uk researchers change game for hydrogen from ammonia for cars
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July 2014 Fuel Cells Bulletin11
would need to know the water layer thickness beforehand but in fuel cells that is usually not possible. The researchers have now found an alternative, by measuring their samples with two neutron beams. The results were recently published in Physical Review Letters.
The new technique called dual spectrum neutron radiography, and based on the use of a polycrystalline beryllium filter enables comparison of how two neutron beams with different neutron energy spectra are attenuated by the water molecules. One beam is filtered so that it only contains low-energy neutrons. The second beam is left in its original form, with the entire neutron spectrum. The proportions of liquid water and ice in the cell are extracted from the ratio of the attenuation of the two beams, without knowing the water-layer thickness beforehand. The attenuation ratio depends solely on the different strengths with which liquid water and ice deflect the neutrons. Therefore, the aggregate state of the water can be determined by comparing the measurements with the filtered and unfiltered neutron beams.
The researchers also found direct evidence for an old hypothesis on the behaviour of water in fuel cells that water might be present in a supercooled state (i.e. it does not freeze at 0C). Direct imaging allowed the researchers to demonstrate that water in the cell remained partly in the liquid state at temperatures as low as 7.5C.
The evidence that there is supercooled water in fuel cells is not just important from a theoretical point of view, says co-author Thomas Justus Schmidt, head of PSIs Electrochemistry Laboratory. For the practical application, it is also good to know that youve got a temperature margin where you dont have to worry about ice formation.
Contact: Professor Dr Thomas Schmidt, Head of Electrochemistry Laboratory, Paul Scherrer Institute, Villigen PSI, Switzerland. Tel: +41 56 310 5765, Email: firstname.lastname@example.org, Web: www.psi.ch/lec
Laboratory for Neutron Scattering and Imaging: www.psi.ch/lns
Research paper: http://dx.doi.org/10.1103/PhysRevLett.112.248301
UK researchers change game for hydrogen from ammonia for cars
Scientists at the UKs Science and Technology Facilities Council (STFC) have announced what they believe to be a game changer in the use of hydrogen as a green fuel for vehicles. Their discovery offers a viable solution
to the challenges of fuel storage and cost, by using ammonia as a clean and secure hydrogen-containing energy source to produce hydrogen on-demand in situ.
There are complications with the safe and efficient storage of hydrogen, and very significant concerns surrounding the costs of a hydrogen infrastructure for transportation. The STFC researchers believe that this new discovery, reported in the Journal of the American Chemical Society, may have found the answers to both of these challenges.
When the components of ammonia are separated (cracking), they form one part nitrogen and three parts hydrogen. Many catalysts can effectively crack ammonia to release the hydrogen, but the best ones are very expensive precious metals. The new method instead involves two simultaneous chemical processes rather than using a catalyst, and can achieve the same result at a fraction of the cost.
Ammonia is already one of the most transported bulk chemicals worldwide. It can be stored onboard vehicles at low pressure in conformable plastic tanks, and the infrastructure technology for providing ammonia on fueling station forecourts is as straightforward as that for liquid petroleum gas (LPG).
Our approach is as effective as the best current catalysts, but the active material, sodium amide, costs pennies to produce, says Professor Bill David, who led the STFC research team at the ISIS Neutron Source. We can produce hydrogen from ammonia on-demand effectively and affordably.
We believe that [ammonia] is the natural alternative to fossil fuels, he continues. For cars, we dont even need to go to the complications of a fuel cell vehicle. A small amount of hydrogen mixed with ammonia is sufficient to provide combustion in a conventional car engine. While our process is not yet optimised, we estimate that an ammonia decomposition reactor no bigger than a 2 litre bottle will provide enough hydrogen to run a mid-range family car.
Having developed this new approach to decompose ammonia, we are now in the process of creating a first low-power static demonstrator system, adds Dr Martin Jones, also from STFC and co-inventor of the new process. Our technology will no doubt evolve, but our research invites scientists and technologists to address a different set of questions.
Contact: Professor Bill David, Senior Research Fellow, ISIS Facility, Rutherford Appleton Laboratory, Harwell, UK. Tel: +44 1235 445179, Email: email@example.com, Web: www.isis.stfc.ac.uk
Research paper: http://pubs.acs.org/doi/abs/10.1021/ja5042836
I N B R I E F
Plug Power for airport ground vehiclesUS-based Plug Power (www.plugpower.com) recently demonstrated its new PEM fuel cell beta unit, designed to power ground support equipment (GSE) vehicles that haul luggage and cargo at airports. The demo took place in front of representatives from the Department of Energy, GSE operator and project partner FedEx Express, and GSE manufacturer Charlatte America. The prototype was used in a Charlatte cargo tractor pulling 40 000 lb (18 tonnes) over four dollies.
The next phase will deliver 15 Plug Power GSE fuel cells to FedExs airport hub in Memphis, Tennessee by the fourth quarter. Plug Power will also provide its GenFuel hydrogen infrastructure solution to support the demo fleet, including a hydrogen supply that can scale up to fueling an entire fleet.
This demo is a significant step in Plug Powers strategy to expand into markets adjacent to materials handling, where its GenDrive fuel cells have proven their value [see the Plug Power feature in FCB, December 2011]. Plug Power is also participating in a DOE project to develop fuel cell range-extenders for FedEx Express electric delivery trucks [FCB, January 2014, p1].
Intelligent Energy, Sure launch Upp techTelecom services supplier Sure (http://international.sure.com) is partnering with UK-based Intelligent Energy (www.intelligent-energy.com) to offer the Upp personal energy device (www.beupp.com) in its retail stores in the Channel Islands and Isle of Man.
The hydrogen PEM fuel cell-based Upp technology is designed to meet the growing power demands of on-the-go portable electronic devices. The Upp fuel cell, launched last autumn [FCB, December 2013, p7], has achieved IEC and ISO certification and is approved for carriage in aircraft cabins [FCB, May 2014, p9].
Intelligent Energy is also busy in other applications [see the IE feature in FCB, August 2009]; it recently introduced its Gen4 air-cooled fuel cell unit, designed in collaboration with Suzuki Motor Corporation for easy integration into two- and four-wheel fuel cell electric vehicles [FCB, June 2014, p4]. It also has a deal with Microqual Techno in India to provide power solutions for mobile telecom base station equipment on electricity transmission towers [FCB, April 2014, p4], and plans to power Hydro Industries water purification technology across India [FCB, March 2014, p1].
In other news, Intelligent Energy recently floated on the London Stock Exchange, which raised some 40 million (US$68 million) in gross proceeds, and initially valued the company at nearly 640 million ($1.1 billion).