Technologies and infrastructures underpinning future CO2 value chains: a comprehensive review and comparative analysis

In addition to carbon capture and storage, efforts are also being focussed on using captured CO2, both directly as a working fluid and in chemical conversion processes, as a key strategy for mitigating climate change and achieving resource efficiency. These processes require large amounts of energy, which should come from sustainable and, ideally, renewable sources. A strong value chain is required to support the production of valuable products from CO2. A value chain is a network of technologies and infrastructures (such as conversion, transportation, storage) along with its associated activities (such as sourcing raw materials, processing, logistics, inventory management, waste management) required to convert low-value resources to high-value products and energy services, and deliver them to customers. A CO2 value chain involves production of CO2 (involving capture and purification), technologies that convert CO2 and other materials into valuable products, sourcing of low-carbon energy to drive all of the transformation processes required to convert CO2 to products (including production of hydrogen, syngas, methane etc.), transport of energy and materials to where they are needed, managing inventory levels of resources, and delivering the products to customers, all in order to create value (economic, environmental, social etc.).

Technologies underpinning future CO2 value chains were examined. CO2 conversion technologies, such as urea production, Sabatier synthesis, Fischer-Tropsch synthesis, hydrogenation to methanol, dry reforming, hydrogenation to formic acid and electrochemical reduction, were assessed and compared based on key performance indicators such as: CAPEX, OPEX, electricity consumption, TRL, product price, net CO2 consumption etc. Technologies for transport and storage of key resources are also discussed. This work lays the foundation for a comprehensive whole-system value chain analysis, modelling and optimisation.