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Hydrogen cars always seemed like a solution waiting for a problem to me. The fact is if you can distribute and store hydrogen reasonably well then ordinary ever

Hydrogen cars always seemed like a solution waiting for a problem to me. The fact is if you can distribute and store hydrogen reasonably well then ordinary everyday cars could run it today, as easily as they do petrol except they only produce H20 as exhaust. If you have to create hydrogen from water and electricity you'd have been just as well using the electricity directly.

digitalengineer 14y ago
Well, for electricity the world still burns coal, gas or destroys nature for things like dams. I imagined it takes a bit of electricity to transform the H2O to hydrogen at first, but than the hydrogen that is released takes over. It would be so great if the only thing cars produce is clean water and oxygen. Imagine entire city's with clean air. That is something to behold.
- VLM 14y ago
  "I imagined it takes a bit of electricity to transform the H2O to hydrogen at first," No talk to a chemist or chemeng. Virtually all industrial H2 comes from steam reforming natgas. At red heat in the absence of air, natgas basically "burns" steam generating reformer gas or syngas or whatever which is carbon monoxide and hydrogen. Then at a much lower "cooking" heat you oxidize the toxic / poisonous carbon monoxide to CO2 with more steam. Separating out the CO2 is moderately annoying an energy intensive, too. In summary H2 comes from partial combustion of natgas, using water as an O2 source. Or another way to phrase it is you burn the carbon out of methane at great effort leaving you with just the hydrogen. As you'd imagine its terribly inefficient, even if you fed that H2 into a 100% eff fuel cell (LOL) you'd get more kilowatt-hours per BTU of natgas by simply burning the natgas in a turbine. Even a small turbine (hybrid car sized) would be a higher system efficiency than H2. In theory is not relevant WRT electrolysis, because in theory you could have a natgas hybrid turbine in a car, or in theory you could have a mr. fusion burning the H2. In practice H2 is just extremely highly processed natgas.
jack-r-abbit 14y ago
> If you have to create hydrogen from water and electricity you'd have been just as well using the electricity directly. Unless you can store more of the hydrogen in your car than you can the electricity. This whole range thing can be solved by more batteries and/or more efficient use of the battery.
VLM 14y ago
"then ordinary everyday cars could run it today" Serious nitrogen oxide issues make life difficult on the exhaust catalyst. If you rip out the cat conv you can never run gasoline again. Fundamentally the flame burns too hot/fast creating nitrogen oxides. If you must burn a gas try butane, there's tons of it dissolved in winter gas right now. Propane is even better. If you absolutely positively "must" use H2 for marketing reasons or whatever then pipe it into a fuel cell and top off a battery, either pure elec or hybrid ICE. The biggest problem is H2 solely commercially comes from natgas, and it turns out that natgas is a great automotive fuel with a huge (mostly non-US) deployed base. So there is no practical advantage in turning natgas into H2 and then inventing a whole new infrastructure for H2 distribution and all new vehicles, when there's already an excellent system for natgas. The fundamental problem of H2 is how do you intermediate yourself if you're not wanted, not needed, and add no value? Outside petrochem, this is a good startup question that always needs answering. You could purchase govt regulations, or do some vertical integration trick, or ...

digitalengineer 14y ago

Well, for electricity the world still burns coal, gas or destroys nature for things like dams. I imagined it takes a bit of electricity to transform the H2O to hydrogen at first, but than the hydrogen that is released takes over. It would be so great if the only thing cars produce is clean water and oxygen. Imagine entire city's with clean air. That is something to behold.

VLM 14y ago
"I imagined it takes a bit of electricity to transform the H2O to hydrogen at first," No talk to a chemist or chemeng. Virtually all industrial H2 comes from steam reforming natgas. At red heat in the absence of air, natgas basically "burns" steam generating reformer gas or syngas or whatever which is carbon monoxide and hydrogen. Then at a much lower "cooking" heat you oxidize the toxic / poisonous carbon monoxide to CO2 with more steam. Separating out the CO2 is moderately annoying an energy intensive, too. In summary H2 comes from partial combustion of natgas, using water as an O2 source. Or another way to phrase it is you burn the carbon out of methane at great effort leaving you with just the hydrogen. As you'd imagine its terribly inefficient, even if you fed that H2 into a 100% eff fuel cell (LOL) you'd get more kilowatt-hours per BTU of natgas by simply burning the natgas in a turbine. Even a small turbine (hybrid car sized) would be a higher system efficiency than H2. In theory is not relevant WRT electrolysis, because in theory you could have a natgas hybrid turbine in a car, or in theory you could have a mr. fusion burning the H2. In practice H2 is just extremely highly processed natgas.

jack-r-abbit 14y ago

> If you have to create hydrogen from water and electricity you'd have been just as well using the electricity directly. Unless you can store more of the hydrogen in your car than you can the electricity. This whole range thing can be solved by more batteries and/or more efficient use of the battery.

VLM 14y ago

"then ordinary everyday cars could run it today" Serious nitrogen oxide issues make life difficult on the exhaust catalyst. If you rip out the cat conv you can never run gasoline again. Fundamentally the flame burns too hot/fast creating nitrogen oxides. If you must burn a gas try butane, there's tons of it dissolved in winter gas right now. Propane is even better. If you absolutely positively "must" use H2 for marketing reasons or whatever then pipe it into a fuel cell and top off a battery, either pure elec or hybrid ICE. The biggest problem is H2 solely commercially comes from natgas, and it turns out that natgas is a great automotive fuel with a huge (mostly non-US) deployed base. So there is no practical advantage in turning natgas into H2 and then inventing a whole new infrastructure for H2 distribution and all new vehicles, when there's already an excellent system for natgas. The fundamental problem of H2 is how do you intermediate yourself if you're not wanted, not needed, and add no value? Outside petrochem, this is a good startup question that always needs answering. You could purchase govt regulations, or do some vertical integration trick, or ...