Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.seppur.2022.122441

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Society of Chemical Engineers, Japan  

DOI： 10.1252/kakoronbunshu.48.35

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.ces.2021.116974

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.fuel.2021.121479

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Authorship：Last author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.fuel.2020.119747

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Publishing type：Research paper (international conference proceedings)   Publisher：EDP Sciences  

Hydrated-based gas separation is a method capable of selectively separating and recovering greenhouse gases. Although a conventional hydrate-based gas separation apparatus is a batch or a semi-batch system, continuous operation is preferable to increase the throughput of gas without changing the apparatus volume. Recently, we proposed a flow type apparatus to allow continuous operation of hydrate formation (absorption) and subsequent decomposition (desorption). The aim of this study is to investigate the mass transfer characteristics of the continuous apparatus using the HFC134a-N2 mixed gas system. The volumetric mass transfer coefficient was calculated especially during a steady state of gas absorption. Besides, we compared mass transfer performance between the hydrate-based gas absorber and a conventional bubble column. Sodium dodecyl sulfate was used as a hydrate dispersant. In the flow type apparatus, the gas-liquid contact was good and the hydrate slurry state was observed during hydrate formation. In the surfactant solution, the volumetric mass transfer coefficient increased in comparison with that in water. The volumetric mass transfer coefficient with hydrate was higher than that of the bubble column. These results suggest that hydrate formation improves gas absorption performance.

DOI： 10.1051/matecconf/202133304002

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：EDP Sciences  

Hydrate-based gas separation is often investigated using batch or semi-batch operations. To increase the throughput of the gas mixture without increasing the apparatus volume, it is preferable to perform a continuous operation of hydrate-based gas separation. Therefore, we proposed a flow-type apparatus for performing continuous formation with passing gaseous mixture and subsequently decomposition with passing gas hydrate particles. Characteristics of multiple fluid and heat and mass transfer of hydrate slurry are essential for the efficient operation of the apparatus. In this study, we focused on heat transfer characteristics in the presence of bubbles in water and surfactant solution. First, an apparent overall heat transfer coefficient under pressure during steady operation of the apparatus was calculated on a simple assumption. Next, to control the hydrate amount and position of hydrate-decomposition and hydrate-formation in the apparatus, we focused on the temperature profile of the inside fluid. A heat transfer model using heat balance of defining heat of hydrate-formation and heat transfer of agitation of fluid was made for hydrate-based gas separation apparatus. To evaluate the validity of the heat transfer model, a calculation value is compared with the experimental value.

DOI： 10.1051/matecconf/202133304001

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：EDP Sciences  

We are focusing on the practical use of methane hydrate. For recovery and use of it as an energy resource, it is necessary to consider the possibility of clogging in the recovery pipe due to the rehydration of bubbles. The purpose of this research was to observe experimentally and evaluate theoretically the decomposition behavior of hydrate sedimentary layer and the rising behavior of bubbles generated by hydrate decomposition. Chlorodifluoromethane was used as a low pressure model gas of methane. Hydrate sedimentary layer was produced by cooling and pressurizing water in countercurrent contact with gas using a hydrate formation recovery device. The recovered hydrate was decomposed by the heating or depressurization method, without flowing water. Two theoretical rising velocities were derived from the theoretical value with using the Navier-Stokes equation or the values in consideration of the bubble shape and hydrate film existence. The experimental rising velocities of small spherical bubbles radius agreed well with the theoretical value by the Navier-Stokes equation. The relatively large elliptical bubbles showed a behavior close to the theoretical value of bubble with hydrate film. Under the pressure and temperature conditions closer to the hydrate equilibrium line, almost no generated bubbles could be identified visually.

DOI： 10.1051/matecconf/202133302007

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Authorship：Last author   Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Informa UK Limited  

DOI： 10.1080/01496395.2019.1705345

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.cherd.2020.01.031

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.cherd.2019.08.007

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institution of Chemical Engineers  

Many studies have been conducted on the application of hydrate-based gas separation to recover or reduce greenhouse-gas emissions. We evaluated the effects of hydrate-slurry decomposition conditions, specifically depressurization and heating, on gas recovery and separation, by using mixtures of refrigerants R22 or R134a with N2 as models of a greenhouse gas and a low-pressure gas, respectively. The recoveries of R22 and R134a were assessed and N2 was released preferentially during the earlier stage of decomposition, such that the highest N2 recovery rate was obtained during that time span. In contrast, the recovery rates of the target gases increased gradually with time up to maximum values. Pressure and temperature had a minimal effect on the N2 recovery rate, whereas the target gas-recovery rates were highly dependent on decomposition pressure and temperature values. The maximum separation factors were approximately 50 for R22 and 20 for R134a. A mechanism for the variation in separation factor is proposed, based on an analysis of gas generation as a function of decomposition time and fluid temperature.

DOI： 10.1016/j.cherd.2018.04.030

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Winterization is one means of improving the low temperature flow properties of biodiesel fuel, by the separation of saturated FAMEs. Additives are also employed to improve separation in the winterization process by modifying the crystallization behavior. This process is referred to as additive winterization. In a previous study, we investigated a novel additive winterization method in which FAMEs are separated without agitation during cooling, allowing improved separation of saturated FAME and unsaturated FAME mixtures. This method is both facile and energy-efficient because vacuum filtration is not required. In this study, we examined the effects of additives (sorbitan mono fatty acids) and agitation on the separation of saturated FAMEs from saturated and unsaturated FAME mixtures via winterization. The additive winterization process resulted in significant improvements in the cloud points of the FAME mixtures following a single separation run, with the cloud point being decreased by 8 K under optimum conditions. In contrast, winterization based on agitation required at least two cycles of sequential cooling, agitation and filtration to obtain similar results. This study therefore highlights the potential of additive winterization using sorbitan mono fatty acid esters to enhance the low-temperature flow properties of biodiesel fuels based on a simple process with reduced energy expenditures.

DOI： 10.1016/j.fuel.2017.11.066

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

This work investigated the removal of saturated fatty acid methyl esters (FAMEs) from FAME mixtures by winterization, employing additives as solid-liquid phase separation improvers during the cooling process. Model mixtures were prepared by blending saturated FAMEs (methyl palmitate and methyl stearate) and an unsaturated FAME (methyl oleate). Sorbitan monopalmitate (Span40) and Sorbitan monostearate (Span60) were selected as separation improvers because their molecular structures were close to those of the saturated FAME in the model mixture. These additives were found to improve the solid-liquid phase separation of FAME mixtures. Four different solid phases were observed during winterization, depending on the additive concentration: a solid wax, a solid incorporating small amounts of liquid, a large crystal agglomeration, and a slurry of fine particles. The formation of the large crystal agglomeration made it easier to perform solid-liquid separation via decantation, such that the saturated FAME was readily removed from the liquid phase when employing the optimum additive concentration. When the additive had an equal or longer carbon chain length compared with the saturated FAME, a greater extent of low temperature separation was obtained. These results will be helpful to the future development of the additive winterization process. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.fuel.2016.10.124

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Language：English   Publishing type：Research paper (international conference proceedings)  

Additive winterization processes using sorbitan monopalmitate and sorbitan monostearate were compared with a conventional agitation winterization for the separation of saturated FAMEs from a mixture of saturated and unsaturated FAMEs. The additive winterization process led to greater improvements in the low-temperature flow properties of the FAME mixtures by a single stage. Furthermore, the agitation winterization required at least three cycles of sequential cooling, agitation and filtration to obtain similar results. This study therefore highlights the potential of additive winterization for improving the low-temperature flow properties of biodiesel fuels containing sorbitan mono fatty acid esters as a simple, energy-saving process.

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

We assessed a simple thermodynamic model, with the aim of identifying biodiesel fuel cloud point (CP) improving additives, by predicting the CP values of fatty acid methyl esters with additives. The results showed that the molar mass of the additive has a significant effect in terms of improving the CP; the melting point and fusion enthalpy of the additive, however, produce lesser effects. On the basis of these results, we selected the additives tert-butyl alcohol, 2-butanol, cineol, 2-decanol, 2-decanone and oleyl alcohol, and examined their effects on the CP of a model biodiesel fuel (a methyl oleate and methyl palmitate mixture). The same trials were carried out using fatty acid methyl ester mixtures derived from commercial cooking oils. As predicted, the selected test additives decreased the sample CP values, with the optimum reduction obtained when using 10 wt.% of the additive. The results demonstrate that additives capable of improving the CP can be readily screened using a simple thermodynamic model. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.fuel.2015.12.053

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

The molecular sieving effect of tetrahydrofuran (THF) clathrate hydrate was experimentally investigated. The capture and release of seven gases, i.e., helium (He), hydrogen (H-2), neon (Ne), nitrogen (N-2), xenon (Xe), methane (CH4), and ethane (C2H6), in THF clathrate hydrate were investigated. For gases with a diameter smaller than the window diameter, the order of the gas uptake rates in the THF clathrate hydrate was in accordance with the order of their van der Waals diameters, except for He. This result indicates that the gas uptake rate is generally controlled by the size of the gas molecules. The apparent diffusion coefficients for these gases in the THF clathrate hydrate were estimated. The van der Waals diameters of CH4 and Xe are larger than the window diameter. However, gas uptake by THF clathrate hydrate was observed for both gases. This can be attributed to the formation of the type I clathrate hydrate of these gases. No significant gas uptake of ethane was observed. Based on the results, H-2/N-2 and H-2/C2H6 separation experiments were conducted. Gas separation of H-2/N-2 by THF clathrate hydrate was successfully achieved using the difference in their gas uptake rates of the gases, and the separation ratios were in the range 4-16 mol/mol. Gas separation of H-2/C2H6 was also achieved utilizing the molecular sieving effect of THF clathrate hydrate. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.seppur.2014.10.023

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：INST CHEMICAL ENGINEERS  

Efficient gas recovery and separation in a hydrate-based system was investigated for a model gaseous mixture of R22 and nitrogen. The formed hydrate settled in the recovery vessel; excess water was recycled and the hydrate was subsequently decomposed by releasing pressure from the vessel. The gas uptake rate of R22 gas from the vapor phase and the gas recovery rate from the hydrate were determined from hydrate formation and decomposition, respectively. The gas recovery rate of R22 gas gradually increased with time. On the contrary, the nitrogen gas recovery rate was a maximum in the initial stage of hydrate decomposition. A high separation factor (S.F.) was achieved by first separating the N-2-rich gas generated during initial hydrate decomposition. An efficient hydrate-based gas separation and recovery process is proposed. (C) 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cherd.2014.02.008

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Hydrogels are widely studied for chemical sensors. However, they are known to adsorb organic compound and metal ions. The adsorption abilities of hydrogels against organic compounds and metal ions will negatively affect the performance of a hydrogel based chemical sensor. To clarify the effect of hydrophobic pollution on swelling behavior of temperature-sensitive gel, the temperature-responses of spherical N,N-diethylacrylamide (DEAA) gel in phenol solution were evaluated using the collective polymer diffusion constant. Phenol was selected as a model hydrophobic pollution. The equilibrium radius of DEAA gel changed discontinuously at about 874 g/m3 phenol solution, and the collective polymer diffusion constant decreased sharply between 874 and 916 g/m3, suggesting a “critical slowing down”. The phenol concentration difference EC was successfully used to correlate phenol concentration with the collective polymer diffusion constant. The correlation will be useful as an estimation of hydrogel response reduction associated with hydrophobic pollution.

DOI： 10.3390/chemosensors1030021

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：MAIK NAUKA/INTERPERIODICA/SPRINGER  

Slow swelling and shrinking rates are a significant challenge for some applications of temperature-sensitive hydrogels. This study reports raspberry-form poly N,N-diethylacrylamide (DEAA) gel particles, which are aggregates of single spherical gel particles. The raspberry-form gel particles show improved temperature-response rates especially for swelling. This improvement in the response rate is attributed to two key factors: the free space between the individual gel particles that make up the aggregated gel particle, and the constraints from the contact points between the individual gel particles. During the swelling process, the polymer chain networks can diffuse at the faster rate characteristic of the individual gel particles constructing the raspberry-form gel, and consequently the response rate of the overall raspberry-form gels can be accelerated. During the shrinking process, the constraints from the contact points between the individual gels dominate the polymer chain diffusion and the shrinking rate because of non-zero shear modulus. The shrinking behavior was affected not by the individual particle size, but rather the apparent gel size and shape.

DOI： 10.1134/S0965545X12100057

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

The kinetics of swelling and shrinking of spherical particles of poly(N,N-diethylacrylamide) (DEAA) gel, prepared with static mixing technology, was investigated experimentally. The shrinking process was separated into late shrinking and initial shrinking by the skin layer effect. When the final temperature of temperature swing experiments was above the lower critical solution temperature (LCST) of polyDEAA, the apparent increase in the response rate constant (k(v)) and the polymer diffusion constant (D) were due to reduction of the friction coefficient between polymer chains and water, arising from decrease in the water viscosity. When the final temperature was below the LCST, the main factor determining k(v) and D was the change in the network structure of DEAA particles caused by the final temperature. The initial temperature affected the values of k(v) and apparent diffusion constant D(app) only in initial shrinking, in which the decrease in D with increase in the initial temperature came mainly from the spatial limitation. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2010.12.029

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

The formation process of CO2 drops in various types of Kenics Static Mixers was analyzed from the perspective of energy dissipation in the mixer, focusing on the formation of drop surfaces. Experimental studies on CO2 drop formation were conducted under varying temperatures, pressure, and flow rates, with and without hydrate formation. Analysis of the CO2 drop size and distribution at several locations within the static mixer was conducted, as of pressure drop in the mixer, to determine dissipation energies. In all the experimental conditions, by considering the surface energy for hydrate formation, the energy required for the formation of CO2 drops correlated well with total energy dissipation by mixer flow, which is represented by a pressure drop along the mixer. This process has important applications to the formation of liquid CO2 for ocean disposal as a countermeasure to global warming. (C) 2010 American Institute of Chemical Engineers AIChE J, 56: 2706-2716, 2010

DOI： 10.1002/aic.12167

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CiNii Article

CiNii Books

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

CiNii Article

CiNii Books

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Extractions of five kinds of lanthanide metal ions by bis(2-ethylhexyl)phosphoric acid (DEHPA) with [1-Cn-3-methylimidazolium][PF(6)](Cn = C(2), C(4)) or [1-butyl-4-methylpyridinium][PF(6)] were carried out under various DEHPA and HNO(3) concentrations from 0 to 1 M and under different temperature conditions from 298 to 333 K. These results were compared with those using the conventional organic solvent, hexane, in terms of their distribution coefficient values. Under all of the conditions in this study, the ionic liquid system shows more than three times greater extractability for lanthanide compared to when hexane was used. The distribution coefficient of lanthanide ions decreased as the length of the alkyl chain increased from the ethyl to the butyl. In addition, the imidazolium cation generally shows a higher distribution coefficient compared to the pyridinium cation in an ionic liquid. The concentration ratio of lanthanides and DEHPA resulted in an extraction affinity transition for lanthanides. Also evaluated in this study were issues related to the selectivity associated with the lanthanide mixture and the dependency of the ionic radius during lanthanide extraction. (C) 2010 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jiec.2009.09.063

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

Gas hydrate formation kinetics were investigated in a Kenics static mixer. When operated Under thermodynamic conditions (pressure or temperature), the hydrate formation rate increased and the HFC-134a gas bubble was covered with a hydrate "shell". This hydrate shell inhibited hydrate growth because of resistance to mass transfer. Water recycling in the hydrate reactor accelerated hydrate formation by increasing the gas-water interface during water-gas cocurrent flow and causing the continued presence of a fresh interface in the counterflow. The kinetic data indicated that the hydrate formation rate would be equal to the mass transfer rate including the rate of hydrate shedding from the gas bubble. Enriched HFC-134a gas could be continously recovered from an HFC-134a-nitrogen mixture in a continuous hydrate formation system. The hydrate formation rate constant for the mixed gas depended on the feed gas components.

DOI： 10.1021/ie901613h

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

Temperature-sensitive hydrogel beads were prepared by Kenics static mixer technology. The temperature-sensitive monomer N,N-diethylacrylamide and photo-crosslinkable pre-polymer ENT were used as model hydrogel materials. Drop dispersion of high viscosity polymer material in low viscosity hexadecane was made using the static mixer. Drops of a solution of the mixed materials were rapidly photo-crosslinked by UV irradiation after mixing in the static mixer, and spherical hydrogel beads with narrow, normal size distribution were thus prepared. The Kenics static mixer is a useful device for the preparation of spherical beads of temperature-sensitive hydrogels. The Sauter Mean Diameter of the hydrogel beads swollen in deionized water at 293 K was measured. The experimentally determined dimensionless swollen hydrogel bead diameter was well correlated with the Weber number, degree of swelling and viscosity ratio. The effects of gelation and ENT addition on the bead size were evaluated from the degree of swelling. The correlation equation can be used for size adjustment of temperature-sensitive spherical hydrogel beads. (C) 2009 Elsevier B. V. All rights reserved.

DOI： 10.1016/j.cej.2009.11.010

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

Direct observation and the measurement of the formation rate of the gas hydrate of HCFC-22 in it Kenics-type static mixer were conducted in it laboratory-scale experimental apparatus. This study focused oil the effect of sodium dodecyl sulfate (SDS) addition oil the hydrate formation process under the SDS concentration below the critical micelle concentration (cmc). The hydrate film was formed ill the surface of bubbles in any case, but the appearance of the hydrate film and its behavior were significantly changed with increasing the SDS concentration. Without SDS. smooth and homogeneous hydrate film was formed at the surface of HCHC-22 bubbles. The HCHC-22 gas wits trapped in the shell of the rigid hydrate film, and the bubbles agglomerated each other to form it grape-like structure. From the addition of SDS, the hydrate Film Formed With it rougher and heterogeneous surface; file hydrate film Seems to have a loose structure and easily Collapsed from the buoyant motion of the HCFC-22 gas trapped in file shell. The enhancement of the gas hydrate formation by the SDS addition can be attributed to the mass transfer through the loose hydrate Film and the surface renewal by the film collapse.

DOI： 10.1021/ef900863y

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

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Two types of gas separation methods, using liquefaction and gas hydrate formation, were compared in terms of the equilibrium recovery ratio for the separation of gaseous mixtures of HFC-134a and nitrogen. The equilibrium recovery ratio is defined as the molar ratio of the target component (HFC-134a, in the present case) recovered in the condensed (recovered) phase to that in the feed (vapor) phase under the equilibrium condition. The equilibrium recovery ratio was evaluated based on the phase equilibrium data for liquid-vapor and hydrate-vapor. It was found the equilibrium recovery ratio for HFC-134a is always higher for the hydrate-based separation method than that for the liquefaction separation method for the conditions of a given initial composition and pressure at 278 K or 282 K. In other words, more HFC-134a can be recovered by the hydrate-based separation than the liquefaction separation method for a given feed. The result can be explained by a simple algebraic analysis based on the phase equilibrium relationship. A two-step separation process combining the liquefaction and hydrate-based separation methods can realize the recovery of high-purity HFC-134a under reduced pressure conditions. (C) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.seppur.2008.10.023

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

The effects of ultrasonication on methane production from excess activated sludge were analyzed in relation to the bioavailability of the solubilized organic matter and the solid fraction. The solubilized organic matter was divided into three categories according to biodegradability: easily-, less-, and un-degradable organic matter. The rapid increase in easily-degradable fraction was observed at a specific sonication power of about 4,000 kJ/kg-TS but the fraction leveled off at specific power inputs above 9,000 kJ/kg-TS. The un-degradable fraction began to increase at specific power inputs of about 6,000 kJ/kg-TS and leveled off at about 9,000 kJ/kg-TS. The effect of ultrasonication on methane production was pronounced by the initial methane production rate, indicating boosted hydrolysis rate that is usually a limiting step of methane production. The methane production rate from the solubilized organic matter leveled off at the specific power input around 6,000 kJ/kg-TS, suggesting that about 60% of solubilized organic matter was converted into methane. Methane production from whole sonicated sludge showed that the amount of methane converted from the solid fraction was larger than that from the solubilized organic matter, and that ultrasonication enhanced the bioavailability of solid. The rationale for the optimal ultrasonication conditions was presented.

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

The effects of ultrasonication on methane production from excess activated sludge were analyzed in relation to the bioavailability of the solubilized organic matter and the solid fraction. The solubilized organic matter was divided into three categories according to biodegradability: easily-, less-, and un-degradable organic matter. The rapid increase in easily-degradable fraction was observed at a specific sonication power of about 4,000 kJ/kg-TS but the fraction leveled off at specific power inputs above 9,000 kJ/kg-TS. The un-degradable fraction began to increase at specific power inputs of about 6,000 kJ/kg-TS and leveled off at about 9,000 kJ/kg-TS. The effect of ultrasonication on methane production was pronounced by the initial methane production rate, indicating boosted hydrolysis rate that is usually a limiting step of methane production. The methane production rate from the solubilized organic matter leveled off at the specific power input around 6,000 kJ/kg-TS, suggesting that about 60% of solubilized organic matter was converted into methane. Methane production from whole sonicated sludge showed that the amount of methane converted from the solid fraction was larger than that from the solubilized organic matter, and that ultrasonication enhanced the bioavailability of solid. The rationale for the optimal ultrasonication conditions was presented.

DOI： 10.1252/jcej.08we129

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

The performance of the Texaco gasifier in hydrogen production was studied numerically. To estimate the accurate carbon conversion, a two-stage equilibrium model was proposed. In the proposed model, the two reactions which determined the carbon conversion were separated from other vapor-vapor reactions. The governing equations of the proposed model were derived and a self-consistent method was developed to solve the governing equations. The %AAD of the calculated carbon conversions from the measured values was 2.89 and that of the calculated gas production rate was 0.64. Calculated gas compositions showed a fairly good agreement with the experimental ones for commercial scale plants. It was found that the chemical reactions that occurred in the Texaco gasifier possess a mechanism for keeping the carbon conversion close to unity against a wide variation in the H2O to coal ratios. (C) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.fuel.2008.01.009

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

hydrate in a Kenics type static mixer was conducted focusing on the effect of an addition of a surfactant, sodium dodecyl sulfate (SDS). The formation pattern of the hydrate was changed by the SDS addition from "slurry" to "plug," and a continuous cycle of hydrate film formation and bubble escape was observed. The hydrate formation rate was increased about 10-fold by the addition of SDS (1000ppm).

DOI： 10.1246/cl.2007.1212

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In recent years, applications of gas hydrates have been intensively studied in the fields of energy and environmental management. To implement such hydrate-related technologies, development of efficient processes of continuous hydrate formation would be necessary. We proposed a new type of method for gas hydrate formation using a static mixer. Flows of HFC-I 34a gas were mixed with water in a Kenics static mixer, and HFC-134a hydrate formation was observed as plug-like hydrate and hydrate slurry. Plug-like hydrate was agglomerated HFC-134a bubbles covered with hydrate, while the hydrate slurry consisted of small hydrate particles dispersed in water. The hydrate formation patterns depended on the rate of hydrate formation according to pressure and temperature conditions. From the experimental results, the pressure and temperature conditions feasible for continuously forming HFC-134a hydrate in this experimental system were determined. (C) 2006 Elsevier B.V All rights reserved.

DOI： 10.1016/j.petrol.2005.08.005

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

DOI： 10.1002/aic.10895

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Hydrogen is used in a wide range of applications, e.g., automobiles and small cogeneration systems. Being highly efficient and eco-friendly, they are expected to be extremely effective in environmental preservation. Hydrogen storage has been recognized as one of the key technologies to progress the PEFC sector toward a hydrogen-based economy. The storage behavior of hydrogen into tetrahydrofuran clathrate hydrate was studied. Several experiments were carried out at a hydrogen pressure from 0 to 10 MPa, at 243-273 K using 5.56 mole % THF hydrate. The storage capacity of hydrogen increased with increasing hydrogen pressure, and approached 0.4 wt % under this condition. This is an abstract of a paper presented at the 2006 AIChE National Meeting (San Francisco, CA 11/12-17/2006).

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An effective hydrogen production process from coal gasification was described. In the process, the CO2 separation step using gas hydrate and the sift reaction step for producing more hydrogen were integrated with the gasification step. In gasification step, the raw gas consisted mainly of hydrogen and CO under high pressure was obtained. In sift reaction step, the raw gas further reacted with steam, and the synthetic gas of hydrogen and CO2 was produced. CO2 was removed from the synthetic gas by forming CO2 hydrate in the separation step. In addition, the thermodynamic equilibrium of the gas constituents was calculated in each step. The effect of solid carbon activity under high pressure was considered. The constituents of the raw gas were predicted. Based on the results, the operating condition for producing the largest amount of hydrogen in the proposed process was determined. This is an abstract of a paper presented at the AIChE Annual Meeting (San Francisco, CA 11/12-17/2006).

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

Formation experiments Of CO2 hydrate from the two-phase flow of liquid CO2 and water were carried out using static mixers with different types of mixing elements to elucidate the effects of mixing functions of the static mixer on CO2 hydrate formation. The mixing principle of the Kenics type static mixer is composed of three mixing functions, flow division, flow reversal, and radial mixing. In this study, three types of mixing elements in addition to the basic Kenics type static mixer were applied for CO2 hydrate formation; each mixing element lacked at least one mixing function among three mixing functions. The observed behaviors Of CO2 hydrate formation could be classified into six patterns: (1) hydrate chunks, (2) CO2 drops agglomerated through the hydrate film, (3) dispersed liquid CO2 drops covered with hydrate film, (4) mixture of tiny liquid CO2 drops and hydrate particles, (5) mixture of hydrate chunks and agglomerated CO2 drops, and (6) mixture of agglomerated and dispersed CO2 drops. Occurrences of the above patterns depended on the type of the mixing element as well as the flow rates of liquid CO2 and water. From the observations, flow division was suggested to be important for the formation of hydrate chunks but not essential, and flow reversal was essential for the formation of dispersed hydrate particles. The formation mechanisms Of CO2 hydrate with the static mixer are discussed according to the results.

DOI： 10.1021/ef0500843

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Process design for a new injection method of liquid CO2 using a static mixer was conducted based on laboratory experimental results on the formation process of liquid CO2 drops covered with hydrate film by a Kenics-type static mixer, and numerical simulation of the liquid CO2 drops at 500 and 1500 m. The Sauter Mean Diameter (SMD) of the liquid CO2 drops covered with hydrate film was dramatically decreased with the use of the static mixer; empirical equations were obtained for the SMD, and also the maximum and minimum diameters of the liquid CO2 drops for a given flow velocity (Weber number, We). The ascending and dissolving behavior of a liquid CO2 drop with hydrate released in the ocean at an intermediate depth was numerically simulated, and the maximum drop diameter to avoid evaporation of the drop before complete dissolution was estimated. Based on these results, scaling up of the static mixer was conducted by assuming a disposal process Of CO2 emitted from a 100-MW thermal power plant, and the mixer diameter was determined as a function of the given SMD. Moreover, the power consumption of the static mixer was evaluated and found to be almost negligible. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.fuproc.2005.01.009

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

A method for predicting the location of a dissociation condition on an H-L-w-V line under isochoric operation was presented. To establish the method, the governing equations for the H-L-w-V coexistence under isochoric conditions were derived. Here, a liquid and a vapor phase were expressed by the PR EOS + MHV2 model and a hydrate phase by the van der Waals-Platteeuw model. The molar volume of the vapor phase was calculated from the equation of state, and a simple expression for the molar volume of the hydrate phase was derived. Then, to prove the validity of the proposed method, experimental studies about the dissociation process of the hydrates were performed. The temperature and pressure traces in the hydrate dissociation process, including the location of the dissociation condition, were successfully predicted by the proposed method. In addition, the thermodynamic consistency among the phase models was discussed. It was pointed out that agreement between the calculated and experimental results about the H-L-w-V equilibrium line did not ensure thermodynamic consistency among the phase models. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.fluid.2005.07.004

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

A method for determining quadruple points of a two-component system containing a simple hydrate phase is proposed. This method utilizes the quasi-static change of the system along three-phase equilibrium lines and was proved to be able to determine the quadruple points as accurately as the conventional method. By using this method, even though some preparation is necessary, a quadruple point can be determined in just a single experimental run. The behavior of the system near the quadruple points was also examined experimentally, for both the quasi-static and the irreversible change cases. At the quadruple points, the temperature and pressure of the system were kept constant for a while, as at the triple point of water. In both cases, the representative point of the state of the system passed through the quadruple point on a p-T diagram. © 2004 Elsevier B.V All rights reserved.

DOI： 10.1016/j.fluid.2004.11.026

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Language：English   Publishing type：Research paper (international conference proceedings)  

A method for predicting the behavior of the system including the simple hydrate phase under constant volume conditions was presented. Experimental studies about formation process of hydrates were conducted to prove the validity of the proposed method. In the experiment, cylindrical shell immersed in a water-ethanol bath whose temperature was controlled by a constant temperature circulator, was used. The predicted Lw-V coexistence lines agreed well with the experimental ones.

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Language：English   Publishing type：Research paper (international conference proceedings)  

The mixing factors of static mixer and their effect on the flow patterns of liquid CO2 and water for a design of a suitable device to form continuously carbon dioxide hydrate were investigated. An experimental system was designed for the operation under pressure at about 10 MPa. The flow velocities of liquid CO2 and water were controlled by the high-pressure pumps in the range of 0.83 to 7.94 cm/s for liquid CO2, and 9.5 to 56.7 cm/s for water. The results indicate that the flow division factors acts mainly in low velocity and the flow reversal factor affect the fluid in high water flow velocity.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：The Society of Chemical Engineers, Japan  

In the previous report (AIChE J., 50, 871-878, 2004), a new type of the injection method of liquid CO<SUB>2</SUB> by a static mixer was proposed by the present authors for the direct ocean disposal of CO<SUB>2</SUB> at the intermediate depths (500-1500 m). The static mixer is effective for producing liquid CO<SUB>2</SUB> drops with uniform size distribution, and would have advantages of the drop size control over simple nozzle injection methods. In this study, the mixing behavior of liquid CO<SUB>2</SUB> and water and its effects on the CO<SUB>2</SUB> drop formations in the Kenics type static mixer was observed in a laboratory-scale experimental apparatus simulating the intermediate ocean conditions. It was found that the size reduction and uniformalization of the liquid CO<SUB>2</SUB> drops were mainly conducted at the first 2 element at the upstream side of the mixer. After that, the size and its deviation decreased quite gradually without coalescence of the drops.

DOI： 10.11491/apcche.2004.0.382.0

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：The Society of Chemical Engineers, Japan  

A new separation method using gas hydrate formation is proposed for separating HFC-134a from gas mixtures containing N<SUB>2</SUB> and HFC-134a. The feasibility of this separation method was investigated from various points of view. First, to determine the mixed hydrate stability region, three-phase equilibria of hydrate (H), liquid water (L<SUB>W</SUB>), and vapor (V) for HFC-134a + N<SUB>2</SUB> + water mixtures with various HFC-134a vapor compositions were closely examined in the temperature and pressure ranges of 275-285 K and 1-27 bar, respectively. Second, the compositions of the hydrate and vapor phases at a three-phase equilibrium state were analyzed for identical mixtures at 278.15 and 282.15 K to confirm the actual separation efficiency. Third, kinetic experiments were performed to monitor the composition change behavior of the vapor phase and to determine the time required for an equilibrium state to be reached. Through an overall investigation of the experimental results, it was verified that more than 99 mol% HFC-134a could be obtained from gas mixtures after hydrate formation and subsequent dissociation processes. Separation of HFC-134a using hydrate formation can be carried out at mild temperature and low pressure ranges. No additive is needed to lower the hydrate formation pressure.

DOI： 10.11491/apcche.2004.0.316.0

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：The Society of Chemical Engineers, Japan  

A method for predicting the behavior of the system including the simple hydrate phase under constant volume condition was presented. Governing equations for H-L<SUB>w</SUB>-V coexistence under constant volume condition were derived based upon the mass balance, the apparent restriction about mole fraction (the sum of the mole fraction must be unity), equal fugacity criteria and the equation for the total volume of the system. Then, to prove the validity of the proposed method, experimental studies about the dissociation process of hydrates were performed. Temperature and pressure traces in the hydrate dissociation process were successfully predicted by the proposed method. The proposed method can predict the change of all intensive and extensive variables in the system with respect to temperature. Thus, it is very useful for engineering and research purposes.

DOI： 10.11491/apcche.2004.0.318.0

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The process energy consumption was estimated for gas separation processes by the formation of clathrate hydrates. The separation process is based on the equilibrium partition of the components between the gaseous phase and the hydrate phase. The separation and capturing processes of greenhouse gases were examined in this study. The target components were hydrofluorocarbon (HFC-134a) from air, sulfur hexafluoride (SF6) from nitrogen, and CO2 from flue gas. Since these greenhouse gases would form hydrates under much lower pressure and higher temperature conditions than the accompanying components, the effective capturing of the greenhouse gases could be achieved by using hydrate formation. A model separation process for each gaseous mixture was designed from the basis of thermodynamics, and the process energy consumption was estimated. The obtained results were then compared with those for conventional separation processes such as liquefaction separation processes. For the recovery of SF6, the hydrate process is preferable to liquefaction process in terms of energy consumption. On the other hand, the liquefaction process consumes less energy than the hydrate process for the recovery of HFC-134a. The capturing Of CO2 by the hydrate process from a flue gas will consume a considerable amount of energy; mainly due to the extremely high pressure conditions required for hydrate formation. The influences of the operation conditions on the beat of hydrate formation were elucidated by sensitivity analysis. The hydrate processes for separating these greenhouse gases were evaluated in terms of reduction of global warming potential (GWP). (C) 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.energy.2004.03.003

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

A new separation method using gas hydrate formation is proposed for separating HFC-134a from gas mixtures containing N-2 and HFC-134a. The feasibility of this separation method was investigated from various points of view. First, to determine the mixed hydrate stability region, three-phase equilibria of hydrate (H), liquid water (L-W), and vapor (V) for HFC-134a + N-2 + water mixtures with various HFC-134a vapor compositions were closely examined in the temperature and pressure ranges of 275-285 K and 0.1 - 2.7 MPa, respectively. Second, the compositions of the hydrate and vapor phases at a three-phase equilibrium state were analyzed for identical mixtures at 278.15 and 282.15 K to confirm the actual separation efficiency. Third, kinetic experiments were performed to monitor the composition change behavior of the vapor phase and to determine the time required for an equilibrium state to be reached. Furthermore, X-ray diffraction confirmed that the mixed HFC-134a + N-2 hydrates were structure II. Through an overall investigation of the experimental results, it was verified that more than 99 mol % HFC-134a could be obtained from gas mixtures after hydrate formation and subsequent dissociation processes. Separation of HFC-134a using hydrate formation can be carried out at mild temperature and low-pressure ranges. No additive is needed to lower the hydrate formation pressure.

DOI： 10.1021/es0497072

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

Formation of CO2 hydrate using a Kenics-type static mixer was studied experimentally. The flows of liquid CO2 and water were mixed in the static mixer, and CO2 hydrate was formed continuously from the two-phase flow. The patterns of hydrate formation were found to be dependent on the flow velocities of liquid CO2 and water. The flow of agglomerated hydrate chunks in water occurred under relatively CO2-rich conditions, while dispersed flow of tiny particles of CO2 hydrate with small liquid CO2 drops was observed under relatively water-rich conditions. These effects could be explained by two mechanisms occurring in the static mixer, namely, continuous shedding of hydrate films from the interface between liquid CO2 and water induced by the shearing force and breakup of the CO2 drops. The energy consumption by the static mixer for the hydrate formation process was estimated, and it was significantly less than that for a stirring vessel type reactor. A continuous hydrate formation process could be achieved using the static mixer.

DOI： 10.1021/ef034087w

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

A new method for ocean disposal of anthropogenic CO2 is proposed. In this method, liquefied CO2 is transported through a pipeline to a Kenics-type static mixer, submerged at a depth between 500 and 1,000 in below the ocean surface and mixed with seawater in the mixer and then released into the ocean. Because the pressure and temperature for seawater at depths &gt; 500 in satisfy those for hydrate formation, CO2 hydrate may form. at the CO2-seawater interface. Thus, the release from the mixer is a mixture of liquid CO2 hydrate, and seawater. The apparent CO2 concentration of the release can be determined by the CO2-seawater mixing rote and distribution of the CO2 drops (with or without a hydrate layer) produced in the mixer. This proposed disposal method was simulated experimentally. The laboratory-scale simulation revealed that sizes of the dispersed CO2 drops and their distribution in the mixer were governed by the mixing rate and the Weber number on the basis of the continuous phase (seawater); larger Weber numbers led to smaller drop sizes and more uniform drop distribution. It was also observed that the drops with a hydrate layer were generally smaller than those without a hydrate layer under the same mixing rate and that a fairly uniform distribution for the dispersed CO2 drops was always obtained if the continuous-phase flow was,fully turbulent. Results of the laboratory simulation suggest that the environmental impact induced by the CO2 released by a Kenics-type static mixer may be better predicted than from conventional injection methods. (C) 2004 American Institute of Chemical Engineers.

DOI： 10.1002/aic.10083

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Language：English   Publishing type：Research paper (international conference proceedings)  

The behavior of released CO2 drop from the injection process of liquid CO2 into the ocean by utilizing a static mixer was studied, and estimation of energy consumption was conducted for the scale-up of the injection process. The static mixer was effective for producing liquid CO2 drops with relatively uniform size distribution. For a simple numerical simulation on the fate of the released CO2 drops after released from the static mixer, the initial diameter of the drop should be &lt
4 mm to make it dissolve completely when the depth to release liquid CO2 was supposed 500 m. Assuming that the CO2 injection process was installed in the disposal process of CO2 emission from 100 Mw thermal power plant, energy consumption to generate drop with mean diameter 4 mm was much smaller than the energy generation per unit CO2 emission. The static mixer was a very energy consumed device for the generation of uniform size drops. Thus, the injection process via a static mixer is a feasible option for the CO2 disposal process.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

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A new type of injection method of liquid CO2 into the seawaters via a Kenics-type static mixer for the ocean sequestration of CO2 has been developed. Flows of liquid CO2 and water will form a two-phase flow in a pipeline, and introduced to a static mixer, where the two-phase flow is mixed by the agitation effects of the mixing elements equipped in the mixer, and converted into various flow patterns. The following flow patterns were observed depending on the flow velocities
dispersed flow of liquid CO 2 drops, flow of CO2 hydrate agglomerates, and flow of CO2 hydrate particles. The results indicate that several options for CO2 injection concerning the form of CO2, size distribution of liquid CO2 drops, could be realized by using the present method. The choice of such options is essential to control the fate of the disposed CO2 and the consequent environmental impact. In this study, application of the present method to the disposal of liquid CO 2 at the intermediate depths (500-1500 m) is assumed. The formation of the liquid CO2 drops by the static mixer was studied experimentally, and the effect of the static mixer on the size distribution of the liquid CO2 drops was investigated. The mean size of the liquid CO2 drops were significantly reduced by using the static mixer, compared with the case without the mixer for a given flow velocity, and a sharper distribution of the drop size was obtained. Based on the experimental results, the ascending-dissolving fate of the liquid CO2 drops disposed of in the ocean at the intermediate depth was numerically simulated. The shaper distribution and smaller mean diameter of the liquid CO2 drops produced by the static mixer would results in the reduction of both the traveling distances and its dispersion of the disposed CO2 drops.

DOI： 10.1115/OMAE2004-51283

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

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DOI： 10.2477/jccj.2.127

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：INTERNATIONAL SOCIETY OFFSHORE& POLAR ENGINEERS  

If hydrates were dissolved under a constant volume condition, decomposition would occur along with a H-L-w-V three phases equilibrium line. Thus the H-L-w-V three phase equilibrium line can be considered to be equivalent with the decomposition condition. So, to determine the H-L-w-V three-phase equilibrium line accurately is very important task in constructing simulation programs of the methane production rate from a hydrate reservoir. There are several methods to improve the prediction accuracy. In three-phase coexistence state, not only a hydrates phase but also a liquid phase and a vapor phase may play important roles. Consequently, by using the correct model of the liquid phase and the vapor phase we can estimate the H-L-w-V three-phase equilibrium condition more accurately.

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We investigated the formose reaction using a zeolite impregnated with thiazolium catalyst. The zeolite catalyzed the formose reaction in an organic solvent and then the reaction rate was pseudo first order with respect to the formaldehyde concentration. The main products were DHA, erythrulose, and 4- hydroxymethyl-2-pentulose. The selectivity of the branched sugar was increased by the choice of conditions. For the reuse of the catalytic zeolite, washing with water was one of the important factors. These results are important for sugar synthesis processes from formaldehyde in one step.

DOI： 10.1252/jcej.35.564

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We quantitatively studied the effects of counter anions and solvents on the catalytic activity of thiazolium due to the completion of the formose reaction using the highly active immobilized catalyst. The relation between counter anions and the catalytic activity of thiazolium was represented very well by the electron donor constant and the basic constant of the anions. The solvent effect was represented by the individual solvent parameter. In this study, it was given an important information about the effects of the counter anion and the solvent on the reaction using an immobilized thiazolium catalyst.

DOI： 10.1252/jcej.34.553

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

In this study, we investigated about the effect of the unsteady diffusion on the reaction rate of an immobilized catalyst in a batch type reaction system. Analyzing the diffusion and reaction under the unsteady state, we showed that true kinetic information can be obtained at the limiting condition of beta --&gt; 0, where beta is the volume ratio of the solid to liquid. For the definite value of beta, we can derive an equation that expresses the relation between the apparent rate constant and beta. This knowledge is valuable for studying immobilized catalyst kinetics.

DOI： 10.1252/jcej.33.894

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

Thiazolium ion catalyst was immobilized on a cation-exchange resin, and the formose reaction was carried out with the resin. As a result, the use of this resin turned out to be useful for the formose reaction in an organic solvent, similar to the free thiazolium catalyst. Interestingly, the catalytic activity of this resin decreases after washing with an organic solvent, but recovers after washing with water. This result suggests that water molecules have an influence on the catalysis in this system.

DOI： 10.1252/jcej.33.793

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

Thiamine is a primary catalyst of carbohydrate production from a simple chemical. As the best immobilization method, we succeeded in immobilization of thiamine on a cation exchange resin, and formaldehyde polymerization with the immobilized catalyst. The desorption and decomposition of the immobilized thiamine can be suppressed in an organic solvent and by using the action exchange resin in the sodium ion form. The main product is 1,3-dihydroxyacetone in all reaction under our conditions. The effect of the base concentration and the diffusion in the particle on the reaction rate are not observed under our conditions. Formaldehyde polymerization with the thiamine immobilized resin in 1,4-dioxane proved to be able to express the equation,-d [formaldehyde]/dt = k [thiamine] [formaldehyde]. The activation energy of the reaction can be estimated to be approximately 82 kJ mol(-1).

DOI： 10.1252/jcej.32.776

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DOI： 10.11491/scej.2005.0.378.0

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Language：English   Presentation type：Poster presentation  

Venue：Denver, USA  

フロン-窒素混合ガスをモデルガスとした。回収した混合ガスハイドレートを分解した際の伝熱挙動について調査した。初期に窒素がリッチになり、遅れてフロンがリッチなガスが回収された。これはハイドレート粒子中のガス組成が不均一であることが原因であると推定した。

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福島市  

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Language：English   Presentation type：Poster presentation  

Venue：Yokohama, Japan  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：桐生  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：桐生  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：桐生  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：桐生  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：桐生  

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Language：Japanese   Presentation type：Poster presentation  

Venue：札幌  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌  

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Language：Japanese   Presentation type：Poster presentation  

Venue：札幌  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Language：English   Presentation type：Poster presentation  

Venue：Beijing, P.R.China  

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Language：English   Presentation type：Poster presentation  

Venue：Beijing, P.R.China  

HCFC22-窒素混合ガスをモデルガスとした。回収した混合ガスハイドレートを分解した際に発生するガスを二つの方法（全回収法、多段回収法）で回収した。多段回収法では全回収法に比べて特に４段目以降でさらにHCFC22ガスが濃縮され、分離効率が向上した。このように、多段回収法は分離効率を高める方法であることが示された。

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：盛岡  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：盛岡  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：盛岡  

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Language：Japanese   Presentation type：Poster presentation  

Venue：盛岡  

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Language：Japanese   Presentation type：Poster presentation  

Venue：盛岡  

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Language：Japanese   Presentation type：Poster presentation  

Venue：盛岡  

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Language：Japanese   Presentation type：Poster presentation  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜  

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Language：Japanese   Presentation type：Poster presentation  

Venue：横浜  

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Language：Japanese   Presentation type：Poster presentation  

Venue：横浜  

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Language：Japanese   Presentation type：Poster presentation  

Venue：横浜  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌  

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Language：Japanese   Presentation type：Poster presentation  

Venue：札幌  

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Language：Japanese   Presentation type：Poster presentation  

Venue：札幌  

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Language：Japanese   Presentation type：Poster presentation  

Venue：札幌  

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Language：Japanese   Presentation type：Poster presentation  

Venue：札幌  

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Language：Japanese   Presentation type：Poster presentation  

Venue：札幌  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌  

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Language：English   Presentation type：Poster presentation  

Venue：Edinburgh, UK  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京  

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Language：English   Presentation type：Poster presentation  

Venue：札幌  

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Language：Japanese   Presentation type：Poster presentation  

Venue：宇都宮  

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Language：Japanese   Presentation type：Poster presentation  

Venue：宇都宮  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：鹿児島  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：米沢  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：米沢  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：米沢  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：米沢  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：米沢  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台  

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Language：English   Presentation type：Oral presentation (general)  

Venue：京都  

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Language：English   Presentation type：Poster presentation  

Venue：京都  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：Japanese   Presentation type：Poster presentation  

Venue：新潟  

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Language：English   Presentation type：Poster presentation  

Venue：Dalian, China  

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Language：English   Presentation type：Poster presentation  

Venue：Dalian, China  

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Language：English   Presentation type：Poster presentation  

Venue：Dalian, China  

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Language：English   Presentation type：Poster presentation  

Venue：Dalian, China  

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Language：Japanese   Presentation type：Poster presentation  

Venue：東京  

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Language：Japanese   Presentation type：Poster presentation  

Venue：東京  

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Language：Japanese   Presentation type：Poster presentation  

Venue：東京  

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Language：Japanese   Presentation type：Poster presentation  

Venue：東京  

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Language：Japanese   Presentation type：Poster presentation  

Venue：東京  

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Language：English   Presentation type：Oral presentation (general)  

Venue：Salt Lake City, Utah  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都  

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Language：Japanese   Presentation type：Poster presentation  

Venue：つくば  

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Language：Japanese   Presentation type：Poster presentation  

Venue：つくば  

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Language：English   Presentation type：Oral presentation (general)  

Venue：San Francisco, CA  

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Language：English   Presentation type：Poster presentation  

Venue：San Francisco, CA  

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Language：English   Presentation type：Oral presentation (general)  

Venue：San Francisco, CA  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡  

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Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：福岡  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京  

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