Solar Pyrolysis of <i>Spirulina platensis</i> Assisted by Fresnel Lens Using Hydrocalumite-Type Precursors

Abstract

Solar pyrolysis is a promising technology as it combines use of biomass and solar energy to generate transportable and storable fuels, as well as chemicals of interest. The most desired product of rapid pyrolysis of microalgae is bio-oil, a liquid and viscous mixture composed of hundreds of chemicals. Among these compounds are many oxygenates that usually bring some undesirable properties to bio-oil, e.g., instability. This study aimed to investigate the potential of Spirulina platensis to produce bio-oil from catalytic solar pyrolysis assisted by Fresnel lens. The performance of the mixed oxides derived from hydrocalumite was evaluated, aiming to improve the yield and quality of the liquid product. The effects of reaction time and percentage of catalyst on the product distribution and bio-oil composition were quantified. An optimization study was performed using the differential evolution (DE) algorithm in order to maximize the bio-oil yield. The results showed that the highest liquid yield (43.4%) was obtained in 23.4 min using a catalyst percentage of 58.6%. The mixed oxides derived from hydrocalumite contributed to the improvement in the bio-oil quality, which presented in its composition a low quantity of oxygenated compounds and a higher percentage of hydrocarbons.

Keywords

• solar pyrolysis
• Fresnel lens
• hydrocalumite
• <i>Spirulina platensis</i>