This paper presents a flexible model and a robust algorithm for simulation of multi-stage multi-component separation processes in which multiple feeds, side streams, strippers and/or side heat exchangers are involved....This paper presents a flexible model and a robust algorithm for simulation of multi-stage multi-component separation processes in which multiple feeds, side streams, strippers and/or side heat exchangers are involved. The improved algorithm effectively accelerates the speed of convergence and offers better stability by introducing a damping factor for updating the stripping factor, and also reduces the requirement on the initial estimates by updating the Joacobian matrix directly with the stripping factor and enthalpy. On the other hand, an efficient algorithm was proposed to solve the approximate tri-diagonal matrix (containing the off-band elements) derived from the material balance equations (M equations) and phase equilibrium equations (E equations), the advantages and simplicity of the “insideout” technique of the Russell are retained. The present algorithm was demonstrated to be effective in simulating complex separation columns with typical case studies.展开更多
PS/SiO2 particles with core-shell structure were synthesized by coating silica on surface of polystyrene(PS) colloidal particles.The reaction parameters,such as initial tetraethyl orthosilicate(TEOS) concentration,wat...PS/SiO2 particles with core-shell structure were synthesized by coating silica on surface of polystyrene(PS) colloidal particles.The reaction parameters,such as initial tetraethyl orthosilicate(TEOS) concentration,water concentration and reaction temperature,have been investigated to control the thickness of silica shells.The shell thickness was prepositional to the square root of the initial concentration of TEOS and first increased with increasing water concentration,reached a maximum at about 2.0 mol/L and then started decreasing beyond that concentration.It was also found that the shell thickness decreased firstly with the reaction temperature added,then tended to a constant.The so-synthesized PS/SiO2 core-shell particles were directly crystallized into 3-D ordered thin film,then sintered at 570℃ into the ordered macroporous thin film.Compared with the conditional method,the present approach avoids repeatedly filling the precursor in the templetes and save time more.展开更多
Partition behavior of penicillins G and V was studied in a novel three-liquid-phase extraction system,which is composed of butyl acetate (BA),polyethylene glycol (PEG),ammonia sulfate (NH4)2SO4 and water (H2O). The ma...Partition behavior of penicillins G and V was studied in a novel three-liquid-phase extraction system,which is composed of butyl acetate (BA),polyethylene glycol (PEG),ammonia sulfate (NH4)2SO4 and water (H2O). The main components in the top,middle and bottom phases are butyl acetate,polyethylene glycol aqueous solution and ammonia sulfate aqueous solution,respectively. Some parameters such as partition coefficients Di/j and mass fractions Ei of penicillins G and V were determined at the room temperature,respectively. Experimental efforts have been made to investigate the partition behavior of penicillin in the three-liquid-phase extraction system,including initial concentrations of phase-forming components PEG and (NH4)2SO4,PEG molecular weight,pH,initial concentration of penicillin. The results indicated that penicillins G and V have the similar partition behavior. They preferentially distribute into the middle phase with the increase of initial concentration of phase-forming components and into the top phase with the decrease of pH,while partition coefficient Dm/b is hardly affected by pH value. The variation of PEG molecular weight has little effect on mass fractions of penicillin. The increase of initial concentration of penicillins G and V could lead to the increase of Dt/b,Dm/b and the decrease of Dt/m,while their mass fractions in all phases were almost independent on their initial concentrations.展开更多
The yield of magnesium hydroxide was investigated via response surface methodology using bischofite and aqueous ammonia as raw materials. The experimental results indicated that the effects of reaction temperature,mag...The yield of magnesium hydroxide was investigated via response surface methodology using bischofite and aqueous ammonia as raw materials. The experimental results indicated that the effects of reaction temperature,magnesium ion and aqueous ammonia concentrations on the yield of magnesium hydroxide gradually decreased. In particular,reaction temperature and magnesium ion concentration had a significant influence on the yield. After the regression and fitting of the response value and each factor,the regression equation was obtained. As proven by experiments,the predicted value and actual value showed a good fit. The products of the center experiment were characterized by particle size analysis,scanning electron microscopy,and X-ray diffraction. The results show that the morphology is irregular and shows a lamellar structure. The particles have a narrow size distribution ranging from 0.64 to 0.68 μm of D50 size. The difference in particle size of D10 and D90 is less than 0.91 μm,and the purity very high.展开更多
Alien atom was used to obtain a series of Li Fe1-xLaxPO4/C(x=0,0.002,0.005,0.01,0.015)cathode materials with the aim of investigating the influence of participation of La on the electrochemical behavior of Li Fe PO4/C...Alien atom was used to obtain a series of Li Fe1-xLaxPO4/C(x=0,0.002,0.005,0.01,0.015)cathode materials with the aim of investigating the influence of participation of La on the electrochemical behavior of Li Fe PO4/C.Combination of X-ray diffractometer,scanning electron microscope equipped with energy dispersive spectrometer and high resolution transmission electron microscope was applied.The results show that all the La-doped Li Fe PO4/C samples are olivine type crystals,La ion is sufficiently introduced into the network,and every element is well homogeneously distributed.There are many pore spaces on the surface of particles.The content of carbon in the prepared cathode materials remains 13.6%calculated by TGA/DTA curves,and the particles are wrapped by a uniformly and continuous carbon layer with the thickness of about 2 nm.Similarly,the content of Fe2P also keeps the same basically in all the cathode materials as a result of the similar ratio(2.35)of peak intensity at 36.5o and 37.1o from XRD.The increasing trend is most pronounced at doped 0.005which presents the highest initial discharge capacity of 163 mA-h/g,lowest charge transfer resistance of 5.52-,superior diffuse ability of lithium ion(10-11 cm2/s)and the best capacity retention current rate of about 93%after 50 cycles at 0.1 C.展开更多
Recent studies on hydrogen combustion were reviewed briefly. The laminar flow and combustion of premixed hydrogen/air mixture in a cylindrical channel of a monolith reactor with and without catalytic wall was numerica...Recent studies on hydrogen combustion were reviewed briefly. The laminar flow and combustion of premixed hydrogen/air mixture in a cylindrical channel of a monolith reactor with and without catalytic wall was numerically modeled by solving two-dimensional (2-D) Navier-Stokes (N-S) equations, energy equation, and species equations. Eight gas species and twenty reversible gas reactions were considered. The control volume technique and the SIMPLE algorithm were used to solve the partial differential equations. The streamlines of the flow field, temperature contours, the entrance length, and the concentration fields were computed. It is found that the entrance zone plays an important role on flow and temperature as well as species distribution. Therefore, the flow cannot be assumed either as fully developed or as plug flow. There is a small but strong thermal expansion zone between the wall and the entrance. Both diffusion and convection affect the heat and mass transfer processes in the expansion zone. Thus the equations of momentum, energy and species conservations should be used to describe hydrogen/air combustion in the monolith reactor. The hot-spot location and concentration field of the homogeneous combustion is strongly influenced by the inlet velocity and temperature, and the equivalence ratio. The catalytic combustion of premixed hydrogen/air mixture over platinum catalyst-coated wall in a cylindrical channel was also simulated.展开更多
N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide was synthesized for the application in ionic liquid based electrolytes in lithium ion battery, 10% vinylene carbonate (VC) and 10% 1,3-propane sultone (...N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide was synthesized for the application in ionic liquid based electrolytes in lithium ion battery, 10% vinylene carbonate (VC) and 10% 1,3-propane sultone (PS) were added to the electrolyte system respectively as additives to improve the property of solid electrolyte interface and cyclic performance. The results of cyclic voltammetry showed that homogenous and compact solid electrolyte interface film formed on graphite electrode which was detected by observing the morphology of cycled graphite anode. Charging and discharging performance of LiFePO4/Li half cell was tested in the electrolyte with or without additives. The initial specific discharging capacities were increased to 129.4 and 123.0 mA·h/g by the addition of VC and PS, respectively, compared with that of additive-free electrolyte. The discharging retentions were 88.9% and 84.6% in electrolyte containing VC and PS after 10 cycles.展开更多
The micellization,intermolecular interaction and microenvironment of molecular segments in the mixed aqueous solution of PEO-PPO-PEO triblock copolymer(Pluronic F88,P84 and P123) and Surfynol 104(S104) were studie...The micellization,intermolecular interaction and microenvironment of molecular segments in the mixed aqueous solution of PEO-PPO-PEO triblock copolymer(Pluronic F88,P84 and P123) and Surfynol 104(S104) were studied by nuclear magnetic resonance method.The results showed that the addition of S104 decreased the critical micellization temperature of copolymer.When its concentration was 0.5 g/L,the most reduction was up to more than 10℃ for F88,which was most hydrophilic in the selected copolymers.This reduction was caused by the hydrophobic interaction between S104 molecules and PPO segments.The addition of S104 enhanced the hydration of PEO segments most obviously for P123.And S104 slightly increased the hydration of PPO segments before the micellization,but obviously decreased their hydration after micellization,which was attributed to the hydrophobic interaction mentioned above and temperature rising.This effect was most observable for F88.展开更多
文摘This paper presents a flexible model and a robust algorithm for simulation of multi-stage multi-component separation processes in which multiple feeds, side streams, strippers and/or side heat exchangers are involved. The improved algorithm effectively accelerates the speed of convergence and offers better stability by introducing a damping factor for updating the stripping factor, and also reduces the requirement on the initial estimates by updating the Joacobian matrix directly with the stripping factor and enthalpy. On the other hand, an efficient algorithm was proposed to solve the approximate tri-diagonal matrix (containing the off-band elements) derived from the material balance equations (M equations) and phase equilibrium equations (E equations), the advantages and simplicity of the “insideout” technique of the Russell are retained. The present algorithm was demonstrated to be effective in simulating complex separation columns with typical case studies.
基金Supported by the National Natural Science Foundation of China(No.:20221603)
文摘PS/SiO2 particles with core-shell structure were synthesized by coating silica on surface of polystyrene(PS) colloidal particles.The reaction parameters,such as initial tetraethyl orthosilicate(TEOS) concentration,water concentration and reaction temperature,have been investigated to control the thickness of silica shells.The shell thickness was prepositional to the square root of the initial concentration of TEOS and first increased with increasing water concentration,reached a maximum at about 2.0 mol/L and then started decreasing beyond that concentration.It was also found that the shell thickness decreased firstly with the reaction temperature added,then tended to a constant.The so-synthesized PS/SiO2 core-shell particles were directly crystallized into 3-D ordered thin film,then sintered at 570℃ into the ordered macroporous thin film.Compared with the conditional method,the present approach avoids repeatedly filling the precursor in the templetes and save time more.
基金Supported by the National Natural Science Foundation of China (No.20236050 20406021)+1 种基金 The Innovative Research Group Fund (No. 20236050 20406021)
文摘Partition behavior of penicillins G and V was studied in a novel three-liquid-phase extraction system,which is composed of butyl acetate (BA),polyethylene glycol (PEG),ammonia sulfate (NH4)2SO4 and water (H2O). The main components in the top,middle and bottom phases are butyl acetate,polyethylene glycol aqueous solution and ammonia sulfate aqueous solution,respectively. Some parameters such as partition coefficients Di/j and mass fractions Ei of penicillins G and V were determined at the room temperature,respectively. Experimental efforts have been made to investigate the partition behavior of penicillin in the three-liquid-phase extraction system,including initial concentrations of phase-forming components PEG and (NH4)2SO4,PEG molecular weight,pH,initial concentration of penicillin. The results indicated that penicillins G and V have the similar partition behavior. They preferentially distribute into the middle phase with the increase of initial concentration of phase-forming components and into the top phase with the decrease of pH,while partition coefficient Dm/b is hardly affected by pH value. The variation of PEG molecular weight has little effect on mass fractions of penicillin. The increase of initial concentration of penicillins G and V could lead to the increase of Dt/b,Dm/b and the decrease of Dt/m,while their mass fractions in all phases were almost independent on their initial concentrations.
基金Supported by the Department of Science and Technology of Qinghai Province(No.2010-G-221A)
文摘The yield of magnesium hydroxide was investigated via response surface methodology using bischofite and aqueous ammonia as raw materials. The experimental results indicated that the effects of reaction temperature,magnesium ion and aqueous ammonia concentrations on the yield of magnesium hydroxide gradually decreased. In particular,reaction temperature and magnesium ion concentration had a significant influence on the yield. After the regression and fitting of the response value and each factor,the regression equation was obtained. As proven by experiments,the predicted value and actual value showed a good fit. The products of the center experiment were characterized by particle size analysis,scanning electron microscopy,and X-ray diffraction. The results show that the morphology is irregular and shows a lamellar structure. The particles have a narrow size distribution ranging from 0.64 to 0.68 μm of D50 size. The difference in particle size of D10 and D90 is less than 0.91 μm,and the purity very high.
基金Supported by the National Natural Science Foundation of China(No.21175012)Ministry of Science and Technology(No.2012DFR40240)
文摘Alien atom was used to obtain a series of Li Fe1-xLaxPO4/C(x=0,0.002,0.005,0.01,0.015)cathode materials with the aim of investigating the influence of participation of La on the electrochemical behavior of Li Fe PO4/C.Combination of X-ray diffractometer,scanning electron microscope equipped with energy dispersive spectrometer and high resolution transmission electron microscope was applied.The results show that all the La-doped Li Fe PO4/C samples are olivine type crystals,La ion is sufficiently introduced into the network,and every element is well homogeneously distributed.There are many pore spaces on the surface of particles.The content of carbon in the prepared cathode materials remains 13.6%calculated by TGA/DTA curves,and the particles are wrapped by a uniformly and continuous carbon layer with the thickness of about 2 nm.Similarly,the content of Fe2P also keeps the same basically in all the cathode materials as a result of the similar ratio(2.35)of peak intensity at 36.5o and 37.1o from XRD.The increasing trend is most pronounced at doped 0.005which presents the highest initial discharge capacity of 163 mA-h/g,lowest charge transfer resistance of 5.52-,superior diffuse ability of lithium ion(10-11 cm2/s)and the best capacity retention current rate of about 93%after 50 cycles at 0.1 C.
基金Foundation item: Partially supported by the Key Laboratory of Multiphase Reaction of the Chinese Academy of Sciences State Key of Coal Conversion of the Chinese Academy of Sciences
文摘Recent studies on hydrogen combustion were reviewed briefly. The laminar flow and combustion of premixed hydrogen/air mixture in a cylindrical channel of a monolith reactor with and without catalytic wall was numerically modeled by solving two-dimensional (2-D) Navier-Stokes (N-S) equations, energy equation, and species equations. Eight gas species and twenty reversible gas reactions were considered. The control volume technique and the SIMPLE algorithm were used to solve the partial differential equations. The streamlines of the flow field, temperature contours, the entrance length, and the concentration fields were computed. It is found that the entrance zone plays an important role on flow and temperature as well as species distribution. Therefore, the flow cannot be assumed either as fully developed or as plug flow. There is a small but strong thermal expansion zone between the wall and the entrance. Both diffusion and convection affect the heat and mass transfer processes in the expansion zone. Thus the equations of momentum, energy and species conservations should be used to describe hydrogen/air combustion in the monolith reactor. The hot-spot location and concentration field of the homogeneous combustion is strongly influenced by the inlet velocity and temperature, and the equivalence ratio. The catalytic combustion of premixed hydrogen/air mixture over platinum catalyst-coated wall in a cylindrical channel was also simulated.
基金Supported by National Natural Science Foundation of China (No.20976174)Open-end Fund of National Key Laboratory of Multiphase Complex Systems (No.MPCS-2011-D-06)
文摘N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide was synthesized for the application in ionic liquid based electrolytes in lithium ion battery, 10% vinylene carbonate (VC) and 10% 1,3-propane sultone (PS) were added to the electrolyte system respectively as additives to improve the property of solid electrolyte interface and cyclic performance. The results of cyclic voltammetry showed that homogenous and compact solid electrolyte interface film formed on graphite electrode which was detected by observing the morphology of cycled graphite anode. Charging and discharging performance of LiFePO4/Li half cell was tested in the electrolyte with or without additives. The initial specific discharging capacities were increased to 129.4 and 123.0 mA·h/g by the addition of VC and PS, respectively, compared with that of additive-free electrolyte. The discharging retentions were 88.9% and 84.6% in electrolyte containing VC and PS after 10 cycles.
基金Supported by the National Natural Science Foundation of China (No.20676137,20876158)The GF Fundamental Research Program (No.A1320070102)
文摘The micellization,intermolecular interaction and microenvironment of molecular segments in the mixed aqueous solution of PEO-PPO-PEO triblock copolymer(Pluronic F88,P84 and P123) and Surfynol 104(S104) were studied by nuclear magnetic resonance method.The results showed that the addition of S104 decreased the critical micellization temperature of copolymer.When its concentration was 0.5 g/L,the most reduction was up to more than 10℃ for F88,which was most hydrophilic in the selected copolymers.This reduction was caused by the hydrophobic interaction between S104 molecules and PPO segments.The addition of S104 enhanced the hydration of PEO segments most obviously for P123.And S104 slightly increased the hydration of PPO segments before the micellization,but obviously decreased their hydration after micellization,which was attributed to the hydrophobic interaction mentioned above and temperature rising.This effect was most observable for F88.
