Possibilities of Graphitization of Unburned Carbon from Coal Fly Ash

The paper presents the characteristics of products annealing at the temperatures of 2400 and 3000 °C of unburned carbon from coal fly ash in terms of its possible use as a starting material in the graphitization process. An amorphous substance (organic substance) with an admixture of some minerals has been found in samples subjected to graphitization. However, the graphite phase is dominant in products subjected to graphitization. Studies have also shown a diverse grain morphology in individual samples. The presence of plate-shaped and tube-shaped grains was found. As the graphitization temperature of the starting material increases (2400 and 3000 °C), the specific surface area in the graphitization products decreases. The total pore volume in the samples after the graphitization process was significantly lower than the pore volume of active carbons produced from other unburned carbon. Average pore diameter is similar to the pore diameter in active carbons. The reflectance value of the matrix for the sample graphitized at 3000 °C is characteristic for graphite. Unburned carbon from Polish fly ash can be used as the starting material for graphitization.

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Experimental Research on the Preparation of Porous Activated Carbon from Orange Wastes

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.1907 ◽

2009 ◽

Vol 79-82 ◽

pp. 1907-1910

Author(s):

Zhi Gang Xie

Keyword(s):

Activated Carbon ◽

Surface Area ◽

Pore Volume ◽

Pore Diameter ◽

Total Pore Volume ◽

Carbonization Temperature ◽

Bet Surface Area ◽

Average Pore ◽

Impregnation Ratio ◽

Heat Preservation

Porous activated carbon was prepared from orange wastes using zinc chloride as an activating agent by one-step carbonization method. Effects of impregnation ratio, carbonization temperature and heat preservation time on pore characteristics of activated carbon were studied. The porous structures of the orange wastes activated carbon were investigated by BET, D-R equations, BJH equations and Kelvin theory. The morphology was observed using transmission electron microscopy (TEM). The mesoporous activated carbon is gained when the impregnation ratio is 3:1; the carbonization temperature is 550°Cand heat preservation time is 1.0 h. The activated carbon has total pore volume 2.098 cm3/g, mesoporous pore volume 1.438 cm3/g, with a high BET surface area 1476m2/g. The pore distribution of the mesoporous activated carbon is very concentrative, with average pore diameter of 3.88nm. While, the high specific surface area activated carbon is gained when the impregnation ratio is 2:1; the carbonization temperature is 550°Cand heat preservation time is 1.0 h. The activated carbon has high BET surface area 1909 m2/g, while the total pore volume is only 1.448cm3/g and microporous pore volume is 0.889cm3/g, with average pore diameter of 2.29 nm.

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Selective Production of Green Hydrocarbons from the Hydrotreatment of Waste Coconut Oil over Ni- and NiMo-supported on Amine-functionalized Mesoporous Silica

BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS ◽

10.9767/bcrec.15.2.7136.415-431 ◽

2020 ◽

Vol 15 (2) ◽

pp. 415-431 ◽

Cited By ~ 1

Author(s):

Wega Trisunaryanti ◽

Savitri Larasati ◽

Triyono Triyono ◽

Cahyarani Paramesti ◽

Nugroho Raka Santoso

Keyword(s):

Electron Microscopy ◽

Mesoporous Silica ◽

Pore Volume ◽

Pore Diameter ◽

Coconut Oil ◽

Total Pore Volume ◽

Average Pore ◽

Functionalized Mesoporous Silica ◽

Amine Functionalized ◽

Green Fuel

In order to overcome the depletion of energy resources, the production of fuel from a renewable source (green fuel) has aroused attention. The present work serves as a comparative study for green fuel production by utilizing monometallic Ni and bimetallic NiMo loaded on amine-functionalized mesoporous silica (MS). Two types of catalysts, denoted as Ni/NH2-MS and NiMo/NH2-MS, were prepared and evaluated for its catalytic activity in the hydrotreatment of waste coconut oil (WCO) at 450 ℃ under the flow of H2 gas (20 mL.min-1). Each catalysts were characterized by using X-ray Diffraction (XRD), Atomic Absorption Spectrometer (AAS), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Fourier Transform Infra Red (FTIR). Study of selectivity by GC-MS showed that gasoline-range hydrocarbon, especially n-undecane, was the major compound in the liquid products generated by the two amine-functionalized catalysts prepared in this study. The result showed that monometallic Ni/NH2-MS with surface area, total pore volume, nickel loading and average pore diameter 328.68 m2.g-1, 0.25 cm3.g-1, 1.90 wt%, 3.10 nm, respectively, exhibited the best performance in producing liquid hydrocarbon and generated higher level of liquid product (77.9 wt%) than bimetallic NiMo/NH2-MS (76.3 wt%). However, it is highlighted that adding 1.08 wt% of Mo in bimetallic NiMo/NH2-MS comprising 0.83 wt% of Ni improved the catalyst selectivity towards producing higher level of gasoline-range hydrocarbon (43 wt%). The bimetallic NiMo/NH2-MS prepared was found to have surface area, total pore volume, and average pore diameter of 325.13 m2.g-1, 0.14 cm3.g-1, 3.22 nm, respectively. Copyright © 2020 BCREC Group. All rights reserved

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Fuels Desulphurisation by Adsorbtion on Fe / Bentonite

Revista de Chimie ◽

10.37358/rc.17.3.5483 ◽

2017 ◽

Vol 68 (3) ◽

pp. 483-486

Author(s):

Constantin Sorin Ion ◽

Mihaela Bombos ◽

Gabriel Vasilievici ◽

Dorin Bombos

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Pore Volume ◽

Pore Diameter ◽

Adsorption Process ◽

Continuous System ◽

Gas Oil ◽

Average Pore ◽

Atmospheric Distillation

Desulfurisation of atmospheric distillation gasoline and gas oil was performed by adsorption process on Fe/ bentonite. The adsorbent was characterized by determining the adsorption isotherms, specific surface area, pore volume and average pore diameter. Adsorption experiments of atmospheric distillation gasoline and gas oil were performed in continuous system at 280�320oC, 5 atm and volume hourly space velocities of 1�2 h-1. The efficiency of adsorption on Fe / bentonite was better at desulphurisation of gasoline versus gas oil.

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Effect of Structure and Chemical Activation on the Adsorption Properties of Green Clay Minerals for the Removal of Cationic Dye

Applied Sciences ◽

10.3390/app8112302 ◽

2018 ◽

Vol 8 (11) ◽

pp. 2302 ◽

Cited By ~ 15

Author(s):

Abdelfattah Amari ◽

Hatem Gannouni ◽

Mohammad Khan ◽

Mohammed Almesfer ◽

Abubakr Elkhaleefa ◽

...

Keyword(s):

Clay Minerals ◽

Pore Volume ◽

Acid Treatment ◽

Structural Changes ◽

Chemical Activation ◽

Total Pore Volume ◽

Batch Adsorption ◽

Acid Activation ◽

Cationic Dye ◽

Average Pore

In this study, natural clay minerals with green appearance were treated with sulfuric acid. Mass percentage of acid (wt%), temperature (T), contact time (t) and liquid-to-solid mass ratio (R) are used as the prevailing factors that determine the extent of acid-activation. The values of these factors range from 15–50%, 60–90 °C, 1.5–6 h and 4–7, respectively. The study has focused on the structural changes as well as textural characteristics of the clay. Three activated clay samples were prepared under different treatment conditions. The samples were characterized using X-ray powder diffraction (XRD), fourier transform infrared (FTIR), scanning electron microscope (SEM), chemical analysis and N2 adsorption techniques. Characterization of the treated clay minerals exhibited significant structural changes to a greater extent of acid-activation, from being partially crystalline to being amorphous silica. The surface area and total pore volume of clay increased proportionally with the level of acid treatment. The average pore diameter behaved differently. During the strong acid treatment, a large increase in pore volume and the enlargement of the pore size distribution were observed. This suggests that considerable structural changes and partial destruction may have occurred in this condition. The removal of methylene blue, used as cationic dye, from aqueous solution by the batch adsorption technique on three prepared acid-activated clay samples was studied. The Langmuir model was found to agree well with the experimental data.

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The development of technology for production of zeolites from fly-ash from Troitskaya power plant

Chimica Techno Acta ◽

10.15826/chimtech.2021.8.1.11 ◽

2021 ◽

Vol 8 (1) ◽

pp. 20218111

Author(s):

V. A. Snegirev ◽

V. M. Yurk

Keyword(s):

Fly Ash ◽

Power Plant ◽

Pore Diameter ◽

Silicon Oxide ◽

Exchange Capacity ◽

Static Exchange Capacity ◽

Average Pore ◽

Hydrochemical Synthesis ◽

Bet Method ◽

Zeolite Production

The study examines the technology of processing fly ash from Troitskaya power plant for the production of zeolite. The paper presents the results of laboratory studies evaluating the suitability of fly ash from Troitskaya power plant for the production of zeolites and the development of the zeolite production process. Fly ash contains a small amount of heavy metals that can complicate processing, but contains a large amount of silicon oxide. The technology consists of high-temperature alkaline activation of fly ash and hydrochemical synthesis. The resulting powder has a specific surface area of 89.7 m2/g, determined by the BET method, and an average pore diameter of 0.345 μm. The static exchange capacity was 220 mg/g.

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Structural and fractal characterization of adsorption pores of middle–high rank coal reservoirs in western Yunnan and eastern Guizhou: An experimental study of coals from the Panguan syncline and Laochang anticline

Energy Exploration & Exploitation ◽

10.1177/0144598718790319 ◽

2018 ◽

Vol 37 (1) ◽

pp. 251-272 ◽

Cited By ~ 9

Author(s):

Junjian Zhang ◽

Chongtao Wei ◽

Gaoyuan Yan ◽

Guanwen Lu

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Pore Volume ◽

Pore Diameter ◽

Structural Parameters ◽

Total Pore Volume ◽

Type A ◽

Type B ◽

Type C

To better understand the structural characteristic of adsorption pores (pore diameter < 100 nm) of coal reservoirs around the coalbed methane production areas of western Yunnan and eastern Guizhou, we analyzed the structural and fractal characteristics of pore size range of 0.40–2.0 nm and 2–100 nm in middle–high rank coals ( Ro,max = 0.93–3.20%) by combining low-temperature N2/CO2 adsorption tests and surface/volume fractal theory. The results show that the coal reservoirs can be divided into three categories: type A ( Ro,max < 2.15%), type B (2.15% < Ro,max <2.50%), and type C ( Ro,max > 2.15%). The structural parameters of pores in the range from 2 to 100 nm are influenced by the degree of coal metamorphism and the compositional parameters (e.g., ash and volatile matter). The dominant diameters of the specific surface areas are 10–50 nm, 2–50 nm, and 2–10 nm, respectively. The pores in the range from <2 nm provide the largest proportion of total specific surface area (97.22%–99.96%) of the coal reservoir, and the CO2-specific surface area and CO2-total pore volume relationships show a positive linear correlation. The metamorphic degree has a much greater control on the pores (pore diameter less than 2 nm) structural parameters than those of the pore diameter ranges from 2 to 100 nm. Dv1 and Dv2 can characterize the structure of 2–100 nm adsorption pores, and Dv1 (volume heterogeneity) has a positive correlation with the pore structural parameters such as N2-specific surface area and N2-total pore volume. This parameter can be used to characterize volume heterogeneity of 2–10 nm pores. Dv2 (surface heterogeneity) showed type A > type B > type C and was mainly affected by the metamorphism degree. Ds2 can be used to characterize the pore surface heterogeneity of micropores in the range of 0.62–1.50 nm. This parameter has a good correlation with the pore parameters (CO2-total pore volume, CO2-specific surface area, and average pore size) and is expressed as type C < type B < type A. In conclusion, the heterogeneity of the micropores is less than that of the meso- and macropores (2–100 nm). Dv1, Dv2, and Ds2 can be used as effective parameters to characterize the pore structure of adsorption pores. This result can provide a theoretical basis for studying the pore structure compatibility of coal reservoirs in the region.

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