Density Measurement of Bunker Fuels

By Dr. Sunil Kumar

Density is one of the most important physical properties in the characterisation of bunker fuels. It also has an influence on other properties such as ignition quality and specific energy of the fuel. Accurate and precise determination of density is therefore important in the characterization of fuel for various applications. It is a parameter which has an impact on assessing the quality of the fuel and which has a significant impact on bunker fuel delivery quantity calculations at measured temperatures. Since bunker fuels are ordered by weight but measured upon delivery by volume, density measurement is the parameter which enables the correct and accurate determination of the quantity of bunker fuel deliveries. Veritas Petroleum Services tracks density differences for our customers during bunker fuel deliveries and see a clear bias for overstating density on bunker delivery notes, leading to fuel delivery shortages.
The composition of a fuel has an influence on the determination of density. Composi tional factors such as the presence of high concentration of waxes, asphaltenes and incompatible nature of a fuel, makes the measurement sometimes lead to erroneous results. The tendency of a fuel to retain water molecules in an emulsified form, where water cannot be separated also has an impact on the accurate determination of density. Measurement devices and their calibration accuracies do matter, especially as density is a temperature dependent property. There are various International standard methods available to measure the density of fuels. The purpose of this article is to assess how well these methods correlate.

Read the full article here