WO2013150294A1

WO2013150294A1 - An engine cleaning composition

Info

Publication number: WO2013150294A1
Application number: PCT/GB2013/050867
Authority: WO
Inventors: Akhil VALJEE
Original assignee: CLEANDRIVE SYSTEMS UK Ltd
Current assignee: CLEANDRIVE SYSTEMS UK Ltd
Priority date: 2012-04-05
Filing date: 2013-04-02
Publication date: 2013-10-10
Anticipated expiration: 2014-10-05
Also published as: GB201206175D0

Description

An Engine Cleaning Composition

The invention relates to an engine cleaning composition, and particularly to an internal combustion engine cleaning composition. The invention extends to various uses of the composition, including cleaning an engine, improving the fuel efficiency, the mechanical performance and the thermal efficiency of an internal combustion engine, improving the quality of the emissions produced in an internal combustion engine exhaust, and cleaning a diesel particulate filter. The invention also includes a method for cleaning an engine. If the build-up of deposits inside an internal combustion engine is left unattended, it can be detrimental to the engine power, fuel efficiency and, ultimately, the drivability of the vehicle. Engine deposits are a by-product of combustion and/or fuel supply and, therefore, the areas that are most susceptible are the fuel tank, the fuel pump, the fuel transfer ducts, the common rail, the injectors, the in take runners and ports and intake valves and the combustion chamber. The troublesome deposits found in the

combustion chamber consist of carbon by-products produced by the combustion process. While these are not new, some modern engine designs are causing these deposits to manifest new symptoms. For example, engine manufacturers have recently been attempting to improve engine efficiency by reducing the space between the top of the piston and the cylinder head in the combustion chamber. A consequence of this is that even if a few millimetres of carbon build up on top of the piston and the cylinder head, such deposits present on each structure would come into contact causing a rapping sound. Combustion chamber deposits can also raise the octane requirements of an engine, increasing the likelihood of knocking or pinging and causing the performance drop-off often associated with higher octane requirements. In addition, hot spots on deposits in the combustion chamber can cause premature fuel detonation.

In both carburettors and fuel injectors, fuel is metered through small, carefully calculated orifices. Over time, fuel evaporation and volatilisation can gradually cause a build-up of gums and varnishes in these openings and, if left un-checked, can block them, restricting fuel flow and compromising engine performance. In particular, the opening of a fuel injector is about the width of a human hair, so it takes very little deposit to block them. Such a blockage can ultimately result in hesitation, stumbling, stalling and loss of power. Downstream from the carburettors and fuel injectors are the intake valves, which since the mid 1980s have become known as another site for deposit build up problems.

Moreover, in many of today's engines, the air-fuel mixture is set as lean as possible to minimise the carbon based emissions and maximise fuel economy. In these lean conditions, any loss of fuel as it is being injected into the combustion chamber affects performance. Since fuel injectors often spray fuel directly onto the intake valve(s), heat generated powdery deposits slowly build up on these valves. When the engine is turned off, it cools and over a few hours the deposits on the intake valves dry out. When the engine is restarted, some of the initial fuel sprayed onto the intake valves clings or is absorbed by the cool, dry valve deposits. This creates even leaner conditions, resulting in performance problems when the engine is started.

There is, therefore, a need for an improved engine cleaning composition that is able to clean an internal combustion engine of the types of deposits referred to above.

According to a first aspect of the invention, there is provided an engine cleaning composition comprising: -

(i) first and second alcohols, each alcohol comprising a C1-C10 alkyl group;

(ii) a ketone;

(iii) an aromatic hydrocarbon; and

(iv) a petroleum distillate.

Alcohols are generally believed to remove the lubricating properties of the composition of the invention, and so there is some concern in the art that they would be detrimental to the working of an engine that has been treated with such a composition. However, counter-intuitively, the inventors have formulated the composition of the invention with not one, but two different alcohols. The inventors have surprisingly found that the composition of the first aspect, including two different alcohols, not only effectively cleans an internal combustion engine, but also improves the fuel efficiency of the engine, improves the quality of the emissions in the engine exhaust, and the engine performance is returned back to the manufacturer's original specifications.

Advantageously, the composition is periodically used in a cleaning cycle, wherein it can be simply added to the engine together with either petrol or diesel, depending upon the engine type, and then the engine is run for a defined period of time on fast idle at its normal operating temperature. The composition may then be exhausted (or even removed from the engine), and then replaced with traditional fuel. Beneficially, no detrimental effect is seen on the drivability of the vehicle powered by the engine when it is run on petrol or diesel with the composition according to the first aspect of the invention. Previously, additives added to petrol or diesel to clean an engine had to be used continually and adversely effected drivability, without producing the other improvements referred to.

Thus, in one embodiment, the composition may be a petrol engine cleaning

composition. In another embodiment, the composition may be a diesel engine cleaning composition. In view of the various advantages and properties exhibited by the composition, it may therefore be defined as being an engine cleaning or rejuvenating composition. The first and second alcohols may be independently selected from a group of alcohols consisting of: methanol; ethanol; propanol; butanol; pentanol; hexanol; heptanol; and octanol.

The first and second alcohols may each comprise a Ci-C₅ alkyl group. For example, one alcohol may comprise a Ci alkyl chain while the other alcohol comprises a C₅ alkyl chain, and so on. Preferably, however the first and second alcohols each comprise a d- C₃ alkyl group, i.e. methanol, ethanol or propanol.

The first and second alcohols may independently be a primary, secondary or tertiary alcohol.

Preferably, the first alcohol comprises methanol.

Preferably, the second alcohol comprises propanol, most preferably i-propanol or N- propanol.

Suitably, the composition comprises between about 0.1% and 10% (v/v) of the first alcohol. However, preferably the composition comprises between about 1% and 9% (v/v) of the first alcohol, or more preferably between about 2% and 8% (v/v) of the first alcohol, or even more preferably between about 3% and 7% (v/v) of the first alcohol, or most preferably between about 4% and 6% (v/v) of the first alcohol. Suitably, the composition comprises between about 1% and 25% (v/v) of the second alcohol. However, preferably the composition comprises between about 3% and 20% (v/v) of the second alcohol, or more preferably between about 5% and 15% (v/v) of the second alcohol, or even more preferably between about 7% and 13% (v/v) of the second alcohol, or most preferably between about 9% and 11% (v/v) of the second alcohol.

The ketone may comprise acetone. Suitably, the composition comprises between about 5% and 40% (v/v) of ketone.

However, preferably the composition comprises between about 10% and 30% (v/v) of ketone, or more preferably between about 15% and 25% (v/v) ketone, or even more preferably between about 18% and 22% (v/v) of ketone, or most preferably between about 19% and 21% (v/v) of ketone.

The aromatic hydrocarbon may comprise benzene, phenol, toluene or xylene.

Preferably, the aromatic hydrocarbon comprises xylene.

Suitably, the composition comprises between about 30% and 70% (v/v) of the aromatic hydrocarbon. However, preferably the composition comprises between about 35% and 65% (v/v) of the aromatic hydrocarbon, or more preferably between about 40% and 60% (v/v) of the aromatic hydrocarbon, or even more preferably between about 45% and 55% (v/v) of the aromatic hydrocarbon, or most preferably between about 48% and 52% (v/v) of the aromatic hydrocarbon.

The petroleum distillate may comprise a mixture of hydrocarbons. The flash point of the petroleum distillate may be at least 70°C. The boiling point of the petroleum distillate may be at least 190°C. Preferably, the petroleum distillate may be that which is sold under the trade name Kensol (for example Kensol 48H), and which may be obtained from American Refining Group, Inc (US).

Suitably, the composition comprises between about 30% and 70% (v/v) of the petroleum distillate. However, preferably the composition comprises between about 35% and 65% (v/v) of the petroleum distillate, or more preferably between about 40% and 60% (v/v) of the petroleum distillate, or even more preferably between about 45% and 55% (v/v) of the petroleum distillate, or most preferably between about 48% and 52% (v/v) of the petroleum distillate.

In addition, trace chemicals selected from a group consisting of toluene; butanone; isopropanol; octanol; nonanol; silanol; methanethiol; butane; propanamine; and benzene may be present.

In the examples, the inventors have demonstrated the numerous advantages that are achieved by cleaning an engine with the composition of the invention.

The composition may include one or more esters, for example any one or more of pentaerythritol tetralaurate, pentaerytritol, neopentylglycol, trimethylolpropane, butyleneoxide, and/ or and methyllaurate.

Thus, in a second aspect of the invention, there is provided use of the composition according to the first aspect for cleaning an internal combustion engine.

In a third aspect of the invention, there is provided use of the composition according to the first aspect for improving the fuel efficiency of an internal combustion engine.

Fuel efficiency may be increased by at least 1, 2, 3, 4, 5 or 6%.

In a fourth aspect of the invention, there is provided use of the composition according to the first aspect for improving the mechanical performance of an internal combustion engine.

According to a fifth aspect of the present invention, there is provided use of the composition according to the first aspect for improving the quality of the emissions in an internal combustion engine exhaust.

According to a sixth aspect of the present invention, there is provided use of the composition according to the first aspect for increasing thermal efficiency of an internal combustion engine.

The engine thermal efficiency may be increased by at least 5, 10 or 15%.

According to a seventh aspect of the present invention, there is provided use of the composition according to the first aspect for restoring an engine back to its

manufacturer's original specifications. According to an eighth aspect of the present invention, there is provided use of the composition according to the first aspect for cleaning or rejuvenating a diesel particulate filter, optionally without having to remove said filter from a vehicle.

In an ninth aspect, there is provided a method for cleaning an engine, the method comprising contacting an engine with the composition according to the first aspect under conditions sufficient to result in the cleaning of the engine.

The method may include, before using the composition, initially treating the engine with one or more esters, for example any one or more of pentaerythritol tetralaurate, pentaerytritol, neopentylglycol, trimethylolpropane, butyleneoxide, and/ or and methyllaurate.

Advantageously, the composition is capable of releasing the deposits in the engine fuel system and which may then be either captured by the fuel filter or are passed to the combustion chamber. This cleans the fuel pump, the connecting pipeline, the common rail, and the injectors and means that a more regular, better atomized diesel spray is delivered, improving the combustion process and the engine fuel efficiency. The method may comprise bringing the engine up to its usual operating temperature. This may be achieved by running the engine for approximately five miles.

The method may comprise passing the composition of the invention into the engine whilst it is running, preferably at fast idle. This step may be carried out for at least one hour. The composition may be passed through the engine by being added to usual fuel, which may be either petrol or diesel.

For example, the ratio of the composition to fuel that is used may be between about 10:1 (v/v) and 50:1 (v/v), or between about 20: 1 (v/v) and 40:1 (v/v), or preferably between about 25:1 (v/v) and 35:1 (v/v) or most preferably between 29:1 (v/v) and 31:1 (v/v).

The method may comprise either exhausting the composition by running the engine until it is expired, or by removing it.

The inventors have found that the various characteristics of the engine can be further improved if it is initially treated with additional compounds prior to the above- described treatment with the composition of the first aspect. For example, the engine may be initially treated with one or more esters, for example any one or more of pentaerythritol tetralaurate, pentaerytritol,

neopentylglycol, trimethylolpropane, butyleneoxide, and methyllaurate.

The method may therefore comprise ensuring that the engine is at its usual

operating temperature and then applying the ester(s), followed by the composition of the first aspect.

Alternatively, the ester(s) may be incorporated as part of the composition itself, and so the method for cleaning an engine, and use of a composition involve the

composition which includes the ester(s).

All of the features described herein (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined with any of the above aspects in any combination, except combinations where at least some of the features and/or steps are mutually exclusive.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings, in which:-

Figure ι is a graph showing the modelled vehicle speed of a lightweight Peugeot C5 versus time baseline, as computed from the vehicle gear ratio and the actual engine test speed. It follows the elementary urban cycle target vehicle speed as specified in the Type 1 test outlined in Directive 91/441/ EEC, within the stated uncertainty. This graph forms a sound baseline from which to evaluate the effect of the composition of the present invention on the test engine mechanical performance;

Figure 2 is a graph showing modelled vehicle speed versus time using a composition comprising a mixture of diesel and an embodiment of the composition of the invention referred to herein as "CleanDrive". This graph illustrates that, under the same Accelerator Pedal Position (APP) time varying input, the engine fuelled by the mixture of 30:i(V/V) diesel and CleanDrive responds similarly to the diesel only fuelled engine

in the baseline test, of Figure 1;

Figure 3 is a graph showing the modelled vehicle speed versus time using only diesel, but after the use of the composition of the invention, i.e. CleanDrive, shown in Figure 2; and

Figure 4 is a graph showing the pressure drop across a diesel particulate filter versus air mass flow rate. Examples

The inventors have developed a novel additive composition for a fuel, and have demonstrated in the following examples that it improves a number of

important

performance features for an internal combustion engine. Example l: Mechanical Performance

The inventors reviewed the European legislation on road vehicle emissions, tracking the evolution of the legislation from 1991 to 2007. The legislation was distilled to obtain a test procedure for, and emission limits applicable to, the HDi 2000 cc diesel test engine housed in the Thermodynamics Laboratory at the University of Leicester. This led to the selection of an appropriate road test protocol for testing this particular engine.

A vehicle dynamic simulator was then developed using mathematical modelling, based on the Peugeot C5 donor vehicle of the engine referred to in the preceding paragraph, to define an appropriate static dynamometer engine protocol analogous to that of a road test

The HDi 2000 cc test engine control system was then modified by the inventors so that it was no longer manually operated through a the accelerator pedal, but instead by a computer. This was done so that repeatable inputs that follow required legislation referred to above could be provided to the engine. In particular, the manual engine control was modified by interfacing the accelerator pedal position sensor with an angular displacement actuator. The two devices were mated by a bespoke plate manufactured by the Mechanical Engineering Workshop at the University of Leicester. The angular displacement motor was driven by the cruise control module of a Carl Schenck eddy current bench dynamometer, model W130, connected to the test engine. Before implementing the test, the dynamometer was calibrated with dead weights, following the manufacturer's calibration procedure, to obtain a traceable calibration. The dynamometer output was adjusted for slope and zero offset, resulting in a linear calibration over the range from o to 400 Nm. This static calibration was performed with the prop-shaft disconnected from the engine, in accordance to the test procedure by Schenck. The prop-shaft was then re-connected and the engine was run to produce an engine torque versus speed map at various electrical braking loads. This map was required to perform the variable speed and variable load test of the European Type 1 test outlined in Directive 91/441/EEC.

The European Type 1 test outlined in Directive 91/441/EEC, adapted for a static engine, was implemented on the HDi 2000 cc test engine in a combined mechanical performance, oil and exhaust gasses test.

Three repetitions were performed of four elementary urban cycles (part one) of the European Type 1 test outlined in 91/441/EEC, using forecourt Diesel, before the engine was treated with the inventor's novel fuel additive composition, referred to herein as "CleanDrive", which included: 1) Xylene - 50% (v/v);

2) Acetone - 20% (v/v);

3) Methanol - 5% (v/v);

4) N-propanol (10%) (v/v); and

5) Kensol 48H (15%) (v/v).

In addition, the following trace chemicals were present - toulene 0.2% (v/v), butanone 0.2% (v/v), isopropanol 2.2% (v/v), octanol 0.5% (v/v), nonanol 0.3% (v/v), silanol 0.75% (v/v), methanethiol 0.75% (v/v), butane 2.5% (v/v), propanamine 0.2% (v/v) and benzene 0.3% (v/v).

One exhaust gas sample was bagged for each of the three repetitions. The engine oil was changed at the start of the first test and samples were taken at the end of each repetition. The fuel consumed by each repetition was measured using an hourglass fuel meter. Plots of engine speed, modelled engine velocity, and crank power versus time have been produced for all three tests individually as an overlay of the three tests, and as ensemble averaged results with confidence interval bars.

Figure 1 illustrates that the speed of the test vehicle, as computed from the Peugeot C5 vehicle gear ratio and the actual engine test speed, follows the target vehicle speed as specified in the Type 1 test outlined in Directive 91/441/EEC, within the stated uncertainty. These tests, therefore, formed a sound baseline or control experiment from which to subsequently evaluate the effect of the composition of the present invention on the test engine mechanical performance.

Following the control experiment, a 30:1 by volume mix of forecourt diesel and the composition of the present invention (CleanDrive) was then prepared by adding 0.3667 litres of the composition in the 11 litre Diesel fuel tank. The engine was run elementary urban cycles (part one) using an in-house Lab View programme. The engine was then run at 2200 rpm with a constant torque load of 55 Nm for one hour. The engine was then run through one further set of elementary urban cycles (part one), following the same test procedure as for the first set of elementary urban cycles (part one). The engine was then run at 2200 rpm with a constant torque load of 55 Nm for a further one hour. Then a further set of elementary urban cycles (part one) were run. Finally, the engine was run at 2200 rpm with a constant torque load of 55 Nm until the 11 litre tank containing a mixture of forecourt diesel and composition of the present invention was empty. One exhaust gas sample was bagged for each of the three sets of elementary urban cycles (part one) The engine oil was changed at the start of the first test and samples were taken at the end of each set of elementary urban cycles (part one) Plots of engine speed, modelled engine velocity, and crank power versus time have been produced for all three tests individually, as an overlay of the three tests, and as ensemble average results with confidence interval bars.

Figure 2 shows the modelled vehicle speed versus time using the 30:1 mixture of diesel and composition of the present invention. As the engine is tested on a fixed bed dynamometer, the vehicle speed is obtained by multiplying the crank speed by the drive-train overall gear ratio, using the gear selection sequence prescribed in the

European Type 1 test set out in Directive 91/441/EEC. The reference wheel diameter and tyre of the Peugeot C5 donor vehicle is used to obtain the vehicle speed from the wheel rotational speed. One difficulty in the model is how to reproduce the vehicle behaviour during clutch operations. In these results, the clutch operation is modelled as a zero time lag clutch change. This results in small duration speed over-shoots in the velocity profile that represent the finite time during which the engine is adjusting from one gear to the next one.

The overshoots can legitimately be replaced by constant speed segments, modelling up to 2 seconds of clutch action, as allowed by the European Type 1 test in Directive

Figure 2 illustrates that, under the same accelerator pedal position time varying input, the engine fuelled by the 30:1 diesel and composition of the present invention mix responds similarly to the diesel only fuelled engine in the baseline test. There is little difference in acceleration and deceleration, indicating the retention of good vehicle drivability in an urban cycle. The mean of the constant speed segments are below the elementary urban cycles (part one) reference line, indicating a constant speed reduction in the order of 2 km/h. After the composition of the present invention was added to the 11 litre fuel tank, sediments and particles were seen flowing through the hourglass and the transparent fuel pipes that are used in the test rig. This indicates that the product may work principally by cleaning the fuel system and clearing any deposit/ clog in the fuel pipeline.

Based on this evidence, it is recommended that the fuel filter be changed after having burnt through the composition and diesel mix, so as to remove the displaced particles and residue trapped by the filter from the fuel circuit.

Two repetitions were performed of the elementary urban cycles (part one) of the European Type ι test using just forecourt diesel, after the engine was treated with the mix comprising the composition of the present invention. One exhaust gas sample was bagged for each of the two repetitions. The engine oil was changed at the start of the first test and samples were taken at the end of each repetition. The fuel consumed by each repetition was measured using an hourglass fuel meter. Plots of engine speed, modelled engine velocity, and crank power versus time have been produced for both tests individually, as an overlay of both tests, and as ensemble averaged results with confidence interval bars.

Figure 3 shows the modelled vehicle speed versus time using the same notation as in Figure 2. The test was conducted with the same accelerator pedal position input signal used for the test before the mix comprising the composition of the present invention was added. This signal was provided electronically using a Lab View script, to make sure the engine was tested under the same input conditions as in the test before the aforementioned mix was added. The trace in Figure 3 shows that the engine follows in general the Elementary urban cycle reference speed but, in places, it is seen to overshoot the Elementary urban cycle reference speed. This indicates that, for the same input command, the engine is now running faster than before the composition of the present invention was added to the diesel. The reduction in constant speed observed when the engine was run with the 30:i(v/v) mixture of diesel and composition of the present invention is no longer present. The engine crank power versus time records confirm that, for the same accelerator pedal position, the engine produced higher power peaks of about 8kW in the acceleration phase of the ECE urban cycle. This is higher than the 6kW peak recorded with the untreated engine before the mix was used. Table 1 and Table 2 compare the mechanical output of the engine before and after it was treated with the above mix. For the same accelerator pedal position input, the engine is generating more work output with less fuel. Indeed, there is a noticeable reduction in specific fuel consumption. The engine is more efficient in converting the chemical energy of the Diesel fuel in mechanical work available to drive the vehicle, as indicated by the increase in the engine brake thermal efficiency. This results in an increase in the fuel economy (mpg) of about 6.1%.

The increment in fuel economy (mpg) is not as significant as the change in the engine thermal efficiency as, under the same accelerator pedal input, the clean engine accelerated harder than the engine before exposure to the composition of the present invention. This resulted in the equivalent road distance covered being higher in the tests after the mix than in the tests before the mix was used. This increase in the equivalent vehicle mean speed has somewhat reduced the gain in fuel economy. By reducing the accelerator pedal input to obtain the same

speed/time curve as in the tests before the mix, some further improvement in the equivalent fuel economy (mpg) above 6.1% would be expected.

Table 2: Engine mechanical performance after CleanDrive.

Example 2: Exhaust Analysis

Exhaust gas analysis was performed on two petrol engines and vehicles. The vehicles were powered respectively by a 130OCC HCS/Endura-E petrol engine and a i6oocc Ford petrol engine, using results provided by a standard MOT station. Both engines were tested before the mix referred to above was added and then just after the 30:i(v/v) diesel and composition of the present invention mix had been added. The i6oocc engine was also tested for a third time 31760 miles afterwards. The effects of the mix on the 1300CC petrol engine were measurable and beneficial, although of limited impact. The 1300CC petrol engine used for this test was relatively new. It was, therefore, performing well within the 2011 MOT exhaust limits, close to its design point, before the mix was added. The test performed on exhaust gas emitted just after the mix had been added demonstrated that the engine was working closer to its stoichiometric lambda design point, leading to a fuller combustion, as indicated by the reduction of CO and hydrocarbon particulates in the gas analyser report. Such reductions were measurable but marginal in terms of their likely impact on the engine mechanical performance. This test has shown that, starting from a well-performing engine, use of the composition of the present invention results in a further small reduction in hydrocarbon emissions.

The effects of using the composition of the present invention on the i6oocc petrol engine were measurable, beneficial, and more substantial. The test just performed on the gas emitted just after the mix had been used demonstrated that the engine was working closer to its stoichiometric lambda design point, similarly to the 130OCC petrol engine test results. The reduction in hydrocarbon particulates in the exhaust gasses was more substantial in this test, from 81 ppm to 32 ppm. The third test performed on exhaust gas expelled by the i6oocc engine after 31760 miles indicated that the engine was still performing well within the MOT limits. These third test results do, therefore, conclusively show that addition of the mix does not adversely affect the engine emissions in the short and medium term. In addition, the emission tests show no evidence of unusual engine wear over the same time scale from the use of the inventive composition. Road Tests

Test on Ford Focus, Registration No.: YR02CXB

Table 3: Fast Idle Test results for Ford Focus

CO% HC (PPM) CO2 O2 Level Lambda

Before Mix 0.11 81 ppm 14.64% 0.79% Vol 1.03

After 0.01 32 ppm 15.08% 0.28% Vol 1.01 % Change 99% 60%

The first test (performed before the mix was used) indicated a CO emission of 0.11% vol. The second test (performed after the mix had been used) gave a CO emission level at 0.01% vol., which was just above the detection threshold of the

instrumentation. From the first to the second test, the CO2 emissions increase from 14.64% vol. to 15.08% vol. The increment in CO2 emissions accompanied by a decrement in CO emissions indicate a more complete oxidation of the carbon content of the fuel, resulting in more thermal energy release per unit of fuel and hence in an opportunity for more specific work output. The above results correspond to a reduction in O2 level from 0.79% vol. to 0.28% vol. between test 1 and test 2. In the second test, more oxygen combines with CO to produce CO2, reducing the excess oxygen content in the exhaust gasses. This inference is confirmed by the variation in the stoichiometric point lambda between test 1 and test 2. In test 1, the lambda ratio 1.03 indicates a slightly air rich air/fuel combination being supplied to the engine. In test 2, the lambda ratio 1.01 is closer to the target value of 1.0, indicating an air/fuel combination closer to the engine design point. In an ideal stoichiometric combustion, all the oxygen in the charge reacts with the carbon rich fuel, so that there is no free molecular oxygen in the exhaust gasses. The second test therefore represents a closer approximation to a stoichiometric combustion, for which lambda is 1.0.

Before the mix is used, the hydrocarbon concentration of 81 ppm indicates the production of un-burnt hydrocarbons in the exhaust gasses. After the addition of the mix, the lambda ratio is reported closer to the target value of 1.0, indicating an air/fuel combination closer to the engine design point. This more balanced combination returns a measurable reduction in the un-burnt hydrocarbon particle count, from 81 ppm to 32 ppm. This indicates that the composition of the present invention has resulted in a measurable improvement in the combustion process caused by a fuller pyrolysis of the fuel in the earlier stages of combustion.

Vehicle YR02CXB has been tested for a third time. This test was conducted at 99408 miles. In the Fast Idle section of the third test the CO emission level is reported at 0.01% vol., which is just above the detection threshold of the instrumentation. This is the same CO emission value recorded in test 2. The lambda ratio from the Fast Idle third test is 1.012, which is also essentially equal to the corresponding value in test 2. The Natural Idle test shows a CO emission level at 0.03% vol., which is also a low value with respect to the emission test limits.

The third test however indicates that an engine treated with the composition of the present invention can age gracefully to 99408 miles while maintaining good emission characteristics, well below the 2011 MOT limits. The third test results are conclusive in that the addition of the composition does not adversely affect the engine emissions in the short and medium term. In addition, the emission tests show no evidence of unusual engine wear over the same time scale from the use of the aforementioned composition.

The first test indicates a CO emission of 0.02% vol., which is just above the detection threshold of the instrumentation. The second test reported the CO emission at 0% vol., indicating CO emissions below the detection threshold. The CO levels between the two tests are too close to the detection threshold of the instrumentation to discern any advantage in using the composition of the present invention from their values alone. However, it is noted that no detectable adverse effect is recorded in the CO emissions.

Before the mix is added, the hydrocarbon concentration of 49 ppm and the lambda ratio of 1.014 suggests a slightly air rich air/fuel combination being supplied to the engine and the production of un-burnt hydrocarbons in the exhaust gasses. After the addition of the mix, the lambda ratio is reported closer to the target value of 1.0, indicating an air/fuel combination closer to the engine design point. This more balanced combination returns a measurable reduction in the un-burnt hydrocarbon particle count, from 49 ppm to 23 ppm. This indicates that the mix has resulted in a measurable improvement in the combustion process caused by a fuller pyrolysis of the fuel in the earlier stages of combustion. Test on Ford KA, Registration No.: CU03EKK -l6-

Table d: Fast Idle Test results for Ford KA

CO% HC (PPM) CO2 02 Level Lambda

Before Mix 0.02 49 ppm 1.014

After 0.00 23 ppm 1.005

% Change 100% 47%

The first test indicates a CO emission of 0.02% vol., which is just above the detection threshold of the instrumentation. The second test reported the CO emission at 0% vol., indicating CO emissions below the detection threshold. The CO levels between the two tests are too close to the detection threshold of the instrument to discern any advantage in using the composition of the present invention from their values alone. However, it is noted that no detectable adverse effect is recorded in the CO

emissions from using said composition.

Before the mix is used, the hydrocarbon concentration of 49 ppm and the lambda ratio of 1.014 suggests a slightly air rich air/fuel combination being supplied to the engine and the production of un-burnt hydrocarbons in the exhaust gasses. After the addition of the mix, the lambda ratio is reported closer to the target value of 1.0, indicating an air/fuel combination closer to the engine design point. This more balanced combination returns a measurable reduction in the un-burnt hydrocarbon particle count from 49 ppm to 23 ppm. This indicates that the mix has resulted in a measurable improvement in the combustion process by a fuller pyrolysis of the fuel in the earlier stages of combustion.

Example 3

The inventors have also found that they can further improve the lubricity of the present invention. This can be achieved by adding to the composition of the present invention:-

1. pentaerythritol tetralaurate (56.826 ml); and

2. methyllaurate (28.41 ml).

Example 4

The test procedure for determining the through-flow resistance of a Diesel Particulate Filter (DPF) before this is treated by running CleanDrive through the Diesel engine and after the engine has been run with a mix of fuel and CleanDrive was documented. Test equipment

Two tests were conducted in the Thermodynamics Laboratory, Department of

Engineering, University of Leicester, on 30 January 2012 and 01 February 2012. The second year laboratory experiment Axial Fan was used as the test rig mainframe. This consists of two horizontal sections of 95mm internal diameter Perspex pipe connected by a 90mm diameter axial fan. The upstream pipe inlet is restricted by a 36mm internal diameter brass orifice plate. The 36mm diameter orifice hole has a sharp bevelled edge, which sits concentric with the Perspex pipe. A static pressure tap is located on the top of the pipe immediately downstream of the orifice plate. The tap is connected through 5mm manometer tubing to a digital differential pressure transducer, TTseries, Model TT470S, serial no. 7988, inventory no. TMAN 012, ranged 0-199.0 Pa, with the manometer response set on fast. This manometer is used to estimate the air mass flow rate through the system. The downstream pipe outlet is connected to the Diesel Particulate Filter outlet, which is tested in a reverse-flow mode. A second static pressure tap is located on the top of the downstream pipe. The tap is connected through 5mm manometer tubing to a second differential pressure transducer, TT Series, model TT370S, serial no. 5845, inventory no. TMAN 014, ranged 0-1999 Pa, with the manometer response set on fast, calibrated by Associated Instruments Repairs on 6/12/10. This second pressure transducer measures the pressure drop across the Diesel Particulate Filter.

A preliminary test, which is not reported herein for brevity, ascertained that the axial fan was producing an insufficient pressure rise for generating a measurable mass flow rate through the orifice plate. The downstream end of the Diesel Particulate Filter was therefore connected to the inlet of a centrifugal fan, from Air Control Instrumentations LTD, model VBL8, serial no. 56845, speed range 0-2800 rpm, 200/250 Volts, 0.5 HP, single phase, 50 Hz. The centrifugal fan outlet discharges freely to the laboratory. The centrifugal fan speed is set through a single-phase variac fan voltage controller, model 012, inventory no. evoi2, with a range 0-260 Volts. The centrifugal fan plastic pipe inducer inlet is instrumented with a side-mounted pressure tap. The tap was connected through 5mm manometer tubing to the second differential pressure transducer, to measure the pressure drop across the Diesel Particulate Filter. With the centrifugal fan connected in series, measurable mass flow rates were recorded through the system. During the tests with the centrifugal fan, the axial fan was powered off. The orifice plate digital differential pressure transducer was operated on its 0-199.9 Pa range, with a precision of 0.1 Pa and an accuracy of ±0.1 Pa. The second digital differential pressure transducer was operated on its 0-1999 Pa range, with a precision of 1 Pa and an accuracy of ±5 Pa. The lower accuracy of the second pressure transducer is due to a greater fluctuation in the readings during testing.

The laboratory ambient conditions are monitored using a mercury-in-glass column barometer, with a precision of 0.05 mmHg from its Vernier scale, a mercury-in-glass thermometer, with a precision of 1 Celsius, and a bimetallic junction hygrometer, measuring the relative humidity to ±5%.

On 30 January 2012, test 1 was performed. This involved taking three sets of data over the full operating range of the centrifugal fan. The laboratory ambient conditions were recorded before and after each set of data. Before and after this test, both digital differential pressure transducers were noted to read o, with no off-set.

After test 1, the Diesel Particulate Filter was collected by Clean Drive Systems UK Ltd. I understand that the filter was re-installed on the donor vehicle, a Peugeot 309 Turbo Diesel, manufactured in 1992, registration KG02 BXV, with 108195 miles. The vehicle was then fuelled by a mix of CleanDrive and Diesel, and the vehicle was driven as normal to 108263 miles. The Diesel Particulate Filter was then removed from the vehicle and re-delivered to the University of Leicester by Clean Drive Systems UK Ltd for re-testing. On 1 February 2012, test 2 was performed. This involved taking two sets of data over the same operating range of the centrifugal fan. The laboratory ambient conditions were recorded before each set of data. The manometer measuring the pressure drop across the Diesel Particulate Filter was noted to read o before and after each test, with zero offset. The after-test offset of the orifice plate pressure transducer was -1.4 Pa after data set 1 and 0.4 Pa after data set 2.

Dry air ideal gas assumptions are used to estimate the ambient air density from the arithmetic average of the laboratory conditions before and after each dataset. The equation of state is used with the air specific gas constant of 287 J/kgK. The mass flow rate is estimated assuming isentropic flow up to the orifice plate bevelled edge. Results

Figure 4 shows by the black symbols the measured pressure drop across the Diesel Particulate Filter from test 1 versus the air mass flow rate through the filter. The continuous magenta line shows a parabolic data fit to the ensemble of the three test 1 data sets. The data are closely clustered around the regressed line. The three datasets show good repeatability. The blue triangles show the measured pressure drop across the Diesel Particulate Filter from test 2. The same ensemble data regression technique gives the continuous black line, about which the data from test 2 are closely clustered. The two sets of data from test 2 confirm the good repeatability of the test.

Figure 4 shows by the magenta line that the flow resistance across the Diesel Particulate Filter increases quite quickly with increasing air flow rate in test 1. The results from test 2 indicate a significant decrement in flow resistance across the Diesel Particulate Filter. Specifically, the pressure drop through the Diesel Particulate Filter in

test 2 is about 1/3 of the pressure drop measured in test 1. This means that, for the same gas flow rate of 4kg/s through the Diesel Particulate Filter, the pressure drop reduces from around 900 Pa to 300 Pa. For approximately the same pressure drop, the Diesel Particulate Filter in test 2 allowed almost three times the gas flow rate than in test 1.

Concluding remarks

This study has assessed the impact of the Diesel Particulate Filter cleaning process by CleanDrive Systems UK Ltd. The tests before and after the cleaning process have quantified a measurable and substantial reduction in the pressure drop across the Diesel Particulate Filter.

Diesel Particulate Filters are designed to work at normal engine temperature conditions. The engine ECU periodically increases the exhaust temperature to burn out trapped particles in the Diesel Particulate Filter. If the vehicle is driven mainly over short urban cycles, the Diesel Particulate Filter may clog up more quickly. The resulting flow resistance of the clogged up filter increases the back-pressure during the exhaust stroke, which requires more power from the engine to complete. This adversely affects the vehicle fuel economy. The tests performed under laboratory conditions have shown that the Diesel Particulate Filter cleaning process by CleanDrive Systems UK Ltd is effective in reducing the back- pressure due to the Diesel Particulate Filter by up to 66%, which is a significant achievement. This cleaning process should benefit the vehicle fuel economy.

An advantageous process for utilising the composition for cleaning an engine may include the following steps:

Ensure that the fuel tank is less than a quarter full (preferably just with a few litres);

Ensure engine is at operating temperature;

Add the full contents of a 475ml bottle to the fuel tank;

Drive the vehicle for about 6 miles;

Then fill the fuel tank in the normal way.

The composition is a cleaning compound which is needed for example once every three months, as distinct to a fuel additive which is mixed with the entire fuel tank and required every time the tank is filled or regularly.

The composition is a compound which uses the little remaining fuel as a carrier to the fuel system. It treats the whole fuel system, freeing up deposits in the fuel system, the fuel pump, the connecting pipeline, the common rail and the injectors. The composition delivers a more regular, better atomized fuel spray, improving the combustion process and the engine fuel efficiency.

The impact of the composition on emissions was also evaluated from MOT emission test data which indicated that, with the addition of the composition, the air/fuel mix supplied to the engine was closer to the engine design point, yielding a more complete combustion process and a reduction in un-burnt hydrocarbon particulate in the exhaust. Summary

The effect of using the composition of the present invention as an internal combustion engine cleaning fluid was evaluated by back to back laboratory tests. The test protocol was derived from the European Type 1 test set out in Directive 91/441/EEC, which is the protocol used by motor vehicle

manufacturers to obtain EC certification, and is applicable to the HDi 200OCC test engine used by the inventors. Tested over the elementary urban cycles (part one), the engine cleaned by the composition of the present invention displayed a measurable improvement in the engine mechanical performance. The composition was also found to improve the fuel economy. In particular, the specific fuel consumption after using the composition decreased from 0.27-0.38 1/MJ to 0.180-0.181 1/MJ. The engine thermal efficiency increased from

7.4-10.4 % to 15.4%. These fixed bed engine tests translate to an improvement in fuel economy of 6%.

The use of transparent sections in the laboratory engine fuel system shed light on the most probable working principle of the composition according to the present

invention. The composition was seen to free up deposits in the fuel system that are then either captured by the fuel filter or are passed to the combustion chamber. This cleans the fuel pump, the connecting pipeline, the common rail, and the injectors and means that a more regular, better atomized diesel spray is delivered, improving the combustion process and the engine fuel efficiency. The exhaust gas emission data from 1300CC and i6oocc petrol engines referred to above indicates measurable reductions in particulate emissions after the engine is treated with the inventive composition, with emissions being retained well below the 2011 MOT limits 30000 miles after the treatment. Consequently, there was a measurable improvement in the quality of the emissions in the engine exhaust and no indication of any unusual engine wear from the exhaust data.

Finally, the inventors were surprised to see that treatment with

pentaerythritol tetralaurate and methyllaurate further improved the

running of the engine. Thus, this project was successful in evaluating under laboratory conditions the performance of the composition of the present invention as a fuel system cleaning fluid for engines.

Claims

An engine cleaning composition comprising: -

(i) first and second alcohols, each alcohol comprising a Ci-do alkyl group;

(ii) a ketone;

(iii) an aromatic hydrocarbon; and

(iv) a petroleum distillate.

An engine cleaning composition as claimed in claim l, wherein the composition is a petrol engine or diesel engine cleaning or rejuvenating composition.

An engine cleaning composition as claimed in claim l or claim 2, wherein the first and second alcohols are selected from a group of alcohols consisting of: methanol; ethanol; propanol; butanol; pentanol; hexanol; heptanol; and octanol.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the first and second alcohols comprise a Ci-C₅ alkyl group.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the first and second alcohols comprise a Ci-C₃ alkyl group.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the first and second alcohols are methanol, ethanol or propanol.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the first and second alcohols are independently a primary, secondary or tertiary alcohol.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the first alcohol comprises methanol.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the second alcohol comprises propanol.

10. An engine cleaning composition as claimed in any one of the preceding claims, wherein the second alcohol comprises l-propanol or N-propanol.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the composition comprises between about 0.1% and 10% (v/v), or between about 1% and 9% (v/v), or between about 2% and 8% (v/v), or between about 3% and 7% (v/v) or between about 4% and 6% (v/v) of the first alcohol.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the composition comprises between about 1% and 25% (v/v), or between about 3% and 20% (v/v), or between about 5% and 15% (v/v), or between about 7% and 13% (v/v) or between about 9% and 11% (v/v) of the second alcohol.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the ketone comprises acetone.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the composition comprises between about 5% and 40% (v/v), or between about 10% and 30% (v/v), or between about 15% and 25% (v/v), or between about 18% and 22% (v/v), or between about 19% and 21% (v/v) of ketone.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the aromatic hydrocarbon is benzene, phenol, toluene or xylene.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the composition comprises between about 30% and 70% (v/v), or between about 35% and 65% (v/v), or between about 40% and 60% (v/v), or between about 45% and 55% (v/v) or between about 48% and 52% (v/v) of the aromatic hydrocarbon. An engine cleaning composition as claimed in any one of the preceding claims, wherein the petroleum distillate comprises a mixture of

hydrocarbons.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the flash point of the petroleum distillate is at least 70°C.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the boiling point of the petroleum distillate is at least 190°C.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the petroleum distillate is that which is sold under the trade name Kensol.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the composition comprises between about 30% and 70% (v/v), or between about 35% and 65% (v/v), or between about 40% and 60% (v/v), or between about 45% and 55% (v/v), or between about 48% and 52% (v/v) of the petroleum distillate.

An engine cleaning composition as claimed in any one of the preceding claims, wherein the composition comprises one or more esters, for example any one or more of pentaerythritol tetralaurate,

pentaerytritol, neopentylglycol, trimethylolpropane, butyleneoxide, and methyllaurate.

Use of a composition as claimed in any one of the preceding claims, for cleaning an internal combustion engine.

Use of a composition as claimed in any one of claims 1 to 21, for improving the fuel efficiency of an internal combustion engine.

Use as claimed in claim 23, wherein fuel efficiency is increased by at least 1, 2, 3, 4, 5 or 6%.

Use of a composition as claimed in any one of claims 1 to 21, for improving the mechanical performance of an internal combustion engine.

27. Use of a composition as claimed in any one of claims 1 to 21, for improving Use of a composition as claimed in any one of claims 1 to 21, for increasin; thermal efficiency of an internal combustion engine.

29. Use as claimed in claim 27, wherein the engine thermal efficiency is

increased by at least 5, 10, or 15%.

30. Use of a composition as claimed in any one of claims 1 to 21, for restoring an engine back to its manufacturer's original specifications. 31. Use of a composition as claimed in any one of claims 1 to 21, for cleaning or rejuvenating a diesel particulate filter, optionally without having to remove said filter from a vehicle.

32. A method for cleaning an engine, the method comprising contacting an engine with a composition as claimed in any one of claims 1 to 21 under conditions sufficient to result in the cleaning of the engine.

33. A method as claimed in claim 31, wherein the method comprises bringing the engine up to its usual operating temperature.

34. A method as claimed in either claim 31 or 32, wherein the method comprises passing the composition into the engine whilst it is running.

35. A method as claimed in any one of claims 31 to 33, wherein the composition is passed through the engine by being added to usual fuel.

36. A method as claimed in claim 34, wherein the ratio of the composition to fuel that is used is between about 10: 1 (v/v) and 50:1 (v/v), or between about 20:1 (v/v) and 40:1 (v/v), or between about 25:1 (v/v) and 35:1 (v/v), or between about 29:1 (v/v) and 3i:i(v/v).

37. A method as claimed in any one of claims 31 to 35, wherein the method

comprises either exhausting the composition by running the engine until it is expired, or by removing it. A method as claimed in any one of claims 31 to 36, wherein the engine is initially treated with the engine may be initially treated with one or more esters, for example any one or more of pentaerythritol tetralaurate, entaerytritol, neopentylglycol, trimethylolpropane, butyleneoxide, and/ or and methyllaurate prior to treatment with the composition as claimed in anyone of claims 1 to 21.