scholarly journals Textural Development of Activated Carbon Prepared from Recycled PET with Different Chemical Activation Agents

2008 ◽  
Vol 587-588 ◽  
pp. 753-757 ◽  
Author(s):  
Isabel P.P. Cansado ◽  
Manuela M.L. Ribeiro Carrott ◽  
Peter J.M. Carrott ◽  
Paulo A.M. Mourão

Activated carbons (AC) were prepared from waste granulated Polyethyleneterephthalate (PET) by chemical activation with phosphoric acid, sodium hydroxide and potassium hydroxide. All AC were characterised by N2 adsorption at 77 K, and those prepared with H3PO4 had a narrow pore size around 0.8 nm, those prepared with NaOH had a larger pore size higher than 1.52 nm and those prepared with KOH presented a pore size varying between 0.66 and 1.58 nm. The results suggest that H3PO4 and NaOH are not the most suitable activating agents for preparing AC with a high pore volume from waste PET. The AC produced with KOH presented a very high porosity, which passed through a maximum of 0.75 cm3g-1, due to an enlargement of the small micropores with an increase of the carbonisation temperature.

2019 ◽  
Vol 60 (10) ◽  
pp. 99-109
Author(s):  
Kim Long Vu ◽  
◽  
Vitaly N. Klushin ◽  
Alexey V. Nistratov ◽  
Hoang Thi Tho ◽  
...  

The possibility of processing wastes based on organoplastics generated at aviation enterprises into activated carbons by chemical activation using potassium hydroxide has been investigated. Powdered and granular activated carbons with a porous structure, characterized by the predominance of micropores or mesopores, are obtained that are superior in many respects to both adsorbents based on organoplastics and most industrial active carbons. The specific surface area of micropores of the obtained granular activated carbons is 1716 m2/g, the absorption capacity is 365 mg/g for methylene blue and 1180 mg/g for iodine. The obtained granular activated carbons are characterized by a stable adsorption value of n-butanol (about 400 mg/g) during three successive adsorption-regeneration cycles. Desorption at 120±5 °C provides an almost complete restoration of the activity of this absorber, fundamentally allowing its multiple use in this technology. It is shown in the work that granular activated carbons of very high quality can be obtained by chemical activation with potassium hydroxide based on organoplastics wastes, the only drawback of which is, in essence, the relatively low (at 60%) abrasion resistance. The possibility of improving the quality properties of granular activated carbons by adding a small amount of carbon fiber (1% of the mass) as a reinforcing component in the process of granulation to raw paste was investigated. The specified method can significantly increase the strength of the granules in compression (about 3 times), while the adsorption properties of activated carbon are practically unchanged. The properties described above allow us to conclude that the obtained granular activated carbon is effective and highly competitive.


2019 ◽  
Vol 70 (2) ◽  
pp. 410-416 ◽  
Author(s):  
Tagne Tiegam Rufis Fregue ◽  
Ioana Ionel ◽  
Anagho Solomon Gabche ◽  
Alin-Cristian Mihaiuti

Avocado seeds based activated carbon was prepared using chemical activation method which consisted of potassium hydroxide treatment. The main factors influencing the preparation of activated carbons at the calcination temperature, the concentration of the activating agent and the duration of calcination were investigated. One used as a mathematical model the response surface methodology to correlate the response. The significant factors identified by the analysis of variance (ANOVA) through the t-test, the Pareto diagram and the diagrams of surfaces. The optimum avocado seeds based activated carbon was obtained by using calcination temperature of 450 oC, concentration of activating agent of 0.3 mol/L and time of calcination of 3.0 h, which resulted to an avocado seed based activated carbon iodine number remove of 1142.1 mg/g and yield of 75.09 %, by mass. The best activated carbon obtained under the previous conditions and the raw biomass was characterized by Fourier transform infrared and Scanning Electronic Microscope.


2017 ◽  
pp. 96-103 ◽  
Author(s):  
Gillian Eggleston ◽  
Isabel Lima ◽  
Emmanuel Sarir ◽  
Jack Thompson ◽  
John Zatlokovicz ◽  
...  

In recent years, there has been increased world-wide concern over residual (carry-over) activity of mostly high temperature (HT) and very high temperature (VHT) stable amylases in white, refined sugars from refineries to various food and end-user industries. HT and VHT stable amylases were developed for much larger markets than the sugar industry with harsher processing conditions. There is an urgent need in the sugar industry to be able to remove or inactivate residual, active amylases either in factory or refinery streams or both. A survey of refineries that used amylase and had activated carbon systems for decolorizing, revealed they did not have any customer complaints for residual amylase. The use of high performance activated carbons to remove residual amylase activity was investigated using a Phadebas® method created for the sugar industry to measure residual amylase in syrups. Ability to remove residual amylase protein was dependent on the surface area of the powdered activated carbons as well as mixing (retention) time. The activated carbon also had the additional benefit of removing color and insoluble starch.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2951
Author(s):  
Mirosław Kwiatkowski ◽  
Jarosław Serafin ◽  
Andy M. Booth ◽  
Beata Michalkiewicz

This paper presents the results of a computer analysis of the effect of activation process temperature on the development of the microporous structure of activated carbon derived from the leaves of common polypody (Polypodium vulgare) via chemical activation with phosphoric acid (H3PO4) at activation temperatures of 700, 800, and 900 °C. An unconventional approach to porous structure analysis, using the new numerical clustering-based adsorption analysis (LBET) method together with the implemented unique gas state equation, was used in this study. The LBET method is based on unique mathematical models that take into account, in addition to surface heterogeneity, the possibility of molecule clusters branching and the geometric and energy limitations of adsorbate cluster formation. It enabled us to determine a set of parameters comprehensively and reliably describing the porous structure of carbon material on the basis of the determined adsorption isotherm. Porous structure analyses using the LBET method were based on nitrogen (N2), carbon dioxide (CO2), and methane (CH4) adsorption isotherms determined for individual activated carbon. The analyses carried out showed the highest CO2 adsorption capacity for activated carbon obtained was at an activation temperature of 900 °C, a value only slightly higher than that obtained for activated carbon prepared at 700 °C, but the values of geometrical parameters determined for these activated carbons showed significant differences. The results of the analyses obtained with the LBET method were also compared with the results of iodine number analysis and the results obtained with the Brunauer–Emmett–Teller (BET), Dubinin–Radushkevich (DR), and quenched solid density functional theory (QSDFT) methods, demonstrating their complementarity.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2045
Author(s):  
Mirosław Kwiatkowski ◽  
Elżbieta Broniek ◽  
Vanessa Fierro ◽  
Alain Celzard

This paper presents the results of an evaluation of the impact of the amount of potassium hydroxide on the obtained porous structure of the activated carbons derived from the shells of pistachios, hazelnuts, and pecans by carbonization and subsequent chemical activation with potassium hydroxide by different adsorption methods: Brunauer–Emmett–Teller, Dubinin–Raduskevich, the new numerical clustering-based adsorption analysis, Quenched Solid Density Functional Theory, and 2D-Non-linear Density Functional Theory for Heterogeneous Surfaces, applied to nitrogen adsorption isotherms at −196 °C. Based on the conducted research, a significant potential for the production of activated carbons from waste materials, such as nut shells, has been demonstrated. All the activated carbons obtained in the present study at the activator/char mass ratio R = 4 exhibited the most developed porous structure, and thus very good adsorption properties. However, activated carbons obtained from pecan shells deserve special attention, as they were characterized by the most homogeneous surface among all the samples analyzed, i.e., by a very desirable feature in most adsorption processes. The paper demonstrates the necessity of using different methods to analyze the porous structure of activated carbons in order to obtain a complete picture of the studied texture. This is because only a full spectrum of information allows for correctly selecting the appropriate technology and conditions for the production of activated carbons dedicated to specific industrial applications. As shown in this work, relying only on the simplest methods of adsorption isotherm analysis can lead to erroneous conclusions due to lack of complete information on the analyzed porous structure. This work thus also explains how and why the usual characterizations of the porous structure of activated carbons derived from lignocellulosic biomass should not be taken at face value. On the contrary, it is advisable to cross reference several models to get a precise idea of the adsorbent properties of these materials, and therefore to propose the most suitable production technology, as well as the conditions of the preparation process.


2012 ◽  
Vol 1 (3) ◽  
pp. 75 ◽  
Author(s):  
W.D.P Rengga ◽  
M. Sudibandriyo ◽  
M Nasikin

Gas storage is a technology developed with an adsorptive storage method, in which gases are stored as adsorbed components on the certain adsorbent. Formaldehyde is one of the major indoor gaseous pollutants. Depending on its concentration, formaldehyde may cause minor disorder symptoms to a serious injury. Some of the successful applications of technology for the removal of formaldehyde have been reported. However, this paper presents an overview of several studies on the elimination of formaldehyde that has been done by adsorption method because of its simplicity. The adsorption method does not require high energy and the adsorbent used can be obtained from inexpensive materials. Most researchers used activated carbon as an adsorbent for removal of formaldehyde because of its high adsorption capacity. Activated carbons can be produced from many materials such as coals, woods, or agricultural waste. Some of them were prepared by specific activation methods to improve the surface area. Some researchers also used modified activated carbon by adding specific additive to improve its performance in attracting formaldehyde molecules. Proposed modification methods on activation and additive impregnated carbon are thus discussed in this paper for future development and improvement of formaldehyde adsorption on activated carbon. Specifically, a waste agricultural product is chosen for activated carbon raw material because it is renewable and gives an added value to the materials. The study indicates that the performance of the adsorption of formaldehyde might be improved by using modified activated carbon. Bamboo seems to be the most appropriate raw materials to produce activated carbon combined with applying chemical activation method and addition of metal oxidative catalysts such as Cu or Ag in nano size particles. Bamboo activated carbon can be developed in addition to the capture of formaldehyde as well as the storage of adsorptive hydrogen gas that supports renewable energy. Keywords: adsorption; bamboo; formaldehyde; modified activated carbon; nano size particles


2015 ◽  
Vol 74 (11) ◽  
Author(s):  
Riry Wirasnita ◽  
Tony Hadibarata ◽  
Abdull Rahim Mohd Yusoff ◽  
Zainab Mat Lazim

An oil palm empty fruit bunch-derived activated carbon has been successfully produced by chemical activation with zinc chloride and without chemical activation. The preparation was conducted in the tube furnace at 500oC for 1 h. The surface structure and active sites of activated carbons were characterized by means of Fourier transform infrared spectrometry and field emission scanning electron microscopy. The proximate analysis including moisture content, ash content, bulk density, pH, and pH at zero charge was conducted to identify the psychochemical properties of the adsorbent. The results showed that the zinc chloride-activated carbon has better characteristics compared to the carbon without chemical activation.  


2012 ◽  
Vol 626 ◽  
pp. 887-891 ◽  
Author(s):  
Mohd Fikri Mokhtar ◽  
Erny Haslina Abd Latib ◽  
Suriati Sufian ◽  
Ku Zilati Ku Shaari

This study presents the preparation of activated carbon from durian shell (DShAC) and durian seed (DSeAC) based by chemical activation with potassium hydroxide (KOH) as an activating agent under the nitrogen flow. In order to find the optimum physical characteristics, variation in concentration of KOH, carbonization temperature and duration time was employed. The result shows that activated carbon from durian waste is a promising activated carbon as the highest yield was obtained from the carbonization process that occurs at 400C for four hours with the KOH concentration is 0.6 M.


Author(s):  
A.A. Popova ◽  
I.N. Shubin

The article discusses significance of the development of activated carbon materials with a high specific surface area and high porosity. The features of the course of chemical activation and the factors influencing the characteristics of the obtained material have been established. The main stages of the activation of the carbon material, including the preliminary raw carbon material carbonization, its alkaline activation, and the post-processing of the created material, have been determined. The mutual influence of temperature and flow rate of an inert gas on the characteristics of a carbon material obtained with a BET specific surface in the range of 2550–2700 m2/g is experimentally investigated. The analysis of the obtained results has been carried out. Recommendations are given for reducing ambiguity and uncertainty during the transition from laboratory research to pilot production. The resulting activated carbon material can be used as a sorbent in gas purification systems, gas accumulators and for solving various environmental problems.


2021 ◽  
Vol 19 (7) ◽  
pp. 156-164
Author(s):  
Ennas Abdul Hussein ◽  
Asraa H. Aljbory ◽  
Sadiq J. Baqir ◽  
Ameera Hassan Hamed ◽  
Azal Shakir Waheeb ◽  
...  

Water pollution is one of the biggest problems facing us, so it requires the need to develop a very high-efficiency and inexpensive absorbent material from natural surfaces and compare it with expensive commercial sorbents. Where in this study an absorbent substance was prepared from the natural surfaces of Syzgium Aromaticum Flower Bud (SAFB), Nigella Sativa (NS) Converted to activated carbon to activated carbon Activated (SAFB), and Activated (NS), as these surfaces are characterized by high porosity, cheap price and very high efficiency in removing dye. The composite was illustrated via different analysis apparatus included FTIR, and FE-SEM, The adsorption result were fitted with Freundlich isotherms. The experimental kinetic result at different primary reactive green dye concentrations, were also analyzed through first model, second model and Elovich model. The obtained data appear that the model pseudo-first model fits the adsorption kinetic result through R2 0.96028, R2 0.9486, R2 0.9016 and R2 0.9620 of SAFB and ACTIVE-SAFB and Nigella Sativa (NS) and Activated (NS) in the same order.


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