2 replies to this topic

[mehran95]

Hey there. 

 

I m working in a refinery as a planning engineer. I m responsible of middle distillates planning. During winter we produce diesel meeting EN590 specifications for winter. Meaning that we have CFPP values lower than -15 C. Recently some clients came up with the gelling problem for of diesel from gas stations. They sent the images and I attached them. From images one can see great amount of gel/wax deposited bottom of the containers. Additionally ambient temperatures in this regions did not go below -5 C. So I m wondering what can be the cause of this gelling. We have 70% diesel hydrotreated from crude unit and 30% kerosen blended which also is hydrotreated from crude unit. I would be thankful if u share any thoughts on this . Thanks in advance .

 

Attached Files

•  diesel gelling 2.jpg   32.41KB   1 downloads
•  Diesel gelling 1.jpg   49.72KB   0 downloads

Edited by mehran95, 22 February 2021 - 08:07 AM.

[PingPong]

First you should check with your laboratory whether the CFPP (and other specs) of that batch of diesel were properly analysed.

Ask them to prove that with the correct paper work.

 

If so check whether your lab is doing the CFPP test properly. Get a copy of the procedure and ask the responsible analyst to perform the test while you watch and verify that the procedure is done correctly.

You can subsequently put a bottle of that diesel in a dark place at low temperature for a week or so and check again.

 

If nothing went wrong on your side and your diesel definitely matched CFPP of -15 ^oC when you delivered it to the client, then ask the client to prove that the diesel as they received it did not meet the CFPP of -15 ^oC.

Did they analyse it immediately after they received it?

If so, what CFPP did they measure? Did it meet the -15 ^oC spec?

If not, why did they not contact you immediately?

If it did meet the specs, why are they complaining?

 

You have no control over your diesel anymore as soon as they start handling it. They could have mixed it with other diesel, or whatever, or stored it in a tank that is also used for other products like VGO, and so cause the problem.

 

The client has to prove that your diesel does not meet the CFPP spec. To do that they should measure it immediately after they receive it. Gel at the bottom of a tank much later is no prove of anything.

Edited by PingPong, 22 February 2021 - 03:03 PM.

[mehran95]

Thanks for detailed comment. We checked samples (sales samples are stored in 4C and dark place for 6 months) and nothing seems problematic. Color is fine and no gelling is observed. For now we clearly see that problem is not in the cargo we loaded. We ll check samples from clients to check the gel in lab and see what can be the origin just to help clients to find out.. I ll update post with findings.