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MPhil in Engineering for Sustainable Development

global challenges, engineering solutions

Studying at Cambridge

Roderick Darling

The steel stock and rate of production in a +2 degree C world

In 2015  the international community agreed to a 2°C limit to global warming. As carbon dioxide (C02) is the greenhouse gas most responsible for global warming, industries that are significant  emitters  of C02  need to decarbonise  in order to  successfully meet  this target. As the production of steel accounts for 8% of global C02 emissions,the industry's decarbonisation is of critical importance.


This paper examines the previously unexplored relationship between the level of atmospheric carbon,the C0 2 emitted from steel production processes,and the dynamics of the global demand for steel. Scenario-based modelling shows that if the rate of steel production continues  as estimated, and the current  technologies  for producing  steel remain unchanged, the  steel industry  will  have consumed its  share of the  remaining global carbon budget within 20 years. This has not previously been quantified.   On the other hand, efforts to reduce emissions through reducing the production of steel would have a significant  impact  on  the accumulation  of  steel  stocks, and on  the ability  of countries to develop.


For the first time,a qualitative assessment of future alternatives for the steel industry is carried out.It shows that retrofitting existing blast furnaces using Top-Gas Recycling with CCS  technology,  and  the  substitution  of  coke  for  charcoal  are  feasible options  for  reducing emissions within  a reasonable timeframe; while many other technologies are not.


Re-running  the  scenario-models  with  the  inclusion  of  these  technologies  shows a significant decline in emissions per tonne of steel, thereby increasing the amount of steel that can be produced for a given carbon budget.


Finally, it shows that if these technologies are used together, the sequestration of carbon dioxide  emitted  from  sustainable charcoal would introduce negative emissions into the system, thereby  reducing C02  emissions and  permitting global demand  for  steel to be met, without surpassing the industry's emissions budget. This is an important new insight.