ULSD oxidative stability

[Milutin]

Hi all,

Recently we faced problem with ULSD oxidative stability in our product tanks. We see this problem for first time.
ULSD is produced on HDS unit, from SR light gas oil and we add additive for lubricity, based on fatty acid esters.
Does overdosing of this additive can cause stability problem?

Regards,

Milutin

 

[consilience1]

Dear Milutin

One of my collegue who is responsible for off-site such as additives for gasoline and diesel said that it could be possibe when some additives is unstable by oxidative environment especially there is agitating or air bubbling.
After he changed Detergent and WAFI into new one, reaction was made into antifoam with Si component in the Detergent.
Actually, they used to be added in diesel, however, it was the first time to happen, so we believe reaction can be occured in the combination aomong the specific components in the additives.

Regards,

Consilence1

 

[25362]

Milutin,

When you say stability do you mean low temperature stability ? I've read that there are some oleates that aren't recommended below +10 deg C. Better ask the supplier about their recommendations.

 

[Milutin]

Hi consilience1 and 25362,

Oxidative stability is determined by ASTM D2274. Our average value for oxidative stability is about 8mg/L.

When problem appeared we intensified lab analysis, results were in very broad range like 45, 62, 102mg/L.
Because there where no changes in feed and process, lab was other area of investigation, we send samples to other laboratory and get results about 4-6mg/L.
It turned out that diesel oxidative stability was OK but lab had some troubles during performing oxidative stability tests.


Regards,


Milutin