Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

The present study investigates the separation and recovery of the valuable metals in the sintered NdFeB permanent magnets by solvent extraction, in which neodymium, dysprosium and cobalt are contained as valuable metals. Neo-decanoic and naphthenic acids, and 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A) and bis(2-ethylhexyl) phosphoric acid (D2EHPA) were used as the metal extractants of carboxylic and organophosphorus acids, respectively, to evaluate the separability of the metals by the liquid-liquid extraction equilibrium. With the single metal ion systems, the distribution ratios of the respective metal ions with D2EHPA were the greatest, followed by those with PC-88A, neo-decanoic acid and naphthenic acid. Although the separation of these metal ions with organophosphorus acids were more effective than those with carboxylic acids, the carboxylic acids showed the sufficient separation efficiency to separate these metal ions. Moreover, the stripping operation with the extractant could be conducted in a relatively high pH range compared to the organophosphorus acid extractants. According to these results, the extraction equilibrium using neodecanoic acid extractant was measured with binary metal ion systems to study the effects of the coexisting metal ions. While the ferric and rare earth elements had little influence on the extraction equilibrium, cobalt ion was coextracted by the ferric or rare earth element ion, thereby making the separation efficiency lower. Then, based on consideration of these trends of extraction equilibrium, the separation scheme to recover the valuable metals in the sintered NdFeB permanent magnet is suggested.

DOI： 10.1252/jcej.16we121

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CROATIAN SOC CHEMICAL ENGINEERING TECHNOLOGY  

To control the water quality in the intensive shrimp mariculture pond by uptaking the total ammonia-nitrogen with sterile Ulva sp., the growth rate of sterile Ulva sp. was experimentally measured and the influence of the rate on the water quality control evaluated. The specific growth rate constant of the seaweed increased with the total ammonia-nitrogen concentration, photosynthetic photon flux density and operating temperature. Then the dynamics of ammonia-nitrogen in the modeled culture pond for the intensive shrimp farming in the tropical region were numerically simulated, in which the seaweed was used to uptake ammonia-nitrogen. The seaweed could uptake ammonia-nitrogen effectively during daytime mainly due to the high intensity of sun light, and the total ammonia-nitrogen concentration in the shrimp pond could be kept very low. The required seaweed density to control the total ammonia-nitrogen concentration less than the recommended maximum concentration of 1.0 . 10(-3) kg N m(-3) was estimated to be reasonable.

DOI： 10.15255/CABEQ.2014.2123

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL INDUSTRY PRESS  

The extraction of ethanol with the solvents of aldehydes mixed with m-xylene was studied for the bioethanol concentration process. Fur fural and benzaldehyde were selected as extraction solvents, with which the solubility of water is small, expecting large distribution coefficient of ethanol. The liquid-liquid two-phase region was the largest with rn-xylene solvent, followed by benzaldehyde and furfural. The region of two liquid-liquid phase became larger with the mixed solvent of m-xylene and furfural than that with furfural solvent.The NRTL model was applied to the ethanol-water-furfural-m-xylene system, and the model could well express the liquid-liquid equilibrium of the system. For any solvent used in this study, the separation selectivity of ethanol relative to water decreased as the distribution coefficient of ethanol increased. The separation selectivity with m-xylene was the largest among the employed solvents, but the distribution coefficient was the smallest. The solvent mixture of furfural and in-xylene showed relatively high distribution coefficient of ethanol and separation selectivity, even in the higher mass fraction of m-xylene in the solvent phase.
The ethanol extraction with a countercurrent multistage extractor by a continuous operation was simulated to evaluate the extraction performance. The ethanol content could be concentrated in the extract phase with relatively small number of extraction stages but low yield of ethanol was obtained. (C) 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.

DOI： 10.1016/j.cjche.2015.07.022

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Taylor's University  

The solvent extraction of neodymium, a rare earth metal, was studied with a continuous stirred vessel. One of the widely used extractants, 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A), diluted with kerosene was selected as an extracting organic solvent. First, the extraction equilibrium of neodymium between aqueous and organic phases was measured in a batch-wise experimental run. The distribution ratio of the metal increased with pH and the relation between the distribution ratio and the conditions was investigated using ordinary slope analysis. In the second stage, the continuous operation of the extraction process was carried out in a laboratory scale standard type stirred vessel, with a 0.08m inner diameter, equipped with six flat blade turbine impeller and four baffles conducted under various operating conditions. The fractional yields of neodymium increased as pH, and flow rate ratio of solvent relative to feed increased. The state of liquid-liquid dispersion, which should affect the mass transfer, was also discussed in terms of the drop size and the holdup of the organic dispersed phase.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN ASSOC SOLVENT EXTRACTION  

The separation of nitrogen heterocyclic compounds by an (O/W)/O emulsion liquid membrane was studied. Quinoline and 2-methylnaphthalene were selected as the representative components of nitrogen heterocyclic and homocyclic compounds, and a toluene or heptane solution of these two compounds was used as the model feed oil. Deionized water or an aqueous solution of 1,3-butandiol was used as the membrane solution. Quinoline preferably permeated through the emulsion liquid membrane and could be separated from 2-methylnaphthalene in the model feed oils. The addition of 1,3-butandiol in the membrane solution could enhance the permeation rates. The separation selectivity of quinoline relative to 2-methyLnaphthalene was larger with the toluene feed oil compared with the heptane solution.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier Ltd  

The transesterification of triglyceride with methanol using alkali catalyst was experimentally measured to study the reaction rate of the transesterification in the heterogeneous system. The liquid-liquid dispersions were measured under the various conditions to examine the effects of the agitation conditions on the drop size distributions. The Sauter-mean diameters were obtained to estimate the specific surface area of the liquid-liquid dispersions during the transesterification. Then the model of transesterification rate in the heterogeneous system was shown, and the reaction rate constants were obtained based on the measurement of the transesterification rates. The constant of the first reaction was the smallest, and the first reaction was found to be rate-limiting in transesterification. The activation energies of formation in the transesterification were measured to be positive
the reactions of the transesterification were endothermic. The obtained constant was correlated in terms of temperature and concentration of alkali catalyst. © 2014 Elsevier Ltd.

DOI： 10.1016/j.jece.2014.07.011

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

This study investigates the liquid-liquid equilibrium measured between coal tar absorption oil and aqueous solution of methanol, ethylene glycol, diethylene glycol, triethylene glycol or 1,3-butandiol, which was expected to increase the distribution coefficients of the nitrogen heterocyclic compounds in the coal tar absorption oil. The distribution coefficients of the nitrogen heterocyclic and homocyclic compounds are found to be larger with the aqueous solution of each selected compound than those with water. The distribution coefficients of the nitrogen heterocyclic compounds are found to be higher than those of the homocyclic compounds. For the emulsion liquid membrane permeation, the aqueous solutions of the organic compounds are used as the membrane solutions. The nitrogen heterocyclic compounds selectively permeated with any membrane solution, and the permeation rates of the components in the absorption oil are found to be enhanced relative to those without additive in the membrane solution. The overall volumetric permeation coefficients increased as the distribution coefficients and the effects of the organic compounds in the membrane solution used in the present study.

DOI： 10.1252/jcej.13we153

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN PETROLEUM INST  

Cracked kerosene, aqueous solution of polyoxyethylene sorbitan monooleate (Tween80), and hexane were used as the feed oil, membrane solution, and solvent, respectively. A baffled stirred vessel was used as the permeator. The aromatic components could selectively permeate through the emulsion liquid membrane and the yields of aromatic components were much larger than those of alkane components. The mass transfer rates of aromatic components were less affected by membrane breakage, and the permeation of aromatic components through the emulsion liquid membrane was controlling relative to the overall mass transfer. The overall volumetric permeation coefficients of total aromatic components were ten-fold more than those of total alkane components. The overall volumetric permeation coefficients were affected by the stirring velocity and surfactant mass fraction in the membrane phase. The stirring velocity was important for the dispersion of the emulsion phase in the extract phase and the specific surface area should increase with the stirring velocity. The mass fraction of surfactant in the membrane phase should be appropriately adjusted to achieve larger overall permeation coefficient. The separation selectivity of total aromatic components relative to total alkane components reached more than 10, similar to the previous results of batch liquid-liquid extraction measurements with sulfolane solvent.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN PETROLEUM INST  

Crude palm and Jatropha oils, obtained from Malaysia and Thailand, respectively, were used as low-value feed oils. To remove free fatty acid (FFA) in the feed oils, alkali or acid deacidification treatments were carried out, in which FFA was neutralized with NaOH, and esterified with methanol by H2SO4 catalyst, respectively. Both methods could reduce FFA to low levels, and the following transesterifications with alkali catalysts were successfully carried out. The yields of the treated oils were smaller with alkali than with acid deacidification. Acid deacidification required much longer treatment time than alkali deacidification. Transesterification with NaOH or CH3ONa catalyst could be conducted with the treated oil of FFA mass fraction less than 0.03. CH3ONa catalyst increased the biodiesel yields to more than 0.99 with the treated crude Jatropha oil. Crude palm oil contained more glycerides with shorter chain alkyl fatty acids, which were more reactive to saponification at transesterification, so the yields of biodiesel became lower at the transesterification.

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Language：English   Publishing type：Research paper (scientific journal)  

Ammonia-nitrogen uptake by sterile Ulva sp. was studied for the control of culture pond water of intensive shrimp farming. The uptake rates were measured by batch and semi-continuous operations, and analyzed with the Michaelis-Menten model of uncompetitive inhibition. For the batch uptake operations, the Michaelis-Menten parameters were estimated, and the maximum rate and Michaelis constants were estimated as 3.4 × 10-2 kg kg-1 h-1 and 5.5 × 10-3 kg m-3, respectively. The inhibitory factor increased with the uptake time and with the decrease of the seaweed density. In the cases of semi-continuous operations, the seaweed could continuously treat with the model farming culture solution. Although the ratio of the seaweed density relative to the rate of ammonia-nitrogen generation should be appropriately adjusted to keep lower inhibitory factor in the seaweed, the ammonia-nitrogen concentration could be maintained at a relatively low level during operation. Then the ammonia-nitrogen uptake by the alga water was roughly simulated and operation with moderate density of the algae in the pond could maintain the ammonia-nitrogen concentration at a sufficiently low level in the shrimp farming pond. The suggested treatment process might be attractive to control pond water quality for intensive shrimp farming.

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Language：English   Publishing type：Research paper (scientific journal)  

Mongolian natural zeolites, whose base components were clinoptilolite, mordenite, and chabazite, were characterized in terms of parameters such as their elemental contents, cation exchange capacities, among others. Since the molar ratios of aluminum to silicon for the Mongolian natural zeolites used in this study were lower than those of pure zeolites, it was surmised that the natural zeolite samples contained substantial amounts of impurities. The cation exchange capacities of the natural zeolite samples were dependent on their aluminum content and were greater for the zeolites with higher aluminum contents. Batch equilibrium adsorptions of heavy metals such as copper, zinc, and manganese from model wastewater using the Mongolian natural zeolites were also carried out. The natural zeolites could adsorb and remove the heavy metals from the aqueous model solutions and also helped to adjust pH of the solutions to appropriate levels. The precipitation of the heavy metals in the form of their hydroxides owing to the addition of natural zeolite also aided the removal of the metals. The amounts of the heavy metals adsorbed at saturation as estimated by the Langmuir equation were almost the same for all the metals. In addition, these amounts increased with the pH of the feed solutions as well as with cation exchange capacities of the natural zeolites. Finally, it was found that the adsorption coefficient in the Langmuir equation was correlated with the hydrated ionic radii of the heavy metals being investigated for removal. © 2013 The Society of Chemical Engineers, Japan.

DOI： 10.1252/jcej.12we137

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN ASSOC SOLVENT EXTRACTION  

The separation of coal tar absorption oil by an ionic liquid supported liquid membrane was studied to recover nitrogen heterocyclic compounds. Batch permeation runs with the supported liquid membrane were conducted using an absorption oil-heptane solution as the feed, an aqueous solution of the ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate, as the membrane liquid, and toluene as the solvent. Under all conditions, the nitrogen heterocyclic compounds selectively permeated through the membrane compared to other compounds. The permeation rates, especially for indole, significantly increased with the addition of the ionic liquid. The overall permeation coefficients increased with the addition of the ionic liquid and the separation selectivity of indole to 2-methylnaphthalene increased.

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Language：English   Publishing type：Research paper (scientific journal)  

Separation of coker gas oil (CGO) by solvent extraction was studied for the recovery of aromatic hydrocarbons and upgrade of the oil to diesel fuel oil. CGO was analyzed by gas chromatograph to identify 17 kinds of aromatics, 16 kinds of alkanes and 6 kinds of alkenes, respectively. The liquid-liquid equilibrium extraction was conducted with furfural, sulfolane and methanol solvents. In all cases, the aromatic components in CGO were selectively extracted with the employed solvents. In the case of furfural without water, the distribution ratios of aromatics were larger than other solvents. With the solvent of sulfolane, the separation selectivities of aromatic components relative to nonaromatic components were larger than those with other solvents, although the distribution ratios of aromatics with sulfolane were approximately the same as those with other solvents. Methanol solvent without water could dissolve both aromatics and nonaromatics, thereby exhibiting low separation selectivity. However, the addition of water could improve the separation selectivities of aromatic components as much as those with furfural without water, and the distribution coefficient of methanol was the largest among the solvents used. When the aqueous solutions of sulfolane and methanol were used, di-cyclic aromatic components were selectively extracted among aromatic components. These kinds of solvents can be expected not only for the recovery of aromatic components, but also for the separation of aromatic components. © 2013 The Society of Chemical Engineers, Japan.

DOI： 10.1252/jcej.13we048

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Language：English   Publishing type：Research paper (scientific journal)  

The transesterification of triglyceride with methanol using an alkali catalyst was experimentally measured, and the obtained equilibrium constants were analyzed by the van't Hoff model. The constant for the conversion of triglyceride to diglyceride was the smallest. The standard enthalpies of formation in the transesterification were measured to be positive, i.e., the reaction is endothermic. Next, the transesterification using the countercurrent multistage reactor system was computationally simulated with the equilibrium stage model, in which the equilibrium constants obtained above were used. The concentrations of the triglyceride remaining in the biodiesel fuel product drastically decreased by the reactor staging, and consequently the reaction temperature and the required amount of methanol could be reduced. The transesterification by the countercurrent multistage reactor was found to be attractive because of the efficient production of the biodiesel fuel. © 2013 The Society of Chemical Engineers, Japan.

DOI： 10.1252/jcej.12we285

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

The liquid-liquid equilibria between coal tar absorption oil and water have been measured. The distribution coefficients of nitrogen heterocyclic compounds in absorption oil are larger than those of homocyclic compounds. The separation of absorption oil by emulsion liquid membrane is studied. Nitrogen heterocyclic compounds selectively permeate through liquid membrane relative to homocyclic compounds. For the emulsion liquid membrane permeation, the effects of membrane instabilities on the mass transfer rates are found to be so small that the mass transfer rates due to the membrane instabilities are negligible relative to the permeation rates in this study. The stirring rate and surfactant concentration are influential factors for the overall volumetric permeation coefficient and the coefficient increased with these parameters. The separation selectivities of the heterocyclic compounds relative to the homocyclic compounds are sufficiently large. The correlation between the overall volumetric permeation coefficient and distribution coefficient between the feed and membrane phases was obtained, and useful for designing a liquid membrane separation process.

DOI： 10.1252/jcej.12we250

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN ASSOC SOLVENT EXTRACTION  

Model hydrocarbon mixtures, consisting of alkene or alkane and/or aromatic components, were utilized as feed oils with methanol, furfural or sulfolane as solvents to evaluate solvent extraction for the separation of aromatic components from cracked oils. Aromatic components were selectively extracted relative to alkane or alkene components with all solvents. The distribution coefficients increased in the order of alkane, alkene and aromatic components. Among the aromatic components, the distribution coefficients of tri cyclic components were the highest, followed by those for di and mono cyclic components. For each aromatic components of the same number of benzene rings, the distribution coefficients generally decreased with the carbon number in the molecule. The separation selectivities of aromatic components relative to nonane were higher with sulfolane than those with the other solvents, and sulfolane has the ability to enhance separations among aromatic components.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN PETROLEUM INST  

Demand for motor gasoline has been shrinking in developed countries, so the production of cracked distillates, used as gasoline blend stocks, requires other uses. Aromatics are widely used in the chemical industry and techniques to recover aromatics from the fractions must be developed. In this study, cracked kerosene was selected as an example of cracked distillates and liquid-liquid equilibria with aqueous solutions of sulfolane or methanol were measured. Firstly, the cracked kerosene was analyzed to identify the 23 major components. The distribution coefficients of aromatics were higher than those of alkanes, and the coefficients decreased with higher mass fraction of water in the aqueous phase. The separation selectivities of aromatics relative to nonane increased with the mass fraction of water in the aqueous phase, and with lower carbon number of the aromatics. The separation selectivities were slightly larger with the aqueous phase of sulfolane than with methanol. The distribution coefficients and separation selectivities of total aromatics relative to alkanes were higher with sulfolane aqueous solution than with aqueous solution of methanol. The addition of water could enhance the separation selectivity and the effects were greater for aqueous solution of methanol.

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Language：English   Publishing type：Research paper (scientific journal)  

Ammonia-nitrogen uptake by seaweed was modeled based on the concept of ammonia- nitrogen permeation through cell membrane, and the derived model of uptake rate was experimentally verified. In this study, sterile Ulva sp. was employed as seaweed to treat model culture solution, and the distribution equilibrium of the ammonia-nitrogen between the culture solution and cell inside was measured to obtain the equilibrium. For this measurement, the seaweed was pretreated before the uptake runs to inhibit the assimilation by methionine sulfoximine for removal of the assimilation effects on the uptake rate. The parameters of the distribution equilibrium and permeation rate of ammonia- nitrogen were measured. The pretreated seaweed could uptake ammonia-nitrogen and the ammonia-nitrogen permeated through the cell membrane from the culture solution into the cell according to the concentration gradient. The seaweed saturated with ammonia-nitrogen was immersed in the culture solution without ammonia-nitrogen and it could excrete ammonia-nitrogen once taken in. In both cases of the uptake and excretion, the systems attained equilibrium after around 6 hours. The ammonia-nitrogen concentration in the cell increased with the concentration in the culture solution at equilibrium. The flux of ammonia-nitrogen was almost proportional to the concentration difference, defined as that between the ammonia-nitrogen concentration in the cell and the hypothetical concentration of ammonia-nitrogen in the cell which is in equilibrium with the culture solution. The overall permeation coefficient was measured as 9.1. 10 -3 m h -1 for both cases of uptake and excretion, and this relationship was valid when the concentration difference was large enough relative to the flux.

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Language：Japanese   Publisher：公益社団法人 化学工学会  

DOI： 10.11491/scej.2009f.0.317.0

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Italian Association of Chemical Engineering - AIDIC  

Because the jatropha fruit gives a high yield of oil and has been expanded in many regions, it was selected as a representative of the inedible fruits and was investigated as a multipurpose biomass to be converted to various kinds of fuels and chemicals equivalent to those from fossil resources. Specifically, in this study, the biodiesel and activated carbon were prepared from its oil and shell, respectively. Although crude jatropha oil contained a higher amount of free fatty acid, this acid could be removed prior to alkali transesterification resulting in improvement of the overall biodiesel yield. The transesterification yield of biodiesel from the crude jatropha oil (CJO) was similar to that from used frying oil (UFO), and greater than that from crude palm oil (CPO), which would be attributed to relatively low C16/C18 ratio in the CJO and UFO. The jatropha shell was successfully converted into activated carbon by thermal treatment under either steam or inert atmosphere. The impregnation, particularly with potassium hydroxide, prior to thermal treatment under inert atmosphere provided the activated carbon with a greater porosity comparable to those obtained under steam atmosphere without impregnation. The obtained activated carbon was expected to be utilized in the purification of glycerol, the by-product of biodiesel production, to enhance the feasibility of the biodiesel production. Copyright © 2009, AIDIC Servizi S.r.l.

DOI： 10.3303/CET0918101

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：AIDIC SERVIZI SRL  

Because the jatropha fruit gives a high yield of oil and has been expanded in many regions, it was selected as a representative of the inedible fruits and was investigated as a multipurpose biomass to be converted to various kinds of fuels and chemicals equivalent to those from fossil resources. Specifically, in this study, the biodiesel and activated carbon were prepared from its oil and shell, respectively. Although crude jatropha oil contained a higher amount of free fatty acid, this acid could be removed prior to alkali transesterification resulting in improvement of the overall biodiesel yield. The transesterification yield of biodiesel from the crude jatropha oil (CJO) was similar to that from used frying oil (UFO), and greater than that from crude palm oil (CPO), which Would be attributed to relatively low C(16)/C(18) ratio in the CJO and UFO. The jatropha shell was successfully converted into activated carbon by thermal treatment under either steam or inert atmosphere. The impregnation, particularly with potassium hydroxide, prior to thermal treatment under inert atmosphere provided the activated carbon with a greater porosity comparable to those obtained under steam atmosphere without impregnation. The obtained activated carbon was expected to be utilized in the purification of glycerol, the by-product of biodiesel production, to enhance the feasibility of the biodiesel production.

DOI： 10.3303/CET0918101

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS INC  

An experimental study of mechanical entrainment in W/O/W emulsions is conducted. W/O/W emulsions are stirred for various stirring times under the conditions that mechanical entrainment solely occurs, and changes in volume of the W/O emulsions and size distribution of the internal water droplets are measured. The rate of change in number of the water droplets entrained is found to be proportional to the volume fraction of W/O emulsions. Based on this result, a new model for mechanical entrainment is developed. The calculated change in W/O emulsion volume with time agrees with the observed ones except in the region near phase inversion. Then, phase inversion is discussed.

DOI： 10.1080/01496390802437115

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

The permeation experiments of aromatics-nonaromatics binary model mixtures were conducted using two kinds of spray columns which formed different sizes of O/W emulsion drops, in order to measure the overall volumetric permeation coefficients and the separation selectivities of aromatics components relative to nonaromatics components. The results of these two kinds of spray columns, and those of the packed column which were reported previously, were compared. The overall volumetric permeation coefficient of aromatics components and the separation selectivities increased in the order of the spray column which formed the relatively large emulsion drops the spray column, the emulsion drops of which were rather fine, and the packed column. The packed column was the most effective permeator among the three. The separation selectivity was correlated with the parameter which corresponds to the number of inner oil droplets in the emulsion on the basis of the previous simple model for emulsion liquid membrane permeation (the multi-layer liquid membrane model). The separation selectivity increased as this parameter decreased, so that the separation selectivity of the packed column, whose number of inner droplets was smallest, was reconfirmed to be highest in the three permeators.

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

The separation of a binary model mixture of benzene and hexane by an emulsion liquid membrane process was calculated with a correlation of the emulsion liquid membrane permeation coefficient. The process consisted of a liquid membrane permeator, a countercurrent packed column with a reflux, and three distillators for the recovery of solvent from the extract and raffinate phases, and for enriching benzene in the permeate. A high yield of high purity benzene, and a high purity hexane could be obtained with the permeator and the two solvent recovery distillators. The size of the permeator and the energy required for the separation were reduced by introducing the benzene enriching distillator. The energy requirement for solvent recovery from the extract phase occupied the largest part of the entire process. The energies for solvent recovery from the raffinate and for enriching benzene were relatively lower. Recycling of a stream in the process and the appropriate means of reflux to the permeator allowed the size of the permeator and the energy requirement for the process to be decreased.

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

In the first stage, an attempt was made to select the type of packing for an emulsion liquid membrane process by permeation experiments with an aromatics non-aromatics binary mixture as an inner oil phase in the emulsion. Mechanical entrainment of a portion of the outer oil phase into the membrane phase, which frequently results in unfavorable phase inversion, was not detected at all with any packing. A packing whose surface is wetted with the emulsion (the dispersed phase) was recommended for this separation technique in order to avoid membrane breakage and to improve separation selectivity, whereas a packing which is not wetted with the dispersed phase is used in an ordinary liquid-liquid operation. Secondly, with the emulsion-wettable packing, further experiments were conducted under various conditions and the mass transfer coefficient was correlated. Major resistance to overall permeation resided in the emulsion. Independently of the feed system and the composition, the dimensionless mass transfer coefficient in the emulsion could be correlated by a simple dimensionless equation with two dimensionless numbers. The mass transfer coefficient for the permeation in the opposite direction (the inward permeation) could also be represented roughly by this equation.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ELSEVIER SCIENCE PUBL B V  

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ELSEVIER SCIENCE PUBL B V  

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Language：English   Publisher：SOC CHEMICAL ENG JAPAN  

The main aim of this paper is to improve the current sawmilling process by utilization of the products from thermal treatment of wood residues. Firstly, batch thermal treatments of rubberwood sawdust were conducted under various conditions to study the effects of the conditions on the yields and the characteristics of the products, pyroligneous acid and activated carbons. Sufficient amounts of crude pyroligneous acid and activated carbon were obtained. In all conditions, the produced pyroligneous acid contained the same amount of components which are essential as preservative, e.g., phenolic compounds. The activated carbon especially that produced under steam atmosphere exhibited a relatively high surface area that is suitable as an adsorbent. Secondly, the model aqueous solution of a single harmful phenolic compound contained in the pyroligneous acid was subjected to batch equilibrium adsorptions with the activated carbon prepared by the above treatment. The activated carbon effectively adsorbed the phenolic compounds in the pyroligneous acid. The overall capacity of the rubberwood activated carbon to fully adsorb any component in pyroligneous acid was considerably higher than the amount of the component produced from the same rubberwood sawdust, showing the feasibility of treating the wastewater containing pyroligneous acid with the activated carbon. Finally, based on these experimental results, we synthesized the outline of an improved sawmilling process: the wood residues are thermally treated to obtain pyroligneous acid, activated carbon, and off-gas; the pyroligneous acid is used as wood preservative instead of the conventional toxic one, the wastewater containing the pyroligneous acid is treated by the activated carbon, and the off-gas with addition of residues is used as a heat and energy source for these additional operations. The proposed method is promising and reliable to give the desired performance to improve the manufacturing process and overcome environmental problems.

DOI： 10.1252/jcej.08we166

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Language：English   Publisher：SOC CHEMICAL ENG JAPAN  

We applied Mongolian natural zeolite to adsorptive removal of hexavalent chromium contained in tannery wastewater. At first, characterization was carried out for various kinds of natural zeolites obtained from Tsagaan Tsav and Urgon deposits in Dornogovi province, southeast part of Mongolia. From the X-ray diffractometry analysis, the zeolite samples were composed of mordenite, quartz, gismondine, clinoptilolite, and chabazite, and many of the samples contained clinoptilolite, which is the most abundant natural zeolite. The BET surface areas and the pore volumes of the samples were much lower than those of pure zeolites, and ranged from 15 to 160 m(2)center dot g(-1) and from 0.03 x 10(-6) to 0.1 x 10(-6) m(3)center dot g(-1), respectively. A part of the zeolite samples were modified by a metal cation, barium cation, in order to adsorb hexavalent chromium, which is anion of chromate in aqueous solution. The content of barium in the modified zeolite was much higher than that in the unmodified one, so that the successful zeolite modification could be confirmed. Secondly, batch equilibrium adsorptions of hexavalent chromium from aqueous solution, the model tannery wastewater, by the natural zeolites were carried out. Although the adsorption performances varied with the natural zeolite, all of the zeolites modified by barium cation could adsorb hexavalent chromium favorably and the fractional removal was over 0.9 at maximum, while the unmodified ones could not almost at all. The higher solution pH gave the higher adsorption performance and, then, main adsorbate was CrO(4)(2-), since this species is dominant in higher pH according to the speciation of hexavalent chromate anion. Consequently, we proposed to utilize Mongolian natural zeolite to treat the tannery wastewater containing hexavalent chromium.

DOI： 10.1252/jcej.08we069

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Language：English   Publisher：JAPAN PETROLEUM INST  

Solvent extraction of absorption oil by aqueous solution of methanol was evaluated using a continuous countercurrent spray column. The structure of the spray column is simple so that the mass transfer phenomenon in the column can be easily examined. The measured liquid-liquid equilibria between the absorption oil and aqueous solution of methanol phases required for calculation of mass transfer coefficients were found to agree with previous values. The operability and separability of extraction using the spray column were then studied. The density of the dispersed raffinate phase was sufficiently larger than that of the continuous extract phase to carry out countercurrent operation without entrainment of dispersed phase droplets into the continuous phase or flooding in the range investigated in this study. Mass transfers of components of interest could be detected in the bench scale spray column with effective height of about 0.5 m. The nitrogen heterocyclic compounds were extracted preferentially to other compounds, such as homocyclic compounds, from the absorption oil, and the separation of these compounds was governed by the liquid-liquid equilibrium. The highest yield and separation selectivity of nitrogen compounds with this column were about 0.4 and 30, respectively. Since the overall mass transfer coefficients increased with the flow rate of the continuous extract phase, some mass transfer resistance occurred in the continuous extract phase.

DOI： 10.1627/jpi.50.218

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Language：English   Publisher：SOC CHEMICAL ENG JAPAN  

We studied the practical use of seaweed to remove inorganic nitrogen, especially ammonia-nitrogen, from the intensive shrimp culture ponds in developing countries. At first, we considered and experimentally evaluated the performance of ammonia-nitrogen uptake by seaweed in terms of parameters essential to the designing of intensive mariculture ponds. Based on the mechanism of ammonia-nitrogen uptake by seaweed, it was predicted that the ammonia-nitrogen concentration in the shrimp culture pond could be controlled by keeping it lower than a certain limit of value using a sufficient amount of seaweed with a condition that the rate of ammonia-nitrogen generation was constant. Experimental ammonia-nitrogen uptake runs confirmed this prediction and gave the parameters essential to design the culture pond with seaweed. Secondly, the control of the pond water quality for the practical shrimp culture batch was simulated by simple calculation based on the material balance of ammonia-nitrogen with parameters obtained from the experiments. The concentration of ammonia-nitrogen could be favorably controlled using seaweed in the practical batch and this method found to be feasible. Consequently, the water quality control using ammonia-nitrogen uptake by seaweed was proposed as a simple and convenient method appropriate for the intensive shrimp culture pond in developing countries.

DOI： 10.1252/jcej.40.454

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Language：English   Publisher：JAPAN ASSOC SOLVENT EXTRACTION  

Firstly, the functional groups composing the solvent predicted to be appropriate for the separation of coal tar distillate were selected. Secondly, liquid-liquid equilibria between coal tar distillates and solvents containing fictitious components consisting of the above selected functional groups were estimated by UNIFAC to determine the effects of these groups on the distribution coefficients. Finally, according to these results, solvents containing real components were selected and compared. These results provide useful information for the selection of appropriate extracting solvents.

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Language：English   Publisher：The Japan Petroleum Institute  

Solvent extraction of absorption oil by aqueous solution of methanol was evaluated using a continuous countercurrent spray column. The structure of the spray column is simple so that the mass transfer phenomenon in the column can be easily examined. The measured liquid-liquid equilibria between the absorption oil and aqueous solution of methanol phases required for calculation of mass transfer coefficients were found to agree with previous values. The operability and separability of extraction using the spray column were then studied. The density of the dispersed raffinate phase was sufficiently larger than that of the continuous extract phase to carry out countercurrent operation without entrainment of dispersed phase droplets into the continuous phase or flooding in the range investigated in this study. Mass transfers of components of interest could be detected in the bench scale spray column with effective height of about 0.5 m. The nitrogen heterocyclic compounds were extracted preferentially to other compounds, such as homocyclic compounds, from the absorption oil, and the separation of these compounds was governed by the liquid-liquid equilibrium. The highest yield and separation selectivity of nitrogen compounds with this column were about 0.4 and 30, respectively. Since the overall mass transfer coefficients increased with the flow rate of the continuous extract phase, some mass transfer resistance occurred in the continuous extract phase.<br>

DOI： 10.1627/jpi.50.218

CiNii Books

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Other Link： https://jlc.jst.go.jp/DN/JALC/00296867790?from=CiNii

Language：English   Publisher：JAPAN PETROLEUM INST  

Distillation was applied to separate the extracted components and the aqueous methanolic solution from the aqueous extract phase obtained from the solvent extraction of coal tar distillate. Equilibrium extraction of absorption oil, one of the coal tar distillates, was carried out with aqueous methanolic solution and confirmed that nitrogen heterocyclic compounds in absorption oil were selectively extracted into the solvent phase and these components and homocyclic hydrocarbons etc. could be separated by the extraction. The extract phase obtained from this extraction was separated by batch simple distillation. The distillation of the extract phase produced the liquid in the still consisting of two immiscible phases, extracted component-rich and water-rich phases, and methanol-rich distillate. The extracted and solvent components in the extract phase could be separated. The distillation also achieved further separation between nitrogen compounds and homocyclic hydrocarbons etc., which remained in the recovered aqueous methanolic solution phase. The aqueous methanolic solution recovered from this distillation was reused as the solvent for another equilibrium extraction of absorption oil. The separability between nitrogen compounds and homocyclic hydrocarbons etc. was improved by the extraction with the recovered solvent, because the hydrocarbons etc. remaining in the recovered solvent restrained the transfers of these components from the feed absorption oil into the solvent phase. Based on these experimental results, a continuous steady state process separating coal tar distillate using solvent extraction and distillation was designed. Distillation has the potential to separate the extract phase in the extraction process to separate coal tar distillate.

DOI： 10.1627/jpi.49.326

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Language：English   Publisher：SOC CHEMICAL ENG JAPAN  

We studied nitrate-nitrogen uptake by sterile Ulva sp. under various conditions including tropical ones. The Sterile Ulva sp., which was collected from Yokohama, Japan, removed nitrate-nitrogen in the culture medium. The algae took in nitrate-nitrogen even without light. The uptake rate of nitrate-nitrogen decreased with the increase of the nitrate-nitrogen content in algal cells. The ambient ammonia-nitrogen lowered the rate of nitrate-nitrogen uptake, whereas the ambient nitrate-nitrogen did not affect the ammonia-nitrogen uptake.

DOI： 10.1252/jcej.39.1128

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Language：English   Publisher：SOC CHEMICAL ENG JAPAN  

We applied seaweed to controlling the ammonia-nitrogen content in intensive shrimp aquaculture ponds in developing countries. Sterile Ulva sp. in Kanazawa Bay, Yokohama, Japan, was selected as model algae. The water content in the alga cells was almost the same as the previous result for Ulva lactuca. The rates of ammonia-nitrogen uptake by algae were measured under various conditions including tropical conditions, i.e., higher light flux density and temperature, to know the effects of these conditions. Sterile Ulva sp. could remove ammonia-nitrogen in culture medium effectively. The algae took up ammonia-nitrogen even under no light. Light enhanced assimilation of ammonia-nitrogen in the alga cell. The tropical condition enhanced ammonia-nitrogen uptake by the alga. The ammonia-nitrogen uptake rate decreased with an increasing ammonia-nitrogen content in the alga cell. Based on these experimental results, we studied the mechanism of ammonia-nitrogen uptake by algae in terms of a Michaelis-Menten model with an inhibitory effect. The ammonia-nitrogen uptake obeyed the Michaelis-Menten model with uncompetitive inhibition by the inhibitor working on the complex of ammonia-nitrogen and its carrier, and the ammonia-nitrogen content in an alga cell was positively related to the inhibitory effect on ammonia-nitrogen uptake. Consequently, the uptake by alga was proposed for controlling the ammonia-nitrogen content in shrimp aquaculture ponds in developing countries, and useful information for shrimp pond design was provided.

DOI： 10.1252/jcej.39.247

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Language：English   Publisher：SOC CHEMICAL ENG JAPAN  

We applied seaweed to controlling the ammonia-nitrogen content in intensive shrimp aquaculture ponds in developing countries. Sterile Ulva sp. in Kanazawa Bay, Yokohama, Japan, was selected as model algae. The water content in the alga cells was almost the same as the previous result for Ulva lactuca. The rates of ammonia-nitrogen uptake by algae were measured under various conditions including tropical conditions, i.e., higher light flux density and temperature, to know the effects of these conditions. Sterile Ulva sp. could remove ammonia-nitrogen in culture medium effectively. The algae took up ammonia-nitrogen even under no light. Light enhanced assimilation of ammonia-nitrogen in the alga cell. The tropical condition enhanced ammonia-nitrogen uptake by the alga. The ammonia-nitrogen uptake rate decreased with an increasing ammonia-nitrogen content in the alga cell. Based on these experimental results, we studied the mechanism of ammonia-nitrogen uptake by algae in terms of a Michaelis-Menten model with an inhibitory effect. The ammonia-nitrogen uptake obeyed the Michaelis-Menten model with uncompetitive inhibition by the inhibitor working on the complex of ammonia-nitrogen and its carrier, and the ammonia-nitrogen content in an alga cell was positively related to the inhibitory effect on ammonia-nitrogen uptake. Consequently, the uptake by alga was proposed for controlling the ammonia-nitrogen content in shrimp aquaculture ponds in developing countries, and useful information for shrimp pond design was provided.

DOI： 10.1252/jcej.39.247

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DOI： 10.1627/jpi.49.326

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Thermal decomposition of Lokpanta oil shale from Nigeria was studied by non-isothermal thermogravimetry (TG) and differential thermal analysis (DTA). The experiments were performed in an inert environment with a temperature range of 25 to 600 degrees C. The geochemical characteristics of the oil shale were also investigated by Rock Eval. pyrolysis. Thermal breakdown of the kerogen content of the oil shale takes place mainly at the temperature range of 300 to 570 degrees C. The estimated decomposable kerogen content of the oil shale ranges from 4.55 to 9.64 wt.%. The activation energies of the pyrolysis process vary from 73.2 to 75.0 kJ/mol. The DTA data reveals the exothermic nature of the decomposition process. The results from the geochemical analysis indicate that the oil shale contains sufficient, good quality kerogen to generate both oil and gas upon pyrolysis. (c) 2005 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.enconman.2005.01.001

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Thermal decomposition of Lokpanta oil shale from Nigeria was studied by non-isothermal thermogravimetry (TG) and differential thermal analysis (DTA). The experiments were performed in an inert environment with a temperature range of 25 to 600 degrees C. The geochemical characteristics of the oil shale were also investigated by Rock Eval. pyrolysis. Thermal breakdown of the kerogen content of the oil shale takes place mainly at the temperature range of 300 to 570 degrees C. The estimated decomposable kerogen content of the oil shale ranges from 4.55 to 9.64 wt.%. The activation energies of the pyrolysis process vary from 73.2 to 75.0 kJ/mol. The DTA data reveals the exothermic nature of the decomposition process. The results from the geochemical analysis indicate that the oil shale contains sufficient, good quality kerogen to generate both oil and gas upon pyrolysis. (c) 2005 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.enconman.2005.01.001

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Language：English   Publisher：JAPAN PETROLEUM INST  

Solvent extraction was applied to the separation of tar light oil and absorption oil, and solvent recovery in the separation of these coal tar fractions by extraction with secondary oil solvent. The liquid-liquid equilibria were measured with various combinations of oil and aqueous methanol phases that occur throughout the whole extraction process. Based on the equilibrium results, a process separating absorption oil and tar light oil simultaneously with a single aqueous solvent is suggested, in which the two feed oils also act as secondary solvents for mutual separation. In the separation of feed oils by aqueous methanol solution as solvent, nitrogen heterocyclic compounds in the absorption oil and the tar light oil were extracted preferentially to other compounds including homocyclic hydrocarbons and oxygen heterocyclic compounds. In the solvent recovery in the separation of absorption oil, the aqueous extract phase containing aqueous solvent and extractants was separated by tar light oil as secondary oil solvent. In the solvent recovery in the separation of tar light oil, the aqueous extract phase was separated by absorption oil as the secondary oil solvent. The distribution coefficients were not affected by the type of oil phase of coal tar fraction and by the presence of the extractants in the aqueous phase. The distribution coefficients in all cases of oil phases of absorption oil and tar light oil could be classified into three groups: monocyclic nitrogen compounds, bicyclic nitrogen compounds, and other compounds including hydrocarbons and oxygen compounds. By integrating the two separation processes of absorption oil and tar light oil into one process separating both coal tar fractions simultaneously with a single aqueous solvent, several extractors and solvents required in the two separate processes can be eliminated.

DOI： 10.1627/jpi.48.60

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Language：English   Publisher：JAPAN ASSOC SOLVENT EXTRACTION  

The multi-stage countercurrent process to remove hydrocarbon contaminants from water with the magnetic particles has been modified from the previous process. A means of continuous contact between the contaminated water phase to be treated and the magnetic particles without any additional water stream to carry the particle has been developed. Multiple magnetic fields and/or tanks for temporary storage of the aqueous phase enabled the process to be operated stagewise and countercurrently. The removal of hydrocarbon in water by this modified process was calculated using simple basic equations derived from the previous experimental results to determine the practical feasibility of the process. This process calculation showed that the hydrocarbon contaminating the water could be removed under practical operation conditions and that the yield of the contaminant was quite high especially with a higher flow rate of the magnetic particles. Consequently, the feasibility of this novel process was confirmed.

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Language：English   Publisher：ELSEVIER SCIENCE BV  

The thermal behavior of the Nigerian oil sand bitumen in an oxidizing environment was studied using non-isothermal thermogravimetric analysis (TGA) and differential thermal analysis (DTA). This condition can occur during in situ thermal recovery. The kinetics of the reactions was also determined by Arrhenius plot method.
Three regions of weight loss corresponding to low-temperature oxidation, fuel deposition and high temperature oxidation were identified. Increasing the heating rate caused a shift in the reaction regions and peak temperatures to higher temperatures. No effect of gas flow rate was observed on the reactions. The oil sands have lower peak temperatures and activation energies compared with their corresponding bitumen extracts, suggesting a catalytic effect of sand on the reactions. The DTA revealed the exothermic nature of the reactions. The exothermicity increased with increasing heating rate.
The results of this study showed that the heating rate and the presence of sand have significant effect on the thermo-oxidative reactions of the bitumen. (C) 2003 Elsevier B.V. All rights reserved.

DOI： 10.1016/S0040-6031(03)00192-8

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Language：English   Publisher：ELSEVIER SCIENCE BV  

The permeation of erythromycin, macrolide antibiotics, into a W/O emulsion globule was simulated with the multi-layer liquid membrane model and the formation of the unfavorable concentration profile in an emulsion globule, this would cause the low separation performance. It was, therefore, proposed that to control the formation of the concentration profile, the feed phase and emulsion should be contacted as the dispersed and continuous phases, respectively, in a spray column contactor. A series of permeation experiments were conducted by both batch and continuous operations with a spray column (height: 0.5 m, i.d.: 0.027 m). In the cases of batch permeation runs, erythromycin permeated through the membrane phase and was concentrated in the stripping phase. By the new contacting method, the improvement in the separation performance was achieved, also the stability of the emulsion membrane improved, specifically mechanical entrainment. Finally, a theoretical evaluation of the permeations with respect to the dispersion in the column is discussed. (C) 2002 Published by Elsevier Science B.V.

DOI： 10.1016/S0376-7388(02)00179-5

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Language：Japanese   Publisher：SOC CHEMICAL ENG JAPAN  

The permeation of a binary model mixture though an O/W/O emulsion liquid membrane was studied experimentally. Considerable axial mixing and coalescence of the emulsion drops were observed near the distributor, which atomized the emulsion, as reported previously. The diameters of the emulsion drops in the middle to bottom section of the column increased, that is, the average specific interfacial area between the emulsion and solvent decreased with column height. The overall volumetric permeation coefficients of the permeates, therefore, fell with column height. There was no substantial effect of the height on the separation factor.

DOI： 10.1252/kakoronbunshu.28.485

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Language：English   Publisher：SOC CHEMICAL ENG JAPAN  

It is essential to know the mechanism and mass transfer rate of hydrocarbon permeation in the column type apparatus, which will be used as a permeator in a practical stage, for the permeator design, the selections of operating conditions, and, furthermore, the process design. The objective of this paper was to obtain the information on this mass transfer rate in the packed column selected among various column type permeators by authors in the previous study.
The permeation of hydrocarbon in the packed column was simulated by the multi-layer liquid membrane model. In the first, the results of this simulation were compared with those of the previous experiments. The dimensionless overall permeation coefficients estimated by the model agreed roughly with the experimental results. This revealed that this simple model could be used to study the mass transfer rate in the column. Secondly, further calculations by the model were carried out under wider ranges of operation factors. These calculations could clarify the effects of these factors on the rate.
The information acquired in these calculations can be useful for the permeator design, selections of operating conditions, and the design of other operations accompanying the permeator in the liquid membrane process, e.g., the emulsifier.

DOI： 10.1252/jcej.35.94

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Language：Japanese   Publisher：Society of Chemical Engineers  

The permeation of a binary model mixture though an O/W/O emulsion liquid membrane was studied experimentally. Considerable axial mixing and coalescence of the emulsion drops were observed near the distributor, which atomized the emulsion, as reported previously. The diameters of the emulsion drops in the middle to bottom section of the column increased, that is, the average specific interfacial area between the emulsion and solvent decreased with column height. The overall volumetric permeation coefficients of the permeates, therefore, fell with column height. There was no substantial effect of the height on the separation factor.

DOI： 10.1252/kakoronbunshu.28.485

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DOI： 10.1627/jpi1958.44.178

CiNii Books

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Language：English   Publisher：JAPAN PETROLEUM INST  

The process for removing toxic benzene from reformate based on an emulsion liquid membrane and distillation was improved and the calculation results of the new and old processes were compared. In the new process, benzene and non-aromatic hydrocarbons with boiling points close to that of benzene are removed from the reformate by two ordinary distillators to yield low-benzene reformate. The benzene and non-aromatic hydrocarbons are separated by the liquid membrane. The process calculation was carried out based on the previous empirical correlation of the mass transfer coefficient in the packed column permeator. Low-benzene reformate of the same flow rate and benzene content as in the previous process could be obtained by distillators with practical numbers of stages and operating conditions. The total aromatics content in the low-benzene reformate was higher than that of the original reformate, in contrast to the previous process. The octane number of the low-benzene reformate is thus higher than that of the original reformate. The yield of benzene was almost the same and the mass fraction of benzene in the product considerably increased. The flow rate of the stream to the permeator, consisting of the benzene and non-aromatics removed from the reformate, was naturally smaller than that in the previous process, where the original reformate was fed directly to the permeator. Therefore, the new process can treat larger amounts of the reformate than the previous process with the equivalent size of permeator. In the solvent recovery step, both the number of distillation stages and the heat energy required could be reduced. Solvent recovery absorbed the major part of the energy for the whole process. The energy requirement for the whole process was therefore lowered.

DOI： 10.1627/jpi1958.43.409

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Language：English   Publisher：JAPAN PETROLEUM INST  

The process for removing toxic benzene from reformate based on an emulsion liquid membrane and distillation was improved and the calculation results of the new and old processes were compared. In the new process, benzene and non-aromatic hydrocarbons with boiling points close to that of benzene are removed from the reformate by two ordinary distillators to yield low-benzene reformate. The benzene and non-aromatic hydrocarbons are separated by the liquid membrane. The process calculation was carried out based on the previous empirical correlation of the mass transfer coefficient in the packed column permeator. Low-benzene reformate of the same flow rate and benzene content as in the previous process could be obtained by distillators with practical numbers of stages and operating conditions. The total aromatics content in the low-benzene reformate was higher than that of the original reformate, in contrast to the previous process. The octane number of the low-benzene reformate is thus higher than that of the original reformate. The yield of benzene was almost the same and the mass fraction of benzene in the product considerably increased. The flow rate of the stream to the permeator, consisting of the benzene and non-aromatics removed from the reformate, was naturally smaller than that in the previous process, where the original reformate was fed directly to the permeator. Therefore, the new process can treat larger amounts of the reformate than the previous process with the equivalent size of permeator. In the solvent recovery step, both the number of distillation stages and the heat energy required could be reduced. Solvent recovery absorbed the major part of the energy for the whole process. The energy requirement for the whole process was therefore lowered.

DOI： 10.1627/jpi1958.43.409

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Language：Japanese   Publisher：JAPAN PETROLEUM INST  

The liquid-liquid equilibrium properties (distribution coefficient and separation selectivity) between the feed of coal tar absorption oil fraction and the solvent (aqueous solution of methanol or that of tetrahydrothiophene-1,1-dioxide (sulfolane)) were experimentally measured with changing various conditions (water content in the solvent, etc.) in order to study the performance of operation and of separation. Nitrogen heterocyclic compounds (2,3-benzopyridine (quinoline), 3,4-benzopyridine (isoquinoline), and 2,3-benzopyrrole (benzo[b] pyrrole, indole)) were extracted preferentially to aromatic hydrocarbon (2-methylnaphthalene) in all cases. The distribution coefficients of heterocyclic compounds and aromatic hydrocarbon decreased, and the separation selectivities of the heterocyclic compounds relative to the aromatic hydrocarbon increased with the water content in the extract. The aqueous solution of methanol was superior as a solvent to that of sulfolane in terms of both operation and separation performances. The above distribution coefficients were used to carry out the simple process simulation of extraction operation where the solvent was the aqueous solution of methanol. The multi-stage structure of equilibrium stage and countercurrent contact between the feed and the solvent improved the concentrations and yields of the heterocyclic compounds in the product that indicated process feasibility of the separation technique.

DOI： 10.1627/jpi1958.43.339

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DOI： 10.1627/jpi1958.43.339

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Language：English   Publisher：JAPAN PETROLEUM INST  

This paper simulates a process for recovering dimethylnaphthalene isomers (DMN) from light cycle oil (LCO), a by-product in cracked gasoline manufacture. The process involves a multistage emulsion liquid membrane permeator for separating aromatics from paraffins in LCO and four distillation towers of which two towers are used to recover solvent from raffinate and permeate and the others are used to separate DMN from other aromatics in permeate. Stirred vessels are employed as contactors. Prior to the simulation, a series of continuous experiments on emulsion liquid membrane permeation were conducted to collect permeation coefficient data. The permeation coefficient data obtained was thereafter used to develop an empirical correlation needed for the simulation. During the simulation, the effects of permeator variables on the energy demands of the distillation towers and on the yield of DMN were investigated at a fixed DMN concentration in the product. The permeator variables studied included solvent-to-feed ratio, stirring rate, number of stages, permeator reflux ratio, and stage volume, as well as the kinds of solvents. DMN yield increased with stirring rate, number of stages, and stage volume, decreasing with permeator reflux ratio, and not affected significantly with solvent-to-feed ratio. The lighter the solvent, the lower were the energy demand and DMN yield. In the conditions of the study, about 80% of DMN in LCO could be recovered. Most of the energy consumed was used to recover the solvent. A quick analysis showed that the energy demands might be met by utilizing the raffinate obtained.

DOI： 10.1627/jpi1958.42.136

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Language：English   Publisher：SOC CHEMICAL ENG JAPAN  

Erythromycin, a macrolide antibiotic, permeates through liquid membranes without a carrier. The contribution of local resistances to the overall permeation resistance is conceived from the permeation mechanism.
According to measured distribution equilibria of erythromycin between aqueous and oil phases and previously reported dissociation equilibrium of erythromycin in the aqueous phase, the distribution coefficient of free erythromycin is constant for each oil phase and independent of proton concentration.
In a supported liquid membrane, a high degree of concentration is attained in the case of a 1-decanol membrane. Not only the membrane phase but also the two aqueous phases contribute to overall resistance. For the heptane membrane, the controlling step is predicted to be in the membrane phase.
An emulsion liquid membrane also concentrates erythromycin in the stripping phase, however, it gives a low degree of concentration which is ascribed to undesirable reduction of the overall permeation coefficient. For a m-xylene membrane, the controlling resistance is in the membrane and stripping phases, and for the heptane membrane, it is in the membrane phase.

DOI： 10.1252/jcej.31.47

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Language：English   Publisher：SOC CHEMICAL ENG JAPAN  

Erythromycin, a macrolide antibiotic, permeates through liquid membranes without a carrier. The contribution of local resistances to the overall permeation resistance is conceived from the permeation mechanism.
According to measured distribution equilibria of erythromycin between aqueous and oil phases and previously reported dissociation equilibrium of erythromycin in the aqueous phase, the distribution coefficient of free erythromycin is constant for each oil phase and independent of proton concentration.
In a supported liquid membrane, a high degree of concentration is attained in the case of a 1-decanol membrane. Not only the membrane phase but also the two aqueous phases contribute to overall resistance. For the heptane membrane, the controlling step is predicted to be in the membrane phase.
An emulsion liquid membrane also concentrates erythromycin in the stripping phase, however, it gives a low degree of concentration which is ascribed to undesirable reduction of the overall permeation coefficient. For a m-xylene membrane, the controlling resistance is in the membrane and stripping phases, and for the heptane membrane, it is in the membrane phase.

DOI： 10.1252/jcej.31.47

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The decolorization of synthetic melanoidin was studied using activated carbon from cane bagasse obtained from Thailand and Brazil. Melanoidin, a nitrogenous brown polymer present in molasses' wastewater, is formed on the interaction between amino acids and carbohydrates. Bagasse, another by-product in the sugar industry, is a cheap material suitable for the preparation of activated carbon.
Samples of cane bagasse were carbonized using nitrogen gas at 300 degrees C and activated with steam at 800 degrees C in a ceramic boat inside a horizontal electric furnace consisting of a batch reactor. Yields were determined and values of 10-20% were obtained. Proximate analyses show that the bagasse samples appear to be adequate precursors for activated carbon because of their low ash content. The activated carbons were characterized for their adsorptive capacities on melanoidin. Results showed that the activated carbons have high adsorptive capacities that favorably compare well with a commercial activated carbon. BET surface areas were determined using nitrogen gas for adsorption and results showed surface areas greater than 400 m(2) g(-1), the value for most commercial activated carbons. The activated carbons produced are therefore comparable commercial ones. Regeneration of the spent carbon showed an increase in the adsorptive capacity and yield. (C) 1997 Elsevier Science Ltd.

DOI： 10.1016/S0008-6223(97)00105-X

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DOI： 10.1627/jpi1958.40.107

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DOI： 10.1627/jpi1958.40.107

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The decolorization of synthetic melanoidin was studied using activated carbon from cane bagasse obtained from Thailand and Brazil. Melanoidin, a nitrogenous brown polymer present in molasses' wastewater, is formed on the interaction between amino acids and carbohydrates. Bagasse, another by-product in the sugar industry, is a cheap material suitable for the preparation of activated carbon.
Samples of cane bagasse were carbonized using nitrogen gas at 300 degrees C and activated with steam at 800 degrees C in a ceramic boat inside a horizontal electric furnace consisting of a batch reactor. Yields were determined and values of 10-20% were obtained. Proximate analyses show that the bagasse samples appear to be adequate precursors for activated carbon because of their low ash content. The activated carbons were characterized for their adsorptive capacities on melanoidin. Results showed that the activated carbons have high adsorptive capacities that favorably compare well with a commercial activated carbon. BET surface areas were determined using nitrogen gas for adsorption and results showed surface areas greater than 400 m(2) g(-1), the value for most commercial activated carbons. The activated carbons produced are therefore comparable commercial ones. Regeneration of the spent carbon showed an increase in the adsorptive capacity and yield. (C) 1997 Elsevier Science Ltd.

DOI： 10.1016/S0008-6223(97)00105-X

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A supported liquid membrane technique was applied for extraction of erythromycin A from its dilute slightly alkaline aqueous solutions. 1-decanol was used as an intermediate (membrane) phase and a buffered acidic aqueous solution to strip the organic membrane.
The antibiotic distribution coefficient between the membrane used and the feed was found to be 122, providing relatively high solute fluxes across the membrane, although the transfer resistance remains in the filled membrane pores.
It was shown that due to existing equilibrium between the protonised and non-protonised forms of the solute, the antibiotic can be completely transferred and concentrated in the receiving, low pH solution.

DOI： 10.1016/0376-7388(95)00282-0

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The permeation experiments of aromatics-nonaromatics binary model mixtures were conducted using two kinds of spray columns which formed different sizes of O/W emulsion drops, in order to measure the overall volumetric permeation coefficients and the separation selectivities of aromatics components relative to nonaromatics components. The results of these two kinds of spray columns, and those of the packed column which were reported previously, were compared. The overall volumetric permeation coefficients of aromatics components and the separation selectivities increased in the order of the spray column which formed the relatively large emulsion drops, the spray column, the emulsion drops of which were rather fine, and the packed column. The packed column was the most effective permeator among the three. The separation selectivity was correlated with the parameter which corresponds to the number of inner oil droplets in the emulsion on the basis of the previous simple model for emulsion liquid membrane permeation (the multi-layer liquid membrane model). The separation selectivity increased as this parameter decreased, so that the separation selectivity of the packed column, whose number of inner droplets was smallest, was reconfirmed to be highest in the three permeators. © 1996, The Society of Chemical Engineers, Japan. All rights reserved.

DOI： 10.1252/kakoronbunshu.22.1234

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Transfer of hydrocarbons in an O/W emulsion drop was simulated by the dimensionless multi-layer liquid membrane model in order to find a way of improving the separation selectivity of an emulsion liquid membrane, which will be of practical use. The results suggested that the selectivity of the emulsion membrane, lowered by the unfavorable concentration profile which appeared in an emulsion drop, would be improved by decreasing the number of inner oil droplets in the emulsion drop.
A series of batch permeation experiments were conducted with a one-dimensional supported liquid membrane and an emulsion liquid membrane. The separation selectivity of the supported membrane was equivalent to that of the mono-layer liquid membrane and that of the emulsion membrane was lower, Selectivity of the emulsion membrane could be improved by decreasing the number of inner droplets in the emulsion drop as suggested by the simulation, These experimental confirmations of the suggested model led to a simple way of improving the separation selectivity of this separation technique.

DOI： 10.1252/jcej.28.38

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To develop the design procedure for preparative liquid chromatography of macrolide antibiotics, parameters for the adsorption isotherms and for the ralated rate processes were estimated experimentally and the measured and calculated chromatograms were compared.
Erythromycin and erythromycin ethyl succinate were selected as a representative antibiotic and a model impurity, respectively. Parameters in Langmuir type adsorption isotherms and rate parameters for silica gel-organic solvent systems were obtained from the values of the moments for the single component chromatograms. Parameters for the adsorption isotherms showed that the extent of separation between solutes varied greatly with the kind and composition of the mobile phase. The mass transfer coefficients in the stationary and mobile phases were compared with the previous correlations. Binary chromatograms were calculated numerically with the use of Markham-Benton type isotherms for the binary solutes and the values of the said parameters. The calculated and measured chromatograms agreed fairly well over all operating conditions.
In conclusion, it was recommended for the design of preparative liquid chromatography to calculate chromatograms of macrolide antibiotics by use of parameters estimated by the method presented here.

DOI： 10.1252/kakoronbunshu.21.158

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Language：Japanese   Publisher：SOC CHEMICAL ENG JAPAN  

To develop the design procedure for preparative liquid chromatography of macrolide antibiotics, parameters for the adsorption isotherms and for the ralated rate processes were estimated experimentally and the measured and calculated chromatograms were compared.
Erythromycin and erythromycin ethyl succinate were selected as a representative antibiotic and a model impurity, respectively. Parameters in Langmuir type adsorption isotherms and rate parameters for silica gel-organic solvent systems were obtained from the values of the moments for the single component chromatograms. Parameters for the adsorption isotherms showed that the extent of separation between solutes varied greatly with the kind and composition of the mobile phase. The mass transfer coefficients in the stationary and mobile phases were compared with the previous correlations. Binary chromatograms were calculated numerically with the use of Markham-Benton type isotherms for the binary solutes and the values of the said parameters. The calculated and measured chromatograms agreed fairly well over all operating conditions.
In conclusion, it was recommended for the design of preparative liquid chromatography to calculate chromatograms of macrolide antibiotics by use of parameters estimated by the method presented here.

DOI： 10.1252/kakoronbunshu.21.158

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DOI： 10.1252/kakoronbunshu.21.936

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Language：English  

Light cycle oil (LCO) contains valuable aromatic hydrocarbons, some of which become intermediates for engineering plastics. To select the best solvent for extraction of these aromatics (naphthalene group), several conventional solvents, which have been employed commercially as extraction solvents for the light aromatics, were tested, through measurement of distribution of several selected hydrocarbons between the solvent and oil phases. The solvents used were sulfolane, dimethyl sulfoxide (DMSO), diethylene glycol and dimethyl formamide. Among many components in the LCO A (LCO+nonane), several hydrocarbons with carbon number of 9-12 were selected for analysis. From the coefficients of distribution and selectivities of naphthalene group, in reference to nonane, DMSO seemed to be the best solvent for separation between naphthalene group and paraffin in the LCO. Furthermore, effects of operation parameters for extraction of naphthalene group in the LCO A were studied by batch equilibrium extraction with DMSO and water mixture as solvent. Distribution coefficients of naphthalene group were found to increase with decreasing temperature, whereas, selectivities of naphthalene group in reference to nonane increase with decreasing temperature. The effect of addition of water in solvent increases the selectivity, with a simultaneous decrease in coefficient of distribution. The coefficients of distribution and selectivities of naphthalene group, in reference to nonane or a mixture of 10 isomers of dimethylnaphthalenes, decreased with increasing carbon number. Selectivity of individual isomer, however, was roughly equal to unity. With DMSO and water mixture as solvent, mass transfer rates for naphthalene group were measured in a baffled batch vessel, agitated with six-flatblade turbines. Continuous phase mass transfer coefficients are measured. © 1995, The Japan Petroleum Institute. All rights reserved.

DOI： 10.1627/jpi1958.38.114

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Language：English  

Transfer of hydrocarbons in an O/W emulsion drop was simulated by the dimensionless multi-layer liquid membrane model in order to find a way of improving the separation selectivity of an emulsion liquid membrane, which will be of practical use. The results suggested that the selectivity of the emulsion membrane, lowered by the unfavorable concentration profile which appeared in an emulsion drop, would be improved by decreasing the number of inner oil droplets in the emulsion drop. A series of batch permeation experiments were conducted with a one-dimensional supported liquid membrane and an emulsion liquid membrane. The separation selectivity of the supported membrane was equivalent to that of the mono-layer liquid membrane and that of the emulsion membrane was lower. Selectivity of the emulsion membrane could be improved by decreasing the number of inner droplets in the emulsion drop as suggested by the simulation. These experimental confirmations of the suggested model led to a simple way of improving the separation selectivity of this separation technique. © 1995, The Society of Chemical Engineers, Japan. All rights reserved.

DOI： 10.1252/jcej.28.38

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DOI： 10.1252/kakoronbunshu.21.349

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

A method was proposed for measuring the parameters of the adsorption isotherm and mass-transfer coefficients using an analytical column in order to simulate chromatograms of preparative liquid chromatography (prep LC). Close agreement between measured and simulated chromatograms was obtained for prep LC purification of erythromycin. The results showed that this method can be fully applied for scale-up from analytical LC to prep LC.

DOI： 10.1252/kakoronbunshu.19.680

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

The dynamic holdup of O/W emulsion in a column packed with McMahon for hydrocarbon separation by a liquid membrane was correlated empirically. The emulsion flowed as a film on the packing surface, because the hydrophilic packing was selected so as to be wetted with the emulsion and to reduce the membrane breakage. The emulsion flow was analogous tb liquid flow for a gas -liquid system with liquid - wettable packing, unlike dispersed-phase flow for an ordinary liquid-liquid system. The correlation roughly fitted previous results for liquid holdup in the gas - liquid systems.

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

A method was proposed for measuring the parameters of the adsorption isotherm and mass-transfer coefficients using an analytical column in order to simulate chromatograms of preparative liquid chromatography (prep LC). Close agreement between measured and simulated chromatograms was obtained for prep LC purification of erythromycin. The results showed that this method can be fully applied for scale-up from analytical LC to prep LC.

DOI： 10.1252/kakoronbunshu.19.680

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Language：English  

The dynamic holdup of O/W emulsion in a column packed with McMahon for hydfocarbon separation by a liquid membrane was correlated empirically. The emulsion flowed as a film on the packing surface, because the hydrophilic packing was selected so as to be wetted with the emulsion and to reduce the membrane breakage. The emulsion flow was analogous to liquid flow for a gas - liquid system with liquid - wettable packing, unlike dispersed - phase flow for an ordinary liquid -liquid system. The correlation roughly fitted previous results for liquid holdup in the gas - liquid systems. © 1993, The Society of Chemical Engineers, Japan. All rights reserved.

DOI： 10.1252/kakoronbunshu.19.676

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

Axial dispersion coefficients and Peclet numbers for fixed beds of various fine particles were measured within the range of mean particle diameter from 4.8x10(-5)m to 1.7x10(-4)m, and that of Reynolds number from 1.0x10(-2) to 2.0. From the experimental results, the effects of Reynolds number, particle diameter and particle size distribution on the Peclet number were investigated and a correlation was proposed. It was suggested from the results of simulation of the chromatogram for preparative HPLC that the Peclet number affected the shape of the chromatogram when the linear velocity of mobile phase was low and the adsorption coefficient was small.

DOI： 10.1252/kakoronbunshu.18.965

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