Desenvolvimento de um fotobiorreator hidrido para a conversão de CO2 em biomassa microalgal

Abstract

The photosynthetic conversion of carbon dioxide (CO2) for the microalgae biomass production need photobioreactors with configurations settings. The objective was to develop a hybrid photobioreactor for CO2 fixation and formation of microalgae biomass. Photobioreactor with height/diameter (L/D) of 1.46, as the principal criterion for the scale-up, was projected. Hydrodynamic parameters of the system were determined by the retention time and mixing, fluid dynamics and volume percentage in lighting versus volume in darkness (VI/VE). The biomass concentration and pH dynamics were evaluated in function of VI/VE, circulation rate, light intensity, temperature and CO2 concentration in reactor operating in continuous and discontinuous system. Maximum productivity 122.38 mg/L.h, concentration 3100 mg/L and carbon biofixation in biomass of 3.4% were achieved. Optimum operating condition of 20% VI/VE, 0.65 L/min circulation rate, 13000 lux light intensity, 25 °C temperature, 15% CO2 concentration, 120 m-1 of S/V ratio and transitional fluid flow. Thus, there is clear evidence of the potential of the concept photobioreactor proposed to provide production processes for carbon biofixation and to obtain high yields of microalgae biomass.