The product distribution and kinetic analysis of low-rank coal vitrinite were investigated during the chemical looping gasification(CLG)process.The acid washing method was used to treat low-rank coal,and the density g...The product distribution and kinetic analysis of low-rank coal vitrinite were investigated during the chemical looping gasification(CLG)process.The acid washing method was used to treat low-rank coal,and the density gradient centrifugation method was adopted to obtain the coal macerals.By combining thermogravimetric analysis and online mass spectrometry,the influence of the heating rate and oxygen carrier(Fe2O3)blending ratio on product distribution was discussed.The macroscopic kinetic parameters were solved by the Kissinger-Akahira-Sunose(KAS)method,and the main gaseous product formation kinetic parameters were solved by the iso-conversion method.The results of vitrinite during slow heating chemical looping gasification showed that the main weight loss interval was 400–600℃,and the solid yield of sample vitrinite-Fe-10 at different heating rates was 64.30%–69.67%.When b=20℃·min^(-1),the maximum decomposition rate of vitrinite-Fe-10 was 0.312%min1.The addition of Fe2O_(3)reduced the maximum decomposition rate,but by comparing the chemical looping conversion characteristic index,it could be inferred that the chemical looping gasification of vitrinite might produce volatile substances higher than the pyrolysis process of vitrinite alone.The average activation energy of the reaction was significantly reduced during chemical looping gasification of vitrinite,which was lower than the average activation energy of 448.69 kJ·mol^(-1) during the pyrolysis process of vitrinite alone.The gaseous products were mainly CO and CO_(2).When the heating rate was 10℃·min^(-1),the highest activation energy for CH4 formation was 21.353 kJ·mol^(-1),and the lowest activation energy for CO formation was 9.7333 kJ·mol^(-1).This study provides basic data for exploring coal chemical looping gasification mechanism and reactor design by studying the chemical looping gasification process of coal macerals。展开更多
INTRODUCTIONThe coast zone is the area where most human activities take place and where the highest economic benefit is produced. The knowledge of the distribution and variation of primary production provides the base...INTRODUCTIONThe coast zone is the area where most human activities take place and where the highest economic benefit is produced. The knowledge of the distribution and variation of primary production provides the bases as reference helping the marine exploitation and management.展开更多
Standards Press of China (SPC), founded in October 1963, is the only publication center in China licensed to publish national standards, trade standards, and books concerned with standardization, quality, and other sc...Standards Press of China (SPC), founded in October 1963, is the only publication center in China licensed to publish national standards, trade standards, and books concerned with standardization, quality, and other science and technology. The main publications are as following:展开更多
The ethanol electro-reforming process was studied over PtRu/C catalysts synthesized by the modified polyol method with different compositions.In particular,this work reports the influence of anodic Pt:Ru ratio(5:1,2:1...The ethanol electro-reforming process was studied over PtRu/C catalysts synthesized by the modified polyol method with different compositions.In particular,this work reports the influence of anodic Pt:Ru ratio(5:1,2:1 and 1:2)on the organic product distribution(acetaldehyde,acetic acid and ethyl acetate)and pure hydrogen generation at different current densities operation levels.Physicochemical characterization of the catalysts was made by X-ray diffraction(XRD),temperature-programmed reduction(TPR)and N_(2) adsorption-desorption measurements.XRD patterns showed that Ru is introduced into the Pt structure,forming an alloy between both metals.Also,the degree of alloy was higher by increasing the Ru amounts.From TPR profiles Pt was found to be properly reduced while Ru was both in metallic state and forming RuO2.The electrochemical behaviour of each catalyst towards ethanol electroreforming process was investigated through electrochemical techniques in a half cell and a single proton exchange membrane(PEM)cell systems.An intermediate Pt:Ru ratio was found to result in high current density and electrochemical surface area(ECSA)values along with lower amounts of adsorbed species.Also,Ru addition seems to diminish the degree of degradation of the catalyst.Based on characterization and in agreement with essays carried out in a PEM cell at mild conditions(80℃ and 1 atm),PtRu/C 2:1 anode provided the best electrocatalytic results in terms of current density(740 mA cm^(-2)),hydrogen production and selectivity toward acetic acid(up to 15%apart from acetaldehyde and ethyl acetate)while requiring the lowest energy consumption.展开更多
Product data management (PDM) has been accepted as an important tool for the manufacturing industries. In recent years, more and mor e researches have been conducted in the development of PDM. Their research area s in...Product data management (PDM) has been accepted as an important tool for the manufacturing industries. In recent years, more and mor e researches have been conducted in the development of PDM. Their research area s include system design, integration of object-oriented technology, data distri bution, collaborative and distributed manufacturing working environment, secur ity, and web-based integration. However, there are limitations on their rese arches. In particular, they cannot cater for PDM in distributed manufacturing e nvironment. This is especially true in South China, where many Hong Kong (HK) ma nufacturers have moved their production plants to different locations in Pearl R iver Delta for cost reduction. However, they retain their main offices in HK. Development of PDM system is inherently complex. Product related data cover prod uct name, product part number (product identification), drawings, material speci fications, dimension requirement, quality specification, test result, log size, production schedules, product data version and date of release, special tooling (e.g. jig and fixture), mould design, project engineering in charge, cost spread sheets, while process data includes engineering release, engineering change info rmation management, and other workflow related to the process information. Accor ding to Cornelissen et al., the contemporary PDM system should contains manageme nt functions in structure, retrieval, release, change, and workflow. In system design, development and implementation, a formal specification is nece ssary. However, there is no formal representation model for PDM system. Theref ore a graphical representation model is constructed to express the various scena rios of interactions between users and the PDM system. Statechart is then used to model the operations of PDM system, Fig.1. Statechart model bridges the curr ent gap between requirements, scenarios, and the initial design specifications o f PDM system. After properly analyzing the PDM system, a new distributed PDM (DPDM) system is proposed. Both graphical representation and statechart models are constructed f or the new DPDM system, Fig.2. New product data of DPDM and new system function s are then investigated to support product information flow in the new distribut ed environment. It is found that statecharts allow formal representations to capture the informa tion and control flows of both PDM and DPDM. In particular, statechart offers a dditional expressive power, when compared to conventional state transition diagr am, in terms of hierarchy, concurrency, history, and timing for DPDM behavioral modeling.展开更多
Liquid chemical looping technology is an innovation of chemical looping conversion technology.Using liquid metal oxide as the oxygen carrier during gasification process could prolong the service life of oxygen carrier...Liquid chemical looping technology is an innovation of chemical looping conversion technology.Using liquid metal oxide as the oxygen carrier during gasification process could prolong the service life of oxygen carrier and improve the process efficiency.In this paper,based on Gibbs minimum free energy method,the thermodynamic characteristics of biomass liquid chemical looping gasification were studied.Cellulose and lignin,the main components of biomass,were taken as the research objects.Bismuth oxide and antimony oxide were selected as liquid oxygen carriers.The results showed that when the temperature increased from 600℃to 900℃,the output of H_(2)and CO in the products of cellulose gasification increased from 0.5 and 0.3 kmol to 1.3 and 2.6 kmol respectively.Different ratios of oxygen carriers to gasification raw materials had the best molar ratio.The addition of steam in the system was beneficial to the increase of H_(2)content and the increase of H_(2)/CO molar ratio.Bi_(2)O_(3)and Sb_(2)O_(3)with different mass ratios were used as mixed oxygen carriers.The simulation results showed that the gasification temperature of biomass with different mixed oxygen carriers had the same equilibrium trend products.It could be seen from the results of product distribution that the influence of the mixing ratio of Bi_(2)O_(3)and Sb_(2)O_(3)on gas product distribution could be neglected.These results could provide simulation reference and data basis for subsequent research on liquid chemical looping gasification.展开更多
In this study, strategic electricity market scenarios are considered in a grid of Scandinavia. This multiple-objective decision environment includes the allocation of a number of renewable forest fuel procurement chai...In this study, strategic electricity market scenarios are considered in a grid of Scandinavia. This multiple-objective decision environment includes the allocation of a number of renewable forest fuel procurement chains to a combined heat and power plant in Finland. The decision environment includes also electricity procurement from Sweden and Russia. The environment is further complicated by sequence-dependent operations of the local procurement chains during different periods. Due to the complex nature of the environment, multiple-objective methods cannot be directly used to solve the electricity production problem in a manner that is techno-economically relevant to the forest energy industry. Therefore, local and time-varying parameters were measured in local wood procurement conditions to improve the solution method. Using these measurements the smart decision-support system automatically adjusted the multiple-objective methodology to better describe the combinatorial complexity of the production sector. The properties of this methodology are discussed and three scenarios of how the system works based on local real-world data and optional feed-in tariff of green electricity are presented. The Finnish electricity market is subject to policy decisions regarding green energy production regulations. These decisions should be made on the basis of local techno-economic analysis presented in this study accounting for the effects of forest operations on the electricity production and import.展开更多
Chemical looping gasification(CLG)characteristics and kinetic analysis of Chlorella(CHL),simulated Chlorella(V-CHL)and medium-chain triglycerides(MCT)were investigated using a thermogravimetric analyzer coupled with a...Chemical looping gasification(CLG)characteristics and kinetic analysis of Chlorella(CHL),simulated Chlorella(V-CHL)and medium-chain triglycerides(MCT)were investigated using a thermogravimetric analyzer coupled with an online mass spectrometer.The apparent activation energy was obtained via Kissinger-Akahira-Sunose(KAS)method.In the result of the weightless behavior,the addition of oxygen carrier inhibited the decomposition of V-CHL at lower temperatures but promoted its decomposition at high temperatures.The values of chemical looping process characteristic parameters showed that a 10 wt%oxygen carrier would maximize the release of volatile products in the CLG of MCT,with 5.12×10^(-6)%⋅min^(-1)⋅℃^(-3).Oxygen carriers also affected gaseous products.The LHV of gaseous products of CHL reached the largest when the oxygen carrier was 10 wt%,which was 8.13 MJ/m^(3).And the gaseous product of MCT had the largest LHV with 30 wt%oxygen carrier,which was 8.83 MJ/m^(3).According to the kinetic analysis,the minimum value of apparent activation energy of MCT chemical looping gasification was 89.54 kJ⋅mol^(-1) with the oxygen carrier of 30 wt%,which was 50%less than that of MCT pyrolysis.And the minimum value for V-CHL was obtained when the mass fraction of Fe2O3 was 50 wt%.This paper could provide a reference for the choice of algae,the design of reactors,and the targeted regulation of the gaseous product for the algae CLG process.展开更多
Hypercoal(HPC)is promising feedstock for producing coal-based chemicals due to its extremely low ash content and high reactivity.However,the conventional methods for HPC preparation through thermal extraction under me...Hypercoal(HPC)is promising feedstock for producing coal-based chemicals due to its extremely low ash content and high reactivity.However,the conventional methods for HPC preparation through thermal extraction under mechanical stirring are difficult to scale-up due to the low HPC yield and large consumption of solvent.This work conducted ultrasonic-assisted extraction(UAE)instead of mechanical stirring to enhance the efficiency of HPC production,and the effect of technological conditions on the HPC yield were examined.It was found that the UAE could remarkably enhance the HPC yield from 52.3%to 82.4%.Moreover,the ratio of soluble(HPC-S)to deposit(HPC-D)increased from 1.65 to 2.85,verifying the high efficiency and the capacity of altering the product distribution of UAE.展开更多
基金support of the National Natural Science Foundation of China(22038011,51976168)the K.C.Wong Education Foundation,China Postdoctoral Science Foundation(2019M653626)+2 种基金Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(2020-KF-06)the Promotion Plan for Young People of Shaanxi Association for Science and Technology(20180402)the Technology Foundation for Selected Overseas Chinese Scholar in Shaanxi Province(2018015).
文摘The product distribution and kinetic analysis of low-rank coal vitrinite were investigated during the chemical looping gasification(CLG)process.The acid washing method was used to treat low-rank coal,and the density gradient centrifugation method was adopted to obtain the coal macerals.By combining thermogravimetric analysis and online mass spectrometry,the influence of the heating rate and oxygen carrier(Fe2O3)blending ratio on product distribution was discussed.The macroscopic kinetic parameters were solved by the Kissinger-Akahira-Sunose(KAS)method,and the main gaseous product formation kinetic parameters were solved by the iso-conversion method.The results of vitrinite during slow heating chemical looping gasification showed that the main weight loss interval was 400–600℃,and the solid yield of sample vitrinite-Fe-10 at different heating rates was 64.30%–69.67%.When b=20℃·min^(-1),the maximum decomposition rate of vitrinite-Fe-10 was 0.312%min1.The addition of Fe2O_(3)reduced the maximum decomposition rate,but by comparing the chemical looping conversion characteristic index,it could be inferred that the chemical looping gasification of vitrinite might produce volatile substances higher than the pyrolysis process of vitrinite alone.The average activation energy of the reaction was significantly reduced during chemical looping gasification of vitrinite,which was lower than the average activation energy of 448.69 kJ·mol^(-1) during the pyrolysis process of vitrinite alone.The gaseous products were mainly CO and CO_(2).When the heating rate was 10℃·min^(-1),the highest activation energy for CH4 formation was 21.353 kJ·mol^(-1),and the lowest activation energy for CO formation was 9.7333 kJ·mol^(-1).This study provides basic data for exploring coal chemical looping gasification mechanism and reactor design by studying the chemical looping gasification process of coal macerals。
文摘INTRODUCTIONThe coast zone is the area where most human activities take place and where the highest economic benefit is produced. The knowledge of the distribution and variation of primary production provides the bases as reference helping the marine exploitation and management.
文摘Standards Press of China (SPC), founded in October 1963, is the only publication center in China licensed to publish national standards, trade standards, and books concerned with standardization, quality, and other science and technology. The main publications are as following:
基金the Spanish Ministry of Economy and Competitiveness(projects CTQ2016-75491-R)for the financial support。
文摘The ethanol electro-reforming process was studied over PtRu/C catalysts synthesized by the modified polyol method with different compositions.In particular,this work reports the influence of anodic Pt:Ru ratio(5:1,2:1 and 1:2)on the organic product distribution(acetaldehyde,acetic acid and ethyl acetate)and pure hydrogen generation at different current densities operation levels.Physicochemical characterization of the catalysts was made by X-ray diffraction(XRD),temperature-programmed reduction(TPR)and N_(2) adsorption-desorption measurements.XRD patterns showed that Ru is introduced into the Pt structure,forming an alloy between both metals.Also,the degree of alloy was higher by increasing the Ru amounts.From TPR profiles Pt was found to be properly reduced while Ru was both in metallic state and forming RuO2.The electrochemical behaviour of each catalyst towards ethanol electroreforming process was investigated through electrochemical techniques in a half cell and a single proton exchange membrane(PEM)cell systems.An intermediate Pt:Ru ratio was found to result in high current density and electrochemical surface area(ECSA)values along with lower amounts of adsorbed species.Also,Ru addition seems to diminish the degree of degradation of the catalyst.Based on characterization and in agreement with essays carried out in a PEM cell at mild conditions(80℃ and 1 atm),PtRu/C 2:1 anode provided the best electrocatalytic results in terms of current density(740 mA cm^(-2)),hydrogen production and selectivity toward acetic acid(up to 15%apart from acetaldehyde and ethyl acetate)while requiring the lowest energy consumption.
文摘Product data management (PDM) has been accepted as an important tool for the manufacturing industries. In recent years, more and mor e researches have been conducted in the development of PDM. Their research area s include system design, integration of object-oriented technology, data distri bution, collaborative and distributed manufacturing working environment, secur ity, and web-based integration. However, there are limitations on their rese arches. In particular, they cannot cater for PDM in distributed manufacturing e nvironment. This is especially true in South China, where many Hong Kong (HK) ma nufacturers have moved their production plants to different locations in Pearl R iver Delta for cost reduction. However, they retain their main offices in HK. Development of PDM system is inherently complex. Product related data cover prod uct name, product part number (product identification), drawings, material speci fications, dimension requirement, quality specification, test result, log size, production schedules, product data version and date of release, special tooling (e.g. jig and fixture), mould design, project engineering in charge, cost spread sheets, while process data includes engineering release, engineering change info rmation management, and other workflow related to the process information. Accor ding to Cornelissen et al., the contemporary PDM system should contains manageme nt functions in structure, retrieval, release, change, and workflow. In system design, development and implementation, a formal specification is nece ssary. However, there is no formal representation model for PDM system. Theref ore a graphical representation model is constructed to express the various scena rios of interactions between users and the PDM system. Statechart is then used to model the operations of PDM system, Fig.1. Statechart model bridges the curr ent gap between requirements, scenarios, and the initial design specifications o f PDM system. After properly analyzing the PDM system, a new distributed PDM (DPDM) system is proposed. Both graphical representation and statechart models are constructed f or the new DPDM system, Fig.2. New product data of DPDM and new system function s are then investigated to support product information flow in the new distribut ed environment. It is found that statecharts allow formal representations to capture the informa tion and control flows of both PDM and DPDM. In particular, statechart offers a dditional expressive power, when compared to conventional state transition diagr am, in terms of hierarchy, concurrency, history, and timing for DPDM behavioral modeling.
基金support of the National Natural Science Foundation of China(22038011,51976168)the K.C.Wong Education Foundation+3 种基金China Postdoctoral Science Foundation(2019M653626)Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(2020-KF-06)the Promotion Plan for Young People of Shaanxi Association for Science and Technology(20180402)the Technology Foundation for Selected Overseas Chinese Scholar in Shaanxi Province(2018015)。
文摘Liquid chemical looping technology is an innovation of chemical looping conversion technology.Using liquid metal oxide as the oxygen carrier during gasification process could prolong the service life of oxygen carrier and improve the process efficiency.In this paper,based on Gibbs minimum free energy method,the thermodynamic characteristics of biomass liquid chemical looping gasification were studied.Cellulose and lignin,the main components of biomass,were taken as the research objects.Bismuth oxide and antimony oxide were selected as liquid oxygen carriers.The results showed that when the temperature increased from 600℃to 900℃,the output of H_(2)and CO in the products of cellulose gasification increased from 0.5 and 0.3 kmol to 1.3 and 2.6 kmol respectively.Different ratios of oxygen carriers to gasification raw materials had the best molar ratio.The addition of steam in the system was beneficial to the increase of H_(2)content and the increase of H_(2)/CO molar ratio.Bi_(2)O_(3)and Sb_(2)O_(3)with different mass ratios were used as mixed oxygen carriers.The simulation results showed that the gasification temperature of biomass with different mixed oxygen carriers had the same equilibrium trend products.It could be seen from the results of product distribution that the influence of the mixing ratio of Bi_(2)O_(3)and Sb_(2)O_(3)on gas product distribution could be neglected.These results could provide simulation reference and data basis for subsequent research on liquid chemical looping gasification.
文摘In this study, strategic electricity market scenarios are considered in a grid of Scandinavia. This multiple-objective decision environment includes the allocation of a number of renewable forest fuel procurement chains to a combined heat and power plant in Finland. The decision environment includes also electricity procurement from Sweden and Russia. The environment is further complicated by sequence-dependent operations of the local procurement chains during different periods. Due to the complex nature of the environment, multiple-objective methods cannot be directly used to solve the electricity production problem in a manner that is techno-economically relevant to the forest energy industry. Therefore, local and time-varying parameters were measured in local wood procurement conditions to improve the solution method. Using these measurements the smart decision-support system automatically adjusted the multiple-objective methodology to better describe the combinatorial complexity of the production sector. The properties of this methodology are discussed and three scenarios of how the system works based on local real-world data and optional feed-in tariff of green electricity are presented. The Finnish electricity market is subject to policy decisions regarding green energy production regulations. These decisions should be made on the basis of local techno-economic analysis presented in this study accounting for the effects of forest operations on the electricity production and import.
基金The authors gratefully acknowledge the support of the National Natural Science Foundation of China(Grant Nos:22038011,51976168)the K.C.Wong Education Foundation,and the Natural Science Basic Research Program of Shaanxi(Program No.2021JLM-17).
文摘Chemical looping gasification(CLG)characteristics and kinetic analysis of Chlorella(CHL),simulated Chlorella(V-CHL)and medium-chain triglycerides(MCT)were investigated using a thermogravimetric analyzer coupled with an online mass spectrometer.The apparent activation energy was obtained via Kissinger-Akahira-Sunose(KAS)method.In the result of the weightless behavior,the addition of oxygen carrier inhibited the decomposition of V-CHL at lower temperatures but promoted its decomposition at high temperatures.The values of chemical looping process characteristic parameters showed that a 10 wt%oxygen carrier would maximize the release of volatile products in the CLG of MCT,with 5.12×10^(-6)%⋅min^(-1)⋅℃^(-3).Oxygen carriers also affected gaseous products.The LHV of gaseous products of CHL reached the largest when the oxygen carrier was 10 wt%,which was 8.13 MJ/m^(3).And the gaseous product of MCT had the largest LHV with 30 wt%oxygen carrier,which was 8.83 MJ/m^(3).According to the kinetic analysis,the minimum value of apparent activation energy of MCT chemical looping gasification was 89.54 kJ⋅mol^(-1) with the oxygen carrier of 30 wt%,which was 50%less than that of MCT pyrolysis.And the minimum value for V-CHL was obtained when the mass fraction of Fe2O3 was 50 wt%.This paper could provide a reference for the choice of algae,the design of reactors,and the targeted regulation of the gaseous product for the algae CLG process.
基金supported by the National Natural Science Foundation of China(Grants 21978002,21878001,22078002,21776001,21875001,21808002 and 22008001).
文摘Hypercoal(HPC)is promising feedstock for producing coal-based chemicals due to its extremely low ash content and high reactivity.However,the conventional methods for HPC preparation through thermal extraction under mechanical stirring are difficult to scale-up due to the low HPC yield and large consumption of solvent.This work conducted ultrasonic-assisted extraction(UAE)instead of mechanical stirring to enhance the efficiency of HPC production,and the effect of technological conditions on the HPC yield were examined.It was found that the UAE could remarkably enhance the HPC yield from 52.3%to 82.4%.Moreover,the ratio of soluble(HPC-S)to deposit(HPC-D)increased from 1.65 to 2.85,verifying the high efficiency and the capacity of altering the product distribution of UAE.