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Archive:000/Hydrogen gas: Difference between revisions
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}} | }} | ||
{{dp | {{dp | ||
|<nowiki>pgm. | |<nowiki>pgm.status_quo_mining_production</nowiki> | ||
|<nowiki>platinum.mine_production + palladium.mine_production</nowiki> | |<nowiki>platinum.mine_production + palladium.mine_production</nowiki> | ||
|<nowiki>Global production of platinum-group metals (PGMs) from mining (status quo)</nowiki> | |<nowiki>Global production of platinum-group metals (PGMs) from mining (status quo)</nowiki> | ||
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}} | }} | ||
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'''Scenario 1:''' If hydrogen gas (from wind power) were to directly replace all fossil fuels (this implies that people would drive [[hydrogen combustion vehicles]]): | |||
<tab name="SEE MATHS" collapsed> | |||
<tab name=" | |||
{{calc | {{calc | ||
|electrolysis.pgm_by_power / electrolysis.efficiency / wind.capacity_factor * fossil_fuels.consumption | |electrolysis.pgm_by_power / electrolysis.efficiency / wind.capacity_factor * fossil_fuels.consumption | ||
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{{calc | {{calc | ||
|... | |... | ||
|years pgm. | |years pgm.status_quo_mining_production | ||
|||'''PGMs needed for hydrogen gas production.''' | |||
}} | }} | ||
</tab> | </tab> | ||
The amount of PGMs needed is pretty reasonable (16% of mineral reserves) | * The amount of PGMs needed is pretty reasonable '''(16% of mineral reserves)'''. We'd still have to mine for PGMs a lot faster than the status-quo (and do it ''without'' exploitative [[labor]]). {{npn}} | ||
To prevent NOx emissions ([[#NOx emissions|see section below]]), hydrogen combustion vehicles need ''catalytic converters'', just like gasoline or diesel vehicles do. Catalytic converters ''also'' contain some PGMs, which could be obtained by recycling old catalytic converters from fossil-fuel vehicles. | {{minor|To prevent NOx emissions ([[#NOx emissions|see section below]]), hydrogen combustion vehicles need ''catalytic converters'', just like gasoline or diesel vehicles do. Catalytic converters ''also'' contain some PGMs, which could be obtained by recycling old catalytic converters from fossil-fuel vehicles.}} | ||
'''Scenario 2:''' If all vehicles were hydrogen [[fuel cell vehicles]] instead: | '''Scenario 2:''' If all vehicles were hydrogen [[fuel cell vehicles]] instead: | ||
<tab name=" | |||
<tab name="SEE MATHS" collapsed> | |||
{{calc | {{calc | ||
|(toyota_mirai.pgm - catalytic_converter.pgm) * world.cars * commercial_factor | |(toyota_mirai.pgm - catalytic_converter.pgm) * world.cars * commercial_factor | ||
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{{calc | {{calc | ||
|... | |... | ||
|years pgm. | |years pgm.status_quo_mining_production | ||
|||Fuel-cell vehicles don't | |||'''PGMs needed to make the fuel-cell vehicles.'''{{minor|Fuel-cell vehicles don't have catalytic converters, but a fuel cell contains far more PGMs than a catalytic converter.}} | ||
}} | }} | ||
</tab> | </tab> | ||
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Maybe I should refactor [[template:calc]] to allow for presenting one calculation in multiple units? This would involve some design decisions. | Maybe I should refactor [[template:calc]] to allow for presenting one calculation in multiple units? This would involve some design decisions. | ||
--> | --> | ||
* One benefit of fuel cell vehicles is that they're more energy-efficient than combustion vehicles (i.e. less hydrogen used per kilometer driven). | |||
* The problem is, the fuel cells alone would need '''7 times more''' PGMs mined than Scenario 1 (estimated). Perhaps too much to be scalable. And this is true ''even though'' we factored in the recycling of old catalytic converters. | |||
<tab name="General principles" collapsed> | |||
{{minor|The mass of PGMs needed is proportional to ''peak power'':}} | |||
* For electrolysis systems, the maximum '''rate of hydrogen production''' {{light|is limited by the amount of PGMs}}. | |||
* For fuel cell vehicles, the '''horsepower''' {{light|is limited by the amount of PGMs}}. | |||
** {{minor|But the vehicle can still achieve ''short bursts'' of higher horsepower if there's a battery or supercapacitor in parallel with the fuel cell.}} | |||
</tab> | |||
<tab name="More notes on these estimates" collapsed> | <tab name="More notes on these estimates" collapsed> | ||
More musings about the calculations above: | More musings about the calculations above: | ||
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In cases where electrolysis is done in weather below 0°C, such as beside wind turbines in cold parts of the world during winter, losses may be somewhat worse. {{x|The water has to be liquid (not frozen) while it's being electrolyzed to become hydrogen and oxygen. Heating takes energy; then again, maybe the waste heat of electrolysis would already be enough to keep the water liquid. In theory it can: For any amount of H<sub>2</sub>O electrolyzed, the waste heat is 8 times more than what it takes to melt that amount of ice: {{p2|'''[See calculation]'''|{{calc|hydrogen_gas.specific_energy * water.hydrogen_by_mass * (100% - electrolysis.efficiency)|water_fusion_heat}} {{pn|Maybe this belongs on a separate page called "hydrogen gas production in winter weather"?}} }}. For this to work, the hydrogen production system would have to be well-insulated from the weather. }} {{npn}} | In cases where electrolysis is done in weather below 0°C, such as beside wind turbines in cold parts of the world during winter, losses may be somewhat worse. {{x|The water has to be liquid (not frozen) while it's being electrolyzed to become hydrogen and oxygen. Heating takes energy; then again, maybe the waste heat of electrolysis would already be enough to keep the water liquid. In theory it can: For any amount of H<sub>2</sub>O electrolyzed, the waste heat is 8 times more than what it takes to melt that amount of ice: {{p2|'''[See calculation]'''|{{calc|hydrogen_gas.specific_energy * water.hydrogen_by_mass * (100% - electrolysis.efficiency)|water_fusion_heat}} {{pn|Maybe this belongs on a separate page called "hydrogen gas production in winter weather"?}} }}. For this to work, the hydrogen production system would have to be well-insulated from the weather. }} {{npn}} | ||
==Shelf life== | ==Shelf life / storage== | ||
{{sum|{{rn}} }} | {{sum|{{rn}} }} | ||
Chemically, hydrogen is the lightest gas (smallest molecules). This makes it harder to store than other gases, but there are still ways. {{en}} | Chemically, hydrogen is the lightest gas (smallest molecules). This makes it harder to store than other gases, but there are still ways. {{en}} | ||
{{pn-block| | |||
read later: some relevant info might be found in: https://europe.autonews.com/suppliers/faurecia-gets-213m-euros-eu-french-hydrogen-project | |||
<br />basic question: can pressurized hydrogen be stored in (perhaps modified) steel tanks, or will it corrode all but the most expensive materials? | |||
}} | |||
==Pipelines== | ==Pipelines== | ||
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</tab> | </tab> | ||
<!-- | <!-- | ||
TODO: | TODO: compare the hydrogen losses to the hydrogen the earth gains from solar winds | ||
TODO: add new heading: | |||
==Climate effects of leaks== | ==Climate effects of leaks== | ||
Hydrogen is not directly a greenhouse gas, but it slows the breakdown of atmospheric methane (which ''is'' a greenhouse gas). Therefore hydrogen gas leaks do have ''some'' effect on warming the climate. {{qn}} | Hydrogen is not directly a greenhouse gas, but it slows the breakdown of atmospheric methane (which ''is'' a greenhouse gas). Therefore hydrogen gas leaks do have ''some'' effect on warming the climate. {{qn}} | ||