Abstract:
A method of production of a biofuel from the open ocean surface by testing the ocean surface waters to determine the nutrients that are missing and testing the currents to determine a suitable area for the application of the missing nutrients so that the increased production of biomass created can be harvested and the harvested biomass processed to obtain a biofuel suitable for energy production.

Description:
[0001]    This application claims the benefit of provisional application No. 60/806,037 filed Jun. 28, 2006. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The field of the invention is the production of bio-diesel or other synthetic fuel from harvesting biomass from the open ocean. The production of biomass through agriculture on land is well known, including the growing of corn, which can then be converted to ethanol for addition to gasoline (gasohol). This is energy intensive and high cost, only being economically effective with crude oil at over $70 a barrel and is enhanced by tax advantages. Another difficulty is that there is not enough suitable land to make a significant impact on the crude oil consumption of the U.S. Only about 16% of the earth&#39;s surface is available for agriculture whereas 72% is open ocean. About 60% of the plant life that grows in the ocean arises from 2% of the ocean surface, an area around the edges of the continents and large islands. That leaves 40% to grow from the 98% of the open ocean away from land. If we could make some portion of that 98% more like the 2% we could greatly increase the fish production, sequester CO 2  to the deep ocean or produce biomass for conversion to biofuel. The burning of this biofuel would not increase the CO 2  content of the atmosphere since the carbon comes from the atmosphere through photosynthesis in the ocean. 
         [0003]    The production of biomass in the open ocean can be enhanced by the addition of fertilizing elements to the ocean surface to produce more seafood catch. See the following U.S. patents: 
         [0000]    
       
         
               
               
             
           
               
                   
               
             
             
               
                 Method of Improving Production of Seafood 
                 5,433,173 
               
               
                 Method of Increasing Production of Seafood in the Ocean 
                 5,535,701 
               
               
                 Method of Increasing Seafood Production in the Barren 
                 5,967,087 
               
               
                 Ocean 
               
               
                 Method of Increasing Seafood Production in the Barren 
                 6,408,792 B1 
               
               
                 Ocean with a Fertilizer Comprising Chelated Iron 
               
               
                 Method of Increasing the Fish Catch in the Ocean 
                 6,729,063 B1 
               
               
                   
               
             
          
         
       
     
         [0004]    Since fish and zooplankton recycle CO 2  to the ocean surface the fertilization should be done to minimize this loss of biomass in order to sequester CO 2  in the deep ocean. See the following U.S. patents: 
         [0000]    
       
         
               
               
             
           
               
                   
               
             
             
               
                 Method of Sequestering Carbon Dioxide 
                 6,056,919 
               
               
                 Method of Sequestering CO 2  with Spiral Fertilization 
                 6,200,530 
               
               
                 Method of Sequestering Carbon Dioxide with a Fertilizer 
                 6,440,367 
               
               
                 Comprising Chelated Iron 
               
               
                   
               
             
          
         
       
     
         [0005]    The ocean currents and diffusion will gradually disburse the biomass created, which is generally in single cells and small aggregates. Therefore areas of the ocean surface must be found that keep the biomass created in a confined area and in a form suitable for harvesting. Once the biomass is harvested it must be processed to form components that are suitable for blending to make biofuels. 
       SUMMARY OF THE INVENTION 
       [0006]    A method for the production of components of biofuels from the open ocean by the following steps: (1) testing the currents to determine that any biomass produced remains in a zone suitable for harvesting; (2) testing the ocean water surface to determine the nutrients that are missing or too low concentration; (3) testing the ocean surface to determine the concentration of plant life in a form suitable for harvesting (this plant life, if missing to any significant extent, can be added to the ocean surface to enhance the harvest of suitable plant life over time); (4) adding a fertilizer that releases an appropriate amount of these nutrients over time in a form that remains available to the plant life (for example, the nutrients should not leave the photic zone by precipitation to any appreciable extent) in the photic zone; (5) harvesting the plant life produced by the fertilization; and (6) processing the harvested plant life to produce useful components of biofuels. 
         [0007]    The testing of the ocean surface water may be carried out by any number of methods that are known to one of ordinary skill in the art, in order to ascertain the nutrients that are missing to a significant extent. A nutrient is missing to a significant extent if the production of biomass is limited to a significant extent by the level of the nutrient in the water. An appropriate amount of a missing nutrient is an amount to raise the concentration of the nutrient in the ocean surface so that the production of biomass is no longer limited to a significant extent by the concentration of the nutrient. 
         [0008]    The fertilization of the open ocean to increase biomass production may be carried out with a fertilizer system that comprises one or more fertilizers and suitable plant systems. The suitable plant system will generally require a fertilizer comprising iron, phosphate and nitrate and will be in the form of seaweed rather than diatoms so that it can be harvested easily from the ocean water. The currents should be such that the biomass created stays in the ocean waters suitable for harvest rather than washed up on shores. Such currents that confine biomass for many years are ocean gyres such as the Sargasso Sea, which is unique since it is large, over 2,000,000 sq mi, and does not have any shore line boundaries. Other converging tropical gyres may also be of use. The fertilizer may contain iron to enhance chlorophyll production, phosphate to enhance biomass and nitrate to enhance growth. If the plant life already there does not produce enough nitrate, this may be added, or Trichodesmium may be added to help to produce the nitrate along with the plant life there. The iron must be added in a form that does not precipitate to any significant extent, especially if phosphate is also required. This can be done by adding the iron in the form of a chelate such as lignin acid sulphonate. The iron and the phosphate can be added in the form of slow release pellets that minimize the chemical reactions between the fertilizers by minimizing their concentration in the ocean water of the fertilization patch. 
         [0009]    As the seaweeds grow in the open ocean they float and aggregate together in the form of loose floating patches as does the Sargassum weed in the Sargasso Sea. This is an ideal form for harvesting using a powered rake to bring the biomass over the bow of the harvesting vessel. The biomass can then be dried and compressed in the vessel hold for shipment back to port for processing to obtain biofuel components. Since the harvesting vessel has just removed biomass from the ocean it is an excellent vehicle to disburse the required fertilizing elements into the ocean surface. It may also be possible to separate seeds or buds from the seaweed and add them back into the ocean water with the fertilizer to enhance the next harvest. 
         [0010]    The harvested biomass is transferred to port for processing into biofuel components. This is similar to what takes place in converting biomass from plant material grown on land but with a different plant source. The same conversion technology applies that results in components for biofuels such as ethanol and bio-oils. Since the area for fertilization has been selected for long term residence of the biomass created, such as the Sargasso Sea, the fertilization can be carried out using a long term pattern. The area of the Sargasso Sea is approximately 2,000,000 sq mi and should be ideal for this purpose. Other smaller ocean areas with greater leakage at the edges must be carefully studied to ascertain the best location for fertilization and harvest. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0011]    The production of biofuel from the fertilization of the ocean surface would greatly increase the biofuels available to the U.S., reducing the nation&#39;s reliance on imported crude oil. In order to do this economically the biomass created must be suitable for efficient harvest. The phytoplankton normally produced by ocean fertilization (see referenced patents) are so small, 1-20 ηm diameter, that they cannot be separated from the water in large tonnages efficiently. Therefore a larger biomass plant must be grown such as seaweed. Seaweeds, like larger terrestrial plants are usually anchored to the ground with hold-fast root systems. This protects them from drifting with the currents to less hospitable areas such as sandy beaches and rocky shores. The Sargasso Sea weed is unique in that it is not anchored by roots and can drift with the currents. However, the currents must be such that they keep the Sargassum weed confined to an enclosed sea away from shore with minimum leakage. The Sargasso Sea, with an area of about 2,000,000 sq mi has no continental shores and has a low leakage rate for the enclosed Sargassum weeds. There may be other areas of the world&#39;s oceans that also have suitable long residence time for floating seaweeds and/or other plant life in the water that will be revealed by further study. 
         [0012]    The Sargassum weed grows in an area of the North Atlantic bounded by the Gulf Stream on the west. The Corriolis force turns this current to the east where the force further turns it to the south off the coast of Europe. This current then turns to the west across the south Atlantic to join the Gulf Stream, completing the entrapment of the North Atlantic Ocean water that forms the Sargasso Sea. The Sargassum weed is the same family of seaweed that grows along the shores of the Atlantic Ocean but has lost its ability to grow roots, allowing it to float with the current and form mats on the ocean surface. The current curves to the right as it circulates slowly moving to the center of the Sargasso Sea where it forms a low hump and slowly sinks through the thermocline. The long-lived weed soon uses up the fertilizing elements in the surface water restricting its growth. However, the weed has developed the ability to use up the iron that is blown into the Sargasso Sea as dust from the Sahara Desert in Africa and also uses up the dissolved phosphate in the water. The weed then uses the refactory organic phosphate to maintain growth while recycling the iron as chlorophyll. The addition of soluble iron as lignin acid sulphonate and the addition of soluble ammonium phosphate should increase the growth rate of the Sargassum weed by 10 to 100 times. The ambient nitrogen-fixing phytoplankton in the area should be able to satisfy the nitrate required but if this is found not to be the case additional nitrogen fixers, such as Trichodesmium can be added to maintain growth. There are few fish in the Sargasso Sea, only a few small crabs and crustaceans in the Sargassum weed. 
         [0013]    The maximum growth rate of the Sargassum weed attainable with fertilization is not accurately known. Other species of brown algae are fast growers, as fast as high-yield agricultural plants such as beans and grains. On land we grow sugar cane, which produces about 25,000 tons of biomass per sq mi per year. We estimate that in the Sargasso Sea we could produce as much as 10,000 tons of biomass per sq mi per year of which 5,000 tons could be converted into biofuel components. The Sargasso Sea is about 2000 miles long, east to west, and 1000 miles north to south, for a total area of about 2,000,000 sq mi. If we could fertilize 20% of this we would have 400,000 sq mi. This area, with a 50% conversion rate, times 5000 tons per sq mi per year gives a total of about 1,000,000,000 tons of biofuel per year. At 350 lbs per barrel (5.7 barrels/ton) this gives 5,700,000,000 barrels per year of biofuel. The current U.S. crude consumption is about 7,700,000,000 barrels/year and the world demand is about 31,000,000,000 barrels/year. This indicates the possibility that the Sargasso Sea project could supply about 74% of the U.S. annual demand for oil and biofuel components. The Sargassum weed, itself, as well as by-products of the biofuel component processing could also be used for cattle fodder and other purposes. There may be other ocean areas that can also be brought into production and there may be many difficulties to bringing about the indicated production. Perhaps the greatest difficulty is the institution of private property rights in the open ocean far from land. This is required if the investment of fertilization can result in the harvesting of the Sargassum weed as required for a robust long-term commercialization of this fuel source. The long term advantage to the U.S. and the world, which will gain from the lowering of the CO 2  concentration of the atmosphere by the application of this technology, will provide the necessary impetus for the privatization of the open ocean required. This can be done by maintaining the free access now enjoyed but restricting the harvesting of the Sargassum weed produced by fertilization. 
         [0014]    Should it be determined that a significant portion of the biomass produced cannot be harvested but is sequestered in the deep ocean as described in the referenced patents, then measurements of the amount of CO 2  sequestered can be made and carbon sequestration credits can be claimed as covered by those patents. Likewise, if fish are caught inadvertently by the harvesting operation, any commercialization of their biomass can be claimed by the holders of the referenced patents for increased fish production. Each of these inadvertent results is expected to be small. 
         [0015]    The cost of fertilization is expected to be low resulting in the increased production of biomass in the fertilized area, which is equal to the harvested biomass plus the increase in biomass left behind after the harvest The total biomass is expected to be about 2×10 9  tons/yr (about 1.2×10 9  tons C). This will require about 1.3×10 6  tons/yr of chelated iron (at 12% Fe) and about 25×10 6  tons of ammonium phosphate per year. Note that the Redfield ratios are increased by about a factor of 8 for phosphate and a factor of 4 for iron. As noted, extra iron and phosphorous will be added to assure continued growth of the Sargassum weed after the harvesting. 
         [0016]    These estimates of return from fertilizing will be changed by measurements at the site and the amounts measured there. They do, however, give an indication of the capacity of the Sargasso Sea and perhaps other ocean gyres to produce biomass for biofuel production. 
         [0017]    The other costs include the ship time for the spreading of the fertilizers and the harvesting of the biomass, the processing of the biomass to biofuel components, the blending to obtain fuels for internal combustion engines (such as bio diesel) and the sale of these fuel blends. The cost of these activities is small in comparison with the expected value of 5.7×10 9  barrels of biofuel, which, at $42/barrel, should be worth $240×10 9  per year. 
         [0018]    Variations of the invention may be envisioned by those skilled in the art and the invention is to be limited solely by the claims hereto.