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My understanding is most hydrogen fueling stations produce the hydrogen onsite via electrolysis of water. EDIT: My understanding was wrong - it's produced loca

by bombcar 9mo ago

My understanding is most hydrogen fueling stations produce the hydrogen onsite via electrolysis of water. EDIT: My understanding was wrong - it's produced locally onsite but via steam-methane reforming: https://www.energy.gov/eere/fuelcells/hydrogen-production-natural-gas-reforming https://www.energy.gov/eere/fuelcells/hydrogen-production-na...

hvb2 9mo ago
If you can do that at a meaningful rate you might as well install ev charging and just not electrolyse when cars are charging
- b112 9mo ago
  He didn't say it doesn't have local tanks. Only that it makes h2 local. You can still make h2 to replenish, and have storage. This is akin to how almost all power used to charge cars, is not-green. For example, there are still Ng, coal, and other types of power plants. If cars switched to gas, instead of electric charging, then some of those could be shut down. But the true point, is as we convert to more and more solar, we'll eventually shut down the last of the fossil fuel burner plants, and eventually the cars will all be green power sourced. Same with h2. Getting non-polling cars out the door and into people's hands, is key. Eventually, where the power comes from will be clean. And really, we're already having issues with power infra, even before AI, so re-purposing Ng pipelines for H2 would be a great thing.
  - estimator7292 9mo ago
    We won't get rid of natural gas any time soon. Ng pipelines are not in any way similar to H2 pipelines except the word 'pipe'. You can't just put hydrogen in them. You can't even retrofit them. You're looking at laying an entirely new pipeline either way. Furthermore, most H2 is produced by fossil fuel extraction. We aren't cracking water to get H2, we're pulling it out of the ground. Cracking water is hideously expensive. All in all, combustion engines are more efficient than green hydrogen. That's the core problem. We simply don't have the absurd amounts of unused energy required for green H2 production. If we did, we'd be pumping fully half of that energy into the atmosphere as waste heat. Hydrogen cars aren't going to happen. We won't have grid-scale hydrogen. It's just a terrible idea. Hydrogen is too difficult to handle and incredibly dangerous to store. The efficiency is so ludicrously bad that you would genuinely do better to create syngas from captured atmospheric carbon and burn it in regular combustion vehicles. Avoiding carbon emissions is not the only concern in regards to the climate. Focusing on carbon and nothing else leads you to really dumb and bad ideas like piping hydrogen gas across the continent.
    - b112 9mo ago
      h2 can be co-mingled with Ng and extracted with a molar filter at the other end. Ng pipelines are everywhere, so it makes perfect sense.
      - adastra22 9mo ago
        None of the pipes or valves are designed for hydrogen. It will steal leak. And leaking a very flammable gas isn’t great.
        mike50 9mo ago
        Let alone the compressors or the flow measurement equipment. Also significant portions of the pipesline (especially in neighborhoods / last mile) aren't metal anymore.
      - reamaer 9mo ago
        [dead]
    - fsh 9mo ago
      This is not quite true. The original gas pipes in most cities were built for "town gas" which was produced from coal and is 50% hydrogen by volume. The infrastructure could handle hydrogen just fine, but the low conversion efficiencies make it impractical.
blibble 9mo ago
this is the case while they're in the hype building phase, when people are paying attention if hydrogen even gained widespread adoption, it would be mass produced via steam reforming of natural gas (which is why the oil majors are the ones desperately pushing it)
- b112 9mo ago
  That makes no sense. If the oil companies were pushing H2, every car would be H2 by now. H2 can be generated anywhere there is power. Any power that can be used to charge a car's battery, can be used to make H2. Yes, I'm sure you have 1000 reasons, but I don't really care, it's just not reasonable to discredit h2 because of made up paranoia. We should embrace any way to get a clean running car on the road.
  - deleted 9mo ago
    [deleted]
  - BadBadJellyBean 9mo ago
    But isn't that a counter point? Just putting the electricity directly into a car seems sensible instead of converting it to H2 and then back to electricity. Especially now that wo don't usually have a huge oversupply of green energy. We can think of ways to use the oversupply when it really becomes a problem. But I'd assume then BEV will be so dominant the no one will go through the hassle of supporting H2.
  - Tade0 9mo ago
    There's no point. EVs go 50% further on the same amount of energy, are easier to charge and are, of course, cheaper.
    - b112 9mo ago
      EVs take forever to charge, rendering long trips unrealistic. They are not cheaper long term, for they rely upon thousands of pounds of heavy batteries. If they go further now, that is not a given down the road. Were you to employ this logic when electric cars first came out, there wouldn't be a single one on the road. It's only through trillions of research dollars, that current battery tech is where it is. But sure, let's not work on multiple paths. Let's discount other attempts at clean tech. Even if they're older, cost less to the environment to build (batteries are terrible, environmentally), and so on.
hannob 9mo ago
Your understanding is entirely wrong. Most hydrogen fueling stations receive it from the next steam reformer, which will make it from fossil gas.
BadBadJellyBean 9mo ago
Okay not driving it around then. But somehow it's worse. You still have to build the special tank and the special pump and also get an electrolysis device that is big enough to create enough hydrogen and also you have to get heaps of power somewhere that could instead be just straight put into a battery in a car. Make it make sense. What's the point? Who is willing to do that?
- MBCook 9mo ago
  Don’t forget keeping everything cold enough. On the vehicle side, you can make a gasoline tank in pretty much any shape you want. We have lots of experience making batteries in different shapes thanks to cell phones. High-pressure tanks only want to be in one shape. And it’s not especially convenient.
  - BadBadJellyBean 9mo ago
    Is the shape round? I bet it's round.
    - flir 9mo ago
      Ultimately, it's shrapnel-shaped.
      - BadBadJellyBean 9mo ago
        Is that shrapnel arranged in a roundish pattern?
    - fuzzfactor 9mo ago
      No need as I have shown in my other coment.
  - fuzzfactor 9mo ago
    One of the reasons we use cryogenic liquidfied gases is so the density can be in the same ball-park of more-easily liquified gases which do not need low temperature to keep from expanding until the tank ruptures. >One of the reasons we use cryogenic liquidfied gases is so the density can be in the same ball-park of more-easily liquified gases which do not need low temperature to keep from expanding until the tank ruptures. Propane, butane, LPG are all gases but the pressure which needs to be contained as the gas is turned into a liquid using pressure, is not too high for the typical welded BBQ tank. Designed to hold about 350 psi. The two lighter hydrocarbons, methane & ethane can be compressed way beyond what a high-pressure spun cylinder (like the typical 3000 psi rated heavy oxygen tank welders use) can handle, and still not liquefy. So similar to oxygen, nitrogen, argon, hydrogen and other "fixed" gases, methane needs to be liquefied cryogenically or any reasonable size tank will still not hold enough to last but a very small fraction of the time compared to the same capacity cryogenic storage. But "storage" is doing a lot of work here. Interestingly, with cryogenics you're going to need to handle even less pressure than the BBQ tanks, and the same size container ends up holding way more than the high-pressure cylinder at 3000 psi. A typical liquid nitrogen cylinder runs at about 50 psi, the tank will be rated quite a bit higher than that but not considered "high-pressure" by anybody. Thinner and non-curved shapes can be fine which can be lighter in weight than higher-pressure ratings would require, but you really have to have plenty of good thermal insulation to boot. The thing is, once you refill your cryogenic tank with cold liquid gas, you can never actually shut the tank completely. There is no additional cooling. The only thing keeping it cold is the low temperature of the liquid itself, no matter how good the insulation is, heat will gradually soak in and given enough time the whole thing would eventually end up at ambient temperature. Not cold enough to remain as a liquid any more. That would be eventually explosive whether it was a flammable gas or not. Instead, the tank is continuously venting a constant stream of gas from top. IOW the rate of heat absorbtion is compensated for under equilibrium as it boils the liquid a little bit constantly and there has to be a way for that gas to escape. The remaining liquid maintains the low temperature because the boiling point of the gas (at that low pressure) is still in the cryogenic range. The liquid self-refrigerates by evaporation to the (negative) boiling point of the substance. Which is why liquid helium is so much colder than liquid nitrogen in an identical cryo tank. That means if you fill a tank with one of these cryo gases, depending on your usage rate the losses to evaporation may be more than the amount you are utilizing. Or if you fill the cryo tank and don't use any at all for a while, it will empty itself by evaporation anyway and it could be before you got to use any of it.
deadbabe 9mo ago
Isn’t this bad? This means H2O molecules are being destroyed and the water is not returning to the water cycle to be reused. We will literally run out of water if everyone did this.
- dxdm 9mo ago
  Water gets split into oxygen and hydrogen using energy. The hydrogen then gets burned to release usable energy, which creates water. At least as far as I remember from chemistry class ages ago.
  - vardump 9mo ago
    There's some truth to what the gp said. Some hydrogen will escape, enter the upper atmosphere, and be blown away by the solar wind and thus be permanently lost.
    - dxdm 9mo ago
      I assume that this has been happening to all gases in the atmosphere for aeons, and thus, while technically correct, it is completely negligible for the relevant time scale.
aunty_helen 9mo ago
That’s not a thing. Anyone who’s seen hydrogen being split from electrolysis knows it takes a lot lot lot of electricity and is very slow. If two people needed to fill up in the same day it would run the well dry.
jasonwatkinspdx 9mo ago
Completely wrong. Globally over 95% of hydrogen is sourced from fossil fuels, particularly natural gas wells. Electrolysis is very limited to niche applications or token projects.
- mmooss 9mo ago
  The electrolysis needs power and could be fueled by fossil fuels.
- bombcar 9mo ago
  Maybe that's what it was - produced onsite via steam extraction from piped in natural gas (which means you could just as easily burn the natural gas in the vehicle). Either way there aren't many trucks full of hydrogen zipping around.

by bombcar 9mo ago

hvb2 9mo ago

If you can do that at a meaningful rate you might as well install ev charging and just not electrolyse when cars are charging

b112 9mo ago
He didn't say it doesn't have local tanks. Only that it makes h2 local. You can still make h2 to replenish, and have storage. This is akin to how almost all power used to charge cars, is not-green. For example, there are still Ng, coal, and other types of power plants. If cars switched to gas, instead of electric charging, then some of those could be shut down. But the true point, is as we convert to more and more solar, we'll eventually shut down the last of the fossil fuel burner plants, and eventually the cars will all be green power sourced. Same with h2. Getting non-polling cars out the door and into people's hands, is key. Eventually, where the power comes from will be clean. And really, we're already having issues with power infra, even before AI, so re-purposing Ng pipelines for H2 would be a great thing.
- estimator7292 9mo ago
  We won't get rid of natural gas any time soon. Ng pipelines are not in any way similar to H2 pipelines except the word 'pipe'. You can't just put hydrogen in them. You can't even retrofit them. You're looking at laying an entirely new pipeline either way. Furthermore, most H2 is produced by fossil fuel extraction. We aren't cracking water to get H2, we're pulling it out of the ground. Cracking water is hideously expensive. All in all, combustion engines are more efficient than green hydrogen. That's the core problem. We simply don't have the absurd amounts of unused energy required for green H2 production. If we did, we'd be pumping fully half of that energy into the atmosphere as waste heat. Hydrogen cars aren't going to happen. We won't have grid-scale hydrogen. It's just a terrible idea. Hydrogen is too difficult to handle and incredibly dangerous to store. The efficiency is so ludicrously bad that you would genuinely do better to create syngas from captured atmospheric carbon and burn it in regular combustion vehicles. Avoiding carbon emissions is not the only concern in regards to the climate. Focusing on carbon and nothing else leads you to really dumb and bad ideas like piping hydrogen gas across the continent.
  - b112 9mo ago
    h2 can be co-mingled with Ng and extracted with a molar filter at the other end. Ng pipelines are everywhere, so it makes perfect sense.
    - adastra22 9mo ago
      None of the pipes or valves are designed for hydrogen. It will steal leak. And leaking a very flammable gas isn’t great.
      - mike50 9mo ago
        Let alone the compressors or the flow measurement equipment. Also significant portions of the pipesline (especially in neighborhoods / last mile) aren't metal anymore.
    - reamaer 9mo ago
      [dead]
  - fsh 9mo ago
    This is not quite true. The original gas pipes in most cities were built for "town gas" which was produced from coal and is 50% hydrogen by volume. The infrastructure could handle hydrogen just fine, but the low conversion efficiencies make it impractical.

blibble 9mo ago

this is the case while they're in the hype building phase, when people are paying attention if hydrogen even gained widespread adoption, it would be mass produced via steam reforming of natural gas (which is why the oil majors are the ones desperately pushing it)

b112 9mo ago
That makes no sense. If the oil companies were pushing H2, every car would be H2 by now. H2 can be generated anywhere there is power. Any power that can be used to charge a car's battery, can be used to make H2. Yes, I'm sure you have 1000 reasons, but I don't really care, it's just not reasonable to discredit h2 because of made up paranoia. We should embrace any way to get a clean running car on the road.
- deleted 9mo ago
  [deleted]
- BadBadJellyBean 9mo ago
  But isn't that a counter point? Just putting the electricity directly into a car seems sensible instead of converting it to H2 and then back to electricity. Especially now that wo don't usually have a huge oversupply of green energy. We can think of ways to use the oversupply when it really becomes a problem. But I'd assume then BEV will be so dominant the no one will go through the hassle of supporting H2.
- Tade0 9mo ago
  There's no point. EVs go 50% further on the same amount of energy, are easier to charge and are, of course, cheaper.
  - b112 9mo ago
    EVs take forever to charge, rendering long trips unrealistic. They are not cheaper long term, for they rely upon thousands of pounds of heavy batteries. If they go further now, that is not a given down the road. Were you to employ this logic when electric cars first came out, there wouldn't be a single one on the road. It's only through trillions of research dollars, that current battery tech is where it is. But sure, let's not work on multiple paths. Let's discount other attempts at clean tech. Even if they're older, cost less to the environment to build (batteries are terrible, environmentally), and so on.

hannob 9mo ago

Your understanding is entirely wrong. Most hydrogen fueling stations receive it from the next steam reformer, which will make it from fossil gas.

BadBadJellyBean 9mo ago

Okay not driving it around then. But somehow it's worse. You still have to build the special tank and the special pump and also get an electrolysis device that is big enough to create enough hydrogen and also you have to get heaps of power somewhere that could instead be just straight put into a battery in a car. Make it make sense. What's the point? Who is willing to do that?

MBCook 9mo ago
Don’t forget keeping everything cold enough. On the vehicle side, you can make a gasoline tank in pretty much any shape you want. We have lots of experience making batteries in different shapes thanks to cell phones. High-pressure tanks only want to be in one shape. And it’s not especially convenient.
- BadBadJellyBean 9mo ago
  Is the shape round? I bet it's round.
  - flir 9mo ago
    Ultimately, it's shrapnel-shaped.
    - BadBadJellyBean 9mo ago
      Is that shrapnel arranged in a roundish pattern?
  - fuzzfactor 9mo ago
    No need as I have shown in my other coment.
- fuzzfactor 9mo ago
  One of the reasons we use cryogenic liquidfied gases is so the density can be in the same ball-park of more-easily liquified gases which do not need low temperature to keep from expanding until the tank ruptures. >One of the reasons we use cryogenic liquidfied gases is so the density can be in the same ball-park of more-easily liquified gases which do not need low temperature to keep from expanding until the tank ruptures. Propane, butane, LPG are all gases but the pressure which needs to be contained as the gas is turned into a liquid using pressure, is not too high for the typical welded BBQ tank. Designed to hold about 350 psi. The two lighter hydrocarbons, methane & ethane can be compressed way beyond what a high-pressure spun cylinder (like the typical 3000 psi rated heavy oxygen tank welders use) can handle, and still not liquefy. So similar to oxygen, nitrogen, argon, hydrogen and other "fixed" gases, methane needs to be liquefied cryogenically or any reasonable size tank will still not hold enough to last but a very small fraction of the time compared to the same capacity cryogenic storage. But "storage" is doing a lot of work here. Interestingly, with cryogenics you're going to need to handle even less pressure than the BBQ tanks, and the same size container ends up holding way more than the high-pressure cylinder at 3000 psi. A typical liquid nitrogen cylinder runs at about 50 psi, the tank will be rated quite a bit higher than that but not considered "high-pressure" by anybody. Thinner and non-curved shapes can be fine which can be lighter in weight than higher-pressure ratings would require, but you really have to have plenty of good thermal insulation to boot. The thing is, once you refill your cryogenic tank with cold liquid gas, you can never actually shut the tank completely. There is no additional cooling. The only thing keeping it cold is the low temperature of the liquid itself, no matter how good the insulation is, heat will gradually soak in and given enough time the whole thing would eventually end up at ambient temperature. Not cold enough to remain as a liquid any more. That would be eventually explosive whether it was a flammable gas or not. Instead, the tank is continuously venting a constant stream of gas from top. IOW the rate of heat absorbtion is compensated for under equilibrium as it boils the liquid a little bit constantly and there has to be a way for that gas to escape. The remaining liquid maintains the low temperature because the boiling point of the gas (at that low pressure) is still in the cryogenic range. The liquid self-refrigerates by evaporation to the (negative) boiling point of the substance. Which is why liquid helium is so much colder than liquid nitrogen in an identical cryo tank. That means if you fill a tank with one of these cryo gases, depending on your usage rate the losses to evaporation may be more than the amount you are utilizing. Or if you fill the cryo tank and don't use any at all for a while, it will empty itself by evaporation anyway and it could be before you got to use any of it.

deadbabe 9mo ago

Isn’t this bad? This means H2O molecules are being destroyed and the water is not returning to the water cycle to be reused. We will literally run out of water if everyone did this.

dxdm 9mo ago
Water gets split into oxygen and hydrogen using energy. The hydrogen then gets burned to release usable energy, which creates water. At least as far as I remember from chemistry class ages ago.
- vardump 9mo ago
  There's some truth to what the gp said. Some hydrogen will escape, enter the upper atmosphere, and be blown away by the solar wind and thus be permanently lost.
  - dxdm 9mo ago
    I assume that this has been happening to all gases in the atmosphere for aeons, and thus, while technically correct, it is completely negligible for the relevant time scale.

aunty_helen 9mo ago

That’s not a thing. Anyone who’s seen hydrogen being split from electrolysis knows it takes a lot lot lot of electricity and is very slow. If two people needed to fill up in the same day it would run the well dry.

jasonwatkinspdx 9mo ago

Completely wrong. Globally over 95% of hydrogen is sourced from fossil fuels, particularly natural gas wells. Electrolysis is very limited to niche applications or token projects.

mmooss 9mo ago
The electrolysis needs power and could be fueled by fossil fuels.
bombcar 9mo ago
Maybe that's what it was - produced onsite via steam extraction from piped in natural gas (which means you could just as easily burn the natural gas in the vehicle). Either way there aren't many trucks full of hydrogen zipping around.