Syzygium cumini residue pyrolysis and chemical dye adsorption using the Plackett–Burman technique
摘要
Prunings of the Suzygium cumini tree were used to produce activated carbon, which was used in a chemical dye adsorption experiment. The characterization analyses of the biomass revealed the following experimental data: moisture 6%, volatile matter 82% and ash content of 0.7%. During the pyrolysis tests of the residue, the following input variables were analyzed: reactor temperature (350–650 °C), carrier vapor flow in the reactor (4–8 mL/min), furnace heating speed (25–45 °C/min), particle size (6–12 mm), heating temperature of the residue with steam (110–130 °C) and residence time of the residue with heated steam (20–40 min). The charcoal obtained presented the following characteristics: (a) pH of 8.5, (b) C/H ratio = 31, (c) pHPCZ = 7.0 and (d) iodine number equal to 1162 mgI2/g. The experimental methodology of Plackett & Burman was used for the methylene blue adsorption test, with the following variables: test temperature (20–30 °C), dye concentration (5–15 mg/L), adsorption time (20–60 min), adsorbent mass (0.5–1 g), shaking table speed (71–167 rpm), pH of the dye solution (6.5–8.5) and activated charcoal particle size (0.45–2 mm). The yield of adsorbent material was approximately 16% at 650 °C. The maximum adsorption capacity of the carbon was approximately 1.5 mg/g. The iodine number of the material produced in this research was much higher than the value established by the standards for adsorbent materials.
Graphical abstract