[math-fun] A modest proposal for carbon sequestration in space
When you have too many lemons, make lemonade. Instead of a "carbon tax", why not incentivize something really useful, like a space elevator? How about a tax paid in carbon fiber nanotubules strong enough to make such a space elevator: http://en.wikipedia.org/wiki/Space_elevator If such an elevator were built in the form of a tube, it would be the world's tallest smokestack. Yes, you would probably have to pressurize the tube in order to lift the gasses inside, but that could be done relatively efficiently at ground level. Since the pressure would decrease with increasing height, the highest pressure would occur at the bottom, so there should be not problem with the pressure higher up. Presumably, other types of waste -- perhaps even radioactive waste -- could possibly be "sequestered" in space the same way. --- I noticed that 1) all of the proposals involve starting the elevator cable at the ground or some high tower, and 2) the exponential taper means that even small increases in elevation of the base of the elevator help a lot. So, why not start from a balloon which is itself tethered -- alternatively, include balloons along the lower portions of the elevator to increase the effective height of the beginning of the elevator ? Weather & winds would affect the balloons, but some sort of active station-keeping scheme could be used, because it could now be powered from the ground (most of the other proposals don't have enough lifting capacity to include a power cable from the ground).
=Henry Baker all of the proposals involve starting the elevator cable at the ground or some high tower
Actually, Hans Moravec's 1977 proposal ("A Non-Synchronous Orbital Skyhook" qv) *has* to start in the middle and grow in both directions, because it's not in geosynchronous orbit. This probably has both some advantages (better dynamics: thick in the middle, tapers toward the ends) and some disadvantages (ferrying up the building materials, rather than being able to use the cable as scaffolding).
On 8/1/06, Henry Baker <hbaker1@pipeline.com> wrote:
I noticed that 1) all of the proposals involve starting the elevator cable at the ground or some high tower, and 2) the exponential taper means that even small increases in elevation of the base of the elevator help a lot.
So, why not start from a balloon which is itself tethered -- alternatively, include balloons along the lower portions of the elevator to increase the effective height of the beginning of the elevator ? Weather & winds would affect the balloons, but some sort of active station-keeping scheme could be used, because it could now be powered from the ground (most of the other proposals don't have enough lifting capacity to include a power cable from the ground).
This has been proposed several times, e.g. http://www.mill-creek-systems.com/se/balloon.html -- Mike Stay metaweta@gmail.com http://math.ucr.edu/~mike
--- Henry Baker <hbaker1@pipeline.com> wrote:
When you have too many lemons, make lemonade.
Instead of a "carbon tax", why not incentivize something really useful, like a space elevator?
How about a tax paid in carbon fiber nanotubules strong enough to make such a space elevator:
http://en.wikipedia.org/wiki/Space_elevator
If such an elevator were built in the form of a tube, it would be the world's tallest smokestack.
Yes, you would probably have to pressurize the tube in order to lift the gasses inside, but that could be done relatively efficiently at ground level. Since the pressure would decrease with increasing height, the highest pressure would occur at the bottom, so there should be not problem with the pressure higher up.
Presumably, other types of waste -- perhaps even radioactive waste -- could possibly be "sequestered" in space the same way.
The smokestack model won't work. The heat of combustion of gasoline is 47 MJ/kg. Each kg of octane produces 3 kg of CO2, and that 47 MJ can raise the CO2 to a height of 1600 km, far short of the geosynchronous orbit needed before it can be flung into space. The fuel consumption needed to pressurize the smokestack will produce more CO2 than can be disposed of by this method. If a space elevator were to be used for this purpose, the CO2 would have to be packaged and carried up the elevator to the point above geosynchronous where the centrifugal energy recovered balances the gravitational energy. Gene __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
participants (4)
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Eugene Salamin -
Henry Baker -
Marc LeBrun -
Mike Stay