SE-76-05-2 -- Alternatives to Mineral Oils

Prior to October, 1973, the search for alternatives to mineral oils had a simple objective: superior performance.

Although mineral oils have served the refrigeration industry quite well, they do have some limitations. For example, they contain wax; they have limited miscibility with polar refrigerants and, they are prone to chemical breakdown at high operating temperatures. During 1974, a fear of a shortage of mineral oils pervaded the industry, and upgrading the capability of refrigerant systems became secondary. The first priority was to keep a plant running, and a search began towards finding any alternative which would function in existing refrigerant systems. Today, partly due to economic conditions and partly due to steps towards oil conservation, there is no fear of a shortage of mineral oils, and once again we are looking for superior performance.

Yet, memories linger. The question most often asked is, IIIf there were to be a real shortage of mineral oils, are there any established alternatives!1I Industry consensus is that researchers should utilize the current pause and search not merely for those alternatives capable of superior performance but also for those which would be equivalent to and for that matter even marginally inferior to current mineral oils. In other words, now is the time to build up a data bank on alternatives to mineral oils which industry can draw upon in all kinds of situations.

It is hoped that this paper will prod the oil chemists to do just that. Towards that goal, I will discuss the feasibility of oil-free compressors, lubricated by refrigerant vapor or by solid-films, and I will discuss the current status of those enigmatic fluids--the synthetic oils.