Posted on 04/26/2007 5:12:06 PM PDT by nypokerface
WEST LIBERTY, W.Va., April 26 (UPI) -- The U.S. Department of Energy is jointly sponsoring the first U.S. test of a system that might significantly reduce greenhouse gas emissions.
Using a new application of existing technology, engineers will attempt to capture methane in underground coalmine air. Scientists said if the technique is successful, it could limit emission of a greenhouse gas with more than 20 times the warming potential of CO2.
Methane in underground coalmine air constitutes approximately 5 percent of all U.S. methane emissions and is the equivalent of about 32 million tons of CO2 per year. The test will evaluate the long-term technical and economic feasibility of reducing methane emissions from underground coal mining.
The eight-month test is being conducted in a closed mine near West Liberty, W.Va., in a $2.1 million experiment co-sponsored by the U.S. Environmental Protection Agency.
uhhhhh...I thought Methane emissions have dropped?
Didn’t they read the IPCC summary?
Well, one could do scrubbing, or absorbtive capture - if one were to ventilate the shaft forcefully, then either pass the air+methane over large charcoal beds or through a scrubber with naphtha oil- and then by reheating the oil or the charcoal [in a separate circuit] most of that methane could be released and caprured.
FYI:
The weight of the Earth’s atmosphere can be calculated as follows. Atmospheric pressure at sea level is on average 14.5 pounds per square inch = 10 tons per square metre. This pressure is due to the weight of atmosphere above an area at sea level of one square metre.
The radius of the Earth “r” is 5,925 km and so the surface area of the Earth (land and ocean) is 4 x “pie” x “r” squared = 4 x 3.142 x 5925 x 5925 = 441 million square kilometres = 441,000 billion square metres.
Therefore the weight of the Earth’s atmosphere is 441,000 billion x 10 = 4.41 million billion tons.
Methane has in the past been a big killer of miners. If capturing the methane in some way concentrates the methane somewhere in the mine it has a potential to increase risk to the miners.
Methane [like most other gases] has two explosion boundaries for its mixtures with air: it would not explode if the concentration is either too low or too high [either below 6 or above 14%]. The trouble is that even with the best ventilation there are gas pockets inside the coal seam with methane under some pressure, and when such a pocket is breached, the forceful gas stream will create locally high concentrations. The best way to concentrate the methane would be from dilute and safe [say, 3% methane] mixtures with air, outside the mineshaft, with the concentration occurring on/in some absorbent, and then releasing it from that absorbent in a separate circuit without much air in it.
This is certainly a safe method, the absorbers being out side of the mine.
It would most likely be expensive. Absorber beds would be large in volume and expensive to purchase. Rapid turnover of the air in a mine is the key in mine safety. So these absorber beds would have to be huge to handle the large volumes of air moving through the mine.
There would need to at least two banks of absorber beds because one would have to be in service while the other was being regenerated.
Regeneration of absorbers usually requires a great deal of energy because they typically are heated in order to get the absorber to release the captured gas.
Considering the cost of purchasing this technology and operating it, I don’t see this being a cost effective proposition.
But then the whole Green House Gas Global Warming thing doesn’t make any sense anyway.
The thing with all these enviro-driven "conservation" projects is that, if they made sense, somebody would've already found a way to do them.
The mere fact that the federal government -- the sponsor of last resort for bad ideas -- has to undertake this project is proof positive that it makes no sense.
Irrelevant. We're talking polar bears hear.
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