Week five in my series on hydrogen. Written in response to the British government’s new hydrogen strategy and the current interest around the subject, I’m looking at the pros and cons, the practical uses and the hype. More posts below.
In earlier posts I’ve looked at how hydrogen could be used in transport or in heating. But what about the steel needed to make the cars? Or the cement for making those buildings in the first place?
Industry is a major user of energy, much of it for heat, and therefore it is a major source of emissions. Global population is growing, many people are getting wealthier and enjoying more consumer products – and is most contexts that’s a good thing. But everything has an impact, and the carbon emissions of materials are almost all rising:
To prevent a climate catastrophe, all of those materials need low carbon solutions, and the higher up that graph they appear, the more significant their impact. Steel and cement are two of the biggest priorities, but glass production, aluminium and other metals are also huge sources of carbon. Cement we’ll have to deal with another time, but hydrogen may have a role in the others.
The reason that metals loom so large in the list of material carbon footprints is that the industry needs huge amounts of energy to extract resources from the earth, refine the materials out of the rock, and then melt the metals into shape. All of these are big challenges for net zero, but industrial heat is perhaps the biggest. This ‘high grade heat’ – temperatures of hundreds of degrees Celsius – is hard to acheive.
Take steel. To make this vital material you need to heat a blast furnace to 1,500C, which is done with coke (a refined version of coal). You could in theory create that heat electrically, but it would be expensive to the point of being uneconomic. You could burn wood or other biomass, but feeding entire forests into steel production sounds like a very bad idea right now. So hydrogen may be the best bet. Hydrogen provides the bridging fuel between industry and renewable energy, so that you could run a steel plant on wind power, hydro or some other form of clean power.
This is being done in Sweden, where the first hydrogen steel plant is due to open next year. Others are working on aluminium production with hydrogen. Chile, known for its copper, is subsidising hydrogen research and development in its mining sector. Hydrogen was used to make glass for the first time this year, by Pilkington in Liverpool. It’s happening where it matters most too – the world’s largest steel producer, China Baowu Steel Group, announced that it would be using hydrogen as part of its net zero by 2050 target. State-owned steel company HBIS has said the same.
Of course, you need big investments in renewable energy to power all that hydrogen production. McKinsey imagine 300 to 1,100 wind turbines, depending on output, to make two million tonnes of hydrogen steel. But by reducing demand, and recycling and reusing steel in a circular economy, future needs for steel could be met this way.
Most of this is in its early stages. It will be a while before hydrogen puts a serious dent in industrial emissions. But it will.