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“The tears on my shoulder
Freeze then boil
I wouldn’t be here
If not for your snake oil…”

-Kristin Hersh – “Snake Oil”

One side-effect of the global warming era is that if you can sell a concept or products as “green” it can go a long way. There is a green alternative for nearly every product that you use on a daily basis – from cars to toilet bowl cleaners. The good thing about this is that it encourages creative thinking to deal with what is certainly a real and dangerous problem. The flip side is that it opens the door for snake oil salesmen, those unprincipled folks that will slap the green label on their product or idea and go out looking for a rube.

I’m not sure which class a paper published in this week’s Nature falls into, but it’s important to know that one of the authors is associated with Norsk Hydro Oil & Energy and that the authors acknowledge BACCHUS2, a consortium that includes nearly all of the major oil companies, for “support, discussions and permission to publish”. In short, this work is heavily funded by Big Oil.

The problem that this group approached was improving the efficiency of energy recovery from oil residues that are left behind as a product of bacterial biodegradation. There are certain types of sulphate-reducing and methanogenic bacteria that “eat” by degrading simple hydrocarbon chains, which are what we are after for energy, into methane. The byproduct of this bacterial dining is “heavy oil”, a sticky residue that requires a massive energy input to recover usable crude oil. However, heavy oil could be an energy, and financial, boom if oil companies could work out ways to increase energy recovery.

The BACCHUS group, led by Steve Larter of the University of Calgary, sought to determine just how these oil-eating bugs were breaking down their meals as different types of bacteria do this in different ways. It seems to be a two step process in which one type of bacteria breaks down long-chain hydrocarbons into acetic acid (vinegar), carbon dioxide and hydrogen. In the second step different types of bacteria can turn those products into methane. Larter and his group hoped to determine which process dominates in “the wild”.

Best approach to a simple question is a simple experiment, so Larter and his colleagues put a couple of oil samples, their bacterial diners and a bit of fertilizer in jars for 18 months and analyzed the isotopic ratios of the breakdown products. They found that the transformation of carbon dioxide and hydrogen to methane is more efficient than the breakdown of acetic acid into methane.

I’m not a geoscientist, but there seems to be a couple of issues with this study. Larter’s group do not attempt to isolate single species of bacteria, but just rely on the isotopic ratios to draw the conclusion that Syntrophus sp. are the most efficient biodegraders , due in part to their dominance in their cultures. More troubling to me is the massive leap to the conclusion that what happens in their jars is representative of the situation in oil fields worldwide.

Larter suggested in an interview that they could improve the efficiency of methane recovery from heavy oil by adding nutrients to “fertilize” the bacteria. He believes that this process could convert at least 20% of the heavy oil to methane. More exciting to Larter is the possibility that with some tweaking you could get hydrogen as a byproduct.

Despite a couple of minor issues, there is nothing massively wrong with the science here. Larter and his colleagues are not peddling snake oil. It’s just that their vision of engineering bacteria to wring the last bits of energy out of oil waste reeks of desperation to me. It’s a pessimistic outlook at best – if we can’t find an alternative to fossil fuels, we could always squeeze a bit of methane out of some rocks. There are many more promising and brighter options out there. One of the most exciting that I’ve heard lately involves work from Texas A&M into bioengineering of bacteria to efficiently produce hydrogen. It’s a long way from being a viable energy source – but all the research into renewable energy resources is much more hopeful than this work.

Image Credits:

Oil fields

Bacteria

Canadian tar fields