Energy News  
Co2 Burial Could Help Extract Methane From Old Coal Mines

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.
by Staff Writers
Pittsburgh PA (SPX) Jun 27, 2007
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.

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.

Email This Article


Blog This Article

Related Links
National Energy Technology Laboratory
Powering The World in the 21st Century at Energy-Daily.com



Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News


Japan And China Struggle To Resolve Gas Dispute
Tokyo (AFP) Jun 26, 2007
Japan and China on Tuesday failed to break the deadlock in a longstanding dispute over drilling rights in the energy-rich East China Sea in their latest round of talks, officials said. The Asian rivals' one-day meeting in Tokyo, the ninth round of talks since the dialogue began in 2004, ended without tangible results and with no fresh formal proposals from either side, Japanese officials said.







  • Co2 Burial Could Help Extract Methane From Old Coal Mines
  • Japan And China Struggle To Resolve Gas Dispute
  • Gazprom Takes Over Another Gas Deposit
  • Russian Authorities Promise Prosperity By 2020

  • Baltic And Polish Premiers To To Build A New Nuclear Power Plant
  • Ukraine To Move Away From Russian Design For Nuclear Plant
  • Cooling Problem Halts Russian Nuclear Reactor
  • Electricite de France In Running To Build Slovak Nuclear Plant

  • AIRS Global Map Of Carbon Dioxide From Space
  • Widespread Twilight Zone Detected Around Clouds
  • Rand Says Further Study Warranted On Save The World Air Technology
  • Noxious Lightning

  • Scientists Close In On Missing Carbon Sink
  • Indonesia Aims To Halve Haze-Causing Fires
  • Researchers Demonstrate Way To Control Tree Height
  • Human Activities Increasing Carbon Sequestration In Forests

  • Organic Farms Provide A Clue For India's Struggling Farms
  • Banned Chinese GM Rice Protein Found In Dutch Shipment To Cyprus
  • Wines Knocked Into Carbon Reduction
  • Down On The Virtual Farm With GrassGro 3

  • Billionaire Hopes To Move Entire Plant From Brazil To China
  • US Senate Clinches Fuel Economy Deal
  • Hybrids Or Diesels A Tough Call For Nissan-Renault
  • Debate Heats Up In US Over Coal Fuel For Cars

  • France Supports Cap On Airline Carbon Emissions
  • Too Little Scope For Development Of Current Aircraft Technology
  • F-35 Lightning 2 Pushing Ahead On All Fronts
  • EU And US Launch Airline Pollution Initiative

  • Could NASA Get To Pluto Faster? Space Expert Says Yes - By Thinking Nuclear
  • NASA plans to send new robot to Jupiter
  • Los Alamos Hopes To Lead New Era Of Nuclear Space Tranportion With Jovian Mission
  • Boeing Selects Leader for Nuclear Space Systems Program

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement