Research Associate, Exxon Research and Engineering Co., Linden, NJ
Senior engineering associate, Exxon Research and Engineering Co., Linden, NJ
Pages: 21 Published: Jan 1985
Residual fuel oils which contain thermally cracked residual components may become incompatible, especially when blended with distillate to make intermediate fuels. When this occurs, asphaltenes precipitate from the fuel and interfere with the proper operation of shipboard centrifuge and fuel handling systems. A study to determine the cause of incompatibility and how to avoid it revealed that asphaltene solubility in fuel oil could be described by general solubility relationships. From these relationships, factors were derived to characterize the relative solubility of the asphaltenes and the solvency of the nonasphaltene portions of the fuel. These factors can be determined by simple analytical procedures.
A semiempirical relationship has been developed between the factor for asphaltene solubility and that for nonasphaltene solvency that predicts whether any asphaltenes will precipitate as sediment, that is, whether a fuel will be compatible. Procedures also have been developed for blending these factors when two components are mixed. Thus, it is possible to predict whether a given blend of two fuel oils or of fuel oil and flux will be compatible based on the properties of the components and their ratio in the blend. This relationship has been used to ensure that fuel oil blends will not contain sediment, that these blends can be used to make sediment-free intermediate fuels, and that the fuels will not be incompatible with other fuels when they are commingled in storage.
residual fuel oils, compatibility, marine intermediate fuels, hot filtration sediment
Paper ID: STP35281S