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In this study, activated carbons were prepared from sugar beet bagasse, which is side product and waste in sugar plants, by chemical activation with ZnCl2. Influence of activation temperature was investigated on to pore structure. ZnCl2/sugar beet bagasse ratio (impregnation ratio) was selected as 1:1. The impregnated sample was raised to the activation temperature under N2 (100ml/min) atmosphere with 10°C/min heating rate and hold at this temperature for 1h. The activation temperature was varied over the temperature range of 400–900°C. BET surface area values were determined in the range of 832–1697m2/g. Under the experimental conditions, 500°C was found to be the optimal condition for producing high surface area carbons with ZnCl2 activation. Sugar beet bagasse was suitable for preparation of activated carbon with essentially microporous structure. Activated carbon ash content was found in the range of 1. 2–2. 7 (%w/w d. B. ). Activated carbon samples and raw material were characterized by XRD, FT-IR, DTA and TGA. [Copyright &y& Elsevier]

Abstract: In this study, active carbon was obtained through chemical activation methods using some pretreatment to Gölbaşı (Adıyaman) and Kangal (Sivas) lignites. For both lignites, pretreatment was carried out in three steps. In the first step, demineralization was achieved by applying HCl–HF pretreatment to raw lignites. In the second one, raw and demineralized lignites were swollen not only with benzene but also with THF (tetrahydrofurane). Later, these two samples at 85 °C were exposed to chemical activation by impregnation with ZnCl2. Chemical activation processes were carried out in a situation where samples on quartz board in a quartz tube in a cylindrical furnace were kept for 1 h at 500 °C, 100 ml/min N2 flow speed and 30 °C/min heating rate. The active carbons produced were washed with 10% HCl and later with demineralized water. BET surface area of the active carbon samples was generally higher than 1000 m2/g. The surface area value of the Gölbaşı lignite was relatively higher than that of Kangal lignites. Similarly, the surface area value of the active carbons produced at the end of pretreatment with THF was higher than that of active carbon produced through pre-swelling using benzene. For all active carbon samples, ash, total sulfur and iodine adsorption values were different. [Copyright &y& Elsevier]

Abstract: Adsorbent (T3K618) has been prepared from Tunçbilek lignite by chemical activation with KOH. Pore properties of the activated carbon such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by t-plot based on N2 adsorption isotherm. The N2 adsorption isotherm of malachite green on T3K618 is type I. The BET surface area of the adsorbent which was primarily contributed by micropores was determined 1000m2/g. T3K618 was used to adsorb malachite green (MG) from an aqueous solution in a batch reactor. The effects of initial dye concentration, agitation time, initial pH and adsorption temperature have been studied. It was also found that the adsorption isotherm followed both Freundlich and Dubinin–Radushkevich models. However, the Freundlich gave a better fit to all adsorption isotherms than the Dubinin–Radushkevich. The kinetics of adsorption of MG has been tested using pseudo-first-order, pseudo-second-order and intraparticle diffusion models. Results show that the adsorption of MG from aqueous solution onto micropores T3K618 proceeds according to the pseudo-second-order model. The intraparticle diffusion of MG molecules within the carbon particles was identified to be the rate-limiting step. The adsorption of the MG was endothermic (ΔH°=6.55–62.37kJ/mol) and was accompanied by an increase in entropy (ΔS°=74–223J/molK) and a decrease in mean value of Gibbs energy (ΔG°=−6.48 to −10.32kJ/mol) in the temperature range of 20–50°C. [Copyright &y& Elsevier]