fulltext.study @t Gmail

Effect of SAPO-34's composition on its physico-chemical properties and deactivation in MTO process

Paper ID Volume ID Publish Year Pages File Format Full-Text
42861 45944 2009 9 PDF Available
Title
Effect of SAPO-34's composition on its physico-chemical properties and deactivation in MTO process
Abstract

Several SAPO-34 samples with different Si/Al ratio (0.05–0.5) of synthesis gel were prepared hydrothermally at crystallization temperature of 190–215 °C. The products were characterized by XRD, SEM/EDX, NH3-TPD, FT-IR and nitrogen adsorption techniques. EDX data showed a deviation of elemental composition of products with respect to the Al, Si, and P from that of the gel mixture, but the increasing trend of Si/Al ratio of the products was confirmed. According to XRD and SEM results, crystallinity of samples increased with Si/Al ratio up to the low to medium range of ca. 0.13. However, a reduction in the crystallinity was observed with further increase of the silicon content of the synthesis gels. Interestingly, temperature programmed desorption of ammonia results did not show any significant change in the number of the strong acid sites which was re-confirmed by Fourier transformed infrared and thermo gravimetery results. These results along with those of reactor performance tests at reaction temperature of 400 °C and methanol flow of WHSV = 1 h−1 indicated that SAPO-34 crystallinity, a factor influenced by the Si/Al ratio, is an important parameter for the coking behavior in the methanol to olefin conversion. The samples with higher crystallinity (Si/Al = 0.13–0.22) led to a longer life time (100% activity) in the reactor of up to 3 h instead of 1 h for those with lower crystallinity.

Graphical abstractCrystallinity of SAPO-34 samples with different Si/Al ratio (0.05–0.5) of synthesis gel showed a maximum at low to medium range of Si/Al ratio around 0.13. Interestingly, NH3-TPD, FTIR and TG results did not show any significant change in the number of the strong acid sites. Performing reactor tests indicated that SAPO-34 samples with higher crystallinity led to a longer life time in the reactor.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
MTO; Acidity; Life time; SAPO-34; Silicon content
First Page Preview
Effect of SAPO-34's composition on its physico-chemical properties and deactivation in MTO process
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 364, Issues 1–2, 31 July 2009, Pages 48–56
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