MATHEMATICAL APPROACH TO ENHANCE PHOTOBIOREACTOR PERFORMANCE AS A SYSTEM

Photobioreactors (PBR) can be considered as a sophisticated system where many parallel physical, chemical, biochemical and other processes proceed. Many phenomena from sub-systems must be taken into account and to be described and optimized in order to improve PBRs functioning and design. In this work, the PBR behavior for removal of CO2 from biogas by microalgae is analyzed mathematically. Model describing mixing conditions of two phases (gas-liquid) in sectioned PBR is analyzed for different gas load where backflows can influence residence time of air bubbles and part of biomass in PBR sections. This will have direct impact on so call flashing light effect (FLE) inside the vessel. This phenomenon has very solid theoretical basis, which lies in the intimate metabolic mechanisms of photosynthesis and improve cell growth and utilization of CO2 from the biogas. Hence, PBR performance and design depends on optimal functioning of its sub-systems. Optimal innovative design of PBRs includes application of system analysis theory and application of different modeling approaches for simulations of different scenarios in order to minimize the time for experiments and to guarantee success of research tasks. This paper analyses the modeling procedure when worked with sectioning column PBRs and results showed some very robust findings which further were proved in Brazilian and Bulgarian laboratories. These findings can be adapted to fulfill the overall picture of integral biorefinery concept for green technologies linked with the environmental protection and ecology.