Energy, Vol.93, 1971-1979, 2015
Effects of C3H8 on hydrate formation and dissociation for integrated CO2 capture and desalination technology
Hydrate-based technology has been developing for decades to meet the demands in industrial applications. With the global demands for reduced carbon dioxide (CO2) emissions and more fresh water, CHBD (CO(2)hydrate-based desalination) was proposed and has developed rapidly. In this study, to provide basic data for the improvement of CHBD, the thermodynamic and kinetic characteristics of CO2 and propane (C3H8) mixed-gas hydrates in salt solution were experimentally investigated in which C3H8 was chosen as the hydrate formation promoter. We studied nine experimental cases (54 cycles) with different C3H8 proportions (ranging from 0 to 13%) and different initial solution saturations (30%, 40% and 50%). The hydrate phase equilibrium data were generated using the isochoric method, and the hydrate formation saturations were calculated using the relative gas uptake equation. The results indicated that the increase in the C3H8 proportion significantly decreases the gas mixture hydrate equilibrium pressure. Additionally, the relative gas uptake was reduced as the C3H8 proportion increased. A lower relative gas uptake was obtained at a lower gas pressure for the same gas mixture. The initial solution saturation exhibited an insignificant effect on the hydrate phase equilibrium conditions. When the initial solution saturations increased from 30% to 50%, the relative gas uptake decreased. (C) 2015 Elsevier Ltd. All rights reserved.