In general, the power consumed in mixing operations have been expressed by using power consumption (P) or power number (Np). These values are the instantaneous ones in the mixing processes. In this work, the change of power from the start to the end of mixing was measured for steady and several unsteady mixing modes, the sum of power per unit volume throughout the mixing process was calculated and the method how to get the optimum mixing conditions to obtain the most economical mode (ECO mode) was proposed.
A vacuum distillation apparatus was developed for distillation of biofuel from microalgal model solution. A residue curve was made to investigate the efficiency of oil distillation, using a modified UNIFAC equation for the calculation. From the results, n-hexane was highly separated from microalgal oil at 40 kPa. Squalane was gradually evaporated with recovery of n-hexane from the feed components.
Japan has urgent issues which are not only reducing CO2 emissions but also reducing imported energy as the whole country. To accomplish this, it is important to construct and expand an energy system that can be combined with natural energy and energy conservation. The system should also satisfy economic efficiency for the end consumer. In one of the solutions, “the Smart Photovoltaic power generation (hereinafter referred to as PV) & Electric Vehicle (hereinafter referred to as EV) System” has been proposed. This system combines both the PV and EV. In this paper, a novel system which is direct charging with PV power to EV and then supplying that power to a home has been studied. As a result, it is clarified that the proposed system can utilize PV power more efficiently than mega-solar through the use of power system. Additionally, it is IRR=5.5% of the system without the Feed-in Tariff scheme and various subsidies. IRR of the new system is higher than IRR of Feed-in Tariff scheme.
A model for an internally heat integrated reactive distillation process without a compressor was developed, and the synthesis of methyl acetate from methanol and acetic acid was simulated. The applicability was evaluated by using the process simulator Aspen Plus. The steady state simulation showed that the energy consumption of the heat integrated reactive distillation process was lower than that of conventional reactive distillation.
Conditions were studied for immobilization of alcohol dehydrogenase from Parvibaculum lavamentivorans on non-porous glass beads for use in a continuous gas-phase bioreactor. The activity and stability of the immobilized enzymes prepared by low-temperature drying and by freeze drying were almost the same. The optimal amount of cofactor NADH added and buffer pH for immobilization were 35 µg/g-glass carriers or above and 7.5, respectively. The immobilized enzyme obtained had high stereoselectively, with an enantiomeric excess of 99% or above.
Microcapsules of super absorbent polymer were synthesized by (W/O/W) emulsion and in-situ polymerization method and, vapor adsorption properties of microcapsules prepared under various conditions were investigated. The microcapsules prepared by adding salt to the outer aqueous phase and by miniaturization of the inner aqueous droplets showed stronger hygroscopicity than commercial silica gel. The supply of sodium ions was found to increase the hygroscopicity. Furthermore, the microcapsules could be used repeatedly, and their regeneration required little energy.
A ternary component coating comprising a blend of water, glycerol (GL) and poly(vinyl alcohol) (PVA) was prepared, and activity curves and drying rate curves of the coating were measured for different blend ratios of GL and PVA. The coating was found to behave as a pseudo-binary component coating. A set of equations for the drying model of the pseudo-binary component coating was derived from an extended Maxwell–Stefan equation of the ternary component coating, assuming the polymer to be a chain of the same diffusion segment and the Maxwell–Stefan binary diffusivity between PVA and GL to be zero. A series of computer simulations based on the drying model was performed in which molecular mass of the diffusion segment was set 1.0–2.0 times that of the structural segment of PVA. The simulated result showed good agreement with the experimental one, in which drying is controlled by Fick-type diffusion.
This research aimed to evaluate the power generation efficiency of a binary-cycle power-generation system that enables conversion to electric power of hot spring thermal energy in the low-temperature domain (140°C or less), one form of renewable geothermal energy. Power generation output, thermal efficiency, exergy efficiency and exergy destruction were estimated for five working fluids by process calculation using HYSYS. When the basic conditions were as hot spring heat temperature of 60–140°C, flow rate of the hot spring of 200 L/min, heat exchange temperature in the evaporator of 20°C, temperature difference at pinch point of 5°C, and i-butane as the working fluids, a difference in power generation output according to the working fluids was found at hot spring heat temperatures of 90°C and above. In order to obtain 19 kW of power generation output, the exergy destruction of the power generation system was 27 kW, and the exergy destruction of the evaporator accounted for 44% of the whole. When groundwater or river water was used in the cooling process of the condenser, the power generation output was decreased by about 20% with the rise in circulating water temperature in summer.