Hierarchical model to find the path reducing CO2 emissions of integrated iron and steel production

Abstract

Improving CO2 emission status of the iron and steel industry is an important problem for China to be able to reach low-carbon development goals. A hierarchical model of CO2 emission was established to find the way to reduce emissions from the iron containing material flow network and the energy flow network in this paper. This model was developed not only based on the interconnection and interrelationship among the iron containing material flow, energy flow and carbon emission, but also added the impact of energies buffer and adjustment. Case study shown that, CO2 emission intensity was 2.23 t/t_s. Significant reasons affecting the CO2 emission intensity, which were the release of gases, the mismatch between coking and iron making capacity, and the less utilization of scrap in convertor, were found. Three optimization scenarios were proposed. Calculation results shown that, CO2 emissions intensity was reduced by 0.01 t/t_s, 0.02 t/t_s and 0.02 t/t_s, respectively. Comparing each scenario with the previous, blast furnace gas buffer capacities were 47.6 × 103tce, 8.4 × 103tce, 25.1 × 103tce, and coke oven gas buffer capacities were 56.3 × 103tce, 20.7 × 103tce, −38.5 × 103tce. At last, some strategy suggestions were put forward.