The 20th International Symposium on Chemical Reaction Engineering (ISCRE 20) was held on Sunday 7–Wednesday 10 September 2008. The scientific theme for ISCRE 20, Green Chemical Reaction Engineering for a Sustainable Future—Beyond the Kyoto Protocol, was chosen for a reason that the global environment issues are of great interest of the world and we, chemical reaction engineers, are requested and able to tackle the issues. The venue was Kyoto International Conference Center where the Kyoto Protocol was agreed at the 3rd Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change (COP 3) in 1997. The year of 2008 was the first year of the commitment period to reduce the overall emissions of greenhouse gases by at least 5 per cent below 1990 levels.

ISCRE 20 was hosted by the Society of Chemical Engineers, Japan (SCEJ) and operated by the SCEJ Divisions of Chemical Reaction Engineering, Energy Engineering, and Environmental Engineering and the Asia–Pacific Chemical Reaction Engineering (APCRE) Working Party. The Japanese Organizing Committee was consisted of 29 chemical reaction engineers of Steering Committee and 17 established scientists and engineers of Advisory Board. The Organizing Committee is grateful to the International Scientific Committee members, 19 members solicited from Asia–Pacific region, 15 members from Europe, and 10 members from the USA, for their great contribution in nominating plenary speakers as well as reviewing the abstracts submitted to the symposium. The Organizing Committee acknowledges Dr. Jan Lerou and Prof. Dan Luss for their kind instruction given to manage the symposium.

Responding to the Call for Papers 374 abstracts were submitted for the presentation from 38 countries and regions worldwide as shown in Figure 1. The submitted abstracts were reviewed by the Scientific Committee and the Organizing Committee members, resulting in the acceptance of 311 papers. Finally 283 papers (76% net acceptance) were presented as 194 oral and 89 poster papers at the meeting. The Organizing Committee took a policy to accept as many oral papers as possible, based on the preference of the contributors. The distribution of oral and poster presentations by topic is shown in Table 1. (See more in PDF)

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The aim of this work was to study the influence of CuO loading and pretreatment procedure on morphological, redox and acidic properties of CuO–CeO₂ catalysts, and correlate them to their water–gas shift (WGS) activity. Catalysts with a 10, 15 and 20 mol% CuO loading were synthesized with a method of coprecipitation, calcined at temperatures ranging from 400 to 750°C, and subjected to XRD, N₂ adsorption/desorption, H₂-TPR/TPD, N₂O decomposition, NH₃ chemisorption and pulse WGS activity tests in the temperature range of 180–400°C. Catalyst samples with a higher CuO content exhibited better WGS performance, due to greater oxygen mobility of the CeO₂ phase. Increasing the calcination temperature on the other hand deactivated the catalysts due to sintering and decrease of the CuO–CeO₂ interface area. A strong positive dependence of H₂ selectivity and consequently higher H₂ yield on increased catalyst surface acidity was observed, being more pronounced for catalysts with 10 mol% CuO content. WGS activity trends of the examined solids were successfully correlated with the extent of CeO₂ reduction and surface acidity, while an influence of active surface area on the activity trends was found to be marginal.

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Fuel reforming with carbon dioxide recovery for hydrogen supply to fuel cell vehicles is discussed experimentally. Ethanol water solution was chosen as the fuel, and carbonation of calcium oxide was performed for carbon dioxide recovery. A packed bed reactor containing calcium oxide and a reforming catalyst was used to produce hydrogen from the ethanol solution under 0.10–0.30 MPa at 450–550°C. Thus, the production of hydrogen with a concentration of over 95% and with less than 0.1% of ethanol, carbon dioxide, and carbon monoxide was demonstrated. On the basis of the experimental results, the hydrogen storage capacity of state of the reforming reactor for a fuel cell vehicle was evaluated and compared with that of other hydrogen storage methods. In comparison with pressurized and liquid hydrogen cylinder storages, the reforming system was more advantageous from the standpoint of storage density, and the need for a compression system explosion risk. The reforming was also found to be better than metal hydrides from the standpoint of material cost. It is expected that a carbon recycle hydrogen system based on the proposed reforming system using ethanol as the fuel can be effectively used for hydrogen storage and transportation for fuel cell vehicles.

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Porous carbongel beads supporting Co or Ni were prepared to enhance decomposition of phenol in water with ozone oxidation. The carbongel beads were synthesized by carbonization of resorcinol-formaldehyde (RF) gel beads whose diameter was approximately 1 mm. Co and Ni were supported on carbongel beads by impregnation with soluble nitrate salts of Co and Ni followed by thermal decomposition and post-oxidation treatment. In the experiments to decompose phenol, the enhancement effects of the carbongels supporting Co or Ni were observed, in which the degradation rate of phenol with these gels were larger than that with pristine carbongel or without any carbongel. In comparison between Co and Ni, Co showed larger enhancement effect. In these experiments, the concentration of the residual ozone in water was monitored. It was revealed that the residual ozone is significantly reduced when Co was used. In the experiments with varied temperature 5, 15, 25°C, the phenol degradation rate became the highest when the temperature was 5°C, while the higher temperature of 25°C was preferable when a reduced concentration of residual ozone is demanded.

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Contamination of soil and ground water by trichloroethylene (TCE) has become a serious problem in recent times. Fenton reaction can be used for the chemical decomposition of polluting substances. In this study, Fenton reagent was used as an in situ oxidizing agent for soils contaminated with TCE. We investigated the kinetics of TCE decomposition by Fenton reaction involving Fe(II). The results of our experiments show that the rates of TCE decomposition in the presence of all soils except Toyoura sand are lower than that in the absence of soils. TCE decomposition by Fenton’s reaction with Fe(II) in the presence and absence of black soil was found to be of the first order to concentrations of TCE and Fe(II) and half-order to hydrogen peroxide concentration. The reaction rate constants in the presence and absence of black soil were determined to be 1.048 and 0.568 (L·mol^–1)^1.5·s^–1, respectively. Assuming the reaction order to be 2.5, the reaction rate constants in the presence of humic acid, Kanuma soil, Toyoura sand, and akadama soil were determined to be 0.849, 0.725, 1.050, and 0.354 (L·mol^–1)^1.5·s^–1, respectively. The decrease in the rate is speculated to be affected by both specific surface area and carbon content of the soil.

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The silicon production process without the use of chlorine has been investigated and can be simply described as follows:

MG-Si → SiH(OCH₃)₃ → SiH₄ → Poly-Si

However, in this process, a large amount of Si(OCH₃)₄ was produced. To overcome this problem, SiO (CH₃)₄ was used to produce pure silica.
It was demonstrated that the manufacture of fine silica is possible by the mixing of H₂O and Si(OCH₃)₄ in vapor phase with carrier gas. In addition to the temperature and reaction kinetic, the shape and size of the generated silica particles seemed to be affected by the carrier gas type and reactor structure. In this study, three different carrier gases and four reactor structures were tested. In fact, the fine SiO₂ particles were produced by the rapid heating and reaction of tetramethoxysilane (TEMS) with heated steam. The particle diameter became smaller in the order of Ar > N₂ > CO₂ due to the increased heat capacity. The higher the heat capacity of carrier gas, the faster is the heating of TEMS and is the formation of the nuclei. The same effect was also expected by the reduced flow rate of pure TEMS with larger flow rate of steam. Feeding the water from the lower part of the reactor avoided the instantaneous thermal decomposition of TEMS and accelerated its hydrolysis. The generated particle diameter was also demonstrated to be affected by the reactor type. By suppressing the back mixing, the standard deviation of the produced fine SiO₂ was reduced.

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Dye-sensitized solar cells (DSSCs) have recently attracted intensive interest because of their simple construction, low cost, and high efficiency of sunlight to electricity conversion. Usually, a mesoporous titanium oxide (TiO₂) film deposited on a transparent electrode is used as a photoanode on which the ruthenium complex dye molecules adsorb. The aim of this work is to prepare pure anatase phase TiO₂ nanoparticles with high surface area for DSSCs application. We used the titanium (IV) n-butoxide as the precursor and acetic acid as a peptizer, after the hydrothermal treatment at 200°C, the anatase TiO₂ (a-TiO₂) can be obtained. The effect of hydrothermal duration on the properties of a-TiO₂ was studied. The TiO₂ products were characterized by XRD, TEM, and BET. The a-TiO₂ particles showed two distinct particle features: the irregular polyhedron and the elongated shaped as observed by TEM. Increasing the hydrothermal reaction time increased the average particle size for both cases and the surface area decreased as well. The a-TiO₂-based DSSCs were prepared with different thickness for the photovoltaic characteristics study. The best efficiency of ~6.61% was obtained for thickness of 24 μm (V_oc = 0.77 V, J_sc = 16.48 mA/cm², FF = 0.56).

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A new process was proposed for the total recycling of shellfish wastes combining the carbonate production with a high-pressure carbon dioxide aqueous solution and methane fermentation. The shell part of shellfish, mainly composed of calcium carbonate was dissolved into the aqueous solution of carbon dioxide at about 30 bar or acetic acid, and will be separated from the flesh part. On the other hand, the flesh part can be anaerobically fermented to produce biogas mainly composed of methane. Two options can be considered for the treatment of the carbonate solution; recovered as pure calcium carbonate, or disposed of into the ocean as a carbon sequestration process. Process feasibility was examined by obtaining key parameters through laboratory-scale experimental studies. The dissolution kinetics of blue mussel samples was examined with a high-pressure CO₂ solution and acetic acid to elucidate the influences of CO₂ pressure, temperature, stirring speed, and the sample size on the dissolution kinetics. The biogas production rate was examined with the flesh part of the sample mussel either treated with an acid solution or untreated. The biogas production rate was found to be almost unaffected by the acid exposure. Based on the experimental results, the process design and evaluation was carried out. The cost of the process with CO₂ treatment and recovery of calcium carbonate was about 21, 000 JPY/t-shellfish waste, that of ocean disposal process was 44, 000 JPY/t-shellfish waste, and that of acetic acid treatment process was 16, 000 JPY/t-shellfish waste, respectively. The proposed processes are competitive with the conventional waste disposal cost, while being simpler and more environmentally benign.

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The oxidation behavior of ethylene as a model organic compound was investigated in a system of ultraviolet (UV)light/hydrogen peroxide aqueous solution to evaluate the usefulness of UV irradiation for the oxidation of volatile organic compounds, and to clarify the gas–liquid reaction mechanism. The light induced chemical absorption of ethylene was observed. UV irradiation induced the chemical absorption of ethylene;ethylene was not oxidize directly by UV irradiation, and it did not dissolve into the hydrogen peroxide aqueous solution in the absence of UV irradiation. Ethylene was converted to intermediates that dissolved in the liquid phase. Carbon dioxide evolved drastically after the disappearance of ethylene in the gas phase. The sequential changes in the concentrations of ethylene, hydrogen peroxide, and carbon dioxide were simulated successfully by assuming serial-consecutive reactions.

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The water pollution by harmful organic compounds is one of the most important environmental problems now. We focused on sonochemistry which is a method of decomposing and removing these pollutants. In this study, relationship between reaction rate of sonochemistry and operational parameters (sound pressure, initial concentration and hydrophilicity of organic compounds) was investigated. Reaction rate was found to be increased with increasing sound pressure. The decomposition rates of compounds were found to increase but their pseudo first order rate constants were found to decrease with their increasing initial concentration, which suggests around half order kinetics. Finally, their reaction rates were found to increase when the smaller the hydrophilicity of decomposed compound (the greater the hydrophobicity of compound) becomes.

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We describe the synthesis of zeolite-A using rice husk ash (RHA)as starting material. Synthesis comprised alkali activation at low temperature (<100°C)using NaOH as reagent. We investigated the effect of experimental conditions on zeolite synthesis from RHA. The process was studied as a function of NaAlO₂ addition, NaOH concentration, temperature, and reaction time. A stirred batch reactor was used under the following reaction conditions:SiO₂/Al₂O₃ molar ratio, 1.7–2.8; NaOH concentration, 2–6 M; temperature, 50–80°C; reaction time, 0–48 h. The obtained solids were identi fied by X-ray diffraction and characterized by scanning electron microscopy;specific surface areas and cation exchange capacity values were also determined. Concentrations of Si and Al in the solution were analyzed to monitor the reaction process. Single zeolite-A can be synthesized from RHA under all our experimental conditions. We proposed the formation mechanism of zeolite-A from RHA. The silicate ion dissolves in NaOH solution from RHA and reacts with aluminate in the solution to form aluminosilicate, from which zeolite-A crystals are generated. The high crystallinity was obtained rapidly when SiO₂/Al₂O₃ ratio, NaOH concentration and temperate were high in this experimental conditions.

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The effects of ultrasonication on methane production from excess activated sludge were analyzed in relation to the bioavailability of the solubilized organic matter and the solid fraction. The solubilized organic matter was divided into three categories according to biodegradability: easily-, less-, and un-degradable organic matter. The rapid increase in easily-degradable fraction was observed at a specific sonication power of about 4,000 kJ/kg-TS but the fraction leveled off at specific power inputs above 9,000 kJ/kg-TS. The un-degradable fraction began to increase at specific power inputs of about 6,000 kJ/kg-TS and leveled off at about 9,000 kJ/kg-TS. The effect of ultrasonication on methane production was pronounced by the initial methane production rate, indicating boosted hydrolysis rate that is usually a limiting step of methane production. The methane production rate from the solubilized organic matter leveled off at the specific power input around 6,000 kJ/kg-TS, suggesting that about 60% of solubilized organic matter was converted into methane. Methane production from whole sonicated sludge showed that the amount of methane converted from the solid fraction was larger than that from the solubilized organic matter, and that ultrasonication enhanced the bioavailability of solid. The rationale for the optimal ultrasonication conditions was presented.

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A novel high-fidelity CFD model is proposed for the process optimization and intensification of methane steam reforming in a packed bed reactor. The random packing of spherical particles is constituted by simulating a dumping of particles into the annular reactor by a commercial code based on discrete element method (DEM). The complex spatial geometry between hundreds of particles is created associated with a developed interparticle bridge method, which eliminates the interparticle and particle–wall contact regions by assuming that the small regions are stagnant and would not affect the reactor behavior. The conservation equations of mass, momentum, energy and chemical species are fully solved by employing a commercial CFD code based on finite volume method. A newly coded subroutine is incorporated into the CFD code to evaluate the reaction rates according to the species partial pressures and temperature on each surface cell covering the particles. The values of reaction, equilibrium and adsorption constants are specified based on the experiments in the literature. According to the reaction rates, the mass and heat sources are given to each fluid cell on the surface cell. It is verified that the developed CFD model is capable of predicting the distributions of species and temperature microscopically as well as macroscopically for methane steam reforming. The present DEM–CFD procedure enables one to investigate the behavior of packed bed reactor in detail once the catalyst is characterized in a conventional way. Therefore it would become a powerful tool to optimize and intensify any process in a packed bed reactor where the plug flow assumption is invalid.

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There has been a considerable interest for long periods in the production of isobutene from n-butene since it can be used with methanol to produce MTBE. In this study, the general rate equation method that is based on the Bodenstein approximation and network reduction technique is used to discriminate the kinetic models for isomerization of n-butene to isobutene. For illustrating the advantages of using the general rate equation method, two proposed mechanisms from literatures were used as examples to analyze the yield ratio and to identify the correct mechanism. The experimental data published in literature were used as the test data in this study. The mechanism with the byproduct polyisobutene produced from product isobutene and adsorbed isobutene is identi fied as reasonable mechanism for the isomerization reaction.

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Metallic nickel particles with sea urchin-like shape have been prepared by rapidly chemical reduction of aqueous nickel sulfate solution with hydrazine. The phase structure and morphology of the particles have been investigated in view of the reduction temperature as well as the addition of sodium carbonate and surfactants. BET specific surface area measurement showed that the particles obtained at 89°C had the roughest surfaces. The probable formation mechanism of the sea urchin-like particles was also discussed.

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The tri-liquid phase ethoxylation (p-chloronitrobenzene in an organic phase with ethanol in an aqueous phase under a phase transfer catalyst in a third phase) was conducted. The reaction has been carried out more efficiently in a microchannel reactor than in a conventional batch reactor. The high surface area-to-volume ratio offered by the microchannel reactor and the development of a third catalytic phase have intensified the rate of reaction several orders of magnitude.

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Melt polycondensation processes to manufacture poly(ethylene terephthalate) with high molecular weight have been realized successfully in a novel reactor, grid falling film tower, in which polymer melt flows through multi-layers grids from top to bottom to form falling film owing to gravity and large gas–liquid interfacial area is generated stably and uniformly by the support of combs. The surface velocity field on falling film was measured to characterize surface renewal of falling film. Little back-mixing exists in down flowing stream, and the fluid flow in GFFT behaves as plug flow. A model has been proposed for continuous PET melt polycondensation process in grid falling film tower and veri fied by pilot-scale experimental data. Calculated degree of polymerization axial distribution can provide some valuable information for how to match the core structure with the progress of PET polycondensation process.

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Coal pyrolysis in hydrogen plasma opens up a direct means for producing acetylene. This process is operated under high temperature conditions (e. g., ~3000 K) with the residence time in milliseconds. To better understand the complex reaction behavior in a 2 MW pilot-scale reactor, a comprehensive CFD model was established to describe the gas–particle reacting flows for the process of coal pyrolysis in hydrogen plasma. Equilibrium chemistry in the gas phase was introduced and the mixture fraction approach with β-shape probability density function was used. The coal particles were modeled by discrete phase model approach so that the heating and devolitilization processes of coal particles can be well quantified in the reactor. The 3-dimensional simulations revealed the detailed flow field, temperature field, devolitilization process of coal and the spatial distribution of product gases. The unique structure of the V-shape plasma torch leads to the non-uniformity of temperature distribution in the reactor as well as the dissimilar courses of devolatilization of coal particles injected from different inlets. The results indicated that coal released its volatile matter in the first third of the reactor. Increasing the coal feeding rate results in the temperature drop of the reactor and an increase of the concentration of methane. The concentration of acetylene may reach its maximum in a good match between the plasma power input and the feeding rate of coal. All the results showed good accordance with the operation experience on the 2 MW pilot-plant reactor.

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Since the last ten years numerous studies have been carried out to develop micro-reactors or micro-structured reactors in order to improve scale of production, economics, safety and environmental impact of chemical production. Consequently Alfa Laval Vicarb has developed a new structured heat exchanger reactor. The design of the reactor is based on high performances heat plate exchanger in which small inserts allow a good mixing of the reactants and to improve the heat transfer phenomena or to increase the heat transfer coefficient. This new technology of heat plate exchange reactors has a modular structure where the exchange zones have two possible configurations: co- and counter counter-current. The structure of the reactor is also flexible, that makes possible to have multiple reactants injections and different local temperature control points. In order to have a rapid prediction of conversion and temperature profiles, a mathematical model conserving the same notion of the structure of the reactor has been developed. This mathematical model is a simple compartmental model which presents advantages in terms of flexibility, possible online simulations and rapid prediction simulations. The structure of the model has been determined with the help of tracer experiment and computational fluid dynamics simulations. Heat and mass transfer equations are written considering each cell and using experimental heat transfer data then chemical kinetics from literature are introduced to the model. A sub-compartmental model has been developed in order to predict the micro-mixing phenomena. Four reactions for which the kinetic laws of reactions are well known have been selected to test the model: alkaline hydrolysis of ethyl acetate, alkaline hydrolysis of ethylene glycol diacetate, oxidation of sodium thiosulphate by hydrogen peroxide and Bourne reactions. The results of comparison between simulations and experimental data in terms of yield, selectivity, temperature profiles and micro-mixing characteristics are in reasonable agreement.

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Most commercial trickle-bed reactors (TBRs)normally operate at high pressures. This study presents the initial development of a comprehensive CFD based model to predict pressure drop and liquid saturation in TBRs under high pressure. A two-phase Eulerian CFD model envisaging the flow domain as porous region for evaluating these hydrodynamic parameters even for high pressure operations, has been proposed. Evaluation of model predictions have been carried out with reported experimental data, collected under varied set of operating conditions. All the comparisons lead to the favorable implementation this less computationally intensive, yet first-principle based CFD model to forecast the two-phase pressure drop and liquid saturation for TBRs operating at high pressures.

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Hydrogenolysis of carbobenzoxy phenylalanine was carried out in the gas–liquid–liquid–solid four-phase upflow and trickle-bed reactor, and the performance of upflow and trickle-bed reactor was compared. The upflow reactor showed higher performance than the trickle-bed reactor. The apparent reaction order was zero to carbobenzoxy phenylalanine. Holdup of each phase was measured at various conditions to determine the reaction rate constant. From Arrhenius plot, the apparent activation energy in upflow reactor was 38.1 kJ/mol.

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Gas–solids circulating fluidized beds involve multiscale interactions and hence it is a challenge to model flow in such a system with detail at a particle level. In present work, flow in co-current upflow mode (riser) as well as co-current downflow mode (downer) is simulated using distinct element method (DEM). Simulations were performed for number of operating conditions. Detailed post processing results of the fluctuational kinetic energy (granular temperature) are presented.

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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.

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Enhancement of gas holdup and oxygen transfer was investigated in the riser of a three-phase circulating fluidized bed, with a diameter of 0.102 m (ID) and a height of 3.5 m, by means of liquid swirling flow. Effects of gas (0.01–0.07 m/s) and liquid (0.17–0.44 m/s) velocities, fluidized solid particle size (1.0, 1.7, 2.1, 3.0 mm), solid circulation rate (2–8 kg/(m² s)) and swirling liquid ratio (0–0.5) on the gas holdup and volumetric oxygen transfer coefficient in the riser were examined. The gas holdup and oxygen transfer coefficient could be increased up to 25–30% and 20–25% respectively, by means of liquid swirling flow in the riser. The values of gas holdup and volumetric oxygen transfer coefficients were well correlated in terms of dimensionless groups as well as operation variables within these experimental conditions.

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Experimental study has been aimed at examining the flow regimes of gas–liquid in up-flow ejectors by planar laser induced fluorescence (PLIF) technology under air–water and carbon dioxide–water system, the velocity fields by particle image velocimetry (PIV) under carbon dioxide–water system and gaining the bubble photos under air–water system. The conclusions were as follows: (1) The PLIF experimental results showed that in the absence of swirl, the liquid formed and maintained jet in the lower part of ejector and the air flowed up around the liquid jet annularly. At some point along the ejector axis, the jet broke up and the gas dispersed into small bubbles in the liquid. In the presence of swirl, the liquid jet didn’t exist any longer and the two phases interpenetrated and diffused immediately when two phases contact each other. (2) In the PIV measurements, the experimental data showed that at steady state the gas bubbles in the liquid flowed up along the axial direction or paralleled to the wall without swirl. However, the existence of swirl makes the velocity vectors of gas bubbles rotated and flowed up with some extent helicity. (3) The bubble photos showed that at low G/L the bubbles in the presence of swirl form the bubble chain while in the absence of swirl the bubbles disperse uniformly. However, when the G/L ratio increases, the difference in the bubble distribution diminish and the bubble tend to fill of the whole diffuser of the ejector with and without swirl.

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In current work, experiments are performed on a laboratory scale downflow bubble column to quantify the effect of operating conditions (gas and liquid flow rates) on gas holdup and its mixing characteristics. Gamma ray densitometry technique is used to find the radial gas holdup profiles in the various sections of column for different operating conditions. Subsequently, residence time distribution (RTD) experiments through conductivity measurements are conducted and the dispersion coefficients are obtained to quantify the mixing behavior. Finally, comparison of experimental results is done against two-fluid Euler–Euler model developed for the downflow bubble column which is studied experimentally.

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Selective de-activation of acid sites located near the outer surface of zeolite was examined using the catalytic cracking of silane (CCS) method. From FT-IR analysis, adsorption species of silane compounds on the acid sites of zeolite during calcination were investigated. Moreover, the effects of types of silane compounds on the changes in zeolite properties, including the amounts of adsorbed ammonia and benzene within zeolite, prior to and after CCS treatment, were examined. The CCS method using diphenylmethylsilane (DPM-silane) was effective in de-activating the acid sites located near the outer surface of ZSM-5 zeolite. Olefin synthesis from acetone was carried out using ZSM-5 zeolite catalysts. The ZSM-5 zeolite after the CCS treatment using DPMsilane exhibited high olefin selectivity as well as low aromatic selectivity.

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The objectivesof thiswork wereto fabricate Cu(I)–Y zeolite nanoparticlesforthe delsulfurizationof commercial gasoline and diesel using fixed-bed adsorption processes at room temperature. The Cu(I)–Y zeolite prepared in the present study showed that the breakthrough capacities of 21 and 9 mg/g of adsorbents of diesel and gasoline, respectively at 298 K for sulfur removal. Under the same experimental conditions, the saturation loadings were 36 and 23 mg/g for diesel and gasoline, respectively. Moreover, the structural morphology, crystallinity, fine structure and characteristics of the adsorbents were also systematically investigated. TPR profile of Cu(II)–Y zeolite indicated that the two reduction steps at 462 and 509 K, respectively were observed. A reduction temperature of about 462 K is sufficient to obtain the cuprous species required for π-complexation. EXAFS spectra showed that the bond distances of Cu–S in Cu₂S and CuS were 2.35 and 2.47 Å, respectively in the sulfur-adsorbed Cu–Y adsorbent.

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Material of CeMg mixed oxide nanoparticle doping with Ni metal can be applied as catalyst for CO oxidation reaction. It was successfully synthesized by macromolecule surfactant modified method and characterized by XRD, BET, and TEM–EDX techniques. Both alkaline-earth (Mg²⁺) and transition metal (Ni²⁺) doped into CeO₂ entered the lattice of CeO₂ to form a solid solution of CeMgO and CeMgNiO, respectively. Ni doping on CeMg mixed oxide showed much better activity of CO oxidation compared to CeMg mixed oxide itself.

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Steam reforming (SR) of dimethyl ether (DME) seems to proceed via a successive two step mechanism: hydrolysis of DME over solid acid catalysts, followed by methanol SR over copper-based catalysts. Since the DME hydrolysis is rate-controlling, it is desirable to continue more systematic study concerning the solid acids for better production of hydrogen. In this work, the composites of mesoporous solid acid catalysts (Al-SBA-15) and copper-based catalysts (Cu/ZnO/Al₂O₃) made the hybrid catalysts, and they were used for DME SR. Acidity of Al-SBA-15 was controlled by tuning Si/Al ratio, which should vary the number of acidic sites. The reducibility of hybrid catalysts was varied with different weight ratio between Al-SBA-15 and Cu/ZnO/Al₂O₃. The catalytic activity of DME SR was analyzed in terms of acid amount and copper reducibility.

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This study deals with the development of artificial neural networkfor optimal titania-based photocatalyst design using over 700 data cases from the literature. In spite of the variability in intrinsic error across laboratories and continents over a 20-year span, feed-forward ANNs relating catalyst preparation variables to photocatalyst properties displayed good predictive capabilities with correlation coefficients generally greater than 0.92. Calcination temperature and dopant concentration exhibited strong negative connection weights to the optophysical properties of the catalyst (surface area, crystallite size, band-gap energy and point of zero charge) while dopant oxidation number and ionic radius have positive connection weights although the optimal ANN ensemblefor each photocatalystproperty contains different numberof neuronsin the hiddenlayer. A global ANN connecting both catalyst preparation variables and reaction conditions as inputs optimised the relationship to photoactivity with a 16-neuron hidden layer with calcination temperature, dopant concentration, molecular weight of the organic substrate and photocatalyst loading having a negative effect on photoactivty while the most important positive influence was provided by the initial concentration of the organic pollutant and dopant ioinic radius. Due to the large spectrum of input variables accommodated by this ANN, it may beusedasa meaningfulguideinthedesignofnew photocatalystsforspecific applications. Thereliabilityof this optimal ANN architecture is demonstrated with test data which has excellent parity plot with the predicted values.

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A thin-disc, catalytic active filter (CAF), consisting of Pt/ceria (PC) as a water–gas shift (WGS) catalyst and metal as the heat transfer media, was prepared to improve the catalytic performance of the exothermic WGS reaction and to facilitate a compact WGS reactor. With the PCA (Pt/ceria + Al) filter, a remarkable improvement of CO conversion was observed compared with the result over the PC-only WGS catalyst. The prepared CAF has the advantages of superior catalytic performance, high mechanical properties and easy stackability due to its compact disc-shape.

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Time-resolved intrinsic reaction rate of catalytic vapor deposition of methane into carbon nanofibers (CNFs) and hydrogen on supported Ni catalysts was determined under different reaction temperatures (773–973 K) and feed compositions (P_H2 = 0–0.29 atm, P_CH4 = 0:28–0.71 atm) and the microstructure of the produced CNFs was characterized by Raman and TEM. The results showed that, increasing the reaction temperature, methane partial pressure and decreasing hydrogen partial pressure increased the initial reaction rate but generally led to fast catalyst deactivation. A high carbon yield per unit catalyst was obtained as a compromise between initial reaction rate and catalyst deactivation rate. The microstructures of the produced CNFs had a close relationship with the initial reaction rate. The CNFs produced with high initial rate tended to have a small angle between the graphene layers and the growth axis, thin diameter and a hollow core. This phenomenon can be used for monitoring and controlling the CNFs synthesis process.

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DME hydrolysis to methanol is accelerated by the presence of acidic sites, and the methanol conversion to hydrogen proceeds relatively fast over copper-based catalysts. Since the equilibrium of DME hydrolysis seems to be shifted to the right due to methanol SR over copper-based catalysts, the catalytic activity of DME SR seems to mainly depend on the design of copper-based catalysts. In this work, different metal oxides were introduced into the copper-based catalyst, and their effects on the physical properties such as copper surface area, acidity and reducibility were investigated. The catalytic performances were analyzed mainly in terms of copper reducibility.

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A Temporal Analysis of Products (TAP)reactor was used to study the mechanism of two green catalytic reactions, namely low-temperature CO oxidation on supported gold catalysts and volatile organic compounds (VOCs)elimination, with propane as model molecule, on vanadia-based catalysts. Single-pulse TAP experiments evidenced a weak and reversible adsorption of CO on Au/Ti(OH)₄^* catalyst and of propane on vanadia-based catalytic materials obtained by DC magnetron sputter deposition, while O₂ adsorption was irreversible on both catalysts. Alternating TAP pulse experiments provided evidence for the nature of oxygen species involved in the oxidation reactions. If the adsorbed oxygen was involved in the CO oxidation, the lattice oxygen was responsible for the propane oxidation. Multi-pulse TAP experiments assessed the degree of reduction of the catalyst while its influence upon the mechanism is determined by single-pulse experiments. The obtained results will allow the optimal formulation of industrial scale catalysts with applicability to a wide range of industrial processes.

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This work presents mathematical modeling and design of a novel implantable biocompatible polymer membrane-based controllable drug release device for delivery and uptake of anionic anti-tumor drugs. The diffusion-mediated transport of the drug from the drug reservoir to the affected tumor tissue is regulated by applying an electric potential across the membrane by a set of batteries. The model comprising of Poisson Boltzmann, Nernst Planck and Diffusion Reaction equations has been written for three separate compartments, namely, the drug reservoir, the polymer membrane and the diseased tissue, with the governing equations for the compartments being linked to each other through the boundary conditions. Analytical solutions of the abovedescribed three compartment model are obtained to quantify the drug delivery rate along the radial coordinate and with time. The analytical solution has been used to quantify the various controlling parameters and analyze the dynamics and efficacy of the drug delivery process for three different chemotherapeutic drugs, namely, Doxorubicin, Chlorambucil and Mitomycin C.

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Titanate nanostructures were synthesized by hydrothermal technique. The sonication pretreatment and reaction temperature were employed to investigate the morphology and specific surface area of the titanate nanostructure. Transmission electron microscopy, dynamic light scattering, and nitrogen adsorption were used to characterize and elucidate the behavior of titanate nanostructures in each experimental condition. By the effect of sonication pretreatment, the length and BET surface area of titanate nanotubes (TNTs) were raised from 50 nm to 490–1760 nm and from 180 to 260 m² g^–1, respectively, because of de-agglomeration of TiO₂ particles in the precursor. The BET surface area of TNTs increased with increasing hydrothermal temperature from 90 to 150°C However, when the reaction temperature increased up to 180°C, BET surface area of TNTs inversely decreased. The reason of the decline in surface area could be explained by morphology of titanate formed. The nanotube structure (hollow) of titanate was transformed to nanofiber structure (non-hollow) at this high temperature.

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Composite of MWCNT and PMMA was prepared by the mean of in-situ polymerization assisted by sonicated mixing. The prepared composites could exhibit electrical conductivity due to conductive path of entangling MWCNT in the polymeric matrix. With the increasing MWCNT content, the conductive path became more uniform, leading to the lower electrical resistance of the composites. Based on experimental results, the 2.0 wt% of MWCNT to PMMA was considered as the percolation threshold. When the composite was exposed to toluene, the polymer matrix would swell, leading to destruction of conductive path and change of the electrical resistance of the composites. Dependence of the sensor sensitivity upon the MWCNT was experimentally investigated. With the lowest MWCNT content, degree of swelling in the composite matrix became much higher. Therefore, the electrical resistance of the composite with the lowest MWCNT content changed substantially.

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In this study, we used minute gas–liquid interfaces around CO₂ microbubbles activated by microwave irradiation as new reaction fields and developed a crystallization technique to produce lithium carbonate (Li₂CO₃) nanoparticles. At the minute gas–liquid interfaces, nucleation occurs predominantly because of the formation of numerous local supersaturation regions at higher temperatures; hence, fine-sized Li₂CO₃ particles with a narrow size distribution are crystallized, as the Li₂CO₃ solubility decreases sharply with an increase in temperature. Microwaves (2.45 GHz) were used to irradiate an aqueous solution containing lithium ions and CO₂ microbubbles in a waveguide-type microwave apparatus. The heating method, rate of temperature increase (r_T) and average bubble size (d_bbl) were considered as the operation parameters and varied; the combined effects of CO₂ microbubble formation and microwave irradiation on the reactive crystallization of Li₂CO₃ nanoparticles were examined. Consequently, during microwave irradiation of the solution containing CO₂ microbubbles, the crystallization of Li₂CO₃ nanoparticles was significantly accelerated with an increase in r_T and a decrease in d_bbl.

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The synthesis of carbon nanofibers at low temperature was performed by plasma-enhanced chemical vapor deposition using a low-temperature CO/Ar/O₂ DC plasma without any catalyst materials. At the optimum oxygen concentration of O₂/CO = 0.002–0.005, vertically aligned CNFs can be synthesized at temperature as low as 90°C. In order to clarify the importance of C₂ molecules in the present CNFs growth process, the correlations among emission intensities of C and C₂ and CNFs growth rates have been evaluated for various O₂/CO ratio. Although the emission intensity of C atom spectra was not influenced by the addition of oxygen, the emission intensity of C₂ HP band decreased drastically with increasing additional oxygen fraction. From the comparison of growth rates of CNFs and optical emission spectroscopic results, it was concluded that C₂ molecules play an important role as the main precursors of CNFs synthesis process in this system because the reduction tendencies of CNFs growth rates and C₂ high-pressure bands emission intensity show a good correlation toward O₂/CO ratio.

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A Pd doped perovskite La_0.85Sr_0.15Cr_0.9Ni_0.05Pd_0.05O₃ (LSCNP) was investigated as a candidate for a metal-free anode material of solid oxide fuel cell. The deposition and the solid dissolution by reduction and oxidation treatment were observed by FE-SEM and the change of crystal structure was observed by XRD. The performance of anode prepared by mixing LSCNP and Sm doped ceria (SDC) was measured using H₂ and dry CH₄ as fuel. The anode voltage gradually decreased during the power generation, but recovered by oxidation treatment. Electrochemical impedance spectra were measured and the interfacial resistance increased during the power generation, but it decreased by oxidation treatment. The recovery of the performance due to the deposition and solid solution was confirmed. The performance of LSCNP-SDC anode using dry CH₄ as fuel showed a maximum at 5ccm, and the maximum current density was 500 mA cm^–2. From the impedance spectroscopy, it was revealed that when the flow rate was high, the relatively low water vapor pressure diminished the reforming reaction, whereas when the flow rate was low, the insufficient supply of fuel increased the diffusion resistance.

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