A Mathematical Tool for Optimising Carbon Capture, Utilisation and Sequestration Plants for e-MeOH Production

Carbon capture, utilisation, and sequestration is key for the decarbonisation of hard-to-abate industries, as it allows avoiding the direct release of CO2 to the atmosphere and generating carbon-based products. However, for these products to be truly carbon-neutral, intermittent renewable electricity must be deployed at scale, leading to the necessity of optimising flexible plants with potential for local buffer storages, geological sequestration, and conversion units. The scope of this work is to provide a mathematical framework for the economic optimisation of a carbon capture, utilisation, and sequestration system, to decarbonise a cement plant located in the Puglia region (Italy), via CO2 geological confinement and/or power and CO2-to-methanol conversion. The final aim is to determine the optimal sizing and cost of the process units of the plant, depending on economic conditions such as the methanol sale price and different perspective costs scenarios. The main outcome is an economic convenience of geological sequestration, as opposed to utilisation, while a long-term scenario would allow for a cost-effective production of methanol when the sale price is above 550 €/t.