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There are many industrially useful reactions accompanied by the change of the gas volume due to the stoichiometry. Although it is important to consider the effects of the gas-volume changes for the accurate estimation of the reactor performance, the effects on the fluidization properties have not been experimentally studied. In this study, experimental simulation was carried out to study the effects of the increase in gas volume on the fluidization properties. The gas volume was increased by the evaporation of water impregnated in the pores of alumina particles at elevated temperature. The effects on the expansion of the emulsion phase, average bubble holdup, bubble size and pressure fluctuations were studied. The bubble growth, splitting and coalescence would become vigorous, whereas the emulsion phase expansion was not affected and the bubble size was slightly increased.

The interface area between the bubble and emulsion phases in a fluidized catalyst bed is one of the important parameters used to analyze and design the fluidized bed reactor. We used a fast-scanning X-ray CT system to observe the bubble shape and structure. We then obtained the transient 2-dimensional cross sectional gas-phase distribution in a fluidized catalyst bed. Using image-processing techniques, pseudo 3-dimensional images of the bubbles were reconstructed. The bubble structure was studied based on the 3-dimensional images and the previously obtained results in a 2-dimensional fluidized bed. It was found that the bubble shape was not spherical but complicated, and that the bubbles ascending in a fluidized catalyst bed consisted of some smaller bubbles.

A room-cooling system of 2 kW capacity fueled by wood pellets was designed, built and tested. The system was demonstrated during summer at the Yakushima Field Station of Kagoshima University, Japan. It contained a pellet feeder, a pellet burner, a heat exchanger, a lithium bromide–water absorption heat pump and a control unit. The volume of the test room was 36.9 m3 and ambient temperature 30 °C. The airflow temperature from the room unit was decreased to 16 °C by the system, and the room temperature could be successfully controlled to 24 °C steady state. Room heating in winter was also demonstrated. Since the air was heat exchanged, the overall energy efficiency of the cooling system was low at about 19%. However, the calculation based on the heat flow showed that the efficiency could be enhanced to about 75% by direct heating of the regenerator by the flue gas.

The oligomerization of light olefi ns, such as ethylene, propylene, 1-butene and isobutene, catalyzed by methane- sulphonic acid (MSA) was evaluated to synthesize liquid hydrocarbons in a high pressure continuous fl ow reactor for 250 min at 20 to 40�C. The liquid hydrocarbons separated from the MSA catalyst were analyzed by combined gas chromatography with mass spectrometry. The hydrocarbons were classifi ed by molecular weight as gasoline, kerosene and light oil. Although ethylene and propylene were slightly dissolved into the MSA, no further liquid product was obtained after the reaction period. The yield of liquid product from isobutene was larger than that from 1-butene. The selectivity for gasoline was lower than that for kerosene or light oil. The recovered MSA was replaced 10 times into the reactor to elucidate the effect of recycling on catalyst deactivation. The activity of recycled MSA was the same as the fresh catalyst. On the other hand, the reaction mixture catalyzed by sulfuric acid was not separated into the hydrocarbon layer and catalyst layer after recycling 3 times. Oligomerization of 1-butene with a small amount of water to clarify the effect of impurity showed that the catalytic activity of MSA sharply decreased with water content. Methanesulphonic acid is an effective catalyst for the selective synthesis of gas oil from butenes.

The vapor phase Beckmann rearrangement of cyclohexanone oxime (CHO) was carried out over TS-1 with an MFI pore structure and SSZ-31 and SSZ-24 with pore sizes larger than that of MFI to elucidate the effect of the pore size on catalyst deactivation. The deactivation constant over SSZ-24 was the highest among the zeolites used in the study. Furthermore, when the ratio between the molecular size of e-caprolactam (CL) and the pore size of zeolite was unity, the deactivation constant was maximum over the zeolites at similar acidity. These results indicate that since CL produced on the active sites cannot diffuse from the micropores, the CL reacts to form coke or its precursor over a long residence time. The pore size of the zeolite is the main controlling factor of catalyst deactivation during the Beckmann rearrangement.

ポリオレフィン（PP・PE等）樹脂の酸化防止効果を向上させる目的で，ビタミンE骨格をもつ2種類の化合物，S-13およびS-19を合成した。これをPPに対して0.005 wt％添加して，酸化防止効果をメルトインデックス（MI）およびイエローインデックス（YI）を用いて評価した。その結果，これらの酸化防止剤は単独でも効果があるが，既存のフェノール系およびリン系酸化防止剤と組み合わせることで相乗的な効果が得られることが分かった。過去の酸化防止作用についての知見等から，今回合成した酸化防止剤のラジカルとの反応速度が非常に大きいため，PPやPE内で生成した炭化水素ラジカルあるいはそのパーオキシラジカルと優先的に反応し，その後リン系あるいはフェノール系酸化防止剤により再生されることが，この相乗効果の原因であると考えられた。

Methanol steam reforming was carried out over catalysts prepared from glassy Cu-Zr alloys containing a small amount of noble metals. The reforming activity increased when the alloys were treated at a temperature above the crystallization point, whereas the as-cast alloy did not have the same activity. The reforming activity of the heat treated alloys increased with the decreasing content of noble metals down to 1 at%. The DSC (differential scanning calorimetry) of the original alloys revealed that the activity was related to the range of the temperature interval between glass transition and crystallization as well as the heat of glass transition. The glassy Cu-Zr alloys with small amount of noble metals changed to fine copper particles supported on zirconium oxide by the heat treatment. The copper particle size of the treated alloys was related to the endothermic heat. These results indicated that the noble atoms were uniformly dispersed into the glassy Cu-Zr alloys at the glass transition temperature. Highly active reforming catalyst can be prepared from an glassy Cu-Zr alloys containing a small amount of noble metals.

The vapor–solid phase Beckmann rearrangement over HZSM-5 zeolite and silica-alumina was carried out to elucidate the effects of reaction temperature and diluent solvent on the selectivity to e-caprolactam (CL) and the catalyst deactivation. When the HZSM-5 was regenerated with oxygen atmosphere after the rearrangement using methanol as the solvent, the cyclohexanone oxime (CHO) conversion decreased with the regeneration number, whereas the caprolactam selectivity was almost constant. The catalyst deactivation at the fresh zeolite was largest among the regenerated zeolites. Although the crystalline structure did not change with the regeneration, the acid strength of the zeolite decreased with the regeneration number. These results suggest that the acid sites in the extra-lattice of the zeolite were responsible for the catalyst deactivation. It was found that the yield of the oligomers of e-caprolactam, such as dimers, trimers and tetramers, changed with the catalyst deactivation constant. The rearrangement was carried out over silica alumina to obtain a significant amount of oligomers. As a result, the catalyst deactivation was related to the selectivity of the tetramer. The tetramer yield significantly changed with the solvent. These results indicate that the oligomer as a coke precursor was easily removed by vapor of a polar solvent, such as alcohol or acetonitrile.

A study was carried out to see if the potential of renewable energy sources other than hy droelectric power, such as wind, photovoltaic, solar thermal, biomass and waste energy sources, can meet the current energy consumption in Yakushima. The current electricity consumption can be covered by wind and photovoltaic energy sources. The total potential of wind and photovoltaic energy sources is 5.4 times as much as the current electricity consumption. LP gas and kerosene can be replaced by solar thermal and biogas energy. The potential of plant biomass and municipal waste is not sufficient (approximately one third) to cover the rest of the fossil fuels (gasoline, diesel oil and heavy oil). Also, plant biomass and municipal waste must be converted into fluid form. This shortage can be covered by the po tential of wind and photovoltaic energy sources. We also investigated the possibility of tourism expansion using the potential of wind and photovoltaic energy sources. Taking into account three types of capacity (energy, accommodation and transportation), Yakushima can accept approximately four times as many tourists as the current number of tourists.

High-silica ZSM-5 zeolites were synthesized by the addition of pentavalent ions, such as phosphorus and arsenic ions, to the mother gel for the zeolite preparation. The Beckmann rearrangement of cyclohexanone oxime in the vapor phase was carried out over the high-silica ZSM-5 zeolites or zeolites modified with noble metals to elucidate the effects of the diluent gas and diluent solvent on the e-caprolactam selectivity and catalyst deactivation. The catalyst lives of the zeolites modified with noble metals were much longer than that of the unmodified zeolite during the rearrangement using carbon dioxide and methanol as the diluent gas and diluent solvent, respectively. Furthermore, the life of the zeolites modified with noble metals was significantly improved by using a small amount of oxygen as the diluent gas. In this case, methanol was the most suitable diluent solvent for the improvement of catalyst life. The catalyst life decreased with increased cyclohexanone oxime concentration in methanol. Therefore, the coke or coke precursor on the acid sites was presumably removed by methanol vapor. These results indicate that a prolonged catalyst life in the vapor phase Beckmann rearrangement can be achieved by the optimum combination of catalyst and reaction atmosphere.

反応によってガス体積(モル数)が減少する反応を流動触媒層で行った場合の流動化状態を調べるために, ガラス製の反応器を使用して層内で起きる現象を観察した. その結果, 反応が進行すると, 条件によっては層上部の触媒粒子が凝集し, 流動化が停止して, 塔径大の粒子層の塊が流動化ガスによって持ち上げられることがわかった. このようにエマルション相が凝集することの原因の一つとして, エマルション相と気泡相のガス密度の違いが考えられるため, この影響について調べた. その結果, 本反応においては, ガスの密度差は原因とならないことがわかった. モル数減少反応が起きている場合の流動性の低下はエマルション相における反応にともなうガス体積の減少によって, 層が収縮し, 気泡の上昇が妨げられることが大きな原因と考えられる.

The effect of asphaltene (ASP) decomposition on catalyst deactivation under deep desulfurization conditions was investigated by reduction of sulfur from 0.3 to 0.1 mass% in a treated atmospheric residue (AR) over two kinds of commercial catalysts, namely CDS-R2 and 46Y-678, in a pilot scale fixed bed reactor. The CDS-R2 catalyst was supported on γ -alumina with medium pore size (11 nm) and the 46Y-678 catalyst was supported on Y-type zeolite. The life of 46Y-678 was longer than that of CDS-R2, but was not adequate for application to commercially operated hydrotreating equipment. The rapid decomposition of ASP on the catalyst may be responsible for the catalyst deactivation from analysis of ASP in the product oil. Characterization of the used catalyst and the asphaltene revealed that coke was uniformly deposited on the catalyst and the coke content after 1000 h of time on stream was almost the same as that after 1 year in a commercial hydrotreating process. The coke content increased at the outer surface of catalyst by growth of a carbon shell. Decomposition of asphaltene is probably responsible for rapid catalyst deactivation in deep hydrodesulfurization.

Hydrodesulfurization (HDS) of atmospheric residue (AR) carried out over Ni_Mo or Co_Mo catalyst requires a sudden increase in the reaction temperature for the desired desulfurization at the end of operation (EOR). This phenomenon is mainly caused by reduced diffusion rate due to metal deposition in the pore mouth. The present study performed HDS over catalysts with different pore size to separately examine the effects of metal and coke deposition on catalyst deactivation. HDS catalysts used in a commercial process for 1 year were analyzed by EPMA to determine the coke and metal distribution along the catalyst radius. A model equation was developed to quantitatively estimate the coke and metal distribution. The model equation could estimate parameters such as Thiele modulus and catalyst properties coefficient. Furthermore, the equation was applicable to used catalyst obtained from commercial equipment and to used catalysts with different pore radii after HDS of Boscan crude containing large amounts of metals and asphaltenes. The distributions of coke and metals could be simulated with the model equation, giving 0.01 and 4 for the Thiele moduli for coke and metal, respectively. The model equation developed in this study is useful to estimate the service life of HDS catalyst.

Hydrodesulfurization (HDS) of atmospheric residue (AR) over Ni-Co-Mo catalysts supported on y-alumina was carried out to examine the effect of alumina pore size on HDS activity, hydrodemetallization (HDM) activity and initial catalyst deactivation under deep hydrodesulfurization conditions. HDM activity slightly increased with alumina pore size, but HDS activity decreased due to the decrease in the surface area of the support. Deactivation of the HDS catalyst was greater on large pore size supports than on medium pore size supports. The combination of HDS catalyst with large pore size supports (40%) and medium pore size supports (60%) did not improve the catalyst life. HDS was carried out with the large pore size support catalyst at the upstream side in the first reactor and the medium pore size support catalyst at the upstream side in another reactor. Catalyst deactivation was greater in the former than in the latter reactor. These results suggest that HDS catalyst supported on alumina with medium pore size has a higher performance than HDS catalyst supported on alumina with large pore size for deep HDS. To examine the behavior of asphaltene (ASP) at the reaction temperature, adsorption of ASP was investigated on catalyst supports with different pore size. ASP was a large molecule at low temperatures, but the molecular size decreased at HDS reaction temperature caused by the dissociation of the molecular structure. Furthermore, ASP containing sulfur was preferentially adsorbed on the catalyst support. The chemical interaction between ASP and alumina indicates that alumina is a good support for the HDS reaction., 常圧残油の水素化脱硫反応（HDS）を細孔径の異なるγ-アルミナに担持したニッケル-コバルト-モリブデン触媒を用いて，深度脱硫条件で常圧残油の反応を行い，水素化脱硫（HDS）活性，水素化脱メタル（HDM）活性および触媒活性劣化に及ぼす細孔径の影響を検討した。HDM活性は細孔径とともにわずかに増加したが，HDS活性は細孔径とともに減少した。また，大きな細孔径をもつ担体に担持した触媒の初期活性劣化は，中位の細孔径をもつ触媒よりも大きくなった。大きな細孔径をもつHDS触媒（40％）と中位の細孔径をもつHDS触媒（60％）の組合せ，あるいは二つの触媒の充填順序を変えて反応を行ったが，組合せによる触媒寿命の延長効果は小さく，特に大きな細孔をもつ触媒を上流側に配置すると触媒寿命は短くなった。アスファルテン（ASP）を多く含む重質な深度脱硫操作に対しては，中位の細孔径をもつ触媒がすぐれた性能を発揮することが分かった。これらの結果を説明する目的で，反応温度付近におけるASPの触媒担体への吸着実験を行った。ASPの吸着量は，低温では細孔径とともに増加したが，温度の上昇に従い，細孔径による吸着量の差が小さくなった。すなわち，ASP分子は高温になると，ミセルの状態を解いて比較的小さな分子になった。さらに，硫黄を含むASPは触媒担体に吸着しやすい性質をもつことが分かった。このような化学的相互作用により，アルミナはHDS触媒の担体として高性能を示すと考えられる。

A new method has been used to visualize particle movement and to observe the emulsion flow in a two-dimensional fluidized bed. The method is based on the ultraviolet light activation of particles impregnated with a photochromic dye solution. When activated, the particles changed their color to dark blue allowing their movement to be easily distinguished and tracked. This method enabled us to observe continuously the movement of bubbles and fine particles around a bubble in a fluidized catalyst bed. A detailed study of the particle movements around the bubbles showed that even when the bubble ascending velocity is large, the bubble is not accompanied by an upward emulsion flow. Author Keywords: Fluidization; Fluidized bed; Visualization; Photochromic dye; Particle movement

高速X線CTスキャナを利用して触媒流動層の分散器より0.6mの高さにおいて気泡の断層画像を得た．流動層には内径46mm，高さ1.5mのアクリル樹脂製のカラムを使用した．空気を流動化ガスとし，空塔ガス速度0.01–0.07ms− 1の範囲で測定を行った．得られた断層画像を使用して気泡の境界部の解析を行った．エマルション相の空隙率が気泡界面付近でどのように変化するか調べた．また，気泡形状を考慮した界面積を求め，気泡長さから球状を仮定して求められる気泡の界面積との比較を行った．その結果，気泡形状を考慮した界面積は気泡を球状と仮定して推算される界面積よりもかなり大きくなることがわかった．

高脂肪族•低硫黄常圧残さ油 (残さ油A) をアルミナに担持した脱硫触媒を用いて水素化改質を行うと, 触媒の活性劣化速度が低脂肪族•高硫黄残さ油 (残さ油B) のそれよりも大きくなった。残さ油の脂肪族部分の分解反応は, 脱メタルおよび脱硫触媒の担体のアルミナ上で進行し, 生成したオレフィンによるコーク生成が活性劣化の原因になることが分かった。アルミナよりも強酸性を示すシリカアルミナを担体とした触媒を用いると, 反応開始後1500時間程度において要求される性能を示す温度 (WAT) を20°C程度低下できるが, その後の触媒活性劣化は大きくなった。残さ油Aに40vol%の残さ油Bを混合して水素化処理を行うと, アルミナを担体とする触媒の活性劣化が抑制された。残さ油に含まれる硫黄が水素化改質反応のコーク生成を抑制するのに重要な役割を演じているが, 現在の触媒の組合せでは, 長い脂肪族炭素鎖をもつ残さ油Aを効率的に処理することはできなかった。

The oxidative coupling of toluene to bibenzyl and stilbene has been studied over lithium-modified lead oxide under anaerobic conditions. The selectivity for the coupled products can be improved by the addition of lithium metals to lead oxide. In order to understand the effect of the reaction conditions on the selectivity, kinetic studies have also been carried out.

重質油の水素化処理触媒の活性劣化に及ぼすコークおよびメタルの同時たい積の影響を検討する目的で, 1年間商業反応装置で使用した触媒からコークおよびメタルたい積量の異なる5種類を採取し, たい積したコークのキャラクタリゼーションと残余活性測定を行った。また, これと合わせて上記と同一新触媒による重質油の反応を行い, 触媒上にコークをたい積させ, そのキャラクタリゼーションを行った。使用済触媒の物性 (表面積, 細孔容積, 平均細孔径) および残余活性は, コークとメタルの比容積を用いて計算したたい積物容量に対して良好な相関があった。また, コークたい積量とC/H比は比例関係にあることから, コークは反応経過時間によらず同質のコーク前駆体から形成され, これが反応器内で徐々に縮重合するメカニズムで進行することが推察された。さらに, たい積したコーク量はメタルたい積量の増加とともに減少する傾向にあり, これとともに脂肪族性炭素が芳香族性炭素より大きく減少した。商業装置から得られた使用済触媒の残余活性は, コークとメタルたい積物容積の和の増加とともに直線的に減少した。以上の結果から, 反応初期の急激な活性低下の後, 緩やかな劣化が進行するのは, メタルのたい積が既に蓄積したコークを排除していることが一つの要因と考えられ, コークとメタルのたい積は, 独立に進行する現象でなく, 互いに関連していることが分かった。

Methanol steam reforming was carried out over catalysts prepared from amorphous Cu50Zr50, (Cu50Zr50)100−xAux and (Cu50Zr50)100−xPdx alloys in a fixed bed reactor operated at atmospheric pressure. The selectivity for carbon dioxide, which is a measure of steam reforming, was dependent on the composition of the amorphous alloy. When the reaction was performed over Cu50Zr50 amorphous alloy, the selectivity for carbon dioxide was essentially unity, whereas methanol conversion was very low. On the other hand, methanol conversion increased with the palladium content over the Cu–Zr–Pd amorphous alloy, but the selectivity for carbon dioxide was lower than that over Cu–Zr alloy. When the reaction was carried out over catalysts prepared from amorphous Cu–Zr–Au alloy, the methanol conversion increased with the gold content, whereas the carbon dioxide selectivity was almost unity over the range of gold content. The surface area measurement revealed that the dispersion of copper, which was effective for the steam reforming reaction, increased with the content of gold in the amorphous alloy. On the other hand, the dispersion of palladium, which was effective for dehydrogenation of methanol, increased with the palladium content. These results indicate that gold in the Cu–Zr alloy plays an important role in increasing the dispersion of copper.

The vapor phase Beckmann rearrangement of cyclohexanone oxime (CHO) over solid acid catalysts including zeolites was carried out to elucidate the effects of the acid strength and the micropore size of the catalysts on the selectivity of e-caprolactam (CL) and the catalyst deactivation rate. It was found that the catalyst deactivation rate was strongly dependent on the acid strength of the acid catalysts. The improvement of catalyst life was achieved by using MFI-type metallosilicates having weak acid sites. The CL selectivity decreased over the acid catalysts with micropores larger than those of the MFI zeolites. Furthermore, using methanol and carbon dioxide as the diluent solvent and diluent gas improved CL selectivity and catalyst life, respectively.

The hydrogenation of benzene in a fixed-bed type reactor operated at atmospheric pressure over amorphous Pt-Zr alloys with different platinum composition (Pt 20 Zr 80 , Pt 28 Zr 72 , Pt 32 Zr 65 ) produced by a rapid solidification technique was investigated. Although the catalytic activity of the alloys was very low at virgin state, it gradually increased with increasing number of regeneration (oxidation and reduction)-reaction cycles. The activity approached a constant value after 5 or 6 regenerations. The hydrogenation activity of Pt-Zr alloy is higher than those of Pd-Zr and Ni-Zr alloys with the same composition. Furthermore, the turnover frequency of Pt-Zr defined as the reacting molecule per active site per second is also higher than those of Pd-Zr and Ni-Zr alloys. The hydrogenation order of the turnover frequency in the present study is almost the same as the order of the hydrogenation of olefins over the corresponding catalysts prepared from impregnation method. The characterization of the platinum catalyst prepared from the amorphous alloy revealed that the dispersion of platinum is higher than the impregnated catalysts, even though the platinum content of the former catalyst is much higher than that of latter. It is considered that this is a remarkable feature of the amorphous alloy catalyst.

それぞれを流動化すると良好な流動化状態を示すアルミナ触媒とFCC触媒を混合すると流動性が大きく低下した．乾燥した状態で流動化すると多量の粒子が塔内壁へ付着し，チャンネリングが観察された．この原因は粒子の化学組成の違いによって，二種の粒子が別方向の電荷を帯び，粒子の凝集性が高まったためと考えられる．粒子細孔内に4wt%の水を含ませた場合や温度を523K以上に上げた場合，帯電の影響は緩和された．

重質油の残さを無触媒で部分燃焼的にガス化するプロセスは, 残さの有効利用法として魅力ある方法の一つである。この系は還元雰囲気下で行われるため, 鉄, バナジウムおよびニッケルを含む炭素 (すすと言う) が生成する。このすすに含まれるニッケルおよびバナジウムを有効に回収することを目的として, 硝酸, 硫酸あるいは硫酸/硫酸アンモニウム水溶液による抽出実験を行い, 金属抽出率に及ぼす操作条件の影響について検討した。ガス化装置から生成したすすをそのまま用いると, バナジウムは80%以上回収できるが, ニッケルの回収率は20%程度と低かった。この原因は, ニッケルが硫化物として存在するため, 硫酸への溶解性が小さいためと考えられた。すなわち, ニッケルの溶解性を向上させるには, ニッケル硫化物を酸化物にする必要があった。そこで, すすを部分酸化した試料を用いて抽出実験を行ったところ, 酸化率が90%以上のすすを用いると80%のニッケルが回収された。さらに, ニッケルおよびバナジウムの抽出率に及ぼす溶液の組成と溶液量等について検討した。これらの結果から, 金属を効率よく回収するための条件を設定し, この回収法を工業的に行うための概念的なフローシートを提案した。

流通式反応器を使用して, 微量の有機硫黄化合物あるいは金属塩を添加した常圧残さ油の熱分解反応を480°Cで行い, 軽質化およびコーク生成に及ぼす添加物の影響について検討した。ここで有機硫黄化合物としては, 末端に4個のチオール基を有する3-pentaerithritol tetrakis-3-mercaptopropionate (PTMP) を用いた。また, 金属塩としては鉄, ニッケル, バナジウムのナフテン酸塩を使用した。PTMPを添加すると, わずかに軽質化が促進されたが, その濃度を変化させても軽質化の程度には差が見られなかった。一方, 鉄を添加すると, 軽質化は促進されたが, 同時にコーク生成が著しく促進され, 反応管の閉そくが起こった。そこで, PTMP (1000ppm) とナフテン酸鉄 (100ppm) を同時に添加すると, コークによる反応管の閉そくなしに大幅な軽質化が観察された。これは, 熱分解で生成した炭化水素ラジカルをチオール基が捕そくして, 再結合を妨げていることによると考えられる。このように, PTMPとナフテン酸鉄の同時添加は, 現在の精製装置に変更を加えることなく, 常圧残さ油の軽質化を促進するすぐれた方法である。

A fast-scanning X-ray CT system, designed for measuring dynamic events in multiphase fluids, was used to obtain the transient 2-dimensional cross sectional gas-phase distribution in a fluidized bed. The captured data was sent to a PC for image reconstruction, and the density distributions across the column cross section were visualized. Using image processing techniques, a pseudo 3-dimensional image of bubbles was obtained. The spatial and time resolutions of the system were sufficient for the measurement of ascending bubble behavior in a fluidized bed with fine particles. Bubble shape, interfacial area, and bubble holdup over the cross section can be measured by this system.

The hydrogenation of benzene and carbon dioxide was carried out over Zr-based catalysts prepared from amorphous alloys containing palladium, platinum, rhodium or nickel as the second metal. Although the hydrogenation activity of the alloys was very low in the virgin state, the activity gradually increased after oxidation and reduction in a hydrogen atmosphere. Characterization of the alloys revealed that the increase in surface area caused by oxidation of zirconium was responsible for the increase in hydrogenation activity. When the amorphous alloys were oxidized in an oxygen atmosphere, both the active metals for the hydrogenation and zirconium in the alloys were simultaneously oxidized. When the oxidized alloys were reduced in a hydrogen atmosphere, the oxides of the active metals were reduced to the respective metals, whereas zirconium remained in the oxide state. As a result, palladium, platinum, rhodium or nickel were highly dispersed on the produced zirconium oxide crystals. The principal advantage of a catalyst prepared from an amorphous alloy is the very high dispersion of active metal on the surface, despite the high metal content. It is considered that amorphous alloys containing zirconium as the second metal are attractive catalyst precursors for hydrogenation.

In the present part of the group study on the preparation of 13 wt% MoO3/Al2O3, the effects of drying processes were investigated on the physicochemical and catalytic properties. Two series of catalysts were prepared by a conventional impregnation technique and by an equilibrium adsorption method using a common extrudate support. XPS and EPMA results demonstrated that the distribution of Mo oxide species in extrudates was strongly affected by drying processes. A rapid drying, in particular at a reduced pressure, was found to induce a strong segregation of Mo oxides on the outer surface of the extrudates, forming a sharp egg shell type distribution of Mo. On the other hand, drying under static conditions produced a moderate egg shell type distribution, suggesting that a slow drying rate is favorable for a homogeneous distribution of Mo. The equilibrium adsorption technique was found to provide considerably flat Mo profiles inside the extrudates except for the utmost surfaces where Mo concentrations increased steeply.

The pore radius of the silica glass prepared from a borosilicate glass could be controlled by the content of alumina in the starting glass in the range from 1.9 run (0 wt% alumina) to 1.9 nm (4.5 wt%). The hydrogenation of three kinds of 1-hexenes and 1-octenes, respectively, was carried out over nickel catalysts supported on a series of the porous glasses different in pore size to elucidate the effects of pore size on the rates of hydrogenation. The rates over the catalyst with the largest pore radius (1.9 nm) were almost the same among the 1-hexenes and 1-octenes, respectively. As the pore radius decreased, however, there was observed an increasing tendency that the rates of branch-ed (or more spherical) olefins such as 3,3-dimethyl-l-butene and 2,4,4-trimethyl-l-pentene far exceeded than those of the corresponding linear olefins, i.e. 1-hexene and 1-octene, respectively. This shape selective behavior is quite different from that of the zeolite-supported catalyst. These results confirm that a catalyst support with unique shape selectivity can be synthesized from the borosilicate glass with a small amount of alumina.

When a fluidizing gas is switched from a low-density gas to a high-density gas, particles in the emulsion phase agglomerate and bubbles disappear. At the same time, channeling occurs and a decrease in the pressure drop over the bed is observed. The disturbance of fluidization is temporary, and normal fluidization is restored after several minutes. The study of mechanisms of the transient phenomena shows that the difference in diffusion rates of the two gases in the emulsion phase caused the agglomeration of particles. Because the mobility of particles was reduced, channels were formed and the fluidizing gas bypassed through them. Effects of the properties of the fluidizing gases and particles on the intensity of the transient phenomena were also studied. The intensity increased with increasing difference in the densities of the two gases. The transient phenomena were considerable for small- and light-particle systems.

The surface area and micropore distribution of the porous glass prepared from borosilicate glass were controlled by the addition of metal oxides. When alumina or zirconia was added to the borosilicate glass, the micropore size distribution was very sharp and the maximum of the distribution was located at 1–2 nm. The addition of manganese oxide or antimonial oxide did not produce a sharp micropore distribution in the porous glass. When the hydrogenation of benzenes, substituted with a different number of methyl groups, was carried out over nickel catalysts supported on the porous glass prepared from the borosilicate glass with zirconia, the hydrogenation rate decreased according to the number of methyl groups and the position of the groups. These results indicate that a shape-selective nickel catalyst can be prepared from the porous glass synthesized from the borosilicate glass with a small amount of metal oxide.

Thiobacillus ferrooxidans, isolated from mine water, utilized not only ferrous iron but also glucose to grow. By using ferrous-iron medium containing glucose, a 7-fold population increase was obtained after 96 h of incubation. The ability to oxidize ferrous iron was maintained during cultivation on the iron-glucose medium.

The Ni2+ resistance of Thiobacillus ferrooxidans was enhanced by repeated culturing in medium containing Ni2+ and gradually increasing the Ni2+ concentration. The extraction of nickel sulfide was enhanced by the adapted strain following the direct leaching mechanism of the microorganism.

The Beckmann rearrangement of cyclohexanone oxime was carried out over high-silica HZSM-5 zeolites and boron-modified HZSM-5 to elucidate the effects of silica alumina ratio and boron modification on the catalyst deactivation rate. The relationship between cyclohexanone oxime conversion and time on stream could be represented by the equation x ( t ) = x (0)·exp(− b · t ) where x ( t ) and x (0) are conversions at a time on stream t and at the initial stage t = 0, respectively, and b is the deactivation coefficient. The deactivation coefficient increased with increasing concentration of strong acid sites. When the deactivated zeolites were evacuated under a pressure of 1 Torr at 573 K for 5 h, the catalytic activity was recovered up to 50% of the initial activity. The deactivation of the ZSM-5-type zeolite was mainly due to the adsorption of volatile material on the acid sites.

ベンゼン及び二酸化炭素の水素化反応をジルコニウムを含むアモルファス合金から調製された触媒を使用して行った.アモルファス合金は, 作製した状態ではほとんど活性を示さないが, 同一合金を繰り返し使用して, 酸化・還元・水素化反応を行うと徐々に活性が向上した.使用済み合金の表面積は, 繰り返し操作とともに大きくなり, これにはジルコニウムの酸化がこれに大きく寄与することが合金のキャラクタリゼーションから明らかになった.アモルファス合金が結晶化温度以下で酸化されると, 結晶化合金よりも大きな速度でジルコニウム及び水素化反応に活性を持つ金属 (Pd, Pt, Rh またはNi) の双方が同時に酸化されるが, 水素処理によって, 後者が金属状態に還元されるのに対して, 酸化ジルコニウムはそのまま残された.この結果, アモルファス合金は徐々に酸化ジルコニウムを担体とする触媒へと変化して行くことが結論された.この触媒の最大の特長は, 水素化活性種となる金属含量が高いにもかかわらず, その分散度が高いために, 反応器体積を小さくできる点にある.ジルコニウムを含むアモルファス合金は, 水素化触媒を調製するためのすぐれた前駆体になることを示した.

The hydrogenation of benzene over amorphous Ni-Zr alloys with different Ni compositions (Ni33Zr67, Ni40Zr60, Ni50Zr50, Ni70Zr30, Ni90Zr10) produced by means of a rapid solidification technique was investigated. Although the catalytic activities of the alloys were very low in the virgin state, they gradually increased with increasing number of regeneration (oxidation and reduction) reaction cycles, and the activity approached a constant value after six regenerations. The benzene hydrogenation activity increased with nickel content up to 50%, but then decreased with Ni content. It was shown that the surface area measured by the nitrogen adsorption method had almost the same dependence on Ni content. These results suggest that the Ni50Zr50 alloy is easily relaxed by the regeneration, and Ni atoms effective for the hydrogenation are highly dispersed on the micro ZrO2 crystals produced from the alloy by the oxidation.

The rearrangement of cyclopentanone oxime was carried out over HZSM-5 and boron-modified HZSM-5 zeolites to elucidate the effect of acid strength distribution on the δ-valerolactam selectivity and catalyst deactivation rate. The results were compared with those of the reaction of cyclohexanone oxime. Although the rearrangement of cyclopentanone oxime was faster than that of cyclohexanone oxime, the catalyst deactivation rate for cyclopentanone oxime was slower than that for cyclohexanone oxime. These results indicated that since the molecular size of cyclopentanone oxime was smaller than that of cyclohexanone oxime, cyclopenatanone oxime could diffuse into the micropores of HZSM-5. The difference in the amount of effective acid sites between the reactions of cyclopentanone oxime and those of cyclohexanone oxime affected the rates of reaction and catalyst deactivation.

The surface area and micropore distribution of porous glass prepared from borosilicate glass were controlled by the addition of alumina up to 8 wt%. The surface area increased with increased alumina content in the range from 0 to 3 wt%, but it suddenly decreased when the percent alumina exceeded 4 wt%. The mean pore diameter and micropore volume also decreased with increased alumina content. When nickel ion was supported into the porous glass, the surface area decreased to about one-half that of the original glass. Since the amount of nickel supported on the porous glass increased directly with surface area, the silanol group was considered to be uniformly distributed on the glass. La surface specifique et la distribution de micropores de verre poreux prepare avec du verre de borosilicate. ont ete contro'lees par l'ajout d'alumine jusqu'a 8% en poids. La surface specifique augmente avec la teneur en alumine dans la gamme de 0 a 3% en poids, mais diminue soudainement lorsque ce taux excede 4% en poids. Le diametre moyen des pores et le volume de micropores diminuent egalement lorsque la teneur en alumine augmente. Lorsque du nickel ionique est depose sur du verre poreux, la surface specifique diminue environ de moitie par rapport a la surface originale. Etant donne que la quantite de nickel depose sur du verre poreux augmente directement avec la surface specifique, on considere que le groupe des silanols est distribue uniformement sur le verre.

The hydrogenation of benzene has been carried out over a catalyst prepared from an amorphous Pd-Zr alloy held in an alumina matrix. The catalytic activity was compared with that over the alloy cut into 1 mm fragments. It was found that the fixed alloy in the alumina had not only higher catalytic activity, but also a smaller catalyst fouling rate than the fragments of the alloy. The effect of palladium content in the amorphous alloy on the hydrogenation activity was examined. It was found that the initial activity increased with the fraction of palladium. However, the activity of the catalyst which had the highest palladium content decreased with repeated regeneration and reaction, whereas the activity of the other catalysts reached a stable value. On a effectue l'hydrogenation du benzene a l'aide d'un catalyseur prepare a partir d'un alliage amorphe de Ph-Zr depose sur une matrice d'alumine. L'activite catalytique a ete comparee a celle de l'alliage decoupe en fragments de 1 mm. On a trouve que l'alliage fixe dans l'alumine a non seulement une activite catalytique plus elevee, mais egale-ment une vitesse d'encrassement du catalyseur plus petite que dans le cas des fragments d'aliiage. On a examine l'effet de la teneur en palladium dans l'alliage amorphe sur l'activite d'hydrogenation. On a trouve que l'activite initiale augmente avec la fraction de palladium. Cependant, l'activite du catalyseur qui a la plus haute teneur en palladium diminue a la suite d'une regeneration et d'une reaction repetees, alors que l'activite des autres catalyseurs atteint une valeur stable.

The hydrogenation of CO2 was investigated over a rhodium catalyst supported on niobium oxide at atmospheric pressure. Niobium oxide was prepared by the hydrolysis of niobium chloride and its crystallitic structure was controlled by calcination temperature. It was found that the activity was lower but the selectivity of C2+ hydrocarbons was higher for the γ and γ′ forms than for the β and α forms of the niobium oxide.

The vapor phase Beckmann rearrangement of cyclohexanone oxime has been carried out over zeolites and boria modified HZSM-5 zeolites to elucidate the effects of acidity and acid strength distribution on the conversion and e-caprolactam selectivity. Although e-caprolactam selectivity was increased with the SiO2Al2O3 ratio in a HZSM-5 zeolite, the highest selectivity in the study was accomplished over a boria modified HZSM-5. The selectivity was dependent on the ratio of weak acid sites to strong acid sites. The boria played an important role in controlling the acid strength distribution of the zeolites. It was found that the production of a polymer over strong acid sites caused a decrease in e-caprolactam selectivity during the reaction. On a effectue la transposition de Beckmann en phase vapeur d'une oxime de cyclohexanone sous l'action de zeolites et de zeolites HZSM-5 modifiees par le bore afin d'elucider les effets de l'acidite et de la distribution de force de l'acide sur la Conversion et la selectivite du e-caprolactam. Bien que la selectivite e-caprolactam soit amelioree avec le rapport SiO2/Al2O3 dans une zeolite HZSM-5, la meilleure selectiavite dans l'etude a ete obtenue avec la HZSM-5 modifiee par le bore. La selectivite depend du rapport des sites acides faibles sur les sites acides forts. Le bore joue un role important dans le controle de la distribution de force de l'acide des zeolites. On a trouve que la production d'un polymere sous l'action de sites acides forts entraǐnait une diminution de la selectivite du e-caprolactam lors de la reaction.

The apparent viscosity was measured in a fluidized bed with fine particles. The measurement was performed in the bed expanded uniformly at gas velocities between minimum fluidizing velocity and minimum bubbling velocity by means of the falling-sphere method. As the apparent viscosity obtained decreased with the diameter of the falling spheres, the viscosity value was determined by extrapolation. The apparent viscosity obtained was correlated with particle diameter, density and bed voidage. An equation for predicting the apparent viscosity in the emulsion phase in a bubbling fluidized bed was introduced by combination with the correlation of the voidage of the emulsion phase. Comparison of the values predicted from this equation with the data in the literature shows good agreement. To investigate the influence of the apparent viscosity on the fluidization quality, deviations of pressure fluctuations and bubble diameter were correlated with the apparent viscosity. It was shown that the proposed correlation for the apparent viscosity was useful for predicting the fluidization quality.

The preparation of ultrafine particles of titania was carried out by the thermal decomposition of titanium tetra-isopropoxide in gas phase. The effects of preparation conditions on the surface area, micropore distribution and acid concentration of the titania were examined to elucidate the applicability of the particles to a catalyst support.It was found that the particles had about 100m2·g-1 of surface area, but they had no pore volume. The acid concentration in the titania was dependent upon the preparation temperature of the particles. Nickel catalyst prepared by an impregnation method on the titania had high activity for benzene hydrogenation.

Methanol steam reforming was carried out over catalysts prepared from amorphous Cu-Zr alloys containing a small amount of noble metals. The reforming activity of the alloy with noble metal below 0.7at% decreased with repetition of oxidation, reduction and steam reforming sequences. The amorphous Cu-Zr alloys with small amounts of noble metals changed to fine copper particles supported on zirconium oxide by the heat treatment. Although the rate constant over the alloy with platinum was smaller than that over the alloy with rhodium, the carbon monoxide selectivity over the former was higher than that over the latter. These results suggest that the catalyst prepared from Cu-Zr alloy with lat% of platinum is suitable for the steam reforming.

Beckmann rearrangement of cyclohexanone over the regenerated TS-1 and SSZ-31 was carried out to clarify the effect of regeneration number and regeneration atmosphere on e-caprolactam selectivity and catalyst deactivation rate. The rearrangement rate constant for the both catalysts decreased with the number of regeneration, but the e-caprolactam selectivity and deactivation factor observed from TS-1 was almost constant. On the other hand, e-caprolactam from SSZ-31 regenerated in Ar atmosphere decreased with the number of regeneration. These behaviors indicated that the coke precursor deposited on the SSZ-21 surface changed to hard coke in the pore, whereas the coke precursor produced on the pore mouth for TS-1 was easily removed in Ar atmosphere.