous.

[00295] The present invention provides a use, in a pressure-jet boiler fuel combustion system, of a fuel composition comprising a base fuel and: i) a dispersant; ii) a demulsifier; iii) a metal deactivator; and iv) an antioxidant; wherein the fuel composition comprises at most 45 ppm of both dispersant and demulsifier combined (i.e. the sum of the individual treat rate for each ingredient); for improving the fuel consumption or fuel economy of the fuel combustion system; wherein suitably improvement of the fuel consumption or fuel economy of the fuel combustion system is instantaneous.

[00296] The present invention also provides a method of obtaining any one or more of the abovementioned benefits (or groups of benefits as defined herein in relation to a use) in a fuel combustion system, the method comprising operating the fuel combustion system with a fuel composition as defined herein.

Instantaneous Nature of the Benefits [00297] Suitably, any instantaneous benefits are instantaneous when the combustion system or one or more component parts thereof (e.g. burner nozzle) is dirty. Suitably, the instantaneous benefits are instantaneous when a burner nozzle and/or heat exchanger of the fuel combustion system is dirty. Such instantaneous benefits suitably apply where the combustion system is a boiler, suitably a pressure-jet boiler.

[00298] Suitably, any instantaneous benefits are instantaneous when the combustion system or one or more component parts thereof (e.g. burner nozzle) is clean. Suitably, the instantaneous benefits are instantaneous when a burner nozzle and/or heat exchanger of the fuel combustion system is clean. Such instantaneous benefits suitably apply where the combustion system is a boiler, suitably a pressure-jet boiler.

[00299] Suitably, any instantaneous benefits are instantaneous whether the combustion system, or one or more component parts thereof (e.g. burner nozzle), is clean or dirty. Suitably, the instantaneous benefits are instantaneous whether a burner nozzle and/or heat exchanger of the fuel combustion system is clean or dirty. Such instantaneous benefits suitably apply where the combustion system is a boiler, suitably a pressure-jet boiler.

[00300] Suitably, any instantaneous benefits are measurable and evident once the combustion system is operated at a state of equilibrium.

[00301] Suitably, any instantaneous benefits are measurable and evident when the combustion system is operated in a continuous firing mode.

[00302] Suitably, any instantaneous benefits are measurable and evident when tests are performed over 24 hours and the measurements suitably averaged (e.g. using mean values).

Emissions [00303] Suitably, using a fuel additive composition (or the component parts thereof) and/or a fuel composition as defined herein, in a combustion system, reduces carbon dioxide and/or carbon monoxide emissions (suitably instantaneously).

[00304] Suitably, using a fuel additive composition (or the component parts thereof) and/or a fuel composition as defined herein, in a combustion system, reduces carbon dioxide emissions (suitably instantaneously) by at least 0.5%, suitably by at least 0.9%, compared to the same combustion system operating without a fuel additive composition and/or a fuel composition of the invention. Suitably, when the combustion system or one or more components parts thereof (e.g. when the burner nozzle is clean, especially in pressure-jet boilers) is clean, using a fuel additive composition (or the component parts thereof) and/or a fuel composition as defined herein, in said combustion system, reduces carbon dioxide emissions (suitably instantaneously) by at least 0.5%, suitably by at least 0.9%, compared to the same combustion system operating without a fuel additive composition and/or a fuel composition of the invention. Suitably, when the combustion system or one or more components parts thereof (e.g. when the burner nozzle is dirty, especially in pressure-jet boilers) is dirty, using a fuel additive composition (or the component parts thereof) and/or a fuel composition as defined herein, in said combustion system, reduces carbon dioxide emissions (suitably instantaneously) by at least 1.0%, suitably by at least 2.0%, suitably by at least 2.5%, suitably by at least 3.0%, compared to the same combustion system operating without a fuel additive composition and/or a fuel composition of the invention.

[00305] Suitably, using a fuel additive composition (or the component parts thereof) and/or a fuel composition as defined herein, in a combustion system, reduces carbon monoxide emissions (suitably instantaneously) by at least 1.0%, suitably by at least 5.0%, suitably by at least 10.0%, compared to the same combustion system operating without a fuel additive composition and/or a fuel composition of the invention, suitably when the combustion system or one or more components pads thereof (e.g. when the burner nozzle is clean, especially in pressure-jet boilers) is clean.

[00306] Emissions are suiably measured using a conventional boiler engineer's equipment (e.g. Testo 327 Flue Gas Analyser). As such, an end user's engineer will generally be able to measure the difference the additive makes.

Efficiency [00307] Suitably, using a fuel additive composition (or the component parts thereof) and/or a fuel composition as defined herein, in a combustion system, improves the efficiency of the fuel combustion system (suitably instantaneously), compared to the same combustion system operating without a fuel additive composition and/or a fuel composition of the invention.

Suitably such a benefit is prevalent whether the combustion system (or component parts thereof -e.g. burner nozzle and/or heat exchanger) is clean or dirty, but especially when it is dirty.

Such improvements in the efficiency of the fuel combustion system (which are suitably instantaneous), are suitably discerned by using measurements and calculations such as those outlined in the Example Section. Efficiency may. alternatively, be expressed as: Efficiency = [Energy delivered for work (e.g. heat exported in circulating water or steam)] / [Energy that can be provided by fuel, e.g. assuming 100% combustion] Fuel Economy [00308] Suitably, using a fuel additive composition (or the component parts thereof) and/or a fuel composition as defined herein, in a combustion system, improves fuel economy (suitably instantaneously), compared to the same combustion system operating without a fuel additive composition and/or a fuel composition of the invention. Suitably such a benefit is prevalent whether the combustion system (or component parts thereof -e.g. burner nozzle and/or heat exchanger) is clean or dirty, but especially when it is dirty. Such improvements in fuel economy are suitably discernable by reference to carbon dioxide emissions, a reduction in which represents an increase in fuel economy. Herein, references to improvements in "fuel consumption" are synonymous with improvements in "fuel economy".

Impact on Nozzle Replacement [00309] Suitably, using a fuel additive composition (or the component parts thereof) and/or a fuel composition as defined herein, in a combustion system, allows for a greater reduction in carbon dioxide emissions (suitably an instantaneous reduction), when a dirty burner nozzle is replaced by a clean burner nozzle, compared to the same combustion system operating without a fuel additive composition and/or a fuel composition of the invention. As such, using a fuel additive composition (or the component pads thereof) and/or a fuel composition as defined herein, in a combustion system, enhances the beneficial effect of replacing a dirty burner nozzle with a clean burner nozzle.

Breakdown Risk [00310] Suitably such a use reduces the risk of breakdown of the fuel combustion system, most suitably through reducing deposits formed on flame luminosity sensor(s) within the combustion system. Such a benefit is typically non-instantaneous but realised over a period of time.

Specific Embodiment [00311] The present invention provides a use, in a pressure-jet boiler fuel combustion system, of: i) 7-17 parts of dispersant; ii) 3-9 pads of demulsifier; iii) metal deactivator; and iv) 15-25 parts of antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for reducing carbon dioxide emissions from the fuel combustion system; wherein the reduction in carbon dioxide emissions is instantaneous.

[00312] The present invention provides a use, in a pressure-jet boiler fuel combustion system, of: i) 7-17 parts of dispersant; ii) 3-9 pads of demulsifier; Ui) metal deactivator; and iv) 15-25 parts of antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as pad of a fuel composition as defined herein) for achieving all of the following benefits: a) reducing carbon dioxide emissions from the fuel combustion system; b) improving the efficiency of the fuel combustion system; and c) reducing the risk of breakdown of the fuel combustion system; wherein benefits a) and b) are instantaneous.

[00313] The present invention provides a use, in a pressure-jet boiler fuel combustion system, of: -7-17 parts polyisobutylene succinimide; to -3-9 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.05-20 parts N,N'-disalicylidene-1,2-diaminopropane; to -5-15 parts 2,6-di-tert-butylphenol; to -5-15 parts amine-aldehyde condensate antioxidant.

(whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for achieving all of the following benefits: a) Reducing carbon dioxide emissions from the fuel combustion system; b) improving the efficiency of the fuel combustion system; and c) reducing the risk of breakdown of the fuel combustion system; wherein benefits a) and b) are instantaneous.

[00314] The present invention provides a use, in a pressure-jet boiler fuel combustion system, of: i) 7-17 parts of dispersant; 3-9 parts of demulsifier; üi) metal deactivator; and iv) 15-25 parts of antioxidant; (whether added separately, as part of a fuel additive composition, or added in any combination, suitably as part of a fuel composition as defined herein) for achieving all of the following benefits: a) improving fuel consumption; b) improving the efficiency of the fuel combustion system; c) reducing emissions from the fuel combustion system; wherein all of the benefits are instantaneous.

[00315] The abovementioned benefits are suitably achieved whether the fuel combustion system is clean or dirty. The abovementioned uses suitably involve the use of a fuel composition wherein the fuel composition comprises at most 45 ppm of both dispersant and demulsifier combined (i.e. the sum of the individual treat rate for each ingredient).

[00316] The present invention provides a fuel composition comprising a base fuel and: -5-25 parts of dispersant; to -1-15 parts of demulsifier; to -a metal deactivator; to -1-35 parts of antioxidant; wherein the fuel composition comprises at most 45 ppm of both dispersant and demulsifier combined (i.e. the sum of the individual treat rate for each ingredient).

[00317] The present invention provides a fuel composition comprising kerosene and: i) 5 ppm -25 ppm dispersant; U) 1 -15 ppm demulsifier; Ui) 5 -30 ppm metal deactivator; and iv) 10 -32 ppm antioxidant.

EXAMPLES

[00318] The invention is now described by reference to the following Examples and supporting data.

Example 1 -Preparation of Fuel Additive Composition [00319] A fuel additive composition was formed through combining and homogenising (through mixing) the ingredients presented below: Agent Chemical %wt Solvent Aromatic solvent 50.8 Metal Deactivator N,N'-Dsalicylidene-1 2-2.15 ______________________ diaminopropane _________ Antioxidants 2,6-di-tert.-butylphenol 10.45 ____________________ Amino aldehyde condensate 10.45 Dispersant / Detergent Polyisobutylene succinimide 9.8 Corrosion inhibitor Dicyclohexylamine 10.0 Demulsifier alkoxylated phenol-6.4 formaldehyde resin-containing _______________________ demulsifier _________ [00320] The aromatic solvent (typically heavy naphtha) was readily commercially sourced.

[00321] The N,N'-Disalicylidene-l,2-diaminopropane was readily commercially sourced.

[00322] The 2,6-di-tert.-butylphenol was readily commercially sourced.

[00323] The amine aldehyde condensate was readily commercially sourced. The term "amine aldehyde condensate" is well known in the art.

[00324] The demulsifier was commercially sourced as an alkoxylated phenol-formaldehyde resin-containing demulsifier.

[00325] The dicyclohexylamine was readily commercially sourced.

[00326] The polyisobutylene succinimide (PIBSI) was readily commercially sourced.

[00327] The fuel additive composition (hereinafter "the inventive fuel additive") was bottled and used as required in the comparative tests described below. The inventive fuel additive was a stable, mobile liquid.

Example 1 A -Comparative Fuel Additive Composition [00328] An older fuel additive composition, previously marketed for use in kerosene for oil-fired pressure-jet domestic heating boilers, was prepared by mixing 10 wt% commercially sourced blend of organic amines and dimer/trimer acids dispersed in organic acid anhydride, 20 wt% antioxidants, and 70 wt% solvent. Again, this fuel additive composition was bottled and used as required in comparative tests described below.

Example 1 B -Alternative Fuel Additive Composition [00329] Another fuel additive composition was formed through combining and homogenising (through mixing) the ingredients presented in Table 1.

Table 1 -Fuel additive formulation Agent Chemical %wt Solvent Heavy Naptha 65 Metal Deactivator N,N'-Disalicylidene-l,2-diaminopropane 5 N-N'-bis(2-ethylhexy-ar-methyl 1 H-3 ____________________ benzotriazol-1 -methanamine ________ Antioxidant 2,6-di-tert.-butylphenol 5 ____________________ N,N'-di-sec-butyl-p-phenylenediamine 5 Dispersant / deposit Polyisobutylene succinimide 15 control additive __________________________________________ ________ Demulsifier alkoxylated phenol-formaldehyde resin-2 ______________________ containing demulsifier _________ [00330] The heavy naphtha was readily commercially sourced.

[00331] The N,N'-Disalicylidene-l,2-diaminopropane was readily commercially sourced.

[00332] The N-N'-bis(2-ethylhexy-ar-methyl 1 H-benzotriazol-1 -methanamine was readily commercially sourced.

[00333] The 2,6-di-tert.-butylphenol was readily commercially sourced.

[00334] The N,N'-di-sec-butyl-p-phenylenediamine was readily commercially sourced.

[00335] The demulsifier was commercially sourced as an alkoxylated phenol-formaldehyde resin-containing demulsifier.

[00336] The polyisobutylene succinimide (PIBSI) was readily commercially sourced.

[00337] The fuel additive composition was bottled and used as required in testing. The fuel additive composition of this Example was a stable, mobile liquid.

Example 1 C -Alternative Fuel Additive Composition [00338] Another fuel additive composition was formed through combining and homogenising (through mixing) the ingredients presented below: Agent Chemical % wt Solvent Aromatic solvent 42.6 Dispersant / Detergent Polyisobutylene succinimide 14.5 Demulsifier alkoxylated phenol-6.3 formaldehyde resin-containing _______________________ demulsifier _________ Metal Deactivator NN'-Dsalicylidene-1 2-16.0 ______________________ diaminopropane _________ Antioxidants 2,6-di-tort.-butylphcnol 10.3 ___________________ Amine aldehyde condensate 10.3 [00339] The ingredients were sourced as per Example 1.

[00340] The fuel additive composition was bottled and used as required in testing. The fuel additive composition of this Example was a stable, mobile liquid. The additive composition may be rendered more mobile by increasing the level of solvent. It will be understood that the fuel treat rates will need to be adjusted accordingly when the additive composition is further diluted.

Example 1 D -Comparative Fuel Additive Composition [00341] Another fuel additive composition was formed, for comparative purposes, through combining and homogenising (through mixing) the ingredients presented below: Agent Chemical %wt Solvent Aromatic solvent 57 Dispersant / Detergent Polyisobutylene succinimide 0 Demulsifier alkoxylated phenol-6.3 formaldehyde resin-containing _______________________ demulsifier _________ Metal Deactivator N,N-Dsalicylidene-1 2-16.0 ______________________ diaminopropane _________ Antioxidants 2,6-di-tert.-butylphenol 10.3 ___________________ Amine aldehyde condensate 10.3 [00342] The ingredients were sourced as per Example 1.

[00343] The fuel additive composition was bottled and used as required in testing. The fuel additive composition of this Example was a stable, mobile liquid. The additive composition may be rendered more mobile by increasing the level of solvent. It will be understood that the fuel treat rates will need to be adjusted accordingly when the additive composition is further diluted.

Example 1 E -Comparative Fuel Additive Composition [00344] Another fuel additive composition was formed, for comparative purposes, through combining and homogenising (through mixing) the ingredients presented below: Agent Chemical %wt Solvent Aromatic solvent 48.4 Dispersant / Detergent Polyisobutylene succinimide 14.5 Demulsifier alkoxylated phenol-0 formaldehyde resin-containing _______________________ demulsifier _________ Metal Deactivator N,N'-Dsalicylidene-1 2-16.0 ______________________ diaminopropane _________ Antioxidants 2,6-di-tert.-butylphenol 10.3 ___________________ Amine aldehyde condensate 10.3 [00345] The ingredients were sourced as per Example 1.

[00346] The fuel additive composition was bottled and used as required in testing. The fuel additive composition of this Example was a stable, mobile liquid. The additive composition may be rendered more mobile by increasing the level of solvent. It will be understood that the fuel treat rates will need to be adjusted accordingly when the additive composition is further diluted.

Example 1 F -Comparative Fuel Additive Composition [00347] Another fuel additive composition was formed, for comparative purposes, through combining and homogenising (through mixing) the ingredients presented below: AQent Chemical %wt Solvent Aromatic solvent 62.9 Dispersant / Detergent Polyisobutylene succinimide 0 Demulsitier alkoxylated phenol-0 formaldehyde resin-containing _______________________ demulsifier _________ Metal Deactivator NN'-Dsalicylidene-1 2-16.0 ______________________ diaminopropane _________ Antioxidants 2,6-di-tert.-butylphenol 10.3 ___________________ Amine aldehyde condensate 10.3 [00348] The ingredients were sourced as per Example 1.

The fuel additive composition was bottled and used as required in testing. The fuel additive composition of this Example was a stable, mobile liquid. The additive composition may be rendered more mobile by increasing the level of solvent. It will be understood that the fuel treat rates will need to be adjusted accordingly when the additive composition is further diluted.

Example 2-Formation of Additised Fuel Composition [00349] An additised fuel composition (hereinafter "the inventive fuel) was prepared by mixing the fuel additive composition of Example 1 with regular oil-fired boiler kerosene manufactured to BS 2869-C2 at a treat rate of 112.4 ppm by weight (i.e. 112.4 ppm by weight of fuel additive composition in kerosene). The fuel composition was then thoroughly stirred for 1 hour to ensure complete homogenisation.

[00350] In the comparative tests described below, other addised fuel compositions were formed in like manner, only with different additives and/or different treat rates.

Example 2C -Alternative Additised Fuel Composition [00351] Another additised fuel composition was formed prepared by mixing the fuel additive composition of Example 1C with regular oil-fired boiler kerosene manufactured to BS 2869-C2 at a treat rate of 113.6 ppm by weight (i.e. 86 ppm by weight of fuel additive composition in kerosene, though higher treat rates are used where the additive composition is more dilute). The fuel composition was then thoroughly stirred for 1 hour to ensure complete homogenisation. The resulting fuel composition therefore comprised kerosene with the individual additive ingredients present at the following treat rates: Agent Chemical ppm by ppm by weight in volume in ____________________ ___________________________ kerosene kerosene Solvent Aromatic solvent 48.3 44 Dispersant / Polyisobutylone succinimide 16.5 15 Detergent _____________________________ _______________ _______________ Demulsifier alkoxylated phenol-7.2 6 formaldehyde resin-containing _____________________ demulsifier _______________ _______________ Metal Deactivator N,N'-Disalicylidene-l 2-18.1 15 ____________________ diaminopropane ______________ ______________ Antioxidants 2,6-di-tert.-butylphenol 11.75 10 ____________________ Amine aldohydo condensate 11.75 10 Example 2D -Comparative Additised Fuel Composition [00352] Another additised fuel composition was formed prepared by mixing the fuel additive composition of Example 1 D with regular oil-fired boiler kerosene manufactured to BS 2869-02 at a treat rate of 113.6 ppm by weight (i.e. 113.6 ppm by weight of fuel additive composition in kerosene, though higher treat rates are used where the additive composition is more dilute). The fuel composition was then thoroughly stirred for 1 hour to ensure complete homogenisation. The resulting fuel composition therefore comprised kerosene with the individual additive ingredients present at the following treat rates: Agent Chemical ppm by ppm by weight in volume in ____________________ ___________________________ kerosene kerosene Solvent Aromatic solvent 64.8 59 Dispersant / Polyisobutylene succinimide 0 0 Detergent _____________________________ _______________ _______________ Demulsifier alkoxylated phenol-7.2 6 formaldehyde resin-containing _____________________ demulsifier _______________ _______________ Metal Deactivator N,N'-Disalicylidene-l 2-18.1 15 ____________________ diaminopropane ______________ ______________ Antioxidants 2,6-di-tert.-butylphenol 11.75 10 ____________________ Amine aldehyde condensate 11.75 10 Example 2E -Comparative Additised Fuel Composition [00353] Another additised fuel composition was formed prepared by mixing the fuel additive composition of Example 1E with regular oil-fired boiler kerosene manufactured to BS 2869-02 at a treat rate of 113.6 ppm by weight (i.e. 113.6 ppm by weight of fuel additive composition in kerosene, though higher treat rates are used where the additive composition is more dilute). The fuel composition was then thoroughly stirred for 1 hour to ensure complete homogenisation. The resulting fuel composition therefore comprised kerosene with the individual additive ingredients present at the following treat rates: Agent Chemical ppm by ppm by weight in volume in ____________________ ___________________________ kerosene kerosene Solvent Aromatic solvent 54.9 50 Dispersant / Polyisobutylene succinimido 16.5 15 Detergent _____________________________ _______________ _______________ Demulsifier alkoxylated phenol-0 0 formaldehyde resin-containing ____________________ demulsifier ______________ ______________ Metal Deactivator N,N'-Disalicylidene-l 2-18.1 15 ____________________ diaminopropane ______________ ______________ Antioxidants 2,6-di-tert.-butylphenol 11.75 10 ____________________ Amine aldehyde condensate 11.75 10 Example 2F -Comparative Additised Fuel Composition [00354] Another additised fuel composition was formed prepared by mixing the fuel additive composition of Example 1 F with regular oil-fired boiler kerosene manufactured to BS 2869-02 at a treat rate of 113.6 ppm by weight (i.e. 113.6 ppm by weight of fuel additive composition in kerosene, though higher treat rates are used where the additive composition is more dilute). The fuel composition was then thoroughly stirred for 1 hour to ensure complete homogenisation. The resulting fuel composition therefore comprised kerosene with the individual additive ingredients present at the following treat rates: Agent Chemical ppm by ppm by weight in volume in kerosene kerosene Solvent Aromatic solvent 71.4 65 Dispersant / Polyisobutylene succinimide 0 0 Detergent _____________________________ _______________ _______________ Demulsifier alkoxylated phenol-0 0 formaldehyde resin-containing ____________________ demulsifier ______________ ______________ Metal Deactivator N,N'-Disalicylidene-l,2-18.1 15 ____________________ diaminopropane ______________ ______________ Antioxidants 2,6-di-tert.-butylphenol 11.75 10 ____________________ Amino aldchydc condcnsatc 11.75 10 Example 3 -Performance and Emissions Tests [00355] Performance and emissions tests were carried out with various fuel compositions using 90,000Btu/hr Warmflow US9OHE balanced-flue Sedbuk category A condensing boilers which provide heating for the Applicant's two production units on the Atchani Trading Estate in Shropshire, England. The combustion process was monitored using gas analysers to measure various parameters such as the temperature and chemical composition of air entering and waste gases exiting the boiler after combustion.

[00356] Two pressure-jet boilers have been run continuously over selected intervals of time burning regular kerosene manufactured to British Standard BS 2869/C2 and comparing their performance when switched to additised fuels of the invention (i.e. the Fuel of Example 2).

In some instances boiler burners were fitted with new nozzles but on other occasions, they were fitted with old, dirty nozzles removed during the annual servicing after operating for twelve months or so. Their performance has been monitored throughout using Testo 327-1 flue gas analysers of the type currently used by boiler service engineers following OFTEC-recommended procedures. In addition, a considerable number of comparisons have been made with kerosenes treated with selective performance additives, formulated to improve the efficiency of the combustion process. Such improvements are complimentary to the improved stability of the fuel during storage in domestic tanks over extended periods, particularly during the summer months when usage can be quite slow and intermittent, allowing more time for potential deterioration in quality. Benefits observed include: less fuel degradation, less sludge and sediment formation and build-up, leading to blocked filters, partially blocked burner nozzles and inferior operation of pressure-jet boilers.

[00357] In domestic oil-fired boilers kerosene, a product derived from the 010-016 fraction of crude oil distillation, burns in air as per the following chemical equation:-CnHm+Air(02+N2)=C02+C0+H20+NOx+ Heat [00358] Air contains approximately 79% nitrogen and 21% oxygen and the latter oxidises the kerosene in an exothermic reaction to produce heat and flue gases containing carbon monoxide (CO), carbon dioxide (C02) and water (H20), while most of the nitrogen is oxidised to oxides of nitrogen (NOx).The amount of heat produced and the composition of the flue gases exiting the boiler can be monitored using flue gas analysers such as the Testo 327-1 instrument, which as well as determining the gas composition, also measures the temperatures of the air entering the combustion chamber (AT) and the flue gases exiting the boiler (FT.) The Testo 327-1 actually measures the oxygen (02) content of the flue gases after combustion, and calculates the carbon dioxide (C02) content, carbon monoxide (00) content, the poison ratio (00/002) and the gross and net efficiencies of the combustion process.

[00359] The instrument is programmed to calculate the efficiency of the combustion process from the chemical composition of the flue gases and the temperatures before (AT) and after combustion (FT).

[00360] The net combustion efficiency of kerosene fuel burned in the Warmflow boilers is typically 97.5%, while the gross efficiency is 91.5%, about 6% lower. The Sedbuk efficiency rating of the boiler as quoted by the manufacturer is 92.8% and this has been determined with the boiler operating at both part and full-loads, using specific National Standard operating procedures carried out in Government-approved independent Test-houses.

[00361] The Applicant's Warmf low boilers are fitted with balanced flues, and the gases emerging after combustion are typically 40°C warmer than the ambient air entering the flue intake. In the UK the ambient air temperature (AT) varies typically from 000 in winter to 25°C in summer, and the combustion process boosts the gas temperature to over 500°C, but this falls to about 70°C after passing through the heat exchangers and ultimately exits the balanced flue at about 50°C (FT).

[00362] After running the boilers under load for an hour, the heating system approaches equilibrium, when the heat produced by the boilers balances the heat transferred to the circulating water and heat lost by the system. At this point, if the flue gas temperature (FT) and intake air temperature (AT) are measured and the flue gas composition analysed, an accurate assessment can be made of various combustion criteria including the amount of C02 and CO produced during combustion and the efficiency of the combustion process.

Boiler Testing Procedures [00363] For the day-to-day heating requirements of the applicant's premises, the two Warmf low Boilers are normally run in parallel and they cut-in and out intermittently to satisfy the thermostat requirements. For the present investigation however, only one of the boilers was used so that it fired continuously rather than intermittently in providing the heat called for by the hot water and central heating thermostats.

[00364] Two tanks were used to store the test fuels; one contained regular kerosene complying with BS 2869-02 the British standard for kerosene for use in oil-fired domestic heating appliances and the second contained the inventive fuel (Example 2 fuel), i.e. regular kerosene containing 100 ppm (w/w) the inventive fuel additive (Example 1 additive), produced by adding the appropriate amount of additive to regular kerosene and stirring for 1 hour with a mechanical stirrer until homogeneous. The fuel delivery lines from each storage tank were connected by a two-way valve to feed the boiler fuel pump suction.

[00365] The boiler burner was fitted initially with a new burner jet nozzle coded 0.6, 60°W supplied by Delavan. The nozzle has a capacity rated at 0.6 US gal / hour at 7 Bar, 3.4 cSt oil, 820Kg/m3, a spray angle of 60° and produces an universal semi-solid spray pattern.

Subsequently the burner was fitted with an "used", identically-sized Delavan nozzle coded 0.6, 6OCW which had been removed during annual servicing from a boiler, after having been in service for 12 months. The used nozzle was in dirty condition but was still considered to perform satisfactorily. Pressure-jet burners must comply with BS 799, Part 8 EN226 and BS EN 267 for forced draught oil burners.

[00366] The boiler, fitted with the new nozzle was fired up and after running on regular kerosene for an hour, the inlet and outlet water temperatures were found to have stabilised at 56 +1-1 t and 70 +1-1 °C respectively. The intake air entering the boiler and combustion gases exiting the boiler flue at a point just after the heat exchanger were sampled at this time and analysed using the TESTO 327-1 gas analyser which had been recently calibrated using gas mixtures and equipment traceable to international standards. The results were recorded as were the results of nine further samples taken at 30 minute intervals thereafter throughout the day.

[00367] The boiler was then switched to burn the inventive fuel (Example 2) by activating the two-way valve and after allowing an hour to stabilise, the combustion gases were sampled and analysed at 30 minute intervals and the results recorded and compared with the results obtained while initially running on regular kerosene.

[00368] The comparative combustion performance of regular kerosene and the inventive kerosene fuel (Example 2) were then evaluated in a similar series of tests but this time the new burner nozzle was replaced by a used" dirty nozzle. The 002 and CO levels determined in all tests were compared and checked for statistical significance using the Student TTest which requires a TTest value of 0.05 or less to confirm 95% or more results are statistically significant.

[00369] The various test results are outlined below.

The Inventive Fuel Additive Increases The CO2 and CO Reduction Impact Of A Clean Nozzle [00370] The applicant's Warmf low boilers test rig and test protocol described above was used to evaluate the impact of running on dirty and clean nozzles when running on both base kerosene and the inventive kerosene fuels over consecutive tests: Table 2 -Impact of Dirty & Clean Nozzles In Test Rip Base Kerosene FASTFIarneTM Nozzle C02(%) CO(ppm) TTEST TTEST Nozzle C02(%) CO(ppm) TTEST nEST Dirty CO Dirty 1202 105 CO2 CO Dirty ________________ 2.40632E-06 164544E-13 Dirty 1203 100 407E-15 1.76E-11 Dirty _______________ Dirty I2MS 120 Dirty * Dirty 12.02 103 Dirty Dirty 12.01 113 Dirty E1EP Dirty 121. 91 Dirty flW1flLtI Dirty 1206 9 Dirty Nt&L Dirty 12.07 80 Dirty.IIIII]I Dirty 1.1S9 94 Dirty ______________ Dirty 1201 105 Clean _________________ Clean 11.68 _______ Clean _________________ Clean 11.67 51 Clean _________________ Clean 1.1.69 45 Clean _________________ Clean 11.64 _______ Clean _________________ Clean 1L5 _______ Clean _________________ Clean 1154 41 Clean _________________ Clean 11.72 38 Clean _________________ Clean 11.67 45 Clean _________________ Clean 11.74 41 Clean _________________ Clean 1L6 44 Average Reduction (%) = 1.8 49.7 Average Reduction (%) = 2.9 56.7 [00371] Table 2 shows that both the CO2 and CO test results were statistically significant (TTEST results below 0.05 means greater than 95% statistical significance). Switching from a dirty to a clean nozzle instantaneously lowered CO2 and CO emissions of by approximately 2 to 3% and 50 to 57% respectively.

[00372] CO2 reductions are directly correlated to fuel economy ("What are carbon emissions?, The Carbon Account", Sept 2012; flv.thecarbonaccount.com/ca!onexcdained/), and it is widely appreciated the combustion deposits can increase fuel consumption by up to 1O°Io. It is interesting to note that this 2 to 3% CO2 impact is just for a dirty nozzle, notwithstanding any heat exchange deposit impacts.

The Inventive Fuel Additive Instantaneously Reduces 002 and GO Using A Glean Nozzle [00373] If the data shown in Table 2 is re-ordered the impact of an inventivefuel when operating on a clean nozzle is shown below in Table 3: Table 3: Impact of the Inventive Fuel Additive In A Clean Nozzle In Test Rip Clean Nozzle Fuel C02(%) C0(ppm) 1TEST TrEST Base flCO2 Co Base ___________________ 0.000367 0.005466 tji Base _____ Base flu11WI11 Base _____ Base s Base.

Base _________________ FASTFIame'TM 1t,6 SI FASTFIameT 1L67 51 FASTFIame'TM 1L59 45 FAsiFlame' 1164 39 FASillame' 11,69 39 FASIFIame' 11.64 41 FASIFIame' ILlS 38 FASIFIame' 1L67 45 FASTFIame'TM 1L74 4 FASIFIame' 1159 44 Average Reduction (%) = 10 11.6 [00374] The inventive fuel additive decreases CO2 and Co emissions 1.0 and 12% respectively.

The Inventive Fuel Additive Instantaneously Reduces 002 and 00 Using A Dirty Nozzle [00375] To check whether the instantaneous emissions impacts were repeatable, the experiment shown in Tables 2 and 3 was repeated over a longer period of time (2 days for each fuel). The same dirty nozzle was used. The results from these repeat tests are shown below in

Table 4:

Table 4: Impact of the Inventive fuel In A Dirty Nozzle In Test Rig Base Kerosene FASTFIameTM Nozzle C02(%) CO(ppm) TEST TrEST Nozzle C02(%) CO (ppm) Dirty IJtMWIMiico7 CO Dirty 10.77 84 Dirty 9.04398E-07 Notsignificant Dirty 1t14 87 Dirty ________________ Dirty 1t2 _______ Dirty _______________ Dirty 11.45 90 Dirty ________________ Dirty 11.51 84 Dirty _________________ Dirty 11.54 83 Dirty _______________ Dirty 11$1 92 Dirty _______________ Dirty 1159 78 Dirty ______________ Dirty 1143 711 Dirty ________________ Dirty 11.73 65 Dirty S Dirty 11.65 68 Dirty Si Dirty 1169 67 Dirty;S Dirty 11.70 62 Dirty _______________ Dirty 11.72 61 Dirty 55 Dirty 1174 65 Dirty -Dirty 11.8 59 Average Reduction (%) = 3.5 Notsignificant [00376] The inventive fuel additive decreased CO2 emissions by 3.5%. This is a larger impact than switching from a dirty to a clean nozzle observed previously (Table 2) This data suggests the inventive fuel additive would have a greater impact if introduced into an un-serviced" boiler.

[00377] As the inventive fuel additive both decreases CO2 and CO in both clean and dirty nozzles PLUS improves the benefit of switching from a dirty to a clean nozzle, it is clear that the inventive fuel additive has an instantaneous impact on both fuel efficiency and emissions.

The Inventive Fuel Additive Provides A Better Instantaneous Benefit Than Older Technology Fuel [00378] To check whether the inventive fuel additive was providing an advancement in combustion performance, the experiment shown in Table 4.3 was repeated using older additive technology (i.e. regular kerosene additised with the fuel additive composition of Example 1A at a treat rate of 200ppm -(1 day for each fuel: 6 tests base kerosene, 6 tests Older Technology followed by a repeat of 6 tests base kerosene).

Table 5: Impact of Older Technology Fuel In A Dirty Nozzle In Test Rig Base Kerosene OlderTechnolo2v Nozzle C02(%) CO (ppm) TFEST 1TEST Nozzle C02(%) CO (ppm) Dirty!COz CO Dirty 11.41 98 Dirty Wi!!!f!1I1 0.040243622 0.001534323 Dirty 11.41 78 Dirty ________________ Dirty 11.46 91 Dirty;-Dirty 1139 104 Dirty ________________ Dirty 1146 91 ________________ Dirty 11.52 101 Dirty ______________ Dirty ______________ Dirty ______________ Average Reduction (%) = -0.6 10.9 [00379] All the test results were statistically significant, but the Older Technology flame did not provide any CO2 benefit. In fact, there was a 0.6% increase under instantaneous conditions compared to a 3.5% decrease for the inventive fuel additives (i.e. of Example 1).

[00380] The inventive fuel additives (i.e. of Example 1), therefore, represents a significant advancement in fuel technology for oil fired pressure jet boiler central heating systems.

The Inventive Fuel Additive Provides A More Complete Chemical Combustion [00381] Kerosene is burnt according to a theoretical complete chemical combustion" simple formula as follows: CxHy + (4x + y) O = x CO2 + (Y/2) H20 + other gasest *The problem is that when kerosene is burnt in boilers there are also small quantiti of CO, nitrogen oxides and sulphur oxides produced along with the C02 and H20.

[00382] The data shown in Tables 3 and 4 demonstrate that by reducing CO the inventive fuel additive provides a more complete chemical combustion of the kerosene fuel even with a clean nozzle.

How the Inventive Fuel Additive He/ps Ak/fuel Mixing By Modifying Droplet Size & Spray Shape Many of the Inventive Fuel Additive's ingredients are surface active and can provide benefits by slightly lowering the fuel surface tension.

Fluid surface tension is an important parameter to take into account in the design of nozzles.

For the same injection system parameters (e.g. pressure) a lower fluid surface tension reduces fluid droplet size, but also increases the spray angle.

Both smaller droplet sizes and greater spray angles increase the potential for better fuel/air mixing to occur as there is a large surface area for the oxygen in the air to be in contact with the fuel. The smaller droplet sizes and larger spray angles arising from the inventive fuels have been found to reduce emissions as the oxygen is better able to help complete the chemical combustion process described earlier.

Conclusions of Tests

[00383] The inventive fuel additives (Example 1) increase the G02 and CO reduction of a clean nozzle.

[00384] The inventive fuel additives (Example 1) instantaneously reduce the C02 and CO generated through a clean nozzle.

[00385] The inventive fuel additives (Example 1) instantaneously reduce C02 and CO generated through an used" dirty nozzle.

[00386] The inventive fuel additives (Example 1) provide a better instantaneous benefit than regular kerosene treated with "older" technology additive.

[00387] The inventive fuel additives (Example 1) by reducing GO, provides a more complete chemical combustion of kerosene fuel, even with a new, clean nozzle.

EXAMPLE 4 -Water Resistance Tests [00388] Comparative tests were performed to assess the water take-up of various fuel compositions, including the inventive fuels (Example 2), regular kerosene, and older additised fuels based on regular kerosene additised at a treat rate of lOOppm with the additive of

Example 1A.

[00389] Fuel additives containing dispersarits and deposit control additives are prone to stabilise waler in fuel emulsions and therefore hold water in the fuel. The inventive fuel additive contains a demulsifier which inhibits water pick-up in storage tanks.

[00390] Work was carried out to find compositions that best remove water from a stabilised water-in-fuel emulsion and produce a distinct interface between water and fuel.

[00391] 10% by volume distilled water was added to standard kerosene (BS2869:Part 2 Class 02) containing additives as listed in the results table, Table 6, and shaken for 2 minutes.

After lh and 24h, the central point of the oil layer was measured for water content by Coulometric Karl Fischer titration (IP 438/01); repeat tests were made in each case; photographs of the fuel / water interface were also taken. The results are shown in Table 6 and photographs of Figures 1-4.

[00392] FIG. 1 is a photograph showing water separation in a measuring cylinder between kerosene and 10% water with no additives; [00393] FIG. 2 is a photograph showing water separation in a measuring cylinder between kerosene and 10% water with an inventive fuel additive (of Example 1) and a dye; [00394] FIG. 3 is a photograph showing water separation in a measuring cylinder between kerosene and 10% water with an inventive fuel additive (of Example 1) without any dye; [00395] FIG. 4 is a photograph showing water separation in a measuring cylinder between kerosene and 10% water with an older-technology additive (of Example 1A) without any dye.

Table 6: Action of demulsifier on stabilised water in fuel emulsion After 24h I Water Water Water Water -content content content content I [wppml LwpprnI Lwppml fwppm] Water Dosage Result Result Result Result Fuel Additive jvppmj 1 2 3 4 _____ 1 Kerosene 0 0 40 40 Kerosene 10 0* 84 49 51 K%. I Inventive I -Kerosene 10 additive + dye 100 133 143 61 67 1 InventLve -Kerosene 10 addiftve 100 158 154 53 45 I Older Kerosene 10 Technology 200 102 108 68 59 1 [00396] The base kerosene contains approx. 4oppm w/w water. After shaking with 10% water and leaving for 1 h the oil layer contained 84ppm; this settled to 5oppm after 24h.

[00397] Addition of 100 ppm of the inventive fuel additive caused the fuel to take up on average 1 Soppm of water; after 24h this dropped back to an average of S6ppm, in-line with the fuel with no additives.

[00398] The older technology additive caused less initial uptake of water into the fuel layer at lOSppm which dropped to 64ppm after 24h. However the photo FIG. 4 shows the fuel layer is hazy and the water I oil interface is indistinct and shows evidence of oil throughout the water layer, promoting mixing of oil and water layers. FIGs. 2 and 3 show fuel I water interfaces after addition of the inventive fuel additive; the fuel layer is clear and bright and there is a distinct oil I water interface with no mixing. FIG. 1 shows fuel with no additives; the fuel layer is clear and bright but the fuel I water interface is indistinct.

[00399] In conclusion the use of the inventive fuel additive removed water from a stabilised waler in fuel emulsion and produced a distinct interface between water and fuel layers.

Example 5 -Boiler Efficiency and Fuel System Protection Tests [00400] The factors influencing boiler efficiency have been previously addressed under Example 3 above. The inventive fuel additive provides efficiency benefits by the instantaneous mechanisms described earlier combined with longer term deposit control benefits -i.e. the inventive-addised fuels (of Example 2) were found to leave few deposits on the nozzle, heat exchanger, and other components of the boilers in comparison to regular kerosene and the fuel additised with the older additives of Example 1A.

[00401] Apart from the impact of nozzle deposits on C02/fuel consumption/efficiency described earlier, others have published information showing the impact of soot layer thickness on fuel consumption (Energy Tips -Process Heating, Process Heating Tip Sheet #4, Industrial Technologies Program, September 2005; arsterroces jJt2ts!pdt) (Kaupp A, The soot and scale problems, www.enerqymar.acjerfrnLnqcom website, Sept 2012 wwwenerclymanagertrainingcom/DocLIments/IectureS.doc).

[00402] Figure 5 is a bar chart showing the correlation between the thickness of soot deposits within a boiler system and the % fuel energy loss. Figure 5 shows that a thin layer of soot can easily cause an additional 8 to 10% fuel energy loss or CO2 reduction. This is why OFTEC guidance for boiler engineers includes thorough cleaning of important heat exchanger surfaces during routine services.

[004031 The boiler efficiency is maximised when using the inventive fuel additive due to a combination of the deposit control benefits described above and the instantaneous combustion benefits.

ExamDle 6-Boiler Breakdown Tests [00404] Fuel compositions were tested in the same manner as Example 3 except that, instead of measuring emissions, the photocells (luminosity sensors which check flame luminosity) within the boiler were monitored for the build up of deposits. This was an important test since deposits on the luminosity sensors can cause the boiler to breakdown.

[00405] Boiler lock-out due to photocell problems have been reported by many boiler engineers and burner manufacturers as an increasing problem. When a boiler "locks out" it requires a total system reset and boiler engineers are often called out to rectify the problems.

The inventors have investigated how the inventive fuel additive can help improve this situation.

[00406] The Warmflow boilers test rig and test protocol described in Example 3 above was used to evaluate the impact of running on both base kerosene and the inventive fuels (of Example 2) over consecutive tests. The test protocol was modified slightly to create artificially severe conditions in order to speed up the testing process. A dirty nozzle was used to maximise deposit formation and boiler was run in "constant firing" mode for part of the test by having the heated water running to drain and cool water constantly being added to top up the heating system. Luminosity measurements were taken by recording the light cell current draw (in micro-amps) -following the protocol recommended by a burner manufacturer.

The Boiler Photocell Gets Covered In Deøosits with A Dirty Nozzle On Base Kerosene [00407] Tests were conducted on the boiler in constant firing" mode when running on base fuel (i.e. regular kerosene).

[00408] FIG. 6 shows the impact of mechanically cleaning a boiler light cell by monitoring the light cell "current draw" (micro amps) with time (in days). The data in FIG. 6 shows that during normal operation a boiler light cell gets gradually dirtier due to deposits settling on its light sensitive surface and is restored when mechanically cleaned with a cloth. This suggests that the reduction in luminosity detected is due to these deposits rather than necessarily a reduction in the flame luminosity itself. The detected luminosity can be considered as "photocell luminosity".

The Inventive Fuel Additive Reduces "Photocell Luminosity" DeQradation With A Dirty Nozzle [00409] The boiler was also run in constant firing" mode for 2 days and readings taken, followed by 3 days intermittent running (normal "on" mode) with a further 2 final days of "constant firing" for both base kerosene and the inventive additised kerosene (Example 2 made with the additive of Example 1).

[00410] Figure 7 shows how light cell current draw" (micro amps) varies with time (in days) for regular kerosene (Base Fuel" -blue line) and the inventive fuels (red line). The graph of FIG. 7 clearly shows that "photocell luminosity" degrades in only a few days of running on base fuel whereas the inventive fuel maintains a high luminosity reading throughout. The inventive fuel additive will therefore reduce the probability of boiler breakdown due to "lock out".

Example 7 -Further Tests [00411] The Testo 327-1 measurements of Example 3 are in effect really measuring the fuel/air mixing efficiency and chemical conversion of the liquid fuel into combustion gases under a particular set of operating conditions. It does not measure the efficiency of heat transfer from the combustion gases into the water circulating through the heat exchangers or the heat lost in the combustion gases exiting the boiler i.e. the stack losses. Combustion efficiency is defined as the energy output from burning the fuel, divided by the energy input less the heat not recovered from the flue gases.

[00412] Numerically, Combustion Efficiency = 100% -L thermal -L chemical where [thermal = the thermal percentage loss of sensible heat of the flue gases [chemical = the chemical losses in To due to incomplete combustion.

[00413] The equation programmed into the Testo 327-1, which enables it to compute the net combustion efficiency of the process is as follows:-Net Comb Efficiency = 100-LK net x (FT-AT) +L(MH2O+GxH)x(21 0+2.1 XFT-4.2xAT) + (Ki xQgr x CO)] C02 Qnetxl000 Qnetx(C02+CO) where K net, 0 net, KI, MH2O. and H are factors specific to the fuel, which for Kerosene are:-K net = 0.51 Q net = 43.12 Ki = 52.36 MH2O = 0 H = 13.6 FT = Flue gas temperature. AT = Ambient temperature. CO = measured CO%. C02= Calculated C02% where C02 = CO2max x (21% -02) whHe CO = 21 -O2rof 21% 21-02 xCOx 1.25 [00414] Most chemical processes are optimised by passing the reactants over catalysts which help promote the particular chemical reaction. The combustion reaction can be catalysed by chemical species such as oxygenates, nitrates, organo-metallic compounds, etc., resulting in improved fuel combustion and increased heat output. The temperature of the emerging flue gases usually shows some increase as a result of the increased heat of combustion, but this depends to some extent on how effective the heat exchanger is in absorbing the extra heat produced.

[00415] If the fuel combustion is poorer, the flue gas temperature (El) will fall somewhat as a consequence of the lower heat produced by combustion, and this can be monitored using the flue gas analyser. The instrument is programmed to calculate the efficiency of the combustion process from the chemical composition of the flue gases and the temperatures before (AT) and after combustion (Fl).

[00416] The parameter (FT-AT) in the combustion efficiency equation above, i.e. the differential between the flue gas temperature exiting the boiler (ET) and the temperature of the air entering the boiler combustion chamber (AT) has a major influence on the numerical value for combustion efficiency. Since the combustion efficiency of a fuel is 100% -[a function of (FT -AT)], then a decrease in (FT-AT) will result in an increase in the efficiency of combustion. The ambient temperature AT invariably increases during the daytime, especially during the summer when daytime temperatures may be 10-15°C higher than night-time temperatures. It should be noted however, that flue gas temperatures increases too so that (ET -AT) often stays relatively constant.

[00417] The efficiency of combustion of the boiler is not the same as the combustion efficiency of the fuel as boiler efficiency also takes into account heat lost through radiation from the boiler casing and heat gained from condensing water vapour from the flue gases, an important attribute of condensing boilers, enabling them to achieve very high efficiency ratings.

[00418] As mentioned in Example 3, the applicant's Warmf low boilers are fitted with balanced flues, and the gases emerging after combustion are typically 40CC warmer than the ambient air entering the flue intake. In the UK the ambient air temperature (AT) varies typically from 0°C in winter to 25°C in summer, but the air temperature measured at the actual point of combustion in the Warmf low units is about 20CC higher than the air entering the balanced flue from outside, having been preheated by heat transference through the surfaces of the concentric inlet and exit flue stacks leading from and to the balanced flue. The combustion process boosts the gas temperature to over 500 CC, but this falls to about 70°C after passing through the heat exchangers and ultimately exits the balanced flue at about 50CC (FT). In the applicant's installation, (FT-AT) the temperature differential measured at the balanced flue outlet and inlet is typically (50°C -10°C) = 40°C, whilst (FT-AT) at locations on the actual boiler itself, just after the heat exchangers and just before the burner nozzle, has the same temperature differential value i.e. 70°C -30°C = 40°C. The Testo instrument is programmed to compute combustion efficiency using FT and AT as defined in the equations mentioned earlier inthetext.

[00419] It is essential that gas analyser probes are located correctly in the boiler flues, so that an accurate assessment can be made of gas and air compositions and temperatures. The balanced flue at the applicant's installation is located outside the building in a position not lending itself readily to monitoring combustion parameters especially in inclement weather. So the Testo instrument probe was instead located centrally in the waste gas stream immediately after the boiler heat exchangers.

[00420] Initially, the Testo ambient temperature sensor was located in the boiler room and recorded room temperature as the ambient temperature (AT). This was observed to be 10- 15°C lower than the temperature of air at the point of combustion, and as a consequence, the factor (FT -AT) was erroneously high and the combustion efficiency correspondingly lower than the correct value. Subsequently AT has been measured at a point in the intake flue, immediately preceding the burner nozzle.

[00421] After running the boilers under load for some hours, the applicant's heating system approaches equilibrium, when the heat produced by the boilers balances the heat transferred to the circulating water and heat lost by the system. At this point, if the flue gas temperature (FT) and intake air temperature (AT) are measured and the flue gas composition analysed, an accurate assessment can be made of fuel combustion efficiency. Early results showed that the temperature differential (FT -AT) varied over the course of a day as shown in the following graph and as a consequence, combustion efficiency varied too.

[00422] FIGs. 8 and 9 show how combustion efficiency varies over a typical 8 hour daytime period due to changes in FT-AT (°C).

[00423] FIG. S is a graph showing how the differential between the flue gas temperature (Fl) and air intake temperature (AT) (i.e. FT-AT) vary with time.

[00424] FIG. 9 is a graph showing how combustion efficiency varies with time. Figure 9 can be correlated with Figure 8 to observe how FT-AT correlates with combustion efficiency.

Tests on regular kerosene complying with BS 2869/G2.

[00425] The Warmflow boilers, running continuously throughout a ten-hour period on regular kerosene, achieve an average net combustion efficiency of 97.65 %, +1-0.2 %, the variation due to changes in ambient air temperature throughout the day.

[00426] The level of C02 present in the flue gases in this case around 11.3%, varies by as little as ÷1-0.1% throughout the period too, while the residual oxygen content is about 4.65%, +/-0.07%. Absolute values and variations in 02 and C02 levels and combustion efficiencies over a test period can be plotted against time and used as a basis for comparison with the same parameters derived for kerosenes dosed with different additives over a range of concentrations.

Tests on kerosene treated with other additives.

[00427] The applicant formulates a comprehensive range of additives for the treatment of fuels. When kerosene fuel is treated with selected chemical additives, its combustion can be improved, resulting in an increase in the amount of heat generated and the overall efficiency of the combustion process. By comparing the combustion characteristics of kerosene containing different additives with those of base kerosene, changes can be correlated with the presence of the particular additive or combination of additives. The graph shown in FIG. 10 illustrates a typical comparison.

[00428] FIG. 10 is a graph showing a typical plot of combustion efficiency (%) against time (minutes) for neat kerosene (coded Base 19) and kerosenes dosed with two different combustion improvers, coded Additive A and Additive B respectively. The graph The combustion improvers can be seen to increase the base kerosene combustion efficiency by 0.1 -0.44%, Additive B having the more beneficial impact.

[00429] Over twenty series of tests have been undertaken in which the Warmflow boilers have been run at identical settings under similar conditions for the same periods of time, so that their performance when burning regular kerosene can be compared with kerosene dosed with candidate additives. Each test series involved multiple samples of combustion gases, one particular series involving 192 samples, all of which were fully analysed by a Testo 327-1. The results of all series have been recorded on a performance database from which the following

main conclusions have been drawn:-

* Regular kerosene burns consistently in the Warmf low boilers, producing a steady amount of heat with little variation in the composition of the gaseous products of combustion, notably carbon monoxide CO and dioxide C02. Combustion efficiency is relatively constant at 97.65%+/-0.2%.

* Kerosene containing different additives burns consistently too, in some cases with up to 0.5% improvement in combustion efficiency, as demonstrated earlier in the graphs displayed.

* Additives such as oxygenates are particularly effective in improving the efficiency of combustion of kerosene.

* The extent to which combustion can be improved is governed by the chemical composition of the additive or combination of additives and the concentration present in the kerosene.

Example B -Comparative tests for instantaneous fuel consumption reduction [00430] The additised fuel compositions of Examples 2C, 2D, 2E, and 2F were comparatively tested to establish the extent of any instantaneous reduction in fuel consumption achieved relative to non-addised kerosene.

Testing Protocols * Measure the fuel consumed by placing a container of fuel on a gravimetric balance (accurate to 0.1 gram) feeding the test boiler -Fill the container with enough fuel to run 10 tests (typically 1.5 litres) -Take weight readings at the start of test and every 5 minutes for 10 tests * Record the following temps at the same time the container weight is noted: o Boiler inlet air temp (nearest 0.5 °C) o Ambient boiler temp (nearest 0.5 °C) o Outside air temp (nearest 0.5 °C) o Boiler inlet water temp (nearest 0.1 °C calibrated thermocouples) [Tiniei] o Boiler outlet water temp (nearest 0.1 °C calibrated thermocouples) [loutlet] * Run base; base÷additive; then back to base: 10 x 3 = 30 tests per fuel consumption result How to calculate specific fuel consumption benefits: Fuel consumed (test fuel) per oC o Many thermodynamic textbooks: Energy used = Konstant X (Toutiet -Tiniet) o Fuel consumed = water flow rate x water heat capacity x Konstant X (Toutiei -Tiniet) o Water flow rate is assumed constant (earlier flow meter tests confirm this) o Fuel consumed (base fuel) = KonstantB x (outlet -Tiniet) o Fuel consumed (base fuel) per oC = KonstantB o Fuel consumed (base + additive) per oC = KonstantA o % improvement = (KonstantB -KonstantA)/ KonstantB * Statistical analysis: Conduct StudentTtest on all 30 Base/Base÷Add/Base test results O Accept % improvements on all results that have >90% statistical significance [00431] Tthe base fuel was tested 3 times to verify there was no statistically significant variation in the results, thereby validating the test protocols and underlining their ability to demonstrate the beneficial effects of the additives. It was found that there was no statistically significant variation in the results for the base fuel, thus the testing protocol was duly validated.

Results [00432] "Instantaneous" fuel consumption test results (30 x 14 = 420 individual test results summarised) are given below in Table 7 below (all ppm values are by weight): Table 7: Fuel Consumption Reduction Tests Additive ingredients Treat rates of individual additive ingredients Ex. ZC Ex. 2D Ex. 2E Ex. 2F (ppm) (ppm) (ppm) (ppm) Component ____________________________________________ __________ ________ ________ ________ Dispersant 16.5 16.5 Deniulsifier 7.2 7.2 Metal Deactivator 18.1 18.1 18.1 18.1 Antioxidant(s) _________________________________________ 23.5 23.5 23.5 23.5 Nozzle 118 (Dirty) 4.7% 6.0% 2.7%, 0 0,0 NozzleS (Dirty) 6.7% Fuel Consumption Reduction (>90% Signif.) NozzleS (Clean) 7.5% 2.5% Nozzle 12 (Clean) 4.3% 4.5% 4.0% 0 Average 5.8% 4.3% 2.2% 0 [00433] The presence of both a dispersant or demulsifier produces the best fuel economy and the best instantaneous reduction in fuel consumption. Compositions with either dispersant or demulsifier, but not both, are inferior. The surprising synergy between the dispersant and demulsifier is thought to stem from an optimal balance of surface tension effects, thereby giving rise to optimum droplet sizes.

[00434] A surprisingly small amount of dispersant and/or demulsifier is also found to be effective.

Claims

CLAIMS1. A fuel additive composition for pressure-jet boilers, comprising: -7-17 parts of dispersant; to -3-9 parts of demulsifier; to -a metal deactivator; to -15-25 parts of antioxidant.
2. The fuel additive composition as claimed in claim 1, comprising: -9-14 parts of dispersant; to -4-7 parts of demulsifier; to -12-16 parts metal deactivator; to -14-21 parts of antioxidant.
3. The fuel additive composition of any preceding claim, wherein the dispersant(s) is selected from PIBSI, PEA, and PIB, or a suitable mixture of two or more thereof.
4. The fuel additive composition of any preceding claim, wherein the dispersant(s) is or includes a polyisobutylenesuccinimide (PIBSI) of formula I: RI B N P1 B) (Formula I) wherein PIB is a polyisobutylene group with an MW between 500 and 2800; wherein n is an integer between 1 and 10; and wherein m is either 0 or 1, such that if m is 0 the polyisobutylenesuccinimide of formula I terminates at an amino moiety.
5. The fuel additive composition of any preceding claim, wherein the demulsifier(s) is selected from the group including polyglycols, acylated polyglycols, alkoxylated phenol-formaldehyde, alkoxylated alkylphenol-formaldehyde resins, alkylated phenols, alkoxylated polyamines, alkoxylated polyols, epoxy resins, oxiranes, methyloxiranes, or a suitable mixture of two or more thereof.
6. The fuel additive composition of any preceding claim, wherein the metal deactivator(s) is suitably selected from the group including N,N'-Disalicylidene-l,2-diaminopropane and benzotriazole derivatives (such as N-N'-bis(2-ethylhexyl)-ar-methyl 1 H-benzotriazol-1-methanamine), or a suitable mixture of two or more thereof.
7. The fuel additive composition of any preceding claim, wherein the antioxidant(s) is selected from 2,6-di-tert.-butylphenol, 2,6-di-tert.-4-methylphenol, 2,4-dimethyl-6-tert.butylphenol, an amine-aldehyde condensate, and N,N'-di-sec-butyl-p-phenylenediamine, or a suitable mixture of two or more thereof.
8. The fuel additive composition of any preceding claim, comprising a corrosion inhibitor wherein the corrosion inhibitor is optionally dicyclohexylamine.
9. The fuel additive composition of any preceding claim, comprising a diluent wherein the diluent optionally is or comprises heavy naphtha.
10. The fuel additive composition of any preceding claim, wherein the dispersant, demulsifier, metal deactivator, and antioxidant are defined as follows: -the dispersant(s) is selected from a polyisobutylene succinimide, a polyetheramine, a polyisobutylene, or a combination of two or more thereof (suitably no more than two thereof); -the demulsifier(s) is selected from the group including polyglycols, acylated polyglycols, alkoxylated phenol-formaldehyde, alkoxylated alkylphenol-formaldehyde resins, alkylated phenols, alkoxylated polyamines, alkoxylated polyols, epoxy resins, oxiranes, methyloxiranes, or a combination of two or more thereof (suitably no more than two thereof); -the metal deactivator(s) is selected from the group including N,N'-Disalicylidene-l 2- diaminopropane and benzotriazole derivatives (such as N-N'-bis(2-ethylhexyl)-ar-methyl 1H-benzotriazol-1-methanamine), or a combination of two or more thereof (suitably no more than two thereof); -the antioxidant(s) is selected from 2,6-di-tert.-butylphenol, 2,6-di-tert.-4-methylphenol, 2,4-dimethyl-6-tert.butylphenol, an amine-aldehyde condensate, and N,N'-di-sec-butyl-p-phenylenediamine, or a combination of two or more thereof (suitably no more than two thereof).
11. The fuel additive composition of any preceding claim, wherein the additive composition comprises: -7-17 parts polyisobutylene succinimide; to -3-9 parts demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -0.05-20 parts N,N'-disalicylidene-1,2-diaminopropane; to -5-15 parts 2,6-di-tert-butylphenol; to -5-15 parts amine-aldehyde condensate antioxidant.
12. The fuel additive composition of any preceding claim, wherein the additive composition comprises: -9-14 parts of polyisobutylene succinimide;to -4-7 parts of demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); to -1-16 parts N,N'-disalicylidene-1,2-diaminopropane; to -7-10.5 parts 2,6-di-tert-butylphenol; to -7-10.5 parts amine-aldehyde condensate antioxidant.
13. A fuel composition for pressure-jet boilers, comprising a base fuel and: -7-17 parts of dispersant; to -3-9 parts of demulsifier; to -a metal deactivator; to -15-25 parts of antioxidant.
14. A fuel composition comprising a base fuel and: i) a dispersant; ii) a demulsifier; Ui) a metal deactivator; and iv) an antioxidant; wherein the fuel composition comprises at most 45 ppm of both dispersant and demulsifier combined (i.e. the sum of the individual treat rate for each ingredient).
15. A fuel composition for pressure-jet boilers, comprising a base fuel and the fuel additive composition as claimed in any of claims 1 to 12; or formed by mixing the fuel additive composition as claimed in any of claims 1 to 12 with a base fuel.
16. The fuel composition as claimed in any of claims 13 to 15, wherein the base fuel is kerosene.
17. The fuel composition as claimed in any of claims 13 to 16, comprising at least 10 ppm and at most SOOppm of the fuel additive composition claimed in any of claims ito 12 or of the combined individual ingredients of the fuel additive composition claimed in any of claims ito 12.
18. The fuel composition as claimed in any of claims 13 to 17, wherein the fuel composition comprises at most 45 ppm of both dispersant and demulsifier combined.
19. The fuel composition as claimed in any of claims 13 to 18, wherein the fuel composition comprises between 10 and 30 ppm of both dispersant and demulsifier combined.
20. The fuel composition as claimed in any of claims 13 to 19, wherein the fuel composition comprises: i) 5 ppm -25 ppm dispersant; U) 1 -15 ppm demulsifier; Vi) 5 -30 ppm metal deactivator; and iv) 10-32 ppm antioxidant.
21. The fuel composition as claimed in any of claims 13 to 20, wherein the fuel composition comprises: i) 5 ppm -25 ppm polyisobutylene succinimide; ii) 1 -15 ppm demulsifier (preferably an alkoxylated phenol-formaldehyde resin-containing demulsifier composition); iii) 5-30 ppm N,N'-disalicylidene-i,2-diaminopropane; and iv) 5 -16 ppm 2,6-di-tert-butylphenol; to v) 5 -16 ppm amine-aldehyde condensate antioxidant.
22. A pressure-jet boiler fuel combustion system for combusting a fuel composition as claimed in any of claims 13 to 21, comprising: a) a fuel storage unit comprising a fuel composition as clamied in any of claims 13 to 21; and b) a combustion unit fluidly connectable to the fuel storage unit and operable to combust the fuel composition provided to the combustion unit from the fuel storage unit.
23. The fuel combustion system of claim 22, wherein the combustion system is a pressure-jet oil-fired domestic heating boiler.
24. A method of combusting a fuel composition, comprising providing the fuel composition as claimed in any of claims 13 to 21 and combusting the fuel composition.
25. A use, in a pressure-jet boiler fuel combustion system, of: i) 7-17 parts of dispersant; ii) 3-9 parts of demulsifier; üi) a metal deactivator; and iv) 15-25 parts of antioxidant; for reducing carbon dioxide emissions from the fuel combustion system; wherein the reduction in carbon dioxide emissions is instantaneous.
26. A use, in a pressure-jet boiler fuel combustion system, of a fuel composition comprising a base fuel and: i) a dispersant; ii) a demulsifier; iii) a metal deactivator; and iv) an antioxidant; wherein the fuel composition comprises at most 45 ppm of both dispersant and demulsifier combined (i.e. the sum of the individual treat rate for each ingredient); for improving the fuel consumption or fuel economy of the fuel combustion system; wherein improvement of the fuel consumption or fuel economy of the fuel combustion system is instantaneous.
27. The use as claimed in claim 25 or 26. wherein the use is for achieving all of the following benefits: a) reducing carbon dioxide emissions from the fuel combustion system; b) improving the efficiency of the fuel combustion system; and c) improving the fuel consumption or fuel economy of the fuel combustion system; d) reducing the risk of breakdown of the fuel combustion system; wherein benefits a), b), and c) are instantaneous.
28. The use as claimed in any of claims 24 to 27, wherein the benefits are instantaneous in that said benefits are realised within 12 hours of continuous operation of the combustion system.
29. A kit of parts comprising all of the components of the fuel additive composition as claimed in any of claims 1 to 12.
30. A fuel additive composition, a fuel composition, a combustion system, a kit, a method, or a use, as substantially hereinbefore described with reference to the accompanying examples and figures.AMENDMENTS TO THE CLPJMS HAVE BEEN FILED AS FOLLOWS:CLAIMS1. A fuel additive composition, comprising: -9-14 parts by weight of polyisobutylene succinimide; to -4-7 parts by weight alkoxylated phenol-formaldehyde resin-containing demulsifier composition; to -1-16 parts by weight N,N'-disalicylidene-l,2-diaminopropane; to -7-10.5 parts by weight 2,6-di-tert-butylphenol; to -7-10.5 parts by weight amine-aldehyde condensate antioxidant.2. The fuel additive composition of claim 1, wherein the additive composition comprises at least 20 wt% of all of polyisobutylene succinimide, alkoxylated phenol-formaldehyde resin- containing demulsifier composition, N,N-disalicylidene-1,2-diaminopropane, 2,6-di-tert-butylphenol, arnine-aldehyde condensate antioxidant combined, and of the remainder of the additive composition at least 90 wt% is constituted by a diluent."cf 3. The fuel additive composition of any preceding claim, further comprising a corrosion "15 inhibitor.C) 4. A fuel composition, wherein the fuel composition: a) comprises a base fuel and the fuel additive composition as claimed in any of claims 1 to 3;or b) is formed by mixing the fuel additive composition as claimed in any of claims 1 to 3 with abase fuel; wherein the fuel composition comprises at most 45 ppm of both polyisobutylene succinimide and alkoxylated phenol-formaldehyde resin-containing demulsifier composition combined.5. The fuel composition as claimed in claim 4, wherein the base fuel is kerosene.6. The fuel composition as claimed in any of claims 4 to 5, wherein the fuel composition comprises between 10 and 30 ppm of both polyisobutylene succinimide and alkoxylated phenol-formaldehyde resin-containing demulsifier composition combined.7. The fuel composition as claimed in any of claims 4 to 6, wherein the fuel composition comprises: i) 5 ppm -25 ppm polyisobutylenc succinimide; U) 1 -15 ppm alkoxylated phenol-formaldehyde resin-containing demulsifier composition; iii) 5-30 ppm N,N'-disalicylidene-1,2-diaminopropane; and iv) 5 -16 ppm 2,6-di-tert-butylphenol; to v) 5 -16 ppm amine-aldehyde condensate antioxidant.8. The fuel composition as claimed in claim 7, wherein the fuel composition comprises: i) 10 ppm -20 ppm polyisobutylene succinimide; ü) 2 -12 ppm alkoxylated phenol-formaldehyde resin-containing demulsifier composition; iii) 12-25 ppm N,N'-disalicylidene-1,2-diaminopropane; and iv) 9 -14 ppm 2,6-di-tert-butylphenol; to v) 9 -14 ppm amine-aldehyde condensate antioxidant.9. A fuel combustion system for combusting a fuel composition as claimed in any of claims 4 to 8, comprising: a) a fuel storage unit comprising a fuel composition as claimed in any of claims 4 to 8; and b) a combustion unit fluidly connectable to the fuel storage unit and operable to combust the fuel composition provided to the combustion unit from the fuel storage o unit.10. The fuel combustion system of claim 9, wherein the combustion system is a pressure-jet oil-fired domestic heating boiler.11. A method of combusting a fuel composition, comprising providing the fuel composition as claimed in any of claims 4 to 8 and combusting the fuel composition.12. A use, in a pressure-jet boiler fuel combustion system, of a fuel composition comprising a base fuel and: -9-14 parts by weight of polyisobutylene succinimide; to -4-7 parts by weight alkoxylated phenol-formaldehyde resin-containing demulsifier composition; to -1-16 parts by weight N,N'-disalicylidene-1,2-diaminopropane; to -7-10.5 parts by weight 2,6-di-tert-butylphenol; to -7-10.5 parts by weight amine-aldehyde condensate antioxidant; wherein the fuel composition comprises at most 45 ppm of both polyisobutylene succinimide and alkoxylated phenol-formaldehyde resin-containing demulsifier composition combined; for reducing carbon dioxide emissions from the fuel combustion system; wherein the reduction in carbon dioxide emissions is instantaneous.13. A use, in a pressure-jet boiler fuel combustion system, of a fuel composition comprising a base fuel and: -9-14 parts by weight of polyisobutylene succinimide; to -4-7 parts by weight alkoxylated phenol-formaldehyde resin-containing demulsifier composition; to -1-16 parts by weight N,N'-disalicylidene-1,2-diaminopropane; to -7-10.5 parts by weight 2,6-di-tert-butylphenol; to -7-10.5 parts by weight amine-aldehyde condensate antioxidant; wherein the fuel composition comprises at most 45 ppm of both polyisobutylene succinimide and alkoxylated phenol-formaldehyde resin-containing demulsifier composition combined; for improving the fuel consumption or fuel economy of the fuel combustion system; wherein improvement of the fuel consumption or fuel economy of the fuel combustion system is instantaneous.o 14. A fuel additive composition of claim 1, a fuel composition of claim 4, a combustion system of claim 9, a method of claim 11, or a use of claim 12 or 13, as substantially hereinbefore described with reference to the accompanying examples and figures.