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).