scholarly journals Effects of Boron Carbide on Coking Behavior and Chemical Structure of High Volatile Coking Coal during Carbonization

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 302
Author(s):  
Qiang Wu ◽  
Can Sun ◽  
Zi-Zong Zhu ◽  
Ying-Dong Wang ◽  
Chong-Yuan Zhang
Keyword(s):  
Boron Carbide ◽  
Chemical Structure ◽  
Coke Quality ◽  
Thermo Gravimetric ◽  
Coking Coal ◽  
Transmission Electron ◽  
Thermo Gravimetric Analyzer ◽  
Crosslinking Reactions ◽  
Boron Carbide B4c ◽  
Secondary Cracking

Modified cokes with improved resistance to CO2 reaction were produced from a high volatile coking coal (HVC) and different concentrations of boron carbide (B4C) in a laboratory scale coking furnace. This paper focuses on modification mechanism about the influence of B4C on coking behavior and chemical structure during HVC carbonization. The former was studied by using a thermo-gravimetric analyzer. For the latter, four semi-cokes prepared from carbonization tests for HVC with or without B4C at 450 °C and 750 °C, respectively, were analyzed by using Fourier transform infrared spectrum and high-resolution transmission electron microscopy technologies. It was found that B4C will retard extensive condensation and crosslinking reactions by reducing the amount of active oxygen obtained from thermally produced free radicals and increase secondary cracking reactions, resulting in increasing size of aromatic layer and anisotropic degree in coke structure, which eventually improves the coke quality.

Immobilization of K7PW11O39 on ZrO2 Nanofiber: Ultra-deep Desulfurization Based in Extraction Catalytic Oxidation Desulfurization System

2021 ◽  
Vol 72 (3) ◽  
pp. 89-101
Author(s):  
Guowei Zeng ◽  
Guihong Wu ◽  
Zhihui Wang ◽  
Xiaonan Li ◽  
Jie Yang ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Catalytic Mechanism ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
Transmission Electron ◽  
Deep Desulfurization ◽  
Thermo Gravimetric Analyzer ◽  
Ft Ir ◽  
Model Oil

In this work, K7PW11O39 (abbreviated as PW11) was immobilized on ZrO2 nanofibers and used as an efficient recyclable catalyst in extraction catalytic oxidation desulfurization system (ECODS).The 500 ppm DBT model oil(5mL) can desulphurize completely within 20 min with the catalytic conditions of 50��, 0.010 g 50 wt%- CTAB�C PW11�CZrO2 nanofibers and O/S molar ratio H2O2/DBT molar ratio�� was 2:1. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and thermo gravimetric analyzer (TGA). The results indicated the PW11�CZrO2 nanofibers were synthesized successfully and the possible catalytic mechanism is also revealed.

Research on the Properties of Nanoparticles Modified Sodium Silicate Adhesive

2012 ◽  
Vol 557-559 ◽  
pp. 1825-1829 ◽  
Author(s):  
Xin Li Zhang ◽  
Yi Qiang Wu ◽  
Yun Chu Hu
Keyword(s):  
Bonding Strength ◽  
Chemical Structure ◽  
Performance Standards ◽  
Nano Silica ◽  
Thermo Gravimetric ◽  
Adhesion Properties ◽  
Good Thermal Stability ◽  
Thermo Gravimetric Analyzer ◽  
Structure Surface ◽  
Infrared Spectrometer

A kind of nanoparticles modified Na2SiO3 adhesive was prepared from Na2SiO3 aqueous solution with nano-silica and nano-magnesia as curing agent, and nano attapulgite as skeleton material. The chemical structure, surface morphology and thermal properties of nanoparticles modified Na2SiO3 adhesive were characterized by Fourier transform infrared spectrometer, scanning electron microscope, and thermo-gravimetric analyzer. As the two main measures of adhesion properties, the bonding strength and water resistance were also determined. The results showed that nanoparticles uniformly dispersed in Na2SiO3 matrix in the state of grain, so the homogenous morphology of cured adhesive was formed and bonding strength of Na2SiO3 adhesive was improved. Nanoparticles modified Na2SiO3 adhesive have good thermal stability in the range of 30~800 °C. The bonding strength and 24h water absorption rate of poplar plywood glued by the nanoparticles modified Na2SiO3 adhesive is 0.8 MPa and 23.7%, respectively, reaching the type-two plywood performance standards.

scholarly journals Dislocation-mediated shear amorphization in boron carbide

2021 ◽  
Vol 7 (8) ◽  
pp. eabc6714 ◽  
Author(s):  
Kolan Madhav Reddy ◽  
Dezhou Guo ◽  
Shuangxi Song ◽  
Chun Cheng ◽  
Jiuhui Han ◽  
...  
Keyword(s):  
Boron Carbide ◽  
Structural Transition ◽  
Activation Volume ◽  
Structural Evolution ◽  
Dislocation Nucleation ◽  
Superhard Materials ◽  
Rate Dependent ◽  
Transmission Electron ◽  
Lower Activation ◽  
Underlying Mechanisms

The failure of superhard materials is often associated with stress-induced amorphization. However, the underlying mechanisms of the structural evolution remain largely unknown. Here, we report the experimental measurements of the onset of shear amorphization in single-crystal boron carbide by nanoindentation and transmission electron microscopy. We verified that rate-dependent loading discontinuity, i.e., pop-in, in nanoindentation load-displacement curves results from the formation of nanosized amorphous bands via shear amorphization. Stochastic analysis of the pop-in events reveals an exceptionally small activation volume, slow nucleation rate, and lower activation energy of the shear amorphization, suggesting that the high-pressure structural transition is activated and initiated by dislocation nucleation. This dislocation-mediated amorphization has important implications in understanding the failure mechanisms of superhard materials at stresses far below their theoretical strengths.

Radiation Induced Formation of Acrylated Palm Oil (APO) Nanoparticles Using Cetyltrimethylammonium Bromide Microemulsion System

2011 ◽  
Vol 364 ◽  
pp. 278-282
Author(s):  
Rida Tajau ◽  
Dahlan Khairul Mohd. Zaman ◽  
Mohd Hilmi Mahmood ◽  
Wan Md Zin Wan Yunus ◽  
Hashim Kamaruddin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Palm Oil ◽  
Chemical Structure ◽  
Cetyltrimethylammonium Bromide ◽  
Control Process ◽  
Microemulsion System ◽  
Transmission Electron ◽  
Radiation Induced ◽  
The Fourier Transform

In this study, we report the preparation of Acrylated Palm Oil (APO) nanoparticles using aqueous Cetyltrimethylammonium bromide (CTAB) microemulsion system. This microemulsion system which contains the dispersed APO nanodroplets was subjected to the gamma irradiation to induce the formation of the crosslinked APO nanoparticles. The dynamic light scattering (DLS), the Fourier Transform Infrared (FTIR) spectrocospy and the Transmission Electron Microscopy (TEM) were used to characterize the size and the chemical structure of the nanoparticle. Sized of the APO nanoor microparticle can be varied depended on the volumes of the modified palm oil and the irradiation doses. Their size is in the range of 73 to 100 nanometer (nm) after irradiation using gamma irradiator. This radiation-induced method provides a free initiator induced and easy to control process as compared to the classical or chemical initiator process.

Adsorption Characteristics of Modified MiL-101(Cr) for Gas (Mainly CH4) Storage Applications

2015 ◽  
Author(s):  
How Wei Benjamin Teo ◽  
Anutosh Chakraborty ◽  
Kim Tiow Ooi
Keyword(s):  
Natural Gas ◽  
X Ray Diffraction ◽  
Uptake Capacity ◽  
N2 Adsorption ◽  
Thermo Gravimetric ◽  
X Ray ◽  
Thermo Gravimetric Analyzer ◽  
Metal Organic ◽  
Ch4 Uptake

As promising material for gas storage applications, MIL-101(Cr) can further be modified by doping with alkali metal (Li+, Na+, K+) ions. However, the doping concentration should be optimized below 10% to improve the methane adsorption. This article presents (i) the synthesis of MIL-101 (Cr) Metal Organic Frameworks, (ii) the characterization of the proposed doped adsorbent materials by X-ray Diffraction, Scanning Electron Microscopy, N2 Adsorption, Thermo-Gravimetric Analyzer, and (iii) the measurements of methane uptakes for the temperatures ranging from 125 K to 303 K and pressures up to 10 bar. It is found that the Na+ doped MIL-101(Cr) exhibits CH4 uptake capacity of (i) 295 cm3/cm3 at 10 bar and 160 K and (ii) 95 cm3/cm3 at 10 bar at 298 K. This information is important to design adsorbed natural gas (ANG) storage tank under ANG-LNG (liquefied natural gas) coupling conditions.

Impact of Chemical Structure of Coal on Coke Quality Produced by Coals in the Similar Category

2022 ◽  
pp. 105432
Author(s):  
Jiang Guo ◽  
Yanfeng Shen ◽  
Meijun Wang ◽  
Wei Xie ◽  
Jiao Kong ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Coke Quality

Enhancement of Thermo-Oxidative Stability of Vegetable Oil Based Lubricant via Chemical Modification Techniques

2015 ◽  
Vol 813-814 ◽  
pp. 695-699
Author(s):  
S. Arumugam ◽  
G. Sriram ◽  
A. Hemanth Sai Kumar Chowdary ◽  
Janga Subramanya Sai
Keyword(s):  
Chemical Modification ◽  
Oxidative Stability ◽  
Vegetable Oils ◽  
Rapeseed Oil ◽  
Chemical Structure ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Transesterification Method ◽  
Unique Chemical

The rising demand for environmentally acceptable lubricant has led researchers to look to vegetable oils as an alternative to petroleum based lubricants. Vegetable oils have radically distinctive properties owing to their unique chemical structure which have greater ability to lubricate and have higher biodegradability. In spite of advantages, they are limited to inadequate thermo-oxidative stability and poor low-temperature properties which hinder their utilization. In the present study in order to produce a bio lubricant with good thermo-oxidative stability, rapeseed oil was subjected to two different chemical modification techniques viz., epoxidation method and successive transesterification method. The thermo-oxidative stability of formulated oil was analysed using Thermo Gravimetric Analysis (TGA). TGA analysis divulges that the thermo-oxidative stability of rapeseed oil was greatly improved with the epoxidation method in comparison with the successive transesterification method.

Preparation of Poly(Vinylbenzyl Chloride)@Lead Sulfide (PVBC@PbS) Core-Shell Nanospheres and Adsorption of Phenol

2013 ◽  
Vol 704 ◽  
pp. 270-274 ◽  
Author(s):  
Jian Ye ◽  
Lan Ping Sun ◽  
Sheng Ping Gao
Keyword(s):  
Electron Microscopy ◽  
Lead Sulfide ◽  
Chemical Structure ◽  
Methyl Chloride ◽  
Core Shell ◽  
Subsequent Reaction ◽  
Chloride Lead ◽  
Transmission Electron ◽  
The Fourier Transform ◽  
Average Size

We have demonstrated the fabrication of novel poly(vinylbenzyl chloride)@lead sulfide (PVBC@PbS) core-shell nanospheres via the atom transfer reversible polymerization (ATRP) of lead dimethacrylate (Pb(MA)2) initiated from methyl chloride groups on surfaces of PVBC nanoparticles and subsequent reaction with ethanethioamide. The chemical structure of the PVBC@PbS nanospheres was confirmed by the fourier transform infrared (FTIR) spectroscopy, and the morphology of the nanospheres were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The average size of the nanospheres was determined to be about 100 nm. The PVBC@PbS nanospheres were able to absorb phenol in the solution, and the balanced adsorption capability of phenol to nanospheres could reach to 7.2 μg/mg.

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