Takashi Yanagida

Combination of hot compressed water treatment and wet disk milling for high sugar recovery yield in enzymatic hydrolysis of rice straw.

Rice straw has attracted significant interest in Japan as a potential raw material for biorefineries. Combination of hot-compressed water treatment (HCWT) and wet disk milling (WDM) was investigated to improve the enzymatic digestibility of rice straw and enhance sugar recovery yield. Rice straw, cut to <3 mm, was autoclaved at 121, 135, and 150 °C for 60 min, and subsequently treated by wet disk milling. WDM with HCWT at 135 °C for 60 min produced maximum xylose and glucose yields of 79% and 90%, respectively, at 10 FPU/g-substrate cellulase loading. Autoclaving at 150 °C leaked a 35% arabinose effluence in the liquid phase. Hydrolysis via WDM with HCWT required a lower enzyme loading (5 FPU/g-substrate) than either pretreatment process in isolation for >70% xylose and 80% glucose yield. Economical analysis indicate that enzymes cost for ethanol production is reduced by 19-67% by WDM with HCWT.

Recovery of activated carbon catalyst, calcium, nitrogen and phosphate from effluent following supercritical water gasification of poultry manure.

A new method for suspending a fine, activated carbon catalyst in a biomass feedstock used for a supercritical water gasification (SCWG) continuous reactor is proposed. In a previous study, the organic matter in poultry manure was shown to be completely converted into gases such as H(2), CO(2) and CH(4) using SCWG. In practice, however, since the feedstock is not only composed of organic matter, but also contains inorganic material, water and catalyst, products such as gas, solid and liquid are produced during SCWG. The aim of this work was to investigate SCWG by-product utilization. This paper describes fundamental studies on the recovery of materials from SCWG products to develop a novel and simple recycling process that utilizes the by-products. A major portion of the activated carbon, monetite and ammonium sulfate can be isolated from the SCWG effluent.

Application of the severity parameter for predicting viscosity during hydrothermal processing of dewatered sewage sludge for a commercial PFBC plant.

Dewatered sewage sludge (approximately 80% water, but with low fluidity) was liquidized by hydrothermal treatment in order to make coal-water paste (CWP) for use in a pressurized-fluidized-bed-combustion (PFBC) power plant. Prediction of the viscosity of the dewatered sewage sludge during batch reactor hydrothermal liquefaction is important in order to avoid inputting excess energy. A single parameter, the severity parameter, has been used to predict viscosity during the hydrothermal process. The relationship between the viscosity of the slurry made from dewatered sewage sludge and the severity value was investigated. Viscosity reduction was associated with an increase in the severity value and was dependent on reaction temperature and time. It was concluded that predicting the viscosity of dewatered sewage sludge during the hydrothermal process by means of the severity parameter is possible. This method is expected to provide a useful guideline for choosing reaction conditions based on prediction of the viscosity of the sludge slurry during the hydrothermal process.

Application of Micro- or Small-Scale Biomass-Derived Fuel System for Power Generation

Biomass being world’s largest renewable fuel source is now considered as the best alternate for fossil fuels owing to the CO2 saving nature as well as more economical as compared to fossil fuels. Although, some pretreatment process is required in order to utilize the raw biomass for power generation. There are various systems to generate power but combined heat and power (CHP) generation has proved to be the most beneficial method to generate electricity as well as heat by recovering the surplus heat to make an overall efficiency of up to 90 %. Various types of CHP systems have been discussed and compared for their working and efficiency along with their applications in different dwellings depending upon their power capacities. Moreover, biomass CHP systems have been thoroughly overviewed for their economic, energy, and environmental aspects.

Effect of Adopting Rice Husk Power Plant on the Industrial Structures in Japan; Input-output Analysis

The economic impacts, CO2 emission, and change in industrial structures using rice husk power plant in Japan were investigated using input-output table of Japan. The direct and second economic impacts by investment to the rice husk power plant sector were 1.5 times higher than that to the power sector. The flow of money shifted to the agriculture, forestry and fisheries sector during introduction rice husk power plant. Increasing rate of using rice husk power plant induce the high-value added and the low CO2 emission society with a very little change in industrial structure.