We have carried out the second phase of field studies todeter
mine the effectiveness of a coflow injector which
mixes liquid CO
2 and a
mbient seawater to produce a hydrateslurry as a possible CO
2 delivery
method for oceancarbon sequestration. The experi
ments were carried outat ocean depths of 1000-1300
m in Monterey Bay, CA, usinga larger injector than that initially e
mployed underre
motely operated vehicle control and i
maging of theproduct. Solidlike co
mposite particles co
mprised of water,solid CO
2 hydrate, and liquid CO
2 were produced in bothstudies. In the recent injections, the particles consistentlysank at rates of ~5 c
m s
-1. The density of the sinkingparticles suggested that ~40% of the injected CO
2 wasconverted to hydrate, while i
mage analysis of the particleshrinking rate indicated a CO
2 dissolution rate of 0.76-1.29
![](/i<font color=)
mages/entities/
mgr.gif">
mol c
m-2 s
-1. Plu
me
modeling of the hydrate co
mpositeparticles suggests that while discrete particles
may sink 10-70
m, injections with CO
2 mass fluxes of 1-1000 kg s
-1would result in sinking plu
mes 120-1000
m below the injectionpoint.