Researchers at Denver, Colorado-based Luca Technologies have made a discovery regarding natural gas production in Wyoming’s Powder River Basin that could lead to a long-term source of renewable energy.
The company yesterday announced that laboratory evidence shows that the Powder River Basin (PRB) coals are generating natural gas in real time through the ongoing activity of anaerobic microbes (bacteria that live in the absence of oxygen) resident in those coal fields. The company has termed sites where this microbial conversion of hydrocarbon deposits (coals, organic shales, or oil) to methane occurs “Geobioreactors,” and believes the careful management of such sites may offer a new long-term solution to US energy needs.
Robert Pfeiffer, LUCA Technologies president and chief executive officer commented, “Our research on native coal, water and microbial samples from the PRB has determined that PRB coals can produce natural gas in real time. This finding suggests that the gas in the PRB need not be an ancient remnant of microbial activity, as generally believed, but instead is being actively created today.
“Moreover, we can increase or decrease methane production by PRB microbes by altering their access to water or nutrients, or halt gas production entirely by exposing the organisms to oxygen or heat sterilisation. This finding holds the potential of turning what is today thought to be a finite energy resource into a renewable source of natural gas that could potentially go on for hundreds of years.”
LUCA believes that in order to attempt to maximise the ultimate recovery of methane from this potentially enormous natural energy resource it will be necessary to amend certain current operating practices as well as review current legal and regulatory underpinnings of energy development. The company is currently discussing its findings with Wyoming and US national agencies, as well as with major energy companies working in the PRB region.
<b>Microbial Methane Production from Coal</b>
It has long been known that certain ancient microorganisms are “methanogens”, which are microbes that generate methane by metabolising 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 PRB. In addition to demonstrating that methane production by these microbes can be stimulated by the introduction of additional nutrient compounds, or suppressed by heat sterilisation or the introduction of oxygen, LUCA has shown that radio-labelled CO2 (carbon dioxide) introduced to these PWB core samples is converted to radio-labelled methane. This demonstrates that the methane formation is the result of a biological process occurring today.
“The United States has enormous amounts of buried hydrocarbon reserves, many of which cannot be extracted in an economically or environmentally benign fashion with current technologies and production practices,” said Mr. Pfeiffer. “Any of these settings, given the right set of conditions, has the potential to produce biogenic methane in a long-term, sustainable fashion.”