Georg Fieg

Bio: Georg Fieg is an academic researcher from Hamburg University of Technology. The author has contributed to research in topics: Fractionating column & Distillation. The author has an hindex of 19, co-authored 162 publications receiving 1295 citations. Previous affiliations of Georg Fieg include Henkel & University of Hamburg.

Concept, Design and Manufacture of a Prototype Hydrogen Storage Tank Based on Sodium Alanate

Abstract: In the framework of the EC project STORHY (Hydrogen Storage for Automotive Applications), the prototype of a solid storage tank for hydrogen based on sodium alanate was developed. A storage tank containing 8 kg sodium alanate was designed and manufactured with the objective of fast refueling. To obtain the optimum design of the storage tank a simulation tool was developed and validated by experiments with a laboratory-scale tubular reactor. Application of the simulation tool to different storage concepts and geometries yielded the final design. The chosen concept is modular, enabling simple scale-up. This is the basis for the future development of fuel cell vehicle storage tanks containing 5 kg of hydrogen.

A monogenetic algorithm for optimal design of large-scale heat exchanger networks

Abstract: The optimal design of large-scale heat exchanger networks is a quite difficult task not only due to its non-linear characteristics but also due to a great number of local optima in its solution space. An explicit analytical solution of stream temperatures for the superstructure heat exchanger networks was developed, which reduces number of decision variables significantly. Based on this solution, a mathematical model for synthesis of heat exchanger networks was formulated for searching the optimal configuration of a heat recovery system by a hybrid genetic algorithm. For large-scale heat exchanger networks, a monogenetic algorithm based on the optimization of sub-networks is proposed. In the first step of the optimization, the hybrid genetic algorithm is applied to the synthesis of the whole heat exchanger network for finding the functional groups (sub-networks) rather than the chromosomes (positions of the heat exchangers and splits of the streams) and genes (areas and heat capacity flow rates). Then the monogenetic algorithm for evolution of the functional groups is carried out to improve the HEN. This procedure was applied to examples taken from literature and better results were obtained.

Applying Model Predictive Control to Dividing Wall Columns

Abstract: The technology of dividing wall columns can offer enormous energy savings compared to common distillation columns and configurations. The technology of model predictive control is also advantageous since such a controller minimizes the future deviation of the predicted controlled variable from the reference point. The practical application of model predictive controllers for dividing wall columns is still limited due to limited experience with high interactions among the process variables. The scope of this work is the development and analysis of a method for the design of model predictive controllers for dividing wall columns. An experimental investigation verifies the practicability of the applied approach. The methods generated are transferable to other applications. Thus, the industrial acceptance of model predictive controllers for dividing wall columns is enhanced.

Evaluation of immobilized enzymes for industrial applications

Abstract: In contrast to the application of soluble enzymes in industry, immobilized enzymes often offer advantages in view of stability, volume specific biocatalyst loading, recyclability as well as simplified downstream processing. In this tutorial review the focus is set on the evaluation of immobilized enzymes in respect to mass transport limitations, immobilization yield and stability, to enable industrial applications.