One of the interesting aspects of living in these times is to see the myriad new concepts for producing energy from available resources. On the overall continuum of energy sources, natural gas is generally considered to be the most benign of the fossil fuels due to its relatively low carbon content. But recent stories about hydro-fracking have raised new concerns about the environmental implications of gas drilling. After all, it becomes much less attractive as a fuel if whatever environmental benefits it offers in burning cleaner are offset by the damage done in collecting it.
So this turns out to be a good time for Luca Technologies, a new startup to show up on the scene. Luca has developed a new bio-process for growing natural gas in abandoned coal mines. They do this by injecting, water and nutrients into dried-up coal bed methane wells to nurture the naturally occurring microbes that feed on coal.
These coal-eating bacteria produce natural gas as a byproduct of their digestion, as in “ah, ooh, excuse me.” But their embarrassment could be our opportunity. Luca Tech certainly thinks so. They have purchased more than 1350 methane wells in Wyoming’s Powder River Basin that were sold off by their owners as being no longer productive. Remembering my high school science I’m picturing a hole with a kind of caked up black baking soda at the bottom, to which vinegar is added, and the resulting gas is collected as it bubbles forth. Of course, theirs is a different reaction producing methane rather than carbon dioxide, but I think the idea is otherwise similar.
Powder River Basin residents are concerned about the large number of wells being drilled in their area and their potential impact on water resources and have in fact resisted some of Luca’s attempts to develop new wells. But one of the nice things about this process, which according to Luca’s CEO Robert Pfeiffer could potentially meet the entire US demand for natural gas is that new wells don’t necessarily have to be drilled, since existing, or even abandoned wells will also provide plenty of gas. Pfeiffer also claims that both the microbes and the nutrients used to feed them are naturally occurring and are therefore not dangerous. The company has been working in conjunction with the US EPA on a number of projects even as local environmental groups oppose them. The company recently withdrew a well application in the face of environmental opposition. A company spokesman claimed that legal constraints in the application process kept them from being able to fully explain their process to all stakeholders.
Luca’s process, once it identifies a natural gas farming candidate, is to withdraw water from the well and pass it through a mobile nutrient module to replenish nutrients vital to sustaining the microbial community. The water is then recycled back into the well through existing infrastructure and the mobile nutrient module is moved to other wells to provide nourishment to new subsurface habitats. The well is then shut down for an average of one month to allow natural microbial populations to flourish. During this time, activated microbes begin producing significant amounts of natural gas. Luca harvests the natural gas using the existing infrastructure. This cycle of restoration and harvesting enables Luca to produce natural gas from depleting wells for decades.
And perhaps decades will be all we need until even cleaner, more sustainable forms of energy become available.
RP Siegel is the co-author of the eco-thriller Vapor Trails, which is all about energy.
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