Featured Hydrogen fuel a strong possibility?

Personally I don't see it in my lifetime - except in niche areas like EVs are at the moment. Most of the world - a long, long time.

But hybrids are improving by 10-13% with every new generation - and I suspect will still do so.

 

I’d say both weight and volume are pretty important on ground vehicles.

For airplanes, volume is still important, but clearly weight is vastly more important.

In the case of rockets, the liquid-hydrogen/liquid-oxygen rockets are easy to spot: They’re very efficient in terms of specific-impulse (thrust per unit mass of fuel), but their tanks are very bulky (e.g., Space Shuttle external tank, or Delta 4 Heavy). Even *liquid* hydrogen still has a surprisingly-low mass density (mass per unit volume): ~71 Kg per cubic meter, compared to 1000Kg per cubic meter for water!

 

maybe they've never heard of hydrogen embrittlement - where the gas itself destroys the plumbing.
and YEA ... using existing oil & natural gas. How is that 'renewable'??
Maybe it just from hearing so many fly-by-night schemes over the last 5 decades - but who knows.
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Maybe we can use all the hydrogen to bring back dirigibles!

In cars, not so much.

 

Yeah, that’s my main concern too. Still, I concur that it’s definitely an improvement over burning the stuff!

 

That would also explain why the Saturn V's hydrogen-fueled second stage is the same diameter, and almost the same total size (volume), as the kerosene-powered first stage.

 

Indeed!

The “S2” (second stage) by the way, was an amazing piece of work. The S4B (third stage) was pretty much already completed and the S1 (first stage) was way too far along, when the weight of the Apollo hardware started increasing weight. So the S2 had to bear almost all of the weight-reduction problem. Those North American Aviation guys did it though!

 

Renewable, no, but the carbon stays in the ground. As long as the company doesn't crack the surrounding rock.

Has any first stage used liquid hydrogen?

 

Delta 4 Heavy is one.

 

so let's say it works tomorrow. Now you still have to do the expense of platinum fuel stacks - 10,000 Lbs psi tanks that have to be decommissioned at 10 years, & my personal favorite - a trillion dollar infrastructure that requires having enough pressure for YOU - so you don't have to wait 25 minutes because the guy in front of you depressurized the station's main refueling tank.
Still, this is great! We get to keep the fossil fuel industry in business (until peak oil actually DOES hit), so maybe we can put a stop to rechargingr electric cars at home for free - using their fully amortized solar panels!

 

I know about the SRB's - but wasn't the space shuttle main engine run off that big gigantic tank?
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Elon Musk's said he'll help humanity more by keeping focused on electric cars, but his vision for electric planes is that it runs on two separate propulsion systems. One system, the more powerful short range one, is designed to go near straight up. The other system, a far more lower power, long range propulsion system flies you to your destination once you reached maximum altitude.

I think this is a much more intelligent and efficient design than just simply replacing jet engine with really powerful electric motors and batteries.

 

Yes, and it was indeed liquid-hydrogen & liquid-oxygen.

 

Forgot those were ignited at take off.

 

The were ignited first, numerous seconds before the SRBs, allowed to stabilize, and put on quite a show of fire and smoke by themselves. But then the SRB igniton put all that to shame.

In flight, those oxygen-hydrogen main engines are relatively dim and 'smokeless' compared to the bright flares and opaque smoke trail of the SRBs, so it is easy to forget that they are even operating.

 

Hydrogen filled, observation balloons were used in the Civil War.

Bob Wilson

 

Interesting, I did not know that... Have any preferred links or shall I just start googling?

 

Oh, yes, I definitely agree that HFC is not ultimately the way to go, for passenger surface vehicles at least. There’s some chance fuel cells could work for long-haul trucking or airplanes, where weight-compounding is a big issue, but I really doubt it’s realistic in the case of cars, SUVs, or pickup trucks.

The perceived viability of HFCEVs is all based upon failure to think outside the gas can: they assume that cars have to be fueled up like we do gasoline cars: approximately-weekly adding large loads of fuel, at a fuel station. This, failing to foresee that a car could instead be charged nightly, at home. Plus of course we’re already starting to see 350KW DC fast chargers that can charge a couple hundred miles in 10ish minutes!

In the case of grid storage (power smoothing), there might be some chance of fuel cells being usable, since that would not require the inefficiency of compressing the hydrogen. That is, in a stationary application, you could use huge, neighborhood-scale inflatable bags of slightly-greater-than-atmospheric-pressure hydrogen. You also don’t have to pay the cost of transportation to a hydrogen filling station. However, fuel cells and PEM electrolysis is still far less efficient than battery dis/charging.

However, yes, this is not about power smoothing; it’s about getting hydrogen from oil, which again, is not “sustainable.” I’m also concerned about what this process “leaves behind” in the oil well: Can it be used to create critically-needed stuff like fertilizers or plastics? Would literally “de-hydrogenated” petroleum be toxic?

 

When I read of such approaches, I'm reminded of Centralia PA and their mine fire.

Bob Wilson

 

As another point of comparison, again if I calculated correctly, a Kg of air under the same conditions occupies about 780 liters of volume.