The effects of stirring speed n and opening ratio of a ring-shaped partition plate A_r, on the exchange rate of vertical vessels with two multiple impellers Q were experimentally investigated. The impeller diameter D_i was one-half of the vessel diameter D_T. The exchange rate Q was proportionally greater than the stirring speed of impellers n and the opening ratio of the ring-type partition plate A_r. In the case of two-stage vertical stirred vessel, the relationship between the modified dimensionless exchange rate Q/(nD_i³A_r) and the agitated Reynolds number N_Re was the same as in the case of the three-stage vertical stirred vessel. The modified dimensionless exchange rate Q/(nD_i³A_r) was found to be proportional to the height of the two-stage vertical stirred vessel at the power of −1.7.

To study the mixing mechanism of various large paddle impellers developed by Japanese mixer companies, the authors evaluated the streak line patterns of the impellers in Newtonian fluid; however, streak line data in non-Newtonian fluids is not available. A larger distance between the liquid free surface and the upper edge of impeller was better for improving the mixing performance of Newtonian fluid with the large paddle impellers. However, it was found that a shorter distance between the liquid free surface and the upper edge of impeller is better in order to produce stress exceeding the yield stress in the mixing of non-Newtonian fluids and expand the cavern area to the entire liquid volume.

Two different ionic liquids, 1-alkyl-3-methylimidazolium hexafluorophosphate and 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, were used as a transport carrier of rhodium (III) extraction. Extraction of rhodium from hydrochloric acid media was conducted by liquid surfactant membranes (LSMs) containing the ionic liquid carrier. The extraction of rhodium was accelerated by the addition of tin (II) to the aqueous feed solution. The effects of various operational parameters on the extraction behavior of rhodium and tin were investigated. The extraction rates of both metals were greatly influenced by the ionic liquid species, the surfactant concentration, and the concentration of stripping reagent. The alkyl-chain length and the anionic part in the ionic liquids were proved to be important to get a high extraction yield of rhodium. In addition, it was found that the concentration of 2-amino-2-hydroxymethyl-1,3-propanediol used as the stripping reagent played a crucial role on the selective extraction of rhodium from a large amount of tin, and there was an optimum concentration to obtain the best performance of LSMs. Under the optimum operating conditions for the present system, rapid and quantitative extraction of rhodium was achieved.

In order to save energy in the cement industry, it is effective to perform clinker burning at as low a temperature as possible. However, if the temperature is too low, the quality of the products will be degraded. It is necessary to measure the temperature of the clinker with high accuracy during the burning process in a furnace. Recently the dust cancellation method of two-color radiation temperature measurement was developed to eliminate the effect of clinker dust suspended in a gas stream of the furnace. However, it requires to introduce a correction using knowledge of the properties at measurement wavelengths into the algorithm for converting from signals of detectors to an accurate temperature, unless the dependence of wavelength on the radiation properties of the dust can be ignored. In this study, the radiation property of cement clinker dust particle cloud was determined in terms of extinction efficiency from spectroscopic measurements by a cold model and hot model. The properties exhibited almost complete independence of the wavelength in visible and near-infrared regions, as well as reasonable agreement between the cold and hot models. Additionally, the properties were only slightly influenced by dust particle sizes and temperatures. The extinction efficiency was also predicted from Mie’s theory applying the complex refractive index determined from the normal reflection on a polished surface of a clinker lump solidified with resin. The predicted efficiency agreed reasonably with the trends and magnitudes of the one obtained from the hot and cold model measurements as well. The results suggest that the two-color radiation temperature combined with the dust cancellation method may be obtained with a reasonable accuracy, without considering the wavelength dependence of radiation properties of the clinker particle cloud.

Air coolers are often used in refineries and petrochemical plants to cool process fluid or circulating cooling water. In general, an overhead air-cooler of atmospheric distillation columns consists of multiple fans including fixed fans and variable flowrate fans that can change flowrate by controlling the pitch angle or the rotation speed. Even when the air-coolers are affected by disturbances on the process side or cooling side, the influence of the disturbances can usually be suppressed by variable fans which control the column overhead pressure or the outlet temperature. However, when the controller output exceeds the operating range of the variable fans, it is necessary to return the controller output into the operating range by starting or stopping the fixed fan in order to restart control. There are two issues to consider in the operation of an air-cooler with multiple fans. One is that the air-flow rate fluctuates when the fixed fan is started or stopped, and the other is that the power consumption of the fans cannot be minimized. In this paper, first, in order to suppress the start/stop disturbance of the fixed fan, a cascade control method which estimates total air flowrate and defines this as an intermediate variable is proposed. On the process dynamic simulator Aspen HYSYS^® Dynamics, it was shown that when starting and stopping the fixed fan, the proposed control system immediately manipulates the variable fans to stabilize the air flowrate and the tower overhead pressure. Next, we propose a method for optimizing the number of fixed fans in operation so as to minimize the power consumption while reducing the frequency of starting and stopping of fixed fans. As a result of applying the proposed method to the simulation data, it was elucidated that the power consumption can be expected to be reduced without changing the frequency of changing the number of fixed fans compared to the conventional method.

The multivariate statistical process control (MSPC) was applied as an anomaly detection method in the continuous manufacturing of drugs. It was confirmed whether abnormal changes in process parameters which were intentionally introduced during operation of a continuous wet granulator could be detected by MSPC. As abnormalities, the water addition rate, center blade rotation speed, and particle sizes of raw materials were varied, whereby all of the abnormalities could be detected with high precision by monitoring of statistics using MSPC. Moreover, it was possible to correctly confirm the normal operating state as being the normal operating.

The dimorphic fungus Geotrichum sp. M111-M3 adsorbs to cellulose fibers, but the fungal component that adsorbs to cellulose fibers has not been elucidated. The present study conducts an absorption characteristic evaluation of potease-treated fungus, analysis of sugar chains derived from cell surface proteins, and detection of cell surface polysaccharides by colloidal iron staining, and attempts to clarify the cell surface components contributing to absorption between fungus and cellulose fibers. The fungus treated by protease hydrolyzed cell surface proteins, whereby their adsorptivity to cellulose fibers decreased. The protease-treated fungus for which 27 types of sugar chains consisting of six kinds of monosaccharides were detected in the degradation product had decreased colloidal iron staining intensity compared to prior to treatment, and thus it became clear that mucopolysaccharide with acidic group was isolated from the cell wall. These results suggested that mucopolysaccharide with acidic group and cell surface proteins influence the adsorption of cellulose fibers.

The power produced from renewable energy sources should ideally be converted into H₂ carrier for the purpose of long-term storage and long-distance transportation. In this study, an energy supply chain was considered by assuming that some large scale photovoltaic (PV) systems of 1.9 MW, 7.5 MW and 1.9 GW classes installed in Yokkaichi City, the electricity generated, was calculated based on meteorological data, the obtained electricity was converted into H₂ by a water electrolyzer, then transported and consumed after (1) compression, (2) liquefaction, (3) conversion into compressed CH₄ or liquefied CH₄, (4) conversion into organic hydride, and (5) conversion into NH₃. The energy efficiency, CO₂ emission reduction and resilience upon transporting to the composition area were evaluated. In addition, a case of utilizing the cold heat generated by vaporization of liquefied natural gas upon liquefaction of H₂ as a supplemental heat source was also evaluated from the viewpoint of energy efficiency. As a result, it was revealed that the energy consumption and CO₂ emissions during the transportation process in the case of liquefied CH₄ were smaller compared to the other H₂ carrier cases. In addition, it became evident that, as the resilience effect for the power generation by H₂ transported to a consumer, the annual available power energy which was supplied for two-person household satisfied the energy demand of 227 households in the case of H₂ carriers excluding compressed and liquefied CH₄, when assuming the photovoltaic system of 1.9 GW class. When providing H₂ to the consumer as a fuel for mobility, the best CO₂ emission suppression effect was the case of using in gasoline vehicles. The energy loss ratio was the smallest in the case of liquefaction of H₂ considering the use of the cold heat generated upon vaporization of liquefied natural gas. This is because the energy assist ratio of the cold heat derived from vaporization of liquefied natural gas, relative to the total energy needed for liquefaction process of H₂, was high at 64.3%. Furthermore, the energy recovery ratio decreased accompanying an increase in the transportation distance. The energy recovery ratios were the best when the transportation distance being 0, in the case of liquefaction of H₂ utilizing the cold heat generated upon liquefied natural gas vaporization, and when considering transport, in the case of compressed CH₄.