Desalination by forming hydrate from brine in cyclopentane dispersion system

To make application of hydrate based desalination technology practical, the kinetic behaviors and separation capability were examined for cyclopentane hydrates formed from brine in cyclopentane dispersion systems at 274.1 K/277.1 K with initial salinity of 3 to 5 wt% for water fractions from 20.0 to 90.0 vol% and rpms from 300 to 500. The excess cyclopentane addition into brine and cyclopentane dispersion significantly increased the yield of dissociated water when the removal efficiency stayed around 80%. This implies enhanced kinetics and controlled encapsulation of residual brine into the hydrate phase for brine in cyclopentane dispersion systems. More hydrates formed under lower temperature or initial salinity. Higher rpm could further promote hydrate formation but would adversely affect the removal efficiency. Desalination efficiency was enhanced with washing during vacuum filtration and effects of ratio of washing water/dissociated water on the removal efficiency were considerable. An inverse correlation exists between the removal efficiency and the yield of dissociated water under the same conditions. Lower temperature (274.1 K) and 60% water cut should be optimal for higher yield of dissociated water from brine in cyclopentane dispersion. The ratio of washing water/dissociated water and rpm conditions should be adjusted depending on the situation. (C) 2017 Elsevier B.V. All rights reserved.