Optimization of Production Conditions for Activated Carbons from Rice Husk by Potassium Carbonate Using Response Surface Methodology

2014 ◽  
Vol 1053 ◽  
pp. 303-310 ◽  
Author(s):  
Mian Wu Meng ◽  
Cong Liang Qi ◽  
Qing Ye Liu ◽  
Liang Lv ◽  
Hao Ai ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Adsorption Capacity ◽  
Response Surface ◽  
Rice Husk ◽  
Activated Carbons ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Average Pore ◽  
Activation Temperature ◽  
Nitrogen Adsorption Isotherm

A three-factor-three-level experiment was developed by the central composite design (CCD) and Response surface methodology to discuss the effects of concentration of K2CO3, activation temperature and time on the adsorption capacity of the activated carbon (AC) derived from the rice husk and to identify the key preparation parameters. The performance of the AC was characterized by nitrogen adsorption isotherm as Brunauer–Emmett–Teller (BET) and scanning electron microscope (SEM), respectively. The optimal parameters were obtained: Rice husk was soaked in K2CO3 solution (2.32 mol/L) with an impregnation ratio (rice husk: K2CO3=1:3) (wt. %), activated at 1239 K for 0.48 h. The results showed that iodine adsorption capacity of the AC was 1268.52 mg/g, the error between the models predicted (1356.98 mg/g) was only 6.2%. The AC has a large apparent surface area (SBET = 1312 m2/g), total pore volume (0.78 cm3/g) and average pore diameter (11.92 Å).

scholarly journals Preparation and characterization of bio-based activated carbon from fish scales

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 614-621
Author(s):  
Qingsong Ji ◽  
Haichao Li ◽  
Jingjing Zhang
Keyword(s):  
Activated Carbon ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Activated Carbons ◽  
Structural Characteristics ◽  
Total Pore Volume ◽  
Bet Surface Area ◽  
Fish Scales ◽  
Average Pore ◽  
Activation Temperature

The object of this study was to prepare activated carbons containing nitrogenous functional groups by a chemical method from nitrogen-containing raw materials. Fish (Ctenopharyngodon idellus) scales were impregnated with phosphoric acid (H3PO4) and activated at varied temperatures. The adsorption ability, structural characteristics, surface chemistry, and morphology of the activated carbons were characterized by methylene blue and iodine values, nitrogen adsorption, the Boehm method, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The total alkaline groups content of the activated carbon produced from fish scales was 0.4330 mmol/g, the total acidic groups was 1.68 mmol/g, the Brunauer–Emmett–Teller (BET) surface area was 501 cm2/g, and the total pore volume was 0.284 cm3/g. The average pore diameter was 1.94 nm under an activation temperature of 550 °C, an activation time of 1 h, and an impregnation ratio of 2. As a result of this study, nitrogenous functional groups that contained acid-base amphoteric adsorbent were produced.

scholarly journals ADSORPTION OF 4-CHLORPHENOL BY BROWN COAL ACTIVATED BY POTASSIUM HYDROXIDE

2021 ◽  
Vol 29 (1) ◽  
pp. 36-48
Author(s):  
Yuliia Tamarkina ◽  
Volodymyr Kucherenko ◽  
Iryna Frolova
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Brown Coal ◽  
Activated Carbons ◽  
Linear Equations ◽  
Specific Capacity ◽  
Total Pore Volume ◽  
Koh Activation ◽  
Activation Temperature ◽  
Alkaline Activation

The purpose of work is to evaluate the 4-chlorophenol (CP) adsorption capacity of brown coal activated carbons (ACs) prepared at different temperature of KOH activation. ACs were obtained in three stages: 1) impregnation of coal with a KOH solution, 2) heating (4 deg/min) in argon to a given temperature t (400-800°C) and exposure for 1 h, 3) cooling, washing from KOH, drying. The samples are designated as AC(t). Based on the N2 adsorption-desorption isotherms, the ACs total pore volume (Vt, cm3/g) and specific surface area (S, m2/g) were determined. The ACs adsorption capacity were measured at 25°С, CP concentration ≤700 mg/L, АC dosage – 1 g/L. The alkaline activation temperature was found to be a key factor in forming porosity of ACs and ability to adsorb CP. The CP maximum capacity (ACP(m), mg/g) increases 6.6 times up to 307 mg/g for AC(800) having S=1142 m2/g. The specific adsorption capacity (ACP(S) = ACP(m)/S, mg/m2) sharply decreases in a sample range from AC(400) to AC(550) and weakly depends on temperature at 550-800°C. The kinetics of CP adsorption is best described by a pseudo-second order model. The rate determining stage is the interaction of CP molecules with AC surface. The CP adsorption isotherms are best described by the Langmuir model. The dependence of the ACP(m) from S can be approximated by three linear equations that probably correspond to the three regions of forming surface adsorbtion centers (AdCs). The first (S≤370 m2/g) is characterized by a small adsorption capacity increment (kS=0.103 mg/m2), but a significant (16.4 times) decrease in the specific capacity ACP(S). In the second region (S=370-770 m2/g, t=550-750°C), capacity increment is 10 times more (kS=0.985 mg/m2) and in the third region (S≥770 m2/g, t≥750°C) the increase in CP capacity is the smallest (kS=0.067 mg/m2). The thermoinitiated formation of AdCs is assumed to be not proportional to the increase in surface area, and their chemical structure and reactivity is determined by the alkaline activation temperature.

scholarly journals Optimized preparation of activated carbon from furfural residue using response surface methodology and its application for bisphenol S adsorption

2021 ◽  
Author(s):  
Chenglin Liu ◽  
Linlin Liang ◽  
Xiuli Han ◽  
Chun Chang ◽  
Junying Chen ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Response Surface ◽  
Isotherm Models ◽  
Bisphenol S ◽  
Activation Temperature ◽  
Preparation Conditions ◽  
Furfural Residue ◽  
Pseudo Second Order

Abstract Furfural residue (FR), a solid waste, was applied as the precursor to prepare activated carbon by steam activation. The Box-Behnken design (BBD) approach-based response surface methodology (RSM) was utilized to optimize the preparation conditions to evaluate their effects on the performance of activated carbon from furfural residue (FRAC). The optimum preparation conditions of FRAC were found as follows: activation temperature of 922 °C, activation time of 62 min, and the mass ratio of char to H2O of 1:4.5, resulting in 1,501.84 mg/g of iodine adsorption capacity and 1,662.41 m2/g of specific surface area. The FRAC was characterized and then the adsorption performance of BPS on FRAC was investigated. Langmuir and Koble-Corrigan isotherm models were well fitted to the experimental data, and the adsorption kinetics process was perfectly described by the pseudo-second-order model. Thermodynamic parameters showed that the adsorption of BPS was a spontaneous exothermic process. Besides, the regeneration efficiency of FRAC was over 97% after five consecutive cycles. The maximum monolayer adsorption capacity of FRAC for BPS was 3.2848 mmol/g at 298 K, indicating that the FRAC was an excellent adsorbent for the removal of BPS from aqueous solutions.

scholarly journals Temperature Dependent Characteristics of Activated Carbons from Walnut Shells for Improved Supercapacitor Performance

2018 ◽  
Vol 20 (2) ◽  
pp. 99 ◽  
Author(s):  
V.V. Pavlenko ◽  
Q. Abbas ◽  
P. Przygocki ◽  
T. Kon’kova ◽  
Zh. Supiyeva ◽  
...  
Keyword(s):  
Activated Carbons ◽  
Electrochemical Techniques ◽  
Electrochemical Capacitor ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Activation Temperature ◽  
Walnut Shells ◽  
Bet Specific Surface Area ◽  
Capacitive Properties ◽  
Supercapacitor Performance

Activated carbons (ACs) have been prepared from chemical treatment of walnut shells (WS) precursor at various temperatures (400‒800 °C) by using phosphoric acid (H3PO4) as activating agent. Influence of activation temperature on the porosity development and capacitive properties of resulting carbons was investigated. Thermal post-treatment of carbons previously activated at moderate temperature, e.g. 400 °C allowed further structural and porosity modification. Then, these carbons were investigated by scanning electron microscopy, Raman spectroscopy, energy-dispersive X-ray spectroscopy, electrochemical techniques and low temperature nitrogen adsorption exhibiting high BET specific surface area of approximately 2100 m2 g-1 and a total pore volume up to 1.3 cm3 g-1. Carbon material obtained through activation by H3PO4 at 400 °C and post-treated at 800 °C was used to make electrodes which were implemented to realize AC/AC capacitor using 1 mol L-1 Li2SO4. The electrochemical capacitor demonstrated high capacitance of 123 F g-1 per mass of one electrode, reduced cell resistance and stable capacitance for 5000 galvanostatic charge/discharge cycles at 1.0 A g-1.

scholarly journals Preparation of High-Performance Activated Carbon from Coffee Grounds after Extraction of Bio-Oil

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 257
Author(s):  
Jie Ren ◽  
Nanwei Chen ◽  
Li Wan ◽  
Guojian Li ◽  
Tao Chen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
High Performance ◽  
Average Pore Size ◽  
Total Pore Volume ◽  
Micropore Volume ◽  
Bet Surface Area ◽  
Average Pore ◽  
Activation Temperature ◽  
Coffee Grounds ◽  
Bio Oil

In this study, a new method for economical utilization of coffee grounds was developed and tested. The resulting materials were characterized by proximate and elemental analyses, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption–desorption at 77 K. The experimental data show bio-oil yields reaching 42.3%. The optimal activated carbon was obtained under vacuum pyrolysis self-activation at an operating temperature of 450 °C, an activation temperature of 600 °C, an activation time of 30 min, and an impregnation ratio with phosphoric acid of 150 wt.%. Under these conditions, the yield of activated carbon reached 27.4% with a BET surface area of 1420 m2·g−1, an average pore size of 2.1 nm, a total pore volume of 0.747 cm3·g−1, and a t-Plot micropore volume of 0.428 cm3·g−1. In addition, the surface of activated carbon looked relatively rough, containing mesopores and micropores with large amounts of corrosion pits.

scholarly journals ADSORPTION OF MALACHITE GREEN DYE USING SPENT COFFEE GROUND BIOCHAR: OPTIMISATION USING RESPONSE SURFACE METHODOLOGY

2020 ◽  
Vol 83 (1) ◽  
pp. 27-36
Author(s):  
Mardawani Mohamad ◽  
Rizki Wannahari ◽  
Rosmawani Mohammad ◽  
Noor Fazliani Shoparwe ◽  
Kwan Wei Lun ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Adsorption Capacity ◽  
Response Surface ◽  
Malachite Green ◽  
Contact Time ◽  
Quadratic Model ◽  
Adsorbent Dosage ◽  
Coffee Grounds ◽  
Spent Coffee Ground ◽  
Coffee Ground

Used coffee grounds usually end up as landfill. However, the unique structural properties of its porous surface make coffee grounds can be transformed into biochar and performed as an alternative low cost adsorbent. Malachite green (MG) is a readily water soluble dye which is used extensively in textile and aquaculture industries. The mordant complex structures of MG generate destructive effects to animals and environment. In this study, adsorption of malachite green using spent coffee ground biochar as adsorbent was investigated. The experiments were designed in two methods: classical and optimisation by response surface methodology. Three parameters were studied, which are adsorbent dosage, contact time and pH while the responses in this study are malachite green removal (%) and adsorption capacity (mg/g). Optimisation studies were performed using response surface methodology. Quadratic model was chosen for both response and studied using central composite design. The correlation coefficient, R2 for the quadratic model of malachite green removal (%) and adsorption capacity (mg/g) were 0.95 and 0.99, respectively. The optimum malachite green removal (%) predicted was found at 99.27%, by using 0.12 g of adsorbent dosage, 43.05 minutes of contact time and pH of 9.45 at desirability of 1.0. The optimum adsorption capacity (mg/g) predicted was found at 118.01 mg/g, by using 0.02 g of adsorbent dosage, 60 minutes of contact time and pH of 10.24 at desirability of 0.98. So, it was concluded that the spent coffee ground biochar can be used as an effective adsorbent for malachite green removal from aqueous solution.

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