Influência da luz na produção de biomassa de microalgas para biocombustíveis: modelagem cinética e análise da literatura

Abstract

With population and technological growth, the demand for energy has increased significantly in recent years. In this context, third-generation biofuels, obtained from microorganism biomass, have emerged as a sustainable alternative. Thus, the present study aimed to evaluate how different lighting conditions, including light intensity and spectrum, influence the growth rate and biosynthesis of biochemical compounds of interest in microalgae, with an emphasis on the production of biofuels, such as biodiesel and SAF. For this purpose, the effect of light on the growth of microalgae was mathematically modeled and evaluated, choosing the species Scenedesmus obliquus, in addition to performing a literature analysis. The results indicated that the mathematical model developed presented good predictive capacity in relation to light intensity, cell concentration and product concentration, since both the simulated values and the behavior remained close to the experimental data. The literature analysis revealed a diversity in the optimal lighting conditions, mainly in relation to light intensity, evidencing that such conditions can vary according to the cultivated species, the cultivation conditions and the objectives of the production process, which determine the metabolites of interest. The literature analyzed shows a predominance of blue and red light, alone or in combination, as the most efficient spectra for microalgae growth and biomass production. When comparing the experimental results with the literature data, there is agreement on the relevance of blue light for microalgae growth. However, experimentally, it was found that red light had a lesser impact. This discrepancy may be related to differences in cultivation conditions, in the species of microalgae used, or to limitations of the modeling applied.