Poll: Hydrogen Feul Cells Vs The Combustion engine.

[mipegg]

For the foreseeable future the combustion engine is going to be more efficient. Why? Simple physics. You cant get energy out of nothing and finding hydrogen on its own is pretty hard. This means that you have to put energy into ammonia or water or whatever your source of hydrogen is to split it apart. The energy that you get out of this is always going to be lower than the energy you put in (unavoidable loss).

Means that your just going to burn fossil fuels to make the hydrogen to make power, the more times you change how the energy is stored the more you loose.

And before someone says you could use renewable to make the hydrogen just think about the logistics of it first. To make enough for everyone you'd need to do something stupid like cover the pacific ocean in turbines

 

[massau]

electric cars are good we only need better battery's and if we have discovered them we wont need stupid fuels. and a hydrogen engine isn't efficient so we really need electric cars.
and we need nuclear fusion so we have enough energy for the whole world and we need green energy its just stupid to use electricity to make a fuel that can be used less efficient and u even lose energy with compressing the gas

 

[BlueTimberwolf]

Agreed. Really a safe hydrogen car will never work. How do you be able to get pure oxygen into the equation? Getting it from the atmosphere would be out of the question cause of massive pollution in parts of the world. So do you carry pure oxygen and hydrogen tanks? The costs to do this would be impossible for the average household

If huge coal power plants that produce gigawatts of power can find enough oxygen in the atmosphere to do what they do then a little car should be no trouble.

 

[mipegg]

Nuclear fusion, the eternal joke...

Hydrogen works perfectly well on a microscale. Look at alot of the northern islands in Scotland. Many of the people up there have a small car which runs on hydrogen which is created from small wind turbines and solar panels on each house. It just wouldnt work brilliantly on the major scale.

Though, that is for the moment. If renewable energy becomes more viable (produces a decent amount of energy for the area used) then i cant see why hydrogen wouldnt be ok. That whole 'the atoms slip out of the tank' thing is just retarded though. Your friend knows anything about the atomic structure of a solid?

 

[BlueTimberwolf]

Nuclear fusion, the eternal joke...

That whole 'the atoms slip out of the tank' thing is just retarded though. Your friend knows anything about the atomic structure of a solid?

Would you care to elaborate?

 

[Grimm91]

I only have one worry with hydrogen, how will vehicle's be safe if they crash? I don't want my new car to be the next Hindenburg.

 

[mipegg]

Nuclear fusion is one of those things thats going to be '10 years away' for a long time. We havent gotten a whole lot further with it since 1952 in all honesty.

Also, a hydrogen atom may be small but the spacing between the atoms in a solid is pretty small too. Take graphite for example, graphite has a spacing of about 1.2 nanometers, it is used specifically to diffract electrons. You actually have to work pretty hard to get the spacing to be that large actually, typical size for an atom is about 10^-11 meters, about the same size as an xray diffraction grating. Its pretty simple to make a polymer with much smaller atom spacing in it than this.

 

[Dys]

To put it simply:

[HEADING=2]Hydrogen Cars won't work[/HEADING]​

Why? Because you can't hold liquid hydrogen anywhere. If you are aware of basic chemistry, hydrogen is the smallest element, meaning no matter what tank you make for it, it will leak hydrogen unless kept at a negative pressure (as if that's viable in a car). This will lead to all fuel tanks after a year becoming brittle and crumbling to bits.
Not to mention, the actual energy needed to create hydrogen would be so larger, it would match the pollution caused by conventional cars. Electric, as I've been told, is the way forward, but a long way off working well.

That arguement is so flawed i dont even know where to begin, you realise that the size of an atom is insanely small compared to the space in between each atom.

Haha, sorry, but that view of fuel cells came from someone doing a physics degree. I think he knows what he's on about. If you think size doesn't matter, then you need to brush up on chemistry & physics and the effects of holding hydrogen e.g. Hydrogen Embrittlement. From what I've been told, even using composite materials may not work/will not work for any extended amount of time. Unless you seriously think it's feasible to use cryogenic tanks onboard every car...

Take it from someone doing well in a mechanical engineering degree, that you're physics friend is completely clueless. Send a current through between a cathode and an anode use hydroxite ions at the anode reacion, there will be a reaction and H2 will be produced (or you could just throw some sodium in water, whatever). You can quite simply catch the H2 in a glass container (I've used a test tube before), and at your leseire release it. Don't beleive me, try it. You can then prove you've caught the H2 by lighting it as you release it from the catchment. It is so absurd to claim H2 cannot be stored. Really I struggle to beleive this friend has even done year 10 physics....
Honestly, think for a second..You know those helium tanks they use to do baloons at parties? Gues what, Helium is the next smallest element, and it still works fine.

I'd also like to point out last week I was toying with a hydrogen fuel cell powered model car, and had no issue with any significant hydrogen leak. The reason, as I said above, for hydrogen fuel cells not taking off is purely becauase of cost.

It is amazing how many completely untrue things people are claiming in this forum. Really, I promise a hydrogen fuel cell powered car uses the same engine as an electric car, it is no less efficent, really I promise. There might be energy lost in the power generation (as in the 2H2+O2 reaction) but as far as power generation goes, it is rather high. A petrol electric car is efficent if it's operating at above 25% efficency. I really don't think I should come back to this thread, it just hurts...

 

[mipegg]

Helium is more or less the same size as hydrogen is it not? (Obviously the electron levels differ minorly but it still only has 1 electron shell)

 

[Zacharine]

This is getting ridiculous. Hydrogen (in cars) is nothing more than a new form of chemical battery. At the moment, a poor one at that. However, it's not like the good old Ford T-model was anything like a modern car. And that is why hydrogen will beat everything else available at the moment: R&D. Once you manage to solve the problems with long-term hydrogen storage AND have the infrastructure to create hydrogen from water using solar-, wind-, geothermal-, water-, nuclear- and (in about 50 years?) fusion power, creating the required amounts of hydrogen will not be a problem.

However, until the technology for hydrogen fuel cells has been developed and general power-generating infrastructure is made essentially coal-free, hydrogen does not have any meaningful place as a method of storing energy. Current batteries are good enough and standard electric engines have over 90% efficiency ratio. Acceleration curves are more than good enough to please the average driver and let's be honest: How large a percentage of people actually drives more than 100 miles in an average day?

That is, if we actually wanted to do something about the situation instead of just navel-gazing about global warming at our living rooms.

 

[BlueTimberwolf]

Nuclear fusion is one of those things thats going to be '10 years away' for a long time. We havent gotten a whole lot further with it since 1952 in all honesty.

Also, a hydrogen atom may be small but the spacing between the atoms in a solid is pretty small too. Take graphite for example, graphite has a spacing of about 1.2 nanometers, it is used specifically to diffract electrons. You actually have to work pretty hard to get the spacing to be that large actually, typical size for an atom is about 10^-11 meters, about the same size as an xray diffraction grating. Its pretty simple to make a polymer with much smaller atom spacing in it than this.

The atomic radius of hydrogen is 53 picometers the bond length of diatomic hydrogen is 74 picometers

= 180 picometers or 0.18 nanometers

The distance between the planes of graphite is 0.335 nm and the separation of the carbon atoms in the hexagons is 0.142 nm. So therefore I would assume that the hydrogen gas could simply slip along the planes of the graphite.

Can you give me an example of a polymer with small atomic spacing?

I am not well informed in polymer chemistry but based on what I know the idea of a solid polymer with a higher density than say a metal seems a little off to me.

 

[Tucarius]

I'd also like to make one comment / suggestion which i will admit i dont have an answer for myself...

One of the electric car problems people keep bringing up is battery life and charge time.

Why exactly isnt anyone researching the capasitor anymore?

it was my understanding they could hold a large charge for their size (probably with research equivilent to a battery) and apparently charge within seconds.

Anyone know why this isnt being persued for electric car or other developments?

 

[SilentHunter7]

The problem with with Hydrogen Fuel Cells is that it takes a lot of energy to separate the hydrogen atoms from the oxygen in water. Energy costs money, and (while we still use coal and oil burning power-plants) pollutes the environment. Thanks to the law of conservation of energy, all hydrogen is is another way of storing energy. Yes it's cleaner than gasoline combustion, but all you're really doing is passing that pollution onto the power plants.

Same thing goes for electric cars. Every time an electric car draws from the power grid, the powerplants will have to work to generate that much electricity. Meaning more fuel, either coal, oil, or whathaveyou needs to be burned, meaning pollution. So actually, saying electric or hydrogen cars are totally clean is a misnomer.

What we need is an energy revolution. All our fossil-fuel plants need to be replaced with nuclear, geothermal, or ideally, solar. Not just because pollution, but because of also the fact that fossil fuels are running out and becoming expensive. A lot of our problems, both environmental, economic, and national security, can be helped with a move to cleaner power.

Getting back on topic; I'm not saying dont retool our vehicles. It would be great, and would solve the issue of rising gas prices, which is a worthy cause in and of itself. If we can do it, great. It's just we need to do a lot more.

 

[SilentHunter7]

I'd also like to make one comment / suggestion which i will admit i dont have an answer for myself...

One of the electric car problems people keep bringing up is battery life and charge time.

Why exactly isnt anyone researching the capasitor anymore?

it was my understanding they could hold a large charge for their size (probably with research equivilent to a battery) and apparently charge within seconds.

Anyone know why this isnt being persued for electric car or other developments?

If I remember Physics class correctly, it's because where batteries provide a steady current, capacitors release their charge all at once. Which is great if you need a large current for only a few seconds, or need to stabilize a circuit, but for something like a car that needs to run several hundred miles on a charge, is infeasible. You'd go from 0-200 in a second, but then your car'd be dead

 

[Aardvark Soup]

Hydrogen is a completely inefficient form of fuel since you will need a lot of energy to electrolyse the water you make it from and because it is a highly combustable gas. At the moment nothing simply beats the regular combustion engine. Electric also have their advantages, of course, but since electricity is mainly generated using fossil fuels and nuclear power they aren't that friendly for the enviroment as well.

Actually nuclear power is very environmentally friendly. Just dig a hole 3 miles deep in the desert, chuck your waste down there, which isn't going to hurt anyone, as it came from there in the first place. It's over 95% recyclable, which means you won't even need to mine for uranium, or once every so many decades.

Over 95% recyclabe? Can you cite a scource? Because that really surprises me. Also, I'm still not a very big fan of chunking materials that will stay highly radioactive for about 1000 years in some hole in the desert. I wouldn't like to be the future archeologist that accidentaly digs that up.

Anyway, I'm pretty optimistic about nuclear fusion since it basically removes almost all disadvantages of contemporary nuclear power.

 

[Dys]

To put it simply:

[HEADING=2]Hydrogen Cars won't work[/HEADING]​

Why? Because you can't hold liquid hydrogen anywhere. If you are aware of basic chemistry, hydrogen is the smallest element, meaning no matter what tank you make for it, it will leak hydrogen unless kept at a negative pressure (as if that's viable in a car). This will lead to all fuel tanks after a year becoming brittle and crumbling to bits.
Not to mention, the actual energy needed to create hydrogen would be so larger, it would match the pollution caused by conventional cars. Electric, as I've been told, is the way forward, but a long way off working well.

That arguement is so flawed i dont even know where to begin, you realise that the size of an atom is insanely small compared to the space in between each atom.

Haha, sorry, but that view of fuel cells came from someone doing a physics degree. I think he knows what he's on about. If you think size doesn't matter, then you need to brush up on chemistry & physics and the effects of holding hydrogen e.g. Hydrogen Embrittlement. From what I've been told, even using composite materials may not work/will not work for any extended amount of time. Unless you seriously think it's feasible to use cryogenic tanks onboard every car...

Take it from someone doing well in a mechanical engineering degree, that you're physics friend is completely clueless. Send a current through between a cathode and an anode use hydroxite ions at the anode reacion, there will be a reaction and H2 will be produced (or you could just throw some sodium in water, whatever). You can quite simply catch the H2 in a glass container (I've used a test tube before), and at your leseire release it. Don't beleive me, try it. You can then prove you've caught the H2 by lighting it as you release it from the catchment. It is so absurd to claim H2 cannot be stored. Really I struggle to beleive this friend has even done year 10 physics....
Honestly, think for a second..You know those helium tanks they use to do baloons at parties? Gues what, Helium is the next smallest element, and it still works fine.

I'd also like to point out last week I was toying with a hydrogen fuel cell powered model car, and had no issue with any significant hydrogen leak. The reason, as I said above, for hydrogen fuel cells not taking off is purely becauase of cost.

It is amazing how many completely untrue things people are claiming in this forum. Really, I promise a hydrogen fuel cell powered car uses the same engine as an electric car, it is no less efficent, really I promise. There might be energy lost in the power generation (as in the 2H2+O2 reaction) but as far as power generation goes, it is rather high. A petrol electric car is efficent if it's operating at above 25% efficency. I really don't think I should come back to this thread, it just hurts...

Fuel Cells use liquid hydrogen. It's somewhat disturbing that you don't understand the long term storage issues of liquid hydrogen which are so well known in the industry & are comparing it to a basic chemistry test...Again, look up hydrogen embrittlement. Plus I thought someone like you would be arguing the issue that hydrocarbons provide much more energy than liquid hydrogen, whilst having no storage issues...
Also you should know the energy used for elctrolosis is far more demanding than a regular combustion engine.

Until the reaction takes place, the hydrogen is stored as H2 gas, positive H+ ions (probably as H30) ....why in gods name would they bother storing it as liquid hydrogen. You're aware that there is a bus line that runs of hydrogn fuel cells in perth, as well as a honda car available in california, what you're claiming still makes no sense whatsoever, there is so much evidence that is physicially works, we have working examples everywhere.

I did acknowloedge that the energy needed for electrolosis is significant and a problem, but I did also provide a soloution. There is an algie the produces H2 as part of is photosynthesis cycle, so getting the H2 is no problem once that has been set up (whether we could get enough for the entire population I don't know). Also the cost involved with this most likely wouldn't be worth it.

The 02 in the athmosphere is more than enough for the cell to work (it wasn't you that said that but I did read someone say you couldn't, and my brain did try to kill itself). The process uses far less oxigen than a combustion engine does.