Posting in Energy
UCLA and South Korean researchers create record-breaking nano-materials capable of storing carbon dioxide and hydrogen gases.
Since the 1990s when MOFs were invented, researchers have been making strides in how much gas the structures can hold. They've done this by increasing the crystal's surface area through intensifying its porosity.
And now, MOFs are more holey than ever.
Publishing this month in the journal Science, chemists at UCLA's California NanoSystems Institute and Soongsil University in Seoul, South Korea report how they have broken the record for the porosity of a nano-material. Apparently, twice as many very tiny cavitities are now possible in the very tiny crystals of MOF-200 and MOF-210.
With twice as many holes, the nano-materials can store twice as much gas. And one gram of the new crystals—about the size of four sugar pills—goes a long way, according to the researchers.
The AP quotes Omar Yagh, the study's senior author:
If I take a gram of MOF-200 and unravel it, it will cover many football fields, and that is the space you have for gases to assemble. It's like magic. Forty tons of MOFs is equal to the entire surface area of California.
Earlier this year, SmartPlanet's Andrew Nusca discussed some of the researchers' previous work (see: Chemists create synthetic 'gene' to capture carbon dioxide)
According to a statement, low-cost ingredients such as zinc oxide and terephthalate, found in plastic bottles, can comprise MOFs, which can be specified to trap certain gases. The researchers hope industrial applications for the crystals could include helping capture emissions of carbon dioxide, a greenhouse gas, and storing hydrogen as a fuel.
BASF, a German company that produces large amounts of MOFs, helped fund the study.
Related on SmartPlanet:
- Chemists create synthetic 'gene' to capture carbon dioxide
- Rocket tech tries to put emissions on ice
- Rising debate over carbon sequestration: should we bury it?
Jul 18, 2010
This is not all new. In the late 1970's, Roger Billings found that sponge lithium could hold more H2 gas at room temperature than an equal volume of liquid hydrogen. That was in the push for hydrogen powered vehicles, under Carter. The reason it never made its way into products was that there was no ready source of hydrogen gas. Later, in the late years of the '90's, they used palladium concentrate hydrogen for the "cold fusion" experiments. the basic work on hydrogen being concentrated by various metals was done in the 1930's (I think). So, the use of materials that store gasses interstitially is not new. These materials are what is new.
The question of "how much CO2 can be stored in 40 tons of dry ice" goes to the "pound of feathers/pound of lead" juxtaposition. Dry ice is a little less than 100 pounds per cubic foot dependent on the ambient temperature. Given that, a 40 ton block would be approximately 10' X 10' X 10'. (A bit less but it makes for a nice round number and you have to consider some sort of vessel). In a liquid state, refrigerated and contained under pressure CO2 is about 64 pounds per cubic foot. The problem that I see is are we proposing to store and/or capture "dirty" CO2? To reuse it for any commercial purposes it must be in excess of 99% pure. Encapsulate it all you want but if it is "dirty" I suspect that it will be considered hazardous or toxic waste unless of course it can purified for reuse prior to or after such containment. To think we can start "sucking" CO2 out of the atmosphere for some form of containment is tantamount to "sucking" all the contaminants from the oceans with a soda straw or two.
Dry Ice has the obvious problem of maintaining the temperature without creating a greater environmental problem. (We might ship it into space, except we need both the carbon and the oxygen, which points storage not being a valid solution anyway.) On the other hand we can compute how much CO2 can be stored in 40 tons of dry ice. For this 'improved' MOF we are told that the internal surface area is greater than California, which seems to beg the critical question.