Abstract:
An apparatus and method for using pure dry biomass carbohydrates as fuels, fuel extenders and fuel oxygenates. Preferably, the apparatus and method would be used in internal combustion engines. The apparatus and method disclose the concept of mixing dry carbohydrates with hydrocarbon fuel to create a carbohydrate slurry fuel that burns as efficiently and cleanly as gasoline alone.

Description:
FIELD OF THE INVENTION 
   This invention relates generally to fuel engines and pertains in particular to an apparatus and method for using pure, dry biomass carbohydrates as fuels, fuel extenders and fuel oxygenates. 
   BACKGROUND OF THE INVENTION 
   Internal combustion engines are heat engines wherein the burning of a fuel occurs in a confined space (combustion chamber). An exothermic reaction occurs when a fuel reacts with an oxidizer, thereby creating gases of high temperature and pressure. The expanding hot gasses perform useful work, i.e. they cause the movement of the engine itself or the movement of the engine&#39;s components, such as its pistons and rotors. 
   Several types of fuel have been used with internal combustion engines. Today, the most common fuels are those that are made up of hydrocarbons and are derived from petroleum, such as diesel, gasoline, and liquefied petroleum gas. However, increasing world demand for, and diminishing reserves of, petroleum are bringing the golden age of abundant, inexpensive petroleum to an end. 
   Recently, some have begun using corn-based ethanol as fuels, fuel extenders, and fuel oxygenates. Ethanol fuels are renewable and less polluting because the photosynthesis that provides carbohydrates for ethanol fermentation also converts atmospheric carbon dioxide to oxygen. However, ethanol fuel production also requires energy-intensive, costly, and polluting distillation/desiccation steps, and overall energy yields exceed energy input by only a small margin. There has also been some discussion of developing renewable biomass fuels, with current emphasis on cellulosic ethanol and bio-diesel oil (vegetable oil ester) fuels. However, these present the drawbacks of high energy expenditure for cellulosic ethanol and land-use competition with food and feed crops for biodiesel. 
   Others have attempted to use powdered coal dust or plant carbohydrates or chemically-modified derivatives of carbohydrates and biomass residues as fuels, fuel-extenders and ignition promoters. However, none of them teach the direct use of dry, non-modified, non-solubilized, non-emulsified carbohydrate powders as fuel and fuel extenders in internal combustion engines. 
   Therefore, a need existed for an apparatus and method for using pure dry biomass carbohydrates as fuels, fuel extenders and fuel oxygenates. Preferably, the apparatus and method would be used in internal combustion engines. Further preferably, the apparatus and method would provide for more rapid and energy-efficient conversion of the biomass carbohydrates into biomass fuels, fuel extenders, and oxygenates. Further preferably, the dry carbohydrates used for the present invention will be starch, sugars, cellulose, hemicellulose, lignins, or any combination thereof. Still further preferably, the apparatus and method would also be less detrimental to the environment. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide an apparatus and a method for using pure biomass carbohydrates as fuels. 
   Another object of the present invention is to provide an apparatus and a method for using pure biomass carbohydrates as fuel extenders. 
   Another object of the present invention is to provide an apparatus and a method for using pure biomass carbohydrates as fuel oxygenates. 
   Another object of the present invention is to provide an apparatus and method for using pure biomass carbohydrates as fuels, fuel extenders, and/or fuel oxygenates in internal combustion engines. 
   Yet another object of the present invention is to provide an apparatus and method for providing fuels, fuel extenders, and/or fuel oxygenates that are energy efficient and less detrimental to the environment. 
   BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   In accordance with one embodiment of the present invention an apparatus for using pure carbohydrates as a fuel additive for an engine is disclosed. The apparatus comprises a carbohydrate slurry fuel comprising dry carbohydrates mixed with hydrocarbon fuel, a carbohydrate slurry fuel tank, and a fuel line coupling the carbohydrate slurry fuel tank to the engine. 
   In accordance with another embodiment of the present invention, an improved internal combustion engine system is disclosed. The improved internal combustion engine system comprises a hydrocarbon fuel tank, a carbohydrate slurry fuel tank, a hydrocarbon fuel line coupling the hydrocarbon fuel tank to the carbohydrate slurry fuel tank, a hopper coupled to the carbohydrate slurry fuel tank for storing dry carbohydrates, and a carbohydrate slurry fuel line coupling the carbohydrate slurry fuel tank to an internal combustion engine. 
   In accordance with another embodiment of the present invention, a method of improving hydrocarbon fuel performance in an internal combustion engine is disclosed. The method comprises the steps of creating carbohydrate slurry fuel by mixing dry carbohydrates with hydrocarbon fuel, providing a carbohydrate slurry fuel tank for storing the carbohydrate slurry fuel, and delivering the carbohydrate slurry fuel from the carbohydrate slurry fuel tank to the internal combustion engine. 
   The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiments of the invention, as illustrated in the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the apparatus of the present invention. The apparatus is shown having a hopper, a slurry tank, and a plurality of fuel lines. 
       FIG. 2  is a perspective view of the interior of the apparatus of  FIG. 1  shown by broken lines. Carbohydrate pellets are shown within the fuel hopper and carbohydrate slurry fuel is shown within the carbohydrate slurry fuel tank. 
       FIG. 3  is a side view of the apparatus of  FIG. 1  being used with an engine. 
       FIG. 4  is a side view of the apparatus of  FIG. 1  being used with an engine. The only difference is the addition of a milling device between the hopper and the carbohydrate slurry fuel tank. 
       FIG. 5  is a side view of an engine using the apparatus of  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The novel features believed characteristic of the invention are set forth in the appended claims. The invention will best be understood by reference to the following detailed description of illustrated embodiments when read in conjunction with the accompanying drawings, wherein like reference numerals and symbols represent like elements. 
   Referring to  FIGS. 1-2 , an apparatus, hereinafter referred to as apparatus  10 , for using pure carbohydrates  30  as a fuel additive for an engine  18  is disclosed. The apparatus  10  preferably comprises a carbohydrate slurry fuel  14 , a carbohydrate slurry fuel tank  12 , and a fuel line  16  coupling the carbohydrate slurry fuel tank  12  to the engine  18 . 
   Preferably, the carbohydrate slurry fuel  14  is created by mixing pure dry carbohydrates  30  with hydrocarbon fuel (not shown). Although starch is the preferred carbohydrate  30  used herein, it should be clearly understood that substantial benefit may be derived from the use of sucrose and cellulose as well as a wide variety of saccharides, oligosaccharides or polysaccharides. Further preferably, the hydrocarbon fuel used for the present invention may be diesel, gasoline, or liquefied petroleum gas. 
   The following experiments were conducted. Those of ordinary skill in the art will realize that the following examples are illustrative only and are not intended to be in any way limiting. 
   EXAMPLE 1 
   A new BRIGS AND STRATON lawnmower engine was operated for over ten hours during a period of two weeks using a slurry of unleaded gasoline plus cornstarch at a ratio of 1 lb. of starch: 1 gal. of gasoline. Running times varied from fifteen minutes to over three hours for each run. The engine was always running on small amounts of gasoline when the starch slurry fuel was additionally added, and refueling of the gas tank during prolonged runs with slurry fuel was done with the engine running full throttle. The slurry fuel in the tank was kept partially-suspended by constant agitation of the entire mower and by occasional stirring with the gas cap removed. The engine operated strongly at the factory-preset high speed with no smoking, soot or dust evident from the exhaust and no loss of power even when very thick sections of heavy grass were mowed with the twenty-inch rotary cutter adjusted to a low height above ground level. At no time was any irregular running or sputtering or power diminution observed. The engine oil and spark plug remained clean over the ten hours of operation. 
   During one run the slurry consisted (volume to volume) of one part gasoline, ¼ part packed cellulose powder (finely ground from high quality paper, then sieved), and less than 5% added corn starch power. This slurry also fueled the engine as efficiently and cleanly as did gasoline alone. 
   EXAMPLE 2 
   A WEEDEATER trimmer with a two-stroke engine operated efficiently using a gasoline slurry fuel with a 1:8 volume/volume cornstarch to hydrocarbon fuel ratio. No increase in smoke, soot, or dust was evident during more than one hour of operation at full throttle while constantly agitating the fuel mixture. Powdered confectioners sucrose at the same ratio to gasoline also exhibited normal operation on this sugar-hydrocarbon slurry fuel on runs exceeding one hour. No evidence of engine fouling was observed. Therefore, powdered monosaccharides or disaccharides are as effective as slurry fuels as are polysaccharides. 
   EXAMPLE 3 
   Another WEEDEATER trimmer engine with a properly-perforated candle-type fuel filter operated efficiently and cleanly using either a 25% slurry of sucrose in gasoline or a 25% slurry of cornstarch in gasoline, even though starch aggregates of 1 mm or more in size could be seen flowing up the clear plastic fuel line to the carburetor. Considerable amounts of aggregated carbohydrate failed to pass the perforated filter into the fuel line, and remained in the fuel tank after fuel depletion. Therefore, even aggregated slurry fuels may still undergo nearly-complete combustion if they reach the carburetor and atomize well. 
   The fact that the carbohydrate slurry fuel  14  burned cleanly and with no detectable increase in exhaust smoke or soot indicates nearly-complete combustion of both the hydrocarbon and the carbohydrate in slurries. It therefore follows that the free energy released by carbohydrate combustion to hot gases in cylinders must, in accord with the first law of thermodynamics, help to drive the engine  18 . 
   The carbohydrate slurry fuel  14  may be premixed at fuel depots or refinery areas. Delivery tankers would therefore preferably have mixers operating in their tanks prior to dispensing these slurry fuels into underground service station tanks. The underground service station tanks would also preferably keep their carbohydrate slurry fuel  14  mixed as a fully-suspended slurry during all hours of operation. Such constant mixing would help to prevent fuel line and engine fouling. 
   In the alternative, the dry carbohydrates  30  could be mixed with the hydrocarbon fuel within the apparatus  10  itself. The dry carbohydrates  30  would preferably be stored within a hopper  24 . The dry carbohydrates  30  would further preferably pass through a dry carbohydrate fuel line  32  into a carbohydrate slurry fuel tank  12 . Hydrocarbon fuel from a hydrocarbon fuel tank  36  will pass through a hydrocarbon fuel line  38  and will enter the carbohydrate slurry fuel tank  12  where it will be mixed with the dry carbohydrates  30  to form the carbohydrate slurry fuel  14 . A carbohydrate slurry fuel line  16  will then deliver the carbohydrate slurry fuel  14  from the carbohydrate slurry fuel tank  12  to the engine  18 . 
   The dry carbohydrates  30  may be in either powder or pellet form. If in pellet form, the pellets may comprise a binder that was soluble in hydrocarbon fuel, therefore causing the pellet to break down into powder form once in contact with the hydrocarbon fuel. If the pellet does not comprise a binder that is soluble in hydrocarbon fuel, the apparatus  10  may further comprise a milling device  26  to crush or grind the pellets to convert them into powder form. The powder may then either fall through the dry carbohydrate fuel line  32  directly into the carbohydrate slurry fuel tank  12  or it may be conveyed to the carbohydrate slurry fuel tank  12  via a rotary drive train  34  housed within the dry carbohydrate fuel line  32 . The milling device  26  and the rotary drive train  34  could be powered by at least one auxiliary motor  28 . 
   When vehicles are idle, settling of carbohydrate  30  powders may occur. In order to help prevent engine fouling, it is preferred that the carbohydrate slurry fuel tank  12  comprise at least one agitator  22  to mix the carbohydrate slurry fuel  14 . Frequent-to-constant mixing and recirculation through fuel lines will allow the carbohydrates  30  to remain suspended within the hydrocarbon fuel and to prevent aggregates from forming and blocking any fuel lines or other engine components. Another way to help prevent engine fouling would be to place a metal sieve-filter (not shown) immediately prior to the point where carbohydrate slurry fuel  14  would enter the fuel injector. This would help to finely disperse any loose aggregates of powdered carbohydrates  30 . 
   Yet another way to help prevent engine fouling is to maintain a low concentration of carbohydrate  30  in the carbohydrate slurry fuel  14 . Oxygen comprises slightly more than half of the molecular weight of carbohydrates  30 . Therefore, a 4% slurry of carbohydrate in hydrocarbon fuel would be able to provide the 2% by weight oxygen content previously mandated for petroleum oxygenates to promote more complete fuel combustion. The rather low concentration of 4% dry carbohydrate  30  powder in a hydrocarbon slurry would allow easier management of aggregation although it would occur at a somewhat slower rate. 
   Referring now to  FIGS. 3-5 , an improved internal combustion engine system, hereinafter referred to as system  100 , is shown. Preferably, the system  100  comprises two separate fuel tanks and lines. A carbohydrate slurry fuel line  16  would deliver carbohydrate slurry fuel  14  from a carbohydrate slurry fuel tank  12  to the engine  18 . A hydrocarbon fuel line  38   a  (referred to generically as hydrocarbon fuel line  38 ) would deliver hydrocarbon fuel from a hydrocarbon fuel tank  36  to the carbohydrate slurry fuel tank  12  where the hydrocarbon fuel will be mixed with dry carbohydrates  30 . Further preferably, a second hydrocarbon fuel line  38   b  (referred to generically as hydrocarbon fuel line  38 ) would deliver pure hydrocarbon fuel to the engine  18 . While it is preferred that the system  100  comprise the second hydrocarbon fuel line  38   b , it should be clearly understood that substantial benefit may be derived from a system  100  that does not have a second hydrocarbon fuel line  38   b  and from a system  100  that has more than two hydrocarbon fuel lines  38 . 
   Preferably, the pure hydrocarbon fuel that would be delivered directly to the engine  18  from the hydrocarbon fuel tank  36  via the second hydrocarbon fuel line  38   b  would automatically drive the engine  18  for an additional period of time (with the ignition system staying on) after the ignition key is turned off. This would help to eliminate unburned carbohydrate  30  residues that could otherwise remain in the engine  18  after shutdown. Further preferably, when starting a cold engine  18 , the pure hydrocarbon fuel would automatically be delivered directly to the engine  18  for a period of time until the engine  18  is warmed up. After the engine  18  is warmed, carbohydrate slurry fuel  14  would preferably be used continuously until initiating engine  18  shutdown. 
   Dry carbohydrates  30  precipitated in carbohydrate slurry fuel lines  16  may be suspended quickly if the carbohydrate slurry fuel line  16  forms a complete circuit back to the carbohydrate slurry fuel tank  12  during start-up and during operation. This will continuously move separated fuel mixture into the stirred carbohydrate slurry fuel tank  12  for full suspension. Additional hydrocarbon fuel from the hydrocarbon fuel tank  36  may also be delivered to the carbohydrate slurry fuel tank  14  via the hydrocarbon fuel line  38  to restore the desired concentration of the carbohydrate slurry fuel  14  prior to the carbohydrate slurry fuel  14  being recycled to the fuel injectors  20  of the engine  18 . While it is preferred that the engine  18  be one that uses electronic fuel injectors  20 , it should be clearly understood that further substantial benefit may be derived from use of the invention with a carbureted engine (not shown). 
   While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.