WHAT IS IT?
Hydrogen (H₂) is the lightest and most abundant element in the universe. As a colourless, odourless, highly flammable gas, it has been used industrially for decades — primarily to make ammonia (via Haber-Bosch) and in petroleum refining. It is now emerging as a critical clean energy carrier for decarbonising hard-to-abate sectors.

COLOUR TAXONOMY (production method)
Grey Hydrogen: Steam methane reforming (SMR) of natural gas — no carbon capture. ~10 kg CO₂ per kg H₂. Current dominant method (~95% of production).
Blue Hydrogen: SMR + CCS (Carbon Capture and Storage). ~1–2 kg CO₂ per kg H₂. Transitional technology.
Green Hydrogen: Electrolysis powered by renewable electricity. Near-zero emissions. Currently expensive but falling.
Turquoise Hydrogen: Methane pyrolysis → solid carbon + H₂. Emerging technology.

HOW ELECTROLYSIS WORKS


Water (H₂O) + electricity → H₂ + O₂
Requires large amounts of renewable power. Electrolyser types: PEM (Proton Exchange Membrane), Alkaline, SOEC.

KEY USES (current)

Ammonia synthesis (~55%): Haber-Bosch process — feeds the world's fertilizer supply

Petroleum refining (~25%): Hydrocracking, hydrotreating, desulphurisation

Methanol production

Food processing (hydrogenation of vegetable oils)

KEY USES (emerging)

Green steel: Direct reduction using H₂ instead of coking coal

Fuel cell vehicles (FCEV): Toyota Mirai, Hyundai Nexo

Power generation and grid balancing

Ammonia carrier for long-distance H₂ transport

Aviation and shipping (via e-fuels and green ammonia)

TRADE CORRIDORS


Current: Not widely traded — consumed captively at production sites.
Future: Green hydrogen export projects in Australia (Pilbara), Middle East (NEOM Oxagon), Chile (Haru Oni), Namibia, Morocco targeting Asia and Europe by 2030.
Tetra relevance: Green ammonia as a hydrogen carrier is the most commercially viable near-term H₂ trade route.

PRICING


No global benchmark. Grey H₂ priced by natural gas cost. Green H₂ levelised cost (LCOH) currently $3–8/kg vs $1–2/kg for grey. Expected to fall to $1.5–2.5/kg by 2030 with scale.

SAFETY


Extremely flammable (4–75% explosive range in air). Very low ignition energy. No colour or odour. Burns with invisible flame. Requires special embrittlement-resistant steel vessels. IMDG Class 2.1.

hydrogen H2 green hydrogen blue hydrogen grey hydrogen ammonia fuel cell electrolysis