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Carbon-free. Synthetic hydrocarbons and biofuels still give off carbon dioxide. Hydrides are just a vector for hydrogen. The advantage of hydrides over hydroge

by kortex 7y ago

Carbon-free. Synthetic hydrocarbons and biofuels still give off carbon dioxide. Hydrides are just a vector for hydrogen. The advantage of hydrides over hydrogen is you don't release all the flammable gas at once, improving safety.

extropy 7y ago
Giving off carbon dioxide might be fine if it's collected back from atmosphere in the manufacturing process.
dTal 7y ago
Is that a problem, though? CO2 emissions aren't locally toxic. The main issue with it today is the fact that the carbon comes from the ground and doesn't get put back. Water vapor is a greenhouse gas too!
- petra 7y ago
  Water vapor is a greenhouse gas, but it is always kept in balance and the air cannot hold more than it is. All that will happen is that it rains. And no amount of water vapor from hydrogen cars compares to what all the oceans contribute to the water vapor. It will basically have no effect. Source:https://www.reddit.com/r/explainlikeimfive/comments/3qhj31/eli5wont_hydrogen_cars_produce_a_lot_of_water/ https://www.reddit.com/r/explainlikeimfive/comments/3qhj31/e...
  - dTal 7y ago
    Right, I wasn't actually suggesting that water vapor emissions from hydrogen vehicles would be a climate issue - on the contrary, I was drawing the comparison to illustrate that greenhouse gas emissions aren't necessarily a problem, if part of a closed loop (or other stabilizing influences like you point out).
- kortex 7y ago
  Entropy. It's easier to just not involve carbon at all via some hydrogen cycle than to burn it and have to capture it, or extract it from the air/water. As I mention elsewhere in this thread, hydrocarbons will dominate the air travel industry long after most others have converted. The less carbon in flux, the better.
  - dTal 7y ago
    Is it easier, though? Both hydrogen and carbon cycles react atmospheric oxygen with some other element, creating a low-energy molecule that is released into the environment. To be sustainable, the feedstock atom must be segregated from that same waste low-energy molecule, an inherently energy-intensive procedure. This energy must be sustainably sourced by either nuclear or energy ultimately from the sun. Separating hydrogen from water requires electricity, a very low-entropy form of energy. Creating combustible carbon from atmospheric CO2 is as simple as planting something that grows fast - it will use sunlight directly. And that's not even getting in to how much more tractable carbon is to work with than hydrogen. Really, it doesn't matter whether we burn hydrogen or carbon. How much carbon is in flux is irrelevant. The main thing - the only thing - is to stop digging it up. The cycle must be closed. After that, it's safe to let the market decide the most efficient energy cycles.

by kortex 7y ago

extropy 7y ago

Giving off carbon dioxide might be fine if it's collected back from atmosphere in the manufacturing process.

dTal 7y ago

Is that a problem, though? CO2 emissions aren't locally toxic. The main issue with it today is the fact that the carbon comes from the ground and doesn't get put back. Water vapor is a greenhouse gas too!

petra 7y ago
Water vapor is a greenhouse gas, but it is always kept in balance and the air cannot hold more than it is. All that will happen is that it rains. And no amount of water vapor from hydrogen cars compares to what all the oceans contribute to the water vapor. It will basically have no effect. Source:https://www.reddit.com/r/explainlikeimfive/comments/3qhj31/eli5wont_hydrogen_cars_produce_a_lot_of_water/ https://www.reddit.com/r/explainlikeimfive/comments/3qhj31/e...
- dTal 7y ago
  Right, I wasn't actually suggesting that water vapor emissions from hydrogen vehicles would be a climate issue - on the contrary, I was drawing the comparison to illustrate that greenhouse gas emissions aren't necessarily a problem, if part of a closed loop (or other stabilizing influences like you point out).
kortex 7y ago
Entropy. It's easier to just not involve carbon at all via some hydrogen cycle than to burn it and have to capture it, or extract it from the air/water. As I mention elsewhere in this thread, hydrocarbons will dominate the air travel industry long after most others have converted. The less carbon in flux, the better.
- dTal 7y ago
  Is it easier, though? Both hydrogen and carbon cycles react atmospheric oxygen with some other element, creating a low-energy molecule that is released into the environment. To be sustainable, the feedstock atom must be segregated from that same waste low-energy molecule, an inherently energy-intensive procedure. This energy must be sustainably sourced by either nuclear or energy ultimately from the sun. Separating hydrogen from water requires electricity, a very low-entropy form of energy. Creating combustible carbon from atmospheric CO2 is as simple as planting something that grows fast - it will use sunlight directly. And that's not even getting in to how much more tractable carbon is to work with than hydrogen. Really, it doesn't matter whether we burn hydrogen or carbon. How much carbon is in flux is irrelevant. The main thing - the only thing - is to stop digging it up. The cycle must be closed. After that, it's safe to let the market decide the most efficient energy cycles.