Riedl, Wolfgang
Lade...
E-Mail-Adresse
Geburtsdatum
Projekt
Organisationseinheiten
Berufsbeschreibung
Nachname
Riedl
Vorname
Wolfgang
Name
Riedl, Wolfgang
10 Ergebnisse
Suchergebnisse
Gerade angezeigt 1 - 10 von 10
- PublikationElectrochemical membrane-assisted pH-swing extraction and back-extraction of lactic acid(Elsevier, 2022) Gausmann, Marcel; Bertram, Franziska; Schuur, Boelo; Jupke, Andreas; Gössi, Angelo; Riedl, Wolfgang [in: Separation and Purification Technology]Reactive 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 Zeitschrift
- PublikationIn-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, Wolfgang [in: Separation and Purification Technology]Membrane 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 Zeitschrift
- PublikationMembrane‐Assisted Liquid‐Liquid Extraction – Where Do We Stand Today?(Wiley, 29.08.2019) Riedl, Wolfgang [in: Chemie Ingenieur Technik]Dank 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 Zeitschrift
- PublikationIndustrial Upscaling of DOPO-Based Phosphonamidates and Phosphonates Derivatives Using Cl2 Gas as a Chlorinating Agent(American Chemical Society, 10/2018) Salmeia, Khalifah A.; Baumgartner, Georg; Jovic, Milijana; Gössi, Angelo; Riedl, Wolfgang; Zich, Thomas; Gaan, Sabyasachi [in: Organic Process Research & Development]Herein, we report the industrial synthesis procedure of phosphonamidate and phosphonate derivatives via an efficient and simple chlorination of 9,10-dihydro-9-oxa-10-phosphaphenanthren-10-oxide (DOPO) with Cl2 gas. The key step in the synthesis is the conversion of the P–H bond to P–Cl of DOPO by flowing Cl2 gas into a solution of DOPO in dichloromethane, affording the key intermediate 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-chloride (DOPO-Cl) compound which is industrially not available. DOPO-Cl was isolated, characterized, and used for this synthesis of DOPO-based phosphonamidates and phosphonates in relatively high yield by reaction with the corresponding amines and alcohols, respectively. The experimental results show that the chlorination reaction occurs in equimolar ratios of Cl2 gas to DOPO compound. Subsequently, the procedure developed in laboratory scale was industrially applied for synthesis of the 6,6′-(ethane-1,2-diylbis(azanediyl))bis(dibenzo[c,e][1,2]oxaphosphinine-6-oxide) (EDA-DOPO) compound and 6-((1-oxido-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octan-4-yl)methoxy)dibenzo[c,e][1,2]oxaphosphinine-6-oxide (DOPO-PEPA). All synthetic compounds thus obtainedwere characterized and found to be identical to the authentic laboratory scale products.01A - Beitrag in wissenschaftlicher Zeitschrift
- Publikation(Semi)‐Kontinuierliche Synthese von Produkten für die Pharma‐ oder Feinchemie in einem neuartigen Rohrreaktor im Pilotmaßstab(Wiley, 08/2018) Leonhardt, Tobias; Skula, Jan; Müller, B.; Schulthess, Pascal; Jeisy, Julius; Riedl, Wolfgang [in: Chemie Ingenieur Technik]01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationContinuous 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, Simon [in: Chimia]This 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
- PublikationEntwicklung eines neuartigen Rohrreaktorsystems für heterogen katalysierte Mehrphasenreaktionen(Wiley, 2017) Leonhardt, Tobias; Zogg, Andreas; Riedl, Wolfgang [in: Chemie Ingenieur Technik]Der einem inversen Festbettreaktor nachempfundene lasergesinterte Rohrreaktor stellt eine interessante Alternative zu anderen innovativen Reaktorkonzepten zur Prozessintensivierung dar. Im Rahmen dieser Arbeit wurde für diesen Reaktortyp eine geeignete Peripherie konzipiert. Das entwickelte Anlagenkonzept soll verschiedene chemische Reaktionen unter inhärent sicheren Bedingungen ermöglichen. Im Fokus stehen heterogen katalysierte Mehrphasenreaktionen, die einen mittleren bis hohen Enthalpiestrom abgeben. Am Beispiel einer oxidativen Zyklisierung wird die Funktionalität des Reaktorsystems beschrieben.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationEntwicklung und Charakterisierung eines innovativen Parallelreaktorsystems für Mehrphasenreaktionen(Wiley, 2017) Leonhardt, Tobias; Schulthess, Pascal; Riedl, Wolfgang [in: Chemie Ingenieur Technik]Mithilfe eines definierten Versuchsaufbaus zur Durchführung von heterogen katalysierten Mehrphasenreaktionen lassen sich Aussagen zur Aktivität unterschiedlicher Katalysatoren und Additive treffen. Das hinsichtlich Stoff- und Wärmeübergang charakterisierte Parallelreaktorsystem eignet sich zur gleichzeitigen Durchführung von bis zu sechs Einzelversuchen bei vergleichbaren und homogen vorliegenden Prozessparametern. Zudem kann der Einfluss der Rührergeometrie, der Begasungsrate und der Zusammensetzung der Reaktionsmasse auf den Reaktionsfortschritt evaluiert werden.01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationEnantioseparation with liquid membranes(Wiley, 2017) Gössi, Angelo; Riedl, Wolfgang; Schuur, Boelo [in: Journal of Chemical Technology & Biotechnology]Chiral resolution of racemic products is a challenging and important task in the pharmaceutical, agrochemical, flavor, polymer and fragrances industries. One of the options for these challenging separations is to use liquid membranes. Although liquid membranes have been known for almost four decades and have been used for optical resolutions, no comprehensive review has been published about the use of this technology for enantioseparations. In this review, the various liquid membrane-related technologies are described and compared, including bulk liquid membranes, emulsion liquid membranes, micelle-extraction and micellar enhanced ultrafiltration, as well as supported liquid membranes. Next to technological advances, an overview of recent developments in chiral recognition chemistry in liquid–liquid equilibria is presented. The following extractant classes have recently been reported in conjunction with chiral separation: cyclodextrines, BINOL's, calixarenes, crown ethers, BINAP's, tartaric acids and ionic liquids. The use of two supported (non-liquid) membranes with an inner loop of extract phase appears to be the most stable liquid membrane configuration, allowing for a large degree of freedom in operational conditions such as solvent to feed ratio. The library of solvents still needs broadening to make the technology more versatile and based on the variety of successes with catalytically active organometallic complexes, development of new chiral selector systems based on asymmetric catalysis literature is suggested for future selector screening studies. © 2017 Society of Chemical Industry01A - Beitrag in wissenschaftlicher Zeitschrift
- PublikationPAT 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, Christian [in: Chimia]An overview of activities in the field of Process Analytical Technologies (PAT) at the Universities of Applied Sciences in Switzerland is presented01A - Beitrag in wissenschaftlicher Zeitschrift