title: Field studies on the formation of sinking CO2 particles for ocean carbon sequestration: effects of injector geometry on particle density and dissolution rate and model simulation of plume behavior.
abstract: We have carried out the second phase of field studies to determine the effectiveness of a coflow injector which mixes liquid CO2 and ambient seawater to produce a hydrate slurry as a possible CO2 delivery method for ocean carbon sequestration. The experiments were carried out at ocean depths of 1000-1300 m in Monterey Bay, CA, using a larger injector than that initially employed under remotely operated vehicle control and imaging of the product. Solidlike composite particles comprised of water, solid CO2 hydrate, and liquid CO2 were produced in both studies. In the recent injections, the particles consistently sank at rates of approximately 5 cm s(-1). The density of the sinking particles suggested that approximately 40% of the injected CO2 was converted to hydrate, while image analysis of the particle shrinking rate indicated a CO2 dissolution rate of 0.76-1.29 micromol cm(-2) s(-1). Plume modeling of the hydrate composite particles suggests that while discrete particles may sink 10-70 m, injections with CO2 mass fluxes of 1-1000 kg s(-1) would result in sinking plumes 120-1000 m belowthe injection point.
authors.affiliation: Oak Ridge National Laboratory, Post Office Box 2008, Oak Ridge, Tennessee 37831, USA.
authors.forename: David E
authors.initials: DE
authors.lastname: Riestenberg
authors.forename: Costas
authors.initials: C
authors.lastname: Tsouris
authors.forename: Peter G
authors.initials: PG
authors.lastname: Brewer
authors.forename: Edward T
authors.initials: ET
authors.lastname: Peltzer
authors.forename: Peter
authors.initials: P
authors.lastname: Walz
authors.forename: Aaron C
authors.initials: AC
authors.lastname: Chow
authors.forename: E Eric
authors.initials: EE
authors.lastname: Adams
mesh_terms: D002244:Carbon / Q000032:analysis / Q000737:chemistry*; D002245:Carbon Dioxide / Q000032:analysis* / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007091:Image Processing, Computer-Assisted; D008962:Models, Theoretical; D009584:Nitrogen / Q000032:analysis; D012623:Seawater / Q000737:chemistry*; D012995:Solubility; D013997:Time Factors
chemical_list: D002245:Carbon Dioxide; D002244:Carbon; D009584:Nitrogen