HOW TO PROTECT AGAINST WAX DEPOSIT IN OIL PIPELINE

[nong]

For short pipeline we can heat the oil and insulate the pipe. I understand that the maximum Temp that we can heat is Boiling Point of Oil, right ?
For insulation material, I know the Mineral wool has K=0.038.
Do they have any better insulator ?
Or have the heating medium and heat it through the line, how ?
Thanks,

 

[jmw]

Insulation:
You may want to consider Calcium silicate which is supplied in molded half pipe sections. This is often specified for steam lines and we use it as insulation for our viscosity analysers because we are interested in reducing to an absolute minimum heat loss through the pipe walls.
You may find that a static mixer may help keep the oil homogenised. This may help prevent laminar flow patterns with slower moving oil in contact with the pipe walls starting to run colder than pipecentre flow and hence this may be the flow layer most likely to waxing. So it might help keep the wax in the oil or re-introduce it if it starts to settle out. I don't KNOW that this will work and you should get another opinion on this. Perhaps the manufacturers can help. Companies like Chemineer, Koflo etc.
http:/

http://www.baker.org

has a useful site on mixing.
How hot can you heat an oil?
I would not assume that i could go to the boiling point as a safe top temperature. You may have problems with carbonising the oil, or even cracking it in the pipe! If waxing is the problem then i would suggest that you are only going to want just enough heating to prevent the wax separating. And if you have wax you may have other components that are heat sensitive.

 

[nong]

jmw,
Thanks you very much for yr opinion.

 

[stanier]

The Jackson to Moonie Pipeline in Australia is 1100km long. The crude is a waxy crude with a pour point of 26C. the viscosity below this temperature is 15000 cp. To modify the wax crystal as it came out of solution requires the use of a pour point depressant. The University of Melbourne conducted extensive rheology trials to determine the effectiveness of the chemicals from Petrolite, Treatolite, Esso, Mitsui etc on this particular crude. Suggest you need to get samples of the wax to the chemical companies to determine if it is economical to treat your material.

You may be able to control the deposition by regular pigging of the line using scraper pigs but will need to dispose of the wax to a mixer tank and add the pour point depressant there. you may have a market for the wax but would need to identify a local wax refiner or tallow handler.

Geoff Stone

 

[nong]

stanier,
Thanks very much. I know PPD technology a little bit . From your case I think it's fine for me. How about making emultion ( add water in P/L) and separate again? Emultion can protect against wax deposit ?