Esterification in an autonomously controlled reactor: exploiting the chemo-mechanical properties of a smart organogel

Iron(III)-reinforced poly(N-isopropylacrylamide-co-acrylic acid) organogel beads inside a casing give an intrinsic chemo-mechanical valve. The valve was incorporated in a setup with a stirred reactor for the heterogeneously acid-catalyzed esterification of acetic acid and ethanol. A noninvasive gravimetric control loop was used to validate the autonomous modulation of the hydrodynamic residence time in response to the composition of the reaction mixture. Operating at a 1:1 molar feed ratio, the valve restricted the initial outflow to less than 7 mL·min–1 and autonomously ramped up to a steady state flow of 135 mL·min–1 as the esterification approached thermodynamic equilibrium. The valve opening rate was about half of the reaction rate. The ionically reinforced organogel had enough resilience inside the casing for multiple uses. Soft actuators were thus successfully applied for reaching a self-regulating reactor loop driven by intrinsic chemical feedback of a smart material.

Content

DDC Class

660: Chemistry; Chemical Engineering

660.2: Chemical Engineering

540: Chemistry

Funding References

Funding(s)

SFB 1615 - SMARTe Reaktoren für die Verfahrenstechnik der Zukunft

SFB 1615 - Teilprojekt A01: Stimuli-responsive Polymere für selbstregulierende Reaktoren: Von grundlegenden Phänomenen zum Reaktordesign

SFB 1615 - Teilprojekt A04: Selbstregulierende optimierte Oberflächen für autonom betriebene Bioprozesse