Technical Discussion
- 200 MT IFO 380 cSt out of specifications
- Goran Jonsson
Pacific Petroleum Ltd.
GMT 10:38
11th Jul 2007200 MT IFO 380 cSt out of specifications causing severe deposits on fuel injectors, piston crown and piston ring seats.
One bulk carrier reported severe problems coming from bunkering a “bad quality” out of spec IFO 380 cSt HFO.
The management company had the fuel analyzed and decided to contact a major international fuel additive supplier for help. After assurance that the problem will be solved by using their product the additive was blended into the bad fuel.
The chief engineer reported after a few days that the additive had no effect what so ever and the previous problems still existed.
The management company contacted a second major additive supplier, and the same happened, no result what so ever.
As a final alternative before eventual de-bunkering the management company contacted our company, and provided a copy of the fuel analyze.
We recommended adding PP3-F Fuel oil treatment with a doze 2 lit. /MT bad fuel into the main bunker tank. Thereafter to leave the fuel for minimum 3 days for the additive to dissolve the petroleum based sediments, and separate the water from the fuel to settle at the bottom of the tank.
The chief engineer reported the following day that all the water was separated so also the remaining of the solid sediments. Therefore he decided to use the bad fuel for a few days as a practical test.
The result was that the engine now performed normally, with no visual deposits on the piston rings and no increase of black smoke.
As a final safety measure he blended the bad fuel with good fuel 50/50 and the total volume was in this way consumed without any more technical problems.
Our PP3-F has a very strong detergent effect to any petroleum based fuel-sludge or sediments.
It also separate water from the fuel to settle in the bottom of the fuel tank so it can be removed quite easy. If you ever run in to a similar case send us a description of the problem or a copy of the fuel analyze and we will give you our advice how the problem eventually can be solved.
A copy of the fuel analyze from the above described case can be obtained from our office.
Goran Jonsson
Pacific Petroleum Ltd
July 2007
additive@otenet.gr
www.pacificpetroleum.gr
- Jon Watson
Razaghi Meyer International
GMT 13:09
6th Aug 2007
IP: x.x.163.183Out of curiosity, how did the fuel analysis compare to the suppliers original specified quality?
Was the fuel supplied with an "exact value" report of its properties, a "typical values" report or "less than" reported properties?
I ask because it is apparent that even with ex-pipe from refineries, the fuel properties might be reported as "typical values" rather than the exact values that one might suspect are required by MARPOL, i.e. the exact values of density and sulphur are not reported, nor the viscosity.
I would, in particular, be interested to know how the density and viscosity of the analysis compared with the original values. - Goran Jonsson
Pacific Petroleum Ltd.
GMT 06:10
7th Aug 2007
IP: x.x.235.85Dear Sir.
We don’t have the information you requested but can just assume that the values given to the vessel was within the specifications.
The reality was however different. I have included the analyze result from the fuel laboratory.
Best regards
Goran Jonsson. - Goran Jonsson
Pacific Petroleum Ltd.
GMT 06:12
7th Aug 2007
IP: x.x.235.85 - Thanks for publishing the quality data.
It was interesting to note the viscosity and density values.
Statistically, (based on analyses of fuels against the previous ISO 8217) if the density and viscosity are within specification then the chance of the fuel not being compliant were about 0.7%.
It would be interesting to see how such data develops for the new standard now that it includes marker properties for used lubes and now that MARPOL Annex VI is said to probably result in more high density cutters being used in blending.
Why density and viscosity? because these two parameters are very easy to measure continuously and in real time online as the fuel is being bunkered and as it is being burnt.
More important than the statistical probabilities of compliance is that for any bunker received today there should now be a fuel analysis report and not just a certificate of conformity.
If the analysis shows the fuel to be acceptable then the density and viscosity measured as it is bunkered would show no significant difference from the density and viscosity quoted on the certificate (959.0 kg/m3 and 171.6cst in the analysis you provided) since most mechanisms by which fuel quality is corrupted would most probably show a change in these values, e.g. separation, adulteration with water, waste chemicals etc.
It would be simple to note such a difference in density or viscosity and to know instantly that the fuel bunkered is ot adequately described by the certificate.
Also, online measurement would reveal if the fuel is homogeneous and if it is entrained with air.
If not during bunkering?
Many more vessels now have digital viscometers for their fuel oil heater control so the density at 15degC and viscosity at 100degC can also be monitored at the engine and again compared with the certificates to detect if the fuel has been degraded aboard the vessel.
No change in the density and viscosity does not 100% show that the fuel is exactly as described and in all particulars, but there it is a "reasonable" assumption to make and these are measurements that are already available at the engine and better use could be made of them.
One would like to think that because the density and viscosity are a simple fingerprint of the fuel and because density is such an important parameter not just because it affects the energy content and the ability to centrifuge the fuel effectively but because it is used to calculate how much fuel has been bunkered, (it is a significant factor in many disputes) that monitoring the density and viscosity would be a reasonable exercise in any event and would help avoid bunkering bad fuels.
Hence, in this case, it would have been helpful to compare the analysis made with the original fuel certificate to determine if there was a density and/or viscosity difference that could have alerted the operators that the fuel certificate was representative of the fuel or not.
