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

Re:Zeolite retains heat indefinitely, absorbs 4x more heat t... by excuse-me on Wednesday June 06, 2012 @03:32PM (#4075699)

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?

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Re:Zeolite retains heat indefinitely, absorbs 4x more heat t... by rcthompson on Wednesday June 06, 2012 @06:53PM (#4076618)

Is it such a major problem that it leads to major efficiency losses (measured as joules of output energy over joules of input energy required to "recharge")?

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Re:Zeolite retains heat indefinitely, absorbs 4x more heat t... by gte910h on Wednesday June 06, 2012 @06:23PM (#4076521)

A drum dryer like you use for clothing sounds built to take water out of these things (with grates smaller than the pellets of course).

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Re:Zeolite retains heat indefinitely, absorbs 4x more heat t... by excuse-me on Wednesday June 06, 2012 @06:53PM (#4076617)

The stuff is fragile (or at least the 5nm molecular sieve type)- if you shake it too much you make dust which blocks the pores

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Re:Zeolite retains heat indefinitely, absorbs 4x more heat t... by Zaak on Wednesday June 06, 2012 @03:46PM (#4075794)

I wonder if you could incorporate a wire mesh into the zeolite to improve the heat distribution.

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Re:Zeolite retains heat indefinitely, absorbs 4x more heat t... by olefoo on Wednesday June 06, 2012 @06:39PM (#4076568)

If you could figure out a good way to integrate the heating element and the the zeolite on a surface like a menger sponge you would have a very high surface area and good thermal response characteristics.

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Re:Zeolite retains heat indefinitely, absorbs 4x more heat t... by nwmcsween on Thursday June 07, 2012 @03:41AM (#4078000)

> ..microwave system but then the inefficiencies are going to hurt.

What inefficiencies? A microwave should be more efficient due to it only energizing H2O bonds.

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Re:Zeolite retains heat indefinitely, absorbs 4x more heat t... by rcthompson on Thursday June 07, 2012 @03:52AM (#4078017)

Surely a microwave oven is not 100% efficient in converting the input electrical energy into output heat in the object to be heated? I'm not sure how near 100% it is.

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Re:Zeolite retains heat indefinitely, absorbs 4x more heat t... by AnthonBerg on Thursday June 07, 2012 @05:16AM (#4078160)

Hey good question. Kitchen microwaves: ~64%

– http://en.wikipedia.org/wiki/Microwave_oven#Heating_efficien...

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Re:Zeolite retains heat indefinitely, absorbs 4x more heat t... by debacle on Thursday June 07, 2012 @11:20AM (#4079406)

That's actually pretty good.

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