Michelle D’urbano
THE past few months have seen temperature records smashed. Global warming has cranked up extreme weather events that have wrecked towns by fire and flood. So it seems an odd time for the UK to consider opening a new coal mine.
Woodhouse Colliery, near Whitehaven in Cumbria, would be the first new deep coal mine in the UK for decades. Although the county council approved the project in principle in 2019, the UK government vacillated over the decision and then announced a public inquiry, which is due to start on 7 September. As the UK prepares to host the COP26 climate summit in November, many argue that Woodhouse Colliery is incompatible with the UK’s climate goals.
The colliery’s coal wouldn’t fuel polluting power stations. Instead, the mine would supply “coking coal” to the steel industry in the UK and Europe. Coke is a dense form of carbon that plays three vital roles in steel-making. Inside a blast furnace, carbon chemically removes oxygen from iron oxide ore to create crude iron. Burning coke also raises the temperature to 2000°C or more, allowing molten iron to be tapped from the bottom of the furnace. Finally, a dash of carbon in the iron strengthens the metal, helping it to become steel inside a second furnace.
Coke-based steel-making generates billions of tonnes of carbon dioxide every year and accounts for 7 to 9 per cent of all human-made CO2 emissions. But advocates for the mine say that a domestic supply of coke could help UK steel-makers curb their emissions because it would avoid the CO2 released by transporting steel-making coal from abroad. In March, West Cumbria Mining, the company behind the colliery proposal, said: “Until an alternative for coking coal is found, such coal production is essential.”
But alternatives already exist. More than 100 commercial plants around the world can use natural gas to convert iron ore into iron. By feeding that iron into an electric arc furnace to make steel, the whole process emits about 35 per cent less CO2 than the conventional blast furnace route.
Replacing the natural gas with hydrogen potentially offers even greater carbon savings. When hydrogen reacts with iron ore, it produces iron and water. A Swedish project called HYBRIT is taking this approach to make “green steel” with about 5 per cent of the carbon footprint of conventional steel. It uses wind-powered electrolysers to split water into hydrogen and oxygen, and uses more renewable electricity to run its furnaces.
HYBRIT is no blue-skies laboratory project. It is a partnership between some of Sweden’s biggest companies – steel-maker SSAB, mining firm LKAB and power company Vattenfall – which is already operating a pilot plant capable of producing about 1 tonne of iron per hour. A larger plant is in the works and HYBRIT aims to have green steel on the market in 2026.
Green steel is currently more expensive than conventional steel. But renewable energy is getting cheaper by the day and the cost of producing hydrogen with electrolysers is falling fast. Meanwhile, the European Union is considering a border tariff that would impose costs on importing carbon-intensive goods like steel. Democratic law-makers in the US proposed a similar border tax in July. These measures would squeeze conventional steel-making, potentially helping low-carbon methods to gain a commercial advantage.
Opening up a new source of coking coal in the UK is a step in the wrong direction. The UK government and industry should instead work together to invest in burgeoning low-carbon steel-making technologies that will play an essential part in tackling climate change.
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