scholarly journals Electrochemical behaviour of activated carbons obtained via hydrothermal carbonization

2015 ◽  
Vol 3 (30) ◽  
pp. 15558-15567 ◽  
Author(s):  
David Salinas-Torres ◽  
Dolores Lozano-Castelló ◽  
Maria Magdalena Titirici ◽  
Li Zhao ◽  
Linghui Yu ◽  
...  
Keyword(s):  
Activated Carbons ◽  
Low Cost ◽  
Electrochemical Behaviour ◽  
Hydrothermal Carbonization ◽  
Porous Carbons ◽  
Synthesis Conditions

Porous carbons were synthesised using hydrochars from low cost precursors. Electrochemical behaviour is influenced by synthesis conditions and precursors used.

scholarly journals Characterization and comparison of walnut shells-based activated carbons and their adsorptive properties

2020 ◽  
Vol 38 (9-10) ◽  
pp. 450-463
Author(s):  
Xiya Li ◽  
Jieqiong Qiu ◽  
Yiqi Hu ◽  
Xiaoyuan Ren ◽  
Lu He ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Activated Carbons ◽  
Low Cost ◽  
Total Pore Volume ◽  
Textural Properties ◽  
Hydrothermal Carbonization ◽  
Bet Surface Area ◽  
Activation Process ◽  
Walnut Shells ◽  
Adsorption Desorption

The production of low-cost biologically activated carbons (BACs) is urgent need of environmental protection and ecological sustainability. Hence, walnut shells were treated by traditional pyrolysis, direct KOH impregnation and combined activation composed of hydrothermal carbonization and two-step H3PO4- and pyrolysis-activation process to obtain porous carbon with high adsorption capacity. It was found that the best adsorption capacity for iodine and organic dye methylene blue (MB) can be obtained using the KOH impregnation at impregnation ratio of 1:1 or combined activation comprising of 2 h H3PO4 activation and 1 h pyrolysis activation at 1000°C. The produced KOH, H3PO4/pyrolysis activated BACs at the optimum conditions are superior to that of commercial ACs, 9.4 and 1.3 times for MB removal, 4 and 4.5 times for iodine number respectively. Characterization results demonstrated their porous structure with very good textural properties such as high BET surface area (1689.1 m2/g, 1545.3 m2/g) and high total pore volume (0.94 cm3/g, 0.96 cm3/g). The N2 adsorption-desorption isotherm of H3PO4/pyrolysis activated hydrochar suggested the co-existence of micro and meso-pores. Moreover, they are more effective for the removal of Fe(III) and Cr(VI) from aqueous solution than the commercial AC, suggesting a promising application in the field of water treatment.

scholarly journals Modulating the porosity of carbons for improved adsorption of hydrogen, carbon dioxide, and methane: A review

2022 ◽  
Author(s):  
L. Scott Blankenship ◽  
Robert Mokaya
Keyword(s):  
Carbon Dioxide ◽  
Activated Carbons ◽  
Low Cost ◽  
Porous Carbons ◽  
Adsorption Of Hydrogen ◽  
Stable Material

Porous carbons provide a potential low-cost route to a highly stable material for the adsorption of various gases. In particular, activated carbons (ACs) and zeolite templated carbons (ZTCs) show promise...

scholarly journals Low-Cost Activated Grape Seed-Derived Hydrochar through Hydrothermal Carbonization and Chemical Activation for Sulfamethoxazole Adsorption

2019 ◽  
Vol 9 (23) ◽  
pp. 5127 ◽  
Author(s):  
Elena Diaz ◽  
Francisco Javier Manzano ◽  
John Villamil ◽  
Juan Jose Rodriguez ◽  
Angel F. Mohedano
Keyword(s):  
Surface Composition ◽  
Activated Carbons ◽  
Low Cost ◽  
Chemical Activation ◽  
Hydrothermal Carbonization ◽  
Grape Seed ◽  
Bet Surface Area ◽  
Grape Seeds ◽  
Porous Texture ◽  
Surface Areas

Activated carbons were prepared by chemical activation with KOH, FeCl3 and H3PO4 of the chars obtained via hydrothermal carbonization of grape seeds. The hydrochars prepared at temperatures higher than 200 °C yielded quite similar proximate and ultimate analyses. However, heating value (24.5–31.4 MJ·kg−1) and energy density (1.04–1.33) significantly increased with carbonization temperatures between 180 and 300 °C. All the hydrochars showed negligible BET surface areas, while values between 100 and 845 m2·g−1 were measured by CO2 adsorption at 273 K. Activation of the hydrochars with KOH (activating agent to hydrochar ratio of 3:1 and 750 °C) led to highly porous carbons with around 2200 m2·g−1 BET surface area. Significantly lower values were obtained with FeCl3 (321–417 m2·g−1) and H3PO4 (590–654 m2·g−1), showing these last activated carbons important contributors to mesopores. The resulting materials were tested in the adsorption of sulfamethoxazole from aqueous solution. The adsorption capacity was determined by the porous texture rather than by the surface composition, and analyzed by FTIR and TPD. The adsorption equilibrium data (20 °C) fitted the Langmuir equation well. The KOH-activated carbons yielded fairly high saturation capacity reaching up to 650 mg·g−1.

scholarly journals Heteroatom-doped porous carbons derived from moxa floss of different storage years for supercapacitors

RSC Advances ◽  
2018 ◽  
Vol 8 (30) ◽  
pp. 16433-16443 ◽  
Author(s):  
Xuelin Zhang ◽  
Qingyuan Niu ◽  
Yaqing Guo ◽  
Xiyan Gao ◽  
Kezheng Gao
Keyword(s):  
Low Cost ◽  
Hydrothermal Carbonization ◽  
Koh Activation ◽  
Porous Carbons ◽  
Moxa Floss

Two novel carbons (MCs) derived from moxa floss of different storage years have been prepared by two low-cost and facile approaches, which are hydrothermal carbonization and direct pyrolysis followed by KOH activation strategy, respectively.

scholarly journals Development of a simplified gas ultracleaning process: experiments in biomass residue-based fixed-bed gasification syngas

2021 ◽  
Author(s):  
Christian Frilund ◽  
Esa Kurkela ◽  
Ilkka Hiltunen
Keyword(s):  
Activated Carbons ◽  
Low Cost ◽  
Fixed Bed ◽  
Carbonyl Sulfide ◽  
Gas Analysis ◽  
Small Scale ◽  
Cleaning Process ◽  
Medium Temperature ◽  
Gas Cleaning ◽  
Adsorption Affinity

AbstractFor the realization of small-scale biomass-to-liquid (BTL) processes, low-cost syngas cleaning remains a major obstacle, and for this reason a simplified gas ultracleaning process is being developed. In this study, a low- to medium-temperature final gas cleaning process based on adsorption and organic solvent-free scrubbing methods was coupled to a pilot-scale staged fixed-bed gasification facility including hot filtration and catalytic reforming steps for extended duration gas cleaning tests for the generation of ultraclean syngas. The final gas cleaning process purified syngas from woody and agricultural biomass origin to a degree suitable for catalytic synthesis. The gas contained up to 3000 ppm of ammonia, 1300 ppm of benzene, 200 ppm of hydrogen sulfide, 10 ppm of carbonyl sulfide, and 5 ppm of hydrogen cyanide. Post-run characterization displayed that the accumulation of impurities on the Cu-based deoxygenation catalyst (TOS 105 h) did not occur, demonstrating that effective main impurity removal was achieved in the first two steps: acidic water scrubbing (AWC) and adsorption by activated carbons (AR). In the final test campaign, a comprehensive multipoint gas analysis confirmed that ammonia was fully removed by the scrubbing step, and benzene and H2S were fully removed by the subsequent activated carbon beds. The activated carbons achieved > 90% removal of up to 100 ppm of COS and 5 ppm of HCN in the syngas. These results provide insights into the adsorption affinity of activated carbons in a complex impurity matrix, which would be arduous to replicate in laboratory conditions.

scholarly journals Kaolin-Enhanced Superabsorbent Composites: Synthesis, Characterization and Swelling Behaviors

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1204
Author(s):  
Mengna Chen ◽  
Xuelong Chen ◽  
Caiyan Zhang ◽  
Baozheng Cui ◽  
Zewen Li ◽  
...  
Keyword(s):  
Water Absorption ◽  
Low Cost ◽  
High Water ◽  
Kinetic Mechanism ◽  
Swelling Kinetics ◽  
Synthesis Conditions ◽  
Ph Tolerance ◽  
Monovalent Salt ◽  
Infrared Spectrometer ◽  
Pseudo Second Order

One type of low-cost and eco-friendly organic‒inorganic superabsorbent composite (SAPC) was synthesized by free radical polymerization of acrylic acid (AA), starch (ST), sodium alginate (SA) and kaolin (KL) in aqueous solution. The structure and morphology of the SAPC were characterized by Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The influence of different reaction conditions on water absorption of SAPC, i.e., SA and KL contents, AA neutralization degree (ND), potassium persulfate (KPS) and N, N′-methylenebisacrylamide (MBA) loading were systematically studied. Under the optimal synthesis conditions, very high water absorption of 1200 g/g was achieved. The swelling kinetic mechanism of SAPC was studied by pseudo-second order swelling kinetics model and Ritger‒Peppas model. The performances of SAPC under different environments were tested and results revealed that this new SAPC had excellent swelling capacity, high water retention, good salt tolerance in monovalent salt solution (NaCl solution) and good pH tolerance between 4 and 10.

scholarly journals Synthesis of catalysts with fine platinum particles supported by high-surface-area activated carbons and optimization of their catalytic activities for polymer electrolyte fuel cells

RSC Advances ◽  
2021 ◽  
Vol 11 (33) ◽  
pp. 20601-20611
Author(s):  
Md. Mijanur Rahman ◽  
Kenta Inaba ◽  
Garavdorj Batnyagt ◽  
Masato Saikawa ◽  
Yoshiki Kato ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
High Performance ◽  
Activated Carbons ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Polymer Electrolyte Fuel Cells ◽  
Supported Platinum ◽  
Platinum Particles

Herein, we demonstrated that carbon-supported platinum (Pt/C) is a low-cost and high-performance electrocatalyst for polymer electrolyte fuel cells (PEFCs).

scholarly journals Evaluation of Porous Carbon Adsorbents Made from Rice Husks for Virus Removal in Water

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1280
Author(s):  
Vu Duc Canh ◽  
Seiichiro Tabata ◽  
Shun Yamanoi ◽  
Yoichi Onaka ◽  
Toshiyuki Yokoi ◽  
...  
Keyword(s):  
Porous Carbon ◽  
Activated Carbons ◽  
Carbon Adsorbents ◽  
Rice Husks ◽  
Porous Carbons ◽  
Inorganic Pollutants ◽  
Steam Activation ◽  
Virus Removal ◽  
Silica Removal ◽  
Effective Removal

Porous carbons are well-known efficient adsorbents for a variety of organic and inorganic pollutants; however, they have difficulty in virus removal. In this study, novel porous carbons (NPCs) (NPC-A, NPC-B, and NPC-C) derived from rice husks were compared with commercially available activated carbons (ACs) for their ability to remove MS2 bacteriophages (MS2) in a batch experiment. NPC-A was produced by the silica removal process. NPC-B was prepared with an additional steam activation applied to NPC-A. NPC-C was obtained with an additional acid rinse applied to NPC-B. The NPCs (particularly NPC-C) exhibited effective removal of up to 5.3 log10 of MS2, which was greater than that of less than 2.7 log10 obtained by other ACs under 10 g/L during the same contact time (60 min). The pore size distribution of the porous carbon adsorbents was found to influence their virus removal performance. The adsorbents with a larger proportion of pores ranging from 200–4500 nm in diameter were able to achieve higher virus removal rates. Thus, NPCs (particularly NPC-C), which had a larger volume of pores ranging from 200–4500 nm in size, demonstrated the potential for use as efficient adsorbents for removing viruses during water purification.

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