How much CO2 a tonne of steel carries depends on the route
Ranges are wide because two things move them: how clean the electricity is, and how much scrap goes into the furnace. Imported routes also carry their transport.
Rows follow TDRI's own order. Every route except blast furnace depends on the carbon intensity of the electricity behind it, which is why the ranges overlap: imported HBI can land near the hydrogen route when the iron is made with green hydrogen, or near the natural gas route when it is not.
Source: Thailand Development Research Institute, Assessing Opportunities for Green Steel Development and Industrial Competitiveness in Thailand, 23 March 2026, page 35.
Iron and steel no longer have to be made in the same place
That single change is what puts a new set of options on the table for a country like Thailand.
Molten iron cannot travel. Both steps had to happen on the same site, which tied ironmaking to wherever the raw materials landed.
ships
Direct reduction produces iron in solid form, and solid iron can be shipped. The most energy-intensive step can happen where clean electricity is cheap, while the steel is made close to the market.
Energy endowment, not tradition or proximity to ore, increasingly decides where ironmaking happens. TDRI notes that countries will not transition uniformly: some will relocate energy-intensive ironmaking and trade HBI, some will import part of the value chain, and a few with abundant renewables and existing electric arc furnace capacity are suited to keeping the whole chain.
Source: Thailand Development Research Institute, Assessing Opportunities for Green Steel Development and Industrial Competitiveness in Thailand, 23 March 2026, page 32.
Five pathways to lower-carbon steel in Thailand
TDRI assessed each route against three tests: whether it can compete economically, whether it can operate reliably on Thailand's energy and infrastructure, and whether it can happen under current policy and institutions.
Source: Thailand Development Research Institute, Assessing Opportunities for Green Steel Development and Industrial Competitiveness in Thailand, 23 March 2026, comparative viability matrix, page 62, with pathway detail from pages 57 to 61.