Certain microbiological problems may arise with respect to the storage and transportation of hydrocarbonaceous products. Hydrocarbons can act as a nutrient for microorganisms; therefore, hydrocarbonaceous products (i.e., fuels such as jet fuel, diesel fuel, naphtha; lubes, and solvents) can be attacked by microorganisms. Microorganisms can slowly grow at the boundary layers of the hydrocarbonaceous product and air, and can grow more rapidly if the hydrocarbonaceous product is also exposed to a layer of water.
Hydrocarbonaceous products are frequently exposed to a layer of water when stored in large storage vessels, such as storage tanks, fuel tanks of aircraft and holds of tankers. In these large storage vessels, water invariably forms due to condensation or it is initially present in the stored hydrocarbonaceous product and slowly separates therefrom. This water gradually forms a layer in the bottom of the storage vessels. The water layer forms an interface with the hydrocarbonaceous product, and becomes a breeding ground for a wide variety of microorganisms. These microorganisms utilize the hydrocarbonaceous product as a nutrient and can multiply.
Eventually the microorganisms can consume a large portion of the hydrocarbonaceous product. The extent to which the microorganisms consume the product is known as the extent of biodegradation, or the biodegradability of the product.
The microorganisms or microbes will grow mostly in the water phase, but when the hydrocarbonaceous product is disturbed during pumping or mixing, the microbes can be dispersed into the hydrocarbonaceous product and cause contamination. When present in the hydrocarbonaceous product, microbial growth can present a problem for several reasons. For example, hydrocarbonaceous products may become contaminated with microbes during storage or shipment and as a result of the microbes, become hazy or cloudy. The growing microorganisms may form sludge in the contaminated hydrocarbonaceous product. When contaminated hydrocarbonaceous products are used in an engine or equipment, the microbes and/or the sludge may decrease the efficiency of the engine or equipment or prevent it from functioning altogether, for example, by plugging filters. In addition, growth of microorganisms, in particular anaerobic sulfate reducing bacteria, in hydrocarbonaceous products during storage or transport may create corrosive sulfur-containing acids and damage the vessels in which the products are contained. This corrosion damage may lead to the need for eventual replacement of these large, expensive vessels.
Further, transport of hydrocarbonaceous products and/or a water layer contaminated with microbes creates a dispersal mechanism for human pathogens, waterborne diseases of plants and animals, and foreign organisms into the environment. For example, infectious bacteria such as cholera have been found in ballast water from marine tankers (“Global Spread of Microorganisms By Ships,” Brief Communications Nov. 2, 2000 issue of Nature). These infectious organisms can create both a human health problem, and a health problem to native species in the receiving country. Water can also be the vehicle for the introduction of foreign higher life forms into the receiving countries' environment. By this route, Zebra clams are believed to have been introduced into the San Francisco Bay region.
There is a need for hydrocarbonaceous products comprising rapidly biodegradable hydrocarbonaceous products that are capable of resisting visible growth of microorganisms and methods of inhibiting the growth and reproduction of microorganisms in rapidly biodegradable hydrocarbonaceous products, containing minor amounts of aqueous liquids.
USPTO Backgrounds
USPTO Backgrounds