Let's not put asbestos like fibers in everything please: https://www.scientificamerican.com/article/carbon-nanotube-d...

They are already all around us, from the coal plants.

Asbestos was a construction material that was often exposed to mechanical forces. Battery cathode is the furthest from that.

And? It does not follow that we should make the situation worse given that we already messed it up badly by our previous ignorance.

Well, if carbon nanotubes give us much better batteries, we might be able to shut off the coal plants and diesel engines sooner.

Yes, but if this happens by increasing the risk of serious contamination of the environment? I think that we should not just ignore this.

The same thing happened with the CFL bulbs that contain mercury - how many of them were disposed correctly? Luckily for us these will be replaced by LED bulbs very soon.

... as compared to the known, ongoing and serious contamination of the environment due to coal plants, of course.

Do you have a citation for the CFL concern? I'm not expert in this area, but my quick checking only reveals this [1]:

> Even if the mercury contained in a CFL was directly > released into the atmosphere, an incandescent would > still contribute 4.65 more milligrams of mercury into > the environment over its lifetime.

Basically the same info from the EPA as well, here [2].

[1]: http://www.popularmechanics.com/home/reviews/a1733/4217864/

[2]: https://www.energystar.gov/ia/partners/promotions/change_lig...

But we're not talking about the atmosphere. That mercury goes directly into landfills.

I don't know why you're being downvoted, we should consider potential side effects in using a material, even if just so we can minimise potential downsides.

In his specific examples, it's grid-scale and cars, and neither of those are really disposed of the same way lightbulbs are (especially for grid-scale you can really crank up the regulation)

Putting them in phones would be a problem though.

Asbestos is only a problem if you inhale a reasonably large amount of it.

There are two (main) kinds of asbestos, what you write is true for one of those two, the other kind you should not be exposed to at all if it is airborne, it is super dangerous (the other is dangerous as well but not nearly as much).

Never ever grind/saw/sand/drill anything made with asbestos in it, just take it apart gently while wearing respiration gear and pack it in plastic, then deliver to a facility set up to handle it (where I live that is the municipality).

If you're dealing with sprayed on asbestos then let a professional company do the demolition, it is not worth lungcancer to save a few bucks and those people will have all the right equipment and will be able to remove it without releasing it into the environment.

"there is no 'safe' level of asbestos exposure for any type of asbestos fiber." [https://www.osha.gov/SLTC/asbestos/]

Surely, that amount would be unreasonable in any case.

Asbestos is similar to cigarettes i.e. it's based on chance.

You can get lung cancer as a non smoker. Or you can not get cancer whilst smoking a pack a day for 80 years. Each cigarette and similarly exposure to asbestos merely increases your chances.

If you inhale battery dust it's not going to end well for you, nanotubes or not. There's a difference between lining your walls with a foot thick of the stuff, and having a small amount in batteries. FYI we still use asbestos today, and it's a good idea as long as you're careful with it.

Would the nanotubes become airborne if the battery exploded?

Why would you use atmospheric carbon? It's incredibly energy-intensive to do so, and there are plenty of far saner sources available.

It's for carbon capture and storage, as a mechanism for slowing climate change.

A mechanism, maybe, but one so expensive, ineffective, and impractical as to be fantastic.

Splitting CO2 will always require more energy than was released in making it. Where does that energy come from? They say solar panels. Because of course they do. But why would you burn fossil fuels to make energy, then use solar panels to turn CO2 into batteries? Why not just use solar panels in the first place? It would be far more efficient.

Also, we put about 10 Gigatons of CO2 into the atmosphere each year. 2.7Gt of that is carbon. Just how many batteries are you planning on making from that? Does each person on Earth need half a ton of batteries?

Who's absorbing the astronomical costs of making batteries with atmospheric CO2, rather than with any of the sane carbon sources just lying around?

This plan is nonsensical. It's like solar roadways. It's stupidly expensive, and it just won't work. It's another bogus project dreamed up to make use of green tech research grants that will never see the light of day.

Half a ton of Lithium-ion for comparison is 50-100kWh of storage. Which actually isn't that crazy. A Tesla per person per year, give or take.

Depending on the lifetime of the batteries, it's probably not far from what it would actually take to switch over to renewable energy while bringing the rest of the world up to a western standard of life.

But you're absolutely right that it's nonsensical to harvest carbon from the atmosphere while you're still pumping it in. That's product design driven by PR, not engineering.

And that points to the rest of it being bullshit as well.

Solar power whether employed by plants or machines. I'd vote on plant absorption myself.

Many solar systems need batteries in the first place though. Of course, whether it is actually feasible to get the energy needed solely using solar panels is a different matter.

I believe you're right. I hold out some hope someone will come up with a magic atmospheric CCS, but realistically what we're doing is lying to ourselves that global-scale negative emissions will become feasible, because it's the only way we haven't already wrecked the planet.

https://www.youtube.com/watch?v=529Og_YR0IU

> But why would you burn fossil fuels to make energy, then use solar panels to turn CO2 into batteries?

Because airplanes cannot fly on solar/batteries just yet?

Anyway, I agree with your main point.

I suppose you've read James Hansen or Kevin Anderson's latest work on climate change, right?

Please illuminate us.

They represent their research better than I can. Just search for the names followed by "2016" and pick your favorite source...

The basic idea is that we are well beyond reasonable co2 levels and that geological time is just catching up. But again, I'm no substitute for these well regarded scientists so it's best to read their research. There's a science based show named radio ecoshock if you're interested.

Yes I imagine most people in the future will need a significant amount of batteries. For the home to store energy when the solar panels are not receiving sunlight e.g. Powerwall. And also for the car, phone, tablet, laptop etc. Batteries are going to be an increasingly critical part of the power lifecycle.

And solar roadways do work. But at least in current incarnations are better suited for pavements, open areas. And it may be expensive but that's only because we don't ascribe costs properly to fossil fuels e.g. carbon tax, health tax etc.

You can't slow climate change by expending more energy... that's not how entropy works.

Earth isn't a closed system

It has an energy budget. Which effects this proposal several ways.

We can (thermodynamic ally speaking) make a huge radiator going from the earth to the moon, warming up the moon and cooling off earth.

Will it happen in 5 (or 500) years? Probably not, but it's not an entropy issue.

How exactly are you going to build a radiator going from the Earth to the Moon?

Please keep in mind that:

1. A Space Elevator would be considerably shorter than the distance from Earth to Moon. Regardless, there is no known material strong enough to support its own weight, let alone a payload, to geostationary orbital heights. [1]

2. The Earth and Moon are not tidally locked. You'll need a slip-path around the Earth's equator (or a gimbal at a pole) to allow the Earth to spin underneath the radiator pipe. Which (at the equator) will be moving at roughly 1,000 mph (1,700 kph).

3. Heat doesn't flow from colder to hotter objects. You'll need a rather large heat pump to make this project work.

4. If you're planning on radiating Earth's heat to the Moon, well, I suppose you could create a large lasing facility. There's been some theoretical work done in this area which you might find ... illuminating.[2]

But keep in mind: there's no need to direct those beams at the Moon. Space itself is a sink, and will absorb any and all energy beamed to it. What's critical is to balance the Earth's energy budget, which is presently too great by roughly 0.60± 0.17W/m².[3] Given Earth's surface area of about 510 million km², that works out to an excess energy of 306 TW. That compares against 12.3 TW total human world energy consumption.[4]

Whilst I'm not a fan of such geoengineering projects, the concept of a solar sunshade, or equivalent aerosol blocking, strikes me as more tractable.[5] It's easier to keep energy off a thing than to get energy out of a thing. Though what's being discussed here are shades of never-gonna-happen impossibility.

________________________________

Notes:

1. See: https://en.wikipedia.org/wiki/Space_elevator Carbon nanotube is about the only material possibly having sufficient tensile strength, though even that is doubtful.

2. https://what-if.xkcd.com/13/

3. https://en.wikipedia.org/wiki/Earth%27s_energy_budget#Earth....

4. https://en.wikipedia.org/wiki/World_energy_consumption

5. https://en.wikipedia.org/wiki/Space_sunshade

That's why I said "thermodynamic-ally speaking". Not practically.

What? What does entropy have to do with it?

Virtually everything, as it happens.

When we get the political consensus to put a price on atmospheric carbon, it will give a subsidy to anyone who can make a solid material out of carbon. What will be the most economical way to get those subsidies? I don't think it will be making carbon nanotubes. That requires an extremely pure source of carbon. I think the biggest application will be construction materials:

Mine CaO, use atmospheric CO2 to convert it to CaCO3 this use that as feeder stock for making limestone-like and marble-like construction materials. These could be premium materials -- I could easily see Salesforce paying a premium to cover the floors of Salesforce tower in 'reclaimed atmospheric marble' to advertise their green creds -- or a down market material -- just mix it in to drywall to get the CO2 credits. Either way, this process would be much less fussy about the purity of the CO2 source.

If we ever do clean up the CO2 produced from consumption of oil the energy cost will be greater than the power gained from the initial consumption. I.e. Every watt of energy paid with oil must be paid with another form of energy plus interest.

of course, that's why everyone's talking about solar powered sequestering processes. oil is ultimately a solar battery, too.

Mostly, yes... You don't necessarilly need to turn CO2 back to hydrocarbon, there may be less expensive ways to capture and store that carbon. Still, you're correct that the costs will be gigantic.

The energy costs are largely in the sequestration of carbon from the atmosphere, or other biospheric sink. (Seawater is actually a highly viable reservoir and sequestration source.)

Once you've got the carbon, what you turn it into is relatively academic. Though if you do turn it into liquid hydrocarbons, it's 1) very long-term stable and 2) can be used, after the atmosphere returns to normal, which could be some centuries or longer, as fuel in dedicated applications so long as the net carbon cycle is appropriately managed.

Why do the costs need to be gigantic? Trees (and other plants) already do it for free, and they cost next to nothing to plant and maintain.

It's got to do with the volumes of carbon we're currently emitting, and which we have emitted.

Keep in mind that the carbon cycle was already in balance before humans started digging out gigatons of coal and pumping gigatons of petroleum. We've skewed that balance -- not by a terrible lot (or we'd have been in trouble a long time ago), but by enough.

The problem now is unwinding ~100 years of industrial fossil fuel use, quickly.

Remember that while plants fix carbon, it doesn't necessarily stay fixed, and you cannot release what you're fixing from the atmosphere if you want this to work.

Trees and plants don't fix CO2 "for free", they have a considerable energy budget they expend for this, and have other things to tend to as well (making leaves, drawing up water, fighting off disease and insects, feeding animals).

So you're talking about increasing plant growth beyond present levels, and preserving the carbon without allowing it to be re-released to the atmosphere for at least a few centuries. That's a tall order.

Humans fixing CO2 requires energy to do so, energy which will have to come from some non-emitting source (solar, wind, geothermal, and nuclear are the only really viable options, hydro, tide and wave are too small to matter), and will compete against other human energy uses. Renewables have their own considerable energy input requirements as well for construction and maintenance, which multiple credible sources find close to the limits which allow technological society to happen (see Charles A.S. Hall's work on EROEI, he's got a book in progress due out next year I believe on the topic).

It depends on the timescale you want to operate with.

Also, you'd need to reverse the topsoil destruction and the spread of agricultural exploitation, which is not going to be easy when the population keeps on growing.

Check your assumptions.

Population frequently finds itself checked, one way or another.

> "Every watt of energy paid with oil must be paid with another form of energy plus interest."

Luckily we have an energy source that can easily pay back that energy debt, the sun.

Yep I think that and more time are the key.

Carbon Nanotubes are the next "leaded gasoline"

For the reference: http://content.time.com/time/specials/packages/article/0,288...

They're asbestos after a week long meth binge. They treat your lungs like a paper target of Bernie at a Texas gun range.

Any source on that?

He huffed some nanotubes before writing that.

How can this powerplant idea work? You get the binding energy from carbo hydrates, then you need to add back more thsn that energy to capture and convert all CO2 back to nanotubes and oxygen. The excess energy comes from solar? Fine, may make sense, but that's not going to be an electrical powerplant anymore. It's a battery factory.

A solar battery factory would be great.

If you can cost effectively extract large quantities of CO2 from the atmosphere, the oil industry would be very interested. CO2 flood is one of the most effective enhanced oil recovery (EOR) methods. The problem is a lack of sources convenient to the oil fields. https://en.wikipedia.org/wiki/Carbon_dioxide_flooding

How much CO2 does a square meter of this remove from the atmosphere compared to a square meter of the most efficient plants?

Take for example moringa. It uses CO2, of course, and its leaves have tons of digestible nutrients. If an animal eats them, it can help maintain good health (separate measurement). If an animal who plants these trees eats them to maintain good health, then you would need to measure many more factors about that animal's life and other interconnected lives to understand the long-term emergent dynamics of healthy life and its effects on CO2.

Do carbon nanotubes biodegrade?

It's graphite basically

I would say it does

About as quickly as a lump of coal. There aren't many things that feed on raw carbon.

We need bacteria that does