Formation of cyclopentane methane binary clathrate hydrate in brine solutions

• Formation rate of cyclopentane–methane hydrate is measured in brine solutions.
• Methane occupancies are estimated at different operating conditions.
• Evaluated the hydrate growth rate reduction caused by salt.

Building on a our previous study on the kinetics of formation of cyclopentane (CP)-methane binary sII-type hydrate in well-agitated fresh water, analogous experiments have been performed in brine solutions at two salinities (3.5% and 7.0% NaCl, w/w) to investigate how salt affects this formation process thermodynamically and kinetically. The hydrate formation rate in salt water is found to be ~2–3 times smaller than that in fresh water at small subcooling levels ΔT<4K but at higher subcooling levels, the two become comparable. The methane occupancy in the small cavities of the sII hydrate is also estimated to be ~0.5 for methane pressures between 1 and 3 MPa under equilibrium conditions, as well as during growth at subcooled conditions (ΔT<~7K).