Valorization of rhizoclonium sp. algae via pyrolysis and catalytic pyrolysis

Abstract

The valorization of Rhizoclonium sp. algae through pyrolysis for obtaining bio-oils is studied in this work. The reaction is carried out at 400°C, at high contact time. The bio-oil has a practical yield of 35% and is rich in phytol. Besides, it is simpler than the corresponding to lignocellulosic biomass due to the absence of phenolic compounds. This property leads to a bio-oil relatively stable to storage. In addition, heterogeneous catalysts (Al-Fe/MCM-41, SBA-15 and Cu/SBA-15), in contact with algae during pyrolysis, are analyzed. The general trend is that the catalysts decrease the concentration of fatty alcohols and other high molecular weight products, since their mild acidity sites promote degradation reactions. Thus, the amount of light products increases upon the use of the catalysts. Particularly, acetol concentration in the bio-oils obtained from the catalytic pyrolysis with SBA-15 and Cu/SBA-15 is notably high. Highlights: Rhizoclonium sp. algae is used for obtaining bio-oils. Pyrolysis of Rhizoclonium sp. is carried out in a vertical glass reactor at 400 °C. Phytol, a high valuable product, is obtained in the bio-oil. The solid catalyst in the reactor increase cracking reactions.