For the purpose of investigating the solid base catalysis of calcium oxide for transesterification of soybean oil with refluxing methanol, the catalyst collected after the reaction was characterized by several instrumental methods : X-ray diffraction, scanning electron microscopy, solid-state ¹³C-NMR. The collected catalyst consisted of calcium glyceroxide, due to the direct combination of calcium oxide with glycerol by-produced from soybean oil. The collected catalyst was reused for the soybean oil transesterification, and we found that the yield of fatty acid methyl esters reached 70% after 1 h. Although the transformation of the catalytically active phase brought a slight decrease in the reaction efficiency, calcium glyceroxide was catalytically tolerant to air-exposure. This is why the collected catalyst could be reused without any deactivation.

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Three types of mill, such as a roll mill, a jaw crusher and a hammer mill, are used as coarse pulverizing devices to find suitable pulverizing conditions for mineral liberation of two kinds of high-ash coals. High-ash coal A, containing a large amount of quartz, and coal B, containing clay, were used as test samples. It was found that the roll mill was the most efficient device, and its characteristic of mineral liberation is suitable to implement an efficient mineral removal method. A grinding load above 1.0 kN in the roll mill for coal A had little effect on mineral liberation, however, the characteristic of mineral liberation and grindability were improved with increasing the roll rotational speed. On the contrary, the mineral liberation for coal B tends to improve at lower roll rotational speeds. Consequently, combustible recovery of 80% and mineral removal ratio of 60% were obtained in the mineral removal test of these coals. Furthermore, it is possible to reduce mineral matters in high-ash coal, such as low-grade coal, to 20 mass% by choosing suitable conditions for coarse grinding mills.

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A two-dimensional numerical simulation is applied to spray flames formed in a laminar counterflow, and the effect of droplet size on soot formation behavior is investigated in detail. N-decane (C₁₀H₂₂) is used as a liquid fuel, and the droplet motion is calculated by the Lagrangian method. A one-step global reaction is employed for the combustion heat release. A kinetically based soot formation model with flamelet model is employed to predict the soot formation. Radiation is taken into account using the discrete ordinate method. The results showed that the diffusion and premixed combustion co-exist in the spray flame and the soot is mainly formed in the spray diffusion flame region. The soot formation behavior is strongly affected by the droplet size. The soot volume fraction increases with the droplet size.

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Coal gasification technology is increasingly important in the world because of the rise in cost of oil and natural gas. Lignite coal is huge in reserved quantity, and is suitable for gasification because of its higher reactivity so that a simple and cheap gasifier is needed for the lignite coal. Circulating fluidized bed with twin reactor (riser combustor and bubbling bed gasifier) is suitable for lignite coal gasification because it can produce syngas with high calorific value without using pure oxygen or pressurized condition. IHI has developed TIGAR® (Twin IHI Gasifier) process based on our commercialized circulating fluidized bed technology. This process can produce syngas with high calorific value and also high hydrogen content with air at the atmospheric pressure. Additionally, both syngas and electricity (from steam) can be produced and also the yields can be controlled by the ratio of combustion and gasification, which will sufficiently meet the demand of the user. In this paper, some results obtained by process simulation, cold model test and pilot scale experiments are shown.

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A halide removal sorbent for hot gas clean-up system was investigated by reactivity tests with a simulated gasification fuel gas. The particulate sorbent containing sodium aluminate (NaAlO₂) reacts with hydrogen chloride (HCl) under diffusion-controlling mechanism in the solid product layer. The sorbent can reduce HCl and hydrogen fluoride (HF) to less than 1 ppm at 573K. The superior performance was brought by the reaction of NaAlO₂ in sorbent with HCl and HF to form sodium chloride (NaCl) and Chiolite (Na₅Al₃F₁₄), respectively.

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Electrostatic precipitator (ESP) is a major dust collection technology for pulverized coal combustion boilers in Japan. Although the collection efficiency of ESP is over 99%, the performance of ESP is affected by dust properties, especially by the electric resistivity of dust. In Japan, many kinds of coal are imported from countries overseas and used in pulverized coal combustion boiler. The property of coal ash formed by the pulverized coal combustion is different by coal species. It is very important to develop a high performance electrostatic precipitator for various types of coal ash.
In this paper, the influence of operation temperature from 363K to 623K on the performance of ESP for pulverized coal combustion boiler is investigated, and the relationship between the coal ash property including electric resistivity and alkalic metal concentration and the collection efficiency of ESP is obtained.

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The effect of parameters for composite powder preparation on the electrochemical performance of cathodes using a mechanically prepared LSM/ScSZ cathode material for solid oxide fuel cells was evaluated. It was revealed that the input process energy, which is defined as a time integration of required power for rotor-blade driving, was successfully described by the changes in BET surface area and particle size distribution of composite powder material. Depending on the composite powder samples, however, the bulk and interfacial resistances for a half-cell test sample varied in a more complex manner when the input process energy was changed. The present results indicated the importance of process parameters such as the input energy besides the absolute values and ratio of particle size for the starting powders and the LSM/ScSZ composition ratio. It can be expected that the electrochemical performance may be further improved with the precise matching and control of these parameters.

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It has been well-known that nanoporous materials show extremely low thermal conductivity, however, they do not retain stiffness enough to be processed into arbitrary shapes. Therefore, it is crucial to realize high thermal insulations as well as high strength. To cope with the problem, we have developed a high performance thermal insulation, which has enough strength to be processed into arbitrary shapes. First, nanoporous composites are prepared by direct bonding of ceramic fibers and nanoparticles. Then, the nanoporous materials are formed simply by dry pressing of the nanoporous composites with SiC particles. In this study, we evaluated the strength and thermal conductivity of the nanoporous materials in detail, and proposed the estimation equation for the thermal conductivity.
The nanoporous material had the bending strength over 0.8MPa. The thermal conductivity was from about 0.023 to 0.04W/(m·K) in the temperature range from 400 to 600°C. Furthermore, the thermal conductivity obtained by the proposed estimation equation agreed with the measurement result within an error of ±15%.

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A multi-stage virtual impaction surface impactor (VIS impactor), which was originally developed by Szymanski for ambient air sampling, was modified to conduct an in-stack measurement of particulates from a stationary source. We carried out separation experiments using model aerosol which was composed of coal fly ash and air, and the classification performance of VIS impactor was evaluated. The separation data using a conventional cascade impactor and a cyclone were also compared and the applicability of these three devices for in-stack measurements of PM₁₀/PM_2.5 mass concentration in flue gas from stationary sources was investigated. The conventional cascade impactor overestimated PM_2.5 concentrations owing to the occurrence of particle bounce-off at the collection plates. VIS impactor clearly showed good classification performance over the wide range of dust concentration (1∼25mg/m³) being independent of the mass of collected dust.

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Chemical looping system makes it possible to construct a clean and efficient energy conversion system without extra-energy consumption for carbon dioxide removal. This paper introduces Chemical looping combustion or gasification, Carbonation/Calcination cycle, and Thermo chemical loop. Furthermore, the phenomenon of particle recirculation in fluidized beds is explained because it is recognized as a key technology of the chemical looping energy conversion.

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An introduction to hydrogen generation from waste plastics and biomass is given in this review. Based mainly on the data from our laboratory, a method consisting of mechanochemical treatment of these samples with some inorganic additives, hydroxides of calcium and nickel, and subsequent heating of the ground sample at low temperature in the range of 400 to 500℃ enables us to produce hydrogen easily and syngas by changing the added molar ratio of the hydroxides.

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