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This research demonstrates the production of activated carbon from scrap tires via physical activation with carbon dioxide. A newly constructed apparatus was utilized for uninterrupted carbonization and activation processes. Taguchi experimental design (L16) was applied to conduct the experiments at different levels by altering six operating parameters. Carbonization temperature (550-700 °C), activation temperature (800-950 °C), process duration (30-120 min), CO flow rate (400 and 600 cc/min) and heating rate (5 and 10 °C/min) were the variables examined in this study. The effect of parameters on the specific surface area (SSA) of activated carbon was studied, and the influential parameters were identified employing analysis of variance (ANOVA). The optimum conditions for maximum SSA were: carbonization temperature=650 °C, carbonization time=60 min, heating rate=5 °C/min, activation temperature= 900 °C, activation time=60 min and CO flow rate=400 cc/min. The most effective parameter was activation temperature with an estimated impact of 49%. The activated carbon produced under optimum conditions was characterized by pore and surface structure analysis, iodine adsorption test, ash content, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The process yield for optimized activated carbon was 13.2% with the following properties: specific surface area=437 m/g, total pore volume=0.353 cc/g, iodine number=404.7 mg/g and ash content=13.9% along with an amorphous structure and a lot of oxygen functional groups. These properties are comparable to those of commercial activated carbons. [ABSTRACT FROM AUTHOR]

A conductive activated charcoal plate (ACP) was prepared from a low-cost, abundant, and non-conductive charcoal. The prepared ACP was characterized using N adsorption/desorption isotherms, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Brunauer-Emmett-Teller (BET) surface area of the charcoal and the ACP was 0.58 m g and 461.67 m g, respectively. The ACP was employed in textile wastewater treatment using electrosorption process. Response surface methodology (RSM) was applied to design the experiments. The decolorization efficiency of 76% at optimum conditions of voltage=450mV, pH=4, and contact time=120 min indicated that the ACP has promising potential to decolorize textile wastewater. Moreover, the results of the kinetic analyses demonstrated that wastewater treatment followed pseudo-first order kinetic model. The ACP electrode could be regenerated and reused effectively at five successive cycles of electrosorption/electrodesorption. [ABSTRACT FROM AUTHOR]

The de-NO performance of sewage sludge chars activated physically using water vapor or chemically using KOH was evaluated. Characteristics of chars activated under different activation temperatures, water vapor concentrations, and KOH/char ratios were analyzed by N adsorption-desorption and FT-IR. Chemically activated chars were more efficient in removing NO due to their higher surface area, oxygen functional group and NH adsorption than physically activated chars. The de-NO performance of the activated chars is influenced more by chemical properties such as oxygen functional groups and NH adsorption sites than by physical properties like specific surface area and pore volume. [ABSTRACT FROM AUTHOR]

This work focused on the preparation of activated carbon from eucalyptus and wattle wood by physical activation with CO2. The preparation process consisted of carbonization of the wood samples under the flow of N2 at 400°C and 60 min followed by activating the derived chars with CO2. The activation temperature was varied from 600 to 900°C and activation time from 60 to 300 min, giving char burn-off in the range of 20/2-83%. The effect of CO2 concentration during activation was also studied. The porous properties of the resultant activated carbons were characterized based on the analysis of N2 adsorption isotherms at −196°C. Experimental results showed that surface area, micropore volume and total pore volume of the activated carbon increased with the increase in activation time and temperature with temperature exerting the larger effect. The activated carbons produced from eucalyptus and wattle wood had the BET surface area ranging from 460 to 1,490 m2/g and 430 to 1,030 m2/g, respectively. The optimum activation conditions that gave the maximum in surface area and total pore volume occurred at 900°C and 60 min for eucalyptus and 800°C and 300 min for wattle wood. Under the conditions tested, the obtained activated carbons were dominated with micropore structure (∼80% of total pore volume). [ABSTRACT FROM AUTHOR]