|Standard test for Total Sediment Potential: ISO 10307-2|
Often identified by sludging in a blended product, is principally caused by an incompatibility between components and blends, a number of hydro-carbons no matter what the ratio just do not mix. This often arises from the limited solving capacity for certain hydro-carbons like asphaltenes that form as the hydro-carbon residue during the conversion processes. The semi-stable balance of these residues are unbalanced by blending with low solubility components (especially paraffinic or less aromatic diluents) and a sludge will form. This can settle in tanks, clog pre-heaters, transfer lines, valves and filters. The sludge will eventually overwhelm seperators.
Therefore, the capacity of the fuel treatment system to handle TSC’s (Total Sediment Content) approaching or breaching the upper levels of ISO standards is paramount. Cleaning the tanks in the next port is essential.
- Blending the unstable product with marine Diesel oil will only aggravate matters due to its paraffinic characteristics.
- Drain as much sludge as possible from the settling tanks in short intervals running also in short intervals both separators in parallel as purifiers.
If the sedimentation is too much for the fuel treatment system, disposing of the out of spec fuel at the next port is unavoidable.