Modeling Algae Growth in an Open-Channel Raceway

Abstract

Cost-effective implementation of microalgae as a solar-to-chemical energy conversion platform requires extensive system optimization; computer modeling can bring this to bear. This work uses modified versions of the U.S. Environmental Protection Agency's (EPA's) Environmental Fluid Dynamics Code (EFDC) in conjunction with the U.S. Army Corp of Engineers' water-quality code (CE-QUAL) to simulate hydrodynamics coupled to growth kinetics of algae (Phaeodactylum tricornutum) in open-channel raceways. The model allows the flexibility to manipulate a host of variables associated with raceway-design, algal-growth, water-quality, hydrodynamic, and atmospheric conditions. The model provides realistic results wherein growth rates follow the diurnal fluctuation of solar irradiation and temperature. The greatest benefit that numerical simulation of the flow system offers is the ability to design the raceway before construction, saving considerable cost and time. Moreover, experiment operators can evaluate the impacts of various changes to system conditions (e.g., depth, temperature, flow speeds) without risking the algal biomass under study.

Energy Balance of Biogas Production from Microalgae: Development of an Energy and Mass Balance Model

“…Raceways typically exhibit plug flow behaviour, with little or no longitudinal mixing (38)(39)(40)(41).…”

Formation of algae growth constitutive relations for improved algae modeling.

“…This work uses a modified version of the U. S. Army Corp of Engineers' water-quality code (CE-QUAL) [29,30] to simulate algal growth kinetics in well-mixed photobioreactor-type systems. The model allows the flexibility to manipulate a host of variables associated with algal growth such as temperature, light intensity, and nutrient availability.…”

Composition of Algal Oil and Its Potential as Biofuel

“…Even if light dilution is considered properly, the effect of environmental factors on the PCE value like temperature-usually assumed as being from Arrhenius type [38]-diffuse light, and day length can hardly be anticipated. Growth-model-based attempts for extrapolation using local weather data or landscape characteristics have nevertheless been proposed [39,40] but not finally proven. Practical experiences are actually missing, whether the advantage of a higher irradiation of a maximum ratio of 2.5 between middle Europe and North Africa can really be exploited facing problems of temperature control, CO 2 and nutrition logistics and higher light dilution factors.…”