Optimization of desilication parameters of low-silica ZSM-12 by Taguchi method

Akyalçın, Sema; Akyalçın, Levent; Bjørgen, Morten

doi:10.1016/j.micromeso.2018.07.014

Cited by 32 publications

(15 citation statements)

References 42 publications

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“…The existence of some broken crystals in the alkalitreated catalysts can be interpreted by the dissolution of zeolite crystals as well as framework destruction. Similar results have been obtained by other researchers after desilication of ZSM-5 zeolites (Gorzin et al 2018(Gorzin et al , 2019aAkyalcin et al 2019;Rahmani and Taghizadeh 2017). One of the advantages of the desilicated catalysts is having open pores that facilitate mass transfer and enhance the catalytic activity in the MTP reaction, which will be presented further.…”

Section: Textural Properties and Morphologysupporting

confidence: 87%

“…This enhancement in acidity is caused by the enhanced Al content, a fact that can be related to a more selective desilication when alkaline treatment at standard conditions is carried out. The increment in the aluminum for specimens that underwent alkaline treatment was also previously reported in the literature (Ahmadpour and Taghizadeh 2015b;Sadowska et al 2013b;Akyalcin et al 2019;Rahmani and Taghizadeh 2017;Tzoulaki et al 2012;Góra-Marek et al 2014). The stability of the specimens and selectivity of the light olefin cut in the MTP process isstrongly dependent on the suitable acid site content.…”

Section: Aciditysupporting

confidence: 74%

“…According to the literature (Gorzin et al 2018;Gou et al 2015;Tang et al 2019;Groen et al 2005), since Si-OH-Si bonding in the presence of OH − (mixture of NaOH and TPAOH solution) is more readly hydrolyzed as opposed to that of the Si-OH-Al bonding, the dissolution of silicon from the zeolite body is easier compared to that of aluminum when treated in alkaline conditions. Silicon is removed from the framework and the zeolite contains more aluminum (Akyalcin et al 2019). As shown in Table 2, a more critical reduction in the Si/Al molar ratio occurred when the highest alkali concentration was used.…”

Section: Chemical Composition and Catalyst Structurementioning

confidence: 99%

See 2 more Smart Citations

Preparation of hierarchical H-[B]-ZSM-5 zeolites by a desilication method as a highly selective catalyst for conversion of methanol to propylene

Beheshti

Ahmadpour

Behzad

et al. 2020

Braz. J. Chem. Eng.

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A hydrothermal route was exploited to prepare high-silica H-ZSM-5 as well as H-[B]-ZSM-5 zeolites, and the boron-modified type was then desilicated with alkaline treatment. The properties of catalysts were investigated by different techniques, and the catalytic performance was evaluated in the methanol to propylene reaction. The effects of three critical desilication parameters, including the alkali concentration, temperature, and treatment time were evaluated on propylene selectivity and mesopore volume. The results of characterizations evinced that the incorporation of B in the H-ZSM-5 zeolite reduced the total surface area as well as the pore volume of the H-[B]-ZSM-5 sample and increased the external surface area. Furthermore, a significant increase in the weak acid site density for the boron-containing specimen was observed. Also, the external surface area and mesopore volume of the desilicated specimens underwent an increment, while the micropore volume was almost constant. As opposed to the H-[B]-ZSM-5 catalyst, the optimum desilicated catalyst exhibited higher selectivity to propylene (48.8 vs. 40.7%) and total light olefins (76.9 vs. 71.2%), and a higher ratio of propylene to ethylene (5.66 vs. 4.15). The optimum catalyst had a higher lifetime in the MTP reaction (867 h) as opposed to the microporous H-[B]-ZSM-5 catalyst (498 h).

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Section: Textural Properties and Morphologysupporting

confidence: 87%

Section: Aciditysupporting

confidence: 74%

Section: Chemical Composition and Catalyst Structurementioning

confidence: 99%

See 1 more Smart Citation

Preparation of hierarchical H-[B]-ZSM-5 zeolites by a desilication method as a highly selective catalyst for conversion of methanol to propylene

Beheshti

Ahmadpour

Behzad

et al. 2020

Braz. J. Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…This likely occurs because not all interactions are reflected when predicting values using the orthogonal array experiment design. For this reason, while orthogonal array experimental design techniques are used in many fields [50][51][52], their experimental predictions are not well utilized. In a study by Chen [53], an optimal process was designed using an orthogonal array table, but a loss function value was used instead of an experimental value.…”

Section: Experimental Evaluation Of the Model Accuracymentioning

confidence: 99%

The Experimental Process Design of Artificial Lightweight Aggregates Using an Orthogonal Array Table and Analysis by Machine Learning

Wie

Lee

et al. 2020

Materials

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The purpose of this study is to experimentally design the drying, calcination, and sintering processes of artificial lightweight aggregates through the orthogonal array, to expand the data using the results, and to model the manufacturing process of lightweight aggregates through machine-learning techniques. The experimental design of the process consisted of L18(3661), which means that 36 × 61 data can be obtained in 18 experiments using an orthogonal array design. After the experiment, the data were expanded to 486 instances and trained by several machine-learning techniques such as linear regression, random forest, and support vector regression (SVR). We evaluated the predictive performance of machine-learning models by comparing predicted and actual values. As a result, the SVR showed the best performance for predicting measured values. This model also worked well for predictions of untested cases.

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“…Despite the broad literature on the subject, the articles do not report the effects of desilication on crystals of different sizes [7][8][9][10][11][12][13][14][15][16] . In this context, the main goal of this study was to characterize the ZSM-5 and ZSM-12 zeolites with different crystals sizes and Si/Al ratio ideal for the generation of intracrystalline porosity by silicon removal.…”

Section: Introductionmentioning

confidence: 99%

Desilication of ZSM-5 and ZSM-12 Zeolites with Different Crystal Sizes: Effect on Acidity and Mesoporous Initiation

et al. 2019

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In the present work, the desilication of the H-ZSM-5 and H-ZSM-12 zeolites with Si/AL ratios of 28 and 56 and crystal sizes of around 200 and 600 nm, respectively, was performed. Through electron transmission microscopy analysis, it was possible to verify the influence of aluminium gradients on smaller crystals in addition to the exact moment at which the formation of mesoporous is initiated inside the zeolitic framework. Moreover, the crystal size exerts a significant influence on the total amount of acid sites remaining after alkaline treatment, as verified by means of temperature-programmed desorption of ammonia. This is because the presence of larger crystals during desilication may increase the likelihood of reinsertion of aluminium atoms in the zeolite framework and, consequently, maintain the same total amount of acid sites in the zeolite as before alkaline treatment. Meanwhile, aluminium atoms tend to be removed from smaller crystals, thereby decreasing the total amount of acid sites.

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Optimization of desilication parameters of low-silica ZSM-12 by Taguchi method

Cited by 32 publications

References 42 publications

Preparation of hierarchical H-[B]-ZSM-5 zeolites by a desilication method as a highly selective catalyst for conversion of methanol to propylene

Preparation of hierarchical H-[B]-ZSM-5 zeolites by a desilication method as a highly selective catalyst for conversion of methanol to propylene

The Experimental Process Design of Artificial Lightweight Aggregates Using an Orthogonal Array Table and Analysis by Machine Learning

Desilication of ZSM-5 and ZSM-12 Zeolites with Different Crystal Sizes: Effect on Acidity and Mesoporous Initiation

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