Bei der Herstellung und Verarbeitung von Polymerdispersionen ist Fouling, also die unerwünschte Belagbildung auf Oberflächen in Wärmeübertragern und Reaktoren, ein zentrales Problem für die ökonomische und ökologische Effizienz. In dieser Studie wird das Foulingverhalten von Polymerdispersionen auf beheizten und gekühlten Oberflächen untersucht. Dabei wird die Foulingneigung auf Wärmeübertragern in Abhängigkeit von betrieblichen (Wärmestromdichte, Fluidtemperatur, Feststoffkonzentration, Strömungsregime) und apparativen (Oberflächenmodifikation, Beschichtung) Parametern analysiert. Hierbei wurden elektropolierte Oberflächen und bestimmte Parameterkonfigurationen der untersuchten Beschichtungen als weniger foulinganfällig bzw. besser zu reinigen identifiziert.

Ionic liquids (ILs) are recyclable acid catalysts for transesterification reactions. In the present study, different acidic ILs were examined in this reaction, with special focus on their recyclability. Furthermore, the IL-catalyzed transesterification reaction was realized in continuous operation. A miniplant reactor with technically representative design and operating characteristics was used for this study. The applied rig has a volume of 5 L and an external thermosyphon reboiler. The miniplant reactor can be operated in batch and in continuous mode. ILs functionalized with a sulfonic acid group were found to be the most suitable IL catalysts for the transesterification reactions under investigation. Using these ILs, reaction rates as high as for H 2 SO 4 could be realized. Moreover, the IL catalyst was demonstrated to be active for at least 1000 h of operation time.

Eco-Balance Assessment of Ionic Liquids as Acid Catalysts in TransesterificationsIonic Liquids may act as homogeneous catalysts for transesterification processes. In contrast to conventional catalysts the ionic liquid may be separated after reaction and recycled. This study investigated the ecological effect of changing from sulfuric acid as catalyst to an ionic liquid. Three different eco-balance approaches have been applied. The EHS method proved to be the most suited tool to assess the ecological potential of process alternatives in the conceptual process design phase. Keywords

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