fulltext.study @t Gmail

Size control of SAPO-34 crystals and their catalyst lifetime in the methanol-to-olefin reaction

Paper ID Volume ID Publish Year Pages File Format Full-Text
42705 45937 2009 7 PDF Available
Title
Size control of SAPO-34 crystals and their catalyst lifetime in the methanol-to-olefin reaction
Abstract

Crystals of SAPO-34 molecular sieves were synthesized under hydrothermal conditions by using tetraethylammonium hydroxide (TEAOH), morpholine (Mor), N,N,N’,N’-tetraethylethane-1,2-diamine (TEEDA), or a mixture of TEAOH and Mor as structure-directing agents (SDA). The crystal growth of SAPO-34 was studied by X-ray diffraction and by scanning electron microscopy and field-emission scanning electron microscopy. The crystal size of SAPO-34 could be controlled between 1.5 and 7 μm by hydrothermal synthesis using a mixture of TEAOH and Mor as the SDA. Small SAPO-34 crystals (800 nm in size) were formed when TEAOH was used as the SDA. The smaller SAPO-34 crystals showed a longer catalyst lifetime in the methanol-to-olefins reactions. The amount of coke deposited on deactivated SAPO-34 catalyst increased with decreasing crystal size, indicating that the effectiveness of the catalyst could be improved by reducing the crystal size of SAPO-34.

Graphical abstractThe crystal size of SAPO-34 could be controlled from 0.8 to 7 μm by the hydrothermal synthesis using tetraethylammonium hydroxide (TEAOH) and a mixture of TEAOH and morpholine. The smaller SAPO-34 crystals showed a longer catalyst lifetime in methanol-to-olefins reactions. The catalyst effectiveness could be improved by reducing the crystal size of SAPO-34.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
SAPO-34; MTO; Crystal size control; Structure-directing agent
First Page Preview
Size control of SAPO-34 crystals and their catalyst lifetime in the methanol-to-olefin reaction
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 362, Issues 1–2, 30 June 2009, Pages 193–199
Authors
, , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis