Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Society of Chemical Engineers, Japan  

DOI： 10.1252/kakoronbunshu.46.200

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Society of Chemical Engineers, Japan  

DOI： 10.1252/kakoronbunshu.46.176

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Society of Chemical Engineers, Japan  

DOI： 10.1252/kakoronbunshu.46.84

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Society of Chemical Engineers, Japan  

A novel rotating coil-shaped spiral gas-solid contacting device was proposed. Cold models of the spiral structure were made by combining 180° elbows of half-hexagonal shape using ID 24 mm transparent plastic tube. A 5-cycle spiral model was continuously driven by a motor to transport particles, and the pressure drop in the solid bed during gas feed was measured when the rotation was stopped. This pressure drop was compared with that in a vertical packed bed of the same diameter (24 mm). The height of the vertical packed bed that gave the same pressure drop as the solid bed in the spiral was defined as the “equivalent bed height for pressure drop.” The equivalent bed height for pressure drop was lower than that expected from the total volume of solids in the spiral assuming straight packed bed. This result is attributable to gas passing by way of shortcuts formed in the spiral. A simplified model of gas flow distribution in the packed bed within the spiral was proposed. The model with a parameter obtained by use of the 5-cycle model agreed with the results obtained using the 1.5-cycle model with wider range of gas flow rate than 5-cycle model. Thus this model is expected to be useful to estimate the gas-solid contact within the spiral. Also, a 1.5-cycle model was used to visually observe the flow pattern and mixing of particles in the spiral. A circulating flow pattern of particle movement was observed when the spiral was rotated. In spite of the shortcut gas flow, uniform solid conversion is expected because of good mixing of particles in the spiral.

DOI： 10.1252/kakoronbunshu.46.1

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

ガスがすべて固体層を通過する良好な気固接触を維持しながら、軸周りの回転運動で粒子を輸送する気固接触装置として、コイル状らせん構造をもつ装置を提案した。コールドモデルを用いて、粒子輸送速度並びに粒子輸送時の逆混合を実験的に評価し、粒子滞留時間分布を推定した。

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© 2019 Elsevier B.V. The utilization of low-temperature waste heat in the endothermic hydrocarbon reforming reaction can improve the energy efficiency of the chemical product synthesis system. In this study, process assessments are conducted, and potential technologies to realize the reforming process using low-temperature waste heat are discussed. Based on the assessment and process design, a low-temperature methane reforming process using circulating fluidized beds is proposed. An investigation into the use of metal oxide nanoparticles fabricated by the supercritical method as an oxygen carrier serves as a partial proof-of-concept for the low-temperature reforming process. The requirements for the oxygen carrier in the process are calculated based on a target for the amount of methane reformed in the methanol production plant.

DOI： 10.1016/j.cep.2019.107531

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Society of Chemical Engineers, Japan  

A novel rotating coil-shaped spiral gas-solid contacting device was proposed, of which the spiral tube would be made of 180° elbows that are commercially produced according to industrial standards as piping parts. Cold models of the spiral structure were made by combining 180° elbows of half-octagonal shape using ID 24 mm transparent plastic tube. A hand-driven 1.5-cycle model and a continuously motor-driven 5-cycle model were used. As solid materials, three types of spherical glass beads and two types of spherical silica-gel particles were employed. The solid transportation rate by volume per rotation was determined to be 29-40 cm3. Solid back-mixing was evaluated by adding a batch of tracer particles of different color at the inlet of the 5-cycle model. The number of tracer particles was counted in samples taken at the exit of the rotating spiral reactor after each rotation. As an index of back-mixing, the probability (p) of particles moving from one unit to the next with one rotation was proposed. The probability was 0.95-0.97 for all particles. Average residence time and residence time distribution were derived from the probability p.

DOI： 10.1252/kakoronbunshu.45.197

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier  

商用規模大型循環流動層燃焼装置に附置する流動層式熱交換器内の伝熱特性を測定するとともに、伝熱モデルにもとづく相関式で整理した。相関式と測定結果はよく一致した。

DOI： 10.1016/j.energy.2018.08.008

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier B.V.  

In this study, brown coals fast pyrolysis/combustion was carried out in a moving furnace coupled with a balance, and the mass change of sample and emission of hydrocarbon components were online recorded. On the basis of the experimental results, the pyrolysis/combustion kinetic parameters were calculated. In the fast pyrolysis process, the apparent activation energy of Loy Yang brown coal, Wara brown coal and Usibelli brown coal was 36.9, 33.1 and 28.1 kJ/mol respectively, which was far lower than that obtained under the slow pyrolysis process. The main light hydrocarbon gases evolved from brow coal fast pyrolysis were CH4, C2H6 and C3H8. At the same time, it was found that the reaction rate of brown coal fast pyrolysis was strongly influenced by the oxygen content of the raw coal. The high oxygen content of the raw coal was beneficial to pyrolytic reaction. The combustion process of the brown coal could be divided two stages: in the first stage, the evolution and combustion of volatile matter occurred simultaneously. In the secondary stage, only char combustion occurred. The apparent activation energy of char combustion was 2.3–20.8 kJ/mol.

DOI： 10.1016/j.fuproc.2018.03.010

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society  

The calcium looping (CaL) process usually employs a dual-fluidized bed (DFB) solid circulating unit. In the regenerator (calcinator or calciner), decomposition of CaCO3 proceeds. To supply the heat of decomposition, oxyfuel combustion of coal is conducted. However, since coal contains nitrogen, the NOx formation occurs during oxyfuel combustion. Because of the fact that NOx formation and destruction during combustion of solid fuels in a fluidized bed is a complex process, a predictive approach of NOx emissions has not yet been sufficiently recognized, especially during oxyfuel combustion conditions in the CaL systems. The paper introduces a regression-based method for the prediction of NOx emissions from a CaL DFB experimental unit. Effects of fuel type, excess oxygen feed, and NO addition to primary or secondary feed gas on NOx emissions in the regenerator were evaluated. The presented way constitutes a straightforward method to run a complementary technique in relation to other methods of data handling, including the programmed computing approach and measurements. The developed model can be simply employed by scientists as well as engineers for optimization purposes.

DOI： 10.1021/acs.energyfuels.8b00944

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Language：Japanese  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

This work proposes an approach to avoid hot-spot formation in the regenerator of Calcium-Looping CO2 capture process. The basic principle is to capture volatile matter evolved from the fuel by porous sorbent (CaO) particles followed by the formation of solid carbon deposit within the particles. By reducing the amount of volatile matter, rapid combustion of volatile matter in the regenerator can be suppressed. Experimental work was carried out to assess the volatile matter capture by CaO particles in a fixed bed. Higher temperature was found to be favorable to capture volatile matter. Also combustion rate of carbon deposit was measured. The combustion rate of carbon deposit was found to be sufficiently lower than the rate of volatile matter combustion. The influences of temperature and oxygen concentration on deposit combustion rate were not remarkable. Several designs for fuel feed modification that enable volatile matter capture are proposed.

DOI： 10.1016/j.fuproc.2017.08.027

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japan Institute of Energy  

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.

DOI： 10.3775/jie.96.228

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：American Institute of Physics Inc.  

The impacts of internal circulation of a mixture of coal-coke particles and quartz sand on the fluidization state in a fluidized bed reactor are investigated by a cold test with a benchtop set-up in order to design 10-30 kWth scale prototype windowed fluidized-bed reactor. Firstly, a basic relationship between pressure loss of inlet gas and gas velocity was experimentally examined using quartz sand with different particle sizes by a small-scale quartz tube with a distributor at ambient pressure and temperature. Based on the results, an appropriate particle range of quartz sand and layer height/layer diameter ratio (L/D ratio) was determined for a design of the fluidized bed reactor. Secondly, a windowed reactor mock-up was designed and fabricated for solar coke gasification using quartz sand as a bed material. The pressure loss between the inlet and outlet gases was examined, and descending cokes and sand particles on the sidewall of the reactor was observed in the reactor mock-up. The moving velocity and distance of descending particles/sands from the top to bottom of fluidized bed were measured by the visual observation of the colored tracer particles on outside wall of the reactor.

DOI： 10.1063/1.4949204

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

A dual-fluidized bed experimental apparatus was operated to study coal combustion behavior under the Calcium Looping (CaL) process temperature conditions. This apparatus consisted of a fast fluidized bed regenerator and a bubbling fluidized bed carbonator. High-volatile bituminous coal and semi-anthracite were burned in oxygen-enriched air in the regenerator. The formation of CO and CO2 in the carbonator caused by oxidation of char, which was transported from the regenerator with circulating bed material, was measured. Inert silica sand was employed as the bed material so that the produced CO2 could be measured without being captured by the bed material. The effect of the O-2 concentration in the fluidizing gas of the carbonator on the formation of CO and CO2 was evaluated. The formation rate of CO and CO2 in the carbonator was governed by different controlling factors depending on coal rank. NOx formation in the regenerator was also measured. The oxygen concentration in the carbonator fluidizing gas had only a minor influence on NOx emissions from the regenerator irrespective of char consumption in the carbonator.

DOI： 10.1252/jcej.14we261

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC CHEMICAL ENG JAPAN  

Decomposition of Japanese cypress volatiles has been found to proceed efficiently under a prepared Ni loaded brown coal (LY-Ni) char at extremely low temperatures around 400-450 degrees C. This temperature range is much lower than conventional gasification methods (600-800 degrees C for catalytic and 800-950 degrees C for non-catalytic). For the low temperature decomposition of biomass volatiles, the LY-Ni coal with about 20 wt% Ni loading content by ion-exchange and impregnation methods showed a higher activity when compared with the lower LY-Ni coal by ion-exchange only and the higher Ni content of 27 wt%. Nickel particles in the 20 wt% LY-Ni coal dispersed well in the brown coal, with a mean particle size of 5 nm after devolatilization treatment at temperatures of 400-500 degrees C. In the presence of 20 wt% LY-Ni char, tarry materials converted fairly significantly into gases so that the carbon amount in tarry materials was less than 2% (based on carbon). Compared with the cases of sand, the LY-Ni char increased the total gases, mainly including H-2, CO, CO2 and CH4, by 3.5-4.5 times, and hydrogen practically by 5.4-6.9 times at decomposition temperatures of 450 to 600 degrees C. Steam addition advanced the tarry materials gasification and carbon conversion into gas products greatly.

DOI： 10.1252/jcej.14we278

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Experimental comparisons of polypropylene combustion in porous and nonporous alumina bed materials were conducted in a semi-pilot scale fluidized bed combustor (FBC). The results indicate that polypropylene can be effectively used as a fuel in both bed materials. The combustion efficiencies of polypropylene in porous alumina (PA) and nonporous alumina (NA) are above 993%, and CO concentrations in flue gas are below 343 ppm. During polypropylene combustion, no obvious flame is observed in PA, which implies the combustion temperature is low. Hence, NO formation can be suppressed. Further, PA has the capacitance effect, which can capture or absorb some combustible hydrocarbons or melted polypropylene in the micropore of PA and causes lower CO emission and high temperatures in PA. Thus, the temperature of the freeboard zone is significantly decreased in PA. In the case of NA, the temperature in the freeboard zone seems to be independent of the height. The influence of temperature on polypropylene combustion in PA is also investigated, the experimental results demonstrate that the combustion efficiency is above 99.9% when the temperature is above 750 degrees C. (C) 2015 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.applthermaleng.2015.10.153

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Language：English   Publishing type：Part of collection (book)   Publisher：Springer Japan  

Biomass is one of the most important primary and renewable energy sources. Among agricultural and forestry by-products, cultivation waste from mushroom production is considered to have several advantages, such as low collection cost if used by the same production facility, and it contains many inorganic nutrients, relative to woody biomass resources. Some kinds of mushroom culture waste contain plant nutrients (P, K, Mg, and Si)
ash from such biomass waste can be used as fertilizer. Here we suggest new concept for a more economical method of using this waste, namely, cascade utilization of enokidake mushroom culture waste, as fuel, followed by the use of the ash as fertilizer.

DOI： 10.1007/978-4-431-55951-1_33

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japan Institute of Energy  

Reaction pathways of NOX and N2O over CaO under carbonator conditions of the calcium-looping (CaL) process were investigated using a laboratory-scale fluidized bed with calcined limestone (CaO) and inert quartz sand as bed materials. Char particles were fed to the fluidized bed to simulate char transportation to the carbonator. With char feed to the sand bed, slight reduction of NO and N2O in the feed gas was observed, but considerable CO formation was observed. When NO was fed to the CaO bed, NO was first adsorbed onto the CaO surface. The adsorbed NO was desorbed when char or gaseous CO2 was fed. Although char feed to the CaO bed decreased NO slightly, the reduction of NO was nearly equal to that in the sand bed. This reduction of NO with char feed was attributable solely to NO reduction by the char. The formation of CO from char oxidation for CaO bed was much less than that for the sand bed. These results suggest that CO was oxidized over CaO before it reduced NO. For N2O decomposition, the CaO bed had high catalytic activity. CaL process is expected as a multifunctional process of CO2 capture and N2O decomposition with low CO emissions.

DOI： 10.3775/jie.95.1115

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Language：Japanese  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

A new approach to nickel recovery from spent electroless nickel-plating (ENP) solution was investigated using ion-exchange method with brown coal. Nickel ion-exchange was influenced by the solution pH, with the optimum values of pH 9.0-10.0, and was hindered by the anion species existing in the spent solution, especially for the high concentrations of phosphorus compounds. Calcium hydroxide precipitated most of the phosphorus from spent ENP solution, with the highest phosphorus removal efficiency of 98.2%. At the same time, pH control is required to prevent the co-precipitation of nickel hydroxide. Phosphorus removal with CaCO3 and CaCl2 showed strong pH dependence. The solution pH dropped with CaCl2 addition. As a result, the formation of calcium sulphate occurred prior to that of P-Ca compounds. In contrast, CO32- anions from CaCO3 dissolution reacted with the H+ ions to neutralize the solution and decrease CaCO3 solubility at last, the phosphorus removal reached its maximum of 51%. Combined use of calcium carbonate and calcium chloride improved phosphorus removal, maximizing the phosphorus removal efficiency at 94.8%, and enabling 62% of nickel in the ENP solution to be ion-exchanged into brown coal. (C) 2015 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.seppur.2015.04.029

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japan Institute of Energy  

A dual-fluidized bed system that comprised a fast fluidized bed regenerator and a bubbling bed carbonator was operated under a temperature condition of Calcium Looping process for CO2 capture. Three kinds of coal with different volatile matter content were burned in the regenerator in oxygen-enriched atmosphere. Gas mixture consisted of NO, O2, and N2 was fed to the carbonator to simulate the interaction between char and NO in the flue gas from an air-blown combustor. Inert quartz sand was used as the bed material. Formation of CO and CO2 in the carbonator from oxidation of char which was entrained from the regenerator was measured. With char combustion, small amount of NOX was formed in the carbonator when NO-free gas was fed. With NO feed to the carbonator, a part of the fed NO was reduced by char. Thus the char particles in the carbonator were effective for NOX reduction when NO concentration in the feed gas was high. Formation of N2O in the carbonator was less than 10 ppm. The increase in greenhouse effect due to N2O emissions was calculated to be far less than the decrease in greenhouse effect by capturing CO2.

DOI： 10.3775/jie.94.841

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN POULTRY SCIENCE ASSOC  

A pyrolysis/ashing process for poultry manure with the aim of recovering both the potential energy and the plant nutrients is proposed. Volatile compounds derived from the pyrolysis process were subsequently decomposed using a catalyst to produce light fuel gases, while the solid residues (char or ash) were applied to plant cultivation to examine their usefulness as fertilizers. During the poultry manure pyrolysis, the evolution of volatiles was found to occur at temperatures below 500 degrees C and the volatiles thus derived were effectively converted into light fuel gases by employing a commercial Ni/Al2O3 catalyst. Steam addition promoted the water-gas-shift reaction and resulted in high yields of hydrogen. The plant nutrients nitrogen, phosphorus, and potassium were concentrated in the poultry manure char. Komatsuna cultivation tests demonstrated that this char represented a source of highly available nutrients and produced higher crop yields than conventional fertilizers. The porous structure of the poultry manure char was considered to be an important factor in terms of its function as a fertilizer.

DOI： 10.2141/jpsa.0130184

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Coal of three kinds was burned in an oxygen-enriched atmosphere using a twin-fluidized bed solid circulation system under conditions of the Calcium Looping Process. This twin-fluidized bed system comprised a fast bed regenerator (calciner), into which fuel and oxygen-enriched gas were fed, and a bubbling bed absorber (carbonator), into which air was fed. Inert quartz sand was used as the bed material to evaluate the coal combustion behavior, including char transportation from regenerator to absorber and formation of CO and CO2 there. First, the circulation rate and the residence time of solids in the regenerator (calciner) were measured to determine the suitable operation conditions. The effect of gas feed staging to the regenerator on the solid residence time was evaluated. By reducing the ratio of the primary gas feed rate to total gas feed rate to 0.5, average solid residence time of about 40 s was attained. Under this gas-feed condition, coal combustion experiments were conducted. Effects of volatile matter content of coal on CO and CO2 formation in the absorber and NOx emissions from the regenerator were investigated. High-volatile matter coal was found to be favorable to reduce CO and CO2 formation in the absorber, but conversion of the fuel-N to NOx of high-volatile matter coal was higher than that from low-volatile coal. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.fuel.2013.06.017

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Coal of three kinds was burned in an oxygen-enriched atmosphere using two types of reactor both of which had the same fast fluidized bed for coal combustion. One was a dual-fluidized bed system (dual-FB), simulating Calcium Looping process comprised a fast fluidized bed regenerator and a bubbling bed carbonator. The other was a conventional single circulating fluidized bed combustor (single-CFBC). In both systems, coal combustion in oxygen-enriched atmosphere was carried out under regenerator temperature condition of Calcium Looping process. Inert quartz sand was used as the bed material to evaluate carbon consumption in the carbonator of dual-FB. Formation of NOx in the fast fluidized beds was measured for both reactors. For dual-FB, formation of CO and CO2 in the carbonator was also measured. High-volatile matter coal was found to be favorable to reduce CO and CO2 formation in the carbonator, but conversion of the fuel-N to NOx of high-volatile matter coal was higher than that from low-volatile coal. The emissions of NOx from single-CFBC were less than those from the regenerator of dual-FB under the same combustion condition. From the emissions of CO and CO2 from the carbonator, the decrease in char combustion in the regenerator of dual-FB was calculated. An empirical relationship between the conversion of fuel-N to NOx in the fast fluidized bed and the ratio of fixed carbon to volatile matter of the fuel was obtained. (C) 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.fuel.2013.12.060

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Language：Japanese   Publisher：Japanese Society for Engineering Education  

DOI： 10.20549/jseeja.2014.0_586

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Language：Japanese   Publisher：The Japan Institute of Energy  

In late years, the consumptions of the fossil fuel are rapidly increased. As the results, the Global warming by increasing in carbon dioxide and lack of the fossil fuel are concerted. We could reduce consumptions of the fossil fuel by using the biomass as new energy. Mushroom bed is agricultural biomass of culture medium. In Niigata area, it is produced 20,000 tons in every year. However the mushroom bed has a problem with very high water content. Therefore we developed the economic drying processes for using energy source. The compressing method is economic process better than thermal drying method.

DOI： 10.20550/jiesekitanronbun.51.0_100

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：TRANS TECH PUBLICATIONS LTD  

Light gases were produced from biomass tar gasification using limonite and dolomite as catalysts. Experiments were performed in a fixed bed reactor with the gasification temperatures of 600-800 degrees C. Limonite gave the obvious effect on the tar gasification, and the light gases of hydrogen and carbon oxides were mainly obtained. Also, the gas yields depended on the catalytic temperature. Hydrogen yields tend to increasing with temperatures from 650 to 800 degrees C. The reaction equilibrium was changed by dolomite addition in the reactor system; hydrogen gas was doubled with the limonite and dolomite mixture compared to limonite only.

DOI： 10.4028/www.scientific.net/AMR.608-609.201

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Language：English   Publisher：Japanese Society for Engineering Education  

The Japanese Student Services Organization (JASSO) has started its "Short-Stay and Short-Visit scholarship programs (SS-SV programs)" in the academic year 2011. The Faculty of Engineering, Niigata University, has obtained these scholarships for both German and Japanese students in 2011 and 2012. The objective of these "SS-SV programs" is to support students to visit a foreign country and stay there for less than three months. Because of our past experience of the "Two-week Summer School", which has been developed within the cooperation between Otto-von-Guericke-University Magdeburg, Germany and Niigata University, Japan since 1996, we experienced that a short term stay in a foreign country works as an initiator for the students' interest and will to study further in foreign countries. The authors believe that this type of short-term exchanges has actually proved to be very effective to encourage the students in engineering fields to start international activities.

DOI： 10.20549/jseeen.2013.0_32

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Language：Japanese   Publisher：電気学会  

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Faculty of engineering, Niigata University has been executing start-up engineering education programs for the first-year students to educate his or her ability to solve engineering problems. They are divided into teams and tackle a task that they expect to easily accomplish. The expected results are hardly obtained. Then they try to seek the gap between the results and their knowledge. They analyze the phenomena and improve the approach. They evaluate the results of second trial and the effectiveness of the measures. That is, the project requires so-called PDCA cycles for students to solve engineering problems. The start-up engineering project is one of the compulsory subjects and seven departments have given the students several tasks based on their technicality. The students exchange their knowledge, ideas and learn how to use knowledge to solve the problems. Their reports and questionnaire survey proved that the projects are highly effective to improve his or her ability to solve engineering problems and give them strong motivation to learn engineering. We introduce the some tasks and the outcomes of the projects set by seven departments; mechanical and production engineering, electrical and electronic engineering, information engineering, biocybernetics, chemistry and chemical engineering, civil engineering and architecture, and material science and engineering.

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Language：Japanese   Publisher：一般社団法人 日本エネルギー学会  

DOI： 10.3775/jie.91.792

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Language：Japanese   Publisher：電気学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

In both pressurized and oxygen-enriched fluidized bed combustion the partial pressure of CO2 in the reactor becomes high, which affects SO2 capture by limestone. Both of these technologies are also applicable to decreasing greenhouse gas emissions; the first one by increasing the efficiency of electric energy production and the latter by enabling capture of carbon dioxide for storage.
Attrition increases the reaction rate by removing the sulphated layer on the particle, thus reducing the diffusion resistance. In the well-known solution for the shrinking core model the reaction time can be presented as the sum of the contributions of the kinetics and diffusion. It is shown that the effect of attrition can be expressed as an auxiliary term in this expression. A method to extract the diffusivity of the product layer from the SO2 response in a bench-scale fluidized bed test using a limestone sample with a wide particle size distribution is presented. Based on a population balance model, a method to estimate the particle-size-dependent attrition rate from measured particle size distributions of the feed and bed material is illustrated for a 71-MWe pressurized power plant. In addition attrition and its effect on the optimization of the limestone particle size for sulphur capture in oxygen-enriched combustion are discussed. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ces.2009.06.023

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS INC  

Waste plastics show a great promise in energy recovery via combustion process due to the high calorific value and the implementation of policies to improve recycling. The output of waste plastics is especially relatively enormous. In this work, energy recycle from waste plastics was investigated in a semi-pilot scale fluidized bed combustor. The waste plastic selected in this work was polypropylene and porous alumina was used as bed material. The results showed that both excess air and temperature increase can suppress the emission of CO, while NOx and SO(2) emission was independent of excess air and temperature. The combustion efficiencies in these tests were in the range of 96 to 99% for firing polypropylene in a wide range of temperatures and excess air.

DOI： 10.1080/15567030802612499

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOS PRESS  

In this paper, temperature measurement of axisymmetric dilute hydrogen flame is described using digital laser-speckle technique, which allows the measurement of refractive index field of the flame without any tracers. The measurement system consists of laser and CCD camera, which are placed in-line configuration. The temperature field of the flame is derived from the refractive index field using the cross-correlation analysis of the speckle pattern with and without flame. The influence of the species concentration on the temperature measurement is evaluated from the gas composition in the flame using gas chromatography. It is found that the temperature field measured by the present method with concentration correction agrees with that of the thermocouple measurement within an experimental accuracy, suggesting the usefulness of this measurement technique.

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Language：Japanese   Publisher：公益社団法人 化学工学会  

DOI： 10.11491/scej.2009.0.429.0

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Porous bed materials capture volatile matter as carbon deposits during fluidized bed combustion of high-volatile fuels such as biomass and wastes. Carbon deposits burn in a dense bed mixed with bed materials; thereby enhancing horizontal dispersion of carbonaceous materials. Commercial scaling-up requires a model that simultaneously assesses carbon deposit combustion and horizontal solid dispersion. This study measured the carbon deposit combustion rate using a fluidized bed. A one-dimensional model of carbon deposit combustion in a fluidized bed is based on the carbon deposit burning rate. A two-dimensional model incorporates reactions and solid dispersion to predict the horizontal concentration profile. Experiments using a bubbling fluidized bed validated that model. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.fuel.2007.11.011

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In this study, the experiments of comparing cedar pellet, cypress pellet, and cypress sawdust combustion in a bubbling fluidized bed combustor (BFBC) was carried out. To improve the combustion efficiency and avoid the agglomeration, the porous alumina sand was used as bed material instead of conventional silica sand. Experimental results indicated that pellet can be sufficiently burned in the BFBC, and the CO emission was only 50-188 ppm. Meanwhile, the unburned carbon in fly ash was considerably limited even neglected; both the unburned carbon in fly ash and CO emission (3,700 ppm) was significantly high during sawdust combustion. Moreover, it was difficult to operate the BFBC above 650 degrees C with the sawdust. Therefore, direct combustion was not a good utilization method for sawdust. It was also observed that volatile matter released from pellet volatilized and mostly burned in the dense zone due to the porous alumina. The effect of operation parameters like temperature and fluidized velocity on the pollution emission and combustion characteristic was also evaluated. High temperatures can promote the combustion efficiency, while SO(2) and NOx emission is independent to temperature. As for fluidized velocity, the optimum fluidized velocity in the tests is about 0.07 m/s.

DOI： 10.1080/15567030701268500

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Language：Japanese   Publisher：The Japan Institute of Energy  

DOI： 10.20550/jietaikaiyoushi.17.0_368

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Emissions of NOx and N2O were measured during mono-combustion of dried sewage sludge and co-combustion with coal in a bench-scale circulating fluidized bed combustor (CFBC). The results were compared with previous results obtained using a bubbling fluidized bed combustor (BFBC). The increase in NOx with sludge ash accumulation in the combustor was less for the CFBC than the BFBC, partly because of the higher attrition rate of sludge ash in CFBC resulting from the higher gas velocity. The influence of sludge ash on the formation of NOx in CFBC was less than that in BFBC during sludge combustion. The effects of fuel type on NOx and N2O emissions were also evaluated. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.fuel.2007.01.033

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Rapid volatile matter evolution from high-volatile fuels such as wastes and biomass is one of problems associated with fluidized bed incinerators and gasifiers. When volatile matter evolves rapidly in the vicinity of the fuel feed point, the mixing of volatile matter with reactant gas is poor, and therefore, unreacted volatile matter is expected to be released from the reactor. In the present work, reduction of the volatile matter evolution rate was attempted by employing porous solids as bed materials instead of nonporous sand. The effect of bed material on the onset of devolatilization was measured by use of a bench-scale bubbling fluidized bed reactor. Volatile matter capture by the porous solids (capacitance effect) and the heat transfer rate within the bed, both of which affect volatile matter evolution rate, were also measured. Four types of porous solids, both with and without capacitance effect, were employed as the bed material. By employing porous solids without capacitance effect, the contributions of reduced heat transfer rate and capacitance effect to the delay of volatile matter evolution can be evaluated separately. For porous bed materials with a moderate capacitance effect (volatile matter capture of up to 20 %), the delay of the onset of devolatilization, which was measured by detecting the flame combustion of the volatile matter, was explained by the lower heat transfer between the fuel and bed. However, for a porous particle with high capacitance effect (volatile matter capture of 30 %), the capacitance effect also affected the delay of the onset of the flame combustion.

DOI： 10.1002/ceat.200600309

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Recovery of hexavalent chromium ion from methanol was investigated with commercially available nine ion exchange resins including weak anion, strong anion, weak cation, and strong cation exchangers. The effects of water concentration in water-methanol mixture on the adsorption capacity of resins were investigated. The strong and weak anion exchange resins showed high adsorption capacity for chromium both in methanol and water. The strong cation exchange resins gave relatively high adsorption capacity in methanol, but the capacity drastically decreased as the water concentration in methanol increased. Dowex SBR had the best adsorption capacity both in aqueous and methanol solutions. The adsorption equilibrium was attained within about 30 min at an initial Cr concentration of 10 mg/L with Dowex SBR. The desorption of Cr from the resin was found to be easily carried out with NaCl solution. The adsorption and desorption equilibria predicted that the concentration of Cr from methanol into NaCl eluent was possible. Furthermore, five successive adsorption-desorption cycles were successfully carried out without any decline in adorption nor desorption efficiencies. Copyright © 2007 The Society of Chemical Engineers, Japan.

DOI： 10.1252/jcej.40.447

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：HUAZHONG UNIVERSITY SCIENCE & TECHNOLOGY PRESS  

The present study aims to compare polypropylene combustion characteristic under the porous alumina sands and nonporous alumina sands in a fluidized bed combustor (FBC). The experimental results indicated that polypropylene was effectively utilized in a FBC under both bed materials. The CO emissions under the non-porous alumina and porous alumina sands were only 343 and 116 ppm, respectively. It was also observed that the porous alumina sands can suppress the formation of the hydrocarbons and NO due to the porous alumina sands can capture part of volatile matters released from fuel. Moreover, the bed material temperature in the case of porous alumina sands was higher and more uniform than those under the nonporous alumina sands even though the less fuel as well as the same air was introduced.

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Language：English   Publisher：The Japan Institute of Energy  

Limestone attrition is a major cause of loss of limestone during pressurized fluidized bed combustion. In the previous works, the analysis of published results of solid attrition and desulfurization was conducted to determine the attrition rate expression. The previous results showed that the attrition rate is second order with respect to particle diameter. This rate expression implies that reduction of feed size of limestone is effective for suppression of loss of limestone by attrition. However, too much grinding of raw limestone will increase the content of fine particles that are readily elutriated by gas stream and do not contribute to the sulfur capture. In this work, modeling works are conducted for particle attrition and desulfurization in order to predict the effect of feed size of limestone on total consumption of limestone and desulfurization is discussed.

DOI： 10.20550/jiesekitanronbun.44.0_104

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：AMER SOC MECHANICAL ENGINEERS  

Rice husk was burned in a bench-scale fluidized bed combustor (53 mm I.D. and 1.3m height) at 1123 K. Silica sand (average size 0.27 mm) was employed as conventional bed material. As an alternative bed material, a kind of porous alumina (average size 0.69 mm) was employed. Unburned gas (CO) emissions were suppressed by employing porous alumina as bed material. NOx emissions from the alumina bed were also suppressed in comparison to the sand bed. N2O emissions were nearly negligible (less than 10 ppm) for both bed materials. During combustion in the sand bed, sudden temperature rise up to 1450 K and increase in pressure drop across the bed were observed. Agglomerates were found in the bed material after the experiments. For the porous alumina bed, such agglomeration trouble did not occur. As conclusion, the present porous alumina was effective for both reduction of pollutants emissions and stable operation.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier Ltd  

Mathematical models of SO2 capture by uncalcined limestone (CaCO3) particles with solid attrition were compared under pressurized fluidized bed combustion conditions. For reaction, we used: (1) a shrinking core model with a distinct border between the product (CaSO4) layer with a conversion of unity and unreacted core with a conversion of zero, and (2) a distributed reaction model with smooth transition from the unreacted part to the product part with conversion between zero and unity. Continuous attrition and intermittent attrition were compared for attrition. Apparent conversion of the solid was overestimated regardless of the reaction model for continuous attrition. Attrition model plays an important role in determining limestone utilization efficiency, whereas the reaction model played only a minor role. © 2003 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0009-2509(03)00157-X

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Language：English   Publishing type：Research paper (international conference proceedings)  

This work is intended to reduce emissions of dioxins and unburned gas from fluidized bed waste incinerators. Combustion of plastic pellets was conducted using a bench-scale bubbling fluidized bed combustor. Porous alumina was used as a bed material instead of conventional bed material (sand). First, we evaluated the effect of bed material on capture of volatile matter in the bed in a nitrogen atmosphere. Porous alumina captured volatile matter while sand did not. Feeding gas asymmetrically to enhance internal circulation of solids in the bed increased volatile capture efficiency of the porous alumina bed, whereas no improvement was found for the sand bed. Next, we performed combustion of plastic pellets by air. Emission of unburned gas was lower for the porous alumina bed than for the sand bed under a uniform gas feed condition. This is attributable to volatile matter capture by bed material that lengthens residence time of volatile matter in the combustor. However, non-uniform air feed for internal circulation was ineffective for suppressing unburned gas emissions. This may be caused by formation of an oxygen-deficient zone in the combustor. Finally, dioxin emissions were measured during PVC pellet combustion in a uniformly fluidized bed. The porous alumina bed was more effective for dioxin emission suppression than the sand bed.

DOI： 10.1115/FBC2003-031

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Maruzen Co. Ltd.  

A mathematical model of SO2 capture by single limestone particle under pressurized fluidized bed combustion conditions was proposed. In the present model, particle attrition was taken into consideration. Effect attrition mode, i.e. continuous attrition or intermittent attrition, on overall reaction rate, overall reaction order with respect to SO2 concentration, and maximum utilization of solid were evaluated. Attrition mode had a great influence on sulfur capture behavior even if the average attrition rate was the same. Attrition mode was found to be very important to make a model of SO2 capture in pressurized fluidized bed.

DOI： 10.3775/jie.81.206

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Language：Japanese   Publisher：The Japan Institute of Energy  

To suppress the emission of tar/soot from fluidized bed pyrolyzer, use of porous solids as bed material was proposed instead of non-porous sand. The carbon retention by the bed material was evaluated by use of a bench-scale fluidized bed reactor. Porous alumina particles were effective for carbon retention whereas non-porous sand was not. By feeding gas non-uniformly to enhance the solid internal circulation, the carbon retention by the porous bed material was increased.

DOI： 10.20550/jiesekitanronbun.39.0_55

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Attrition rate of limestone and SO2 capture rate in a large scale pressurized fluidized bed combustor was evaluated. The average attrition rate (reduction rate of radius) was found to be approximately 0.2-0.7 nm/s. The SO2 capture rate per unit external surface area of bed material was found to be independent on SO2 concentration in the flue gas. A mathematical model Of SO2 capture by single limestone particle under attrition conditions was proposed. Apparent reaction order with respect to SO2 concentration was close to zero when attrition was taken into consideration. It was suggested that the rate Of SO2 capture in the present PFBC was governed by the limestone attrition. (C) 2001 Elsevier Science Ltd. All rights reserved.

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SO2 capture by limestone was conducted within a 71 MWe pressurized fluidized bed combustor. Mixtures of high-sulfur petroleum coke and low-sulfur coal with different mixing proportion were used as fuels. The effect of the size distribution of limestone on SO2 removal efficiency was evaluated. The SO2 removal efficiency was well correlated with feed rate of external surface area of limestone greater than the cut size of cyclone that recycled elutriated fine particle into the bed. A semi-theoretical correlation between size distribution of fed limestone and SO2 removal efficiency was proposed. This model assumed the uniform formation of SO2 in the dense bed, SO2 capture in the dense bed by fresh limestone of fractions greater than elutriation size, and SO2 capture in the freeboard by fresh limestone of fractions smaller than the elutriation size but greater than the cyclone cut size.

DOI： 10.3775/jie.80.758

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Maruzen Co. Ltd.  

In order to reduce emission of dioxins from fluidized bed incinerators, porous alumina particles were used as bed material instead of conventional bed material (sand). Polyvinyl chloride pellets were burnt in a bench-scale fluidized bed combustor. The emission of dioxins was reduced by employing porous bed material instead of non-porous sand.

DOI： 10.3775/jie.80.1060

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Maruzen Co. Ltd.  

Attrition and fragmentation of limestone in a 71MWe pressurized fluidized bed combustor were estimated. Formation of Ca-containing fine particles due to attrition rate was calculated from the material balance of calcium in fly-ash which was captured at the exit of combustor. The average rate of attrition (rate of reduction of radius) of limestone was estimated to be approximately 1 μ m/h. A population balance model was established to estimate the particle size distribution in the bed from the size distribution of fed limestone and attrition rate of bed material in the bed. For some cases, the measured bed material size was far smaller than that of the estimated size distribution. These results suggest that the fragmentation of limestone particle took place in the bed. The size distribution of limestone after fragmentation was estimated so that the difference between estimated bed material size distribution and measured size distribution should be minimized. The results indicates that the large limestone particles (greater than approximately 1 mm) were broken into small particles when they were fed into the combustor.

DOI： 10.3775/jie.80.747

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Language：Japanese   Publisher：一般社団法人日本エネルギー学会  

DOI： 10.20550/jietaikaiyoushi.10.0_131

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DOI： 10.1021/ef980179n

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A new process is proposed for CO2 removal from flue gas using the reaction CaO + CO2 ↔ CaCO3. This process consists of two fluidized bed reactors connected by solid transportation lines. In one reactor (absorber), CO2 in the flue gas is captured by CaO at 873 K and the produced CaCO3 is transported to another reactor (regenerator), in which CaCO3 is decomposed to CaO at 1223 K. The produced CaO is transported to the absorber again. The heat of decomposition in the regenerator is supplied by feeding coal and pure oxygen, thus the flue gas from the regenerator is high purity CO2 (&gt
95%, dry base). In this work, a conceptual study is conducted for material balance, heat balance, power generation, and power consumption for O2 production and CO2 liquefaction (compression). Also, a kinetic study of CaO + CO2 → CaCO3 was conducted to design the absorber. The required bed height of the absorber was calculated by use of a bubbling fluidized bed model. The bed height was found to be determined not by the chemical reaction rate but by the arrangement of heat transfer tubes for heat recovery.

DOI： 10.1205/026387699525882

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Society of Chemical Engineers, Japan  

For a complex control process, ordinary control such as PID cannot usually realize a desirable response and robustness for the system. Therefore, we tried to apply IMC (Internal Model Control) to a heat exchanger model which describes the dynamic behavior of the distributed parameter systems. Also, to facilitate IMC controller design, we proposed a new method of determining the low-pass filter parameter. In conclusion, we discussed the results of the simulation and compared the IMC to the PID control. Copyright ©1998 The Society of Chemical Engineer:.

DOI： 10.1252/jcej.31.320

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DOI： 10.1002/aic.690411216

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In this work, decomposition of NH3 to N2 over limestone was investigated as a mean to reduce NOx emission from fluidized bed combustors. A fixed bed study was conducted and the effect of CO2 and H2O on the products of NH3 decomposition over limestone was studied. In the absence of CO2 and H2O, NH3 was decomposed to N2. From a NH3-CO2 mixture, (NH2)2CO was formed through NH3 decomposition over both calcined limestone at a CO2 concentration of 15% and uncalcined limestone at a CO2 concentration of 75%. However, from the NH3-CO2-H2O mixture, (NH2)2CO was not formed. The presence of H2O is necessary to evaluate the rate and the products of NH3 decomposition over limestone under commercial fluidized bed combustion conditions. © 1995, American Chemical Society. All rights reserved.

DOI： 10.1021/ef00054a004

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Language：Japanese   Publishing type：Doctoral thesis  

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A kinetic study was conducted for hydrolysis and oxidation of HCN over limestone at 1123 K with a fixed bed reactor. In the absence of O2, HCN was hydrolyzed to mainly NH3. However, the reaction rate of hydrolysis was far lower than that of oxidation. In the presence of O2 at concentrations higher than 0.5%, oxidation of HCN was dominant and most of HCN was oxidized to NO, while only a small amount of NH3 was produced. Conversion of HCN to N2O for oxidation over limestone was far lower than the conversions which had been reported for homogeneous oxidation of HCN. © 1993, American Chemical Society. All rights reserved.

DOI： 10.1021/ef00041a013

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Catalytic activity of uncalcined limestone to decompose N2O was evaluated with a quartz fixed bed reactor at 1123K under elevated CO2 partial pressure conditions to suppress decomposition of CaCO3. The rate of SO2 capture was also measured for uncalcined limestone. The rate of N2O decomposition over uncalcined limestone was found to be more than two order of magnitude lower than that of SO2 capture. The rate of N2O decomposition over uncalcined limestone was more than three order of magnitude lower than N2O decomposition rate over calcined limestone. © 1993, The Japan Institute of Energy. All rights reserved.

DOI： 10.3775/jie.72.199

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A kinetic study was carried out to evaluate the rates of N2O decomposition and SO2 capture over calcined limestone by use of a fixed bed reactor. N2O decomposition was inhibited by H2O and CO2. On the other hand, SO2 capture was enhanced by H2O and it was not affected by CO2. A flue gas treatment study was also conducted by passing flue gas from a bench-scale circulating fluidized bed combustor through a fluidized bed of calcined limestone
thus the activity of calcined limestone to decompose N2O and the activity to capture SO2 were evaluated under an actual fluidized bed combustion condition. N2O decomposition and SO2 capture within the fluidized bed was numerically analyzed using the kinetic data obtained for the present fixed bed study. The results of the numerical simulation agreed well with the experimental results when the kinetic data obtained in the presence of H2O was used. On the other hand, the kinetic data obtained in the absence of H2O overestimated the N2O decomposition within the fluidized bed reactor. © 1993, American Chemical Society. All rights reserved.

DOI： 10.1021/ef00041a014

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Language：Japanese   Publisher：The Japan Institute of Energy  

Catalytic effects of limestone on oxidation of NH3 and HCN were investigated with a quartz fixed bed reactor at temperatures between 923K and 1123K. Limestone was found to be an active catalyst of oxidation of NH<SUB>3</SUB> and HCN. The major product of NH<SUB>3</SUB> oxidation was NO.N<SUB>2</SUB>O was not detected as a product of NH<SUB>3</SUB> oxidation. The intrinsic selectivity of NH<SUB>3</SUB> to N<SUB>2</SUB>O was calulated by eliminating the effect of secondary decomposition of N<SUB>2</SUB>O by coexisting limestone. The intrinsic selectivity of NH<SUB>3</SUB> to N<SUB>2</SUB>O was no higher than 3%. The major products of HCN oxidation were NO and N<SUB>2</SUB>. Selectivity of HCN to N2O for catalytic oxidation was 3 to 10%, which are considerably lower than the reported value of selectivity for homogeneous HCN oxidation.

DOI： 10.3775/jie.72.189

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The effect of limestone addition for SO2 removal on emissions of NOxand N2O was evaluated with a laboratory-scale circulating fluidized bed combustor. It was found that NOx emission increased with increasing SO2 removal whereas N2O emission decreased. The rates of HCN oxidation, NH3 oxidation, NO reduction by CO, N2O decomposition, and SO2 removal over limestone were evaluated with a fixed bed reactor. The major product of HCN oxidation was NO. N2O formation was observed slightly among the products of HCN oxidation. The rates of HCN oxidation, NH3 oxidation, and N20 decomposition in the presence of CO were found to be higher than that of SO2 removal, while the rate of NO reduction by CO was far lower. The change in NOx and N2O emissions from CFBC is explained by the results of the kinetic study. The increase in NOx emission is attributed to the formation of NO through oxidation of HCN and NH3 over limestone. The decrease in N2O emission of CFBC is partly attributed to catalytic activity to decompose N2O. Also, consumption of HCN through oxidation over limestone is considered to reduce N2O emission since conversion of HCN to N2O for catalytic oxidation is far lower than reported value of the conversion for gas-phase oxidation. © 1992, American Chemical Society. All rights reserved.

DOI： 10.1021/ef00036a008

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The effect of sorbent addition for SO2 removal on emissions of NOx and N2O was studied with a laboratory-scale bubbling fluidized-bed combustor. A batch of calcined limestone was injected into the bed and the changes in emissions of SO2, NOx and N2O with time were observed. NOx increased with increasing SO2 removal. N2O emission decreased slightly on limestone addition with single-stage air feed, but with staged air feed it was not affected by limestone addition. © 1992.

DOI： 10.1016/0016-2361(92)90140-J

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This paper proposes a parallel combination model of the well-known transfer function G(s)-Kexp(-Ls)/(1+Ts) and shows its ability to approximate complex dynamic behaviour such as that of distributed parameter systems. First, the gain and phase of the transfer function were calculated and were shown to have resonance in its frequency response with appropriate parameters, which means that their slopes can be varied in a wide range. As a result, the function can approximate various dynamic behaviours well. Next, their asymptotic behaviours, which can represent the relation between the parameters of the function and help to estimate approximate values of the parameters, were shown. Fitting to frequency and indicial response data of heat exchangers which are common in chemical industries and the dynamic behaviours of which have been studied from theoretical and experimental points of view were done. Results of the fitting showed a good approximation, not only in frequency response but also in indicial response. This indicates that the transfer function model presented here can fit to various complex dynamic models. © 1992, The Society of Chemical Engineers, Japan. All rights reserved.

DOI： 10.1252/kakoronbunshu.18.862

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Effect of ammonia injection on emissions of NOx (NO and NO2) and N20 was investigated by use of a laboratory scale bubbling fluidized bed combustor. High volatile bituminous coal was employed as a sample. Effects of temperature, injection location and air ratio on change in NOx and N20 emissions by ammonia injection were observed. Ammonia injection in oxidizing zone of freeboard was effective for NOx reduction at temperatures higher than 1123K, however, it increased N20 emission. Ammonia injection in reducing atmosphere in freeboard did not reduce NOx but increased N20. Ammonia injection in the bottom of the dense bed increased both NOx emission and N20 emission. Conversion of NH3 to N20 for NH3 injection in dense bed was lower than that in freeboard. © 1992, The Japan Institute of Energy. All rights reserved.

DOI： 10.3775/jie.71.50

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Conversion of char-bound nitrogen to NOx during combustion was measured for chars formed from nine coals. The effects of pyrolysis condition and coal rank of the parent coal on conversion of char-bound nitrogen to NOx are discussed. A model of NOx formation through combustion and NOx reduction on the internal surface of a single char particle was developed. The experimental results were fairly well explained by the model. © 1992.

DOI： 10.1016/0016-2361(92)90022-G

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Language：Japanese  

DOI： 10.3775/jie.65.194

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Language：Japanese   Publisher：The Japan Prosthodontic Society  

DOI： 10.2186/jjps.29.1162

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Language：Japanese   Publisher：一般社団法人 日本エネルギー学会  

&lt;p&gt;Reaction pathways of NOx and N2O in Calcium-Looping CO&lt;sub&gt;2&lt;/sub&gt; capture process were investigated by use of a two-stage fluidized bed system. Calcined limestone particles were employed as the bed material. Simulated flue gas containing CO&lt;sub&gt;2&lt;/sub&gt;, NO, and N&lt;sub&gt;2&lt;/sub&gt;O was fed to the carbonator,. During CO&lt;sub&gt;2&lt;/sub&gt; capture in the carbonator by CaO particles, a part of N&lt;sub&gt;2&lt;/sub&gt;O was decomposed in the carbonator. In addition, a part of NO fed to the carbonator was adsorbed by CaO particles, then the adsorbed NO was transported to the regenerator and released to the gas phase at high temperatures.&lt;/p&gt;

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Language：English   Publisher：Japanese Society for Engineering Education  

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Language：Japanese   Publisher：一般社団法人 日本エネルギー学会  

Enokitake (Flammulina velutipes) is one of the most popular cultivated mushrooms in Japan. A huge amount of waste culture is disposed thus its utilization as biomass fuel is needed. In addition, the ash can be used as fertilizer because the waste culture contains plant nutrients (P, K, Mg and Si). Due to high moisture content of waste mushroom culture, however, drying is necessary prior to use. As an approach for drying, compositing was conducted. The waste culture after drying was burned in a semi-pilot scale combustor with a combustor volume of 535 L. Reduction of NOx emissions by urea solution injection and SO_2 capture by Ca(OH)_2 powder injection were attempted. The ash was analyzed to determine contents of plant nutrients. Though the content of silica was high, the contents of water-soluble and citric-acid-soluble components were low. The treatment at high temperatures is considered to decrease the solubility of silica. Heavy metal contents were sufficiently lower than the acceptable level for the case of sludge fertilizer.

DOI： 10.20550/jiebiomassronbun.11.0_45

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Language：English   Publisher：一般社団法人 日本エネルギー学会  

A natural limonite ore is used as catalyst for tar reforming at 650 ℃. Researches on the catalytic role of the limonite ore, deactivation mechanism, influence of steam addition were conducted. The characteristics of the catalyst were analysed by X-ray diffraction (XRD) and scanning electron microscope (SEM). Effects of steam addition and the steam/carbon ratio on catalyst activity and lifetime were discussed.

DOI： 10.20550/jiebiomassronbun.11.0_67

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Language：Japanese   Publisher：一般社団法人 日本エネルギー学会  

&lt;p&gt;Decomposition of nitrous oxide (N&lt;sub&gt;2&lt;/sub&gt;O) was conducted under a condition of carbonator of Calcium-Looping process for CO&lt;sub&gt;2&lt;/sub&gt; separation. Absorbent (CaO) catalyzed decomposition of N&lt;sub&gt;2&lt;/sub&gt;O at 873 K and its rate was as fast as the rate of CO&lt;sub&gt;2&lt;/sub&gt; capture. With the presence of CO&lt;sub&gt;2&lt;/sub&gt;, CaO gradually lost activities for CO&lt;sub&gt;2&lt;/sub&gt; capture and N&lt;sub&gt;2&lt;/sub&gt;O decomposition, thus CaCO&lt;sub&gt;3&lt;/sub&gt; was found to be ineffective for N&lt;sub&gt;2&lt;/sub&gt;O decomposition. The present results imply that Calcium-Looping process is effective for mitigation of greenhouse gas emissions not only by CO&lt;sub&gt;2&lt;/sub&gt; capture but also N&lt;sub&gt;2&lt;/sub&gt;O reduction.&lt;/p&gt;

DOI： 10.20550/jietaikaiyoushi.25.0_180

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Language：Japanese   Publisher：The Japan Institute of Energy  

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Language：Japanese   Publisher：Japanese Society for Engineering Education  

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Language：Japanese   Publisher：一般社団法人 日本エネルギー学会  

In a biomass gasification process, the separation of tar is brought into question to cause piping obstruction. Various catalysts are reported in tar reforming, but most of them are expensive, and difficult to be used in practice. Limonite is a cheap, natural mineral, which is reported to have high tar resolution performance. Basing on this, the low temperature operation for tar reforming could contribute to improvement of cold gas efficiency and the cost reduction. The biomass gasification was carried out in a fixed bed reactor at 400-700 ℃. As results, limonite improved the biomass tar gasification, and the gas yields increased notably with the temperature increasing. The hydrocarbons gasification was confirmed even at the low temperature of 400℃, there the hydrogen formation was observed.

DOI： 10.20550/jiebiomassronbun.10.0_89

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Language：Japanese   Publisher：The Japan Institute of Energy  

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Language：Japanese   Publisher：一般社団法人 日本エネルギー学会  

Enokitake (Flammulina velutipes) is one of the most popular cultivated mushrooms in Japan. A huge amount of waste culture is disposed thus its utilization as biomass fuel is needed. Due to high moisture content of waste mushroom culture, drying is necessary prior to use. As an approach for drying, compositing is proposed. Composters of various scale, from laboratory scale composter to semi-pilot scale composter (3 m^3 by volume) were operated. Temperature was measured during composting. A mathematical model is also proposed to predict the change in temperature.

DOI： 10.20550/jietaikaiyoushi.23.0_158

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Language：Japanese   Publisher：一般社団法人日本エネルギー学会  

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Language：Japanese   Publisher：Japanese Society for Engineering Education  

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Language：Japanese   Publisher：一般社団法人 日本エネルギー学会  

Enokitake (Flammulina velutipes) is one of the most popular cultivated mushrooms in Japan. A huge amount of waste culture is disposed thus its utilization as biomass fuel is needed. Due to high moisture content of waste mushroom culture, drying is necessary prior to use. As an approach for drying, compositing is proposed. A laboratory scale composter is operated. Change in temperature, CO_2 formation, and water evaporation with time was measured during composting. A mathematical model is also proposed to predict the change in temperature and moisture evaporation.

DOI： 10.20550/jiesekitanronbun.49.0_88

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Language：Japanese   Publisher：一般社団法人 日本エネルギー学会  

In this study, light gases were produced from biomass tar gasification by using iron-based catalysts. Catalytic gasification was performed in a fixed bed reactor at 550 to 800℃. Hydrogen yield increased with temperature increasing from 550 to 600℃, but it decreased over 600℃. The tar decomposition was further improved with K_2CO_3 addition, which however gave little effect on the coke deposition at the present conditions.

DOI： 10.20550/jietaikaiyoushi.21.0_88

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Language：Japanese   Publisher：Japanese Society for Engineering Education  

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Language：Japanese   Publisher：一般社団法人 日本エネルギー学会  

In this study, light gases were produced from biomass tar gasification by using limonite and dolomite, as catalysts. Catalytic gasification was performed in a fixed bed reactor at 600-800℃. Hydrogen yield was increased with temperature increasing among 650-800℃, because the water shift reaction was promoted by catalyst. Hydrogen gas doubled its yield under the limonite and dolomite mixture compared to limonite only.

DOI： 10.20550/jietaikaiyoushi.20.0_66

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DOI： 10.20549/jseeja.2011.0_128

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DOI： 10.20549/jseejaarc.2010.0_538

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DOI： 10.20549/jseejaarc.2009.0_152

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Language：Japanese   Publisher：Japanese Society for Engineering Education  

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Language：Japanese   Publisher：電気学会  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (other)   Publisher：化学工学会  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本エネルギー学会  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本エネルギー学会  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本エネルギー学会  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本エネルギー学会  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本エネルギー学会  

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Language：Japanese   Publisher：Niigata University  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本エネルギー学会  

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Language：Japanese   Publisher：Niigata University  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本エネルギー学会  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)   Publisher：化学工業社  

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Language：Japanese   Publisher：The Japan Institute of Energy  

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Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

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Award type：Award from Japanese society, conference, symposium, etc.  Country：Japan

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