HHO Gas Cars

[Jim Ford]

Using water as fuel is pure balderdash!

Water is the _waste_ product of burning Hydrogen. The process can be reversed by splitting the water back into Hydrogen and Oxygen - but you need _at_least_ as much energy to do so as that you would get from recombining (burning) the two gasses again. If you can get the energy to split the water for free eg. from sunlight, then you're getting there. But you need to store the Hydrogen somehow, either compressed, needing more energy - or at atmospheric pressure, which would be impractically bulky.

You can get a nice model fuel-cell car from the Science Museum:

Science Museum Store | Fuel Cell Hydrocar Kit

We've got a similar one at the school where I work, and they work rather well.

Jim

[eeyore]

Originally Posted by Jim Ford

Using water as fuel is pure balderdash!

Water is the _waste_ product of burning Hydrogen. The process can be reversed by splitting the water back into Hydrogen and Oxygen - but you need _at_least_ as much energy to do so as that you would get from recombining (burning) the two gasses again. If you can get the energy to split the water for free eg. from sunlight, then you're getting there. But you need to store the Hydrogen somehow, either compressed, needing more energy - or at atmospheric pressure, which would be impractically bulky.

fuel cell technology does have a real future as a way of storing energy generated from intermitent energy sources such as solar or wind - however it works better on a massive scale and is best used at power station level

in cars its a total non starter - not least because making a compressed hydrogen cylinder crash safe would make it so heavy it would screw up the cars performance. You only have to look at the hindenberg to see a graphic example of why having non crash safe stored hydrogen is a really really bad idea.

also as every phase transformation is inefficient you would be better off using your electricty generated from "free" means to charge batteries powering an electric car.

[Jim Ford]

Originally Posted by eeyore

You only have to look at the hindenberg to see a graphic example of why having non crash safe stored hydrogen is a really really bad idea.

A few years ago, there was on television a programme that showed a drum of petrol and a cylinder of hydrogen, being shot with a rifle bullet. The drum of petrol exploded in a huge fireball, but the hydrogen in the cylinder ignited, but with little luminous flame, and hence not a lot of heat radiated sideways. The burning hydrogen went straight up. It was quite clear that the petrol was far more damaging.

Jim

[eeyore]

Originally Posted by Jim Ford

A few years ago, there was on television a programme that showed a drum of petrol and a cylinder of hydrogen, being shot with a rifle bullet. The drum of petrol exploded in a huge fireball, but the hydrogen in the cylinder ignited, but with little luminous flame, and hence not a lot of heat radiated sideways. The burning hydrogen went straight up. It was quite clear that the petrol was far more damaging.

Jim

it depends on the air mix - a drum full to the brim with petrol wont explode at all - all you will get is a leak or at worst a jet of flame

likewise a drum full of hydrogen shouldnt blow up though it is easier to ignite so you will as you say get a flash flame straight up

a drum which is semi full of petrol will go bang as a result of the vapour igniting - the reason that petrol tanks have to be crash safe

however the issue with hydrogen is that if a non crash safe container ruptures and the gas mixes with the air before igniting you will get one heck of a big bang.

also if it is stored in a compressed state (which petrol isnt but hydrogen is) just rupturing the cylinder will give you an explosive decompression with bits of frag whanging arround even before the gas itself ignites

[Meta menardi]

You cynical lot!!

Let's have a quiet thought for Otto Brown, murdered for .... Oh I can't be bothered.

And if you think it is untrue, search for Otto Brown Murder on google and it comes up with ... nothing (probably will pull this thread tomorrow). That proves it, it has been suppressed!

[Jim Ford]

Originally Posted by eeyore

it depends on the air mix - a drum full to the brim with petrol wont explode at all - all you will get is a leak or at worst a jet of flame

A high velocity rifle bullet will generate a shock wave in a drum of fluid that will rupture the drum and partially vaporise the fluid.

Jim

[JW]

An interesting thread this.

I remember reading that the thing holding hydrogen cars back was the re-fuelling system. As already mentioned it goes bang pretty easily.

Something I saw about a year ago was an news report about some French bod who had developed a car that would run on compressed air. This was produced via an onboard compressor whe nthe vehicle was plugged into the mains at night. It was supposed to retail around the £2500 mark.

Anyone else heard anything about it?

[eeyore]

Originally Posted by JW

An interesting thread this.

I remember reading that the thing holding hydrogen cars back was the re-fuelling system. As already mentioned it goes bang pretty easily.

Something I saw about a year ago was an news report about some French bod who had developed a car that would run on compressed air. This was produced via an onboard compressor whe nthe vehicle was plugged into the mains at night. It was supposed to retail around the £2500 mark.

Anyone else heard anything about it?

is this what you mean : Air Car Factories - The Air Cars

its an interesting idea but still suffers from loss of energy at the transformation stage - if you have to generate electricty to compress the air you might as well use it directly to power the vehicle.

the other problem is the length of time it takes to recompress a tankfull - great for short journeys but not the best for motorway travel.

[eeyore]

Originally Posted by Jim Ford

A high velocity rifle bullet will generate a shock wave in a drum of fluid that will rupture the drum and partially vaporise the fluid.

Jim

good point - but outside of holywood (and war zones) cars arent routinely hit by high velocity rifle fire - they are however routinely crashed into each other and petrol spills in these situations very rarely ignite , whereas a cloud of flamable hydrogen would pose a far higher risk

[JW]

I wonder what the answer will be?

I live ten miles from the nearest large town so a car that can transport me around 40 miles between top ups would be excellent. I reckon solar power will be the way ahead eventually.

You know, it seems that the major manufacturers are dragging their heels when it comes to engines that use alternative energy sources.