Scenario Analysis of Sulfur Dioxide Emissions Reduction Potential in China's Iron and Steel Industry

Acid rain remains an important environmental problem. The Chinese steel industry is becoming a key domestic emitter of sulfur dioxide (SO2), the central molecular component of acid rain. In this study SO2 emission potential is assessed by developing a material flow analysis (MFA) model and generating four different SO2 industry emission scenarios from 2006 to 2030, with each scenario representing a possible development path for the industry. When SO2 emission factors in every unit of steel production are presumed to remain constant through 2030, scenario analysis results show that under a business‐as‐usual (BAU) scenario SO2 emissions will experience sustained growth to a peak value of 1.73 million metric tons (megatons, Mt) through 2020, approximately 52% higher than that in 2006, and that this trend is unlikely to be reversed. The high scenario and medium scenario demonstrate that it is difficult to control SO2 emissions to an acceptable level by only upgrading technology and making industrial structural adjustments. Yet through the incorporation of sintering gas desulfurization, the low scenario can smoothly bridge the gap between the simulative SO2 emissions and the envisioned value, since sintering is the biggest emitter in this industry. Once the desulfurization rate of sintering gas reaches 60%, SO2 emissions will be less than the level of 0.60 Mt in 2030 and will also meet the reduction goals. Moreover, scenario analysis suggests that single terminal control cannot solve the problem of high SO2 emissions. Therefore, in order to control the total SO2 emissions of the steel industry it is imperative that two or more measures be combined.