The equilibrium hydrate formation conditions for CO2/H2 gas mixtures with different CO2 concentrations in 0.29 mol% TBAB aqueous solution are firstly measured.The results illustrate that the equilibrium hydrate format...The equilibrium hydrate formation conditions for CO2/H2 gas mixtures with different CO2 concentrations in 0.29 mol% TBAB aqueous solution are firstly measured.The results illustrate that the equilibrium hydrate formation pressure increases remarkably with the decrease of CO2 concentration in the gas mixture.Based on the phase equilibrium data,a three stages hydrate CO2 separation from integrated gasification combined cycle （IGCC） synthesis gas is investigated.Because the separation efficiency is quite low for the third hydrate separation,a hybrid CO2 separation process of two hydrate stages in conjunction with one chemical absorption process （absorption with MEA） is proposed and studied.The experimental results show H2 concentration in the final residual gas released from the three stages hydrate CO2 separation process was approximately 95.0 mol% while that released from the hybrid CO2 separation process was approximately 99.4 mol%.Thus,the hybrid process is possible to be a promising technology for the industrial application in the future.展开更多
Phosphorus （P） reserve, largely derived from phosphate rock, is essential for crop growth to support the growing world population. However, a significant proportion of phosphorus used as a fertilizer runs into natur...Phosphorus （P） reserve, largely derived from phosphate rock, is essential for crop growth to support the growing world population. However, a significant proportion of phosphorus used as a fertilizer runs into natural waters, causing eutro- phication and ecological damage. Moreover, most P in the food is eventually discharged as waste after being digested by human and animals. Thus, industrial activities have created a one-way flow of non-renewable P from rocks to farms to lakes, rivers and oceans.展开更多
A recent study published in Nature has uncovered a novel regulatory mechanism that enhances start-codon selection during mitosis in mammalian cells by intensifying the interaction between the 40S ribosome subunit,whic...A recent study published in Nature has uncovered a novel regulatory mechanism that enhances start-codon selection during mitosis in mammalian cells by intensifying the interaction between the 40S ribosome subunit,which binds messenger RNA(mRNA)and initiates translation,and the eukaryotic translation initiation factor 1(eIF1),a central regulator of start-codon selection.1 This discovery reveals a sophisticated layer of translational control that helps maintain cell viability and cell cycle stability,with potential implications for understanding cellular regulation and improving cancer therapies.展开更多
The most difficult problem in hot gas desulfurization in Integrated Coal Gasification Combined Cycle （IGCC） is the pulverization of sulfur removal sorbents.Appropriate binders for hot gas sulfur removal sorbents can...The most difficult problem in hot gas desulfurization in Integrated Coal Gasification Combined Cycle （IGCC） is the pulverization of sulfur removal sorbents.Appropriate binders for hot gas sulfur removal sorbents can solve the pulverization problem.In this paper,six sorbents with binders of different argillaceous minerals were prepared by mechanical mixing method.Desulfurization behavior for hot gas desulfurization sorbents was investigated in a fixed-bed reactor.Result showed that sorbent NTKW2 with binder of clay had a better sulfidation performance.NTKW2 had a more stable performance than other sorbents in the continuous sulfidation-regeneration cycles.Sulfur capacity of sorbent remained the same in each cycle.The desulfurization efficiency and mechanical strength of NTKW2 were the best among the tested sorbents.The behavior of NTKW2 at different temperatures showed different performances,and the best reaction temperature was 550 ℃.Higher heat stability,sulfur capacity and desulfurization efficiency were found on NTKW2 in six continuous sulfidation-regeneration cycles.展开更多
A combined system including a solid oxide fuel cell(SOFC)and an internal combustion engine(ICE)is proposed in this paper.First,a 0-D model of SOFC and a 1-D model of ICE are built as agent models.Second,parameter anal...A combined system including a solid oxide fuel cell(SOFC)and an internal combustion engine(ICE)is proposed in this paper.First,a 0-D model of SOFC and a 1-D model of ICE are built as agent models.Second,parameter analysis of the system is conducted based on SOFC and ICE models.Results show that the number of cells,current density,and fuel utilization can influence SOFC and ICE.Moreover,a deep neural network is applied as a data-driven model to conduct optimized calculations efficiently,as achieved by the particle swarm optimization algorithm in this paper.The results demonstrate that the optimal system efficiency of 51.8%can be achieved from a 22.4%/77.6%SOFC-ICE power split at 6000 kW power output.Furthermore,promising improvements in efficiency of 5.1%are achieved compared to the original engine.Finally,a simple economic analysis model,which shows that the payback period of the optimal system is 8.41 years,is proposed in this paper.展开更多
A new conceptual water-gas-shift(WGS) process is designed for integrated gasification combined cycle(IGCC), using membrane reactor(MR) equipped with H2-permselective zeolite membranes for the WGS reaction.The new proc...A new conceptual water-gas-shift(WGS) process is designed for integrated gasification combined cycle(IGCC), using membrane reactor(MR) equipped with H2-permselective zeolite membranes for the WGS reaction.The new process makes it possible to capture CO2 before power generation process by converting CO in the syngas to CO2 which can be collected after WGS reaction. The new process also produces purer H2 for combustion in gas turbine. Conceptual design of the MR, mass and heat balance analysis, and cost estimation of the new process are also provided in this paper.展开更多
The sustainable design approach presented in this paper supports an increased commitment to environmental stewardship and conservation, and results in an optimal balance of cost, environmental, societal, and human ben...The sustainable design approach presented in this paper supports an increased commitment to environmental stewardship and conservation, and results in an optimal balance of cost, environmental, societal, and human benefits while meeting the mission and function of the intended space structure. The aim of this paper is to develop the guidelines that could be applied in the design of a space structure in order to achieve the optimal overall lifetime performance of the space structure. Space structures are more than inanimate hunks of metal, glass and fabric. Every space structure that we design as structural engineers is like a child - a child that is conceived with a passionate vision of its form, structure and purpose; nurtured through the schematic design phase and the development of construction documents; and cared for during the labor pains of plan check corrections, requests for information, shop drawing review, and construction observation. Like children, our space structures mature, perform necessary functions during their lives, and eventually, grow old and die. The design of a sustainable space structure is a much more challenging and cross-disciplinary process than in the past and therefore it is necessary that the space structure is viewed as an integrated system and that all members of the design team work in a fully integrated fashion.展开更多
China has a huge demand for energy.Under the present energy structure of rich coal,lean oil,less gas,limited and low-rising rate renewable energy,discussion focus is now on the high-efficient mining of coal as well as...China has a huge demand for energy.Under the present energy structure of rich coal,lean oil,less gas,limited and low-rising rate renewable energy,discussion focus is now on the high-efficient mining of coal as well as its clean-and-low-carbon use.In view of this,based on an analysis of the problems in the coal chemical industry and the present coal utilization ways such as Integrated Gasification Combined Cycle(IGCC),this paper proposes that underground coal gasification(UCG)technology is a realistic choice.By virtue of its advantages in many aspects such as safety&environment,integrated use of superior resources,economic feasibility,etc.this technology can serve as the front-end support and guarantee for coal chemical industry and IGCC.Under the present situation,the following proposals were presented to promote the development of this technology.First,R&D of technical products should be strengthened,a comprehensive feasibility study assessment system should be established,and the relevant criteria in the industry should be formulated.Second,precise market positioning of UCG products should be made with much concern on the integrated economic indicators of each product's complete flow scheme,following the principle of“Technical Feasibility First,Economic Optimization Followed”.Third,a perfect operation and management pattern should be established with strict control over high-efficient,environmentally-friendly,safe,harmonious&compact objectives in the whole industry chain.In conclusion,to realize the large-scale UCG commercial production will strongly promote the optimization and innovation of fossil fuels supply-side economics in China.展开更多
The current studies on power plant technologies suggest that Integrated Gasification Combined Cycle(IGCC)systems are an effective and economic CO_(2) capture technology pathway.In addition,the system in conventional c...The current studies on power plant technologies suggest that Integrated Gasification Combined Cycle(IGCC)systems are an effective and economic CO_(2) capture technology pathway.In addition,the system in conventional configuration has the advantage of being more“CO_(2) capture ready”than other technologies.Pulverized coal boilers(PC)have,however,proven high technical performance attributes and are economically often most practical technologies.To highlight the pros and cons of both technologies in connection with an integrated CO_(2) capture,a comparative analysis of ultrasupercritical PC and IGCC is carried out in this paper.The technical design,the mass and energy balance and the system optimizations are implemented by using the ECLIPSE chemical plant simulation software package.Built upon these technologies,the CO_(2) capture facilities are incorporated within the system.The most appropriate CO_(2) capture systems for the PC system selected for this work are the oxy-fuel system and the postcombustion scheme using Monoethanolamine solvent scrubber column(MEA).The IGCC systems are designed in two configurations:Water gas shift reactor and Selexol-based separation.Both options generate CO_(2)-rich and hydrogen rich-gas streams.Following the comparative analysis of the technical performance attributes of the above cycles,the economic assessment is carried out using the economic toolbox of ECLIPSE is seamlessly connected to the results of the mass and energy balance as well as the utility usages.The total cost assessment is implemented according to the stepcount exponential costing method using the dominant factors and/or a combination of parameters.Subsequently,based on a set of assumptions,the net present value estimation is implemented to calculate the breakeven electricity selling prices and the CO_(2) avoidance cost.展开更多
The existence and uniqueness of limit cycle for the E 1 3 type of cubic systems with two integral straight lines has been studied in this paper. It is found that the system has no limit cycle when the two int...The existence and uniqueness of limit cycle for the E 1 3 type of cubic systems with two integral straight lines has been studied in this paper. It is found that the system has no limit cycle when the two integral straight lines intersect each other; it has a unique limit cycle when the two integral straight lines are paralleled. The sufficient and necessary conditions are also given to guarantee the existence of the unique limit cycle.展开更多
In 2023,1888 Mt of steel were produced worldwide,with 70%via integrated cycle steel plant,generating 34 Mt of dust and 25 Mt of sludge.These wastes are rich in Fe and C but are too fine for direct recycling.Agglomerat...In 2023,1888 Mt of steel were produced worldwide,with 70%via integrated cycle steel plant,generating 34 Mt of dust and 25 Mt of sludge.These wastes are rich in Fe and C but are too fine for direct recycling.Agglomeration is therefore essential to recycle them as suitable feedstock.This work studies how water-powder interactions affect the mechanical(impact resistance,cold compressive strength)and metallurgical(degree of reduction,swelling)properties of self-reducing briquettes made by combining two iron-bearing dusts(BOF dust and a secondary dust)with two reducing agents(BF sludge and another secondary dust)to form hydrophilic-hydrophilic,hydrophobic-hydrophilic,and hydrophobic-hydrophobic mixtures.Water expelled from hydrophobic dust acts as a lubricant during compaction,reducing surface cracks and enhancing eight times the impact resistance.Hydrophilic particles,however,lower impact resistance(failing 10-drop tests)due to hydration repulsion that weakens the briquette.While water absorbed by hydrophilic powders forms gasification channels on drying,enabling a reduction degree up to 94%,it also causes severe swelling below 1200℃.The best overall performance was achieved by a hydrophobic-hydrophilic combination with double water content,yielding compressive strength of 18 MPa,degree of reduction of 91%and swelling of-1.86%.展开更多
基金supported by the National Natural Science Foundation of China (51076155)Science & Technology Program of Guangdong Province(2009B050600006)
文摘The equilibrium hydrate formation conditions for CO2/H2 gas mixtures with different CO2 concentrations in 0.29 mol% TBAB aqueous solution are firstly measured.The results illustrate that the equilibrium hydrate formation pressure increases remarkably with the decrease of CO2 concentration in the gas mixture.Based on the phase equilibrium data,a three stages hydrate CO2 separation from integrated gasification combined cycle （IGCC） synthesis gas is investigated.Because the separation efficiency is quite low for the third hydrate separation,a hybrid CO2 separation process of two hydrate stages in conjunction with one chemical absorption process （absorption with MEA） is proposed and studied.The experimental results show H2 concentration in the final residual gas released from the three stages hydrate CO2 separation process was approximately 95.0 mol% while that released from the hybrid CO2 separation process was approximately 99.4 mol%.Thus,the hybrid process is possible to be a promising technology for the industrial application in the future.
基金supported by the National Key Research and Development Program of China (No. 2017YFA0207204)
文摘Phosphorus （P） reserve, largely derived from phosphate rock, is essential for crop growth to support the growing world population. However, a significant proportion of phosphorus used as a fertilizer runs into natural waters, causing eutro- phication and ecological damage. Moreover, most P in the food is eventually discharged as waste after being digested by human and animals. Thus, industrial activities have created a one-way flow of non-renewable P from rocks to farms to lakes, rivers and oceans.
文摘A recent study published in Nature has uncovered a novel regulatory mechanism that enhances start-codon selection during mitosis in mammalian cells by intensifying the interaction between the 40S ribosome subunit,which binds messenger RNA(mRNA)and initiates translation,and the eukaryotic translation initiation factor 1(eIF1),a central regulator of start-codon selection.1 This discovery reveals a sophisticated layer of translational control that helps maintain cell viability and cell cycle stability,with potential implications for understanding cellular regulation and improving cancer therapies.
基金supported by the National Key Fundamental Research Project of Science and Technology (973,No.G1999022104-1)NSFC (No.29976029)the National 95 plane (No.97-A26-03-02-02)
文摘The most difficult problem in hot gas desulfurization in Integrated Coal Gasification Combined Cycle （IGCC） is the pulverization of sulfur removal sorbents.Appropriate binders for hot gas sulfur removal sorbents can solve the pulverization problem.In this paper,six sorbents with binders of different argillaceous minerals were prepared by mechanical mixing method.Desulfurization behavior for hot gas desulfurization sorbents was investigated in a fixed-bed reactor.Result showed that sorbent NTKW2 with binder of clay had a better sulfidation performance.NTKW2 had a more stable performance than other sorbents in the continuous sulfidation-regeneration cycles.Sulfur capacity of sorbent remained the same in each cycle.The desulfurization efficiency and mechanical strength of NTKW2 were the best among the tested sorbents.The behavior of NTKW2 at different temperatures showed different performances,and the best reaction temperature was 550 ℃.Higher heat stability,sulfur capacity and desulfurization efficiency were found on NTKW2 in six continuous sulfidation-regeneration cycles.
文摘A combined system including a solid oxide fuel cell(SOFC)and an internal combustion engine(ICE)is proposed in this paper.First,a 0-D model of SOFC and a 1-D model of ICE are built as agent models.Second,parameter analysis of the system is conducted based on SOFC and ICE models.Results show that the number of cells,current density,and fuel utilization can influence SOFC and ICE.Moreover,a deep neural network is applied as a data-driven model to conduct optimized calculations efficiently,as achieved by the particle swarm optimization algorithm in this paper.The results demonstrate that the optimal system efficiency of 51.8%can be achieved from a 22.4%/77.6%SOFC-ICE power split at 6000 kW power output.Furthermore,promising improvements in efficiency of 5.1%are achieved compared to the original engine.Finally,a simple economic analysis model,which shows that the payback period of the optimal system is 8.41 years,is proposed in this paper.
文摘A new conceptual water-gas-shift(WGS) process is designed for integrated gasification combined cycle(IGCC), using membrane reactor(MR) equipped with H2-permselective zeolite membranes for the WGS reaction.The new process makes it possible to capture CO2 before power generation process by converting CO in the syngas to CO2 which can be collected after WGS reaction. The new process also produces purer H2 for combustion in gas turbine. Conceptual design of the MR, mass and heat balance analysis, and cost estimation of the new process are also provided in this paper.
文摘The sustainable design approach presented in this paper supports an increased commitment to environmental stewardship and conservation, and results in an optimal balance of cost, environmental, societal, and human benefits while meeting the mission and function of the intended space structure. The aim of this paper is to develop the guidelines that could be applied in the design of a space structure in order to achieve the optimal overall lifetime performance of the space structure. Space structures are more than inanimate hunks of metal, glass and fabric. Every space structure that we design as structural engineers is like a child - a child that is conceived with a passionate vision of its form, structure and purpose; nurtured through the schematic design phase and the development of construction documents; and cared for during the labor pains of plan check corrections, requests for information, shop drawing review, and construction observation. Like children, our space structures mature, perform necessary functions during their lives, and eventually, grow old and die. The design of a sustainable space structure is a much more challenging and cross-disciplinary process than in the past and therefore it is necessary that the space structure is viewed as an integrated system and that all members of the design team work in a fully integrated fashion.
文摘China has a huge demand for energy.Under the present energy structure of rich coal,lean oil,less gas,limited and low-rising rate renewable energy,discussion focus is now on the high-efficient mining of coal as well as its clean-and-low-carbon use.In view of this,based on an analysis of the problems in the coal chemical industry and the present coal utilization ways such as Integrated Gasification Combined Cycle(IGCC),this paper proposes that underground coal gasification(UCG)technology is a realistic choice.By virtue of its advantages in many aspects such as safety&environment,integrated use of superior resources,economic feasibility,etc.this technology can serve as the front-end support and guarantee for coal chemical industry and IGCC.Under the present situation,the following proposals were presented to promote the development of this technology.First,R&D of technical products should be strengthened,a comprehensive feasibility study assessment system should be established,and the relevant criteria in the industry should be formulated.Second,precise market positioning of UCG products should be made with much concern on the integrated economic indicators of each product's complete flow scheme,following the principle of“Technical Feasibility First,Economic Optimization Followed”.Third,a perfect operation and management pattern should be established with strict control over high-efficient,environmentally-friendly,safe,harmonious&compact objectives in the whole industry chain.In conclusion,to realize the large-scale UCG commercial production will strongly promote the optimization and innovation of fossil fuels supply-side economics in China.
文摘The current studies on power plant technologies suggest that Integrated Gasification Combined Cycle(IGCC)systems are an effective and economic CO_(2) capture technology pathway.In addition,the system in conventional configuration has the advantage of being more“CO_(2) capture ready”than other technologies.Pulverized coal boilers(PC)have,however,proven high technical performance attributes and are economically often most practical technologies.To highlight the pros and cons of both technologies in connection with an integrated CO_(2) capture,a comparative analysis of ultrasupercritical PC and IGCC is carried out in this paper.The technical design,the mass and energy balance and the system optimizations are implemented by using the ECLIPSE chemical plant simulation software package.Built upon these technologies,the CO_(2) capture facilities are incorporated within the system.The most appropriate CO_(2) capture systems for the PC system selected for this work are the oxy-fuel system and the postcombustion scheme using Monoethanolamine solvent scrubber column(MEA).The IGCC systems are designed in two configurations:Water gas shift reactor and Selexol-based separation.Both options generate CO_(2)-rich and hydrogen rich-gas streams.Following the comparative analysis of the technical performance attributes of the above cycles,the economic assessment is carried out using the economic toolbox of ECLIPSE is seamlessly connected to the results of the mass and energy balance as well as the utility usages.The total cost assessment is implemented according to the stepcount exponential costing method using the dominant factors and/or a combination of parameters.Subsequently,based on a set of assumptions,the net present value estimation is implemented to calculate the breakeven electricity selling prices and the CO_(2) avoidance cost.
文摘The existence and uniqueness of limit cycle for the E 1 3 type of cubic systems with two integral straight lines has been studied in this paper. It is found that the system has no limit cycle when the two integral straight lines intersect each other; it has a unique limit cycle when the two integral straight lines are paralleled. The sufficient and necessary conditions are also given to guarantee the existence of the unique limit cycle.
文摘In 2023,1888 Mt of steel were produced worldwide,with 70%via integrated cycle steel plant,generating 34 Mt of dust and 25 Mt of sludge.These wastes are rich in Fe and C but are too fine for direct recycling.Agglomeration is therefore essential to recycle them as suitable feedstock.This work studies how water-powder interactions affect the mechanical(impact resistance,cold compressive strength)and metallurgical(degree of reduction,swelling)properties of self-reducing briquettes made by combining two iron-bearing dusts(BOF dust and a secondary dust)with two reducing agents(BF sludge and another secondary dust)to form hydrophilic-hydrophilic,hydrophobic-hydrophilic,and hydrophobic-hydrophobic mixtures.Water expelled from hydrophobic dust acts as a lubricant during compaction,reducing surface cracks and enhancing eight times the impact resistance.Hydrophilic particles,however,lower impact resistance(failing 10-drop tests)due to hydration repulsion that weakens the briquette.While water absorbed by hydrophilic powders forms gasification channels on drying,enabling a reduction degree up to 94%,it also causes severe swelling below 1200℃.The best overall performance was achieved by a hydrophobic-hydrophilic combination with double water content,yielding compressive strength of 18 MPa,degree of reduction of 91%and swelling of-1.86%.
