Catalytic pyrolysis of natural algae over Mg-Al layered double oxides/ZSM-5 (MgAl-LDO/ZSM-5) for producing bio-oil with low nitrogen content

Cyanobacteria were catalytically pyrolyzed over Mg-Al layered double oxide/ZSM-5 composites (MgAl-LDO/ZSM-5) to produce bio-oil. MgAl-LDO/ZSM-5 with a Mg/Al molar ratio of four was proved to be the best catalyst. Under the optima condition that the final temperature was 823 K, heating rate was 10 K/min and catalyst/algae mass ratio was 0.75, a maximum yield of liquid (41.1%) was achieved at 823 K with a heating rate of 10 K/min and a catalyst/algae mass ratio of 0.75, which was much higher than the one obtained without catalyst. The element analysis results proved that this bio-oil had much lower O/C molar ratio and higher HHV. The GC-MS results showed that the bio-oil had less nitrogenous compounds. MgAl4-LDO/ZSM-5 was proved to be an applicable and effective catalyst to obtain bio-oil from catalytic pyrolysis of water-blooming algae.