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Advisor(s)
Abstract(s)
The preparation of a-alumina supported zeolite Beta membranes was successfully achieved and sped up
by exploring combinations of three seeding techniques and three synthetic methods. The surface of the
membranes was completely covered by well intergrown crystals; the thickness of the zeolite layers ranged
from 2 to 6 lm depending on the synthesis method used. The quality of the membranes was tested
by means of pervaporation of ethanol/1,3,5-triisopropylbenzene (TIPB) mixtures together with permporometry
experiments. The performance in the vapour separation of quaternary equimolar mixtures of nhexane
(nHEX), 3-methylpentane (3MP), 2,3-dimethylbutane (23DMB) and 2,2-dimethylbutane (22DMB)
in the range 343–443 K showed that permeate flux decreases as the branching degree increases following
the order: nHEX 3MP > 23DMB > 22DMB. In the retentate, the fractions of monobranched and normal
hexane decrease while the concentration of dibranched isomers is increased compared to the feed composition.
The influence of the temperature in the permeation fluxes indicates the existence of an activated
transport mechanism which favours the permeation of more nHEX and 3MP with regard to their
dibranched isomers. The octane number (ON) of the quaternary mixture was enhanced up to 5 points
with the best synthesized membrane.
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Citation
Bárcia, Patrick; Silva, Jose A. C.; Gascon, Jorge; Aguado, Sonia; Ferreira, Alexandre; Rodrigues, Alirio; Kapteijn, Freek (2010). Zeolite Beta membranes for the separation of hexane isomers. Microporous and Mesoporous Materials. ISSN 1387-1811. 128:1-3, p.194-202.
Publisher
Elsevier