James Dewar, frozen air and a new way to store energy

Today is the second time we meet up with Scottish scientist James Dewar. We’ve already discussed his ingenious Dewar flask, made famous by the Thermos company. As mentioned at the time, Dewar worked with some rather chilly subjects – liquified and frozen gases, to be exact – and he created his insulating flask to serve his practical need for a container that could maintain the low temperatures of the liquified gases he studied.

The reason Dewar pops up on this blog today, is again related to his low temperature work. It was on this day, 9 March 1893, that he informed a meeting of the Royal Society that he had succeeded in freezing air into a clear and transparent solid. As reported in The Manufacturer and Builder Volume 25 Issue 7, he requested additional funding to further study the exact properties of this frozen air; he postulated that “it may be a jelly of solid nitrogen containing liquid oxygen, much as calves’ foot jelly contains water diffused in solid gelatine. Or it may be a true ice of liquid air, in which both oxygen and nitrogen exist in the solid form.” Part of this confusion on the part of Dewar was that he had not been able to freeze pure oxygen, hence it was not clear how the oxygen part of the frozen air behaved.

I have no idea how frozen air would look, but it will surely be very, very chilly!(© All Rights Reserved)
I have no idea how frozen air would look, but it will surely be very, very chilly!
(© All Rights Reserved)

Interestingly, frozen air has recently resurfaced as an subject of research interest. As reported last year on various sites such as ecogeek, sustainable business.com and NBC News, a UK-based company Highview Power Storage has developed a proprietary process using cryogenic air (actually nitrogen, liquified at -321 degrees Fahrenheit) as a way to store energy. Available energy is used to freeze/liquify the nitrogen, which is then kept in its frozen form in a highly isolated, giant vacuum flask. When energy is required, the nitrogen is allowed to warm to ambient temperature, and the energy released during its transition to a gas phase, is harvested to drive a turbine that generates electricity.

While the technology is not yet able to achieve the efficiency of current battery technologies, it is a potentially less environmentally harmful, greener approach.

Now there’s a reason to raise a glass of very chilled liquid to James Dewar and his frozen air!

James Dewar, Thermos and the vacuum flask

Today we celebrate the birthday of Sir James Dewar, Scottish chemist and physicist, born on 20 September 1842.

Dewar was a dynamic, innovative scientist who was responsible for many scientific advances in both chemistry and physics at the turn of the century, but is perhaps best remembered for an innovation that he never received any financial recognition for. In 1892 he developed an insulating flask known as the Dewar flask, which became the inspiration for the legendary Thermos insulating flasks. The design of Dewar’s vacuum flask, commercially introduced by Thermos in 1904, is so simple and elegant that it has remained virtually unchanged to this day, and it remains as useful as it was more than a century ago.

A thermos flask and a steaming cuppa – gotta love a simple, effective design.
(© All Rights Reserved)

Dewar’s initial motivation for developing an insulating container came from his work in the liquefaction of gases, where he needed to keep the liquified gases at a very low temperature. In the early 1890’s he designed a vacuum-jacketed container (a double-walled flask with a vacuum between the two silvered layers of steel or glass) to store the gas. The vacuum layer in the flask proved so efficient at preventing the transfer of heat to the gas that he was able to preserve it in liquid form for much longer than was previously possible, thus enabling him to study the properties of the liquified gas in much more detail.

Sadly, Dewar never patented his invention, which allowed the newly formed German company Thermos GmbH to take over the concept and develop a commercial version of the vacuum flask.

The Thermos flask was an international success, used extensively in both domestic and industrial applications ever since it’s release. The name “Thermos” became colloquially synonymous with vacuum flasks in general, to such an extent that it was declared a ‘genericized trademark’ in the US in 1963.

Personally, while I find it sad that Dewar never got any financial recognition for this amazing invention, I have to admit my undying commitment to my good old Thermos flask. It goes everywhere with me – I am seldom on assignment out of town without a trusty flask of hot, home-brewed coffee by my side.

Come to think of it, I should definitely pour myself a steaming cuppa from my trusty Thermos in celebration of Dewar and his great invention!