Sources

There are two types of CO₂ emission sources: stationary sources and non-stationary sources. Stationary source emissions come from a particular, identifiable, localized source, such as a power plant. CO₂ from stationary sources can be separated from stack gas emissions and subsequently transported to a geologic sequestration injection site for subsurface storage. The "North American CO₂ Sources" map displays the location and relative magnitude of a variety of CO₂ stationary sources. || View Interactive Map of All Sources || View Static Map

Non-stationary source emissions include CO₂ emissions from the transportation sector. The evolving terrestrial sequestration technologies are one way to address these emissions.

According to the EPA, in 2006, total U.S. GHG emissions were estimated at 7,054.2 million metric tons CO₂ equivalent . This estimate included CO₂ emissions as well as other GHGs such as methane (CH₄), nitrous oxide (N₂O), and hydrofluorocarbons (HFCs). Annual GHG emissions from fossil fuel combustion primarily CO₂ were estimated at 5,637.9 million metric tons with 3,781.9 million metric tons from stationary sources.

The "Percentage CO₂ Stationary Source Emissions by Category" pie chart contains values, gathered by the RCSPs and NATCARB (illustrated on the "North American CO₂ Sources" map), showing that CO₂ stationary source emissions result largely from power generation, energy use and industrial processes. While not all potential GHG sources have been examined, NETL's RCSPs have documented the location of more than 4,796 stationary sources with total annual emissions of 3,276 million metric tons of CO₂. The "CO₂ Stationary Source Emission by Partnership" pie chart displays the amount of CO₂ stationary source emissions identified by each RCSP.

Cement is the most abundant manufactured material in the world and used in concrete as one of the world's most commonly used building materials. In 2005, United States consumed almost 124 million metric tons (MMt), while Canada consumed of 9.2 MMt Portland cement. Of that total approximately 93 MMt of Portland cement and about 5 MMt of masonry cement were produced in the U.S. and 12.6 MMt in Canada. Roughly a half tonne of CO₂ is released from the combustion of fuels in the kiln and calcination of the limestone for every tonne of cement (clinker) produced. The total estimated CO₂ emissions for cement production from both combustion and non-combustion processes inventoried in NatCarb is 104.8 million metric tons. || More... || Methodology || View Map

Oil and Gas Refineries are good sources of high-quality CO₂. Carbon dioxide from the refining process has purities at 99+%, making capture of the gas both economical and efficient. || View Map.

Ethanol plants use corn, sorgum, sugar cane, and other grains and starches to create ethanol. CO₂ is a byproduct of the fermentation process and is nearly 100% pure. Capturing CO₂ from ethanol plants is already a common practice and is considered food-grade--making it usable for soft-drinks, dry ice, and other processes. Capturing CO₂ from ethanol plants is for enhanced oil recovery (EOR) or sequestration is both possible, economic, and efficient. || View Map.

Electric Power Utilities produce a large percentage of the non-transportation-related carbon dioxide released to the atmosphere. Carbon dioxide from power plants is high volume, but low quality, as it composes less than 15% of the waste stream of coal- and natural gas-fired power plants. Capturing CO₂ from power plants is neither efficient nor inexpensive at this time, though the potential is great. Integrated Gasification, Combined Cycle (IGCC) power plants hold great potential for CO₂ capture from coal-combustion. || View Map || Static Map.

In 2004, total U.S. greenhouse gas emissions were estimated at 7,074.4 million metric tons CO₂ equivalent and include CO₂ and other greenhouse gases (e.g., CH4, N2O, and HFC's) [Note: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2004(April 2006), USEPA #430-R-06-002, http://www.epa.gov/climatechange/emissions/usinventoryreport.html, accessed October 30, 2006.]. The primary greenhouse gas emitted by human activities in the United States was CO₂ and totaled 5,988 million metric tons. CO₂ emissions result mostly from energy use and industrial processes (e.g., iron and steel and cement). These emissions are driven largely by economic growth, fuel used for transportation and electricity generation, and weather patterns affecting heating and cooling needs. In 2004, carbon dioxide emissions, related to the transportation sector were 1860.2 million metric tons. This results in a total of approximately 4,128 million metric tons of CO₂ emissions from stationary sources.

While not all potential stationary greenhouse gas sources have been examined, NETL's Carbon Sequestration Partnerships have documented the location of more than 4,365 stationary sources with total emissions of 3,809 million metric tons of CO₂. Included are sources such as ethanol plants that are not included in inventories of greenhouse gasses. However, these sources are important in that they produce high quality CO₂ from plant material and can be used to offset emissions from the combustion of fossil fuels.