No abstract

No abstract

A central problem in bioengineering is the processing of the valuable substances produced. Approximately 5 % (in the case of wholesale products) up to 90 % (in the case of pharmaceuticals) of the production costs result from downstream processing. Adsorption in fluidized beds represents an interesting alternative operation for the selective separation of colloidal particles and macromolecules. In the last years this method was worked on intensively and shows a great potential since adsorption in fluidized beds compared with fixed bed processes has the advantage to be able to handle solutions which do not need to be free of particles [1]. Thus, the subsequent process can be carried out in fewer stages, which means a faster and more cost-effective production process.The intense turbulent motion and the resulting longitudinal backmixing of fluid and particles are the main difficulties of the adsorption process in fluidized beds. Operating with magnetizable adsorption particles the movement of particles can be restricted by means of a homogeneous magnetic field. A stabilized bed is obtained, which is more permeable than a packed-bed adsorption column but simultaneously characterized by less backmixing than conventional fluidized beds. The following investigations deal with such magnetically stabilized fluidized beds (MSFB).

No abstract

in vielen Arbeitsgebieten Mikropartikel eingesetzt. Partikel, die neben den notwendigen chemischen Eigenschaften zusatzlich magnetisierbar sind, eroffnen fur viele Bereiche neue Perspektiven in der Entwicklung von Prozessen. Insbesondere zahlen hierzu Trennoperationen wie Adsorption und Chromatographie sowie Stoffumwandlungen mit Katalysatoren. Eine hohe spezifische Oberflache ist bei vielen dieser Applikationen wichtig, die dazu notwendigen Partikel sind aber durch ihre geringe Gro13e nicht einfach zu handhaben. Das magnetisch stabilisierte fluidisierte Wirbelbett (magnetically stabilized fluidized bed -MSFB) ist ein fur diese Anwendungen interessantes Beispiel eines sol-1 Einleitung