Sustainable Biofuel Production from Brown and Green Macroalgae through the Pyrolysis

Abstract

The escalating demand for energy coupled with environmental concerns necessitates exploring sustainable alternatives to fossil fuels. The study explores the viability of using large ocean-based seaweeds as a source of third-generation biomass, specifically focusing on their conversion to biofuel via the process of pyrolysis. Sargassum plagiophyllum and Ulva lactuca represent prevalent forms of macroalgae, posing significant discharge challenges for coastal regions globally. However, the exploration of their potential for bio-oil generation via pyrolysis remains limited. This study investigates the pyrolysis process of S. plagiophyllum and U. lactuca for biofuel production, aiming to provide valuable insights into their utilization and optimization. Pyrolysis experiments were conducted within temperature ranges of 400°C to 600°C and durations of 10 to 50 min using a batch reactor. The chemical analysis of the synthesized bio-oil indicated it contains critical compounds such as organic acid derivatives, fur-ans, nitrogenous aromatics, and aliphatic hydrocarbons. The effectiveness of converting the initial biomass into bio-oil is significantly influenced by the pace at which the biomass undergoes decomposition, underscoring the importance of comprehending the kinetic aspects of this conversion. By applying the Arrhenius formula, we calculated the activation energies and frequency factors, with the findings for S. plagiophyllum being 15.27 kJ/mol and 0.477 s −1 , and for U. lactuca, the values were 43.17 kJ/mol and 0.351 s −1 , correspondingly. These findings underscore the potential of brown and green macroalgae as sustainable sources for biofuel production via pyrolysis , offering insights for further optimization and valorization efforts in the quest for renewable energy solutions