logo
    Highly Selective and Stable Carbon Dioxide Uptake in Polyindole-Derived Microporous Carbon Materials
    83
    Citation
    48
    Reference
    10
    Related Paper
    Citation Trend
    Abstract:
    Adsorption with solid sorbents is considered to be one of the most promising methods for the capture of carbon dioxide (CO2) from power plant flue gases. In this study, microporous carbon materials used for CO2 capture were synthesized by the chemical activation of polyindole nanofibers (PIF) at temperatures from 500 to 800 °C using KOH, which resulted in nitrogen (N)-doped carbon materials. The N-doped carbon materials were found to be microporous with an optimal adsorption pore size for CO2 of 0.6 nm and a maximum (Brunauer–Emmett–Teller) BET surface area of 1185 m2 g–1. The PIF activated at 600 °C (PIF6) has a surface area of 527 m2 g–1 and a maximum CO2 storage capacity of 3.2 mmol g–1 at 25 °C and 1 bar. This high CO2 uptake is attributed to its highly microporous character and optimum N content. Additionally, PIF6 material displays a high CO2 uptake at low pressure (1.81 mmol g–1 at 0.2 bar and 25 °C), which is the best low pressure CO2 uptake reported for carbon-based materials. The adsorption capacity of this material remained remarkably stable even after 10 cycles. The isosteric heat of adsorption was calculated to be in the range of 42.7–24.1 kJ mol–1. Besides the excellent CO2 uptake and stability, PIF6 also exhibits high selectivity values for CO2 over N2, CH4, and H2 of 58.9, 12.3, and 101.1 at 25 °C, respectively, and these values are significantly higher than reported values.
    Keywords:
    Carbon fibers
    BET theory
    Bar (unit)
    Specific surface area
    The microvoid activated carbon with large specific surface area was prepared from reed pulping black liquor through chemical activation with K2CO3 as activator. The effect of activation temperature on the specific surface area, micropore volume and mesopore volume of the prepared activated carbon BET was closely investigated. The optimum temperature for preparing large specific surface area activated carbon is 800℃. The BET surface area and pore volume of the carbon activated at 800℃ were 1401 m2/g and 0.79 ml/g respectively. XRD shows that silicon crystals appeared in the activated carbon. The activated carbon had a good adsorption of heavy metal C(rVI)at pH=7 and the maximum adsorptive capacity could reach 54.23 mg/g and Langmuir model was better for describing the adsorption process than Freundlich model.
    BET theory
    Specific surface area
    Carbon fibers
    Citations (0)
    The effect of pressure, temperature, microporous size of activated carbon on adsorption process of isopro-pyl alcohol on activated carbon was studied by Grand Canonical Monte Carlo Simulation. The result shows that the adsorption process can be described reliably by the activated carbon microporous model. When the pressure is 1kPa, the adsorption quantity of activated carbon with microporous size of 1. 7nm is higher. While activated carbon with microporous size of 2. 0nm has higher adsorption quantity when the pressure is 2-4kPa. At the pressure of 4 -10kPa, the adsorption quantity of activated carbon with microporous size of 2. 5nm is higher. The adsorption quantity of the system which jaws width of activity carbon is 2. 5nm is higher. The best recovery temperature of iso-propyl alcohol desorbed from activated carbon is 140℃.
    Isopropyl alcohol
    Carbon fibers
    Activated Charcoal
    Citations (0)
    The feasibility study of preparing activated carbon from durian peels by physical activation with CO{2} was investigated. Two pyrolysis conditions were employed and compared: nitrogen atmospheric and vacuum pyrolysis. After synthesis of activated carbon, influence of chemical treatment on properties of the activated carbons was investigated. The results showed that activated carbon synthesised under vacuum pyrolysis exhibited better properties than that synthesised under nitrogen atmospheric pyrolysis. Those properties included BET surface area, pore volume and adsorption capacities of iodine and methylene blue. Treatment of activated carbon synthesised from both pyrolysis conditions with 2 M HCl aqueous solution increased BET surface area, pore volume and adsorption capacities of iodine and methylene blue. FTIR spectra showed that treatment of activated carbon with 2 M HCl or NaOH solution unchanged functional groups of the activated carbon. Instead, BET surface area and pore volume of activated carbon treated with the acid solution were enhanced due to the removal of impurities.
    BET theory
    Methylene blue
    Carbon fibers
    Specific surface area
    Citations (0)
    Activated carbons were prepared from coconut shell by chemical activation method and utilized as electrode materials for electrochemical double layer capacitor (EDLC). A preliminary characteristic of activated carbon from coconut shell includes the Brunnaeur Emmett Teller (BET) analysis and cyclic voltammetry measurements. The BET surface area is not affected by the variation of activation temperature as both of the samples showed BET surface area of about 850-870 m2g-1. The N2 adsorption–desorption isotherms showed that the sample exhibited type I characteristics according to IUPAC classification, which confirms its micro-porosity. Compared with the un-activated carbon samples, the activated ones exhibited the better electrochemical properties with a specific capacitance of 150 F g−1 at a scan rate of 2 mV s−1. The good performance of activated carbon is attributed to the enhancement of surface area due to the KOH pretreatment which can open new pores accessible for the ionic transport
    BET theory
    Specific surface area
    Carbon fibers
    Horizontal scan rate
    BET equation was used to calculate surface area of different powder solids,such as mesoporous Al_2O_3 and microporous zeolites,at different relative pressure(P/P_0).The results showed that when relative pressure is in the range of 0.01-0.10,surface area of microporous materials calculated is more reliable.For most microporous materials,BET surface area calculated at P/P_0=0.05-0.20 is less than that at P/P_0=0.01-0.10.For some hydrothermally-treated ZSM-5 samples,their isotherms have hysteresis loop at lower relative pressure;BET surface area calculated at P/P_0=0.05-0.20 is smaller that that calculated at P/P_0=0.01-0.10.The more microporous material in the catalysts,the larger the difference in BET surface area calculated at the two relative pressure ranges.For some pure zeolites,this difference can be up to 15%.
    BET theory
    Specific surface area
    Hysteresis
    Citations (2)
    Activated carbons are prepared from hemp stem with KOH as activating agent under different ratio of KOH to carbon conditions. The BET(Brunauer Emmett and Teller) specific surface area of the hemp stem-based activated carbons first increases and then decreases with the increasing ratio of KOH to carbon. The specific surface area, micropore surface area and volume of the activated carbons reach a maximum of 1589.27m 2 /g 1420.52m 2 /g, 89% of the total area, 0.751m 3 /g at the ratio of 4.5:1. The micropore size distribution shows the activated carbons contain a large number of ultramicropore and supermicropore.
    Specific surface area
    Carbon fibers
    BET theory
    To quantitatively describe and analyze specific surface area and pore structure of graphite fibers,in this paper,nitrogen adsorption-desorption isotherms of graphite fibers were measured by low temperature nitrogen adsorption method at liquid nitrogen temperature and different pressures.It showed that graphite fibers are microporous material which contains a large number of microporous and a few of mesoporous;the BET specific surface area,total pore volume and average pore size of graphite fibers were 541.00m2/g,0.2436cm3/g and 1.8010nm,respectively,and the specific surface area,pore volume and pore diameter of its microporous were 535.53m2 / g,0.2331cm3/g and 0.9896nm,respectively;there is a narrow pore size distribution of graphite fibers,which are a large number of microporous about 1.4nm and a few of mesoporous about 2.0-7.7nm,and the microporous is the greatest contribution to the specific surface area and the pore volume.
    Specific surface area
    BET theory
    Citations (0)