Back in November, I noted an intriguing bit of news on microbes busily belching out methane beneath a Wisconsin coal field:
It has long been known that certain ancient microorganisms are "methanogens" – microbes that generate methane by metabolizing other hydrocarbon sources. While it has also been generally accepted that much of the methane resident in coal fields was produced by such organisms, most of this production was thought to have occurred millions of years ago, when the hydrocarbon deposits were less mature and closer to the surface of the earth.
More recently, however, research has suggested that living methanogenic organisms may be present and actively forming methane within some major coalfields. LUCA scientists, employing the tools of modern biotechnology and genomics, have confirmed the presence of such microbes within anaerobic core samples from the [Powder River Basin coalbed]. In addition to demonstrating that methane production by these microbes can be stimulated by the introduction of additional nutrient compounds, or suppressed by heat sterilization or the introduction of oxygen, LUCA has shown that radio-labeled CO2 (carbon dioxide) introduced to these PWB core samples is converted to radio-labeled methane. This demonstrates that the methane formation is the result of a biological process occurring today.
The same company has demonstrated the existence of more of these methanogens in a Utah oilfield (via Eurekalert!'s energy news):
Luca Technologies LLC today announced that its researchers have confirmed the presence of a resident, methane-generating community of microorganisms ("microbial consortium") in substrate samples taken from the 110,000 acre Monument Butte oilfield located in North Eastern Utah. This site represents the latest in a series of active "GeobioreactorsTM" that Luca Technologies has identified since its first demonstration of this phenomenon in the Powder River Basin coalfields of Wyoming. Geobioreactors are sites where microbial conversion of underground hydrocarbon deposits (oil, oil shales, and coal) to methane is ongoing. Such Geobioreactors may offer the potential of turning currently finite energy reserves into methane "farms" capable of long-term, sustainable energy generation.
"The hydrocarbon resources available in the Monument Butte oilfield are very large, making the possibility of shifting from oil production to the ongoing farming of clean, natural gas an attractive consideration," said Robert Pfeiffer, president and chief executive officer of Luca Technologies. He noted that the Monument Butte site was one of six oil fields across the United States that Luca has been studying. The company has demonstrated two of those sites to be robust, methane-generating Geobioreactors, and two to be less actively generating methane. Three additional sites are not currently active but may have the potential to be turned into active Geobioreactors through cross-inoculation with microbial consortia from active sites.
The appeal of the process is obvious, but at this early stage the economics are still unclear, natch. Randall FuturePundit speculates, with an assist from Gary Jones (who is following this on his own crumb trail) in the comments.