4. Iron and steel module: RMC|Steel
RMC|Steel is a sectoral module within the RMC model family that models the low-carbon transition of China’s iron and steel industry. It is designed to analyze the evolution of supply and demand, technological composition, energy structure, and the demand for specific energy carriers (such as hydrogen) in China’s steel industry during its low-carbon transition. The module is also implemented in MESSAGEix and covers 31 provincial-level administrative regions as in the RMC main model. It incorporates, in a bottom-up manner, the major production processes and key technological details of the steel sector, and has been calibrated using empirical historical data on production capacity, output, and technology costs.
4.1. Model structure
Fig. 4-1: Reference energy system of RMC|Steel Model.
As shown in Fig. 4-1, the RMC|Steel model mainly models raw material processing, pig iron smelting, and crude steel smelting, and does not involve the subsequent processing of steel coils, billets, and other products. Among them, raw material processing mainly includes:
Coking (coking)
Calcination of limestone (calcin)
Sintering and pelletizing of iron ore (sint_pelle)
The principal ironmaking technologies include:
Blast furnace ironmaking (bf)
Hydrogen-enriched blast furnace ironmaking (bf_h2)
Natural gas-based direct reduced iron (dri)
Hydrogen-based direct reduced iron (hdri)
Hydrogen-based direct smelting reduction (hmr)
The main steelmaking technologies include:
Basic oxygen furnace steelmaking (bof)
Electric arc furnace steelmaking using scrap as the primary feedstock (eaf_scrap)
Electric arc furnace steelmaking using DRI as the main feedstock (eaf_spg)
For BF, DRI, and BOF facilities, carbon capture and storage (CCS) technologies can be incorporated to mitigate CO2 emissions. The BF facilities can also be retrofitted with hydrogen injection systems to achieve partial hydrogen substitution. In addition, the model provides a detailed breakdown of hydrogen production pathways, distinguishing among coal gasification, natural gas reforming, and water electrolysis from a technological perspective, each of which can be coupled with corresponding CCS technologies.
The input–output relationships among these major processes and technologies are summarized in Table 4-1.
Technology |
Input |
Output |
|---|---|---|
BF |
coke, elec, raw iron, qklime |
molten iron |
DRI |
h2, raw iron |
sponge iron |
BOF |
molten iron, elec, qklime |
crude steel |
EAF (sponge iron) |
sponge iron, elec |
crude steel |
EAF (scrap) |
scrap, elec |
crude steel |
Coal to H2 |
coal, elec |
H2 |
Gas to H2 |
ch4, elec |
H2 |
Electrolysis |
elec, water |
H2 |
4.2. Parameter settings
Technology |
CAPEX |
Unit |
Data source |
|---|---|---|---|
Sintering/pelletizing |
45.87 |
M$/Mtpa |
|
Limestone Calcination |
109.6 |
M$/Mtpa |
|
Coking |
446.2 |
M$/Mtpa |
|
BF iron-making |
211 |
M$/Mtpa |
|
BF w/ H2 injection |
40 |
M$/Mtpa |
- |
BF w/ CCS |
80.24 |
M$/Mtpa |
|
H-DRI |
580 |
M$/Mtpa |
|
BOF steel-making |
100 |
M$/Mtpa |
|
BOF w/ CCS |
80.24 |
M$/Mtpa |
|
EAF (using DRI as main feedstock) |
143 |
M$/Mtpa |
|
EAF (using scrap as main feedstock) |
143 |
M$/Mtpa |
|
Coal to H2 |
10692 |
M$/Mtpa |
|
Coal to H2 w/ CCS |
444 |
M$/Mtpa |
|
Gas to H2 |
3641.3 |
M$/Mtpa |
|
Gas to H2 w/ CCS |
2693 |
M$/Mtpa |
|
Electrolysis |
8296.5 |
M$/Mtpa |
Technology |
Fixed OPEX |
Unit |
Data source |
|---|---|---|---|
Sintering/pelletizing |
1.835 |
M$/Mtpa |
|
Limestone Calcination |
8.05 |
M$/Mtpa |
|
Coking |
17.18 |
M$/Mtpa |
|
BF iron-making |
14.14 |
M$/Mtpa |
|
BF w/ H2 injection |
10 |
M$/Mtpa |
- |
BF w/ CCS |
4.07 |
M$/Mtpa |
|
H-DRI |
20 |
M$/Mtpa |
|
BOF steel-making |
15.45 |
M$/Mtpa |
|
BOF w/ CCS |
2.16 |
M$/Mtpa |
|
EAF (using DRI as main feedstock) |
81.24 |
M$/Mtpa |
|
EAF (using scrap as main feedstock) |
81.24 |
M$/Mtpa |
|
Coal to H2 |
433 |
M$/Mtpa |
|
Coal to H2 w/ CCS |
18 |
M$/Mtpa |
- |
Gas to H2 |
454.5 |
M$/Mtpa |
|
Gas to H2 w/ CCS |
50.2 |
M$/Mtpa |
- |
Electrolysis |
182.5 |
M$/Mtpa |
Technology |
Variable OPEX |
Unit |
Data source |
|---|---|---|---|
Iron ore supply |
110.61 |
M$/Mt |
|
Limestone supply |
19.59 |
M$/Mt |
|
Coal supply |
195.89 |
M$/Mt |
|
Natural gas supply |
694 |
M$/Mt |
|
Electricity supply |
0.085 |
M$/GWh |
State-owned Assets Supervision and Administration Commission of the State Council, 2020 |
Water supply |
0.676 |
M$/Mt |
|
Scrap supply |
349.8 |
M$/Mt |
|
Sintering/pelletizing |
20 |
M$/Mt |
|
Coal to H2 |
434.1 |
M$/Mt |
|
Coal to H2 w/ CCS |
0 |
M$/Mt |
- |
Gas to H2 |
338.5 |
M$/Mt |
|
Gas to H2 w/ CCS |
0 |
M$/Mt |
- |
Electrolysis |
0 |
M$/Mt |
- |
Technology |
Emission factor |
Unit |
Data source |
|---|---|---|---|
Sintering/pelletizing |
0.2 |
t-CO2/t-output |
CSteelNews, 2023; Steelonthenet, 2025; ZHAO Zedong, LI Jiaxuan, and LI Yuanye, 2025 |
Limestone Calcination |
1 |
t-CO2/t-output |
Shenlan Environmental Protection Industry Development Co., Ltd., 2025 |
Coking |
0.794 |
t-CO2/t-output |
|
BF iron-making |
1.22 |
t-CO2/t-output |
|
BF w/ H2 injection |
0.67 |
t-CO2/t-output |
|
BF w/ CCS |
0.0523 |
t-CO2/t-output |
|
H-DRI |
0.04 |
t-CO2/t-output |
|
BOF steel-making |
0.181 |
t-CO2/t-output |
|
BOF w/ CCS |
0.03 |
t-CO2/t-output |
|
EAF (using DRI as main feedstock) |
0.03 |
t-CO2/t-output |
|
EAF (using scrap as main feedstock) |
0.03 |
t-CO2/t-output |
|
Coal to H2 |
20.1 |
t-CO2/t-output |
|
Coal to H2 w/ CCS |
2.1 |
t-CO2/t-output |
|
Gas to H2 |
10.13 |
t-CO2/t-output |
|
Gas to H2 w/ CCS |
2.32 |
t-CO2/t-output |