Difficulties arise in pumping and/or transporting petroleum fuel or crude oil through flow lines, valves, and pumps in cold climate. Paraffin hydrocarbon waxes naturally occur in many crude oils and are particularly problematic at lower temperatures and in colder climates. As the temperature drops and approaches the crude oil's pour point, such waxes tend to precipitate and crystallize, causing the oil to lose its fluidity.
Various additives, known as pour point depressants, have been developed to reduce pour points in petroleum fuels and crude oils. (Pour point is defined by the ASTM D-97 as “the lowest temperature at which the crude oil will still flow when it is held in a pour point tube at ninety degrees to the upright for five seconds.”) Further, paraffin inhibitors have been developed which retard the formation of paraffin deposits.
Many of the pour point depressants and paraffin inhibitors that are presently available solidify at temperatures ranging from −5° C. to 60° C. Such systems are not particularly useful in the field at cold temperatures or under winter conditions. Alternatives have therefore been sought for reducing pour points in hydrocarbon fluids as well as inhibiting or retarding paraffin deposits.
USPTO Backgrounds
USPTO Backgrounds