SEQUESTRATION RESEARCH PROMISING

CO2 and other greenhouse gas emissions are acidic and therefore potentially dangerous to store. Natural underground concentrations of CO2 have been known to bubble to the surface, release gases and do harm to nearby populations. This relatively small scale study is encouraging about the possibility of safely storing captured carbon dioxide emissions from fossil fuel-burning power plants.

Research is always a good thing. This research is a genuine contribution.

Now if they can only come up with a way to capture all the emissions from the power plants (instead of a small part of them). And transport raw fossil fuels without releasing emissions. And, of course, there is the small matter of the havoc to the landscape coal mining causes. Solve these remaining problems and it really is clean coal. Leave them unsolved and it’s “clean” coal, an oxymoron.

Carbon dioxide could be injected into earth: study
November 26, 2007 (Canadian Broadcasting Company)

WHO
Researchers at the University of Leeds, BP PLC

BP schematic of the capture and sequestration concept. (click to enlarge)

WHAT
A new study suggests sequestration of carbon dioxide captured from natural gas- or coal-burning power plants may be as safe as proponents have hoped. CO2 was injected into pourous sandstone structures from which oil had been pumped. The sandstone reacted with CO2-saturated fluids and neutralized them more quickly than predicted, suggesting stability.

WHEN
- The few previous studies of the subject have been equivocal as to safety and permanency of sequestration.
- This study published in the December issue of the UK journal Geology.

WHERE
- Research done at the University of Leeds, near Yorkshire in Great Britain
- The study was done using the Miller oilfield in the North Sea.

WHY
- BP owns oil wells used.
- The CO2 was neutralized by the sandstone in the non-producing wells more rapidly than expected. This suggests that it would remain in the wells and stable rather than acidifying the sandstone and leeching back to the surface.
- The study was done by studying seawater pumped into the sandstone oil reservoirs. When the researchers extracted samples of the seawater less than a year after injecting CO2, they found the water was “rich in silicates,” meaning the CO2 had dissolved and been neutralized by the sandstone.
- A neutralized silicate-seawater mixture would be expected to remain stable inside the reservoirs indefinitely.

The Miller Field North Sea drilling platform where the sequestration experiment was done. (click to enlarge)

QUOTES
Bruce Yardley, professor, University of Leeds school of earth and environment: "If CO2 is injected underground, we hope that it will react with the water and minerals there in order to be stabilized…That way it spreads into its local environment rather than remaining as a giant gas bubble which might ultimately seep to the surface. It had been thought that reaction might take place over hundreds or thousands of years, but there's a clear implication in this study that if we inject carbon dioxide into rocks, these reactions will happen quite quickly making it far less likely to escape."