24-10-2012, 03:24 PM
Calcium Carbonate Production by Coccolithophorid Algae in Long Term, Carbon Dioxide Sequestration
ABSTRACT
Predictions of increasing levels of anthropogenic carbon dioxide (CO(sub 2)) and the specter of global warming have
intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered,
including bioprocessing methods to promote and accelerate biosequestration of CO(sub 2) from the environment through the
growth of organisms such as coccolithophorids, which are capable of sequestering CO(sub 2) relatively permanently. Calcium
and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is
readily oxidized and releases CO(sub 2) through microbial decomposition on land and in the sea, carbonates can sequester
carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are
the major global producers of calcium carbonate--to sequester CO(sub 2) emissions from power plants. Cultivation of
coccolithophorids for calcium carbonate (CaCO(sub 3)) precipitation is environmentally benign and results in a stable product
with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics,
it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of
CO(sub 2) into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately
and the amount of carbon sequestered as CaCO(sub 3) could be readily quantified. The significant advantages of this approach
warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result
in the maximum amount of CO(sub 2) sequestration through coccolithophorid calcite production and to evaluate the
costs/benefits of using coccolithophorid cultivation ponds or bioreactors to abate CO(sub 2) emissions from power plants.
ABSTRACT
Predictions of increasing levels of anthropogenic carbon dioxide (CO(sub 2)) and the specter of global warming have
intensified research efforts to identify ways to sequester carbon. A number of novel avenues of research are being considered,
including bioprocessing methods to promote and accelerate biosequestration of CO(sub 2) from the environment through the
growth of organisms such as coccolithophorids, which are capable of sequestering CO(sub 2) relatively permanently. Calcium
and magnesium carbonates are currently the only proven, long-term storage reservoirs for carbon. Whereas organic carbon is
readily oxidized and releases CO(sub 2) through microbial decomposition on land and in the sea, carbonates can sequester
carbon over geologic time scales. This proposal investigates the use of coccolithophorids--single-celled, marine algae that are
the major global producers of calcium carbonate--to sequester CO(sub 2) emissions from power plants. Cultivation of
coccolithophorids for calcium carbonate (CaCO(sub 3)) precipitation is environmentally benign and results in a stable product
with potential commercial value. Because this method of carbon sequestration does not impact natural ecosystem dynamics,
it avoids controversial issues of public acceptability and legality associated with other options such as direct injection of
CO(sub 2) into the sea and ocean fertilization. Consequently, cultivation of coccolithophorids could be carried out immediately
and the amount of carbon sequestered as CaCO(sub 3) could be readily quantified. The significant advantages of this approach
warrant its serious investigation. The major goals of the proposed research are to identify the growth conditions that will result
in the maximum amount of CO(sub 2) sequestration through coccolithophorid calcite production and to evaluate the
costs/benefits of using coccolithophorid cultivation ponds or bioreactors to abate CO(sub 2) emissions from power plants.