Dissolution behavior and hydrate effect on CO2 ocean sequestration

2005 ◽  
Vol 19 (5) ◽  
pp. 1216-1225 ◽  
Author(s):  
Kim Namjin ◽  
Kim Chongbo
Energy ◽  
2005 ◽  
Vol 30 (11-12) ◽  
pp. 2308-2317 ◽  
Author(s):  
Kentaro Niwa ◽  
Sanai Kosugi ◽  
Takayuki Saito ◽  
Takeo Kajishima ◽  
Kenji Hamaogi

2002 ◽  
Vol 12 (1) ◽  
pp. 40-49
Author(s):  
Izuo AYA ◽  
Kenji YAMANE ◽  
Ryuji KOJIMA ◽  
Sadahiro NAMIE

2004 ◽  
Vol 60 (4) ◽  
pp. 797-805 ◽  
Author(s):  
Baixin Chen ◽  
Yongchen Song ◽  
Masahiro Nishio ◽  
Makoto Akai

Author(s):  
Yongchen Song ◽  
Baixin Chen ◽  
Masahiro Nishio ◽  
Makato Akai

Against the background of carbon dioxide (CO2) ocean sequestration technology, we investigated the solubility of CO2 in seawater at a thermodynamic state similar to that at an ocean depth of 1000 m. The experiment was performed in two steps. In the first step, we reexamined and modified the fundamental relationship between Sherwood (Sh) number and Rayleigh (Ra) number in a natural convective flow over an up-down CO2 droplet. We derived a new expression of the Grashof number for CO2 dissolution in water and seawater with the aid of the relation between the density of CO2 solution and CO2 concentration. In the second step, this new expression was applied to the estimation of solubility of CO2 from experiments examining the dissolution of an individual CO2 droplet in seawater at hydrate-formable pressure and temperature states. We found from our experiments: that (1) at hydrate-formable conditions (step two), no hydrate appeared at interface between liquid CO2 and seawater throughout the experiments within 5 hours, which suggested that a thermodynamic state (pressure and temperature) is indispensable but not a complete condition for hydrate formation; and (2) associated with this dual nature, the data of CO2 solubility estimated from this experiment are much larger than those obtained by Kimuro et al [1] from experiments of hydrate coexistence. Our data ranged from 0.052 to 0.062 in mass fraction.


Author(s):  
Baixin Chen ◽  
Masahiro Nishio ◽  
Yongchen Song ◽  
Makoto Akai

A new version of a two-phase numerical model is developed to simulate CO2 droplet dissolution and the plume dynamics of CO2 enriched seawater produced by direct release of liquid CO2 into deep ocean from a towed pipe. This Lagrangian framework model consists of three sub-models. They are the CO2 droplet moving and dissolving sub-model, the turbulent dispersion of CO2 enriched seawater sub-model, and the biological impact sub-model. We performed simulations of direct injection of liquid CO2 from a release platform towed by a moving-ship into mid-depth seawater to examine the roles of injection parameters, including release platform type and initial CO2 droplet size. Results from the simulations show that a horizontal release platform can create a plume with less physical and biological impacts than a plume created by a vertical release platform. With an injection rate of 100kg/s, simulations predict that injection of small droplets (5mm in diameter) would produce up to 1.5 times the pH reduction of larger droplets (15 mm in diameter). This large pH reduction may significantly affect ambient zooplankton.


Sign in / Sign up

Export Citation Format

Share Document