BACKGROUND 2. Description of Related Art The publications and other reference materials referred to herein to describe the background of the invention and to provide additional detail regarding its practice are hereby incorporated by reference. Because of various Federal and State regulatory requirements, there is a growing need to control or reduce engine exhaust emissions because of their impact on health and environment. Combustion engine emissions have been shown to be major contributors to air pollution in urban areas. Vehicle emissions are classifie as regulated and unregulated pollutants. Regulated polluants are carbon monoxide (CO), nitrogen oxides (NOX), and unburned fuel or partly oxidized hydrocarbons (HC). The levels of emissions of these polluants are specified by law. Unregulated polluants include carbon deposits, polycyclic aromatic hydrocarbons (PAHs), and carbon dioxide. Carbon deposits increase engine wear and tear, while some of the PAH isomers are known to be carcinogenic and mutagenic (Westerholm, R. N. (1988) Environ. Sci. Technol., 22: 925).

In a study conducted by South Coast Air Quality Management District (SCAQMD), mobile source emissions were shown to contribute about 98% of CO, 84% of NOIX, and 62% of volatile organic compound in the urban atmosphere (South Coast Air

Quality Management District,"Draft Air Quality Management Plan Revision,"Diamond Bar, California (1994)).

In addition to the possible carcinogenic role of engine exhaust emissions, acute health effects from exposure to exhaust emissions have been well established. The possible connection between cancer and exposure to diesel engine exhaust has been investigated in occupationally exposed people (Screepers, P. T. J. et al., (1992) Int. Arch.

Occup. Environ. Health 64: 163). Based on animal studies, it has been postulated that the main culprits in cancer formation in humans are the PAHs, and their substituted derivatives (methyl-PAHs, nitro-PAHs, oxygenated nitro-PAHs, and oxy-PAHs), and the particulate matter, i. e. carbon deposits from the exhaust on which the PAHs are adsorbe (Screepers, P. T. J. et al., (1992) Int. Arch. Occup. Environ. Health 64: 163; Sjogren, M. Et al. (1996) Chem. Res. Toxicol. 9: 197; Crebelli, R. et al. (1995) Mutation Research 346: 167).

Accordingly, there is a need for an effective, non-hydrocarbon, non-toxic and environmentally friendly fuel additive to reduce the amount of carbon deposited in internal combustion engines.

DISCLOSURE OF THE INVENTION The present invention achieves the above-stated needs by providing a method for reducing carbon deposited in a combustion engine from the burning of hydrocarbon fuel.

The method comprises the steps of forming a fuel-water-based additive mixture, and introducing the fuel-water additive mixture to the engine during engine operation such that carbon deposited on the engine from combustion of the fuel-water additive mixture is less than carbon deposited from the combustion of the fuel without the additive. The water-based additive is a structured liquid comprising IE crystal structured liquid.

The invention, in another aspect, provides a fuel-water additive mixture which comprises a fuel and a water-based additive.

Accordingly, objects of the method of the invention and of the fuel-water additive mixture of the invention involve reduction of carbon buildup in an engine which allows use of lower octane fuel. Another object of the invention is the avoidance of problems associated with pre-ignition caused by carbon buildup inside the cylinders. Another object of the invention is the improvement in performance of an engine by the reduction in carbon erosion of valve seats and other control surfaces. Another object of the invention is the

reduction in emissions caused by such carbon erosion which allows incomplete combustion products to escape into the exhaust thus raising emissions. Another object of the invention is the maintenance of combustion efficiency for a longer period of the life of the engine thus saving fuel and reducing maintenance costs.

These and many other features and attendant avantages of the present invention will become better understood by reference to the following detailed description of the invention when taken in conjunction with the accompanying drawings.

FIGURES Figure 1 is a diagram of the apparats and equipment set-up to determine the effects of the additive of the invention.

Figure 2 shows engine exhaust total hydrocarbon (THC) emission in the absence of the water-based additive.

Figure 3 shows engine exhaust carbon monoxide (CO) emission in the absence of the water-based additive.

Figure 4 shows engine exhaust nitrogen oxides (NOx) emission in the absence of the water-based additive.

Figure 5 shows that the amount of carbon deposited on the piston head in 30 minutes over a range of engine speeds with and without the water-based additive.

Figure 6 shows a reverse osmosis membrane set-up used for concentrating IE crystal structure solutions for making the water based additive.

DETAILED DESCRIPTION AND MODES OF CARRYING OUT TEE INVENTION The present invention provides a method for reducing carbon deposited in a combustion engine from the burning of hydrocarbon fuel. The method comprises the steps of forming a fuel-water based additive mixture by adding a sufficient amount of a water-based additive to a fuel to form the fuel-water based additive mixture. The fuel-water based additive mixture is introduced to the engine during engine operation such that carbon deposited on the engine from combustion of the fuel-water based additive mixture is less than carbon deposited from the combustion of the fuel without the additive.

The invention, in another aspect, provides a fuel-water based additive mixture which comprises a fuel and the water based additive.

As set forth in the detailed example below, which is offered by way of illustration and is not intended to limit the invention in any manner, the method and mixture of the invention reduced carbon buildup in an engine. As a result, the invention also provides methods for achieving use of lower octane fuel, avoidance of problems associated with pre-ignition caused by carbon buildup inside the cylinders, reduction in fuel costs of an engine by allowing use of lower octane fuel, improvement in performance of an engine by the reduction in carbon erosion of valve seats and other control surfaces, and reduction in emissions caused by such carbon erosion which allows incomplete combustion products to escape into the exhaust thus raising emissions, and maintenance of higher combustion efficiency for a longer period of the life of the engine thus saving fuel and reducing maintenance costs. These other methods provided by the invention are achieved by the steps of forming a fuel-water additive mixture, and introducing said mixture to said engine during said engine operation such that carbon deposited on the engine from combustion of said mixture is less than carbon deposited from the combustion of the fuel in the absence of the additive.

Water-Based Additive In the present invention, the water-based additive comprises a small amount of crystalline structured water with crystals, refend to herein as IE crystals, in the micron or submicron size range. Growth and formation of these IE crystalline water structures and preparation of the water-based additive are described below. Pending U. S. Patent

Applications 08/558,330 and 08/799,645, which are incorporated by reference, also disclose IE crystalline water structures, solutions thereof, methods for making the IE crystals, and methods for making concentrated solutions of the IE water crystals. The type of microscopic crystalline structure, referred to therein is also referred to herein as IE crystal structured water.

Accordingly, the water-based additive of the present invention is an IE crystal based additive.

IE crystal structured water is a structured liquid in which the IE crystal structures are induced in the liquid by strong electric fields from the electric field of an ion or from the dipole moment of molecules. While structured liquids can be formed from a variety of polar solvents, IE structured water is a specific case of the general class of structured liquids that is formed from water molecules.

By way of explanation, not limitation, the formation of IE structured water is illustrated as follows: When salt (e. g. NaCl) is dissolve in water, the sodium and the chlorine become ions in the water because of the strong dipole moment of water molecules.

Very dilute solutions are considered in which positively or negatively charged ions attract water molecules which have electric dipole moments. However, under these very dilute conditions, one fonds that the water molecules surrounding an ion turn into a form of ice, not the ordinary ice where the unit cell has translational invariance, but one in which the crystalline structure of water surrounding the ion has a special symmetry due to the spherical nature of the coulombic force between the ion and the water molecule. The spherical symmetric icy structure surrounding ions is called IE structure indicating it is an icy structure formed under the effect of an electric field. The IE structures were observe and recorde under electron microscopy, as disclosed in U. S. Patent Application 08/799,645, and as disclosed in Lo, Shui-Yin (1996)"Anomalous State of Ice,"Modern Physics Letters B, 10: 909-919; and (1996)"Physical Properties of Water with IE Structures," Modern Physics Letters B, 10: 921-930.

Preparation of the Water-based additive Generating more IE structures and preparation of the water-based additive of the present invention, are described in U. S. Patent Applications 08/799,645 and 08/558,330, and involves forcing concentrated crystal solutions of IE structures. The method involves forming a first structured liquid comprising the IE structures and/or fragments of IE structures.

This structured liquid comprises a liquid having a dielectric constant greater than 1 and a material having an uneven distribution in charge on the surface of the material. An example of such material is NaCl. The first structured liquid is sufficiently diluted by repetitive dilution to form a second structured liquid. From the second structured liquid, the IF- structures are concentrated to form a concentrated crystal solution.

Methods for concentrating IE solutions are disclosed in a patent application, incorporated herein, which was filed in the United States Patent and Trademark Office by the inventor of the present invention on July 10,1997 but for which applicant has not yet received notice of a serial number assigne by the USPTO. The disclosed methods include reverse osmosis, doping a solution with beads that release an IE nucleating material, gas chromatography, fractional distillation, use of an electrical wire dipole, and dynamic freezing.

For example, a concentrated IE solution has been achieved using a reverse osmosis membrane. The exact size and type of filter depended on the dipole liquid selected to start with in creating the crystal structure solution. As a result, the reverse osmosis membrane pore size selection and concentration of the structured liquid is achieved according to the physical size of the crystal structures involved. To be specific, a quantity of a dilute or weak IF crystal structure solution is passed through a reverse osmosis unit which contains a membrane with a pore size of about 1.8 nanometers. This size filter is small enough and intended to allow only the passage of single molecules of water at one time through the pore.

The reverse osmosis unit is typical of those commercially available in various sizes and flow capacities and consists of an outside housing, a membrane and sealed end caps with holes for tubing to be connecte. A carbonator type vane pump with an electric motor is attache by tubing to the reverse osmosis unit inlet side and when the motor is turned on, the pump maintins a pressure on the membrane by means of the tubing, kept in the range of 100-200 psi by adjusting a valve on the outlet side of the reverse osmosis unit. A key strategy for varying the concentration of the very dilute IE crystal solution is the use of the reverse osmosis machine in reverse from its intended method by disposing of the output water and recycling the water that will not pass through the filter pore size selected. It has been determined that the selection of pore size will be dependent on the size of the molecule of the liquid utilized. For water, the membrane pore size selected was just slightly smaller than the size of the water molecule, about 1.8 nanometers, but it can vary from 1.0 nanometers to 3.0

nanometers or more depending on the liquid/material system selected. Figure 6 illustrates a reverse osmosis system 10 for concentrating crystal structured water. The weak solution 102 is added to tank 100 then said weak solution is drawn up through pipe 108 by means of pump 118 then pressurized into tube 112 which goes through pressure gage 116 and on through tube 114 into the entry side of the reverse osmosis unit 120. The weak solution then flows through the membrane assembly 122 wherein the single water molecules are driven through said membrane 122 by the pressure created by pump 118 acting against valve 126 and exit through port 128 and are collecte through tube 130 into tank 104 as a weaker solution 106.

The crystal structure water, being compose of groups of water molecules, does not go through the membrane 122 and so it flows out of the reverse osmosis unit 120 through port 124. The now more concentrated crystal structure water then flows through ajustable valve 126 which is adjusted to create the membrane back pressure as shown at the valve 116. The crystal structure water then returns through tube 110 to the original tank 100 where it mixes with the weak solution 102 remaining in tank 100. By constant recirculation around the system described above, the single Water molecules are continuously removed from the weak solution and are stored in tank 104 causing the mixture in tank 100 to become a stronger concentration of crystal structure water solution. As a result, one can stop the procedure as the desired concentration level desired.

The water-based additive of the invention used in the example disclosed herein was prepared by a doping method. In this method, water was used as a dipole liquid.

0.05 moles of platinum chloride was mixed with 100 ml of pure 18 Meg source water, which is a highly pure water. Removal of impurities from the dipole liquid was extremely important. The resulting mixture was called D0. D0 was then serially diluted to produce progressively more dilute solutions which were designated, respectively, D 1 through D9. For example, D 1 was produced by mixing 10 ml of DO with 90 mi of pure 18 Meg source water.

Then D2, D3, D4 and so on up to D9 were produced in the same manner as D 1, that is by adding 10 ml of each dilution to 90 mi of 18 Meg pure source water. Equal volumes of D9 solution and PVC beads (i. e. 50% v/v) were mixed. Tulle PVC beads were 65 durometer, food grade PVC pellets. The D9-PVC solution was allowed to stand for about two hours, at which time the LTV absorbance (wavelength 195 nm) of the solution was, in the various solutions prepared by this method, from about 0.5 to about 2.0. In order to concentrate the IE

structures, this solution was then processed through a reverse osmosis filter and the volume reduced to 1/10th to 1/40th of the original volume. This reduced volume had a W absorbance at 195 nm of about 1.5 to about 3.0 in the various reduced volume solutions prepared by this method. By examination of electron micrographs of IE solutions prepared for electron microscopy, it was estimated that the percent by weight of IE structures in this dipole liquid (i. e. water) was from about 2% to about 10% of the weight of the water. This IE structured liquid is considered the water-based additive of the invention. As used herein, a percent IE solution means (100) weight of IE structures/[weight of H20 + weight of E structures in a given volume.

As used in the example below, the water based additive had a IJV absorbance at 195 nm of 2.5. The water-based additive was mixed with 95% 2-propanol in a ratio of one part water-based additive to 20 parts 2-propanol, a ratio of 1: 20. The water-based additive- isopropanol mixture was mixed with the fuel in a ratio of two parts of water-based additive- isopropanol mixture to 98 parts fuel, such that the water based additive (IE structured liquid) was 0.1 % or 1000ppm in the fuel, forming a fuel-water based additive mixture.

For use in the present invention, the concentration of IE structures in the water- based additive (i. e. the percentage IE solution) can vary from about 0.2 % to about 20 %. A preferred range of concentrations is from about 0.5% to about 10%.

As set forth in the Example below, the water based additive of the invention was first mixed in a 1: 20 ratio with 95% 2-propanol. The water based additive-isopropanol mix was added to the fuel to form a 0.1 % (v/v) fuel-water additive mixture, i. e 1000 ppm..

At the 0.1% (v/v) loading, the fuel-water additive mixture reduced carbon deposited when the mixture was introduced to the engine and underwent combustion. The loading levels of water-based additive to fuel that find use in the invention range from about 0.02% (v/v) to about 5.0% (v/v), a preferred range being from about 0.03% (v/v) to about 3.0% (v/v).

The hydrocarbon fuel which comprise the fuel-water based additive of the invention was 87 RON (research octane number) Chevron regular gasoline that was

commercially available. The hydrocarbon fuels which fonds utility in the invention inclue, but are not restricted to, the group consisting of gasoline, diesel fuel, methane, propane, heating oils, bunker oils, naptha, and methanol, which hydrocarbon fuels are used in internal combustion engines, including spark-ignited engines, diesel engines, gas turbines, and in boilers and heaters.

EXAMPLE Two sets of studies were performed to determine the effects of the IE fuel additive on carbon deposition and on engine out emissions. In both studies, the following conditions were used. Referring to Figure 1, studies were done using a single cylinder spark- ignited Mark III Transparent Combustion Engine (Megatech Corp., Billerica, MA) without an exhaust emission control catalyst. Engine specifications are given in Table 1.

Table 1-Experimental Engine Specifications Bore 1 5/8" Stroke 2" Compression Ratio 3: 1 Operating Speed 400-4000 RPM Power Approximately 1/2 HP Cooling System Forced Air Fuel Injection System Carburetor injection Lubricant Oil-less The dynamometer was used to start and load the engine. It was also possible to monitor engine speed, torque, cylinder pressure, manifold pressure, cooling air pressure, and power output of the engine by the dynamometer. The cylinder or combustion chamber in the engine is made of a special heat resistant glass. This enabled one to monitor carbon deposition during engine operation.

High accuracy rotometers were used to measure both the flow rates of fuel and air. An electronic fuel pump and surge-tank were used to establish reliable fuel and air delivery, respectively. The engine system had two carburetor controls. A needle valve

controlled the amount of fuel that flowed through the lines, and a throttle valve controlled the amount of air in the airfuel mixture to establish the equivalence ratio (, defined as the actual airfuel ratio to the stoichiometric airfuel ratio). A commercially available gasoline with 87 RON was used as the fuel. In order to avoid fuel composition changes, the same batch of gasoline was used for all of the studies described herein.

The water-based fuel additive used an IE crystal solution having a concentration of about 2% IE. crystals. The water based additive was prepared as described above. A fuel-water based additive mixture was formed by adding a water-based additive (which, as described above, is a 1: 20 mixture of the IE solution and 2-propanol) to the fuel and homogeneously dispersing it into the fuel. At the 0.1 % (v/v) loading (i. e. the final volume of the IE crystal solution in the fuel was 0.1 % v/v or 1000 ppm) used in the studies, no clouding was observe initially and over an extended period of time, and the gasoline-water based additive mixture was clear. The fuel-water based additive mixture was introduced to the engine during engine operation.

Engine-out emissions for NOX, total hydrocarbons (THC) and CO were measured by an on-line digital gas analyzer (OTC RG240 Digital Gas Analyzer, Owatonna, MN) connecte to the exhaust pipe by a sample line.

Carbon deposits in the engine were measured gravimetrically as follows. The engine was operated under sufficiently fuel-ric conditions that led to mesurable amounts of carbon deposits on the piston head in a 30-minute run. After each expriment in which either fuel without water-based additive or the fuel-water based additive mixture was introduced to the engine during engine operation, the engine was completely dismantled, and the carbon deposited on the piston head was carefully scraped off, and weighed using a sensitive analytical balance. The engine was then reassembled to undertake the next study.

In the first set of studies, procedures were carried out in the absence of the water based additive to establish the baseline conditions. In the second set of studies, identical procedures were performed in the presence of the water based additive that was homogeneously disperse into the gasoline at 0.1% (v/v) to form a fuel-water based additive mixture.

Engine exhaust emissions were determined as a fonction of engine speed at 1500,1750,2250, and 2500 rpm and at different equivalence ratios, both for the base case

and in the presence of the fuel-additive mixture.

Engine exhaust emissions are presented in Figures 2,3 and 4 for the baseline conditions. These results showed that CO and NOX were strongly dependent on the equivalence ratio while THC was not. As seen in Figure 2, THC emissions showed a slight minimum around ¢= 0.96-1.0 depending on the engine speed. In addition, an increase in engine RPM decreased THC emissions. Minimum THC emissions was obtained at 2500 RPM. As seen in Figure 3, CO concentration uniformly increased with decreasing equivalence ratio as expected at a constant RPM. The production of some CO is inevitable when fuel is burned with insufficient air. However, some CO will be emitted under a broad range of conditions because of the mixing and rection rate limitations.

The importance of NOX emissions from combustion sources lies in its contribution to the formation of secondary atmospheric pollutants. As seen in Figure 4, NOX emissions increased with increasing equivalence ratio within the range investigated as expected from flame temperature considerations. For engine speeds of 2000,2250, and 2500 RPM, NOX concentration showed maxima around equivalence ratio of 1.05, as expected (Bosch Automotive Handbook, 3rd ed. p. 478-9, Robt. Bosch GmBh). Since the combination of temperature and fuel and oxygen concentration determines the amount of NOX formation, an NO, emissions peak occurred on the fuel lean side (¢ (1.0). Minimum NOX emissions were observe at engine speed of 2250 RPM.

In the second set of experiments, i. e. in the presence of the fuel-water based additive mixture, the engine exhaust emissions showed no systematic departure from the trends observe in the absence of the water based additive. In addition, the levels of Noix, THC, and CO were well within the limits of accuracy of the measurements made in the absence of water based additives.

Carbon formation studies were performed under sufficiently fuel-ric conditions in which mesurable carbon deposition on the piston head occurred over a 30- minute period. In this study, carbon deposition rates occurred at an equivalence ratio of 0.72 (fuel rich). Lower equivalence ratios led to excessive carbon formation and resulted in the early termination of runs. At higher equivalence ratios, carbon formation rate was too slow, and longer operating times became necessary to accumulate mesurable quantities of deposits.

In Figure 5, the amount of carbon deposited on the piston head was plotted as a fonction of engine speed at the airfuel equivalence ratio of 0.72 and at the end of a 30- minute operating time, both for the base case and in the presence of the additive. The experiments corresponding to each data point were repeated three times to assess the repeatability of the results. Average standard deviations for the base case and in the presence of additive were 0.16 and 0.11, respectively.

As seen in Figure 5, carbon deposition rates decreased with increasing RPM.

Decrease in residence time in the engine at high RPM is a possible explanation for this fading. However, it is particularly important to note that the presence of 0.1 % (v/v) water based additive in the fuel significantly decreased the rate of carbon deposition at a given RPM. In addition, this effect was observe consistently over the entire engine speed range investigated. As can be seen in Figure 5, carbon deposition rate decreased by as much as 32%, 20%, 44% at 1750,2000, and 2250 RPM, respectively.

These results demonstrated that the method, water-based additive, and fuel- water based additive mixture of the invention decreased carbon deposition rate on the piston head of an internal combustion engine by as much as 44% compare with the use of the fuel in the absence of the water based additive.

Accordingly, the steps of the invention which involved forming the fuel-water based additive mixture and introducing the mixture to the engine during engine operation comprise the following methods which the invention also provides: method for using lower octane fuel; method for increasing efficiency of engine performance by reducing the rate of pre-ignition caused by carbon build-up in the cylinders); method for reducing fuel costs of an engine by allowing use of lower octane fuel; method for increasing engine performance by reducing carbon erosion of valve seats and other control surfaces; method for reducing emissions caused by such carbon erosion which allows incomplete combustion products to escape into the exhaust thus raising emissions; method for maintaining combustion efficiency for a longer period of the life of the engine thus saving fuel and reducing maintenance costs.

Having thus described exemplary embodiments of the present invention, it should be noted by those skilled in the art that the disclosures herein are exemplary only and that various other alternatives, adaptations and modifications may be made within the scope of the present invention. Accordingly, the present invention is not limited to the specific embodiments as illustrated herein, but is only limited by the following claims.