scholarly journals Induction-thermal action effect on the surface area of titanium products

2021 ◽  
Vol 2086 (1) ◽  
pp. 012181
Author(s):  
M Fomina ◽  
A Shchelkunov ◽  
A Shumilin
Keyword(s):  
Surface Area ◽  
Average Pore Size ◽  
Thermal Action ◽  
Induction Heat ◽  
Average Pore ◽  
Action Effect ◽  
Induction Heat Treatment ◽  
Exposure Temperature ◽  
Area Increase ◽  
Increasing Temperature

Abstract The changes in the surface area of titanium samples occurring during induction heat treatment (IHT) were studied. The dependence of the surface area of titanium samples on the exposure temperature was revealed. When a titanium sample was heated to a temperature of 1000 °C in the air at an exposure time of 60 s, there was a 45-fold area increase. The assessment of the porosity of the formed coating is carried out. The number of pores increased with increasing temperature from 374 to 1029 pieces. Accordingly, the average pore size decreased by 40%.

scholarly journals Acid Modification of the Unsupported NiMo Catalysts by Y-Zeolite Nanoclusters

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 344
Author(s):  
Chengwu Dong ◽  
Changlong Yin ◽  
Tongtong Wu ◽  
Zhuyan Wu ◽  
Dong Liu ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Pore Size ◽  
Y Zeolite ◽  
Active Components ◽  
Acid Modification ◽  
Total Acid ◽  
Average Pore ◽  
Nimo Catalysts

Unsupported NiMo catalyst has high hydrogenation activity due to its high active site distribution. However, low specific surface area and pore distribution greatly limit the efficient utilization of the active components. The Y-zeolite nanoclusters were hydrothermally synthesized and introduced into the unsupported NiMo catalysts from a layered nickel molybdate complex oxide. The XRD, N2 adsorption-desorption, FT-IR, Py-IR, SEM, NH3-TPD, and TEM were used to characterize all catalysts. The dibenzothiophene (DBT) hydrodesulfurization (HDS) reaction was performed in a continuous high pressure microreactor. The results showed that the specific surface area, pore volume, and average pore size of the unsupported NiMo catalysts were greatly increased by the Y-zeolite nanoclusters, and a more dispersed structure was produced. Furthermore, the Lewis acid and total acid content of the unsupported NiMo catalysts were greatly improved by the Y-zeolite nanoclusters. The HDS results showed that the unsupported NiMo catalysts modified by the nanoclusters had the same high desulfurization efficiency as the unmodified catalyst, but had more proportion of direct desulfurization (DDS) products. The results offer an alternative to reducing hydrogen consumption and save cost in the production of ultra clean diesel.

scholarly journals Biodiesel Processing Using Sodium and Potassium Geopolymer Powders as Heterogeneous Catalysts

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2839 ◽  
Author(s):  
Renata F. Botti ◽  
Murilo D.M. Innocentini ◽  
Thais A. Faleiros ◽  
Murilo F. Mello ◽  
Danilo L. Flumignan ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Heterogeneous Catalysts ◽  
Average Pore Size ◽  
Thermal Shrinkage ◽  
Average Pore ◽  
Base Catalysts ◽  
Sodium And Potassium

This work investigates the catalytic activity of geopolymers produced using two different alkali components (sodium or potassium) and four treatment temperatures (110 to 700 °C) for the methyl transesterification of soybean oil. The geopolymers were prepared with metakaolin as an aluminosilicate source and alkaline activating solutions containing either sodium or potassium in the same molar oxide proportions. The potassium-based formulation displayed a higher specific surface area and lower average pore size (28.64–62.54 m²/g; 9 nm) than the sodium formulation (6.34–32.62 m²/g; 17 nm). The reduction in specific surface area (SSA) after the heat treatment was more severe for the sodium formulation due to the higher thermal shrinkage. The catalytic activity of the geopolymer powders was compared under the same reactional conditions (70–75 °C, 150% methanol excess, 4 h reaction) and same weight amounts (3% to oil). The differences in performance were attributed to the influences of sodium and potassium on the geopolymerization process and to the accessibility of the reactants to the catalytic sites. The Na-based geopolymers performed better, with FAME contents in the biodiesel phase of 85.1% and 89.9% for samples treated at 500 and 300 °C, respectively. These results are competitive in comparison with most heterogeneous base catalysts reported in the literature, considering the very mild conditions of temperature, excess methanol and catalyst amount and the short time spent in reactions.

scholarly journals Production of Highly Porous Biochar Materials from Spent Mushroom Composts

Horticulturae ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 46
Author(s):  
Wen-Shing Chen ◽  
Wen-Tien Tsai ◽  
Yu-Quan Lin ◽  
Chi-Hung Tsai ◽  
Yao-Tsung Chang
Keyword(s):  
Surface Area ◽  
Agricultural Waste ◽  
Average Pore Size ◽  
Chemical Properties ◽  
Edible Mushroom ◽  
Bet Surface Area ◽  
Mushroom Compost ◽  
Average Pore ◽  
Spent Mushroom Compost ◽  
Pore Properties

The edible mushroom industry has grown significantly in recent years due to the dietary change and the demand for heathy food. However, the spent mushroom compost (SMC) will be produced in large quantities after the harvest, thus forming an agricultural waste requiring proper management other than dumping or burning. In this work, two types of SMCs with the cultivation of shiitake fungus (SF) and black fungus (BF) were converted into porous biochar products (a series of SMC-SF-BC and SMC-BF-BC) at higher pyrolysis temperatures (i.e., 400, 600 and 800 °C) based on their thermochemical characteristics, using thermogravimetric analysis (TGA). The pore and chemical properties of the resulting products, including surface area, pore volume, average pore size, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier Transform infrared spectroscopy (FTIR), were studied to correlate them with the most important process parameter. The results showed that the pore properties of the biochar products indicated a significant increase with the increase in the pyrolysis temperature from 400 to 600 °C. The data on the maximal Brunauer-Emmett-Teller (BET) surface area for the biochar products produced at 800 °C (i.e., SMC-SF-BC-800 and SMC-BF-BC-800) were found to be 312.5 and 280.9 m2/g, respectively. Based on the EDS and FTIR, plenty of oxygen-containing functional groups were found on the surface of the resulting biochar products.

Synergy of Pore Size and Specific Surface Area on the CO2 Sorption Performance of Nano CaO-Based Sorbents

2019 ◽  
Vol 19 (6) ◽  
pp. 3205-3209 ◽  
Author(s):  
Shangqing Lu ◽  
Qirui Lin ◽  
Sufang Wu
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Sorption Capacity ◽  
Specific Surface Area ◽  
Partial Correlation ◽  
Average Pore Size ◽  
Partial Correlation Analysis ◽  
Average Pore ◽  
Carbon Dioxide Sorption

This study focuses on the synergy effect of pore size and specific surface area (SSA) on the carbon dioxide sorption performance. Nano CaO-based CO2 sorbents with various pore size (15–55 nm) under similar SSA, and different SSA (14.50–48.90 m2/g) under similar pore size are prepared using selected organic templates. Results indicate that increasing the proportion of macropore in 47–96 nm could significantly improve sorbent’s sorption rate and corresponding sorption capacity. Besides, sorption capacity could be also by SSA. Moreover, partial correlation analysis reveals that sorption capacity is slightly more dependent on average pore size than SSA.

Catalytic Oxidation of Toluene with Ozone Over the Ru-Mn/Desilicated Nanoporous H-Zeolite Socony Mobil-5 at Room Temperature

2021 ◽  
Vol 21 (7) ◽  
pp. 3868-3871
Author(s):  
Jihee Kim ◽  
Jung Eun Lee ◽  
Abid Farooq ◽  
Sang Chai Kim ◽  
Sang-Chul Jung ◽  
...  
Keyword(s):  
Pore Size ◽  
Catalytic Oxidation ◽  
Surface Area ◽  
Removal Efficiency ◽  
Pore Volume ◽  
Bimetallic Catalysts ◽  
Room Temperature ◽  
Average Pore Size ◽  
Average Pore ◽  
Zeolite Support

In this study, the effect of Ru-Mn bimetallic catalysts in combination with a zeolite support on the removal of toluene in the presence of ozone at room temperature was investigated. Desili-cated HZSM-5 (DZSM) was fabricated and applied as a Ru-Mn support for the removal of toluene (100 ppm) in the presence of ozone (1000 ppm) at room temperature. The surface area, pore volume, and average pore size of Ru-Mn with a DZSM support (RuMn/DZSM) were measured and compared with those of Ru-Mn/HZSM-5 (RuMn/HZSM). The pore size of RuMn/DZSM (69 Å) was much larger than that of RuMn/HZSM-5 (5.5 Å). In addition, the pore volumes of RuMn/DZSM and RuMn/HZSM were 0.64 and 0.25 cm3/g, respectively. Furthermore, the ratios of Mn3+/Mn4+ and Ovacancy/Olattice of RuMn/DZSM were larger than those of RuMn/HZSM-5. The removal efficiency of toluene of RuMn/DZSM was higher than that of RuMn/HZSM due to its larger pore volume, pore size, and the increased ratios of Mn3+/Mn4+ and Ovacancy/Olattice.

Preparation and Structural Analysis of Magnesium Oxide Aerogels

MRS Advances ◽  
2017 ◽  
Vol 2 (57) ◽  
pp. 3505-3510
Author(s):  
Jiankai Zhang ◽  
Xiaohong Chen ◽  
Ran Liu ◽  
Huaihe Song ◽  
Zhihong Li
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Magnesium Oxide ◽  
Specific Surface Area ◽  
Average Pore Size ◽  
Sol Gel ◽  
Average Pore ◽  
X Ray ◽  
Water As Solvent ◽  
Saxs Analysis

ABSTRACTMagnesium oxide aerogels were made by sol-gel process using magnesium methoxide as precursor, methanol and deionized water as solvent with ethanol supercritical fluid drying. The influences of the different factors on the gel time and the specific surface area of magnesium oxide aerogels were studied, and the structure and morphology were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscope (TEM) and X-ray diffraction (XRD), and the Small Angle X-ray Scatter (SAXS) was utilized to determine the fractural structure of the magnesium oxide aerogels. The results show that MgO aerogels belong to the typical mesoporous materials with rich network and highly developed pore structure, and the specific surface area is 904.9 m2/g, the apparent density is 0.055 g/cm3, the average pore size is 19.6 nm. The results of SAXS analysis show that the fractal dimension of the MgO aerogels is 2.32 in high q area which proves the existence of rough surface and pore fractal structure.

scholarly journals Ionic Liquids-Functionalized Zeolitic Imidazolate Framework for Carbon Dioxide Adsorption

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2361 ◽  
Author(s):  
Xuyan Song ◽  
Jialin Yu ◽  
Min Wei ◽  
Ran Li ◽  
Xi Pan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Surface Area ◽  
Average Pore Size ◽  
Carbon Dioxide Adsorption ◽  
Zeolitic Imidazolate Frameworks ◽  
Zeolitic Imidazolate Framework ◽  
Average Pore ◽  
Solid Sorbents

Ionic-liquid-functionalized zeolitic imidazolate frameworks (ZIF) were synthesized using the co-ligands of 2-methylimidazole and amine-functionalized ionic liquid during the formation process of frameworks. The resulting ionic-liquid-modified ZIF had a specific surface area of 1707 m2·g−1 with an average pore size of about 1.53 nm. Benefiting from the large surface area and the high solubility of carbon dioxide in ionic-liquid moieties, the synthesized materials exhibited a carbon dioxide adsorption capacity of about 24.9 cm3·g−1, whereas it was 16.3 cm3·g−1 for pristine ZIF at 25 °C under 800 mmHg. The results demonstrate that the modification of porous materials with ionic liquids could be an effective way to fabricate solid sorbents for carbon dioxide adsorption.

scholarly journals Fine Activated Carbon from Rubber Fruit Shell Prepared by Using ZnCl2 and KOH Activation

2021 ◽  
Vol 11 (9) ◽  
pp. 3994
Author(s):  
Suhdi ◽  
Sheng-Chang Wang
Keyword(s):  
Activated Carbon ◽  
Carbon Content ◽  
Surface Area ◽  
Average Pore Size ◽  
Absorption Capacity ◽  
Bet Surface Area ◽  
Koh Activation ◽  
Average Pore ◽  
Impregnation Ratio ◽  
Precursor Material

Fine activated carbon (FAC) is prepared from rubber fruit shells (RFS) using two chemical activating agents (ZnCl2 and KOH) and three impregnation ratios (1:3, 1:4, and 1:5). The Brunauer–Emmett–Teller (BET) results show that for a constant impregnation ratio, the ZnCl2 activating agent yields a higher specific surface area than the KOH agent. In particular, for the maximum impregnation ratio of 1:5, the FAC prepared using ZnCl2 has a BET surface area of 456 m2/g, a nitrogen absorption capacity of 150.38 cm3/g, and an average pore size of 3.44 nm. Moreover, the FAC structure consists of 70.1% mesopores and has a carbon content of 80.05 at.%. Overall, the results confirm that RFS, activated using an appropriate quantity of ZnCl2, provides a cheap, abundant, and highly promising precursor material for the preparation of activated carbon with high carbon content and good adsorption properties

scholarly journals INFLUENCE OF SYNTHESIS TECHNO-CHEMICAL PARAMETERS ON PHYSICOCHEMICAL CHARACTERISTICS OF BIOMIMETIC CALCIUM-PHOSPHATE NANOCOMPOSITE DOPED BY SILICATE AND CARBONATE ANIONS

2020 ◽  
Vol 5 (10) ◽  
pp. 47-56
Author(s):  
M. Troubitsin ◽  
Viet Hung Hoang ◽  
L. Furda
Keyword(s):  
Calcium Phosphate ◽  
Specific Surface ◽  
Crystallite Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Average Pore Size ◽  
Average Crystallite Size ◽  
Average Pore ◽  
The Impact

The object of our investigation is a biomimetic calcium-phosphate nanocomposite doped by silicate and carbonate anions (BMHAP) synthesized by chemical deposition from aqueous solutions. The obtained samples are investigated using X-ray phase analysis (XRD), FTIR spectroscopy, and low-temperature nitrogen adsorption (BET method). The influence of the techno chemical synthesis parameters on the products characteristics (including phase composition, crystal lattice parameters, average crystallite size, specific surface area) is evaluated. The study on the effect of the synthesis temperature shows that with increasing in temperature from 22°C to 80°C, reveals a slight increase in the parameters of unit cells a and c, which leads to an increase in its volume. There is also a tendency towards a decrease in the average size of coherent scattering regions of crystallites (from 7,52 to 4,65 nm) and specific surface area (from 192,51 to 74,72 m2/g), but the pore volume and average pore diameter of the synthesized powders increases. The effect of the aging time of the sediment in the mother liquor is studied from 0,5 to 24 hours. It is found that with an increase in the maturation time of the sediment, the percent crystallinity of the powders improves by 1,7 times, an increase in the specific surface area from 163,43 to 192,51 m2/g and a slight decrease in the pore volume and average pore size of the samples are observed. The impact of the stirring rate of the reagents is investigated. An increase in speed from 300 to 1300 rpm has been shown to decrease the average crystallite size from 8,80 to 6,41 nm, and as a result, to increase the specific surface area of the synthesized samples from 178,58 to 192,51 m2/g, respectively.

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