Fuel reactions

[Irenicus]

Hi dear reader,

I wasn't sure where to post this so I posted it here and on the chemical forum (hope you guys don't mind). I'm a marine engineer and I have a question about my fuel. Our fuel is following the ISO 8217:2010 standard, which speaks of maximum allowance of fuel contamination. Onboard my vessel we're using HFO.

The iso standard says I'm allowed to have up to 300 ppm of Vanadium in my HFO fuel. Now lets take for this example that the standard consumption of fuel is a constant of 100 m³ per week. If I have fuel of 100 ppm does that mean that the damage caused to my engine take 3 times as long as it would for fuel with 300 ppm of Vanadium?

The expected reaction is high temperature corrosion, especially considering that the exhaust line has temperature of 600°C. Take into account that this is a marine engine so high sodium values in the air can be expected. Now I quote: "sodium vanadyl vanadate 5Na2 O. V2O5 . 11 V2 O5 melts at 545 °C. Liquid deposits formed in this way flux the protective oxide layers on structural alloys, making them vulnerable to rapid corrosion." (ref.

http://www.swcc.gov.sa/files\assets...INDUCED HOT CORROSION OF BOILER TUBES....pdf)

A colleague of mine says the ppm reactions scales logarithmic, but can't explain how and what. Personally this doesn't really sound correct, considering at the end of the 3 weeks, you'll have the same weight of vanadium that went through the engine. The only sense that would make is that perhaps the chemical reactions are caused more often with higher concentrations?

A lot of damage can be expected at my piston crown, turbo charger, exhaust seats & valves and exhaust pipelines, therefor this information is interesting to me. Anybody that knows and can explain the answer to my question? Thanks in advance!

 

[GregLocock]

It's too long since i did chemistry but this might be a place to start

https://en.wikipedia.org/wiki/Rate_law

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[chicopee]

I suspect that the reason for higher concentrations of vanadium in fuels for marine engines is probably due to the fact that marine engines are more robust than non-marine engines and consequently less prone to failures.

 

[Irenicus]

Heh, Chicopee, you clearly did not read the question and to answer your suspicion : there is no proper process to remove vanadium from the crude oil in an economical way. It is an oil-soluble and the amount is dependent on the source of the crude. Venezuelan crude oil for instance is known to have high concentrations of vanadium, therefor the HFO obtained from there almost always has a high ppm of vanadium.