Author
L.L. van Dierendonck
Bio: L.L. van Dierendonck is an academic researcher from University of Groningen. The author has contributed to research in topics: Plug flow reactor model & Polymerization. The author has an hindex of 4, co-authored 5 publications receiving 55 citations.
Papers
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TL;DR: The hydrodynamics and mass transfer characteristics of a straight tube ejector have been investigated in this article, where it was concluded that two different hydrodynamic zones exist in the ejector.
Abstract: The hydrodynamics and mass transfer characteristics of a straight tube ejector have been investigated From the experiments it can be concluded that two different hydrodynamic zones exist in the ejector In the first zone, the “mixing shock” region, extremely high k L a values are obtained In the remaining part of the ejector volume a fine and homogeneous bubble flow appears in which the mass transfer rate is lower These observations indicate that for a proper design of gas-liquid ejectors the ejector should be considered as a system of two units in series, requiring separate modelling Further, it has been shown that the presence of a swirl device in the upstream section of the nozzle has a significant effect on the hydrodynamics and mass transfer performance of ejectors
26 citations
TL;DR: In this article, a fundamental model of fluid circulation in polymerization reactors agitated by helical ribbon impellers is presented, and an expression is developed for the circulatory flow generated by a double helical impeller in a reactor with a draught tube.
12 citations
TL;DR: In this paper, the results of an experimental and theoretical study concerning the possible applicability of a new packing material for hydrogenation processes in a trickle-bed reactor is presented. But the results show that the application of KATAPAKTM does not significantly improve the overall performance of the cascade.
11 citations
TL;DR: In this paper, the Buss-Kneader was used as a plug flow reactor with axial dispersion for co-polymerization of n-butyl acrylate and hydroxyethyl methacrylate.
Abstract: The Buss-Kneader is generally known as a compounding device. Although a reasonable number of papers have been published on extruders as polymerization reactors, only little is known about the behavior of the Buss-Kneader when used as a polymerization reactor. Its good mixing properties in the radial and axial directions make it a suitable reactor for exothermal polymerization reactions. This paper describes experiments with the co-polymerization of n-butyl acrylate and hydroxyethyl methacrylate in a Buss-Kneader. For model calculations the Buss-Kneader was treated as a plug flow reactor with axial dispersion. Experimental results on axial temperature profile, monomer conversion and molecular weight are compared with model calculations. Model parameters are based on independently measured data on the heat transfer coefficient, axial dispersion and polymerization kinetics.
7 citations
TL;DR: The Buss-Kneader has proven to be a suitable reactor for the polymerization of acrylates as discussed by the authors, and the ter-polymerization of methyl methacrylate (MMA), hydroxyethyl methcrylate and n-butylmethacrylated is carried out in a pilot Busskneader, which had to be pressurized up to about 10 bars to avoid evaporation of MMA.
Abstract: The Buss-Kneader has proven to be a suitable reactor for the polymerization of acrylates. In this second part, the polymerization of methyl methacrylate and the ter-polymerization of methyl methacrylate (MMA), hydroxyethyl methacrylate and n-butylmethacrylate is carried out in a pilot Buss-Kneader. The reactor had to be pressurized up to about 10 bars to avoid evaporation of MMA. Instabilities in output rate and temperature profiles were observed as a result of fluctuating die pressures. Because of good mixing there may be no diffusion limitation for radicals. As a result, even at high conversions, no gel effect was observed.
4 citations
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TL;DR: In this paper, a kinetic study into the styrene hydrogenation over a palladium on alumina catalyst has been made and a kinetic rate expression has been derived and the inhibiting effect of sulfur components has been included.
130 citations
TL;DR: In this article, a packed-bed micro-reactor was used for the hydrogenation of o-nitroanisole to o-anisidine in a pharmaceutical and fine chemicals industry with the aim of investigating the reactor performance and kinetics of the reaction.
90 citations
TL;DR: In this paper, the effect of ejector configuration on the rate and energy effectiveness of gas suction and on the values of gas hold-up in ejector loop reactors was examined.
81 citations
TL;DR: In this paper, the authors extended basic information on mixing and circulation times for mixing systems equipped with helical ribbon impellers and provided guidelines on the influence of the helical impeller geometry on the mixing effectiveness.
Abstract: The purpose of this paper is to extend basic information on mixing and circulation times for mixing systems equipped with helical ribbon impellers. In a first part, from a survey of existing literature, we have reviewed the different effects of the geometrical parameters of the helical mixing systems (clearance-wall, pitch size ratio, blade width, number of blades) on the mixing process. From this qualitative analysis, useful guidelines are provided on the influence of the helical impeller geometry on the mixing effectiveness. In a second part, the homogenization effectiveness of an atypical helical ribbon impeller was investigated and compared with the performance of classical helical ribbons impellers.
72 citations
TL;DR: In this article, the upflow ejector with and without swirls was measured and the cocurrent ejector-distributor bubble column as well as gas and liquid phase backmixing in the column.
60 citations