Methanol Inhibition Effect on Hydrate-Containing Phase Equilibria of Carbon Dioxide and Water

Abstract

In this work, we investigated the inhibition effect of methanol on the carbon dioxide hydrate-forming conditions in two and three phases. The effect of the amount of carbon dioxide relative to the aqueous methanol solution was also studied to examine the effect of the overall composition on hydrate-forming conditions. In the three-phase region at pressures from (5.0 to 20.0) MPa, the measured isobaric dissolution temperature of hydrate was found to increase as the loading ratio of carbon dioxide increases at the same methanol content, indicating a decreased inhibition effect of methanol. In two-phase region at the pressure of (6.0 and 10.0) MPa, however, the measured solubility of water was found to be unaffected by methanol of 0.200 mass fraction. CSMGem (Sloan and Koh, Clathrate Hydrates of Natural Gases, 3rd ed.; CRC Press: Boca Raton, FL, 2007) calculations qualitatively agree with the present data sets.