CO2 MITIGATION WITH MICROALGAE SYSTEMS

Microalgae present one of the few technologies for the capture and uti lization of CO2 emitted by power plants, These microscopic plants woul d be grown in large open ponds, into which power plant flue gas or pur e CO2 (captured from power plants) is sparged, and, after harvesting, the biomass would be converted to a fossil fuel replacement, preferabl y a high value liquid fuel such as biodiesel. The requirements for lar ge areas of land, favorable climate, and ample water supplies will res trict the potential of this technology. Also, even with rather favorab le technical assumptions, the currently projected costs of microalgae- fuels are high, similar to most power plant CO2 capture and disposal o ptions. However, if the technology of microalgae could achieve very hi gh productivities, equivalent to 10% solar energy conversion, and if p rojected low-cost cultivation, harvesting and processing techniques co uld be developed, microalgae technology could become a low-cost CO2 mi tigation option, particularly if prices for fossil fuels increase in t he future. In the nearer-term microalgae CO2 utilization can be integr ated with wastewater treatment and reclamation, providing an early app lication of this technology. Long-term basic and applied R&D are requi red to develop this technology, as one of the many options that may be required in the future to help preserve our planetary atmosphere and biosphere. (C) 1997 Elsevier Science Ltd.