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  #916  
Old 03-01-2008, 02:49 AM
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HT

Originally Posted by hightower99
Fuel Cells burn hydrogen creating water as there only emission. Why wouldn't you consider them combustion engines? Also a fuel cell burns the hydrogen much more efficiently then any other type of internal combustion engine could ever hope to achieve and it doesn't need/burn oil at all because it doesn't have any big moving parts (because it makes electric energy instead of physical motion) it also will not make any NOx emissions. In the end fuel cells are more efficient and are true zero emission engines."

A fuel cell system which includes a fuel reformer can utilize the hydrogen from any hydrocarbon fuel from natural gas or methanol, and even gasoline. Since the fuel cell relies on CHEMISTRY and NOT COMBUSTION, emissions from this type of a system would still be much smaller emissions from the cleanest fuel combustion process , besides hydrogen run fuel there are many types of fuel cells Phosphoric Acid fuel , Proton Exchange Membrane fuel , Molten Carbonate fuel , Solid Oxide fuel , Alkaline fuel , Direct Methanol fuel , Regenerative fuel , Zinc Air fuel cell , Protonic Ceramic fuel , Microbial fuel cell ect , they all produce pollution waste, the combustion running on hydrogen doesn't.
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  #917  
Old 03-01-2008, 03:19 AM
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Ht + Fuel Cells

The US Military are very keen on the public sector spending money on this as their after a plane that would make barely any noise or leave any thermal signature and have the ability to attain high altitude.
Its not all as to be made out to!
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  #918  
Old 03-01-2008, 06:04 AM
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Quote:
Originally Posted by 3yearsharehold View Post
A fuel cell system which includes a fuel reformer can utilize the hydrogen from any hydrocarbon fuel from natural gas or methanol, and even gasoline.
Yes but using a system like that is not very intelligent because you are throwing away alot of the fuel (all the carbon). The best fuel cells are fuelled with pure hydrogen.

Quote:
Originally Posted by 3ysh
Since the fuel cell relies on CHEMISTRY and NOT COMBUSTION, emissions from this type of a system would still be much smaller emissions from the cleanest fuel combustion process
Combustion is a chemical process... In fuel cells hydrogen is oxidized (burned) creating water. This happens inside the fuel cell, hence it is an internal combustion engine.


Quote:
Originally Posted by 3ysh
besides hydrogen run fuel there are many types of fuel cells Phosphoric Acid fuel , Proton Exchange Membrane fuel , Molten Carbonate fuel , Solid Oxide fuel , Alkaline fuel , Direct Methanol fuel , Regenerative fuel , Zinc Air fuel cell , Protonic Ceramic fuel , Microbial fuel cell ect , they all produce pollution waste, the combustion running on hydrogen doesn't.
You seem to have misunderstood alot there.

Fuelcells have been made that use phosphoric acid as the electrolyte (not the fuel, the fuel is still pure hydrogen). A proton exchange membrane is a part in a fuel cell not a fuel. Molten Carbonate refers again to an electrolyte (could be lithium carbonate and potassium carbonate, or lithium carbonate and sodium carbonate) not a fuel. Solid oxide is again another form of electrolyte. Alkaline also refers to a type of electrolyte. Direct methanol fuel cells are fuelled by methanol and therefore emit both water and CO2. Regenerative systems means a complete system that runs in a loop but it need external energy to provide the hydrogen. Zinc-air means it has a zink electrolyte and can get the oxygen from the air. Microbial fuel cells can run on form of hydrocarbons and use bacteria to produce a stream of electrons.
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  #919  
Old 03-01-2008, 06:18 AM
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Quote:
Originally Posted by hightower99 View Post
Combustion is a chemical process... In fuel cells hydrogen is oxidized (burned) creating water. This happens inside the fuel cell, hence it is an internal combustion engine.
Combustion and oxidation are different chemical PROCESSES.
A fuel cell does not COMBUST the chemicals, it COMBINES them.
Hence it is NOT ... ICE
Logic .... A in B does NOT mean B in A !!
Quote:
You seem to have misunderstood alot there.
ROFLMAO

Stop being an a** and post positively, rather than infantile points scoring attempts
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  #920  
Old 03-01-2008, 06:52 AM
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Quote:
Originally Posted by Matra et Alpine View Post
Combustion and oxidation are different chemical PROCESSES.
Combustion requires oxidation, oxidation does not require combustion.

Quote:
Originally Posted by Matra
A fuel cell does not COMBUST the chemicals, it COMBINES them.
Hence it is NOT ... ICE
How would you define combustion then?

Is producing water from hydrogen and oxygen not an exothermic reaction between a fuel and an oxidant accompanied by the production of heat?

If it is then it is considered combustion, granted it is slow combustion (like cellular respiration) but still combustion, hence they are ICEs.


Quote:
Originally Posted by Matra
Stop being an a** and post positively, rather than infantile points scoring attempts
WTF? unless 3ysh forgot to write the word "cell" 8 times in the quoted text then he implied that fuel cells use the different things he mentioned as fuel. Is telling him that the assorted chemicals are used as electrolytes (as opposed to fuel) wrong? childish (infantile)? or ass-like?
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Last edited by hightower99; 03-01-2008 at 06:54 AM.
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  #921  
Old 03-01-2008, 07:31 AM
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ht, go talk to a High School junior who is doing chemistry.
I'm not wasting MY time explaining the difference to you
Will give you one "hint" though to see how silly your equal comparison is ...

Is the suspension arm on your car currently combusting ? Is it burning as you drive along ?? Nope --- but it IS oxidising ;D
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  #922  
Old 03-02-2008, 02:58 PM
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Quote:
Originally Posted by hightower99 View Post
Combustion requires oxidation, oxidation does not require combustion.

How would you define combustion then?
Well look at rust/corrosion....Corrosion is oxidization, but definitely not combustion.

The definition of combustion means by way of burning or using a flame. There are no flames or burning in a fuel cell.

The definition of a fuel cell:

An electrochemical cell in which the energy of a reaction between a fuel, such as liquid hydrogen, and an oxidant, such as liquid oxygen, is converted directly and continuously into electrical energy.

The fuel cell reaction usually involves the combination of hydrogen (H) with oxygen (O) [reaction (1)]. Under standard conditions of temperature and pressure, 25°C (77°F) and 1 atm (100 kilopascals), the reaction takes place with a free-energy change ΔG = −56.69 kcal (237 kilojoules) per mole of water. Since the formation of water involves two electrons, this value corresponds to −1.23 electronvolts (1 eV = 23.06 kcal/equivalent). Thus, at thermodynamic equilibrium (zero current), the cell voltage should be 1.23 V, yielding a theoretical efficiency based on the heat of combustion [ΔH for H2O(l) = −1.48 eV] of 83.1%.


Last edited by revetec; 03-02-2008 at 03:04 PM.
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  #923  
Old 03-02-2008, 04:35 PM
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Quote:
Originally Posted by Matra et Alpine View Post
Is the suspension arm on your car currently combusting ? Is it burning as you drive along ?? Nope --- but it IS oxidising ;D
Well the majority of suspension arms on my car are aluminium so they have long since stopped oxidizing (due to them creating a passivation layer).

I still think that metal corrosion (rust) can be described as a slow form of combustion as it fits the definition.

I think that your thoughts on oxidation and combustion being seperate processes are valid but I would use a different example to show it.

NOx production seems to be good as it does not furfill the definition for combustion yet it does furfill the definition for oxidation. While Nitrogen can be oxidized to create NOx it happens as an endothermic reaction and can not be classified as a combustion (which must be exothermic).

Quote:
Originally Posted by revetec
The definition of combustion means by way of burning or using a flame. There are no flames or burning in a fuel cell.
Not totally true. The definition for combustion does not say that there needs to be a flame of any sort. As long as a fuel reacts with an oxidant and produces heat in any form then it can be considered combustion.

Thank you for the information about fuel cells. But as you can see because it is an exothermal reaction and heat is produced it can be considered a form of slow combustion.
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  #924  
Old 03-02-2008, 05:04 PM
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Read the Wikipedia definition of combustion

Wikipedia Combustion
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  #925  
Old 03-02-2008, 05:09 PM
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Quote:
Originally Posted by Wiki
Combustion or burning is a complex sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat or both heat and light in the form of either a glow or flames.
Please note that the key words in the definition are:

Exothermic

Fuel

Oxidant

and that it says: Heat or both heat and light.

Meaning you don't need to produce a flame to be considered combustion.

What is it about 2(H2) + O2 = 2(H2O) + E (or Q if you like) that does not furfill the definition of combustion?
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Last edited by hightower99; 03-02-2008 at 05:12 PM.
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  #926  
Old 03-02-2008, 05:13 PM
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So your thinking that corrosion produces heat in a level you can detect and confidently claim that corrosion is combustion? And is there a glow or flame when corrosion occurs? I think not! Oxidization is not always combustion.

Last edited by revetec; 03-02-2008 at 05:16 PM.
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  #927  
Old 03-02-2008, 05:18 PM
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Originally Posted by revetec View Post
So your thinking that corrosion produces heat in a level you can detect and confidently claim that corrosion is combustion? And is there a glow or flame when corrosion occurs? I think not!
Corrosion does produce heat but you aren't going to be able to boil water with a piece of old rusty iron

The definition does not require a glow or flame as long as the chemical reaction is exothermic that is enough.

To put your logic in prospective when you blow powdered iron through a torch flame does it rust quickly? or combust?

If you are basing the definition for combustion on a time componant (ie how fast the chemicals react) then you are adding criteria to the definition (there is not time contraint in the original definition).
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  #928  
Old 03-02-2008, 05:28 PM
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Look...Combustion requires a glow or flame.

It's like saying: (1) All cows are heifers, or; (2) All heifers are cows.

Only the second statement is true.

All combustion is oxidation, but not all oxidation is combustion.

Combustion can start at which point an ignitable mix with air can be achieved.

I found a good website for you... School of Champions - Oxidation which puts it into 2 categories 1) slow oxidation which produces no light or noticeable heat, 2) rapid oxidation which produces light and noticeable heat. They state that Combustion or Burning is Rapid Oxidation.

So lets say from now on that a fuel cell has Slow oxidation and an IC engine has Rapid oxidation.

Last edited by revetec; 03-02-2008 at 05:56 PM.
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  #929  
Old 03-02-2008, 09:01 PM
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hightower99

Originally Posted by hightower99

"POST #900
I am not building the engine that was quoted (the 1000cc I4 diesel revetec CRSV engine). I am in the process of developing my own original design that has no relation to revetec technology at all (except for the fact that they are both internal combustion engines).

POST#904
My new design is original as far as I know (I have checked through alot of patents to check) however since I don't have a final design and no patent on the idea I am not going to talk about it much here.

POST#914
As I have stated several times my design that I am now developing has nothing to do with revetec technology or CSRV tech or any other existing ICE tech. It is a totally original idea (not a combination of other ideas) and as far as I know from doing my own research it is original (although I have by no means checked every existing patent and I am sure that I will find one that somewhat resembles my design)."

HT....... Don't waste anymore time checking existing patents as yours will be the first, that's if your building what I think you are THE WORLDS FIRST ( ICE FUEL CELL) !

Good luck with your invention although you might have some problems getting a patent for it !
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  #930  
Old 03-03-2008, 12:35 AM
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Quote:
Originally Posted by revetec View Post
Look...Combustion requires a glow or flame.
No according to the definition it does not. An exothermal chemical reaction between a fuel and oxidant is enough.

Quote:
Originally Posted by revetec
All combustion is oxidation, but not all oxidation is combustion.
I totally agree. I have never said that all oxidation is combustion as there are several oxidation reactions that are endothermic.

Quote:
Originally Posted by revetec
So lets say from now on that a fuel cell has Slow oxidation and an IC engine has Rapid oxidation.
I already pointed out that the reaction that occurs in fuelcells occurs slowly. However since the definition doesn't include a time componant I still believe it to be valid.
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