ISSN:
0006-3592
Keywords:
solar irradiance
;
tubular photobioreactor
;
microalgal culture
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
A macromodel is developed for estimating the year-long biomass productivity of outdoor cultures of microalga in tubular photobioreactors. The model evaluates the solar irradiance on the culture surface as a function of day of the year and the geographic location. In a second step, the geometry of the system is taken into account in estimating the average irradiance to which the cells are exposed. Finally, the growth rate is estimated as a function of irradiance, taking into account photoinhibition and photolimitation. The model interconnects solar irradiance (an environmental variable), tube diameter (a design variable), and dilution rate (an operating variable). Continuous cultures in two different tubular photobioreactors were analyzed using the macromodel. The biomass productivity ranged from 0.50 to 2.04 g L-1 d-1, and from 1.08 to 2.76 g L-1 d-1, for the larger and the smaller tube diameter photobioreactors, respectively. The quantum yield ranged from 1.1 to 2.2 g E-1; the higher the incident solar radiation, the lower the quantum yield. Simultaneous photolimitation and photoinhibition of outdoor cultures was observed. The model reproduced the experimental results with less than 20% error. If photoinhibition was neglected, and a growth model that considered only photolimitation was used to fit the data, the error increased to 45%, thus reflecting the inadequacy of previous outdoor growth models that disregard photoinhibition. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 58: 605-616, 1998.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
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