Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[smjjames]

Sure.  How about some data in favor of eating the rich?

100 Companies Are to Blame For 71% of The World's Greenhouse Gas Emissions

Further proof that replacing coal with natural gas would help save the planet.

It would be even better to replace natural gas with something else

[Lord Shonus]

There will always be a place for some sort of fuel-based power generation, because renewables or nuclear power can't adapt quickly to drastic changes in power needs, while fuel based systems can.

Of the available options, natural gas is by far the best - not only is it very clean burning, but you can fuel a natural gas plant with methane. Not only is methane something that can be obtained in virtually unlimited supply, it is a dangerous greenhouse gas in and of itself, and can be extracted from the atmosphere relatively easily. This means that dangerous pockets of methane can be harvested (relatively) harmlessly, but also that it can be used as a chemical "battery" for excess renewable-based power.

[Doomblade187]

Sure.  How about some data in favor of eating the rich?

100 Companies Are to Blame For 71% of The World's Greenhouse Gas Emissions

Further proof that replacing coal with natural gas would help save the planet.

It would be even better to replace natural gas with something else

Yes, but market pressures are already forcing many utilities to run Natural Gas instead of Coal.

[MrRoboto75]

There will always be a place for some sort of fuel-based power generation, because renewables or nuclear power can't adapt quickly to drastic changes in power needs, while fuel based systems can.

Of the available options, natural gas is by far the best - not only is it very clean burning, but you can fuel a natural gas plant with methane. Not only is methane something that can be obtained in virtually unlimited supply, it is a dangerous greenhouse gas in and of itself, and can be extracted from the atmosphere relatively easily. This means that dangerous pockets of methane can be harvested (relatively) harmlessly, but also that it can be used as a chemical "battery" for excess renewable-based power.

mmmmm cow fart power

[SalmonGod]

You mean... pig gas!

[Trekkin]

There will always be a place for some sort of fuel-based power generation, because renewables or nuclear power can't adapt quickly to drastic changes in power needs, while fuel based systems can.

That is to some degree mitigable by grid storage solutions on a municipal scale, though, and while technologies like pumped hydroelectric or molten salt don't scale down well, hydrogen or superconducting batteries potentially could.

So yes, there's a place, but it's smaller than our fickle power demands would indicate.

[Max™]

Let me just say as a Texan, I never need to use anything except "pardon" and "ya'll" to avoid sticky possible obscure situations, but I have a pre-emptive stutter effect with certain initial sounds so I learned to avoid being locked into saying certain things in a certain way to prevent the syllable blockage, noting that as an asshole I never need to care about any of those situations in the first place, your choosing to be offended and get all frothed up at my innocent mistake is entirely on you and my only obligation is to point and laugh while noting that "u mad" if it comes up.

Sure.  How about some data in favor of eating the rich?

100 Companies Are to Blame For 71% of The World's Greenhouse Gas Emissions

Further proof that replacing coal with natural gas would help save the planet.

I mean, saved for what is the question you'll get from these rich fuckers, they can't take it with them, so they're obligated to burn it all up first right?

[redwallzyl]

Strangely enough "guys" has become a gender neutral plural where I'm from.

[Doomblade187]

Strangely enough "guys" has become a gender neutral plural where I'm from.

I use it as one personally.

[Kagus]

Methane can be harvested from the atmosphere? I thought most air-filtration harvesting methods were about as effective as those ion air purifiers at doing nothing for a steep price.

[wierd]

If you compress and chill atmospheric gasses, they will stratify.  Methane has a very very low freezing point, but a reasonably high vapor transition point. (eg, oxygen, nitrogen, and pals will stay gasses while methane will turn liquid.)  CO2 has a pretty high freezing point, comparatively.

[Trekkin]

If you compress and chill atmospheric gasses, they will stratify.  Methane has a very very low freezing point, but a reasonably high vapor transition point. (eg, oxygen, nitrogen, and pals will stay gasses while methane will turn liquid.)  CO2 has a pretty high freezing point, comparatively.

I suspect Kagus was asking if methane harvesting by air liquefaction is economical, not merely if it's possible, given the subsequent comment about price.

So, weird, given your evident familiarity with cryogenic air separation, what is the energy input required to separate out the methane from a given quantity of atmospheric air relative to the energy provided by the methane in that air?

Just to be clear, I am asking for actual numbers here.

[SaberToothTiger]

replace all forms of address with "m8"

problem solved, m8s

[Enemy post]

G8 idea m8.

[McTraveller]

If you compress and chill atmospheric gasses, they will stratify.  Methane has a very very low freezing point, but a reasonably high vapor transition point. (eg, oxygen, nitrogen, and pals will stay gasses while methane will turn liquid.)  CO2 has a pretty high freezing point, comparatively.

I suspect Kagus was asking if methane harvesting by air liquefaction is economical, not merely if it's possible, given the subsequent comment about price.

So, weird, given your evident familiarity with cryogenic air separation, what is the energy input required to separate out the methane from a given quantity of atmospheric air relative to the energy provided by the methane in that air?

Just to be clear, I am asking for actual numbers here.

This is veering off Ameripol...

Spoiler (click to show/hide)

There are any number of online and hard-copy resources for the heat capacities and latent heats of fusion of atmospheric gases.  But also remember that you need roughly 10000kg atmosphere to get 1kg methane.  If you are using cooling, you'd better have a very efficient process, because the energy to cool 10000kg air down to the boiling point of methane dwarfs the heat of combustion of methane.  Air (which includes methane) takes about 1kJ to cool 1kg by 1K. You only get 55000 kJ/kg for combusting methane.  10k kg * 175K of cooling (288K down to 111K) is roughly 175000kJ - so at least three times the energy you get from combustion.

I realize that is assuming constant atmospheric pressure; I didn't do the math to see the energy balance if you want to compress it first (but note that compressing adds heat, which you'd have to cool away... so it may not help).

If you want methane from air, you're better to use some other mechanism than cooling. Look for catalysts, or something.  Note that is how most CO2 sequestering approaches are done - they look for materials that chemically pull the CO2 out, rather than use cooling.