scholarly journals Mesoporous Carbon-Based Rhodium Catalysts for Benzene Hydrogenation

2011 ◽  
Vol 14 (1) ◽  
pp. 37
Author(s):  
J.M. Jandosov ◽  
Z.A. Mansurov ◽  
M.A. Biisenbayev ◽  
Z.R. Ismagilov ◽  
N.V. Shikina ◽  
...  
Keyword(s):  
Activated Carbons ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Benzene Hydrogenation ◽  
Rhodium Catalysts ◽  
X Ray ◽  
Elemental Analyses ◽  
Adsorption Data ◽  
Naoh Solution ◽  
Nitrogen Adsorption Data

<p>Two different carbons, namely CAS-P-500 and CRH-P-500, were prepared from apricot stones and rice husk by H<sub>3</sub>PO<sub>4</sub>-activation at 500 °C and H<sub>3</sub>PO<sub>4</sub>/precursor (wt/wt) impregnation ratio of 2:1 followed by water washing and desilication by NaOH solution respectively. Elemental analyses of both samples using X-ray fluorescence spectroscopy and VARIO ELEMENTAR III elemental analyzer detected up to 1% of remained phosphorus and about 88% of carbon. SEM characterization and nitrogen adsorption data revealed that highly mesoporous materials were obtained. According to BJH scheme calculations, N<sub>2</sub> BET-surface area and pore volume for CAS-P-500 reached the values of 2030 m<sup>2</sup>/g and 1.64 cm<sup>3</sup>/g, while for CRH-P-500: 1690 m<sup>2</sup>/g and 1.95 cm<sup>3</sup>/g respectively. Activated carbons CAS-P-500 and CRH-P-500 were used as catalyst supports for the conversion of small amounts of benzene into cyclohexane to obtain cleaner gasoline. According to Euro-3 standards, gasoline should contain less than 1% of benzene, since the incomplete combustion of gasoline, which contains benzene, leads to formation of benzopyrene- a powerful carcinogen in exhaust gases. The activity of rhodium catalysts based on the CAS-P-500 and CRH-P-500 allow complete conversion of benzene into cyclohexane at 40 atm and 80 °C temperature and is comparable to those of based on conventional carbons: “Sibunit”, etc.</p>

Adsorption of Iodine from Aqueous Solutions on to Activated Carbons: Correlation with Nitrogen Adsorption at 77K

1989 ◽  
Vol 6 (1) ◽  
pp. 18-26 ◽  
Author(s):  
J. Fernandez-Colinas ◽  
R. Denoyel ◽  
J. Rouquerol
Keyword(s):  
Carbon Black ◽  
Activated Carbons ◽  
Nitrogen Adsorption ◽  
Micropore Volume ◽  
Iodine Molecule ◽  
Reference Analysis ◽  
Adsorption Data ◽  
Iodine Adsorption ◽  
Vulcan Carbon ◽  
Nitrogen Adsorption Data

The adsorption of iodine has been examined on a set of four microporous charcoals subjected to increasing activation, and also on a Vulcan carbon black used as a non-porous reference. Analysis of the iodine adsorption isotherms and of the corresponding differential enthalpies of displacement is consistent with the nitrogen adsorption data, provided that the slightly larger size of the iodine molecule is kept in mind. The αs method, which is normally applied to adsorption from the gaseous phase, has been usefully extended to these liquid/solid systems and leads to a reasonable micropore volume. This approach provides a useful alternative, especially in those cases where the adsorbent cannot be subjected to drying.

scholarly journals New approach in the application of lignin for the synthesis of hybrid materials

2017 ◽  
Vol 89 (1) ◽  
pp. 161-171 ◽  
Author(s):  
Beata Podkościelna ◽  
Marta Goliszek ◽  
Olena Sevastyanova
Keyword(s):  
Suspension Polymerization ◽  
Nitrogen Adsorption ◽  
Experimental Protocol ◽  
New Approach ◽  
Surface Areas ◽  
Adsorption Data ◽  
Novel Method ◽  
Derivatives Of ◽  
Polymerization Method ◽  
Nitrogen Adsorption Data

AbstractIn this study, a novel method for the synthesis of hybrid, porous microspheres, including divinylbenzene (DVB), triethoxyvinylsilane (TEVS) and methacrylated lignin (L-Met), is presented. The methacrylic derivatives of kraft lignin were obtained by reaction with methacryloyl chloride according to a new experimental protocol. The course of the modification of lignin was confirmed by attenuated total reflectance (ATR-FTIR) and nuclear magnetic resonance (NMR) spectroscopy. The emulsion-suspension polymerization method was employed to obtain copolymers of DVD, TEVS and L-Met in spherical forms. The porous structures and morphologies of the obtained lignin-containing functionalized microspheres were investigated by low-temperature nitrogen adsorption data and scanning electron microscopy (SEM). The microspheres are demonstrated to be mesoporous materials with specific surface areas in the range of 430–520 m2/g. The effects of the lignin component on the porous structure, shape, swelling and thermal properties of the microspheres were evaluated.

Removal of Cu, Fe, and Zn from Peat Water by Using Activated Carbon Derived from Oil Palm Leaves

2021 ◽  
Vol 1162 ◽  
pp. 65-73
Author(s):  
Rakhmawati Farma ◽  
Ona Lestari ◽  
Erman Taer ◽  
Apriwandi ◽  
Minarni ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Activated Carbon ◽  
Oil Palm ◽  
Activated Carbons ◽  
Nitrogen Adsorption ◽  
Surface Characteristics ◽  
Batch Adsorption ◽  
X Ray ◽  
Turbidity Level ◽  
Adsorption Desorption

Heavy metal such as Cu, Fe, and Zn are the most serious contributers to environmental problems. The removal of heavy metal from the environment is the research interest nowdays. The adsorption of Cu, Fe and Zn from wastewater was investigated with various activated carbons as adsorbents. The activated carbons were produced from oil palm leaves by using multi-activation methods. The H3PO4, NaOH, ZnCl2 and KOH were chosen as chemical activating agents. Batch adsorption experiment was used to test the ability of activated carbon to remove Cu, Fe, and Zn from wastewater. The surface characteristics of activated carbon were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption-desorption isotherms. The Activated carbons were able to purify wastewater with a maximum turbidity level of 2.83 NTU. The AC-H3PO4 activated carbon showed the highest absorbability of Cu metal as 91.540%, while the highest absorbabilities of Zn and Fe metals were indicated by AC-KOH activated carbon of 22.853% and 82.244% absorption respectively. Therefore, these results enable the oil palm leaves to become a high potential for activated carbon as removal the heavy metals.

scholarly journals Thermodynamic Behaviors of Adsorbed Methane Storage Systems Based on Nanoporous Carbon Adsorbents Prepared from Coconut Shells

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2243
Author(s):  
Ilya Men’shchikov ◽  
Andrey Shkolin ◽  
Evgeny Strizhenov ◽  
Elena Khozina ◽  
Sergey Chugaev ◽  
...  
Keyword(s):  
Storage Tank ◽  
Activated Carbons ◽  
Storage System ◽  
Nitrogen Adsorption ◽  
Methane Adsorption ◽  
Carbon Adsorbents ◽  
X Ray ◽  
Coconut Shells ◽  
Activation Conditions ◽  
Charge Discharge

The present work focused on the experimental study of the performance of a scaled system of adsorbed natural gas (ANG) storage and transportation based on carbon adsorbents. For this purpose, three different samples of activated carbons (AC) were prepared by varying the size of coconut shell char granules and steam activation conditions. The parameters of their porous structure, morphology, and chemical composition were determined from the nitrogen adsorption at 77 K, X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), and scanning electron microscopy (SEM) measurements. The methane adsorption data measured within the temperature range from 178 to 360 K and at pressures up to 25 MPa enabled us to identify the most efficient adsorbent among the studied materials: AC-90S. The differential heats of methane adsorption on AC-90S were determined in order to simulate the gas charge/discharge processes in the ANG system using a mathematical model with consideration for thermal effects. The results of simulating the charge/discharge processes under two different conditions of heat exchange are consistent with the experimentally determined temperature distribution over a scaled ANG storage tank filled with the compacted AC-90S adsorbent and equipped with temperature sensors and heat-exchanger devices. The amounts of methane delivered from the ANG storage system employing AC-90S as an adsorbent differ from the model predictions by 4–6%. Both the experiments and mathematical modeling showed that the thermal regulation of the ANG storage tank ensured the higher rates of charge/discharge processes compared to the thermal insulation.

scholarly journals Textural properties of synthetic clay-ferrihydrite associations

Clay Minerals ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 395-407 ◽  
Author(s):  
R. Celis ◽  
J. Cornejo ◽  
M. C. Hermosin
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mercury Porosimetry ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Fractal Approach ◽  
Adsorption Data ◽  
Synthetic Clay ◽  
Nitrogen Adsorption Data

AbstractKaolinite-ferrihydrite and montmorillonite-ferrihydrite associations were prepared following a procedure based on the Russell method for the synthesis of ferrihydrite and the texture of the clay-ferrihydrite complexes was studied using different techniques. The textural properties of kaolinite were little affected by the Fe association, showing only a slight increase in the specific surface area measured by nitrogen adsorption and a decrease in the largest pores (>10 µm), as measured by mercury porosimetry. In contrast, the nitrogen specific surface area of the montmorillonite complexes was much higher than that of the clay without Fe and the pore structure depended on the amounts of Fe in the complexes. Application of the fractal approach to nitrogen adsorption data indicated that the surface roughness (microporosity) was greater for the complexes prepared from diluted Fe(III) solutions, in agreement with the information obtained from classical interpretation of the adsorption isotherms (shape of the isotherms and t-plots).

scholarly journals Comparison of Surface and Structural Properties of Carbonaceous Materials Prepared by Chemical Activation of Tomato Paste Waste: The Effects of Activator Type and Impregnation Ratio

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Nurgul Ozbay ◽  
Adife Seyda Yargic
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Low Cost ◽  
Chemical Activation ◽  
Nitrogen Adsorption ◽  
Xrd Analysis ◽  
Point Of Zero Charge ◽  
Activation Process ◽  
X Ray ◽  
Tomato Paste

Activated carbons were prepared by carbonization of tomato paste processing industry waste at 500°C followed by chemical activation with KOH, K2CO3, and HCl in N2 atmosphere at low temperature (500°C). The effects of different activating agents and impregnation ratios (25, 50, and 100 wt.%) on the materials’ characteristics were examined. Precursor, carbonized tomato waste (CTW), and activated carbons were characterized by using ultimate and proximate analysis, thermogravimetric analysis (TG/DTG), Fourier transform-infrared (FT-IR) spectroscopy, X-ray fluorescence (XRF) spectroscopy, point of zero charge measurements (pHPZC), particle size analyzer, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, nitrogen adsorption/desorption isotherms, and X-ray diffraction (XRD) analysis. Activation process improved pore formation and changed activated carbons’ surface characteristics. Activated carbon with the highest surface area (283 m3/g) was prepared by using 50 wt.% KOH as an activator. According to the experimental results, tomato paste waste could be used as an alternative precursor to produce low-cost activated carbon.

Coating Iron Oxides on Kaolinite for the Adsorption of Fluoride

2012 ◽  
Vol 479-481 ◽  
pp. 250-254
Author(s):  
Wen Jun Xiang
Keyword(s):  
Iron Oxides ◽  
Freundlich Isotherm ◽  
Zero Point ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fluoride Adsorption ◽  
Adsorption Data ◽  
Co Precipitation

Iron oxides-coated kaolinite (Fe-Kaolinite) was prepared by co-precipitation and indentified using X-ray diffraction (XRD). Moreover, the surface properties and fluoride adsorption characteristics of Fe-Kaolinite were investigated and compared with those of kaolinite. Compared to kaolinite, the BET surface area and surface fractal dimension of Fe-Kaolinite increased significantly. The pH at zero point of charge (pHZPC) of kaolinite and Fe-Kaolinite was 3.16 and 6.24, respectively. In the suspensions of pH 6.0, the fitted maximum adsorption capacity (qmax) for fluoride of kaolinite and Fe-Kaolinite was 1.32 and 5.86 mg/g, respectively. The adsorption data for fluoride by Fe-Kaolinite could be fitted using Freundlich isotherm (R2 =0.987), and Langmuir isotherm was very suitable for describing the fluoride adsorption of kaolinite (R2 =0.991).

Sign in / Sign up

Export Citation Format

Share Document