The 2016 Paris Agreement’s goal of achieving net zero CO2 emissions by 2050 has prompted a series of industries to develop plans to decarbonise, and governments have been incentivising this transition to a sustainable economy through emissions trading schemes and investment in carbon capture, utilisation and storage (CCUS) technologies. As one of the top three emissions producers in the world, responsible for 8% of CO2 emissions, the steel industry is an important player in decarbonising, and using CCUS has the potential to be both environmentally and economically beneficial to the industry and the planet. 


Why the steel industry is suited to carbon capture

Steel plants are well suited to adopting CCUS technology because their emissions can largely be captured directly from their process gas and off gas, and once captured, these emissions can either be buried in long-term storage, or repurposed and fed back into a circular economy as a useful product in biofuel and other materials. Repurposing captured carbon allows plants to keep costs down while also contributing towards achieving net zero by transforming a former harmful waste product into a valuable raw material. Carbon capture is a mature technology which can be incorporated into preexisting steel plants and is more affordable than many other decarbonisation options. The affordability of carbon capture is also helped by the fact that the captured carbon and/or carbon credits can be sold by the steel company within emissions trading schemes and increase cash flow.


Financial incentives to capture carbon

Due to incentives such as tighter regulations which raise the cost of CO2 emissions, the global steel industry will have up to 14% of its potential value at risk if it does not reduce its environmental impact now. In order to remain economically competitive decarbonisation has to be one of the industries main goals over the next 30 years. This need is also driven by subsidies and tax credits which some jurisdictions reward to businesses that use CCUS to decarbonise. This incentive then drives further developments in CCUS technology innovation and decreases the cost of implementing it in the steel industry. The UK government’s approach to deploying CCUS technology across industries including the steel industry is outlined in the 2017 Clean Growth Strategy, which also describes how CCUS innovation and knowledge sharing can best be supported within industry and academia. 


How carbon is captured from steel plants

The methods of implementing CCUS into steel plants are part of what makes it such a viable technology and well suited to the industry. Carbon capture technologies can be retrofitted onto existing plants so that instead of rebuilding or otherwise disrupting the production process, the technology can be implemented non-invasively. This works by capturing CO2 from either blast furnace gases or cogeneration plant flue gases. The blast furnace contains 60% of the CO2 produced by the plant, as well as the combustible gases hydrogen and carbon monoxide. Capturing CO2 directly from this mixture of gases requires similar techniques to commercial hydrogen production. Alternatively CO2 can be captured from the gas stream of the cogeneration plant using chemical solvent based separation. Commercial examples of these technologies already exist and need to be expanded to steel plants across the world, with an aim of capturing 506 Mt of CO2 annually.


Final thoughts

The steel industry is an ideal candidate for expanding the use of CCUS technology, and one that will make a significant contribution to the net zero 2050 goal by decarbonising. Implementing carbon capture technology within steel plants will be economically beneficial to the industry, and have a positive environmental impact on the rest of the world.