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Volkswagen develops hydrogen car that can travel 2k kilometers on one tank

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Re: Volkswagen develops hydrogen car that can travel 2k kilometers on one tank

#71

Post by pfdietz »

jxf wrote: post #68
Tagbert wrote: post #65

Earlier quoted context omitted.

Fertilizer requires the production of ammonia NH4. That is one nitrogen bonded to 4 hydrogens. The nitrogen can come from the air but the hydrogen has to come from some other compound.

Dumb question: why can't the hydrogen also come from the water vapor in the air?

That would be highly endothermic. The energy needed to separate the hydrogen from the water has to come from somewhere. If you meant "why can't we electrolyse that water to get the hydrogen", well yes of course that could be done, and that's what's being talked about (using water from some other source, though; why from the air?) But the water doesn't just decompose on its own.

Re: Volkswagen develops hydrogen car that can travel 2k kilometers on one tank

#72

Post by bombcar »

gibsonf1 wrote: post #47
pengaru wrote: post #23

Earlier quoted context omitted.

Hydrogen combustion doesn't produce co2, optimize a petrol-fueled ICE all you want and it's still a problem WRT emissions. I think the assumption is that hydrogen fuel would be produced via "green" electricity sources like wind/solar/nuclear.

There is that subtle issue of how do you get hydrogen.... Takes energy to make it.

You can just break apart water with very small tiny little hammers.

Finding the miniature dwarfs to do this is the tricky part.

Re: Volkswagen develops hydrogen car that can travel 2k kilometers on one tank

#73

Post by pfdietz »

throwaway894345 wrote: post #59
bryanlarsen wrote: post #39

Earlier quoted context omitted.

The best balanced overview of hydrogen's future I've seen has been the Hydrogen Science Coalition: https://h2sciencecoalition.com/principles/ Green hydrogen is desperately required to produce fertilizer cleanly, so it is a problem that must be solved. It also looks very promising in a couple of other industrial processes, like the production of steel. And that's about all we can say with any degree of certainty.

Why do fertilizer and steel require hydrogen in particular rather than just green-electricity-powered induction heating? Is the hydrogen meant to be a chemical component in the manufacture of fertilizer and steel rather than merely a heat fuel?

Hydrogen is needed for the Haber-Bosch process for making ammonia. For steel making, hydrogen would be used for reduction of iron ores to iron metal (currently, most of that is done with coke).

There's also a large market for using hydrogen to upgrade petroleum (hydrodesulfurization), but that market continuing to exist presumes some way of dealing with the CO2. Direct air capture, perhaps. There could also be markets developed to make synfuels from CO2 and hydrogen, or using hydrogen to upgrade biomass to get more fuel (hydrodeoxygenation).

There are various smaller markets using hydrogen. For example, making one of the precursors to polyurethane involves hydrogen as a reagent, as does manufacture of hydrogen peroxide.

Re: Volkswagen develops hydrogen car that can travel 2k kilometers on one tank

#74

Post by throwaway894345 »

jxf wrote: post #68
Tagbert wrote: post #65

Earlier quoted context omitted.

Fertilizer requires the production of ammonia NH4. That is one nitrogen bonded to 4 hydrogens. The nitrogen can come from the air but the hydrogen has to come from some other compound.

Dumb question: why can't the hydrogen also come from the water vapor in the air?

You can, but doing so with renewable power would be under the rubric of "solving green hydrogen for industrial processes". In practice it's probably just easier to use renewably powered electrolysis to separate hydrogen and oxygen atoms from liquid water rather than try and use some chemical process to pull them out of the air.

Re: Volkswagen develops hydrogen car that can travel 2k kilometers on one tank

#75

Post by noogle »

geijoenr wrote: post #14

Some time ago I saw a presentation from the chaos computer club where an expert on the matter explained there is a lot of misunderstandings about hydrogen technology as an energy source and how is gonna useful for society and why it is necessary. In a nutshell some industries that currently rely on natural gas cannot switch effectively to electricity, hydrogen seems to be the only solution at the moment. Regarding tr…

Batteries needed electric vehicles are still expensive and seem to essentially be the bottleneck for mass change to EV.

The infrastructure needed to support battery electric vehicles seem to be expensive/complex to run sufficiently well in practice. In the US Tesla's supercharger network is often cited as a moat against other manufacturers. It's not even building the chargers - it's maintenance and compatibility. Charger network are a losing operation, but they are critical for adoption. Tesla affords this via huge margins, but that won't work for the rest of the market outside of the luxury segment.

Could it be that the BEV market (in the US at least) lends itself to monopolization? If so, hydrogen can make sense as a technology that does not rely on losing charger network to operate (just like no car manufacturer needs to subsidize fuel stations).

Re: Volkswagen develops hydrogen car that can travel 2k kilometers on one tank

#76

Post by dpq »

Somewhat off-topic: why "2k kilometers" instead of 2 megameters? I do realize that in daily life people rarely use distances of that order of magnitude, but the semantic connections between kilobitsmegabits, kilowattsmegawatts appears to be entirely accessible to essentially all adults, so why use the awkward "thousands of kilometers" instead?

Re: Volkswagen develops hydrogen car that can travel 2k kilometers on one tank

#77

Post by greenthrow »

jonwest wrote: post #19
geijoenr wrote: post #14

Some time ago I saw a presentation from the chaos computer club where an expert on the matter explained there is a lot of misunderstandings about hydrogen technology as an energy source and how is gonna useful for society and why it is necessary. In a nutshell some industries that currently rely on natural gas cannot switch effectively to electricity, hydrogen seems to be the only solution at the moment. Regarding tr…

What about using hydrogen as a generator for an EV like in the Hyundai 74 concept? I’m far from an expert but something like that, at least intuitively, feels like a nice compromise with having portability of fuel, but still allowing for alternative power sources via electricity (like if grid power was sourced via solar, hydro, wind, etc).

Hydrogen makes no sense for passenger vehicles. It requires building out a massive infrastructure that doesn't exist and is just far less efficient than storing the elecricity in a battery.

Check out this video for more on where Hydrogen does and does not make sense: https://youtu.be/JlOCS95Jvjc

Re: Volkswagen develops hydrogen car that can travel 2k kilometers on one tank

#78

Post by bastawhiz »

noogle wrote: post #75
geijoenr wrote: post #14

Some time ago I saw a presentation from the chaos computer club where an expert on the matter explained there is a lot of misunderstandings about hydrogen technology as an energy source and how is gonna useful for society and why it is necessary. In a nutshell some industries that currently rely on natural gas cannot switch effectively to electricity, hydrogen seems to be the only solution at the moment. Regarding tr…

Batteries needed electric vehicles are still expensive and seem to essentially be the bottleneck for mass change to EV. The infrastructure needed to support battery electric vehicles seem to be expensive/complex to run sufficiently well in practice. In the US Tesla's supercharger network is often cited as a moat against other manufacturers. It's not even building the chargers - it's maintenance and compatibility. Cha…

Counterpoint: I can't even refill my damn inkjet without the manufacturer doing their damnedest to get me to pay multiples for what's essentially commodity ink. I have no faith that hydrogen won't work the same.

Re: Volkswagen develops hydrogen car that can travel 2k kilometers on one tank

#79

Post by Waterluvian »

bombcar wrote: post #66
Waterluvian wrote: post #60

Earlier quoted context omitted.

Sigh. This is the kind of obvious, simple, sensible answer that I feel silly not immediately considering. The only downside (shared by my initial thought) is that they aren’t collapsible. So that volume is committed even 1/4 way through my trip

Why can't they be? You want a fuel bladder: https://www.liquidcontainment.com.au/category/2/Fuel-Bladder...

When I think “Jerry can” I think the very specific rigid 20L vessel. I guess we can call other things a Jerry can too.

I’m curious if these are legally allowed in Canada. If so they seem decent!

Re: Volkswagen develops hydrogen car that can travel 2k kilometers on one tank

#80

Post by ranieuwe »

Waterluvian wrote: post #60
tomxor wrote: post #53

Earlier quoted context omitted.

Yes, Jerrycans. Seriously. + you can easily swap back to arbitrary storage once you are finished with your rare 2000 km journey. For all it's issues, petroleum is extremely convenient in that it can be transferred and contained in such a low tech way with (relative) safety.

Sigh. This is the kind of obvious, simple, sensible answer that I feel silly not immediately considering. The only downside (shared by my initial thought) is that they aren’t collapsible. So that volume is committed even 1/4 way through my trip

They sell those! They are used frequently in rescue settings. The can is basically a big cubical heavy plastic bag.

Your alternative is of course to fill some plastic bags from your local grocery store like this [1] lady did.

[1] https://twitter.com/FiendishlyYours/status/13919904872220016...

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