A new Home-Base (HB) impeller with 3S performance (simple, speedy and stable) was developed by Kato et al. (2015a, 2015b). In this paper, authors attempted to apply an HB impeller to a stirring bar for an experimental test tube and to scale up to an industrial scale as a practical application of an HB impeller, authors developed an optimal HB-type stirring bar for test tube and found that it had shorter mixing time than the normal stirring bae. In addition, the authors measured the mixing time of HB type impeller from the pilot scale to the experimental scale. From the results, it was shown that the HB impeller could be efficiently scaled up from the experimental scale to the industrial scale without changing the impeller geometry.

A large two blade paddle impeller GD220 was developed for aeration agitation, and its performances were evaluated by measuring the power consumption, mixing time, and aeration power consumption. The mixing performance was equivalent to that of similar large paddle MR203. In addition, the impeller blade tips were retracted and provided with cutouts, which made it difficult to form cavities during aeration, and the aerated power consumption was not reduced much.

In the previous work(Marui and Tokanai, 2021), the heat transfer reduction was observed in the low Reynolds number region by means of the particle sedimentation and heat transfer enhancement was confirmed in the high Reynolds number region because of the particle dispersion. In this work, the experimental investigation was carried out to resolve the heat transfer inhibition by use of the larger particles under the dilute particle concentration conditions. As a result, it was found that the sedimentation of particles was avoided and the heat transfer was not suppressed in the low Reynolds number region. In the high Reynolds number region, on the other hand, the heat transfer was enhanced because of the disturbance effect of large-diameter particles. Furthermore, it was confirmed that the heat transfer coefficients including the data of previous work, can correlate well by correcting the parameters of the correlation equation proposed in the previous report.

We attempted to purify water using chitosan derived from crab shells, combined with calcined shell powder and demonstrated that sterilization, virus inactivation, and flocculation and sedimentation of the components of turbidity occurred. Consequently, sanitary, safe, and clear water was obtained. Bacteria and viruses were inactivated by calcined shell powder, which is mainly composed of calcium oxide. Clay particles, bacteria, and calcined shell powder, which are components of turbidity, formed flocs with chitosan, a cationic polymer, and the flocs quickly settled. The addition of calcined shell powder facilitated the incorporation of fine particles into the flocs, and the combined use of chitosan and calcined shell powder was effective in obtaining highly clarified water with a smaller amount of chitosan. The proposed method leads to the effective utilization of food waste because the additives for water purification are made from crab shells and seashells. In addition, since the process is simple, requiring only stirring and no special equipment, it has the advantage of purifying water anywhere in the world, making it a useful method for obtaining safe water in unsanitary conditions.

A new method for calculating both chromatograms and breakthrough curves was developed using an equilibrium stage model based on material balance. In this calculation method, chromatograms can be calculated for impulse input and breakthrough curves for step input. This calculation method based on chemical engineering is expected to be applied as a thermodynamic equilibrium model for prediction of both chromatograms and breakthrough curves.

This paper aimed to extract more natural essential oil from the juice residue of yuzu (Citrus junos), a type of Japanese citrus fruit, by using enzymatic pretreatment in supercritical CO₂ extraction. Enzyme pretreatment time, enzyme water concentration, and enzyme species were investigated. As a result, it was found that 1 h reaction time, equal amounts of water to raw materials, and use of Sclase™ A, a complex enzyme mainly composed of pectinase, were optimal. Supercritical CO₂ extraction was performed at 40°C and 25 MPa for 240 min. The model proposed by Sovová was applied as the numerical analysis, and it was found quantitatively that the effect of the enzymatic pretreatment was expressed in both values of the mass transfer coefficient in solids, k_s, and the surface abundance of the target extract, x_p/x₀. To clarify its effect, the obtained natural essential oil was tested on perimenopausal women (saliva analysis and questionnaire analysis). In addition, the anti-allergic activity of the extracted residue was evaluated by using mice, and it was shown that the effective utilization of the residue.

The k_La value (Oxygen-transfer coefficient) is widely used as a scale-up indicator for culture tanks, and several methods have been used to measure it. Among them, the static method is very simple because it does not require bacteria cultivation, allows flexible changes in measurement conditions, and facilitates repeated measurements. On the other hand, the conventional galvanic cell dissolved oxygen sensor has a significant response delay, making it impossible to evaluate culture conditions with high k_La values such as those used in actual culture. In this study, it was clarified that a high k_La of 300 h⁻¹ or higher can be measured by a static method using an optical dissolved oxygen sensor with a remarkably fast response time. Furthermore, we correlated the results with various k_La measurement methods under exactly the same conditions.

A laboratory- level continuous composting unit consisting of two small fermenters was constructed to utilize heat from composting fermentation for heating the composting material. The relatively hot composting exhaust gas from the first fermenter was directly introduced into the second fermenter without heat exchange. The compost composition before and after composting was measured, and the effect of exhaust gas on composting was investigated by comparing with composting with normal air supply. The following differences were recognized in the composter that introduced the composting exhaust gas compared to the composter that supplied air. The maximum temperature of the compost increased and the temperature distribution along the height of the compost became uniform to some extent. The amount of water discharged from the equipment tended to decrease, the drying of the compost was suppressed, and the moisture content distribution in the height direction became smaller. Carbon dioxide emissions increased by about 10% and ammonia decreased by more than 50%. As for the components of the compost, the carbon removal ratio was 1.1 times higher and the nitrogen removal ratio was 1.4 times higher. Therefore, the decomposition of organic matter in the composted material was promoted in the composter that introduced composting exhaust gas compared to the case that air was supplied.