Agglomerated anatase TiO₂-oyster shell powders were sprayed by high-velocity oxy-fuel (HVOF) spraying on an A5052 (Al-Mg alloy) substrate. The powders were prepared by the spray dry method with various mixing ratios of 20%, 40%, and 60%. The primary particle size of TiO₂ was 7 nm, 30 nm and 200 nm. Phase transformation from anatase to rutile occurred during the HVOF spraying process. A higher anatase ratio could be obtained for the 200 nm-agglomerated powder. Therefore, the TiO₂ powder was used for the agglomerated TiO₂-oyster shell powder with mean diameters varying from 30 to 35μm.Sprayed coatings consisted of anatase-TiO₂, rutile-TiO₂, CaCO₃, and CaTiO₃. In gas examination of decomposition, the decomposition rate decreased by the addition of oyster powder. Conversely, the coating exhibits high antibacterial activity. Especially, the 60% TiO₂-oyster shell powder exhibited high antibacterial activity without black light irradiation.

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In the present study, we used a Japanese industrial standard method (JIS Z8818 ; test method for minimum explosible concentration of combustible dusts) to examine ignition limit concentration. We examined the possibility to apply this JIS method to the evaluation of stable combustion conditions of pulverized coal fired burners. We evaluated flame stability by measuring the relationship between coal concentration and flame length obtained by using the JIS method. We defined the minimum coal concentration when the flame length became longer than a pre-set length as ignition limit concentration. Effects of coal properties, particle diameter, and, water content in coals on ignition limit concentration were investigated. The results obtained by the JIS method agreed with other fundamental experimental results and blow-off limit concentration obtained from a large-scale burner. As for the JIS standard method, the experimental equipment was cost-effective and it was relatively easy to operate. Application of the method provided quick estimation of flame stability of an actual burner.

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Since a low rank coal has a large amount of oxygen-containing functional groups, metal cations can be incorporated into coals by ion-exchanging. Ni-loaded brown coal was prepared in this study. A novel low temperature gasification of biomass was developed by using Ni-loaded brown coal char as a catalyst for cracking and reforming tarry materials. When Ni-loaded brown coal char was used in the gasification of wood chip, the gas yield enormously increased by 3.1 times compared with that obtained using silica sand and almost no tarry material was produced.
Functional materials are recovered and prepared from spent catalyst （Ni-loaded brown coal char） and biomass char. NiO fine particles of ca. 75 nm were recovered by burning Ni-loaded brown coal char. The activated carbon and fertilizer were prepared from waste from silk industry, black liquor and poultry manure. High specific surface area of 2600～3100 m²･g^-1 were achieved for activated carbon from silk worm pupa and black liquor. The resultant specific capacitance of EDLC was 47 F･g^-1 which was higher than EDLC fabricated from conventional phenol resin.

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