Online‐Analytik zur Prozessführung

Online Analyzers for the Process Control Save, efficient, and economical operation of chemical processes more and more relies on online analyzers. The use of component properties (e.g., concentrations) for control becomes even more common. The combination of online analyzers and advanced control technologies holds an enormous economic potential, though a rocky path is leading there. As a result the number of existing applications is only growing slowly, but steadily. The main part of this contribution shows the potential of the combination of advanced control technologies and online analyzers using some illustrative examples like a batch distillation column, a continuous isomer distillation unit and the automation of a complete fine chemicals unit. Based on the experiences and problems encountered in the past projects, some guidelines and requests are formulated to optimize the definition and implementation of these projects in an interdisciplinary team and the integration of the online analyzers in a distributed control system.     

Kontinuierliche Fermentation mit tierischen Zellen. Teil 1. Aspekte der kontinuierlichen Prozessführung

The continuous fermentation offers in comparison to the discontinuous process a number of advantages. These include the long‐term operation with a largely constant substrate, cell mass and product concentrations and high plant productivity. In contrast there is a more sophisticated technique and the need to secure long‐term sterility. First of all the basics of the continuous fermentation for starting operation and steady‐state operation are treated. A consistently applied dimensionless formulation of the relevant relationships enables a compact and very clear presentation of the basic laws for the cell mass and product formation. The special features of the continuous fermentation with and without cell retention and fundamental aspects of the continuous fermentation with cell retention are discussed.     

Kontinuierliche Fermentation mit tierischen Zellen. Teil 2. Techniken und Methoden der Zellrückhaltung

The retention of the animal cells in the fermenter is essential for an efficient continuous fermentation. In this review, the techniques based on sedimentation, centrifugation and filtration are discussed, which have been proven to be important for the fermentation of animal cells. Their suitability is analyzed and an assessment of various techniques is given. From the comparison of systems recommendations are derived for the most appropriate retention techniques.     

Einsatz von Prozessberechnungsprogrammen zur Optimierung fortschrittlicher Dampfkraftprozesse

Computational tools are used for the design analysis of power plant cycles. Combination of these with optimisation codes yields efficient optimisation of both cycle topology and cycle parameters. The efficiency of these tools is demonstrated for an advanced steam cycle with double reheating and multiple feed water preheating. For feed water preheating, it is shown that the optimum total amount of preheating, represented by the maximum pressure level of steam extraction, is largely decoupled from the distribution of the individual pressure levels of the succeeding stages of steam extraction.     

Chemical Synthesis in Micro Reactors

This article reviews the current applications of micro reactors in the field of combinatorial chemistry and discusses how the methodology could be applied to drug discovery. Liquid phase reactions have been used to illustrate the advantages of performing chemical reactions in micro reactors which illustrate that reactions can be performed very rapidly in high conversion to enable the preparation of combinatorial libraries of structurally related compounds.