Architectural Innovation and Energy Savings Could Result from Super-insulator Breakthrough
by Christine Lepisto, Berlin on 07. 3.08
Image credit: Roger Ressmeyer/CORBIS
Aerogel was invented in 1931. But at $3000 per kilogram, it's use has been limited to visionary projects and unique structural applications like reinforcement of tennis raquets. But that could change soon. Halimaton Hamdan, a Cambridge-trained professor of chemistry at the Universiti Teknologi Malaysia (Technical University of Malaysia), has announced the discovery of a cheap process for turning waste rice husks into aerogel. Actually into "Maerogel", as Hamdan has dubbed the "Malaysian aerogel".
The translucent, smoky material weighs only three times as much as air. It is, in fact, mostly air; air cleverly trapped in a silicon matrix which gives the material insulating properties 37 times better than fiberglass. The image demonstrates the insulating capability as a layer of aerogel prevents a blowtorch from burning the hand below.
Aerogel can also bear mechanical pressure of up to 2000 times its weight. The combination of low weight and strength make aerogel a multifaceted green construction material. As a coating for walls, the insulation could greatly reduce energy needs for air conditioning or heating. Thin layers verge on complete transparency, so aerogel sandwiched between panes of glass could achieve extremely energy efficient windows.
TreeHugger talked to a colleague of Hamdan, Dr. Dieter Freude of the University of Leipzig, who was quoted calling Hamdan's work "an exciting breakthrough". Freude confirms that the Hamdan's work shows great promise. He points out that knowledge of the possibility to purify a high quality silicon from rice husks pre-exists Hamdan's breakthrough. The true achievement in Hamdan's work is her goal-oriented translation of research into process development. Freude notes that it is not common in Malaysian universities for academics to develop processes for commercial application.
But this is where the excitement starts. Hamdan has had great success with processes at a small-scale pilot level. Hamdan has now received US$62.5 million in funding from the Malaysian government to demonstrate her process on a large scale. Hamdan expects that aerogel, or Maerogel, from her process will cost one-fifth as much as by conventional production methods. And, of course, there will always be plenty more rice husks.
Aerogel elsewhere in TreeHugger:
Greenshift Invests in Aerogel
Aerogel Roofing
Aerogel Walls, Japanese Style
Aerogel Building Design
Via tipster Syawal and ::IHT
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That is indeed very exciting! I'm hoping that the 'several' years quoted in the IHT article about the expected time before it makes its way into consumer products will be reduced to just a couple of years.
Aerogel is so cool it seems like science fiction. Would be awesome to see how people can apply it when it's not so darned expensive.
1/5th is still $600. A kilogram. 1/10th is $300.
I will be the first to admit aerogel is pretty cool and captured my imagination when I first saw it, but it's not even close to being a household material in the next decade or so. As for insulation, what's wrong with using straw bale so as to avoid the whole laboratory process to generate something you can get direct from the stalk? I'm sure there are other uses however that could benefit more.
a step in the right direction :)
To be fair, a kilogram is a _lot_ of aerogel.
"The translucent, smoky material weighs only three times as much as air. It is, in fact, mostly air; air cleverly trapped in a silicon matrix which gives the material insulating properties 37 times better than fiberglass. "
Seems like one gets a lot of material per kilo. $600 might go a long, long way.
Building a straw bale house is very labor intensive.
Highly insulating panels that could be glued together and then covered with a quick coat of 'stucco' could make for efficient houses. Attaching panels to the outside of existing concrete/mud houses could greatly improve the quality of life where AC/heating is difficult to afford.
Wait wait wait. There is silicon, element Si, in rice husks???
Yeah, Aerogel is very light, so 1kg is a lot of it. Also, you can actually get th density as low as 20% higher than that of air, by varying the amount of air trapped.
The strength reported is compression strength. The material is fragile if you aren't being very careful. So this stuff could be good as a layer between panes of glass, but I wouldn't expect to see stand-alone applications.
That said, I recently heard a colleague report (though it hasn't yet been published, let alone industrialized) a piece of aerogel stopping a bullet. Don't know what kind or at what range, but pretty cool.
I am a bit surprised that there would be so much silicon in rice husks. You would expect that these mostly consist of carbohydrates. However if rice husks are indeed a good source of pure silicon, it would be interesting to know if this could be a cheap source for the photovoltaics industry.
"Building a straw bale house is very labor intensive"
Not to mention that the big bad wolf might huff and puff and blow it down.
Straw bale is not recommended in hot, humid areas.
Cubic foot of air: .075 lbs
1 kg of air = .833 m^3
1 kg of aerogel = .2777 m^3
Works out to $2160 per cubic meter of gel
Spread a centimeter thick, it would take roughly 2 cubic meters to sheathe a small 1-story house in the stuff.
Seems like a better application for skylights which are great for lighting but lose heat like crazy in cold climes.