Comprehensive assessment of energy conservation and CO2 emissions mitigation in China's iron and steel industry based on dynamic material flows

To investigate the potential of energy saving and emissions mitigation during 2015-2050 in China's iron and steel industry (CISI), a comprehensive assessment approach was developed and applied on the basis of the dynamic Material Flow Analysis (MFA) model and the energy consumption and carbon dioxide (CO2) emission model. Four scenarios including the business-as-usual (BAU) scenario, the structure adjustment (STA) scenario, the energy-efficiency improvement (EEI) scenario, and the strengthened policy (STP) scenario have been set to describe future energy saving and carbon mitigation strategies in relation to the development of the iron and steel industry. The modeling results show that China's steel demand will gradually decrease from 789.35 Mt in 2013 to 440.38 Mt in 2043 and will stabilize at around 450 Mt, and the scrap resources are sufficient to support the promotion of the production structure under all four scenarios. The results also indicate that energy consumption and CO2 emissions will gradually decline under the synergistic effect of technology promotion and structure adjustment during the period. In the short term, they will depend more on technology improvement; in the long term, particularly after 2040, promotion of the production structure adjustment will be the main force. The selected 35 energy saving technologies (ESTs) contribute to 3.01 GJ/t and 398.22 kg CO2/t crude steel when the discount rate of 15% is applied.