Heavy Fuel Oil Has Changed in Quality and Quantity

In many of the world's crude reservoirs running out of sweet light crude, refineries increasingly are required to refine heavier sour crude oil that contains a larger amount of impurities, including significantly higher quantities of asphaltenes. The viscosity and density are also greatly increased. The residual oil (refinery residue) is that is converted into heavy fuel oil has changed in quality and quantity. The heavy fraction in the fuel, which consists mainly of asphaltenes, presents problems when is used as burner fuel. This fraction represents a significant caloric value, which can be utilized after treatment. Homogenization of the heavy fuel greatly improves the burning efficiency and can reduce exhaust emissions such as NOx and SOx. This is accomplished by a specialized fuel-homogenizing Allen Oil Filtration System. Asphaltenes consist primarily of carbon, hydrogen, nitrogen, oxygen, and sulfur, as well as trace amounts of vanadium and nickel. They constitute the non-volatile, high molecular weight fraction of petroleum. They are non-soluble and as a consequence they remain in solid form in the crude. They have the tendency to be attracted towards each other thus resulting in the formation of an agglomeration. The structure of the agglomeration is similar to that of a book: a compact stack of thin sheets. Asphaltenes which exist in crudes in a dispersed state are kept in this condition by resins. Asphaltenes have been shown to have a distribution of molecular masses in the range of 400 up to 1500 micron with an average of around 750 micron. They have several characteristics that make them problematic to a fuel system: They constitute the largest aromatic fraction in petroleum as well as being the highest molecular weight component. They have no definite melting point and therefore remain in solid form thus contributing to carbon residue. Asphaltenes are not crystallized and cannot be separated into individual components or narrow fractions. The color of crude oils and residues is due to the combined effect of neutral resins and asphaltenes. The molecular weight of asphaltenes is very high, ranging from 1,000 to 2,000,000, depending on the type of crude and the source of the reservoir. Asphaltene dispersants are used to destabilize the natural resins and will keep the asphaltenes evenly distributed by preventing their aggregation. Dispersants will break up the asphaltene molecules in the fuel system and convert them to stable colloidal suspensions. The photograph above shows the effect of an asphaltene dispersant when added to a heavy crude compared to crude with a dispersant added. The result of the additive is a homogeneous mixture where the asphaltenes a more evenly dispersed. Applications of the Additive: Additive is a dispersant/stabilizer and a combustion catalyst that keeps the fuel system clean and improves combustion of the fuel, The dispersant prevents the asphaltenes from from agglomerating, which reduces sludge formation, Complete dispersion of asphaltenes improves fuel injection, atomization and combustion efficiency, The dispersant keeps the fuel mixture more homogeneous, eliminates stratification and reduces fuel compatibility problems, Reduces injector and burner tip fouling, carbon deposits on pistons and rings, smoke and soot emissions, caused by incomplete combustion, Soluble in all fuels. Normal dosage is 1 part additive to 10,000 parts fuel. Source: allenfiltersinc.com