Assessment of CO₂ emissions pathways for the Japanese iron and steel industry towards 2030 with consideration of process capacities and operational constraints to flexibly adapt to a range of production levels

This paper analysed CO₂ emission pathways for the Japanese iron and steel industry towards 2030, taking into account the likely development of process capacities that could flexibly adapt to a range of projected future crude steel production levels (“optimal capacities”) while maintaining minimum capacity utilisation rates. Coke and pig iron production capacities were optimised to the levels that enable flexible operation for 90–120 Mt-crude steel/y, compared to 110 Mt/y in 2010. Operational constraints were applied to the capacity utilisation rates (minimum of 85%) and the maximum use of coke and pig iron substitutes. This paper also assessed the implications of the aforementioned flexible operation across a range of crude steel production levels on the future scrap balances. This study calculated the optimal capacities for coke ovens and blast furnaces in 2030 to be 29 Mt-coke/y (compared to 43 Mt/y in 2010) and 83 Mt-pig iron/y (compared to 90 Mt/y in 2010). Under these optimal capacities and the aforementioned range for crude steel production levels, the projected total CO₂ emissions were 4–21% below 2010 levels. If the 2030 production level remains at 105 Mt/y, which equals the 2015 production level and the 1973–2015 average, the total emissions will be 9–16% below 2010 levels, depending on the level of emissions reduction effort. These results indicate that the industry is likely to considerably overachieve its voluntary emissions reduction target for 2030 (0.1% below 2010 levels). Moreover, it was found that the lifetime extensions for existing blast furnaces and coke ovens have limited impact on CO₂ emissions while significantly reducing the investment needs. The study also showed that the low crude steel production (90 Mt/y) combined with high pig iron and coke consumption levels to maintain minimum capacity utilisation rates may lead not only to an increase in specific CO₂ emissions per tonne of crude steel but also to a net export of obsolete scrap up to 17 Mt, which is nearly twice the historical high. Towards 2030, Japan would need to consider not only opportunities to maximize the use of steel scrap but also the development of an extended steel scrap trade infrastructure.