Thermocatalytic Pyrolysis of Exhausted Arthrospira platensis Biomass after Protein or Lipid Recovery

Microalgae and cyanobacteria are unicellular microorganisms that contain high-added value compounds. To make their extraction economically feasible the biorefinery concept is the only solution. In this study, the residue resulting from lipid or protein extraction from Arthrospira platensis biomass was valorized by catalytic pyrolysis using ZSM5 zeolite or amorphous silica-alumina as catalyst. The reaction was performed in a quartz reactor, and the catalyst was placed in a fixed bed to force the reaction gases to pass through it. The reaction products were analyzed by FTIR and GC-MS analyses. The reaction gases and liquids obtained from the extraction residues had higher hydrocarbon contents compared to untreated biomass. Moreover, pyrolysis of biomass after protein or lipid extraction led to fractions with lower contents of nitrogenated or oxygenated components, respectively. This study showed that the pyrolysis process could be used to valorize the microalgae extraction residues aiming to make biofuels production and extraction of high added-value products more economically feasible.