As I mentioned in past columns, getting industry to decarbonize is a crucial piece of the climate puzzle. That said, businesses like concrete and steel manufacturing pose a formidable challenge due to the difficulty of removing carbon emissions from their fundamental manufacturing processes. Together, they’re responsible for about 14% of global greenhouse gas emissions according to the World Steel and Global Cement and Concrete associations, making it clear that dealing with their emissions is a priority. This column will delve into the complexities and challenges of decarbonizing industries like concrete and steel, shedding light on the broader picture of transitioning toward a sustainable industrial landscape.
The basics of concrete and steel
The basics of making concrete are pretty straightforward. To make it, you need a few ingredients: water, sand, gravel, and cement, with cement being the problem child. To make cement, you need calcium, and to get calcium, you have to burn limestone, which contains calcium, oxygen, and carbon. The burning produces the needed calcium but also carbon dioxide as an unwanted byproduct. Unfortunately, there was no way around the chemical reaction.
Steel is similar. To make it, you need iron and carbon, iron in its pure form, which, for all practical purposes, doesn’t exist in the natural world. Luckily, there’s plenty of iron ore in the ground, which consists of pure iron and oxygen. To make steel, you heat the iron ore and a form of coal, coke. The carbon in the coke combines with the pure iron to produce steel, but the unwanted byproduct is carbon dioxide, and lots of it, almost twice as much as the steel produced.
While folks in the steel and concrete industries are experimenting with new ways to make steel and cement, many others, including me, believe it will be decades before we have a viable alternative. This suggests we need other solutions, and the ones most often discussed are carbon capture systems.
Carbon capture systems
There are two kinds of carbon capture systems: point of capture and direct air. Point-of-capture systems capture carbon dioxide from industrial smokestacks and inject it into the ground, where it is safely stored as a solid. The technology exists for point-of-capture systems but is expensive and not widely used.
Direct-air-capture systems pull carbon dioxide out of the air, process it, and inject it into the ground. The technology for air capture systems is still in its infancy, and there are two issues with it: The cost of extracting carbon dioxide is too high, and the scale required to pull enough carbon dioxide out of the air to make a difference is enormous. Thousands, if not hundreds of thousands, of plants are needed in every corner of the world to make a meaningful reduction. Still, most believe a breakthrough in this area is necessary to solve the crisis, and all of the Intergovernmental Panel on Climate Change climate models have built carbon capture systems into their projections. One potential huge benefit of direct-air-capture systems is that they may allow us to generate negative emissions, which is defined as taking more carbon out of the air than we put in, and in doing so, undoing the damage we caused in the last 100 years.
Beyond concrete and steel
Beyond concrete and steel, numerous industrial sectors contribute to carbon emissions, each with its unique challenges. These sectors include chemicals, plastics, petrochemicals, and more. Decarbonizing these industries involves finding alternative processes or materials that emit fewer or no greenhouse gasses or using one or both of the carbon capture systems mentioned above to offset emissions.
Unfortunately, implementing carbon capture and use technologies in industrial facilities requires overhauling existing infrastructure, which often needs to be updated. This can be costly and may disrupt production during the transition period, which is why many business executives have been hesitant to make the necessary changes.
Finally, finding alternative materials for industries that are traditionally carbon intensive is another significant challenge, but one that industry must pursue. For instance, developing low-carbon or carbon-neutral construction materials as an alternative to traditional cement and steel is a complex scientific and engineering problem, but if industry experts can pull it off, it would be a significant win.
Conclusion
Decarbonizing industry is a vital piece of the climate puzzle. While the concrete and steel industries often steal the spotlight for their emissions, the challenges go way beyond them. Taking on a whole range of industrial sectors, shifting to clean energy, managing the costs of carbon capture technology, and making air capture systems both feasible and affordable at scale are all part of the equation.
Next month, I’ll write about trends in global carbon monoxide emissions.
Rich Marcello is a novelist and a member of the Climate Initiative Committee. In writing his latest novel, “The Means of Keeping,” he spent several years researching the climate crisis.
