Zero-CO₂ metals

A hydrogen-based steelmaking process that produces water rather than CO₂ as a by-product could help us to reduce our carbon footprint.

Many manufacturing processes for essential industrial materials emit CO₂ and other environmentally harmful waste streams. These waste products are typically by-products of the underlying chemical processes and the accompanying combustion heating requirements.

The science

New ‘green chemistry’ methods for the processing of inorganic materials—such as metals and ceramics—are attracting plenty of interest worldwide. At Paihau—Robinson Research Institute, we're taking a whole-of-systems approach to traditional materials manufacturing processes. We're focusing on minimising emissions through changing the underlying chemistry.

Our flagship project is using hydrogen to eliminate fossil-based carbon from the industrial steelmaking process. Instead of CO₂, the by-product of the process is—quite simply—water. This high-temperature reaction is performed in a high-temperature reactor which has been custom-built at the Institute.

We are also exploring new routes to producing critical materials like vanadium, as well as sintered technical ceramics and industrial inorganic compounds.

Our automated sampling system means reactor studies that typically took weeks to work through can now be done at the Institute in just a single day.

Impact and potential

In New Zealand alone, the steelmaking industry accounts for 14 percent of net national CO₂ emissions. In order for us to meet future CO₂ emission targets, we will need to minimise or eliminate carbon inputs in the steelmaking industry. Our work has shown that this could be achieved using our alternative process technology, which employs hydrogen as a reactant and high-temperature electromagnetic furnaces.

Using hydrogen instead of carbon not only creates opportunities to improve environmental sustainability, it also increases the purity of the final metal product and reduces the overall size of the reactor that is required. Changing to a hydrogen-based process has additional advantages for the steel plant owner, as it simultaneously increases revenue and significantly decreases capital costs.

The people

Dr Chris Bumby leads the Zero-CO₂ metals programme at the Institute. He recognises the unprecedented benefits that the Institute brings by having engineers, physicists, and materials scientists collaborating closely to accelerate progress on a complex problem. Novel experimental reactor designs are conceived, designed, built, and tested in house. Automation of purpose-designed systems enables a wide range of conditions to be studied in detail and quickly.