High-Pressure Processing: A Smart Way to Increase Energy Efficiency with Less Toxic Residues

High-pressure processes involving sub and supercritical fluids enable the design of products with special physical characteristics, less toxic residues, low energy consumption, and are eco-friendly and sustainable. Supercritical fluids show potential as solvents in boosting green chemistry by replacing environmentally harmful conventional organic solvents. Tunable physical properties of the supercritical fluids enable selective extraction, purification and fractionation of value-added products and by-products. Absorption of compressed gas in polymer matrices results in a wide spectrum of possible applications in the field of sustainable polymer processing, for example, production of fibers, microparticles and foams. As a heat transfer fluid, supercritical CO2 has been reintroduced as an environmentally friendly refrigerant in heat pumps working cycles. There is also great potential in the treatment of sewage wastes with supercritical fluids and production of value compounds from waste streams. Several supercritical fluid applications are presented from the perspective of their environmental and economic benefits.