A Microbe That Could Keep Coal in the Ground

The bacterial approach itself is only part of a larger concept called “underground coal gasification” (UGC). Companies and governments around the world are looking at UGC as a way to avoid sending miners underground, which often results in deaths. UGC can’t come fast enough for places like Utah, for instance, where a mining accident two years ago left nine dead and is today leading to tougher, more expensive regulation on the industry.

The more typical method of UGC, practiced by companies like Laurus Energy, is creating a controlled burn along a coal seam, allowing a utility to harvest heat energy and methane without ever extracting the coal. Projects of this sort are further along than using microorganisms to break down the coal.

Neither method is well tested, so for the moment we’re still mining and burning coal the usual way. The technology for doing that, from boring holes and collecting the coal to transporting to coal-burning plants, has been perfected over decades, so it’s not likely that UGC will be a competitor on price alone for some time.

Later, the balance may shift toward UGC. Using microbes is promising because it’s possible that the bacteria in question are already well-optimized by nature to convert coal to methane. It’s not clear where all naturally-occuring natural gas comes from, but at least some might be the remnants of coal eaten by microorganisms. Assuming that process could be sped up a bit, coal miners could have a cheap new extraction method on hand.

The question is how long it will take. My guess is that UGC will become important sooner rather than later. Pressure from environmentalists to stop building traditional coal-burning plants is growing, and new technologies like carbon capture and sequestration (CCS) will only raise prices for coal plants.

Coal itself, on the other hand, won’t change: Environmentalists can’t force its energy potential to go away. All that’s needed is a new way to tap into that value.

Correction: An earlier version of this post suggested that GreatPoint Energy is involved in UGC. The company does not work with coal underground. Instead, it applies catalysts to coal, biomass and other materials to produce methane in a process called hydromethanation.