Tuesday, January 23, 2018

candle studies: paraffin, an attempt to distill

It is difficult to draw up a classification of petroleum waxes that could not be subjected to criticism.
And so begins Chapter 5 in The Chemistry and Technology of Waxes (Warth), and, hoo boy, some things do not change. Paraffin (petroleum waxes) and criticism still go together. After reading what Warth had to say about paraffin, I read about paraffin online. For a while my chapter on paraffin was dubbed “Paraffin: The Deadly Dastardly Villain of the Wax World” and/or “Paraffin: The Pariah of All Candles.” (Sarcasm intended.) That so many are so compelled to label paraffin “toxic” reminds me of the story about beeswax and negative ions (that clean the air!) as well as the story about that Christmas bayberry candle putting gold in your pocket. Which is not to say there is no wisp of truth to the matter of paraffin and toxicity.

But talking about paraffin as one distinct product is like talking about soy wax as one distinct product, or, for that matter, cereal or cheese. There are endless permutations. Paraffin can refer to any of the wax that is found in crude oil at any stage it is in as it is refined to one degree or another through one method or another. The various classifications, or grades, of paraffin mainly differ in hardness, oil content, and melting point, all of which lend it to different uses. But, according to my old friend Warth, its characteristics also differ from the get-go.
Pennsylvania and Mid-continent oils contain a high percentage of paraffin wax; California oils are almost wax-free. … Differences in the physical characteristics of the paraffin waxes can often be ascribed to the origin of the crude.
This reminds me of beeswax, as the scent and color of beeswax is directly affected by its origin, specifically by the flora the bees visit. As crude oil is the ancient remains of various organic materials, it makes sense that its specific characteristics would vary by where it is found.

I doubt I fully understand the refinement of crude oil, but it seems basically to involve a lot of distillation, which reminds me of whiskey, and both whiskey and oil are stored in barrels, but perhaps similarities end there. The American Petroleum Institute has on its Website a fairly succinct description (complete with video) of current-day oil refining, but when it comes to refining paraffin, I’ll go back to my old book for a description. (Today’s process, though making more use of solvents, may be similar.)
A wax distillate containing 80 per cent of oil and 20 per cent of wax is distilled over at 315º to 425º (600º to 800º F). This distillate is chilled and pressed to give: slack wax containing somewhat less than 50 per cent of oil and more than 50 per cent of wax; spindle oils with pour point of plus 6º to 7º (20º F). The slack wax is chilled and sweated to form scale wax which contains 1 to 6 per cent of oil, 99 to 94 per cent of wax, and foots oil, made up of lower melting point wax plus oil. The scale wax is then refined to paraffin waxes of different melting points, leaving a slop oil of little or no value.
All this talk of sweating and chilling makes me think of people in saunas during winter—they heat up, sweat, jump in snow, chill out, repeat—but also, again, of beeswax. When beeswax is first scraped off the comb, it contains a percentage of honey. Through successive steam or hot water baths the honey is washed out, leaving behind a lesser percentage of honey. When I am processing beeswax—melting it in a pot with a bit of water and then straining it through cloth before pouring it into a mold—there is always some slum gum left on the cloth as well as on the bottom of the cake of wax that remains in the pot. Like slop oil, slum gum has little or no value. All things of value—the honey, beeswax, pollen, propolis from the beehive; the gasoline, kerosene, diesel (et al.), and paraffin from the crude oil—have been removed.

The refining of paraffin can go on and on by various measures and means resulting in several different products used in several different applications. I saw somewhere that food packaging is the number one use for paraffin. Candles come in second. I enjoyed this article about paraffin’s use with food, and here’s an odd thing: Beekeepers in New Zealand using paraffin.

But the pressing question, of course, is which of these various paraffins is used to make candles? In general, that paraffin, often just called candle wax, fits a standard general definition: it is a solid mass of hydrocarbons that is colorless (or translucent), odorless, tasteless. It can be of varying quality, melting point being one measure of quality as usually the lower grades of paraffin have a lower melting point than the higher grades. (I have seen various ranges of melting points for paraffin so hesitate to give one here, but, generally speaking, the range seems to be around 120 to 150 degrees Fahrenheit.) Also, your cheaper paraffin candles most likely are not high grade paraffin. But, then again, just because someone slaps a high price and fancy label on something, well, you know: meaningless. And nowadays, one must also consider that most paraffin candles have been doused with scent and that can affect how a candle burns and what it leaves behind in the air and on your stuff. (I have read nothing about the affect of the dyes used in candles.)
Coming Soon to a Highly Aromatic Theater Near You:
Black Soot Deposit!
Due to the refining process that oil goes through to get to paraffin and that paraffin goes through to get to all of its possibilities, I understand why some think paraffin is not a natural wax. But, in my book, it is. It exists down there in the oily depths of our planet (as well as in shale and peat), and maybe we shouldn’t be pulling so much of that stuff up and out of the earth, using it willy-nilly, but we are and have been since the mid-1800s and even if we try to slow it down, use less oil, less gas, turn to alternative fuel sources, which I’m all for, as long as oil is being dredged up, why not use every bit of it? Why not use paraffin for candles? They’ve been doing it for years!

Ah. So maybe you’ve heard. “Paraffin is toxic.” Sounds like one of those statements we better question.

Dum de dum dum.