Abstract
Differential scanning calorimetry was used to study the effect of isotopic substitution on the eutectic and melting temperatures in the water-tetrahydrofuran (THF) system with THF molar fractions near the stoichiometry of the hydrate phase. Deuteration of the host causes an opposite effect from that of the guest with respect to the hydrate liquidus curve and eutectic melting temperature. The eutectic temperature in D2O-containing systems is approximately 3.7 K higher than that in H2O-containing systems. The melting temperatures of THF and deuterated THF hydrates increase by roughly 3.5 K with heavy water. The inclusion of deuterated THF causes a depression of the hydrate liquidus temperatures and a small but measurable effect on the eutectic temperature.
Highlights
Tetrahydrofuran (THF, C4H8O) hydrate plays a prominent role in the study of numerous hydrate properties, for example, their formation [1], structure [2], and dynamics [3]
The onset temperature of the eutectic melting peak is taken as the eutectic temperature, and the maximum temperature of hydrate melting peak is taken as the melting temperature
We have used microcalorimetry to determine the effect of isotopic substitution on the eutectic and hydrate
Summary
Tetrahydrofuran (THF, C4H8O) hydrate plays a prominent role in the study of numerous hydrate properties, for example, their formation [1], structure [2], and dynamics [3]. Rosso and Carbonnel [6] and Carbonnel and Rosso [7] determined the phase diagram at low temperatures and found a miscibility gap with a critical temperature of approximately 286 K and a peritectic reaction at 278 K forming the structure II clathrate hydrate at a composition of 17 : 1 H2O : THF. This makes the structure II hydrate an incongruently melting phase.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
