The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

J Jaap C Schouten - One of the best experts on this subject based on the ideXlab platform.

  • micromixing in a rotor stator Spinning Disc Reactor
    Industrial & Engineering Chemistry Research, 2017
    Co-Authors: Arturo Manzano Martinez, J Jaap C Schouten, Kmp Kevin Van Eeten, John Van Der Schaaf
    Abstract:

    This paper presents the micromixing times in a rotor–stator Spinning Disc Reactor. Segregation indices are obtained at different rotational speeds performing the Villermaux–Dushman parallel-competitive reaction scheme. Consequently, the corresponding micromixing times are calculated using the engulfment model, while considering the self-engulfment effect. It was found that the segregation index decreases with an increasing Disc speed. Furthermore, for the investigated operational conditions, the estimated micromixing times are in the range of 1.13 × 10–4 to 8.76 × 10–3 seconds, in agreement with the theoretical dependency on the energy dissipation rate of e–0.5. In a rotor–stator Spinning Disc Reactor it is thus possible to further continue the theoretical trend of decreasing micromixing times with very high levels of energy dissipation rates that are unattainable in traditional types of process equipment.

  • liquid solid mass transfer to a rotating mesh electrode in a rotor stator Spinning Disc configuration
    International Journal of Heat and Mass Transfer, 2017
    Co-Authors: Granados P Mendoza, J Jaap C Schouten, J.t.f. Keurentjes, S J C Weusten, M T De Groot, J. Van Der Schaaf
    Abstract:

    Here we present the mass transfer coefficient for liquid–solid mass transfer to a rotating mesh electrode and a smooth flat Disc electrode in a rotor–stator Spinning Disc Reactor. The mass transfer coefficients are measured with the limiting current density technique. Additionally, the torque is measured and the energy dissipation rate in the system is calculated. The volumetric mass transfer coefficient of the mesh electrode increases a factor 5 compared to that of the flat Disc electrode at virtually equal energy dissipation rates. Due to the characteristics of the mesh, the mesh electrode offers 2.77 times higher electrode area than the flat Disc. The mass transfer coefficients measured for the rotating mesh electrode are a factor 1.74 higher compared to the flat Disc. Average Sherwood numbers are reported and a correlation is presented that predicts mass transfer rates of rotating meshes in rotor–stator Spinning Disc Reactor configurations.

  • bubble formation in co fed gas liquid flows in a rotor stator Spinning Disc Reactor
    International Journal of Multiphase Flow, 2016
    Co-Authors: M.m. De Beer, J Jaap C Schouten, J.t.f. Keurentjes, J. Van Der Schaaf
    Abstract:

    Abstract The gas–liquid flow in a rotor-stator Spinning Disc Reactor, with co-feeding of gas and liquid, is studied for high gas volumetric throughflow rates and high gas/liquid volumetric flow ratios. High speed imaging and spectral analysis of pressure drop signals are employed to analyse the flow. Two mechanisms of bubble formation are observed, one due to gas overpressure leading to large irregular bubbles, and one due to liquid turbulent vortices leading to small, well-defined bubbles. The two mechanisms lead to three distinct gas dispersion regimes, distinguished by their characteristic oscillations in pressure drop. At low rotational Reynolds numbers ( Re ω 6 ), in the gas spillover regime, the gas is dispersed as large bubbles only. Above this critical Re ω , small bubbles are sheared off as well, thus forming a heterogeneous dispersion. At sufficiently high Re ω , depending on the gas flow rate, the gas is homogeneously dispersed as small bubbles. The maximum gas flow that can be dispersed as small bubbles is linearly proportional to the local energy dissipation rate. The understanding of the bubble formation mechanisms and pressure signature allows prediction and detection of the prevailing hydrodynamic regime in scaled up Spinning Disc Reactors and for different reaction fluids.

  • hydrodynamics of high gas liquid ratio flows in a rotor stator Spinning Disc Reactor
    10th European Congress of Chemical Engineering (ECCE 2015), 2015
    Co-Authors: De Mm Michiel Beer, Joost J B Keurentjes, J Jaap C Schouten, Van Der John J Schaaf
    Abstract:

    The rotor-stator Spinning Disc Reactor (rs-SDR) is a versatile continuous flow Reactor aiming at intensification of (micro)mixing and intensification of mass and heat transfer rates for both single and multiphase processes [e.g. 1,2]. For such transfer processes the hydrodynamics of the fluids govern the performance of the Reactor. While for a single liquid flow the hydrodynamics in the rs-SDR are relatively well understood [3], for gas-liquid flows only low gas-liquid volumetric flow ratios (φv,G/φv,L≤1) have been described [2]. However, in many applications (such as boiling/condensing fluids, gas absorption) much higher gas-liquid flow ratios are encountered. To be able to perform (and more important, to control) such processes using a rs-SDR, the current work presents gas-liquid hydrodynamics (using high-speed image analysis), and the accompanying pressure drop, for high gas-liquid flow ratios (φv,G/φv,L = 120).

  • engineering model for single phase flow in a multi stage rotor stator Spinning Disc Reactor
    Chemical Engineering Journal, 2014
    Co-Authors: De Mm Michiel Beer, J Jaap C Schouten, Jtf Jos Keurentjes, Van Der John J Schaaf
    Abstract:

    An engineering model for single-phase flow in a multi-stage rotor–stator Spinning Disc Reactor is presented. The model is based on residence time distribution data, obtained by tracer injection experiments. Measurements are done for gap ratios of G = 0.017 and 0.03, rotational Reynolds numbers of Re = 4.4 × 104 to 2.05 × 106 and superposed dimensionless throughflow rates of Cw = 127–421. A single rotor–stator cavity can be described by regions of radial plug flow at low radial Disc positions, in combination with a single ideally mixed region at high radial positions. The radial position where transition between plug flow and ideally mixed regions occurs decreases with increasing rotational Reynolds number and gap ratio, and increases with increasing superposed throughflow rate. The resulting flow model is explained by the throughflow and rotation dominated regions observed in rotor–stator cavities with superposed throughflow. The model can be used to quantify performance characteristics of rotor–stator Spinning Disc Reactors, without application of extensive numerical simulations. Results indicate that the model can be scaled up with any number of rotor–stator cavities in series, as well as with increasing Disc radius and gap ratio. This makes it a valuable tool in scaling up production capacity of the Spinning Disc Reactor.

John Van Der Schaaf - One of the best experts on this subject based on the ideXlab platform.

  • micromixing in a rotor stator Spinning Disc Reactor
    Industrial & Engineering Chemistry Research, 2017
    Co-Authors: Arturo Manzano Martinez, J Jaap C Schouten, Kmp Kevin Van Eeten, John Van Der Schaaf
    Abstract:

    This paper presents the micromixing times in a rotor–stator Spinning Disc Reactor. Segregation indices are obtained at different rotational speeds performing the Villermaux–Dushman parallel-competitive reaction scheme. Consequently, the corresponding micromixing times are calculated using the engulfment model, while considering the self-engulfment effect. It was found that the segregation index decreases with an increasing Disc speed. Furthermore, for the investigated operational conditions, the estimated micromixing times are in the range of 1.13 × 10–4 to 8.76 × 10–3 seconds, in agreement with the theoretical dependency on the energy dissipation rate of e–0.5. In a rotor–stator Spinning Disc Reactor it is thus possible to further continue the theoretical trend of decreasing micromixing times with very high levels of energy dissipation rates that are unattainable in traditional types of process equipment.

  • Residence time distribution in a rotor-stator Spinning Disc Reactor
    2015
    Co-Authors: F. Visscher, John Van Der Schaaf, Mart H J M De Croon, J.c. Schouten
    Abstract:

    This paper describes the residence time distribution in a rotor-stator Spinning Disc Reactor. This Reactor consists of a Disc with high rotation speed (up to 2000 rpm), between two stators with a small rotor-stator gap (0.5 to 3 mm). Residence time distribution experiments, at flow rates of 0.45 to 1.8 L/min, show that the flow in the rotor-stator Spinning Disc Reactor can be described by a plug flow – mixer model. Predicted hydrodynamic velocity profiles confirm plug flow conditions in the center, and well mixed behavio

  • single phase fluid stator heat transfer in a rotor stator Spinning Disc Reactor
    Chemical Engineering Science, 2014
    Co-Authors: Mm Michiel De Beer, J.c. Schouten, Joost J B Keurentjes, Pezzi Martins L Loane, John Van Der Schaaf
    Abstract:

    Abstract Single phase fluid-stator heat transfer coefficients for a multi-stage rotor–stator Spinning Disc Reactor are presented. The overall heat transfer coefficient is obtained by fitting experimentally obtained steady state outlet temperatures to an engineering model for the fluid flow inside the rotor–stator cavities. Heat transfer measurements are done for gap ratios of G =0.017 and 0.03, rotational Reynolds numbers of Re ω = 0 to 12×10 5 and superposed dimensionless throughflow rates of C w =211–421. From the overall heat transfer coefficient values for the fluid-stator Nusselt number Nu s are obtained. For all values of C w and G , Nu s increases more than a factor of 4 by increasing Re ω from 0 to 1.3×10 5 . A throughflow dominated regime occurs for Re ω 0.2 × 10 5 , where Nu s increases with increasing C w and decreasing G . For Re ω > 0.2 × 10 5 , rotation dominates the heat transfer and no influence of C w and G on Nu s is observed. The thermal performance of the multi-stage rotor–stator Spinning Disc Reactor, quantified in the volumetric overall heat transfer coefficient, increases from U ov AV R − 1 = 0.46 ± 0.2 to 0.93±0.16 MW m −3  K −1 by increasing Re ω from 0 to 4.5×10 5 . The volumetric overall heat transfer coefficient of the multi-stage rotor–stator Spinning Disc Reactor is more than a factor of 5 higher than in conventional tubular Reactors.

  • water and n heptane volume fractions in a rotor stator Spinning Disc Reactor
    Industrial & Engineering Chemistry Research, 2012
    Co-Authors: F. Visscher, Andre Bieberle, John Van Der Schaaf, Uwe Hampel, Mart H J M De Croon, Markus Schubert, J Jaap C Schouten
    Abstract:

    This paper presents the volume fractions of n-heptane and water measured in a rotor-stator Spinning Disc Reactor. The volume fractions were measured using γ-ray tomography and photographic image analysis. The volume fractions were determined as a function of rotational Disc speed, flow ratio, position in the Reactor, and rotor material. In addition, the effect of the density difference between water and n-heptane was determined by dissolving potassium iodide in the water phase. Below a rotational Disc speed of 75 rpm the volume fraction measured by tomography and photographic image analysis are within 10% deviation. For low rotational Disc speeds, the n-heptane volume fraction decreases slightly with increasing rotational Disc speed: the centrifugal force accelerates the larger n-heptane droplets to the center. At higher rotational Disc speeds the droplets become smaller accordingly, the friction between the phases determines the flow, and the n-heptane volume fraction becomes equal to the n-heptane to to...

  • liquid liquid mass transfer in a rotor stator Spinning Disc Reactor
    Chemical Engineering Journal, 2012
    Co-Authors: F. Visscher, John Van Der Schaaf, Mart H J M De Croon, J.c. Schouten
    Abstract:

    Abstract This paper presents the liquid–liquid flow behaviour and the liquid–liquid mass transfer rates for a rotor–stator Spinning Disc Reactor, with an axial Disc spacing of 1 mm, a rotor radius of 0.066 m, and rotational Disc speeds up to 1600 rpm. The liquid–liquid mass transfer rate is determined from extraction experiments of benzoic acid from n -heptane to water. For the calculation of the overall mass transfer rate the dimerization and acid dissociation equilibria are taken into account. Three flow patterns are characterized. Up to 100 rpm continuous radially inwards spiralling n -heptane patterns are observed. Between 100 rpm and 300 rpm this continuous spiral changes to spiralling n -heptane droplets. Above 300 rpm fully dispersed phase flow is observed. The overall mass transfer rate increases from 0.17 m ORG 3 m R − 3  s − 1 at 100 rpm and a water flow rate of 2.5 × 10 − 6 m AQ 3  s − 1 (water: n -heptane = 1.1:1) to 51.47 m ORG 3 m R − 3 s − 1 at 1600 rpm and a water flow rate of 12.5 × 10 − 6 m AQ 3  s − 1 (water: n -heptane = 5.6:1). These mass transfer rates are at least 25 times higher compared to those in packed columns, and at most 15 times higher compared to mass transfer rates in state of the art microchannels.

Marco M Meeuwse - One of the best experts on this subject based on the ideXlab platform.

  • multistage rotor stator Spinning Disc Reactor
    Aiche Journal, 2012
    Co-Authors: Marco M Meeuwse, John Van Der Schaaf, J Jaap C Schouten
    Abstract:

    The scale up of a rotor-stator Spinning Disc Reactor by stacking single stage rotor-stator units in series is demonstrated. The gas-liquid mass transfer per stage is equal to the mass transfer in a single stage Spinning Disc Reactor. The pressure drop per stage increases with increasing rotational Disc speed and liquid flow rate. The pressure drop is more than a factor 2 higher for gas-liquid flow than for liquid flow only, and is up to 0.64 bar at 459 rad s−1. The high mass and heat transfer coefficients in the (multistage) rotor-stator Spinning Disc Reactor make it especially suitable for reactions with dangerous reactants, highly exothermic reactions and reactions where selectivity issues can be solved by high mass transfer rates. Additionally, the multistage rotor-stator Spinning Disc Reactor mimics plug flow behavior, which is beneficial for most processes. © 2011 American Institute of Chemical Engineers AIChE J, 2012

  • effect of rotor stator distance and rotor radius on the rate of gas liquid mass transfer in a rotor stator Spinning Disc Reactor
    Chemical Engineering and Processing, 2011
    Co-Authors: Marco M Meeuwse, John Van Der Schaaf, E F Hamming, J Jaap C Schouten
    Abstract:

    Abstract This paper describes the effect of rotor radius, rotor–stator distance, liquid flow rate and rotational Disc speed on the rate of gas–liquid mass transfer in a rotor–stator Spinning Disc Reactor. A rotor radius of 0.135 m is studied with rotor–stator distances of 1, 2 and 5 mm, at rotational Disc speeds up to 209 rad s−1, and compared with a rotor radius of 0.066 m. At rotational Disc speeds lower than 70 rad s−1, elongated gas bubbles are formed, that are larger than the rotor–stator distance. At rotational Disc speeds above 100 rad s−1, spherical gas bubbles are formed that are smaller than the rotor–stator distance. The volumetric gas–liquid mass transfer coefficient increases with increasing rotational Disc speed and decreases with increasing liquid flow rate. This decrease is larger than predicted by the Wallis drift flux model because of the complex two-phase flow pattern. The rate of gas–liquid mass transfer per unit of Reactor volume increases with decreasing rotor–stator distance. The maximum observed volumetric mass transfer coefficient in case of the 0.135 m rotor is a factor 3 higher than in case of the 0.066 m rotor, while the rate of energy dissipation is a factor 15 higher.

  • Effect of rotor–stator distance and rotor radius on the rate of gas–liquid mass transfer in a rotor–stator Spinning Disc Reactor
    Chemical Engineering and Processing, 2011
    Co-Authors: Marco M Meeuwse, John Van Der Schaaf, E F Hamming, Jc Jaap Schouten
    Abstract:

    Abstract This paper describes the effect of rotor radius, rotor–stator distance, liquid flow rate and rotational Disc speed on the rate of gas–liquid mass transfer in a rotor–stator Spinning Disc Reactor. A rotor radius of 0.135 m is studied with rotor–stator distances of 1, 2 and 5 mm, at rotational Disc speeds up to 209 rad s−1, and compared with a rotor radius of 0.066 m. At rotational Disc speeds lower than 70 rad s−1, elongated gas bubbles are formed, that are larger than the rotor–stator distance. At rotational Disc speeds above 100 rad s−1, spherical gas bubbles are formed that are smaller than the rotor–stator distance. The volumetric gas–liquid mass transfer coefficient increases with increasing rotational Disc speed and decreases with increasing liquid flow rate. This decrease is larger than predicted by the Wallis drift flux model because of the complex two-phase flow pattern. The rate of gas–liquid mass transfer per unit of Reactor volume increases with decreasing rotor–stator distance. The maximum observed volumetric mass transfer coefficient in case of the 0.135 m rotor is a factor 3 higher than in case of the 0.066 m rotor, while the rate of energy dissipation is a factor 15 higher.

  • Multistage rotor‐stator Spinning Disc Reactor
    Aiche Journal, 2011
    Co-Authors: Marco M Meeuwse, John Van Der Schaaf, Jc Jaap Schouten
    Abstract:

    The scale up of a rotor-stator Spinning Disc Reactor by stacking single stage rotor-stator units in series is demonstrated. The gas-liquid mass transfer per stage is equal to the mass transfer in a single stage Spinning Disc Reactor. The pressure drop per stage increases with increasing rotational Disc speed and liquid flow rate. The pressure drop is more than a factor 2 higher for gas-liquid flow than for liquid flow only, and is up to 0.64 bar at 459 rad s−1. The high mass and heat transfer coefficients in the (multistage) rotor-stator Spinning Disc Reactor make it especially suitable for reactions with dangerous reactants, highly exothermic reactions and reactions where selectivity issues can be solved by high mass transfer rates. Additionally, the multistage rotor-stator Spinning Disc Reactor mimics plug flow behavior, which is beneficial for most processes. © 2011 American Institute of Chemical Engineers AIChE J, 2012

  • liquid solid mass transfer and reaction in a rotor stator Spinning Disc Reactor
    Industrial & Engineering Chemistry Research, 2010
    Co-Authors: Marco M Meeuwse, John Van Der Schaaf, Sanne S Lempers, J Jaap C Schouten
    Abstract:

    The heterogeneously catalyzed oxidation of glucose is performed in a rotor−stator Spinning disk Reactor. One side of the rotor is coated with a Pt/C and Nafion catalytic layer, resulting in a liquid−solid interfacial area of 274 mi2 mR−3. At the lowest rotational disk speed, 26 rad s−1, the reaction is liquid−solid mass transfer limited; at the highest rotational disk speed, 180 rad s−1, the intrinsic kinetics are rate determining. The experimental overall reaction rates are fitted with a resistances in series model, with the activation energy, pre-exponential factor, and volumetric liquid−solid mass transfer coefficient as parameters. The volumetric liquid−solid mass transfer coefficient, kLSaLS, increases from 0.02 to 0.22 mL3 mR−3 s−1 for a rotational disk speed of 26 to 157 rad s−1. These values are high in comparison to conventional Reactors, like packed beds, in spite of the low liquid−solid interfacial area used in this study. The values of the liquid−solid mass transfer coefficient kLS are 1 order...

Kamelia Boodhoo - One of the best experts on this subject based on the ideXlab platform.

  • Intensification of Continuous Ortho-Lithiation at Ambient Conditions—Process Understanding and Assessment of Sustainability Benefits
    Organic Process Research & Development, 2017
    Co-Authors: Ruili Feng, Kamelia Boodhoo, Sushil Ramchandani, Balamurugan Ramalingam, Song Wei Benjamin Tan, Soo Khean Teoh, Paul Sharratt
    Abstract:

    The feasibility of performing an ortho-lithiation reaction in a T-Reactor and a Spinning Disc Reactor (SDR) at ambient temperature has been demonstrated and compared experimentally to a conventional batch stirred tank Reactor (STR) process performed at a cryogenic temperature of −70 °C. The benefits of significantly improved mixing and much shorter residence times in the flow Reactors eliminated the need for cryogenic cooling in batch processing which is a costly requirement. A theoretical evaluation of a scaled up process with a design product output of 3 tons per year highlights that significant process intensification is achievable in the flow Reactors which demonstrate higher energy efficiency, better volume efficiency, smaller processing inventory, and smaller equipment footprint. For this reaction, the performance of the T-Reactor is the best among the three Reactors leading to much lower Reactor investment and operating cost. The SDR was also demonstrated to be effective, even though this reaction ...

  • Higee Technologies and Their Applications to Green Intensified Processing
    Green Chemistry Series, 2016
    Co-Authors: Kamelia Boodhoo
    Abstract:

    Higee technologies which involve the application of high gravity fields, typically of the order of 100–1000 g, in order to intensify the fluid dynamics, mixing and heat/mass transfer in processing fluids, have long been considered promising candidates for achieving process intensification. This chapter explores the recent advancements in applying well known Higee technologies such as the Spinning Disc Reactor (SDR) and rotating packed beds (RPB) as well as more recent versions of the latter such as the rotor–stator SDR (RSSDR) and the rotating zig-zag bed (RZB) for achieving green processing benefits. Examples of several industrially-relevant applications such as polymerisation, reactive-precipitation, catalytic and enzymatic transformations and CO2 sequestration amongst others are presented and Discussed.

  • Synthesis of TiO2 nanoparticles in a Spinning Disc Reactor
    Chemical Engineering Journal, 2014
    Co-Authors: S Mohammadi, Adam P. Harvey, Kamelia Boodhoo
    Abstract:

    Abstract Reactive precipitation of TiO2 in a Spinning Disc Reactor (SDR) has been performed. Physical parameters such as rotational speed, Disc surface texture, and operating parameters such as flowrate, ratio of water to precursor and location of feed introduction points have been studied in terms of their effects on TiO2 particle size, particle size distribution (PSD) and particle yield. Smaller particles of less than 1 nm mean diameter with narrower PSDs are generally formed at higher yields at higher Disc speeds, higher flowrates and on grooved Disc surfaces, all of which provide the best hydrodynamic conditions for intense micromixing and near ideal plug flow regime in the fluid film travelling across the Disc surface. Similar observations are made for particle characteristics at higher water/TTIP ratios which are attributed to the increased rate of the hydrolysis reaction favouring nucleation over growth. The introduction of the TTIP feed stream into the water stream away from the centre of the Disc is also conducive to the generation of smaller and more uniformly sized particles due to the greater energy dissipation for improved micromixing at these locations. Comparisons with reactive-precipitation of TiO2 in a conventional stirred tank Reactor (STR) also demonstrate that the SDR performs better in terms of much improved particle characteristics and higher TiO2 yields per unit processing time. This is attributed to more uniform and intense mixing conditions in the smaller volume, continuous SDR than in the STR.

  • Monte Carlo simulation of free radical polymerization of styrene in a Spinning Disc Reactor
    Chemical Engineering Journal, 2014
    Co-Authors: Yousef Mohammadi, Amir Saeid Pakdel, Mohammad Reza Saeb, Kamelia Boodhoo
    Abstract:

    We report on modeling of free-radical polymerization of styrene in a stirred tank Reactor–Spinning Disc Reactor (STR–SDR) arrangement using Kinetic Monte Carlo (KMC) simulation algorithm. The prepolymer from batch Reactor was transferred to SDR and simulation results were validated comparing conversion and molecular weight of the generated molecules in the batch Reactor and SDR with corresponding values from experimental data. The developed model was also applied to simulate SDR under a range of different operating conditions to accurately predict the resulting polymer properties. In this way, different prepolymer conversions were theoretically adapted to probe the evolution in chain microstructure until polymerization terminated on the rotating Disc. The developed computer code based on KMC approach enables precise monitoring of molecular-level events in the Reactor like variations in molar concentration of macroradicals and molecular weight distribution with time, and provides a greater insight into the STR–SDR cascade polymerization of styrene monomer.

  • Control of a Spinning Disc Reactor: An Experimental Study
    Industrial & Engineering Chemistry Research, 2013
    Co-Authors: Dena Ghiasy, Ming T. Tham, Kamelia Boodhoo
    Abstract:

    Despite abundant experimental work on intensification aspects of Spinning Disc Reactors (SDRs), research on control characteristics of such novel devices are rather scarce. Control of SDRs may be challenging due to fast dynamics and high responsiveness of the system. However, the readily controllable rotational speed of the Disc may offer an extra degree of freedom in control system design. In the present work, two test processes, namely, neutralization of HCl and NaOH and precipitation of barium sulfate, are chosen to investigate the control aspects of SDRs experimentally. The most commonly used controllers based on PI/PID algorithms implemented in LabVIEW, coupled with commercially available instrumentation, are employed to achieve the control objectives. The pH control of the neutralization process was successfully achieved using a PID controller which manipulated the flow rate of the base stream to the SDR. Addition of a disturbance observer scheme resulted in further enhancement of the control perfor...

Roshan Jeet Jee Jachuck - One of the best experts on this subject based on the ideXlab platform.

  • Classical cationic polymerization of styrene in a Spinning Disc Reactor using silica‐supported BF3 catalyst
    Journal of Applied Polymer Science, 2006
    Co-Authors: Kamelia Boodhoo, Roshan Jeet Jee Jachuck, Marija Vicevic, William Dunk, Valerie Sage, Duncan J. Macquarrie, James H. Clark
    Abstract:

    The carbo-cationic polymerization of styrene has been studied in a Spinning Disc Reactor (SDR) and the results were compared to those observed in a conventional Stirred Tank Reactor (STR). Addition of styrene to a slurry of silica-supported boron trifluoride (BF3/SiO2) in 1,2-dichloroethane led to uncontrollable reactions in the STR at monomer concentrations > 25%w/w and initial temperatures of 20–25°C. By comparison, monomer concentrations of 75% w/w were safely and controllably polymerized in the SDR at 40°C to yield polymers with molecular weights comparable to those reported in the literature for polymer prepared at −60°C. Exceptional heat transfer rates achieved in the SDR are sufficient to deal with the heat evolved when styrene is polymerized at concentrations as high as 75% w/w, the reaction proceeding under essentially isothermal conditions. In the present study, the effects of monomer/solvent feed rates, monomer concentrations, Disc size, and Disc speed on monomer conversions, polymer molecular weights, and polydispersities achieved in the SDR are investigated. Speculative explanations of the observed results are presented in terms of enhanced mixing effects on the polymerization mechanisms in the SDR. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 8–19, 2006

  • classical cationic polymerization of styrene in a Spinning Disc Reactor using silica supported bf3 catalyst
    Journal of Applied Polymer Science, 2006
    Co-Authors: Kamelia Boodhoo, Roshan Jeet Jee Jachuck, Marija Vicevic, William Dunk, Valerie Sage, Duncan J. Macquarrie, James H. Clark
    Abstract:

    The carbo-cationic polymerization of styrene has been studied in a Spinning Disc Reactor (SDR) and the results were compared to those observed in a conventional Stirred Tank Reactor (STR). Addition of styrene to a slurry of silica-supported boron trifluoride (BF3/SiO2) in 1,2-dichloroethane led to uncontrollable reactions in the STR at monomer concentrations > 25%w/w and initial temperatures of 20–25°C. By comparison, monomer concentrations of 75% w/w were safely and controllably polymerized in the SDR at 40°C to yield polymers with molecular weights comparable to those reported in the literature for polymer prepared at −60°C. Exceptional heat transfer rates achieved in the SDR are sufficient to deal with the heat evolved when styrene is polymerized at concentrations as high as 75% w/w, the reaction proceeding under essentially isothermal conditions. In the present study, the effects of monomer/solvent feed rates, monomer concentrations, Disc size, and Disc speed on monomer conversions, polymer molecular weights, and polydispersities achieved in the SDR are investigated. Speculative explanations of the observed results are presented in terms of enhanced mixing effects on the polymerization mechanisms in the SDR. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 8–19, 2006

  • Determination of liquid–solid mass transfer coefficients for a Spinning Disc Reactor using a limiting current technique
    International Journal of Heat and Mass Transfer, 2005
    Co-Authors: John Burns, Roshan Jeet Jee Jachuck
    Abstract:

    Abstract Liquid–solid mass transfer performance on a 30 cm diameter Spinning Disc Reactor is determined by use of the limiting current technique for copper deposition at different radial locations. Values for the local mass transfer coefficient are determined for a range of liquid flow rates and rotational speeds. The experimental data is compared with a model based on diffusion into a laminar flowing film and the enhancement in performance over this model is examined.

  • determination of liquid solid mass transfer coefficients for a Spinning Disc Reactor using a limiting current technique
    International Journal of Heat and Mass Transfer, 2005
    Co-Authors: John Burns, Roshan Jeet Jee Jachuck
    Abstract:

    Abstract Liquid–solid mass transfer performance on a 30 cm diameter Spinning Disc Reactor is determined by use of the limiting current technique for copper deposition at different radial locations. Values for the local mass transfer coefficient are determined for a range of liquid flow rates and rotational speeds. The experimental data is compared with a model based on diffusion into a laminar flowing film and the enhancement in performance over this model is examined.

  • Monitoring of CaCO3 production on a Spinning Disc Reactor using conductivity measurements
    Aiche Journal, 2005
    Co-Authors: John Burns, Roshan Jeet Jee Jachuck
    Abstract:

    A method of monitoring CaCO3 production from absorption of CO2 into an aqueous solution of Ca(OH)2 is described. Its application to the measurement of Ca(OH)2 conversion across different radial zones on a Spinning Disc Reactor is Discussed and results from experiments are presented. Links between conversion and models based on diffusive mass transfer into a thin rotating film are examined and a correlation with Fourier and Reynolds numbers shown. Estimations of mass-transfer coefficients based on the experimental results are provided and comparisons made with previous work. © 2005 American Institute of Chemical Engineers AIChE J, 2005