Papers by Keyword: Activated Carbon (AC)

Abstract: Activated carbon was prepared from blue coke powder by physical activation. The results show that the specific surface area (BET) is 697.05m2/g, the total pore volume is 0.4569cm3/g and the average pore size is 2.6221nm. The adsorption properties of Cr( ) onto blue coke powder activated carbon are discussed from the kinetics and thermodynamics viewpoints. The pseudo-second-order kinetic model shows the best correlation with experimental data. Langmuir and Freundlich models are used to fit the equilibrium, and it is indicated that Freundlich best fits these data. The adsorption of Cr( ) onto blue coke powder activated carbon is found to be an endothermic process in nature.

Abstract: A new process was investigated which combines both fast pyrolysis carbonization and CS activated carbons with H3PO4 activation (CSAC). ACs were obtained as by-product from the preparation process of bio-oil with fast pyrolysis under different temperatures (T=727–973 K), in which the reaction ended in a very short duration. A two-step process of reaction is proposed to govern carbonization and activation: firstly fast pyrolysis reaction removing disorganized material was associated with considerable weight loss but with low generation of porosity, pyrolysis/carbonization under the flow of N2 is suggested to ensure fluidization of CS powders and bed material, enhance decomposition of raw material, initiates controlled gasification at different temperatures. Then H3PO4 activation process dominated at 573 K, which leads to considerable evolution of porosity. In this research, the adsorption characteristics were determined from N2 adsorption isotherms and subsequent analysised by the BET-and BJH-methods. As a result, the iodine adsorption number of AC was 1310 mg/g and the SSA of AC was 1421.38 m2/g .

Abstract: Effect of a furniture interior air purifying device on reducing concentrations of formaldehyde in air

Abstract: In order to improve the Cd2+ adsorption ability, the granular activated carbon (GAC) was modified with different treatments, and the Cd2+ removal efficiencies (REs) by the treated GACs were then comparatively investigated under different conditions. The surface physical-chemical properties of these carbons were further characterized in virtue of BET and Boehm’s titration, etc. The results demonstrate that the specific surface area and surface oxy acidity functional groups of GAC changed to some certain after the different treatments, especially for that with HNO3 oxidizing. It therefore led to an improvement of Cd2+ adsorption ability, and the corresponding REs by the N-GACs that were respectively modified with 10% and 70% HNO3 were significantly higher than that by the original GAC (i.e., 41% and 57% vs. 10%). pH was found to be the most vital influencing factor for the Cd2+ adsorption, and the Cd2+ REs by the tested GACs were all increased with an elevation in the pH value.

Abstract: In this paper, the feasibility of preparing activated carbon from corncob furfural residue with ZnCl2 by microwave irradiation was studied. The effect of the ratio by weight of ZnCl2 to corncob furfural residue, ZnCl2 solution soaking time, microwave irradiation time and the pH value of ZnCl2 solution on the quality of activated carbon was investigated. On the condition that the microwave power is 800 W and ZnCl2 solution mass concentration is 50%, the best technological parameter on preparing activated carbon with ZnCl2 by microwave irradiation is obtained: at the ratio of 3.5:1 by weight of ZnCl2 to corncob furfural residue, microwave irradiation time is 20 min, ZnCl2 solution soaking time is 12 h, the pH value of ZnCl2 solution is 2, the activated carbon yield reached 33.1% and the decolorizing capacity for methylene blue is 202.5 mg/g, the product is used in treating Cr6+ solution(pH value 4.0, concentration 50 mg/L), its adsorption capacity of Cr6+ is 7.583 mg/g.

Abstract: Removal of Phthalate Easters (PAEs) by softstem bulrush carbon (SBC) in aqueous solution was studied. In this work, the effects of pH, adsorbent dosage (0.8-2.8g), and initial DMP concentration (20-100 mg/L) on the adsorption system were investigated. It turned out that the effective pH was 7.0 and the optimum adsorbent dose was 2.0 g/L. Equilibrium experimental data at 283, 293 and 308 K were better represented by Freundlich isotherm than Langmuir isotherm. In addition, adsorption kinetics was determined using pseudo-first-order model, pseudo-second-order model. The results indicated that the adsorption of DMP onto SBC followed pseudo-second-order model.

Abstract: Titania nanoparticles were anchored onto active carbon (AC) through a hydrothermal process to obtain TiO2/AC composites. The optimal TiO2 loading and hydrothermal pH were investigated. The prepared TiO2/AC composites were used as adsorbents for dibenzothiophene (DBT) from model fuel. The adsorption capacity of TiO2/AC composite in the optimal synthesis conditions has enhanced 12.4% compared with pure AC. The adsorbents were regenerated by toluene washing, and the TiO2/AC composite showed higher adsorptive capacity than AC even after three recycles. The pore structure and surface chemical proprieties of TiO2/AC composite and AC were also investigated by N2 adsorption-desorption isotherms and Beohm titration. The results indicate that the surface acidic sites of TiO2/AC may play an important role in the improved adsorption performance.

Abstract: The activated carbons(AC) with high specific area were used widely as the electrode materials for the supercapacitors. Here we report the synthesis of nano-activated carbon electrode materials with different pore size distributions by vibration milling at room temperature. The size of the active carbon particles decreased from 20 to 30~50nm depended on the experimental conditions, and the particle distribution became more reasonable. The influence of important preparation technique condition(milling time， exciting frequency， vibration additive) on the nm-AC microstructure were found. Based on SEM, AFM, XRD and BET tests, we experienced the microstructure (crystalline, surface area, pore volume, pore size) of the nm-AC materials. It is found that manganese oxide as milling additive has more notable influence on improvement of material microstructure. Active carbon samples can gain more mesopores in shorter milling time and higher exciting frequency is useful to sample microstructure improvement. In short time，we can gain mesopore structure suitable nano-activated carbon electrode materials through vibration milling method.

Abstract: Activated carbons (ACs) were prepared by microwave−assisted heating of bituminous coal with KOH as activation agent in different gas media for supercapacitors. The pore structure parameters of ACs are obtained by using nitrogen adsorption technique. ACs prepared in static nitrogen, flowing nitrogen and carbon dioxide are denoted as ACStatic-N2, ACFlowing-N2, ACFlowing-CO2. The specific surface area of ACFlowing-N2 is the biggest among the three ACs, which reaches 1201 m2g-1 with total pore volume being at 0.64 cm3 g-1. The specific capacitance of ACFlowing-N2 electrode and energy density of ACFlowing-N2 capacitor is the biggest among the three AC samples with specific capacitance being at 302.6 F g-1 and energy density being at 10.1 Wh kg-1 after 400 cycles. The microwave−assisted KOH activation of coal is an efficient approach to the preparation of ACs for supercapacitors.

Abstract: In this article, the sludge-based activated carbon was prepared by the sewage sludge from the municipal wastewater treatment plants with ZnCl2 as the activator. The concentration of the activator was 30% and the pyrolysis temperature and duration were 500°C and 1 hour, respectively. The yield of sludge-based activated carbon was 30.14% with 4.66% ash. Under the best preparation condition, carbon content would be highest and the pore structure would be clear. The sludge-based activated carbon was mainly composed of mesopores. The main adsorption peaks of the sludge-based activated carbon were C-O-C (1078.3 cm-1), C=C（1568.7 cm-1）and –OH（3190.9 cm-1）groups.