Effect of CO2 enhancement in an outdoor algal production system usingTetraselmis

Abstract

One of the objectives of microalgal culture is to provide reliable production technology for important live aquaculture feed organisms. Presented here are the results of experiments designed to provide a better understanding of the relationship between inorganic carbon availability and algal production.Our results suggest that through additions of CO 2 gas we were able to maintain sufficient dissolved carbon to stabilize outdoor algal cultures. Increases in the rate of addition of CO 2 increased levels of dissolved CO 2 , total dissolved inorganic carbon (CO 2 ), and decreased pH in the growth medium. This translated into improved buffering capacity of the culture medium and higher growth rate. A minimum of 2.4 mM YCO 2 was found necessary to maintain a maximal growth rate of 0.7 doublings/day. We also found that the increased productivity more than offsets the cost of adding the CO 2 .

Airlift-driven external-loop tubular photobioreactors for outdoor production of microalgae: assessment of design and performance

“…Because the k * a * value in the loop was low, pure carbon dioxide was indicated for injection to improve the gas}liquid mass transfer driving force and prevent carbon limitations (Camacho Rubio et al, 1999). However, injecting pure carbon dioxide can a!ect local pH values and culture productivity (Olaizola, Duerr, & Freeman, 1991;Mazzuca Sobczuk et al, 2000). This e!ect may be reduced by diluting the injected gas with air or nitrogen.…”

Recovery and Sequestration of Co2 From Stationary Combustion Systems by Photosynthesis of Microalgae

“…Depending on the process, the microalgal cells may need to be physically disrupted. Both ball mills and high pressure homogenizers have been used successfully to disrupt microalgal cells [36,37] to enhance recovery of astaxanthin from Haematococcus at commercial scale, but other methods may be possible [38]. Use of solvents and enzymes might help with cellular disruption and product recovery but care must be taken regarding what aids are used if the product is intended for human consumption.…”

“…Over the last 15 years several companies have attempted to establish commercial operations to supply natural astaxanthin to the feed market. In practice, reliable production of Haematococcus astaxanthin at industrial scale was not accomplished until the late 1990's [36,37].…”

Culturing of Autoflocculating Microalgal Consortium in Continuous Raceway Pond Reactor

“…CO 2 was sparged into the pond through a fine bubble diffuser at the rate of 100 std. mL/minute to ensure unlimited availability of CO 2 for photosynthesis [9].…”