Hybridization zeolite

S. M. Knznicki, V. A. Bell, T. W. Langner, and J. S. Curran, Porous static wate softener containing hybrid zeolite-silicate composition. U.S. Pat. Appl Publ 20020074293,... 

Garcia, R.A., Serrano, D.P., Otero, D., 2005. Catalytic cracking of HOPE over hybrid zeolitic—mesoporous materials. Journal of Analytical and Applied Pyrolysis 74 (1—2),... 

The desulfurization process reported by the authors was a hybrid process, with a biooxidation step followed by a FCC step. The desulfurization apparently occurs in the second step. Thus, the process seems of no value, since it does not remove sulfur prior to the FCC step, but only oxidizes it to sulfoxides, sulfones, or sulfonic acids. The benefit of such an approach is not clearly outlined. The benefit of sulfur conversion can be realized only after its removal, and not via a partial oxidation. Most of the hydrotreatment is carried out prior to the FCC units, partially due to the detrimental effect that sulfur compounds exert on the cracking catalyst. It is widely accepted that the presence of sulfur, during the regeneration stage of the FCC units, causes catalyst deactivation associated with zeolite decay. In general terms, the subject matter of this document has apparent drawbacks. 

Zeolite-bentonite hybrid catalysts for the pyrolysis of woody biomass... 

Hybrid catalysts consisting of a zeolite (ZSM-5 or Beta) and bentonite as a binder were prepared and characterized by XRD, pyridine FTIR and nitrogen adsorption. The hybrid catalysts exhibited similar properties as the combined starting materials. Catalytic pyrolysis over pure ZSM-5 and Beta as well as hybrid catalysts has been successfully carried out in a dual-fluidized bed reactor. De-oxygenation of the produced bio-oil over the different zeolitic materials was increased compared to non-catalytic pyrolysis over quartz sand. 

The objective of this work is to synthesize and characterize zeolite-bentonite hybrid catalysts and perform test reactions in the pyrolysis of woody biomass in a dual-fluidized bed reactor. The aim is to produce catalytic materials which have good mechanical strength and are still able to de-oxygenate the pyrolysis oil. 

Zeolite-bentonite hybrid catalysts have been prepared from ZSM-5 and Beta zeolites supplied by Zeolyst International and bentonite. The zeolite to bentonite ratio was 35/65. The Si02 to A1203 ratio of ZSM-5 and Beta was 23 and 25, respectively. The preparation of the material was conducted in the following way. The zeolite and the bentonite were bound together through mixing in a 6 1 aqueous solution at 60°C for 2h,... 

Pyrolysis and catalytic de-oxygenation of pine wood biomass was successfully carried out in a dual-fluidized bed reactor. Hybrid catalysts consisting of zeolites Beta and ZSM-5 and bentonite were used. Pure zeolites Beta and ZSM-5 and also pure bentonite were tested as bed materials in the fluidized bed reactor. 

Keywords polysaccharides, zeolite shaping, zeolitisation, hybrid materials. 

As will be shown throughout the chapter, the parent PPV 1 is extensively used as a holetransporting layer (HTL) in combination with other EL polymers. Recently, improved photostability of organic inorganic hybrid EL material, prepared by incorporating PPV 1 into zeolite capsules, was described [54]. However, the material showed only weak EL (at driving voltage of 2.5 V). 

Ren, Z., et ah, Hybridizing photoactive zeolites with graphene a powerful strategy towards superiorphotocatalytic properties. Chemical Science, 2012. 3(1) p.209-216. 

In addition to this, solid acid catalysts can also be used in the hydroisomerization cracking of heavy paraffins, or as co-catalysts in Fischer-Tropsch processes. In the first case, it could also be possible to transform inexpensive refinery cuts with a low octane number (heavy paraffins, n-Cg 20) to fuel-grade gasoline (C4-C7) using bifunctional metal/acid catalysts. In the last case, by combining zeolites with platinum-promoted tungstate modified zirconia, hybrid catalysts provide a promising way to obtain clean synthetic liquid fuels from coal or natural gas. 

The past nearly six decades have seen a chronological progression in molecular sieve materials from the aluminosilicate zeolites to microporous silica polymorphs, microporous aluminophosphate-based polymorphs, metallosilicate and metaHo-phosphate compositions, octahedral-tetrahedral frameworks, mesoporous molecular sieves and most recently hybrid metal organic frameworks (MOFs). A brief discussion of the historical progression is reviewed here. For a more detailed description prior to 2001 the reader is referred to [1]. The robustness of the field is evident from the fact that publications and patents are steadily increasing each year. 

Eerey, G. (2007) Hybrid porous solids, in Introduction to Zeolite Science and Practice, 3rd Revised edn, (eds J. Cejka,... 

Oxidations initiated by thermally induced electron transfer in an oxygen-CT complex represent the thermal analog of the Frei photo-oxidation and are properly classified as hybrid type IlAOi-type IIaRH oxidations (Fig, 2), Such reactions require either zeolites with high electrostatic fields or substrates with low oxidation potentials. In addition, elevated temperatures are known to promote the thermally initiated electron-transfer step, although the possible intrusion of a classical free-radical initiation chain oxidation at higher temperatures must be considered. 

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