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Zongqing Bai - One of the best experts on this subject based on the ideXlab platform.

  • the viscosity and crystallization behavior of slag from co gasification of Coal and extraction residue from Direct Coal Liquefaction residue at high temperatures
    Fuel, 2021
    Co-Authors: Baozi Peng, Lingxue Kong, Jin Bai, Zhen Liu, Zongqing Bai
    Abstract:

    Abstract Co-gasification of Coal and extraction residue (ER) of Direct Coal Liquefaction residue (DCLR) is an efficient route for DCLR utilization. The synthetic ash samples of different composition were designed to investigate the crystallization of slag and its effect on slag viscosity to optimize co-feedstock of Coal and ER. FactSage, XRD, SEM and single hot thermocouple technique (SHTT) were used to investigate crystallization behavior of slags. The viscosity-temperature curves were measured by the high temperature rotating viscometer. The results indicated that the slag viscosity and crystallization behavior are dominated by chemical composition. With the ratio of acid/basic oxides (A/B) increasing, slag viscosity at high temperature increased dramatically due to higher polymerization degree. The polymerized structure of poor atomic mobility limits the growth of crystallization, so the initial crystallization temperature increases and crystallization rate decreases. Meanwhile, the change of SiO2/Al2O3 (Si/Al) showed the similar influence on slag viscosity and crystallization. Fe2+ has stronger depolymerization ability than Ca2+ on aluminosilicates structure. The decreasing CaO/Fe2O3 ratio leads to low viscosity and then the slag crystallization tendency is observed increasing. However, Fe2+ does not involve anorthite crystallization reaction, so the change of slag viscosity and crystallization depends on the Ca/Fe of liquid phase. To obtain the smooth slag tapping of Coal and ER in the entrained flow gasifier, the chemical composition ranges as 2.10

  • behaviors of hydrogen bonds formed by lignite and aromatic solvents in Direct Coal Liquefaction combination analysis of density functional theory and experimental methods
    Fuel, 2020
    Co-Authors: Ranran Hou, Zongqing Bai, Lingxue Kong, Zhenxing Guo, Hongyan Zheng, Zhihao Feng, Jin Bai
    Abstract:

    Abstract Hydrogen bonds play a crucial role in thermal conversion of low rank Coal, especially Direct Coal Liquefaction (DCL) because of their wealthy abundance and great influence on generation of light products. Relative distribution of hydrogen bonds was evaluated with in-situ diffuse reflectance infrared Fourier transformation (DRIFT), while visualization analysis of hydrogen bonds (OH-π in particular) between Coal and solvents were performed using density functional theory (DFT) and reduced density gradient (RDG) analysis. In terms of their effects, DCL experiments of demineralized Yunnan lignite (DeYN) with/without addition of benzene at 200, 250 and 300 °C were carried out, and oxygen-containing functional groups were investigated by solid-state 13C NMR and in-situ DRIFT. Relative content of OH-π hydrogen bonds increased with temperature rising. Benzene is the stronger hydrogen bonds acceptor compared to tetralin (THN). Conclusions drawn from DCL experiments are consistent with DFT calculations. To be specific, benzene with mass concentration of 2% promotes cleavage of O–H bonds, carboxyl groups and the generation of aryl ether bonds, and the differences caused by benzene are intensified when DCL temperature rises.

  • flow properties of ash and slag under co gasification of Coal and extract residue of Direct Coal Liquefaction residue
    Fuel, 2020
    Co-Authors: Xi Cao, Zongqing Bai, Jin Bai, Lingxue Kong, Baozi Peng, Zhen Liu, Ziyang Feng, Andrzej Szlek
    Abstract:

    Abstract Efficient utilization of the extraction residue (ER) of Direct Coal Liquefaction residue is a bottle neck for the efficiency of Direct Coal Liquefaction process. The co-gasification of the ER and Coal is a promising way for large-scale utilization of ER. Flow properties of the feedstock including ash fusibility and slag viscosity are important parameters for the gasification process. To optimize co-gasification of the ER and Coal, the ash fusibility and slag viscosity behavior of ER and Coal under gasification conditions were studied. The results show that the ash fusion temperatures (AFTs) of the blending were lowered with the increasing blending ratio of ER due to the high content of calcium and iron in ER. The content of quartz and anorthite in the blended ashes decreased with the increasing ER blending ratio. The slag viscosities at high temperatures also decreased as the blending ratio of ER increased. The high content of calcium and iron in ER resulted in the decrease in the slag polymerization degree because of the break of Si-O structure and transformation from [AlO4]5− to [AlO6]9−. Besides, the slag presented the behavior of a crystalline slag when the ER blending ratio was increased up to 25% for the formation of anorthite during cooling. For the entrained flow gasification, the ER addition can effectively lower the operation temperature of the gasifiers, improve the gasification efficiency and avoid the slag tapping problems. The optimal ER addition should be in the range of 10–20%, and the corresponding tapping temperature was 1258–1575 °C.

  • insight into cross linking reactions induced by carboxylates in Direct Coal Liquefaction using Coal related model compounds and hydrogen transfer calculation
    Fuel, 2019
    Co-Authors: Zongqing Bai, Jinglei Zhang
    Abstract:

    Abstract Low-rank Coals, preferred feedstocks for Direct Coal Liquefaction (DCL), are rich in ion-exchange metal species which are present in the form of carboxylates. In this work, to better understand the negative effects and mechanisms of ion-exchange metal species on oil yield in DCL, cross-linking reactions which were possibly induced by ion-exchange metal species were investigated by hydrogenation of Coal-related model compounds and hydrogen transfer calculation for the first time. The results show that CO and CO2 are main products from thermal decomposition of benzoates, implying that decarboxylation of low-rank Coals is active during DCL. Compared with benzoic acid, an obvious change of product distribution during hydrogenation of benzoates is that the total yields of biphenyl, diphenylmethane, and benzophenone (products of cross-linking reactions) increase significantly. Besides, the content of CO2 released from hydrogenation of benzoates is much higher than that from benzoic acid. These phenomena indicate that ion-exchange metal species can accelerate decarboxylation reactions and promote formation of free radicals. In addition, hydrogen transfer calculation further proves that ion-exchange sodium species can affect the formation of free radicals. With the increase of the content of ion-exchange sodium species, more free radicals are generated by decarboxylation reactions and combination among free radicals is enhanced. Eventually, less hydrogen is consumed during DCL, which leads to decrease of oil yield. To conclude, cross-linking reactions can be promoted by ion-exchange metal species through enhancing formation of free radicals.

  • effects of temperature and solvents on structure variation of yunnan lignite in preheating stage of Direct Liquefaction
    Fuel, 2019
    Co-Authors: Ranran Hou, Zongqing Bai, Lingxue Kong, Xin Dai, Zhenxing Guo, Pan Hao, Hongyan Zheng, Jin Bai
    Abstract:

    Abstract Preheating stage is of significance for Direct Coal Liquefaction process, especially for the low-rank Coals, with high reactivity and suitable for Direct Coal Liquefaction. Properties of solvents used in preheating stage could greatly affect structure of Coal and conversion of its oxygen-containing functional groups. In this work, the preheating process of one Chinese Yunnan lignite (YN lignite) was conducted in tetralin (THN) and 1-methylnaphthalene (1-MN) to figure out the interactions between YN lignite and nonpolar aromatic solvents. In-situ diffuse reflectance infrared Fourier transformation (DRIFT) technique coupled with curve-fitting analysis and ion-exchange titration analysis and solid-state 13C NMR were used to investigate the structural changes of YN lignite when preheated in different solvents at different temperatures. Additionally, swelling ratio determination and density function theory (DFT) calculation were employed to evaluate the strength of interactions existing between YN lignite and THN or 1-MN. The results show that, the decrease of oxygen-containing functional groups and increase of aromaticity occur when YN lignite are preheated in THN and 1-MN, and these changes are intensified with temperature rising. Moreover, THN and 1-MN have different effects on variation of YN lignite, especially for phenolic hydroxyl groups, which are more likely to be decomposed in THN, while carboxyl groups break down more easily in 1-MN at 200–300 °C. DFT calculation and swelling ratio results show that stronger noncovalent interactions (OH π hydrogen bonds in particular) between THN and YN lignite result in weaker O H bond in phenolic hydroxyl groups and subsequently decomposition of more phenolic hydroxyl groups compared to 1-MN.

Jin Bai - One of the best experts on this subject based on the ideXlab platform.

  • the viscosity and crystallization behavior of slag from co gasification of Coal and extraction residue from Direct Coal Liquefaction residue at high temperatures
    Fuel, 2021
    Co-Authors: Baozi Peng, Lingxue Kong, Jin Bai, Zhen Liu, Zongqing Bai
    Abstract:

    Abstract Co-gasification of Coal and extraction residue (ER) of Direct Coal Liquefaction residue (DCLR) is an efficient route for DCLR utilization. The synthetic ash samples of different composition were designed to investigate the crystallization of slag and its effect on slag viscosity to optimize co-feedstock of Coal and ER. FactSage, XRD, SEM and single hot thermocouple technique (SHTT) were used to investigate crystallization behavior of slags. The viscosity-temperature curves were measured by the high temperature rotating viscometer. The results indicated that the slag viscosity and crystallization behavior are dominated by chemical composition. With the ratio of acid/basic oxides (A/B) increasing, slag viscosity at high temperature increased dramatically due to higher polymerization degree. The polymerized structure of poor atomic mobility limits the growth of crystallization, so the initial crystallization temperature increases and crystallization rate decreases. Meanwhile, the change of SiO2/Al2O3 (Si/Al) showed the similar influence on slag viscosity and crystallization. Fe2+ has stronger depolymerization ability than Ca2+ on aluminosilicates structure. The decreasing CaO/Fe2O3 ratio leads to low viscosity and then the slag crystallization tendency is observed increasing. However, Fe2+ does not involve anorthite crystallization reaction, so the change of slag viscosity and crystallization depends on the Ca/Fe of liquid phase. To obtain the smooth slag tapping of Coal and ER in the entrained flow gasifier, the chemical composition ranges as 2.10

  • behaviors of hydrogen bonds formed by lignite and aromatic solvents in Direct Coal Liquefaction combination analysis of density functional theory and experimental methods
    Fuel, 2020
    Co-Authors: Ranran Hou, Zongqing Bai, Lingxue Kong, Zhenxing Guo, Hongyan Zheng, Zhihao Feng, Jin Bai
    Abstract:

    Abstract Hydrogen bonds play a crucial role in thermal conversion of low rank Coal, especially Direct Coal Liquefaction (DCL) because of their wealthy abundance and great influence on generation of light products. Relative distribution of hydrogen bonds was evaluated with in-situ diffuse reflectance infrared Fourier transformation (DRIFT), while visualization analysis of hydrogen bonds (OH-π in particular) between Coal and solvents were performed using density functional theory (DFT) and reduced density gradient (RDG) analysis. In terms of their effects, DCL experiments of demineralized Yunnan lignite (DeYN) with/without addition of benzene at 200, 250 and 300 °C were carried out, and oxygen-containing functional groups were investigated by solid-state 13C NMR and in-situ DRIFT. Relative content of OH-π hydrogen bonds increased with temperature rising. Benzene is the stronger hydrogen bonds acceptor compared to tetralin (THN). Conclusions drawn from DCL experiments are consistent with DFT calculations. To be specific, benzene with mass concentration of 2% promotes cleavage of O–H bonds, carboxyl groups and the generation of aryl ether bonds, and the differences caused by benzene are intensified when DCL temperature rises.

  • flow properties of ash and slag under co gasification of Coal and extract residue of Direct Coal Liquefaction residue
    Fuel, 2020
    Co-Authors: Xi Cao, Zongqing Bai, Jin Bai, Lingxue Kong, Baozi Peng, Zhen Liu, Ziyang Feng, Andrzej Szlek
    Abstract:

    Abstract Efficient utilization of the extraction residue (ER) of Direct Coal Liquefaction residue is a bottle neck for the efficiency of Direct Coal Liquefaction process. The co-gasification of the ER and Coal is a promising way for large-scale utilization of ER. Flow properties of the feedstock including ash fusibility and slag viscosity are important parameters for the gasification process. To optimize co-gasification of the ER and Coal, the ash fusibility and slag viscosity behavior of ER and Coal under gasification conditions were studied. The results show that the ash fusion temperatures (AFTs) of the blending were lowered with the increasing blending ratio of ER due to the high content of calcium and iron in ER. The content of quartz and anorthite in the blended ashes decreased with the increasing ER blending ratio. The slag viscosities at high temperatures also decreased as the blending ratio of ER increased. The high content of calcium and iron in ER resulted in the decrease in the slag polymerization degree because of the break of Si-O structure and transformation from [AlO4]5− to [AlO6]9−. Besides, the slag presented the behavior of a crystalline slag when the ER blending ratio was increased up to 25% for the formation of anorthite during cooling. For the entrained flow gasification, the ER addition can effectively lower the operation temperature of the gasifiers, improve the gasification efficiency and avoid the slag tapping problems. The optimal ER addition should be in the range of 10–20%, and the corresponding tapping temperature was 1258–1575 °C.

  • the factors on metallic iron crystallization from slag of Direct Coal Liquefaction residue sio2 al2o3 fe2o3 cao mgo tio2 na2o k2o system in the entrained flow gasification condition
    Fuel, 2019
    Co-Authors: Lifei Zhi, Jin Bai, Lingxue Kong, Stefan Guhl, Bernd Meyer
    Abstract:

    Abstract The gasification of Direct Coal Liquefaction residue (DCLR) enhances the overall economy of the Direct Coal Liquefaction process. However, the DCLR ash is rich in iron due to pyrite as the catalyst during Liquefaction. Coal blending plan with DCLR for gasification should consider the possibility of metallic iron crystallization and agglomeration ahead of suitable viscosity range. In this study, the iron behavior in the DCLR slag in the gasification condition was discussed by the thermodynamic modelling of SiO2-Al2O3-Fe2O3-CaO-MgO-TiO2-Na2O-K2O. Results show that the metallic iron forms only in the dry feed entrained flow gasifier for the high content of reducing gases. The metallic iron crystallizes when Fe2+ of the liquid phase fails to be stabilized by -Si-O. The competition reaction with -Si-O between Ca2+ and Fe2+ and the formation of calcium aluminum-silicate also contribute the metallic iron crystallization. In the gasification condition, the metallic iron crystallization can be inhibited by decreasing the iron content/α value (α = CaO/(SiO2 + Al2O3), mass ratio) or by increasing S/A (S/A = SiO2/Al2O3, mass ratio) of DCLR ash. Finally, the DCLR blends with 3.5 wt% sand/8.0 wt% mullite/50.0 wt% Dalai Nur Coal/90.0 wt% Duolun Coal is the feasible feedstock for pulverized Coal gasifier, because the temperature of iron crystallization is below the tapping temperature of 1350 °C and the viscosity is less than 25 Pa·s.

  • effects of temperature and solvents on structure variation of yunnan lignite in preheating stage of Direct Liquefaction
    Fuel, 2019
    Co-Authors: Ranran Hou, Zongqing Bai, Lingxue Kong, Xin Dai, Zhenxing Guo, Pan Hao, Hongyan Zheng, Jin Bai
    Abstract:

    Abstract Preheating stage is of significance for Direct Coal Liquefaction process, especially for the low-rank Coals, with high reactivity and suitable for Direct Coal Liquefaction. Properties of solvents used in preheating stage could greatly affect structure of Coal and conversion of its oxygen-containing functional groups. In this work, the preheating process of one Chinese Yunnan lignite (YN lignite) was conducted in tetralin (THN) and 1-methylnaphthalene (1-MN) to figure out the interactions between YN lignite and nonpolar aromatic solvents. In-situ diffuse reflectance infrared Fourier transformation (DRIFT) technique coupled with curve-fitting analysis and ion-exchange titration analysis and solid-state 13C NMR were used to investigate the structural changes of YN lignite when preheated in different solvents at different temperatures. Additionally, swelling ratio determination and density function theory (DFT) calculation were employed to evaluate the strength of interactions existing between YN lignite and THN or 1-MN. The results show that, the decrease of oxygen-containing functional groups and increase of aromaticity occur when YN lignite are preheated in THN and 1-MN, and these changes are intensified with temperature rising. Moreover, THN and 1-MN have different effects on variation of YN lignite, especially for phenolic hydroxyl groups, which are more likely to be decomposed in THN, while carboxyl groups break down more easily in 1-MN at 200–300 °C. DFT calculation and swelling ratio results show that stronger noncovalent interactions (OH π hydrogen bonds in particular) between THN and YN lignite result in weaker O H bond in phenolic hydroxyl groups and subsequently decomposition of more phenolic hydroxyl groups compared to 1-MN.

Hou Yanglong - One of the best experts on this subject based on the ideXlab platform.

  • Ultra-large-scale Synthesis of Fe3O4 Nanoparticles and Their Application for Direct Coal Liquefaction
    industrial engineering chemistry research, 2014
    Co-Authors: Li Yizhao, Ma Fengyun, Su Xintai, Shi Longjiao, Pan Beibei, Sun Zhigiang, Hou Yanglong
    Abstract:

    Ultra-large-scale synthesis of iron oxide nanoparticles (875 g) has been achieved in a single reaction via a facile solution-based dehydration process. The obtained nanoparticles capped with hydrophobic oleic acid ligands are magnetite with the average size of 5 nm. The synthesized samples exhibit a higher catalytic activity toward the Direct Coal Liquefaction (DCL) than the commercial Fe3O4 powders. The conversion, oil yield, and Liquefaction degree with the synthesized Fe3O4 nanoparticles are 89.6, 65.1, and 77.3%, respectively. The excellent catalytic performance of the synthesized Fe3O4 nanoparticles can be attributed to their extremely small size and high dispersity. This facile approach to prepare highly active nanocatalyst for the DCL will be applicable for future industrial processes.Engineering, ChemicalSCI(E)EI1ARTICLEsuxintai827@163.com; hou@pku.edu.cn166718-67225

  • Synthesis and catalysis of oleic acid-coated Fe3O4 nanocrystals for Direct Coal Liquefaction
    catalysis communications, 2012
    Co-Authors: Li Yizhao, Ma Fengyun, Su Xintai, Sun Chao, Liu Jianchao, Sun Zhiqiang, Hou Yanglong
    Abstract:

    Oleic acid-coated Fe3O4 nanocrystals have been prepared by thermal decomposition of iron-oleate complex in the presence of oleic acid. The nanocrystals were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM) and Fourier transform infrared spectrometry (FTIR). The results show that the oleic acid-coated Fe3O4 nanocrystals are spherical, around 15 nm in diameter. The as-synthesized Fe3O4 nanocrystals are highly effective catalysts for the Direct Liquefaction of Jiangjunmiao Coal. With 1.5 wt.% Fe of dry and ash-free (daf) Coal added as the synthesized nanocatalysts, the conversion, oil yield, and Liquefaction degree reached 97.2, 86.5, and 92.0%, respectively. (C) 2012 Elsevier B.V. All rights reserved.Chemistry, PhysicalSCI(E)EI5ARTICLE231-2342

Lingxue Kong - One of the best experts on this subject based on the ideXlab platform.

  • the viscosity and crystallization behavior of slag from co gasification of Coal and extraction residue from Direct Coal Liquefaction residue at high temperatures
    Fuel, 2021
    Co-Authors: Baozi Peng, Lingxue Kong, Jin Bai, Zhen Liu, Zongqing Bai
    Abstract:

    Abstract Co-gasification of Coal and extraction residue (ER) of Direct Coal Liquefaction residue (DCLR) is an efficient route for DCLR utilization. The synthetic ash samples of different composition were designed to investigate the crystallization of slag and its effect on slag viscosity to optimize co-feedstock of Coal and ER. FactSage, XRD, SEM and single hot thermocouple technique (SHTT) were used to investigate crystallization behavior of slags. The viscosity-temperature curves were measured by the high temperature rotating viscometer. The results indicated that the slag viscosity and crystallization behavior are dominated by chemical composition. With the ratio of acid/basic oxides (A/B) increasing, slag viscosity at high temperature increased dramatically due to higher polymerization degree. The polymerized structure of poor atomic mobility limits the growth of crystallization, so the initial crystallization temperature increases and crystallization rate decreases. Meanwhile, the change of SiO2/Al2O3 (Si/Al) showed the similar influence on slag viscosity and crystallization. Fe2+ has stronger depolymerization ability than Ca2+ on aluminosilicates structure. The decreasing CaO/Fe2O3 ratio leads to low viscosity and then the slag crystallization tendency is observed increasing. However, Fe2+ does not involve anorthite crystallization reaction, so the change of slag viscosity and crystallization depends on the Ca/Fe of liquid phase. To obtain the smooth slag tapping of Coal and ER in the entrained flow gasifier, the chemical composition ranges as 2.10

  • behaviors of hydrogen bonds formed by lignite and aromatic solvents in Direct Coal Liquefaction combination analysis of density functional theory and experimental methods
    Fuel, 2020
    Co-Authors: Ranran Hou, Zongqing Bai, Lingxue Kong, Zhenxing Guo, Hongyan Zheng, Zhihao Feng, Jin Bai
    Abstract:

    Abstract Hydrogen bonds play a crucial role in thermal conversion of low rank Coal, especially Direct Coal Liquefaction (DCL) because of their wealthy abundance and great influence on generation of light products. Relative distribution of hydrogen bonds was evaluated with in-situ diffuse reflectance infrared Fourier transformation (DRIFT), while visualization analysis of hydrogen bonds (OH-π in particular) between Coal and solvents were performed using density functional theory (DFT) and reduced density gradient (RDG) analysis. In terms of their effects, DCL experiments of demineralized Yunnan lignite (DeYN) with/without addition of benzene at 200, 250 and 300 °C were carried out, and oxygen-containing functional groups were investigated by solid-state 13C NMR and in-situ DRIFT. Relative content of OH-π hydrogen bonds increased with temperature rising. Benzene is the stronger hydrogen bonds acceptor compared to tetralin (THN). Conclusions drawn from DCL experiments are consistent with DFT calculations. To be specific, benzene with mass concentration of 2% promotes cleavage of O–H bonds, carboxyl groups and the generation of aryl ether bonds, and the differences caused by benzene are intensified when DCL temperature rises.

  • flow properties of ash and slag under co gasification of Coal and extract residue of Direct Coal Liquefaction residue
    Fuel, 2020
    Co-Authors: Xi Cao, Zongqing Bai, Jin Bai, Lingxue Kong, Baozi Peng, Zhen Liu, Ziyang Feng, Andrzej Szlek
    Abstract:

    Abstract Efficient utilization of the extraction residue (ER) of Direct Coal Liquefaction residue is a bottle neck for the efficiency of Direct Coal Liquefaction process. The co-gasification of the ER and Coal is a promising way for large-scale utilization of ER. Flow properties of the feedstock including ash fusibility and slag viscosity are important parameters for the gasification process. To optimize co-gasification of the ER and Coal, the ash fusibility and slag viscosity behavior of ER and Coal under gasification conditions were studied. The results show that the ash fusion temperatures (AFTs) of the blending were lowered with the increasing blending ratio of ER due to the high content of calcium and iron in ER. The content of quartz and anorthite in the blended ashes decreased with the increasing ER blending ratio. The slag viscosities at high temperatures also decreased as the blending ratio of ER increased. The high content of calcium and iron in ER resulted in the decrease in the slag polymerization degree because of the break of Si-O structure and transformation from [AlO4]5− to [AlO6]9−. Besides, the slag presented the behavior of a crystalline slag when the ER blending ratio was increased up to 25% for the formation of anorthite during cooling. For the entrained flow gasification, the ER addition can effectively lower the operation temperature of the gasifiers, improve the gasification efficiency and avoid the slag tapping problems. The optimal ER addition should be in the range of 10–20%, and the corresponding tapping temperature was 1258–1575 °C.

  • the factors on metallic iron crystallization from slag of Direct Coal Liquefaction residue sio2 al2o3 fe2o3 cao mgo tio2 na2o k2o system in the entrained flow gasification condition
    Fuel, 2019
    Co-Authors: Lifei Zhi, Jin Bai, Lingxue Kong, Stefan Guhl, Bernd Meyer
    Abstract:

    Abstract The gasification of Direct Coal Liquefaction residue (DCLR) enhances the overall economy of the Direct Coal Liquefaction process. However, the DCLR ash is rich in iron due to pyrite as the catalyst during Liquefaction. Coal blending plan with DCLR for gasification should consider the possibility of metallic iron crystallization and agglomeration ahead of suitable viscosity range. In this study, the iron behavior in the DCLR slag in the gasification condition was discussed by the thermodynamic modelling of SiO2-Al2O3-Fe2O3-CaO-MgO-TiO2-Na2O-K2O. Results show that the metallic iron forms only in the dry feed entrained flow gasifier for the high content of reducing gases. The metallic iron crystallizes when Fe2+ of the liquid phase fails to be stabilized by -Si-O. The competition reaction with -Si-O between Ca2+ and Fe2+ and the formation of calcium aluminum-silicate also contribute the metallic iron crystallization. In the gasification condition, the metallic iron crystallization can be inhibited by decreasing the iron content/α value (α = CaO/(SiO2 + Al2O3), mass ratio) or by increasing S/A (S/A = SiO2/Al2O3, mass ratio) of DCLR ash. Finally, the DCLR blends with 3.5 wt% sand/8.0 wt% mullite/50.0 wt% Dalai Nur Coal/90.0 wt% Duolun Coal is the feasible feedstock for pulverized Coal gasifier, because the temperature of iron crystallization is below the tapping temperature of 1350 °C and the viscosity is less than 25 Pa·s.

  • effects of temperature and solvents on structure variation of yunnan lignite in preheating stage of Direct Liquefaction
    Fuel, 2019
    Co-Authors: Ranran Hou, Zongqing Bai, Lingxue Kong, Xin Dai, Zhenxing Guo, Pan Hao, Hongyan Zheng, Jin Bai
    Abstract:

    Abstract Preheating stage is of significance for Direct Coal Liquefaction process, especially for the low-rank Coals, with high reactivity and suitable for Direct Coal Liquefaction. Properties of solvents used in preheating stage could greatly affect structure of Coal and conversion of its oxygen-containing functional groups. In this work, the preheating process of one Chinese Yunnan lignite (YN lignite) was conducted in tetralin (THN) and 1-methylnaphthalene (1-MN) to figure out the interactions between YN lignite and nonpolar aromatic solvents. In-situ diffuse reflectance infrared Fourier transformation (DRIFT) technique coupled with curve-fitting analysis and ion-exchange titration analysis and solid-state 13C NMR were used to investigate the structural changes of YN lignite when preheated in different solvents at different temperatures. Additionally, swelling ratio determination and density function theory (DFT) calculation were employed to evaluate the strength of interactions existing between YN lignite and THN or 1-MN. The results show that, the decrease of oxygen-containing functional groups and increase of aromaticity occur when YN lignite are preheated in THN and 1-MN, and these changes are intensified with temperature rising. Moreover, THN and 1-MN have different effects on variation of YN lignite, especially for phenolic hydroxyl groups, which are more likely to be decomposed in THN, while carboxyl groups break down more easily in 1-MN at 200–300 °C. DFT calculation and swelling ratio results show that stronger noncovalent interactions (OH π hydrogen bonds in particular) between THN and YN lignite result in weaker O H bond in phenolic hydroxyl groups and subsequently decomposition of more phenolic hydroxyl groups compared to 1-MN.

Yanglong Hou - One of the best experts on this subject based on the ideXlab platform.

  • ultra large scale synthesis of fe3o4 nanoparticles and their application for Direct Coal Liquefaction
    Industrial & Engineering Chemistry Research, 2014
    Co-Authors: Longjiao Shi, Beibei Pan, Zhiqiang Sun, Yanglong Hou
    Abstract:

    Ultra-large-scale synthesis of iron oxide nanoparticles (875 g) has been achieved in a single reaction via a facile solution-based dehydration process. The obtained nanoparticles capped with hydrophobic oleic acid ligands are magnetite with the average size of 5 nm. The synthesized samples exhibit a higher catalytic activity toward the Direct Coal Liquefaction (DCL) than the commercial Fe3O4 powders. The conversion, oil yield, and Liquefaction degree with the synthesized Fe3O4 nanoparticles are 89.6, 65.1, and 77.3%, respectively. The excellent catalytic performance of the synthesized Fe3O4 nanoparticles can be attributed to their extremely small size and high dispersity. This facile approach to prepare highly active nanocatalyst for the DCL will be applicable for future industrial processes.

  • Ultra-large-scale Synthesis of Fe3O4 Nanoparticles and Their Application for Direct Coal Liquefaction
    2014
    Co-Authors: Longjiao Shi, Beibei Pan, Zhiqiang Sun, Yanglong Hou
    Abstract:

    Ultra-large-scale synthesis of iron oxide nanoparticles (875 g) has been achieved in a single reaction via a facile solution-based dehydration process. The obtained nanoparticles capped with hydrophobic oleic acid ligands are magnetite with the average size of 5 nm. The synthesized samples exhibit a higher catalytic activity toward the Direct Coal Liquefaction (DCL) than the commercial Fe3O4 powders. The conversion, oil yield, and Liquefaction degree with the synthesized Fe3O4 nanoparticles are 89.6, 65.1, and 77.3%, respectively. The excellent catalytic performance of the synthesized Fe3O4 nanoparticles can be attributed to their extremely small size and high dispersity. This facile approach to prepare highly active nanocatalyst for the DCL will be applicable for future industrial processes

  • synthesis and catalysis of oleic acid coated fe3o4 nanocrystals for Direct Coal Liquefaction
    Catalysis Communications, 2012
    Co-Authors: Chao Sun, Zhiqiang Sun, Jianchao Liu, Yanglong Hou
    Abstract:

    Abstract Oleic acid-coated Fe3O4 nanocrystals have been prepared by thermal decomposition of iron–oleate complex in the presence of oleic acid. The nanocrystals were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM) and Fourier transform infrared spectrometry (FTIR). The results show that the oleic acid-coated Fe3O4 nanocrystals are spherical, around 15 nm in diameter. The as-synthesized Fe3O4 nanocrystals are highly effective catalysts for the Direct Liquefaction of Jiangjunmiao Coal. With 1.5 wt.% Fe of dry and ash-free (daf) Coal added as the synthesized nanocatalysts, the conversion, oil yield, and Liquefaction degree reached 97.2, 86.5, and 92.0%, respectively.