Nitrogenous compounds produced by catalytic pyrolysis of cyanobacteria over metal loaded MCM-41 with vaporized methanol

Abstract

The pyrolysis of cyanobacteria provides a promising path for the production of nitrogenous compounds. In this work, several catalysts were prepared and applied to the cyanobacteria pyrolysis. The result showed that the synergistic effect between the acidic catalyst and methanol contributes to the formation of bio-oils and nitrogenous compounds. The yield of nitrogenous compounds increased from 46.79% to over 70% with the help of methanol and an acidic catalyst. Pyrolysis over Ni–Al layered double oxide loaded MCM-41 (NiAl-LDO/MCM-41) provided an optimum bio-oil yield of 26.02%, and 25.82% of the nitrogen in the cyanobacteria was transferred into the bio-oil. Nitriles are the main components in nitrogenous compounds and pentadecanenitrile is the major component of nitriles. Although the bio-oil yield upon pyrolysis over Al₂O₃ loaded MCM-41 (Al₂O₃/MCM-41) was only 21.18%, the concentration of nitrogenous compounds in the bio-oil was up to 92.59%, and 87.58% of the bio-oil was made of nitriles, whereas pentadecanenitrile accounted for 78.92%. These results gave us a potential way to obtain nitrogenous compounds such as pentadecanenitrile from renewable resources.