Gas Solubility in Oils
Gas Solubility in Oils
(OP)
Can anybody point me in the way of data on gas solubility in lubricating oils (ISO VG 20-30 grades say). What I am particularly interested in is the solubility of Nitrogen and the relationship between solubilty and temperature. I had always assumed that as temperature increased gas solubility decreased, but apparently there are exceptions to this rule.





RE: Gas Solubility in Oils
RE: Gas Solubility in Oils
Books tabulate the Ostwald coefficient C, i.e., the ratio of volume of dissolved gas to volumen of liquid solvent at given T,P.
For nitrogen in hydrocarbon oils at 273K, C=0.075.
The temperature dependence of C can be assessed by the following formula:
CT=0.3*e[(0.639(700-T)/T]ln(3.333C)
If you take the ln on both sides it'd become easier to understand the effect of absolute temperature T(K) changes.
Formulated lubes may show a bit different behaviour due to the chemistry of the additives. Same could be said concerning some synthetic lubricants.
RE: Gas Solubility in Oils
RE: Gas Solubility in Oils
RE: Gas Solubility in Oils
RE: Gas Solubility in Oils
We are measure dependence of gas in transformer oil solubolity mainly for the headspace application. The Henry law is obeyed, in the way that increasing the pressure will lower the gas concentration in gas phase. This is not appeear in the standart (ASTM) deal with this technique.
A paper is prepared