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Internal versus external surface active sites in ZSM-5 zeolite: Part 2: Toluene alkylation with methanol and 2-propanol catalyzed by modified and unmodified H3PO4/ZSM-5

Paper ID Volume ID Publish Year Pages File Format Full-Text
43735 45986 2007 15 PDF Available
Title
Internal versus external surface active sites in ZSM-5 zeolite: Part 2: Toluene alkylation with methanol and 2-propanol catalyzed by modified and unmodified H3PO4/ZSM-5
Abstract

Vapor-phase methylation of toluene with methanol and isopropylation of toluene with 2-propanol has been investigated in a down flow reactor under atmospheric conditions using N2 gas carrier over a series of surface modified and unmodified ZSM-5 (Si/Al = 60–170) loaded with H3PO4, differing in the external surface treatment of the zeolites. The feed molar ratios of toluene/methanol and toluene/2-propanol were varied over a wide range (8–0.125), and the optimum feed ratio of toluene/alcohol was less than 0.5 in both cases. Space velocity employed in toluene methylation reported as WHSV (toluene) = 1.2 h−1, and the space velocity employed in toluene isopropylation reported as WHSV (toluene) = 0.8 h−1. The methylation reactions were carried out in the temperature range of 623–773 K, and the isopropylation reactions were carried out in the temperature range of 483–583 K. Atmospheric pressures was maintained in all runs. Catalysts containing 0–4.9 wt.% P were prepared using modified and unmodified ZSM-5 zeolites, and their catalytic performance for vapor-phase alkylation of toluene with methanol and 2-propanol were investigated. The optimum phosphorous content for methylation was 2.1 wt.% P which was greater than the optimum phosphorous loading for isopropylation (0.7 wt.% P).

Graphical abstractVapor-phase methylation of toluene with methanol and isopropylation of toluene with 2-propanol has been investigated in a down flow reactor under atmospheric conditions using N2 gas carrier over a series of surface modified and unmodified ZSM-5 (Si/Al = 60–170) loaded with H3PO4. Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Toluene alkylation; 2-Propanol; H3PO4; Modified ZSM-5; Cymene; Xylene; Catalyst
First Page Preview
Internal versus external surface active sites in ZSM-5 zeolite: Part 2: Toluene alkylation with methanol and 2-propanol catalyzed by modified and unmodified H3PO4/ZSM-5
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 316, Issue 1, 2 January 2007, Pages 32–46
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis