99-62-7Relevant articles and documents
Stabilizing Low-Silica Zeolites through Aluminum Sulfate Assisted Cannibalistic Dealumination
Shi, Zongbo,Ji, Peng,Zhu, Zhiguo,Jiang, Jin-Gang,Fu, Wenhua,Wu, Peng,Wang, Yimeng,He, Mingyuan
, p. 1891 - 1895 (2016)
A versatile dealumination strategy was proposed to stabilize low-silica zeolites through cannibalistic interaction between the host framework Al (FAL) and the guest aluminum salt. It is possible to capture selectively the FAL and Na ions in NaY zeolite by employing a special external Al source such as aluminum sulfate as the dealuminating agent. This unique postmodification reduces the FAL amount efficiently and converts the chemically reacted Al species into a γ-alumina support for the catalytically active component of zeolite, which avoids wasting Al sources. Possessing greatly enhanced hydrothermal stability, newly generated intracrystal mesopores, as well as an optimized distribution of FAL, the resultant dealuminated Y zeolite catalysts can be used practically in heavy oil cracking.
PROCESS FOR MAKING CUMENE BY ALKYLATION OF BENZENE USING AN ORGANOTEMPLATE-FREE ZEOLITE BETA
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Paragraph 0079, (2017/04/23)
A process for making cumene by the alkylation of benzene with propylene using a benzene alkylation catalyst that comprises an organotemplate-free zeolite beta having a silica-to-alumina molar ratio of less than 20 and synthesized without an organic structure directing agent (SDA).
A comparative study on catalytic performance of modified nanocrystalline and microcrystalline zeolite X for synthesis of cumene by transalkylation of 1,4-diisopropylbenzene with benzene
Thakur,Barman
, p. 592 - 601 (2016/10/18)
Cumene is a commercially important product in the petrochemical industries. In isopropylation of benzene, 1,4-diisopropyl benzene (1,4-DIPB) is produced as low value by-product. This low value by-product DIPB is used to maximize the production of commercially important product cumene by transalkylation reaction. Reduction of crystal size in zeolite can increase surface area of the external surface and in this way bring about substantial changes in catalytic activity. Moreover modification with rare-earth metal enhances the acidity of zeolite. In this work, nanocrystalline and microcrystalline zeolite X were modified with cerium to study the combine effect of crystal size and ion modification of zeolite on selectivity of cumene in commercially important transalkylation reaction. Benzene and 1,4-diisopropylbenzene in a molar ratio of 1 to 12.5 were subjected to vapour-phase reaction in the temperature range of 498 to 593 K at atmospheric pressure with space time of 5.27–10.54 kg h/kmol. Nanosized crystalline zeolite gives much higher conversions of 1,4-DIPB than microcrystalline zeolite. Over cerium modified nanosized zeolite CeXN 81.85% conversion of 1,4-DIPB and 97% cumene selectivity were achieved. It was found that stability and activity of CeXN for cumene synthesis was much higher than that of CeXM zeolite. Kinetic constants for the reactions were estimated and the activation energies for various reactions over CeXM were determined. The activation enegy for transalkylation reaction was found to be 78.54 kJ/mol.