The standards proposed for the production of vegetable oils used as electricity transformer oil are “unnecessary”, and prevent the inclusion of smaller producers who stand to benefit the most and create the greatest number of new employment opportunities, says retired chemical engineer John Fletcher.

State-owned power utility Eskom and public investment body the Industrial Development Corporation (IDC) agreed in October to develop a supply chain to produce vegetable-oil-based transformer oils. Eskom noted that such ester oils were widely produced and used in other countries.

Fletcher says the proprietary additives and refining techniques proposed by the memorandum of agreement between Eskom and the IDC are unnecessarily restrictive and will stifle the creation of new entrants and new suppliers.

He avers that the proposed proprietary licensing model for the production of ester oils will entrench the current market structure and increase the dominance of large, established suppliers.

Fletcher says there are well-established refining methods that can produce the necessary ester oils without the use of proprietary additives or processes.

New technical standards would “distort” the application of the technically reliable standards for transformer ester oils – which also apply to base mineral transformer oils – used for cooling purposes in transformers, he adds.

“The process of manufacture must not be confused with the issue of intellectual property. There is no need to alter existing and adequately proven technical standards.”

Vegetable oils, such as palm or pumpkin seed oils, have a common chemical construction: a straight chain of single carbon-to-carbon atoms. The difference arises in the number of double-bond, carbon-to-carbon links, sometimes up to three or four, and their position along the chain.

These unsaturated links are chemically reactive and are the means through which vegetable oils can be rendered virtually identical to other vegetable oils. Therefore, ease of farming and market price determine the choice of vegetable oil for transformers.

“Most vegetable oils can be converted into transformer ester oils using basic chemistry, as these oils have common physical and chemical properties that not only meet but also exceed the equivalent properties of base mineral oils. The reaction can be carried out reliably with simple equipment that is economically suited to smaller producers,” emphasises Fletcher.

Other chemical functional groups can be introduced at the double-bond positions; therefore, a technique can be proprietary without offering any improvement.

“However, no further research is needed to produce an acceptable and reliable ester oil and there is no need to rely on proprietary processes or additives,” he avers.

Base mineral oil is inexpensive, compared with ester transformer oils. Therefore, most transformers will continue to be filled with mineral oil, except under demanding conditions where the need for ester transformer oils can be justified.

Subsequently, demand for ester oils will be slow and will not justify a large factory and the proposed vast agricultural activity will therefore not be commercially viable.

If the purpose is to create jobs, it is possible to grow plants that will yield oils suitable for conversion or biodiesel production in small factories, concludes Fletcher.