TY  - JOUR
A1  - Wiesen, Sebastian
A1  - Tippkötter, Nils
A1  - Muffler, Kai
A1  - Suck, Kirstin
A1  - Sohling, Ulrich
A1  - Ruf, Friedrich
A1  - Ulber, Roland
T1  - Adsorption of fatty acids to layered double hydroxides in aqueous systems
JF  - Adsorption
N2  - 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−.
Y1  - 2015
VL  - 21
IS  - 6-7
SP  - 459
EP  - 466
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Wiesen, Sebastian
A1  - Tippkötter, Nils
A1  - Muffler, Kai
A1  - Suck, Kirstin
A1  - Sohling, Ulrich
A1  - Ruf, Nils
A1  - Ulber, Roland
T1  - Adsorptive Vorbehandlung von Rohglycerin für die 1,3-Propandiol Fermentation mit Clostridium diolis
JF  - Chemie Ingenieur Technik
N2  - Bei der Gewinnung von Fettsäuren aus Pflanzenölen, z. B. zur Herstellung von Biopolymeren, oder bei der Biodiesel- und Seifenproduktion, fällt Glycerin als Nebenprodukt an. Bei der Biokonversion dieses Rohstoffes zu 1,3-Propandiol wird der Produktionsorganismus Clostridium diolis durch Verunreinigungen im Rohglycerin gehemmt. Als inhibierende Substanzen konnten freie Fettsäuren identifiziert werden. Mithilfe eines adsorptiven Aufarbeitungsverfahrens ist es gelungen, die Fettsäuren zu entfernen und die Konversionseffizienz zu 1,3-Propandiol zu erhöhen.
Y1  - 2014
U6  - http://dx.doi.org/10.1002/cite.201300080
N1  - Englischer Titel: Adsorptive Pretreatment of Crude Glycerol Prior to Fermentation to 1,3-Propanediole by Clostridium Diolis
VL  - 86
IS  - 1-2
SP  - 129
EP  - 135
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Tippkötter, Nils
A1  - Duwe, Anna-Maria
A1  - Wiesen, Sebastian
A1  - Sieker, Tim
A1  - Ulber, Roland
T1  - Enzymatic hydrolysis of beech wood lignocellulose at high solid contents and its utilization as substrate for the production of biobutanol and dicarboxylic acids
JF  - Bioresource Technology
N2  - The development of a cost-effective hydrolysis for crude cellulose is an essential part of biorefinery developments. To establish such high solid hydrolysis, a new solid state reactor with static mixing is used. However, concentrations >10% (w/w) cause a rate and yield reduction of enzymatic hydrolysis. By optimizing the synergetic activity of cellulolytic enzymes at solid concentrations of 9%, 17% and 23% (w/w) of crude Organosolv cellulose, glucose concentrations of 57, 113 and 152 g L⁻¹ are reached. However, the glucose yield decreases from 0.81 to 0.72gg⁻¹ at 17% (w/w). Optimal conditions for hydrolysis scale-up under minimal enzyme addition are identified. As result, at 23% (w/w) crude cellulose the glucose yield increases from 0.29 to 0.49gg⁻¹. As proof of its applicability, biobutanol, succinic and itaconic acid are produced with the crude hydrolysate. The potential of the substrate is proven e.g. by a high butanol yield of 0.33gg⁻¹.
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.biortech.2014.06.052
VL  - 167
SP  - 447
EP  - 455
PB  - Elsevier
CY  - Amsterdam
ER  -