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Publikation Liquid extraction with immobilized liquids for product recovery from fermentation broths(Elsevier, 2022) Pérez, Alan; Gössi, Angelo; Riedl, Wolfgang; Schuur, Boelo; Fontalvo, Javier; Thatoi, Hrudayanath; Mohapatra, Sonali; Das, Swagat KumarNowadays, many fermentation chemicals are produced at an industrial scale. Numerous technological improvements have been developed and implemented to achieve high quality and quantity of fermentation products. However, several drawbacks in fermentation processes still limit their application at an industrial level. In situ product removal (ISPR) is a potential alternative to overcome the conventional drawbacks of the fermentative processes, increasing the fermentation's productivity and reducing the separation steps for recovery and purification. Currently, liquid extraction has emerged as a promising separation technology for ISPR, with immobilized liquids such as membrane-assisted extraction and microchannel liquid membrane, due to the high mass transfer rates, scalability, easy integration, and efficiency. This chapter will discuss these technologies regarding their integration into fermentative processes.04A - Beitrag SammelbandPublikation Electrochemical membrane-assisted pH-swing extraction and back-extraction of lactic acid(Elsevier, 2022) Gausmann, Marcel; Bertram, Franziska; Schuur, Boelo; Jupke, Andreas; Gössi, Angelo; Riedl, WolfgangReactive extraction of carboxylic acids such as lactic acid with tertiary amines is a state-of-the-art process but suffers strongly from reduced extraction efficiency in buffered environments like fermentation broths. In order to increase the efficiency of in-situ product removal, we here propose the combination of a membrane-assisted reactive extraction with an electrochemical pH shift. Prior to extraction in the membrane module, the fermentation broth containing the lactic acid at neutral pH is treated by anodic electrolysis to reduce the pH and thereby improve the extraction yield. Additionally, the cathodic reaction is used to increase the pH of the aqueous stream used for back-extraction of the loaded organic phase. Model solutions were used to develop a mathematical model, capable of calculating the required membrane area for in-situ extractions, considering the effect of the aqueous pH on the extraction performance. Additionally, using electrochemical pH shift, we were able to concentrate lactic acid from 1 wt% in the dilute broth to 7 wt% in the back extract.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Membrane‐Assisted Liquid‐Liquid Extraction – Where Do We Stand Today?(Wiley, 29.08.2019) Riedl, WolfgangDank Weiterentwicklungen in den Materialwissenschaften und der Fertigungstechnik stehen heute Membranen für stabile Flüssig/Flüssig‐Extraktionsprozesse zur Verfügung. Mit rigorosen Berechnungsmodellen lassen sich sowohl die für eine Trennaufgabe erforderlichen Membranflächen berechnen als auch Optimierungen der Modulform durchführen. In Schnelltests können die prinzipielle Eignung sowie kinetische Parameter ermittelt werden. Damit sind die Voraussetzungen geschaffen, die spezifischen Vorteile dieser Trenntechnik im technischen Einsatz nutzen zu können.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation In-situ recovery of carboxylic acids from fermentation broths through membrane supported reactive extraction using membrane modules with improved stability(Elsevier, 15.06.2020) Gössi, Angelo; Burgener, Florian; Kohler, David; Urso, Alessandro; Kolvenbach, Boris; Riedl, WolfgangMembrane supported reactive extraction (MSE) coupled to back-extraction (MSBE) using a new type of Teflon (PTFE) capillary membrane contactor was studied for the in-situ removal of carboxylic acids from aqueous streams, e.g. fermentation broths. The use of microporous membranes as extraction interface helps avoiding emulsification problems, allows the use of extreme phase ratios, and protects microorganisms, as they are less affected by solvent toxicity during in-situ extractions. The use of PTFE capillary membranes is suitable for long-term use due its high chemical and thermal stability. A simple toxicity screening identified n-decanol with tri n-octyl amine (TOA) as a suitable solvent. MSE experiments were performed using membrane contactors (0.005 m2 to 0.15 m2), working with solvent to feed phase ratios down to 1:40 (mass based). The in-situ removal of lactic acid out of fermentation broths using lactobacillus plantarum led to a glucose conversion rate of 80 mol%. Additionally, a concentration factor up to 7.8 could be shown during back-extraction.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation PAT at the Universities of Applied Sciences(Schweizerische Chemische Gesellschaft, 08/2015) Dabros, Michal; Vorlet, Olivier; Marti, Roger; Riedl, Wolfgang; Grundler, Gerhard; Vaccari, Aldo; Zinn, Manfred; Ecker, Achim; Hinderling, ChristianAn overview of activities in the field of Process Analytical Technologies (PAT) at the Universities of Applied Sciences in Switzerland is presented01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Maximales Aroma Geschmackserhaltende Entalkoholisierung von Bier mittels Membranverfahren(2015) Riedl, WolfgangAlkoholfreies Bier ist stets eine Frage des Geschmacks: „Echten“ Biertrinkern immer noch suspekt, ermöglicht es Brauereien, neue Märkte zu erschließen und wettbewerbsfähig zu bleiben. Dies ändert jedoch nichts an dem Sachverhalt, dass mit jedem der konkurrierenden Entalkoholisierungsverfahren der Geschmack des ursprünglichen Bieres mehr oder weniger verändert wird. Im Folgenden soll gezeigt werden, wie mit einem optimierten Membranverfahren ein „gutes“ alkoholfreies Bier gewonnen werden kann und welche Rolle dabei die Craft-Bier-Szene spielt.01B - Beitrag in Magazin oder ZeitungPublikation Continuous Processes and Flow Chemistry at the Universities of Applied Sciences in Switzerland(Schweizerische Chemische Gesellschaft, 08/2017) Allemann, Christophe; Marti, Roger; Vorlet, Olivier; Martin, Olivier; Riedelberger, Peter; Leonhardt, Tobias; Gössi, Angelo; Riedl, Wolfgang; Segura, Jean-Manuel; Zinn, Manfred; Crelier, SimonThis article provides an overview of activities in the fields of continuous processes, flow chemistry and microreactors at the Universities of Applied Sciences in Switzerland.01A - Beitrag in wissenschaftlicher Zeitschrift
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