Pyrolysis
experiments of the microalgal samples before and after the addition
of the catalyst were performed via thermogravimetric analysis (TGA)
in nitrogen and air using the Setaram TAG 16 Simultaneous Symmetrical
Thermo Analyzer (Setaram, France). First, 10–20 mg of sample
in an alumina cup was exposed to nitrogen (140 mL/min) for 10 min
before being heated from room temperature to 850 °C at a 10 °C/min
heating rate. This temperature was maintained in the nitrogen gas
stream for 20 min before switching to air at a flow rate of 70 mL/min
for another 20 min at the same temperature. The temperature was then
reduced to 20 °C at a rate of 20 °C/min in an air stream
(70 mL/min). This temperature was held constant for 30 min.
The TG and dTG curves of the pyrolysis of Botryococcus braunii with and without the catalyst were analyzed based on the method
described in our previous study.39 (link) The
curves were divided into three temperature ranges in a manner similar
to that reported by Chen et al.53 (link) The temperature
at which the first peak of the dTG curve slopes is the maximum temperature
in the first stage (lowest dTG value). The first stage of the dTG
curve has only one peak, while the second stage has several peaks.
The temperature range in the second stage is the temperature at which
the peaks on the dTG curve have flattened after the first stage is
completed. The temperature after the end of the second stage is the
initial temperature in the third stage.
experiments of the microalgal samples before and after the addition
of the catalyst were performed via thermogravimetric analysis (TGA)
in nitrogen and air using the Setaram TAG 16 Simultaneous Symmetrical
Thermo Analyzer (Setaram, France). First, 10–20 mg of sample
in an alumina cup was exposed to nitrogen (140 mL/min) for 10 min
before being heated from room temperature to 850 °C at a 10 °C/min
heating rate. This temperature was maintained in the nitrogen gas
stream for 20 min before switching to air at a flow rate of 70 mL/min
for another 20 min at the same temperature. The temperature was then
reduced to 20 °C at a rate of 20 °C/min in an air stream
(70 mL/min). This temperature was held constant for 30 min.
The TG and dTG curves of the pyrolysis of Botryococcus braunii with and without the catalyst were analyzed based on the method
described in our previous study.39 (link) The
curves were divided into three temperature ranges in a manner similar
to that reported by Chen et al.53 (link) The temperature
at which the first peak of the dTG curve slopes is the maximum temperature
in the first stage (lowest dTG value). The first stage of the dTG
curve has only one peak, while the second stage has several peaks.
The temperature range in the second stage is the temperature at which
the peaks on the dTG curve have flattened after the first stage is
completed. The temperature after the end of the second stage is the
initial temperature in the third stage.
