Dr.-Ing. Lisa-Marie Terdenge

Crystallization is widely used as a separation or purification step in chemical industries and a high effort for optimization and process control is made to achieve the desired quality characteristics of the crystalline products. The quality of crystalline products is defined by the crystal form and size as well as by the crystal size distribution (CSD) and purity. To characterize the CSD responses, like median crystal size, width of CSD, or the coefficient of variation, are used in general. However, no information about the particle morphology or the amount of agglomerates is given by these responses respectively. The lack of information about the particle morphology in CSD can lead to misunderstand the crystallization process, especially if agglomeration takes place during solid-liquid separation or drying and an off-line CSD measurement technique is used. Through agglomeration the width of CSD might be broadened and mother liquor inclusions lead to less purity. To avoid a misconception of crystallization processes and due to an increasing purity demand in industry, the detection and localization of agglomeration plays an important role.

The aim of the study is to increase the understanding of product quality influencing processes, like agglomeration, to allow a synergistic process optimization of crystallization, solid-liquid separation, and drying to get the final product. Therefore, the wash liquid selection, cake washing and different drying methods are investigated systematically to identify main influence factors for the development of heuristics and a methodology for detection and localization of agglomerates is established.

Ziel der Studie ist es, das Verständnis für die die Produktqualität beeinflussenden Prozesse wie die Agglomeration zu verbessern, um eine synergetische Prozessoptimierung von Kristallisation, Fest-Flüssig-Trennung und Trocknung zur Gewinnung des Endprodukts zu ermöglichen. Daher werden die Auswahl der Waschflüssigkeit, das Waschen des Kuchens und verschiedene Trocknungsmethoden systematisch untersucht, um die Haupteinflussfaktoren für die Entwicklung von Heuristiken zu ermitteln, und es wird eine Methodik zur Erkennung und Lokalisierung von Agglomeraten entwickelt.

Dissertation

• L.-M. Terdenge
  Measurement and Control of Agglomeration for the Design of Crystalline Products
  TU Dortmund, 2016, Verlag Dr. Hut, München ISBN  978-3-8439-2891-5

Paper

• L.-M. Terdenge, J. A. Kossuch, G. Schembecker, K. Wohlgemuth
  Potential of gassing crystallization to control the agglomeration degree of crystalline products
  Powder Technology 320 (2017) 386-396, doi.org/10.1016/j.powtec.2017.07.044
   
• L.-M. Terdenge, K. Wohlgemuth
  Effect of drying method on agglomeration degree of crystalline products
  Chemical Engineering Science 167 (2017) 88-97, doi.org/10.1016/j.ces.2017.04.003
   
• L.-M. Terdenge, K. Wohlgemuth
  Impact of agglomeration on crystalline product quality within the crystallization process chain
  Crystal Research & Technology 51 (2016) 513-523, doi.org/10.1002/crat.201600125
   
• L.-M. Terdenge, S. Heisel, G. Schembecker, K. Wohlgemuth
  Agglomeration degree distribution as quality criterion to evaluate crystalline products
  Chemical Engineering Science 133 (2015) 157-169, doi.org/10.1016/j.ces.2015.03.002

Oral presentations

• L. Terdenge, G. Schembecker, K. Wohlgemuth,
  How agglomeration affects the crystal size distribution of a crystalline product during crystallization process chain
  Jahrestreffen des Fachausschusses Kristallisation (2015), Magdeburg
   
• L. Terdenge, S. Heisel, G. Schembecker, K. Wohlgemuth,
  Determination of agglomeration degree distribution of crystals using image analysis
  19th International Symposium on Industrial Crystallization (2014), Toulouse, France
   
• L. Terdenge, S. Heisel, G. Schembecker, K. Wohlgemuth,
  Characterization of crystalline products by determining the agglomeration degree distribution using image analysis
  Jahrestreffen des Fachausschusses Kristallisation (2014), Münster
   
• L. Terdenge, G. Schembecker, K. Wohlgemuth,
  Investigation of influences of washing and drying parameters on crystal size distribution
  Jahrestreffen des Fachausschusses Kristallisation und Mischvorgänge (2013), Magdeburg

Poster presentations

• L. Terdenge and K. Wohlgemuth,
  The influence of downstream processes on the crystal size distribution of organic solids
  19th International Symposium on Industrial Crystallization (2014), Toulouse, France
   
• L. Terdenge, G. Schembecker, K. Wohlgemuth
  Influences of washing and drying parameters on crystal size distribution
  BIWIC 2013 20th International Workshop on Industrial Crystallization, Odense, Denmark