Image Source: https://www.bbc.com/
The two red-and-white silos of the aluminium smelter at Straumsvík are conspicuous from afar to everyone travelling from Iceland’s international airport to the capital city, Reykjavík. These silos house a mineral called alumina, the raw material used to produce aluminium. The alumina makes its way via an automated system to potrooms – three grey, long, low-lying buildings – where the manufacture of aluminium happens. These potrooms are perhaps less noticeable than the towers, yet they are playing a crucial role in reducing Iceland’s carbon emissions.
Heavy industry in Iceland contributes 48% of the country’s carbon dioxide (CO2) emissions, according to the Environment Agency of Iceland, excluding greenhouse gases from land use and forestry. Even though these industrial facilities run on renewable energy from hydroelectricity and geothermal power, CO2 is released as part of the process of producing metals like aluminium. The larger of the country’s industrial facilities produces silicon metals, which are used in steel manufacturing, as well as aluminium, much of which is exported and used in the automobile industry.
At present, three aluminium smelters, two manufacturing plants and the energy company Reykjavik Energy are investigating becoming carbon neutral by 2040. Together, the facilities release about 1.76 million tonnes of CO2 each year. Getting from that figure to zero might seem like a tall order, especially when much of Iceland’s heavy industry already runs on renewables.
But for the remaining carbon there is another way – capturing the CO2 released from the facilities’ smokestacks, injecting it into the Icelandic basalt rock nearby and waiting for it to turn into stone.
The concept is known as carbon capture and storage (CCS), and versions of the technology have been tried and tested for years. Typically, carbon capture and storage involves capturing the CO2 and separating it from other gases, transporting it by pipeline or ship to a suitable site, and then injecting it deep underground. It can be injected into in large areas of sedimentary rock or depleted oil and gas fields, among other sites. There it is stored, usually at depths of at least one kilometre, and over time it is turned into a harmless carbonate mineral, such as calcite – one of the main components of marble and limestone.