scholarly journals Catalytic Cracking of Biodiesel Waste Using Metal Supported SBA-15 Mesoporous Catalysts

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 291 ◽  
Author(s):  
Duangkamon Jiraroj ◽  
Tunyatorn Tongtooltush ◽  
Joongjai Panpranot ◽  
Piyasan Praserthdam ◽  
Duangamol Tungasmita
Keyword(s):  
Electron Microscopy ◽  
Catalytic Cracking ◽  
Liquid Fraction ◽  
Batch Reactor ◽  
Biodiesel Production ◽  
Gaseous Products ◽  
Pure Glycerol ◽  
Transmission Electron ◽  
N2 Atmosphere ◽  
Cracking Performance

Palladium (Pd) and aluminium (Al) supported on SBA-15 were prepared as catalysts for cracking biodiesel waste from biodiesel production. Mesoporous silica SBA-15 was first synthesized by a hydrothermal method and then loaded with Al or Pd particles were loaded using postsynthesis or aqueous wet impregnation methods, respectively. The physical properties of the catalysts were characterized by X-ray diffraction (XRD), nitrogen (N2) adsorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. The catalytic cracking performance of biodiesel waste was evaluated at reaction temperatures above 400 °C under a N2 atmosphere in a batch reactor for 40 min in comparison with that for pure glycerol, where the conversion of biodiesel waste reached 86.8% with 10 wt% Pd-SBA-15 at 650 °C. The product types depended on whether the starting material was pure glycerol or biodiesel waste. The main gaseous products were carbon monoxide as synthesis gas, carbon dioxide, and 1,3-butadiene. Additionally, 2-cyclopenten-1-one and 2-propen-1-ol were major products in the liquid fraction, which can be used in pharmaceuticals and as a flame retardant, respectively.

Effect of Crystallization on the Catalytic Cracking Performance of Zeolite Socony Mobil-5

2018 ◽  
Vol 18 (12) ◽  
pp. 8437-8446
Author(s):  
Maojiong Cao ◽  
Youyong Su ◽  
Bing Xue ◽  
Yuxiang Yang ◽  
Xiangnong Liu
Keyword(s):  
Electron Microscopy ◽  
Crystallization Temperature ◽  
Catalytic Cracking ◽  
Acid Value ◽  
Temperature Programmed Desorption ◽  
Crystallization Time ◽  
X Ray ◽  
Transmission Electron ◽  
Cracking Performance ◽  
Temperature Programmed

In the research, zeolite socony mobil-5 (ZSM-5) catalyst was prepared by hydrothermal method and characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), NH3-temperature programmed desorption (NH3-TPD) and Brunauer- Emmett-Teller (BET). The catalytic products from Jatropha carcass L. oil were analyzed by gas chromatography-mass spectrometer (GC-MS). The effects of crystallization time and crystallization temperature on catalytic cracking performance of ZSM-5 were investigated. According to the results, the catalytic cracking performance of ZSM-5 was closely associated with its pore structure. When the crystallization time was 60 h and the crystallization temperature was 170 °C, ZSM-5 with optimal catalytic cracking performance was synthesized. Catalyzed by the optimal ZSM-5, Jatropha carcass L. oil showed the liquid conversion rate of 26.60% and the acid value of 1.24 mg KOH·g−1. The main catalytic products from Jatropha carcass L. oil included benzene (10.02%), methylbenzene (20.52%), o-xylene (14.45%) and p-xylene (6.59%).

Surface nitridation of Ta powder by molten-salt electrolysis of Ta2O5 under N2 atmosphere

2020 ◽  
Vol 13 (07) ◽  
pp. 2050032
Author(s):  
Qing Huang ◽  
Guojin Zheng ◽  
Tian Wu
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Cell Voltage ◽  
X Ray Diffraction ◽  
Molten Salt Electrolysis ◽  
X Ray ◽  
Structured Catalysts ◽  
Transmission Electron ◽  
N2 Atmosphere

The electro-deoxidation of Ta2O5 in molten CaCl2 under N2 atmosphere is a facile way for the in situ surface nitridation of Ta particles. The cell voltage and electrolysis time of Ta2O5 are rationalized to realize the in situ surface nitridation of Ta. All the characterization results including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elements mapping as well as X-ray photoelectron spectroscopy (XPS) confirm the formation of Ta2N layers on the surface of Ta particles, with the thickness of 3–4[Formula: see text]nm. This method provides a strategy for the facile in situ surface nitridation with N2 as the nitrogen source for the fabrication of core-shell structured catalysts.

Investigation on Fracture Mechanism of A356 during Thixo-Forging

2006 ◽  
Vol 116-117 ◽  
pp. 140-144 ◽  
Author(s):  
Kai Kun Wang ◽  
R. Kopp ◽  
Gerhard Hirt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Melting Point ◽  
Fracture Mechanism ◽  
Liquid Fraction ◽  
Irregular Shape ◽  
High Melting ◽  
High Melting Point ◽  
Microstructural Changes ◽  
Transmission Electron

Transmission electron microscopy (TEM) was used to assess the microstructural changes accompanying semisolid molding of a creep resistant Mg-5%Al-2%Sr alloy. It was revealed that the processing created thixotropic morphologies with globular solids of α-Mg, having well-developed sub-structures. The quickly-solidified liquid fraction, enriched in Al and Sr, led to the formation of increased volumes of a lamellae type Al4Sr phase, surrounding the secondary α-Mg. Traces of Mg17Al12 still existed, predominantly as irregular shape compounds located mainly in grain interiors. Both the primary solid and high melting point precipitates of Mn-Al modified with Sr, acted as nucleation substrates for secondary α-Mg grains.

Kinetic and structural constraints during glauconite dissolution: implications for mineral disposal of CO2

2008 ◽  
Vol 72 (1) ◽  
pp. 27-31 ◽  
Author(s):  
S. Fernandez-Bastero ◽  
C. Gil-Lozano ◽  
M. J. I. Briones ◽  
L. Gago-Duport
Keyword(s):  
Electron Microscopy ◽  
Batch Reactor ◽  
Bet Surface Area ◽  
Dissolution Mechanism ◽  
Structural Constraints ◽  
X Ray Diffraction ◽  
Ph Values ◽  
Transmission Electron ◽  
Ph Range

AbstractThe kinetics of glauconite dissolution have been determined in the pH range 2—10 (T = 25°C) using flow-batch reactor experiments. Besides the kinetic characteristics, the structural and textural aspects which could influence its long-term reactivity have also been characterized by means of X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and BET surface area measurements. The results from these analyses showed that glauconite follows a dual dissolution pathway which is pH-dependent, being more stable at neutral or slightly alkaline pH values. Under acidic conditions, glauconite is slightly more soluble than other ubiquitous silicates present in the marine sediments. The dissolution mechanism is incongruent at very acid pH values and tends to be congruent for intermediate and neutral ones. In addition, the results from the structural analyses suggest that the dissolution is a two-step process: the first one involves the disorder of the octahedral and tetrahedral layers, probably following a turbostratic mechanism which is evident in the XRD spectra as selective broadening of several reflections. In the second step, the dissolution of the cations from interlayer positions takes place and leads to the formation of an amorphous residue which acts as a passivating layer and reduces the reactive surface considerably. The influence of these aspects on CO2 capture via carbonation reactions is discussed.

Pd/SiO2 Inorganic–Organic Composite Membrane Calcined Under N2 Atmosphere: Thermal Stability and H2/CO2 Separation

2019 ◽  
Vol 19 (6) ◽  
pp. 3210-3217
Author(s):  
Jing Yang ◽  
Wang-Qing Fan ◽  
Ruihua Mu ◽  
Yamei Zhao
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Total Pore Volume ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
N2 Atmosphere ◽  
Bet Specific Surface Area ◽  
The Mean

A novel Pd/SiO2 inorganic–organic composite material was developed for the selective separation of H2 from a mixture of H2 and CO2. Its thermal stability and microstructure calcined under N2 atmosphere were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and N2 sorption–desorption measurements. Pd element in Pd/SiO2 gel material exists in PdCl2 form, calcination at 350 °C can result in the complete transformation of Pd2+ to metallic Pd0. With the increase of calcination temperature, the hydrophobic Si–CH3 bands decreased in intensity. The residue of Pd/SiO2 material calcined at 800 °C was mainly composed of Si–O–Si, metallic Pd0, CSi4 and some elemental C0. The mean pore size, BET specific surface area and total pore volume of the as-prepared Pd/SiO2 material calcined at 350 °C was about 2.26 nm, 417.35 m2 g−1 and 0.288 m3 g−1, respectively. The mean H2 and CO2 permeances of the corresponding Pd/SiO2 membrane were 9.90×10−6 and 9.10×10−7 mol m−2 Pa−1 s−1, respectively, when operating at 200 °C and a pressure difference of 0.3 MPa. After the steam exposure at 200 °C for 168 h, the H2 permeance decreased by 3.23% while the H2/CO2 permselectivity increased by 2.50%.

scholarly journals Transmission Electron Microscopy Study of Iron Oxide Poisoning in Fluid Catalytic Cracking Catalysts

2011 ◽  
Vol 17 (S2) ◽  
pp. 1378-1379 ◽  
Author(s):  
Y Tang ◽  
D Cullen ◽  
D Coffey ◽  
M Allahverdi ◽  
W Reagan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Iron Oxide ◽  
Catalytic Cracking ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Fluid Catalytic Cracking ◽  
Transmission Electron Microscopy Study ◽  
Transmission Electron ◽  
Cracking Catalysts

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

TEM Study of a Creep-Resistant Mg-5Al-2Sr Alloy after Semisolid Molding

2006 ◽  
Vol 116-117 ◽  
pp. 136-139
Author(s):  
Frank Czerwinski ◽  
Anna Zielinska-Lipiec
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Melting Point ◽  
Liquid Fraction ◽  
Irregular Shape ◽  
High Melting ◽  
High Melting Point ◽  
Microstructural Changes ◽  
Transmission Electron

Transmission electron microscopy (TEM) was used to assess the microstructural changes accompanying semisolid molding of a creep resistant Mg-5%Al-2%Sr alloy. It was revealed that the processing created thixotropic morphologies with globular solids of α-Mg, having well-developed sub-structures. The quickly-solidified liquid fraction, enriched in Al and Sr, led to the formation of increased volumes of a lamellae type Al4Sr phase, surrounding the secondary α-Mg. Traces of Mg17Al12 still existed, predominantly as irregular shape compounds located mainly in grain interiors. Both the primary solid and high melting point precipitates of Mn-Al modified with Sr, acted as nucleation substrates for secondary α-Mg grains.

Biodiesel Production with Nanotubular Sodium Titanate Doped with Potassium as a Catalyst

MRS Advances ◽  
2016 ◽  
Vol 1 (6) ◽  
pp. 415-420 ◽  
Author(s):  
Elena Martínez-Klimova ◽  
Patricia Hernández-Hipólito ◽  
Tatiana E. Klimova
Keyword(s):  
Electron Microscopy ◽  
Sodium Titanate ◽  
Biodiesel Production ◽  
Titanate Nanotubes ◽  
Molar Ratio ◽  
Transmission Electron ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Sodium And Potassium ◽  
Ft Raman

ABSTRACTIn the present work, sodium titanate nanotubes doped with potassium were synthesized by the Kasuga method and tested as catalysts for biodiesel production. Potassium was added to the nanotubes in order to increase their basicity and, consequently, improve their performance in the transesterification of soybean oil with methanol. In the synthesis, the NaOH:KOH molar ratio was changed from 9:1 to 7:3 in order to increase potassium loadings in the obtained nanotubular solids. Synthesized catalysts were characterized by N2 physisorption, powder XRD, scanning electron microscopy (SEM-EDX), transmission electron microscopy (TEM), FT-IR, FT-Raman and CO2 temperature-programmed desorption (CO2-TPD). Obtained results showed that sodium trititanate nanotubes containing 1.5 wt. % of potassium were obtained when 10 M alkali solution with NaOH:KOH molar ratio of 9:1 was used. In this case, the proportion of sodium and potassium in the synthesized material was similar to that used in the synthesis. An increase in the proportion of KOH to 20 and 30 molar % in the NaOH-KOH solutions used in the synthesis allowed obtaining titanate nanotubes with larger potassium loadings (3.2 and 3.3 wt. %, respectively). As it was expected, potassium addition to the sodium titanate nanotubes resulted in an increase in the amount of medium and strong basic sites. Potassium-containing nanotubes showed higher catalytic activity in the transesterification reaction than the pure sodium counterpart used as a reference. The best results were obtained with the samples containing 3.2-3.3 wt. % of potassium where a biodiesel yield of about 94-96 % was obtained at 80 °C and 1 h reaction time.

Hydrothermal process development for the treatment of crocidolite asbestos waste

2019 ◽  
Vol 37 (9) ◽  
pp. 914-924
Author(s):  
CT Nzogo Metoule ◽  
S Delaby ◽  
JH Ferrasse ◽  
O Boutin
Keyword(s):  
Electron Microscopy ◽  
Supercritical Water ◽  
Process Development ◽  
Batch Reactor ◽  
Hydrothermal Process ◽  
Ultrapure Water ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
First Results

The asbestos-containing waste management is a public health topic for countries which have used this mineral. Treatment of chrysotile (white asbestos), a phyllosilicate from serpentine, crocidolite (blue asbestos, first results on this kind of asbestos), one of the five asbestos varieties of amphibole family and asbestos-containing waste conversion process is proposed by using hydrothermal treatment in supercritical water. All samples were treated in an Inconel Batch Reactor. The treatment durations range is from 1 to 6 hours, temperatures range is from 400°C to 750°C, mass concentration range is from 0.02 to 170 mg. mL−1 and pressures are higher than 23 MPa. Ultrapure water is used for sample preparation. This ultrapure water is used to monitor mineral leaching on the aqueous phase and to avoid particle cross-contamination. Transmission electron microscopy analyses were carried out to check the presence or not of asbestos phase. According to these analyses, the best conditions of conversion were 1 hour and 0.02 mg. mL−1 for chrysotile, 3 hours and 0.02 mg. mL−1 for crocidolite and 1 hour and 20 mg. mL−1 for asbestos-containing waste, at T = 750°C. Supercritical water conditions were maintained during the whole treatment. The X-ray diffraction showed that the main phases present after treatments were riebeckite and magnetite (crocidolite), forsterite and enstatite (chrysotile), and calcite, spurrite and gehlenite (asbestos-containing waste). Finally, a scanning electron microscopy analysis was performed to monitor morphological fibre change. The elongated structure, partially fragmented, was found in all samples.

Hydrodeoxygenation of stearic acid for the production of “green” diesel

2014 ◽  
Vol 3 (6) ◽  
Author(s):  
Antonina A. Stepacheva ◽  
Linda Zh. Nikoshvili ◽  
Esther M. Sulman ◽  
Valentina G. Matveeva
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Photoelectron Spectroscopy ◽  
Hypercrosslinked Polystyrene ◽  
Biodiesel Production ◽  
Scanning Calorimetry ◽  
Green Diesel ◽  
X Ray ◽  
Transmission Electron

AbstractThe current work is devoted to the second-generation biodiesel production via fatty acids catalytic hydrodeoxygenation (HDO). Pd-containing catalysts based on polymeric matrix of hypercrosslinked polystyrene (HPS) with different metal loading were investigated in the process. The catalysts were characterized by low-temperature nitrogen physisorption, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The selectivity of the process (regarding to

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