Catalytic Pyrolysis of Algae (Scenedesmus dimorphus)

Algae biomass has the potential to produce inexpensive biofuels because of its ability to produce high yields of lipids under stressed growth conditions.   Scenedesmus dimorphus algae were prepared under stressed growth conditions were freeze-dried and used for the catalytic pyrolysis studies.  The pyrolysis was conducted in a fluidized bed reactor using various zeolite catalysts as the fluidizing medium.  The pyrolysis temperatures ranged from 400 to 450 C.  The oil yields ranged from 38 to 45 wt%. The zeolites with small pores produced very viscous acidic oils while the zeolites with large pores produce very low viscosity oils.   The nitrogen content of the oils was relatively high and the higher heating values of the oils ranged from 38 to 42 MJ/kg.  Simulated distillation of the oils showed that 35 to 45% of the distillate was in the diesel fraction. These oils could be potentially used as biocrude oils for refinning in a conventional petroleum refinery.