Patent Publication Number: US-2005132642-A1

Title: Heating fuel blend

Description:
This application claims the benefits and priority of U.S. provisional application No. 60/516,170 filed Oct. 29, 2003, the entire disclosure of which is incorporated herein by reference. 
    
    
     CONTRACTUAL ORIGIN OF INVENTION  
      The United States Government may have rights in this invention pursuant to United States Department of Agriculture Grant No. 01-52104-11227. 
    
    
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a heating fuel blend and method of making a heating fuel blend for use in commercial and residential building heating devices such as furnaces and boilers.  
      2. Description of Related Art  
      Carbonaceous fuel substances, other than natural petroleum, are widely distributed throughout the world. The United States has large reserves of some of these carbonaceous fuel substances. Unfortunately, estimates of the quantities of in-place reserves that may be recoverable with current technology range no higher than about 10%. There is considerable pressure for new recovery technology and for advances that reduce the demand of non-renewable petroleum oil.  
      Renewable vegetable derived oil for use as residential heating oil alternative has the potential of reducing the demand for non-renewable petroleum oil. In particular soybeans, which made up 57% of the total world wide oilseed production of 2002, have produced promising results in lab and field tests at Purdue University. United States farmers harvested 72.16 million acres of soybeans with an average yield of 37.8 bushels/acre (USDA-NASS). The United States soybean oil and meal production industry produced 21.81 billion pounds of oil in 2002 utilizing an estimated 57 million acres of soybeans (USDA-NASS). This is equivalent to 2.91 billion gallons of soybean oil ready for industrial, commercial, and food product use.  
      According to the United States Department of Energy&#39;s Energy Information Administration, nearly 8.1 million homes used petroleum heating oil, also known as No. 2 fuel oil, in the year 2002. The primary area of market potential is in the Northeast and Midwest with 75% and 10% of the total household respectively. This trend is also supported by the national residential fuel oil consumption data.  
      The price of petroleum heating oil fluctuates drastically in the winter months due to increased usage. Many consumers stockpile petroleum heating oil during the warmer months to avoid the price spikes of winter. Therefore, there is a need for a heating fuel blend comprising a petroleum based fuel and a vegetable oil where no major modifications would be required to use the heating fuel blend in a commercial or residential heating device.  
     SUMMARY OF THE INVENTION  
      An embodiment of the invention provides a heating fuel blend comprising a petroleum based fuel and a vegetable oil. The petroleum based fuel can be selected from diesel fuel, fuel oil, and kerosene. The vegetable oil may be crude oil, degummed oil, or a mixture of crude and degummed oil and is selected from the group consisting of soybean oil, cottenseed oil, rapeseed oil, corn oil, peanut oil, sunflowerseed oil, palm kernel oil, copra oil and other oils of similar composition produced by plants. In a preferred embodiment, the vegetable oil is present in the blend in an amount greater than zero and up to about 50% by volume. In a more preferred embodiment, the vegetable oil is present in an amount greater than zero and up to about 20% by volume.  
      Another preferred embodiment of the invention comprises a petroleum based fuel and crude, degummed, or a mixture of crude and degummed soybean oil in the blend. In a preferred embodiment, the soybean oil is present in an amount greater than zero and up to about 50% by volume, more preferably present in an amount greater than zero and up to about 20% by volume.  
      In still another embodiment the heating fuel blend comprises No. 2 fuel oil and degummed soybean oil, where the soybean oil is present in an amount greater than zero and up to 20% by volume.  
      A method embodiment of the invention comprises mixing a petroleum based fuel and a vegetable oil to make a heating fuel blend. The vegetable oil can be either crude oil, degummed oil, or a mixture of crude and degummed oil.  
      Another method embodiment of the invention involves heating a building comprising the step of burning a fuel blend comprising a petroleum based fuel and a vegetable oil using a heating device adjusted to produce a predetermined fuel efficiency. At least one of the spray angle of the nozzle, pattern of the spray, pump pressure, fuel flow rate, and air shutter can be adjusted in the heating device.  
      Advantages of this heating fuel blend can include reduced heating fuel costs to the consumer without requiring major furnace modifications, increased demand for vegetable oils, reduced demand for non-renewable petroleum products, and reduced harmful emissions. 
    
    
     DESCRIPTION OF DRAWINGS  
       FIG. 1  shows the heat content in British Thermal Units/gallon, hereinafter BTU/gal, of heating fuel blends having varying percentages by volume of crude, degummed, or transesterified (soy methyl ester) soybean oil and No. 2 fuel oil determined using a Parr calorimeter.  
       FIG. 2  shows the heat content in BTU/gal of heating fuel blends having varying percentages by volume of crude, degummed, or transesterified (soy methyl ester) soybean oil and No. 2 fuel oil determined using a Parr calorimeter. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      An embodiment of the invention provides a heating fuel blend comprising a petroleum based fuel and a vegetable oil. The petroleum based fuel can be diesel fuel, fuel oil, and kerosene including but not limited to No. 1 diesel fuel, No. 2 diesel fuel, No. 1 fuel oil, and No. 2 fuel oil.  
      The vegetable oil can be selected from the group consisting of soybean oil, cottenseed oil, rapeseed oil, corn oil, peanut oil, sunflowerseed oil, palm kernel oil, copra oil, or other oils of similar composition as listed in table 1 below produced by plants.  
               TABLE 1                          Fatty Acid content in Vegetable Oil: Percent by Weight                                 Fatty Acid               Composition           Fatty Acid   % by Weight                                                 Myristic   C 14 H 28 O 2     C14:0   0.3-6             Palmitic   C 16 H 32 O 2     C16:0    2-47           Palmitoleic   C 16 H 30 O 2     C16:1   0-1           Stearic   C 18 H 36 O 2     C18:0   1-6           Oleic   C 18 H 34 O 2     C18:1   10-52           Linoleic   C 18 H 32 O 2     C18:2    2-69           Lenolenic   C 18 H 30 O 2     C18:3   0.3-10            Arachidic   C 20 H 40 O 2     C20:0   0.9-10            Behenic   C 22 H 44 O 2     C22:0           Eicosenoic   C 20 H 38 O 2     C20:1   50-60           Eurcic   C 22 H 42 O 2     C22:1                      
 
      The blend preferably comprises a petroleum based fuel and a vegetable oil present in an amount greater than zero and up to about 50% by volume. More preferably, the vegetable oil can be present an amount greater than zero and up to about 20% by volume of the blend.  
      The vegetable oil can be either crude oil, degummed oil, or a mixture of crude and degummed oil. The crude oil is substantially unrefined, unprocessed oil and can contain compounds such as free fatty acids, carbohydrates, proteins and their degradation products, water, pigments, fat oxidation products, minerals, and phospholipids. Crude oil can be recovered from a plant using physical methods, such as pressing, expellers, expanders, and/or extruders; and/or chemical methods, such as solvent extraction, without further treatment or refinement. For example, crude soybean oil is typically recovered using a solvent extraction method where the soybeans are flaked to provide a large surface area; a solvent, commonly hexane, is then pumped through the soybean flakes to dissolve the oil in the solvent; and the oil is then separated from the solvent. Crude vegetable oil is sensitive to oxidation and does contain impurities such as phospholipids; however, it is less expensive than degummed vegetable oil.  
      Degummed oil is crude oil that has been degummed by a conventional degumming method to remove the phospholipid compounds that can be hydratable phospholipids or non-hydratable phospholipids. Small amounts of calcium and magnesium complex with a portion of the phospholipids to form the non-hydratable phospholipids. A conventional degumming method such as water degumming can remove the hydratable phospholipids. When water is added to crude oil, most of the hydratable phospholipids in the oil are hydrated and become insoluble in oil. The hydrated phospholipids are then separated from the oil by a suitable method such as settling or centrifugation. The removal of non-hydratable phospholipids is considerably more difficult and expensive, requiring further chemical treatment, typically chemical refining, to break the chemical bonds between the calcium or magnesium ions and the phospholipid. See Dijkstra et al., U.S. Pat. No. 4,698,185, issued Oct. 6, 1987 which is hereby incorporated by reference. The degummed vegetable oil is suitable for transit, storage, or further refining.  
      A mixture of crude and degummed vegetable oil can be used in the blend and is especially useful in a boiler heating device with a larger nozzle opening.  
      Another preferred embodiment of the invention offered for purposes of illustration and not limitation involves a heating fuel blend comprising a petroleum based fuel and a soybean oil. The soybean oil can be crude oil, degummed oil, or a mixture of crude and degummed oil and can be present preferably in an amount greater than zero and up to about 50% by volume. In a more preferred embodiment, the soybean oil is present in an amount greater than zero and up to about 20% by volume of the blend. A comparison of the heat content of heating fuel blends using crude soybean oil, degummed soybean oil, and transesterified soybean oil at varying percentages was made.  
      For example,  FIGS. 1 and 2  show the heat output of fuel blends using crude or degummed soybean oil and No. 2 fuel oil and, for comparison, fuel blends using soy methyl ester (biodiesel) and No. 2 fuel oil, determined using a Rapp calorimeter. The heat contents of crude soybean oil, degummed soybean oil, and soy methyl ester soybean oil at various percentages of the total fuel blend were compared. The soy methyl ester soybean oil is transesterified soybean oil that is commonly available in the market and referred to as biodiesel. The triglyceride structure is rearranged in the biodiesel without chemically modifying the fats. The crude oil fuel blends and the degummed oil fuel blends having up to 50% soybean oil by volume had similar heat output when compared to the biodiesel blends having up to 50% biodiesel (transesterified soybean oil). The crude oil and degummed oil blends are preferred over the biodiesel blends because the crude oil blends and degummed oil blends are less expensive while providing a similar heat content, as apparent in  FIGS. 1 and 2 , when compared to the biodiesel blends. For example, the current cost of biodiesel (100% transesterified soybean oil) is $2.25-3.50 per gallon, which is currently higher than that of diesel $2.18 per gallon, No. 2 fuel oil $1.99 per gallon, or degummed soybean oil $1.77 per gallon. This invention, thus, can advantageously reduce heating fuel cost to the consumer without requiring major furnace modifications to use the heating fuel blend.  
      In still another preferred embodiment of the invention the heating fuel blend can comprise No. 2 fuel oil and degummed soybean oil where the degummed soybean oil is present in an amount greater than zero and up to about 20% by volume. For purposes of illustration and not limitation, a preferred heating fuel blend comprising No. 2 fuel oil and 20% by volume degummed soybean oil can have a viscosity of 3.46 centistokes at 72.5° Fahrenheit; a heat of combustion of 135,490 BTU/gal or 18,871 BTU/lb; a cloud point at −17° Fahrenheit; a pour point at −22° Fahrenheit; and a flash point at 160° Fahrenheit.  
      A method embodiment of the invention involves making a heating fuel blend comprising mixing a petroleum based fuel and a vegetable oil. The vegetable oil used in the blend can be crude oil, degummed oil, or a mixture of crude and degummed oil. The fuel blend can be mixed by any method sufficient to blend the petroleum based fuel and vegetable oil such as “splash mixed” by adding the vegetable oil to a container and then adding the petroleum based fuel to the same container.  
      Another method embodiment of the invention involves heating a building comprising the step of burning a fuel blend comprising a petroleum based fuel and a vegetable oil using a heating device adjusted to produce a predetermined fuel efficiency that is at least equal to or comparable to burning biodiesel in a heating device. The vegetable oil can be crude oil, degummed oil, or a mixture of crude and degummed oil. The heating device can be a commercial or residential building heating device such as an oil burning furnace or boiler. The heating fuel blend in this invention can have combustion characteristics similar to commercially available petroleum heating oil and can produce a heat output of about 135,490 BTU/gal, which is only 1-3% lower than No. 2 fuel oil. Therefore, no major modifications are required when using a heating fuel blend pursuant to this invention in a conventional heating device such as a furnace or boiler.  
      Some minor modifications can be performed by a trained oil heat technician to easily adjust the heating device to operate efficiently and provide a good flame just as he/she would a heating device using petroleum heating oil. For purposes of illustration and not limitation, a conventional type residential furnace can be adjusted by a technician to any of the following parameters depending on the type of heating device and size of the building to be heated: a nozzle spray angle between 60°-90°; a nozzle spray pattern of hollow cone, solid, or a combination thereof; a pump pressure between 100-160 psi; a fuel flow rate between 0.50 to 0.85 GPH; and an air shutter adjusted empirically to achieve a good flame as determined by the technician.  
      An exemplary method embodiment of the invention provided for illustration and not limitation involves burning heating fuel blends comprising No. 2 fuel oil and soybean oil in a residential type heating furnace, commercially available as model no. chb68-112b from Thermopride of North Judson, Ind., where the soybean oil in the blends ranged from 10%, 30%, and 50% of the total volume. The furnace was connected to a heating duct for conveying the heated air away from the furnace and a flue for conveying combustion emissions to a source of outer air. The interior of the heating duct was fitted with a conventional thermal couple connected to a conventional multi-meter to track the temperature of the heated air in the heating duct. The flue was fitted with a combustion gas analyzer to continuously collect data of NO, NO 2 , NO x , CO 2 , CO, and O 2  emissions and the ambient and flue emission temperature and is commercially available as as IMR 28000 by IMR Environmental Equipment, Inc of St. Petersburg, Fla. The combustion gas analyzer was connected to a computer to store the emission and temperature data for later analysis. A draft was provided on the flue for regulating the flow of the emissions.  
      The furnace was connected to a fuel tank for holding the fuel blend comprising a petroleum based fuel and a vegetable oil and provided a sight gauge to estimate the amount of fuel blend remaining in the tank. A fuel line communicated the tank to the furnace and can comprise a conventional rubber hose. A conventional filter and flow meter were provided between the tank and the furnace to filter (pore size of 10 μm) and to monitor the flow rate of the fuel blend in the fuel line. A fuel pump in the furnace was provided to pump the blend from the tank to a nozzle in the furnace.  
      A burner disposed in the furnace was connected to a thermostat to turn the furnace on or off. When the furnace was turned on, the fuel was pumped from the tank to the burner and an air shutter opened to provide air to the burner. In the burner, the fuel blend and air were mixed. The mixture was sprayed from a nozzle within a combustion chamber in the furnace. An igniter proximate the sprayed mixture ignited the fuel blend in the mixture to form a flame. The flame warmed a heat exchanger thereby heating the air flowing over the heat exchanger. The heated air flowed from the furnace to the heating duct where the temperature of the heated air was measured. The combustion emissions generated from the flame exited via the flue pipe and were also monitored.  
      Each blend was tested in the furnace at various settings. The nozzle was adjusted to provide a pattern angle of either 60°, 80°, 90° and spray patterns of hollow cone, solid, or a combination thereof. The nozzle was a pressure nozzle rated within 0.5 to 0.85 gallons per hour, hereinafter GPH. The pump pressure to the nozzle was tested at 100, 130, 150, and 200 psi. The air shutter was also adjusted empirically to achieve a good flame as determined by the furnace technician for improving the flame characteristics and reducing harmful emissions. For each blend the settings and pressures were evaluated and, if necessary, adjustments were made to maximize the BTU output. The soybean oil blends show promising results in lower SO 2  emissions. The lower percentage blends, i.e. blends containing less than 30% by volume degummed soybean oil, had combustion characteristics similar to petroleum heating oil. Burned blends of 50% or lower vegetable oil did not require any major modifications to the furnace or additional equipment. Overall, heating fuel blends comprising a petroleum based fuel and up to 50% by volume degummed soybean oil were burned in a standard oil-burning furnace with no major furnace modifications or additional equipment.  
      Additionally, a heating fuel blend pursuant to the invention can advantageously reduce price pikes during the winter months. A four year historic cost comparison was performed between regular petroleum oil and a 20% by volume degummed soybean oil blend. A 20% soybean oil heating fuel blend can be effective in reducing the price spikes experienced by petroleum products, such as No. 2 fuel oil, during winter months. If the trend continues, a heating fuel blend pursuant to this invention can be a viable competitor in the heating fuel market in terms of performance and cost.  
      Furthermore, the storage of heating oil is a concern in the summer months when there is no turn over of fuel. Studies of heating fuel blends pursuant to this invention show no stratification or loss in heat content even after one year of storage in different environments.  
      The heating fuel blend can also benefit the agricultural industry due to a projected increase in the demand of vegetable oil. For example, if only 25% of the fuel oil in the Northeast were replaced with a 20% soybean oil blend (20% degummed soybean oil and 80% petroleum oil), then 290 million gallons of soybean oil would be required. This is equivalent to 5.7 million acres of soybean crop or 8.0% of the total U.S. Production in 2002. The vegetable oil used in the heating fuel blend can increase the demand for vegetable oil while reducing the demand for non-renewable petroleum oil.  
      Another advantage of using the heating fuel blend in a heating device can be a reduction in harmful emissions when compared to No. 2 fuel oil emissions. For example, testing of heating fuel blends pursuant to the invention show promising results in reducing SO 2 , CO 2 , and NO x , emissions.  
      It is to be understood that the invention has been described with respect to certain specific embodiments thereof for purposes of illustration and not limitation. The present invention envisions that modifications, changes, and the like can be made therein without departing from the spirit and scope of the invention as set forth in the following claims.