Riedl, Wolfgang

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Wolfgang
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Riedl, Wolfgang

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Gerade angezeigt 1 - 8 von 8
  • Publikation
    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, 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
  • 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 Kumar [in: Innovations in fermentation and phytopharmaceutical technologies]
    Nowadays, 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 Sammelband
  • Publikation
    Mass transfer analysis and kinetic modeling for process design of countercurrent membrane supported reactive extraction of carboxylic acids
    (Elsevier, 2021) Schuur, Boelo; Gössi, Angelo; Riedl, Wolfgang [in: Chemical Engineering Science: X]
    Countercurrent membrane supported reactive extraction (MSRE) was studied for removal of carboxylic acids from aqueous streams with a PTFE capillary membrane. Analysis of the mass transfer rates was per- formed to support modeling of the process. Total mass transfer coefficients ranging from 2.0 10-7 to 4.0 10-7 m/s were obtained when extracting lactic acid with 20 wt% tri-N-octyl amine in 1-decanol with membrane thicknesses of 260 mm and 80 mm. The limiting mass transfer resistance in all experiments was in the membrane phase. The developed model based on mass transfer and reaction in parallel allows to predict countercurrent extraction. Experimental validation with 5, 7 and 12 m long membrane modules showed excellent accordance for two acids, validating the model simulations. Simulated membrane con- tactor lengths required for single, two and three countercurrent stages varied between 10 and 39 m/stage for lactic, mandelic, succinic, itaconic and citric acid, depending on acid, membrane, and diluent.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publikation
    Direktextraktion von Milchsäure aus Fermentationsbrühen mittels membrangestützter flüssig-flüssig Extraktion
    (09/2018) Kohler, David; Gössi, Angelo; Riedl, Wolfgang; Venus, Joachim; Schuur, Boelo
    06 - Präsentation
  • Publikation
    Enantioseparation 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 Industry
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publikation
    Extraction of lactic acid from fermentation broths using membrane supported reactive extraction
    (2017) Gössi, Angelo; Urso, Alessandro; Riedl, Wolfgang; Schuur, Boelo
    06 - Präsentation
  • Publikation
    Extraction and back-extraction of lactic acid from aqueous feeds using membrane supported reactive extraction
    (11/2016) Riedl, Wolfgang; Gössi, Angelo; Schär, Pascal; Schuur, Boelo
    06 - Präsentation
  • Publikation
    Extraction of lactic acid from aqueous feeds using membrane supported reactive extraction
    (09/2016) Gössi, Angelo; Riedl, Wolfgang; Schuur, Boelo
    06 - Präsentation