CO_(2) hydrogenation to CH3OH is of great significance for achieving carbon neutrality.Here,we show a urea-assisted grinding strategy for synthesizing Cu-Zn-Ce ternary catalysts(CZC-G)with optimized interfacial synerg...CO_(2) hydrogenation to CH3OH is of great significance for achieving carbon neutrality.Here,we show a urea-assisted grinding strategy for synthesizing Cu-Zn-Ce ternary catalysts(CZC-G)with optimized interfacial synergy,achieving superior performance in CO_(2) hydrogenation to methanol.The CZC-G catalyst demonstrated exceptional methanol selectivity(96.8%)and a space-time yield of 73.6 gMeOH·kgcat^(–1)·h^(–1) under optimized conditions.Long-term stability tests confirmed no obvious deactivation over 100 h of continuous operation.Structural and mechanistic analyses revealed that the urea-assisted grinding method promotes the formation of Cu/Zn-O_(v)-Ce ternary interfaces and inhibits the reduction of ZnO,enabling synergistic interactions for efficient CO_(2) activation and selective stabilization of formate intermediates(HCOO^(*)),which are critical for methanol synthesis.In-situ diffuse reflectance infrared Fourier transform spectra and X-ray absorption spectroscopy studies elucidated the reaction pathway dominated by the formate mechanism,while suppressing the reverse water-gas shift reaction.This work underscores the critical role of synthetic methodologies in engineering interfacial structures,offering a strategy for designing high-performance catalysts for sustainable CO_(2) resource utilization.展开更多
This article aims tomodel and analyze the heat and fluid flow characteristics of a carboxymethyl cellulose(CMC)nanofluid within a convergent-divergent shaped microchannel(Two-dimensional).The base fluid,water+CMC(0.5%...This article aims tomodel and analyze the heat and fluid flow characteristics of a carboxymethyl cellulose(CMC)nanofluid within a convergent-divergent shaped microchannel(Two-dimensional).The base fluid,water+CMC(0.5%),is mixed with CuO and Al2O3 nanoparticles at volume fractions of 0.5%and 1.5%,respectively.The research is conducted through the conjugate usage of experimental and theoretical models to represent more realistic properties of the non-Newtonian nanofluid.Three types of microchannels including straight,divergent,and convergent are considered,all having the same length and identical inlet cross-sectional area.Using ANSYS FLUENT software,Navier-Stokes equations are solved for the laminar flow of the non-Newtonian nanofluid.The study examines the effects of Reynolds number,nanoparticle concentration and type,and microchannel geometry on flow and heat transfer.The results prove that the alumina nanoparticles outperform copper oxide in increasing the Nusselt number at a 0.5% volume fraction,while copper oxide nanoparticles excel at a 1.5%volume fraction.Moreover,in the selected case study,as the Reynolds number increases from 100 to 500,the Nusselt number rises by 56.26% in straight geometry,52.93% in divergent geometry,and 59.10%in convergent geometry.Besides,the Nusselt number enhances by 18.75% when transitioning from straight to convergent geometry at a Reynolds number of 500,and by 19.81%at a Reynolds number of 1000.Finally,the results of the research depict that the use of thermophysical properties derived from the experimental achievements,despite creating complexity in the modeling and the solution method,leads to more accurate and realistic outputs.展开更多
For the efficient harnessing of solar energy and mitigation of environmental pollution,the develop-ment and application of semiconductor photocatalysis technology is paramount.Herein,a novel SubPc-Br/CdS supramolecula...For the efficient harnessing of solar energy and mitigation of environmental pollution,the develop-ment and application of semiconductor photocatalysis technology is paramount.Herein,a novel SubPc-Br/CdS supramolecular array with an S-scheme heterojunction was synthesized through the intermolecu-larπ-stacked self-assembly of subphthalocyanine(SubPc-Br)and nanometer cadmium sulfide(CdS).This self-assembly system features a highly structured architecture and excellent stability.Experiments and ground-state differential charge calculations demonstrate that SubPc-Br and CdS form a built-in electric field during the self-assembly process,a critical factor in promoting the dissociation of electrons and holes.Additionally,this study utilized time-dependent density functional theory(TDDFT)to simulate the dynamic adsorption behavior of excited oxygen molecules on the SubPc-Br/CdS interface for the first time.The analysis of molecular charge differential density under different excited states proved that the addi-tion of SubPc-Br molecules not only improves the photocorrosion resistance of CdS in an O2 adsorption environment but also enhances the production of advanced reactive oxygen species under the synergistic action of h+and·O2-.When subjected to visible light,the degradation efficiency of minocycline(MC)achieved 96.8%within 60 min and maintained 80.3%after 5 cycles.In summary,this study highlights the feasibility of creating advanced S-scheme heterojunction photocatalysts through the strategic incor-poration of organic supramolecules with semiconductor catalysts.展开更多
Experiments were made for the adsorption of CO2 and N2 on typical adsorbents to investigate the effects of porous structure and surface affinity of adsorbents as well as those of adsorption temperature and pressure th...Experiments were made for the adsorption of CO2 and N2 on typical adsorbents to investigate the effects of porous structure and surface affinity of adsorbents as well as those of adsorption temperature and pressure that might cause the variation of adsorption mechanism. It is shown that polar surface tends to enlarge the adsorption difference between CO2 and N2, and the difference is more sensitive to temperature than the adsorbents with non-polar surface. The adsorbents with non-polar surface are not much sensitive to the effect of water vapor, though the water vapor interferes the separation remarkably. The separation coefficient linearly increases with the micro- pore volume per unit surface area of activated carbons, but no rule is shown on mesoporous silicon materials. The function of adsorption mechanism on the separation is not as much as expected.展开更多
Process optimization in equation-oriented(EO)modeling environments favors the gradient-based optimization algorithms by their abilities to provide accurate Jacobian matrices via automatic or symbolic differentiation.H...Process optimization in equation-oriented(EO)modeling environments favors the gradient-based optimization algorithms by their abilities to provide accurate Jacobian matrices via automatic or symbolic differentiation.However,computational inefficiencies including that in initial-point-finding for Newton type methods have significantly limited its application.Recently,progress has been made in using a pseudo-transient(PT)modeling method to address these difficulties,providing a fresh way forward in EO-based optimization.Nevertheless,research in this area remains open,and challenges need to be addressed.Therefore,understanding the state-of-the-art research on the PT method,its principle,and the strategies in composing effective methodologies using the PT modeling method is necessary for further developing EO-based methods for process optimization.For this purpose,the basic concepts for the PT modeling and the optimization framework based on the PT model are reviewed in this paper.Several typical applications,e.g.,complex distillation processes,cryogenic processes,and optimizations under uncertainty,are presented as well.Finally,we identify several main challenges and give prospects for the development of the PT based optimization methods.展开更多
Coal has a highly complex chemical structure,similar to polymers,coal is a macromolecular structure composed of a large number of“similar compounds”,which is called the basic structural unit.Understanding coal struc...Coal has a highly complex chemical structure,similar to polymers,coal is a macromolecular structure composed of a large number of“similar compounds”,which is called the basic structural unit.Understanding coal structure is the basis of its transformation and utilization.Shendong(SD)coal was analyzed by FTIR,XRD,XPS,and NMR.The results show that SD coal normalized structure formula is C_(100)H_(68.5)O_(35.7)N_(1.2)S_(0.2)and the average number of aromatic rings is 1.98.-CH_(2)-content accounts for about 82%in aliphatic CeH region,and the ratio of ether bond CeO,aromatic ether C-O and C=O is about 2:1:11 in oxygen-containing functional group region.The d_(002),L_(C),L_(a)and N_(C)of S_(D)coal microcrystalline structure parameters are 0.1832 nm,1.4688 nm,2.0852 nm and 9.017,respectively.Aromatic carbon and aliphatic carbon ratios of SD coal are 55.67%and 29.97%,aromatic cluster size and average methylene chain length are 0.224 and 1.817.Based on these structural parameters,molecular model of SD coal was constructed with^(13)C SSNMR experimental spectra as a reference.The model was constructed with an atom composition of C_(214)H_(214)O_(49)N_(2)S.展开更多
The pyrolysis process of Shendong coal(SD)was first studied by combining the characteristics of thermal gravimetric(TG),pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS)and Gray-King assay(GK).The results show ...The pyrolysis process of Shendong coal(SD)was first studied by combining the characteristics of thermal gravimetric(TG),pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS)and Gray-King assay(GK).The results show that the order of coke yields is G-K(76.35%(mass))>TG(73.11%(mass))>Py(70.03%(mass)).G-K coke yield caused by condensation reaction and secondary reaction accounts for 3.08%(mass)and 3.24%(mass),respectively.Compared with slow pyrolysis,fast pyrolysis has stronger fracture ability to coal molecules and can obtain more O-compounds,mono-ring aromatics and aliphatics.Especially,the content of phenolics increases significantly from 15.49%to 35.17%,but the content of multi-ring aromatics decreases from 23.13%to 2.36%.By comparing the compositions of Py primary tar and G-K final tar,it is found that secondary reactions occurred during G-K pyrolysis process include the cleavage of alkane and esters,condensation of mono-ring aromatics with low carbon alkene,ring opening,isomerization of tri-ring aromatics,hydrogenation of aromatics and acids.展开更多
The liquid hold-up in a reactive distillation(RD)column not only has a significant impact on the extent of reactions,but also affects the pressure drop and hydraulic conditions in the column.Therefore,the liquid hold-...The liquid hold-up in a reactive distillation(RD)column not only has a significant impact on the extent of reactions,but also affects the pressure drop and hydraulic conditions in the column.Therefore,the liquid hold-up would be a critical design factor for RD columns.However,the existing design methods for RD columns typically neglect the influence of considerable amount of liquid hold-up in downcomers owing to the difficulties of solving a large-scale nonlinear model system by considering downcomer hydraulics,resulting in significant deviations from actual situation and even operation infeasibility of the designed column.In this paper,a pseudo-transient(PT)RD model based on equilibrium model considering tray hydraulics was established for rigorous simulation and optimization of RD plate columns considering the liquid hold-up both in downcomers and column trays,and a steady-state optimization algorithm assisted by the PT model was adopted to robustly solve the optimization problem.The optimization results of either ethylene glycol RD or methyl acetate RD demonstrated that assuming all the liquid hold-up of a stage belonged to the tray will cause significant deviations in the column diameter,weir height,and the number of stages,which leads to not meeting the separation requirements and even operation hydraulic infeasibility.The rigorous model proposed in this study which considers the liquid hold-up both on trays and in downcomers as well as hydraulic constraints can be applied to systematically design industrial RD plate columns to simultaneously obtain optimal operating variables and equipment structure variables.展开更多
The isobaric energy recovery device can significantly reduce the energy consumption of the seawater reverse osmosis system by recycling the residual pressure energy of high-pressure concentrated brine.Three-cylinder v...The isobaric energy recovery device can significantly reduce the energy consumption of the seawater reverse osmosis system by recycling the residual pressure energy of high-pressure concentrated brine.Three-cylinder valve-controlled energy recovery device(TC-ERD)solves the fluid pulsation of traditional two-cylinder devices,but the use of a“liquid piston”exacerbates the mixing between brine and seawater.Herein,the evolutionary law of“liquid piston”and the relationship between volumetric mixing degree and operating conditions are explored.The results show that the“liquid piston”first axially expands and then gradually stabilizes,isolating the brine and seawater.Additionally,as long as the volume utilization ratio(U_(R))of the pressure exchange cylinder remains constant,there will not be much difference in the volumetric mixing degree after stabilization of the“liquid piston”(Vm-max)regardless of changes in the processing capacity(Q)and cycle time(T_(0)).Therefore,the equation for Vm-max with respect to the operating parameters(Q,T_(0))is derived,which can not only predict the Vm-max of the TCERD,but also provide an empirical reference for the design of other valve-controlled devices with“liquid piston”.When the Vm-max is 6%,the efficiency of the TC-ERD at design conditions(30 m^(3)·h^(-1),5.0 MPa)is 97.53%.展开更多
A series of Ni-based catalysts were prepared via structural topological transformation from the Ni@Al_(2)O_(3)layered double hydroxides(LDHs)precursors,and applied for the deep catalytic hydrogenation saturation of py...A series of Ni-based catalysts were prepared via structural topological transformation from the Ni@Al_(2)O_(3)layered double hydroxides(LDHs)precursors,and applied for the deep catalytic hydrogenation saturation of pyrene in a high-pressure reactor.The pore structures,active species dispersion,surface morphology,amount and type of acid of the prepared catalysts were characterized by BET,XRD,SEM,TEM,XPS,SEM,NH_(3)-TPD and Py-IR.We studied the influence of physicochemical properties of Ni-based catalysts on the regularity and mechanism of deep hydrogenation of pyrene.Meanwhile,the synergy between Ni and Mo,and the interaction between active metals and support were discussed to further reveal the constitutive relationship during the hydrogenation reaction of pyrene.The results of the evaluation of the catalytic hydrogenation of pyrene show that the as-prepared NiMo mixed metal oxide(MMO)catalyst showed excellent catalytic activity:~95%pyrene conversion,90.12%for the selectivity of deep hydrogenation products(hexahydropyrene,decahydropyrene and hexadecahydropyrene).It was expected that the successfully preparation and utilization of NiMo-MMO catalyst could provide a theoretical basis for the design of this kind of catalysts for deep catalytic hydrogenation of polycyclic aromatic hydrocarbons(PAHs).展开更多
Reactive transport equations in porous media are critical in various scientific and engineering disciplines,but solving these equations can be computationally expensive when exploring different scenarios,such as varyi...Reactive transport equations in porous media are critical in various scientific and engineering disciplines,but solving these equations can be computationally expensive when exploring different scenarios,such as varying porous structures and initial or boundary conditions.The deep operator network(DeepONet)has emerged as a popular deep learning framework for solving parametric partial differential equations.However,applying the DeepONet to porous media presents significant challenges due to its limited capability to extract representative features from intricate structures.To address this issue,we propose the Porous-DeepONet,a simple yet highly effective extension of the DeepONet framework that leverages convolutional neural networks(CNNs)to learn the solution operators of parametric reactive transport equations in porous media.By incorporating CNNs,we can effectively capture the intricate features of porous media,enabling accurate and efficient learning of the solution operators.We demonstrate the effectiveness of the Porous-DeepONet in accurately and rapidly learning the solution operators of parametric reactive transport equations with various boundary conditions,multiple phases,and multiphysical fields through five examples.This approach offers significant computational savings,potentially reducing the computation time by 50–1000 times compared with the finite-element method.Our work may provide a robust alternative for solving parametric reactive transport equations in porous media,paving the way for exploring complex phenomena in porous media.展开更多
The catalytic performance of different acidic catalysts for diethyl oxalate synthesis from the one-step transesterification of dimethyl oxalate and ethanol was evaluated.The effects of different factors(e.g.,acidity,e...The catalytic performance of different acidic catalysts for diethyl oxalate synthesis from the one-step transesterification of dimethyl oxalate and ethanol was evaluated.The effects of different factors(e.g.,acidity,electron accepting capacity,cations type and crystalline water)on the catalytic activity of acidic catalysts were investigated respectively.It was proposed and confirmed that the transesterification reaction catalyzed by a Lewis acid(FeCl3)and a Bronsted acid(H2SO4)follows a first-order kinetic reaction process.In addition,the Lewis acid-catalyzed transesterification processes with different ester structures were used to further explore and understand the speculated reaction mechanism.This work enriches the theoretical understanding of acid-catalyzed transesterification reactions and is of great significance for the development of highly active catalysts for diethyl oxalate synthesis,diminishing the industrial production cost of diethyl oxalate,and developing downstream bulk or high-value-added industrial products.展开更多
The separation between methane and nitrogen is an inevitable and important task in the C1 chemicaltechnology and the utilization of methane from coalbed, yet it is considered to be one of the tough tasks in thefield o...The separation between methane and nitrogen is an inevitable and important task in the C1 chemicaltechnology and the utilization of methane from coalbed, yet it is considered to be one of the tough tasks in thefield of separation. Pressure swing adsorption is a preferable technology if an adsorbent that allowing a largecoefficient of separation for the CH4/N2 system is available. The separation coefficients between CH4 and N2were obtained on analyzing the breakthrough curves measured experimentally with nine adsorbents. A technique ofmeasuring the temperature-pulse was incorporated in the experiments, and the reliability of the result was improved.Superactivated carbon with large surface area and plenty of micropores was shown to have the largest separationcoefficient and to be promising for the commercial utilization.展开更多
The performance of combined Fenton oxidation and membrane bioreactor （MBR） process for the advanced treatment of an effluent from an integrated dyeing wastewater treatment plant was evaluated. The experimental resul...The performance of combined Fenton oxidation and membrane bioreactor （MBR） process for the advanced treatment of an effluent from an integrated dyeing wastewater treatment plant was evaluated. The experimental results revealed that under the optimum Fenton oxidation conditions （initial pH 5, H 2 O 2 dosage 17 mmol/L, and Fe^ 2＋ 1.7 mmol/L） the average total organic carbon （TOC） and color removal ratios were 39.3% and 69.5% after 35 min of reaction, respectively. Results from Zahn-Wallens Test also represented that Fenton process was effective to enhance the biodegradability of the test wastewater. As for the further purification of MBR process, TOC removal capacity was examined at different hydraulic retention times （HRT） of 10, 18 and 25 hr. Under the optimum HRT of 18 hr, the average TOC concentration and color of the final MBR effluent were 16.8 mg/L and 2 dilution time, respectively. The sludge yield coefficient was 0.13 g MLSS/g TOC and TOC degradation rate was 0.078 kg TOC/（m ^3 ·day）. The final effluent of MBR can meet the reuse criteria of urban recycling water – water quality standard for miscellaneous water consumption GBT18920-2002.展开更多
The reactions of exo-cellulase （cellobiohydrolase, CBH） and endo-cellulase （endoglucanase, EG） were investigated by analyzing the insoluble residues of microcrystalline cellulose （MCC） and filter paper cellulose...The reactions of exo-cellulase （cellobiohydrolase, CBH） and endo-cellulase （endoglucanase, EG） were investigated by analyzing the insoluble residues of microcrystalline cellulose （MCC） and filter paper cellulose （FPC） during enzymatic hydrolysis. Molecular parameters including molecular weight and its distribution, degree of polymerization, and radii of gyration were measured by size exclusion chromatography coupled with multi-angle laser light scattering. No significant change in MCC chains was found during the whole reaction period, indicating that CBH digestion follows a layer-by-layer solubilization manner. This reaction mode might be the major reason for slow enzymatic hydrolysis of cellulose. On the other hand, the degree of polymerization of FPC chains decreases rapidly in the initial reaction, indicating that EG digestion follows a random scission manner, which may create new ends for CBH easily. The slopes of the conformation plots for MCC and FPC increase gradually, indicating stronger chain stiffness of cellulose during hvdrolvsis展开更多
Membrane separation technology has popularized rapidly and attracts much interest in gas industry as a promising sort of newly chemical separation unit operation. In this paper, recent advances on membrane processes f...Membrane separation technology has popularized rapidly and attracts much interest in gas industry as a promising sort of newly chemical separation unit operation. In this paper, recent advances on membrane processes for CO_2 separation are reviewed. The researches indicate that the optimization of operating process designs could improve the separation performance, reduce the energy consumption and decrease the cost of membrane separation systems. With the improvement of membrane materials recently,membrane processes are beginning to be competitive enough for CO_2 separation, especially for postcombustion CO_2 capture, biogas upgrading and natural gas carbon dioxide removal, compared with the traditional separation methods. We summarize the needs and most promising research directions for membrane processes for CO_2 separation in current and future membrane applications. As the time goes by, novel membrane materials developed according to the requirement proposed by process optimization with increased selectivity and/or permeance will accelerate the industrialization of membrane process in the near future. Based on the data collected in a pilot scale test, more effort could be made on the optimization of membrane separation processes. This work would open up a new horizon for CO_2 separation/Capture on Carbon Capture Utilization and Storage(CCUS).展开更多
An economic and effective method of preparing enriched 10B boric acid was established by chemical reactionof enriched 10BF3 and CaCO3. A process of boron trifluoride reacting with water was investigated under certainc...An economic and effective method of preparing enriched 10B boric acid was established by chemical reactionof enriched 10BF3 and CaCO3. A process of boron trifluoride reacting with water was investigated under certainconditions. Calcium carbonate was selected to counteract hydrofluoric acid followed on. Some key operation factorswere investigated, such as temperature, reaction time and the ratio of CaCO3 to 10BF3. The results showed that the yieldof enriched 10B boric acid could reach 97. 2% and the purity was up to 94. 1% under the following conditions: the temperaturewas 50-60,℃, the reaction time was 28 h and the ratio of CaCO3 to 10BF3 was 4. In addition, after recrystallizationand titration analysis, the purity of the product could reach over 99. 2% from 94.1%.展开更多
To date, many models have been developed to calculate the flow field in the structured packing by the computational fluid dynamics （CFD） technique, but little experimental work has been carried out to serve the vali...To date, many models have been developed to calculate the flow field in the structured packing by the computational fluid dynamics （CFD） technique, but little experimental work has been carried out to serve the vali-dation of flow simulation. In this work, the velocity profiles of single-phase flow in structured packing are measured at the Reynolds numbers of 20.0, 55.7 and 520.1, using the laser Doppler velocimetry （LDV）. The time-averaged and instantaneous velocities of three components are obtained simultaneously. The CFD simulation is also carried out to numerically predict the velocity distribution within the structured packing. Comparison shows that the flow pattern, velocity distribution and turbulent kinetic energy （for turbulent flow） on the horizontal plane predicted by CFD simulation are in good agreement with the LDV measured data. The values of the x-and z-velocity components are quantitatively well predicted over the plane in the center of the packing, but the predicted y-component is sig-nificantly smaller than the experimental data. It can be concluded that experimental measurement is important for further improvement of CFD model.展开更多
文摘CO_(2) hydrogenation to CH3OH is of great significance for achieving carbon neutrality.Here,we show a urea-assisted grinding strategy for synthesizing Cu-Zn-Ce ternary catalysts(CZC-G)with optimized interfacial synergy,achieving superior performance in CO_(2) hydrogenation to methanol.The CZC-G catalyst demonstrated exceptional methanol selectivity(96.8%)and a space-time yield of 73.6 gMeOH·kgcat^(–1)·h^(–1) under optimized conditions.Long-term stability tests confirmed no obvious deactivation over 100 h of continuous operation.Structural and mechanistic analyses revealed that the urea-assisted grinding method promotes the formation of Cu/Zn-O_(v)-Ce ternary interfaces and inhibits the reduction of ZnO,enabling synergistic interactions for efficient CO_(2) activation and selective stabilization of formate intermediates(HCOO^(*)),which are critical for methanol synthesis.In-situ diffuse reflectance infrared Fourier transform spectra and X-ray absorption spectroscopy studies elucidated the reaction pathway dominated by the formate mechanism,while suppressing the reverse water-gas shift reaction.This work underscores the critical role of synthetic methodologies in engineering interfacial structures,offering a strategy for designing high-performance catalysts for sustainable CO_(2) resource utilization.
文摘This article aims tomodel and analyze the heat and fluid flow characteristics of a carboxymethyl cellulose(CMC)nanofluid within a convergent-divergent shaped microchannel(Two-dimensional).The base fluid,water+CMC(0.5%),is mixed with CuO and Al2O3 nanoparticles at volume fractions of 0.5%and 1.5%,respectively.The research is conducted through the conjugate usage of experimental and theoretical models to represent more realistic properties of the non-Newtonian nanofluid.Three types of microchannels including straight,divergent,and convergent are considered,all having the same length and identical inlet cross-sectional area.Using ANSYS FLUENT software,Navier-Stokes equations are solved for the laminar flow of the non-Newtonian nanofluid.The study examines the effects of Reynolds number,nanoparticle concentration and type,and microchannel geometry on flow and heat transfer.The results prove that the alumina nanoparticles outperform copper oxide in increasing the Nusselt number at a 0.5% volume fraction,while copper oxide nanoparticles excel at a 1.5%volume fraction.Moreover,in the selected case study,as the Reynolds number increases from 100 to 500,the Nusselt number rises by 56.26% in straight geometry,52.93% in divergent geometry,and 59.10%in convergent geometry.Besides,the Nusselt number enhances by 18.75% when transitioning from straight to convergent geometry at a Reynolds number of 500,and by 19.81%at a Reynolds number of 1000.Finally,the results of the research depict that the use of thermophysical properties derived from the experimental achievements,despite creating complexity in the modeling and the solution method,leads to more accurate and realistic outputs.
基金the National Natural Science Foun-dation of China(No.22278334)。
文摘For the efficient harnessing of solar energy and mitigation of environmental pollution,the develop-ment and application of semiconductor photocatalysis technology is paramount.Herein,a novel SubPc-Br/CdS supramolecular array with an S-scheme heterojunction was synthesized through the intermolecu-larπ-stacked self-assembly of subphthalocyanine(SubPc-Br)and nanometer cadmium sulfide(CdS).This self-assembly system features a highly structured architecture and excellent stability.Experiments and ground-state differential charge calculations demonstrate that SubPc-Br and CdS form a built-in electric field during the self-assembly process,a critical factor in promoting the dissociation of electrons and holes.Additionally,this study utilized time-dependent density functional theory(TDDFT)to simulate the dynamic adsorption behavior of excited oxygen molecules on the SubPc-Br/CdS interface for the first time.The analysis of molecular charge differential density under different excited states proved that the addi-tion of SubPc-Br molecules not only improves the photocorrosion resistance of CdS in an O2 adsorption environment but also enhances the production of advanced reactive oxygen species under the synergistic action of h+and·O2-.When subjected to visible light,the degradation efficiency of minocycline(MC)achieved 96.8%within 60 min and maintained 80.3%after 5 cycles.In summary,this study highlights the feasibility of creating advanced S-scheme heterojunction photocatalysts through the strategic incor-poration of organic supramolecules with semiconductor catalysts.
文摘Experiments were made for the adsorption of CO2 and N2 on typical adsorbents to investigate the effects of porous structure and surface affinity of adsorbents as well as those of adsorption temperature and pressure that might cause the variation of adsorption mechanism. It is shown that polar surface tends to enlarge the adsorption difference between CO2 and N2, and the difference is more sensitive to temperature than the adsorbents with non-polar surface. The adsorbents with non-polar surface are not much sensitive to the effect of water vapor, though the water vapor interferes the separation remarkably. The separation coefficient linearly increases with the micro- pore volume per unit surface area of activated carbons, but no rule is shown on mesoporous silicon materials. The function of adsorption mechanism on the separation is not as much as expected.
基金supported by the National Natural Science Foundation of China(21978203,21676183).
文摘Process optimization in equation-oriented(EO)modeling environments favors the gradient-based optimization algorithms by their abilities to provide accurate Jacobian matrices via automatic or symbolic differentiation.However,computational inefficiencies including that in initial-point-finding for Newton type methods have significantly limited its application.Recently,progress has been made in using a pseudo-transient(PT)modeling method to address these difficulties,providing a fresh way forward in EO-based optimization.Nevertheless,research in this area remains open,and challenges need to be addressed.Therefore,understanding the state-of-the-art research on the PT method,its principle,and the strategies in composing effective methodologies using the PT modeling method is necessary for further developing EO-based methods for process optimization.For this purpose,the basic concepts for the PT modeling and the optimization framework based on the PT model are reviewed in this paper.Several typical applications,e.g.,complex distillation processes,cryogenic processes,and optimizations under uncertainty,are presented as well.Finally,we identify several main challenges and give prospects for the development of the PT based optimization methods.
基金financed by the Department of education of Gansu Province:Young Doctor Fund Project(2022QB-029)the Fundamental Research Funds for the Central Universities(31920240125-06,31920240059)+1 种基金the Scientific Research Project of Introducing Talents of Northwest Minzu University(xbmuyjrc202215,xbmuyjrc202216)the National Natural Science Foundation of China(22178289).
文摘Coal has a highly complex chemical structure,similar to polymers,coal is a macromolecular structure composed of a large number of“similar compounds”,which is called the basic structural unit.Understanding coal structure is the basis of its transformation and utilization.Shendong(SD)coal was analyzed by FTIR,XRD,XPS,and NMR.The results show that SD coal normalized structure formula is C_(100)H_(68.5)O_(35.7)N_(1.2)S_(0.2)and the average number of aromatic rings is 1.98.-CH_(2)-content accounts for about 82%in aliphatic CeH region,and the ratio of ether bond CeO,aromatic ether C-O and C=O is about 2:1:11 in oxygen-containing functional group region.The d_(002),L_(C),L_(a)and N_(C)of S_(D)coal microcrystalline structure parameters are 0.1832 nm,1.4688 nm,2.0852 nm and 9.017,respectively.Aromatic carbon and aliphatic carbon ratios of SD coal are 55.67%and 29.97%,aromatic cluster size and average methylene chain length are 0.224 and 1.817.Based on these structural parameters,molecular model of SD coal was constructed with^(13)C SSNMR experimental spectra as a reference.The model was constructed with an atom composition of C_(214)H_(214)O_(49)N_(2)S.
基金financed by the Department of Education of Gansu Province:Young Doctor Fund Project(2022QB-029)the Fundamental Research Funds for the Central Universities(31920240059,3192024125-06)+1 种基金the Scientific Research Project of Introducing Talents of Northwest Minzu University(xbmuyjrc202215)the National Natural Science Foundation of China(22178289).
文摘The pyrolysis process of Shendong coal(SD)was first studied by combining the characteristics of thermal gravimetric(TG),pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS)and Gray-King assay(GK).The results show that the order of coke yields is G-K(76.35%(mass))>TG(73.11%(mass))>Py(70.03%(mass)).G-K coke yield caused by condensation reaction and secondary reaction accounts for 3.08%(mass)and 3.24%(mass),respectively.Compared with slow pyrolysis,fast pyrolysis has stronger fracture ability to coal molecules and can obtain more O-compounds,mono-ring aromatics and aliphatics.Especially,the content of phenolics increases significantly from 15.49%to 35.17%,but the content of multi-ring aromatics decreases from 23.13%to 2.36%.By comparing the compositions of Py primary tar and G-K final tar,it is found that secondary reactions occurred during G-K pyrolysis process include the cleavage of alkane and esters,condensation of mono-ring aromatics with low carbon alkene,ring opening,isomerization of tri-ring aromatics,hydrogenation of aromatics and acids.
基金supported by the National Natural Science Foundation of China(22378304).
文摘The liquid hold-up in a reactive distillation(RD)column not only has a significant impact on the extent of reactions,but also affects the pressure drop and hydraulic conditions in the column.Therefore,the liquid hold-up would be a critical design factor for RD columns.However,the existing design methods for RD columns typically neglect the influence of considerable amount of liquid hold-up in downcomers owing to the difficulties of solving a large-scale nonlinear model system by considering downcomer hydraulics,resulting in significant deviations from actual situation and even operation infeasibility of the designed column.In this paper,a pseudo-transient(PT)RD model based on equilibrium model considering tray hydraulics was established for rigorous simulation and optimization of RD plate columns considering the liquid hold-up both in downcomers and column trays,and a steady-state optimization algorithm assisted by the PT model was adopted to robustly solve the optimization problem.The optimization results of either ethylene glycol RD or methyl acetate RD demonstrated that assuming all the liquid hold-up of a stage belonged to the tray will cause significant deviations in the column diameter,weir height,and the number of stages,which leads to not meeting the separation requirements and even operation hydraulic infeasibility.The rigorous model proposed in this study which considers the liquid hold-up both on trays and in downcomers as well as hydraulic constraints can be applied to systematically design industrial RD plate columns to simultaneously obtain optimal operating variables and equipment structure variables.
基金supported by the Natural Science Foundation of Fujian Province(2023J011020)the Education Department of Fujian Province/Sanming University(JAT220348/B202202)Sanming University(22YG12,PYT2202).
文摘The isobaric energy recovery device can significantly reduce the energy consumption of the seawater reverse osmosis system by recycling the residual pressure energy of high-pressure concentrated brine.Three-cylinder valve-controlled energy recovery device(TC-ERD)solves the fluid pulsation of traditional two-cylinder devices,but the use of a“liquid piston”exacerbates the mixing between brine and seawater.Herein,the evolutionary law of“liquid piston”and the relationship between volumetric mixing degree and operating conditions are explored.The results show that the“liquid piston”first axially expands and then gradually stabilizes,isolating the brine and seawater.Additionally,as long as the volume utilization ratio(U_(R))of the pressure exchange cylinder remains constant,there will not be much difference in the volumetric mixing degree after stabilization of the“liquid piston”(Vm-max)regardless of changes in the processing capacity(Q)and cycle time(T_(0)).Therefore,the equation for Vm-max with respect to the operating parameters(Q,T_(0))is derived,which can not only predict the Vm-max of the TCERD,but also provide an empirical reference for the design of other valve-controlled devices with“liquid piston”.When the Vm-max is 6%,the efficiency of the TC-ERD at design conditions(30 m^(3)·h^(-1),5.0 MPa)is 97.53%.
基金supported by the National Natural Science Foundation of China(21536009)Science and Technology Plan Projects of Shaanxi Province(2017ZDCXL-GY-10-03)+1 种基金National Natural Science Foundation of China(22008198)the Special Scientific Research Plan Project of Education Ministry of Shaanxi Province,China(19JK0854).
文摘A series of Ni-based catalysts were prepared via structural topological transformation from the Ni@Al_(2)O_(3)layered double hydroxides(LDHs)precursors,and applied for the deep catalytic hydrogenation saturation of pyrene in a high-pressure reactor.The pore structures,active species dispersion,surface morphology,amount and type of acid of the prepared catalysts were characterized by BET,XRD,SEM,TEM,XPS,SEM,NH_(3)-TPD and Py-IR.We studied the influence of physicochemical properties of Ni-based catalysts on the regularity and mechanism of deep hydrogenation of pyrene.Meanwhile,the synergy between Ni and Mo,and the interaction between active metals and support were discussed to further reveal the constitutive relationship during the hydrogenation reaction of pyrene.The results of the evaluation of the catalytic hydrogenation of pyrene show that the as-prepared NiMo mixed metal oxide(MMO)catalyst showed excellent catalytic activity:~95%pyrene conversion,90.12%for the selectivity of deep hydrogenation products(hexahydropyrene,decahydropyrene and hexadecahydropyrene).It was expected that the successfully preparation and utilization of NiMo-MMO catalyst could provide a theoretical basis for the design of this kind of catalysts for deep catalytic hydrogenation of polycyclic aromatic hydrocarbons(PAHs).
基金supported by the National Key Research and Development Program of China(2022YFA1503501)the National Natural Science Foundation of China(22378112,22278127,and 22078088)+1 种基金the Fundamental Research Funds for the Central Universities(2022ZFJH004)the Shanghai Rising-Star Program(21QA1401900).
文摘Reactive transport equations in porous media are critical in various scientific and engineering disciplines,but solving these equations can be computationally expensive when exploring different scenarios,such as varying porous structures and initial or boundary conditions.The deep operator network(DeepONet)has emerged as a popular deep learning framework for solving parametric partial differential equations.However,applying the DeepONet to porous media presents significant challenges due to its limited capability to extract representative features from intricate structures.To address this issue,we propose the Porous-DeepONet,a simple yet highly effective extension of the DeepONet framework that leverages convolutional neural networks(CNNs)to learn the solution operators of parametric reactive transport equations in porous media.By incorporating CNNs,we can effectively capture the intricate features of porous media,enabling accurate and efficient learning of the solution operators.We demonstrate the effectiveness of the Porous-DeepONet in accurately and rapidly learning the solution operators of parametric reactive transport equations with various boundary conditions,multiple phases,and multiphysical fields through five examples.This approach offers significant computational savings,potentially reducing the computation time by 50–1000 times compared with the finite-element method.Our work may provide a robust alternative for solving parametric reactive transport equations in porous media,paving the way for exploring complex phenomena in porous media.
基金funded by the Key Projects of Xinjiang Production and Construction Corps(2022AB007)the Key Projects of innovation team of Xinjiang eighth division Construction Corps 2023TD04)Liaoning Innovation Capability Fund(2021-NLTS-12-02).
文摘The catalytic performance of different acidic catalysts for diethyl oxalate synthesis from the one-step transesterification of dimethyl oxalate and ethanol was evaluated.The effects of different factors(e.g.,acidity,electron accepting capacity,cations type and crystalline water)on the catalytic activity of acidic catalysts were investigated respectively.It was proposed and confirmed that the transesterification reaction catalyzed by a Lewis acid(FeCl3)and a Bronsted acid(H2SO4)follows a first-order kinetic reaction process.In addition,the Lewis acid-catalyzed transesterification processes with different ester structures were used to further explore and understand the speculated reaction mechanism.This work enriches the theoretical understanding of acid-catalyzed transesterification reactions and is of great significance for the development of highly active catalysts for diethyl oxalate synthesis,diminishing the industrial production cost of diethyl oxalate,and developing downstream bulk or high-value-added industrial products.
文摘The separation between methane and nitrogen is an inevitable and important task in the C1 chemicaltechnology and the utilization of methane from coalbed, yet it is considered to be one of the tough tasks in thefield of separation. Pressure swing adsorption is a preferable technology if an adsorbent that allowing a largecoefficient of separation for the CH4/N2 system is available. The separation coefficients between CH4 and N2were obtained on analyzing the breakthrough curves measured experimentally with nine adsorbents. A technique ofmeasuring the temperature-pulse was incorporated in the experiments, and the reliability of the result was improved.Superactivated carbon with large surface area and plenty of micropores was shown to have the largest separationcoefficient and to be promising for the commercial utilization.
基金supported by HuPao Dyeing Plant,JiangSu Province,China
文摘The performance of combined Fenton oxidation and membrane bioreactor （MBR） process for the advanced treatment of an effluent from an integrated dyeing wastewater treatment plant was evaluated. The experimental results revealed that under the optimum Fenton oxidation conditions （initial pH 5, H 2 O 2 dosage 17 mmol/L, and Fe^ 2＋ 1.7 mmol/L） the average total organic carbon （TOC） and color removal ratios were 39.3% and 69.5% after 35 min of reaction, respectively. Results from Zahn-Wallens Test also represented that Fenton process was effective to enhance the biodegradability of the test wastewater. As for the further purification of MBR process, TOC removal capacity was examined at different hydraulic retention times （HRT） of 10, 18 and 25 hr. Under the optimum HRT of 18 hr, the average TOC concentration and color of the final MBR effluent were 16.8 mg/L and 2 dilution time, respectively. The sludge yield coefficient was 0.13 g MLSS/g TOC and TOC degradation rate was 0.078 kg TOC/（m ^3 ·day）. The final effluent of MBR can meet the reuse criteria of urban recycling water – water quality standard for miscellaneous water consumption GBT18920-2002.
基金Supported by the National Natural Science Foundation of China （20976130 and 20806057）, National Science and Technology Pillar Program of China （2007BAD42B02）, Program for New Century Excellent Talents in University of Ministry of Education of China （No. NCET-08-0386）, and the R＆D program of Tianjin Binhai New Area （2010-BK17C004）..
文摘The reactions of exo-cellulase （cellobiohydrolase, CBH） and endo-cellulase （endoglucanase, EG） were investigated by analyzing the insoluble residues of microcrystalline cellulose （MCC） and filter paper cellulose （FPC） during enzymatic hydrolysis. Molecular parameters including molecular weight and its distribution, degree of polymerization, and radii of gyration were measured by size exclusion chromatography coupled with multi-angle laser light scattering. No significant change in MCC chains was found during the whole reaction period, indicating that CBH digestion follows a layer-by-layer solubilization manner. This reaction mode might be the major reason for slow enzymatic hydrolysis of cellulose. On the other hand, the degree of polymerization of FPC chains decreases rapidly in the initial reaction, indicating that EG digestion follows a random scission manner, which may create new ends for CBH easily. The slopes of the conformation plots for MCC and FPC increase gradually, indicating stronger chain stiffness of cellulose during hvdrolvsis
基金Supported by the National Key R&D Program of China(No.2017YFB0603400)the National Natural Science Foundation of China(No.21436009)Tianjin Research Program of Basic Research and Frontier Technology(No.15JCQNJC43400)
文摘Membrane separation technology has popularized rapidly and attracts much interest in gas industry as a promising sort of newly chemical separation unit operation. In this paper, recent advances on membrane processes for CO_2 separation are reviewed. The researches indicate that the optimization of operating process designs could improve the separation performance, reduce the energy consumption and decrease the cost of membrane separation systems. With the improvement of membrane materials recently,membrane processes are beginning to be competitive enough for CO_2 separation, especially for postcombustion CO_2 capture, biogas upgrading and natural gas carbon dioxide removal, compared with the traditional separation methods. We summarize the needs and most promising research directions for membrane processes for CO_2 separation in current and future membrane applications. As the time goes by, novel membrane materials developed according to the requirement proposed by process optimization with increased selectivity and/or permeance will accelerate the industrialization of membrane process in the near future. Based on the data collected in a pilot scale test, more effort could be made on the optimization of membrane separation processes. This work would open up a new horizon for CO_2 separation/Capture on Carbon Capture Utilization and Storage(CCUS).
基金Supported by the Independent Innovation Fund of Tianjin University(No.1307)
文摘An economic and effective method of preparing enriched 10B boric acid was established by chemical reactionof enriched 10BF3 and CaCO3. A process of boron trifluoride reacting with water was investigated under certainconditions. Calcium carbonate was selected to counteract hydrofluoric acid followed on. Some key operation factorswere investigated, such as temperature, reaction time and the ratio of CaCO3 to 10BF3. The results showed that the yieldof enriched 10B boric acid could reach 97. 2% and the purity was up to 94. 1% under the following conditions: the temperaturewas 50-60,℃, the reaction time was 28 h and the ratio of CaCO3 to 10BF3 was 4. In addition, after recrystallizationand titration analysis, the purity of the product could reach over 99. 2% from 94.1%.
基金Supported by the National Natural Science Foundation of China （No.20476072）.
文摘To date, many models have been developed to calculate the flow field in the structured packing by the computational fluid dynamics （CFD） technique, but little experimental work has been carried out to serve the vali-dation of flow simulation. In this work, the velocity profiles of single-phase flow in structured packing are measured at the Reynolds numbers of 20.0, 55.7 and 520.1, using the laser Doppler velocimetry （LDV）. The time-averaged and instantaneous velocities of three components are obtained simultaneously. The CFD simulation is also carried out to numerically predict the velocity distribution within the structured packing. Comparison shows that the flow pattern, velocity distribution and turbulent kinetic energy （for turbulent flow） on the horizontal plane predicted by CFD simulation are in good agreement with the LDV measured data. The values of the x-and z-velocity components are quantitatively well predicted over the plane in the center of the packing, but the predicted y-component is sig-nificantly smaller than the experimental data. It can be concluded that experimental measurement is important for further improvement of CFD model.
