Fuels in storage and bunkering:
Though many fuels are blended, only some fuels are blended during bunkering, the rest will have been blended into storage and then sampled and analysed prior to bunkering. Some will be still be supplied as straight run residual fuels.
In this section the comments on fuel management mostly also apply to fuels that will be used as components for blending and they will als apply to loading barges and bunkering vessels.
In this section the concern is with fuels that are bunkered and a bunker fuel quality certificate supplied which has been produced from sample analysis. This analysis may have been produced by the refiner or it may be the result of samples taken by the immediate supplier from the fuel in storage.
Considering that as much as 65% of fuel supplied is imported or blended from imported fuels, some care must be taken to ensure that the refiners certificate is still valid or else a new sample must betaken and a fresh analysis provided; the longer the supply chain and the more fuel transfers that have taken place from refinery to storage, to tanker and transit etc., the more opportunities for the fuel quality to have been compromised.
Today it makes more sense to monitor the fuel quality at each transfer using the Integrity system to test the validity of the certificates and, if necessary, to take fresh samples for analysis.
Fuel Management in storage is a key to the resolution of many quality problems:
Fuel may be transferred from one tank to another, transferred to barges for delivery or to mixing processes or simply retained in storage until required.
It is in storage that many problems originate.
In each of these cases the INtegrity solution is to use the digital viscometer to monitor fuel conditions and to use the “fuel fingerprint” method to match the fuel to a fuel analysis.
For each storage tank there will be an associated fuel analysis. That reports the density and viscosity as well as the other properties. Integrity tests the density and viscosity values of the fuel against the certificate.
Changes in practice:
For some suppliers there will be no significant changes in how they handle fuels but for other suppliers some changes are needed to stay competitive and supply demonstrably compliant fuels.
Fuels will stratify and they may tend to separate over time.
One supplier using static storage and consolidating different batches together discovered that the “380cst” fuel in storage had stratified into 450cst fuel at the bottom and 150cst fuel at the top.
Hence the fuels drawn from the tank could not be guaranteed as ISO 8217 compliant fuels.
For MARPOL it is not possible with this system to provide an exact density or an exact sulphur content and especially if different batches of fuel have been consolidated together in the same tank.
Fuels in storage should be maintained homogenous and, if consolidating fuel stocks, it is essential to ensure they are compatible and then homogenise the fuels together. The resultant fuel must then be sampled and analysed before transferring fuel out of the tank.
In Tank Monitoring:
It is not necessarily practicable to measure the quality or homogeneity of the fuel within the tank.
The diagram (right) illustrates a simple arrangement of the INtegrity viscometer to continuously monitor fuel quality.
The “Fuel Fingerprint” will match the fuel to its analysis and validate the fuel when subsequently transferred or bunkered.
INtegrity software will manage a number of such tanks and collate the fuel analyses with the appropriate tank contents.
Most importantly, when any transfer occurs, the program will automatically identify the fuel by selecting the appropriate certificate or comparing to the certified analysis for the fuel held in that tank.
All deficiencies will initiate an alarm. All data is logged.
To find out more, contact Razaghi Meyer International. Please use the drop down menu to see how Integrity aids in other supplier operations.
|Bunkering Pretested Fuels|
|Bunkering Batch Blended Fuels|
|Bunkering Inline Blended Fuels|