![Image for illustrative purposes a table with a glass jug of oil and a spoon full of nuts against a field and blue sky background](/images/2023/News_/chris_kenney_main.jpg)
GREEN INSULATING OILS
In this month’s issue of Transformer Technology, there is a well-informed podcast presentation on the current state of power transformer insulating fluids. This included, among other topics, their availability and technical aspects. The major suppliers of these fluids were all contributors to the presentation. It also includes a question-and-answer segment at the end. A short recap of the products discussed were hydrocarbon naphthenic-based oils as well as natural ester vegetable oil-based fluids. To drill down a little deeper as to the availability of hydrocarbon type fluids, we should mention a paraffinic chemical composition type of hydrocarbon fluid is also marketed to the transformer industry. Ester fluids can be obtained as either a natural ester derived from seed oils such as soy, canola, rapeseed, sunflower etc. The synthetic esters are derived from a selection of alcohols and acids through a chemical reaction of esterification.
If we look at these products strictly from a marketplace use perspective, hydrocarbon naphthenic-based oil type and natural soy ester fluids comprise most oils used to fill power transformers. If we segment naphthenic-based oils and esters, I will estimate the hydrocarbons fill out approximately 98% of the market.
If we look at these products strictly from a marketplace use perspective, hydrocarbon naphthenic-based oil type and natural soy ester fluids comprise most oils used to fill power transformers.
We can say a few words about paraffin-based fluids, their characteristics, and ultimately why they lag so far behind naphthenic-based oil products among users. Paraffin-based oils make excellent insulating oils. Paraffin-based oils, because of their natural chemical composition, are in some ways superior to the naphthenic oils. Paraffin-based oils are the overwhelming choice to blend almost all lubricant formulations. 50% of the lubricant market in the US falls into the motor oil category. Apart for synthetic motor oil formulations, paraffin-based oils are 100% exclusively specified as the preferred base stock. Many of the technical aspects of paraffin-based oils, primarily oxidation stability, translate well when used as a transformer oil. The current technology used to make current generation motor oil is known as hydrocracking. Hydrocracking produces low pour points, very low Sulphur, and aromatic content, as well as low polynuclear hydrocarbons, which are considered hazardous to people’s health. They require no passivators when blending transformer oils to make type 1 or 2 transformer oils. In many ways, they check all the boxes when it comes to specifying a clean, non-toxic insulating oil, as they also meet FDA 178-3620 incidental food contact requirements. Amidst all this, they have failed to make any dent in the macro market consumption percentage, because the pricing of these products is simply not competitive with their cousin, naphthenic-based oils. This price question will come up again when we talk about the ester products. It is not that the marketers of paraffin-based oil insulation fluids have not tried to make their case as to the value add of these oils. They have. I have personal experience going down this road. It is just the value proposition has been inadequate to make many potential customers make the switch to the higher priced product.
Paraffin-based oils make excellent insulating oils. Paraffin-based oils, because of their natural chemical composition, are in some ways superior to the naphthenic oils.
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The natural ester product has run into the same resistance in the marketplace as the paraffin-based oil. The natural soy ester fluids exhibit chemical properties when subjected to ASTM 3487 requirements and show them to be excellent candidates to make power transformer insulating fluids. They especially shine when it comes to flash and fire point. The natural soy ester material has a flashpoint of 330°C and a fire point of 360°C. The naphthenic-based oil has a flash point of 145°C and a fire point of 160°C. They can also boast of being biodegradable and rated non-hazardous in soil and water. Mineral oil is not readily biodegradable and has the potential for toxicity. Natural soy ester fluids do not exhibit sludge formation. Mineral oils, when subjected to overheating, begin to oxidize. This oxidation causes a buildup of acids which will lead to sludge formation and eventually begin to destroy the cellulose inside the transformer. The synthetic ester oils are used in much lower quantity than the natural vegetable seed oil product. They are also much more expensive than the natural ester. They have a more specialized application field as well: marine transformers, underground transformers, and rail and traction transformers. As it stands today, only one producer of natural soy ester oil supplies the American market. This presents a difficulty for other companies which might want to enter this market. The distribution and medium power oil insulated transformer manufactures who use this product by application will have one tank from which to feed their plant fill. Currently, as far as I can tell, the ester product is not being used in any large power transformer field fills. I am not making any technical claims as to why this is true. I am involved in the sale and marketing of insulation fluids to the North American field fill market. My company represents the mineral oil products, as well as a new entry into the natural soy ester insulating fluid market. I simply see no demand in the substation type large power transformer space for ester fluids.
The natural soy ester fluids exhibit chemical properties when subjected to ASTM 3487 requirements and show them to be excellent candidates to make power transformer insulating fluids.
Lastly, we can talk a little more about the who, why and where of these various fluids and what the future holds for them in the future. We are all aware of the scientific and cultural demands for heavy industry and consumer products in the transition to a green economy. Mostly this revolves around climate change. I’m not a scientist, but I am aware of some of the conflicting claims entered by the proponents both for and against the path to follow to achieve such a monumental task. As pertains to transformer oils, the effort to replace hydrocarbons as insulating fluids has been affected by this movement as well… but with little success. As I mentioned earlier, naphthenic-based oils fulfill approximately 98% of the macro market for new power transformer fill. The green ester products have made some inroads, but is very small sliver of the market. The esters, as I have said, make excellent insulating oils. One of characteristics most often mentioned is their high flash and fire points. Their biodegradability is often touted as one their most important benefits. These benefits are real and can, in those cases where relevant, make a big difference in an outcome where a potential fire or explosion would take place. I suppose the question should be what is the incidence of this occurrence? According to T@D World, the average probability of a serious transformer fire is on the order of 0.06% and 0.1% per service year, or one fire per 1000 to 1500 transformer service years.
Thankfully, large power transformer fires are rare. The high price of ester transformer fluid like paraffin-based oil transformer fluids when compared to green benefits is slowing the sales and usage of these fluids. The other consideration is the fact that the acceptance specifications for transformer oils have been established over the years to accommodate the hydrocarbon mineral oil products.They are what they are because the standards committees who have established the specifications have agreed they were adequate to fulfill the demands of transformer operating conditions to insure a long and trouble-free life. The green and technical data used to promote the higher price has not proven to cause a large industry-wide migration to the green product slate. It must be noted a major manufacturer of both natural and synthetic ester insulation fluids recently sold this segment of their business to a major oil company.
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I believe green products, where applicable, should always be the first choice to insure a safe environment for us all to live in. By the same token, they must be able to compete value-wise with the products they replace.
I believe green products, where applicable, should always be the first choice to insure a safe environment for us all to live in. By the same token, they must be able to compete value-wise with the products they replace. It seems at the present time the dominant fluid will be the naphthenic-based oil hydrocarbon. Until competing products, be they other hydrocarbon-based oil fluids, or natural or synthetic ester prices come more in line with conventional hydrocarbon fluids, the transition to green products will remain slow.
![Image](/images/2023/12/28/chris-kenney.jpg)
Chris Kenney spent the majority of his time in the refining industry in the sales and marketing of specialty hydrocarbon fluids, more specifically in transformer oil sales. Chris has worked in sales and sales management with Ergon Refining, Cross Oil, Petro Canada and Calumet Specialty Products. In all these assignments, he was at the forefront in business development roles dedicated to developing net new transformer oil market share. Chris is an expert in the technical aspects of both naphthenic and paraffinic transformer oils and has established worldwide contacts in the power transformer industry and US utility industry. Chris holds a Bachelor of Arts from St. Joseph’s University, and currently resides in Acworth, GA with his wife Karen. Chris is available for either full, or part-time consultation arrangements regarding the sales and marketing of transformer oils.