Sustainable catalytic reaction engineering with gas-expanded liquids

Gas-expanded liquids (GXLs) are a continuum of tunable solvents generated by mixing liquid solvents and compressed near-critical gases such as CO2 and light olefins. The compressed gas provides tunability of the physical and transport properties of GXLs making them ideal for performing sustainable catalysis characterized by process intensification at mild conditions, high product selectivity and facile separation of catalyst and products. Sustainable technology alternatives to industrial hydroformylations and epoxidations that employ GXLs as enabling solvents are provided. In these examples, the GXLs involve conventional organic as well as non-traditional solvents such as ionic liquids (ILs) and compressible gases such as CO2 (as inert) or light olefins (as substrates). Such technologies are essential for facilitating sustainable growth of the fledgling biorefining industry.

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► Near-critical gases dissolved in solvents (including ionic liquids) form GXLs.
► Density, viscosity and gas (CO, H2, O2) solubilities in GXLs are pressure-tunable.
► GXLs enable sustainable catalysis with intensified rates and reduced C footprint.
► Hydroformylation and epoxidation in GXLs offer unique, practically viable processes.