Here's how is works: there is some coal that is buried so deep in the earth that it's not worth is to bring it to the surface. But, because coal contains methane, if there were a way to extract that gas without needing the coal itself, that would be something energy producers would be interested in. Enter the Dutch research and development institute TNO, which last year tested a new CBM process in Poland. Traditional CBM, as civil engineer Henk Pagnier explained to Radio Netherlands, means "you can simply pump away the water column from a coal reservoir at a depth of, say, five to six hundred metres. Thus, the coal is depressurised and the gas naturally escapes. It's a rather crude method and it doesn't get all the gas out of the coal, but it is efficient in easily accessible layers." The new Enhanced Coal Bed Methane process uses unwanted CO2 that is pumped into the ground to help push the methane to the surface. Again, Pagnier talking to RN:
"The beauty of the whole thing is that CO2 happens to bind to the coal when injected. Better still, it dissolves the methane gas from the coal in the same chemical process. Instead of the 40 percent of gas which can be extracted from the coal by using the old method, CBM, Enhanced Coal Bed Methane can extract up to 80 percent, and that makes the whole concept economically viable in many more cases."
Pagnier said he expects up to 80 percent of the methane in coal beds could be extracted this way, which "can fulfil the energy needs of the planet for about 200 years. That gives us time to make the change to a hydrogen economy." So, there's one hydrogen economy ETA for ya.
[Source: Radio Netherlands / Thijs Westerbeek]