Carbon Capture & Storage(CCS)

1. Carbon Capture & Storage(CCS) • Method to reduce carbon • Capture CO2 from point sources • Coal plants • Store it, not release it • Could reduce emissions 80-90% from plants

2. Problems • Capturing CO2 requires much energy • About 25-40% more fuel for coal plants • Would result in higher prices for energy

3. Where to Store CO2 (Sequestration) • Geological Formations • Deep Oceans • Minerals

4. Costs • Depends on cost of capture and storage • Depend on where stored • Storage in salt or depleted oil fields • $0.5-8.0/CO2 ton injected + $.10-.30 for monitoring (2003 oil prices)

5. Enhanced Oil Recovery (EOR) • Could cut cost of CCS • Used to increase oil production from field • Inject CO2, Nitrogen, or steam • Gases expand, force oil to well bore • Improves recovery up to 30% • ½ - 2/3 CO2 returns, rest remains in reservoir • Canada Example –Saskatchewan • Inject 18 million ton CO2 • Recover 130 million more oil barrels • In this case, more CO2 emissions

6. CCS Environmental Effects • Reduction of CO2 up to 90% depending on plant • Energy required for storage • Means more fuel use • Pollutants increase = dirty air

7. Removing CO2 • Post Combustion • Pre Combustion • Fuel oxidized • Eventually generate CO2 and H2 • CO2 removed • Oxy fuel combustion • Burn in oxygen, not air • Produce CO2 and H2O • Remove water by cooling • Store CO2 • Requires lots of energy

8. Geological Storage (Sequestration) • Inject in: • Oil & Gas fields • Depleted Coal seams • Salt deposits • Saline filled basalts • Problems with oil fields • Limited distribution and size • Increase emissions with EOR • Coal Seams • CO2 adsorbs to coal surface • Coal must be permeable • Will displace methane adsorbed • Can burn methane, produce CO2 • Salt deposits • Large storage volume, common • Not much is known about them

9. Ocean Storage • Inject CO2 by ship or pipeline • CO2 dissolves in deep water • Inject to deeper than 3000m • CO2 denser than waters, forms lake • Convert CO2 to bicarbonate • Store CO2 in clathrate hydrates

10. Problems with Ocean Storage • CO2 kills organisms • CO2 increases acidity of water • After 1600 deep ocean circulates to surface • Expensive

11. Mineral Storage • Minerals have Mg and Ca • Add CO2, convert to carbonates • Minerals are common • Carbonates are stable • Must have environmentally friendly method • Must be economically feasible

12. Problems with CSS • Leakage from geological formations • Well selected site, CO2 trapped millions of years • 1000-3000 meters in Ocean • 50-80% CO2 retained for 500 years • Mineral storage no leakage

13. Other Methods • Reforestation • Use CO2 • Already used in Brazil • Deforestation contributes 20% of CO2 in atmosphere • Forest preservation from logging, clearing • Leave carbon in the ground • Requires alternative energy sources

14. More Methods • Substitute bio-based fuels for fossil fuels • Conservation tillage • Leave some percentage of biomass in ground • Carbon sequestered in soil • Rotational grazing • Enhances soil sequestration • Harvest dead/old trees • Bury in trenches in soil

15. Ocean Iron Seeding • Enhancing productivity in oceans • Add iron • Plants/algae grow, use up CO2

16. Synthetic Trees • Removes CO2 by combining with minerals • Air flow through sodium hydroxide (NaOH) inside trees • Creates Na2CO3 liquid • Liquid pumped to sediments below ocean • Stored for millions of years • 1 tree removes 1000x more than real tree • 250,000 trees need to remove 22 billion tons of CO2 produced annually from fossil fuels