Carbon Sequestration Red Balansay ESS 315

What Is It? Also known as “carbon capture” A geoengineering technique for the long-term storage of carbon dioxide (or other forms of carbon) for the mitigation of global warming More than 33 billion tons of carbon emissions (annual worldwide) Ways that carbon can be stored (sequestered): –In plants and soil “terrestrial sequestration” (“carbon sinks”) –Underground “geological sequestration” –Deep in ocean “ocean sequestration” –As a solid material (still in development)

Terrestrial Carbon Sequestration

The process through which CO2 from the atmosphere is absorbed naturally through photosynthesis & stored as carbon in biomass & soils. Tropical deforestation is responsible for 20% of world’s annual CO2 emissions, though offset by uptake of atmospheric CO2 by forests and agriculture Ways to reduce greenhouse gases: –avoiding emissions by maintaining existing carbon storage in trees and soils –increasing carbon storage by tree planting or conversion from conventional to conservation tillage practices on agricultural lands

Terrestrial Carbon Sequestration (continued) Carbon seq. rates differ based on the species of tree, type of soil, regional climate, topography & management practice –Pine plantations in SE United States can accumulate almost 100 metric tons of carbon per acre after 90 years (~ 1 metric ton : 1 year) Carbon accumulation eventually reaches saturation point where additional sequestration is no longer possible (when trees reach maturity, or when the organic matter in soils builds back up to original levels before losses occurred) After saturation, the trees or agricultural practices still need to be sustained to maintain the accumulated carbon and prevent subsequent losses of carbon back to the atmosphere

Geological Sequestration Midwest Geological Sequestration Consortium (Illinois)

Geological Sequestration Storing of CO 2 underground in rock formations able to retain large amounts of CO 2 over a long time period –Held in small pore spaces (have held oil and nat. gas for millions of years) Layers shown: Coal, brine aquifer, gas bearing sandstone, gas bearing shale

Geological Sequestration (continued) Midwest Geological Sequestration Consortium (Illinois Basin) –1/7 regional partnerships selected to determine the best approaches for capturing and storing CO2 that might otherwise contribute to global climate change –assess geological carbon sequestration options in the 60,000 square mile Illinois Basin (Within the Basin are deep, noneconomic coal resources, numerous mature oil fields and deep saline rock formations with potential to store CO2) –Feb 2009: Successfully completed 8,000 ft deep injection well By 2013, a total of one million metric tons of carbon dioxide (roughly the annual emissions of 220,000 automobiles) is expected to be stored within the formation.

Ocean Sequestration

“Carbon is naturally stored in the ocean via two pumps, solubility and biological, and there are analogous man-made methods, direct injection and ocean fertilization, respectively. Eventually equilibrium between the ocean and the atmosphere will be reached with or without human intervention and 80% of the carbon will remain in the ocean. The same equilibrium will be reached whether the carbon is injected into the atmosphere or the ocean. The rational behind ocean sequestration is simply to speed up the natural process.”

Ocean Sequestration Carbon sequestration by direct injection into the deep ocean involves the capture, separation, transport, and injection of CO2 from land or tankers 1/3 of CO2 emitted a year already enters the ocean Ocean has 50 times more carbon than the atmosphere

National Energy Technology Laboratory

(NETL) Develop technologies to capture, separate, and store carbon dioxide (CO2) in order to reduce greenhouse gas emissions without adversely influencing energy use or hindering economic growth Contributes greatly to Obama’s goal of the development of technologies to reduce greenhouse gas emissions NETL envisions having a technology portfolio of safe, cost-effective, commercial-scale greenhouse gas capture, storage, and mitigation technologies that are available for commercial deployment beginning in 2020.

National Energy Technology Laboratory NETL’s primary Carbon Sequestration Research & Development Objectives: –lowering the cost and energy penalty associated with CO2 capture from large point sources –improving the understanding of factors affecting CO2 storage permanence, capacity, and safety in geologic formations and terrestrial ecosystems Once met, new and existing power plants and fuel processing facilities in the U.S. (and around the world) will have the potential to be retrofitted with CO2 capture technologies.

Offset Greenhouse Gas Emissions? At the global level, the IPCC Third Assessment Report estimates that ~100 billion metric tons of carbon over the next 50 years could be sequestered through forest preservation, tree planting and improved agricultural management. –Offset 10-20% of estimated fossil fuel emissions Obama’s Clean Coal Plan –fund five essentially pilot projects with commercial scale coal-fired power plants that have carbon capture & sequestration

Offset Greenhouse Gas Emissions? Carbon Sequestration is not yet viable at a commercial level Small scale projects demonstrated (lab experiments) but CS is still a developing technology Concern with injecting carbon dioxide into ground or ocean because fear of leaks into water table or escape of CO 2 into a massive bubble that can potentially suffocate humans and animals

Sources Overview: Obama: Terrestrial Sequestration: Geological Sequestration: Ocean Sequestration