DYNAMIC MODELLING OF MIXOTROPHIC MICROALGAE GROWTH

Microalgae are unicellular microorganism that can do photosynthesis converting CO2 into biomass as well as use organic compounds into the medium. They've been cultivated for various purposes, and their large-scale implementation is limited by high operational costs which could be reduced using vinasse as a nutrient source. Despite the existing works, the knowledge of the constructive and operational parameters influence is lacking, which could be estimated by mathematical models. Thus, through the improvement of different models already published, it proposes a model considering constructive and operational parameters, vinasse particularities and dynamic of growth factors. In response, it provides the surface and volumetric productivity, as well as the ratio between the energy required and produced by the system (NER). Considering a cultivation system with surface and volumetric productivity and NER of 14,73 g.m-2.d-1, 0,04 g.L-1.d-1 and 0,19 respectively, the model indicates the system improvement altering constructive and operational parameters, reducing NER by 53,71% and increasing the surface and volumetric productivity by 56% and 25%. Despite the low productivity, the model confirms the possibility to use vinasse as a nutrient source and allows a better sizing of the cultivation system, improving the process viability, providing a new destination and treatment to vinasse.