Thermochemical conversions are pathways for biomass utilization to produce various value-added energy and chemical products. For the development of novel thermochemical conversion technologies, an accurate understandi...Thermochemical conversions are pathways for biomass utilization to produce various value-added energy and chemical products. For the development of novel thermochemical conversion technologies, an accurate understanding of the reaction performance and kinetics is essential. Given the diversity of the thermal analysis techniques, it is necessary to understand the features and limitations of the reactors, ensuring that the selected thermal analysis reactor meets the specific need for reaction characterization. This paper provides a critical overview of the thermal analysis reactors based on the following perspectives: 1) gas flow conditions in the reactor, 2) particle’s external and internal heat and mass transfer limitations, 3) heating rate, 4) temperature distribution, 5) nascent char production and reaction, 6) liquid feeding and atomization, 7) simultaneous sampling and analyzing of bed materials, and 8) reacting atmosphere change. Finally, prospects and future research directions in the development of analysis techniques are proposed.展开更多
The global shift toward carbon neutrality,driven by growing concerns about climate change,requires collaborative efforts.While cleaner energy and carbon capture are crucial,addressing some high-carbon-emission industr...The global shift toward carbon neutrality,driven by growing concerns about climate change,requires collaborative efforts.While cleaner energy and carbon capture are crucial,addressing some high-carbon-emission industrial processes that significantly and disproportionally contribute to our carbon footprint is more important than ever.Analysis reveals that over 90%of total carbon emissions from human activities are attributed to a few super-emitting thermochemical processes.We urgently need breakthrough technologies and transformative alternatives to combat this excess of carbon dioxide emissions effectively.Engineering Thermochemistry is the scientific discipline that offers both scientifically sound and practical solutions to the pressing carbon neutrality challenges.展开更多
The Paris Agreement has set the goal of carbon neutrality to cope with global climate change.China has pledged to achieve carbon neutrality by 2060,which will strategically change everything in our society.As the main...The Paris Agreement has set the goal of carbon neutrality to cope with global climate change.China has pledged to achieve carbon neutrality by 2060,which will strategically change everything in our society.As the main source of carbon emissions,the consumption of fossil energy is the most profoundly affected by carbon neutrality.This work presents an analysis of how China can achieve its goal of carbon neutrality based on its status of fossil energy utilization.The significance of transforming fossils from energy to resource utilization in the future is addressed,while the development direction and key technologies are discussed.展开更多
Micro reactors are the essential part of thermal analysis techniques for characterizing gas-solid thermochemical reactions. The dynamic and diversified needs for investigating various complex materials and gas-solid r...Micro reactors are the essential part of thermal analysis techniques for characterizing gas-solid thermochemical reactions. The dynamic and diversified needs for investigating various complex materials and gas-solid reactions have led to the development of a variety of different microreactors over the years. Solid particles in microreactors are normally heated by furnaces from outside, resistive elements from inside, direct contact with bed particles, or other non-resistively methods. Solid particles can be fixed or fluidized in reactors where gas-solid contacts vary from diffusion-dominated to nearly diffusion-free conditions. Based on these characteristics, in this article we presented a broad classification for microreactors used for thermal analysis of gas-solid reactions. For each of the most popularly used microreactors, their features and limitations are briefly reviewed. By addressing the diversity of the microreactors used in the field of thermal analysis, the review aims at providing general guidance for the selection and operation of the microreactor to satisfy one's practical specific needs.展开更多
Developing an efficiently supported Cu-based catalyst with promoters to substitute the existing non-supported Cu-based catalysts is highly desirable to the Rochow-Müller reaction. Using a simple ball-milling meth...Developing an efficiently supported Cu-based catalyst with promoters to substitute the existing non-supported Cu-based catalysts is highly desirable to the Rochow-Müller reaction. Using a simple ball-milling method and CeO_(2) support, we prepared a high-performance CuO-ZnO-P-Sn/CeO_(2) catalyst by integrating highly dispersed multicomponent promoters of ZnO, Sn, and P with the active component CuO. This catalyst shows a significantly enhanced dimethyldichlorosilane selectivity because these promoters can substantially increase the Cu+ content and the formation of an active CuxSi phase. This work provides a new approach to efficiently designing Cu-based catalysts for the Rochow-Müller reaction.展开更多
Forsterite is a highly demanded material in high-temperature industries due to its superior performance in elevated temperatures.This study proposes synthesizing high-quality forsterite via high-temperature thermochem...Forsterite is a highly demanded material in high-temperature industries due to its superior performance in elevated temperatures.This study proposes synthesizing high-quality forsterite via high-temperature thermochemical reactions using abundant boron mud waste.The new synthesis method capitalizes on the high reactivity of fine raw powder materials,enabling the reaction to reach completion at low temperatures rapidly.The chemical characteristics,microscopic morphology,and structure of synthe-sized samples are systematically studied using XRD and SEM.The results confirm that boron mud can be efficiently transformed into forsterite after 10 min of reactions at 1500℃.The synthesized products attain over 98.7%densification and contain more than 85.0%forsterite with well-developed grains.The activation energy of forsterite grain growth in the 1100-1500℃temperature range is 165.5 kJ/mol.This study provides a low-cost method for producing forsterite and an efficient and environmentally friendly solution for treating solid waste.展开更多
Fluidized-bed reactors are widely employed in various high-temperature industrial processes.Thus,it is crucial to understand the temperature effect on various fluidization phenomena,specifically the minimum fluidizati...Fluidized-bed reactors are widely employed in various high-temperature industrial processes.Thus,it is crucial to understand the temperature effect on various fluidization phenomena,specifically the minimum fluidization velocity(U_(mf))that governs various aspects of fluidized bed behavior.In this study,we comprehensively analyze U_(mf) data from the literature to unravel the complexity and underlying mechanisms of temperature influence on this critical velocity.The research examines experimental data encompassing a wide range of temperatures,pressures,and solid particles.The analysis reveals that the influence of temperature on U_(mf) is fundamentally determined by the relative importance of hydrodynamic forces and interparticle forces within fluidized beds and is realized by three distinctive temperature-induced changes:gas properties,bed voidage,and physiochemical characteristics of particles.On this basis,an equation is derived to enable predictions of temperature influences on the minimum fluidization velocity under broad temperature conditions.展开更多
Turbulent fluidized bed proves effective in industrial processes due to superior heat and mass transfer and chemical reaction performance. However, understanding the transition to turbulent fluidization remains limite...Turbulent fluidized bed proves effective in industrial processes due to superior heat and mass transfer and chemical reaction performance. However, understanding the transition to turbulent fluidization remains limited, especially at temperatures exceeding 1000 ℃, making it challenging to develop high-temperature fluidized bed applications. This paper presents an experimental investigation on the turbulent fluidization onset velocity (U_(c)), measured in a 30 mm diameter bed using corundum particles with average diameters from 0.68 mm to 1.58 mm in temperatures from ambient to 1600 ℃. Experimental results reveal that U_(c) increases with temperature up to 600 ℃, stabilizes within the 600–1200 ℃ range, and then decreases above 1200 ℃, demonstrating the varying relative significance of hydrodynamic and interparticle forces at different temperatures. To help design and operate high-temperature applications of turbulent fluidization, we developed U_(c) correlations based on experimental data from both literature sources and this study, covering temperatures of up to 1600 ℃ and particles of Groups A to D.展开更多
Fuel conversion and clean energy reaction systems involve a variety of catalytic and non-catalytic gas-solid thermochemical reactions.A good understanding of the correct reaction mechanism and kinetics,as well as the ...Fuel conversion and clean energy reaction systems involve a variety of catalytic and non-catalytic gas-solid thermochemical reactions.A good understanding of the correct reaction mechanism and kinetics,as well as the profiles of reaction products,is of great significance to the development,design,and operation of such reaction systems.The micro fluidized bed reaction analysis provides an efficient and reliable method to acquire this essential information with low capital and operating costs,low energy consumption and enhanced safety.This paper provides an overview of the system and its characteristics for the micro fluidized bed reaction analyzer that has been well proven to be a reliable new approach as well as an instrument for characterizing various gas-solid thermochemical reactions.展开更多
Homogeneous noble metal catalysts used in alkene hydrosilylation reactions to manufacture organosilicon compounds commercially often suffer from difficulties in catalyst recovering and recycling,undesired disproportio...Homogeneous noble metal catalysts used in alkene hydrosilylation reactions to manufacture organosilicon compounds commercially often suffer from difficulties in catalyst recovering and recycling,undesired disproportionation reactions,and energyintensive purification of products.Herein,we report a heterogeneous 0.5Ruδ+/ZrO_(2) catalyst with partially charged single-atom Ru(0.5 wt.%Ru)supported on commercial ZrO_(2) nanocrystals synthesized by the simple impregnation method followed by H2 reduction.When used in the ethylene hydrosilylation with triethoxysilane to produce the desired ethyltriethoxysilane,0.5Ruδ+/ZrO_(2) showed excellent catalytic performance with the maximum Ru atom utilization and good recyclability,even superior to homogeneous catalyst(RuCl3·H2O).Structural characterizations and density functional theory calculations reveal the atomic dispersion of the active Ru species and their unique electronic properties distinct from the homogeneous catalyst.The reaction route over this catalyst is supposed to follow the typical Chalk-Harrod mechanism.This highly efficient and supported singleatom Ru catalyst has the potential to replace the current homogeneous catalyst for a greener hydrosilylation industry.展开更多
基金supported by the National Natural Science Foundation of China(U1908201,U1903130)the Ministry of Science and Technology of the People’s Republic of China(2020YFC1909300)the Natural Science Foundation of Liaoning Province of China(2021-NLTS-12-09).
文摘Thermochemical conversions are pathways for biomass utilization to produce various value-added energy and chemical products. For the development of novel thermochemical conversion technologies, an accurate understanding of the reaction performance and kinetics is essential. Given the diversity of the thermal analysis techniques, it is necessary to understand the features and limitations of the reactors, ensuring that the selected thermal analysis reactor meets the specific need for reaction characterization. This paper provides a critical overview of the thermal analysis reactors based on the following perspectives: 1) gas flow conditions in the reactor, 2) particle’s external and internal heat and mass transfer limitations, 3) heating rate, 4) temperature distribution, 5) nascent char production and reaction, 6) liquid feeding and atomization, 7) simultaneous sampling and analyzing of bed materials, and 8) reacting atmosphere change. Finally, prospects and future research directions in the development of analysis techniques are proposed.
基金partially supported by the National Natural Science Foundation of China(U22A20410).
文摘The global shift toward carbon neutrality,driven by growing concerns about climate change,requires collaborative efforts.While cleaner energy and carbon capture are crucial,addressing some high-carbon-emission industrial processes that significantly and disproportionally contribute to our carbon footprint is more important than ever.Analysis reveals that over 90%of total carbon emissions from human activities are attributed to a few super-emitting thermochemical processes.We urgently need breakthrough technologies and transformative alternatives to combat this excess of carbon dioxide emissions effectively.Engineering Thermochemistry is the scientific discipline that offers both scientifically sound and practical solutions to the pressing carbon neutrality challenges.
文摘The Paris Agreement has set the goal of carbon neutrality to cope with global climate change.China has pledged to achieve carbon neutrality by 2060,which will strategically change everything in our society.As the main source of carbon emissions,the consumption of fossil energy is the most profoundly affected by carbon neutrality.This work presents an analysis of how China can achieve its goal of carbon neutrality based on its status of fossil energy utilization.The significance of transforming fossils from energy to resource utilization in the future is addressed,while the development direction and key technologies are discussed.
基金supported by both the National Natural Science Foundation of China(U1903130 and U1908201)the Ministry of Science and Technology of the People's Republic of China(2020YFC1909300).
文摘Micro reactors are the essential part of thermal analysis techniques for characterizing gas-solid thermochemical reactions. The dynamic and diversified needs for investigating various complex materials and gas-solid reactions have led to the development of a variety of different microreactors over the years. Solid particles in microreactors are normally heated by furnaces from outside, resistive elements from inside, direct contact with bed particles, or other non-resistively methods. Solid particles can be fixed or fluidized in reactors where gas-solid contacts vary from diffusion-dominated to nearly diffusion-free conditions. Based on these characteristics, in this article we presented a broad classification for microreactors used for thermal analysis of gas-solid reactions. For each of the most popularly used microreactors, their features and limitations are briefly reviewed. By addressing the diversity of the microreactors used in the field of thermal analysis, the review aims at providing general guidance for the selection and operation of the microreactor to satisfy one's practical specific needs.
基金support from the National Natural Science Foundation of China(Nos.21978299 and 21878301)supported by the Open Research Fund of State Key Laboratory of Multiphase Complex Systems(MPCS-2021-D-08)+2 种基金GRINM Group(G12620213102035)Y.J.thanks the financial support from the Outstanding Youth Cultivation Program of Beijing Technology and Business University(No.19008021144)the Research Foundation for Advanced Talents of Beijing Technology and Business University(No.19008020159).
文摘Developing an efficiently supported Cu-based catalyst with promoters to substitute the existing non-supported Cu-based catalysts is highly desirable to the Rochow-Müller reaction. Using a simple ball-milling method and CeO_(2) support, we prepared a high-performance CuO-ZnO-P-Sn/CeO_(2) catalyst by integrating highly dispersed multicomponent promoters of ZnO, Sn, and P with the active component CuO. This catalyst shows a significantly enhanced dimethyldichlorosilane selectivity because these promoters can substantially increase the Cu+ content and the formation of an active CuxSi phase. This work provides a new approach to efficiently designing Cu-based catalysts for the Rochow-Müller reaction.
基金support provided by the National Natural Science Foundation of China (grant number U22A20410).
文摘Forsterite is a highly demanded material in high-temperature industries due to its superior performance in elevated temperatures.This study proposes synthesizing high-quality forsterite via high-temperature thermochemical reactions using abundant boron mud waste.The new synthesis method capitalizes on the high reactivity of fine raw powder materials,enabling the reaction to reach completion at low temperatures rapidly.The chemical characteristics,microscopic morphology,and structure of synthe-sized samples are systematically studied using XRD and SEM.The results confirm that boron mud can be efficiently transformed into forsterite after 10 min of reactions at 1500℃.The synthesized products attain over 98.7%densification and contain more than 85.0%forsterite with well-developed grains.The activation energy of forsterite grain growth in the 1100-1500℃temperature range is 165.5 kJ/mol.This study provides a low-cost method for producing forsterite and an efficient and environmentally friendly solution for treating solid waste.
基金supported by the National Natural Science Foundation of China(grant No.U22A20410).
文摘Fluidized-bed reactors are widely employed in various high-temperature industrial processes.Thus,it is crucial to understand the temperature effect on various fluidization phenomena,specifically the minimum fluidization velocity(U_(mf))that governs various aspects of fluidized bed behavior.In this study,we comprehensively analyze U_(mf) data from the literature to unravel the complexity and underlying mechanisms of temperature influence on this critical velocity.The research examines experimental data encompassing a wide range of temperatures,pressures,and solid particles.The analysis reveals that the influence of temperature on U_(mf) is fundamentally determined by the relative importance of hydrodynamic forces and interparticle forces within fluidized beds and is realized by three distinctive temperature-induced changes:gas properties,bed voidage,and physiochemical characteristics of particles.On this basis,an equation is derived to enable predictions of temperature influences on the minimum fluidization velocity under broad temperature conditions.
基金supported by the National Natural Science Foundation of China(grant No.U22A20410).
文摘Turbulent fluidized bed proves effective in industrial processes due to superior heat and mass transfer and chemical reaction performance. However, understanding the transition to turbulent fluidization remains limited, especially at temperatures exceeding 1000 ℃, making it challenging to develop high-temperature fluidized bed applications. This paper presents an experimental investigation on the turbulent fluidization onset velocity (U_(c)), measured in a 30 mm diameter bed using corundum particles with average diameters from 0.68 mm to 1.58 mm in temperatures from ambient to 1600 ℃. Experimental results reveal that U_(c) increases with temperature up to 600 ℃, stabilizes within the 600–1200 ℃ range, and then decreases above 1200 ℃, demonstrating the varying relative significance of hydrodynamic and interparticle forces at different temperatures. To help design and operate high-temperature applications of turbulent fluidization, we developed U_(c) correlations based on experimental data from both literature sources and this study, covering temperatures of up to 1600 ℃ and particles of Groups A to D.
基金the financial supports of the Ministry of Science and Technology of People’s Republic of China(2018YFE0103400)the National Natural Science Foundation of China(U1908201).
文摘Fuel conversion and clean energy reaction systems involve a variety of catalytic and non-catalytic gas-solid thermochemical reactions.A good understanding of the correct reaction mechanism and kinetics,as well as the profiles of reaction products,is of great significance to the development,design,and operation of such reaction systems.The micro fluidized bed reaction analysis provides an efficient and reliable method to acquire this essential information with low capital and operating costs,low energy consumption and enhanced safety.This paper provides an overview of the system and its characteristics for the micro fluidized bed reaction analyzer that has been well proven to be a reliable new approach as well as an instrument for characterizing various gas-solid thermochemical reactions.
基金the National Natural Science Foundation of China(No.22002004)Y.J.J.thanks the financial supports from the Outstanding Youth Cultivation Program of Beijing Technology and Business University(No.19008021144)+1 种基金Research Foundation for Advanced Talents of Beijing Technology and Business University(No.19008020159)Z.Y.Z.thanks the financial support of Guangdong Key discipline fund for this collaboration.
文摘Homogeneous noble metal catalysts used in alkene hydrosilylation reactions to manufacture organosilicon compounds commercially often suffer from difficulties in catalyst recovering and recycling,undesired disproportionation reactions,and energyintensive purification of products.Herein,we report a heterogeneous 0.5Ruδ+/ZrO_(2) catalyst with partially charged single-atom Ru(0.5 wt.%Ru)supported on commercial ZrO_(2) nanocrystals synthesized by the simple impregnation method followed by H2 reduction.When used in the ethylene hydrosilylation with triethoxysilane to produce the desired ethyltriethoxysilane,0.5Ruδ+/ZrO_(2) showed excellent catalytic performance with the maximum Ru atom utilization and good recyclability,even superior to homogeneous catalyst(RuCl3·H2O).Structural characterizations and density functional theory calculations reveal the atomic dispersion of the active Ru species and their unique electronic properties distinct from the homogeneous catalyst.The reaction route over this catalyst is supposed to follow the typical Chalk-Harrod mechanism.This highly efficient and supported singleatom Ru catalyst has the potential to replace the current homogeneous catalyst for a greener hydrosilylation industry.
