Molten salt gasification is a promising technology for biomass conversion due to its advantages of superior heat transfer and the ability of utilizing solar energy to reduce carbon emission.In this study,the character...Molten salt gasification is a promising technology for biomass conversion due to its advantages of superior heat transfer and the ability of utilizing solar energy to reduce carbon emission.In this study,the characteristics of corncob CO_(2)-gasification in molten salt environments is thoroughly investigated,and the approach of introducing Fe_(2)O_(3) as catalyst to enhance the syngas yield is proposed.The results showed that the molten salts significantly promoted the conversion of corncob into gaseous products with very low tar and char yield.Compared to O_(2) and H_(2)O atmospheres,utilizing CO_(2) as gasifying agent enhanced the yield of gaseous products during the corncob gasification,especially the yields of CO and H_(2).The introduction of Fe_(2)O_(3) as a catalyst could further increase the yield of gaseous products and the cold gas efficiency(CGE),and the yield of syngas was increased into 2258.3 ml·g^(−1) with a high CGE of 105.8%in 900℃.The findings evidenced that CO_(2) gasification in the molten salt environment with Fe_(2)O_(3) addition can promote the cracking of tar,increasing the syngas yield significantly.Moreover,the energy required to drive the gasification process was calculated,and the total energy consumption was calculated as 16.83 GJ·t^(−1).The study opened up a new solution for the biomass gasification,exhibiting a great potential in distributed energy or chemical systems.展开更多
Present industrial decarbonization technologies require an active CO_(2)-concentration system,often based on lime reaction or amine binding reactions,which is energy intensive and carries a high CO_(2)-footprint.Here ...Present industrial decarbonization technologies require an active CO_(2)-concentration system,often based on lime reaction or amine binding reactions,which is energy intensive and carries a high CO_(2)-footprint.Here instead,an effective process without active CO_(2)concentration is demonstrated in a new process-termed IC2CNT(Insulationdiffusion facilitated CO_(2) to Carbon Nanomaterial Technology)decarbonization process.Molten carbonates such as Li_(2)CO_(3)(mp 723℃)are highly insoluble to industrial feed gas principal components(N2,O_(2),and H2O).However,CO_(2) can readily dissolve and react in molten carbonates.We have recently characterized high CO_(2) diffusion rates through porous aluminosilicate and calcium-magnesium silicate thermal insulations.Here,the CO_(2) in ambient feed gas passes through these membranes into molten Li_(2)CO_(3).The membrane also concurrently insulates the feed gas from the hot molten carbonate chamber,obviating the need to heat the(non-CO_(2))majority of the feed gas to high temperature.In this insulation facilitated decarbonization process CO_(2)is split by electrolysis in the molten carbonate producing sequestered,high-purity carbon nanomaterials(such as CNTs)and O_(2).展开更多
A static corrosion experiment of 347H stainless steel alloyed with elements Cu and Mo was carried out in a nitrate molten salt(60%NaNO_(3)+40%KNO_(3))at 565℃ for 720 h.The effects of elements Cu and Mo on the corrosi...A static corrosion experiment of 347H stainless steel alloyed with elements Cu and Mo was carried out in a nitrate molten salt(60%NaNO_(3)+40%KNO_(3))at 565℃ for 720 h.The effects of elements Cu and Mo on the corrosion resistance of 347H stainless steel in molten salt were investigated by analyzing the phase composition,microstructure and chemical composition of the corrosion products.The results show that the grain refinement induced by element Mo imparts the stainless steel with optimal corrosion resistance at a medium grain size.Furthermore,the formation of MoC significantly enhances the intergranular corrosion resistance of the stainless steel.The stainless steel exhibits uniform corrosion in the nitrate solution.The corrosion layer displays a dual-layer structure,and the corrosion products protecting matrix are present in both the inner and outer layers.The outer layer consists of a mixture of Fe oxides(Fe_(2)O_(3),Fe_(3)O_(4)),NaFeO_(2),and a minor amount of MgFe_(2)O_(4).Conversely,the inner layer is primarily composed of a spinel layer(FeCr_(2)O_(4),MgCr_(2)O_(4))and a thin Cu_(2)O layer.The oxidation of Cu in the inner layer leads to the formation of a dense Cu_(2)O layer,effectively impeding O_(2)-plasma infiltration into the matrix.展开更多
Herein, the electrochemical behaviors of Sr on inert W electrode and reactive Zn/Al electrodes were systematically investig-ated in LiCl–KCl–SrCl2molten salts at 773 K using various electrochemical methods. The chem...Herein, the electrochemical behaviors of Sr on inert W electrode and reactive Zn/Al electrodes were systematically investig-ated in LiCl–KCl–SrCl2molten salts at 773 K using various electrochemical methods. The chemical reaction potentials of Li and Sr on re-active Zn/Al electrodes were determined. We observed that Sr could be extracted by decreasing the activity of the deposited metal Sr onthe reactive electrode, although the standard reduction potential of Sr(II)/Sr was more negative than that of Li(I)/Li. The electrochemicalextraction products of Sr on reactive Zn and Al electrodes were Zn13Sr and Al4Sr, respectively, with no codeposition of Li observed.Based on the density functional theory calculations, both Zn13Sr and Al4Sr were identified as stable intermetallic compounds with Zn-/Al-rich phases. In LiCl–KCl molten salt containing 3wt% SrCl2, the coulombic efficiency of Sr in the Zn electrode was ~54%. The depolar-ization values for Sr on Zn and Al electrodes were 0.864 and 0.485 V, respectively, exhibiting a stronger chemical interaction between Znand Sr than between Al and Sr. This study suggests that using reactive electrodes can facilitate extraction of Sr accumulated while elec-trorefining molten salts, thereby enabling the purification and reuse of the salt and decreasing the volume of the nuclear waste.展开更多
Owing to the worldwide trend towards carbon neutrality,the number of Dy-containing heat-resistant Nd magnets used for wind power generation and electric vehicles is expected to increase exponentially.However,rare eart...Owing to the worldwide trend towards carbon neutrality,the number of Dy-containing heat-resistant Nd magnets used for wind power generation and electric vehicles is expected to increase exponentially.However,rare earth(RE)elements(especially Dy)are unevenly distributed globally.Therefore,an environmental-friendly recycling method for RE elements with a highly precise separation of Dy and Nd from end-of-life magnets is required to realize a carbon-neutral society.As an alternative to traditional hydrometallurgical RE separation techniques with a high environmental load,we designed a novel,highly efficient,and precise process for the separation and recycling of RE elements from magnet scrap.As a result,over 90%of the RE elements were efficiently extracted from the magnets using MgCl_(2)and evaporation loss was selectively suppressed by adding CaF_(2).The extracted RE elements were electrolytically separated based on the formation potential differences of the RE alloys.Nd and Dy metals with purities greater than 90%were estimated to be recovered at rates of 96%and 91%,respectively.Almost all the RE in the scraps could be separated and recycled as RE metals,and the byproducts were easily removed.Thus,this process is expected to be used on an industrial scale to realize a carbon-neutral society.展开更多
Molten salt reactors(MSRs)are a promising candidate for Generation IV reactor technologies,and the small modular molten salt reactor(SM-MSR),which utilizes low-enriched uranium and thorium fuels,is regarded as a wise ...Molten salt reactors(MSRs)are a promising candidate for Generation IV reactor technologies,and the small modular molten salt reactor(SM-MSR),which utilizes low-enriched uranium and thorium fuels,is regarded as a wise development path to accelerate deployment time.Uncertainty and sensitivity analyses of accidents guide nuclear reactor design and safety analyses.Uncertainty analysis can ascertain the safety margin,and sensitivity analysis can reveal the correlation between accident consequences and input parameters.Loss of forced cooling(LOFC)represents an accident scenario of the SM-MSR,and the study of LOFC could offer useful information to improve physical thermohydraulic and structural designs.Therefore,this study investigates the uncertainty of LOFC consequences and the sensitivity of related parameters.The uncertainty of the LOFC consequences was analyzed using the Monte Carlo method,and multiple linear regression was employed to analyze the sensitivity of the input parameters.The uncertainty and sensitivity analyses showed that the maximum reactor outlet fuel salt temperature was 725.5℃,which is lower than the acceptable criterion,and five important parameters influencing LOFC consequences were identified.展开更多
Large-sized titanium alloy ingots produced by vacuum arc remelting(VAR)technology are susceptible to metallurgical imperfections such as compositional segregation,inconsistent solidification microstructures,black spot...Large-sized titanium alloy ingots produced by vacuum arc remelting(VAR)technology are susceptible to metallurgical imperfections such as compositional segregation,inconsistent solidification microstructures,black spots,and inclusions.These defects are intricately linked to the electromagnetic effects,temperature distribution,and fluid dynamics during the melting process.The self-induced magnetic field created by the electric current,along with the axial magnetic field applied to stabilize the arc,significantly influences the solidification of titanium alloy ingots.A mathematical model optimized for the integrated analysis of multiple fields—electromagnetic,fluid,and thermal—was developed for the VAR solidification process of titanium alloys.The influence mechanism of electromagnetic field on the macroscopic solidification process of titanium alloy was investigated.The findings indicate the presence of two competing forces within the VAR molten pool,namely,thermal buoyancy and the Lorentz force.Introducing a coupled self-induced magnetic field and elevating the current to 15 kA led to an increase in the molten pool depth by 42.9%and a reduction in the thickness of the mushy zone by 25.2%.The application of a constant axial magnetic field enhances a unidirectional momentum buildup within the molten pool,thereby enhancing the flow velocity and cooling efficiency of melt.展开更多
Within the framework of carbon neutrality,lithium-ion batteries(LIBs)are progressively booming along with the growing utilization of green and clean energy.However,the extensive application of LIBs with limited lifesp...Within the framework of carbon neutrality,lithium-ion batteries(LIBs)are progressively booming along with the growing utilization of green and clean energy.However,the extensive application of LIBs with limited lifespan has brought about a significant recycling dilemma.The traditional hydrometallurgical or pyrometallurgical strategies are not capable to maximize the output value of spent LIBs and minimize the potential environmental hazards.Herein,to alternate the tedious and polluting treatment processes,we propose a high-temperature molten-salt strategy to directly regenerate spent cathodes of LIBs,which can also overcome the barrier of the incomplete defects'restoration with previous low-temperature molten salts.The high-energy and stable medium environment ensures a more thorough and efficient relithiation reaction,and simultaneously provides sufficient driving force for atomic rearrangement and grains secondary growth.In consequence,the regenerated ternary cathode(R-NCM)exhibits significantly enhanced structural stability that effectively suppresses the occurrence of cracks and harmful side reactions.The R-NCM delivers excellent cycling stability,retaining 81.2%of its capacity after 200 cycles at 1 C.This technique further optimizes the traditional eutectic molten-salt approach,broadening its applicability and improving regenerated cathode performance across a wider range of conditions.展开更多
The synergistic effects of irradiation and tensile deformation on the corrosion behavior of the GH3535 alloy in FLi-NaK molten salt were explored.Helium bubbles were introduced into the GH3535 alloy,followed by mechan...The synergistic effects of irradiation and tensile deformation on the corrosion behavior of the GH3535 alloy in FLi-NaK molten salt were explored.Helium bubbles were introduced into the GH3535 alloy,followed by mechanical loading with the plastic strain up to 10%.After immersion in molten salt for 300 h,all the samples exhibited a corrosion-induced Cr depletion layer.The depth of the Cr depletion layer increased by 40% for the alloy with helium ion irradiation and 10% plastic deformation,compared with that for the only corroded sample.Moreover,the proportion of large-sized helium bubbles increased with plastic deformation.These results indicate that the coupling effects of irradiation and tensile deformation accelerate the corrosion of the GH3535 alloy.In addition,in a molten salt environment,an unexpected outward migration behavior of helium bubbles was observed under different plastic deformation.Helium bubbles migrated closer to the surface as the strain increased up to 3%,while the migration depth declined when the strain reached 10%.This is ascribed to the interaction between deformation-induced dislocations and helium bubbles.展开更多
Direct utilization of co-existed ferrous oxide(FeO)dust in CO_(2)flue gas from the steel industry to product value-added materials is yet to be established.Inspired by the form of CaO-CaCO_(3)as natural carbon cycle a...Direct utilization of co-existed ferrous oxide(FeO)dust in CO_(2)flue gas from the steel industry to product value-added materials is yet to be established.Inspired by the form of CaO-CaCO_(3)as natural carbon cycle and the high oxide dissolution capacity of molten salts,CaO is herein introduced into the affordable molten NaCl-CaCl_(2)-FeO salt to generate CO_(3)^(2-)through an efficient capture of CO_(2).The subsequent coelectrolysis of FeO and CO_(3)^(2-)successfully produces cathodic Fe-encapsulated carbon nanotubes(Fe@CNT)with enhanced energy efficiency(current efficiency of 83.1%for CO_(2)reduction and energy consumption of 22.49 kWh kg^(1)for Fe@CNT generation).The in-situ capture of CO_(2)by O^(2)generated from the electro-deoxidation of FeO bridges the electrolysis of CO_(2)and FeO,rendering the enhanced current efficiency of the co-electrolysis and template-free generation of Fe@CNT.When evaluated as functional materials for electromagnetic wave absorption,the Fe@CNT integrates dielectric loss of CNT and electromagnetic loss from Fe.The Fe well-defined in CNT induces the synergistic loss and further improves the impedance matching,resulting in excellent electromagnetic wave absorption performance.The coelectrolysis establishes a promising strategy for converting CO_(2)into highly functional materials directly from CO_(2)-containing flue gas from steel industrial without dust removal.展开更多
Single crystalline nickel rich Li[Ni_(x)Co_(y)Mn_(1-x–y)]O_(2)(SCNCM)layered oxide cathodes show higher ionic conductivity and better structure integrity than polycrystalline NCM(PCNCM)cathodes by eliminating grain b...Single crystalline nickel rich Li[Ni_(x)Co_(y)Mn_(1-x–y)]O_(2)(SCNCM)layered oxide cathodes show higher ionic conductivity and better structure integrity than polycrystalline NCM(PCNCM)cathodes by eliminating grain boundaries.However,it remains challenges in the controlled synthesis process and restricted cycling stability of SCNCM.Herein,take single crystalline nickel rich Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)(SC811)as an example,a dual molten salts(LiOH and Li_(2)SO_(4))assisted secondary calcination method is proposed,for which LiOH salt improves primary crystal size and Li_(2)SO_(4)prevents the aggravation of NCM nanocrystals.To further reduce the interfacial side reactions,Mg-doping and B-coating surface modification was carried out,which effectively suppress anisotropic lattice changes and Li/Ni disorder.In addition,a thin and uniform H_(3)BO_(3)coating effectively prevents direct contact between the electrode and electrolyte,thus reducing harmful parasitic reactions.The single crystal structure engineering and surface modification strategy of oxide layered cathodes significantly improve the cycling stability of the modified SC811 cathode.For example,during a long-term cycling of 470 cycles,a high-capacity retention of 74.2%obtained at 1C rate.Our work provides a new strategy for engineering high energy nickel rich layered oxide NCM cathodes.展开更多
A new flow control technology in continuous casting process named permanent magnet flow control-mold(PMFC-Mold)was proposed,in which the permanent magnets are arranged in Halbach array near the narrow region of the mo...A new flow control technology in continuous casting process named permanent magnet flow control-mold(PMFC-Mold)was proposed,in which the permanent magnets are arranged in Halbach array near the narrow region of the mold.The behavior of molten steel flow and the fluctuation of molten steel/slag interface in the PMFC-Mold under different continuous casting speeds were investigated.Firstly,a physical experiment of liquid Ga-In-Sn alloy circulating flow was carried out in Perspex mold with Halbach’s permanent magnets(HPMs)to investigate the magnetic field distribution of HPMs and its impactful electromagnetic braking effect.The numerical simulation of 1450 mm×230 mm slab shows that a stronger magnetic field over 0.3-0.625 T is formed at the wide surface and the narrow surface of the mold,which provides an effective electromagnetic braking for controlling the impingement of molten steel jet and suppressing the fluctuation of molten steel/slag interface.The numerical simulation results show that in the PMFC-Mold,the region with the turbulent kinetic energy greater than 0.01 and 0.04 m^(2)s^(-2)on the upper backflow zone and near the narrow surface of the mold are significantly reduced.The maximum turbulent kinetic energy of the submerged entry nozzle(SEN)jet in front of the narrow surface is significantly reduced,and the SEN jet moves downward before impacting the narrow surface of the mold.In the PMFC-Mold,the region with the surface velocity greater than 0.2 m s^(-1)on the steel/slag interface is eliminated,the flow pattern and fluctuation profiles on the molten steel/slag interface become regular on both sides of SEN,and the vortex near SEN disappears.The maximum fluctuation height of molten steel/slag interface is controlled below 2.59 and 5.40 mm corresponding to the casting speed of 1.6 and 2.0 m min-1,respectively.展开更多
The thermocline energy storage tank(TEST)serves as a crucial component in thermal energy storage systems,utilizing the working fluid that enters through a diffuser to store and harness energy.However,the conventional ...The thermocline energy storage tank(TEST)serves as a crucial component in thermal energy storage systems,utilizing the working fluid that enters through a diffuser to store and harness energy.However,the conventional double-plate radial diffuser is ill-suited for a single-medium TEST’s full tank storage due to its unidirectional fluid inflow.There has been a notable lack of optimization analysis of diffusers.Two innovative tubular diffuser designs with reduced cross-sectional areas have been introduced:the annular-arranged diffuser(AAD)and the cross-arranged diffuser(CAD).To elucidate the impact of diffuser designs on energy storage efficiency,a 3D transient computational fluid dynamics(CFD)model was established to simulate a thermocline formation under two diffuser types.The model was validated against experimental data.Results showed that the thermocline of AAD was 11.39%thinner than that of a traditional double-plate diffuser.In the process of charging and discharging,the time-varying thermocline and factors influencing thermocline thickness were analyzed.Results indicate that in the mixed dominant region,increased turbulent kinetic energy correlates with reduced thermocline thickness.Notably,the AAD’s stable thermocline was 4.23%and 5.41%thinner than the CAD’s during charging and discharging,respectively,making the AAD preferable for engineering applications.The effects of tube diameter and orifice opening angle on temperature stratification performance were also examined.The findings suggest that an inclined impact jet and large-diameter tubes are more conducive to temperature stratification.Moreover,an orifice diameter optimization method was developed,which can decrease the thermocline by 6.78%.展开更多
In photothermal power(solar energy)generation systems,purging residual molten salt from pipelines using highpressure gas poses a significant challenge,particularly in clearing the bottom of regulating valves.Ineffecti...In photothermal power(solar energy)generation systems,purging residual molten salt from pipelines using highpressure gas poses a significant challenge,particularly in clearing the bottom of regulating valves.Ineffective purging can lead to crystallization of the molten salt,resulting in blockages.To address this issue,understanding the gas-liquid two-phase flow dynamics during high-pressure gas purging is crucial.This study utilizes the Volume of Fluid(VOF)model and adaptive dynamic grids to simulate the gas-liquid two-phase flow during the purging process in a DN50 PN50 conventional molten salt regulating valve.Initially,the reliability of the CFD simulations is validated through comparisons with experimental data and findings from the literature.Subsequently,simulation experiments are conducted to analyze the effects of various factors,including purge flow rates,initial liquid accumulation masses,purge durations,and the profiles of the valve bottom flow channels.The results indicate that the purging process comprises four distinct stages:Initial violent surge stage,liquid discharge stage,liquid partial fallback stage,liquid dissipation stage.For an initial liquid height of 17 mm at the bottom of the valve,the critical purge flow rate lies between 3 and 5 m/s.Notably,the critical purge flow rate is independent of the initial liquid accumulation mass.As the purge gas flow rate increases,the volume of liquid discharged also increases.Beyond the critical purge flow rate,higher purge gas velocities lead to shorter purge durations.Interestingly,the residual liquid mass after purging remains unaffected by the initial liquid accumulation.Additionally,the flow channel profile at the bottom of the valve significantly influences both the critical purge speed and the efficiency of the purging process.展开更多
Rare earth molten salt electrolytic slag(RMES)has emerged as a promising secondary resource for rare earth elements(REEs).This study introduces an innovative leaching technique for extracting REEs from RMES under atmo...Rare earth molten salt electrolytic slag(RMES)has emerged as a promising secondary resource for rare earth elements(REEs).This study introduces an innovative leaching technique for extracting REEs from RMES under atmospheric conditions,employing an alkali phase reconstruction method followed by an acid leaching process.Additionally,the external electric field was employed to enhance the reaction.Under the optimal reaction conditions:NaOH initial concentration of 70 wt%,NaOH-slag mass ratio of 4:1,temperature of 160℃,current density of 1000 A/m^(2),reaction time of 90 min,stirring speed of 300 r/min,HCl concentration of 4 mol/L,liquid-solid ratio of 15:1,and leaching time of 20 min,the leaching efficiencies of Nd and Pr reach up to 99.21%and 99.14%,respectively.Phase analysis indicates that the rare earth fluorides transform into rare earth hydroxides,significantly enhancing their solubility in acid solution.The imposition of an external electric field leads to pronounced disruption of the RMES surface,thereby promoting the formation of stable reactive oxygen species in the alkaline medium.This facilitates the decomposition of fluorinated rare earths and hastens the phase reconstruction,resulting in an enhanced leaching process.The achieved leaching efficiency with an external electric field is 37%higher than that without an electric field.展开更多
The large and dense rare earth (RE)-oxide inclusions in high-oxygen RE metal increase the risk of producing variable properties in RE steel. Consequently, a self-developed electrolysis cell was utilized for the produc...The large and dense rare earth (RE)-oxide inclusions in high-oxygen RE metal increase the risk of producing variable properties in RE steel. Consequently, a self-developed electrolysis cell was utilized for the production of low-oxygen La/Ce mischmetal. The electrolysis process and the origin of oxygen in mischmetal were comprehensively investigated. The results indicate that the reaction between La/Ce oxide and fluoride molten salt results in the formation of La/Ce oxy-fluoride. The deposition of oxy-fluoride at the bottom of the electrolysis cell is the primary factor contributing to the increased oxygen content in mischmetal. The comprehensive influence of oxide addition quantity, feeding interval, and electrolysis temperature on oxygen content, purity, and current efficiency using the response surface methodology model is revealed. The results for industrial experiment show that the purity of mishcmetal reaches higher than 99.78 wt.%, the oxygen content of mischmetal is only 0.0047 wt.% and the current efficiency of the electrolysis process achieves 80.79% under the optimized parameters of 225 kg/d, 30 s and 1069 ℃. The findings offer valuable insights into the application of molten salt electrolysis for the production of low-oxygen mischmetal.展开更多
One-dimensional titanium dioxide(TiO_(2))whiskers with controllable aspect ratios were synthesized by molten salt method adopting anatase TiO_(2)nanoparticles as precursor,sodium chloride(NaCl)and dibasic sodium phosp...One-dimensional titanium dioxide(TiO_(2))whiskers with controllable aspect ratios were synthesized by molten salt method adopting anatase TiO_(2)nanoparticles as precursor,sodium chloride(NaCl)and dibasic sodium phosphate(Na_(2)HPO_(4))as medium.The particle size of TiO_(2)nanoparticles and ratio of precursor and medium that can help to generate high aspect ratio TiO_(2)whiskers were studied and selected.Light-colored antimony-doped tin oxide@titanium dioxide(ATO@TiO_(2))conductive whiskers were prepared by coating ATO on TiO_(2)whiskers through coprecipitation then.Finally,the ATO@TiO_(2)light-colored conductive whiskers were dispersed in polyacrylonitrile(PAN)to fabricate light-colored conductive fibers.The experimental results show that the ATO@TiO_(2)whiskers exhibits ideal whiteness and conductivity with 65.5 Wb and 106Ω·cm,respectively,and the resistivity of conductive fibers was 6.07×10^(6)Ω·cm with 15wt%whisker content.展开更多
A thermal–hydraulic model was developed to analyze the three-dimensional(3D)temperature field of a graphite-moderated channel-type molten salt reactor(GMC-MSR).This model solves the temperature distribution of both t...A thermal–hydraulic model was developed to analyze the three-dimensional(3D)temperature field of a graphite-moderated channel-type molten salt reactor(GMC-MSR).This model solves the temperature distribution of both the graphite moderator and fuel salt using a single convection–diffusion equation.Heat transfer at the interface between the fuel salt and graphite was addressed by introducing an additional thermal resistance component at the interface and modifying the anisotropic thermal conductivity of the fuel salt.The mass flow distribution in different flow passages was determined by adjusting the mass flow rate until a uniform pressure drop was achieved across all fuel channels.This thermal–hydraulic model,constructed on COMSOL Multiphysics,was verified by comparing its temperature results with those from the RELAP5 code across two demonstration cases.A steady-state thermal–hydraulic simulation of this model was performed to evaluate the conceptual design of a 2-MW experimental molten salt reactor(2MW-MSR).In addition,detailed discussions of the 3D temperature field,heat flux,and mass flow distribution of the 2MW-MSR were presented.This model allows for a comprehensive 3D thermal–hydraulic analysis of the GMC-MSR.Moreover,it only requires the solution of a single convection–diffusion equation,which makes it invaluable for GMC-MSR design.展开更多
Lithium-carbon dioxide(Li-CO_(2))batteries using high ion-conductive inorganic molten salt electrolytes have recently attracted much attention due to the high energy density and potential application of carbon neutral...Lithium-carbon dioxide(Li-CO_(2))batteries using high ion-conductive inorganic molten salt electrolytes have recently attracted much attention due to the high energy density and potential application of carbon neutrality.However,the poor Li-ion conductivity of the molten-salt electrolytes at room temperature(RT)makes these batteries lose most of their capacity and power as the temperature falls below 80℃.Here,inspired by the greenhouse effect,we report an RT molten salt Li-CO_(2)battery where solar energy can be efficiently harvested and converted into heat that is further localized on the cathode consisting of plasmonic ruthenium(Ru)catalysts and Li_(2)CO_(3)-based products via a greenhouse-like phenomenon.As a result,the solar-driven molten salt Li-CO_(2)battery demonstrates a larger full discharge/charge capacity of 9.5 mA h/8.1 mA h,and a longer cycle lifespan of 250 cycles at 500 mA/g with a limited capacity of 500 mA h/g at RT than the molten salt Li-CO_(2)battery at 130℃.Notably,the average temperature of the cathode increases by 8℃ after discharge to 0.75 mA h,which indicates the infrared radiation from Ru catalysts can be effectively suppressed by discharged Li_(2)CO_(3)-based products.This battery technology paves the way for developing low-temperature molten salt energy storage devices.展开更多
A nonlinear dynamic simulation model based on coordinated control of speed and flow rate for the molten salt reactor and combined cycle systems is proposed here to ensure the coordination and stability between the mol...A nonlinear dynamic simulation model based on coordinated control of speed and flow rate for the molten salt reactor and combined cycle systems is proposed here to ensure the coordination and stability between the molten salt reactor and power system.This model considers the impact of thermal properties of fluid variation on accuracy and has been validated with Simulink.This study reveals the capability of the control system to compensate for anomalous situations and maintain shaft stability in the event of perturbations occurring in high-temperature molten salt tank outlet parameters.Meanwhile,the control system’s impact on the system’s dynamic characteristics under molten salt disturbance is also analyzed.The results reveal that after the disturbance occurs,the controlled system benefits from the action of the control,and the overshoot and disturbance amplitude are positively correlated,while the system power and frequency eventually return to the initial values.This simulation model provides a basis for utilizing molten salt reactors for power generation and maintaining grid stability.展开更多
基金supported by the National Natural Science Foundation of China(52066007,22279048)the Major Science and Technology Project of Yunnan Province(202202AG050017).
文摘Molten salt gasification is a promising technology for biomass conversion due to its advantages of superior heat transfer and the ability of utilizing solar energy to reduce carbon emission.In this study,the characteristics of corncob CO_(2)-gasification in molten salt environments is thoroughly investigated,and the approach of introducing Fe_(2)O_(3) as catalyst to enhance the syngas yield is proposed.The results showed that the molten salts significantly promoted the conversion of corncob into gaseous products with very low tar and char yield.Compared to O_(2) and H_(2)O atmospheres,utilizing CO_(2) as gasifying agent enhanced the yield of gaseous products during the corncob gasification,especially the yields of CO and H_(2).The introduction of Fe_(2)O_(3) as a catalyst could further increase the yield of gaseous products and the cold gas efficiency(CGE),and the yield of syngas was increased into 2258.3 ml·g^(−1) with a high CGE of 105.8%in 900℃.The findings evidenced that CO_(2) gasification in the molten salt environment with Fe_(2)O_(3) addition can promote the cracking of tar,increasing the syngas yield significantly.Moreover,the energy required to drive the gasification process was calculated,and the total energy consumption was calculated as 16.83 GJ·t^(−1).The study opened up a new solution for the biomass gasification,exhibiting a great potential in distributed energy or chemical systems.
文摘Present industrial decarbonization technologies require an active CO_(2)-concentration system,often based on lime reaction or amine binding reactions,which is energy intensive and carries a high CO_(2)-footprint.Here instead,an effective process without active CO_(2)concentration is demonstrated in a new process-termed IC2CNT(Insulationdiffusion facilitated CO_(2) to Carbon Nanomaterial Technology)decarbonization process.Molten carbonates such as Li_(2)CO_(3)(mp 723℃)are highly insoluble to industrial feed gas principal components(N2,O_(2),and H2O).However,CO_(2) can readily dissolve and react in molten carbonates.We have recently characterized high CO_(2) diffusion rates through porous aluminosilicate and calcium-magnesium silicate thermal insulations.Here,the CO_(2) in ambient feed gas passes through these membranes into molten Li_(2)CO_(3).The membrane also concurrently insulates the feed gas from the hot molten carbonate chamber,obviating the need to heat the(non-CO_(2))majority of the feed gas to high temperature.In this insulation facilitated decarbonization process CO_(2)is split by electrolysis in the molten carbonate producing sequestered,high-purity carbon nanomaterials(such as CNTs)and O_(2).
基金Science and Technology Program Project of Gansu Province(21ZD3GB001)。
文摘A static corrosion experiment of 347H stainless steel alloyed with elements Cu and Mo was carried out in a nitrate molten salt(60%NaNO_(3)+40%KNO_(3))at 565℃ for 720 h.The effects of elements Cu and Mo on the corrosion resistance of 347H stainless steel in molten salt were investigated by analyzing the phase composition,microstructure and chemical composition of the corrosion products.The results show that the grain refinement induced by element Mo imparts the stainless steel with optimal corrosion resistance at a medium grain size.Furthermore,the formation of MoC significantly enhances the intergranular corrosion resistance of the stainless steel.The stainless steel exhibits uniform corrosion in the nitrate solution.The corrosion layer displays a dual-layer structure,and the corrosion products protecting matrix are present in both the inner and outer layers.The outer layer consists of a mixture of Fe oxides(Fe_(2)O_(3),Fe_(3)O_(4)),NaFeO_(2),and a minor amount of MgFe_(2)O_(4).Conversely,the inner layer is primarily composed of a spinel layer(FeCr_(2)O_(4),MgCr_(2)O_(4))and a thin Cu_(2)O layer.The oxidation of Cu in the inner layer leads to the formation of a dense Cu_(2)O layer,effectively impeding O_(2)-plasma infiltration into the matrix.
基金financially supported by the National Postdoctoral Program for Innovative Talents, China (No. BX2021327)the National Natural Science Foundation of China (Nos. 22206194 and U2267222)+1 种基金the Ningbo Natural Science Foundation of China (No. 2023J337)the Yongjiang Talent Introduction Programme, China (No. 2 021A-161-G)。
文摘Herein, the electrochemical behaviors of Sr on inert W electrode and reactive Zn/Al electrodes were systematically investig-ated in LiCl–KCl–SrCl2molten salts at 773 K using various electrochemical methods. The chemical reaction potentials of Li and Sr on re-active Zn/Al electrodes were determined. We observed that Sr could be extracted by decreasing the activity of the deposited metal Sr onthe reactive electrode, although the standard reduction potential of Sr(II)/Sr was more negative than that of Li(I)/Li. The electrochemicalextraction products of Sr on reactive Zn and Al electrodes were Zn13Sr and Al4Sr, respectively, with no codeposition of Li observed.Based on the density functional theory calculations, both Zn13Sr and Al4Sr were identified as stable intermetallic compounds with Zn-/Al-rich phases. In LiCl–KCl molten salt containing 3wt% SrCl2, the coulombic efficiency of Sr in the Zn electrode was ~54%. The depolar-ization values for Sr on Zn and Al electrodes were 0.864 and 0.485 V, respectively, exhibiting a stronger chemical interaction between Znand Sr than between Al and Sr. This study suggests that using reactive electrodes can facilitate extraction of Sr accumulated while elec-trorefining molten salts, thereby enabling the purification and reuse of the salt and decreasing the volume of the nuclear waste.
基金supported by a Grant-in-Aid from the Japan Society for the Promotion of Science(JSPS)Fellows(19J20301).
文摘Owing to the worldwide trend towards carbon neutrality,the number of Dy-containing heat-resistant Nd magnets used for wind power generation and electric vehicles is expected to increase exponentially.However,rare earth(RE)elements(especially Dy)are unevenly distributed globally.Therefore,an environmental-friendly recycling method for RE elements with a highly precise separation of Dy and Nd from end-of-life magnets is required to realize a carbon-neutral society.As an alternative to traditional hydrometallurgical RE separation techniques with a high environmental load,we designed a novel,highly efficient,and precise process for the separation and recycling of RE elements from magnet scrap.As a result,over 90%of the RE elements were efficiently extracted from the magnets using MgCl_(2)and evaporation loss was selectively suppressed by adding CaF_(2).The extracted RE elements were electrolytically separated based on the formation potential differences of the RE alloys.Nd and Dy metals with purities greater than 90%were estimated to be recovered at rates of 96%and 91%,respectively.Almost all the RE in the scraps could be separated and recycled as RE metals,and the byproducts were easily removed.Thus,this process is expected to be used on an industrial scale to realize a carbon-neutral society.
基金supported by the Youth Innovation Promotion Association(YIPA)(No.E329290101)of the Chinese Academy of Sciences。
文摘Molten salt reactors(MSRs)are a promising candidate for Generation IV reactor technologies,and the small modular molten salt reactor(SM-MSR),which utilizes low-enriched uranium and thorium fuels,is regarded as a wise development path to accelerate deployment time.Uncertainty and sensitivity analyses of accidents guide nuclear reactor design and safety analyses.Uncertainty analysis can ascertain the safety margin,and sensitivity analysis can reveal the correlation between accident consequences and input parameters.Loss of forced cooling(LOFC)represents an accident scenario of the SM-MSR,and the study of LOFC could offer useful information to improve physical thermohydraulic and structural designs.Therefore,this study investigates the uncertainty of LOFC consequences and the sensitivity of related parameters.The uncertainty of the LOFC consequences was analyzed using the Monte Carlo method,and multiple linear regression was employed to analyze the sensitivity of the input parameters.The uncertainty and sensitivity analyses showed that the maximum reactor outlet fuel salt temperature was 725.5℃,which is lower than the acceptable criterion,and five important parameters influencing LOFC consequences were identified.
基金financially supported by the National Natural Science Foundation of China(Nos.52422408 and 52171031)the Excellent Youth Fund of Liaoning Natural Science Foundation(No.2023JH3/10200001)the Liaoning Xingliao Talents-Top-notch Young Talents Project(No.XLYC2203064).
文摘Large-sized titanium alloy ingots produced by vacuum arc remelting(VAR)technology are susceptible to metallurgical imperfections such as compositional segregation,inconsistent solidification microstructures,black spots,and inclusions.These defects are intricately linked to the electromagnetic effects,temperature distribution,and fluid dynamics during the melting process.The self-induced magnetic field created by the electric current,along with the axial magnetic field applied to stabilize the arc,significantly influences the solidification of titanium alloy ingots.A mathematical model optimized for the integrated analysis of multiple fields—electromagnetic,fluid,and thermal—was developed for the VAR solidification process of titanium alloys.The influence mechanism of electromagnetic field on the macroscopic solidification process of titanium alloy was investigated.The findings indicate the presence of two competing forces within the VAR molten pool,namely,thermal buoyancy and the Lorentz force.Introducing a coupled self-induced magnetic field and elevating the current to 15 kA led to an increase in the molten pool depth by 42.9%and a reduction in the thickness of the mushy zone by 25.2%.The application of a constant axial magnetic field enhances a unidirectional momentum buildup within the molten pool,thereby enhancing the flow velocity and cooling efficiency of melt.
基金support by National Natural Science Foundation of China(22379166)Natural Science Foundation for Distinguished Young Scholars of Hunan Province(2022JJ10089)Central South University Innovation-Driven Research Programme(2023CXQD034).
文摘Within the framework of carbon neutrality,lithium-ion batteries(LIBs)are progressively booming along with the growing utilization of green and clean energy.However,the extensive application of LIBs with limited lifespan has brought about a significant recycling dilemma.The traditional hydrometallurgical or pyrometallurgical strategies are not capable to maximize the output value of spent LIBs and minimize the potential environmental hazards.Herein,to alternate the tedious and polluting treatment processes,we propose a high-temperature molten-salt strategy to directly regenerate spent cathodes of LIBs,which can also overcome the barrier of the incomplete defects'restoration with previous low-temperature molten salts.The high-energy and stable medium environment ensures a more thorough and efficient relithiation reaction,and simultaneously provides sufficient driving force for atomic rearrangement and grains secondary growth.In consequence,the regenerated ternary cathode(R-NCM)exhibits significantly enhanced structural stability that effectively suppresses the occurrence of cracks and harmful side reactions.The R-NCM delivers excellent cycling stability,retaining 81.2%of its capacity after 200 cycles at 1 C.This technique further optimizes the traditional eutectic molten-salt approach,broadening its applicability and improving regenerated cathode performance across a wider range of conditions.
基金supported by the National Natural Science Foundation of China(Nos.12425511,12375280,U2341261,U23B2072 and 12305293).
文摘The synergistic effects of irradiation and tensile deformation on the corrosion behavior of the GH3535 alloy in FLi-NaK molten salt were explored.Helium bubbles were introduced into the GH3535 alloy,followed by mechanical loading with the plastic strain up to 10%.After immersion in molten salt for 300 h,all the samples exhibited a corrosion-induced Cr depletion layer.The depth of the Cr depletion layer increased by 40% for the alloy with helium ion irradiation and 10% plastic deformation,compared with that for the only corroded sample.Moreover,the proportion of large-sized helium bubbles increased with plastic deformation.These results indicate that the coupling effects of irradiation and tensile deformation accelerate the corrosion of the GH3535 alloy.In addition,in a molten salt environment,an unexpected outward migration behavior of helium bubbles was observed under different plastic deformation.Helium bubbles migrated closer to the surface as the strain increased up to 3%,while the migration depth declined when the strain reached 10%.This is ascribed to the interaction between deformation-induced dislocations and helium bubbles.
基金supported by the National Key R&D Program of China(2023YFA1508001)the National Natural Science Foundation of China(22272120 and U2202251)+2 种基金the Fundamental Research Funds for the Central Universities(2042022kf1174)the Hainan Province Science and Technology Special Fund(ZDYF2023SHFZ120 and ZDYF2021SHFZ058)the Research Foundation of Marine Science and Technology Collaborative Innovation Center of Hainan University(XTCX2022HYB01)。
文摘Direct utilization of co-existed ferrous oxide(FeO)dust in CO_(2)flue gas from the steel industry to product value-added materials is yet to be established.Inspired by the form of CaO-CaCO_(3)as natural carbon cycle and the high oxide dissolution capacity of molten salts,CaO is herein introduced into the affordable molten NaCl-CaCl_(2)-FeO salt to generate CO_(3)^(2-)through an efficient capture of CO_(2).The subsequent coelectrolysis of FeO and CO_(3)^(2-)successfully produces cathodic Fe-encapsulated carbon nanotubes(Fe@CNT)with enhanced energy efficiency(current efficiency of 83.1%for CO_(2)reduction and energy consumption of 22.49 kWh kg^(1)for Fe@CNT generation).The in-situ capture of CO_(2)by O^(2)generated from the electro-deoxidation of FeO bridges the electrolysis of CO_(2)and FeO,rendering the enhanced current efficiency of the co-electrolysis and template-free generation of Fe@CNT.When evaluated as functional materials for electromagnetic wave absorption,the Fe@CNT integrates dielectric loss of CNT and electromagnetic loss from Fe.The Fe well-defined in CNT induces the synergistic loss and further improves the impedance matching,resulting in excellent electromagnetic wave absorption performance.The coelectrolysis establishes a promising strategy for converting CO_(2)into highly functional materials directly from CO_(2)-containing flue gas from steel industrial without dust removal.
基金financially supported by the National Natural Science Foundation of China under the Grant No.22209075。
文摘Single crystalline nickel rich Li[Ni_(x)Co_(y)Mn_(1-x–y)]O_(2)(SCNCM)layered oxide cathodes show higher ionic conductivity and better structure integrity than polycrystalline NCM(PCNCM)cathodes by eliminating grain boundaries.However,it remains challenges in the controlled synthesis process and restricted cycling stability of SCNCM.Herein,take single crystalline nickel rich Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2)(SC811)as an example,a dual molten salts(LiOH and Li_(2)SO_(4))assisted secondary calcination method is proposed,for which LiOH salt improves primary crystal size and Li_(2)SO_(4)prevents the aggravation of NCM nanocrystals.To further reduce the interfacial side reactions,Mg-doping and B-coating surface modification was carried out,which effectively suppress anisotropic lattice changes and Li/Ni disorder.In addition,a thin and uniform H_(3)BO_(3)coating effectively prevents direct contact between the electrode and electrolyte,thus reducing harmful parasitic reactions.The single crystal structure engineering and surface modification strategy of oxide layered cathodes significantly improve the cycling stability of the modified SC811 cathode.For example,during a long-term cycling of 470 cycles,a high-capacity retention of 74.2%obtained at 1C rate.Our work provides a new strategy for engineering high energy nickel rich layered oxide NCM cathodes.
基金the National Natural Science Foundation of China(Grant No.U1760206 and Grant No.51574083)the 111 Project(2.0)of China(No.BP0719037)for the financial support.
文摘A new flow control technology in continuous casting process named permanent magnet flow control-mold(PMFC-Mold)was proposed,in which the permanent magnets are arranged in Halbach array near the narrow region of the mold.The behavior of molten steel flow and the fluctuation of molten steel/slag interface in the PMFC-Mold under different continuous casting speeds were investigated.Firstly,a physical experiment of liquid Ga-In-Sn alloy circulating flow was carried out in Perspex mold with Halbach’s permanent magnets(HPMs)to investigate the magnetic field distribution of HPMs and its impactful electromagnetic braking effect.The numerical simulation of 1450 mm×230 mm slab shows that a stronger magnetic field over 0.3-0.625 T is formed at the wide surface and the narrow surface of the mold,which provides an effective electromagnetic braking for controlling the impingement of molten steel jet and suppressing the fluctuation of molten steel/slag interface.The numerical simulation results show that in the PMFC-Mold,the region with the turbulent kinetic energy greater than 0.01 and 0.04 m^(2)s^(-2)on the upper backflow zone and near the narrow surface of the mold are significantly reduced.The maximum turbulent kinetic energy of the submerged entry nozzle(SEN)jet in front of the narrow surface is significantly reduced,and the SEN jet moves downward before impacting the narrow surface of the mold.In the PMFC-Mold,the region with the surface velocity greater than 0.2 m s^(-1)on the steel/slag interface is eliminated,the flow pattern and fluctuation profiles on the molten steel/slag interface become regular on both sides of SEN,and the vortex near SEN disappears.The maximum fluctuation height of molten steel/slag interface is controlled below 2.59 and 5.40 mm corresponding to the casting speed of 1.6 and 2.0 m min-1,respectively.
基金supported by the National Natural Science Foundation of China(No.52375274)the Zhejiang Provincial Natural Science Foundation of China(No.LD21E050003)+1 种基金the Key R&D Program of Zhejiang Province(No.2023C01229)the Central Government Fund for Regional Science and Technology Development of China(No.2023ZY1033).
文摘The thermocline energy storage tank(TEST)serves as a crucial component in thermal energy storage systems,utilizing the working fluid that enters through a diffuser to store and harness energy.However,the conventional double-plate radial diffuser is ill-suited for a single-medium TEST’s full tank storage due to its unidirectional fluid inflow.There has been a notable lack of optimization analysis of diffusers.Two innovative tubular diffuser designs with reduced cross-sectional areas have been introduced:the annular-arranged diffuser(AAD)and the cross-arranged diffuser(CAD).To elucidate the impact of diffuser designs on energy storage efficiency,a 3D transient computational fluid dynamics(CFD)model was established to simulate a thermocline formation under two diffuser types.The model was validated against experimental data.Results showed that the thermocline of AAD was 11.39%thinner than that of a traditional double-plate diffuser.In the process of charging and discharging,the time-varying thermocline and factors influencing thermocline thickness were analyzed.Results indicate that in the mixed dominant region,increased turbulent kinetic energy correlates with reduced thermocline thickness.Notably,the AAD’s stable thermocline was 4.23%and 5.41%thinner than the CAD’s during charging and discharging,respectively,making the AAD preferable for engineering applications.The effects of tube diameter and orifice opening angle on temperature stratification performance were also examined.The findings suggest that an inclined impact jet and large-diameter tubes are more conducive to temperature stratification.Moreover,an orifice diameter optimization method was developed,which can decrease the thermocline by 6.78%.
文摘In photothermal power(solar energy)generation systems,purging residual molten salt from pipelines using highpressure gas poses a significant challenge,particularly in clearing the bottom of regulating valves.Ineffective purging can lead to crystallization of the molten salt,resulting in blockages.To address this issue,understanding the gas-liquid two-phase flow dynamics during high-pressure gas purging is crucial.This study utilizes the Volume of Fluid(VOF)model and adaptive dynamic grids to simulate the gas-liquid two-phase flow during the purging process in a DN50 PN50 conventional molten salt regulating valve.Initially,the reliability of the CFD simulations is validated through comparisons with experimental data and findings from the literature.Subsequently,simulation experiments are conducted to analyze the effects of various factors,including purge flow rates,initial liquid accumulation masses,purge durations,and the profiles of the valve bottom flow channels.The results indicate that the purging process comprises four distinct stages:Initial violent surge stage,liquid discharge stage,liquid partial fallback stage,liquid dissipation stage.For an initial liquid height of 17 mm at the bottom of the valve,the critical purge flow rate lies between 3 and 5 m/s.Notably,the critical purge flow rate is independent of the initial liquid accumulation mass.As the purge gas flow rate increases,the volume of liquid discharged also increases.Beyond the critical purge flow rate,higher purge gas velocities lead to shorter purge durations.Interestingly,the residual liquid mass after purging remains unaffected by the initial liquid accumulation.Additionally,the flow channel profile at the bottom of the valve significantly influences both the critical purge speed and the efficiency of the purging process.
基金supported by the Natural Science Foundation of the Jiangxi Province(20224BAB204038)the Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)+2 种基金the Ganzhou City Science and Technology Innovation Talent Project(2023CYZ26999)Jiangxi Provincial Key Laboratory of LowCarbon Processing and Utilization of Strategic Metal Mineral Resources(2023SSY01041)the Jiangxi Province Graduate Student Innovation Special Fund Project(YC2023-S642)。
文摘Rare earth molten salt electrolytic slag(RMES)has emerged as a promising secondary resource for rare earth elements(REEs).This study introduces an innovative leaching technique for extracting REEs from RMES under atmospheric conditions,employing an alkali phase reconstruction method followed by an acid leaching process.Additionally,the external electric field was employed to enhance the reaction.Under the optimal reaction conditions:NaOH initial concentration of 70 wt%,NaOH-slag mass ratio of 4:1,temperature of 160℃,current density of 1000 A/m^(2),reaction time of 90 min,stirring speed of 300 r/min,HCl concentration of 4 mol/L,liquid-solid ratio of 15:1,and leaching time of 20 min,the leaching efficiencies of Nd and Pr reach up to 99.21%and 99.14%,respectively.Phase analysis indicates that the rare earth fluorides transform into rare earth hydroxides,significantly enhancing their solubility in acid solution.The imposition of an external electric field leads to pronounced disruption of the RMES surface,thereby promoting the formation of stable reactive oxygen species in the alkaline medium.This facilitates the decomposition of fluorinated rare earths and hastens the phase reconstruction,resulting in an enhanced leaching process.The achieved leaching efficiency with an external electric field is 37%higher than that without an electric field.
基金supported by the National Natural Science Foundation of China(No.52101165)the Inner Mongolia Science and Technology Major Project(No.2020ZD0010)the Key Research Program of the Chinese Academy of Sciences(No.ZDRW-CN-2021-3).
文摘The large and dense rare earth (RE)-oxide inclusions in high-oxygen RE metal increase the risk of producing variable properties in RE steel. Consequently, a self-developed electrolysis cell was utilized for the production of low-oxygen La/Ce mischmetal. The electrolysis process and the origin of oxygen in mischmetal were comprehensively investigated. The results indicate that the reaction between La/Ce oxide and fluoride molten salt results in the formation of La/Ce oxy-fluoride. The deposition of oxy-fluoride at the bottom of the electrolysis cell is the primary factor contributing to the increased oxygen content in mischmetal. The comprehensive influence of oxide addition quantity, feeding interval, and electrolysis temperature on oxygen content, purity, and current efficiency using the response surface methodology model is revealed. The results for industrial experiment show that the purity of mishcmetal reaches higher than 99.78 wt.%, the oxygen content of mischmetal is only 0.0047 wt.% and the current efficiency of the electrolysis process achieves 80.79% under the optimized parameters of 225 kg/d, 30 s and 1069 ℃. The findings offer valuable insights into the application of molten salt electrolysis for the production of low-oxygen mischmetal.
基金Funded by the National Natural Science Foundation of China(No.51803076)the Natural Science Foundation of Jiangsu Province of China(No.BK20180629)+1 种基金the China Postdoctoral Science Foundation(No.2018M632231)the Key Laboratory of Special Protective Textiles of Ministry of Education(Jiangnan University)(No.TZFH-24-006)。
文摘One-dimensional titanium dioxide(TiO_(2))whiskers with controllable aspect ratios were synthesized by molten salt method adopting anatase TiO_(2)nanoparticles as precursor,sodium chloride(NaCl)and dibasic sodium phosphate(Na_(2)HPO_(4))as medium.The particle size of TiO_(2)nanoparticles and ratio of precursor and medium that can help to generate high aspect ratio TiO_(2)whiskers were studied and selected.Light-colored antimony-doped tin oxide@titanium dioxide(ATO@TiO_(2))conductive whiskers were prepared by coating ATO on TiO_(2)whiskers through coprecipitation then.Finally,the ATO@TiO_(2)light-colored conductive whiskers were dispersed in polyacrylonitrile(PAN)to fabricate light-colored conductive fibers.The experimental results show that the ATO@TiO_(2)whiskers exhibits ideal whiteness and conductivity with 65.5 Wb and 106Ω·cm,respectively,and the resistivity of conductive fibers was 6.07×10^(6)Ω·cm with 15wt%whisker content.
基金supported by the National Natural Science Foundation of China(No.12075169)。
文摘A thermal–hydraulic model was developed to analyze the three-dimensional(3D)temperature field of a graphite-moderated channel-type molten salt reactor(GMC-MSR).This model solves the temperature distribution of both the graphite moderator and fuel salt using a single convection–diffusion equation.Heat transfer at the interface between the fuel salt and graphite was addressed by introducing an additional thermal resistance component at the interface and modifying the anisotropic thermal conductivity of the fuel salt.The mass flow distribution in different flow passages was determined by adjusting the mass flow rate until a uniform pressure drop was achieved across all fuel channels.This thermal–hydraulic model,constructed on COMSOL Multiphysics,was verified by comparing its temperature results with those from the RELAP5 code across two demonstration cases.A steady-state thermal–hydraulic simulation of this model was performed to evaluate the conceptual design of a 2-MW experimental molten salt reactor(2MW-MSR).In addition,detailed discussions of the 3D temperature field,heat flux,and mass flow distribution of the 2MW-MSR were presented.This model allows for a comprehensive 3D thermal–hydraulic analysis of the GMC-MSR.Moreover,it only requires the solution of a single convection–diffusion equation,which makes it invaluable for GMC-MSR design.
基金supported by the National Natural Science Foundation of China(NSFC,62104099,61921005,62105048,62204117 and 62073299)the Science and Technology Research Program of Chongqing Education Commission(KJQN202100633)+5 种基金the Postdoctoral Science Foundation of China(2021M693768 and 2021M701057)the Key Scientific Research Project in Colleges and Universities of Henan Province,China(21A416001)the Key Laboratory for Special Functional Materials(KEKT2022-06)the Natural Science Foundation of Jiangsu Province(BK20210275 and BK20230498)the support from Jiangsu Province Science Foundation for Youths(BK20210275)National Natural Science Foundation of China(NSFC,62204117)。
文摘Lithium-carbon dioxide(Li-CO_(2))batteries using high ion-conductive inorganic molten salt electrolytes have recently attracted much attention due to the high energy density and potential application of carbon neutrality.However,the poor Li-ion conductivity of the molten-salt electrolytes at room temperature(RT)makes these batteries lose most of their capacity and power as the temperature falls below 80℃.Here,inspired by the greenhouse effect,we report an RT molten salt Li-CO_(2)battery where solar energy can be efficiently harvested and converted into heat that is further localized on the cathode consisting of plasmonic ruthenium(Ru)catalysts and Li_(2)CO_(3)-based products via a greenhouse-like phenomenon.As a result,the solar-driven molten salt Li-CO_(2)battery demonstrates a larger full discharge/charge capacity of 9.5 mA h/8.1 mA h,and a longer cycle lifespan of 250 cycles at 500 mA/g with a limited capacity of 500 mA h/g at RT than the molten salt Li-CO_(2)battery at 130℃.Notably,the average temperature of the cathode increases by 8℃ after discharge to 0.75 mA h,which indicates the infrared radiation from Ru catalysts can be effectively suppressed by discharged Li_(2)CO_(3)-based products.This battery technology paves the way for developing low-temperature molten salt energy storage devices.
基金This work was supported by the Chinese TMSR Strategic Pioneer Science and Technology Project(No.XDA02010300).
文摘A nonlinear dynamic simulation model based on coordinated control of speed and flow rate for the molten salt reactor and combined cycle systems is proposed here to ensure the coordination and stability between the molten salt reactor and power system.This model considers the impact of thermal properties of fluid variation on accuracy and has been validated with Simulink.This study reveals the capability of the control system to compensate for anomalous situations and maintain shaft stability in the event of perturbations occurring in high-temperature molten salt tank outlet parameters.Meanwhile,the control system’s impact on the system’s dynamic characteristics under molten salt disturbance is also analyzed.The results reveal that after the disturbance occurs,the controlled system benefits from the action of the control,and the overshoot and disturbance amplitude are positively correlated,while the system power and frequency eventually return to the initial values.This simulation model provides a basis for utilizing molten salt reactors for power generation and maintaining grid stability.
