Washington: In a novel way to fight global
warming, scientists are trying how they could remove excess
carbon dioxide from the atmosphere and store the gas deep
under the sea bed where it can cause no trouble.
Researchers at the University of Iceland are studying
the possibility of sequestration of carbon dioxide (CO2) in
basalt, a common extrusive volcanic rock that makes up most of
the world's oceanic crust.
Sequestration is the carbon-capturing method which
involves injecting the gas directly into underground
geological formations. Oil fields, gas fields, saline
formations, unminable coal seams, and saline-filled basalt
formations have been suggested as storage sites.
Sigurdur Gislason, of University of Iceland, who is is
leading an international team of scientists on the "Carbfix
Project" for an Icelandic geothermal power plant, presented
his findings today at the annual Goldschmidt Conference at the
University of Tennessee, Knoxville.
Gislason's project aims at pumping carbon deep
underground in southwest Iceland where it will mix with
minerals and become rock.
The project involves capturing and separating flue gases
at the Hellisheidi Geothermal Power Plant in Hengill,
transporting the gas, dissolving it in water, and injecting it
at high pressures to a depth between 400 and 800 meters into a
thick layer of basalt. Then the researchers will verify and
monitor the storage.
"If successful, the experiment will be scaled up and can
be used wherever carbon dioxide is emitted," said Gislason.
"Currently, carbon may be captured as a byproduct in
processes such as petroleum refining. It can be stored in
reservoirs, ocean water and mature oilfields."
Carbon sequestration is currently the most promising way
to reduce greenhouse gases and Gislason's project is aimed at
finding a storage solution that is long lasting,
thermodynamically stable and environmentally benign.
The researchers said that the storage of CO2 as solid
magnesium carbonates or calcium carbonates deep underground in
basaltic rocks may provide a long-term and thermodynamically
stable solution.
However, many experts fear that CO2 may leak over time.
PTI
First Published: Thursday, June 17, 2010, 18:04