Microalgal removal of CO2 from flue gases: Changes in medium pH and flue gas composition do not appear to affect the photochemical yield of microalgal cultures

Our research objectives are to determine under what conditions microalgal-based CO2 capture from flue gases is economically attractive. Specifically, our objective here was to select microalgae that are temperature, pH and flue gas tolerant. Microalgae were grown under five different temperatures, three different pH and five different flue gas mixtures besides 100% CO2 (gas concentrations that the cells were exposed to ranged 5.7-100% CO2, 0-3504 ppm SO2, 0-328 ppm NO, and 0-126 ppm NO2). Our results indicate that the microalgal strains tested exhibit a substantial ability to withstand a wide range of temperature (54 strains tested), pH (20 strains tested) and flue gas composition (24 strains tested) likely to be encountered in cultures used for carbon sequestration from smoke stack gases. Our results indicate that microalgal photosynthesis is a limited but viable strategy for CO2 capture from flue gases produced by stationary combustion sources.