Estimation of mass transfer coefficient, thermal balance and growth indicators associated to a microalgae cultivation system

Biological indirect air capture has been a great opportunity to deal with carbon emissions rising in the atmosphere. It is a useful approach where basically microorganisms use as a main carbon source the CO2 circulated in the air to grow up in presence also of sunlight radiation and with the photosynthesis process liberates O2 to the environment. For that reason, has been proposed to use an aliquot of microalgae in order to determine the capability of this microorganism to capture as nutrient only the carbon coming from the CO2 presence in the atmosphere and transform it into O2. Initially was evaluated the hydrodynamic parameters of the 2 types of photobioreactors (vessel and tubular) in order to quantify the potential mass transfer of the system insufflating air. Then, a preliminary tubular photobioreactor prototype was tested in order to evaluate an aliquot of Arthrospira maxima was capable to uptake the inorganic carbon source presence in the air without any other carbonate feed as a nutrient to growth. In the system, were also tested several parameters in order to optimize its performance quantifying its average algae concentration and volumetric productivity (biomass produced) under ranges of pH and constant optimal Temperature. Finally, a simulator model was designed in order to quantify the Energy demand of a photobioreactor plant inside a Green House with a dynamic sun pattern through the year adjusting photobioreactor dimensions, single or double configuration and distances within tubes to mitigate shading factors that might reduce its performance. The results of the sections mentioned, indicates that the microalgae is capable to uptake as carbon source only the Carbon present in the atmosphere without additional carbon nutrient feed, and also is able to grow up with several modifications at the same level of tests done in the laboratory with high CO2 concentrations and optimized pH and Temperature conditions.