Claramunt Carbonell, S. / Dittmeyer, R. / Franzreb, M. (2023)

Hochschulschrift KIT, KITopen-ID:

Abstract
The World Health Organization recommends reducing the daily sugar intake to a maximum of 10% of the daily energy intake. Polydextrose is a low-calorie polysaccharide that is added to a wide variety of foods as an alternative to sugar due to its properties as a bulking agent. The polycondensation reaction of glucose to form polydextrose is a reversible reaction that can be carried out at high temperatures and low residence times with a high yield in
microreactors. A collaboration between Cargill Inc. (Wayzata, US) and the Institute for Micro Process Engineering of the Karlsruhe Institute of Technology (Karlsruhe, DE) led to a new way of conducting a polycondensation process to form polydextrose, in which the reaction equilibrium is shifted to higher product yields by removing water in an expansion chamber between two microchannel reactors (EP 2528950). To avoid the intermediate step of water separation and thus further simplify the process, this dissertation investigated two different routes for process intensification, targeting one single reactor stage. (1) The use of internal inserts in a double-pipe reactor, known as fluid guiding elements (FGE) and (2) the use of a membrane microchannel reactor, in which steam is separated from the reacting liquid flow through the pores of a temperature-resistant hydrophobic membrane.

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