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Zeolite retains heat indefinitely, absorbs 4x more heat than water

extremetech.com

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Re: Zeolite retains heat indefinitely, absorbs 4x more heat than water

#11

Post by ktizo »

ChuckMcM wrote: post #6
ktizo wrote: post #2

So, assuming it is cheap and available, that's storage for solar power solved.

Not exactly but its a good start. But some interesting ideas come to mind. Using a conveyor to carry Zeolite to the top of a CSP plant and take the resulting stuff down to the reservevoir where its dumped into steam generators for turbines. If it replaced molten sodium as the working 'fluid' then that would make construction of such plants somewhat less challenging from an engineering perspective. I miss the days whe…

Why not exactly? Is basically decent heat storage and transfer with fairly low losses and minimal decay. Silos of these seem perfect for solar.

Admittedly the big question, if you were going to rely on it, is whether there is enough zeolite globally to scale to the terawatt-hour range.

Re: Zeolite retains heat indefinitely, absorbs 4x more heat than water

#12

Post by ktizo »

jerf wrote: post #8
ktizo wrote: post #2

So, assuming it is cheap and available, that's storage for solar power solved.

I'd like to see some energy density numbers in units I can understand before I would jump up and down about this use. (I'm not saying you're wrong so much as saying I can't provide evidence you're right, and I'm hoping someone else can. Or at least tell us what exactly "the heat storage capability of water" is such that something can have 4 times as much. Please hold wild-assed guesses, please, I can compute the ener…

Fair point. Although the exact energy per volume is a less important measure, given that we know the ballpark, than the energy stored per energy invested, and the maximum storage available when considered as a commodity in the market and resource availability.

Re: Zeolite retains heat indefinitely, absorbs 4x more heat than water

#14

Post by Splines »

rcthompson wrote: post #3

Short version of the science: The heat is released via an exothermic chemical reaction between the Zeolite and water. However, unlike the one-time-use chemical-reaction heating pads you can buy in a pharmacy, this reaction is reversible, so you can "recharge" the Zeolite by heating it and removing the water as it is released in order to force the reaction to reverse itself. The reaction goes something like this: Zeol…

On that topic, does anyone know how these things work?

http://www.amazon.co.uk/Magic-Gel-Reusable-Hand-Warmer/dp/B0...

I've seen them in person and they're remarkable if you've never encountered them before.

Re: Zeolite retains heat indefinitely, absorbs 4x more heat than water

#16

Post by excuse-me »

rcthompson wrote: post #3

Short version of the science: The heat is released via an exothermic chemical reaction between the Zeolite and water. However, unlike the one-time-use chemical-reaction heating pads you can buy in a pharmacy, this reaction is reversible, so you can "recharge" the Zeolite by heating it and removing the water as it is released in order to force the reaction to reverse itself. The reaction goes something like this: Zeol…

Recharging it isn't that simple

We use zeolite as a water scavenger in high vacuum systems, it's tremendously good at grabbing onto water BUT because it's so porous and very low thermal conductivity it's a real pain to heat it enough to get all the water out again. We have a heater resistor at the bottom of a small can of this and the top of the pellets a few cm away is cool enough to touch. You might do better with a microwave system but then the inefficiencies are going to hurt.

Why not use one of the many phase change salt solutions that are also used for rechargeable heater packs?

Re: Zeolite retains heat indefinitely, absorbs 4x more heat than water

#17

Post by samstave »

rcthompson wrote: post #3

Short version of the science: The heat is released via an exothermic chemical reaction between the Zeolite and water. However, unlike the one-time-use chemical-reaction heating pads you can buy in a pharmacy, this reaction is reversible, so you can "recharge" the Zeolite by heating it and removing the water as it is released in order to force the reaction to reverse itself. The reaction goes something like this: Zeol…

If they could use a similar process to how aerogel is made, creating a foam structure of the zeolite, then surface area would be considerable.

Re: Zeolite retains heat indefinitely, absorbs 4x more heat than water

#18

Post by hexagonal »

Splines wrote: post #14
rcthompson wrote: post #3

Short version of the science: The heat is released via an exothermic chemical reaction between the Zeolite and water. However, unlike the one-time-use chemical-reaction heating pads you can buy in a pharmacy, this reaction is reversible, so you can "recharge" the Zeolite by heating it and removing the water as it is released in order to force the reaction to reverse itself. The reaction goes something like this: Zeol…

On that topic, does anyone know how these things work? http://www.amazon.co.uk/Magic-Gel-Reusable-Hand-Warmer/dp/B0... I've seen them in person and they're remarkable if you've never encountered them before.

Sodium Acetate.

https://en.wikipedia.org/wiki/Sodium_acetate

Re: Zeolite retains heat indefinitely, absorbs 4x more heat than water

#19

Post by limmeau »

Splines wrote: post #14
rcthompson wrote: post #3

Short version of the science: The heat is released via an exothermic chemical reaction between the Zeolite and water. However, unlike the one-time-use chemical-reaction heating pads you can buy in a pharmacy, this reaction is reversible, so you can "recharge" the Zeolite by heating it and removing the water as it is released in order to force the reaction to reverse itself. The reaction goes something like this: Zeol…

On that topic, does anyone know how these things work? http://www.amazon.co.uk/Magic-Gel-Reusable-Hand-Warmer/dp/B0... I've seen them in person and they're remarkable if you've never encountered them before.

I think there's a saturated solution of sodium acetate inside. The metal clickie causes the solution to crystallize, which happens to happen exothermically.

(IANAchemist)

Re: Zeolite retains heat indefinitely, absorbs 4x more heat than water

#20

Post by hexagonal »

jerf wrote: post #8
ktizo wrote: post #2

So, assuming it is cheap and available, that's storage for solar power solved.

I'd like to see some energy density numbers in units I can understand before I would jump up and down about this use. (I'm not saying you're wrong so much as saying I can't provide evidence you're right, and I'm hoping someone else can. Or at least tell us what exactly "the heat storage capability of water" is such that something can have 4 times as much. Please hold wild-assed guesses, please, I can compute the ener…

The term of art you're looking for is "specific heat".

https://en.wikipedia.org/wiki/Specific_heat

The relevant number for water at 25C is 4.184 joules per gram. But this isn't a strict apples to apples comparison: if you heat and cool zeolite in a vacuum chamber, it'll have a pathetic specific heat. (Like perlite, another foamed mineral, which has a specific heat of something like 0.1) That's because there's a chemical reaction taking place, not pure dumb-matter heating or cooling.

Meanwhile, the energy density of a lithium ion battery is 720 joules per gram, and the energy density of gasoline is 47,200 joules per gram. This does not "solve" energy storage, in any way, shape, or form.

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