Chemical Engineering and Processing (CHEM ENG PROCESS)

Publications in this journal

• Source

  Available from: uva.nl

  Article: Rise velocity of single circular-cap bubbles in two-dimensional beds of powders and liquids

  R Krishna, J M Van Baten, M I Urseanu, J Ellenberger
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  ABSTRACT: An expression for the rise velocity of single circular-cap gas bubbles in two-dimensional (2D) beds consisting of powders or liquids is developed with the aid of experimental data and computational fluid dynamics. Experiments were performed in a two-dimensional rectangular column of width D T =0.3 m by injecting air bubbles in fluidised beds of silica (mean particle size, d p =38 mm) and polystyrene (mean particle size, d p = 570 mm) and in water. The rise velocity of single gas bubbles in the size range d b =0.015–0.12 m were found to decrease significantly with increasing ratio of bubble diameter to bed width, d b /D T . Computational fluid dynamics simulations of single gas bubbles rising in water, carried out using the volume-of-fluid (VOF) method, showed good agreement with experiment and were used to develop a common expression for the rise velocity of single gas bubbles in gas–solid fluidised beds and bubble columns. The 2D circular-cap bubble rise velocity is found to 10 – 30% lower than that of a 3D spherical-cap bubble having the same equivalent diameter.
  Chemical Engineering and Processing ; 39:433-440.
• Article: Fluid flow and pumping efficiency in an ejector-venturi scrubber

  X Gamisans, M Sarra, F J Lafuente
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  ABSTRACT: The air self-entrainment by a liquid jet is investigated in an industrial scale ejector-venturi scrubber. A mathematical model based on steady-state macroscopic mechanical energy balances is formulated and arranged in order to obtain simple equations useful for design purposes. Experiments are carried out in order to evaluate empirical values for the frictional coefficients. Gas entrainment and void pressure measurements are presented by using different geometric combinations for the venturi tube throat and the pressure-swirl atomizer used for inducing the gas flow rate. (C) 2003 Elsevier B.V. All rights reserved.
  Chemical Engineering and Processing 05/2013; 43:127-136.
• Article: Application of ATR-MIR Spectroscopy in the Pilot Plant–Scope and Limitations using the Example of Paracetamol Crystallizations

  Lydia Helmdach, Martin P. Feth, Clemens Minnich, Joachim Ulrich
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  ABSTRACT: The use of an access unit connected to a recirculation loop has shown to be a good solution for the integration of various Process Analytical Technology (PAT) techniques in reactors of pilot plant or industrial scale without time and cost intensive modifications of the existing setup. The drawback of such a setup in crystallization processes can be the influence on the particle size (distribution) and morphology of the solid product induced by the recirculation. The access unit enables to monitor the concentration (supersaturation) of the model compound Paracetamol by the installation of an Attenuated Total Reflectance Fourier Transform-Mid-Infrared (ATR-FT-MIR) probe and therefore allows a rapid optimization of chemical and crystallization processes. The transferability of calibration models which were established at lab scale, was tested and evaluated in pilot plant experiments. It could be shown that a direct transfer of the Peak Integration model is possible under specific conditions. Effects such as water vapor in the spectrometer, movements of the fiber optic cable or minor encrustations of the sensor, however, can only be compensated by the application of Indirect Hard Modeling (IHM). The method is capable of handling even non-constant external influences on the spectra as they are present in the pilot plant and therefore facilitate an inherent calibration transfer.
  Chemical Engineering and Processing 04/2013;
• Article: A review on combustion synthesis intensification by means of microwave energy

  Roberto Rosa, Paolo Veronesi, Cristina Leonelli
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  ABSTRACT: Combustion synthesis (CS) is a materials manufacturing technique, which gained increased attention by both academia and industries, due to its intrinsic energy saving characteristics and high purity of the products. Energy requirements for CS are limited to the ignition step, since the desired products are obtained by using the heat generated by exothermic reactions occurring between the reactants. CS has been here addressed from a process intensification perspective, since CS characteristics perfectly fit into several process intensification definitions, aims and approaches. Particular attention has been dedicated to the use of microwaves as energy source for CS, and the benefits deriving from the combination of these two techniques have been reviewed. The doubtless better energy transfer efficiency of microwaves, with respect to conventional heating techniques, arising from the direct interaction of the electromagnetic energy with the reactants, contributes to further intensify both solid state and solution CS processes. Moreover, microwaves peculiarities, such as their selective and volumetric nature, together with their energy transfer nature, open new attractive opportunities for CS in different fields of materials science, like joining and advanced protective coatings. Innovative strategies of microwaves-ignited and/or sus- tained CS for the process intensification of advanced materials manufacturing are proposed as well.
  Chemical Engineering and Processing 02/2013;
• Article: Optimization of electrocoagulation process for removal of an azo dye using response surface methodology and investigation on the occurrence of destructive side reactions

  A.R. Amani-Ghadim, S. Aber, A. Olad, H. Ashassi-Sorkhabi
  Chemical Engineering and Processing 02/2013;
• Article: Control of temperature wave trains in periodically forced networks of catalytic reactors for methanol synthesis

  Altimari, Mancusi
  Chemical Engineering and Processing 01/2013; 63:25.
• Article: Successive Processes for Purification and Extraction of Phosphoric Acid Produced by Wet Process

  N S awwad, Y A El-Nadi and M M Hamed
  Chemical Engineering and Processing 12/2012;
• Article: Effect of CO2 pre-treatment on scCO2 extraction of natural material

  F. Meyer, P. Jaeger, R.Eggers, M. Stamenic, S. Milovanovic, I. Zizovic
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  ABSTRACT: Pre-treatment of natural materials prior to their extraction strongly influences the efficiency of the process. Therefore, proper selection of pre-treatment method enables intensification of extraction process. Within this study “rapid gas decompression” (RGD) was investigated as a pretreatment method using carbon dioxide as working fluid. Oilseeds (rapeseed and sunflower seed), St. Johns Wort and Hop were studied as valuable raw materials for industrial application of supercritical fluid extraction. The sorption behaviour of carbon dioxide within the natural materials was examined gravimetrically under high pressure conditions between 5 and 26 MPa and at temperatures between 40 and 60 ◦C. It was observed that considerable amounts of carbon dioxide sorb within natural materials and a combination of dissolution within the solute phase and adsorption on the plant matrix occurs. RGD was used as a pre-treatment method prior to the extraction or as an intermediate treatment during the extraction process. The results showed that effect of RGD on extraction was the most pronounced for St. Johns Wort but also the extraction kinetics of the other materials were affected. Probable mechanisms occurring during RGD are discussed.
  Chemical Engineering and Processing 02/2012; 56:37-45.
• Article: Bio-hybrid organs and tissues for patient therapy: A future vision for 2030

  Loredana De Bartolo, Andreas Leindlein, Dieter Hofmann, Augustinus Bader, Aubrey de Grey, Efrem Curcio, Enrico Drioli
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  ABSTRACT: The regeneration of tissues and organs has been a matter of dream and Greek mythology since ancient times as the liver regeneration in Prometheus punished by Zeus. It is now emerging a new way of treating injuries and diseases, which is based on regenerative medicine. Clinical and social needs related to the aging and diseases led to innovative medical therapies that will enable the repairing and regeneration of damaged tissues and organs. This position paper gives a future vision for 2030 of the biohybrid organs and tissues that will be used for patient therapy and in the overcoming the age-related pathologies. The research strategies for the next 20 years will focus on the implantation of bioartificial tissues and the induction of the regeneration. Biomaterials and bioreactor technologies will play pivotal roles in the regeneration and in the production of individualized biological implants. Future challenges will include the development of multifunctional biohybrid organs and tissues. These concepts are based on a multidisciplinary approach bringing together various scientific fields, which will contribute to the new and fascinating medical therapies.
  Chemical Engineering and Processing 01/2012; 51:79-87.
• Article: Transposition from a batch to a continuous process for microencapsulation by interfacial polycondensation

  Félicie Therona, Zoé Anxionnaz-Minviellec, Nathalie Le Sauzea, Michel Cabassuda
  Chemical Engineering and Processing 01/2012; 54:42.
• Article: Printability of functional inks on multilayer curtain coated paper

  Roger Bollström, Daniel Tobjörk, Peter Dolietis, Pekka Salminen, Janet Preston, Ronald Österbacka, Martti Toivakka
  Chemical Engineering and Processing 01/2012; Accepted for publication.
• Article: Numerical Investigation of Laminar Mass Transport Enhancement in Heterogeneous Gaseous Microreactors

  M. Shaker, H. Ghaedamini, A.P. Sasmito, J.C. Kurnia, S.V. Jangam, A.S. Mujumdar
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  ABSTRACT: Laminar mass transport enhancement of gaseous mixing and catalytic reaction in a semi T-shaped microreactor was examined via numerical simulations. The mathematical model considers a multi-component species mixture with multi-step heterogeneous reactions and comprises of conservation equations of mass, momentum, species and energy. The mass transport performance is evaluated by modeling the catalytic reaction of a mixture of methane and air. Several innovative channel designs are proposed to improve mixing and reaction kinetics, e.g. innovative circular and rectangular configuration, flow splitting, redirection, recirculation and impingement. The results suggest that the rectangular design yields better conversion rate than the rate obtained with its circular counterpart. Flow splitting and impingement are found to be beneficial to improve mixing and reaction rate; albeit this imposes a greater pressure drop penalty. Effect of pre-mixing is also investigated with regard to the mass transport performance. Finally, advantages and limitations of each design are discussed in the light of the numerical results.
  Chemical Engineering and Processing 01/2012;