A group of 14 different bio-sourced, renewable feedstocks (homoserine, 1; glutamic acid, 2; aspartic acid, 3; 2,5-furandicarboxylic acid, 4; fumaric acid, 5; oxalacetic acid, 6; tartaric acid, 7; malic acid, 8; succinic acid, 9; levulinic acid, 10; g-hydroxybutyrolactone, 11; xylitol, 12; mannitol, 13; sorbitol, 14) have been examined for their solubility/miscibility in a variety of ‘green’ solvents, including water, supercritical carbon dioxide (scCO2), and ionic liquids. Two other bio-based compounds 5-hydroxymethylfurfural, 15, and D-xylose, 16, were studied in selected solvents. Trends in solubility have been assessed so that these data may be extrapolated to help predict solubilities of other related compounds. For example, 10, 11 and 15 all demonstrated appreciable solubility in scCO2, as they possess weak intermolecular interactions. The dicarboxylic acids studied (4–9) all proved soluble in modified scCO2 (by use of MeOH as a cosolvent). While the polyols (12–14) and 1 were insoluble in scCO2 but water of various pHs and ionic liquids proved adept at their dissolution. Some of the amino acids studied (2 and 3) were only soluble in water with an adjustment of pH.
Samantha M. Payne and Francesca M. Kerton*
Centre for Green Chemistry and Catalysis, Department of Chemistry, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, Canada A1B 3X7. E-mail: email@example.com; Fax: +1 709 7373702; Tel: +1 709 7378089
Green Chem., 2010, 12, 1648–1653 DOI: 10.1039/c0gc00205d