The Experts below are selected from a list of 3534 Experts worldwide ranked by ideXlab platform
Zhicai Wang - One of the best experts on this subject based on the ideXlab platform.
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Effect of volatile Reactions on the yield and quality of tar from pyrolysis of Shenhua bituminous coal
Journal of Analytical and Applied Pyrolysis, 2019Co-Authors: Lin Dong, Zhiping Lei, Jingchong Yan, Zhanku Li, Hengfu Shui, Shigang Kang, Wenhao Yu, Kai Zhang, Song Han, Zhicai WangAbstract:Abstract Pyrolysis was an important route for coal conversion and also the fundamental for clean and efficient utilization of coal. As an important product of pyrolysis, coal tar can be used as the raw material for producing premium liquid fuels and high value-added chemicals (benzene-toluene-xylene, naphthalene, phenols, etc.). The products’ distribution and quality were significantly affected by the secondary Reaction of Volatiles. In this work, Shenhua bituminous coal was pyrolyzed with a two-stage reactor at a relatively low temperature, and the released Volatiles underwent secondary Reactions at various temperatures and residence time. The yields and quality of coal tar were characterized by gas chromatography–mass spectroscopy (GC–MS) and Fourier transformed infrared spectroscopy (FTIR). The results showed that secondary volatile Reactions decrease tar yield but increase gas and coke yield. The volatile Reaction results in a decrease in the content of aliphatics and phenols, and an increase in the content of arenes and polar compounds. The volatile Reaction includes the following Reactions: dehydroxylation, deoxygenation, cleavage of long chain aliphatic structures into short ones, and condensation of aromatic clusters, etc. The higher heating rate of pyrolysis reduces the content of aliphatic and polar compounds while increases that of arenes and phenols in the light tar (HS).
Qiaoqiao Zhou - One of the best experts on this subject based on the ideXlab platform.
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behaviors of coking and radicals during Reaction of Volatiles generated from fixed bed pyrolysis of a lignite and a subbituminous coal
Fuel Processing Technology, 2017Co-Authors: Qiaoqiao ZhouAbstract:Abstract The Reaction of Volatiles generated from coal during pyrolysis determines the yield and quality of products. To understand this Reaction in detail particularly on the condensation Reaction that forms coke, this paper studies the Reaction of Volatiles generated from a lignite and a subbituminous coal using a two-stage fix-bed reactor, with the first stage for coal pyrolysis and the second stage for Reaction of Volatiles. The yields of tar, gas and coke formed on the wall and presented in tar at a second-stage temperature range of 440–700 °C and a residence time range of 1.5–6.9 s are quantified. The concentration, g value and linewidth of radicals in tars, mainly in coke presented in tars, are measured by electron spin resonance (ESR) and discussed to explore the transformation of coke in structure. It is found that the Reactions of Volatiles generated from the lignite and the subbituminous coal are different in the temperature range studied but the structure of coke formed in these two Volatiles differs mainly at temperatures lower than 600 °C. The proportion of coke formed on the reactor wall is small at 440 °C, but large at 650 and 700 °C, close to 50% in 4.2 s. The increase in concentration and decreases in g value and linewidth of radicals with increasing temperature over time suggest that the coke undergoes condensation, leading to loss in oxygen and increase in aromaticity.
Zhenyu Liu - One of the best experts on this subject based on the ideXlab platform.
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coke formation during thermal Reaction of tar from pyrolysis of a subbituminous coal
Fuel Processing Technology, 2017Co-Authors: Qingya Liu, Lei Shi, Renxing Wang, Xiaojin Guo, Zezhou Chen, Zhenyu LiuAbstract:Abstract The Reaction of Volatiles in a coal pyrolysis reactor determines the yield and quality of tar. This paper studies the yield, group composition and radical concentration of tars obtained from pyrolysis of a subbituminous coal, mainly on the effect of the tars' residence time in the pyrolysis reactor and in post-pyrolysis heating. The latter operation simulates the environment of tars, if they were in a large fast pyrolysis reactor. It is found that an increase in the Volatiles' residence time in the pyrolysis reactor reduces the yield and increases the radical concentration of tars. The pitch fraction of the tars is mainly responsible for coke formation which occurs significantly at temperatures higher than 420 °C. The tars contain radicals, mainly in their coke and pitch fractions. The coke concentration in the tars increases with increasing heating time, linearly at 420 and 450 °C but in a sigmoidal pattern at higher temperatures. The coking behavior within 10 min can be expressed by the zero-order or zero-order + autocatalytic kinetics with activation energies of 128–138 kJ/mol.
Lin Dong - One of the best experts on this subject based on the ideXlab platform.
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Effect of volatile Reactions on the yield and quality of tar from pyrolysis of Shenhua bituminous coal
Journal of Analytical and Applied Pyrolysis, 2019Co-Authors: Lin Dong, Zhiping Lei, Jingchong Yan, Zhanku Li, Hengfu Shui, Shigang Kang, Wenhao Yu, Kai Zhang, Song Han, Zhicai WangAbstract:Abstract Pyrolysis was an important route for coal conversion and also the fundamental for clean and efficient utilization of coal. As an important product of pyrolysis, coal tar can be used as the raw material for producing premium liquid fuels and high value-added chemicals (benzene-toluene-xylene, naphthalene, phenols, etc.). The products’ distribution and quality were significantly affected by the secondary Reaction of Volatiles. In this work, Shenhua bituminous coal was pyrolyzed with a two-stage reactor at a relatively low temperature, and the released Volatiles underwent secondary Reactions at various temperatures and residence time. The yields and quality of coal tar were characterized by gas chromatography–mass spectroscopy (GC–MS) and Fourier transformed infrared spectroscopy (FTIR). The results showed that secondary volatile Reactions decrease tar yield but increase gas and coke yield. The volatile Reaction results in a decrease in the content of aliphatics and phenols, and an increase in the content of arenes and polar compounds. The volatile Reaction includes the following Reactions: dehydroxylation, deoxygenation, cleavage of long chain aliphatic structures into short ones, and condensation of aromatic clusters, etc. The higher heating rate of pyrolysis reduces the content of aliphatic and polar compounds while increases that of arenes and phenols in the light tar (HS).
Qingya Liu - One of the best experts on this subject based on the ideXlab platform.
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coke formation during thermal Reaction of tar from pyrolysis of a subbituminous coal
Fuel Processing Technology, 2017Co-Authors: Qingya Liu, Lei Shi, Renxing Wang, Xiaojin Guo, Zezhou Chen, Zhenyu LiuAbstract:Abstract The Reaction of Volatiles in a coal pyrolysis reactor determines the yield and quality of tar. This paper studies the yield, group composition and radical concentration of tars obtained from pyrolysis of a subbituminous coal, mainly on the effect of the tars' residence time in the pyrolysis reactor and in post-pyrolysis heating. The latter operation simulates the environment of tars, if they were in a large fast pyrolysis reactor. It is found that an increase in the Volatiles' residence time in the pyrolysis reactor reduces the yield and increases the radical concentration of tars. The pitch fraction of the tars is mainly responsible for coke formation which occurs significantly at temperatures higher than 420 °C. The tars contain radicals, mainly in their coke and pitch fractions. The coke concentration in the tars increases with increasing heating time, linearly at 420 and 450 °C but in a sigmoidal pattern at higher temperatures. The coking behavior within 10 min can be expressed by the zero-order or zero-order + autocatalytic kinetics with activation energies of 128–138 kJ/mol.
