1. Large Scale Utilization of Carbon Dioxide: From Its Reaction with Energy Rich Chemicals to (Co)-processing with Water to Afford Energy Rich Products. Opportunities and Barriers

This chapter makes the analysis of the possible routes for large scale CO₂ utilization (CCU). Processes that convert CO₂ into chemicals, materials and fuels are discussed, as they are part of the strategy for reducing the CO₂ emission into the atmosphere. Technical uses of CO₂, which do not imply its chemical conversion, are discussed in Chap. 3, while mineralization and carbonation reactions for the production of inorganic materials are treated in Chap. 4. Here, the catalytic synthesis of organic products with a market close to, or higher than, 1 Mt/year is discussed, presenting the state of the art and barriers to full exploitation. Minor applications are summarized, without a detailed analysis as their contribution to CO₂ reduction is low, even if they can favour the development of a sustainable chemical industry with reduction of the environmental impact. Energy products (C1 and Cn molecules) are discussed for some peculiar aspects in this chapter, as their catalytic production will be extensively presented in following chapters where the potential of using CO₂ and water as source of fuels is analysed for its many possible applications setting actual limits and future perspectives. A comparison of Carbon Capture and Storage-CCS and CCU is made, highlighting the pros and cons of each technology.