This study aimed to clarify the optimum combustion condition from the viewpoint of rice husk charcoal and heat utilization, assuming the design and operation of the rice husk combustion furnace. Rice husk charcoal was prepared by electric furnace on the 18 combustion conditions, combination of combustion temperature (400, 600, and 800°C), combustion time (3 and 60 min) and air supply speed (0.0, 0.3, and 0.5 m/s). The amount of rice husk charcoal produced was calculated from the weight difference before and after burning, and the acquired heating value was calculated from unburned carbon. As a result, it was shown that combustion at high temperature (800°C), short time (3min), small to moderate (0.0 - 0.3 m/s) air supply speed is suitable. In the future, it is necessary to evaluate rice husk combustion considering utilization of rice husk charcoal.

In our previous studies, the char produced from woody biomass pyrolysis for 10 min was gasified at the same temperature in a small fluidized bed. When both of the gasification rate measurement and pyrolysis were conducted at the same temperature, structure of the char produced at different pyrolysis temperatures was not same. In the present study, the char produced at a temperature from Eucalyptus camaldulensis (a broadleaf tree) was once cooled in 45 min to various temperatures and the gasification rate was measured at the temperatures. It was found that the gasification rate was increased again after it was once decreased, which was explained by the possible re-opening of pores with the progress of the gasification. Furthermore, though the rate was increased with temperature as expected up to the 1,000°C, it was reduced between 1,100 and 1,200°C, which was explained by the pore plugging with melted ash.

We focused on co-pyrolysis of wood and plastic mixture, which is a way to convert them into smaller hydrocarbon molecules. This process requires only heat, while the reaction is complex and the mechanism is not completely understood. In order to maximize effective recovery of desired products, understanding of pyrolytic reaction mechanism of these mixtures is important. Therefore, we investigated pyrolytic interactions between beech wood (BW) and polyethylene (PE) during co-pyrolysis as representative wood and plastic, respectively. We revealed an interaction mechanism, stabilization of radical species by H-exchange between BW and PE pyrolystes in gas phase. It resulted in enhanced production of levoglucosan and methoxyphenols with unsaturated alkyl side chains, while formation of methoxyphenols with saturated alkyl side chains, phenols, and catechols were decelerated.

Co-firing carbonized woody biomass in coal-firing power generation plant is effective to reduce greenhouse gas emissions because its high energy density and good pulverization property enable high mixing rate of 30calorie-% or more. Tar, by-produced during the carbonization process at 300-400°C, contained high valuable diterpenes of about 5-20%, as previously reported. However, it is difficult to extract diterpenes by means of an HPLC (high performance liquid chromatograph) because the tar is a black and gluey semisolid, which is a mixture of diterpenes, decomposed materials from lignocellulose and small particles. Thermal treatment and hot-water rinsing were effective to separate diterpenes. For example, ferruginol was condensed from 12% to 22% after thermal treatment at 120°C during 24hours and to 33% after hot-water rinsing.

The power output characteristics of the press-type DCFC were studied. By pressing the perforated anode on the carbon/carbonate-packed bed, the carbon particles remained in contact with the anode, while the gas products was released through the perforation. As a result, with increasing the carbon load, the power output in the press-type DCFC increased, whereas continuous discharge was terminated at the carbon content of 5.0 wt% at high current density. This was because the resistance of ion diffusion in the packed bed increased due to gas bubbles formed during discharge

In 2017, certification of biomass power generation of Japan's Feed-in Tariff (FIT) reaches more than 12 million kW, and 90% of that is using imported biomass. As a measure to this situation, introducing sustainability criteria is considered to be effective. This study is to consider the way of sustainability criteria for biomass power generation fuel based on cases and knowledge of domestic and overseas.

We tried to formulate the relationship between unit cost or environmental load such as CO₂ emissions and energy consumption per amount of logging residue and transportation distance. Generally larger scale transportation modes have an advantage over smaller scale transportation modes. The mode transfer from smaller scale to larger scale can be accomplished with an investment such as a setting of intermediate landing. In a case study, four transportation modes were considered, i.e, light truck, 2t truck, 4t truck and 10t truck, with a loading by a grapple loader at a landing. Results showed that the smallest mode (light truck) should be transferred to larger scale modes less than 2 km while middle scale mode still has similar advantage as the largest mode till around 10 km of transportation distance.

Material flow and effect of carbon emission of woody products were quantitatively assessed by a combined eco- and social-system model (Biomass Integrated Model or BaIM) under varios forest management scenarios upto 2080. The BaIM consisted of forest growth model, cost calculation model of woody biomass, and assessment of carbon emission reduction. The effective carbon sequestration rate (ESR) is difined and the BaIM assessed to identify the optimal proportion of energy use to construction use through woody biomass considering ESR. Soundness of eco-social system could be achieved by promoting the use of regional woody biomass by a sustainable way that was mentionded from the results of BaIM.

This study extracted production forests and estimated the annual available amounts of forest biomass resources under profitable forest management in Tochigi prefecture. Production forests were extracted as sub-compartments where expected revenues surpassed all costs—from planting to final harvesting—for a 55-year rotation. Then, annual available amounts of forest biomass resources were estimated on the basis of annual supply potentials from production forests. Annual supply potentials from precommercial, commercial thinning and final felling operations were 80,235 tons, 196,265 tons, and 216,982 tons, respectively. Annual available amounts were estimated at 29,920 tons, 72,639 tons, and 80,871 tons. When considering the profits to the forest owners, those were 8,594 tons, 20,279 tons, and 23,520 tons. The available amounts for Nakagawa and Mibu woody biomass power generation plants were 37,598 tons and 14,795 tons, which were 107% and 49% of annual demands for these plants, 35,000 and 30,000 tons, respectively.

The supercritical water gasification (SCWG) of wet-biomass holds promise as a technology to convert biological effluent into fuel gas, environmentally and friendly energy. Shochu is Japanese popular distilled liquor and Shochu residue is waste, as organic effluent by-produced at distillation process in Shochu distillers. Shochu residue is problem for Shochu distiller because of high treatment cost. SCWG is expected for solution for this problem; however one of major obstacles was tar plugging in heat exchanger tube of SCWG facility. 24 h continuous test and 60 h DSS test of SCWG for Shochu residue with pilot plant (1 t-wet/d) has been conducted and achieved by adding radical scavenger and using rapid heating rate. The difference of radical scavenger concentration was considered by some verification test and we report the results.

Amid the trend of global CO₂ reduction, effective use of hydrogen as a clean energy has attracted attention. In the present situation, however, hydrogen is produced by steam reforming of fossil fuels, mainly natural gas. Many researches are being conducted utilizing renewable resources such as biomass as its production method, but many problems still remain to obtain adequate results as a substitute for fossil fuels. We focused on sewage sludge with inevitable accumulation and low recycling rate and proposed a novel method of generating hydrogen directly with the aid of mixing treatment. In that process sewage sludge is mixed with calcium hydroxide and nickel hydroxide to produce hydrogen with relatively low temperature heating of about 600 degrees. By this method, a high hydrogen generation amount of 50 g per 1 kg of dried sewage sludge was obtained. However, in this method, since a large amount of calcium hydroxide and nickel hydroxide are used, it is a problem that a large amount of solid residue is generated and that the ratio of nickel hydroxide to the cost of hydrogen production is high It was. Therefore, in this study, it was confirmed that hydrogen is generated by recycling the solid residue after once generating hydrogen and reusing the solid residue.

In this work, molybdenum carbide catalysts were prepared by using alkaline or dealkaline lignin (DAL) as the carbon sources and supporting materials. The catalysts were prepared by the wet impregnation method followed with the carbonization at 800°C under an argon gas flow and characterized by XRD and FT-IR. The effect of the lignin type on the performance of the as-prepared molybdenum carbide catalyst for formic acid decomposition was investigated. Formic acid decomposition was performed in a temperature range of 150-350°C and the gas products were analyzed by using GC-TCD. It is found that the catalyst prepared by using dealkaline lignin as the carbon source showed better catalytic activity and the best catalytic performance was found when 2.5% Mo-DAL catalysts was used, on which the highest TOF reached 152 mol_H2‧ mol_Mo^-1‧ h^-1 at 250°C while the selectivity towards carbon monoxide was as low as 0.7 mol%.

With the aim of the efficient utilization of lipids as alternative fuels, the deoxygenation of triglycerides and wax esters in a catalytic cracking process was investigated. Even under hydrogen-free atmosphere, most oxygens contained in the feedstocks were removed as H₂O by hydrogen transfer reaction. The decomposition and deoxygenation of unsaturated triglycerides proceeded rapidly and produced a large amount of polyaromatics, whereas the deoxygenation of saturated triglycerides was slow. In the co-processing of saturated and unsaturated triglycerides, the acceleration of saturated triglyceride deoxygenation and the suppression of polyaromatics formation was achieved simultaneously by the synergistic effect. In the case of wax ester cracking, rapid deoxygenation with low aromatics formation was observed. This is because wax esters rapidly produce saturated fatty acids and higher olefins, which can react synergistically.

In-situ transesterification of C. vulgaris with excess methanol was conducted by acid or alkaline catalyst at 60 °C for 90 min. By using an alkaline catalyst, transesterification was completed at rather lower concentrations of catalyst ([OH^-]=5-25N). At higher hydroxyl concentrations than the range, FAME yield decreased probably due to successive soap formation. By using an acidic catalyst, a higher concentration range than 40 N of proton was required for completion of transesterification. This trend was observed by 100 N of proton. At lower transesterification conversion range, C16:0 and C18:1 were transesterified preferably than others regardless of catalyst type, alkaline or acidic. Soap formation during transesterification by alkaline catalyst consumed C18:3 more slowly than others. These two trends were also observed by using oil extracted from C. vulgaris. Therefore, this selective transesterification observed for C. vulgaris is not originated from the cell structure.

Three processes for the production of 1,3-butadiene (1,3-BD) from lignin via syngas were proposed and their 1,3-BD yields and input energy such as electric power and heat loads were estimated through process simulation. These processes consisted of lignin gasification, conversion of syngas to light olefins (LOs) via (1) dimethyl ether (DME), (2) methanol, or (3) direct synthesis, and isomerization/dehydrogenation of n-C₄H₈. The process capacity was 200 t/d on a wet lignin basis. When each reaction proceeded ideally, the process featuring the conversion of syngas to LOs via DME exhibited the maximum 1,3-BD yield (13.4 wt%).

The reducing abilities and thermal decomposition properties of cellulose nanofiber (CNF) prepared from bleached hardwood pulp were investigated and compared with those of commercial CNF in order to develop heat-resistant CNF. The reducing ability of the sample was analyzed by a modified 2,2'-bicinchoninate method and was correlated with its thermal decomposition temperature in the same material.

A technological combination about enzyme hydrolysis, ethanol fermentation and waste water treatment were evaluated which influences the ethanol production cost. The operating cost (OPEX) was calculated using the data obtained by the pilot plant, and the equipment cost (CAPEX) is based on an estimate amount by engineering firm.

Snβ -zeolite was sucessfully synthesized by direct immobilization of SnCl₂ on high silica commercial β-zeolite (1700 Si/Al) with the assistance of Choline chloride (ChCl) in aqueous solution. The method facilitated the dispersion of tin through SnCl/ChCl complex formation and reduced the generation of inactive tin oxides species on β-zeolite as indicated by the good solubility of SnCl₂, XRD, UV-VIS diffuse reflectance and electronic microscopy measurements. ChCl also had effect on dealumination which led tin to get into the framework of β-zeolite with the calcination as indicated by NH₃-TPD, and UV-VIS spectroscopy. The catalyst with 1.3 wt% Sn loading amount was proved to be active and selective for the sugars isomerization, trioses conversion into lactates and glycolic acid formation from glyoxal.

This study aims to design the regional biomass energy system considering effective utilization rate of resource and fossil fuel reduction rate. First of all, energy density maps in Koriyama city are drawn, and the demand buildings are selected from higher heat density area. As heat demands, the fuel consumption of space heating and hot water are estimated. The district heating network is designed instead of traditional individual heating system, and the total heat pipe length is 1,787 m. Woody biomass are collected from Koriyama city, and average transportation distance is 23 km. As results, the chip boiler has the largest fossil fuel reduction rate 0.85, and the gasification CHP has the smallest CO₂ reduction cost 38,000 JPY/t-CO₂.

NPO Hyogo Japan Consulting Engineers Association newly established the utilization promotion study group of the biomass to contribute for development and creation of local area of Japan. The study group will research the present condition of the biomass and focus the subjects of the biomass in the area. We will utilize research results for effective use of natural energy, industrial promotion, solving problems such as depopulation, aging, talent shortage by applying the new technology of A.I. Artificial Intelligence, IoT, ICT, a robot, new materials, etc. Furthermore, the countermeasure for global warming prevention is due to be proposed.

District heating is effective for energy saving, efficient use of energy, and reduction of greenhouse gas emissions in terms of easy use of natural energy as well as economic effects on the area. For this reason, in various European countries aggressive in countering global warming, the spread of district heating using renewable energy such as woody biomass has been promoted. Here we report the result of the simulation of the district heating and cooling by introducing the wood pellet boiler into the residential development area accompanying the installation of the JR New Station (Jike station) in Higashi Hiroshima City. We will discuss issues on district heating in Japan based on visits to Shiwa Town and Denmark, which are developed areas.

Due to the recent changes in social and economic circumstances, the design of energy systems has been recognized as a regional issue. In this study, we modeled the design process of a biomass energy system in the perspective of mathematical optimization problems. In a case of energy supply to basic facilities (hot bath facilities) in a hilly and mountainous area of Japan, this study evaluated the impacts of regional conditions, social system, business-based behavioral norms, etc., on the indicators such as costs, CO₂ emissions, and resource consumption through optimized selection of energy system. Results indicate that in current situations, it is possible to popularize the biomass energy system utilizing local woody biomass, while additional social burden is likely to occur.

Wood pavement has advantage for lighter weight, better walkability and lower heat storage, but has disadvantages for short life-time due to biological degradation, compared to the conventional asphalt-concrete pavement. In this study torrefaction was employed to upgrade wood for pavement production, and then the optimum torrefaction condition was found to show enough characteristics in the laboratory scale. Demonstration of the pavement has been done at several areas in Japan and their characteristics are being investigated

The purpose of the study is to design woody biomass harvesting system with high productivity to utilize efficiently forest resources. The system is designed based on a spatial analysis of forest volume, forest slope, forest age, and forwarding distance. The performance of the designed systems is evaluated by labor productivity, energy consumption, and CO₂ emissions. The labor productivity of the systems is ranged in 4 - 44 m³/man-day (average, 19 m³/man-day), the averaged energy consumption and CO₂ emission are 130MJ/m³ and 9 kg-CO2/m³, respectively. The results of this analysis can provide helpful information to the design of woody biomass supply chain.

The purpose of this study is to show evidences for designing a sustainable supply-demand system of both food and energy. Analytical method includes designing an integrated flow diagram of food and energy. This shows series of flows from food production to consumption and the energy consumed in the process of food chain. In this study, biofuel production is 1.4×10^-2 EJ, which accounts for 0.08% of Japan's total primary energy supply (TPES) 18.5 EJ. TPES in the food chain is 1.84 EJ, which reaches 10% of Japan’s TPES. It’s important to understand the mutual relationship of all related resources, in order to deal with multiple problems at the same time like increasing biofuel production and stabilizing food and energy prices.

In this study, we have designed a wastewater heat energy utilization system by spatial analysis of both wastewater heat utilization potential and heat demand using GIS. The system consists of a heat exchanger, a heat pump, and a heat consumer. The potential is estimated by multiplying wastewater flow rate to specific heat and temperature difference. Heat demand is estimated by multiplying unit of heat demand to total floor area or number of households. As a result of case study in Hirosaki city, Aomori prefecture, wastewater heat utilization potential of 0.17 PJ/year corresponds to 0.7 % of primary energy supply in the city. In addition, it is found that introducing medical facilities into the system as a heat resources, the primary energy supply and the CO₂ emission can be reduced by 38 % and 50 %, respectively.

In order to study the regional energy plan using agricultural biomass, it is necessary to estimate the geographical distribution of biomass locally existing in the region. I made Agricultural population proportion ratio of Census of Agriculture and Level 3 mesh data of the feeding number of dairy cattle using GIS software. The mesh data is similar to that of the regional data, and it can be used for consideration of regional energy use.

Firewood use at home has been increasing in recent years. Firewood producers are also expanding with timber producers, Forestry households, forest volunteers, wood stove user groups, etc. However, there is little accumulation of research on firewood retail and production. There are few data that surveyed retailers / producers in a certain area. Therefore, we surveyed retail and production in Nagano prefecture where wood stove penetration rate is high As a result, it is clear that there are many producers who produce a small amount of hardwood firewood with high selling price, and at the present time it is clear that producers tend not to want to expand business.

Recent years have seen a greater attention for forest resources in Japan due to the upward pressure on domestic energy demand. One of the key criteria for conjecturing available supplies of forest resources is the economic evaluation of harvesting activities. This study evaluated the timber harvesting costs of planted forests throughout Japan. The cost evaluation was performed using GIS (geographic information system) technology and currently-available GIS data (e.g., digital elevation models, vegetation maps and road network data). The average costs were 6203.0 yen/m3 for Hokkaido region, 6396.8 yen/m3 for Tohoku region, 6793.3 yen/m³ for Kanto region, 7015.6 yen/m3 for Chubu region, 7612.2 yen/m³ for Kinki region, 7166.0 yen/m³ for Chugoku region, 7470.3 yen/m³ Shikoku and 6386.3 yen/m³ for Kyushu region. The results showed that timber harvesting costs vary greatly depending on the characteristics of the regions.

The increase of woody biomass demand for electricity in Japan has promoted log production in many regions, together with large-scale and stable log demand of sawmills which have pursued the advantage of scale. By contrast, only limited planted forests fulfill requirements necessary for efficient logging operation such as stand conditions, forest road conditions and forest owners’ agreement, and increase of clearcutting is required for short-span increase of log production. Then, the constraint of clearcutting ruled in Forest Management Plan system, which has promoted sustainable forest management by motivated management bodies, can be an obstacle. Clearcutting is not allowed when its harvested logs exceed the ruled constraint, meaning that what can affect the available amount of clearcutting log volume are the current volume and distribution of non-industrial stands within the target of each Forest Management Plan.

This research confirmed the extent of pine tree (Pinus densiflora) wilt disease through employing remote sensing techniques with Landsat images taken each winter between 2000 and 2016 in a “Satoyama” area, Ueda City, Nagano Prefecture, Japan. Field studies were conducted by university student volunteers through forestry operations and seminar activities. The results showed that pine trees with signs of wilt disease increased by 43% to 74% between 2000 and 2016. Plot surveys showed that 5.5 trees per 100m² had wilt disease. An average of 5.3 volunteers supplied 23.7 GJ over an average of 4.4 hours field by one operation.

The purpose of this study is to analysis and design for a global supply chain of EFB (Empty Fruit Bunch) consists of palm oil mills, pelletizers and ports. The process is to collect EFB around mills, transport to pelletizers, pelletize, transport to ports and export. Energy consumption, carbon emission and total cost are evaluated at each process and integrated for Inventory Analysis. Energy production by substituting biomass energy from fossil fuel is also analyzed. As a result of a case study in Malaysia and Japan for three cases, total energy surplus becomes 6.43 – 6.84 GJ per unit ton of EFB, CO₂ emission becomes 0.203 – 0.208 t-CO₂, and total cost reaches 6.65×10⁴ - 6.71×10⁴ USD, respectively.

The energy use of woody biomass in Japan has been mainly covered by large scale power generations using FIT for the reason of emphasis on profitability. However, at the present time especially small-scale heat supply systems using woody fuel that can be utilized in local agriculture and public facilities are attracting attention. Regarding woody fuel, it is important to make use of domestic local woody biomass products and wastes from them. In this study, we developed a material-thermal equilibrium simulation model for a woody biomass heat supply plant that utilizes waste timber generated within the local area and the heat is supplied to local projects. We also used the simulation model to calculate the heat energy efficiencies for various operating conditions for the plant.

CO₂ emission to the atmosphere by the use of fossil fuels is estimated at around 8.7Gton-C/year. On the other hand, afforestation can reduce the CO₂ at the rate of 5.37ton-C/ha/year. .Hence if 1.6 G ha (160,000 km²) is newly afforested, all the CO₂ emission by the use of fossil fuels can be fixed. As a result, CO₂ emission can be efficiently encountered and it can solve the global warming issue. If 1 ha of afforestation cost is assumed as $1,600, the global warming issue can be solved at a cost approx. 2,560 Billion $ is raised by financial institution using the financial engineering and 1.6G ha is afforested. This created employment for people under poverty and also can increase the food supply. If all of the people becomes rich, war will be lost and war expenditure will become unnecessary.

To produce the wood fuel with low moisture content for the small CHP system by gasification, the fry-drying of two kinds of wood biomass fuels (Wood chip and Hog fuel) using the edible oil was tried. As a result, it was revealed that the fry-drying condition to achieve moisture content under 15% in the both fuels were 30minutes at 105°C, and 5 minutes or more at 150°C. Since it was confirmed that the calorific value increased (about 29MJ/kg) by absorption of oil, fly drying is considered to be an effective process for improving fuel quality.

The demand of wood chips increases along with the expansion of woody biomass use. However, wood as a resource has finitude. So, it is required to utilize the calorific value of wood as efficiently as possible. Therefore, focusing on the drying process as a means for it, and a test using a batch type drying facility was conducted. The test facility was a convective heat transfer system in which wood chips of about 6 m³ were filled in containers and warm air was applied from the bottom. Comparative study was conducted by changing the main test factors as air volume per 1 cubic meters chip. As a result, it was confirmed that the increase in air volume is effective for improving water evaporation rate, but the drying efficiency growth slowed when the air volume per 1 cubic meters of chips exceeded 200 m³/ h.

We investigated the clinker generated when bark Cryptomeria pellets are combusted and developed a technology to prevent clinker formation. First, we measured the combustion temperature range of the bark pellet boiler, the chemical composition and the identification of the crystalline phase of the ash produced, and the thermal properties. As a result, it was found that the clinker was formed by fusing the low melting point crystal material contained in the ash produced in the combustion temperature range of the bark pellet boiler and welding the ash particles to each other. Also, in the case of adding a certain amount of magnesium oxide (MgO) to the ash, the melting point of the ash rose and did not coagulate the oven combustion temperature range of the boiler. Based on these fundamental findings, a new bark pellet with MgO as a clinker formation inhibitor was prototyped, a verification test was conducted using a houseboiler for agriculture, and it was confirmed that no clinker was produced.

In this study, we burn the bamboo powder packed layer placed on stainless steel mesh to know how the clinker is made. We carried out the mass change of the mesh after burning, mesh surface observation and also measured the adsorption amount and size of bottom ash. In the process of bottom ash formation, two stages were confirmed. Firstly, as the emission of volatiles from bamboo pyrolysis and their combustion at about 1000 K or less occurred, the metal oxides with low melting point andfine white particles of about 10 μm are adsorbed on the stainless steel mesh. Secondly, as char combustion at about 1000 K occurred, there could be two cases of clinker generate. For case one, the small particles with low and high melting points deposit repeatedly and change to clinker in a large massive state. For the other case, lump is adsorbed by the high melting point oxide and small particles due to the low melting point oxide adhere so as to cover the giant lump and become huge.

In order to recycle much wood ash back to the forest as fertilizer, modifications of their solubility are necessary. In this study, we evaluated the dissolution properties of stabilized wood ashes by using single batch leaching tests with different leaching times (10 minutes, 1, 3, and 6 hours). Two types of stabilized ashes (distilled water and magnesium lignosulfonate treated type) were compared with control. The both stabilization treatment suppressed the increases of pH (values) of leaching test eluates. In short leaching time, the eluates from the magnesium lignosulfonate type exhibited lowest pH. The elutes from the magnesium lignosulfonate type also exhibited lowest electric conductivity in the short leaching time, but the difference in electric conductivity of elutes with different stabilization methods become smaller as the leaching time increased.

This research aims to clarify the suitable combustion condition, combustion temperature and time, for enhancing economics as heat use and rice husk charcoal use. The combustion conditions contain 30 combinations with combustion temperature 200, 400, 600, 800 and 1000°C and combustion time 3, 5, 10, 20, 40 and 60 min. Economics as heat use was evaluated by the ratio of burnt plant fiber in rice husk and economics as rice husk charcoal use was evaluated by the amount of eluted soluble silica. The condition of combustion temperature 400°C and combustion time over 40 min was resulted in most suitable for enhancing economics. More, the condition of combustion temperature 600°C regardless combustion time also showed the second highest economics. Therefore, rice husk burner should be designed and controlled under this combustion condition for optimizing economics as heat use and rice husk charcoal use.

Due to the accident at Fukushima Daiichi Nuclear Power Plant occurred in 2011, radioactive cesium was dispersed over a wide range of eastern Japan including forest area. Biomass utilization as gasification feedstock may cause radioactive cesium volatilization, triggering condensation or scattering at a higher temperature. However, much remains unclear about the behavior of radioactive cesium during gasification process. Therefore, the goal of this research is to reveal the behavior of radioactive cesium during gasification for safe biomass use. Through an operation of a laboratory scale gasifier, the behavior were measured in various gasification conditions. As a result, it is revealed that firstly radioactive cesium vaporized at the high reaction temperature (T =900—1000°C), and that secondary the vaporized cesium increases with increasing carbon-conversion-to-gas and S/C ratio at T = 1000°C.

Recently, hydrogen is an attractive fuel as a secondary energy. In the future, the fuel consumption would be expanded from the viewpoint of contribution to the global warming protection. The hydrogen production from biomass feedstock is a promising candidate among hydrogen production. Especially, the production scheme through a steam-based gasification system would be more effective. Thus, in this paper, using the measurement index of exergy which can be evaluated on the availability of effective energy, the exergy analysis was carried out for our designed systems. As a result, the influence on syngas compensated in the combustor was found out. That is, it was found that the exergy loss on a proposed system in which much heat loss in the reactors was prevented decreases in comparison to a conventional system.

In previous study of Bio-H₂ purification, the advantage of 2-step pressure swing adsorption (2-stepPSA) using HAS-Clay and Zeolite A-5 was discussed. These advantages are mainly the abatement of auxiliary power and the sequestration of CO₂ gas from syngas. In order to estimate the performance in the dynamic aspect, the simulation software of gPROMS (PSE Inc.) was used. In this program, the input parameters of a thermal conductivity of each adsorbent etc. are necessary. However, so far, the data of HAS-Clay has not been measured at all. Thus, in this study, fabricating the experimental apparatus on basis of a hot wire method, the data was measured, and the result was validated by other data which was measured by another method. Finally, using the experimental data, the dynamic performance of 2-step PSA was simulated.

In order to use the tar produced from the arsenic-containing construction waste wood as an alternative to regenerative additives of recycled asphalt, the pyrolysis of arsenic-containing wood pellet was carried out. The correlation between the viscosity and the component of product tar and the arsenic behavior in the pyrolysis were investigated.

Heat and mass transfer during pyrolysis of major components bed have been investigated numerically. For Cellulose powder, the calculation temperature and velocity vector distributions had a quasi-steady state during pyrolysis because the gas volume increased near the side wall of the packed bed and then the effective thermal conductivity decreased. The calculation temperature with the effect of volume shrinking of the packed bed agreed qualitatively with the experimental ones for all kinds of powder when the temperature plateau appeared.

Currently, petroleum and other products are separated and refined into LPG, gasoline, naphtha, kerosene, light oil, heavy oil, etc. due to boiling point difference, and petroleum products are made. Disposal of plastics in petroleum products is one of the environmental problems. There are three recycling methods to effectively utilize this waste plastic, and among them, we focused on the oilification process (chemical recycling). In this study, we blast blast furnace slag and newly blast furnace slag into FCC waste catalyst which extracts many conventionally known naphtha ingredients, and we are doing oil conversion experiment. Difference in oil conversion ratio depending on mixing ratio and results of durability test are reported.

In this study, we conducted component analysis, measurement of high heating value after torrefaction and measurement of heat and mass transfer during the torrefaction in three types of biomass powder: Bamboo, Douglas fir and Bark. It was found that the high heating value (HHV) of Bamboo had the maximum value when the torrefaction temperature was 623 K. The HHV of Bamboo was larger than that of Douglas fir and Bark. The gas flow rate during torrefaction of Bamboo had a constant value because cellulose decomposition could be occurred partly after exothermic decomposition of Xylan. It was suggested that the torrefaction of Douglas fir and Bark would be controlled by thermal decomposition of Mannan and Lignin, respectively.