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Innovation

Meet the tonic for a clean energy future: Molten salts

They're good for hydrogen production, CO2 removal, solar energy storage, nuclear reactors, carbon-light oil sands extraction and much more. No industry complete without 'em.
Written by Mark Halper, Contributor
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Salting the highway. Molten salts can help produce hydrogen that would power cars such as this Mercedes Benz prototype.

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So the world has an energy hangover from its centuries long binge on fossil fuels. Here's the coming cure: molten salts.

These intriguing elixirs and their handy thermodynamic properties will soon stream and bathe their way into any number of power and industrial applications that will help the planet kick its addiction to hydrocarbons.

Want to produce hydrogen? Store solar energy? Remove CO2 from fossil fuels? Build a much safer and more effective nuclear reactor? Slash the carbon footprint of oil sand production?

Then try a molten salt.

HOT STUFF

As the name implies, these substances are salts that melt at a high temperature - hundreds of degrees C, depending on the particular salt. They're stable, they're good at absorbing heat, they don't boil easily (convenient when you need a very hot liquid) and they flow like water.

Many of you will already know that molten salts could hold the key to turning solar electricity into a round-the-clock affair, rather than the intermittent "only when the sun shines" state that characterizes it today. A handful of "solar thermal" power plants - Gemasolar in Spain and Crescent Dunes in Nevada, for example - are or soon will start to warm up molten salts with special reflective mirrors in order to store heat that by night they can convert to steam and drive a generator.

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Keeping the heat on. Mirrors reflect sunlight that warms molten salt in this Gemasolar plant in Spain. The salt releases heat to drive a turbine at night.

Regular readers of my blog will also know that alternative nuclear reactors that use molten salt fuel and coolants at high temperatures could trump today's conventional reactors in many ways. They'd be safer, meltdown proof, would operate more efficiently, leave much less long-lived waste, and their waste would be less suitable for fashioning bombs. Use thorium instead of uranium in those reactors, as China is planning, and those advantages hold even truer.

Here's another potential use, as I wrote recently on my blog for the Weinberg Foundation, a London-based non-profit group that advocates alternative forms of nuclear energy:

Molten salts can help extract hydrogen while at the same time removing CO2 from hydrocarbons like oil sands, according to Western Hydrogen Ltd., a Calgary-based company.

Deploying molten salt technology developed at the U.S. Department of Energy’s Idaho National Laboratory, Western Hydrogen thinks it can pull hydrogen out of “carbonaceous” materials such as the bitumen in the oil sands common in Canada, as well as from other petroleum residue and petroleum coke.

Their so-called molten salt catalyzed gasification process runs water and carbon compounds through a bed of high temperature (around 850 degrees C) molten salts, out of which comes hydrogen and “sequestration ready” carbon dioxide, Western Hydrogen’s website explains in a “low carbon” energy scenario.

The hydrogen could be used as transportation fuel in the elusive hydrogen economy, and it could also feed petrochemical production processes which today use hydrogen derived from more expensive and less environmentally friendly processes, Western Hydrogen claims.

Western Hydrogen also plans to use its process to yield carbon monoxide and deuterium (an isotope of hydrogen that, incidentally, is key to nuclear fusion plans) that it would combine into synthetic liquid fuels.

CANADIAN KICK-OFF

The company hopes to start operating a pilot plant during the first half of this year near Fort Saskatchewan, Alberta in partnership with Aux Sable, a Canadian company that processes “offgases” from oil sands and would thus provide Western Hydrogen with a feedstock of presumably bitumen. The plant is being fabricated by Burlington, Ontario-based Zeton.

Western Hydrogen, which says it funded the DOE project and has exclusive rights to the technology, hopes to establish a larger demonstration plant by late 2014 and to be “commercially ready” by 2015.  It appears to be targeting the oil sands industry as a main source of raw material.  Chairman Guy Turcotte and CEO Neil Camarta have extensive experience in the oil and oil sands industry.

The company also envisions a  “zero carbon” hydrogen production process in which it would feed algae and water into the molten salt bed and route the resulting CO2 back into an algae farm to help replenish the hydrogen production process. According to the company’s website, the process could also tap other biomass sources such as wood chips.

Western Hydrogen’s fondness for molten salts extends to other processes as well. In partnership with Salt Lake City based Ceramatec, it is developing a molten salt technique to “upgrade” bitumen into a pipeline-ready heavy fuel oil.

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The methanol man. Jiang Mianheng, son of former Chinese leader Jiang Zemin, wants to use thorium molten salt reactors to produce hydrogen that would form methanol for cars. Jiang, who is head of the Shanghai branch of the Chinese Academy of Sciences, sees many other uses for the reactors, including coal gasification.

MOLTEN V. MOLTEN

Perhaps in competition with the Western Hydrogen-Ceramatec process, small, molten salt nuclear reactors (MSRs) could serve the same purpose of powering the separation of oil from the tar-like sands, as could other forms of alternative nuclear reactors. China is looking at using thorium MSRs to produce hydrogen and for various fossil fuel production processes, including coal gasification.

I know what some of you financial wizards might be thinking: What companies are developing molten salts, and can I invest?

I'm expecting to reveal the names of companies and researchers as they make business breakthroughs. I'm unable to say more at the moment. So for now, you'll have to settle for the half-full glass of molten salt that you've just consumed. That was more than half, in fact. I'll be serving fully topped drinks just as soon as some non-disclosure agreements allow.

So please come back to the bar soon - or follow me on Twitter for instant service. Feel free in the meantime to write in with the names of your favorite molten salty in the comments section below.

Cheers!

Photos: Mercedes-Benz hydrogen car from icedsoul photography, Teymur Madjderey via Flickr. Gemasolar tower from Toresol Energy. Jiang Mianheng from Mark Halper.

More salt for your energy diet, on SmartPlanet:

This post was originally published on Smartplanet.com

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