Japan's Railway Company to Run World's First Fuel-Cell Trains

Reviewed by Hitoshi URABE

Article:
Japan's Railway Company to Run World's First Fuel-Cell Trains
Monsters and Critics
http://science.monstersandcritics.com/news/ article_1154738.php/Japans_railway_company_to_run_worlds_ first_fuel-cell_trains

Comments:

Japan's railway service has been praised for its high performance trains, the cleanliness of the cars, and the punctuality of sticking to the schedule while providing very frequent service - less than 2-minute intervals at peak hours - and the high level of maintenance standards to support all this.

(This morning, as the writer was riding a commuter train, the conductor kept apologizing that the train was being delayed for 2 minutes because of the fog, although, by the time the train reached the terminal, the delay was recovered and arrived just on time.)

As the article introduced above reports, the East Japan Railway Co., a part of what was used to be the state-owned operator, split and privatized to serve eastern Japan including Tokyo area is developing a fuel-cell powered trains, While most of the railroad tracks in and around Tokyo, and near other large cities and also trunk lines to connect them are already electrified, those in less populated and rural areas are serviced by diesel-powered trains. Over the years the diesel engines used on trains have been improved significantly to the practical limit with regard to fuel-efficiency and emission (and noise) reduction. But this also means that it has reached the limit in terms of being environment-friendliness of diesel engines used to run trains. This is how the EJR decided to develop fuel-cell powered trains.

Hydrogen is the lightest element and the most abundant in universe. It is also found in abundance around us but not in its natural form but as various sorts of compounds with other elements. Among the variety of the compounds, the most common is arguably water, comprised of hydrogen and oxygen. Children would visualize this by an electrolytic experiment whereby water is decomposed into the two gases by running electric current through water. Fuel cells, as they are conceived today, use the opposite of this phenomenon. By combining hydrogen and oxygen, produce electricity, with the only by-product to emit being pure water.

The theory is simple. But realization of a practical engine has not been easy. The electric motor to spin the wheel is no problem. Current technology is sufficient to produce the required motors - or probably it is even possible to use off-the-shelf motors, at least as a start. The generator part, or the chemical reactor where electricity is produced from the gasses needs a little twist. Simply combining hydrogen and oxygen would produce a fierce combustion - where a better description might be a huge explosion. So the speed of the chemical reaction process must be slowed and controlled. This has already been overcome through several means, and the technology is now out of the invention and initial development stage to be at the improvement stage.

The method to carry hydrogen onboard is one of the difficult issues to overcome. It is the lightest gas that if leaked in small amounts would immediately rise to the top of the atmosphere to become unrecoverable. And if the leak is in large amount, it would react to and combine with oxygen in the air very fiercely like a bomb - as recorded in the case of the tragedy of the airship Hindenburg. Recently a number of methods to store hydrogen efficiently and safely have been suggested, and some seem promising. But before being utilized on a real vehicle, it must be tested thoroughly for such as what would happen in case of accidents such as collisions.

Then there is of course the fundamental issue of whether the fuel-cell power is really friendly to the environment compared with the current internal combustion engines. System as a whole, from the production process of hydrogen to the actual spinning of the wheel of the vehicles must be considered in comparing with gasoline/diesel powered systems.

As such, there is a lot to study, develop, improve, test, and evaluate before fuel-cell powered trains become an everyday gadget.

It is, however, generally recognized more advantageous for trains to adopt fuel-cell power than vehicles on the roads. All the hurdles mentioned above are in fact applicable also for the development of fuel-cell powered automobiles running on roads. But trains are better suited in many respects. Larger body means it is more adaptable to carry bigger engine system which would allow for easier design and layout leading to superior efficiency and safety. Trains are kept and serviced by a small number of professionals so as to make it easier to maintain the performance and safety levels - and recognize defects and other possibilities of improvement easily feedbacked to the designers and manufacturers.