UTILIZATION OF CARBON-DIOXIDE FROM FOSSIL-FUEL - BURNING POWER-PLANTS WITH BIOLOGICAL-SYSTEMS

Physical-chemical processes for the capture and sequestration of CO2 from fossil fuel-fired power plant flue-gases are very expensive. Biological processes for CO2 utilization involve plant photosynthesis and conversion of the biomass to fuels, with no net CO2 production. Terrestrial plants cannot utilize flue gas CO2 directly. Only submerged aquatic plants, particularly microalgae, can utilize CO2 from power plant flue gases in a practical process. Microalgae have the potential for achieving high productivities and can be converted to gaseous and liquid fuels. A-preliminary cost-analysis of such a process is presented that suggests that, if high productivities are achievable, overall costs would compare favorably with alternative physical-chemical processes for flue gas CO2 capture and sequestration, but would be higher than CO2 mitigation with terrestrial plants. Microalgae CO2 utilization systems would be most applicable where land and water (seawater, brackish) resources, not readily utilized by agriculture, are available.