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That enclosure has a huge volume - area the size of several football fields, and at least 15 stories high. The article says it holds 2k tons of co2, which is ~1,000,000 cubic meters in volume.
CO2 is denser than air will pool closer to the ground, and will suffocate anyone in the area.
See https://en.wikipedia.org/wiki/Lake_Nyos_disaster
Edit: It holds 2k tons, not 20K tons.
what happens if that large enclosure fails and the CO2 freely flows outside? That enclosure has a huge volume - area the size of several football fields, and at least 15 stories high. The article says it holds 2k tons of co2, which is ~1,000,000 cubic meters in volume. CO2 is denser than air will pool closer to the ground, and will suffocate anyone in the area. See https://en.wikipedia.org/wiki/Lake_Nyos_disaster Edi…
what happens if that large enclosure fails and the CO2 freely flows outside? That enclosure has a huge volume - area the size of several football fields, and at least 15 stories high. The article says it holds 2k tons of co2, which is ~1,000,000 cubic meters in volume. CO2 is denser than air will pool closer to the ground, and will suffocate anyone in the area. See https://en.wikipedia.org/wiki/Lake_Nyos_disaster Edi…
It would not be good, but it wouldn't be Bhopal. And there are still plenty of factories making pesticides.
No mention of round-trip efficiencies, and claims are that it's 30% cheaper than Li-Ion. Which might give it an advantage for a while, but as Li-Ion has become 80% cheaper in the last decade that's not something which will necessarily continue. Great if it can continue to be cheaper, of course. Fingers crossed that they can make it work at scale.
I'm seeing round trip efficiencies around 75%. That's not terrible. These things would probably pair well with district heating and cooling.
...in 2019, the U.S. utility-scale battery fleet operated with an average monthly round-trip efficiency of 82%, and pumped-storage facilities operated with an average monthly round-trip efficiency of 79%....
Does pure-ish CO2 have advantages over regular air or the freon-like substance used in air conditioning? How much energy us used to purify and maintain the CO2?
It's easy to liquefy, so it has a density advantage over air, and would be bad if released but not super bad.
Earlier quoted context omitted.
Lithium supply is limited. So an alternative based on abundant materials is interesting for that reason I guess?
Lithium is not that limited, current reserves are based on current exploration. More sources will be found and exploited as demand grows. And if you want an alternative, sodium batteries are already coming online.
Sodium iron phosphate batteries, if Li prices don't continue to fall, will be some of the cheapest batteries out there. If they can be made solid state then you are looking at batteries that will dominate things like grid and home power storage.
what happens if that large enclosure fails and the CO2 freely flows outside? That enclosure has a huge volume - area the size of several football fields, and at least 15 stories high. The article says it holds 2k tons of co2, which is ~1,000,000 cubic meters in volume. CO2 is denser than air will pool closer to the ground, and will suffocate anyone in the area. See https://en.wikipedia.org/wiki/Lake_Nyos_disaster Edi…
The last section of TFA is called "What happens if the dome is punctured?". The answer: a release of CO2 equal to about 15 transatlantic flights. People have to stand back 70m until it clears. It would not be good, but it wouldn't be Bhopal. And there are still plenty of factories making pesticides.
Also that statement of 70 meters seem very off, looking at the size of the building. What leads to suffocation is the inability to remove co2 from your body rather than lack of oxygen, and thus can be life threatening even at 4% concentration. It should impact a much much larger area.
Earlier quoted context omitted.
Lithium supply is limited. So an alternative based on abundant materials is interesting for that reason I guess?
There are over 200 billion tonnes of lithium in seawater, it's just the least economical out of all sources of this element. There are plenty more, but they're explored only when there's a price hike.
What I'm somewhat surprised about is that we've not seen synergies with desalination and ocean mineral extraction. IDK why the brine from a desalination plant isn't seen as a prime first step in extraction lithium, magnesium, and other precious minerals from ocean water.
Earlier quoted context omitted.
The last section of TFA is called "What happens if the dome is punctured?". The answer: a release of CO2 equal to about 15 transatlantic flights. People have to stand back 70m until it clears. It would not be good, but it wouldn't be Bhopal. And there are still plenty of factories making pesticides.
Comparing it to X flights maybe correct from a greenhouse emissions standpoint, but extremely misleading from a safety perspective. A jet emits that co2 spread over tens of thousands of miles. The problem here is it all pooled in one location. Also that statement of 70 meters seem very off, looking at the size of the building. What leads to suffocation is the inability to remove co2 from your body rather than lack of…
This seems almost too good to be true, and the equipment is so simple that it would seem that this is a panacea. Where are the gotchas with this technology? Clearly power capacity cost (scaling compressors/expanders and related kit) and energy storage cost (scaling gasbags and storage vessels) are decoupled from one another in this design; are there any numbers publicly available for either?
As far as the storage vessel, CO2 has much lower pressure demands than something like, say, hydrogen. On something like a paintball marker the burst disc (i.e. emergency blow off valve) for a CO2 tank is in the range of of 1500-1800PSI [0].
A compressed air tank that has a 62cubic inch, 3000PSI capacity, will have a circumference of 29cm and a length close to 32.7cm, compared to a 20oz CO2 tank that has a circumfrence of 25.5cm and a length of around 26.5cm [1]. The 20oz tank also weighs about as much 'filled' as the Compressed air tank does empty (although compressed air doesn't weigh much, just being through here).
And FWIW, that 62/3000 compressed air vs 20oz CO2 comparison... the 20oz of CO2 will almost certainly give you more 'work' for a full tank. When I was in the sport you needed more like a 68/4500 tank to get the same amount of use between fills.
Due to CO2's lower pressures and overall behavior, it's way cheaper and easier to handle parts of this; I'm willing to bet the blowoff valve setup could in fact even direct back to the 'bag' in this case, since the bag can be designed pessimistically for the pressure of CO2 under the thermal conditions. [2]
I think the biggest 'losses' will be in the energy around re-liquifying the CO2, but if the system is closed loop that's not gonna be that bad IMO. CO2's honestly a relatively easy and as long as working in open area or with a fume hood relatively safe gas to work with, so long as you understand thermal rules around liquid state [also 2] and use proper safety equipment (i.e. BOVs/burst discs/etc.)
[0] - I know there are 3k PSI burst discs out there but I've never seen one that high on a paintball CO2 tank...
[1] - I used the chart on this page as a reference: https://www.hkarmy.com/products/20oz-aluminum-co2-paintball-...
[2] - Liquid CO2 does not like rapid thermal changes or sustained extreme heat; This is when burst discs tend to go off. But it also does not work nearly as well in cold weather, especially below freezing. Where this becomes an issue is when for one reason or another liquid CO2 gets into the system. This can be handled in an industrial scenario with proper design I think tho.