Featured Research

from universities, journals, and other organizations

Greenhouse Gas Burial: Storing Unwanted Carbon Dioxide In Unmineable Coal Seams

Date:
June 26, 2007
Source:
Inderscience Publishers
Summary:
Deep coal seams that are not commercially viable for coal production could be used for permanent underground storage of carbon dioxide generated by human activities, thus avoiding atmospheric release, according to two studies published in the Journal of Environment and Pollution. An added benefit of storing carbon dioxide in this way is that additional useful methane will be displaced from the coal beds.

Deep coal seams that are not commercially viable for coal production could be used for permanent underground storage of carbon dioxide (CO2) generated by human activities, thus avoiding atmospheric release, according to two studies published in Inderscience's International Journal of Environment and Pollution. An added benefit of storing CO2 in this way is that additional useful methane will be displaced from the coal beds.

Related Articles


Finding ways to store (sequester) the greenhouse gas CO2, indefinitely, is one approach being investigated in efforts to reduce atmospheric CO2 levels and so help combat climate change. CO2 might be pumped into oil wells to extract the last few drops of oil or be placed deep underground in brine aquifers or unmineable coal seams.

Researchers at the U.S. Department of Energy's National Energy Technology Laboratory have carried out initial investigations into the potential environmental impacts of CO2 sequestration in unmineable coal seams. The research team collected 2000 coal samples from 250 coal beds across 17 states. Some sources of coal harbor vast quantities of methane, or natural gas. Low-volatile rank coals, for instance, average the highest methane content, 13 cubic meters per tonne of coal.

The researchers found that the depth from which a coal sample is taken reflects the average methane content, with much deeper seams containing less methane. However, the study provides only a preliminary assessment of the possibilities. The key question is whether methane can be tapped from the unmineable coal seams and replaced permanently with huge quantities of carbon dioxide; if so, such coal seams could represent a vast sink for CO2 produced by industry. The researchers point out that worldwide, there are almost 3 trillions tonnes of storage capacity for CO2 in such deep coal seams.

To replicate actual geological conditions, NETL has built a Geological Sequestration Core Flow Laboratory (GSCFL). A wide variety of CO2 injection experiments in coal and other rock cores (e.g., sandstone) are being performed under in situ conditions of triaxial stress, pore pressure, and temperature.

Preliminary results obtained from Pittsburgh No. 8 coal indicate that the permeability decreases (from micro-darcies to nano-darcies or extremely low flow properties) with increasing CO2 pressure, with an increase in strain associated with the triaxial confining pressures restricting the ability of the coal to swell. The already existing low pore volume of the coal is decreased, reducing the flow of CO2, measured as permeability. This is a potential problem that will have to be overcome if coal seam sequestration is to be widely used.

The research team has also investigated some of the possible side-effects of sequestering CO2 in coal mines. They tested a high volatility bituminous coal with produced water and gaseous carbon dioxide at 40 Celsius and 50 times atmospheric pressure. They used microscopes and X-ray diffraction to analyze the coal after the reaction was complete. They found that some toxic metals originally trapped in the coal were released by the process, contaminating the water used in the reaction.

"Changes in water chemistry and the potential for mobilizing toxic trace elements from coal beds are potentially important factors to be considered when evaluating deep, unmineable coal seams for CO2 sequestration, though it is also possible that, considering the depth of the injection, that such effects might be harmless" the researchers say. "The concentrations of beryllium, cadmium, mercury, and zinc increased significantly, though both beryllium and mercury remained below drinking water standards." However, toxic arsenic, molybdenum, lead, antimony, selenium, titanium, thallium, vanadium, and iodine were not detected in the water, although they were present in the original coal samples.


Story Source:

The above story is based on materials provided by Inderscience Publishers. Note: Materials may be edited for content and length.


Cite This Page:

Inderscience Publishers. "Greenhouse Gas Burial: Storing Unwanted Carbon Dioxide In Unmineable Coal Seams." ScienceDaily. ScienceDaily, 26 June 2007. <www.sciencedaily.com/releases/2007/06/070626080602.htm>.
Inderscience Publishers. (2007, June 26). Greenhouse Gas Burial: Storing Unwanted Carbon Dioxide In Unmineable Coal Seams. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2007/06/070626080602.htm
Inderscience Publishers. "Greenhouse Gas Burial: Storing Unwanted Carbon Dioxide In Unmineable Coal Seams." ScienceDaily. www.sciencedaily.com/releases/2007/06/070626080602.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Will New A350 Help Airbus Fly?

Will New A350 Help Airbus Fly?

Reuters - Business Video Online (Dec. 22, 2014) Qatar Airways takes first delivery of Airbus' new A350 passenger jet. As Joel Flynn reports it's the planemaker's response to the Boeing 787 Dreamliner and the culmination of eight years of development. Video provided by Reuters
Powered by NewsLook.com
Man Parachutes Off Lawn Chair Airlifted By Helium Balloons

Man Parachutes Off Lawn Chair Airlifted By Helium Balloons

Buzz60 (Dec. 22, 2014) A BASE jumper rides a lawn chair, a shotgun, and a giant bunch of helium balloons into the sky in what seems like a country version of the movie 'Up." Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins