Fuel Cell Car Goes Cross-Country

person-0.9a writes "CNN is currently running a story about Daimler-Chrysler's fuel-cell concept car completing a trek across America. The CNN article is more about the trip, but details about the vehicle can be found here."

Comments

And current cars do well at this...

[MosesJones]

The European standards body that does this stuff has its results here and one to note is the abysmal results on this MPV. I quote The Voyager did so badly in the frontal impact that it earned no points, making it the worst of the group by some margin. The body structure became unstable and the steering column was driven back into the driver's chest and head.

So while there may be concerns about these cars if all cars had to get decent scores in these tests that it would ensure that everyone was safe. As it is the gap between the worst and the best is enough to make the fuel inside it only one of the considerations in safety.

BioDiesel

[wowbagger]

Every time the issue of alternative fuel vehicles comes up, I want to find the nearest "eco-friendly" type and beat some sense into them. This is going to be a longish rant, and like all people's rants is largely my opinion....

As I see it, most of the people who push for hydrogren powered vehicles don't want to make clean cars, they want to make expensive cars. They seem to feel that if they can just make it a legal requirement that all cars cost US$100K and US$10/kilometer, then we will all happily stop driving cars and go back to walking.

Why do I feel this way? Because the folks who push hydrogen never seem to consider the facts that make hydrogen a poor fuel choice, and never consider that better alternatives exist.

First, let's consider the goals of alternative fuels:

1. Use a renewable resource for fuel
2. Reduce the amount of carbon oxides released into the atmosphere
3. Reduce the low-altitude pollution (unburned hydrocarbons, ozone, oxides of nitrogen and sulfur, etc.)

Also, let's review the barriers to adoption of any new system:

1. Cost of the vehicle
2. Ease of fuel containment
3. Presence of a distribution infrastructure (this includes both moving bulk fuel around as well as providing fuel to end users)
4. Cost of fuel

Now, consider hydrogen in light of those requirements:

• Hydrogen is hard to contain - you either use expensive cryogenics, or you have to use zeolite entrainment to contain it. It weakens steel containers by diffusing into the container and migrating to the ever-present microfractures and expanding them (hydrogen embrittlement)
• You have to make hydrogen from something - you therefor have to have some other energy source. Either that source is burning carbon in some form, or it's splitting atoms. Wind and wave are cool, but not universally available nor do they have the power density to meet all needs (not to say that they shouldn't be harvested....)
• There aren't hydrogen stations on every corner. Until there are, anyone driving a hydrogen car will have to plan any long trips very carefully. True, this would correct itself if enough people drive H2 vehicles, but they won't drive them until the stations exists, but the stations won't be built until the cars are bought....
• Hydrogen requires a special engine to burn - either a fuel cell, or a modified internal combustion engine. If you DO take a trip and screw up your planning, you are stuck.
• Hydrogen engines DO reduce the low-altitude pollution - no unburned hydrocarbons, and fuel cells produce little NOx and no SOx
• Fuel cells are expensive right now. They might get cheaper later, however

Now, let us consider biodiesel - made from peanut oil, canola, corn, hemp, or whatnot.

• The net carbon released is zero to negative - the plants PULL CO2 from the air when they grow, and the fuel releases CO2 when burned. If anything is left of the plant after making the fuel, then you have a carbon sink. (This is why the hemp fans have a good idea - grow hemp, make fuel and paper, and you have a dandy carbon sink).
• The energy to make the fuel comes from that big fusion reactor 93 million miles away. And unlike methanol, the energy requirements to turn a canola plant into biodiesel are pretty small - you end up with an energy surplus. Methanol requires you to get rid of most of the water, which takes a lot of energy.
• Biodiesel contains little sulphur, and when it burns it burns more completely since it already contains some oxygen, unlike mineral diesel. So you reduce unburned hydrocarbons. I don't know what the NOx emissions of a diesel engine are relative to a gasoline engine, however
• Containing biodiesel is easy. If you have a decently stocked kitchen, you have some already - cooking oil. Also, biodiesel is considerably less toxic than mineral diesel.
• Because it is easy to contain, shipping it around and dispensing it to end users is easy.
• IIRC, an engine that can run on biodiesel can also run on mineral diesel without modification. As a result, if you drive you biodiesel car to the Grand Canyon, and you need fuel at the rim, you have mineral diesel. Also, a station can start pumping biodiesel whenever - no special equipment needed. This decouples the support network from the vehicle uptake, allowing each to grow on their own merits.
• Diesel engines are a known quantity, and are already being mass produced relatively cheaply.
• The only issue is the cost of biodiesel relative to mineral diesel. Compared to hydrogen, biodiesel is MUCH cheaper.

So, if your goal is to reduce pollution and dependance on a non-renewable resource, you logically would be pressing for biodiesel. So why do so many of these people push for hydrogen? I believe it is because they want cars to be expensive in the mistaken belief that this will push us toward their utopian ideal of us all living in bark houses, wearing bushes and eating bugs.

Re:Safety?

[jukal]

Here is an article on hydrogen fuel cells and safety, including results of BMW's simulated collisions:

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Many real-life tests have demonstrated the safety of pressurized hydrogen storage. Simulated 55 mph crash tests left the car totaled, but the hydrogen tank intact. To prove the safety of its hydrogen vehicles, BMW tested its hydrogen tanks in a series of accident simulations that included collision, fire and tank ruptures. In all cases, the hydrogen cars fared as well as conventional gasoline vehicles. And hydrogen-fueled cars are designed to preclude the possibility of leaked hydrogen collecting within the vehicle.
<clip>

practical fuel cells run on hydrocarbons

[peter303]

An alternative fuel cell technology extracts hydrogen from hydrocarbons on the way to combustion. These are more likely to see implementation because there is a hydrocarbon deliver infrastructure in place. Probably will start with laptop fuel cell batteries that have triple lifetime over alternatives.