@article{ThielTippkoetterSucketal.2013,
  author    = {Thiel, Alexander and Tippk{\"o}tter, Nils and Suck, Kirstin and Sohling, Ulrich and Ruf, Friedrich and Ulber, Roland},
  title     = {New zeolite adsorbents for downstream processing of polyphenols from renewable resources},
  series = {Engineering in Life Sciences},
  volume    = {13},
  journal   = {Engineering in Life Sciences},
  number    = {3},
  publisher = {Wiley},
  address   = {Weinheim},
  doi       = {10.1002/elsc.201200188},
  pages     = {239 -- 246},
  year      = {2013},
  abstract  = {Commercial materials with polyvinylpolypyrrolidone and polymeric amberlites (XAD7HP, XAD16) are commonly used for the adsorptive downstream processing of polyphenols from renewable resources. In this study, beta-zeolite-based adsorbent systems were examined, and their properties were compared to organic resins. Batch adsorption experiments were conducted with synthetic solutions of major polyphenols. Adsorption isotherms and desorption characteristics of individual adsorbent were determined based on these results. Maximum adsorption capacities were calculated using the Langmuir model. For example, the zeolites had capacities up to 203.2 mg/g for ferulic acid. To extend these results to a complex system, additional experiments were performed on rapeseed meal and wheat seed extracts as representative renewable resources. HPLC analysis showed that with 7.5\% w/v, which is regarded as the optimum amount of zeolites, zeolites A and B could bind 100\% of the major polyphenols as well as release polyphenols at high yields. Additionally, regeneration experiments were performed with isopropyl alcohol at 99°C to evaluate how zeolites regenerate under mild conditions. The results showed only a negligible loss of adsorption capacity and no loss of desorption capacity. In summary, it was concluded that beta-zeolites were promising adsorbents for developing new processes to isolate polyphenols from renewable resources.},
  language  = {en}
}
@article{ThielMufflerTippkoetteretal.2015,
  author    = {Thiel, Alexander and Muffler, Kai and Tippk{\"o}tter, Nils and Suck, Kirstin and Sohling, Ulrich and Ruf, Friedrich and Ulber, Roland},
  title     = {Aufarbeitung von Polyphenolen aus Weizen mittels Zeolithen am Beispiel der Ferulas{\"a}ure},
  series = {Chemie IngenieurTechnik},
  volume    = {87},
  journal   = {Chemie IngenieurTechnik},
  number    = {1-2},
  publisher = {Wiley},
  address   = {Weinheim},
  doi       = {10.1002/cite.201400031},
  pages     = {128 -- 136},
  year      = {2015},
  abstract  = {Aufarbeitung von Polyphenolen aus Weizenmittels Zeolithen am Beispiel der Ferulasa¨ ureAlexander Thiel1, Kai Muffler1, Nils Tippko¨ tter1, Kirstin Suck2, Ulrich Sohling2, Friedrich Ruf3und Roland Ulber1,*DOI: 10.1002/cite.201400031Bei der Ferulasa¨ure handelt es sich um einen Wertstoff, der aus Weizen gewonnen und in der Lebensmittel- und Pharma-industrie eingesetzt werden kann. Der Einsatz von Weizen als nachwachsende Rohstoffquelle ist allerdings nur dann wirt-schaftlich durchfu¨hrbar, wenn eine Prozessintegration in die bestehenden industriellen Verfahren gewa¨hrleistet oder einedirekte Konkurrenz zur Mehl- und Sta¨rkeindustrie vermieden werden kann. In diesem Artikel wird ein Verfahren aufge-zeigt, welches hohe Ausbeuten ermo¨glicht und eine Konkurrenz zu bestehenden Verwertungspfaden vermeidet.},
  language  = {de}
}
@article{WiesenTippkoetterMuffleretal.2015,
  author    = {Wiesen, Sebastian and Tippk{\"o}tter, Nils and Muffler, Kai and Suck, Kirstin and Sohling, Ulrich and Ruf, Friedrich and Ulber, Roland},
  title     = {Adsorption of fatty acids to layered double hydroxides in aqueous systems},
  series = {Adsorption},
  volume    = {21},
  journal   = {Adsorption},
  number    = {6-7},
  publisher = {Springer},
  address   = {Berlin},
  pages     = {459 -- 466},
  year      = {2015},
  abstract  = {Due to their anion exchange characteristics, layered double hydroxides (LDHs) are suitable for the detoxification of aqueous, fatty acid containing fermentation substrates. The aim of this study is to examine the adsorption mechanism, using crude glycerol from plant oil esterification as a model system. Changes in the intercalation structure in relation to the amount of fatty acids adsorbed are monitored by X-ray diffraction and infra-red spectroscopy. Additionally, calcination of LDH is investigated in order to increase the binding capacity for fatty acids. Our data propose that, at ambient temperature, fatty acids can be bound to the hydrotalcite by adsorption or in addition by intercalation, depending on fatty acid concentration. The adsorption of fatty acids from crude glycerol shows a BET-like behavior. Above a fatty acid concentration of 3.5 g L-1, intercalation of fatty acids can be shown by the appearance of an increased interlayer spacing. This observation suggests a two phase adsorption process. Calcination of LDHs allows increasing the binding capacity for fatty acids by more than six times, mainly by reduction of structural CO32-.},
  language  = {en}
}