Amorphous Ni Alloy Hydrogenation Catalyst and Magnetically Stabilized Bed Reaction Technology

A new hydrogenation technology is introduced. This hydrogenation technology includes two new concepts: amorphous Ni alloy and magnetically stabilized bed. Amorphous metal alloys are new kinds of catalytic materials with short-range orderly but long-range disorderly structure. The disadvantages of the amorphous Ni alloy materials in terms of small specific surface area and low thermal stability have been solved to develop these materials into practical catalyst to substitute for the Raney Ni catalyst. The magnetically stabilized bed reactor, a fluidized bed of magnetically stabilized particles by applying a spatially uniform and time-invariant magnetic field oriented axially relative to the fluidizing fluid flow, has many advantages such as the low pressure drop and the high mass transfer efficiency. The cold model tests had revealed that the magnetically stabilized bed reactor displayed three different forms, i.e., the scattered particulates mode, the chain mode and the magnetic condensation mode. The chain mode was conductive to good contact between solid and liquid to promote the catalytic reaction. Two commercial units of the magnetically stabilized bed reactor were set up, with the capacity of 200 and 250 kt/a, respectively. Integration of the amorphous Ni alloy catalyst and the magnetically stabilized bed reactor was developed in the process for purification of caprolactam at RIPP, SINOPEC. The new reaction process has enhanced the hydrogenation reaction to reduce the reaction volume to 1/8 and 1/3 of those of kettle-type reactor and the fixed-bed reactor of the same throughput, respectively.     

一种新型光电催化反应器的研制及甲酸的光电催化深度氧化

 研制出一种新型的悬浮态光电催化反应器，并以甲酸为研究对象，对该光电反应器进行了光电流增强和COD脱除的表征．研究了光催化、电催化氧化及光电协同催化体系降解甲酸的电压－电流曲线．数据表明，在相同的电压下，光电协同催化体系的电流远高于电化学氧化体系的电流与光催化体系中光电流之和．同时，还研究了一系列物理化学因素如外加电压、光催化剂浓度和空气流量等对光电催化反应的影响．实验结果表明，自行研制的新型悬浮态光电催化反应器具有良好的协同效应，且所需光催化剂的最佳浓度远低于其他同类光电催化反应器的最佳浓度．在该光电催化反应器中，压缩空气可有效地增强传质效应和悬浮态中光激发的TiO2颗粒在电极表面的碰撞几率，从而使得外电场可有效地捕获光生电子．     

Bulk Polymerisation or Copolymerisation in a Novel Continuous Kneader Reactor

A new type of kneader reactor is proposed for the continuous radical (co-) polymerisation without solvent, based on the proven design of mature (kneader-) dryer technology. The reactor has been developed to satisfy all major aspects required for (co-) polymerisation while maintaining the safety and reliability of the previous mechanical design. The new kneader reactor offers a perfect combination of surface renewal and evaporative cooling to control temperature to high conversion (85 to 95%), even for bulk systems that have a strong gel effect (Trommsdorff's effect) and high exothermicity. The reactor can be tested batch-wise to optimise the recipe, as shown in this work for bulk free radical polymerisation of methyl methacrylate (MMA). A simulation program was correlated to the experimental batch data to determine the optimum concentrations of initiator and of chain transfer agent to target a given molecular weight of PMMA. Design of a continuous kneader reactor to optimise the conversion as a function of residence time, to eliminate foam formation, and to produce copolymers without composition drift, is also presented.     

Enzyme-linked flow-injection immunoassay using immobilized secondary antibodies

A fast, non-equilibrium enzyme-linked flow-injection immunoassay (FIIA) system using an immobilized secondary-antibody reactor is described. The assay method is based on the competition between the enzyme-labeled antigen and analyte (unlabeled antigen) for a limited amount of soluble primary-antibody binding sites. This mixture is then introduced via flow-injection into the secondaryantibody reactor. The reactor bound enzyme activity, as measured by flowing an appropriate substrate solution through the reactor, is inversely proportional to the concentration of free analyte in the sample. By using non-equilibrium conditions, a single assay takes a total time of 13 min or less including regeneration of the reactor. To illustrate the application of this system, theophylline and insulin were chosen as model hapten and macromolecule analytes, respectively. Preliminary studies suggest that the new FIIA system is suitable for determining theophylline in serum with acceptable accuracy and precision.     

Combining enabling techniques in organic synthesis: continuous flow processes with heterogenized catalysts

The concepts article describes enabling techniques (solid-phase assisted synthesis, new reactor design, microwave irradiation and new solvents) in organic chemistry and emphasizes the combination of several of them for creating new synthetic technology platforms. Particular focus is put on the combination of immobilized catalysts as well as biocatalysts with continuous flow processes. In this context, the PASSflow continuous flow technique fulfils both chemical as well as chemical engineering requirements. It combines reactor design with optimized, monolithic solid phases as well as reversible immobilization techniques for performing small as well as large scale synthesis with heterogenized catalysts under continuous flow conditions.     

Nickel on Oxidatively Modified Carbon as a Promising Cost-Efficient Catalyst for Reduction of P-Nitrophenol

The reduction of p-nitrophenol to p-aminophenol has become a benchmark reaction for testing the efficiency of new catalytic systems. In this study, we use oxidatively modified carbon (OMC) as a structural support to develop a new cost-efficient nickel-based catalytic system. The newly developed material comprises single nickel ions, chemically bound to the oxygen functional groups on the OMC surface. The highly oxidized character of OMC ensures the high lateral density of nickel ions on its surface at relatively low nickel content. We demonstrate excellent catalytic properties of the new material by using it as a stationary phase in a prototype of a continuous flow reactor: the reagent fed into the reactor is p-nitrophenol, and the product, exiting the reactor, is the fully converted p-aminophenol. The catalytic properties of the new catalyst are associated with its specific morphology, and with high lateral density of active sites on the surface. The reaction can be considered as an example of single-atom catalysis. The resulting material can be used as an inexpensive but efficient catalyst for industrial wastewater treatment. The study opens the doors for the synthesis of a new series of catalytic systems comprising transition metal atoms on the OMC structural support.     

Laser-Induced Fluorescence (LIF) Probe for <Emphasis Type="Italic">In-situ</Emphasis> Nitric Oxide Concentration Measurement in a Non-thermal Pulsed Corona Discharge Plasma Reactor

Laser-induced fluorescence (LIF) is an effective in-situ probe for NO concentrations below 300 ppm in a non-thermal plasma reactor. A new method has been developed to measure in-situ NO concentration in the reactor discharge region using a long-time—on the order of seconds—averaged fluorescence detection. This method, for quantifying NO concentration in a nonthermal plasma reactor, is simpler than a short-time—on the order of nanoseconds—fluorescence detection. For accurate measurement based on the new method, the LIF intensity must be close to the corona-induced fluorescence (CIF) intensity; the CIF intensity serves as a guide in selecting the LIF intensity. We find that a kinetic model proposed earlier works for two-tube reactors and represents the NO concentration in the middle of the reactor, which verifies the assumption of gas plug flow.     

A new approach for isothermal calorimetric technique

Using flexible heat flux sensors mounted on the lateral and bottom of outside reactor wall, a new approach is developed for isothermal calorimetric technique to overcome the disadvantages of heat flow calorimetric methods. Although the proposed system needs a calibration procedure before or after the reaction completion to evaluate the lateral heat transfer area, the measurement is versatile and totally independent of the reaction media, jacket fluid, and the variations of heat transfer coefficient. Knowledge of the variations of the heat transfer coefficient is essential for the effective control and scale up of a reactor and can be inferred by the new method during the reaction. The stirrer power and the heat loss can be determined easily as well. No pre-calibration is needed for the sensors and no heating element is applied inside the reactor for temperature control. Experiments are carried out to validate the performance of the new proposed technique. With the help of a heater, the heat generated in the reactor is measured at various levels of power input. The predicted heater power inputs are in good agreement with the corresponding heat inputs. The relative detection limit in the range of 0.8–1 W L⁻¹ is expected for this technique. Using the hydrolysis of acetic anhydride, the heat of reaction at 25°C is determined, which is within the range reported in the literatures. The capability of the system to deal with the variations in the overall heat transfer coefficient is also demonstrated using a simulated reaction.     

A novel reactor for photochemical post-column derivatisation in HPLC

Summary It is well known that UV-absorbing substances can be transformed into fluorescent substances by irradiation with UV-light. This principle is used for HPLC by means of a post-column reactor. The factors influencing the performance of the reactor, such as contribution to peak broadening and optimization of the photochemical reaction, are discussed leading to a new and versatile design.Dedicated to Professor Dr. István Halász for his 60th birthday.     

Immobilized enzyme kinetics analyzed by flow-through microfluorimetry : Resorufin-β-d-galactopyranoside as a New Fluorogenic Substrate for β-Galactosidase

Bioreactor kinetics depend on the dispersion of catalytic parameters within the catalyst particle population. In the conventional determination, reactor performance is assessed from the total turnover rate. In the proposed method the dispersion of turnover rates in reacting immobilized enzyme gel spheres of a continuously stirred tank reactor is evaluated. This more informative method is based on flow-through microfluorimetry and is exemplified with β-galactosidase immobilized on Sepharose 4B, with resorufin-β-d-galactopyranoside as a new fluorogenic substrate. By use of sieved gel fractions, effectiveness factors and Damköhler numbers determined in individual beads can be correlated with integral turnover rates of the reactor.     

A pulsed light reactor for molecular weight control in free-radical polymerization

A new controlled polymerization reactor is introduced. The reactor design is based on the principles of pulsed initiation polymerization. The 1 l reactor is equipped with a high-voltage UV-stroboscope, the frequency of which can be raised up to 250 Hz. In this reactor pulsed initiation polymerizations of n-butyl acrylate were performed. Results indicate that the use of high pulse frequencies in this set-up may resolve problems associated with chain transfer to polymer in the determination of propagation rate coefficients for acrylates at temperatures above 30 °C.     

Zirconium dioxide-based solid electrolyte as a means of oxidation of organic compounds during isotopic assay of carbon

It is demonstrated that a high-temperature electrochemical reactor on the basis of zirconium dioxide (0.9ZrO₂ · 0.1Y₂O₃) with platinum electrodes may be promising as a device for preparing samples of organic gases for isotopic assay of carbon. Owing to a high catalytic activity of the surface of a porous platinum coating, it is possible to realize full oxidation of organic gases to stoichiometric oxides at 900–950°C and an oxygen flux equivalent to an electric current of 100 μA and higher. The reproducibility of the results of isotopic assay is better than that yielded by a standard oxidation reactor. Use of the solid-electrolyte reactor in a new device as a sensor makes it possible to simultaneously measure the concentration of organic gases passing through the reactor on the basis of the charge transported by oxygen ions through the wall of a ceramic tube. Simultaneously one can monitor purity of the carrier gas. Original Russian Text ? V.S. Sevast’yanov, E.M. Galimov, N.E. Babulevich, A.A. Arzhannikov, 2007, published in Elektrokhimiya, 2007, Vol. 43, No. 4, pp. 472–478.     

Supramolecular Strategies for the Recycling of Homogeneous Catalysts

Supramolecular approaches are increasingly used in the development of homogeneous catalysts and they also provide interesting new tools for the recycling of metal-based catalysts. Various non-covalent interactions have been utilized for the immobilization homogeneous catalysts on soluble and insoluble support. By non-covalent anchoring the supported catalysts obtained can be recovered via (nano-) filtration or such catalytic materials can be used in continuous flow reactors. Specific benefits from the reversibility of catalyst immobilization by non-covalent interactions include the possibility to re-functionalize the support material and the use as “boomerang” type catalyst systems in which the catalyst is captured after a homogeneous reaction. In addition, new reactor design with implemented recycling strategies becomes possible, such as a reverse-flow adsorption reactor (RFA) that combines a homogeneous reactor with selective catalyst adsorption/desorpion. Next to these non-covalent immobilization strategies, supramolecular chemistry can also be used to generate the support, for example by generation of self-assembled gels with catalytic function. Although the stability is a challenging issue, some self-assembled gel materials have been successfully utilized as reusable heterogeneous catalysts. In addition, catalytically active coordination cages, which are frequently used to achieve specific activity or selectivity, can be bound to support by ionic interactions or can be prepared in structured solid materials. These new heterogenized cage materials also have been used successfully as recyclable catalysts.     

Fast neutron induced fission neutron spectra below the incident energy

A fast pneumatic transfer system for an instrumental neutron activation analysis and delayed neutron counting system were reconstructed with new designs of a functional improvement at the HANARO research reactor in 2006. The design, conception, operation and control of these systems are described. Also the experimental characteristic parameters by a functional operation test and an irradiation test of these systems, such as the transfer time, the neutron flux, the temperature of the irradiation position with an irradiation time, the radiation dose rate when the rabbit is returned, etc., are reported to provide a user information as well as for the management and safety of the reactor.     

Oscillatory control of sample dispersion in a continuous flow system

A new strategy for the instrumental control of sample dispersion in continuous flow systems is presented. The method is based on shaking a loosely held straight reactor while the sample travels through the flow injection manifold. This external disturbance yields a sample transport more similar to the plug flow type because of the changes promoted on the flow pattern. Up to a three-fold increase in peak height, a comparable reduction in peak width and a more Gaussian peak profile are observed when the signals obtained with the shaken reactor are compared with those obtained with the same reactor but static. Improvements in the analytical performance as a function of different operational variables are shown for systems with or without a chemical reaction. Analytical implications and possible uses are discussed since this strategy allows the control of dispersion by simply selecting the frequency and amplitude of oscillation.     

Continuous attrition bioreactor with enzyme recycling for the bioconversion of cellulose

A new type of reactor, the attrition bioreactor, has been developed to increase the rate of the enzymatic hydrolysis of cellulose and also to cut pretreatment costs. It was found that the attrition bioreactor could be operated continuously or semicontinuously in conjunction with a membrane filter to produce a high cellulose conversion rate and low enzyme consumption. The membrane filter served to contain the enzyme and cellulose within the reactor while allowing sugar to permeate as a product.     

Influence of the Electromagnetic Forces on Momentum and Heat Transfer in a 3-Phase ac Plasma Reactor

A new 3-phase ac plasma reactor has been developed within the framework of research on hydrocarbon cracking for the production of carbon black and hydrogen. ^(1,2) One of the main characteristics of the system is related to the 3-phase, 50 Hz ac current plasma generator which induces a very particular arc motion affecting the heat and mass transfer inside the reactor. In a first step, the general flow inside the reactor in the absence of hydrocarbon injection has been studied. A simplified approach to characterize the heat and mass transfer inside the reactor is presented in this paper. The arc zone analysis is carried out simultaneously by a theoretical analysis of the electromagnetic forces and by an ultrahigh-speed cine-camera analysis. The flow in the reactor is modeled with a CFD commercial code. Results are compared with experimental temperature measurements.     

粒径对煤在H2/Ar等离子体中热解的影响

对粒径在H2／Ar等离子体煤热解制乙炔中的影响进行了研究，得到了煤的粒径与煤的裂解程度（转化率）、乙炔收率、乙炔在产品气体中摩尔分数和反应器壁结焦的关系，并且在考虑各种因素的制约下，对如何选择最佳粒径和粒径分布的问题进行了讨论。根据煤等离子体热解制乙炔反应器壁结焦的机理和煤粒径是影响反应器内结焦的重要因素，提出了进料粒径双峰分布缓解煤等离子体热解制乙炔装置结焦的新方法，实验证明该方法可行。     

The reactor granule technology: A revolutionary approach to polymer blends and alloys

The new plastic materials frontier in general and in thermoplastic polyolefins in particular developed in the last years and into next century are and will be represented by polymer alloys. The new trend in polymer alloy is to obtain them from monomer directly in the reactor, replacing the polymer blends previously made by mechanical melt extrusion of preformed polymers. It discloses new opportunities in term of properties together with better economics. The reactor granule technology developed by Himont/Montecatini produces spherical form alloys that are a synergistic combination of morphological, chemical, rheological and thermomechanical properties, by which the polymer finds many applications not previously suitable for polypropylene or polyethylene. In reactor granule technology the multimonomer random and heterophasic copolymers can be produced primarly within the granule enclosed by a solid polymer skin free from sticky nature, typical of polymers obtained by gas-phase technology and causing many problems like particles agglomeration and fouling.     

Highly Efficient Self-Assembly of Metallacages and Their Supramolecular Catalysis Behaviors in Microdroplets

Developing a new strategy to improve the self-assembly efficiency of functional assemblies in a confined space and construct hybrid functional materials is a significant and fascinating endeavor. Herein, we present a highly efficient strategy for achieving the supramolecular self-assembly of well-defined metallacages in microdroplets through continuous-flow microfluidic devices. The high efficiency and versatility of this approach are demonstrated by the generation of five representative metallacages in different solvents containing water, DMF, acetonitrile, and methanol in a few minutes with nearly quantitative yields, in contrast to the yields obtained with the hour-scale reaction time in a batch reactor. A ring-opening catalytic reaction of the metallacages was selected as a model reaction for exploring supramolecular catalysis in microdroplets, whereby the catalytic yield was enhanced by 2.22-fold compared to that of the same reaction in the batch reactor. This work illustrates a new promising approach for the self-assembly of supramolecular systems.