Equilibrium and Dynamic Adsorption of Bioethanol on Activated Carbon in the Liquid Phase

Coconut granular activated carbon (CGAC) was modified by impregnating with ZnCl2solution to remove nitrate from aqueous solutions. Sorption isotherm and kinetic studies were carried out in a series of batch experiments. Nitrate adsorption of both ZnCl2-modified CGAC and CGAC fitted the Langmuir and Freundlich models. Batch adsorption isotherms indicated that the maximum adsorption capacities of ZnCl2-modified CGAC and CGAC were calculated as 14.01 mgN·g−1and 0.28 mgN·g−1, respectively. The kinetic data obtained from batch experiments were well described by pseudo-second-order model. The column study was used to analyze the dynamic adsorption process. The highest bed adsorption capacity of 1.76 mgN·g−1was obtained by 50 mgN·L−1inlet nitrate concentration, 20 g adsorbents, and 10 ml·min−1flow rate. The dynamic adsorption data were fitted well to the Thomas and Yoon–Nelson models with coefficients of correlationR2 > 0.834 at different conditions. Surface characteristics and pore structures of CGAC and ZnCl2-modified CGAC were performed by SEM and EDAX and BET and indicated that ZnCl2had adhered to the surface of GAC after modified. Zeta potential, Raman spectra, and FTIR suggested the electrostatic attraction between the nitrate ions and positive charge. The results revealed that the mechanism of adsorption nitrate mainly depended on electrostatic attraction almost without any chemical interactions.

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Dynamic adsorption of propane and propylene on activated carbon

10.31274/rtd-180813-3147 ◽

1970 ◽

Author(s):

Fred Baxter Smith

Keyword(s):

Activated Carbon ◽

Dynamic Adsorption

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Aminated Activated Carbon in Liquid-phase Hydrogenation of Organic Compounds

HERALD of Dagestan State University ◽

10.21779/2542-0321-2020-35-3-103-110 ◽

2020 ◽

Vol 35 (3) ◽

pp. 103-110

Author(s):

N.A. Magdalinova ◽

◽

K.M. Puzakova ◽

M.V. Klyuev ◽

◽

...

Keyword(s):

Activated Carbon ◽

Liquid Phase ◽

Organic Compounds ◽

Liquid Phase Hydrogenation

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Catalytic Performance of Nitrogen-Doped Activated Carbon Supported Pd Catalyst for Hydrodechlorination of 2,4-Dichlorophenol or Chloropentafluoroethane

Molecules ◽

10.3390/molecules24040674 ◽

2019 ◽

Vol 24 (4) ◽

pp. 674 ◽

Cited By ~ 2

Author(s):

Haodong Tang ◽

Bin Xu ◽

Meng Xiang ◽

Xinxin Chen ◽

Yao Wang ◽

...

Keyword(s):

Activated Carbon ◽

Liquid Phase ◽

Gas Phase ◽

Nitrogen Doping ◽

Catalyst Surface ◽

Catalytic Performance ◽

Atomic Ratio ◽

Pd Catalyst ◽

Nitrogen Doped ◽

The Stability

Nitrogen-doped activated carbon (N-AC) obtained through the thermal treatment of a mixture of HNO3-pretreated activated carbon (AC) and urea under N2 atmosphere at 600 °C was used as the carrier of Pd catalyst for both liquid-phase hydrodechlorination of 2,4-dichlorophenol (2,4-DCP) and gas-phase hydrodechlorination of chloropentafluoroethane (R-115). The effects of nitrogen doping on the dispersion and stability of Pd, atomic ratio of Pd/Pd2+ on the surface of the catalyzer, the catalyst’s hydrodechlorination activity, as well as the stability of N species in two different reaction systems were investigated. Our results suggest that, despite no improvement in the dispersion of Pd, nitrogen doping may significantly raise the atomic ratio of Pd/Pd2+ on the catalyst surface, with a value of 1.2 on Pd/AC but 2.2 on Pd/N-AC. Three types of N species, namely graphitic, pyridinic, and pyrrolic nitrogen, were observed on the surface of Pd/N-AC, and graphitic nitrogen was stable in both liquid-phase hydrodechlorination of 2,4-DCP and gas-phase hydrodechlorination of R-115, with pyridinic and pyrrolic nitrogen being unstable during gas-phase hydrodechlorination of R-115. As a result, the average size of Pd nanocrystals on Pd/N-AC was almost kept unchanged after liquid-phase hydrodechlorination of 2,4-DCP, whereas crystal growth of Pd was clearly observed on Pd/N-AC after gas-phase hydrodechlorination of R-115. The activity test revealed that Pd/N-AC exhibited a much better performance than Pd/AC in liquid-phase hydrodechlorination of 2,4-DCP, probably due to the enhanced stability of Pd exposed to the environment resulting from nitrogen doping as suggested by the higher atomic ratio of Pd/Pd2+ on the catalyst surface. In the gas-phase hydrodechlorination of R-115, however, a more rapid deactivation phenomenon occurred on Pd/N-AC than on Pd/AC despite a higher activity initially observed on Pd/N-AC, hinting that the stability of pyridinic and pyrrolic nitrogen plays an important role in the determination of catalytic performance of Pd/N-AC.

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Synergy between Ionic Liquids and CuCl2 in Gas–Liquid Phase Reactions of Acetylene Hydrochlorination

Catalysts ◽

10.3390/catal9060504 ◽

2019 ◽

Vol 9 (6) ◽

pp. 504 ◽

Cited By ~ 4

Author(s):

Yi Yu ◽

Yuxue Yue ◽

Bolin Wang ◽

Haihua He ◽

Zhong-Ting Hu ◽

...

Keyword(s):

Catalytic Activity ◽

Ionic Liquids ◽

Activated Carbon ◽

Liquid Phase ◽

Dft Calculations ◽

Synergetic Effect ◽

Good Explanation ◽

Experimental Results ◽

Acetylene Hydrochlorination ◽

Reaction Media

We studied the acetylene hydrochlorination in gas–liquid phase reactions using ionic liquids (IL) as the reaction media and CuCl2 as the catalyst. The Cu-IL catalyst showed strong synergy between the IL and the Cu(II) active catalytic species. For [PrMIm]Cl, the Cu-IL catalyst exhibited significant enhancement of the catalytic activity in comparison with the CuCl2 catalyst supported on activated carbon and the IL alone as the catalyst. We have also performed DFT calculations of the reaction process, which provides a good explanation of our experimental results and for the synergetic effect. Our result suggests that ILs may be used to improve the activity of other metallic catalysts for the hydrochlorination reaction of acetylene.

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