Greenhouse gas removal in the Iron and steel industry was the subject of our fourth lunchtime webinar which was presented by Dr Phil Renforth from Heriot-Watt University who discussed the potential carbonation of outlying materials from the sector as a means to remove CO2 from the atmosphere.
The global potential for CO2 removal through enhanced weathering of by-products from the iron and steel industry is difficult to assess because of the lack of statistics on the amounts of these materials. The GGR programme project has estimated these figures based on how much steel and iron we are currently producing and drivers for future production.
It is estimated that the global GGR potential in the iron and steel industry will be about 0.5 Gt CO2/year by 2100. Together with other alkaline materials (demolition wastes, mine waste etc.) the total may be more than 3GtCO2/year.
Although in the context of current emissions this may seem small, when thinking about future scenarios where emission levels will be lower this figure could make a more significant contribution. Additionally, if CO2 capture in slag is combined with other decarbonisation methods, the CO2 emissions from using lower quality ore could be negated, increasing the feasibility of using lower grade ore and changing the value proposition of the steel industry.
An important consideration is the uneven geographical distribution of these by-products, indicating there is an important role to play for local policy initiatives on CO2 removal strategies.
In order to provide greater insight into carbonating these materials with atmospheric CO2 (rather than high purity or flue gases) researchers from the project have been analysing samples from Consett in County Durham which is the site of a former steel plant. This has shown that much of the carbon capture potential of the area is still present and traditional slag management practices are insufficient to maximise this potential. The next step for the project will be to run an experimental programme to see how best to capture CO2 from the area.
More information on the other webinars in the series can be found here.