Some very interesting reports on use of algae to capture and recycle carbon.
Microalgae as a source of liquid fuels. Final technical report USDOE -OER http://www.osti.gov/bridge/product.biblio.jsp?query_id=0&page=0&osti_id=6374113
Design and analysis of microalgal open pond systems for the purpose of producing fuels: A subcontract report USDOE
Systems and economic analysis of microalgae ponds for conversion of CO2 to biomass.
Final report. US DOE
Look Back at the U.S. Department of Energy's Aquatic Species Program: Biodiesel from Algae; Close-Out Report. 325 pp.; NREL Report No. TP-580-24190 available on: http://www.nrel.gov/docs/legosti/fy98/24190.pdf
Greenhouse Gas Abatement with Microalgae http://www.co2captureandstorage.info/networks/networks.htm