The use of fossil fuels as an energy source has resulted in a greater level of greenhouse gases accumulating in the atmosphere. Many different greenhouse gases are present, with carbon dioxide being the gas with the highest concentration.
Carbon Sequestration
The process by which atmospheric carbon dioxide is captured and stored is called carbon sequestration. This process can not only be used for atmospheric carbon, but it can also be used to capture carbon when it is emitted. Following the Kyoto protocol, the level of combustion gases, such as carbon dioxide, being emitted has become an area of international focus.
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There are several alternative energy methods that can help to lower carbon dioxide emissions, one being the use of carbon-free energy sources such as solar, nuclear, wind, biomass fuel, and geothermal. Improvements in engine and fuel efficiencies could also help to improve the amount of energy generated by fossil fuel combustion, meaning less carbon dioxide is emitted per watt of energy produced.
Whilst these methods are promising, they currently only have a small impact on the global use of fossil fuels, which continue to be the energy source of choice around the globe. It is expected that this will remain the status quo in the coming decades as our need for energy continues to increase and fossil fuels remain cheap and available, whilst alternative energy sources remain not fully established.
Storage of Sequestrated Carbon Dioxide in Deep Geological Formations
To help mitigate the damage from this outcome, intense research is being carried out on methods of safely capturing large volumes of carbon dioxide from industrial emissions and in the atmosphere for its safe storage. Many researchers now believe that storing sequestrated carbon dioxide in deep geological formations is a long-term solution to this problem.
This could be achieved by the compression of sequestrated carbon dioxide into a dense fluid, which can then be injected into a deep geological formation and sealed using a cap of impermeable rock.
The technology to carry out sequestered carbon injections already exists in the United States, where there is a wealth of experience in the storage of natural gas, CO2, injections for enhanced coal bed methane recovery (ECBM) and enhanced oil recovery (EOR), and also acid gas injection into saline geological structures; making this a deliverable method.
The Department of Energy in the US, led by the Regional Carbon Sequestration Partnerships and NETL, and in collaboration with academia and industry, is currently working on a carbon dioxide Sequestration Research, Development, and Demonstration Program.
Field tests for this program are currently being carried out throughout North America. Some of the possible storage areas include unmineable coal seams, empty oil and gas reservoirs, and deep saline formations.
Many of the formations being investigated have already stored natural carbon dioxide, fluids, and other gases for over millions of years. For this reason, it is hoped that they have the potential to store human-generated carbon dioxide.
This technology has also been tested before in other countries; over the last fifteen years, three different large-scale carbon dioxide storage projects have started in Algeria (2004), Canada (2000), and Norway (1996), with no reported problems.
Whilst these formations could be used to store anthropogenic carbon dioxide, it is estimated that every year more than one billion metric tons of the gas must be sequestered in order to have a noticeable impact.
There are many different factors that must be considered before choosing a site in which to carry out large-scale sequestration. These include the hydrologic, geochemical, and geomechanical processes that occur at the site subsurface, as well as the engineering and design needs to carry out the injection and monitor the stored carbon afterward. To investigate this, researchers must be able to characterize the geological materials at the site.
Analytical Tools
Micromeritics have supplied analytical tools for the measurement of surface area and porosity, and other important measurements for the surveying of possible sites for CO2 sequestration, since 1962. Surface area and mercury porosimetry measurement systems have been used as vital tools to measure the fluid-transport and sealing properties of fine-grained sediments under geological conditions for carbon dioxide.
Measurements of pore volumes can be used to determine the capacity of a formation. Pore size is also an important parameter that can be used to determine the rate at which CO2 will pour into a formation as it is filled.
AutoPore Mercury Porosimeter from Micromeritics
The AutoPore Mercury Porosimeter from Micromeritics has been used to determine the pore-throat aperture size distribution and sealing capacity of core samples from reservoirs. The ASAP 2020 Accelerated Surface and Porosimetry System alongside mercury porosimetry data can be used to complement fluid transport data with B.E.T. specific surface area data.
This combination allows differences in a sample’s sealing efficiency and transport properties to be determined. The ASAP 2020 is also perfect for the measurement of the distribution of mesopores and micropores in coal, providing useful information for ECBM research.
ASAP 2050 Xtended Pressure Sorption Analyzer and HPVA-100 High-Pressure Volumetric Analyzer
The ASAP 2050 Xtended Pressure Sorption Analyzer and the HPVA-100 High-Pressure Volumetric Analyzer make evaluating the storage capacity of carbon dioxide-sorbents at high pressures effortless.
The ASAP 2050 is a high-resolution analyzer that can determine a material’s capacity with respect to the storage pressure ranging between vacuum conditions to 10 bar. The use of the HPVA can extend this capability from 10 to 100 or 200 bar. Both instruments allow materials to be researched in conditions that emulate the real world.
International powers, with the aid of research from the scientific community, have to find a way to remove the excess carbon dioxide that is present in our atmosphere as a result of fossil fuel combustion. Preliminary research is indicating that carbon dioxide sequestration into deep geologic formations could be the answer to this problem.
Conclusion
In order to determine the best site for the storage of large volumes, different geologic sites must be evaluated and compared with one another. Systems provided by Micromeritics can be used to achieve this. Their novel, expert-produced analysis systems are already being used in crucial roles in these evaluations, and will remain a popular choice in the future.
This information has been sourced, reviewed and adapted from materials provided by Micromeritics Instrument Corporation.
For more information on this source, please visit Micromeritics Instrument Corporation.