The new performance figures for the rx-8 hydrogen version.

Performance figures
Power 120 bhp / 89.5 kW @ 7200 rpm
BHP/Liter 91.7
Torque 120 Nm / 88.5 ft lbs @ 5000 rpm
Power to weight ratio N/A
Top Speed N/A
0-60 mph Acceleration N/A

I'll post pics later

Pic 1

Hmm, doesn't sound like much fun to drive. Hopefully more research will result in more power and torque.

The nice thing about the hyrdro rx-8 is you can switch to gasoline fuel on the fly if you need the original power.

Good point. Didn't realise that it was dual fuel.

It's makes up what it loses in the performance department

For all who want to see the engine.

Another engine shot

I have trouble wondering why you'd have a hydrogen internal combustion engine. If hydrogen is to be the fuel, then fuel cells are the preferred medium for energy conversion. That's leaving aside the cost of producing the hydrogen, of course and its lousy energy density. The current method of hydrogen production is by electrolysis of water. That consumes molto electricity, which is OK for countries which produce most of their power from clean nuclear stations like Canada, France and Japan, but lousy for Australia which never had the sense to build nuclear power. We have to rely on burning carbon fuel for our electricity.

It makes little sense burning a greenhouse friendly fuel like hydrogen when the mode of production of the hydrogen is distinctly greenouse unfriendly.

I suspect that much of this sort of stuff is PR hype to boost Mazda's green credentials. Could you make a diesel rotary?

I think this is more of a prototype car because it's gonna be a while before get hydrogen cars here in Australia

That is that a turbo I see in the first engine pic !!

Power seems low. A hybrid might be nice.

Originally posted by labrat
Could you make a diesel rotary?

Rolls-Royce already did. In fact, it was one Rotary compressing into another - i.e. the first was a bigger Rotary that provided some of the compression, and that got fed into a smaller rotary, where further compression took place, and the diesel injected.

There is a diagram around somewhere, don't know if it is hosted on the web somewhere.

Cheers,
Hymee.

The first hydrogen service station has been built in Sweden, I think.
The good think about these H2 prototype engines is to know that petrol engines can burn a lot of different fuels and therefore might survive beyond the last droplet of black gold. However as Labat said, fuel cells are probably the way to go to transform H2 into motion, not petrol engines.
Another point : did you see that huge H2 tank. It goes in the boot so bye-bye luggage capacity.
And the main point Labat raised is the fact that there is little point in offsetting the fuel consumption and related emissions to the nearest fossil fuel power plant. But there, it looks like they're working on clean ways to make H2 (sun,...).
By the way, I'm in favour of nuclear power until we find something better.

They made it to reduce the amount of carbon dioxide which was causes the greenhouse effect so even if it was low in power it is good for the Earth :)

Labrat,
It's only ever intended as a middle ground car. Something to use while the hydrogen infrastructure is still in it's infancy. So you can switch to petrol if you can't find any hydrogen around. The dual fuel setup obviously hurts power, BMW have a H2 only engine that makes as much power as the petrol version did. In a 4.4 litre V8 no less!

Incidentally, BMW had the first H2 service station in Munich. You have to stand behind a huge barrier while robots refill your car from a safe distance!

rx-8_boi02 misses my point. There's no point in burning a greenhouse friendly fuel in your car if you have to use a greenhouse unfriendly method to produce it (i.e., coal-burning power stations). Because of the inefficiencies in electricity production, transmission, and the electrolysis process, it ends up costing you lots more in energy to get the hydrogen to the car (and producing more CO2) than otherwise would be the case in using petrol or diesel directly.

The hydrogen fuel thing is part of a massive PR exercise by the car companies to enhance or establish their green image. It's meant to buy them time.

Hydrogen isn't a good choice for passenger cars because it isn't energy dense - it takes up a lot of room. Sorry, but I have to introduce some science, but I promise it won't hurt.

The combustion of hydrogen to produce energy can be written as:

H2 + [0] <-> H2O (-285.8 kJ/mol)

That means that for every mole of hydrogen (or 2 grams of hydrogen) you get 285.8 kJ of energy. Turn this reaction around (the two-way arrows indicate it's reversible), and this is how much energy you have to put into 18 grams of water to produce 2 grams of hydrogen. In science, there is no such thing as a free lunch. Concerning energy density, this 2 grams of hydrogen occupies approximately 22.4L at ambient temperature and air pressure. Unlike LPG, you can't liquify hydrogen at normal temperatures. Hydrogen only liquifies at a few degrees above absolute zero. So you have to compress it as high as you dare to carry enough fuel around. This is not a trivial exercise. Not only do you have to introduce extreme safety measures during filling, the material science in long-term storage and transfer of hydrogen is not trivial. Hydrogen embrittlement of metals is well known.

OK, now that you've got your highly expensive hydrogen into your car, are you going to burn it in a notoriously inefficient device as an internal combustion engine, or go to the much more efficient fuel cell, whereby the energy from the above reaction is extracted as electricity to drive electric motors? Seems like a no-brainer doesn't it, only fuel cell membrane technology is still a few years off before being commercially viable. So why are the car manufacturers messing around with hydrogen in internal combustion motors? Brand management - keeping governments and consumers on side until the fuel cell car becomes a reality.

My preference for an interim technology would be common rail diesel engines. This is a much better bet than the petrol/electric hybrid Toyota technology. It offers nearly as good fuel efficiency, and it is much better suited for passenger cars as you don't require expensive and space-consuming storage batteries. On the downside, the petrol/electric sounds environmentally sexier. And that may be thing that counts in the end.

My preference would be to turn the entire car into something with quantum entanglement properties, and we would teleport down the road a few millimetres at a time.

Car crashes would be interesting though ...

Post of the day, Labrat. Any links to the common rail diesels? (I'm lazy ;) )

Cheers,
Hymee.

OK - Not too lazy...

http://www.dieselforum.org/factsheet/commonrail.html

In laymans terms, the equivalent of electronic injection for diesels, at very high rail pressure.

Cheers,
Hymee.

Out of interest, most industrial hydrogen is made from fossil fuels, specifically natural gas not by electrolysis. But using massive amounts of energy in the compression process is pretty unavoidable I guess.

Further trivia : there is more hydrogen already in a litre of petrol than there is in a litre of liquid hydrogen because petrol is denser by more than it's hydogen mole fraction.

Your comment hit the nail on the head, dbb. I would also imagine that getting hydrogen from fossil fuels is energy intensive as well. My crystal ball shows that by the year 2020, we'll be driving cars powered by fuel cells burning methanol, which is a liquid, only contains one carbon, and can be made easily from natural gas. Unfortunately, we'll probably also have to get a permit from the Department of the Environment to start up our RX-8's at classic car shows.

*******CAUTION, THREAD HIJACK, CAUTION*******

Don't care, did anyone notice how good the car looks in white?!

YOWZA......!

Originally posted by labrat
Your comment hit the nail on the head, dbb. I would also imagine that getting hydrogen from fossil fuels is energy intensive as well. My crystal ball shows that by the year 2020, we'll be driving cars powered by fuel cells burning methanol, which is a liquid, only contains one carbon, and can be made easily from natural gas. Unfortunately, we'll probably also have to get a permit from the Department of the Environment to start up our RX-8's at classic car shows.

Or perhaps Ethanol or Propane? They also have (reasonably) good energy density comparisons.

Anyway, oil production is currently peaking, and will start to dwindle in the near future. Meanwhile, China and India and adding more and more cars to their domestic markets. And Americans continue to purchase more and more SUVs. This will lead us inevitably to oil/resource wars in the next 15 years or so, and we won't be around to worry about what we put in our cars.

Originally posted by Gomez
*******CAUTION, THREAD HIJACK, CAUTION*******

Don't care, did anyone notice how good the car looks in white?!

YOWZA......!

NO IT DOSN'T LOOK GOOD IN WHITE! it sucks, all white cars do!

you have been watching way to much B&W TV Gomez :p

anyone notice the port profiles on the motor? very large area and looks like the port closes early (short intake duration). very funny shape that looks hand carved too!

Gomezgetwithit....some of us have been raving about the Japan-only white for almost a year now. I had a Subaru SVX in pearlescent white which would suit the 8 incredibly.
Some say the white may be here next year.

apologies oh merciful moderator,
jack.

Originally posted by labrat
...

My preference for an interim technology would be common rail diesel engines. This is a much better bet than the petrol/electric hybrid Toyota technology. It offers nearly as good fuel efficiency, and it is much better suited for passenger cars as you don't require expensive and space-consuming storage batteries. On the downside, the petrol/electric sounds environmentally sexier. And that may be thing that counts in the end.

Very nice post indeed. Can we have more of these please.

On the interim solution, common rail diesel is the direction car manufacturers have taken for the european market. And these diesel powered cars are almost as fuel efficient as the existing e-petrol hybrids.

I have nevertheless a few remarks considering this diesel technical/marketing option :

- I have yet to drive a mainstream diesel engined car that passes my very stringent NVH standards. I'm talking here about mainstream small 4 cylinder engines (up to 2.2l), not the big and smooth I/V6 and V8 exclusively limited to executive cars. Apparently the new Honda diesel engine found in the new Accord is a big step forward in term of NVH. The fact that it was designed by VTEC-san (a petrolhead) might count.
The VW/Audi solutio of 'pump-düse', is absolutely disastrous in term of NVH but is very good for emissions and performances.

- I wonder how clean, economical and performing a petrol engine could be should the car manufacturers decide to invest the same amount of ressources (and cost/unit) they did for its diesel counterparts. We don't see enough stratified charge, direct injection, turbo-charged petrol engines around here.

- Electric hybrids have the advantage to be able to become ZEV in city centres, parkings, congestioned area... But they carry a larger, heavier powertrain, hurting packaging, handling, costs and fuel economy!

- Why don't we see diesel/electric hybrids : now that must be relally economical (not as clean though).

I hope this thread can stand some 'industrial' input....

It's 3am where I am, operating a huge plant, using millions of cubic feet of hydrogen to make Benzene.

You guys are right, if you need industrial quantities of H2, it will come from Methane Reformer, a very energy intensive, and none-too-greenhouse-friendly process.

Methane and steam are heated over a catalyst that breaks them down into hydrogen and carbon monoxide. It takes a LOT of energy to break up the water molecules!
Methane (CH4) and steam (H2O) becomes CO and H6. We seperate the heavy carbon compounds out, and use the hydrogen for the process. Our plant is the biggest hydrogen producer in the world.

Using the hydrogen in your car would only give you a 'warm/cuddly' feeling until you realised how much greenhouse gas was produced to make it!

Mr. Labrat is correct that methanol would be a better source of hydrogen than hydrogen compressed in a tank - it might use more energy to compress it than it would produce burning!
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doc

Thanks labrat for putting in a simple version for me

Hey Labrat,

Would it be possible to split the hydrogen from the oxygen in the car - so that in effect you fill it up with water?

Please don't flame me if that was a real dumb question!

Deano.



Originally posted by labrat
Your comment hit the nail on the head, dbb. I would also imagine that getting hydrogen from fossil fuels is energy intensive as well. My crystal ball shows that by the year 2020, we'll be driving cars powered by fuel cells burning methanol, which is a liquid, only contains one carbon, and can be made easily from natural gas. Unfortunately, we'll probably also have to get a permit from the Department of the Environment to start up our RX-8's at classic car shows.

suposedly this is what top fuel cars do when you see the white flames out the pipes. aparently nitro burns clear so you should see no flame but because of the heat the h2o in the air splits and burns off the hydrogen gas giving the white flames.
might be a urban myth tho.

Originally posted by deano
Hey Labrat,

Would it be possible to split the hydrogen from the oxygen in the car - so that in effect you fill it up with water?

Please don't flame me if that was a real dumb question!

Deano.

I think the fundamental problem with that is that it requires enourmous amounts of energy to split the molecules - that energy has to come from somewhere.

Cheers,
Hymee.

Originally posted by rotarenvy
suposedly this is what top fuel cars do when you see the white flames out the pipes. aparently nitro burns clear so you should see no flame but because of the heat the h2o in the air splits and burns off the hydrogen gas giving the white flames.
might be a urban myth tho.

I suppose there is a massive amount of wasted energy (heat) coming out of the exhaust that this is entirely possible - but it obviously is wasted as well.

Cheers,
Hymee.

As Hymee says, it requires an enormous amount of energy to dissociate water into its component atoms. Reportedly, thermite fires (the reaction of iron oxide with powdered aluminium metal to form molten iron and aluminium oxide) are hot enough to dissociate water, but you are looking at temperatures at which literally iron is a liquid. If you can see the colour of a hydrogen-oxygen flame, it is due to the presence of an impurity in the flame. Pure hydrogen oxygen flames are completely colourless

This is why some extiguishers are foam / inert gas filled. Water can just feed some fires.