Adsorption characteristics of bamboo activated carbon

Dye is difficult to remove from aqueous solution with common adsorbents due to its large molecular size. Mesoporous bamboo activated carbon is utilized in the adsorption of Black 5, Red E and phenol. The adsorption performance of the carbon is experimentally examined along with the characterization of the adsorbent. The comparison of adsorption capacity of the bamboo activated carbon with that of coconut activated carbon and carbon cryogel indicates that the large volume of mesopore in the carbon helps the expansion of adsorption capacity. Microscopic observation, the measurement of pore characteristics and fitting to the adsorption isotherms are conducted in the characterization of the bamboo activated carbon.     

Preparation and adsorption performances of mesopore-enriched bamboo activated carbon

Activated carbon with high specific surface area and considerable mesopores was prepared from bamboo scraps by phosphoric acid activation. The effect of activation conditions was studied. Under the conditions of impregnating bamboo with 80% H₃PO₄ at 80°C for 9 days and activation at 500°C for 4 h, the prepared activated carbon had the highest mesopore volume of 0.67 cm³/g, a specific surface area of 1567 m²/g, and the mesopore ratio reached 47.18%. The study on adsorption isotherms of CH₄, CO₂, N₂ and O₂ on the activated carbon were carried out at 298 K. The considerable difference in the adsorption capacity between CO₂ and the other gases was observed, which would be of interest for the adsorptive separation/purification of gaseous CO₂ from its mixtures, especially from mixtures with N₂ and/or O₂.     

Adsorption of acid dyes by bamboo derived activated carbon

Bamboo, indigenous to Hong Kong and China, is widely used as scaffolding in construction and building projects. However, over 50,000 tonnes of bamboo scaffolding waste is disposed as landfill waste each year. Nevertheless, these wastes can be used as raw materials for the production of a range of high value added activated carbons. The bamboo cane can be heated (charred) at a high temperature in the presence of selected activation chemicals to produce activated carbons for various applications e.g. adsorbents, catalysts or catalyst supports. In the present study, activated carbons produced by thermal activation of bamboo with phosphoric acid were used for adsorption of acid dyes. Two acid dyes with different molecular sizes were used, namely Acid Yellow 117 (AY117) and Acid Blue 25 (AB25). It was found that dye with smaller molecular size, AB 25, was readily adsorbed onto the carbon while the larger size dye, AY117, showed little adsorption. It is possible to tailor-make the carbon for the adsorption of dye mixtures in industrial applications, especially textile dyeing. Furthermore, experimental results were fitted to equilibrium isotherm models, Langmuir, Freundlich and Redlich-Peterson.     

Preparation and adsorption performances of mesopore-enriched bamboo activated carbon

Activated carbon with high specific surface area and considerable mesopores was prepared from bamboo scraps by phosphoric acid activation. The effect of activation conditions was studied. Under the conditions of impregnating bamboo with 80% H₃PO₄ at 80°C for 9 days and activation at 500°C for 4 h, the prepared activated carbon had the highest mesopore volume of 0.67 cm³/g, a specific surface area of 1567 m²/g, and the mesopore ratio reached 47.18%. The study on adsorption isotherms of CH₄, CO₂, N₂ and O₂ on the activated carbon were carried out at 298 K. The considerable difference in the adsorption capacity between CO₂ and the other gases was observed, which would be of interest for the adsorptive separation/purification of gaseous CO₂ from its mixtures, especially from mixtures with N₂ and/or O₂. __________ Translated from Journal of Functional Materials, 2008, 39(3): 420–423 [译自: 功能材料]     

Facile synthesis of activated carbon/carbon nanotubes compound for supercapacitor application

A large number of carbon nanotubes (CNTs) have been produced commingled in activated mesocarbon microbeads (AMCMBs) activated by potassium hydroxide in a stainless steel container at 900 °C, in which an especial buried-protection method with petroleum coke powders was used to protecting the product during activation. The CNTs were found to be about 50 nm in diameter and characteristic length more than 10 μm. In addition, the AMCMBs/CNTs compound when used for electrode material of electrochemical double-layer capacitors exhibited a specific capacitance of 243 F g^?1 in 6 M KOH aqueous solution.     

The effect of biological studies of polyester composites filled carbon black and activated carbon from bamboo (Gigantochloa scortechinii)

The development of composites using various filler material increased significantly nowadays. Composite materials need to implement the biological and mechanicals impact in their life cycle. The carbon black (CB) and activated carbon (AC) from bamboo (Gigantochloa scortechinii) were used as filler in polyester composites. CB and AC were pyrolized to 700°C and activated with ZnCl₂. The composites were prepared with 40% filler loading. The degradation of the composites CB and AC (mechanical properties) to the soil burial test was determined. Tensile, flexural, impact and mass changes of the buried samples were investigated. The deterioration of the samples affected by the biological attack was confirmed by SEM studies. The assessment was done after 0, 3, 6, and 12 months of the biological exposure and the results were compared with the composites filled CaCO₃ (commercial filler) and cast polyester resin (as control). POLYM. COMPOS. 28:6–14, 2007. © 2007 Society of Plastics Engineers     

孔隙发达竹质活性炭的制备及其电化学性能

以毛竹废料为原料采用磷酸活化法制备了孔隙发达的活性炭,根据77 K氮气吸附等温线对其结构性质进行了表征.以具有最高比表面积的活性炭为电极材料组装双电层电容器,测试了其充放电性质和循环伏安特性.实验结果表明:在实验考察范围内,活化所得产品具有较高比表面积(1485～2127 m2/g)并含有大量中孔,中孔体积为0.43～0.67 cm3/g,活性炭总孔容最高达1.53 cm3/g.以活性炭为电极材料的双电层电容器具有良好的充放电性能和功率特性,电极比电容达197 F/g.     

Direct synthesis of carbon nanofibers on modified biomass-derived activated carbon

Carbon nanofibers were synthesized on activated carbons produced from agricultural waste using chemical vapor deposition. Importantly, iron already present in the ash content of the activated carbon was employed as a natural catalyst for nanofiber formation. The need for a wet chemical catalyst preparation step was avoided.     

Dimethyl carbonate synthesis from methyl nitrite and CO over activated carbon supported Wacker-type catalysts: The surface chemistry of activated carbon

A series of supported Wacker-type catalysts under treatment of nitric acid were prepared and utilized in the synthesis of dimethyl carbonate from CO and methyl nitrite. Nitrogen adsorption, Boehm titration, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and H₂-temperature-programmed reduction (H₂-TPR) were employed to explore the relationship between the physicochemical properties and reactivity of catalysts. Correlated with the results of Boehm titration, it was found that catalytic activities increased monotonically with the number of phenolic group on activated carbon surface. XPS spectra showed that the catalysts, which had much more amount of phenolic group, were possessed of large amount of Cu^2 + species. H₂-TPR results indicated that the phenolic group contributed to the easier reducibility of Cu^2 + species, further facilitating the oxidation cycle between Pd and Cu species and consequently the catalytic performance.     

Thermal plasma synthesis of Si/SiC nanoparticles from silicon and activated carbon powders

In this study, Si/SiC nanocomposites were synthesized by non-transferred arc thermal plasma processing of micron-sized SiC powder. First, micron-sized SiC was synthesized by solid-state method where waste silicon (Si) and activated carbon (C) powder were used as precursor materials. The effect of Si/C mole ratio and solid-state synthesis temperature on structural and phase formation of SiC was investigated. Diffraction pattern confirmed the formation of SiC at 1300 °C. High C content was required for the synthesis of pure SiC as Si remained unreacted when Si/C mole ratio was below 1/1.5. Highly agglomerated micron-size (0.6–10 µm) SiC particles were formed after solid-state synthesis. Thermal plasma processing of solid-state synthesized micron-sized SiC resulted into the formation of uniformly dispersed (20–60 nm) Si/SiC nanoparticles. It was proposed that Si/SiC nanocomposites were formed due to partial decomposition of SiC during high temperature plasma processing. The formation of Si/SiC nanoparticles from micron-sized SiC was resulted from dissociation of grains from their grain boundary during plasma processing.     

活性炭载体对钌催化剂制备及其活性的影响

选择 5 种活性炭作为载体制备负载型钌催化剂，采用元素分析、物理吸附和化学吸附等表征手段，考察活性炭载体的化学组成和表面结构对钌催化剂金属分散状况的影响。以不同活性炭为载体制备了一系列钡助催钌催化剂，并在450 ℃、10.0 MPa条件下进行氨合成活性评价。研究结果表明，活性炭载体的原材料及其制备工艺决定了载体的化学组成和表面结构，以具有高纯度、较大比表面积、较大比孔容和适当孔结构分布的活性炭为载体制备的钌催化剂具有较高的氨合成催化活性。     

二氧化碳再生乙酸乙烯合成用触媒载体活性炭

提出用二氧化碳活化法再生乙酸乙烯合成用触媒载体活性炭工艺。研究了活化温度、活化时间和二氧化碳流量对活性炭吸附性能和得率的影响。确定最佳工艺条件为活化温度1 273 K,活化时间100 m in,二氧化碳流量0.5 L/m in,在此条件下得到的活性炭碘吸附值为1 091.33 mg/g,乙酸吸附值为518.30 mg/g,强度为72%,活化得率为80.33%,并对制得的活性炭做了比表面积测定和孔结构分析。再生后的活性炭强度和乙酸吸附值均达到标准,符合乙酸乙烯合成用触媒载体活性炭的要求。     

CO_2活化生物质水解残渣制备活性炭的正交实验

以玉米秸秆酸水解残渣为原料、CO2为活化剂,制备了一系列活性炭,采用正交试验方法分析了原料颗粒大小、CO2/N2体积比、活化温度、活化时间4个因素对生物质水解残渣原料活性炭的比表面积、孔径和得率的影响。正交试验结果表明,活化温度和CO2/N2体积比是影响该类活性炭吸附性能的主要因素。制备的活性炭产品最大比表面积达到845.4m2/g,对应的制备工艺:原料颗粒50目、CO2/N2体积比1∶1、活化温度1000℃、活化时间210min。     

以纸巾为模板制备活性炭纤维

以纸巾为前驱体通过NaOH化学活化制备活性炭纤维,扫描电镜观测其微观结构为多孔纤维状。通过活性炭纤维对亚甲基蓝的吸附实验研究活性炭纤维吸附动力学,Pseudo-second-order方程比Pseudo-first-order方程更适于吸附数据模型,相关系数高达0.998,所制备活性炭纤维对亚甲基蓝最大平衡吸附量为200mg/g。