scholarly journals Gasification Characteristics and Kinetics of Unburned Pulverized Coal in Blast Furnaces

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4324 ◽  
Author(s):  
Rian Zan ◽  
Wei Wang ◽  
Runsheng Xu ◽  
Johannes Schenk ◽  
Heng Zheng ◽  
...  
Keyword(s):  
Specific Surface ◽  
Heating Rate ◽  
Surface Area ◽  
Specific Surface Area ◽  
Reaction Rate ◽  
Pulverized Coal ◽  
Maximum Reaction Rate ◽  
Coke Layer ◽  
Apparent Activation Energies ◽  
Gasification Reaction

Pulverized coal injected into a blast furnace (BF) burns incompletely in a very limited amount of time. A considerable amount of unburned pulverized coal (UPC) escapes from the raceway to the coke layer. The unburned pulverized coal reacts with CO2 in the coke layer, and this has a very significant impact on the operation of the BF. The gasification reaction characteristics of the UPC with CO2 were assessed by thermogravimetric analysis. The microstructure and specific surface area of the pulverized coal and UPC were characterized by scanning electron microscopy (SEM), and a specific surface area testing apparatus together with the Brunauer-Emmett-Teller (BET) method, respectively. The results showed that Qingding UPC requires a higher temperature to complete the gasification reaction. At the same heating rate, the Tm (maximum reaction rate temperature) of the Shenhua UPC is much lower and the reaction rate is larger than those of the Qingding UPC. An increased heating rate is beneficial for the gasification reaction of the two UPCs. The kinetics analysis results showed that the optimal mechanism function models for the Shenhua and Qingding UPCs are chemical reaction models. The apparent activation energies of gasification of the Shenhua UPC and Qingding UPC under different conditions were 269.89–223.41 KJ/mol and 266.70–251.54 KJ/mol, respectively.

scholarly journals Anti-corrosion porous RuO2/NbC anodes for the electrochemical oxidation of phenol

RSC Advances ◽  
2019 ◽  
Vol 9 (30) ◽  
pp. 17373-17381 ◽  
Author(s):  
Jing Ma ◽  
Guotong Qin ◽  
Wei Wei ◽  
Tianliang Xiao ◽  
Shaomin Liu ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Electrochemical Oxidation ◽  
Specific Surface Area ◽  
Anode Materials ◽  
Reaction Rate ◽  
High Specific Surface Area ◽  
Porous Structures ◽  
Slow Reaction ◽  
Oxidation Of Phenol

Efficient anode materials with porous structures have drawn increasing attention due to their high specific surface area, which can compensate for the slow reaction rate of electrochemical oxidation.

scholarly journals Study of the effect of Mg (II) addition and the annealing conditions on the structure of mesoporous aluminum oxide using Plackett-Burman design

2015 ◽  
Vol 80 (12) ◽  
pp. 1529-1540 ◽  
Author(s):  
Tatjana Novakovic ◽  
Ljiljana Rozic ◽  
Srdjan Petrovic ◽  
Zorica Vukovic ◽  
Miodrag Mitric
Keyword(s):  
Specific Surface ◽  
Crystallite Size ◽  
Heating Rate ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Magnesium Nitrate ◽  
Degree Of Crystallinity ◽  
Burman Design ◽  
Plackett Burman Design

A statistical design was used to investigate the effect of various processing conditions on the structure of sol-gel derived Mg(II) doped alumina. Six processing variables were selected based on the Plackett-Burman design: concentration of magnesium nitrate, time and temperature of alcohol evaporation, temperature and time of annealing and heating rate were changed at two levels. For every set of conditions, samples with different specific surface area and degree of crystallinity were obtained. Analysis of the results showed that annealing temperature , heating rate and concentration of magnesium nitrate were the main factors affecting average crystallite size of the predominant phase of alumina. In the case of the specific surface area, two of selected six variables had pronounced effect; however the temperature of annealing was more effective than others. The present results show that the proposed model that uses crystallite size as a response variables is preferable to further research.

Influence of Heat Treatment Process on Properties of Polycrystalline Alumina Fiber

2011 ◽  
Vol 399-401 ◽  
pp. 822-827 ◽  
Author(s):  
Jian Feng Xu ◽  
Shun De Fu ◽  
Ke Zhang
Keyword(s):  
Tensile Strength ◽  
Specific Surface ◽  
Heating Rate ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Polycrystalline Alumina ◽  
Average Tensile Strength ◽  
Alumina Fibers ◽  
Crystalline Growth

Polycrystalline alumina fibers were prepared by sol-gel method. The influence of heating rate on average tensile strength of fibers as well as the influence of calcining temperature on average tensile strength of fibers, crystal phases form, specific surface area of fibers were studied. The results show that when the heating rate (below 600°C) is 4°C/min,the average tensile strength of fibers over 1000Mpa The fibers pulverize obviously when the heating rate＞7°C/min. The average tensile strength and the specific surface area of fibers decreased with calcining temperature rising. When the calcining temperature reaches over 1300°C, the average tensile strength of fibers decreased quickly and the specific surface area of fibers decreases slowly for the crystalline growth.

Analysis of Char Specific Surface Area and Porosity from the Fast Pyrolysis of Biomass and Pulverized Coal

2012 ◽  
Vol 608-609 ◽  
pp. 383-387 ◽  
Author(s):  
Ji Yi Luan ◽  
Xue Mei Wu ◽  
Gui Fu Wu ◽  
Dong Wei Shao
Keyword(s):  
Fractal Dimension ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Rice Husk ◽  
Pore Volume ◽  
Nitrogen Adsorption ◽  
Pulverized Coal ◽  
Wood Dust ◽  
Corn Straw

In this paper, the chars of wood dust, corn straw, rice husk and coal pulverized were obtained at different residual time of various pyrolysis temperature (1173 K, 1273 K and 1373 K) during the process of flash pyrolysis in the drop tube furnace (DTF). In order to obtain the parameters of porous structure which included specific surface area, pore volume and fractal dimension of char, low-temperature nitrogen adsorption method was employed to obtain nitrogen adsorption isotherm of chars sample. For the four chars, the corn straw char had the biggest specific surface area and pore volume, the rice husk in second place, the wood dust in third place, and the pulverized coal char in the last one. By taking Frenkel-Halsey Hil (FHH) method to analyze the fractal character of char surface structure, we found that the fractal dimension of biomass except wood char is higher than those of pulverized coal char.

scholarly journals Synthesis, structure, and photo-Fenton activity of PrFeO3-TiO2 mesoporous nanocomposites

2021 ◽  
Vol 23 (4) ◽  
pp. 548-560
Author(s):  
Anna S. Seroglazova ◽  
Maria I. Chebanenko ◽  
Vadim I. Popkov
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Pore Size ◽  
Aqueous Media ◽  
Methyl Violet ◽  
Combustion Method ◽  
Diffuse Reflection Spectroscopy ◽  
Average Pore ◽  
Maximum Reaction Rate

Porous nanocomposites based on PrFeO3-TiO2 were synthesized using the glycine-nitrate combustion method with different values of mass content of TiO2 (0–7.5 %) and subsequent heat treatment in air. The results of X-ray phase analysis and Raman spectroscopy confirmed the presence of ultradispersed TiO2, structurally close to that of anatase. The morphology, specific surface area, and porous structure of the obtained powders were characterized by scanning electron microscopy and adsorption-structural analysis, the results of which showed that the samples had a foam-like mesoporous structure.The specific surface area and the average pore size were in the ranges of 7.6–17.8 m2/g and 7.2–15.2 nm, respectively, and varied depending on the TiO2 content. The optical properties of the nanocomposites were studied by UV-visible diffuse reflection spectroscopy, the energy of the band gap was calculated as 2.11–2.26 eV. The photocatalytic activity of PrFeO3‑TiO2 nanocomposites was investigated in the process of photo-Fenton-like degradation of methyl violet under the action of visible light. It was shown that the maximum reaction rate constant was 0.095 min-1, which is ten times higher than the value for the known orthoferrite-based analogs. The obtained photocatalysts were also characterized by their high cyclic stability. Based on the studies carried out, the obtained porous PrFeO3-TiO2 nanocomposites can be considered to be apromising basis for photocatalysts applied in advanced oxidative processes of aqueous media purification from organic pollutants.

scholarly journals Demonstration of the Influence of Specific Surface Area on Reaction Rate in Heterogeneous Catalysis

2021 ◽  
Author(s):  
Paweł Bernard ◽  
Paweł Stelmachowski ◽  
Paweł Broś ◽  
Wacław Makowski ◽  
Andrzej Kotarba
Keyword(s):  
Heterogeneous Catalysis ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Reaction Rate
Sign in / Sign up

Export Citation Format

Share Document