Effects Of Impregnation Ratio Research Articles

Preparation and Characterization of Activated Carbon from Chestnut Shell and its Adsorption Characteristics for Lead

Activated carbons were prepared from chestnut shell by phosphoric acid activation and the prepared activated carbons were used to remove lead(II) from aqueous solutions. The effects of impregnation ratio (IR) and activation temperature on activated carbon production were investigated. The produced activated carbons were characterized by N2 adsorption, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. The highest surface area (1611 m2/g) and total pore volume (0.7819 cm3/g) were obtained at a carbonization temperature of 500°C with an impregnation ratio of 3/1. The resulting activated carbon was used for removal of lead(II) from aqueous solution. The effects of temperature, contact time, and adsorbent dosage were investigated. The adsorption isotherm studies were carried out and the obtained data were analyzed by the Langmuir, Freundlich, and Temkin equations. The rate of adsorption was found to conform to the pseudo-second-order kinetic model. The Langmuir isotherm equation showed better fit for all temperatures and the maximum adsorption capacities of lead(II) was obtained as 138.88 mg/g at 45°C.

Preparation of High Surface Area Activated Carbon from Elaeagnus angustifolia Seeds by Chemical Activation with ZnCl2 in One-Step Treatment and its Iodine Adsorption

The present study was conducted with the preparation of activated carbon through one-step chemical activation using zinc chloride (ZnCl2) as the activating agent from Elaeagnus angustifolia seeds (EAS). The effect of impregnation ratio, activation temperature, and activation time on activated carbon surface area was discussed. The properties of activated carbon were characterized by N2 adsorption (BET), thermogravimetric analyses (TGA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The best conditions for preparing activated carbon were identified to be temperature of 500°C, impregnation ratio of 150%, impregnation time of 48 h, and activation time of 60 min with BET surface area of 1836 m2/g. The adsorption capacity was demonstrated by the iodine numbers.

Optimization preparation of activated carbon from Enteromorpha prolifra using response surface methodology and its adsorption studies of fluoroquinolone antibiotics

Enteromorpha prolifera, a marine solid waste abundantly available in Asia, was used as a low-cost precursor to prepare activated carbon (EPAC) using pyrophosphoric acid, H4P2O7, as a chemical activating agent. The effects of impregnation ratio, activation temperature and activation time on the specific surface area of the activated carbon were investigated through response surface methodology. The optimum preparation conditions were described as follows: impregnation ratio, 1.26; activation temperature, 455°C; activation time, 48 min. The characteristics of EPAC were examined by nitrogen adsorption–desorption isotherms, Fourier transformed infrared spectroscopy and scanning electron microscopy. The total pore volume and specific surface area of EPAC under optimum conditions were identified as 1.365 cm3/g and 1124.1 m2/g. The EPAC possessed high BJH pore volume, 1.276 cm3/g and methylene blue value, 330 mg/g, indicating the existence of abundant mesopores. The adsorption kinetic data of ciprofloxacin were well fitted to pseudo-second-order model, displaying a monolayer adsorption capacity for CIP of 216.55 mg/g. The equilibrium data can be well described by Langmuir model. The dominant sorption mechanism is electrostatic attraction.

Catalytic Cracking of <i>Cornus wisoniana </i>Oil to Liquid Bio-Fuel Oil Using KF/CaO as a Solid Base Catalyst

In this study, catalytic cracking ofCornus wisonianaoil to liquid bio-fuel oil using KF/CaO as a solid base catalyst was studied. The catalyst characteristic by SEM, XRD, CO2-TPD was proposed and the separate effects of impregnation ratio, calcination temperature and calcination time were investigated. This paper also studied the separate influence of mass of catalyst and reaction time on catalytic cracking ofCornus wisonianaoil. The experimental results showed that a 41.7% impregnation ratio, 630°C calcination temperature, and 4h reaction time can obtain option catalyst. When addition of 0.1% KF/CaO catalyst and 35min reaction time gave the best results, and the liquid oil yield exceeded 82.7%. The catalyst basicity was not too high, formed flake porous layer structure.* Corresponding authors:Changzhu Li (lichangzhu2013@aliyun.com)

Pore characteristics of activated carbons from the phosphoric acid chemical activation of cotton stalks

Abstract Activated carbons were prepared by phosphoric acid activation of cotton stalks in a nitrogen atmosphere at various temperatures in the 500–800 °C range and at different H 3 PO 4 acid to cotton stalk impregnation ratios (0.3–3). In addition pyrolysis was undertaken in a thermogravimetric analyser in the presence of different ratios of phosphoric acid in order to establish the nature of the biomass to carbon transformations involved. It was established that the total activation process of H 3 PO 4 -impregnated cotton stalks occurred in four stages with the main degradation at 740 °C, compared with 330 °C for raw cotton stalks. The effects of impregnation ratio and activation temperature on the yield and adsorption capacities of activated carbon were evaluated. The chemical composition of the carbons was investigated by elemental analysis and infrared spectroscopy. The impregnation ratio and activation temperature show a strong influence on the yields and the porous texture of the resultant activated carbons. It was demonstrated that increasing impregnation ratio favours the development of mesopores especially at high activation temperature. The activated carbons showed BET surface areas ranging from 330 to 1720 m 2 g −1 , total pore volumes of 0.15–1.23 cm 3 g −1 with mesopore volumes between 0 and 0.61 cm 3 g −1 . Results suggest the practical feasibility of phosphoric acid activation of cotton stalks, which produces high quality activated carbons with high fractions of micropores and mesopores.

Activated carbon fibers with a high content of surface functional groups by phosphoric acid activation of PPTA

Activated carbon fibers (ACFs) were prepared by chemical activation of poly(p-phenylene terephthalamide (PPTA) with phosphoric acid, with a particular focus on the effects of impregnation ratio and carbonization temperature on both surface chemistry and porous texture. Thermogravimetric studies of the pyrolysis of PPTA impregnated with different amounts of phosphoric acid indicated that this reagent has a strong influence on the thermal degradation of the polymer, lowering the decomposition temperature and increasing the carbon yield. As concerns surface chemistry, TPD and chemical analysis results indicated that the addition of phosphoric acid increases the concentration of oxygenated surface groups, with a maximum at an impregnation ratio of 100wt.%. The resulting materials present uncommon properties, namely a large amount of oxygen- and phosphorus-containing surface groups and a high nitrogen content. Porosity development following H3PO4 activation was very significant, with values close to 1700m2/g and 0.80cm3/g being reached for the BET surface area and total pore volume, respectively. The pore size distributions remained confined to the micropore and narrow mesopore (<10nm) range.

Preparation and characterizations of microwave assisted activated carbons from industrial waste lignin for Cu(II) sorption

Industrial waste lignin was used to prepare activated carbons by zinc chloride activation by using different impregnation methods (with and without microwave treatment) at 500–800 °C. Effect of impregnation ratio was also studied. The textural properties of the samples were investigated by means of SEM, cryogenic N 2 adsorption, whereas, surface chemistry was probed through FTIR and modified Boehm's titration method. Textural properties and surface chemistry of activated carbons were found to be strongly depending on the activation temperature, impregnation ratio and impregnation method. BET surface area, total pore volume, micropore volume and micropore area increased with increase in activation temperature up to 600 °C and then decreased on further increase in temperature. Maximum surface area of 1172.2 m 2/g, total pore volume 0.640 cm 3/g, and total oxygen surface functional groups 3.14 meq/g was observed in case of microwave treated sample at activation temperature 600 °C and impregnation ratio 1:1.5 whereas, for the sample obtained by simple impregnated method the above said values are 917.5 m 2/g, 0.506 cm 3/g and 2.66 meq/g respectively, using same precursor and conditions. The adsorption of Cu 2+ from aqueous solution on samples could be favorably described by Langmuir isotherm, and the adsorption kinetics was well fitted in pseudo-second-order model. Results revealed usefulness of microwave treatment in influencing BET surface area, micropore surface area and type and extent of surface oxygen functional groups and ultimately greater uptake capacity.

ACTIVATED CARBON FROM DURIAN SEED BY H&lt;sub&gt;3&lt;/sub&gt;PO&lt;sub&gt;4&lt;/sub&gt; ACTIVATION: PREPARATION AND PORE STRUCTURE CHARACTERIZATION

Activated carbons have been produced from the natural biomaterial durian (Durio zibethinus) seed, using phosphoric acid (H3PO4) as the activating agent. The effects of impregnation ratio, activation temperature, heating rate on the carbon surface area, porosity and mass yield are presented. A two step process has been used, the first step was a low temperature impregnation at 150 °C using phosphoric acid and the second step was the carbonization at high temperatures, namely, 600 and 900 °C. The most outstanding carbon with the highest surface area of 2123 m2/g was prepared using an impregnation ratio of 2, an activation temperature of 600 °C for 4 h and a heating rate of 1 °C/min. Keywords: activated carbon, durian seed, phosphoric acid activation

Removal of nitrate from aqueous solutions by activated carbon prepared from sugar beet bagasse

In this study, activated carbons were prepared from sugar beet bagasse by chemical activation and the prepared activated carbons were used to remove nitrate from aqueous solutions. In chemical activation, ZnCl 2 was used as chemical agent. The effects of impregnation ratio and activation temperature were investigated. The produced activated carbons were characterized by measuring their porosities and pore size distributions. The microstructure of the activated carbons was examined by scanning electron microscopy (SEM). The maximum specific surface area of the activated carbon was about 1826 m 2/g at 700 °C and at an impregnation ratio of 3:1. The resulting activated carbon was used for removal of nitrate from aqueous solution. The effects of pH, temperature and contact time were investigated. Isotherm studies were carried out and the data were analyzed by Langmuir, Freundlich and Temkin equations. Three simplified kinetic models were tested to investigate the adsorption mechanism.

Experimental Research on the Preparation of Porous Activated Carbon from Orange Wastes

Porous activated carbon was prepared from orange wastes using zinc chloride as an activating agent by one-step carbonization method. Effects of impregnation ratio, carbonization temperature and heat preservation time on pore characteristics of activated carbon were studied. The porous structures of the orange wastes activated carbon were investigated by BET, D-R equations, BJH equations and Kelvin theory. The morphology was observed using transmission electron microscopy (TEM). The mesoporous activated carbon is gained when the impregnation ratio is 3:1; the carbonization temperature is 550°Cand heat preservation time is 1.0 h. The activated carbon has total pore volume 2.098 cm3/g, mesoporous pore volume 1.438 cm3/g, with a high BET surface area 1476m2/g. The pore distribution of the mesoporous activated carbon is very concentrative, with average pore diameter of 3.88nm. While, the high specific surface area activated carbon is gained when the impregnation ratio is 2:1; the carbonization temperature is 550°Cand heat preservation time is 1.0 h. The activated carbon has high BET surface area 1909 m2/g, while the total pore volume is only 1.448cm3/g and microporous pore volume is 0.889cm3/g, with average pore diameter of 2.29 nm.

Salt-Catalyzed Activation of Olive-Seed Waste Residue Using Fluidized-Bed Reactor

Activation of olive-seed waste residue was carried out under nitrogen atmosphere in a fluidized-bed reactor system. Initially, the starting materials were impregnated with two different salts. The salts were zinc chloride (ZnCl2) and potassium chloride (KCl). The effects of some process variables on both yield and quality of the prepared products were studied. Adsorption quality was measured in terms of adsorptive capacity towards methylene blue dye and iodine number. The effects of impregnation ratio, activation temperature, time, and particle size on adsorption quality were investigated. In general, it was found that ZnCl2 was more effective than KCl. Overall, higher activation temperature, longer activation time and smaller particle size produced a higher quality activated carbon. The produced materials were compared to a physically prepared activated carbon. They were comparable and found to be more superior.