scholarly journals The Influence of the Activation Temperature on the Structural Properties of the Activated Carbon Xerogels and Their Electrochemical Performance

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Nguyen Khanh Nguyen Quach ◽  
Wein-Duo Yang ◽  
Zen-Ja Chung ◽  
Hoai Lam Tran

The effect of activation temperature on the structural properties and the electrochemical performance of KOH-activated carbon xerogel was investigated in range of 700 to 1000°C. At a high temperature (1000°C), the chemical activation regenerated a more crystalline network structure of activated carbon xerogels, which was observed by Raman, XRD, and TEM images. Additionally, SEM images, BET, BJH, and t-plot were used to study the structural properties of carbon xerogels. The carbon xerogel sample activated at 900°C was found with the most appropriate structure, which has the high micropore area and a more-balanced porosity between the micropores and mesopores, for using as an electrode material. The highest obtained specific capacitance value was 270 Fg−1 in 6 M KOH electrolyte at scan rate of 5 mVs−1 from the cyclic voltammetry.

2016 ◽  
Vol 10 (2) ◽  
pp. 201-208
Author(s):  
Abhijit Jadhav ◽  
◽  
Govindraj Mohanraj ◽  

Activated carbon from Cocos nucifera leaves agrowaste was derived. The effect of impregnation ratio was studied by chemical activation method using phosphoric acid as an activating agent. Activated carbon was produced at the activation temperature of 673 K by slow pyrolysis. Nitrogen adsorption isotherms study was performed. Effect of impregnation ratio on the yield, methylene blue number, iodine number, and acid adsorption was studied. The FT-IR spectra show the presence of activated carbon. The TGA investigation reveals that activated carbon is thermally stable at 723 K. The SEM images show the incorporation of activated carbon particles which lead to the systematic change in the morphology of activated carbon. Surface chemistry study predicts the acidic and basic functional groups of Cocos nucifera leaves activated carbon.


2020 ◽  
Vol 5 (3) ◽  
pp. 221
Author(s):  
Muhammad Azam ◽  
Muhammad Anas ◽  
Erniwati Erniwati

This study aims to determine the effect of variation of activation temperature of activated carbon from sugar palm bunches of chemically activatied with the activation agent of potassium silicate (K2SiO3) on the adsorption capacity of iodine and methylene blue. Activated carbon from bunches of sugar palmacquired in four steps: preparationsteps, carbonizationstepsusing the pyrolysis reactor with temperature of 300 oC - 400 oC for 8 hours and chemical activation using of potassium silicate (K2SiO3) activator in weight ratio of 2: 1 and physical activation using the electric furnace for 30 minutes with temperature variation of600 oC, 650 oC, 700 oC, 750 oC and 800 oC. The iodine and methyleneblue adsorption testedby Titrimetric method and Spectrophotometry methodrespectively. The results of the adsorption of iodine and methylene blue activated carbon from sugar palm bunches increased from 240.55 mg/g and 63.14 mg/g at a temperature of 600 oC to achieve the highest adsorption capacity of 325.80 mg/g and 73.59 mg/g at temperature of 700 oC and decreased by 257.54 mg/g and 52.03 mg/g at a temperature of 800 oCrespectively.However, it does not meet to Indonesia standard (Standard Nasional Indonesia/SNI), which is 750 mg/g and 120 mg/g respectively.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2951
Author(s):  
Mirosław Kwiatkowski ◽  
Jarosław Serafin ◽  
Andy M. Booth ◽  
Beata Michalkiewicz

This paper presents the results of a computer analysis of the effect of activation process temperature on the development of the microporous structure of activated carbon derived from the leaves of common polypody (Polypodium vulgare) via chemical activation with phosphoric acid (H3PO4) at activation temperatures of 700, 800, and 900 °C. An unconventional approach to porous structure analysis, using the new numerical clustering-based adsorption analysis (LBET) method together with the implemented unique gas state equation, was used in this study. The LBET method is based on unique mathematical models that take into account, in addition to surface heterogeneity, the possibility of molecule clusters branching and the geometric and energy limitations of adsorbate cluster formation. It enabled us to determine a set of parameters comprehensively and reliably describing the porous structure of carbon material on the basis of the determined adsorption isotherm. Porous structure analyses using the LBET method were based on nitrogen (N2), carbon dioxide (CO2), and methane (CH4) adsorption isotherms determined for individual activated carbon. The analyses carried out showed the highest CO2 adsorption capacity for activated carbon obtained was at an activation temperature of 900 °C, a value only slightly higher than that obtained for activated carbon prepared at 700 °C, but the values of geometrical parameters determined for these activated carbons showed significant differences. The results of the analyses obtained with the LBET method were also compared with the results of iodine number analysis and the results obtained with the Brunauer–Emmett–Teller (BET), Dubinin–Radushkevich (DR), and quenched solid density functional theory (QSDFT) methods, demonstrating their complementarity.


2011 ◽  
Vol 366 ◽  
pp. 412-415
Author(s):  
Yu De Liu ◽  
Bo Quan Jiang ◽  
Zheng Qiang Xiao

The activated carbon loaded copper oxide catalyst was prepared from Hainan abandoned coconut shells using chemical activation method and applied in treatment of acid bright red GR simulation dyeing wastewater. The effects of phosphoric acid concentration, ratio of liquid to solid, activation time and activation temperature on the COD and color removal rates were investigated by orthogonal experiment. The results showed that the optimal values of the parameters above were 65% (in mass), 3:1, 2.5h and 500°C under the designed copper oxide loading conditions of calcining temperature 300°C,calcining time 3.0 h and use level of copper nitrate 15 mL. Using the prepared sample for the treatment of the wastewater, the COD and color removal rates reached 94.384% and 99.840%, respectively.


2017 ◽  
Vol 75 (9) ◽  
pp. 2047-2055 ◽  
Author(s):  
Thuan Van Tran ◽  
Quynh Thi Phuong Bui ◽  
Trinh Duy Nguyen ◽  
Van Thi Thanh Ho ◽  
Long Giang Bach

The present study focused on the application of response surface methodology to optimize the fabrication of activated carbon (AC) from sugarcane bagasse for adsorption of Cu2+ ion. The AC was synthesized via chemical activation with ZnCl2 as the activating agent. The central composite design based experiments were performed to assess the individual and interactive effect of influential parameters, including activation temperature, ZnCl2 impregnation ratio and activation time on the AC yield and removal of Cu2+ ion from the aqueous environment. The statistically significant, well-fitting quadratic regression models were successfully developed as confirmed by high F- and low P-values (<0.0001), high correlation coefficients and lack-of-fit tests. Accordingly, the optimum AC yield and removal efficiency of Cu2+ were predicted, respectively, as 48.8% and 92.7% which were approximate to the actual values. By applying the predicted optimal parameters, the AC shows a surprisingly high surface area of around 1,500 m2/g accompanied by large pore volume and narrow micropore size at low fabrication temperature.


2011 ◽  
Vol 213 ◽  
pp. 427-431 ◽  
Author(s):  
Li Jiang ◽  
Fei Ma ◽  
Ai Jun Gu ◽  
Li Jun Zhang

Activated carbon(AC)were prepared from lignin by chemical activation with sodium hydroxide(NaOH). The influence of activation temperature,activation time and impregnation ration on the BET surface areas were investigated. Based on the central composite design (CCD) and response surface methodology(RSM),the optimized technological parameters were as follows: temperature 751°C, time 57min and impregnation ration 2.06, BET surface areas was up to 1437.20 m2/g.The adequacy of the model equation for predicting the optimum response values was verified effectively by the validation.


2009 ◽  
Vol 59 (12) ◽  
pp. 2387-2394 ◽  
Author(s):  
X. Wang ◽  
N. Zhu ◽  
J. Xu ◽  
B. Yin

An improved method for preparing activated carbons from wet waste activated sludge (WAS) by direct chemical activation was studied in this paper. The effects of processing parameters on iodine adsorption capacity of the product were investigated. Results show that sludge-based activated carbon prepared with KOH had a larger iodine value than those activated with ZnCl2 and KCl. The maximum iodine value was observed at the KOH concentration of 0.50 M. Increasing the impregnation time from 10 to 20 h resulted in a 20% increase in the iodine value. The highest iodine value was obtained at the activation temperature of 600°C and holding time of 1 h. Sludge water content had insignificant effects on the iodine value of products. Raw WAS with a water content of 93.2% can be converted into an activated carbon with a high specific surface area of 737.6 m2 g−1 and iodine value of 864.8 mgg−1 under optimum experimental conditions. Other physical properties such as total pore volume, micropore volume and mean pore diameter of the product were also reported and compared with those of commercial activated carbon.


2013 ◽  
Vol 773-774 ◽  
pp. 471-477
Author(s):  
Md Mokhlesur Rahman ◽  
Mohamed Awang ◽  
Mohosina Bintey Shajahan ◽  
Tariq Abdul Razak ◽  
Kamaruzzaman Yunus

The optimum condition for preparing a highly efficient activated carbon has been investigated in this work. The effects of different activation temperatures on the pore structure and surface morphology of highly efficient activated carbon (AC) derived from waste palm shell by chemical activation method using phosphoric acid as activating agent were studied. For activation, different activation temperatures in the range of 550 °C-650 °C were carried out. Activated carbon with well developed pore size were produced at activation temperature of 600 °C for 2 hours. At this temperature the Brunauer , Emmett and Teller (BET) surface areas are 1287 m2g-1, the total pore volume for adsorption and desorption are 0.742 cm3 g-1. Scanning Electron Microscope also confirmed the porosity of the highly efficient activated carbon. Finally it was tested in vitro to determine its adsorbing capacity for paraquat as a toxin. For optimum adsorption ability of activated carbon for paraquat, 0.9% NaCl solution is the most suitable solvent. The paraquat preferentially adsorbed onto the activated carbon in NaCl solution. The adsorption ability of the activated carbon (the amount adsorbed) for paraquat observed to be 99.9 mg g-1.


2008 ◽  
Vol 115 (3) ◽  
pp. 480-490 ◽  
Author(s):  
Leire Zubizarreta ◽  
Ana Arenillas ◽  
Jean-Paul Pirard ◽  
José Juan Pis ◽  
Nathalie Job

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