The Influence of Mechanochemical Treatment on the Acid and Catalytic Properties of Modified Natural Zeolite

Vassilina, Gulzira; Raisa, Moisa; Yermoldina, Elmira; Zhaksyntay, Kayrbekov

doi:10.4028/www.scientific.net/amr.535-537.2127

Cited by 2 publications

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“…Zeolite materials have a microporous structure, which is constructed from the combination of SiO 4 and AlO 4 tetrahedral units. These materials have been widely applied in catalysts as well as in separation and purification processes due to their regular porous structures, high thermal resistance, and high surface areas. − Several studies have investigated the acidity and structural properties of zeolite. − In general, the pore size and acidity of zeolite are modified to minimize coke formation and to maximize the selectivity to light fuel. In fact, strong acidic sites are needed to initiate the cracking process, and special characters of pore structures are needed to limit the coke formation .…”

Section: Introductionmentioning

confidence: 99%

Catalytic Study of Hexadecane Cracking over Novel and Efficient HY/Al-HMS/K10 Hybrid Catalysts

Masoudinejad

Mahdavi

2019

Energy Fuels

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The aim of this study is to provide a new and high-performance catalytic system for the cracking process by combining HY-zeolite, Al-hexagonal mesoporous molecular sieves (HMS) as a new matrix, and montmorillonite K10 as filler components. The Al-HMS molecular sieve was synthesized with different Si/Al molar ratios in the range of 2.5–35 and assembled with various amounts of HY-zeolite and montmorillonite K10 to prepare two- and three-component catalysts. After calcination, their catalytic activities were investigated in a cracking reaction of n-hexadecane at 500 °C and atmospheric pressure as a model reactant. The structure and surface properties of the synthesized catalysts were characterized by X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller, temperature-programmed desorption of NH3, and pyridine-IR techniques. Results indicated that the desired hybrid catalysts were successfully synthesized with the micro-mesoporous structures, high surface area, and suitable pore volume, and their performance was directly related to the strength of Lewis and Brønsted acid sites as well as the ratio of microporous–mesoporous structures. The optimized ZAK(35) catalyst (containing 35 wt % NH4Y, 50 wt % K10, 15 wt % Al-HMS(5), and Si/Al molar ratio of 5 in matrix) with proper textural properties, appropriate ratio of mesopore to microspore structure, suitable thermal stability to about 750 °C, and a higher Brönsted/Lewis acid sites ratio exhibited an excellent ability in the cracking of n-hexadecane. In optimum condition over the ZAK(35) catalyst, n-hexadecane conversion of 69% was achieved, and the selectivity values of gasoline, liquefied petroleum gas, and dry gas were 71, 20, and 4.5%, respectively.

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Section: Introductionmentioning

confidence: 99%

Catalytic Study of Hexadecane Cracking over Novel and Efficient HY/Al-HMS/K10 Hybrid Catalysts

Masoudinejad

Mahdavi

2019

Energy Fuels

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An FCC Catalyst for Maximizing Gasoline Yield

He¹,

Zheng²,

Dai³

2017

Kem. Ind.

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A Y zeolite-containing wide-pore composite was synthesized by in situ technique using polyvinyl alcohol and silica sol material. A fluid catalytic cracking (FCC) catalyst for maximizing gasoline yield was successfully developed with the modified composition. The as-made zeolite Y in its sodium form had a relative crystallinity of 52.9 % with a high silica/alumina amount of substance ratio of 5.7. The FTIR analysis showed that the acid distribution of the catalyst modified with rare earth, phosphorus and steaming stabilization process was more concentrated on the range of intermediate and strong acidity. This kind of modification can direct more hydrocarbons to enter into the pores to be converted, as well as remarkably increases the possibility of gasoline formation through a cracking reaction. The nitrogen adsorption-desorption analysis showed that the catalyst had more meso-and macro-pores distribution, which can effectively reduce the mass-transfer resistance in the reaction process and accelerate the diffusion of the product molecules. The evaluated results indicated that the prepared catalyst could decrease the excessive cracking of middle distillate and improve the gasoline yield effectively. The gasoline yield by mass had increased by 2.69 %, while the coke yield and dry gas yield had decreased by 0.91 % and 0.19 %, respectively, and then the olefin content by volume in the cracked gasoline reduced by 4.6 %, the research octane number (RON) and motor octane number (MON) increased by 0.6 and 0.5, respectively. The good product selectivity and higher gasoline yields of the prepared catalyst were obviously related to its wide pore structure and its optimized acidity distribution.

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The Influence of Mechanochemical Treatment on the Acid and Catalytic Properties of Modified Natural Zeolite

Cited by 2 publications

References 1 publication

Catalytic Study of Hexadecane Cracking over Novel and Efficient HY/Al-HMS/K10 Hybrid Catalysts

Catalytic Study of Hexadecane Cracking over Novel and Efficient HY/Al-HMS/K10 Hybrid Catalysts

An FCC Catalyst for Maximizing Gasoline Yield

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