Spinning Basket Reactor Research Articles

Polyetheretherketone fiber-supported polyethylene glycols for phase-transfer catalysis in its surface layer

Cleaner and more efficient catalytic processes are becoming more relevant to the synthetic chemistry for reducing wastes. And herein, a commercially available ultra-high strength textile fiber polyetheretherketone (PEEK) was directionally modified by post-functionalization procedure to graft polyethylene glycols (PEG) into its surface layer to form a hydrophilic interface, and the resulted PEEK-PEG materials capable of acting as the supported phase-transfer catalysts for sorts of organic conversions in a cleaner manner were reported. The fiber samples generated during the preparation and utilization processes were observed and characterized in detail by various techniques such as morphology, mechanical properties, elemental analysis, FTIR spectroscopy and X-ray diffraction and TG analysis, and rest assured that the strategy was dependable. Moreover, the phase-transfer catalytic performance of the fiber-supported catalyst PEEK-PEG was verified in different kinds of substitution reactions, and the effects of PEG type, PEG loading and the correspondingly reaction conditions on the phase-transfer catalytic system were inspected meticulously, which were further conducive to sustain the proposed phase-transfer catalytic mechanism, and with the synergistic effect of the fiber support and PEG chain in the hydrophilic interface to afford the substitutions proceeded smoothly to obtain good to excellent product yields. Additionally, the fiber catalyst could be recycled simply and reused over 15 cycles with excellent stability under the strong caustic condition, and the catalytic system could be enlarged to the gram-scale in a spinning basket reactor, to provide a cleaner manner for phase-transfer catalysis in organic conversions with the potential of industrial application.

Modeling and experimental investigation for development of Combined Electrolysis and Catalytic Exchange process for hydrogen isotope separation

A process based on the Combined Electrolysis and Catalytic Exchange (CECE) has been developed for separation of hydrogen isotopes. Indigenously developed Platinum supported on Carbon Aerogel based hydrophobic catalyst was used for hydrogen-water isotope exchange reaction combined with hydrophilic packing in a catalytic exchange column. The exchange column has been studied in detail for various operating conditions in this study. The intrinsic kinetics for the catalytic reaction was determined through spinning basket reactor experiments, and activation energy was estimated to be 29.7 kJ/mol. The overall mass transfer co-efficient in a mixture of hydrophilic packing and hydrophobic catalyst packed bed was determined experimentally in a pilot scale counter current trickle bed reactor to be in the range of 0.15–0.25 s-1 for the proposed range of operating conditions. Individual mass transfer resistances for vapour-liquid mass transfer, external gas mass transfer and gas-solid mass transfer were estimated using widely accepted empirical correlations. Under benchmark operating conditions, the Damkohler number for the exchange column was found to be between 0.10 and 0.16, indicating a significant contribution of surface reaction to overall mass transfer resistance. The vapour liquid mass transfer was found to be fast compared to the gas-vapour reaction. Therefore, increasing hydrophobic catalyst proportion relative to hydrophilic packing was found to increase the overall mass transfer. A steady state process model has been developed to predict the performance of overall exchange process using the experimentally determined parameters. Validation of the process model was carried out using the experimental data generated on the pilot scale trickle bed reactor. Optimum operating conditions of temperature, hydrophobic catalyst to hydrophilic packing ratio, gas and liquid superficial velocities were determined.

Quaternary ammonium salt functionalized polyetheretherketone fiber: A novel fibrous material for phase-transfer catalysis

Herein, the commercially available ultra-high-strength textile fiber polyetheretherketone (PEEK) was directionally functionalized by afterward immobilization procedures to graft quaternary ammonium salts into its surface layer, and the resulted fibrous materials were capable of acting as the heterogeneous-supported phase-transfer catalysts were presented in the etherification of halogenated nitrobenzenes for the synthesis of nitroanisoles. The acquiring fiber samples from different processes were observed and characterized detailedly by diversified technologies of morphologies, mechanical properties, elemental analysis, FTIR spectroscopy, X-ray diffraction, and thermogravimetric analysis to confirm the reliability of this methodology. Moreover, the effect of functionalized degree on the PEEK fiber was inspected, and the phase-transfer catalytic system mediated by the fibrous material showed superior performance in terms of simple procedures, high yields of nitroanisoles (up to 99%), and excellent recyclability (over 30 cycles). Additionally, the newly developed fibrous catalyst exhibited superior stability (at least for 4 months) and effectively gram-scale operation in a concise spinning basket reactor, which is very attractive for various phase-transfer catalysis reactions in chemical productions.

A novel fiber-supported superbase catalyst in the spinning basket reactor for cleaner chemical fixation of CO2 with 2-aminobenzonitriles in water

The chemical fixation of CO2 with a more effective pathway is of great significance from the sustainable chemistry viewpoint. Herein, a novel fiber-supported superbase was successfully synthesized by rooting 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) into the surface layer of commercially available polyetheretherketone (PEEK) fiber and efficiently served as a heterogeneous catalyst for the conversion of CO2 in a sample spinning basket reactor. The resulting fiber samples were characterized detailedly by elemental analysis, mechanical property, FTIR spectroscopy and morphology during both of the preparation and the utilization processes. Moreover, the fiber catalyst was applied in the spinning basket reactor under mild conditions (100 °C and 1 MPa) for the cycloaddition of CO2 with a series of 2-aminobenzonitriles in water to obtain good to excellent yields of the corresponding quinazoline-2,4-(1H,3H)-diones (82–95%). In addition, the fiber-supported TBD in impellers of the agitation system was shown to be reused over 15 times without distinctly performance degradation, and stored on shelves remained equally active after at least up to 4 months. Furthermore, the operation process was convenient and effective for scaling-up procedure and thereby the fiber catalyst has good prospects in industrial applications.

Effects of metallic cobalt crystal phase on catalytic activity of cobalt catalysts supported on carbon nanotubes in Fischer–Tropsch synthesis

The effects of metallic cobalt crystal phase on catalytic activity of cobalt catalysts in the Fischer–Tropsch synthesis were investigated in a continuous spinning basket reactor. The cobalt catalysts were prepared by impregnation of the cobalt active phase in a microemulsion system on multiwall carbon nanotube supports. A series of cobalt catalysts with different Co particle sizes was prepared by variation of the water-to-surfactant molar ratio from 2 to 12 in the microemulsion system. The X-ray diffraction results validate a complex composition of cobalt phases containing cobalt oxides and metallic cobalt with hexagonal close-packed and face-centered cubic phases. The results show that larger cobalt particles exhibit more face-centered cubic and less hexagonal close-packed metallic cobalt. The experimental results show that the catalysts with higher fractions of hexagonal close-packed phase exhibited higher conversion in the Fischer–Tropsch reaction.

Modeling of Fischer-Tropsch synthesis product over an industrial fe-mn catalyst in a spinning basket reactor

Terms of process conditions such as H2/CO ratio, space velocity, pressure, and temperature and their effects on the Fischer-Tropsch product model were studied using a statistical approach. The effect of the operating parameters and the interaction between them and, the product models, were investigated. The models that can predict the reaction's product were determined. Through these models, the optimal conditions can be adjusted so that the most optimal product can be obtained. The maximum optimal product for oil, wax and water are 16.473(g), 33.572(g) and 40.285(g), respectively. Also, the most effective interactions for products are H2/CO ratio and space velocity.

Tuning anion species and chain length of ligands grafted on the fiber for an efficient polymer-supported Ni(II) complex catalyst in one-pot multicomponent A3-coupling

Herein, a new series of polymer-supported Ni(II) complex catalysts with different ligand chain lengths grafted on the fiber for one-pot multicomponent A3-coupling reactions, is reported. The fiber catalysts were prepared conveniently from commercially available polyacrylonitrile fiber via a simple two-step procedure by polyamine-amination and nickel-chelation in water respectively, and the resulting materials from the modification and utilization processes were characterized detailedly by morphology, mechanical property, elemental analysis, FTIR spectroscopy and SEM. Moreover, the fiber-supported Ni(II) complex catalysts with chlorine anion and longer chain ligands exerted higher efficiency than short chains, and the mediated reactions showed broad applicability and proceeded smoothly to afford a number of substituted propargylamines under mild conditions. Furthermore, the newly developed fiber catalyst held high strength, good flexibility and exhibited excellent stability and recyclability (over 15 cycles), and the procedure was scalable on a gram scale in a concise spinning basket reactor with good industrialization prospect.

Fiber-supported Fe(iii) complex catalyst in spinning basket reactor for cleaner ring-opening of epoxides with alcohols

An available, nontoxic, efficient, recyclable and gram-scaleable fiber-supported Fe(iii) complex catalyst in spinning basket reactor for cleaner ring-opening reactions.

Synthesis of exo-tricyclopentadiene from endo-dicyclopentadiene over mesoporous aluminosilicate catalysts prepared from Y zeolite

A highly ordered mesoporous aluminosilicate (MMZY) was prepared by a top-down and bottom-up method using HY zeolite as a raw material. A pellet-type catalyst was prepared through extrusion using a twin-screw extruder. The effects of the Si/Al2 ratio of the HY zeolite used in the MMZY catalyst preparation on the physicochemical and acid properties of MMZY catalysts were investigated. The oligomerization of endo-dicyclopentadiene (endo-DCPD) was performed in a spinning basket reactor, and the deactivated catalyst was repeatedly regenerated to verify the possibility of reusing the catalyst. It was confirmed that ordered hexagonal arrays of mesopores were well developed in the MMZY(27) and MMZY(48) catalysts, whereas the mesoporous structure of the MMZY(6) and MMZY(12) materials with relatively large amounts of Al collapsed. As the Si/Al2 molar ratio of the MMZY catalyst was increased, the number of weak acid sites increased prominently and the acid strength decreased. MMZY(27) and MMZY(48) are more effective for the oligomerization of endo-DCPD to exo-tricyclopentadiene (exo-TCPD) compared to a microporous HY catalyst. This is attributed to the abundant acid sites and to the well-developed mesopore structure. Calcination in air was found to be effective for the regeneration of the deactivated MMZY pellet catalyst for synthesis of exo- TCPD from endo-DCPD.

Fiber-polyquaterniums@Cu(I) as recyclable polymer-supported copper complex catalysts for alkyne coupling and cycloaddition reactions

Herein, a newly designed and synthesized fiber-supported polyquaterniums@Cu(I) served as efficient and recyclable polymer-supported copper complex catalysts for alkyne coupling and cycloaddition reactions, is reported. The fiber-supported copper complex catalyst was prepared systematically from commercially available polyacrylonitrile fiber, and characterized detailedly by elemental analysis, FTIR spectroscopy, mechanical properties, and SEM during both of the preparation and utilization processes. Moreover, the fiber-supported polyquaterniums@Cu(I) has been verified to possess high catalytic activities for the homocoupling of terminal alkyne in ethyl acetate (10 samples yields 83–99%, 10 cycles from 98% to 95%), A3 coupling of alkyne, aldehyde and amine in toluene (10 samples yields 81–94%, 10 cycles from 94% to 90%), and click chemistry of CuAAC reactions in water (10 samples yields 82–99%, 21 cycles from 97% to 96%). Furthermore, the newly developed fiber catalyst in spinning basket reactor displayed excellent stability and recyclability, and the concise and effective gram-scalable operation has extensive application prospect on chemical productions.

Fiber-Supported Poly(quaternaryammonium Bromide)s as Supported-Phase Transfer Catalysts in the Spinning Basket Reactor

In this paper, a newly developed fiber-supported poly(quaternaryammonium bromide)s, which served as an efficient and recyclable supported phase-transfer catalyst in the spinning basket reactor for a series of nucleophilic substitutions, is reported. The fiber catalysts were designed and synthesized systematically from commercially available polyacrylonitrile fiber, and the properties of fiber samples at different stages were characterized in detail by sorts of technologies. Moreover, the nucleophilic substitutions mediated with fiber-supported phase-transfer catalyst exhibited high efficiency to afford a range of substituted products in excellent yields (91–98%) under mild conditions, and on this basis, a solid–liquid phase-transfer catalysis mechanism was proposed. Markedly, the spinning basket reactor with fiber catalyst in its impellers revealed prominent recyclability at least for 15 cycles, and the concise method of operation also exerted a good perspective application in chemical industry.

Modeling of the Fischer–Tropsch process using a Fe–Cu–K catalyst

ABSTRACTIn a bid to increase Fischer–Tropsch product selectivity, inorganics substances, such as copper, potassium, and others, were added to the catalyst. Although this approach in Fischer–Tropsch synthesis is very important, it has not been discussed widely. Isothermal product models in this type of synthesis and effective parameters are the same as pressure, while the H2/CO feed ratio and space velocity have been studied over the spray-dried Fe–Cu–K catalyst by using statistical methods with experimental data. P = 1.0–2.5 MPa, H2/CO feed ratio = 0.6–2.0, and space velocity = 0.07–0.1 1/h are the range of operating conditions in the spinning basket reactor. The experiment was carried out at a constant temperature of 523 K. The models can predict the reaction's product. Through these the optimal conditions in the reactor models can be determined, while the maximum and minimum amounts of products for oil, wax, and water are obtained under the optimized conditions. The models showed that the interaction between parameters played a key role. The main interactions for products are pressure and space velocity.

Kinetic Study of Fischer–Tropsch Synthesis Using a Co/CNTs Catalyst

The intrinsic kinetics of the Fischer–Tropsch synthesis reaction in the conversion of synthesis gas into liquid hydrocarbons in a spinning basket reactor over a cobalt catalyst supported on carbon nanotubes were studied. The catalyst was synthesised by the impregnation wetness technique and the reactor tests were done at 215–245 °C, 20 bar, a H2/CO molar ratio of 2 and a gas hourly space velocity of 2.4–12 Nl gcat−1 h−1. To develop an appropriate kinetic model for syngas consumption, five different mechanisms were considered as possibilities for the Fischer–Tropsch reaction, each with a rate-determining step. The rate equations obtained were based on the Langmuir–Hinshelwood–Hougen–Watson model and statistical analyses were used for comparing the resulting values. The activation energies were found to be limited within the range 89–145 kJ mol−1 and the adsorption constants of hydrogen and carbon monoxide were in the range −32 to −76 kJ mol−1 and −13 to −64 kJ mol−1 respectively.

A new kinetic model for direct CO2 hydrogenation to higher hydrocarbons on a precipitated iron catalyst: Effect of catalyst particle size

The kinetic of the direct CO2 hydrogenation to higher hydrocarbons via Fischer–Tropsch synthesis (FTS) and reverse water-gas shift reaction (RWGS) mechanisms over a series of precipitated Fe/Cu/K catalysts with various particle sizes was studied in a well mixed, continuous spinning basket reactor. The iron catalysts promoted with copper and potassium were prepared via precipitation technique in various alcohol/water mixtures to achieve a series of catalyst particle sizes between 38 and 14nm. A new kinetic model for direct CO2 hydrogenation was developed with combination of kinetic model for FTS reaction and RWGS equilibrium condition. For estimate of structure sensitivity of indirect CO2 hydrogenation to higher hydrocarbons, the kinetic parameters of developed model are evaluated for a series of iron catalysts with various particle sizes. For kinetic study a wide range of syngas conversions have been obtained by varying experimental conditions. The results show that the new developed model fits favorably with experimental data. The values of activation energies for indirect CO2 hydrogenation reaction are fall within the narrow range of 23–16kJ/mol.

Evaluation of Hydrogen-Oxygen Recombiner Catalysts Under Various Conditions for Nuclear and Non-Nuclear Hydrogen Safety

Hydrogen plays an important role in nuclear and non-nuclear safety, as the unsafe manipulation of hydrogen can lead to dangerous accidents. This concern has led the Hydrogen Isotopes Technology Branch at the Canadian Nuclear Laboratories to develop catalysts in order to aid in the recombination of hydrogen and oxygen. This research project evaluates catalysts with different compositions under various conditions (i.e. dry, humid) in a spinning basket reactor (SBR). Results suggest that catalysts with lower wetproof coating loading have higher activity levels after being exposed to water vapour or immersed in liquid water compared to catalysts with higher amounts of wetproof coating. The specific activity levels were 1.91 cm3 H2/s·gCAT and 1.57 cm3 H2/s·gCAT, normalized to the benchmark catalyst’s activity in humid conditions, for catalysts with low and high amounts of wetproof coating, respectively. Normalization was performed so that the activity levels of the benchmark catalyst in humid conditions was equal to one, thus assigning the other activity level values based on their relation to the benchmark catalyst’s activity levels in humid conditions. For the benchmark catalyst, activity levels in water vapour and immersion conditions were about the same, whereas activity levels for the newly developed catalysts (with low and high wetproofing agent loadings) varied depending on the water exposure levels of the test. Thus, despite the wetproofing, the amount of water exposure had an effect on catalyst activity levels. This trend demonstrates that the benchmark catalyst was well wetproofed and suggests that further improvement is needed in the wetproofing method used for the new catalyst.

A new LHHW kinetic model for CO2 hydrogenation over an iron catalyst

A new Langmuir–Hinshelwood–Hougen–Watson (LHHW) type kinetic model is developed for carbon dioxide hydrogenation over a precipitated Fe/Cu/K catalyst in a continuous spinning basket reactor. A number of possible reaction sets originating from the combination of the formate mechanism for the water gas shift reaction and the enolic mechanism for the Fischer–Tropsch synthesis, with various rate determining steps, are considered. The results show that the CO2 hydrogenation process is limited by the reaction between surface CO and hydrogen species to form enolic (HCO) units. This surface reaction is the key reaction step in producing higher hydrocarbons by the Fischer–Tropsch synthesis.

Kinetic studies of the methanation of CO over a Ni/γ-Al2O3 catalyst using a batch reactor

The methanation of CO was investigated in a gradientless, spinning-basket reactor at temperatures 443–473K and pressures up to 16bar. The reactor was operated in batch and the composition of its contents was determined periodically. Temperature programmed studies and DRIFTS analysis were performed to gain an understanding of the nature of the surface of the catalyst. In all experiments, the reaction initially proceeded with a constant rate period. This was followed by a marked increase in the rate of production of CH4 after the depletion of CO, attributed to the hydrogenation of remaining carbonyl groups on the surface as well as the hydrogenolysis of long-chained paraffins in the reactor. The selectivity for CH4 was found to be significantly lower than that observed in CO2 methanation, consistent with the low H2 to CO ratio on the surface of the catalyst. Temperature-programmed studies and DRIFTS studies of the spent catalyst identified two main types of carbonaceous species on the surface of the catalyst, with the results being consistent with the presence of (i) carbonyl species on nickel clusters and (ii) formate groups on nickel sites which have a stronger interaction with the alumina support. The former were found to be reactive at the temperatures studied. Finally, the rate of methanation was found to be insensitive to H2O. This was attributed to the strong affinity of the nickel catalyst for CO, which saturates the surface of the catalyst leaving little opportunity for the adsorption of H2O. Two models were derived assuming that the rate-limiting steps were either (i) the adsorption of H2 on the catalyst, or (ii) the reaction of gaseous H2 with adsorbed CO. The strong adsorption of CO on the surface of the catalyst, evident from various experimental observations, is consistent with both mechanisms.

Advanced fundamental modeling of the kinetics of Fischer–Tropsch synthesis

The kinetic modeling of Fischer–Tropsch Synthesis on an iron catalyst starting from experimental data collected in a spinning basket reactor and proceeding through the Single Event approach to limit the number of independent parameters is reported. The elementary steps are based on the carbide mechanism with hydrogen assisted CO insertion and CH2 as the growth monomer. The evolution with the chain length of alkane‐, alkene‐, and alcohol‐selectivities in the synthesis product and their exponential‐like behavior is fundamentally generated by accounting for the effect of the structure of reactants and transition state intermediates on the rate coefficients. The olefin readsorption is included in the model but its influence on the product distribution is found to be negligible. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1668–1682, 2016

New Particle Size-Dependent Kinetic Model of the Water–Gas-Shift Reaction Using an Iron-Based Catalyst under Fischer – Tropsch Conditions

The effect of nanoparticle size on the kinetics of the water–gas-shift (WGS) reaction using an iron based catalyst used in the Fischer – Tropsch synthesis (FTS) was studied in a continuous spinning basket reactor. A series of iron oxide particles with different particle sizes doped with copper and lanthanum was prepared as the catalyst. A new size-dependent kinetic model for the WGS reaction has been developed by a thermodynamic method. The kinetic parameters of the model were evaluated from experimental results for iron catalysts with different particle sizes. The results show that the parameters of the size-dependent model changed with temperature and particle size. The surface tension energy (σ) of the iron oxide catalyst and the size-independent activation energy for the WGS reaction was calculated from the experimental results. The size-independent activation energy for the WGS reaction is calculated as 4 kJ mol–1 based on haematite particles.

Detailed kinetics of Fischer–Tropsch synthesis on a precipitated iron catalyst

A Langmuir–Hinshelwood–Hougen–Watson kinetic model for FTS hydrocarbon production rates is developed. The concept of dual Anderson–Schulz–Flory (ASF) distribution with two chain growth probabilities is used for developing the kinetic model. The experiments were carried out in a continuous spinning basket reactor. The iron catalyst promoted by lanthanum as a low basic promoter is used for activity evaluations. The results show that the kinetic model developed by dual ASF product distributions is more consistent with experimental results than simple ASF. The activation energy for the formation of methane, ethane and ethylene are calculated as 68, 76 and 72 kJ mol−1, which can explain the lower selectivity of ethane than ethylene. The activation energy for paraffin formation with lower carbon number is 91 kJ mol−1 and for paraffin formation with larger carbon number is 102 kJ mol−1, which can explain the lower selectivity of heavy paraffins. Also, the activation energy of light olefin formation is 98 kJ mol−1 and the activation energy of heavy olefin formation, is 148 kJ mol−1.