Institut für Chemie und Bioanalytik
Dauerhafte URI für die Sammlunghttps://irf.fhnw.ch/handle/11654/24
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Publikation Continuous in situ lactic acid extraction from sweet whey fermentation broth using a tubular membrane contactor(2022) Demmelmayer, Paul; Pérez, Alan; Riedl, Wolfgang; Kienberger, MarleneBackground Whey, as the major dairy by-product, has become a severe problem for the dairy industry because its demand has decreased, while its production has increased in the past years. Since the high demand for dairy products tends to further increase, suitable routes for whey valorization are required. Whey contains valuables like lactate, but due its composition matrix, processing is challenging. The high sugar content in whey makes it a potential feedstock to produce lactic acid (LA) via microbial fermentation. Still, the known drawbacks of biotechnological LA production, such as growth inhibition by the product, the use of neutralizers, low productivity, and high overall costs of the process must be overcome. In situ LA recovering using a suitable separation technology is a potential strategy to overcome the mentioned drawbacks. In this work, the in situ LA extraction from a whey fermentation broth was evaluated. Sweet whey was used as feedstock for lactic acid production via microbial fermentation, while LA was recovered by reactive liquid-liquid extraction using a tubular membrane contactor. Method The feed material used in this work is a fermentation broth from sweet whey, which was filtered prior to extraction experiments using microfiltration. In a first series of experiments, two-phase extraction experiments were conducted in temperature controlled separation funnels, to investigate different solvent phase combinations for the lactic acid extraction. Special attention was paid to replace commonly applied fossil-based solvents with green alternatives, such as deep eutectic solvents (DES). After extraction, the extract was treated in a back-extraction step to recover LA from the solvent phase. Here, an anti-solvent, e.g. heptane or p-cymene, was used to transfer LA to the receiving phase, which was water. Afterwards the performance of reactive liquid-liquid extraction of LA using a PTFE membrane contactor was evaluated by using two potential solvent phases, namely tri-n-octyl amine (TOA) with n-decanol and a DES formed from thymol and menthol. From the experimental results the overall mass transfer coefficient was calculated based on a rigorous mass transfer model to predict the LA concentration in both phases. Finally, performance of the in situ LA recovery from sweet whey by using membrane contactor was investigated from both, experimentally and theoretically points of view. Results & Conclusion In the two-phase extraction experiments, the reactive extractants Aliquat336, TOA, trioctylphosphinoxid (TOPO), and the mixture Aliquat336/TOA were found to be most efficient with the diluents 1-decanol, limonene, and a deep eutectic solvent consisting of thymol and menthol. Especially, the DES and limonene are promising as they can be produced from renewable resources. With respect to back-extraction, heptane and p-cymene showed the highest efficiencies for transferring lactic acid into the receiving phase water. In the next step, the selected solvents were used to perform LA recovery in the tubular membrane contactor from a model aqueous solution of LA and a fermentation broth of sweet whey. The proposed technology for valorizing dairy waste through LA biotechnological production shows the feasibility to scaling it up.06 - PräsentationPublikation Using membrane-supported liquid–liquid extraction for the measurement of extraction kinetics(Swiss Chemical Society, 2011) Riedl, Wolfgang; Mollet, Daniel; Grundler, GerhardMembrane-supported liquid–liquid extraction uses artificial membranes for the generation of a phase interface between the two liquid phases involved in extraction. Additional equipment for the generation of droplets as well as phase separation afterwards is no longer necessary. Since the membranes used for this special type of extraction are quite well described concerning thickness, porosity, tortuosity and material it is possible to generate information about the diffusion coefficient of the component to be extracted within the preferred solvent from extraction trails easily. This article describes an experimental set-up for both the proof of principle of membrane-supported liquid–liquid extraction and, using a dedicated computer-aided data treatment, how to calculate the overall mass transfer coefficient as well as the diffusion coefficient for a given system within moderate testing duration.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Energy-related chemical research at the universities of applied sciences(Swiss Chemical Society, 2013) Riedl, Wolfgang; Fischer, Fabian; Marti, Roger; Brühwiler, DominikAn overview of current activities in the field of energy-related chemical research at the Swiss Universities of Applied Sciences is presented.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Sustainable Chemistry at the Universities of Applied Sciences(Swiss Chemical Society, 2012) Sanglard, Pauline; Rogano, Frank; Naef, Olivier; Riedl, Wolfgang; Crelier, Simon; Fischer, Fabian; Morganti, Franziska; Hinderling, ChristianAn overview of activities in the field of sustainable or 'green' chemistry at the Universities of Applied Sciences in Switzerland is presented.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Prozessoptimierung von 4 Stufen zur Herstellung eines Pharma-Zwischenprodukts(Hochschule für Life Sciences FHNW, 2024) Güner, Merve; Zogg, Andreas11 - Studentische ArbeitPublikation Development of a tool for the automated visualization of batch recipes(Hochschule für Life Sciences FHNW, 2024) Gentner, Jannick; Zogg, Andreas; Bachem AG11 - Studentische ArbeitPublikation Modified oligonucleotides(World Intellectual Property Organization, 08.01.1998) De Mesmaeker, Alain; Wendeborn, Sebastian; Lebreton, JaquesIt is one object of the present invention to provide an oligonucleotide of formula (1): 5'-(U)n-3' in which U is an identical or different radical of a natural or a synthetic nucleoside, wherein the oligonucleotide comprises at least one modified nucleotide dimer comprising two nucleoside analogs connected via an amide-bond that has a certain configuration; the synthesis of these compounds and their use in pharmaceutical preparations.12 - PatentPublikation Dynemicin analogs: Syntheses, methods of preparation and use(United States Patent and Trademark Office, 04.01.1994) Smith, Adrian L.; Hwang, Chan-Kou; Wendeborn, Sebastian; Nicolaou, Kyriacos C.; Schreiner, Erwin P.; Stahl, Wilhelm; Dai, Wei-Min; Maligres, Peter E.; Suzuki, ToshioA fused ring system compound is disclosed that contains an epoxide group on one side or the fused rings and an enediyne macrocyclic ring on the other side of the fused rings. The compounds have DNA-cleaving, antimicrobial and tumor growth-inhibiting properties. Chimeric compounds having the fused ring system compound as an aglycone bounded to (i) a sugar moiety as the ogligosaccharide portion or(ii) a monoclonal antibody or antibody combining site portion thereof that immunoreacts with target tumor cells are also disclosed. Compositions containing a compound or a chimer are disclosed, as are methods or preparing a compound.12 - PatentPublikation Enantiomeric dynemicin analogs, preparation and use thereof(World Intellectual Property Organization, 25.11.1993) Smith, Adrian L.; Wendeborn, Sebastian; Nicolaou, Kyriacos; Schreiner, Erwin P.; Dai, Wei-Min; Susuki, ToshioAn enantiomer of a fused ring system compound is disclosed that contains an epoxide group on one side of the fused rings and an enediyne macrocyclic ring on the other side of the fused rings. The enantiomeric compounds have DNA-cleaving, antimicrobial and tumor growth-inhibiting properties that are enhanced over their racemates. Chimeric compounds having the enantiomeric fused ring system compound as an aglycone bonded to (i) a sugar moiety as the oligosaccharide portion or (ii) a monoclonal antibody or antibody combining site portion thereof that immunoreacts with target tumor cells are also disclosed. Compositions containing an enatiomeric compound or an enantiomeric chimer are disclosed, as are methods of preparing an enantiomeric compound.12 - PatentPublikation Scaling down the heat transfer in multipurpose plants(26.06.2024) Zogg, Andreas04B - Beitrag Konferenzschrift