INTENSIFICATION EFFECT ON CATALYTIC CO2 HYDROGENATION TO DME PROMPTED BY WATER-ADSORBENT SYSTEMS

In recent years numerous R&D strategies have been proposed for the establishment of sustainable CCU technology chains, so to boost an effective recycle of carbon dioxide in presence of green hydrogen for the production of bulk chemicals or fuels [1]. In this framework, particular interest has been addressed to the catalytic hydrogenation of CO2 into dimethyl ether (DME), requiring a hybrid catalyst for the direct DME synthesis in one step, wherein a methanol-synthesis phase (CuO-ZnO-Al2O3 or CuO-ZnO-ZrO2) and a methanol dehydration phase (typically zeolites) are closely integrated [2]. Nevertheless, the catalyst performance and its lifetime are strongly limited by water formed during the process, so that the efforts on novel system architectures, nature and location of active sites, even probed in a large set of experimental conditions, do not allow to overcome the equilibrium restrictions preventing their industrial scale-up [3]. In this work, we investigated the intensification effect prompted by the combination of in situ water adsorbent agents (like zeolites) with a previously optimized hybrid Cu-ZnOZrO2/ MFI system [2,3], so to demonstrate how the effective removal of water from the reaction medium can shift the equilibrium of CO2 conversion to more favourable values, also determining a higher DME productivity (Fig. 1).