Hydrogen car

In news:dfpblm$7q8$ snipped-for-privacy@news1.greatnowhere.com, Peter blithered:

Don't forget the energy cost to compress said Hydrogen, could easily outsrip the pure generation cost.

The problem with hydrogen isn't how to use it. It has to be created or transformed from another source and transported. Those costs and energy losses reduce the relative efficiency to something close to that acheived with fossil fuels.

The conversion of a car engine to hydrogen is not simple, but not super high tech either. It has been done many times. However, the idea of generating hydrogen in your home worries me a lot.

Simpler and safer to convert engine to methanol and make the methanol yourself from wood. Or, easiest way may be to make the car wood burning to begin with. This was done a lot in various countries during WW2. There are still books around that detail how to do this. You build a "reactor" in the trunk that heats wood in absence of oxygen. This gives off a combustible gas/liquid combination that is sent to carburetor, which needs a conversion similar to that used to burn natural gas or hydrogen.

It is much easier to do any of the above conversions on a carburetor than to try and engineer a FI system conversion. So have in mind a simple carburetor-using car to do this.

there was actually a nuclear answer in a hardended unit which I recall from the 70's. The big thing was about accidents and safety at the time.

I can't imagine hydrogen being any more dangerous than propane tanks. Its certainly more volatile, but an explosive tanked gas is what it is. It sure needs to be made practical, but than we'll have another Mars planet on our hands once we use all the dang H2O up.

It's not like the water gets "used" and it never comes back. When that hydrogen burns, it combines with oxygen and becomes water again.

JS> JS> The problem with hydrogen isn't how to use it. It has to be created or JS> transformed from another source and transported. Those costs and JS> energy losses reduce the relative efficiency to something close to that JS> acheived with fossil fuels. JS>

Besides production, hydrogen molecules are the smallest of all, and I don't think we can have a system tight enough (while moving a vehicle) to prevent them from escaping before mating with oxygen. Maybe a rocket car... that sure would slow down tailgaters!

I guess I don't see the point. The hydrogen car seems to be basically an electric car, when you come right down to it, with the electricity stored in the form of "cracked" water rather than a conventional battery or capacitor. Is the energy density of hydrogen really so much greater than that of a battery that it makes all the inherent inefficiencies of converting back and forth worthwhile?

nate

I've heard something along those lines.

But, do you get super oxygenated water as a byproduct?

not my thread , but an interesting subject.

When you burn hydrogen in air, water, and essentially nothing else, is formed.

There are busses running on hydrogen in airports in Europe (Frankfurt, I believe) I guess it is just an experiment, but they seem to work fine.

We can argue expense on any alternative fuel you want to discuss, but - facing the facts - fuel costs are going to go up as cheaply available petroleum fades into history.

They predicted today that natural gas prices are expected to surge 70% here in Gringolandia, and that is going to hurt.

With the current (Errr... no pun intended) battery technology? Firewood burning under a boiler to make steam to power a generator would likely give you better energy density than any battery available right now. And let's don't even *LOOK LIKE* we're interested in capacitors... Capacitor technology, while improving, still leaves batteries looking like champions in the field of energy storage. Storing electricity is definitely one of our "weak spots", technology-wise. That's one of the prime reasons that fully electric cars are still impractical.

H2O is no problem, since it's a side effect of burning the hydrogen. Which may turn out to be a bad thing if we start dumping too much water into the air in our cities and screwing up the weather patterns.

--scott

It's not that the energy density of hydrogen is so good, it's that the energy density of batteries is so poor.

It's really hard to beat gasoline for energy density. There are some pretty serious problems with gasoline storage and safety, but we have had a hundred years or so to work out most of them.

Given that many years of sustained development work, hydrogen could have become practical too.

--scott

One could also mandate that cars condense and collect some portion of their waste water in a holding tank. This water might just be cleaner than some local water supplies...

just a thought

nate

(still not sold on hydrogen, but that would be a nifty side benefit)

The problem is that electrolysis is so incredibly inefficient that it such a system's cost would never be recouped over its lifetime.

The future is probably going to be biodiesel and genetically engineered algae. Such a fuel would have no net carbon polution since the carbon would be pulled out of the air when the fuel is grown.

No, electrolysis is 100% efficient! All of the electric power goes directly into the hydrogen, and burning the hydrogen gets all of that power back.

What is horribly inefficient is the process of generating the electricity in the first place. And the process of burning the hydrogen to make power isn't so efficient either.

Hydrogen isn't really a power source, it's a power storage method. You generate power, use it to make hydrogen, then transport and store the hydrogen. You still have to burn something to generate power in the first place, but you can do that in someone else's backyard.

--scott

Not at all true. Electrolysis can be extremely efficient..

Bullshit.

What about oxides of nitrogen, and it's compounds, particularly in the presence of hydrogen!

Actually, discounting the losses in generating the power used for electrolysis in the first place, a substantial amount of the energy is wasted as heat when you electrolyze water into H and O2. Then more power is consumed to compress and cryo the H, and presumably the O2 since that's a commercial gas that can be sold. Then more energy is lost storing and transporting the liquid H, or LH. Then finally it gets burned in an engine where more than 70% of the energy is lost as waste heat out the tail pipe and the radiator.

It would be far more effective to just use the electricity at the beginning to charge batteries. An electric is a natural vehicle to use regenerative braking, so a significant amount of energy is recycled instead of being lost as brake rotor heat. The electric motor is much less wastefull of energy, i.e. much less waste heat compared to a combustion motor, and if nuclear/wind/hydro/geothermal/solar is used to generate the electricity then you are almost completely out of the carbon business.

Of course, electric is only good for in town and short out of town trips right now, but that is improving every day, and as it turns out, almost all the miles driven by almost all the people in this country are in town and short trips, what a surprise.

Ultimately, developing and EV infrastructure has the effect of separating transportation (primary source of energy consumption) from power generation, freeing up technology and resources to develop other forms of power generation.

In the real world unfortunately we'll put off this change until it's too late, and then it won't matter.

JazzMan