Search

Your search keyword '"Tempelman, Christiaan H.L."' showing total 8 results
Start Over Author "Tempelman, Christiaan H.L." Language english
8 results on '"Tempelman, Christiaan H.L."'

7. Deactivation of Sn-Beta during carbohydrate conversion

Author

Van Der Graaff, William N.p., Tempelman, Christiaan H.l., Hendriks, Frank C., Ruiz-martinez, Javier, Bals, Sara, Weckhuysen, Bert M., Pidko, Evgeny A., Hensen, Emiel J.m., Sub Inorganic Chemistry and Catalysis, Inorganic Chemistry and Catalysis, Inorganic Materials & Catalysis, Chemical Engineering and Chemistry, Sub Inorganic Chemistry and Catalysis, and Inorganic Chemistry and Catalysis

Subjects
Catalyst deactivation, 010402 general chemistry, Photochemistry, 01 natural sciences, Catalysis, chemistry.chemical_compound, Fluorescence microscope, Zeolite, Biology, Flow chemistry, Ethanol, Biomass conversion, 010405 organic chemistry, Process Chemistry and Technology, organic chemicals, Carbohydrate, 0104 chemical sciences, Solvent, Chemistry, Confocal fluorescence microscopy, chemistry, Zeolite catalysis, Isomerization, Sn-Beta
Abstract

The deactivation of Sn-Beta zeolite catalyst during retro-aldolization and isomerization of glucose is investigated. Confocal fluorescence microscopy reveals that retro-aldolization of glucose in CH3OH at 160 °C is accompanied with the build-up of insoluble oligomeric deposits in the micropores, resulting in a rapid catalyst deactivation. These deposits accumulate predominantly in the outer regions of the zeolite crystals, which points to mass transport limitations. Glucose isomerization in water is not only accompanied by the formation of insoluble deposits in the micropores, but also by the structural degradation of the zeolite due to desilication and destannation. Enhanced and sustained catalytic performance can be achieved by using ethanol/water mixtures as the reaction solvent instead of water.

Published
2018

8. Texture, acidity and fluid catalytic cracking performance of hierarchical faujasite zeolite prepared by an amphiphilic organosilane.

Author

Tempelman, Christiaan H.L., Zhu, Xiaochun, Gudun, Kristina, Mezari, Brahim, Shen, Baojian, and Hensen, Emiel J.M.

Subjects
*CATALYTIC cracking, *ZEOLITE Y, *ZEOLITE analysis, *AMPHIPHILES, *SILANE compounds, *METALS, *CRYSTAL texture
Abstract

Mesoporous zeolite Y was synthesized by using an amphiphilic organosilane. The texture and acidity of the mesoporous zeolite samples were compared with a reference microporous faujasite zeolite. The synthesis of the most suitable mesoporous zeolite Y was scaled up in order to prepare composite catalysts that could be tested for fluid catalytic cracking. Composite catalysts were prepared by spray-drying the zeolite with kaolin as filler and an alumina sol as binder. The acidic properties of composite FCC catalysts prepared from conventional and mesoporous faujasite zeolites were compared. While IR spectroscopy after H/D exchange with deuterated benzene indicates that strong bridging hydroxyl groups are present in the freshly prepared composite catalysts, these zeolite-type acid sites are absent in the lab-deactivated composite catalysts. These samples contain a significant number of weaker Brønsted acid sites. The strength of the acid sites in the composite catalysts is comparable with the acidity of amorphous silica–alumina. The composite catalysts show an excellent catalytic performance in the fluid catalytic cracking of vacuum gas oil. Our data indicate that relatively weak acid sites catalyze the FCC reactions. The well-embedded mesoporosity in the parent hierarchical zeolite crystals results in increased diesel and decreased gasoline and coke yield in the composite FCC catalyst. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results