Chemical Engineering & Technology

Cover image for Vol. 38 Issue 5

Early View (Online Version of Record published before inclusion in an issue)

Impact Factor: 2.175

ISI Journal Citation Reports © Ranking: 2013: 39/133 (Engineering Chemical)

Online ISSN: 1521-4125

Associated Title(s): Chemie Ingenieur Technik, ChemBioEng Reviews, Energy Technology

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  1. Research Articles

    1. Hydrogen Production by a Photosynthetic Bacterium: Some Analytical Solutions

      Muthuramalingam Rasi and Lakshmanan Rajendran

      Article first published online: 13 MAY 2015 | DOI: 10.1002/ceat.201400381

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      Hydrogen can be produced by the photosynthetic bacterium Rhodobacter capsulatus. Here, the mathematical model for the production in a batch photobioreactor is discussed. Approximate analytical expressions for the concentrations of biomass and substrate and the production of H2 were obtained in terms of the kinetic parameters. The sensitivity analysis of the model parameters is also presented.

    2. Effect of Seeding and pH Conditions on the Size and Shape of Au Nanoparticles in Reduction Crystallization

      Hiroko Akiba, Masumi Ichiji, Hideyuki Nagao and Izumi Hirasawa

      Article first published online: 11 MAY 2015 | DOI: 10.1002/ceat.201400671

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      A simple method is suggested to control the sizes and shapes of nano/submicron-sized Au particles by reduction without additive to inhibit agglomeration. The mechanism of particle growth was analyzed by TEM-monitoring the crystallization process. The mean particle diameters of the Au particles were controlled at 6–650 nm by seeding or using pH-controlled ascorbic acid solutions.

    3. Performance Comparison of Trisection Helical Baffle Heat Exchangers with Different Circumferential Overlap Sizes

      Cong Dong, Ya-Ping Chen and Jia-Feng Wu

      Article first published online: 11 MAY 2015 | DOI: 10.1002/ceat.201300499

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      The circumferential overlap trisection helical baffle heat exchanger is a modification based on a quadrant baffle and anti-shortcut structure to improve heat transfer performance. The mechanisms of heat transfer enhancement for four circumferential overlap structures were investigated. Pressure contours plotted with velocity vectors on special slices reveal secondary flow and bypass stream.

  2. Reviews

    1. Relevance of the Second Harmonic Generation to Characterize Crystalline Samples

      Florent Simon, Simon Clevers, Valérie Dupray and Gérard Coquerel

      Article first published online: 8 MAY 2015 | DOI: 10.1002/ceat.201400756

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      The application of second harmonic generation-based techniques to characterize crystalline samples is presented. Several examples are detailed for chemical purity, structural purity and polymorphism studies, with particular relevance to the pharmaceutical industry where crystalline active pharmaceutical ingredients are often made of a single enantiomer and are therefore non-centrosymmetric.

  3. Research Articles

    1. Polymorphism, Size and Shape Control of Calcium Carbonate Crystals in the Presence of a Polyelectrolyte

      Yuko Sonobe, Hiroto Watamura and Izumi Hirasawa

      Article first published online: 6 MAY 2015 | DOI: 10.1002/ceat.201400731

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      The effects of polyelectrolyte addition during reactive crystallization on the characteristics of calcium carbonate crystals were investigated. The supersaturation state, the material feed order, and the polyelectrolyte type and concentration were found to have great influence on the polymorphism, particle size and shape, and the crystal number of calcium carbonate.

    2. Non-Equimolar Discrete Phases Formed in the System of Malic Acid Enantiomers

      Anton I. Isakov, Elena N. Kotelnikova and Heike Lorenz

      Article first published online: 6 MAY 2015 | DOI: 10.1002/ceat.201400753

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      Non-equimolar discrete compounds formed by malic acid S- and R-enantiomers in ratios 3:1 and 1:3 are investigated by means of X-ray powder diffraction. The corresponding S3R and SR3 compounds are found to be stable or metastable phases in dependence on synthesis conditions. The phases are characterized and discussed with regard to their identity and crystallochemical nature.

    3. Solubility Characteristics and Crystallization Behavior of Oxalic Acid in the Presence of Sulfuric Acid

      Naoko Imura and Izumi Hirasawa

      Article first published online: 6 MAY 2015 | DOI: 10.1002/ceat.201400710

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      For effective recovery of oxalic acid from acidic wastewater by crystallization, oxalic acid solubility was investigated and found to be influenced by sulfuric acid concentration. Based on the solubility data, cooling crystallization of oxalic acid in sulfuric acid aqueous solution was conducted. Columnar-type crystals of oxalic acid precipitated in sub-mm size.

    4. Production of High-Tensile-Strength Paracetamol Tablets Using the Freeze-Casting Process

      Phuong Thi Nhat Nguyen and Joachim Ulrich

      Article first published online: 6 MAY 2015 | DOI: 10.1002/ceat.201400700

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      Low tensile strength limits the applicability of freeze-casted tablets in industrial production. Modified starch may serve as a binder for solid particles of the active pharmaceutical ingredient enhancing the mechanical strength of produced tablets. Freeze-casted paracetamol tablets are able to compete with commercial compressed tablets in terms of disintegration time and tensile strength.

  4. Communications

    1. Saccharose Inversion and Metastable Zone

      Stefanie Selbmann, Julia Herfurth, Sandra Petersen and Joachim Ulrich

      Article first published online: 6 MAY 2015 | DOI: 10.1002/ceat.201400684

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      To control the crystallization of sugar such as saccharose in foods, knowledge of the position of the process in the phase diagram, and of the metastable zone in particular, is needed. The exposure time to citric acid and the amount of acid are shown to lead to an increased saccharose inversion. The metastable zone shifts to lower temperatures, but does not change in its width during inversion.

  5. Research Articles

    1. Growth and Dissolution Kinetics of A and B Polymorphs of L-Histidine

      Lek Wantha and Adrian E. Flood

      Article first published online: 29 APR 2015 | DOI: 10.1002/ceat.201400732

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      The essential amino acid L-histidine has shown to exhibit polymorphism and it exists in the solid phase as a stable polymorph A and a metastable polymorph B. The kinetics of growth and dissolution of the polymorphs which contribute to the rate of transformation between the polymorphs are investigated. The results indicate that the transformation is a growth-controlled process.

    2. Protein Composite Materials by Crystallization: Product and Process Design

      Patrick Frohberg and Joachim Ulrich

      Article first published online: 29 APR 2015 | DOI: 10.1002/ceat.201400720

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      Product and process design approaches to control and optimize the properties of novel protein composite materials produced by reactive extrusion are presented. It was found that the control of crystalline structures within the protein material in conjunction with enzymatic cross-linking leads to advanced and application-oriented properties.

    3. Dynamic Search Algorithm of Solubility in a Salt-Water System Based on the Solubility Product

      Jianxin Chen, Zhifei Chen, Shuchun Pang, Qing Wu and Yunlong Zhong

      Article first published online: 29 APR 2015 | DOI: 10.1002/ceat.201400699

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      A dynamic search algorithm is introduced to predict the solubility based on equilibrium equations and solubility product in salt-water systems. A comparison between the calculated results of the algorithm and the experimental solubility data proves the high accuracy and efficiency of this algorithm. It exhibits great potential for low-salt system dissolution equilibrium calculations.

    4. Analytic Setup for Multicomponent High-Pressure Phase Equilibria via Dual Online Gas Chromatography

      Frederick C. v. N. Fourie, Cara E. Schwarz and Johannes H. Knoetze

      Article first published online: 29 APR 2015 | DOI: 10.1002/ceat.201400643

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      Supercritical fluid solvents may provide improved selectivity or solvating ability and enable the execution of difficult extractions. Ternary phase behavior data assist supercritical fluid extraction process design. A high-pressure static analytic phase equilibria setup was developed. The setup produces accurate supercritical phase composition data and can accommodate diverse mixture constituents.

    5. Correlation between Thermal Properties and Chemical Composition of Palm Oil Top Olein Fractions

      Xin Huang, Jingkang Wang, Jinbo Ouyang, Hongxun Hao, Yongli Wang, Yuan Gao, Qiuxiang Yin and Ying Bao

      Article first published online: 29 APR 2015 | DOI: 10.1002/ceat.201400597

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      In the palm oil industry, the iodine value is normally determined by a titration method that uses toxic solvents. An innovative method is proposed to quickly determine the iodine value of oil samples. This approach can provide statistically similar results to those given by traditional official procedures, with the advantages of being extremely rapid and environmentally friendly.

    6. Electrostatic Charge Measurements of Droplets of Various Liquids Falling over a Large Distance

      Sylvia Lüttgens, Günter Lüttgens, Anders Thulin, Thierry Paillat and Gérard Touchard

      Article first published online: 27 APR 2015 | DOI: 10.1002/ceat.201400747

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      Due to the generated electrostatic charges, the splash filling process poses some dangers. Here, the charge evolution of a single droplet is examined along its fall. From experiments with droplets of many different liquids, falling over 5 m, it is confirmed that the assumption that droplets are charged by friction with air, as still discussed in the explosion hazard community, does not hold true.

    7. Growth Rate Dispersion at the Single-Crystal Level

      Emilie Bobo, Samuel Petit and Gérard Coquerel

      Article first published online: 27 APR 2015 | DOI: 10.1002/ceat.201400766

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      Crystal growth rate dispersion of ammonium perchlorate crystallized by evaporation of an aqueous solution at room temperature is evidenced by considering some Friedel pairs of faces. The relationship between the formation of inclusions and a high growth rate of crystal faces is highlighted. Considering the locations of the inclusions, the results demonstrate a high heterogeneity of crystal growth rates, from which the history of crystal growth can be retraced.

    8. Isomer Treatment by Additive Application in the Liquid Stage as Known from Industrial Crystallization

      Franziska Kreißig, Christian Schäfer, Elodie Verdurand and Joachim Ulrich

      Article first published online: 24 APR 2015 | DOI: 10.1002/ceat.201400673

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      The principle of additive usage in crystallization was exploited to enhance the stability of dissolved all-trans astaxanthin (AXT), which is in high demand for feed supplementation. A variety of substances/factors triggers the isomerization and/or degradation of AXT. Application of an additive in solution provides the AXT-employing industries with a tool to improve their production economics.

    9. Axial Dispersion and Heat Transfer in a Milli/Microstructured Coiled Flow Inverter for Narrow Residence Time Distribution at Laminar Flow

      Safa Kutup Kurt, Marius Gerrit Gelhausen and Norbert Kockmann

      Article first published online: 24 APR 2015 | DOI: 10.1002/ceat.201400515

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      A microstructured coiled flow inverter offers a behavior close to a plug-flow reactor in terms of residence time distribution (RTD) at laminar flow regimes. Experimental characterization of the RTD for such tubular reactor or static mixer allowed for developing a novel microreactor concept, the so-called short helical alternating reactor capillary which provides efficient heat transfer with narrow RTD.

    10. Generation of Crystalline Microcontainers of Salicylic Acid

      Julia Seidel and Joachim Ulrich

      Article first published online: 8 APR 2015 | DOI: 10.1002/ceat.201400716

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      The formation of liquid inclusions in crystals could offer the option to generate microcontainer systems by means of controlled crystallization. Crystals containing large inclusions are necessary in order to fill them with another substance. Optimization of the inclusion sizes of salicylic acid crystals by means of antisolvent crystallization is investigated.

    11. Crystallization of Terutroban Sodium Salt Hydrate from the Deliquescent State

      Nicolas Couvrat, Yohann Cartigny, Julie Linol, Lucile Vaysse-Ludot, Pascal Langlois and Gérard Coquerel

      Article first published online: 8 APR 2015 | DOI: 10.1002/ceat.201400692

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      Besides studies on the crystallization processes of active pharmaceutical ingredients, stability studies at varying temperature and relative humidity are required. With Terutroban sodium salt as an example, the appearance of a hydrate (initially undesired) during storage is rationalized and its improvements in terms of stability are demonstrated.

    12. Feasibility of the Constrained Free Energy Method for Modeling NO Formation in Combustion

      Petteri Kangas, Pertti Koukkari, Anders Brink and Mikko Hupa

      Article first published online: 10 MAR 2015 | DOI: 10.1002/ceat.201400633

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      An alternative thermochemical approach for modeling NOX emissions is proposed. NO emissions in combustion are modeled with the constrained free energy (CFE) method which allows calculations of local restricted thermodynamic equilibrium by implementing reaction kinetic rates as constraints. Thermal and fuel NO emissions were successfully estimated with the CFE approach.

    13. Nafion-H-Catalyzed High-Temperature/High-Pressure Synthesis of a Triarylmethane in Continuous-Flow Mode

      Stephan Hayden, Toma Glasnov and C. Oliver Kappe

      Article first published online: 10 MAR 2015 | DOI: 10.1002/ceat.201400581

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      Friedel-Craft reactions are important types of C–C bond-forming reactions. Here, the synthesis of triarylmethanes from aromatic aldehydes and benzene using the super acid Nafion-H as the catalyst is evaluated under both batch and continuous-flow conditions. Using high-temperature/high-pressure conditions, excellent reaction yields are obtained within a few minutes reaction time.

    14. Ultrasonic Hot Embossed Polymer Microreactors for Optical Measurement of Chemical Reactions

      Alexander Tollkötter, Johannes Sackmann, Tobias Baldhoff, Werner Karl Schomburg and Norbert Kockmann

      Article first published online: 4 DEC 2014 | DOI: 10.1002/ceat.201400522

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      Ultrasonic hot embossing of chemically resistant polymers as a simple and cost-effective fabrication method of microstructures and an optical analysis tool for tracing the progress of chemical reactions are introduced and evaluated. The simplicity of the fabrication method itself and good similarities of produced polymer micromixers with conventional ones made of other materials are pointed out.

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