Equilibrium conditions for clathrate hydrates formed from carbon dioxide or ethane in aqueous solutions of 1,4-dioxane and 1,3-dioxolane were determined experimentally using an isochoric method. Addition of the 1,4-dioxane and 1,3-dioxolane to water shifted the equilibrium conditions of carbon dioxide hydrates to a higher temperature, indicating that they promote carbon dioxide hydrate formation. In contrast, 1,4-dioxane and 1,3-dioxolane inhibited ethane hydrate formation at pressures greater than 0.7 MPa. (C) 2014 Elsevier B.V. All rights reserved.