Abstract:
A microemulsion composition for treatment of pollution comprises a first component including any non-toxic, non-flammable surfactant known in the art for emulsifying fats and oils. The second component is a water soluble ester. The third component is a carbon containing non-toxic, non-flammable stabilizer for diluting the composition to a viscosity suitable for spraying or otherwise distributing the emulsion safely and evenly onto or into petroleum contaminated water. The emulsion is assimilated by the contamination such that hydrocarbon in the petroleum/water medium forms an agglomerated solid phase whereby the entire petroleum medium is physically separable from the water.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     The present application claims the benefit of U.S. Provisional Patent Application No. 60/674,766, filed Apr. 26, 2005, which is incorporated herein by reference in its entirety, and is related to U.S. Patent Application No. 60/900,596, filed Jul. 6, 2001. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to compositions and methods for treating pollutants and, more particularly, for treating pollution caused by spills of petroleum products on and into the Earth&#39;s water systems, as well as removal of petroleum products that are intermixed with water as a result of oil drilling and production operations.  
       BACKGROUND OF THE INVENTION  
       [0003]     As reliance on oil and oil based products continues to grow, oil pollution will occur with greater frequency. To date, the oil pollution remediation industry has primarily relied on mechanical means to remove oil contamination from water. However, these methods are not satisfactory. In the best case, most but not all of the pollutant is collected, leaving residual hydrocarbon pollution to contaminate additional areas. In the worst case, the hydrocarbon pollution is left on the water to continue contaminating pristine areas and wildlife, thereby causing irreparable harm and even death. The process by which the mechanical means “removes” the contaminant is simply not able bring the affected area back to its original state.  
         [0004]     A number of factors impact the efficiency of existing mechanical oil spill remediation technology. Examples of mechanical remediation equipment include booms and skimmers. Containment of a spill on water using booms has inherent shortcomings. For example, soluble hydrocarbon cannot be contained by booms. And, non-soluble hydrocarbon cannot be effectively contained in the boom area if there is wave action or tidal currents. Likewise, mechanical skimmers cannot collect soluble hydrocarbons and do not collect all of the non-soluble hydrocarbons. Skimmers also do not collect hydrocarbons that do not float. Further, skimmers leave residual hydrocarbon pollution on the surface of the water after they have completed collection. Similar to booms, strong wave action limits the ability of mechanical skimmers to collect the hydrocarbon. Absorbent rags are also used to clean up spills of hydrocarbon on water surfaces. Again, like booms and skimmers, absorbent rags are inherently incapable of collecting all of the hydrocarbon pollution, thereby leaving material behind to continue polluting the environment. Dispersants have also been used as a quasi-mechanical means of remediating water-borne oil spills. However, dispersants do not remove the hydrocarbon pollution. Rather they “hide” the pollution by changing the oil&#39;s surface tension and/or particle size whereby the hydrocarbon becomes distributed or dispersed throughout the water column.  
         [0005]     An alternative to mechanical hydrocarbon removal methods is hydrocarbon agglomeration. While the concept of agglomeration is decades old, currently available products ironically fail to conform to government environmental standards related to worker exposure, risk assessment within operating facilities, and inherent toxicity. Thus, presently existing so-called “green” agglomeration technology is compromised of products that are not, themselves, “green.” This gap between available technology and market need has prevented the widespread use of agglomeration. Moreover, presently available agglomeration technologies are limited in the degree that they can recover and agglomerate both soluble and non-soluble hydrocarbons in a water medium.  
         [0006]     Another water contamination problem occurs in connection with oil drilling and production operations. When oil is extracted from the Earth, it is often intermixed with water. Indeed, pressurized water is often used to displace oil from the rock formation from which it is being extracted. In new drilling operations, the water is required to be separated from the petroleum and returned to the environment with undetectable levels of petroleum.  
         [0007]     An advantage exists, therefore, for a safe and environmentally friendly hydrocarbon agglomeration composition for effectively remediating water-borne hydrocarbon spills and for extracting oil from water in oil drilling and production operations.  
       SUMMARY OF THE INVENTION  
       [0008]     The solution to bridging the gap between existing agglomeration technologies and satisfying governmental and industrial requirements begins with understanding the advantages and shortcomings of existing technology and applying “environmental” criteria to advance performance. To that end, the present invention provides a composition and methods for removal of petroleum materials that have been spilled upon the surface of water or intermixed with water as a consequence of certain oil drilling and production operations. The composition is a unique, non-toxic, non-flammable, stable microemulsion consisting of three components. It may be deposited onto petroleum materials that have been spilled upon a water surface by spraying or by any other means for distributing the emulsion safely and evenly. Similarly, the composition may be intermixed with contaminated water associated with oil drilling and production operations.  
         [0009]     The first component of the composition is any primary non-ionic, non-toxic surfactant such as a fatty acid, ester, or alcohol (or combination thereof) known in the art for emulsifying fats and oils. The second component is a water soluble ester. The third component is a carbon containing non-toxic, non-flammable stabilizer which also functions to dilute the composition to a viscosity suitable for spraying or other conventional means of application. When applied to water-borne petroleum, the emulsion is assimilated by the contamination such that all of the hydrocarbon in the petroleum/water medium forming an agglomerated solid phase such that the entire petroleum medium is physically separable from the water phase. The solid phase hydrocarbon can then be gathered and easily removed from the water phase by mechanical or other means. The composition removes both soluble and non-soluble hydrocarbons from the water phase thereby effectively eliminating hydrocarbon pollution from water bodies.  
         [0010]     By conforming to OSHA, DOT, and EPA environmental standards, the agglomeration product according to the invention can be used for removal of both soluble and non-soluble hydrocarbons from a water medium. That is, it can be used for complete cleanup of hydrocarbon pollution in a water medium. It can be used on both fresh and marine the waters and can be applied without damaging the environment in any way and without exposing workers applying the material to any harm.  
         [0011]     Other details, objects and advantages of the present invention will become apparent as the following description of the presently preferred embodiments and presently preferred methods of practicing the invention proceeds. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]     The present invention provides a composition and processing methods for safe application of materials to promote the agglomeration of petroleum on water. The component materials are in the form of a microemulsion composed of a carbon containing emulsifying agent as a lipophilic external phase for an internal package dissolved in water as distinct, uniform, suspended droplets as a water-in-oil emulsion. The oil portion may be any primary, hydrophobic, non-ionic, non-toxic, straight-chained carbon source surfactant such as a fatty or carboxylic acid, an ester, or an alcohol such as an ethoxylated alcohol (or combinations of any of the foregoing) known in the art for emulsifying fats and oils. The oil portion serves as an initial source of material for agglomerating the targeted hydrocarbon pollutant. A second composition component is in the form of a non-toxic, non-flammable water soluble ester compound such as, for example, a phosphate ester in the form of an aqueous solution of lauryl phosphate. This component serves a second source of agglomerating material, especially useful for agglomeration of soluble hydrocarbons including, but not limited to, phenols and MTBE (methyl tertiary butyl ether). The water based agglomerating material is preferably introduced into the emulsifying component under high shear to create a microemulsion with distinct droplets having a size between about 20 to about 400 angstroms.  
         [0013]     Essential to the invention is a third component comprising a diluent added to the first and second components. The diluent may comprise any non-toxic, non-flammable, carbon containing and biodegradable compound which is soluble in the first component and is selected to facilitate viscosity stabilization of the composition for extended storage. A suitable material for the third component is butyl carbitol [2-(2-butoxyethoxy)ethanol] which has been demonstrated to stabilize the microemulsion, maintain a flashpoint for the product above the “application critical” point of 100° F. and ensure the product is not harmful to humans either exposed through direct application or by working in contiguous areas. The third component facilitates safe application of the agglomerating active ingredients evenly and thoroughly onto and/or into the petroleum/water contamination. The introduction of the third component in an amount of about 10 to 35 weight percent has been demonstrated to reduce the viscosity of the first and second components to less than 200 cps to allow delivery of the composition by spray or other dispersion methods. The third component also preferably maintains the microemulsion of the first and second components in suspension as a pourable and sprayable liquid with a shelf life of 12 months or more in a 40° F. to 100° F. environment.  
         [0014]     The composition according to the invention can be used in any open or closed aqueous environment including oceans, lakes, ponds, rivers, slurry pits, ground water, fresh water, marine water, brackish water, and the like. The composition is applied to or mixed with the contamination to begin the agglomerating development. The preferred dosage is a rate between 2% and 40% by weight of the hydrocarbon contamination and the application can be achieved by any conventional means including, but not limited to, spraying, pouring, or physical mixing. The present invention is highly advantageous when applied in petroleum contaminated aqueous environments requiring agglomeration activities in that it provides a way to efficiently deliver essential components in an environmentally sound way. The invention further provides significantly enhanced levels of agglomeration by virtue of the unexpected results achieved by using a low evaporation stabilizer source. In contrast, current stabilizers available on the market rapidly evaporate, thereby not only polluting the environment, but also working to the detriment of the overall remediation system.  
         [0015]     The materials employed in the present invention deliver carbon and an aqueous ester to the agglomeration mechanism. The ester must be delivered in a substantially non-toxic, non-flammable form. A representative but non-limitative agglomerating ester suitable for the purposes of the present invention is a phosphate ester, e.g., in the form of an aqueous lauryl phosphate solution. Carbon is delivered in a substantially non-toxic, non-flammable form such as a fatty or carboxylic acid, including but not limited to, oleic acid or stearic acid and butyl carbitol [2-(2-butoxyethoxy) ethanol]. A portion of the carbon delivered to the system must be in the form of a microemulsion external phase to ensure delivery of the other ingredients within the oil/water interface. This combination of constituents yields optimum results from readily available, safe and cost-effective ingredients.  
         [0016]      FIG. 1  is a table of physical constants showing the non-toxic and non-flammable characteristics of the individual component ingredients and composite materials making up a representative, but not limitative, composition according to the invention. The data in  FIG. 1  is extracted from “The Condensed Chemical Dictionary, 9 th  Edition,” 1977 Van Nostrand Reinhold Co., New York, N.Y. and the flashpoint of the composite materials was determined using a Pensky-Martens Closed Tester, pursuant to ASTM Standard 93. The composite material is non toxic as defined by the reporting requirements of Section 313 Title III of SARA (Superfund Amendments and Reauthorization Act of 1986) and non-flammable with a flash point above the current standard for flammability (100° F.).  
         [0017]     The amount of carbon and ester-containing material can be varied in the product to achieve successful results. For instance, compositions having from about 15 to about 65 weight percent carbon and from less than 1 to about 40 weight percent ester have proven effective. Diluent/stabilizer levels may range from about 10 to about 50 weight percent. In a presently preferred embodiment, the total carbon is 32 weight percent, the total ester (in the form of phosphorous ester) is 25 weight percent, the total diluent/stabilizer is 20 weight percent and water is present at 23 weight percent. The result of such a composition is a material that is as environmentally sound as the process it facilitates. The instant composition enables rapid emulsification and subsequent agglomeration of petroleum products in water, including soluble and non-soluble hydrocarbons, whereby the agglomerated petroleum may be easily separated and eliminated from the water.  
         [0018]     It can be seen from the foregoing that a novel microemulsion is provided that is effective and safe. The existence of this microemulsion will allow the expansion of agglomeration technologies into significant new markets that were hitherto inaccessible. It will be apparent that the present invention enables a cost effective, environmentally superior approach to one of the most basic environmental challenges facing industry today.  
         [0019]     Although the invention has been described in detail for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention as claimed herein.