fulltext.study @t Gmail

Selective synthesis for light olefins from acetone over ZSM-5 zeolites with nano- and macro-crystal sizes

Paper ID Volume ID Publish Year Pages File Format Full-Text
41418 45888 2011 9 PDF Available
Title
Selective synthesis for light olefins from acetone over ZSM-5 zeolites with nano- and macro-crystal sizes
Abstract

Production of light olefins such as ethylene, propylene and isobutylene from acetone was examined over ZSM-5 zeolites. These light olefins are produced from acetone over the acid sites of the zeolite via a series of consecutive reactions where olefins such as ethylene and propylene are obtained by cracking of isobutylene produced from aldol condensation products of acetone. Macro- and nano-sized ZSM-5 zeolites were prepared by conventional hydrothermal and emulsion methods, respectively, and the ZSM-5 zeolites with nearly the same acidity and BET surface area were obtained regardless of the crystal sizes. From SEM observations, the crystal sizes of the zeolites were approximately 2000 nm and 30–40 nm. These zeolites with different crystal sizes were applied to light olefins synthesis from acetone, and the effect of crystal size on catalytic activity and stability was investigated. As compared with the macro-seized zeolite, the nano-sized zeolite exhibited a high activity over a long lifetime. However, because the nano-sized zeolite possesses a large external surface area, undesirable reactions to form aromatics from the produced light olefins occurred on the acid sites located near the external surface. To inhibit aromatics formation, selective deactivation of the acid sites located near the outer surface of the zeolite was achieved via the catalytic cracking of silane (CCS) method using diphenyl silane (DP-silane). The CCS method was effective in deactivating the acid sites located near the external surface of the ZSM-5 zeolite. Moreover, the nano-size zeolite after the CCS treatment using DP-silane exhibited high olefins and low aromatics yields under high acetone conversion conditions.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (195 K)Download as PowerPoint slideHighlights► C2–C4 light olefins synthesis from acetone over ZSM-5 zeolites. ► The nano-sized zeolite shows longer catalyst lifetime than macro-sized zeolite. ► Selective deactivation of acid sites near the external surface. ► Improvement of olefins yield by the selective deactivation of acid sites.

Keywords
ZSM-5 zeolite; Crystal size; Light olefins
First Page Preview
Selective synthesis for light olefins from acetone over ZSM-5 zeolites with nano- and macro-crystal sizes
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 403, Issues 1–2, 22 August 2011, Pages 183–191
Authors
, , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us