Applications of supercritical CO2 in more sustainable processes

Abstract

Supercritical fluids (SF) have unique properties because they offer the possibility of manipulating, as necessary, the parameters of the reaction medium, such as density, viscosity, diffusivity or surface, through pressure and temperature control. This review refers to recent developments of supercritical fluid extraction (SFE) in different fields, such as food, natural products, byproduct recovery, pharmaceutical, environmental and textile industry. Reactions are reviewed as the heterogeneous catalytic hydrogenation of organic compounds in SF. The potential is examined as the limitations of the application of supercritical fluids as
solvents on the basis of existing knowledge. SFs, in particular CO₂, offers some attractive opportunities as substitutes for classical organic solvents, but their beneficial application requires care of economic and ecological factors. Next, a series of cases are described in which supercrítica CO₂ (scCO₂) offers real chemical advantages over many conventional solvents, for example, by controlled phase separation, adjustable selectivity and oxidation. In general, this review indicates that scCO₂ could offer an increasing number of applications in the coming years.