Effect of petroleum coke expanding by perchloric acid on the performance of the resulted activated carbon

2014 ◽  
Vol 07 (01) ◽  
pp. 1350066 ◽  
Author(s):  
Mei-Gen Deng ◽  
Ren-Qing Wang

Petroleum coke (PC) was expanded by using KMnO 4 as oxidant and HClO 4 as intercalator so as to decrease the amount of KOH needed for the successive activation. Activated carbon (AC) was prepared by activation of the expanded PC (EPC) at KOH /coke mass ratio of 3:1 (denoted as EAC-3). As a comparison, AC was also made by activation of PC at KOH /coke mass ratio of 3:1, 4:1 and 5:1 (denoted as AC-3, AC-4 and AC-5). Influence of expanding modification on the structure and performance of PC and AC was investigated. The results revealed that the expanding treatment increased the interplanar distance of PC microcrystalline from 0.344 to 0.362 nm and decreased the microcrystalline thickness from 2.34 to 1.57 nm. The specific surface area of EAC-3 and AC-5 was 3461 and 3291 m2⋅g-1, respectively. The average pore size of EAC-3 was 2.19 nm, which is 0.11 nm larger than that of AC-5. At a scan rate of 0.5 mV⋅s-1, EAC-3 and AC-5 achieved a specific gravimetric capacitance of 486 and 429 F⋅g-1, respectively. Supercapacitor based on EAC-3 possessed lower resistance and better power performance.

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 257
Author(s):  
Jie Ren ◽  
Nanwei Chen ◽  
Li Wan ◽  
Guojian Li ◽  
Tao Chen ◽  
...  

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Huaxing Xu ◽  
Biao Gao ◽  
Hao Cao ◽  
Xueyang Chen ◽  
Ling Yu ◽  
...  

Nanoporous activated carbon material was produced from the waste rice husks (RHs) by precarbonizing RHs and activating with KOH. The morphology, structure, and specific surface area were investigated. The nanoporous carbon has the average pore size of 2.2 nm and high specific area of 2523.4 m2 g−1. The specific capacitance of the nanoporous carbon is calculated to be 250 F g−1at the current density of 1 A g−1and remains 80% for 198 F g−1at the current density of 20 A g−1. The nanoporous carbon electrode exhibits long-term cycle life and could keep stable capacitance till 10,000 cycles. The consistently high specific capacitance, rate capacity, and long-term cycle life ability makes it a potential candidate as electrode material for supercapacitor.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 241 ◽  
Author(s):  
Jian Guo ◽  
Yaqin Song ◽  
Xiaoyang Ji ◽  
Lili Ji ◽  
Lu Cai ◽  
...  

The aim of this study was to optimize the adsorption performance of activated carbon (AC), derived from the shell of Penaeus vannamei prawns, on heavy metal ions. Inexpensive, non-toxic, and renewable prawn shells were subjected to carbonization and, subsequently, KOH-activation to produce nanoporous K-Ac. Carbonized prawn shells (CPS) and nanoporous KOH-activated carbon (K-Ac) from prawn shells were prepared and characterized by FTIR, XRD, BET, SEM, and TEM. The results showed that as-produced K-Ac samples were a porous material with microporous and mesoporous structures and had a high specific surface area of 3160 m2/g, average pore size of about 10 nm, and large pore volume of 2.38 m3/g. Furthermore, batches of K-Ac samples were employed for testing the adsorption behavior of Cd2+ in solution. The effects of pH value, initial concentration, and adsorption time on Cd2+ were systematically investigated. Kinetics and isotherm model analysis of the adsorption of Cd2+ on K-Ac showed that experimental data were not only consistent with the Langmuir adsorption isotherm, but also well-described by the quasi-first-order model. Finally, the adsorption behaviors of as-prepared K-Ac were also tested in a ternary mixture of heavy metal ions Cu2+, Cr6+, and Cd2+, and the total adsorption amount of 560 mg/g was obtained.


2016 ◽  
Vol 11 (4) ◽  
pp. 784-795 ◽  
Author(s):  
Abolghasem Alighardashi ◽  
Shooza Shahali

Excessive nitrate in the water impose a danger to human health and contribute to eutrophication. The present continuous fixed bed pilot study was carried out using granular activated carbon made from walnut shell for removal of nitrate from aqueous solution and natural groundwater. The carbon was characterized using SEM, FTIR and BET. The BET specific surface area and average pore size before nitrate adsorption were 1434.6 m2g−1 and 2.08 nm, respectively, and after were 633.28 m2g−1 and 2.04 nm, respectively. Optimum removal of nitrate was achieved at a contact time of 2 min, pH of 6.5 and a nitrate concentration of 200 mg/l. The hydraulic loading rate was calculated to be 10 m3/h.m2 and the maximum adsorption capacity using the Langmuir adsorption isotherm model (R2 = 0.99) was 10 mg NO3/g. These experiments were also carried out using groundwater and the removal of nitrate decreased from 68% to 60% because of competition with other cations and anions.


2017 ◽  
Vol 889 ◽  
pp. 215-220 ◽  
Author(s):  
Siti Anis Mohd Amran ◽  
Khudzir Ismail ◽  
Azil Bahari Alias ◽  
Syed Shatir Asghrar Syed-Hassan ◽  
Ali H. Jawad

Single and mixed coconut shell (CS) and palm kernel shell (PKS) were successfully converted to activated carbon by using potassium hydroxide (KOH) as activating agent. Mixed activated carbon was produced from coconut shell: palm kernel shell at different KOH concentrations of 30%, 40% and 50%. Activation process was performed in a conventional microwave oven at fixed power and time of 600W and 20 minutes respectively. The results showed that activated carbon produced from single and mixed biomass at 40% concentration of KOH exhibited higher adsorption capacity for iodine number and percentage removal of MB with comparison to 30% and 50% of KOH concentrations. The highest BET surface area of 441.19 m2/g was obtained by CSAc-40. Further both CSAc-40 and PKSAc-40 produced an average pore size diameter of less than 2.0 nm which is in the range of micropore region. On contrary, the mixed CSPKSAc-40 produced an average pore size diameter of 6.0 nm which is in the region of mesopore. All the CSAc-40, PKSAc-40 and mixed CSPKSAc-40 showed similar adsorption trend for iodine number and percentage removal of MB. Interestingly, this finding showed that in the mixed activated carbon some chemical reactions might have occurred during the activation process producing mesoporous instead of microporous as obtained by the single biomass activated carbon.


2010 ◽  
Vol 156-157 ◽  
pp. 1347-1351 ◽  
Author(s):  
Yu Hong Tian ◽  
Xin Zhe Lan ◽  
Lin Bo Li ◽  
Xiang Yang Chen ◽  
Tang Hua Hu

Activated carbon was prepared from blue coke powder by physical activation. The results show that the specific surface area (BET) is 697.05m2/g, the total pore volume is 0.4569cm3/g and the average pore size is 2.6221nm. The adsorption properties of Cr( ) onto blue coke powder activated carbon are discussed from the kinetics and thermodynamics viewpoints. The pseudo-second-order kinetic model shows the best correlation with experimental data. Langmuir and Freundlich models are used to fit the equilibrium, and it is indicated that Freundlich best fits these data. The adsorption of Cr( ) onto blue coke powder activated carbon is found to be an endothermic process in nature.


2010 ◽  
Vol 113-116 ◽  
pp. 2134-2140 ◽  
Author(s):  
Zhao Lin Chen ◽  
Xiao Wei Sun ◽  
Hong Fei Guo ◽  
Cun Yi Song

Activated carbon (AC) electrodes to electrosorption NaCl from aqueous solution were modified. The electrodes were characterized using scanning electron micrograph (SEM), nitrogen adsorption and cyclic voltammetry. The electrosorption removal efficiency is improved by 3 M HNO3 modification due to increased hydrophilic groups enhance adsorption of inorganic ion. The electrosorption removal efficiency is decreased by 15 M HNO3 modification due to the combined effects of increased hydrophilic groups and decreased average pore size. The improvement of electrosorption performance by TiO2 nanoparticles modification due to TiO2 nanoparticles boned with the polar groups works as electrosorption sites with enhanced adsorption strength. The reversal operation mode is better than non-reversal operation mode for electrosorption application.


2021 ◽  
Vol 11 (9) ◽  
pp. 3994
Author(s):  
Suhdi ◽  
Sheng-Chang Wang

Fine activated carbon (FAC) is prepared from rubber fruit shells (RFS) using two chemical activating agents (ZnCl2 and KOH) and three impregnation ratios (1:3, 1:4, and 1:5). The Brunauer–Emmett–Teller (BET) results show that for a constant impregnation ratio, the ZnCl2 activating agent yields a higher specific surface area than the KOH agent. In particular, for the maximum impregnation ratio of 1:5, the FAC prepared using ZnCl2 has a BET surface area of 456 m2/g, a nitrogen absorption capacity of 150.38 cm3/g, and an average pore size of 3.44 nm. Moreover, the FAC structure consists of 70.1% mesopores and has a carbon content of 80.05 at.%. Overall, the results confirm that RFS, activated using an appropriate quantity of ZnCl2, provides a cheap, abundant, and highly promising precursor material for the preparation of activated carbon with high carbon content and good adsorption properties


Author(s):  
Erman Taer ◽  
R. Taslim ◽  
Sugianto Sugianto ◽  
M. Paiszal ◽  
Mukhlis Mukhlis ◽  
...  

Activated carbon monoliths (ACMs) with average pore diameters in the meso- and micropore regions were successfully produced from biomass material. ACM synthesis uses chemical activation with KOH and ZnCl<sub>2</sub> activating agents. The carbon and activating agent mass ratios were 1:1, 1:3, 1:5 and 1:7. Both activating materials produced an ACM with an average pore diameter of 3.2 nm. The specific capacitance, specific surface area, energy and power were as high as 63 F/g, 650 m<sup>2</sup>/g, and 0.23 Wh/kg for KOH and 73 F/g, and 522 m<sup>2</sup>/g, and 19 W/kg for ZnCl<sub>2</sub> activating agents, respectively. For comparison, we also studied the physical and electrochemical properties of ACM with an average pore size in the micropore range from the same raw material.


Author(s):  
Yuvarat Ngernyen ◽  
Werawit Phiewruangnont ◽  
Narathorn Mahantadsanapong ◽  
Chantakorn Patawat ◽  
Ketsara Silakate ◽  
...  

Dipterocarpus alatus tree grows prolifically throughout Thailand and can be tapped to yield significant quantities of oil to be used as natural diesel. However, such practices lead to waste dried fruit dropping from the tree. At present, there is no utilization of this dropped fruit, therefore costeffective processes need to be applied to obtain higher value products from this waste. A possible to utilization is the conversion to activated carbon for adsorption applications including the removal of heavy metals, dyes, and other contaminants in water purification and other decontamination process. A major challenge of current commercial activated carbon is the high production cost and recently it has been shown that chemical activators comprise a significant proportion of these costs. This feasibility study investigates the use of Dipterocarpus alatus fruit as raw material to produce low cost activated carbon adsorbents. Activated carbon was prepared from Dipterocarpus alatus fruit: endocarp, mesocarp, and wing by chemical activation with ZnCl2, FeCl3, and KOH. Each part of the fruit was impregnated with 30 wt% activating agent at a ratio of 1:2 for 1 h and then carbonized at 500 oC for a further 1 h. The surface area, pore volume, and average pore size of the resulting carbons were characterized by nitrogen gas adsorption. Activation of mesocarp with ZnCl2, KOH, and FeCl3 gave activated carbons with the surface area of 447, 256, and 199 m2/g, respectively. In the same way, ZnCl2 activation gave a maximum surface area of 312 and 278 m2/g for wing and endocarp, respectively. All of the aforementioned samples have an average pore size of around 2 nm. In contrast, KOH and FeCl3 activation of wing and endocarp produced activated carbon with very low surface area (below 25 m2/g), but with an average pore size of 5- 14 nm. The maximum surface area of activated carbon prepared from Dipterocarpus alatus fruit was higher than some literature examples for activated carbon from other biomass. Consequently, Dipterocarpus alatus fruit demonstrated significant potential as a feedstock for the preparation of low cost activated carbons.


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