Direct Injection Options

Direct Injection Options

Direct Injection
Model Requirements for Simulation of Direct Injection
Preliminary Model Simulations of Direct Injection
Direct CO₂ Injection Research Issues

Direct Injection:
Capture, Separate, Transport, Inject into Deep Sea

CO₂ is captured at centers of fossil fuel use (eg. power plants) and transported for dispersion into deep sea water via fixed or towed pipelines.
One option for injecting CO2 into the deep ocean is to discharge the CO2 below the thermocline at depths of 1000 - 1500 m. Two methods of injection have been proposed. One is to transport the liquid CO2 from shore in a pipeline and discharge it from a manifold lying on the ocean bottom, forming a rising droplet plume about 100 m high. Alternatively, the liquid CO₂ could be transported by tanker and then discharged from a pipe towed by the moving ship. Although the means of delivery are different, the plumes resulting from these two options would be quite similar and,therefore, research on these two injection methods should be considered complementary.

Another approach is to inject the CO ₂ as deeply as possible in order to maximize the sequestration efficiency. In order to accomplish this, new technology would need to be developed, with unknown costs. One such idea is to inject the liquid CO ₂ to a sea floor depression forming a stable "deep lake" of CO ₂ hydrates at a depth of about 4000 m.

Model Requirements for Simulation of Direct Injection

Numerical simulation of deep sea injection of CO₂ using an Ocean General Circulation Model (OGCM) requires knowledge of ocean physics on a wide range of spatial and temporal scales.
Initially, we will ink these scales by parameterizing results of the higher resolution models and then using these parameterizations as source functions in the coarser scale models.

Preliminary Model Simulations of Direct Injection

Simulated distribution of relative CO₂ concentration after 20 years of CO₂ injection near Cape Hatteras at 1720 m depth, as computed by the LLNL Ocean General Circulation Model (OGCM). At this depth, the carbon is swept southward with the counter-current that runs beneath the Gulf Stream, and remains relatively isolated from the atmosphere.

Direct CO₂ Injection Research Issues

Ecosystem and carbonate chemistry impacts. There is scant knowledge of the biological impacts of changes of CO₂ concentration in the deep ocean. Most studies addressed acute impacts to shallow water organisms and have been short lived.

Research is needed to understand the effects of elevated CO₂ concentrations on biogeochemistry and ecosystem structure and function in both mid water and deep water habitats.

Changes in carbonate chemistry will impact benthic and planktonic organisms, sediments and geochemical fluxes. Therefore, it is important to incorporate interactions of sea-floor carbonate sediments (Archer et al., 1998) into our ocean general circulation model.

Model requirements. Predictions of the efficacy of direct injection are only as reliable as the underlying ocean General Circulation Model (GCM).

It is important to have the best possible representation of boundary layer processes, the intermediate depth circulation, and sub-grid scale mixing and convection. It is necessary to evaluate model performance using tracer fields and neutrally buoyant drifter information.

This depends on physical models that adequately represent mixed layer and intermediate water processes.

Near field and far field simulations. It is important to use the results of near-field modeling in producing far-field predictions.

The near-field modeling work of Teng, Masutani, and Kinoshita (1997) indicates that the plume generated by a CO₂ point source can be parameterized and used to provide the initial conditions for simulations of the far-field distribution of carbon dioxide.

Data synthesis. Development of effective parameterizations for biological processes requires analysis of existing field data sets and samples

Monitoring. Sequestration research requires development of new cost-effective ways to monitor biogeochemical processes on longer temporal and greater spatial scales than previously possible.

Environmental Policy Links. Understanding the efficiency and environmental impacts will require knowledge, tools, standards, and policies that we do not as yet have.

Background | Home | Ocean Fertilization

Direct Injection: Capture, Separate, Transport, Inject into Deep Sea
CO₂ is captured at centers of fossil fuel use (eg. power plants) and transported for dispersion into deep sea water via fixed or towed pipelines. One option for injecting CO2 into the deep ocean is to discharge the CO2 below the thermocline at depths of 1000 - 1500 m. Two methods of injection have been proposed. One is to transport the liquid CO2 from shore in a pipeline and discharge it from a manifold lying on the ocean bottom, forming a rising droplet plume about 100 m high. Alternatively, the liquid CO₂ could be transported by tanker and then discharged from a pipe towed by the moving ship. Although the means of delivery are different, the plumes resulting from these two options would be quite similar and,therefore, research on these two injection methods should be considered complementary. Another approach is to inject the CO ₂ as deeply as possible in order to maximize the sequestration efficiency. In order to accomplish this, new technology would need to be developed, with unknown costs. One such idea is to inject the liquid CO ₂ to a sea floor depression forming a stable "deep lake" of CO ₂ hydrates at a depth of about 4000 m.
Model Requirements for Simulation of Direct Injection
	Numerical simulation of deep sea injection of CO₂ using an Ocean General Circulation Model (OGCM) requires knowledge of ocean physics on a wide range of spatial and temporal scales. Initially, we will ink these scales by parameterizing results of the higher resolution models and then using these parameterizations as source functions in the coarser scale models.
Preliminary Model Simulations of Direct Injection
	Simulated distribution of relative CO₂ concentration after 20 years of CO₂ injection near Cape Hatteras at 1720 m depth, as computed by the LLNL Ocean General Circulation Model (OGCM). At this depth, the carbon is swept southward with the counter-current that runs beneath the Gulf Stream, and remains relatively isolated from the atmosphere.
Direct CO₂ Injection Research Issues
Ecosystem and carbonate chemistry impacts. There is scant knowledge of the biological impacts of changes of CO₂ concentration in the deep ocean. Most studies addressed acute impacts to shallow water organisms and have been short lived. Research is needed to understand the effects of elevated CO₂ concentrations on biogeochemistry and ecosystem structure and function in both mid water and deep water habitats. Changes in carbonate chemistry will impact benthic and planktonic organisms, sediments and geochemical fluxes. Therefore, it is important to incorporate interactions of sea-floor carbonate sediments (Archer et al., 1998) into our ocean general circulation model. Model requirements. Predictions of the efficacy of direct injection are only as reliable as the underlying ocean General Circulation Model (GCM). It is important to have the best possible representation of boundary layer processes, the intermediate depth circulation, and sub-grid scale mixing and convection. It is necessary to evaluate model performance using tracer fields and neutrally buoyant drifter information. This depends on physical models that adequately represent mixed layer and intermediate water processes. Near field and far field simulations. It is important to use the results of near-field modeling in producing far-field predictions. The near-field modeling work of Teng, Masutani, and Kinoshita (1997) indicates that the plume generated by a CO₂ point source can be parameterized and used to provide the initial conditions for simulations of the far-field distribution of carbon dioxide. Data synthesis. Development of effective parameterizations for biological processes requires analysis of existing field data sets and samples **Monitoring. Sequestration research requires development of new cost-effective ways to monitor** biogeochemical processes on longer temporal and greater spatial scales than previously possible. Environmental Policy Links. Understanding the efficiency and environmental impacts will require knowledge, tools, standards, and policies that we do not as yet have.

Direct Injection:

Model Requirements for Simulation of Direct Injection

Preliminary Model Simulations of Direct Injection

Direct CO2 Injection Research Issues

Direct CO₂ Injection Research Issues