The capture of carbon dioxide and its utilization as a building block in chemical synthesis aim at reducing the depletion of fossil resources and the emission of greenhouse gases. The project Carbon2Chem (R)-L5 is dedicated to the development of processes using CO2 for the production of polymer building blocks for polyurethanes. In this work, a process concept is presented for the CO2-based synthesis of diisocyanates, the main starting material in polyurethane manufacture. Key parameters for process performance are discussed.