Monday, December 15, 2014

A side of bacon...or algae?

In mid-November here in Easton, Pennsylvania, before winter temperatures descended on us with a thud and preceding the turkey frenzy of Thanksgiving, Bacon Fest was held in our center square. (Through spring into early fall, our Farmer's Market, the nation's oldest continuous open-air market (~1752) is held in the square.) I did not go to Bacon Fest this year, but last year my dog and I enjoyed some delicious bacony macaroni and cheese, looked at the little piggies before the piglet races, and drooled over beautiful imaginative bacon-ingredient cupcakes in the baking competition. I did not realize until a few years ago, that some people are crazy for bacon!

Last entry, I mentioned the petroleum potential of amorphous organic marine snow. Sometimes I have used frying bacon as an analogy, for non-scientists, to describe petroleum generation from kerogen (insoluble organic matter residue in rocks): heat up the fatty bacon and liquid grease is produced, some greasy gas, and eventually one ends up with more grease and a burnt up solid, if the cook has not been paying attention. Same in a rock: oil-prone organic matter, such as lipid-rich plankton. algae, marine snow, spores/pollen, will, as temperature slowly increases with deep burial over geologic time, eventually produce oil as they are cooked in the "petroleum kitchen" (AKA hydrocarbon kitchen, oil kitchen: yes, they really do use that term in the oil business). A solid refractory high-carbon-content residue usually remains.

You may wonder, why we just don't industrially fry up algae to produce oil? There has actually been research into that, both fossil algae and fresh algae. Thirty-to-forty years ago, after the 1973 Arab Oil Embargo, there was a peak of research and pilot plants, in the United States, for producing liquid fuels from Western US oil shale, a rock rich in algal kerogen. The research looked at the feasibility of heating oil shale to produce and extract oil that had not yet been geologically cooked out of the fossil algae. The Green River Shale in Wyoming, Utah, Colorado, was a prime target rock. A positive outcome of this research was improved understanding of the chemical reaction kinetics of petroleum generation; kinetic algorithms by Lawrence Livermore National Lab scientists are the standard today in petroleum generation modeling (A nice review of proposed oil shale extraction methods, research, and economics can be found at http://www.ceri-mines.org/documents/A14b-AlanBurnhampaper.pdf). A major environmental, and political, issue, however, is that some methods can require a lot of water, which would monopolize excessive amounts of upstream Colorado River water to the detriment of downstream agricultural and drinking water customers in the SW US and Mexico.

Considering that farming algae on a large scale would be a possible transportation biofuels source, ExxonMobil, in 2009, supported ongoing research on growing algae on a large (numbers) scale and then extracting the lipids. (http://www.bloomberg.com/news/2013-05-21/exxon-refocusing-algae-biofuels-program-after-100-million-spend.html).  Advantages of the algae-farm technique is that it is renewable on the short term, may consume carbon dioxide, and does not include mining or mine waste disposal, like the Synfuels oil shale project would. However, as the Bloomberg article says, existing strains of algae were found not to produce an economically viable amount of product. Research by Exxon's partner will now focus on potential genetic modifications that may in a couple decades be successful. The business reports bemoan the project as a failure since $100 million (out of the original $600 million budgeted) has been spent without success. But actually . . . it is a success of the scientific method! There was a hypothesis, experiments were designed to test it. Even though the hypothesis was not proven true, there is valuable knowledge gained, and a new path proposed. It did cost money, but scientific inquiry does cost money, and advancement of basic science and technology can not happen without it.