When applied to steelmaking the CCU/S process involves capturing the CO2 contained in blast furnace waste gases using a chemical solvent, extracting the CO2 from the solvent, and putting it under low pressure. This allows the CO2 to be re-used in furnaces or stored away. The process also yields heat, which can be harnessed to reduce the operating cost of furnaces. CCU/S therefore has the potential to reduce dependence on fossil resources and contribute to the decarbonisation of steelmaking.
Developed over a decade of research, the DMX™ process reduces the energy intensity of CCU/S by nearly 30%. This is made possible by using heat-recovery methods, as well as a patented demixing solvent, the DMX™ solvent, created and marketed by our partners in the 3D Project. Not only is the DMX™ solvent more chemically stable than the aqueous monoethanolamine (MEA) solution commonly used in CCU/S today, it also has a higher capture capacity, making it both more efficient and cost-effective.
Upon contact with CO2-laden waste gases, the DMX™ solvent – composed of two amines in an aqueous solution – splits (or demixes) into two separate liquid phases. The CO2 becomes concentrated in only one of these liquid phases. The DMX™ process thus yields a smaller volume of CO2-rich liquid solvent. By extension, it consumes less energy in the subsequent regeneration phase of the CCU/S process, in which the CO2 is stripped from the liquid solvent by injecting steam.