This paper addresses the demonstration of the DMX™ process under industrial conditions. The DMX™ technology is an innovative CO2 chemical absorption process involving a demixing solvent. From previous studies, this process showed promising results in terms of energy penalty reduction (-30% on energy penalty) and in terms of process stability with a tailored pilot plant at IFP Energies Nouvelles, in France. A demonstrator plant with a capacity to capture 0.5 ton CO2/hour has been installed in 2022 at the ArcelorMittal industrial site in Dunkirk, France (AMF). The demonstrator is connected to the blast furnace gas network of AMF site and started operation on October 2022. In this paper, the demonstrator and its features are described, a preliminary set of results of the experimental campaigns are presented and some lessons learned of the start-up and operation of the unit are discussed. This work is supported by the European Union and the French Agency for Ecological Transition (ADEME).