Analysis of bentonite specific surface area by kinetic model during activation process in presence of sodium carbonate

2011 ◽  
Vol 141 (1-3) ◽  
pp. 81-87 ◽  
Author(s):  
L. Karimi ◽  
A. Salem
Keyword(s):  
Kinetic Model ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sodium Carbonate ◽  
Activation Process

Effects of Carbonization on the Co-Activation of Sludge and Biomass to Produce Activated Coke

2021 ◽  
Vol 143 (10) ◽  
Author(s):  
Liwei Wang ◽  
Lin Lu ◽  
Minghua Li ◽  
Yulin Liu ◽  
Xiaohan Ren ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Functional Groups ◽  
Specific Surface Area ◽  
Proximate Analysis ◽  
Carbonization Temperature ◽  
Activation Method ◽  
Physical Activation ◽  
Activation Process ◽  
Activated Coke

Abstract Activated coke was prepared by mixing sewage sludge and waste poplar bark biomass from furniture manufacturing. The physical activation method of these feedstocks with steam for 1 h at 850 °C was implemented. The elemental composition, pore distribution, microstructure, and surface functional groups of the activated coke products were analyzed by proximate analysis, ultimate analysis, N2 adsorption, scanning electron microscopy, and Fourier transform infrared spectroscopy, respectively. The effects of different mixing ratios of sludge and biomass, preactivation carbonization temperature, and activation method on the activated coke were investigated. When the proportion of biomass was two-thirds of the total feedstock mass and the carbonization temperature was 300 °C, the produced activated coke had the highest specific surface area and the most extended micropore structure. Water vapor (steam) activation was found to be beneficial to the formation of oxygen-containing functional groups. This study established that steam is beneficial to pore expansion and promotes pore development. It was found that the carbonaceous feedstocks acquired initial porosity through carbonization in nitrogen, which proved to be instrumental in the ensuing activation process. After sequential carbonization and activation, the produced active coke acquired a higher specific surface area and microporosity, compared with the active coke produced by activation alone.

Production and characterization of lignocellulosic biomass-derived activated carbon

2010 ◽  
Vol 62 (11) ◽  
pp. 2637-2646 ◽  
Author(s):  
A. B. Namazi ◽  
C. Q. Jia ◽  
D. G. Allen
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Lignocellulosic Biomass ◽  
Specific Surface Area ◽  
Chemical Activation ◽  
Pulp Mill ◽  
Activation Process ◽  
Activation Temperature ◽  
Biomass Ratio

The goal of this work is to establish the technical feasibility of producing activated carbon from pulp mill sludges. KOH chemical activation of four lignocellulosic biomass materials, two sludges from pulp mills, one sludge for a linerboard mill, and cow manure, were investigated experimentally, with a focus on the effects of KOH/biomass ratio (1/1, 1.5/1 and 2/1), activation temperature (400–600°C) and activation time (1 to 2 h) on the development of porosity. The activation products were characterized for their physical and chemical properties using a surface area analyzer, scanning electron microscopy and Fourier transform infrared spectroscopy. Experiments were carried out to establish the effectiveness of the lignocellulosic biomass-derived activated carbon in removing methylene blue (MB), a surrogate of large organic molecules. The results show that the activated carbon are highly porous with specific surface area greater than 500 m2/g. The yield of activated carbon was greater than the percent of fixed carbon in the dry sludge, suggesting that the activation process was able to capture a substantial amount of carbon from the organic matter in the sludge. While 400°C was too low, 600°C was high enough to sustain a substantial rate of activation for linerboard sludge. The KOH/biomass ratio, activation temperature and time all play important roles in pore development and yield control, allowing optimization of the activation process. MB adsorption followed a Langmuir isotherm for all four activated carbon, although the adsorption capacity of NK-primary sludge-derived activated carbon was considerably lower than the rest, consistent with its lower specific surface area.

Batch and packed bed techniques for adsorptive aqueous phase removal of selected phenoxyacetic acid herbicide using sugar industry waste ash

2020 ◽  
Vol 18 (12) ◽  
Author(s):  
Sunil K. Deokar ◽  
Pooja G. Theng ◽  
Sachin A. Mandavgane
Keyword(s):  
Kinetic Model ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sugar Industry ◽  
Batch Process ◽  
Packed Bed ◽  
Breakthrough Curves ◽  
Isotherm Models ◽  
Phenoxyacetic Acid

AbstractBatch and packed bed adsorption of 4-chloro-2-methylphenoxyacetic acid (MCPA) herbicide was performed using bagasse fly ash (BFA) as an adsorbent. In batch process, characteristics of adsorbent, and the influence of adsorbent dosage, initial herbicide concentration, time, pH, particle size of adsorbent and temperature on adsorption were studied. Results disclose higher removal of MCPA on bigger particles of BFA owing to higher specific surface area because of greater carbon and lesser silica percentage in bigger particles. Application of isotherm models in present study indicates the best fitting of Langmuir and Temkin isotherms whereas the kinetic models suggest the suitability of pseudo second order and Elovich models. Thermodynamic study specifies the temperature preferred adsorption process. In packed bed technique, the effect of influent concentration, flow rate and bed height were investigated. The deactivation kinetic model which was previously considered only for studies in gas-solid adsorption is applied in this study to solid-liquid adsorption along with conventional packed bed models. In packed bed study, Bohart-Adams and Wolborska models are appropriate to explain the experimental data upto 60% saturation of the column. The deactivation kinetic model is found the best to elucidate the nature of breakthrough curves till the complete saturation of column. Batch capacity and packed bed capacity per m2 specific surface area of BFA is found about two and three times greater than the previously used adsorbents for MCPA respectively.

Preparation of Activated Carbon Fibers by Chemical Activation Method with Hydroxides

2006 ◽  
Vol 510-511 ◽  
pp. 750-753 ◽  
Author(s):  
Sook Young Moon ◽  
Myung Soo Kim ◽  
Hyun Sik Hahm ◽  
Yun Soo Lim
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Fibers ◽  
Chemical Activation ◽  
Lower Surface ◽  
Activation Process ◽  
Temperature Profiles ◽  
Activated Carbon Fibers

Activated carbon fibers were prepared from stabilized PAN-based fibers by chemical activation using hydroxides at different concentrations. The experimental data showed variations in specific surface area, microstructure, pore size distribution, and amounts of iodine adsorbed by the activated carbon fibers. Specific surface area of about 2244m2/g and iodine adsorption of 1202mg/g were obtained in the KOH 1.5M. However, the use of NaOH in the activation process rather than KOH and using the same time/ temperature profiles resulted in a carbon with a much lower surface area. KOH is a more developed pore structure than NaOH, which means that KOH is a better activation agent in producing ACF than NaOH.

scholarly journals CHARACTERISTICS OF NEW PROMISING BENTONITE COAL SORBENTS MODIFIED BY DIFFERENT COMPOUNDS

2021 ◽  
Vol 17 (3) ◽  
pp. 87-95
Author(s):  
Ilkhom Tagaev ◽  
Manzura Muratova ◽  
Lyudmila Andriyko ◽  
Mohigul Yusuf Kizi Boykhonova
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mechanical Stability ◽  
Low Cost ◽  
Industrial Process ◽  
High Strength ◽  
Activation Process ◽  
Carbon Sorbents

Introduction. Bentonite clays are traditional inexpensive and effective adsorbents that have a high potential for removing heavy metals from wastewater due to their abundance, chemical and mechanical stability, high exchange ability, and unique structural properties.Problem Statement. To obtain activated carbon, high-temperature muffle furnaces are used with the consumption of a large amount of electricity, which is economically unprofitable. In addition, the resulting sorbents must be in the form of granules or tablets, have high strength and the ability to be repeatedly used in technological processes.Purpose. Development of a method for the production of low-cost granular sorbents based on bentonite as amineral component, activated carbon, as well as natural production waste (sunflower husk, straw, sawdust, etc. as modifiers), which can be removed from the activation process to increase porosity of these materials.Materials and Methods. Angren brown coal; bentonite of the Navbakhor deposit was used as a sorbent and a basic substance for the granules formation; modifiers were sodium chloride, potassium, chopped straw, sawdust. Methods of thermal decarbonization and activation of the obtained granules under the optimal conditions (950 °С, 45 min) were applied; the bulk density, the specific surface area, pore types and their total volume was determined by optical microscopy and nitrogen adsorption methods.Results. Inexpensive hybrid bentonite-carbon sorbents in the form of high-strength granules were synthesized.The optimal ratio of the main components is Bentonite:Coal = 1 : 2, size (2.5 mm) and strength of granules (83—99%), total pore volume 0.863—1.01 cm3/g, confirmed the presence of macro-, meso- and micropores. The most promising sample has a specific surface area (Langmuir) 184 m2/g.Conclusions. The method for obtaining new effective granular carbon sorbents of low cost, having high sorption capacity relative to organic and inorganic pollutants for purification of industrial process waters has been proposed.

Preparation and Characterization of Mesoporous Activated Carbon Fiber

2011 ◽  
Vol 480-481 ◽  
pp. 6-10
Author(s):  
Yan Feng Yang ◽  
Xue Jun Zhang ◽  
Hai Yan Li
Keyword(s):  
Activated Carbon ◽  
Carbon Fiber ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Raw Materials ◽  
Activated Carbon Fiber ◽  
Activation Process ◽  
Cobalt Salt

General purpose pitch-based carbon fiber (PCF) was pretreated with steam to develop pores on the surface of fiber. After immersed in cobalt salt solution, PCF was used as raw materials to prepare activated carbon fiber (ACF) through steam activation process. The effect of pretreatment of carbon fiber on specific surface area, mesopore volume and pore size distribution was investigated by N2 adsorption, and morphology of the resultant ACF was observed with scanning electron microscope(SEM). The results show that pretreatment of PCF enlarges specific surface area and mesopore ratio of ACF remarkably. The best ACF obtained in experiment is the one with specific surface area of 2670 m2/g and mesoporosity of 61.8%. Cobalt has evident catalysis in preparing ACF from activation of PCF, while specific surface area and pore size of ACF get smaller with cobalt salt immersion when pretreatment is too strong.

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