Monday, March 12, 2007

Zeolite Refrigerants.

Claude Blaizat is a French inventor who has patented the use of zeolites in the transfer of heat using the evaporation and condensation of water in a closed vacuum-system. I have discussed zeolites previously in their application as ion-exchange materials for cleaning toxic metal cations from the environment. For example half a million tonnes of zeolites were used in the clean-up operation after the disaster at Chernobyl in 1986, mainly to remove radioactive strontium and caesium from contaminated land and water supplies. Zeolites were fed to cows to keep the radioactive contamination out of their milk, and even baked into bread and cookies to remove similar contamination from the bodies of children. It is the presence of cations, which are strongly hydrated by water, that provides the basis of the zeolite-cooling system. In its simplest form, water is placed at one end of the apparatus the the dried zeolite at the other. The whole is pumped-out under vacuum which encourages the water to evaporate, so taking heat from its surroundings and providing cooling. The water vapour is adsorbed into the zeolite, which causes heating. Because the heat of hydration of the cations is greater than the heat of condensation of liquid water, around twice the amount of heat is generated by using the zeolite. Such systems can be combined with a solar collector, so that during the day, water is driven out of the zeolite by the heat from the Sun's rays, and at night heat is provided by evaporation and re-adsorption of water into the zeolite. The principle can be incorporated into a heating-system.
It is reported that the technology has been demonstrated in the food industry, for quick evaporative cooling of fresh and cooked products resulting in freezing with a minimum effect of the quality of the food, and also blanching, cooking and cooling fruits and vegetables without any production of wastewater and also for freeze-drying food. Large refrigerated containers have also been demonstrated of up to 10,000 gallons capacity that do not require energy to keep their cargo cool, just so long as there is water in the system to be evaporated and the zeolite is not saturated with water. A heat-pump that could draw its energy either from a renewable source like biomass or from the exhaust gas of an engine has also been demonstrated. In the latter example, cold water can be provided in an air-conditioning unit for truck or train cabs or even for drinking.
Writing in "Chemical and Engineering News" Jean-Paul Vignal commented: "That this technology has never been industrially developed puzzles me. Maybe the price of oil is still way too low and the greenhouse effect way too unproven? The Department of Energy and the Natural Resources Ecology lab. told me that the matter had been extensively investigated and that it would never work. I have seen it work well and maintain a 22-foot container between 0 and 3 deg. C for several days without wires or an onboard generator."
If true the latter does sound like an amazing device, but even as applied on the smaller scale of a solar-powered adsorption cooling tube, 4 kg of water can be heated to about 50 deg. C in daytime and to about 39 deg. C at night while also producing a refrigeration capacity of about 276 kJ. This amounts to a heating power of around 5 kW... and all for free in terms of energy input! Combined with the waste heat from the exhaust of an engine, water at 8 - 12 deg. C can be provided for the fan-coil in a locomotive operator cabin, and 10 kW might thus be achieved.

17 comments:

Lawrence said...

How are the zeolites manufactured and at what costs?

energybalance said...

Most zeolites, certainly those used for applications like this, are naturally occurring minerals and are mined. They can be synthesised on a large scale e.g. for cracking oil into gasoline etc. in the petroleum industry, and there are various methods for this. If you look through these postings there a a few articles about zeolites, which will tell you more.

Regards,

Chris Rhodes.

energybalance said...

Oh, cost? They are somewhere around $100 per tonne - more or less, depending on how much zeolite there actually is in the mineral (that's for clinoptilolite).

Jean-Paul VIGNAL said...

Thank you very much for posting this comment on Claude Blaizat’s work with zeolite. For the record, my message was supposed to be humorous. There is indeed nothing amazing or magic in the zeolite/water/vacuum technology. It’s just a quite simple way to produce usable cold from low level heat sources. What is amazing is that no company has ever decided to market equipment based on this technology.

Sincerely,

Jean-Paul Vignal
jaypeevee(a)aol.com

energybalance said...

Hi,

I felt there was some tongue-in-cheek aspect of your message, nonetheless, it is odd that the technology has not been exploited. Probably there is no incentive so long as there is enough cheap oil. Since that resource is going to run-out beginning in 10 years or so (I estimate) the incentive to exploit forms of serious energy saving strategies may well emerge.

I agree, there are some very interesting devices (heat-pump systems) based on zeolites, as I have written about in a forthcoming article for the Royal Society of Chemistry. I am checking the proofs now but it is called "Zeolites - Physical Aspects and Environmental Applications" and will be published in Annual Reports on the Progress of Chemistry, 2007, Vol. 102, p. 1-39.

If you like, I can send you a reprint when I have them. I just need your e.mail address.

Thanks for your interest in my blog, which aims to look at the broader context of energy provision and energy saving into the future.

Regards, Chris Rhodes.

Anonymous said...

Chris,


Thank you very much for your message. I would indeed appreciate if you could send me this article. My e-mail is jaypeevee@aol.com. If you have any question, please do not hesitate to contact me. Claude Blaizat has worked this subject since almost 30 years now, and I would be surprised if we could not come with an appropriate answer.

Best regards,

Jean-Paul

Tahir said...

Hi Chris
I need your paper published in Annu. Rep. Prog. Chem 102: 1-39, 2007
Regards
Tahir

energybalance said...

Hi Tahir,

if you give me your e.mail address I will try to send you a copy of it.

Regards,

Chris.

Tahir said...

Hi Chris
My email is:
trashid@ecoventure.ca
Thanks
Tahir

Tahir said...

Hi Chris
I am waiting for the paper

energybalance said...

I sent it to you three days ago. I have just sent it again.

Are you a student by the way?

Eldhose said...

Hi Chris,
Thanks for posting this.
This idea is interesting.
Could you please send me a copy of your paper "Zeolites - Physical Aspects and Environmental Applications"?

My E-mail ID : eldhoseiype@gmail.com

Thanks
Eldhose

energybalance said...

I am sending the proofs of the article as a pdf file to your e-mail address. The final
version is almost identical.

I hope it's useful to you.

If you quote it (or from it) would you please cite as follows:

C.J.Rhodes, "Zeolites: Physical Aspects and Environmental Applications," Annual Reports on the Progress of Chemistry, Sect. C: Phys. Chem., 2007, 103, 287.

Regards,

Chris.

Iqbal said...

Hi Chris,
I'm doing my practical semester on zeolith adsorption heat pump.
I would be very grateful if you can send me your paper "Zeolites - Physical Aspects and Environmental Applications".
This would really help me much!
Thanks in advance!

My email ID: ichbal85@yahoo.com.my

Sivan said...

I need a copy of your "Zeolite-Application aspects and environmentac application"
You can send it thro my e-mail id.
ukgemspondy@gmail.com.
Sundaram. India

Anonymous said...

hi
Chris
i m very much interested in knowing more about use of zeolites for refrigeration could please mail me your paper Zeolites - Physical Aspects and Environmental Applications
my email id is suhasbhagat@aol.com
please send an copy i will really appreciate it.

Chris Rhodes said...

I don't have a copy of that article available but this might be useful to you on the subject:

http://fc.uni.edu.pe/mhorn/ISES2003%20%28solar%20refrigeration%29.pdf

Regards,

Chris