Fuel Cell Powered Japanese Trains on Trial in July

ScorpFromHell writes "As per this yahoo! news item, "East Japan Railway Co. is to conduct a test run of the world's first fuel-cell-powered train in July. The fuel cells, which generate power from a chemical reaction between hydrogen and oxygen, will help reduce environmental pollution compared to the existing electric and diesel engines, the company said." But I wonder how much energy did it consume to produce those huge amounts of Hydrogen & Oxygen? Will it be lesser than the power generated by the reaction between them? In other words, can this technology be used by countries with not so deep pockets as Japan?"

I think we all know the problem with this

[Baron_Yam]

Fuel cells are an energy storage medium, not an energy source.

Centralizing power generation should be more efficient than millions of smaller generators all over the place.

Now, it's just a matter of finding out if generating, transporting, and storing the required hydrogen is environmentally/economically better than diesel or gasoline.

Electro-chemical reaction.

[Anonymous Coward]

It's a lot closer to the way a battery works than it is to combustion. The hydrogen and oxygen react in the presence of a catalyst. Not much heat is generated. The energy that is released is in the form of an electron which is stripped, travels through your circuit releasing that energy as useful work and returns to complete the water molecule.

Re:Chemical Reaction? - yes, and a very efficient

[Blasphemy]

Combustion is a chemical reaction.

The way a fuel cell works is the same as burning straight Hydrogen. 4 Hydrogen atoms combine with 2 Oxygen atoms to form 2 Water molecules. When you burn Hydrogen, it happens all at once in one big pop (or bang!). In a fuel cell, the atoms dissolve into the water at the electrodes and combine in solution. The reaction is much more controled and generates an electric potential at the electrodes.

As far as efficiency is concerned, the seperation of Hydrogen and Oxygen (by electrolosis) from water and the subsequent recombination in a fuel cell (creating electrical energy) is over 95% efficient. That compares to around 30% for a good diesel engine.

In high school, I actully built a rudementary fuel cell as a science project.

Re:I think we all know the problem with this

[DaoudaW]

Fuel cells are an energy storage medium, not an energy source.

You are half right. Fuel cells are neither an energy storage medium nor an energy source. The source of the electricity used to hydrolyze the water is the energy source. Hydrogen is the energy storage medium The fuel cell is an energy conversion device same as an internal combustion engine except way more efficient.

Re:I think we all know the problem with this

[Breakfast Pants]

"But I wonder how much energy did it consume to produce those huge amounts of Hydrogen & Oxygen? Will it be lesser than the power generated by the reaction between them?"
 
Not if they produced it from water...

Re:electric pollution?

[drinkypoo]

I think by "diesel and electric" they mean "diesel-electric". Basically, a diesel engine (usually with separate cylinders which can be independently replaced) drives an electric generator, or bank thereof. This in turn is used to provide power to electric motors which provide motive force for the train. The benefit is that by doing this you eliminate the need for a drivetrain, gearbox, and so on. Thus, the total weight is not changed much, but you get peak starting torque (electric motors make peak torque at 0 rpm) and you aren't constantly replacing gearboxes, drivelines, clutches, et cetera, as you would be if you were trying to put all that power through a conventional drive system. Of course, it's not exceptionally efficient. At best, the generator might be 90% efficient, and so might the drive motors, and the most efficient internal combustion engine in the world is a diesel the size of a house in a container ship that's only 50% efficient... the engines in trains are probably pretty efficient (another benefit is being able to run the engine in its powerband most of the time, except when it's running at low power and maybe at max load) but they're not even 50%.

hydrogen economy

[perrin5]

Having spent a lot of time analyzing the hydrogen economy in terms of generation, this topic is near and dear to my heart.

Hydrogen is a method of TRANSPORTING and STORING energy. It is not a solution to energy generation. As a storage and transport method, IMSO (S=Scientific), it is not particularly cost effective, and has as much potential for unforseen concequenses as any other untested energy method.

That said, I am highly in favor of fuel cells in general, and am happy to see them adopted more often.

In relation to the question asked about poorer countries, I would also hasten to point out that the fuel cells themselves are expensive, as they require (I believe) a platinum catalyst.

That is all.

Re:Good echnology applied at the wrong place

[martijnd]

I think you are looking at the wrong kind of trains -- the Japanese have lots of commuter trains connecting smaller cities, and literally millions of miles of track, don't think Tokyo, think outback.

These trains are actually more like busses, they have maybe 2-4 cars and run infrequencly, so electrifying these tracks doesn't make much economic sense; or is just downright ugly and expensive to maintain. They are mostly diesel powered (with the engines located below the passenger compartments, there is no seperate loc).

For these, replacing a noisy diesel engine with much quieter electrical ones makes very good sense.

Re:Chemical Reaction? - yes, and a very efficient

[grqb]

Wow...pop? dissolve?

"As far as efficiency is concerned, the seperation of Hydrogen and Oxygen (by electrolysis) from water and the subsequent recombination in a fuel cell (creating electrical energy) is over 95% efficient."

Whoa! Sure that's the efficiency of electrolysis but then you have to compress and store the hydrogen (hydrogen storage is a whole thing in itself), then you have to feed it to a fuel cell that has an efficiency much less than 95%...usually less than 50% system efficiency. Overall, the total efficiency of hydrogen fuel cells is comparable to a diesel fueled vehicle, maybe even a bit less.

Of course, that's if you make the hydrogen by electrolysis. Most hydrogen comes from natural gas at the moment, which is less efficient and produces CO2.

----
theWattPodcast.com [thewattpodcast.com] - energy news and issues in an mp3

Re:Chemical Reaction? - yes, and a very efficient

[grqb]

The efficiency of electrolysis is very high, 95% is actually possible. BUT, electrolysis has nothing to do with generating power, electrolysis is how you separate water into H2 and O2. A fuel cell is actually less than 50% efficient, and the overall efficiency of hydrogen fuel cells is comparable or a little less than diesel fueled cars.

Thermodynamics

[Blackeagle_Falcon]

"But I wonder how much energy did it consume to produce those huge amounts of Hydrogen & Oxygen? Will it be lesser than the power generated by the reaction between them?"

First law of thermodynamics says . . . NO!

And as Homer Simpson put it, "In this house we obey the laws of thermodynamics!"

Numbers are wrong.

[WindBourne]

A pure Fuel cells system is in the order of 70-80% Combined with an average 80% motor, you have 50-60% efficiency. [howstuffworks.com]

OTH, if use a reformer rather than a regular storage system, you lose the bulk of the efficiency (lowers you to 30-40%). Combine that with the 80% motor, and you are in the 24-32% efficiency.

Sadly, an autmobile is around 20% efficiency. [howstuffworks.com] And that is only from the Gas forward. It does not include the previous inefficiencies.

Basically, we are using one of the worse systems possible. It just got developed and marketed first.

Re:A train or a space ship

[magetoo]

You gotta give the Japan people props about their notorious trains

Yes.

Also most of them don't actually touch the rails they fly on a magnetic fields or something, right?

Hardly "most", but they certainly seem to be more active than most other countries. I mean, they actually build the things. :-)

Has it happened that a Japanese train can't take a corner and just flies off never to be seen anymore?

Well, there's this [bbc.co.uk] crash [bbc.co.uk]... (It wasn't doing more than about 100 km/h (60 mph) at the time though)

Chemical reactor, not battery

[Elfich47]

Short form: I believe you are missing the point. Fuel cells use the same reactions as buring fuel, only under a very controlled circumstance. Fuel cells do not act like batteries. Longer form (with a small amount of chemistry): If you start with a hydrocarbon (methane, gasoline etc). It is made up of Hydrogen and Carbon. Methane being CH4. There is a certain amount of energy in the bonds holding those together. If you introduce Oxygen (O2) and an initiating energy (a spark), the following happens:

CH4 + O2 + Energy --> CH3 + H02 (Chain initiation)

(I'll skip the rest of heavy organic chemistry lecture. The short form is here [wikipedia.org] but be ready to consult an organic chemistry and and a combustion theory [amazon.com] book for the nitty gritty details.)

From there you have a series of other chemical reactions where energy is released as the compounds break down into CO2 and H20 (Carbon Dioxide and Water).

The amount of energy released is fixed by the amount of methane burned. (I am assuming an idealized stoichiometric reaction with no left overs or pollutants) The method of capturing and using the energy released is what is important.

If you burn the fuel you get: heat and pressure. From there you can use it to generate steam power, electrical power, etc etc etc. The current efficiencies on gasoline engines (in your car) is running around 30%. Most of the waste energy goes out the tail pipe or the radiator. If you are planning on producing electrical energy or driving a vehicle from the power of the engine, you also have to start considering drive train losses.

In a fuel cell: energy is provided to strip chemical bonds that hold methane together, then hydrogen is seperated and then allowed to recombine with the oxygen to make water, the carbon forms carbon dioxide. The second two reactions produce energy. The trick to the fuel cell is that less of the energy is wasted in lost heat, pressure, etc. Efficiencies in fuel cells easily run over forty percent, are quieter and have less drive train losses. The electrical power drives the motor directly with no transmission or gear losses.

Re:What's the advantage of fuel cells in trains?

[maiku32]

Ah...

"Much of Japan's fabulous rail system is electrified, but for those routes still running diesel-electric locomotives the NE-train is coming. The diesel generator is replaced with two 65 Kw Hydrogen powered fuel cells and a hydrogen tank to power the motors and it stores regenerative braking energy in batteries."

From here [treehugger.com].

Re:Hydrogen production

[markdd]

I've done a tour of a pumped-storage power plant in North wales. Dinorwig (sp?) from memory. Anyway, it used cheap, off peak electricity to pump a metric buttload of water up to a reservoir on top of the mountain, and then generate power during the daytime and sell it back to the grid at peak rates. Big advantage was that you could go from 0 output to ** MW within a minute or two. Pretty amazing place, huge man made gallery inside the hill. http://en.wikipedia.org/wiki/Dinorwig_power_statio n [wikipedia.org]

Where's the Kaboom?

[uisqebaugh]

The problems with any hydrogen/oxygen storage mediums are: 1) Even liquid hydrogen has low densities 2) The potential for a devastating explosion with a hydrogen leak is a serious danger. And since hydrogen is colorless and odorless, one may not detect the leak until it's too late.

Re:Fuel cell water vapor by product is a pollutant

[iggymanz]

difference with the greenhouse gas water vapor is that there's a quick removal cycle for water (days to months) compared to carbon dioxide and methane (takes centuries to process by being absorbed by ocean). So once water gets back to liquid form the cycle is complete. So you'll essentially be increasing local rain near cities rather than driving a long term accumulation like we're doing now.