The evolution of the pore structure of coconut shells during the preparation of coconut shell-based activated carbons

2008 ◽  
Vol 112 (1-3) ◽  
pp. 284-290 ◽  
Author(s):  
Osei-Wusu Achaw ◽  
George Afrane
Keyword(s):  
Pore Structure ◽  
Activated Carbons ◽  
Coconut Shell ◽  
Coconut Shells

scholarly journals Surface Modification and Characterization of Coconut Shell-Based Activated Carbon Subjected to Acidic and Alkaline Treatments

2017 ◽  
Vol 4 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Tan I. A. W. ◽  
Abdullah M. O. ◽  
Lim L. L. P. ◽  
Yeo T. H. C.
Keyword(s):  
Activated Carbon ◽  
Surface Morphology ◽  
Surface Chemistry ◽  
Pore Structure ◽  
Surface Area ◽  
Functional Groups ◽  
Activated Carbons ◽  
Coconut Shell ◽  
Bet Surface Area ◽  
Textural Characterization

Activated carbon derived from agricultural biomass has been increasingly recognized as a multifunctional material for various applications according to its physicochemical characteristics. The application of activated carbon in adsorption process mainly depends on the surface chemistry and pore structure which is greatly influenced by the treatment method. This study aims to compare the textural characteristics, surface chemistry and surface morphology of coconut shell-based activated carbon modified using chemical surface treatments with hydrochloric acid (HCl) and sodium hydroxide (NaOH). The untreated and treated activated carbons were characterized for their physical and chemical properties including the Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and textural characterization. The FTIR spectra displayed bands confirming the presence of carboxyl, hydroxyl and carbonyl functional groups. The Brunauer–Emmett–Teller (BET) surface area of the untreated activated carbon was 436 m2/g whereas the surface area of the activated carbon modified using 1M NaOH, 1M HCl and 2M HCl was 346, 525 and 372 m2/g, respectively. SEM micrographs showed that many large pores in a honeycomb shape were clearly found on the surface of 1M HCl sample. The pore structure of the activated carbon treated with 2M HCl and NaOH was partially destroyed or enlarged, which decreased the BET surface area. The modification of the coconut shell-based activated carbon with acidic and alkaline treatments has successfully altered the surface functional groups, surface morphology and textural properties of the activated carbon which could improve its adsorptive selectivity on a certain adsorbate.

Pore structure of the activated coconut shell charcoal carbon

2014 ◽  
Author(s):  
E. Budi ◽  
H. Nasbey ◽  
B. D. P. Yuniarti ◽  
Y. Nurmayatri ◽  
J. Fahdiana ◽  
...  
Keyword(s):  
Pore Structure ◽  
Coconut Shell

scholarly journals Adsorption Characteristics and Pore Structure of Activated Carbons Prepared from Sorghum Distillery Residue

2015 ◽  
Vol 60 (1) ◽  
pp. 173-182
Author(s):  
Han Chien Lin ◽  
Jhih–Siang Hu ◽  
Wen-Ju Lee ◽  
Chia-Wen Peng ◽  
Lai ,Ying–Jang ◽  
...  
Keyword(s):  
Pore Structure ◽  
Activated Carbons ◽  
Adsorption Characteristics

scholarly journals INVESTIGATION OF THE SORPTION CHARACTERISTICS OF ACTIVATED CARBONS

2021 ◽  
Vol 2 (446) ◽  
pp. 105-109
Author(s):  
A.E. Ilyassov ◽  
A.О. Baikonurova ◽  
B.N. Surimbayev
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Raw Materials ◽  
Reference Sample ◽  
Heap Leaching ◽  
Gold Content ◽  
Coking Coal ◽  
Industrial Facilities ◽  
Coconut Shells ◽  
Sorption Characteristics

The article presents the results of a comparison of the sorption characteristics for gold of crushed activated carbon of the foreign Haycarb brand, obtained from expensive raw materials - coconut shells, and crushed activated carbon of the domestic Shubarkol brand, obtained from relatively cheap raw materials - low-ash coking coal. The activated carbon Shubarkol crushed to a class of -3.6+1.0 mm, was produced in Kazakhstan from coking coal by Shubarkolkomir JSC. To test the crushed coal Shubarkol, industrial crushed coal Haycarb, made from coconut shells, was used as a reference sample. This coal is widely used in gold mining enterprises for the sorption of dissolved gold from cyanide solutions and pulps. For research, a productive solution of the process of heap leaching of gold from oxidized ore of one of the deposits of Kazakhstan was used with the composition, mg/L: gold 0.82; silver 0.44; copper 8.34; pH 11.05. Determination of the sorption characteristics of coals was carried out by the method of saturation with gold when changing solutions. The results of changes in the gold content in the mother solution, its extraction and saturation of coals with precious metal after each sorption cycle from the productive heap leaching solution using crushed coals of the Shubarkol and Haycarb brands are presented. It follows from the obtained data that Shubarkol activated carbon has similar sorption characteristics compared to Haycarb activated carbon. The working capacity for gold of Shubarkol coal was 2.28 kg/ton of sorbent, and of Haycarb coal - 2.57 kg/ton. Thus, crushed coal Shubarkol, obtained from relatively cheap raw materials, can be successfully used at industrial facilities instead of foreign sorbent.

scholarly journals Effect of Ammonia Activation and Chemical Vapor Deposition on the Physicochemical Structure of Activated Carbons for CO2 Adsorption

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 801
Author(s):  
Liu ◽  
Li ◽  
Dong ◽  
Li ◽  
Feng ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Pore Structure ◽  
Nitrogen Content ◽  
Vapor Deposition ◽  
Co2 Adsorption ◽  
Activated Carbons ◽  
Chemical Vapor ◽  
Physical Activation ◽  
Adsorption Performance ◽  
Physicochemical Structure

Focusing on the bottlenecks of traditional physical activation method for the preparation of activated carbons (ACs), we established a simple and scalable method to control the physicochemical structure of ACs and study their CO2 adsorption performance. The preparation is achieved by ammonia activation at different volume fractions of ammonia in the mixture (10%, 25%, 50%, 75%, and 100%) to introduce the nitrogen-containing functional groups and form the original pores and subsequent chemical vapor deposition (CVD) at different deposition times (30, 60, 90, and 120 min) to further adjust the pore structure. The nitrogen content of ACs-0.1/0.25/0.5/0.75/1 increases gradually from 2.11% to 8.84% with the increase of ammonia ratio in the mixture from 10% to 75% and then decreases to 3.02% in the process of pure ammonia activation (100%), during which the relative content of pyridinium nitrogen (N-6), pyrrolidine (N-5), and graphite nitrogen (N-Q) increase sequentially but nitrogen oxygen structure (N-O) increase continuously. In addition, ACs-0.5 and ACs-0.75, with a relatively high nitrogen content (6.37% and 8.84%) and SBET value (1048.65 m2/g and 814.36 m2/g), are selected as typical samples for subsequent CVD. In the stage of CVD, ACs-0.5-60 and ACs-0.75-90, with high SBET (1897.25 and 1971.57 m2/g) value and an appropriate pore-size distribution between 0.5 and 0.8 nm, can be obtained with the extension of deposition time from 60 to 90 min. The results of CO2 adsorption test indicate that an adsorption capacity of ACs-0.75-90, at 800 mmHg, is the largest (6.87 mmol/g) out of all the tested samples. In addition, the comparison of CO2 adsorption performance of tested samples with different nitrogen content and pore structure indicates that the effect of nitrogen content seems to be more pronounced in this work.

scholarly journals Thermodynamic Behaviors of Adsorbed Methane Storage Systems Based on Nanoporous Carbon Adsorbents Prepared from Coconut Shells

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2243
Author(s):  
Ilya Men’shchikov ◽  
Andrey Shkolin ◽  
Evgeny Strizhenov ◽  
Elena Khozina ◽  
Sergey Chugaev ◽  
...  
Keyword(s):  
Storage Tank ◽  
Activated Carbons ◽  
Storage System ◽  
Nitrogen Adsorption ◽  
Methane Adsorption ◽  
Carbon Adsorbents ◽  
X Ray ◽  
Coconut Shells ◽  
Activation Conditions ◽  
Charge Discharge

The present work focused on the experimental study of the performance of a scaled system of adsorbed natural gas (ANG) storage and transportation based on carbon adsorbents. For this purpose, three different samples of activated carbons (AC) were prepared by varying the size of coconut shell char granules and steam activation conditions. The parameters of their porous structure, morphology, and chemical composition were determined from the nitrogen adsorption at 77 K, X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), and scanning electron microscopy (SEM) measurements. The methane adsorption data measured within the temperature range from 178 to 360 K and at pressures up to 25 MPa enabled us to identify the most efficient adsorbent among the studied materials: AC-90S. The differential heats of methane adsorption on AC-90S were determined in order to simulate the gas charge/discharge processes in the ANG system using a mathematical model with consideration for thermal effects. The results of simulating the charge/discharge processes under two different conditions of heat exchange are consistent with the experimentally determined temperature distribution over a scaled ANG storage tank filled with the compacted AC-90S adsorbent and equipped with temperature sensors and heat-exchanger devices. The amounts of methane delivered from the ANG storage system employing AC-90S as an adsorbent differ from the model predictions by 4–6%. Both the experiments and mathematical modeling showed that the thermal regulation of the ANG storage tank ensured the higher rates of charge/discharge processes compared to the thermal insulation.

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