Geologic Sequestration

Geologic sequestration is the process by which CO2 is captured and stored by geologic formations.

Geological Carbon Sequestration Options

Figure from IPCC

Carbon Capture and Storage

http://www.climatechange.utah.gov/imagessimplifiedCCGSProcess_small.jpg

Storage Capacity

• Oil and gas fields = 675 -900 GtCO2• Unminable coal seams = 3 – 200 GtCO2• Deep saline formations 1000 – 104 GtCO2• Basalt and shales = ?

Source: IPCC Special Report on Carbon dioxide Capture and Storage

Carbon Capture

• Will work on large point source CO2 sources. – This means it will not work on cars, trucks etc.

• Will work by various techniques. • Currently expensive!

Four Corners Power plant (epa.gov)

CO2 Transport

• Pipelines – These will have to connect the sources with the

sequestration sites– Many of these exist already in oilfields

http://www.nicholas.duke.edu/thegreengrok/graphics/CO2piplines-us

http://www.isgs.illinois.edu/maps-data-pub/publications/geobits/graphics/fold-rocks.gif

Reservoir quality• Porosity• Permeability

Photomicrographs by Peter Mozley

Photo by Greg Smith

Caprock (Seal) Integrity• Must have very low permeability• Understanding fractures is critical

Photo by Peter Mozley

Navajo (reservoir)

Carmel (seal)

Challenges to Large-Scale Sequestration

• Technological– Cost of carbon capture

• Legal– Liability, regulations, pore space ownership

• Societal– CCS will add to cost of energy– Benefits of CCS are long term and hard to directly

see