Removing Methane From Earth's Atmosphere

[PallElendro]

Since the Industrial Revolution, a height of airborne pollutants have spread across Earth's atmosphere. Cleaner energies have been spreading to reduce the current effect and hopefully reduce the atmospheric content by waiting out the molecules' lifetimes.
Yet, raising of cattle and other forms of livestock have been impeding atmospheric recovery, worse than carbon emission. It's methane.

I want to build a large capsule that can trap methane, but can filter out oxygen, much like a gas mask. But first, I'd like to know what the projections are if I remove a portion, say 8-15%, of Earth's gaseous methane. Environmental hazards, atmospheric destabilisation, industrial downfall. If it's negligible, I'd like to hear what a bigger measure, maybe 25%, would bring.

[Ravens_cry]

Tricky. Cows aren't the only source of methane, especially now that a lot of permafrost is melting. All this suddenly rotting biomass is releasing quite a bit of the stuff itself. Otherwise, I'd recommend activated charcoal diapers for cows.

[Admiral Squish]

Hmm... Interesting idea. I'm imagining such a device. A small air-pump that pups air into a chamber, which then separates the methane from the rest of the air. A one-way membrane, perhaps? Then the air portion is released the the chamber is refilled. Since methane is lighter than air, you'd probably get a better harvest by raising the filter off the ground. So, you attach the pump to a balloon of a non-reactive lighter than air gas. The harvester then fills a second storage balloon with the methane. One the storage balloon is full, you detach it, and attach it to another pump that compresses it into a canister.

I could see such devices being anchored all around a pasture, or tied into the rafters of a cattle barn.

[Seffbasilisk]

Why tether it at all? Why need another lighter than air gas? It's made to trap methane, let it trap methane and use that to keep itself airborne. Make it a large disposable unit. Eventually it'll be struck by lightning, the concentrated methane will ignite, and the rest of the balloon packing until will either burn up or fall to earth depending on it's construction.

If you can make every bit of it flammable and cheap, we'll have flashes in the sky, and it'll be a tad more hazardous for pilots, but it should cut down on the methane in the atmosphere.

[georgie_leech]

Why tether it at all? Why need another lighter than air gas? It's made to trap methane, let it trap methane and use that to keep itself airborne. Make it a large disposable unit. Eventually it'll be struck by lightning, the concentrated methane will ignite, and the rest of the balloon packing until will either burn up or fall to earth depending on it's construction.

If you can make every bit of it flammable and cheap, we'll have flashes in the sky, and it'll be a tad more hazardous for pilots, but it should cut down on the methane in the atmosphere.

If the plan is already to burn it, why not trap it and at least use it to generate power or something?

[Ravens_cry]

If the plan is already to burn it, why not trap it and at least use it to generate power or something?

I was about to say this. I know manure has been collected for methane production.

[Admiral Squish]

If the plan is already to burn it, why not trap it and at least use it to generate power or something?

Basically that point, exactly. If you make them disposable, then you make it into a charity operation. If you make it reusable, and profitable, then people have a reason to buy and use these devices as much as possible.

Also, the lift balloon is because, to get it off the ground, you need a certain about of methane to lift it off the ground, and it would be very inefficient to run it on the ground.

[Knaight]

Why tether it at all? Why need another lighter than air gas? It's made to trap methane, let it trap methane and use that to keep itself airborne. Make it a large disposable unit. Eventually it'll be struck by lightning, the concentrated methane will ignite, and the rest of the balloon packing until will either burn up or fall to earth depending on it's construction.

If it's a disposable unit that traps a bunch of methane once, there's the matter of energy costs in creating it, including getting the materials. I'd be much more inclined to look more at the efforts to polymerize atmospheric methane. You get a useful solid which stays out of the atmosphere, it's likely profitable, and it doesn't have the waste issues disposable units do. Some of the reactions involved are already being developed even.

[Eldan]

Hm. I was familiar with carbon sequestration on CO2, but not Methane. Where are you working on this? I'd quite like to read up on it.

[PallElendro]

It's not a current project. I'm just a dumb secondary school student with a dream. When I graduate from university, I plan to analyse a gas mask filter, make a reversed version that 'breathes' methane instead of oxygen, and see if I can make a capsulised version of it.

[Admiral Squish]

I don't think you need to develop a filter that allows methane through and excludes the rest of air. I mean, if there are canisters of isolated methane, then there's got to be something that lets you filter out everything else. I think what you need to do is figure out a way to make one that's lightweight, fast, and cheap.

[Grinner]

I love the idea, but I have to wonder if it won't make things worse...What is methane converted into when burned?

[georgie_leech]

I love the idea, but I have to wonder if it won't make things worse...What is methane converted into when burned?

Pure Methane? Carbon dioxide and water, mostly. There's a small amount of carbon monoxide produced, as in any combustion reaction, and any impurities will affect it, but CH4 itself burns fairly cleanly.

[Knaight]

Pure Methane? Carbon dioxide and water, mostly. There's a small amount of carbon monoxide produced, as in any combustion reaction, and any impurities will affect it, but CH4 itself burns fairly cleanly.

The amount of carbon monoxide really depends on the amount of oxygen involved - if you can get it burned in an area with good air flow which maintains a high oxygen partial pressure, it's almost pure CO2 and steam. If said burning is in an enclosed space with limited oxygen, it's not necessarily a small amount of CO.

As far as impurities go, the main one is usually ethane, which will also produce almost pure CO2 and steam with good airflow, so that's not as much of a concern as it could be.

[Eldan]

I love the idea, but I have to wonder if it won't make things worse...What is methane converted into when burned?

Mostly carbon dioxide and water. Both are also greenhouse gases, but weaker ones.

[Amidus Drexel]

There are a lot of ways that you could do something like this... I imagine that if you wanted to collect waste gasses from farm animals, poultry plants would be a good place to start - they're already enclosed, so you don't need more than a regular gas filtering system (read: you don't have to make something like that float in the air and be retrievable). You could probably get enough gas to burn for energy from those, although I couldn't say how cost-efficient it would be.

[Admiral Squish]

There are a lot of ways that you could do something like this... I imagine that if you wanted to collect waste gasses from farm animals, poultry plants would be a good place to start - they're already enclosed, so you don't need more than a regular gas filtering system (read: you don't have to make something like that float in the air and be retrievable). You could probably get enough gas to burn for energy from those, although I couldn't say how cost-efficient it would be.

That would work fine to keep more methane from getting into the atmosphere (though, I have to say, I doubt barns and coops are particularly airtight), which would certainly be a good step. But the idea is removing the methane from the atmosphere to reduce the greenhouse effect.

Also, I just figured out how to adapt the design for high-altitude. You would need a significantly larger balloon, helium or similar, like a weather balloon, and replace the storage balloon with a hard canister. It's got to be strong enough to lift the canister, the pump, and a little computer/GPS (brain). Probably not bigger than a smartphone. It also needs to have a small stick/hook, and a little drone that can go hook and tow it.
You release the balloon just like a weather balloon, designed to float wherever methane's most dense. The pump does it's work, putting the methane into the hard canister. Once the canister reads full, it sends a signal to the little brain. The brain opens a valve and starts venting the helium until it reaches a certain altitude. Then it just waits. The drone hones in on the signal and flies up, catches the hook, and tows the little zeppelin back home. You then remove/replace the canister, recharge the battery, refill the helium balloon, and repeat.
There's always potential for problems with lightning strikes, birds, and such, but I'm sure somebody has/can figure out how to deal with 'em.

[Grinner]

Idea: Why not plug the collection unit directly into the cow?

[PallElendro]

Unfortunately, there is a lot of trouble with directly issuing organisms with these devices, both physical and ethical. I would have to plant these collectors around zones of interest.

[Eldan]

Idea: Why not plug the collection unit directly into the cow?

Has been done, actually. Usually by making an external opening directly into the stomaches.

[PallElendro]

Talked to some guys over on Star Trek Online. They tell me I need a zeolite derivative that can adsorb methane. If I can condense a zeolite that functions for methane and coat it with a sticky metal, I'd be able to trap methane.

[Admiral Squish]

Talked to some guys over on Star Trek Online. They tell me I need a zeolite derivative that can adsorb methane. If I can condense a zeolite that functions for methane and coat it with a sticky metal, I'd be able to trap methane.
To google! *rapid research*

So you have to manufacture a zeolite derivative, then coat it in metal, then drop it in a hole somewhere. You have to pay for the zeolite, the metal to coat it with, and then pay rent/taxes on the land you dump it in forever. I'm just saying, it's not cheap and when you're done with the task you just have tons and tons of coated zeolite with nothing to do with it.

The problem in filtration is that methane's a medium-sized molecule. You could set up two filters, one with holes large enough for methane to fit through, and another with holes just a little too small. You then vaccum from the small side. Larger particles get stopped on the far side, methane gets stuck in the middle, and all the smaller ones go through. Then you stop the suction, partition the sections, then vacuum out all three. The two sides go out, the methane goes to containment somewhere to be later polymerized/burned/encapsulated whatever. It seems like it would be slow, though.

[Eldan]

That would still be far too unspecific. Molecules aren't often sorted by size, that's too vague. You could probably improve it by also filtering out hydrophilic molecules, but even then, you wouldn't get just Methane.

[Autopsibiofeeder]

Most of the CH4 is produced outside. How are you going to lead all that air through your trap? CH4 concentrations are so low that it may cost too much energy to do so?

[Douglas]

Some quick googling says there is ongoing research into methane-adsorbing zeolites, with some promising results published April last year. Article (https://www.llnl.gov/news/newsreleases/2013/Apr/NR-13-04-03.html)


So you have to manufacture a zeolite derivative, then coat it in metal, then drop it in a hole somewhere. You have to pay for the zeolite, the metal to coat it with, and then pay rent/taxes on the land you dump it in forever. I'm just saying, it's not cheap and when you're done with the task you just have tons and tons of coated zeolite with nothing to do with it.
Why the hell would you dump it in a hole and bury it? Gather the purified methane off of it, pump it into a generator, and burn it for power generation you can sell.


Most of the CH4 is produced outside. How are you going to lead all that air through your trap? CH4 concentrations are so low that it may cost too much energy to do so?
Put the trap in a naturally windy area? Just ask the folks who sell electricity from wind-powered generators, they've already got a long list of impressively high-volume windy areas.