Reaction-integrated separation of isomaltose by ad- and desorption on zeolite

Holtkamp, Manuel; Erhardt, Frank A.; Jördening, Hans‐Joachim; Scholl, Stephan

doi:10.1016/j.cep.2008.11.001

Cited by 17 publications

(15 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, ethanol should be able to fasten desorption of isomaltose due to a displacement effect. But, as shown by Holtkamp et al (2009) the desorption rate on zeolite crystals could not be enhanced by addition of ethanol. In contrast, desorption rate on extrudates with 5% ethanol in water as eluent was much faster than in pure water.…”

Section: Sorption Kinetics and Diffusivitymentioning

confidence: 72%

Adsorption properties of BEA zeolites and their aluminum phosphate extrudates for purification of isomaltose

Holtkamp

Scholl

2011

Adsorption

View full text Add to dashboard Cite

The disaccharide isomaltose is produced via an enzymatic reaction and is adsorbed to BEA zeolite. This reaction integrated adsorption can be achieved as fluidized bed as well as fixed bed. We investigated isotherms, adsorption enthalpies and sorption kinetics of BEA zeolite and extrudates with a novel aluminum phosphate sintermatrix. These extrudates contain 50% (w/w) of BEA 150 zeolites (Si/Al = 75) as primary crystals. BET-surface for extrudates is 245 m 2 ·g −1 and 487 m 2 ·g −1 for zeolite. Extrudates show a monomodal macropore structure with a maximum at 90 nm. All isotherms show a type I shape. For lower equilibrium concentrations, which occur during the enzymatic reaction, Henry's law is applied and compared to a Langmuir model. Adsorption equilibrium constant K i,L calculated from Langmuir for extrudates at 4°C is 64.7 mL·g −1 and more than twice as high as obtained from Henry's law with K i is 26.8 mL·g −1 . Adsorption on extrudates at 4°C is much stronger than on zeolite crystals where the Henry coefficient K i is 17.1 mL·g −1 . Adsorption enthalpy h Ad calculated from van't Hoff plot with the Henry equation is −44.3 kJ·mol −1 for extrudates and −29.6 kJ·mol −1 for zeolite crystals. Finally, the kinetics for ad-and desorption were calculated from the initial slope. The diffusion rate for adand desorption on extrudates were in the same range while adsorption on zeolites is three orders of magnitudes faster than desorption.

show abstract

Section: Sorption Kinetics and Diffusivitymentioning

confidence: 72%

Adsorption properties of BEA zeolites and their aluminum phosphate extrudates for purification of isomaltose

Holtkamp

Scholl

2011

Adsorption

View full text Add to dashboard Cite

show abstract

“…These results show that an additional effort has to be made to remain the capacity of the zeolite. As shown in [9] the zeolite lost capacity due to longer contact with the buffer solution. In consequence, the usage of the zeolite-column-based approach is not feasible.…”

Section: Reactivationmentioning

confidence: 97%

“…The resulting zeolite cake is resuspended for desorption. As shown in [9], harsh conditions and long reaction times are required for the desorption of used BEA-zeolite. An effective desorption in a stirred tank occurs at 70°C.…”

Section: Desorptionmentioning

confidence: 99%

Downstream Processing for Isomaltose following a Reaction Integrated Adsorption

Holtkamp

Scholl

2011

Chemie Ingenieur Technik

View full text Add to dashboard Cite

Downstream processing for isomaltose by purification on BEA-zeolites was investigated. The important process steps are washing procedure, desorption, and reactivation of the adsorbent. Purity and yield were influenced by the enzyme system. Desorption kinetics was determined at 50°and 70°C. Complete desorption was performed in a three stage cross-flow-sequence. The reactivation of BEA-zeolite is feasible with additional effort for Na + -cation exchange.

show abstract

“…Purities were calculated on a w/v basis and yields of processed zeolites were benchmarked against the immediately desorbed zeolite aliquot. Detailed information is given in Holtkamp et al (2009).…”

Section: Assessment Of Isomaltose Bound On Zeolitementioning

confidence: 99%

Development of a multiphase reaction system for integrated synthesis of isomaltose with a new glucosyltransferase variant

Erhardt¹,

Rosenstock²,

Hellmuth³

et al. 2009

Biocatalysis and Biotransformation

View full text Add to dashboard Cite

A new genetically derived variant of the glucosyltransferase from Streptococcus oralis has been characterized physicochemically and kinetically. Compared with the industrially used glucosyltransferase from Leuconostoc mesenteroides, the enzyme variant GTF-R S628D possesses 25 times higher affinity for the specific glucosylation of glucose. For a concept of integrated reaction and product isolation, a fluidized bed reactor with in situ product removal was applied. The technical feasibility and the applicability of the kinetic models for reaction and adsorption could be demonstrated. The immobilized enzyme was stable (20% activity loss after 192 h) and product could be obtained with 90% purity. A bioprocess model was generated which allowed the integral assessment of the enzymatic synthesis and in situ product adsorption. The model is a powerful tool which assists with the localization of optimal process parameters. It was applied for the process evaluation of other glucosyltransferases and demonstrated key characteristics of each enzymatic system.

show abstract

Reaction-integrated separation of isomaltose by ad- and desorption on zeolite

Cited by 17 publications

References 7 publications

Adsorption properties of BEA zeolites and their aluminum phosphate extrudates for purification of isomaltose

Adsorption properties of BEA zeolites and their aluminum phosphate extrudates for purification of isomaltose

Downstream Processing for Isomaltose following a Reaction Integrated Adsorption

Development of a multiphase reaction system for integrated synthesis of isomaltose with a new glucosyltransferase variant

Contact Info

Product

Resources

About