Synthesis Of Activated Carbon Research Articles

Adsorption performance of activated carbon synthesis by ZnCl2, KOH, H3PO4 with different activation temperatures from mixed fruit seeds

ABSTRACT In this study, new activated carbons (ACs) were synthesized from a mixture of lemon and orange seeds (LOS) for toxic metal removal from aqueous solutions. Adsorbents have been produced by chemical activation with different activation agents (with H3PO4, ZnCl2 and KOH) and activation temperature (600°C, 700°C, 800°C). The elemental analysis, FT-IR, XRD and SEM analyses were performed to determine the characterization of the ACs. A series of batch adsorption experiments were done to research the influence of various parameters such as pH, adsorbent dosage, contact time, temperature, the complexing agents on the toxic metal ions (Cu(II), Cr(III) and Ni(II)) removal capacity of ACs. Adsorption equilibration time was 60 min, the adsorption capacity was 118.02 mg/g for Ni(II) ions, 146.03 mg/g for Cr(III) ions and 150.45 mg/g for Cu(II) ions. The adsorption of toxic metal ions was observed as a maximum at pH = 5 on AC-ZnCl2 (600°C) produced under N2 atmosphere. The adsorption process was fitted with a Langmuir isotherm model and a pseudo-second-order kinetic equation, showing the metal ions adsorption on AC was monolayer coverage. Thermodynamic studies show that the adsorption is endothermic and spontaneous in nature. AC produced from the LOS mixture has not been encountered in the literature. A simple, easy-to-apply method has been developed for a new adsorbent prepared from a mixture of LOS with environmentally friendly, easy to produce, reusable, cost-effective, non-toxic and with good adsorption-desorption capacity. Therefore, this study will contribute to the world economy in terms of environmental and wastewater cleaning.

Synthesis of ActivaTED Carbon from Plant Raw Materials by a Self-Activation Modified Method

In order to increase environmental safety and reduce the cost of production, a modified method of self-activation for the synthesis of activated carbon from plant wastes - cherry stones and wheat straw. A 5% solution of orthophosphate acid was used as an additional activator. Synthesis of activated carbon at temperatures of 600 °C, 700 °C and 800 °C was performed. It was found that coal from cherry stones has a production of 1.3-1.6 times higher than the production of activated carbon from wheat straw. The obtained coal was studied by electron microscopy and the method of isothermal adsorption / desorption of nitrogen. It is shown that all synthesized coal has a well-developed porous structure, which is determined mainly by micropores. An increase in the synthesis temperature leads to an increase in the specific surface area, the volume of micro-and mesopores and a decrease in the average pore radius. The reduction of the average pore radius for activated carbon from cherry stones occurs at lower temperatures compared to coal from wheat straw.

Yield Enhancement of Activated Carbon Palm Kernel Shells Based through Carbonization Solidification Process

Utilization of palm oil waste in palm kernel shells as activated carbon, the activated carbon manufacturing goes through several processes, including dehydration, carbonization, and activation. Palm shell particle size was controlled during the activated carbon synthesis process through the temperature of the milling time and carbonization processes. The carbonization process was carried out using an electric furnace at carbonization temperatures 400, 600, and 800 °C, respectively. A carbonization time was 1 hour under vacuum condition to produce initial values of particle and grain sizes that had a neat structure and had absorption capacity. The particle size of formed activated carbon was measured by PSA (particle size analyzer) type Coulter LS 100Q micron scale. The particle size of active carbon was dependent on the carbonization temperature at 400, 600, and 800 °C was obtained particle size 19,90, 9,507, and 6,264 μm, respectively. Several characterizations are required to determine the properties of activated carbon was obtained. FTIR Spectrophotometer was used to observe activated carbon’s molecule structure before and after dehydration and carbonization process. It was found that the specific fingerprint at 2913,91 cm-1 and 2923,56 cm-1 for the carbon chain of activated carbon. Other physical and chemical properties were conducted to investigate moisture content, thermal property, yield enhancement, and formed product appearance.

Synthesis of activated carbon in the presence of hydrochar from chickpea stalk and its characterization

In this study, hydrochar was obtained from chickpea stalk by hydrothermal method. Then, activated carbon was synthesized by chemical activation method using ZnCl2 activator in the presence of this hydrochar. The effects of parameters such as impragnation rate (hydrochar/ZnCl2), impragnation rate, activation temperature and activation time on activated carbon synthesis were investigated. The iodine number of the obtained activated carbon was determined and its characterization was performed by SEM, BET, FTIR measurements. It was determined that the highest iodine number of synthesized activated carbon was 734 mg/g under conditions of impragnation time (24 hour), impragnation rate (1/2), activation temperature (400 oC), and activation time (45 minutes). The BET surface area of the activated carbon with the highest iodine number was determined as 572 m2 /g. The methylene blue number of synthesized activated carbon and hydrochar were found as 105 mg/g and 45 mg/g, respectively.

Biowaste-Based Porous Adsorbent for Carbon Dioxide Adsorption

Activated carbon is known as one of the effective adsorbents in carbon dioxide adsorption, which is mainly attributed to its highly porous structure. Utilizing biowaste as the precursor for the activated carbon synthesis is considered as an attractive approach due to the biowaste being an inexpensive, renewable, abundant, and environmental-friendly material. This review article covers the various biowaste precursors used for activated carbon synthesis along with the comparison of its activating methods (which are physical and chemical activation). The relation between the activation methods and carbon dioxide adsorption performance is elucidated for better understanding. The functionalization of the biowaste-based activated carbon with basic nitrogen functionalizing agent as well as the challenges in the application of these adsorbents in carbon dioxide adsorption are also discussed.

Synthesis of multi-application activated carbon from oak seeds by KOH activation for methylene blue adsorption and electrochemical supercapacitor electrode

In the current study, an oak as a non-expensive, renewable, and a biomass resource was used to generate a nano-porous activated carbon applicable in methylene blue adsorption from wastewater and energy storage equipment. Furnace activation in the temperature range of 450, 550, 650 and 750 °C was used for activated carbon synthesis after infusion with potassium hydroxide. The synthesized activated carbon was characterized using different techniques including nitrogen adsorption/desorption, scanning electron microscopy, and fourier-transform infrared spectroscopy. The results showed that temperature has significant effect on activated carbon efficiency. Specific surface and pore volumes increased with the enhancement of temperature until 650 °C, but then it was decreased. Pores volume was consisting of mesoporous and microporous structure. The highest surface area (2896 m2/g) and pores volume (1.554 cm3/g) was obtained for the sample prepared at 650 °C. Freundlich isotherm model is appropriate for methylene blue adsorption isotherm by the synthesized activated carbon. The maximum adsorption capacity of MB was obtained as 24 mg/g. Moreover, the synthesized activated carbon exhibited the highest specific capacitance when it was used as electrode (551 F/g at current density of 1 A/g) in 1 M sulphuric acid electrolyte and 96% specific capacitance was remained after 5000 charge-discharge cycles at a current density of 10 A/g.

Low Cost Activated Carbon Synthesis, Characterization and Adsorption Applications

In this study, activated carbon was synthesis from peach kernel shell, which is an agricultural waste. The synthesized activated carbons were characterized and their adsorption properties were examined. Activated carbons were synthesized by physical activation method and CO2 was used as the activation gas. The synthesis was carried out in two steps. In the first step, it was subjected to carbonization process at 4 different temperatures. During the carbonization process, two different gas flow were used. In the activation process, a temperature of 800 ° C was used. The surface area and morphological properties of the obtained activated carbons were studied by BET, XRD, FTIR and elemental analyzes. Methylene blue was used during adsorption. The adsorption capacities of the samples were calculated.

Activated carbon processed from Citrus sinensis: Synthesis, characterization and application for adsorption-based separation of toxic pesticides from soils

ABSTRACT Citrus sinensis peels activated carbon synthesis was done by means of sulfuric acid activation. Activated carbon was analysed by SEM, XRD, UV-Vis and FT-IR. Two concentrations of pesticides; Thiencarbazone-methyl, Isopyrazam and Zoxamide were separated from ten agricultural and contaminated soils. Removal potential was evaluated for a time span of 3 and 6 hours. Maximum elimination was detected in soil S5 (65% and 92% for 5 mg/L and 7.5 mg/L, respectively) for Thiencarbazone-methyl, 89% and 96% for Isopyrazam and 84% and 88% for Zoxamide. Results of the current work supports the efficient removal achieved with the prepared activated carbon.

Activated carbon synthesis from tangerine peel and its use in hydrogen storage

Activated carbon samples were synthesized by chemical and physical activations of tangerine peel. The activated carbons were characterized via using Fourier Transform Infrared-Attenuated Total Reflectance spectroscopy (FTIR-ATR), Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET), Differential Thermal Analysis-Thermogravimetry (DTA/TG) techniques. It was found that the activated carbon samples were porous, and their surface areas were increased by treating with the various concentrations of ZnCl2 and KOH. After the formation of activated carbons, they turned into a structure that was formed from carbon atoms, and their residual amounts decreased. In addition, the hydrogen storage capacities of the activated carbon samples were measured in different pressures at 77 and 298 K using the Hiden IMI PSI instrument. The results, confirmed that the hydrogen storage capacities of the activated carbons were higher at the cryogenic temperatures, and higher hydrogen storage capacity were observed by the increasing concentrations of activation agents in the synthesized activated carbons. The activated carbons synthesized by ZnCl2 had higher hydrogen storage capacity than those by KOH.

Iron-Incorporated Activated Carbon Synthesis from Biomass Mixture for Enhanced Arsenic Adsorption

This study discusses synthesis and characterization of iron-incorporated activated carbon (MAC) from biomass mixture by FeSO4 impregnation and subsequently pyrolysis, and its application in arsenic adsorption from aqueous solution. The textural, morphological, and structural properties were determined with BET surface area, total pore volume, average pore size, pHpzc, XRD, VSM, and SEM-EDX analysis. The results showed that the MAC has 375.32 m2/g surface area and 0.2391 cm3/g of total pore volume and contains a single iron compound in the magnetite structure. Arsenic removal efficiency was evaluated depending on MAC dosage, pH, contact time, and As(V) concentration. The data was analyzed by Freundlich and Langmuir isotherms. Also, pollution potential of the adsorption residue was examined by TCLP. 10 mg/l of As(V) in the solution could be removed in the presence of 1.5 g/l of MAC at pHs above 2.5 for 60 min. As(V) adsorption fitted better to the Langmuir isotherm, and adsorption capacity was found to be 42.92 mg/g. It has been found that the adsorption residue has no potential pollutants; thus, they are safe for regular landfill waste disposal. The results suggested that FeSO4 impregnation and subsequently pyrolysis were suitable process for synthesis of MAC from biomasses for arsenic adsorption.

High porosity activated carbon synthesis using asphaltene particles

The study aims to use asphaltene particles (As) extracted from natural bitumen to synthesize activated carbon (ACAs). The asphaltene particles were mixed with a fixed weight of potassium hydroxide (KOH) as an activating agent, preheated to 600 °C, and then treated with 15% hydrofluoric acid (HF). The methylene blue (MB) 20 mg/l was used to determine the adsorption capacity of ACAs and reactivated carbon (RACAs). The morphology of ACAs and its components were characterized using scanning electron microscopy–energy dispersive X-ray (SEM–EDX) and Fourier-transform infrared spectroscopy (FTIR). The study included the application of adsorption isotherms Freundlich and Langmuir on the experimental data of the studied systems. The yield of ACAs was 92% of the raw material. The activated carbon displayed high adsorption capacity and can be reprocessed after reactivation using microwave radiation. The active surface area of ACAs is found to be 970 m2/g. The effectiveness and adsorption ability of ACAs and RACAs, as proven by its adsorption capacity (218.15 and 217.907 mg/g) for MB, demonstrate that ACAs and RACAs have a large external surface area and an extensive array of pores. The ACAs are most sensitive at 30 °C and neutral pH. The results also showed that the isotherms have a good fit to the experimented data.

Synthesis and characterization of high-quality activated carbons from hard-shelled agricultural wastes mixture by zinc chloride activation

In this study, a mixture apricot and peach stones, and almond shell, which are hard-shelled agricultural wastes, was evaluated as a precursor for activated carbon synthesis. Effects of the impregnation and pyrolysis conditions on ACs synthesis were investigated. The ACs were characterized by surface area, pore size, pore volume, surface functional groups by Boehm’s titration and FTIR analysis, ash content, pHpzc, and SEM-EDX. It has been found that the impregnation conditions and pyrolysis temperature have important effect on the microspores formation. ACs having specific surface area in the range of 1,125.73–2,073.04 m2g−1 and total pore volumes in the range of 0.5498–1.0918 cm3 g−1 can be synthesized from the mixture activated by ZnCl2 at impregnation ratios of higher than 15/40. These values are higher than those of the most commercial ACs. Therefore, it can be concluded that the mentioned wastes mixture is a promising precursor for producing high-quality ACs.

Grape stalk application for caffeine removal through adsorption

Concern over emerging pollutants presence in water resources is growing, justifying the search for alternative or additional techniques to those applied in conventional water treatment processes. Use of adsorption with agricultural wastes directly as adsorbents or as precursors for activated carbon synthesis is a viable method, combining removal efficiency, low cost and biodegradability of the material applied. This study investigated the employability of grape stalk, a waste from grape industrialization process without effective use, in caffeine removal from aqueous solution. Grape stalk was used in three different forms: raw with only grain size adjustment (GS), modified by phosphoric acid action (MGS) and as activated carbon (GSAC). In the first two cases parameters pH, residence time and adsorbent concentration were varied in order to find optimum batch process conditions. For GSAC, on the other hand, caffeine removal percentages were high even for the least amount of adsorbent that could be measured with acceptable accuracy, which did not justify concentration parameter variation. Better adsorption capacities were observed in acidic solutions, with optimum pH values being considered as 2.0 for GS and MGS and 4.0 for GSAC. Optimum residence time and adsorbent concentration were 40 min and 25 g L−1 (GS), 30 min and 15 g L−1 (MGS) and 30 min (GSAC). Moreover, equilibrium was evaluated through adsorption isotherms construction, which were best represented by Sips model, displaying determination coefficients R2 equal to 0.994, 0.999 and 0.987 and maximum adsorption capacities equal to 89.2, 129.6 and 916.7 mg g−1. Adsorbents particular characteristics such as specific surface areas and micropore volumes were also determined, resulting in 6.23, 4.21 and 1099.86 m2 g−1 and 0.003, 0.002 and 0.568 cm3 g−1 for GS, MGS and GSAC, respectively.

Effect of the conditions of activated carbon synthesis from wood on its porous structure and the specific characteristics of double layer supercapacitors with a sulfuric acid-based electrolyte

For supercapacitors with sulfuric acid electrolyte, a promising carbon material was suggested, namely, activated carbon from waste wood. It was shown how the synthesis conditions of activated carbon affect its porous structure and electrochemical characteristics of supercapacitors on its basis. The changes in the porous material under different synthesis conditions were controlled using the highly informative limited evaporation method, which allows us to obtain complete information about the porous structure of the micro- and mesopores of the material within a relatively short period of time. The negative effect of the excess volume of macropores in the electrode on the capacity and energy based on the dry mass of electrodes was shown experimentally and analyzed. The properties of the synthesized material were compared with those of other carbon materials. The best samples of the developed material possess a specific electric capacity of over 390 F/g.

Evaluation of the adsorption potential of eco-friendly activated carbon prepared from cherry kernels for the removal of Pb2+, Cd2+ and Ni2+ from aqueous wastes

Development, characterization and evaluation of the efficiency of cost-effective medium for the removal of Pb2+, Cd2+ and Ni2+ from aqueous systems, as a novel, eco-friendly solution for wastewater remediation were done. The precursors for low-cost adsorbent were lignocellulosic raw materials (sweet/sour cherry kernels), as industrial byproducts and components of organic solid waste. Activated carbon synthesis was carried out by thermochemical conversion (H3PO4, 500 °C) in the complete absence of inert atmosphere. Characterization of the activated carbon was performed by elemental analysis, FTIR, SEM, EDX and BET. BET surface area corresponds to 657.1 m2 g−1. The evaluation also included the influence of pH, contact time, solute concentration and adsorbent dose on the separation efficiency in the batch operational mode. The equilibrium and kinetic studies of adsorption were done. The maximum adsorption capacity of the activated carbon for Cd2+ ions was calculated from the Langmuir isotherm and found to be 198.7 mg g−1. Adsorption of Pb2+ and Ni2+ were better suitable to Freundlich model with the maximum adsorption capacity of 180.3 mg g−1 and 76.27 mg g−1, respectively. The results indicate that the pseudo-second-order model best describes adsorption kinetic data. Based on desorption study results, activated carbon was successfully regenerated with HNO3 for 3 cycles. In order to provide the results for basic cost-effective analysis, competing ion-effects in a real sample have been evaluated.

Experimental Study and Artificial Neural Networks Simulation of Activated Carbon Synthesis in Fluidized Bed Reactor

In this work, thermal activation of pistachio shell was studied in a fluidized bed reactor. The effects of operating conditions on the pore development within the char particles were studied experimentally. The results showed that activation temperature, residence time, oxidizing gas type and concentration have main effects on the Iodine adsorption capacity of the product. The highest surface area was obtained using steam activation at temperature 850°C for 45 min. The synthesis process was also simulated using artificial neural networks (ANNs) to estimate the Iodine number of the product. The present work applied a Tan-sigmoid transfer function in three layers in the feed forward neural network with back propagation algorithm. The results of the network are in good agreement with the experimental data with a maximum relative deviation of 0.015%.

Relationship between reflectance and structure of high surface area carbons

Reflectance measurements have been used to try to track the structural alterations during activated carbon synthesis by chemical activation. H 3PO 4 has been used as a chemical reagent with white oak, subbituminous coal and a bituminous coal, and KOH with a bituminous coal. The reflectance of thermally treated carbons follows a single correlation with heat treatment temperature (HTT), consistent with thermally induced increases in aromaticity and structural order. For chemically activated carbons, the relationship between reflectance and HTT depends upon the precursor-activant combination that is used. At low HTT, chemically activated carbons have higher reflectance than their thermally treated counterparts, due to accelerated chemical change. At higher HTT this situation is reversed, despite further increase in aromaticity. It is proposed that the development of significant porosity (principally in pores 2–50 nm in diameter) reduces the measured reflectance by contributing to the scattering of incident light.

Activated carbon synthesis from bituminous coals by chemical activation

Activated carbon synthesis from bituminous coals by chemical activation

Experimental optimization of activated carbon synthesis by the simplex search method

To compete with the low price of petrol, thermochemical conversion of biomass should be viewed as both an energy and chemical source. Catalytic pyrolysis can produce activated carbon as a chemical and energy as a by-product, if inexpensive catalysts are available. In this paper, two parameters, namely NaCl (used as catalyst) and temperature, were found to affect the quality of the activated carbon produced from coconut shell and sawdust. Without mathematical modelling of the process, the Simplex search method led to the following maximum iodine numbers: for coconut shell, 685·8 mg/g at 794°C and 3·15 g NaCl/g coconut shell; for sawdust, 581·1 mg/g at 751°C and 5·52 g NaCl/g sawdust.