The potential of forced periodic operation for improving reactor performance in terms of methanol production rate and methanol yield is explored in a theoretical study. Optimal periodic operation conditions are found by combining the nonlinear frequency response and rigorous optimization.

The homogenously Rh-catalyzed hydroaminomethylation of 1-decene was investigated in a thermomorphic solvent system (methanol/n-dodecane) with the ligand sulfoxantphos. The influence of temperature, pressure and catalyst concentration was studied experimentally. Simulations based on a simplified kinetic model and experimental data were in good agreement.

Im Beitrag wird eine hierarchische Betrachtung der membranunterstützten Reaktionsführung auf Katalysator-, Reaktor- und Prozessebene inkl. Rückführungsstrategien am Beispiel von vier heterogen katalysierte Selektivoxidationen analysiert. Durch Einstellung optimaler Konzentrationsprofile können Selektivität und Ausbeute signifikant gesteigert werden.

Hot spot formation and reactor performance is studied for fixed-bed and membrane reactors of various scales, applied to the oxidative dehydrogenation of propane to propene. As a new degree of freedom, the influence of the membrane flow temperature is investigated for large-scale applications.

Die Fakultät für Verfahrens- und Systemtechnik der Otto-von-Guericke-Universität Magdeburg umfasst die vier Institute Verfahrenstechnik, Chemie, Strömungstechnik und Thermodynamik sowie Apparate- und Umwelttechnik. Anhand ausgewählter Beispiele präsentieren die Lehrstühle des Instituts für Verfahrenstechnik ihre Forschungsschwerpunkte.

Unter Verwendung der Gleichgewichtstheorie der Adsorption werden die Positionen und Formen von Druchbruchskurven sowie die Konzentrationen von in Festbettadsorbern auftretenden Zwischenplateaus effizient abgeschätzt.

The paper deals with the evaluation and parametrization of two postulated reaction networks for the direct conversion of ethene to propene. A Ni/AlMCM-41 was used for this heterogeneous catalyzed process. Based on experimental results, parameters were estimated, which predict a corresponding product spectrum.

The homogenous Rh/Xantphos-catalyzed reductive amination of 1-undecanal was investigated in two different thermomorphic solvent systems. On this basis a kinetic model was developed and parametrized for both solvent systems. Simulations and Experiments were in good agreement, making the model a promising way to describe the RA.

The knowledge of phase diagrams provides key information for separation process design. The ternary solubility phase diagram of the chiral amino acid methionine in water and its application for crystallization-based enantioseparation are discussed. Two strategies exploiting the shift of the eutectic composition in the chiral system experimentally verified the feasibility of pure enantiomer production.

Different integrated reactor concepts for the dehydrogenation of propane are presented and compared. These concepts incorporate membranes for distributed reactant dosing of O₂/CO₂ as well as the integration of thermal and oxidative dehydrogenation in one apparatus to enhance selectivity and yield of the overall process.

Separation of enantiomers of fluorinated anesthetic gases was investigated in gas-chromatographic columns employing a selector based on γ-cyclodextrin. The batch process with repetitive injections was theoretically analyzed to define the conditions that provide maximal productivity and high purity. The designed process can produce enough single enantiomers needed for further medical tests.

The success of multistage distillation processes has been a key motivator for the development of many other principles of countercurrent separation processes. Applying a generalized equilibrium stage model selected alternative applications based on exploiting other phase situations and operating principles are presented and compared.

This work provides two approaches regarding the enhancement of the enzymatic production of prebiotic galacto-oligosaccharides from lactose, which is a by-product of dairy industry. In the first concept, the shift of reaction equilibrium is examined, and in the second one, process intensification by substrate substitution and influence of ions/salts is investigated.

The palladium-catalyzed methoxycarbonylation of unsaturated long chain substrates is an atom-efficient way to produce esters using carbon monoxide and methanol. For the first time, kinetic models for the complex Pd/DTBPMB-catalyzed isomerizing methoxycarbonylation of 1-decene were derived and parametrized based on experimental investigations.

The simulated moving bed process is considered as one of the most productive improvements in preparative chromatography, by periodic operation of a multicolumn to simulate a countercurrent flow between the phases. Advances in this process are described with a focus on introducing novel concepts and providing examples and advantages of recently proposed operating strategies in specific areas.

Phase-contrast magnetic resonance imaging (PC-MRI) applied on rotating systems is highly challenging since a non-ferromagnetic system has to be developed before. The complex 3D unsteady flow in a stirred tank representing a rotating batch crystallizer is considered. The hydrodynamics in space and time could be noninvasively quantified using flow-sensitive PC-MRI.

Some aspects like process modeling, monitoring, and control problems in continuous mixed-solution mixed-product removal crystallization are still challenging. An innovative approach for online measurement of the crystal size distribution is proposed. Discrepancy-based control is designed and applied to a nonlinear model taking system nonlinearities into account.

The direct transformation of ethene to propene is better explained by proposing a conjunct polymerization than the classical reaction network proposed by Iwamoto. This process produces a complex mixture of hydrocarbons. The results show that metathesis activities of the Ni/AlMCM-41 catalysts could not be observed in the direct conversion of ethene to propene.

Chiral lactide is a model substance to study the solution thermodynamics of a chiral racemic compound-forming system. The solution enthalpy is considered to consist of three thermodynamic steps: melting of the crystal, transition of the subcooled melt to an infinite dilution, and the subsequent transition to a saturated solution. This model is an alternative way to obtain the solution enthalpy from measured solubilities.

Calcium propionate is frequently used as food additive. Basic studies on its solubility and solid-state forms in water and ethanol-water mixtures as well as thermal behavior were performed. The results obtained provide a better understanding of thermal and solubility behavior of calcium propionate and serve as base to improve its crystallization process in the future.