There are some trial project that replace pulverized coal with bio-char to target the pulverized coal power plant. These will have to solve a lot of issues. However, an electric energy demand is expected to increase more and more in the future by sustainable energy resources. We developed the solid biomass fuel (hereinafter refer to as Bio-coke:BIC) and studies to use as a replacement for coal coke advance. But, BIC has a few demerit. One of them is that the calorific value for unit quantity decrease because it contains a lot of free water and volatile matters. Torrefaction processing is one of the way how to improve the energy efficiency. In this study, we produced BIC from green tea and improved fixed carbon content ratio by torrefaction processing. And we execute thermal analysis
and the combustion experiment using torrefied BIC (hereinafter refer to as T-BIC). The purpose of the use in a pulverized coal power plant, the sample crushed it beforehand. Results are found in the following. (1) In the case of volatile matter content ratio less than about 45 %, as volatile matter content ratio is high, gasification time for unit quantity increase. In the case of volatile matter content ratio more than about 45 %, gasification time for unit quantity close to constant. (2) In the case of fixed carbon content ratio in more than about 50 %, as fixed carbon content ratio is high, char combustion time for unit quantity decrease. In the case of fixed carbon content ratio in less than about 50 %, char combustion time for unit quantity close to constant.
The Construction of a sustainable and renewable recycling society system most specifically, recycling of general waste is an
important issue. Local governments have been given bigger responsibilities.
In this study, we tried to focus on Biocoke technology which could make high density and hard biofuel from branches, leaves, grass from households and pruned tree branches in the street.
We made an analyzation by thermal decomposition TG-DTA using pretreatment biomass. We made small Biocoke in some cases like initial moisture, heating temperature et al. We got production conditions’ outcome which has maximum compressive strength for room and hot temperature that corresponds to the maximum specific gravity. In line with this, we examined the correlation of the cold compressive strength and hot compression strength of Biocoke. As new index between the cold-hot compressive characteristic ratios (maximum cold/hot compressive strength), the branches, leaves and grass Biocoke has about 50 ratio, while pruned branches Biocoke has about 89. The difference of Biocoke’s fundamental properties between branches, leaves, grass and pruned tree branches has been shown through these results.
By the Fukushima Daiichi nuclear disaster, substantial amounts of radioactive material, that is estimated about 770 thousand terabecquerel(TBq), was released. In accordance with the Act on Special Measures concerning the Handling of Environment Pollution by Radioactive Materials Discharged by the Nuclear Power Station Accident Associated with the Tohoku District – Off the Pacific Ocean Earthquake that Occurred on March 11, 2011, decontamination area is divided into two areas. In one area decontamination is conducted by Japanese government, and in other area it is conducted by local governments. Gathered waste contaminated with radioactive materials is planned to be carried into ISF(Interim Storage Facility) or burned by an incinerator at local government. But they are not almost performed by opposition by local residents. Now almost of gathered waste is stored in temporal space, so effective utilization of space is desperately required. It is considered that Biocoke having characteristic of a high density and poor reactivity is one of the effective downsizing technologies. In this study, the biocoke manufacturing unit suitable for work in the field is designed and field test is carried out.
Bio-coke is produced by heating biomass with moderate moisture while being pressurized at a prescribed time. In the case of producing large-sized bio-cokes, the thermal conductivity of the biomass and the friction between the biomass and the inner walls of the molds result to uneven internal qualities of the product. To evaluate the quality of large-sized bio-cokes, a simple non-destructive test method is ideal. This study verifies the applicability of ultrasonic propagation velocity as a simple tool to evaluate the quality of bio-cokes of different sizes. Results showed that the ultrasonic propagation velocities in the axial direction and in the radial direction, perpendicular to the axial direction, were consistent in determining the quality of the smaller-sized 48 mm in diameter biocokes.
However, in the case of the larger 100 mm diameter bio-cokes, determining the quality of the bio-coke through ultrasonic propagation velocity worked well only for the axial direction. Due to the uneven qualities of the large bio-coke as a consequence to the opposing frictional forces during its production process, cracks in the axial direction seem to separate the large bio-coke into a peripheral crust-like layer and a core-like layer and redirects the ultrasonic propagation around and along the peripheral layer instead of going straight into the middle of the bio-coke.
Over five years after the Great East Japan Earthquake has passed, we have felt that decontamination has not
progressed enough. This study examined the long-term stability effect by the volume reduction of radioactive biomass based on Biocoke technology. Biocoke is considered as an effective means of volume reduction of radioactive contaminated deciduous leaves and woods because of its excellent features of high density and high strength. Besides, recycled fuels such as RDF(Refused Derived Fuel) and wood pellet can cause fire or explosion by spontaneous ignition if stored under improper management. Results suggested that Biocoke is stable for a long time from TG-DTA analysis, Biocoke technology shifts the exothermic peak to the high temperature. The level of heat generation index was measured using, isothermal and scanning calorimeter (C-80), TAM Micro-calorimeter (TAM-Ⅲ) and Spontaneous-ignition Tester (SIT) shows that the Biocoke has high safety and low hazard due to the chemical reaction between components of raw material. Furthermore, Biocoke is safer than other recycled fuels because low heat and hydrogen generation was measured during storage.
The aging behavior of Al-10%Si-Mg system alloys cast into sand mold were investigated by optical microscopy, scanning electron microscopy and micro-vickers hardness measurement. The castings were demolded and water-quenched at 323, 473, 573, 673 and 773K after cast, and then those were artificial aged at 423, 473 and 523 K. With increasing Mg content from 0.3 % to 0.9 %, the agehardenability (ΔHV: difference of hardness between as-cast and peak-aged condition) was increased relatively gradually, because the solid solubility of Mg and Si in the matrix was decreased due to the crystallization of π-Fe and Mg2Si phases. The ΔHV of sand mold castings was larger than that of permanent mold castings when the demolded temperatures were 673 K and 773 K. This is due to the difference in the amount of precipitates, which were attributed from passing time at high temperature range above solvus line of metastable Mg2Si phase.
Ecological studies of the aquatic organisms using data loggers have been carried out in order to research a resources state of the aquatic organisms. One of data loggers to be used in the studies is an archival pop-up tag. Archival pop-up tags widely used have an ARGOS transmitter for facilitating recovery of tags. On the other hand, they have few sensors such as an illuminometer, a pressure sensor and a temperature sensor by the reason of a small-capacity battery and small buoyancy. Therefore it is difficult to know finescale movements of aquatic organisms from data collected by typical pop-up tags with an ARGOS transmitter. We have developed a smart pop-up tag which has a 3-axis accelerometer and a 3-axis angular velocity sensor in addition to an illuminometer, a pressure sensor and a temperature sensor. This tag allows us to obtain fine-scale movements of target animals. This tag also has an ARGOS transmitter which is driven by a solar cell. We have verified that the tag works properly in a pretest.