Understanding the evolution mechanism of hydrogen-rich coke oven gas in vitrinite pyrolysis is crucial for improving the clean utilization of coal. This work focused on the vitrinite extracted from Fangezhuang coal as the sample. Its three-dimensional molecular model was constructed based on elemental analysis, IR spectroscopy, C NMR, and density functional theory. ReaxFF molecular dynamics simulation, combined with TG-MS, was used to study the vitrinite pyrolysis process and its mechanism of hydrogen-rich gas evolution. Experimental results indicated that H and CH, the main hydrogen-rich gases, originated from the aliphatic and partially aromatic moieties of vitrinite, and required the participation of a large number of transferable hydrogen atoms. The reaction network confirmed that the transferable hydrogen atoms included not only the easily-dissociated hydrogen atoms in vitrinite but also the active hydrogen atoms in the gas-phase hydrocarbon radicals. In particular, the latter significantly increased the diffusivity of condensed hydrogen atoms and the collision probability with other components through the gas-phase hydrogen transfer cycle, which favors the generation of gas products. This work provided theoretical support for optimizing the production of coke and coke oven gas in synergy, as well as improving the quality of hydrogen-rich gas in the industry.
{"title":"Exploration of hydrogen-rich gas evolution mechanism during vitrinite pyrolysis: A combined TG-MS and ReaxFF study","authors":"Yuan-Yuan Jiang, Jie-Ping Wang, Jin-Xiao Dou, Rui Guo, Li-Hua Fan, Guang-Yue Li, Ying-Hua Liang, Jiang-Long Yu","doi":"10.1016/j.fuel.2024.132435","DOIUrl":"https://doi.org/10.1016/j.fuel.2024.132435","url":null,"abstract":"Understanding the evolution mechanism of hydrogen-rich coke oven gas in vitrinite pyrolysis is crucial for improving the clean utilization of coal. This work focused on the vitrinite extracted from Fangezhuang coal as the sample. Its three-dimensional molecular model was constructed based on elemental analysis, IR spectroscopy, C NMR, and density functional theory. ReaxFF molecular dynamics simulation, combined with TG-MS, was used to study the vitrinite pyrolysis process and its mechanism of hydrogen-rich gas evolution. Experimental results indicated that H and CH, the main hydrogen-rich gases, originated from the aliphatic and partially aromatic moieties of vitrinite, and required the participation of a large number of transferable hydrogen atoms. The reaction network confirmed that the transferable hydrogen atoms included not only the easily-dissociated hydrogen atoms in vitrinite but also the active hydrogen atoms in the gas-phase hydrocarbon radicals. In particular, the latter significantly increased the diffusivity of condensed hydrogen atoms and the collision probability with other components through the gas-phase hydrogen transfer cycle, which favors the generation of gas products. This work provided theoretical support for optimizing the production of coke and coke oven gas in synergy, as well as improving the quality of hydrogen-rich gas in the industry.","PeriodicalId":325,"journal":{"name":"Fuel","volume":null,"pages":null},"PeriodicalIF":7.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141575823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-05DOI: 10.1016/j.fuel.2024.132395
Jie Luo, Mei Zhong, Caifeng Nan, Yang Liu, Zhenghua Dai, Lijun Jin
Pyrolysis is considered as an effective method to convent coal tar residue (CTR) with carcinogenic polycyclic aromatic hydrocarbons into high value-added products. However, high contents of heavy components in tar restrict the efficient utilization of CTR. In this paper, USY zeolite was leached by HNO and subsequently loaded by Zr and Ni for upgrading of CTR pyrolysis volatiles. The effects of the modified catalysts on the distribution of pyrolysis products, the yield and compositions of light tar (boiling point below 360 °C) were investigated. Results showed that compared with raw USY, the modified USY with HNO leaching for 2 h (UN2) improved light tar fraction up to 63.55 % and naphthalene content in tar increased by 96.01 %. The contents of toluene, xylene and naphthalene in tar were 32.00 %, 32.89 % and 11.57 % higher than that of UN2 and light tar fraction was improved up to 66.00 % when 10 wt% Zr was introduced into UN2 (10Z-UN2). Ni loading resulted in further upgrading of the tar. The fraction of light tar was up to 73.13 % at Ni content of 8 wt% (8Ni-10Z-UN2), and toluene content in upgraded tar was 3.56 times that over 10Z-UN2. To further improve the upgrading performance, steam was introduced in the action of 8Ni-10Z-UN2. The highest yields of tar (41.56 wt%) and light tar (31.07 wt%) were obtained at the mass ratio of steam to material (S/M) being 0.28, and the average molecular weight of tar was decreased to 219 amu from 744 amu before upgrading. Isotope tracing using DO as tracer was coupled with the cracking of cetane, -cresol and 1-methylnaphthalene as tar model compounds over 8Ni-10Z-UN2 to reveal the mechanism for high tar yield under steam. It was confirmed that •H produced by reaction of HO with model compounds participated in tar formation over 8Ni-10Z-UN2, and the contents of benzene and naphthalene were obviously enhanced. This work provides a sample route to upgrade the CTR pyrolysis volatiles into aromatic hydrocarbons.
{"title":"Modification of USY by leaching and Zr, Ni loading for upgrading pyrolysis volatiles from coal tar residue","authors":"Jie Luo, Mei Zhong, Caifeng Nan, Yang Liu, Zhenghua Dai, Lijun Jin","doi":"10.1016/j.fuel.2024.132395","DOIUrl":"https://doi.org/10.1016/j.fuel.2024.132395","url":null,"abstract":"Pyrolysis is considered as an effective method to convent coal tar residue (CTR) with carcinogenic polycyclic aromatic hydrocarbons into high value-added products. However, high contents of heavy components in tar restrict the efficient utilization of CTR. In this paper, USY zeolite was leached by HNO and subsequently loaded by Zr and Ni for upgrading of CTR pyrolysis volatiles. The effects of the modified catalysts on the distribution of pyrolysis products, the yield and compositions of light tar (boiling point below 360 °C) were investigated. Results showed that compared with raw USY, the modified USY with HNO leaching for 2 h (UN2) improved light tar fraction up to 63.55 % and naphthalene content in tar increased by 96.01 %. The contents of toluene, xylene and naphthalene in tar were 32.00 %, 32.89 % and 11.57 % higher than that of UN2 and light tar fraction was improved up to 66.00 % when 10 wt% Zr was introduced into UN2 (10Z-UN2). Ni loading resulted in further upgrading of the tar. The fraction of light tar was up to 73.13 % at Ni content of 8 wt% (8Ni-10Z-UN2), and toluene content in upgraded tar was 3.56 times that over 10Z-UN2. To further improve the upgrading performance, steam was introduced in the action of 8Ni-10Z-UN2. The highest yields of tar (41.56 wt%) and light tar (31.07 wt%) were obtained at the mass ratio of steam to material (S/M) being 0.28, and the average molecular weight of tar was decreased to 219 amu from 744 amu before upgrading. Isotope tracing using DO as tracer was coupled with the cracking of cetane, -cresol and 1-methylnaphthalene as tar model compounds over 8Ni-10Z-UN2 to reveal the mechanism for high tar yield under steam. It was confirmed that •H produced by reaction of HO with model compounds participated in tar formation over 8Ni-10Z-UN2, and the contents of benzene and naphthalene were obviously enhanced. This work provides a sample route to upgrade the CTR pyrolysis volatiles into aromatic hydrocarbons.","PeriodicalId":325,"journal":{"name":"Fuel","volume":null,"pages":null},"PeriodicalIF":7.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141575828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ester-based hydrocarbon oils, possessing hydrophobic, dispersant, and eco-friendly properties have gained the attention of researchers as flotation collectors for low-rank coal flotation. This study innovatively applied molecular docking technology typically used in the biomedical field to investigate ester-based collectors for low-rank coal flotation and analyzed the feasibility of molecular docking in the selection of flotation reagents. The structural characteristics of low-rank coal were analyzed using scanning electron microscopy–energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, nuclear magnetic resonance spectroscopy, transmission electron microscopy, and a 3D macromolecular structure of low-rank coal was constructed. A holistic docking approach was applied to score and analyze methyl alkylate and caprylate ester series flotation collectors. The methyl alkylate series collectors exhibited effectiveness in the order of methyl caprylate < methyl pelargonate < methyl caprate < methyl undecanoate < methyl laurate < methyl tridecrate, and the caprylate ester series collectors displayed effectiveness in the order of methyl caprylate < ethyl caprylate < propyl caprylate < butyl caprylate. These results are consistent with the subsequent analysis of the binding configurations and surface adsorption of the collectors, indicating that a collector with a high score has a tight adsorption configuration and exhibits good surface hydrophobic modification. Practical flotation experiments with methyl alkylate series and caprylate ester series collectors showed that, for both types of collectors, the combustible recovery of separated coal increased with increasing score, and a positive correlation was observed between flotation recoverability and the scoring value. This result suggests that the molecular docking method can be used to evaluate the performance of coal flotation collectors, providing a new approach for computer-aided coal flotation reagent screening.
{"title":"Applying molecular docking in screening and analyzing ester-based collectors for low-rank coal flotation: A novel approach","authors":"Yangchao Xia, Yaowen Xing, Budeebazar Avid, Jia Tian, Xiahui Gui, Yijun Cao","doi":"10.1016/j.fuel.2024.132315","DOIUrl":"https://doi.org/10.1016/j.fuel.2024.132315","url":null,"abstract":"Ester-based hydrocarbon oils, possessing hydrophobic, dispersant, and eco-friendly properties have gained the attention of researchers as flotation collectors for low-rank coal flotation. This study innovatively applied molecular docking technology typically used in the biomedical field to investigate ester-based collectors for low-rank coal flotation and analyzed the feasibility of molecular docking in the selection of flotation reagents. The structural characteristics of low-rank coal were analyzed using scanning electron microscopy–energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, nuclear magnetic resonance spectroscopy, transmission electron microscopy, and a 3D macromolecular structure of low-rank coal was constructed. A holistic docking approach was applied to score and analyze methyl alkylate and caprylate ester series flotation collectors. The methyl alkylate series collectors exhibited effectiveness in the order of methyl caprylate < methyl pelargonate < methyl caprate < methyl undecanoate < methyl laurate < methyl tridecrate, and the caprylate ester series collectors displayed effectiveness in the order of methyl caprylate < ethyl caprylate < propyl caprylate < butyl caprylate. These results are consistent with the subsequent analysis of the binding configurations and surface adsorption of the collectors, indicating that a collector with a high score has a tight adsorption configuration and exhibits good surface hydrophobic modification. Practical flotation experiments with methyl alkylate series and caprylate ester series collectors showed that, for both types of collectors, the combustible recovery of separated coal increased with increasing score, and a positive correlation was observed between flotation recoverability and the scoring value. This result suggests that the molecular docking method can be used to evaluate the performance of coal flotation collectors, providing a new approach for computer-aided coal flotation reagent screening.","PeriodicalId":325,"journal":{"name":"Fuel","volume":null,"pages":null},"PeriodicalIF":7.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141575831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ZnInS (ZIS) has limited photocatalytic hydrogen production due to low visible light utilisation and insufficient separation efficiency of photogenerated carriers. This study utilized a simple hydrothermal method to prepare InS/ZnInS (INS/ZIS) heterojunctions. The addition of InS (INS) improves the separation and movement of photogenerated charges, and makes better use of visible light. The material was analysed using SEM, TEM, XRD, XPS and photoelectrochemical tests. Results from the transient photocurrent (TPR) and photoluminescence (PL) experiments show a photocurrent density of approximately 1.8 μA/cm, which is 3 times greater than the ZIS (0.6 μA/cm) density, when the INS mass is 5 %. And at this time, INS/ZIS boasts the most effective photogenerated carrier separation. The hydrogen photocatalytic generation test results showed that the photocatalytic hydrogen production rate of 5-INS/ZIS (5690 μmol/g/h) was 8.4 and 66.9 times higher than that of pure ZIS (710 μmol/g/h) and INS (89 μmol/g/h), respectively. The enhanced activity is due to the creation of type II heterojunctions, which improve the separation and transfer of light-generated charges. The research presents an innovative approach to creating composites based on ZIS.
{"title":"In2S3-modified ZnIn2S4 enhanced photogenerated carrier separation efficiency and photocatalytic hydrogen evolution under visible light","authors":"Jianhong Ye, Zheyuan Fan, Zhiling Wang, Yiqiao Wang, Jian Li, Yu Xie, Yun Ling, Yong Chen","doi":"10.1016/j.fuel.2024.132401","DOIUrl":"https://doi.org/10.1016/j.fuel.2024.132401","url":null,"abstract":"ZnInS (ZIS) has limited photocatalytic hydrogen production due to low visible light utilisation and insufficient separation efficiency of photogenerated carriers. This study utilized a simple hydrothermal method to prepare InS/ZnInS (INS/ZIS) heterojunctions. The addition of InS (INS) improves the separation and movement of photogenerated charges, and makes better use of visible light. The material was analysed using SEM, TEM, XRD, XPS and photoelectrochemical tests. Results from the transient photocurrent (TPR) and photoluminescence (PL) experiments show a photocurrent density of approximately 1.8 μA/cm, which is 3 times greater than the ZIS (0.6 μA/cm) density, when the INS mass is 5 %. And at this time, INS/ZIS boasts the most effective photogenerated carrier separation. The hydrogen photocatalytic generation test results showed that the photocatalytic hydrogen production rate of 5-INS/ZIS (5690 μmol/g/h) was 8.4 and 66.9 times higher than that of pure ZIS (710 μmol/g/h) and INS (89 μmol/g/h), respectively. The enhanced activity is due to the creation of type II heterojunctions, which improve the separation and transfer of light-generated charges. The research presents an innovative approach to creating composites based on ZIS.","PeriodicalId":325,"journal":{"name":"Fuel","volume":null,"pages":null},"PeriodicalIF":7.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141575827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-05DOI: 10.1016/j.fuel.2024.132410
Zahra Taherinia, Arash Ghorbani-Choghamarani, Ali Naghipour
In this study, the synthesis of a new stable hexagonal boron nitride (h-BN) is reported via the combustion of boric acid and urea using a pyrolysis method. The surface of hBN particles was modified and the physical/chemical properties of h-BN-APTS-SOH were examined by different characterization, confirming the modification of h-BN. The effects of methanol/acid molar ratio, temperature, and amount of catalyst were investigated. The results showed that the optimal conditions for the esterification of palmitic acid were as follows: methanol to a palmitic acid molar ratio of 30:1, a temperature of 50 °C, a catalyst of 300 mg for 5 h, and a maximum yield of biodiesel of 90 % was achieved. Furthermore, the quality parameters of the biodiesel were made according to ASTM methods [ASTM D445: Kinematic viscosity, ASTM D445: Flash-point, ASTM D92: Ash content, ASTM D6751: Density]. Tests indicate that the quality parameters of the prepared biodiesel were within ASTM standards. Significantly, the h-BN@APTS-SOH(1) catalyst showed excellent stability on repeated reuse and can be recycled several times without much activity loss.
{"title":"Catalytic performance of hexagonal boron Nitride@ APTS-SO3H as heterogeneous nanocatalyst for biodiesel production","authors":"Zahra Taherinia, Arash Ghorbani-Choghamarani, Ali Naghipour","doi":"10.1016/j.fuel.2024.132410","DOIUrl":"https://doi.org/10.1016/j.fuel.2024.132410","url":null,"abstract":"In this study, the synthesis of a new stable hexagonal boron nitride (h-BN) is reported via the combustion of boric acid and urea using a pyrolysis method. The surface of hBN particles was modified and the physical/chemical properties of h-BN-APTS-SOH were examined by different characterization, confirming the modification of h-BN. The effects of methanol/acid molar ratio, temperature, and amount of catalyst were investigated. The results showed that the optimal conditions for the esterification of palmitic acid were as follows: methanol to a palmitic acid molar ratio of 30:1, a temperature of 50 °C, a catalyst of 300 mg for 5 h, and a maximum yield of biodiesel of 90 % was achieved. Furthermore, the quality parameters of the biodiesel were made according to ASTM methods [ASTM D445: Kinematic viscosity, ASTM D445: Flash-point, ASTM D92: Ash content, ASTM D6751: Density]. Tests indicate that the quality parameters of the prepared biodiesel were within ASTM standards. Significantly, the h-BN@APTS-SOH(1) catalyst showed excellent stability on repeated reuse and can be recycled several times without much activity loss.","PeriodicalId":325,"journal":{"name":"Fuel","volume":null,"pages":null},"PeriodicalIF":7.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141575826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-05DOI: 10.1016/j.fuel.2024.132234
Huajun Liu, Chengyi Liu, Wen Nie, Yun Hua, Xiao Yan, Jie Lian, Hao Wu, Xinyue Song
In this study, the temporal and spatial distribution of NO and PM emissions from multiple underground diesel vehicles under different idling conditions were studied, and the high exhaust concentration risk zone from idling vehicles were identified, which posed a serious threat to the health of underground personnel. The results show that the working conditions of diesel vehicles in the meeting chamber have a certain impact on the exhaust emissions of diesel vehicles in the straight roadway. When the rear of the vehicle enters the chamber first, the diffusion trends of NO and PM from the rear vehicle in the straight roadway are basically consistent. However, when the front of the vehicle enters the chamber first, the diffusion of PM from the rear vehicle in the straight roadway is slower than that of NO, and the diffusion distances differ by 4 m. In addition, drivers at the rear of vehicles in the straight roadway and drivers at the front of vehicles in the chamber are more likely to encounter high exhaust concentrations. Therefore, suitable protective measures must be employed to ensure safe production.
本研究对井下多辆柴油车在不同怠速工况下的 NO 和 PM 排放时空分布进行了研究，确定了怠速车辆的高尾气浓度风险区，对井下人员的健康构成了严重威胁。结果表明，会车室柴油车的工况对直行巷道柴油车的尾气排放有一定影响。当车辆后部先进入硐室时，后部车辆的 NO 和 PM 在笔直巷道中的扩散趋势基本一致。此外，在直行道上位于车辆后部的驾驶员和在密室中位于车辆前部的驾驶员更容易遇到高浓度的废气。因此，必须采取适当的防护措施，以确保安全生产。
{"title":"Numerical analysis of spatial and temporal distribution of exhaust emissions from multiple underground diesel vehicles under different idling conditions","authors":"Huajun Liu, Chengyi Liu, Wen Nie, Yun Hua, Xiao Yan, Jie Lian, Hao Wu, Xinyue Song","doi":"10.1016/j.fuel.2024.132234","DOIUrl":"https://doi.org/10.1016/j.fuel.2024.132234","url":null,"abstract":"In this study, the temporal and spatial distribution of NO and PM emissions from multiple underground diesel vehicles under different idling conditions were studied, and the high exhaust concentration risk zone from idling vehicles were identified, which posed a serious threat to the health of underground personnel. The results show that the working conditions of diesel vehicles in the meeting chamber have a certain impact on the exhaust emissions of diesel vehicles in the straight roadway. When the rear of the vehicle enters the chamber first, the diffusion trends of NO and PM from the rear vehicle in the straight roadway are basically consistent. However, when the front of the vehicle enters the chamber first, the diffusion of PM from the rear vehicle in the straight roadway is slower than that of NO, and the diffusion distances differ by 4 m. In addition, drivers at the rear of vehicles in the straight roadway and drivers at the front of vehicles in the chamber are more likely to encounter high exhaust concentrations. Therefore, suitable protective measures must be employed to ensure safe production.","PeriodicalId":325,"journal":{"name":"Fuel","volume":null,"pages":null},"PeriodicalIF":7.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141575829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-05DOI: 10.1016/j.fuel.2024.132393
Baisheng Nie, Hao Zhang, Xianfeng Liu, Chao Peng, Fangfang Hu, Hengyi He, Song Bao, Haowen Zhou, Tao Yang
In order to study the influence of microstructure parameters of coal dust on explosion characteristics, a spherical explosive device is employed to examine the explosion characteristics of coal dust with various low concentrations/particle sizes, and the microstructure change characteristics of solid products, the risk of re-explosion of gaseous products and the correlation between macroscopic explosion characteristics and microstructure are appropriately evaluated. The obtained results reveal that the and (d/d) rises with increasing the concentration. The smaller the particle size and the higher the concentration, the shorter the explosion time. A linear correlation can be observed between the flame propagation speed and both and . Furthermore, the oxygen consumption and combustible gas products increased with the concentration of coal dust, which increasing the risk of secondary explosion. After the explosion, branched-chains and aliphatic carbon chains increased, and the content of functional groups in different absorption peaks changed, in which the aliphatic and hydroxyl structures had a significant correlation with the explosion intensity. The objective of this study is to provide a robust theoretical foundation for future research and development in the field of coal dust explosion suppression technology.
{"title":"Study on explosion characteristics and microstructure correlation analysis of coal dust in the presence of various concentrations and particle sizes","authors":"Baisheng Nie, Hao Zhang, Xianfeng Liu, Chao Peng, Fangfang Hu, Hengyi He, Song Bao, Haowen Zhou, Tao Yang","doi":"10.1016/j.fuel.2024.132393","DOIUrl":"https://doi.org/10.1016/j.fuel.2024.132393","url":null,"abstract":"In order to study the influence of microstructure parameters of coal dust on explosion characteristics, a spherical explosive device is employed to examine the explosion characteristics of coal dust with various low concentrations/particle sizes, and the microstructure change characteristics of solid products, the risk of re-explosion of gaseous products and the correlation between macroscopic explosion characteristics and microstructure are appropriately evaluated. The obtained results reveal that the and (d/d) rises with increasing the concentration. The smaller the particle size and the higher the concentration, the shorter the explosion time. A linear correlation can be observed between the flame propagation speed and both and . Furthermore, the oxygen consumption and combustible gas products increased with the concentration of coal dust, which increasing the risk of secondary explosion. After the explosion, branched-chains and aliphatic carbon chains increased, and the content of functional groups in different absorption peaks changed, in which the aliphatic and hydroxyl structures had a significant correlation with the explosion intensity. The objective of this study is to provide a robust theoretical foundation for future research and development in the field of coal dust explosion suppression technology.","PeriodicalId":325,"journal":{"name":"Fuel","volume":null,"pages":null},"PeriodicalIF":7.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141575830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The hydroformylation reaction is very important in industry. However, the leaching of the noble metal Rhodium (Rh) and the separation of homogeneous catalyst have always been difficult problems to solve. And even heterogeneous Rh-base catalyst was developed to solve the separation problem, the serious Rh losing is still hard to avoid. In this work, heterogeneous encapsulated Rh@NaX was prepared by using one-step synthesis method and used as catalyst without reduction in 1-hexene hydroformylation reaction. Rh@NaX catalyst exhibited outstanding catalytic performance. When directly complexed with ligand triphenylphosphine (PPh), it achieved high heptanal yield of 97.53 %, high n/i ratio of 2.59 and high TOF of 6588 h. Interestingly, encapsulated catalyst exhibited higher recycling stability and much lower Rh leaching compared to impregnated catalyst. In addition, in situ XPS and DRIFT analyses were conducted to elucidate the reduction process of Rh and the reaction pathway.
{"title":"In situ synthesis of Rh@NaX catalyst for 1-hexene hydroformylation","authors":"Gongcheng Sun, Wan Chen, Yaoying Li, Subing Fan, Junmin Lv, Tiansheng Zhao","doi":"10.1016/j.fuel.2024.132327","DOIUrl":"https://doi.org/10.1016/j.fuel.2024.132327","url":null,"abstract":"The hydroformylation reaction is very important in industry. However, the leaching of the noble metal Rhodium (Rh) and the separation of homogeneous catalyst have always been difficult problems to solve. And even heterogeneous Rh-base catalyst was developed to solve the separation problem, the serious Rh losing is still hard to avoid. In this work, heterogeneous encapsulated Rh@NaX was prepared by using one-step synthesis method and used as catalyst without reduction in 1-hexene hydroformylation reaction. Rh@NaX catalyst exhibited outstanding catalytic performance. When directly complexed with ligand triphenylphosphine (PPh), it achieved high heptanal yield of 97.53 %, high n/i ratio of 2.59 and high TOF of 6588 h. Interestingly, encapsulated catalyst exhibited higher recycling stability and much lower Rh leaching compared to impregnated catalyst. In addition, in situ XPS and DRIFT analyses were conducted to elucidate the reduction process of Rh and the reaction pathway.","PeriodicalId":325,"journal":{"name":"Fuel","volume":null,"pages":null},"PeriodicalIF":7.4,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141575936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-04DOI: 10.1016/j.fuel.2024.132404
Kai Sun, Shiqi Geng, Jiaqian Yang, Faen Song, Yongqiang Gu, Haozhe Feng, Noritatsu Tsubaki, Qingde Zhang, Yisheng Tan
A set of K-promoted CuCoAl nanoplates were synthesized via precipitation followed by impregnation method and assessed for syngas conversion. The optimized 1K-CuCo catalyst manifested a relatively higher total alcohols selectivity of 48.4 %, with ethanol comprising 35.4 % of total alcohols. As indicated by in situ CO DRIFT and XPS outcomes, on the 1K-CuCo catalyst surface, a distinct preference was observed for the adsorption of CO on Cu species (non-dissociative CO*) and bridging CO adsorption on Co species (dissociative CO*). A substantial presence of strongly adsorbed formate species, which contributed favorably to the production of CH* intermediates, was also identified on the optimal catalyst surface. More importantly, operando DRIFT characterization confirmed that K-modified CuCo catalyst effectively inhibited the hydrogenation (or coupling) of adsorbed CH* intermediates derived from formate species to generate methane and CH. Instead, the adsorbed CH* intermediates coupled with non-dissociated CO* to form CHCO* species. Therefore, the K promoter can finely regulate the adsorption strength and distribution of intermediates species, thus furnishing sufficient CH* intermediates and CO* species to take part in CH-CO coupling reaction to synthesize ethanol.
{"title":"Potassium-mediated control of adsorbed intermediates on CuCoAl layered nanoplates for ethanol synthesis from syngas","authors":"Kai Sun, Shiqi Geng, Jiaqian Yang, Faen Song, Yongqiang Gu, Haozhe Feng, Noritatsu Tsubaki, Qingde Zhang, Yisheng Tan","doi":"10.1016/j.fuel.2024.132404","DOIUrl":"https://doi.org/10.1016/j.fuel.2024.132404","url":null,"abstract":"A set of K-promoted CuCoAl nanoplates were synthesized via precipitation followed by impregnation method and assessed for syngas conversion. The optimized 1K-CuCo catalyst manifested a relatively higher total alcohols selectivity of 48.4 %, with ethanol comprising 35.4 % of total alcohols. As indicated by in situ CO DRIFT and XPS outcomes, on the 1K-CuCo catalyst surface, a distinct preference was observed for the adsorption of CO on Cu species (non-dissociative CO*) and bridging CO adsorption on Co species (dissociative CO*). A substantial presence of strongly adsorbed formate species, which contributed favorably to the production of CH* intermediates, was also identified on the optimal catalyst surface. More importantly, operando DRIFT characterization confirmed that K-modified CuCo catalyst effectively inhibited the hydrogenation (or coupling) of adsorbed CH* intermediates derived from formate species to generate methane and CH. Instead, the adsorbed CH* intermediates coupled with non-dissociated CO* to form CHCO* species. Therefore, the K promoter can finely regulate the adsorption strength and distribution of intermediates species, thus furnishing sufficient CH* intermediates and CO* species to take part in CH-CO coupling reaction to synthesize ethanol.","PeriodicalId":325,"journal":{"name":"Fuel","volume":null,"pages":null},"PeriodicalIF":7.4,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141575940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of efficient inexpensive catalysts for the oxygen reduction reaction (ORR) is one of the keys to the realization of energy conversion devices. Herein, we have synthesized a series of spinel-type metal oxides (CoZnFeO) by varying the amount of Zn substitution (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) using a simple one-step co-precipitation method. A combination of structural characterization and electrochemical analysis shows that the CoZnFeO exhibits not only the most excellent ORR activity (half-wave potential: 0.815 V and Tafel slope: 76 mV dec) compared to the other samples with different Zn substitution but also the better stability than that of commercial Pt/C catalyst. The improved reason of ORR performance for the CoZnFeO nanoparticles may be attributed to the Zn introduction and abundant oxygen vacancies. These discoveries will offer insights for exploring the synthesis of spinel-type oxides for their potential applications in oxygen-related energy conversion technologies.
{"title":"Facile synthesis of Co1-xZnxFe2O4 spinel oxides for enhanced alkaline oxygen reduction reaction","authors":"Xufeng Yang, Yufei Wang, Shun Li, Dongdong Chen, Tanlai Yu, Zhenyuan Liu, Xian Jiang","doi":"10.1016/j.fuel.2024.132398","DOIUrl":"https://doi.org/10.1016/j.fuel.2024.132398","url":null,"abstract":"The development of efficient inexpensive catalysts for the oxygen reduction reaction (ORR) is one of the keys to the realization of energy conversion devices. Herein, we have synthesized a series of spinel-type metal oxides (CoZnFeO) by varying the amount of Zn substitution (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) using a simple one-step co-precipitation method. A combination of structural characterization and electrochemical analysis shows that the CoZnFeO exhibits not only the most excellent ORR activity (half-wave potential: 0.815 V and Tafel slope: 76 mV dec) compared to the other samples with different Zn substitution but also the better stability than that of commercial Pt/C catalyst. The improved reason of ORR performance for the CoZnFeO nanoparticles may be attributed to the Zn introduction and abundant oxygen vacancies. These discoveries will offer insights for exploring the synthesis of spinel-type oxides for their potential applications in oxygen-related energy conversion technologies.","PeriodicalId":325,"journal":{"name":"Fuel","volume":null,"pages":null},"PeriodicalIF":7.4,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141576072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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