The economics of CO₂ utilization are discussed from a critical perspective, with a concise analysis of the state-of-the-art of economics in power-to-X (methanol, methane). The main elements of the analysis of the economics are commented to provide guidelines on how to interpret the techno-economic results in the area of CO₂ utilization. It remarks the need of a careful analysis of the specific context, and of the limits of the evaluation, in order to go beyond the just use of the results without a proper analysis of how the data support the conclusions, their limits and applicability. Case examples discussed in a more detail regard the CO₂ to methanol or methane conversion, from the perspective of highlighting possible issues or limits rather than to indicate which results are more valuable, which is out of the scope of this contribution.

The development of a chemical industry characterized by resource efficiency, in particular with reference to energy use, is becoming a major issue and driver for the achievement of a sustainable chemical production. From an industrial point of view, several application areas, where energy saving and CO₂ emissions still represent a major concern, can take benefit from the application of membrane reactors. On this basis, different markets for membrane reactors are analyzed in this paper, and their technical feasibility is verified by proper experimentation at pilot level relevant to the following processes: (i) pure hydrogen production; (ii) synthetic fuels production; (iii) chemicals production. The main outcomes of operations in the selected research lines are reported and discussed, together with the key obstacles to overcome.

Pd-based membrane reactors are strongly recognized as an effective way to boost H2 yield and natural gas (NG) conversion at low temperatures, compared to conventional steam reforming plants for hydrogen production, thereby representing a potential solution to reduce the energy penalty of such a process, while keeping the lower CO2 emissions. On the other hand, the exploitation of solar energy coupled with a membrane steam reformer can further reduce the environmental impact of these systems. On this basis, the paper deals with the design activities and experimentation carried out at a pilot level in an integrated prototype where structured catalysts and Pd-based membranes are arranged together and thermally supported by solar-heated molten salts for steam reforming reaction

Municipal solid waste (MSW) is one of the residue materials considered as a potential source for biofuel production in the EU Renewable Energy Directive (RED), which establishes that a minimum of 10% biofuels for transport shall be used in every Member State by 2020, thus promoting advanced biofuel from waste. A high-temperature gasification technology transforms MSW into a syngas rich in hydrogen and carbon monoxide and free of tar, char and harmful compounds like dioxins appearing as a promising root for methanol production. The overall process including MSW high-temperature gasification, syngas purification and conditioning up to methanol synthesis has been modeled with Aspen Plus analyzing the influence of waste composition and operating conditions on syngas composition and methanol yield. The evaluation of CAPEX and OPEX has been carried out to obtain a cost of production (COP) estimation. The greenhouse gas (GHG) emission has also been estimated and compared with the conventional waste incineration process and methanol production. The technology assessment shows interesting results technically and economically, when compared with waste to energy processes: over 50% of incoming carbon is fixed into methanol molecule, and due to the negative cost paid for RDF disposal, the bio-methanol COP provides a reasonable industrial margin.