Measurements of vapor-liquid distribution coefficients (K-values) of compounds contained in hops-extract ethanol solution in high pressure CO₂ system were carried out at temperatures of 313–373 K and pressures of 5–14 MPa with a continuous flow apparatus for fractionation of hops-extract by using supercritical counter–current extraction process. Using available experimental data for 105 K-values, a correlation equation for the vapor–liquid distribution coefficient of solutes was constructed based on entropy-based solubility parameter (eSP) and dimensionless temperature. The dimensionless distribution equation that takes into account the eSP concept, originally developed in the previous work (Ota et al., 2017), was also applied to the available experimental data, and four universal constants were re-determined. From the established calculation methods, the K-values of solutes could be applied to the counter–current extraction systems with supercritical CO₂.

Experiments and simulation of counter-current extraction by supercritical CO₂ with hops-extract ethanol solution were carried out at temperatures of 313–353 K and pressures of 5–12 MPa for continuous fractionation of hops-extract. The correlation equation for the vapor-liquid distribution coefficient of solutes based on entropy-based solubility parameter was applied to the counter–current extraction simulation, which revealed that flavor compounds were highly fractionated at higher temperatures and higher pressures in the experimental conditions studied in this work. In contrast, it was found that resin components were likely to fractionate in the raffinate phase. From these results, highly effective separation of hops-extract was observed in this system.

A CO₂ adsorption simulation technique was built and implemented to clarify the design requirements of PTSA CO₂ adsorption. In the simulation, a CO₂ adsorber was connected with a methanation reactor, which converted CO₂ and H₂ to CH₄. Exothermal heat of the methanation reaction was recovered with oil and then used as the energy for temperature swing in the CO₂ adsorber. The CO₂ adsorber featured a shell-and-tube design that has high heat exchange performance. Configuration of the adsorber, i.e., tube number, diameter, length, thickness and oil flow channel width, was investigated using the simulation. The results showed that the CO₂ recovery ratio was determined by the cooling performance of the adsorption process and the heating performance of the desorption process. The cooling performance depended on the specific surface area, defined as the heat exchange area divided by adsorbent volume. The heating performance depended on the heat capacity ratio, defined as the adsorbent heat capacity divided by total adsorber heat capacity. Thus, CO₂ recovery ratio was determined by the specific surface area and heat capacity ratio of the CO₂ adsorber.

In a water-cooled rotary stoker combustor (WRC) used in industrial waste treatment, the effect of the preheating temperature of the combustion air on clinker generation and the concentrations of lead, zinc, and chromium in the incineration residue was examined. First, the temperatures and gas components in the WRC were measured. It was confirmed that the vapor phase temperature rises rapidly near the WRC outlet when the combustion air temperature is room temperature, whereas this rapid rise is eliminated when the combustion air temperature is 180°C. By eliminating the high temperature field and forming a relatively mild combustion field, the interval between occurrences of clinker trouble at the combustion air temperature of 180°C could be extended to about twice that at room temperature. Next, the mass balance of ash, lead, zinc, and chromium in the waste throughout the process was examined, and reasonable results were obtained. Comparison of the concentrations of the three heavy metals in the incineration residue and fly ash further revealed increasing migration of the metals from waste to fly ash with increasing preheated air temperature. This was explained in relation to the measured temperature distribution in the WRC.

The effects of temperature and amount of stored NO_X on the performance of Rh/Ba/Al₂O₃ for a NO_X storage and reduction catalyst were studied by spatially and temporally resolved operando X-ray absorption spectroscopy. By simultaneously analyzing the spatial distribution of the oxidation state of Rh in the catalytic reactor, and the concentration profile of the outlet gas, it was found that the NO_X conversion rate was reduced by three factors: 1) an inadequate number of vacant NO_X storage sites in the catalyst when the amount of stored NO_X was too high, 2) a lower reduction rate for Rh oxide at lower temperature and 3) a higher decomposition rate for stored NO_X at higher temperature. Therefore, the NSR catalyst should be employed at a moderate temperature, at which the reduction rate for Rh oxide is sufficiently high and the decomposition rate for stored NO_X is sufficiently low. In addition, the amount of stored NO_X should be controlled in order to maintain vacant storage sites in the catalyst.

A bicelle is a non-spherical, bilayer molecular assembly that has potential application as a functional membrane material. In this study, we examined the effect of molar ratio in preparing bilayer molecular assemblies from oleic acid (OA) and a detergent (CHAPSO) by evaluating the size and the membrane packing of the prepared molecular assemblies. As a result of the measurement by dynamic light scattering, the size of the solubilized molecular assemblies could be controlled in the range of 22.5–135 nm by varying the molar ratio of OA, X_OA (=[OA]/([OA]+[CHAPSO])), in the range of 0.3–0.7. The fluorescent probe method employing Laurdan revealed that the membrane packing of the solubilized assemblies prepared from OA and CHAPSO was heterogeneous, and that a bilayer structure containing bicelles was probably formed. Moreover, it was found that addition of Na⁺ as a counterion improved the dispersion stability of the bilayer molecular assembly prepared.