This work aims to produce activated carbon using Flamboyant pods as precursor material. The
research had the following phases: biomass characterization, biomass pyrolysis and activated
carbon characterization. Biomass was characterized through immediate analysis (moisture,
volatile material, ash and fixed carbon), elemental analysis (carbon, hydrogen, nitrogen),
analysis of lignocellulosic materials (cellulose, hemicellulose and lignin), thermogravimetric
analysis (TG) and spectroscopy of Fourier transform infrared (FTIR). Biomass pyrolysis took
place in a fixed bed reactor with a reaction time of 30 minutes. Two variables were studied in
the pyrolysis of biomass: (a) process temperature (408, 450, 550, 650 and 691 °C) and (b)
reactor heating rate (13, 15, 20, 25 and 27 °C/ min). Activated carbon was characterized by
immediate and elemental analysis, iodine number and thermogravimetric analysis. A methylene
blue adsorption test was carried out with the carbon produced during the research, and two
variables were studied: (a) carbon mass (0.2; 0.4 and 0.6 g) and (b) dye concentration (20, 60
and 100 mg/L), with adsorption time of 30 minutes. The volatile material and ash content in the
Flamboyant pod samples were 80 and 2.4%, respectively. The average contents of cellulose,
hemicellulose and lignin in Flamboyant pods were 27.0; 24.5 and 28.0%. The C/H ratio for
Flamboyant pods was 7.3. The data obtained during the pyrolysis of the biomass indicate that
the temperature of the process had a negative regression coefficient (-3.85) for obtaining coal,
indicating that the increase in temperature from 408 to 691 ºC favors a decrease in the yield of
the material. During the characterization of the charcoal produced, a C/H ratio of 28.3 was
observed, a value approximately 4 times higher when compared to the precursor biomass. In
the thermogravimetric analysis of activated carbon, a final residue of approximately 73% was
observed, detected at a temperature of 900 oC. During the methylene blue adsorption test using
a sample of activated carbon produced in this investigation, results of dye removal efficiency
above 93% were obtained. For the response of the experimental design adsorption ratio (Q),
carbon mass and dye concentration (both with p-value less or equal to 0,05) are variables with
statistically significant effects in the adsorption step. The data presented show that the
temperature of the coal manufacturing process interferes with the Iodine Number of the
adsorbent material. The lowest iodine number observed was 110 mgI2/g, with a value of 623
mgI2/g obtained for a sample of coal produced at 691 oC.
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