Seawater desalination by coupling cyclopentane hydrate formation and capacitive deionization processes in the presence of Fe3O4 nanoparticles and magnetic field

Abstract

This study investigates seawater desalination by coupling cyclopentane hydrate formation and capacitive deionization processes. High induction time, low conversion of water to hydrate, and low ion removal efficiency are the challenges of the hydrate desalination process. In order to reduce the cost of hydrate formation, cyclopentane was used as a hydrate former. Also, the promotion effects of Fe3O4 nanoparticles and magnetic field on the cyclopentane hydrate formation in pure water, seawater, and synthetic saline waters containing NaCl, KCl, CaCl2, and MgCl2 at different concentrations were investigated. The results showed that the Fe3O4 nanoparticles and magnetic field could improve the hydrate formation and the effect of Fe3O4 nanoparticles is greater than the magnetic field. However, the promoting effect on the induction time and removal efficiency was intensified when the Fe3O4 nanoparticles and the magnetic field were used simultaneously. The results of hydrate formation in seawater showed that the induction time in the presence of 0.07 wt.% Fe3O4 nanoparticles, magnetic field, and simultaneous use of both of them were reduced by 89, 22, and 92%, respectively. The ion removal efficiency reached 79% for Na+ and higher than 99% for K+, Ca2+, and Mg2+ when capacitive deionization was used as post-treatment.