So, is it enough to pressurize the column at the bottom of the stack, and wait/hope that a few molecules at the top of the column of gas are energetic enough to fly out the hole at synch. orbit? I think (but I don't know) that one might need to exert a lot of pressure to make this work, probably with as much energy as what Gene suggested, to pump out the gas. Can we assume that the pipe is not heated (is insulated), so that any energy for the molecules comes from the gas itself or the from pump? In that case, it would seem that the energy required to overcome the gravitational potential energy (up to geosynch) is a good way to look at it. Bill -----Original Message----- From: math-fun-bounces+cordwell=sandia.gov@mailman.xmission.com [mailto:math-fun-bounces+cordwell=sandia.gov@mailman.xmission.com] On Behalf Of Henry Baker Sent: Tuesday, August 01, 2006 3:34 PM To: Eugene Salamin Cc: math-fun Subject: Re: [math-fun] A modest proposal for carbon sequestration in space If I remember my physics correctly, air pressure is approx. 14.7#/sq in, which is the weight of the entire column of air 1 inch square sitting on the square inch. According to a source on the internet, standard air has an average molecular weight of ~29, while CO2 has a molecular weight of ~44. So I would estimate that the same column of pure CO2 would produce a pressure of approx 22.3#/sq in. This would mean that to pump pure CO2 into the "stack", it should take a head pressure of 7.6#/sq in. I suspect that this kind of pressure is easily available from the tailpipe of a 4-stroke internal combustion engine. If you diluted the CO2 with air in the ratio 1:1, then the molecular weight would be 36.5 and the head pressure would be only 3.8#/sq in. Diesel engines can be run very, very leanly, thus producing a relatively small % of CO2 in the output; this is not the most efficient way to run such an engine, however, but it does allow one to match the exhaust pressure with the required head pressure. At 01:39 PM 8/1/2006, Eugene Salamin wrote:
--- Henry Baker <hbaker1@pipeline.com> wrote:
True, but I'm not saying that you don't have to pump. Furthermore, in order to "sequester" the CO2, we only have to get it into orbit, so we don't have to send it any further than geosynchronous orbit.
What I said in my original reply could be restated as: The diesel engines that pump CO2 into the space tube at ground level will generate
about (4/e) times the amount of CO2 that they can pump up to geosynchronous, where e is the efficiency of the sequestration system.
Gene
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