Tuning solvents for sustainable technology

The key to sustainable technology is achieving an economic benefit for envi ronmental improvements. The tunability of benign compounds such as CO2 and water as supercritical and near-critical fluids offers improved performance and greater flexibility for separation and reaction processes, leading to economic advantages. Examples of such behavior are supercritical CO2 extrac tions and separations, CO2-expanded polar liquids for separations, and reac tions in near-critical water. In each case the tunability is achieved throu gh density changes or cosolvents and may augment product yield, quality, or rates.