Comparison studies of xylene isomerization and disproportionation reactions between SSZ-33, TNU-9, mordenite and ZSM-5 zeolite catalysts
TL;DR: In this paper, the effect of reaction conditions on m -xylene conversion, p-xylene/ o -oxylene (P/O) ratios, ratio of isomerization to disproportionation (I/D) products were investigated over four zeolite catalysts (ZSM-5, mordenite, SSZ-33 and TNU-9) in a riser simulator reactor over the temperature range of 300-400°C.
About: This article is published in Chemical Engineering Journal.The article was published on 2011-01-01. It has received 61 citations till now. The article focuses on the topics: Xylene & Mordenite.
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TL;DR: In this paper, the authors highlight key catalytic discoveries and the main industrial catalytic processes over the last 300 years that involved commodities, fine chemicals, petrochemicals, petroleum transformation for fuels and energy supply, emission control, and so forth.
309 citations
TL;DR: The rational construction of pore models, especially hierarchical features, is highlighted with a careful classification from an industrial perspective accompanied by a detailed analysis of the theoretical mechanisms.
Abstract: The kaleidoscopic applications of zeolite catalysts (zeo-catalysts) in petrochemical processes has been considered as one of the major accomplishments in recent decades. About twenty types of zeolite have been industrially applied so far, and their versatile porous architectures have contributed their most essential features to affect the catalytic efficiency. This review depicts the evolution of pore models in zeolite catalysts accompanied by the increase in industrial and environmental demands. The indispensable roles of modulating pore models are outlined for zeo-catalysts for the enhancement of their catalytic performances in various industrial processes. The zeolites and related industrial processes discussed range from the uni-modal micropore system of zeolite Y (12-ring micropore, 12-R) in fluid catalytic cracking (FCC), zeolite ZSM-5 (10-R) in xylene isomerization and SAPO-34 (8-R) in olefin production to the multi-modal micropore system of MCM-22 (10-R and 12-R pocket) in aromatic alkylation and the hierarchical pores in FCC and catalytic cracking of C4 olefins. The rational construction of pore models, especially hierarchical features, is highlighted with a careful classification from an industrial perspective accompanied by a detailed analysis of the theoretical mechanisms.
254 citations
25 Sep 2014
TL;DR: A comprehensive review of zeolite-based acid catalysts can be found in this paper, where major reactions of mono-, di-, and tri-alkylbenzenes such as disproportionation, alkylation, transalkylation, isomerization, etc.
Abstract: Alkylbenzenes form an important segment of petrochemical industry for the manufacture of widely used commodities and specialty products. Since the last review on this topic (8), numerous new zeolite-based catalysts have been synthesized, characterized and evaluated in various transformations of aromatic hydrocarbons. This comprehensive review covers major reactions of mono-, di-, and tri-alkylbenzenes such as disproportionation, alkylation, transalkylation, isomerization, etc., over different zeolite-based acid catalysts. During the last decade, significant progress was made in the synthesis and structure determination of novel zeolites, mesoporous single crystals, hierarchic zeolites and two-dimensional zeolites. These developments have enhanced the understanding of the role of zeolites (effects of structural type, morphology, acid sites, accessibility of acid sites, shape selectivity factors) in transformations of aromatics. In this review, the emphasis is on the influence of the type of acid sites, zeo...
150 citations
Cites background from "Comparison studies of xylene isomer..."
...Zeolites MFI, MOR, CON, and TUN were also investigated in a riser simulator reactor in m-xylene isomerization and disproportionation in the temperature range 300–400◦C (141)....
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TL;DR: In this article, a kinetic study of toluene alkylation with methanol was performed over pure HZSM-5, mordenite and ZM13 catalysts, and a simplified power law kinetic model consisting of three reactions was developed to estimate the activation energies of methylation and disproportionation simultaneously.
65 citations
TL;DR: The physicochemical properties of the catalysts were investigated by XRD, MP-AES, FESEM, TEM, N2 physisorption and FTIR.
53 citations
References
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TL;DR: In this article, the integrated molar extinction coefficients for infrared absorption bands of pyridine adsorbed on acid sites in Si/Al-based catalysts were determined for infrared spectra of five zeolites and two amorphous silica-aluminas.
2,429 citations
TL;DR: In this article, data were presented for para-selective and nonselective formation of xylenes from alkylation of toluene with methanol and disproportionation over ZSM-5 class zeolite catalysts.
381 citations
TL;DR: In this article, a review of catalytic reactions leading to mono-and dialkyl benzenes over zeolites is presented, with an emphasis on the effect of the type of acid sites, zeolite structure, and reaction conditions on the activity and selectivity of these complex reactions.
Abstract: This review describes mechanisms of catalytic reactions leading to mono- and dialkyl benzenes over zeolites, which represent an important part of petrochemical products. The emphasis is given to the effect of the type of acid sites, zeolite structure, and reaction conditions on the activity and selectivity of these complex reactions, and particularly to the individual products with respect to their iso- vs. n- and ortho-, meta-, and para-isomers. The first part of the paper deals with the description and analysis of the structure and properties of the acid sites, and zeolite pore inner structure applied in synthesis of alkyl benzenes. Individual reactions leading to the synthesis of propyl benzene, xylenes, ethyl toluenes, diethyl benzenes, and transformation of trimethyl benzenes to xylenes from the view point of the reaction mechanism, function of the acid sites, and inner pore geometry of zeolites are described in the second part.
340 citations
TL;DR: In this article, the authors discuss the recent advances in process technology with special focus on improvements of para-isomer selectivity and catalyst stability, and provide perspective trends in related research and development.
Abstract: Disproportionation and transalkylation are important processes for the interconversion of mono-, di-, and tri-alkylbenzenes. In this review, we discuss the recent advances in process technology with special focus on improvements of para-isomer selectivity and catalyst stability. Extensive patent search and discussion on technology development are presented. The key criteria for process development are identified. The working principles of para-isomer selectivity improvements involve the reduction of diffusivity and the inactivation of external surface. In conjunction with the fundamental research, various practical modification aspects particularly the pre-coking and the silica deposition techniques, are extensively reviewed. The impact of para-isomer selective technology on process economics and product recovery strategy is discussed. Furthermore, perspective trends in related research and development are provided.
331 citations