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Recycling Greenhouse gases

Posted by reece.arnott 
Recycling Greenhouse gases
January 05, 2008 11:28PM
I was thinking it would be a good idea to make a 'miracle machine' that took CO2, CH4, and H2O (cabon dioxide, methane, and water) vapors out of the air and produced something (solid or liquid) useful. And it just so happens that these are some of the major greenhouse gases (CO2 everyone knows about but methane is about 20 times more efficent at trapping heat and water accounts for around 60% of the natural - not man made - greenhouse effect).

Ethanol is the simplest thing that comes to mind as an endproduct but it would be great if you could fine tune it to get your hydrocarbon of choice and/or directly produce feedstock for a Reprap.

We're probably a couple of years away from considering it yet but I thought I'd get the idea out there so that people can be thinking of how to design such a machine.

I have no idea how it would work but I think it would be a world-changer in all senses of the word.
Re: Recycling Greenhouse gases
January 06, 2008 01:22PM
Looks like somebody is working on it : [hardware.slashdot.org]

Re: Recycling Greenhouse gases
January 06, 2008 03:06PM
... because pure carbon is the ever best (ultra-strong and hyper-rigid) building-material (fullerenes/bucky-balls, carbon-nanowires, graphene-sheets and diamond) it should be enough to convert all Cx-stuff in carbon or carbonmonoxide as basis and exhaust the 'additives' as O2, N2, water or elementar ressources for second-stage processes ...

I think in some years there should be the technology to build every needed hardware from carbon, so let's focus on this - all the greenhouse-gases, old plastic-scrap, compost and other waste would then be a very welcome source for it winking smiley

Re: Recycling Greenhouse gases
January 06, 2008 03:09PM
How about we don't make the stuff in the beginning to create the energy we need.
1. Take the ch4 (methane) convert it to carbon and hydrogen. Use the carbon to build things (carbon fiber and such) and use the hydrogen for energy source.
2. Use part of the hydrogen and burn it to create the above conversion process and use the excess heat to make steam for a turbine and make electric power. Also recover all the heat generated none is wasted.
3. Because you burnt the hydrogen inside a closed container all of the gases are easily controlled. When you burn hydrogen in air you get H2O and if you recover all the heat made then the water will condense and NOT be release as a greenhouse gas. I since you just made the water it is pure and considered "Potable" (drinking quality). So now you have water at your home because all of this came out of a cabinet attached to the back of your house.

Your electricity, your water, your heat and also your cooling (propane refrigerator makes cold from heat).

By the way the methane comes from a biodigester that converts organic waste into methane and carbon dioxide. Use the methane for power and put the CO2 thru the hose that you water your plants with and dump it on the plants. It makes them grow twice as fast and the plants give off Oxygen.

One question about your suggestion.
How much gas do you have to collect give standard distribution of gases in the air. The article uses solar energy and converts gases out of tanks and creates 2.5 gallons per day of fuel.
What kind of energy budget is needed to make this work?

Please I am not saying not to do it but I have started projects like this in the past and when you get down to the current practical technology we have, it cannot be done at 10 times a reasonable price. Sorry..

It does not seem reasonable to try to remove things from air BUT it is entirely reasonable NEVER to have put them there in the first place.

Bob Teeter
"What Box?"
Re: Recycling Greenhouse gases
January 06, 2008 03:36PM
... best way for collecting low-concentrated gases like CO2 or methane from air is filtering in 'bio-filters' with algae or bacteria in water or in a big greenhouse with fast-growing plants as reeds or special C4-plants.

Then convert the bio-stuff in a high-pressure temp-curing process with citric acid as catalyst to pure carbon and water or a fractionable oil-basis.

This would be some bigger, then normal home-brew, but shouldn't be a problem for a small community winking smiley

Power and heat best with solar and for 'concentrating' the ressources you can associate with farmers and/or recycle old plastic-scrap ...

Re: Recycling Greenhouse gases
January 24, 2008 11:16AM
Things that use solar insolation to combine CO2 and H20 exhausting Oxygen and making things from the carbon and hydrogen are extremely common they are called..........


>grinning smiley<

We need though to be able to take plant matter and convert it into exhausts, bucky balls and carbon fiber

That would be clever

I wonder if the strength to weight ration of carbon fiber composites is such that we can make vacuum filled lighter than air transports yet ????

That would be clevererererer still.

You could even use the technique to lift space vehicles part of the way up the gravity well and make them more economically viable.

Then we would be clevererererer than this planet and we could go somewhere more peaceful to fabricate.



Necessity hopefully becomes the absentee parent of successfully invented children.
Re: Recycling Greenhouse gases
April 16, 2008 02:16AM
sounds like inventing anti-grav unit for me. anywho nothing wrong with little global warming i like the warm winters these last years around here. btw carbon isnt super strong material take graphite for example: quite soft and breaks easyly but 100% carbon. its all about the crystal structure. depending on what you can get pencil leads or diamonds.
about the vacuum balloon:

* 50% of the atmosphere by mass is below an altitude of 5.6 km.
* 90% of the atmosphere by mass is below an altitude of 16 km. The common altitude of commercial airliners is about 10 km.
* 99.99997% of the atmosphere by mass is below 100 km. The highest X-15 plane flight in 1963 reached an altitude of 354,300 ft (108,000 m).

Therefore, most of the atmosphere (99.9997%) is below 100 km, although in the rarefied region above this there are auroras and other atmospheric effects.

therefore you can get max 100km higher with your vacuum balloon, given earth's radius ~6,371.0 km thats hardly anywhere close to significance
Re: Recycling Greenhouse gases
April 16, 2008 05:03AM
Hi r2kordmaa,

... first - with carbon you can build materials and fabrics much stronger than steel or any other organic or anorganic material.

I have some nanotubes in a little box, which were grown on a metall-surface and then measured in their mechanical characteristics: a single carbon nanotube of this mass is nearly 2 nanometers in diameter, between 100 and 200 nanometers long, has a young-module (e.g. stiffnes) 5 times more then steel and you need 2000 times the force to rip it apart, than with a steel-fibre in the same dimensions ...

A single (short) nanotube isn't so a big deal, but imagine a bunch of much longer nanotubes (some millimeters or even centimeters), fused together in a fiber, where you have thousand tubes in the diameter and some assembled to a rope some kilometers length, then it comes in the interesting area.

Think of 'planetary' lifts from earth into the orbit, lightweight building-material, where you make thin sheets of criscrossed wires, fused/glued together for sheets, thick as paper, but stronger then concrete of half a meter thickness, and so on ...

Imagine skyscrapers, miles high, extremely strong, but only a fraction the weight of a 'normal' building, or battle-tanks, completelly bulletproof, but with a weight of 100 kilograms (without motor and crew) instead of 10 tons.

Apply helicopter- or jet-engines and you have air-vehicles often viewed in sci-fi-films ...

When the mechanical properties of carbon nanotubes become common, a race started, which group would first solve the problem to make nanotubes in makroskopic quantities and lengths and which company first would first apply this sort of materials for 'common' fabbing ...

And for the spacies - build some scy-platforms in 10 to 20 km height with lifts to the ground and you have bases for near-orbit-space-vehicles, what would make space-flight much cheaper, then naow ...

Re: Recycling Greenhouse gases
April 16, 2008 07:34AM
On the topic off topic, topic of vacum vessel lift.

Beg to differ, not anti gravity at all, buoyant lift. A very different concept. (Much beloved by Scuba Divers and Airship Owners)

If you can pre lift orbital payloads to 100KM up before launch your fuel requirement is significantly reduced and your payload to launch vehicle weight ratio becomes much more favorable. (A Gravity, Mass and decrease in gravity strength as a function of radial distance from source calculation)

It is a sad fact that the majority of the weight in a sea level launch vehicle is the fuel and casing (necessary to hold all the fuel) to get the thing through the very first part of it's flight ie Lift Off. You need X amount of stored energy to lift payload mass Y. The mass of X though is sufficiently significant that you need even more X to to lift the X that you needed to lift your Y und so on (said in best Werner Braun Rocket Scientist Style Accent) until you have more than enough to lift payload plus fuel plus vehicle plus additional fuel and vehicle.

You can get the same benefits by launching from mountain tops it is just very inconvenient (They don't put them where you want them) and costly and not as beneficial as ad hoc pre lifting. (This is why NASA were pre-lifting the space shuttle and launching it from the back of aircraft)

For terrestrial transport the benefits are greater still. Having attained a degree of buoyant lift and height it takes no further energy input to keep you there, unlike current air flight technologies.

If you wanted an aerocar (Luke Skywalkers Landspeeder) for example as a family saloon you could do much worse than to reduce the weight of the vehicle to be lifted by adding some quantity of buoyant lift to the mix.

The buoyant lift benefits were facts well known to the Graff Zeppelin company, shame about the hydrogen. (Incidentally their safety record was very good)

Fortunately vacuum doesn't burn and has more lift. (If the mass of the container isn't so much greater than the increase in lift/buoyancy the vacuum provides)

Sorry guys, I know its not about what else would be good to print. I will add no more here off topic.



Necessity hopefully becomes the absentee parent of successfully invented children.
Re: Recycling Greenhouse gases
May 04, 2008 08:38AM
well yeah getting out of atmosphere before starting to gather orbital speed would indeed greatly reduce fuel/cargo ratio and launch cost. that aside growing carbon nanotubes is still in experimental not industrial stage and promises to stay that way for quite a while, unfortunately.
todays launch cost arent that high because it requires so much fuel anyway, fuel is rather small percentage of launch cost. the problem is that most launch systems are built following military principles not commercial ones. the cold war mentality still rules in space industry - you can waste anything but people and time. and that is why more money is spent than necessary. launching 1kg to orbit costs usually around 7-20 thousand dollars, international space station costs 100 billion euros. for example the european automated transfer vehicle that had lots of storage space, fuel tanks, rocket motors etc was simply discarded and burnt in atmosphere after it completed its task of taking some cargo to iss. seems to me like it might have been used more efficiently as storage area and remain as part of the station. as already huge amounts of money had been spent to get it up there
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