Green Hydrogen
Hydrogen produced by electrolyzing water using renewable energy like hydropower, solar, and wind, with no carbon emissions.
Hydrogen (H)
Atomic number 1, abundant in the universe (75%), with a very low density (1/16 of air).
Hydrogen Classification by CO₂ Emissions
- Gray hydrogen from fossil fuels or reforming, emitting high CO₂, accounts for 96% of global production.
- Blue hydrogen from fossil fuels, with CO₂ captured and stored using CCS.
- Pink hydrogen from water electrolysis using nuclear energy, with no CO₂ emissions and improved efficiency from heat or cooling.
- Green hydrogen from water electrolysis using renewable energy, with no CO₂ emissions.
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Gray hydrogen
CO₂ is generated through hydrogen production by reforming fossil fuels such as natural gas.
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Blue hydrogen
Capture / storage generated CO₂
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Pink hydrogen
Electrolysis using nuclear power
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Green hydrogen
No CO₂ generation based on renewable energy(Ultimate goal)
Hydrogen Classification by Production Method
- Byproduct hydrogenproduced from refining byproduct gases in chemical processes. Example ) Cracking → refining → gasoline, naphtha, and byproduct hydrogen.
- Hydrogen extractedfrom natural gas (methane), generating CO₂ as a byproduct. * Endothermic reaction : CH₄ + 2H₂O (over 700°C) → 4H₂ + CO₂
- Electrolytic hydrogenHydrogen produced by electrolyzing water, with indirect CO₂ emissions depending on the electricity type.
Hydrogen Classification by Location
- On-siteProduced and utilized at the same location in small plants.
- Off-siteProduced in large plants and transported for supply.