scholarly journals Evaluation of Hydrogen Yield Evolution in Gaseous Fraction and Biochar Structure Resulting from Walnut Shells Pyrolysis

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6359
Author(s):  
Elena David
Keyword(s):  
Heating Rate ◽  
Pyrolysis Temperature ◽  
Walnut Shell ◽  
Hydrogen Yield ◽  
X Ray Diffraction ◽  
Fast Heating ◽  
X Ray ◽  
Walnut Shells ◽  
Water Vapors ◽  
Gaseous Fraction

Conversion experiments of wet and dry walnut shells were performed, the influence of moisture content on the hydrogen yield in the gas fraction was estimated and the resulted biochar structure was presented. Measurements of the biochar structures were performed using X-ray diffraction and scanning electron microscopy methods. The results demonstrate that heating rate played a key role in the pyrolysis process and influenced the biochar structure. Under fast heating rate, the interactions between the water vapors released and other intermediate products, such as biochar was enhanced and consequently more hydrogen was generated. It could also be observed that both biochar samples, obtained from wet and dry walnut shells, had an approximately smooth surface and are different from the rough surface of the raw walnut shell, but there are not obvious differences in shape and pores structure between the two biochar samples. The increasing of the biochar surface area versus pyrolysis temperature is due tothe formation of micropores in structure. The biochar shows a surface morphology in the form of particles with rough, compact and porous structure. In addition the biochar structure confirmed that directly pyrolysis of wet walnut shells without predried treatment has enhanced the hydrogen content in the gas fraction.

Texture Evolution Under Fast Heating and Cooling Rates of Zirconium Alloys Studied In-Situ by Synchrotron X-Ray Diffraction

2020 ◽  
Author(s):  
Chi-Toan Nguyen ◽  
Alistair Garner ◽  
Javier Romero ◽  
Antoine Ambard ◽  
Michael Preuss ◽  
...  
Keyword(s):  
Texture Evolution ◽  
Zirconium Alloys ◽  
X Ray Diffraction ◽  
Fast Heating ◽  
Cooling Rates ◽  
X Ray ◽  
Heating And Cooling

Pyrolysis of Imperata cylindrica with Varies Parameters and its Characterization

2015 ◽  
Vol 754-755 ◽  
pp. 1007-1011 ◽  
Author(s):  
M.H. Fatin ◽  
N.Z. Noriman ◽  
M.Z. Salihin ◽  
N.R. Munirah ◽  
Mohd Firdaus Omar
Keyword(s):  
Heating Rate ◽  
Pyrolysis Temperature ◽  
Imperata Cylindrica ◽  
Operational Parameters ◽  
Carbon Yield ◽  
Invasive Weed ◽  
X Ray ◽  
Higher Temperature ◽  
Pyrolysis Experiment ◽  
Temperature Heating

This study was undertaken to characterize pyrolysis of novel biobased invasive weed from ImperataCylindrica. The effects of various temperatures on the pyrolysis stages were characterised. Different operational parameters such as pyrolysis temperature, heating rate temperature are studied. Pyrolysis experiment of groud ImperataCylindrica was performed at temperature 350°C, 550°C and 750°C, and particle size of 0-125μm and heating rate of 5°C/min and 15°C/min. The synthesis carbonaceous was characterized by Fourier Transform Infrared Spectroscopy (FTIR), and different physical properties such as carbon yield, Carbon Hydrogen Nitrogen (CHN analysis), and X-Ray Fluorescence (XRF) was determined. It is observable that pyrolysis at the 15°C / min with 750°C shows that higher temperature produced a higher carbon yield and higher carbon content.

scholarly journals A Biosorption-Pyrolysis Process for Removal of Pb from Aqueous Solution and Subsequent Immobilization of Pb in the Char

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2381
Author(s):  
Yue Wang ◽  
Jinhong Lü ◽  
Dongqing Feng ◽  
Sen Guo ◽  
Jianfa Li
Keyword(s):  
Heavy Metals ◽  
Pyrolysis Temperature ◽  
Acidic Solution ◽  
Potential Solution ◽  
Pyrolysis Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Pretreated Biomass ◽  
Pb Immobilization

The application of biosorption in the removal of heavy metals from water faces a challenge of safe disposal of contaminated biomass. In this study, a potential solution for this problem was proposed by using a biosorption-pyrolysis process featured by pretreatment of biomass with phosphoric acid (PA). The PA pretreatment of biomass increased the removal efficiency of heavy metal Pb from water by sorption, and subsequent pyrolysis helped immobilize Pb in the residual char. The results indicate that most (>95%) of the Pb adsorbed by the PA-pretreated biomass was retained in the char, and that the lower pyrolysis temperature (350 °C) is more favorable for Pb immobilization. In this way, the bioavailable Pb in the char was hardly detected, while the Pb leachable in acidic solution decreased to <3% of total Pb in the char. However, higher pyrolysis temperature (450 °C) is unfavorable for Pb immobilization, as both the leachable and bioavailable Pb increased to >28%. The reason should be related to the formation of elemental Pb and unstable Pb compounds during pyrolysis at 450 °C, according to the X-ray diffraction study.

Generation of a Two-Dimensional Silicon Carbide Lattice*

1965 ◽  
Vol 9 ◽  
pp. 142-151 ◽  
Author(s):  
R. L. Prickett ◽  
R. L. Hough
Keyword(s):  
Silicon Carbide ◽  
Vertical Integration ◽  
Tungsten Wire ◽  
Pyrolysis Temperature ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Organic Vapors ◽  
X Ray ◽  
Fine Tungsten

AbstractSilicon carbide vvas generated by pyrolysis of gas mixtures consisting of silicon tetrachloride, hydrogen, and organic vapors, such as acetone, on fine tungsten wires resistance-heated at 1500°C. Prominent two-dimensional structure was demonstrated for the 220 reflection. All other lines were of the normal threedimensional lattice type.Elevation of less than 100° in the pyrolysis temperature eliminated the twodimensional reflection, and simultaneously changed the visible crystallite size.Specialized techniques were used td generate the silicon carbide deposits and also to examine the structure of these deposits by X-ray diffraction to obtain lines from only the silicon carbide while ignoring the tungsten wire core. Diffraction techniques include offset collimation and vertical integration.

Synthesis of Nanocrystalline TiO2 by the Extraction-Pyrolytic Method and its Phase Transformation in the Presence of Gadolinium

2021 ◽  
Vol 903 ◽  
pp. 149-154
Author(s):  
Regīna Burve ◽  
Vera Serga ◽  
Aija Krumina
Keyword(s):  
Pyrolysis Temperature ◽  
Nanocrystalline Powders ◽  
Electrophysical Properties ◽  
Temperature Differential ◽  
X Ray Diffraction ◽  
X Ray ◽  
Novel Synthesis ◽  
Nanocrystalline Titanium ◽  
Synthesis Approach ◽  
Xrd Method

Due to its to its optical, thermal, photocatalytic and electrophysical properties, nanocrystalline titanium oxide (TiO2) is widely used in various fields. In the present work, a series of pure and Gd-modified (0.5, 5, 50 mol%) TiO2 nanocrystalline powders were prepared by a novel synthesis approach – extraction-pyrolytic method (EPM). Metal containing extracts on the basis of valeric acid were used as precursors. Thermal behavior of produced individual and mixed precursors were investigated by thermogravimetric analysis (TGA) and high temperature differential scanning colometry (HDSC). Phase composition of pure and Gd-modified TiO2 powders were studied as a function of pyrolysis temperature (450o -850°C ) and gadolinium content by X-ray diffraction (XRD) method. Photocatalytic activity of produced powders was studied by photocatalytic degradation of methylene blue (MB) under UV/VIS light irradiation.

scholarly journals Annealing Effects on Photocatalytic Activity of Zn0.2Cd0.8S Films Prepared by Chemical Bath Deposition

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Yi-Feng Chai ◽  
Ling-Ling Wang ◽  
Gui-Fang Huang ◽  
Wei-Qing Huang ◽  
Yan-Hua Zhu
Keyword(s):  
Photocatalytic Activity ◽  
Heating Rate ◽  
Chemical Bath Deposition ◽  
Visible Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Mean Grain Size ◽  
Annealing Effects ◽  
The Mean

Zn0.2Cd0.8S alloyed films were prepared on glass substrates at room temperature using chemical bath deposition method. The obtained films were annealed at temperatures ranging from 200°C to 500°C with heating rate of 5°C/min and annealed at 400°C with heating rate of 2°C/min and 10°C/min. The films were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and UV-VIS spectrophotometer. The increasing of annealing temperature increases the crystallinity and the mean grain size of Zn0.2Cd0.8S alloyed films and significantly enhances the absorption in the visible region. The efficient visible light photocatalytic activity for annealed Zn0.2Cd0.8S alloyed films is associated with the larger size grain and the higher crystallinity.

Microstructures of Zirconium Titanate Powders and Ceramics Prepared by Solid-State Mixed Oxide Method

2008 ◽  
Vol 55-57 ◽  
pp. 145-148
Author(s):  
C. Puchmark ◽  
P. Tipparak
Keyword(s):  
Electron Microscope ◽  
Solid State ◽  
Scanning Electron Microscope ◽  
Heating Rate ◽  
Sintering Temperature ◽  
Zirconium Titanate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Jcpds File ◽  
Scanning Electron

Zirconium titanate (ZrTiO4): ZT powders were prepared by solid-state mixed oxide method. The mixed powder was calcined at various temperatures for 3 h ranging from 1100 to 1400 oC with a heating rate of 5 oC/min. X-ray diffraction analysis of the powders was performed using a diffractometer with Cu Ka. Pyrochlore phase was observed for calcinations below 1300 oC. In general, the strongest reflections apparent in patterns could be matched with a JCPDS file number 74-1504. The optimum calcination temperature for the formation of ZrTiO4 phase was found to be about 1300 oC for 3 h with heating rate of 5 oC/min. The microstructures of calcined powders were examined using scanning electron microscope (SEM). The particle size of powder increased with increasing calcination temperature. The ZT ceramics sintered at 1450, 1500, 1550 and 1600 oC for 4 h with heating rate of 5 oC/min, were checked for phase formation by X-ray diffraction. The density of sintered samples was measured by Archimedes method. The microstructures of sintered samples were examined using scanning electron microscope (SEM). The average grain sizes were checked by linear interception method. It was found that, the samples sintered at 1450 and 1500 oC gave rise to high purity ZT ceramics and the peaks matched well with ZrTiO4 phase in a JCPDS file number 74-1504. Unknown phases were found in ZT ceramics sintered at 1550 and 1600 oC. The value of density was in the range of 4.32 - 4.92 g/cm3 or 84.26 - 96.12 % of the ZT theoretical density. The densification of ZT ceramics decreased with increasing sintering temperature. The ZT ceramics sintered at 1450 and 1500 oC showed the average grain size of 8.55 and 12.55 µm, respectively. At sintering temperature 1550 and 1600 oC, morphology of grains changed to plate like crystals of second phases.

Study of the Glass Transition Temperature of (Se100-xBix)90Te10 (x = 0, 0.5, 1, 1.5, 2, 2.5, 3) Alloys

2011 ◽  
Vol 316-317 ◽  
pp. 55-58 ◽  
Author(s):  
Deepshikha Sharma ◽  
Saneel K. Thakur
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Heating Rate ◽  
Network Model ◽  
Differential Analysis ◽  
X Ray Diffraction ◽  
Glass Transition Temperatures ◽  
X Ray ◽  
Xrd Studies

Alloys of (Se100-xBix)90Te10 (x =0, 0.5, 1, 1.5, 2, 2.5, 3 at.%) were prepared by using a conventional melt-quench technique. The samples under investigation were characterized using X-ray diffraction (XRD) and differential analysis (DTA) at a heating rate of 10K/min. It was found, from the XRD studies, that the alloys were amorphous in nature. The glass transition temperatures of the alloys were found to increase with increasing bismuth content. This increase in the glass transition temperature was explained on the basis of a chemically ordered network model.

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