Landfills, mines, and livestock give off methane, a form of natural gas that could be used as fuel if it were captured and recycled in some useful way. Methane is also a potent greenhouse gas, and some research shows that controlling methane may actually lead to larger effects than controlling carbon dioxide emissions. Doing so with livestock is difficult; I had a group of students do a research project a couple of years ago on research in Australia and New Zealand on bovine flatulence (what they found was research on modifying livestock feed so that the sheep and cows became less gassy). But capturing and using landfill and mine methane through a combined heat and power (CHP) installation would reduce energy bills and reduce greenhouse gas emissions.
Problem is, landfill gas is a combination of methane and nitrogen, both of which are inert and of about the same molecular size. So isolating the methane is an important step in allowing this transformation to occur. According to this Wired article, a company in central Ohio called Veolcys has figured out how to do just that:
Velocys has devised a way to separate nitrogen from methane by forcing it through tiny channels less than a millimeter wide. Engineers add a compound such as porous carbon to these microchannels, then cool them. The carbon binds to methane molecules, holding them in place inside the channels.
While methane molecules get stuck, nitrogen passes straight through. Engineers then warm the channels, allowing the methane to detach from the carbon.
This is pretty neat. It does require additional resources to build the carbon microchannels and energy to cool the carbon, but it’s easy to imagine the value of the isolated methane exceeding the cost of isolating it.
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