RESIDUAL FUEL OIL

Residual fuel oil is the fuel oil that is manufactured from the distillation residuum, and the term includes all residual fuel oils, including fuel oil obtained by visbreaking as well as by blending residual products from other operations. The significance of the measured properties of residual fuel oil is dependent to a large extent on the ultimate uses of the fuel oil. Important specifications for residual fuel oils are the viscosity and sulfur content, although limits for flash point, pour point, water and sediment, and ash production must be monitored. Test methods of interest for hydrocarbon analysis of residual fuel oil include tests that measure physical properties such as elemental analysis, density, refractive index, molecular weight, and boiling range. Contamination in residual fuel oil may be indicated by the presence of excessive amounts of water, emulsions, and inorganic material such as sand and rust.