Friday, July 27, 2007

Abiotic snake oil

I usually don’t bother with antiscience. It’s kinda like researching and dobbing in companies that advertise Mexican sex drugs- debunking takes way more effort than spewing crap, so it is hard to win. But Sabine pointed me to a recent article on abiotic oil that is a textbook case of argument from ignorance.

An argument from ignorance generally works like this:
1: “I have no idea how much I don’t know. In fact, I think I know everything worth knowing.”
2: “I have no understanding of X, and since I know everything worth knowing, X can’t be important or correct”
3: “Because X is not important or correct, any arguments based on X must be irrelevant or wrong.”

In this article, we have:

“Kerogen, it turns out, is not a chemist's term. Kerogen is a loose, geological term…”

And:
“Kerogen is not a term typically found in chemistry textbooks or specifically used by professional chemists. Use of the term kerogen is generally a signal that you are dealing with a petroleum geologist or engineer, not a chemical scientist.”

“A petroleum geologist, not a chemical scientist.” The obvious implication is that geology is not a science, and that any arguments based on geological knowledge are suspect.

This is NOT the same as arguing that geological processes must conform to the rules of chemistry. It is arguing that knowing the rules of chemistry excuse us from having to learn geology when studying geological processes.

The article continues to attack the concept of kerogen, saying that, “Chemical textbooks typically do not provide chemical formulae for kerogen.”

Does this mean that it isn't made of molecules? After all, it isn’t in the book! This is like saying that dirt doesn’t have a chemical formula that you can look up in a textbook, so it can't be studied.

Of course, the purpose of chemistry is not to list in rote format every reaction that exists. So the complaint that:
“We have yet to find a chemistry textbook that refers to "kerogen" or describes any combination of ancient algae, tiny Mesozoic sea animals, or dinosaurs as necessary or sufficient ingredients in the formation of common saturated hydrocarbons such as methane, ethane, propane or butane.”


…Is ignorant of the idea that the types of reactions shown in chemistry textbooks can be applied to natural materials of variable compositions with predictable results. After all, a real chemist would suggest that the same processes that allow hydrocarbons to be derived from whales or pigs ought to be applicable to dinosaurs as well. The author’s argument suggests that since we don’t know the chemical formula for pigs, they can’t possibly produce natural gas.

Luckily, the internet is slightly less ignorant. Wikipedia and the British chemguide both explain, in general terms, how thermal cracking occurs, and many more detailed studies are available.

In fact, the author doesn’t even seem to realize that crude oil is a mixture of all sorts of fairly heavy hydrocarbons. But it only gets worse from there.

He references an abstract that shows a wustite/calcite/water system will generate methane at mantle P and T to suggest that:
“The observation of methane formation at mantle pressures is significant because it demonstrates the existence of abiogenic pathways for the formation of hydrocarbons in the Earth's interior”


Once again, this is an argument from ignorance. In this case, it is ignorance of the composition of the earth- Wustite is not stable in the presence of magnesium silicates, which are what comprise the mantle. Discovering a reaction between arbitrary minerals that occurs in the (very large) P, T range of the mantle tells you nothing about the actual mantle unless that mineral assemblage is realistic.

It also assumes that because something can happen, it did happen. As it turns out, abiotic methane can be produced during serpentinization. But this gas is not mined. Doing so would not be economic. The natural gas that we actually pump out of the ground to cook stirfry with happens to be from dead bugs.

This post is already too long, so I’ll ignore the planetary non-sequiturs and the butchery of thermodynamics. I’ll also stay away from the entire field of biomarker geochemistry, which uses molecular fossils contained in hydrocarbons to determine the type of organism from which they are derived.

Instead I’ll just skip to his last question:
“Has anyone ever taken a flask of downed flora or dead protoplasm and produced a hydrocarbon fuel out of the mixture, or is this a process for alchemy?”

Of course they have. We call that hydrocarbon fuel “biodiesel”. Most of it is made from plant oils, but there is a New Zealand company that is now producing biodiesel from the natural algae found in sewerage plants.

2 comments:

Heather said...

That's a great analysis of the article Lab.

Now I need to post some of the pre-plate tectonics explanations of geologic landforms from the ancient physical geology textbook I ran across.

Chuck said...

You mean it made sense? Far out.