Debunking the hydrogen economy

[RMForbes]

The cylinder is exposed to hydrogen roughly half the time the engine is running, regardless of the cycle time, and at high temperature which accelerates embrittlement. I don't think embrittlement qualifies as chemical reaction; http://en.wikipedia.org/wiki/Hydrogen_embrittlement#Process" the process is due to the formation of molecular hydrogen inside flaws in the metal lattice, worsening them. Since all gas is removed during the evacuation stroke perhaps this slows the diffusion of H into the metal lattice vs the rate seen in a static container, but a same time evacuation cycle is not going to pull all of the atoms back out of the lattice.

No doubt some coating or lubricant can help protect the cylinder on an engine designed for H2, but I think it likely unprepared gasoline engines are likely to see damage with extensive H2 burning.

Yeah, I saw that Wiki quote before, but I thought you guys were serious scientists. This is obvious bunk. So many errors, where to begin. Hydrogen is not exposed to the cylinder half the time, try less than 25%. There is no left over hydrogen after combustion, not even hiding in the metal lattice. Hydrogen is far too reactive for any not to combust. All gas is not removed during the exhaust stroke, depending on rpm as much as 22% remains. There has never been proof of any hydrogen embrittlement on any ICE running hydrogen enrichment.

 

[mheslep]

Yeah, I saw that Wiki quote before, but I thought you guys were serious scientists. This is obvious bunk. ...

H embrittlement is obvious bunk?

There is no left over hydrogen after combustion, not even hiding in the metal lattice. Hydrogen is far too reactive for any not to combust.

You don't know what you are talking about. High vacuum chambers require hours or days depending on the metal to bleed off gas molecules trapped in the metal.

 

[Topher925]

There has never been proof of any hydrogen embrittlement on any ICE running hydrogen enrichment.

Wtf are you talking about there is tons of proof. During the last energy crisis of the 70s there was a @#$% load of work done on hydrogen enrichment and hydrogen embriddlement was a common failure mode. The crank case and/or liner along with the pistons will be affected by hydrogen embriddlement with standard materials, there is no debate. And the engine is exposed to H2 at least 35% of the time. And FYI, the ignition temp of hydrogen is hell of a lot higher than gasoline, about 250K greater IIRC. Do you even know the stoichy equation of combustion in a gasoline engine with hydrogen enrichment?

 

[RMForbes]

H embrittlement is obvious bunk?
You don't know what you are talking about. High vacuum chambers require hours or days depending on the metal to bleed off gas molecules trapped in the metal.

I'm sure hydrogen embrittlement exists, but there has never been any evidence that a ICE running hydrogen enhanced fuel suffered any of these effects. It has not even been an issue for experimental engines running hydrogen as the only fuel. And, I did not say all gases are removed from the metal, only that hydrogen reacts too easily to be left over after combustion. Therefore, how can it cause any ill effects. Your theory that engines using hydrogen enrichment will wear poorly because of hydrogen embrittlement, does not hold water. Actually, hydrogen enhancement has been proven to improve engine wear because carbon deposits are not allowed to form in the cylinder. Carbon deposits don't build up on the piston rings to cause uneven wear to the cylinder walls. Deposits in the cylinder are removed so pre-ignition misfires are greatly reduced. The stresses caused by pre-ignition misfires are far more damaging to metal parts than your theory would ever be.

 

[RMForbes]

Wtf are you talking about there is tons of proof. During the last energy crisis of the 70s there was a @#$% load of work done on hydrogen enrichment and hydrogen embriddlement was a common failure mode. The crank case and/or liner along with the pistons will be affected by hydrogen embriddlement with standard materials, there is no debate. And the engine is exposed to H2 at least 35% of the time. And FYI, the ignition temp of hydrogen is hell of a lot higher than gasoline, about 250K greater IIRC. Do you even know the stoichy equation of combustion in a gasoline engine with hydrogen enrichment?

Calm down and just prove it. Show me one documented case that absolutely proves that the engines failure was due to hydrogen embrittlement only. I don't think you can.