16.07.2017–19.07.2017 | Trade Show | Loews Philadelphia Hotel, Philadelphia, PA, U.S.A.

PREP 2017

30th International Symposium on Preparative and Process Chromatography

KNAUER exhibits at PREP 2017 in Philadelphia.

Our representatives Dr. Christian Benkhäuser (Product Manager) and Dr. Yannick Krauke (Application Specialist) will be on site to inform you about the AZURA® Systems by KNAUER. 

With our long time experience in the configuration of classical batch LC systems and in the field of continuous chromatography, KNAUER can offer you the right solution for your purification tasks. Take the chance and see our new AZURA® presented at our booth 303.

Talk to our experts about the wide range of HPLC and FPLC products and services KNAUER offers.

Join the SMB product presentation at our booth 303 on July 20, 2017, at 11am.

During the poster sessions we will describe a purification  examples of Xylitol by HPLC methods and SMB technology from fermented biomass (July 17th 1:00PM and July 18th 3:30PM, Millennium Exhibition Hall, 2nd floor)


Poster 1: Purification of Xylitol by HPLC methods from fermented biomass

Yannick Krauke, C. Benkhaeuser, M. Luebbert

KNAUER Wissenschaftliche Geräte GmbH


Biofuels are an important alternative energy source to commonly used fossil fuels. The first generation of bio refinery uses carbon rich sources such as corn to convert C6 sugars into ethanol by fermentation. These biomass sources compete for land and water usage with food crops and this results in ethical issues. Therefore, research is ongoing in a second generation of bio refinery that uses plant materials with low C6 sugar content such as straw and wood.

The Valor Plus (financed by the EU) project aims to optimize the entire process of second generation biofuel production. A key aspect is the complete utilisation and valorisation of by-products during this process. One task of this project is the conversion of C5 sugars such as xylose with yeasts to ethanol. During the process development alternative applications for xylose were investigated, including the conversion of xylose to xylitol.

Xylitol is used for example in the food industry as a replacement for sucrose in chewing gums in order to reduce caries formation. It is produced by chemical degradation of xylose from wood, a process which consumes high amounts of chemicals and energy. Therefore, alternative xylitol sources are of great interest.

The first phase of the project focused on the analysis of a fermentation mash from xylose to xylitol conversion by yeast. This analysis revealed high contents of xylitol indicating successful conversion of xylose to xylitol. Furthermore, glycerol, mannitol and arabinose were detected.

Next, the feasibility of the chromatographic separation and purification of xylitol from the fermentation mash was investigated. The KNAUER polymer based Eurokat columns with different ionic charges were used to optimize the separation and purification process. The Eurokat Ca column displayed the best separation profile and analysis revealed a good separation of xylitol from other compounds allowing the establishment of an efficient purification process.

Overload studies showed that an efficient batch purification process of xylitol is possible. As this separation process was performed in isocratic mode a continuous purification process using the SMB (simulated moving bed) system is possible This continuous multi-column technology increases the yield of xylitol purification. Initial experiments were undertaken to establish this process and further method development is ongoing.

This project has received funding from the European Union's Seventh Framework Program for research, technological development and demonstration under grant agreement no FP7-KBBE-2013-7-613802


Poster 2: Simulated Moving Bed (SMB) - a powerful tool for continuous purification of Xylitol

Yannick Krauke, C. Benkhaeuser, M. Luebbert, K. Monks

KNAUER Wissenschaftliche Geräte Gmbh


Simulated moving bed chromatography (SMB) is a continuous chromatography technique that enables binary or pseudo-binary mixtures to be separated into pure substances or fractions. Compared to traditional batch chromatography this process leads to higher yields of purified substances while consuming less eluent and packing material. In traditional chromatographic separations with one column only a small part of the column contributes in the separation, while the predominant part remains unused. This results in a significantly lower productivity compared to a SMB process where the whole column bed is efficiently used.

The SMB process was used to purify xylitol from fermentation mash of a fed-batch culture. Xylitol is the sugar alcohol of xylose which is mainly used in food industry as glucose replacement e.g. in chewing gums. It is classically produced by chemical conversion of xylose from birch to xylitol.

Within the European Valor Plus research project an alternative, biological way of xylose conversion was investigated.  By using a Candida yeast strain, xylose from a hemicellulose hydrolysate was converted to xylitol. HPLC analysis of the fermentation mash revealed that the xylose to xylitol conversion was successful. The chromatogram showed a baseline separation of xylitol from all other compounds potentially allowing efficient purification of xylitol. This was tested and confirmed by a semi-preparative single column batch process. The applied polymer based Eurokat Ca columns have the advantage that they are customized for sugar separation and that water is used as eluent.

In a next step, a SMB process was designed for xylitol purification using the new Knauer AZURA SMB system. A set-up with eight polymer based Eurokat Ca columns was chosen. The fractions from the two outlets extract and raffinate, were analysed via HPLC. The results confirmed that xylitol was successfully separated. In one hour 1.8 g of xylitol was purified with 99 % purity and 100 % recovery. In future, experiments the SMB process will be further optimized to increase the throughput, purity, and concentration of xylitol.

This project has received funding from the European Union's Seventh Framework Program for research, technological development and demonstration under grant agreement no FP7-KBBE-2013-7-613802.




Date/time16.07.2017–19.07.2017 | CEST
PlaceLoews Philadelphia Hotel, Philadelphia, PA, 1200 Market Street, 19107 Philadelphia, PA
Map and directions