Ryuichi Egashira

• Doctor of Engineering
• Institute of Science Tokyo

To separate both copper and 2,2',2'',2'''-(ethane-1,2-diyldinitrilo)tetraacetic acid (EDTA) from the waste electroless copper plating solution by solvent extraction, the liquid–liquid equilibria of the copper-EDTA complex and unbound EDTA ion were experimentally measured. An organic solution of tri-n-octylmethylammonium chloride (TOMACl) was used a...

Duckweed (Lemna aoukikusa), a common aquatic plant found worldwide, was used to treat a solution polluted with the model antibiotics, ciprofloxacin (fluoroquinolone group) and sulfamethoxazole (sulfonamide group), which were selected because they were frequently present in pharmaceutical wastewater. The plant could grow even in an aqueous solution...

The main aim of this study is to remove lignin, which is one of the main colored substance in palm oil mill effluent (POME), by adsorption using activated carbon prepared from palm kernel shell (PKSAC) for POME decolorization in Thailand’s palm industry. First, PKSAC was prepared by a chemical activation method using orthophosphoric acid and the ef...

Issues related to food wastage have become a significant threat to sustainable development, particularly in developing countries. Cooked rice, reported as one of the abundant regional food wastes, is a...

The main aim of this study is to treat palm oil mill effluent (POME) containing phenol, which is a hazardous compound, using activated carbon (AC) prepared from palm kernel shell (PKS), one of the byproducts of the palm oil industry. First, PKS from Thailand was characterized by proximate, elemental, and thermogravimetric analyses. The high carbon...

In Asia, uneaten cooked rice is the highest portion amongst many forms of food wastes that are thrown away. In order to make use of the thrown-away rice and potentially use it for liquid fuels, steamed Japanese rice was evaluated on biobutanol production through a two-step fermentation by amylase-producing Aspergillus oryzae, and solvent-producing...

To improve biodiesel production from jatropha, its shell, a waste material, was thermally treated to produce activated carbon (AC) and the AC was applied to purification of glycerol from transesterification. The AC was prepared by chemical activation method using H3PO4 as the activation agent. The yield of the chemically activated carbon was better...

For the separation of petroleum-derived heavy fractions by solvent extraction, the liquid-liquid equilibrium extraction of model heavy fractions, binary and multicomponent model oils, with aqueous methanol solutions was measured, and the effects of nitrogen heterocyclic and other coexisting compounds on the equilibrium extraction were studied. The...

Methods for obtaining high-concentration (ca. 40 g/L) ethanol from cassava stem (CS) were explored by investigating the effects of acid hydrolysis conditions, hydrolysate concentration, and intermittent inoculation of yeast on ethanol fermentation. Two-step acid hydrolysis demonstrated that a reduction in autoclaving temperature from 121 °C to 111...

To improve the versatility of light cycle oil (LCO), separation of aromatic compounds from LCO by solvent extraction was investigated. LCO was analyzed to identify 35 components: 19 aromatics and 16 alkanes. The batch liquid–liquid equilibrium extraction of LCO was performed using furfural, sulfolane, and methanol as extraction solvents. In each so...

A process to deacidify crude plant oil by the esterification of free fatty acid with methanol was studied. A reaction model in a heterogeneous system was developed, and the equilibrium and rate constants of the esterification reaction were measured experimentally using a standard type of stirred vessel. In this measurement range, the liquid-liquid...

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) phosph...

The extraction of ethanol with the solvents of aldehydes mixed with m-xylene was studied for the bioethanol concentration process. Furfural 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 m...

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 aqueo...

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 phas...

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 Sau...

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...

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 furfur...

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 redu...

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 wer...

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,...

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...

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 thr...

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 zeoli...

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 tetrafluorob...

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...

In the first, Mongolian natural zeolites, whose base components were clinoptilolite, mordenite, and chabazite, were characterized in terms of element content, cation exchange capacity, and the like. Since the molar ratios of aluminum relative to silicon contained in Mongolian natural zeolites used in this study were lower than those of pure zeolite...

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...

Automated targeting technique has recently been developed for various resource conservation network problems in continuous and batch processes. The technique is built on the targeting concept of insight-based pinch analysis technique, and implemented on mathematical optimization framework. For batch water networks, the water sinks and sources are l...

Removal of chromium (Cr (III) ) as well as hexavalent chromium (Cr (VI) ) from tannery wastewater at same time by adsorption using Mongolian natural zeolite was studied in terms of the characteristics, modification, and chromium adsorption performance of the zeolite. The cation exchange capacity of the zeolite ranged from 37×10 −3 to 144×10 −3 eq·g...

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 cul...

Ethanol distributions between selected organic and aqueous phases were measured for recovery and concentration of bioethanol from fermented solution. The strategy of solvent selection was based on the background of biofuel production, and m-xylene was selected as the primary solvent and capric acid, 1-hexanol and 2-ethyl hexanol secondary solvents...

Various low-value oils, namely, crude palm oil (CPO), crude jatropha oil (CJO), and used frying oil (UFO), were investigated by comparing them as feed oils used in biodiesel (BD) production, with the objective of clarifying the effects of various factors that influence the feed oil characteristics on the required feed pretreatment (FP), operating c...

This special issue, “IWPI 2008,” is an outcome of the International Workshop on Process Intensification 2008 held in Tokyo, Japan on October 15–18, 2008. This workshop had been organized as the second workshop on this research field in Asia and is held every two years. The main objectives of this workshop were to provide the current achievements an...

Aromatics extraction was studied using aqueous solution of sulfolane as the solvent phase and model gasoline, consisting of a BTX and hexane mixture, and reformate gasoline as the feed phase. The distribution coefficients and selectivities of benzene were the highest, followed by those of toluene and xylene. Increased water content of the solvent p...

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 wate...

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 aci...

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 sampl...

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 ph...

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 pond...

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 o...

Large amount of residues are discharged from the rubberwood manufacturing process and in some countries these residues are illegally disposed and burned which lead to serious pollution problems. The objective of this study is to utilize and treated these residues to produce the useful products such as pyroligneous acid (PA), char and off-gas. First...

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 heterocy...

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...

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 w...

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 °C. The geochemical characteristics of the oil shale were also investigated by Rock Eval. pyrolysis. Therma...

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....

Five coal samples from Nigeria were characterized by thermogravimetry (TG) analysis. Thermal decomposition in air (combustion) and inert (pyrolysis) environment at temperature up to 1000°C classified the coals as belonging to the low-rank class, within the Lignite and sub-bituminous group. The coals are not cokable alone but could serve as suitable...

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. Multip...

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...

Effects of agitation and addition of synthetic polymer surfactants, Pluronic F68, to culture medium on cell proliferation and metabolism of t-PA (Tissue plasminogen activator) producing recombinant Chinese Hamster Ovary (CHO) cells in serum-free medium were investigated. Increasing agitation speed reduced cell proliferation even at moderate speed (...

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...

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 incre...

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 tr...

The liquid-liquid equilibrium properties between the coal tar absorption oil fraction feed and the solvent (aqueous solution of methanol and aluminum chloride) were experimentally measured for nitrogen heterocyclic compounds (2,3-benzopyridine (quinoline), 3,4-benzopyridine (isoquinoline), and 2,3-benzopyrrole (indole)), homocyclic compounds (aroma...

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 distill...

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.) i...

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 fro...

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 equilibri...

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 suitabl...

A series of batch permeation runs using an emulsion liquid membrane was conducted with binary, quaternary, and multi-component hydrocarbon mixtures as feeds. The emulsion phase mass transfer coefficient in a stirred batch vessel was not affected by the type of feed. This suggested that the previous correlation observed with binary feeds in a contin...

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 t...

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...

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 measur...

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 concentra...

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 antibiot...

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 nonaromatics 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...

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 th...

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...

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 sho...

Permeation and separation in emulsion drops were simulated by a multi-layer liquid membrane model. This resulted in a procedure for improving separation selectivity by decreasing the number of the inner oil droplets in an emulsion drop. Predicted results were confirmed by batch experiments of permeation. (from Authors)

The process considered in this work consisted mainly of a multi-staged stirred permeator with extract reflux, a distillation tower with ideal stages and a mechanical demulsifier. Amounts of energy required for several separation problems were estimated under specified stage numbers of the permeator and distillator. Numerical values of volumetric co...

Axial dispersion coefficients and Peclet numbers for fixed beds of various fine particles were measured within the range of mean particle diameter from 4.8×10-5m to 1.7× 10-4m, and that of Reynolds number from 1.0× 10-2 to 2.0. From the experimental results, the effects of Reynolds number, particle diameter and particle size distribution on the Pec...

Adsorption isotherms and mass transfer coefficients were measured for one of macrolide antibiotics, erythromycin, with combinations of spherical silica gel and various organic solvents. Measured and simulated chromatorgams agreed well for various combinations and several operating conditions. The effects of equilibrium and rate parameters on the sh...