Geological disposal of CO2.
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Carbon dioxide is one of the driving forces behind global warming and has long been tied to fossil fuel production and use. Burning coal, oil and natural gas releases significant quantities of carbon dioxide. Drilling for natural gas can also bring up some carbon dioxide from subsurface reservoirs. This waste carbon dioxide is normally vented into the atmosphere.
However, a partial solution to the carbon dioxide problem is to pump the gas down wells and into the same reservoir rocks that yielded the fossil fuels. This is not a new idea. The oil industry has long pumped carbon dioxide into depleting reservoir rocks in an effort to drive the oil to a production well. This can't be done all of the time because the availability of carbon dioxide is not geographically matched with the secondary recovery of oil (see
carbon dioxide flooding article at the Occidental Petroleum website).
In the North Sea, Statoil,
Norway's largest petroleum company, has been injecting a million tons per year of carbon dioxide into subsurface formations. These efforts are done to save the company $53 million per year in Norwegian taxes on carbon dioxide emissions. For Statoil, disposing of carbon dioxide is a cost-saving response to an environmental protection tax (see article on
carbon dioxide emissions buried at sea).
Researchers at Western Michigan University are working on ways to create an income stream by using the billions of cubic feet of porous rock beneath
Michigan as a disposal site for waste carbon dioxide. They envision developing injection well fields that are supplied by pipelines full of waste carbon dioxide gas emitted by coal-fired power plants, ethanol plants, cement factories and other facilities (see their article on
geological carbon sequestration).
If carbon dioxide emissions become stringently regulated then it is likely that companies will try to find ways to match the production of waste carbon dioxide and uses of that gas for economic gain. Secondary oil recovery could consume very large amounts of carbon dioxide. The gas is also used for methanol production, urea production, propellants, refrigerants and many other minor uses (see
uses of carbon dioxide at the UIG website).
Labels: Global-Warming
