Preparation Of Activated Carbon Research Articles

Activated carbon preparation from pistachio shell pyrolysis and gasification in a spouted bed reactor

Spouted bed technology was applied for the production of activated carbons from pistachio nut shells for the first time. Both of the pyrolysis and the gasification stages were carried out in the same spouted bed reactor. The produced bio-char and activated carbon were analyzed via scanning electron microscopy (SEM), Iodine number, and BET surface area. Temperature of 600 °C, hold time of 60 min, with particle size of 3.36–4.76 mm were the best conditions to produce a char with 430 m2 g-1. While the carbonization tests were carried out in a shorter time, BET surface area of the bio-chars were as large as those obtained in other reactors. BET surface area of the best produced activated carbon was 2596 m2 g−1 with the burn-off 90 % at temperature 850 °C and 20 min activation. A comparison was made between the activated carbon characteristics produced in spouted bed reactor with those obtained previously in fixed bed reactors. According to the results, spouted bed reactors are suitable equipment for performing the both carbonization and gasification stages thanks to excellent mixing and high circulation rates of the materials inside a spouted bed.

REMOVAL OF DYES (METHYLENE BLUE, MALACHITE GREEN, METHYL VIOLET) ON ACTIVATED CARBON PREPARED FROM COPPER POD FLOWER.

31Jul 2017 REMOVAL OF DYES (METHYLENE BLUE, MALACHITE GREEN, METHYL VIOLET) ON ACTIVATED CARBON PREPARED FROM COPPER POD FLOWER. N Saravanan and G Rathika. Department of Chemistry, Nandha Engineering College, Erode- 638 052, Tamil nadu, India. Department of Chemistry, PSG College of Arts and Science, Coimbatore-641 014, Tamil nadu, India.

Preparation and Characterization of Activated Carbon from Hydrochar by Phosphoric Acid Activation and its Adsorption Performance in Prehydrolysis Liquor

Hydrochar was used to produce activated carbon with high BET surface area and large pore volume via phosphoric acid activation. The hydrochar described here can be obtained from hydrothermal carbonization of corn cob residue (CCR). Porous structure of activated carbons was characterized by nitrogen adsorption and scanning electron microscopy (SEM). Results showed that the specific surface area and total pore volume of activated carbon were increased to 2192 m2/g and 1.269 cm3/g, respectively, under conditions of 400 °C, 1 h, and an impregnation ratio of 3, from 5.69 m2/g and 0.136 cm3/g of the starting material. The chemical properties of hydrochar and activated carbons were further characterized by Fourier transform infrared spectroscopy (FT-IR), which confirmed the chemical transformation. Furthermore, the localized graphitic nature of the porous carbon was shown by the X-ray diffraction pattern. Thus, the adsorption capacity was enhanced for activated carbon in comparison with commercial carbon. The process of activated carbon preparation provided a high value-added application of hydrochar.

Carbon material from polyvinyl chloride as an adsorbent of 2,4-dichlorophenoxyacetic acid

The adsorption of 2,4-dichlorophenoxyacetic acid (2,4-D) as a typical herbicide from aqueous solutions on activated carbons prepared based on polyvinyl chloride by its alkaline dehydrochlorination and the subsequent heat treatment was studied. The structure of the activated carbon surface and the presence of functional groups on it were established. The kinetics of the process of adsorption was studied. The influence of activated carbon preparation conditions on the properties of the adsorbents was demonstrated.

Progress in Methods for Preparation of Monolithic Active Carbons

Progress in Methods for Preparation of Monolithic Active Carbons

Optimization of the green and low-cost ammoniation-activation method to produce biomass-based activated carbon for Ni(II) removal from aqueous solutions

Activated carbon (AC) is an adsorbent that is used extensively in environmental treatment, and improving its performance and reducing costs remain sustainable goals. To reduce production costs and attain a green production process, a novel ammoniation-activation method (AAM) for the preparation of AC to enhance its physicochemical and adsorptive performance was provided. The experimental parameters were optimized by orthogonal experiments and the carbon product was characterized. These results show that the SBET (1142.0 m2/g), Vtot (0.618 cm3/g) and content of carbon functional groups (2.953 mmol/g) from the AAM method (hereafter termed AAC) were higher than those obtained by conventional methods (AC, 863.6 m2/g, 0.506 cm3/g and 2.071 mmol/g, respectively). Accordingly, the AAC (38.91 mg/g) demonstrated a 30% higher adsorptive capacity for Ni(II) than the AC (27.55 mg/g). Furthermore, the behavior of Ni(II) sorption on the AAC was investigated by batch experiments using various Ni(II) concentrations, time durations, pH levels and ionic strengths. The associated sorption isotherms and kinetics well fitted to the Langmuir model and pseudo-second-order model, respectively. Possible sorption mechanisms were further explored by XPS. The chemical affinity of Ni(II) toward oxygen- and nitrogen-containing groups plays a key role in the sorption process.

Potential of used Camellia sinensis leaves as precursor for activated carbon preparation by chemical activation with H3PO4; optimization using response surface methodology

Abstract In this study, an attempt was made to produce a low cost activated carbon (AC) from a cheap precursor material, used tea leaves (UTLs) by chemical activation with H 3 PO 4 . The operating variables of the preparation process were optimized by central composite design (CCD), a subset of response surface methodology (RSM). The conditions optimized were activation temperature, chemical impregnation ratio (IR) and activation time with % age yield, iodine (I 2 ) and methylene blue (MB) number as the targeted responses. The optimization was carried out to maximize yield, I 2 and MB number values. The optimal preparation conditions were determined as: activation temperature of 600 °C, IR of 1.30 and activation time of 130 min, under which a carbon yield 33.55%, I 2 and MB uptake of 1051 mg g −1 and 321 mg g −1 respectively, could be achieved. The surface properties of optimized AC were characterized by various physio-chemical techniques including scanning electron microscope imaging (SEM), FTIR analysis, surface area and X-rays diffraction analysis, Boehm’s titration, point of zero charge (pH PZC ) and proximate-ultimate analysis. The results showed that the surface of AC was highly porous with many channels and cracks and has acidic nature, have large amount of acidic functional groups and low ash content.

Preparation of Activated Carbon from Waste Residue of Chinese Prickly Ash Seeds Activated with K2CO3 and Its Adsorption Properties for p-Nitrophenol

Preparation of Activated Carbon from Waste Residue of Chinese Prickly Ash Seeds Activated with K2CO3 and Its Adsorption Properties for p-Nitrophenol

Polyethylenimine Modified Sugarcane Bagasse Adsorbent for Methyl Orange Dye Removal

This study is investigated the potential of sugarcane bagasse, an agriculture waste as adsorbent for the removal of methyl orange dye from aqueous solution. Numerous research had been done in preparing low cost adsorbent from agricultural by-products. Activated carbon undoubtedly is the most prevailing adsorbent because of its high surface area adsorption capacity, and degree of surface reactivity. The activation process during preparation of activated carbon is normally been performed at high temperature (i.e. higher than 500 °C) and involved with a harsh chemical. This study investigated the potential of modified sugarcane bagasse with polyethylenimine (PEI) for removal of methyl orange (MO) dyes. The effect of PEI modified sugarcane bagasse adsorbent parameter on the efficiency of dyes removal including contact time, initial dye concentration, adsorbent dosage, temperature and pH have been investigated. The optimum result for MO dye removal achieve up to 82.0 % for parameters, contact time (240 min), initial dye concentration (0.01 g/L), adsorbent dosage (0.15 g/50 mL), temperature (30 oC) and pH (7). The maximum percentage dye removal of MO dye was reached at contact time 240 min with percentage 82.78 % for 240 min and initial dye concentration 0.05 g/L at percentage 82.78 %. Based on the optimum result, the adsorbent was efficient in decolorised diluted solution. PEI modified sugarcane has high potential as low cost adsorbent for wastewater treatment containing dyes.

Hetero-atom Decoration of Activated Carbon Without Post-treatment

In this work, we attempt to decorate heteroatoms, including nitrogen and sulphur, into activated carbon without post-treatment. These atoms can be introduced into the carbon framework by the strong acid/base reactions after the carbonisation and activation. Raw materials, which contain the desired heteroatoms, were selected so that the obtained activated carbon would have the heteroatom without the harmful chemical process. Crab and shrimp shells were used as the raw material for nitrogen-doped activated carbon since they both contain chitin, which is the organic compound containing nitrogen atom. Similarly, lignite from Mae Moh (Lampang province, Thailand) which has high sulphur content, is suitable for the preparation of sulphur-doped activated carbon. Two types of activating agents, K2CO3 and KOH, were used as the activating agents and the effect from the ratio of raw materials to activating agents were studied. The surface area and the pore structures were determined by nitrogen adsorption analysis and the elemental compositions were characterised by CHNS analysis. It is found that activated carbon prepared from shrimp shells has a higher nitrogen content (1.40 wt%) than that prepared from crab shells (0.47 wt%). The specific area of the obtained activated carbonwas as high as 2,100 m2/g with the optimal condition. Sulphur-doped activated carbon can be easily preparedfrom lignite with high sulphur contents (14.34 wt%) and commercially comparable specific surface area (650 m2/g).

Methylene blue removal using a low-cost activated carbon adsorbent from tobacco stems: kinetic and equilibrium studies.

The aim of this study was to prepare activated carbon from tobacco stalks using microwave heating. The prepared activated carbon was applied as an adsorbent in methylene blue (MB) removal from water. The optimum conditions for activated carbon preparation were a radiation power of 280 W for a period of 6 minutes after the impregnation of the precursor material with 30% ZnCl2 for 24 hours. The activated carbon yield and iodine number were 49.43% and 1,264.51 mg/g respectively. The activated carbon also had a point of zero charge of 5.81 with an adsorption capacity of 123.45 mg/g for MB. The optimum conditions for MB adsorption were a pH of 6.5 with an adsorbent dosage of 0.2 g/50 mL at 25 °C. The MB adsorption kinetics followed the pseudo second order kinetic model with the intra-particle diffusion model suggesting a two-step adsorption mechanism. The adsorption data also fitted well within the Langmuir adsorption isotherm model. Tobacco stalks can successfully be turned into an economically important product.

Active carbons from waste biochars

Studies of preparation of active carbons of good structural and adsorption properties based on commercial biochars, which become wastes after removal of precious volatile components from natural raw materials of different origin, i.e., from wheat straw, Miscanthus grass, walnut shells, and energetic willow were carried out. There was applied the physical activation under atmospheric pressure in the fluidal reactor using CO2 or overheated steam and in the closed system in the high pressure microwave reactor under hydrothermal conditions. The obtained active carbons were investigated by means of adsorption (N2), thermal (TG, DTG, DTA), spectral (Raman spectra) as well as electron microscopy methods. The adsorbents obtained as a result of modification were characterized by a well-developed porous structure and greater thermal resistance compared to the initial biochars.

Manufacture of Low-cost Activated Carbon Using Sago Palm Bark and Date Pits by Physiochemical Activation

Two raw materials, sago palm bark (SPB) and date pits, were utilized as precursors to prepare high porosity activated carbon (AC). The porosity of these two raw materials was compared with that of commercial AC made from coconut shells. The physicochemical activation method was used for AC preparation, and it consisted of two steps, carbonization and activation. The activation process was performed using zinc chloride (ZnCl2) as an activation agent. N2 adsorption-desorption analysis was carried out to characterize the porosity of AC. Thermogravimetric analysis (TGA) was conducted for the two raw materials. The adsorbent made from SPB, which showed the maximum surface area of 1634 m2/g at the 700 °C activation temperature for one hour, while the surface area of prepared AC from date pits was 1367 m2/g. Both prepared ACs had a larger surface area than commercial AC made with coconut shell (1348 m2/g).

Optimisation of Activated Carbon Preparation by Chemical Activation of Ayous Sawdust, Cucurbitaceae Peelings and Hen Egg Shells Using Response Surface Methodology

Optimisation of Activated Carbon Preparation by Chemical Activation of Ayous Sawdust, Cucurbitaceae Peelings and Hen Egg Shells Using Response Surface Methodology

Experimental Study on Preparation of Straw Activated Carbon by Microwave Heating

Activated Carbon (AC) is amorphous carbon which was obtained through carbonaceous material. AC has a large specific surface area, so it has good adsorption capacity for inorganic substances, organic substances and colloidal particles in the gas or solution. Annual consumption is huge. Corn stalks are the remnants of agricultural production. China is one of the countries with the largest straw production in the world, but straw has not been fully utilized for a long time. A large number of straws were discarded or burned, which will waste resources and cause environmental pollution. Corn stalks were selected as raw material, pyrophosphoric acid was selected as activator, and microwave irradiation method was used to study the preparation technology of corn stalk based activated carbon in this paper. The optimum conditions for the preparation of AC from corn stalks were determined by the orthogonal experiment. The optimum parameters for the preparation of AC by microwave heat activation in the laboratory stage were obtained. The concentration of pyrophosphate was about 45% (wt), the impregnation ratio was 1: 2, the impregnation time was 8 hours, the radiant power was 400W, and the activation time was 8 minutes.

Preparation of the sludge activated carbon with domestic sludge mixed agricultural straw

Urban sewage sludge with complicated composition produce largely each year, pollution problem and resource utilization has increasingly become the focus of attention. Sewage sludge is utilized to prepare adsorbent that is a new type method. Agricultural stalks was added to material (urban sewage sludge) and activator (ZnCl2), calcined under the condition of no inert gas, and obtained domestic sludge activated carbon. The properties were measured by iodine adsorption value and BET, discussed influence factors of sludge activated carbon preparation, including activator concentration, solid-liquid ratio, calcific temperature and calcific time. The best process condition of orthogonal experiment had explored that activated time is 10 minutes, calcific temperature is 350°C, the activator concentration ZnCl2 is 3 mol/L and the mixing ratio of raw materials and activator is approximately 1:5. The iodine adsorption value and the optimal BET of as-obtained domestic sludge activated carbon is 445.06 mg/g, 525.31m2/g, respectively.

Improving low-pressure CO2 capture performance of N-doped active carbons by adjusting flow rate of protective gas during alkali activation

Alkali-activated N-doped active carbon (AC) is a promising material for capturing CO2, but the possible role of flow rate of protective gas during alkali activation in adjusting CO2 capture performance of AC is unknown. In this study, N-doped ACs for low-pressure CO2 capture were prepared from chitosan char by KOH activation under flowing N2 to study the effects of protective-gas flow rate on ultramicropore volume, chemical composition, and CO2 capture performance of ACs. The results showed that increasing the flow rate changed the low-pressure CO2 uptake and CO2/N2 selectivity by varying the ultramicropore volume and/or surface N/C ratio of ACs. Adopting a moderate flow rate during AC preparation was most favorable for enhancing low-pressure CO2 capture performance. The sample prepared at this flow rate displayed high CO2/N2 selectivity, excellent recyclability, and moreover, a CO2 uptake of 1.86 mmol/g (0.15 bar, 25 °C) which ranked among the highest values ever reported for N-doped ACs. This research revealed that controlling gas flow rate was an effective strategy to improve the CO2 capture performance of ACs and should be taken seriously during preparation of ACs for CO2 capture.

Optimization of transesterification of biodiesel using green catalyst derived from Albizia Lebbeck Pods by mixture design

The present investigation involves the production of biodiesel from Rubber Seed Oil (RSO) using a novel carbon based lignocelluloses material Albizia Lebbeck Pods (ALP). Carbonized char is prepared from ALP which is chemically activated by concentrated sulphuric acid and sodium bicarbonate. The prepared activated carbon was characterized by proximate-ultimate analysis; BET surface area, iodine number, FT-IR analysis, XRD, SEM analysis and particle size distribution. The Activated Carbon (AC) was impregnated with NaOH and KOH with different mixing ratio and the process is optimized using mixture design. It is found that the 97.2% maximum yield was obtained for the mix ratio of 3: 1.6: 1.4 (KOH: NaOH: AC). The physicochemical properties of rubber seed methyl ester is examined using ASTM and EN Standards. Evaluating with all the models, the results show that the quadratic and cubic model in the mixture design exhibit the excellent fit. It shows good R2, adjusted R2 and predicted R2 values. The experimental investigation confirmed that the potential use of ALP is the herald material for the preparation of AC.

Structural elucidation of physical and chemical activation mechanisms based on the microdomain structure model

Activated carbons (ACs) prepared by chemical activation commonly show higher specific surface areas and higher yields than those prepared by physical activation. In this study, the differences in the pore development mechanisms between physical and chemical activation processes for AC preparation were studied from a structural point of view, based on the microdomain structure model. Phenol resin-based spherical carbon was used as the starting material. AC preparation via potassium hydroxide (KOH) activation (chemical activation) did not induce noticeable changes in the particle or microdomain sizes, despite the abundant development of pores. On the other hand, ACs produced via steam activation (physical activation) showed remarkable reductions in both particle and microdomain sizes, depending on the activation temperature. Considering the differences in activation yield and degree of developed porosity between chemical and physical activations, we concluded that, in the case of KOH activation, pore development homogeneously progressed overall for all microdomains consisting of carbon particles without apparent morphological change; however, steam activation caused inhomogeneous gasification from the outer surface of the carbon particles and microdomains. For this reason, KOH-ACs showed higher yield and superior pore development.

Optimization of Activated Carbon Preparation from Pomegranate Peel (Punica granatum Peel) Using RSM

This research involves the optimization of different variables of the operating conditions to prepare activated carbon from pomegranate peels (Punica granatum peel). For this purpose, a statistical method called Response Surface Methodology (RSM) has been adopted to economize the number of experiments and their meaningful interpretation. Activated carbon was produced by chemical activation (H3PO4). RSM was used to evaluate the variables considered in the preparation of activated carbon such as impregnation ratio (2–4 g H3PO4/g pomegranate peel), temperature (400–600°C), and activation time (30–90 min), experimented using a three-variable Box–Behnken Design (BBD) based on a quadratic model and an RSM tool provided by Design Expert 8.0.4 (STAT-EASE Inc., Minneapolis, USA). The responses analyzed for optimization were the methylene blue number and the iodine number. The factors that are significant influencing the activated carbon preparation have been identified by an analysis of variance (ANOVA). The optimum conditions established were impregnation ratio of 2.78, activation temperature of 575°C, and activation time of 73 min.