Sulfidation Experiments in a Pressurized Thermogravimetric Analyzer With Chinese Calcined Limestones

2005 ◽  
Author(s):  
Zhanlong Song ◽  
Mingyao Zhang
Keyword(s):  
Partial Pressure ◽  
Reaction Temperature ◽  
Total Pressure ◽  
Volume Fraction ◽  
Nitrogen Adsorption ◽  
Reaction Rates ◽  
Thermogravimetric Analyzer ◽  
Morphological Studies ◽  
Shrinking Core ◽  
Structure Properties

The sulfidation experiments with two kinds of Chinese calcined limestones were performed in a pressurized thermogravimetric analyzer (PTGA). The effects of reaction temperature (700–950°C), total pressure (0–1MPa), particle size (0.055–2mm), and H2S concentration (0.1–4%) on the sorbent conversions were analyzed. Morphological studies with scanning electron microscope and energy dispersive spectroscopy (SEM-EDS) equipment were made to obtain the pictures of solid surface and of the cross-sectioned samples. Nitrogen adsorption measurements were applied to determine the pore structure properties of the particles. Experimental results show that the sulfidation rate increases with total pressure when the volume fraction of H2S is constant. However, the rate of sulfidation decreases with the increase of total pressure when the H2S partial pressure is constant. Reaction temperature affects the sulfidation greatly, and the reaction rate increases with temperature. The sulfidation is the first order with respect to H2S partial pressure. Moreover, larger particles result in lower conversions and reaction rates. The unreacted shrinking core model was applied to describe the sulfidation to determine the kinetic parameters.

A study on the kinetics and thermal properties of polystyrene/diatomite nanocomposites prepared via in situ ATRP

2018 ◽  
Vol 33 (2) ◽  
pp. 180-197 ◽  
Author(s):  
Khezrollah Khezri ◽  
Yousef Fazli
Keyword(s):  
Molecular Weight ◽  
In Situ Polymerization ◽  
Structural Characteristics ◽  
Nitrogen Adsorption ◽  
Linear Increase ◽  
Size Exclusion ◽  
Scanning Calorimetry ◽  
Morphological Studies ◽  
Exclusion Chromatography

Pristine mesoporous diatomite was employed to prepare polystyrene/diatomite composites. Diatomite platelets were used for in situ polymerization of styrene by atom transfer radical polymerization to synthesize tailor-made polystyrene nanocomposites. X-Ray fluorescence spectrometer analysis and thermogravimetric analysis (TGA) were employed for evaluating some inherent properties of pristine diatomite platelets. Nitrogen adsorption/desorption isotherm is applied to examine surface area and structural characteristics of the diatomite platelets. Evaluation of pore size distribution and morphological studies were also performed by scanning and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography, respectively. Linear increase of ln ( M0/M) with time for all the samples shows that polymerization proceeds in a living manner. Addition of 3 wt% pristine mesoporous diatomite leads to an increase of conversion from 72% to 89%. Molecular weight of polystyrene chains increases from 11,326 g mol−1 to 14134 g mol−1 with the addition of 3 wt% pristine mesoporous diatomite; however, polydispersity index values increases from 1.13 to 1.38. Increasing thermal stability of the nanocomposites is demonstrated by TGA. Differential scanning calorimetry shows an increase in glass transition temperature from 81.9°C to 87.1°C by adding 3 wt% of mesoporous diatomite platelets.

scholarly journals Efficient Catalytic Dehydration of High-Concentration 1-Butanol with Zn-Mn-Co Modified γ-Al2O3 in Jet Fuel Production

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 93 ◽  
Author(s):  
Jing Wu ◽  
Hong-Juan Liu ◽  
Xiang Yan ◽  
Yu-Jie Zhou ◽  
Zhang-Nan Lin ◽  
...  
Keyword(s):  
Reaction Temperature ◽  
Inductively Coupled Plasma ◽  
Nitrogen Adsorption ◽  
Space Velocity ◽  
Jet Fuel ◽  
Interactive Effects ◽  
Emission Spectrometry ◽  
High Concentration ◽  
Plasma Atomic Emission Spectrometry ◽  
Fuel Production

It is important to develop full-performance bio-jet fuel based on alternative feedstocks. The compound 1-butanol can be transformed into jet fuel through dehydration, oligomerization, and hydrogenation. In this study, a new catalyst consisting of Zn-Mn-Co modified γ-Al2O3 was used for the dehydration of high-concentration 1-butanol to butenes. The interactive effects of reaction temperature and butanol weight-hourly space velocity (WHSV) on butene yield were investigated with response surface methodology (RSM). Butene yield was enhanced when the temperature increased from 350 °C to 450 °C but it was reduced as WHSV increased from 1 h−1 to 4 h−1. Under the optimized conditions of 1.67 h−1 WHSV and 375 °C reaction temperature, the selectivity of butenes achieved 90%, and the conversion rate of 1-butanol reached 100%, which were 10% and 6% higher, respectively, than when using unmodified γ-Al2O3. The Zn-Mn-Co modified γ-Al2O3 exhibited high stability and a long lifetime of 180 h, while the unmodified γ-Al2O3 began to deactivate after 60 h. Characterization with X-ray diffraction (XRD), nitrogen adsorption-desorption, pyridine temperature-programmed desorption (Py-TPD), pyridine adsorption IR spectra, and inductively coupled plasma atomic emission spectrometry (ICP-AES), showed that the crystallinity and acid content of γ-Al2O3 were obviously enhanced by the modification with Zn-Mn-Co, and the loading amounts of zinc, manganese, and cobalt were 0.54%, 0.44%, and 0.23%, respectively. This study provides a new catalyst, and the results will be helpful for the further optimization of bio-jet fuel production with a high concentration of 1-butanol.

Thermal Analysis Characteristics of the Eucalyptus Leaves under Various N2/O2 Conditions

2013 ◽  
Vol 316-317 ◽  
pp. 181-184
Author(s):  
Zhi Qiang Wu ◽  
Shu Zhong Wang ◽  
Jun Zhao ◽  
Lin Chen ◽  
Hai Yu Meng
Keyword(s):  
Fossil Fuel ◽  
Volume Fraction ◽  
Renewable Energy Sources ◽  
Pollutant Emission ◽  
Energy Sources ◽  
Chemical Characteristics ◽  
Exponential Factor ◽  
Thermogravimetric Analyzer ◽  
Eucalyptus Leaves ◽  
Reaction Atmosphere

Thermal chemical conversation of biomass is studied as a means to reduce the greenhouse gases and pollutant emission caused by the traditional fossil fuel. Eucalyptus is one of the fast growing tress in the south of China, which has great potential as a kind of renewable energy sources. An experimental study on eucalyptus leaves was carried out in thermogravimetric analyzer to investigate the effects of reaction atmosphere on thermal chemical characteristics. The volume fraction of oxygen was 0, 0.21, 0.27 and 0.33 respectively. Experimental results show that with the increasing of the oxygen concentration, the reaction time decreased significantly. The kinetic Parameters were also calculated, including the activation energy (E) and pre-exponential factor (A).

scholarly journals Tandem buildup of complexity of aromatic molecules through multiple successive electrophile generation in one pot, controlled by varying the reaction temperature

2016 ◽  
Vol 14 (5) ◽  
pp. 1680-1693 ◽  
Author(s):  
Akinari Sumita ◽  
Yuko Otani ◽  
Tomohiko Ohwada
Keyword(s):  
Reaction Temperature ◽  
Reaction System ◽  
Reaction Rates ◽  
Aromatic Molecule ◽  
One Pot ◽  
Aromatic Molecules

The unmasking reaction rates and the time of generation of highly reactive electrophiles can be controlled. This reaction system demonstrates the conceptual validity of one-pot build-up of a complex aromatic molecule from multiple starting components.

Characterization and Application Process Optimization of CuO/γ-Al2O3 Catalyst in CWAO Technology

2014 ◽  
Vol 1008-1009 ◽  
pp. 338-341
Author(s):  
Yu Xiu Zhang ◽  
Cheng Zhi Wang ◽  
Yong Li Zhang ◽  
Zhang Wei Li
Keyword(s):  
Reaction Time ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Reaction Temperature ◽  
Removal Rate ◽  
Influence Factors ◽  
Carrier Distribution ◽  
Influent Water ◽  
Catalyst Dosage ◽  
Stirring Intensity

CuO/γ-Al2O3 catalyst was used to deal with the waste leachate in CWAO technology of, and the SEM and TEM characterization showed: active component in the surface of the carrier distribution is uniform; In CWAO process, six factors, based on the CODCr removal rate and turbidity removal rate, the biggest impact factor is reaction temperature, and the influence factors of the top three were reaction temperature, catalyst dosage and reaction time. The influence factors of those in the bottom three are influent water pH, oxygen partial pressure, stirring intensity, and three factors of influence on the strength is close. Optimizing operation process, in order: reaction temperature of 200 °C, catalyst dosage of 1.5 g, oxygen partial pressure of 2.0 MPa, stirring intensity 800 rpm, influent water pH of 7.0, the reaction time of 70 min.

Pulsed Laser Deposited Oxide Green Emitting Thin Film Phosphors : Optimization of Growth Conditions

2006 ◽  
Vol 988 ◽  
Author(s):  
P. Thiyagarajan ◽  
M. Kottaismay ◽  
M S Ramachandra Rao
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Diffuse Reflectance Spectroscopy ◽  
Quartz Substrate ◽  
Pulsed Laser ◽  
Growth Conditions ◽  
Ex Situ ◽  
Morphological Studies

AbstractStructural and photoluminescence (PL) properties of Zn2(1-x)MnxSiO4 (1 ≤ x ≤ 5) and diffuse reflectance spectroscopy (DRS) and morphological studies of ZnGa2O4:Mn thin film green emitting phosphors grown using pulsed laser deposition (PLD) technique have been investigated. Zn2(1-x)MnxSiO4 thin films grown on Si substrate at 700°C in 300 mTorr of oxygen partial pressure, upon ex-situ annealing at higher temperatures exhibit superior PL intensity. ZnGa2O4:Mn phosphor thin films grown on quartz substrate at 650oC and in-situ annealed in 300mTorr of oxygen partial pressure show better emission intensity. For both Zn2SiO4:Mn and ZnGa2O4:Mn phosphors, luminescence can be assigned to 4T1 – 6A1 transition of Mn2+ within the 3d orbital giving rise to emission at 525 and 503 nm, respectively.

THE SYSTEM ETHANOL-METHANOL AT 40 °C.

1942 ◽  
Vol 20b (10) ◽  
pp. 207-211 ◽  
Author(s):  
A. C. Morris ◽  
L. T. Munn ◽  
G. Anderson
Keyword(s):  
Partial Pressure ◽  
Total Pressure ◽  
Experimental Error ◽  
Pressure Curve ◽  
Raoult’S Law ◽  
Raoult's Law

The system ethanol-methanol was studied at 40 °C. using the original and also a modified form of the apparatus of Ferguson and Funnell. The total pressure curve is linear and the partial pressure curves agree with Raoult's law within the experimental error.

scholarly journals The dissolution study of a South African magnesium-based material from different sources using a pH-stat

2011 ◽  
Vol 17 (4) ◽  
pp. 459-468 ◽  
Author(s):  
Rutto Limo ◽  
Christopher Enweremadu
Keyword(s):  
Particle Size ◽  
Dissolution Rate ◽  
South African ◽  
Reaction Temperature ◽  
Liquid Ratio ◽  
Efficient Operation ◽  
Shrinking Core ◽  
Ph Stat ◽  
Hcl Concentration ◽  
Different Sources

One of the main steps in the wet flue gas desulphurization (WFGD) process is the dissolution of either magnesite or limestone. Evaluating the magnesite dissolution rate is vital for the design and efficient operation of wet FGD plants. A study on the dissolution of magnesite from different sources in South Africa is presented in this work. The effect of reaction temperature (303.15-343.15K), solid-to-liquid ratio (0.5-2.5g/200 ml), particle size (25-125?m), pH (4-6) and HCl concentration (0.5-2.5 mol/l) on the dissolution rate was studied. It was found out that the dissolution reaction follows a shrinking-core model with the chemical reaction control as the rate-controlling step. The dissolution rate increased with an increase in concentration and reaction temperature and with a decrease in particle size and solid-to-liquid ratio. The activation energy of this dissolution process was found to be 45.685 kJ/mol.

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