A laser light scattering technique was used for the determination of the mutual solubilities in two-liquid systems at moderate pressures. The solubility data and the upper critical solution temperatures are reported for the binary systems of methanol with octane and 2, 2, 4-trimethylpentane. The experimentally determined cloud points were satisfactorily correlated by the NRTL equation and Tsuboka–Katayama’s modification of the Wilson equation.

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A high speed photographic technique has been employed to measure the Sauter mean diameter of bubbles experimentally in a gas liquid ejector using a sodium chloride-air system. The measured values are compared with the theoretically predicted maximum bubble size diameter using Sprow’s correlation. Bubble size as a function of the liquid flow rate and also of its distance from the throat of the ejector has been reported in this paper. The results obtained for this non-reactive system are also compared with those obtained earlier for the air-water system.

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A modified airlift reactor with rectangular wire-mesh draft tubes was developed. The draft tubes improved the liquid mixing and decreased the bubble coalescence in the airlift reactor. Mixing time, volumetric mass transfer coefficient and gas holdup were employed to describe the performance of the proposed reactor. The reactor, in both the small and large scales, had the higher capabilities of liquid mixing and mass transfer in comparison with those of the conventional bubble column. By using the proposed reactor, the mixing time reduced up to 30%, volumetric mass transfer coefficient and gas holdup increased up to 50% and 90%, respectively.

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A nylon-polystyrene microcapsule sensitive to an outside stimulus such as an electric field was prepared by a combined process of interfacial polymerization and solvent evaporation. A ferroelectric liquid crystal monomer containing carboxyl-p-benzoyloxybenzoate (the mesogenic core) and carboxyl-(s)-(-)-2-methylbutylester (the terminal group) was much effective as a functional component which responds to an electrical field. The monomer extremely has a sensitive response to the outside stimulus, because it has spontaneous polarization. The microcapsule immobilized ferroelectric liquid crystal could controll the permeability of L-tryptophan, which is used as an encapsulated core material, compared to that of the microcapsule with no monomer under the external intermittent electrical field.

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Solubility of water in typical reformate in a multicomponent system, water + isopropanol + reformate, was studied over a temperature range of 288.15 to 318.15 K. The system studied exhibits type 1 liquid-liquid phase diagram. A simplification of the homogenous multicomponent mixture to a pseudoternary system is recommended. Based on the experimental data, the mutual reformate-water solubility increased as the concentration of isopropanol increased. This observation is very important when assessing both the water pollution by gasoline and sensitivity of gasoline to water. Temperature has no effect on the solubility of reformate in water, but it has a modest effect on the solubility of water in reformate. The experimental results were used to estimate the interaction parameters between each of the three pairs of components for the NRTL and the UNIQUAC equations as a function of temperature. Both equations satisfactorily correlate with the experimental data, however, the UNIQUAC fit was slightly better than that obtained with the NRTL model.

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The adsorption kinetics and equilibria of N₂ and CH₄ in pelletized zeolite 4A, 5A and CaX were studied theoretically and experimentally at the range of 273–293 K and 0.0–0.8 atm. Using the isothermal and nonisothermal adsorption rate models, the diffusion mechanism was investigated from the experimental uptake curves through a gravimetric method. While the diffusion rates of N₂ and CH₄ were controlled by micropore diffusion in zeolite 4A, they were significantly affected by macropore diffusion in zeolite 5A. In the case of zeolite CaX, the controlling mechanism of diffusion rate was changed from macropore diffusion to micropore diffusion as the pressure increased. The diffusion rate in the N₂/4A system was faster than that in CH₄/4A due to the sieving effect in the crystal pore. In both N₂ and CH₄, the diffusion rates in zeolite 5A were faster than those in zeolite CaX because of the slope of adsorption isotherm. The diffusion rate obtained from the nonisothermal model was similar to the diffusion rate from the isothermal model in the range of low pressure, but showed a significant difference at the high pressure because the slope of the isobar became great with pressure in the case of a linear isotherm. In the case of the systems controlled by micropore diffusion, the micropore diffusivity showed a moderately increasing trend with fractional coverage according to the Darken equation. In the systems controlled by macropore diffusion, the effective macropore diffusivity increased with pressure due to its favorable isotherm, and the macropore diffusivity kept a constant value in the domain of Knudsen diffusion.

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Porous silica-zirconia (ZrO₂: 50 mol%) membranes of pore size around 0.5 nm were prepared by the sol-gel methods for separation of IPA/water mixtures by pervaporation. The prepared membranes showed a long time dependency in separation performance for about 30 hours before their steady states were attained. The IPA flux decreased gradually down to less than 1 mol·m^–2h^–1, while the water flux was nearly constant (about 300 mol·m^–2h^–1) at 73 mol% of IPA (10 wt% of water) in the feed mixture at 75°C, resulting in a drastic increase of separation factor from around 40 to 2500. The membranes also showed a high stability even at high water concentration (60 mol% of water) at 75°C, where the water flux exceeded 800 mol·m^–2h^–1.
The time dependency of the separation performance is probably due to the formation of -OH groups on the pore surface and the succeeding adsorption and/or the reaction of IPA molecules which can reduce the effective pore diameter.

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Bergamot oil is a kind of citrus oil which contains terpenes, oxygenated compounds, and waxes. Terpenes were removed conventionally by vacuum distillation or solvent extraction. Recently, supercritical carbon dioxide is focused as an alternative solvent for citrus oil processing. A fractionation process of bergamot oil was developed by using a pressure swing adsorption (PSA) concept in supercritical carbon dioxide. The objective of the fractionation is to separate oxygenated compounds from terpenes (deterpenation). The pressure swing operation between the adsorption step at a lower pressure and the desorption step at a higher pressure was carried out with silica gel as adsorbent. Oxygenated compounds were satisfactorily concentrated in the desorption step and the de-pressurization step. A mathematical model simulated the performance of the PSA process. An increase in the pressure ratio (desorption/adsorption) gave high purity, recovery and yield in the desorption step. The purity of 0.84 was obtained in the desorption step at a pressure ratio of 2.5. Model calculations agreed roughly with the experimental results, although the mathematical model was simple.

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The structure of solid aggregates was investigated by using three particle analyzers; an electrical sensing zone, laser light diffraction and electron microscopy. Four particulate materials; aluminum trihydrate, aluminum phosphate, fly ash and iron hydroxide were used for the analysis of particle shape, size and floc structure. One of the primary conclusions of this work is that the floc structure could be characterized by the evaluation of the fractal dimension based on the experimental relationship between floc size and floc density through the free-settling test. It revealed that coarser flocs had a looser structure with a low value of fractal dimension.

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On-line model-based tuning of the parameters of conventional PI control algorithms is considered. This is accomplished to satisfy the requirement of preset performance specifications. The specifications are defined as time-domain response envelopes, which are appealing to the practitioner. The parameter adaptation at each sampling point is accomplished via using a linear relationship between process outputs and PI tuning parameters. Thus the adaptation strategy directly uses the sensitivity of the closed-loop response to the parameters. In this paper, the model used for calculating the sensitivity is a first order model developed by a simple step testing of the plant. Such a model is very common in industrial practice. The efficiency of the method is presented through simulated implementation on two nonlinear reactor examples.

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A method for automatic generation of operating procedures for a batch production process plant is presented. Knowledge about plant structure and material conversion procedures are represented by plant-structure graph and material-procedures graph respectively. By using these two graphs interactively, a recursive search algorithm is developed to obtain detailed operating procedures for the production of specified materials. The methodology is successfully illustrated by a case study.

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FIE, FIIIE, FIIE and FIVE were purified from Meicellase CEP-6000 as cellulose components. The former two were tentatively named CMCase-type components and the latter two, MCCase-type components. To confirm the previous finding that the fragmentation of MCC with FIVE played an important role in the expression of the synergistic effect, one of FIE, FIIIE and FIVE was adsorbed to MCC at a low temperature (3°C) for a constant time (24 h or 96 h) before starting the hydrolysis (pre-adsorption). On the basis of the findings obtained, the effective adsorption of FIVE to MCC in the early stage of the reaction appeared to raise the synergistic effect, but the excessive adsorption of FIE or FIIIE to MCC in the early stage of the reaction did to inhibit an effective adsorption of FVIE to MCC and consequently to lower the synergistic effect. It was confirmed that, as proposed previously by Tanaka et al. (2000), the expression of the synergistic effect was closely related with the adsorption of FIVE as a pure MCCase-type component to MCC and the fragmentation of MCC by the MCCase-type component in the early stage of the reaction. However, the influence of the pre-adsorption on the synergistic effect was limited in the early stage of MCC hydrolysis.

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Model garbage was liquidized by a thermochemical process at 150–250°C and 3.5–7.0 MPa and by a mechanically disrupted process. The organic compositions of the liquidized model garbage, the mechanically disrupted garbage and their separated phases were analyzed. The liquidized garbage had a large amount of lower molecular weight organic acids compared with the mechanically disrupted garbage. On the other hand, it had a small total sugar amount, including simple sugars, oligosaccharides, polysaccharides, and their derivatives. The HPLC results also indicated that the amounts of fructose and glucose decreased during the liquidization. They were decomposed to other compounds, such as sugar derivatives and acids. Considering that low molecular weight organic acids can be easily decomposed by anaerobic digestion, these results show that the anaerobic digestion of the liquid phase could contribute to a higher digestion rate compared with that of the mechanically disrupted garbage.

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