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Diffusion Characteristics and Removal of Cyclohexane in Polyolefin Elastomer Melt

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China Petroleum Processing & Petrochemical Technology 2022年第4期24卷 76-85页

作者： Qi Jibing Yang Tong Liu Yandong Yuan Zhiguo Zhang Qiaoling Liu Youzhi Yi Jianjun Shanxi Province Key Laboratory of Higee-Oriented Chemical Engineering North University of ChinaTaiyuan 030051China Petrochemical Research Institute PetroChina Co.Ltd.Beijing 102206China

The diffusion coefficient of volatiles in polymer solutions is a crucial parameter to describe the mass transfer efficiency and ability of *** this research,polyolefin elastomer(POE)was used as a polymer,and cyclohexane was used as a volatile.A gravimetric analysis was applied to measure the diffusion coefficient of cyclohexane in *** devolatilization rate of the POE-cyclohexane system under different conditions was *** effects of temperature,film sample thickness,and initial concentration of volatiles on the devolatilization rate were *** on the devolatilization rate data,the average diffusion coefficient of cyclohexane in POE was obtained by fitting with a mathematical *** experimental results indicate that the devolatilization rate increased with increasing temperature and initial concentration of volatiles,but it decreased with increasing sample *** the thickness increased,the overall diffusion resistance *** the temperature increased,the molecular movement increased,resulting in the increase of average diffusion *** relationship between the diffusion coefficient of the POE-cyclohexane system and temperature follows the Arrhenius *** diffusion activation energy E=6201.73 J/mol,and the pre-exponential factor of the diffusion coefficient D0=2.64×10^(-10) m^(2)/*** work can provide basic data for exploring the devolatilization of POE polymers and serves as a useful reference for enhancing the effect of devolatilization.

关键词： diffusion coefficient gravimetric analysis polyolefin elastomer(POE) cyclohexane devolatilization rate

In-situ investigation on real-time suspended sediment measurement techniques:Turbidimetry, acoustic attenuation,laser diffraction (LISST) and vibrating tube densimetry

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International Journal of Sediment Research 2018年第1期33卷 3-17页

作者： David Felix Ismail Albayrak Robert Michael Boes Laboratory of Hydraulics Hydrology and Glaciology(VAW)ETH Zürich

Real-time measurements of Suspended Sediment mass Concentration（SSC） and Particle Size Distribution（PSD） are of prime importance for the investigation and management of fine-sediment related processes in surface water systems and hydraulic schemes. In a field study at the waterway of the hydropower plant（HPP） Fieschertal in the Swiss Alps, the real-time measurement performance of the following techniques and instruments were assessed based on measurements in the sediment seasons of the years 2013 and 2014:（1） turbidimetry,（2） single-frequency acoustic attenuation using a standard acoustic discharge measurement（ADM） installation,（3） laser diffraction（Laser In-Situ Scattering and Transmissometry, LISST）, and（4） vibrating tube densimetry using a Coriolis Flow and Density Meter（CFDM）.Reference SSCs were obtained from gravimetric analysis of 219 automatically pumped water *** additionally supplied PSD every minute. The median particle diameter, d50, was usually 15μm and increased occasionally to 100μm. The turbidimeter and the ADM underestimated the SSC when the transported particles were coarser than usual. Such temporary biases resulted from the poor correlation between d50and SSC at this study site. The SSCs from CFDM and LISST were not or less biased by PSD variations. Mainly due to angular and flaky particle shapes, SSC from LISST needed a correction by 79% on average. With the usually prevailing silt particles, an optical path length of 5 mm and no dilution, the SSC measurement range of LISST was limited to about 1.5 g/l. The CFDM allowed measuring higher SSC than the other investigated instruments（e.g. up to 13.5 g/l）. With a periodic offset correction, its relative SSC measurement uncertainty was gravimetric reference measurements.

关键词： Suspended sediment concentration Turbidity Acoustic attenuation Laser diffraction Coriolis flow and density meter gravimetric analysis

Synthesis and Application of Novel Triazine-Based Charring-Foaming Agents in Intumescent Flame Retardant Polypropylene

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Transactions of Tianjin University 2017年第3期23卷 221-229页

作者： Ligong Chen Yanyan Yuan Bowei Wang Na Liu Yuzhi Xing Yang Li School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072China

Three novel triazine-based charring-foaming agents (M2-CFA, M4-CFA, and M6-CFA) were synthesized successfully with only water as the solvent and were characterized by FT-IR and thermal gravimetric analysis (TGA). These three charring-foaming agents and the byproduct 944-by were employed to study the effectiveness of the novel intumescent flame retardant dopant on the fire retardancy of polypropylene(PP) investigated through UL-94 and limiting oxygen index (LOI) tests. TGA results showed that the M4-CFA presented good char formation ability (char residue: 26.8% at 700 °C). It was found that the sample with a 2/1 mass ratio of APP to M4-CFA exhibited the best flame retardancy among all the PP composites: 35.5% LOI and a V-0 rating of UL-94. Additionally, the microstructure and morphology of char residues were further studied by XRD, Raman spectroscopy and SEM. © 2017, Tianjin University and Springer-Verlag Berlin Heidelberg.

关键词： Blowing agents Flame retardants gravimetric analysis Thermodynamic stability Thermogravimetric analysis

Catalytic performances of Ni/mesoporous SiO_2 catalysts for dry reforming of methane to hydrogen

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Journal of Energy Chemistry 2016年第4期25卷 709-719页

作者： Fei Huang Rui Wang Chao Yang Hafedh Driss Wei Chu Hui Zhang College of Chemistry and Chemical Engineering Southwest Petroleum University Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province Drilling & Production Engineering Technology Research Institute CNPC Chuanqing Drilling Engineering Co.Ltd. SABIC Chair in Catalysis King Abudulaziz University Department of Chemical Engineering Sichuan University

Several mesoporous silicas with different morphologies were controllably prepared by sol-gel method with adjustable ratio of dual template, and they were further impregnated with aqueous solution of nickel nitrate, followed by calcination in air. The synthesized silica supports and supported nickel samples were characterized using N2-adsorption/desorption, X-ray diffraction (XRD), H2temperature-programmed reduction (H2-TPR), Scanning electron microscope (SEM), Transmission electron microscope (TEM) and thermo-gravimetric analysis (TGA-DTG) techniques. The Ni nanoparticles supported on shell-like silica are highly dispersed and yielded much narrower nickel particle-size than those on other mesoporous silica. The methane reforming with dioxide carbon reaction results showed that Ni nanoparticles supported on shell-like silica carrier exhibited the better catalytic performance and catalytic stability than those of nickel catalyst supported on other silica carrier. The thermo-gravimetric analysis on used nickel catalysts uncovered that catalyst deactivation depends on the type and nature of the coke deposited. The heterogeneous nature of the deposited coke was observed on nickel nanoparticles supported on spherical and peanut-like silica. Much narrower and lower TGA derivative peak was founded on Ni catalyst supported on the shell-like silica. © 2016 Science Press

关键词： Carbon Catalyst activity Catalyst deactivation Catalysts Catalytic reforming Coke gravimetric analysis Hydrogen Methane Nanoparticles Nickel Particle size Scanning electron microscopy Silica Sol gel process Sol gels Solutions Thermogravimetric analysis Transmission electron microscopy X ray diffraction