Bioethanol made from woody biomass is thought to be one of the promising renewable energy sources. Cellulose, a main component of woody biomass, is hard to hydrolyze due to its high crystallinity. Pretreatment of cellulose with some ionic liquids has been known to be effective to lower the crystallinity of cellulose and make the hydrolysis easier. However, fermentation efficiency is not high in the presence of ionic liquids because the wild type yeast does not have high tolerance to ionic liquids. In the present study, a yeast strain with increased tolerance to ionic liquids (IL-tolerant yeast) was developed by repeating the growth of yeast in the presence of ionic liquid. This IL-tolerant yeast was use d to produce bioethanol from cellulose in the presence of ionic liquid. The IL-tolerant yeast produce d ethanol with high efficiency. Therefore, the IL-tolerant yeast was shown to be useful to improve the efficiency of bioethanol production from woody biomass.

In order to improve the efficiency of lignocellulose biomass pulverization by the vibration mill with ring media, a combined the ozone and pulverization treatment that simultaneously decomposes the lignin structure was investigated. As a result, the enzymatic saccharification efficiency of 71% was obtained in the 60 min pulverization adding ozone. However, the saccharification efficiency was 55% in the pulverization without adding ozone. On the other hand, the saccharification efficiency reached 55% in about 30 minutes in pulverization adding ozone. Therefore, it was confirmed that the pulverization time can be halved by simultaneously performing dry pulverization and weakening of lignocellulose by ozone.

Nitrogen-doped titanium oxide was easily supported on Japanese cedar using a ball mill, and then the Japanese cedar was carbonized to produce Japanese cedar char supporting nitrogen-doped titanium oxide. In this study, we evaluated adsorption performance and decomposition performance for methylene blue of the nitrogen-doped titanium oxide supported on Japanese cedar char. The Japanese cedar char supporting nitrogen-doped titanium oxide showed high adsorption performan ce for methylene blue and decomposition performance in visible light irradiation.

We have been examined t he recovery of phosphorus from aqueous solution by adsorption using rice husk char and the reuse of the recovered phosphorus as fertilizer are examined.

In this study, the rice husk char and Japanese cedar char were prepared and their phosphorus adsorption performance was evaluated. Phosphorus adsorption isotherms of the rice husk char and the Japanese cedar were Freundlich type. The total pore volume of the char tends to increase as the carbonization temperature rises. The adsorption constant (1/n) of Freundlich tends to increase as the total pore volume of the char increases.

To obtain advanced cellulose and lignin, preparation of lignocellulosic nanofibers from prehydrolyzed soda pulp with trace amount of phenolic chemicals was investigated. The softwood powder was soaked in acetone dissolved trace amount of p-cresol, prehydrolyzed with dilute sulfuric acid, digested by soda pulping, and mechanically nano-fibrillated. Lignocellulosic nanofibers could be prepared from softwood powder with trace amount of p-cresol.

Spent coffee grounds (SCG), the residual materials obtained from the treatment of coffee powder with hot water, are the main coffee industry residues and founded to be rich hemicellulose, such as mannan and galactan. In this work, this material was treated under hot-compressed water condition at 140-260°C for recover the oligosaccharides derived from hemicellulose. The highest oligosaccharides yield (152.8 mg/g-SCG) was obtained at 180°C for 15 min under hot-compressed water condition. On the other hand, the obtained main monosaccharaide was mannnose, which could be used for a chemical with a wide variety of uses in the food industry. It was shown that hot compressed water treatment was effective for oligosaccharides recovery from SCG..

Bisque firing is typically applied to strengthen the green body of ceramics. In this study, TEMPO-oxid ized cellulose nanofiber (TOCN) was added to ceramic material slurry for the same purpose, and t he flow characteristics of the slurry with 0.5% TOCN were investigated by using rheometer. Although the fluidity of the slurry was decreased by the addition of TOCN, slip casted body was successfully produced from TOCN-containing slurry with water content between 40 and 60%. In future works, we would test addition of CNFs with lower viscosity.

We analyzed the FIT business profitability of the woody biomass power generation in case of fluctuation of the unit price of electricity in the future. We set six characteristic projects from small-scale combined heat and power generation to large-scale power generation. In the current FIT system, in the power generation business with less than 10,000kW, where the selling price of “general wood” is high, it is considered realistic to use “unused wood” as the main fuel and to supplement the shortage with PKS and sawdust. Needless to say, it is important to reduce the mixing ratio of “general wood” as much as possible.

In considering climate change mitigation measures, it is important to consider woody biomass such as forest resources sustainably. This study aims to evaluate woody biomass for heating consumption of households considering the amounts of available woody biomass in the Okuaizu region of Fukushima Prefecture. GHG emissions of households heating systems such as kerosene stove, air conditioner with high or low energy efficiency, heating systems that use woody biomass resource are evaluated and compared.

To reduce environmental impact and improve the economic efficiency of combined heat and power (CHP) using woody pellets, sensitivity analysis was performed to the plant scale based on the inventory data from the collection of log to the treatment of ash. As a result, environmental and economic evaluations showed that carbon dioxide (CO₂) emissions decreased and net revenue increased with increasing plant scale.

There are five million tons of waste wood building materials in a time span of a year in Japan. 50% of the energy used in a waste wood building materials recycling plant is light oil used as the fuel for a heavy machine. The production of this light oil from waste wood building materials promises not only the recycling promotion but also the reduction of CO₂ emissions. In this study, a Biomass to Liquid (BTL) process involving the gasification of waste wood building materials, dry product gas cleaning, and Fischer-Tropsch synthesis (FTS) was designed using a commercial simulation software package to investigate environmental and economic analysis.

In general, a high pressure tank is used as fuel storage of fuel cell. Here, metal hydride is known to absorb and/or desorb hydrogen at near room temperature and lower pressure. Due to these properties, it is expected that metal hydride is alternative proposal. However, an endothermic reaction occurs during hydrogen desorption. This leads to decrease the hydrogen flow rate, that is, PEFC cannot operate continuously. In this study, it is investigated that the relationship between the hydrogen flow rate and the operating temperature on metal hydride. Moreover, weight energy density is calculated under the storage of bio hydrogen. As a result, there was a temperature distribution of 25°C in the radial direction when hydrogen cannot be discharged. Also, it was found that weight energy density of metal hydride was 133Wh/kg. In the future, we develop suitable design of metal hydride reactor under these results.