Fixation of CO₂ to cyclic carbonates is one of the most important reactions since it represents a much greener alternative to the traditional phosgene process. In this context, the transformation of CO₂ with epoxides into cyclic carbonates with respect to the newly emerged ionic liquid (IL) technology is discussed from a multi-scale viewpoint, including (1) the mechanism considering the “cooperative effect” at the basic atom and molecule level; (2) the reactor configuration at the unit level; (3) and the related process integration at the system level.