This study aims to make a quantitative wood flow chart in Japan. The wood flow chart includes basic information for designing the wood utilization system. The wood demand and the wasted wood amount in each industry are estimated based on the supplied wood amount. It is obtained that the estimated production amounts are similar to statistical data. According to the drawn wood flow chart in 2014, it is found that the main resources of the wood energy are the residues from the wood industry and the construction waste, and the share of the round wood in the energy use is less than 10%. 8.1 million m³ wood residues such as sawdust are generated, and 95% is utilized to the chip, self-consumption, and other wood material products. Therefore, it is required to utilize the round wood to energy use for increasing the wood self-sufficiency. According to the drawn wood flow chart in 2025 that expects higher wood self-sufficiency, it is obtained that the imported round wood amount is zero, the generated residue amount is increased because of increasing the wood production amount. It is required to increasing the domestic wood supply amount for the pulp industry for increasing the wood self-sufficiency because 16 million m³ chip for pulp is still imported.

This study aims to compare burner combustion method with conventional method from the viewpoint of total amount of eluted soluble silica in rice husk charcoal (RHC). RHC was prepared in an electric furnace by controlling the combustion temperature and time. The amount of eluted soluble silica in RHC was measured by the molybdenum blue absorptiometric method. The amount of unburned carbon and the crystallization of silica were measured by weight change between RHC production and by the specific surface area and pore volume of RHC, respectively. As a result, RHC combusted at 900 °C for 3 min as a developed rice husk burner contained 60% of the amount of eluted soluble silica in RHC combusted by conventional method at 400°C for 60 min. With regard to the mechanism of silica elusion, in short-term combustion assuming a developed rice husk burner, high temperature was suitable for increasing the amount of eluted soluble silica because it was determined by eliminating the plant fiber covering silica in rice husk. On the other hand, in long-term combustion assuming conventional method, low temperature combustion showed the possibility for increasing the amount of eluted soluble silica because it was determined by the crystallization of silica.

A dual-fluidized bed solid circulating system that comprised a bubbling bed carbonator and a fast fluidized bed regenerator was operated under a condition of Calcium Looping (CaL) CO₂ capture process. Calcined limestone (CaO) was employed as bed material. Gas mixture simulating flue gas from air-blown combustor consisted of CO₂, N₂O, NO, O₂, and N₂ was fed to the carbonator. Most part of the fed CO₂ was captured by the calcined limestone particles, then the partially carbonated particles were transported to the regenerator, in which thermal decomposition of CaCO₃ was carried out in air stream. The carbonator of CaL process was found to be effective for N₂O reduction when the sorbent particles had activity to capture CO₂. A part of NO in the feed gas was also adsorbed by CaO particles, then the adsorbed NO was transported to the regenerator, and released to the gas phase there, though the net decomposition of NOx was not observed. CaL process was revealed to be a multifunctional process of CO₂ capture, N₂O decomposition, and removal of a part of NO in the flue gas fed to the carbonator.

Bioethanol is an important transportation fuel but the resource is finite and unevenly distributed in the world. The purpose of this study is to evaluate strategies for export and import regions in the international bioethanol market. For that purpose, simulation studies using a global energy model to which an agent technique was applied were conducted, and the following results were obtained. (1) If bioethanol importer regions adopt a strategy of a rigid mixture ratio of bioethanol to gasoline-type fuel, and if only a dominant bioethanol exporter region can control the price premium of exported bioethanol in the case of high cost cellulosic ethanol production, the international bioethanol price would converge at a high price. This is because of the high production cost of the cellulosic bioethanol and the high price premium of the exported ethanol. (2) If the bioethanol importer regions adopt a strategy of flexible mixture ratios, the regions could avoid the high price premium. (3) If cellulosic bioethanol is commercialized at a low cost, approximately the cost of starch biomass, the simulation results converge at high mixture ratios and low price premiums. In this case, bioethanol could be one of the major transportation fuels in the future.

The effect of Co precursor and Pt additive on catalytic activity was investigated for Co/SiO₂ catalysts used for Fischer-Tropsch (FT) synthesis. FT reaction activity of Co/SiO₂ prepared using Co acetate as Co precursor was not high, but it was improved notably by adding small amount of Pt. It was found that small Co particles, which were hard to be reduced, were formed in the catalyst prepared using Co acetate. It is believed that the enhanced activity by Pt additive was mainly attributed to the improved reduction of small Co particles due to the added Pt. In addition, although the activity of Pt-Co/SiO₂ prepared using Co acetate as precursor was extremely high, but the selectivity of C₅₊ hydrocarbons was relatively low because of smaller Co particle size, and consequently there was no much difference on C₅₊ hydrocarbons productivity when the Co precursor was varied.