Thermal energy generation through integrated photobioreactor in a commercial building for water heating under humid subtropical climate

Abstract

Discussion regarding renewable energy generation is a relevant issue in the building sector. Some innovative strategies for renewable energy generation in this sector have emerged in the last decade, such as microalgae photobioreactors (PBRs). Bioenergy can be produced from biomass by the PBRs. Temperature is an important parameter of photobioreactors as this system can overheat and demand cooling. Thus, techniques have been developed to extract heat from PBRs and use it to meet the demands of the building. In this context, the present study performed an energy balance in a photobioreactor associated with a building under a Humid Subtropical climate (Brazil) – in Belo Horizonte, Minas Gerais. A thermoenergetic model was developed to obtain an annual temperature profile of a single photobioreactor. The results indicated that the PBR overheats concerning the optimal temperature range for microalgae biomass production. It was presented as an initial alternative to cool the photobioreactor. The volumetric flow rate of 0,016 L s-1 in the PBR and input cultivation temperature ranging from 20 to 24 °C could cool the PBR. The results presented seek to offer an initial alternative for the use of photobioreactors in buildings in Humid Subtropical climates. In addition, the annual PBR temperature profile obtained may guide future works.