scholarly journals The structural transformation and reburning characteristics of gas coal in Ningwu coalfield fire

2021 ◽  
pp. 014459872110238
Author(s):  
Haihui Xin ◽  
Jianguo Sun ◽  
Wenjiang Tian ◽  
Banghao Zhou ◽  
Zuo Tang ◽  
...  
Keyword(s):  
Pyrolysis Temperature ◽  
Structural Parameters ◽  
Ignition Point ◽  
Pyrolysis Characteristics ◽  
Hydrocarbon Content ◽  
Thermal Analyzer ◽  
Gas Coal ◽  
Quantum Chemistry Method ◽  
Residual Weight ◽  
Maximum Separation

With the expansion of the scale of coal mining, the safety problems caused by the reburning of coal are becoming more and more serious. In this paper, the pyrolysis characteristics of gas coal and the exothermic characteristics of reoxidation of residues were studied by using a synchronous thermal analyzer. The functional groups of pyrolysis residues were tested, and the group content and characteristic structural parameters were calculated based on quantum chemistry method. The results show that with the increase of pyrolysis temperature, Volatile maximum separation rate (Vmax) and the change in the residual weight of the coal sample (ΔWvp) increase. The increase of temperature will lead to the decrease of hydroxyl and aliphatic hydrocarbon content in coal, and the increase of aromatic hydrocarbon. With the deepening of pyrolysis, the ignition point temperature of coal samples decreases first and then rises, the combustion intensity and combustion concentration are strengthened. The pyrolysis results show that 462.8°C is the critical temperature for the transition during pyrolysis. The ignition point of the residue is less affected by the pyrolysis conditions, and the ignition temperature of the raw coal and the pyrolysis residue varies within 330.57°C–334.98°C.

Effects of Zn on Pyrolysis Characteristics of Shenhua Lignite

2014 ◽  
Vol 1008-1009 ◽  
pp. 247-251
Author(s):  
Wipawan Sangsanga ◽  
Chuan Na ◽  
Jin Xiao Dou ◽  
Jiang Long Yu
Keyword(s):  
Pyrolysis Temperature ◽  
Fixed Bed ◽  
Coal Pyrolysis ◽  
Pyrolysis Gas ◽  
Gaseous Products ◽  
Pyrolysis Characteristics ◽  
Maximum Value ◽  
Product Gas ◽  
Zn Content ◽  
Catalytic Effects

The catalytic effects of Zn on the release of the gaseous products during pyrolysis of Shenhua lignite was investigated by using a fixed-bed quartz reactor. The product gas compositions from the coal pyrolysis were analyzed by a gas chromatography (GC). Experimental results show that Zn had noticeable catalytic effects on lignite pyrolysis. With the increase in Zn content, lignite weight loss increases during pyrolysis. However, there was an optimum content for amount Zn into the coal. Pyrolysis temperature had a great impact on the composition of pyrolysis gas. As the pyrolysis temperature increased, char yield decreased and gas yield increased. There existed a temperature that tar yield reached its maximum value.

scholarly journals Quality Properties and Pyrolysis Characteristics of Cassava Rhizome Pellets Produced by Alternating between Pelletizing and Torrefaction

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 930
Author(s):  
Nitipong Soponpongpipat ◽  
Paisan Comsawang ◽  
Suwat Nanetoe
Keyword(s):  
Chemical Composition ◽  
Thermogravimetric Analysis ◽  
Energy Density ◽  
Bulk Density ◽  
Moisture Absorption ◽  
Pyrolysis Temperature ◽  
Quality Properties ◽  
Pyrolysis Characteristics ◽  
Durability Index ◽  
The Difference

This work investigated quality properties of pellets of raw cassava rhizome (P-RC), pellets of pelletized cassava rhizome followed by torrefaction (T-CP), and pellets of torrefied cassava rhizome followed by pelletizing (P-TC). Torrefaction was conducted at temperatures of 230, 250, and 280 °C for 30 min. Pyrolysis characteristics of T-CP and P-TC at torrefied temperatures of 230 and 250 °C were studied using thermogravimetric analysis. It was found that at the similar torrefied temperature, P-TC had a higher bulk density, energy density, and pellet durability than that of T-CP and P-RC while T-CP had a higher HHV and moisture absorption than P-TC and P-RC. The bulk density of P-TC was 1.13–1.19 and 1.33–1.52 times higher than that of P-RC and T-CP, respectively. The HHV of T-CP was 1.07 and 1.29 times higher than P-TC and P-RC, respectively. The energy density of P-TC was 1.24–1.56 and 1.20–1.41 times higher than that of P-RC and T-CP. In terms of Pellet Fuel Institute (PFI) standard, the durability index of P-RC, P-TC, and T-CP at torrefied temperatures of 230 and 250 °C was acceptable. However, dramatically low and unacceptable durability index was found in case of T-CP at torrefied temperature of 280 °C. The moisture absorption of P-TC was lower than that of P-RC and T-CP. Finally, T-CP had a lower pyrolysis temperature and had a much lower solid yield than that of P-TC. Variation of pyrolysis characteristics indicated the difference in chemical composition between T-CP and P-TC.

scholarly journals Development of New Algorithm for Aniline Point Estimation of Petroleum Fraction

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 912
Author(s):  
Kaiyue Wang ◽  
Xiaoyan Sun ◽  
Shuguang Xiang ◽  
Yushi Chen
Keyword(s):  
Physical Property ◽  
Point Estimation ◽  
Petroleum Fraction ◽  
Estimation Methods ◽  
Hydrocarbon Mixture ◽  
Ternary Interaction ◽  
Ignition Point ◽  
Hydrocarbon Content ◽  
Petroleum Fractions ◽  
Average Boiling Point

The aniline point (AP) is an important physical property of a petroleum fraction. The AP gives an indication of the aromatic hydrocarbon content in a hydrocarbon mixture and can also be an indicator of the ignition point of a diesel fraction. In this study, common estimation methods were introduced and evaluated, and their limitations were analyzed. Multiple linear regression was used in constructing a quantitative function to solve for the AP using the average boiling point and specific gravity. The iterative modification algorithm of the ternary interaction algorithm was used to obtain the predicted value of the petroleum fraction AP, and the proposed algorithm was tested using 127 actual petroleum fractions. The average estimation deviation of the proposed method was 3.55%; hence, compared to the commonly used estimation methods, the prediction accuracy was significantly improved. This method offers important practical value in the calculation of the petroleum fraction AP and other petroleum fraction properties, thereby providing reference significance.

Study on Mechanism of Low Temperature Co-Pyrolysis of Duckweed and Flame Coal

2013 ◽  
Vol 724-725 ◽  
pp. 300-305
Author(s):  
Xuan Ming He ◽  
Jia Qi Fang ◽  
Ye Pan ◽  
Wei Li ◽  
Xiao Juan Wang
Keyword(s):  
Activation Energy ◽  
Low Temperature ◽  
Synergistic Effect ◽  
Kinetic Analysis ◽  
Kinetic Parameters ◽  
Pyrolysis Temperature ◽  
Light Component ◽  
Average Activation Energy ◽  
First Order ◽  
Pyrolysis Characteristics

Co-pyrolysis characteristics of long flame coal mixed with duckweed in different proportions were studied by using TG. And the kinetic parameters was also figured out by using the method of Coats-Redfern. It was exhibited significant synergistic effect created more the light component between duckweed and coal during co-pyrolysis, The pyrolysis rate of flame coal is much smaller than biomass, and the starting pyrolysis temperature of flame coal is higher than biomass. The kinetic analysis indicated that the pyrolytic processes can be described as first order reactions model. The average activation energy of duckweed and coal was 39.14kJ/mol and 46.43kJ/mol , and with the increasing of the duckweed proportion, pyrolysis activation energy was decreased.

Pyrolysis Characteristics and Recovery of the Metallic and Nonmetallic Materials in Wasted Printed Circuit Boards

2011 ◽  
Vol 347-353 ◽  
pp. 2107-2111
Author(s):  
Hong Ting Ma ◽  
Guo Li Yang ◽  
Su Feng Hao
Keyword(s):  
Weight Loss ◽  
Heating Rate ◽  
Printed Circuit Boards ◽  
Pyrolysis Temperature ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Pyrolysis Characteristics ◽  
Electrical Components

A typical printed circuit boards (PCBs) has been investigated by using thermo-gravimetric analyser to study its pyrolysis characteristics, the results indicate that the maximum weight loss rate occurs at temperature between 320°C and 360°C. A higher heating rate results in higher initial, final, peak temperature, and a longer process of significant weight loss. At the same pyrolysis temperature, heating rate has little effect on the total weight loss. In addition, 1kg PCBs based FR-4 was pyrolyzed in a fixed-bed reactor. The pyrolysis residues are very friable, the organic, glass fiber and metallic fractions can easily be separated, and the electrical components can easily be removed from the remains. Considering energy-saving, better control and design of the pyrolysis process, the optimal pyrolysis parameters were suggested at heating rate 10°C/min, final pyrolysis temperature 500°C and holding time 30 min.

scholarly journals Kinetic Analysis of Low-Rank Coal Pyrolysis by Model-Free and Model-Fitting Methods

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Qiuli Zhang ◽  
Min Luo ◽  
Long Yan ◽  
Aiwu Yang ◽  
Xiangrong Hui
Keyword(s):  
Model Fitting ◽  
Decomposition Reaction ◽  
Low Rank ◽  
Coal Pyrolysis ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Pyrolysis Characteristics ◽  
Model Free ◽  
Thermal Analyzer ◽  
Thermogravimetric Data

Coal SJC, coal WJG, coal ZJM, and coal HCG were selected to investigate the pyrolysis kinetics of northern Shaanxi coals. TG and DSC experiments of four coals were carried out with a synchronous thermal analyzer at heating rates 5, 10, 15, and 20 C/min, respectively. The pyrolysis characteristics were described by thermogravimetric data, and the kinetic parameters were calculated by Flynn–Wall–Ozawa (FWO), Kissinger, general integration, and MacCallum–Tanner methods. The results show that coal SJC, coal ZJM, and coal HCG all conform to the reaction series equation, the thermal decomposition reaction rate is controlled by chemical reaction, and coal WJG conforms to Avrami–Erofeev equation. The activation energies of the four coals are 177.53 kJ/mol, 200.34 kJ/mol, 158.59 kJ/mol, and 240.47 kJ/mol, respectively.

Studies on Rapid Pyrolysis Characteristics of Huainan Coal

2013 ◽  
Vol 316-317 ◽  
pp. 32-35 ◽  
Author(s):  
Zhen Jing Shi ◽  
Meng Xiang Fang ◽  
Qing Hui Wang ◽  
Zhong Yang Luo
Keyword(s):  
Mass Spectrometry ◽  
Aromatic Hydrocarbons ◽  
Pyrolysis Temperature ◽  
Aliphatic Hydrocarbon ◽  
Normal Alkanes ◽  
Influence Of Temperature ◽  
Pyrolysis Characteristics ◽  
Influence Of Temperature On ◽  
Derivatives Of ◽  
Rapid Pyrolysis

This paper aims to investigate the rapid pyrolysis characteristics of Huainan coal using a tube furnace. Influence of temperature on yields and compounds of tar and char are tested. The result shows that aliphatic chains break gradually with increasing pyrolysis temperature. This leads an increase in aromaticity. Maximum tar yields were obtained at about 550°C, the char yields decreased and the gas yields increased with the pyrolysis temperature. The tar was isolated to aliphatic hydrocarbon aromatic hydrocarbon, non hydrocarbon and asphaltene, and characterized by chromatography-mass spectrometry (GC/MS). The main content of tar include normal alkanes from C16-C30, two-,three- and four-ring aromatic hydrocarbons and alkyl-substituted hydroaromatic derivatives of polycyclic, phenols, indoles, quinines esters and others compounds.

Pyrolysis characteristics and Cr speciation of chrome-tanned leather shavings: influence of pyrolysis temperature

2018 ◽  
Vol 41 (7) ◽  
pp. 881-891 ◽  
Author(s):  
Chunqi Fang ◽  
Xuguang Jiang ◽  
Guojun Lv ◽  
Jianhua Yan ◽  
Xuliang Lin ◽  
...  
Keyword(s):  
Pyrolysis Temperature ◽  
Pyrolysis Characteristics
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