Biomass, Biofuels, Biochemicals: Circular Bioeconomy: Chapter 27 - Circular Economy and Carbon Capture, Utilization, and Storage

The CO2 concentration in the atmosphere has increased by almost 50% since the industrial revolution. As the global economy might still be dependent on fossil fuels for the next decades, unprecedented measures will be required to avoid further irreversible consequences of potential global warming. Carbon capture, storage, and utilization offer a broad panel of techniques that could tackle carbon emissions and contribute to replacing the “carbon to waste economy” with a “sustainable carbon circular economy.” Carbon capture and reuse techniques offer economic incentives but generally suffer from high-cost penalty. Carbon to methanol gained considerable interest as it allows recycling of CO2 into a product that can be reused as a fossil fuel or converted to other value-added chemicals. Another solution that gained considerable interest recently is mineral carbonation. This leads to permanent and safe CO2 storage in the form of solid carbonates. Industrial alkaline wastes, such as cement kiln dust; fly ash; steel slag; or magnesium- and calcium-rich silicate minerals such as olivine, serpentine, and wollastonite, have been considered as interesting candidates. Nevertheless, mineral carbonation suffers from slow kinetics under natural conditions, and acceleration techniques are associated with important energy demand, which hinders industrial application. This chapter will focus on carbon capture, utilization, and storage techniques, with a special scope on mineral carbonation, as a promising solution toward a carbon circular economy. The challenges and perspectives of these different technologies will also be exposed.