scholarly journals Research on Coal Tar Pitch Catalytic Oxidation and Its Effect on the Emission of PAHs during Co-Carbonation with Coal

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1428
Author(s):  
Liqing Chen ◽  
Fanhui Guo ◽  
Jianjun Wu ◽  
Ping Li ◽  
Yixin Zhang

Coal tar pitch (CTP) is abundant and widely used, but its properties will be affected due to oxidation aging during storage. In this study, CTP was oxidized by simulating the air oxidation process, and the change of chemical structure has been analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and both gas chromatography and mass spectrometry (GCMS). The effects of the oxidized and unoxidized CTP co-carbonization with coal on the polycyclic aromatic hydrocarbons (PAHs) emission were detected by GCMS. The small and medium-molecule aromatic substances were reduced during CTP oxidation, while the intermolecular condensation reaction increased the macromolecules content. The catalytic can effectively facilitate the dehydrogenation and condensation reaction of CTP and the entry of oxygen molecules, which leads to the increase of oxygen-containing groups and the decrease of PAHs. Compared to the raw CTP, the catalytic oxidized CTP significantly reduced the emissions of toxic PAHs during the co-carbonization with coal. A possible catalytic mechanism of CTP catalytic oxidation is proposed.

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Maciej Gubernat ◽  
Tomasz Lis ◽  
Janusz Tomala ◽  
Jakub Kawala ◽  
Aneta Fraczek-Szczypta ◽  
...  

Silicon carbide nanoparticles (nSiC) have been used to modify coal tar pitch (CTP) as a carbon binder. The influence of ceramic nanoparticles on the structure and microstructure was studied. The structure of CTP-based carbon residue with various nSiC contents was analyzed by using SEM with EDAX, Raman spectroscopy, and X-ray diffraction. The effect of ceramic nanofiller on the crystallite sizes (Lc, La) and the c-axis spacing (d002) in carbonized samples after heating from 1000 to 2800°C was analyzed. Ceramic nanofillers inhibit structural changes in carbonized samples heated to 1000°C. After heating CTP with nSiC above 2000°C, the carbon samples contained two carbon components differing in structural ordering. Ceramic nanoparticles increase carbon crystallite growth, while their impact on the c-axis spacing is low.


2000 ◽  
Vol 53 (6) ◽  
pp. 507 ◽  
Author(s):  
Martin A. Bennett ◽  
Mark Bown ◽  
David C. R. Hockless

From the reaction of [Ru2Cl3(PMe2Ph)6] Cl with the appropriate radical anions, yellow complexes of general formula [Ru(PMe2Ph)3(η4-arene)] [arene = naphthalene (C10H8) (1), anthracene (C14H10) (2), and triphenylene (C18H12) (3)] have been isolated in poor yield and characterized by elemental analysis, n.m.r. (1H, 13C, 31P) spectroscopy and single-crystal X-ray diffraction. Crystal data: (1), monoclinic, C2/c, a 31.096(8), b 12.012(4), c 17.078(8) Å, β 104.41(3)˚, V 6178(4) Å3, ? 8, refined to final R value of 0.032 with use of 3641 reflections [I > 3σ(I)]; (2), monoclinic, C2/c, a 55.909(4), b 14.348(5), c 17.573(5) Å, β 105.41(1)˚, V 13590(6) Å3, Z 16 (two molecules per asymmetric unit), refined to final R value of 0.049 with use of 7770 reflections [I > 3σ(I)]; (3), mono-clinic, Pn, a 9.377(3), b 12.229(3), c 15.975(3) Å, β 103.51(2)˚, V 1781.2 (7) Å3, Z 2, refined to final R value of 0.026 with use of 2830 reflections [I > 3σ(I)]. In each case, coordination of the zerovalent metal fragment Ru(PMe2Ph)3 to the diene section of one of the terminal rings causes the aromatic molecule to be folded by c. 40˚ at the outer carbon atoms of the diene. The coordination geometry about ruthenium is approximately square pyramidal, with the diene and two tertiary phosphines in the equatorial plane and the remaining tertiary phosphine in the axial site.


2021 ◽  
Vol 17 ◽  
Author(s):  
Ke Huan ◽  
Li Tang ◽  
Dongmei Deng ◽  
Huan Wang ◽  
Xiaojing Si ◽  
...  

Background: Hydrogen peroxide (H2O2) is a common reagent in the production and living, but excessive H2O2 may enhance the danger to the human body. Consequently, it is very important to develop economical, fast and accurate techniques for detecting H2O2. Methods: A simple two-step electrodeposition process was applied to synthesize Pd-Cu/Cu2O nanocomposite for non-enzymatic H2O2 sensor. Cu/Cu2O nanomaterial was firstly electrodeposited on FTO by potential oscillation technique, and then Pd nanoparticles were electrodeposited on Cu/Cu2O nanomaterial by cyclic voltammetry. The chemical structure, component, and morphology of the synthesized Pd-Cu/Cu2O nanocomposite were characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical properties of Pd-Cu/Cu2O nanocomposite were studied by cyclic voltammetry and amperometry. Results: Under optimal conditions, the as-fabricated sensor displayed a broad linear range (5-4000 µM) and low detection limit (1.8 µM) for the determination of H2O2. The proposed sensor showed good selectivity and reproducibility. Meanwhile, the proposed sensor has been successfully applied to detect H2O2 in milk. Conclusion: The Pd-Cu/Cu2O/FTO biosensor exhibits excellent electrochemical activity for H2O2 reduction, which has great potential application in the field of food safety.


2021 ◽  
Vol 72 (3) ◽  
pp. 89-101
Author(s):  
Guowei Zeng ◽  
Guihong Wu ◽  
Zhihui Wang ◽  
Xiaonan Li ◽  
Jie Yang ◽  
...  

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.


2009 ◽  
Vol 24 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Rabkwan Chuealee ◽  
Timothy S. Wiedmann ◽  
Teerapol Srichana

Sodium cholesteryl carbonate ester (SCC) was synthesized, and its phase behavior was studied. The chemical structure was assessed by solid-state infrared spectroscopy based on vibration analysis. The wave number at 1705 and 1276 cm−1 corresponds to a carbonyl carbonate and O–C–O stretching of SCC, respectively. Molecular structure of SCC was further investigated with 1H and 13C NMR spectroscopy. The chemical shift, for the carbonyl carbonate resonance appeared at 155.5 ppm. A molecular mass of SCC was at m/z of 452. Differential scanning calorimetry (DSC), video-enhanced microscopy (VEM) together with polarized light microscopy, and small-angle x-ray scattering (SAXS) were used to characterize the phase behavior as a function of temperature of SCC. Liquid crystalline phase was formed with SCC. Based on the thermal properties and x-ray diffraction, it appears that SCC forms a structure analogous to the type II monolayer structure observed with cholesterol esters.


2015 ◽  
Vol 17 (2) ◽  
pp. 87 ◽  
Author(s):  
Ch.N. Barnakov ◽  
G.P. Khokhlova ◽  
A.N. Popova ◽  
S.A. Sozinov ◽  
Z.R. Ismagilov

The structure of some commercial graphites and carbon materials (CMs) obtained by the low-temperature catalytic graphitization of coal tar pitch with iron salt, needle coke, foamed graphite as the catalysts has been studied. The study was performed using the X-ray diffraction technique with reflections from base plane and their decomposition into two components corresponding to the structural phases of graphite which have different XRD characteristics. Various CMs were compared with respect to the structural phase ratio, distance between polyarene layers in these phases, and sizes of the coherent scattering regions. The (004) reflection provided a better fit of some properties of graphites to the calculated XRD characteristics as compared to calculation from the (002) reflection. In the case of carbonization of coal tar pitch with investigated catalyst additions, prepared carbon materials have a higher degree of graphitization and a crystallite size greater than in the other case of carbonization of the individual pitch. The highest catalytic activity is shown by foamed graphite. It was found that the use of foamed graphite as the catalyst at 800-900 ºC produced carbon materials possessing a crystalline structure with interplanar spacing close to that in commercial graphites, while in the absence of catalyst the coal tar pitch material has an amorphous structure.


Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1954 ◽  
Author(s):  
Xiaomei Yang ◽  
Guangzhong Yin ◽  
Zhiyong Li ◽  
Pengfei Wu ◽  
Xiaopei Jin ◽  
...  

In this work, we reported the preparation and chemical analysis of novel polyhedral oligomeric silsesquioxane (POSS)-based porous materials, which were prepared according to Friedel-Crafts chloromethylation by using aluminum chloride as the catalyst and dichloromethane as the solvent. Through controlling the treatment solvent (water or methanol) and kinds of POSS, several materials with different morphologies were conveniently obtained. The chemical structure of porous materials was systematically characterized by Fourier-transform infrared (FTIR) spectra, 29Si Nuclear Magnetic Resonance (NMR), 13C NMR, and X-ray photoelectron spectroscopy (XPS). The samples were further characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) to study their crystallinity, morphology, and thermal properties, respectively. The work systematically demonstrated the chemical structure of the porous materials. Moreover, the advantages and disadvantages of the preparation method and typical properties of the material were evaluated through a comparative analysis with other related research works.


2011 ◽  
Vol 347-353 ◽  
pp. 615-620
Author(s):  
Ying Jia ◽  
Tian Tian Liu ◽  
Cheng Luo

Ce0.67Zr0.33O2 (CZ) nanorods are successfully synthesized by glycol-assisted hydrothermal method using zirconium oxychloride, cerium nitrate and urea, with the presence of sodium hypochlorite. The products are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectra. The catalytic oxidation characters about Pd/CZ three-way catalyst (TWC) prepared with different loads of Pd are also investigated. The results show that the as-prepared Pd/CZ has excellent catalytic oxidation character to CO.


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