fulltext.study @t Gmail

Modifications in the HZSM-5 zeolite for the selective transformation of ethylene into propylene

Paper ID Volume ID Publish Year Pages File Format Full-Text
39742 45834 2014 9 PDF Available
Title
Modifications in the HZSM-5 zeolite for the selective transformation of ethylene into propylene
Abstract

•K, P and mild in situ steaming decreases acidity and acid strength of HZSM-5 zeolite.•The decrease in acid strength attenuates secondary reactions and coke deposition.•Ethylene conversion needs an intermediate acidity for selectively obtaining propylene.•HZSM-5 (SiO2/Al2O3 = 80) modified by mild in situ steaming yields 37% of propylene.

Propylene production in the transformation of ethylene has been studied on HZSM-5 zeolite catalysts of different SiO2/Al2O3 ratio (30, 80 and 280), doped (1 wt.%) with K or P or treated by mild in situ steaming, in order to attenuate their acidity. The experiments have been carried out in a fixed bed reactor at 500 °C, space time of 3.2 (gcatalyst h)(molCH2)−13.2 (gcatalyst h)(molCH2)−1 and time on stream up to 15 h. The results highlight the effect catalyst acidity has on ethylene conversion, catalyst stability (deactivation by coke deposition) and propylene yield. The balance between these indices entails the use of a zeolite of moderate acidity subjected to a mild treatment in order to maintain a suitable activity for propylene formation by oligomerization-cracking reactions, and thus minimizing secondary reactions of hydrogen transfer and aromatization. A propylene yield of 37% is obtained for a time on stream of 11.3 h with the HZSM-5 zeolite catalyst of SiO2/Al2O3 = 80 modified by mild in situ steaming treatment.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (122 K)Download as PowerPoint slide

Keywords
HZSM-5 zeolite; Propylene; Ethylene; Deactivation; Acidity
First Page Preview
Modifications in the HZSM-5 zeolite for the selective transformation of ethylene into propylene
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 479, 5 June 2014, Pages 17–25
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