Process intensification of continuous emulsion polymerization in smart scale tubular reactors
May 10-15, 2015
Smart scale processes can be developed with less time-consuming strategies. This reduces substantially the time-to-market for product innovations. They also offer a high potential of process intensification, which makes cost optimized made-to-measure solutions for specific product qualities and quantities possible. A significant cost reduction of specific investments can be expected by using smart scale technology which allows the development and production of high specialized products. There are generally only few efforts in process intensification of polymerization processes in tubular reactors, and even less in continuous emulsion copolymerization. This paper will report briefly the progress in continuous emulsion polymerization processes in different types of tubular reactors during the last 25 years. Emphasis is placed on various secondary flow phenomena, subsequently on increase in radial mixing as well as mass and heat transport enhancement. The focus of the presentation will be on an intensified emulsion copolymerization of styrene/n-butyl acrylate in a smart scale tubular reactor with pulsating flow. KENICS static mixing elements are built in every 12.5 cm in a helically coiled tubular reactor (helix diameter = 22 cm) made of PTFE with a total length of 10 m (OD = 12 mm; ID = 10 mm). The interaction of static mixing elements, secondary flow phenomena derived by the coiling of the tube and the pulsation of feed flow leads to non-laminar flow behavior and very narrow residence time distributions equivalent to a train of more than 400 CSTRs in series at mean residence times of 12 min. Reactor geometry has been optimized via CFD simulations with respect to heat and mass transfer, which will be demonstrated in short video sequences at the oral presentation. Total pressure drop along the reactor is in the order of 0.1 bar for a mass fraction of 40 % co-monomers in the emulsion recipe and below 2 bar for 50 % of solids. Due to the large specific heat exchange area of 400 m2/m3 quite a smooth temperature profile can be adjusted even at high space time yield. Resulting particle size distributions, average molecular weights and space time yields of styrene/n-butyl acrylate copolymerization will be discussed including reactor fouling behavior in long term runs.
Fabian Lueth, Kristina Rossow, Werner Pauer, and Hans Moritz, "Process intensification of continuous emulsion polymerization in smart scale tubular reactors" in "Polymer Reaction Engineering IX", E. Vivaldo-Lima, UNAM; J. Debling, BASF; F. Zaldo-Garcia, CP-COMEX; J. Tsavalas, Univ. of New Hampshire Eds, ECI Symposium Series, (2015). http://dc.engconfintl.org/polymer_rx_eng_IX/39