CO2 and oil

Happy 2013 to you all!
My happy new year starts with a story from a client who had some broken compressors and the question how that could happen.
We are talking a NH3/CO2 cascade system. CO2 is pumped from the CO2 reciever to the -10C clients and to the -40C separator. From there the CO2 is pumped to the -40C clients and to the compressors. CO2 from the separator is compressed by Sabroe HPC104S and HPC106S compressors. A separate NH3 system cools the CO2 in the condenser and the condensate falls back into the CO2 reciever.

The CO2 system was originally charged with PAO 68, later changed for EMKARATE RL- 32 H, than replaced by FUCHS RENISO C 85 E an finely re-charged with STAR POE.

That made me realized how little I know about all those oils that are on the market and how they deal with CO2.
I've heart scary tales about changing stratification depending temperature and the like.....
I can't even find basic spec's from all these oils e.g. solvability and miscibility.

So I would like to know all about these oils, the tricks and loopholes and when/why I should use or not use them.

Nico.

I found few words about oil and CO2 in an EU sponsored paper
Very interesting study about both sub and trans-critical CO2 ref. systems
http://www.irefrigeration.eu/nareco2...anual_2009.pdf
page 376-381 is all about oil
The writer also says that oil data is very hard to find.
Is there anyone with data for these oils, users, salespeople or people working for these oil firms?

Attachment 9886
Hi Nico,

the right oil was Fuchs C85E. Bitzer, Grasso and Sabroe reciprocating compressors are using this oil.....and only this one.
Screws are using Fuchs C170E. C oils are designed for CO2.
sorry about the document, it's in French

kind regards

Thanks Cricri.
I found someone from Fuchs and requested spec's for there oil in English.
The same for the Star POE which seem to come from PetroBrandGlobal
EMKARATE RL- 32 H seems to come from ICI, but I have no idea how to contact them.
Anybody with contact address or better a short line?