IN SUMMARY
Indonesia's stainless steel output is projected to reach roughly 10 million tonnes by 2030, making the carbon intensity of its integrated production route increasingly important for international competitiveness. This whitepaper identifies where those emissions arise and where decarbonisation efforts should focus.
Indonesian hot-rolled coil stainless steel 304 (18/8) has more than three times the climate change impact of production in regions such as Finland, Kazakhstan and China.
Upstream alloy production (ferronickel, nickel pig iron, charge chrome and pig iron) accounts for about 94% of the cradle-to-gate impact. Argon oxygen decarburisation, casting and hot rolling contribute around 3%.
Captive coal-fired electricity, and coal used as fuel and reductant, dominate across every route, so meaningful reductions depend on structural change to power and feedstock supply.
Rapid growth, rising carbon exposure
Indonesia supplied more than 60% of global nickel production in 2024. Its nickel downstreaming strategy, backed largely by Chinese investment, has driven stainless steel output from under 1 million tonnes in 2016 to more than 6 million tonnes in 2023, with roughly 10 million tonnes projected by 2030.
That growth has delivered significant economic development. But the integrated production route used in Indonesia is among the most carbon-intensive pathways for stainless steel, which exposes producers to financial risk under emerging climate regulation such as the EU’s Carbon Border Adjustment Mechanism (CBAM).
Stainless steel 304 (18/8) is the most widely used stainless grade in the world, containing 18-20% chromium and 8-11% nickel. This whitepaper quantifies the carbon footprint of one kilogram of hot-rolled coil (HRC) produced in Indonesia and identifies where in the supply chain emissions are concentrated.
How the footprint was modelled
Minviro carried out a product carbon footprint study using life cycle assessment (LCA) consistent with ISO 14040, ISO 14044 and ISO 14067. The functional unit is one kilogram of HRC stainless steel 304 (18/8) at the factory gate. The boundary is cradle-to-gate: from raw material extraction to the finished coil leaving the facility.
The route modelled is Indonesia’s integrated rotary kiln-electric furnace (RKEF), submerged arc furnace (SAF) and argon oxygen decarburisation (AOD) process. Iron, chromium and nickel were modelled as foreground data. Ferrosilicon and ferromanganese, assumed to be imported from China, were modelled with background data from ecoinvent 3.12. Hot charging raw materials into the AOD removes the need for electric arc furnace remelting.
Primary data on the RKEF-SAF-AOD configuration, direct CO2 emissions and top gas flows came from the Minviro database and were validated with Indonesian stainless steel stakeholders. The model was built in XYCLE, Minviro’s LCA software, and the results were benchmarked against published carbon footprint studies and Minviro’s critical minerals database.
Where the emissions sit
Upstream production of the alloying inputs accounts for approximately 94% of the cradle-to-gate climate change impact. These inputs are ferronickel (FeNi), nickel pig iron (NPI), charge chrome, pig iron, ferrosilicon and ferromanganese. Energy used in AOD refining, continuous casting and hot strip milling contributes only around 3%, and other process inputs such as argon, oxygen, nitrogen and refractories make up the remaining 3%.
Compared with other routes in Minviro’s database, Indonesian HRC stainless steel 304 (18/8) has more than three times the climate change impact of production in regions such as Finland, Kazakhstan and China.
The three main upstream hotspots
Ferronickel and nickel pig iron: electricity for the electric furnace accounts for up to 50% of the impact, and coal used as fuel and reductant in the rotary dryer and kiln accounts for approximately 40%.
Charge chrome: more than half of the impact comes from the electricity used to smelt chromium sinter pellets in the SAF. Mining, beneficiation and transport of chromite account for less than 5%.
Pig iron: direct CO2 from iron reduction with coke in the blast furnace contributes more than 50%, followed by sintering at more than 30%, then coke making.
The industrial parks that host these plants draw electricity from captive coal-fired power, which is why power supply recurs as the main hotspot.
What it means for decarbonisation and CBAM
Because the footprint is set upstream, improvements in AOD, casting or hot rolling will not meaningfully change the overall result. Reducing the carbon intensity of the electricity supply is the greatest opportunity, but it would require structural change to the integrated industrial park model on which current production depends.
As output approaches roughly 10 million tonnes by 2030, the emissions quantified here will grow in absolute terms. CBAM, together with growing demand for product carbon footprint disclosures, makes robust emissions quantification across steel supply chains increasingly important for market access.
Producers seeking to stay competitive will need to look beyond steelmaking operations to upstream alloy production and power supply. Engineering-based LCA gives a transparent way to evaluate alternative decarbonisation pathways before investment decisions are made.