Synthesis Of ZSM-5 Zeolite Research Articles

Kinetic modeling of the removal of phenolic compounds from olive mill wastewater by hierarchical zeolite/carbon nanotubes: Isotherm, kinetics, and thermodynamic

ABSTRACT In this study, plain zeolite (ZSM5) and hierarchical zeolite (H-ZSM5) were synthesized as efficient adsorbents for the removal of polyphenolic/antioxidant compounds from olive mill wastewater (OMW). The XRD and FTIR results confirmed the successful synthesis of ZSM5 zeolites. SEM images and BET demonstrated that H-ZSM5 possessed a markedly greater surface area of 337.99 m2/g in contrast to ZSM5 (162.84 m2/g). For H-ZSM5, the values determined for pore volume, total volume, and pore diameters are 77.655 cm3 g−1, 0.1844 cm3 g−1, and 2.1826 nm. The absolute zeta potential values varied between 5.36 ± 1.21 and − 46.41 ± 1.32 mV, with the peak absolute value of − 46.41 ± 1.32 mV occurring at pH 4. The optimal conditions for the removal of phenolic compounds, achieving an efficiency exceeding 90%, were identified as a pH of 4, an adsorbent dosage of 50 mg, and a contact duration of 90 minutes. The adsorption isotherm was found to align with the Langmuir model rather than the Freundlich model, indicating a monolayer adsorption capacity of 48.7 mg/g. Kinetic studies were consistent with a pseudo-first-order model (R2 >0.99). Ultimately, the thermodynamic analysis suggested that the adsorption of OMW onto ZSM5 is both spontaneous and governed by a physisorption mechanism.

Hierarchized ZSM-5 Zeolite Synthesis using N-Methyldiethanolamine as a Novel Desilicate Agent: Impact on Methanol Adsorption and Resistance Improvement to Coke Poisoning

Hierarchized ZSM-5 Zeolite Synthesis using N-Methyldiethanolamine as a Novel Desilicate Agent: Impact on Methanol Adsorption and Resistance Improvement to Coke Poisoning

Biochar-mediated synthesis of ZSM-5 zeolite for the methanol-to-olefins reaction

The present study reports the successful synthesis of ZSM-5 zeolites with high external specific surface area by using biochar as a hard template. The physicochemical properties of the biochars (originated from grass, tea and lignin) were studied using XRD, SEM EDX, FTIR and other characterization techniques. The results showed that biochars obtained from different plants, due to the differences in morphology, particle size, composition and surface functional groups, led to significant effects on the morphology and acidity of the zeolite crystals. These ZSM-5 zeolites exhibited a significantly improved performance in the Methano-To-Olefins (MTO) reaction. Indeed, the catalyst lifetime of parent ZSM-5 started to decline after 6 h, whilst ZSM-5 modified by Grass-C only suffered a loss in conversion after 10 h on stream (at 400 °C, WHSV=8 h−1).

Tuning crystal size and inhibiting aggregation by adding guanidinoacetic acid in ZSM-5 zeolite synthesis for catalysing methanol-to-olefin reaction

Tuning crystal size and inhibiting aggregation by adding guanidinoacetic acid in ZSM-5 zeolite synthesis for catalysing methanol-to-olefin reaction

Synthesis of ZSM-5 Zeolites from Quang Ninh Coal Ash Components and Activity for Catalytic Cracking of Low-density Polyethylene

Synthesis of ZSM-5 Zeolites from Quang Ninh Coal Ash Components and Activity for Catalytic Cracking of Low-density Polyethylene

Design synthesis of ZSM-5 zeolite with yolk-shell structure by Oswald ripening for aromatization of coal-oil co-refining oils

Aiming to improve the catalytic performance of HZSM-5 in the catalytic conversion of coal-oil co-refining oil, a range of zeolite catalysts (HZ5-xD) were prepared by adjusting the recrystallization times of dissolution–recrystallization of HZSM-5 basing on the Oswald ripening mechanism. The results show that HZ5-xD processes more easily accessible active sites and mixed microporous-mesoporous structures. Larger pore size and moderate acidity were beneficial for the generation of benzene, toluene, ethylbenzene and xylene (BTEX). The selectivity and yield of reached as high as 29.76 % and 236.83 mg·g−1 over HZ5-2D at 700 °C, respectively. Both HZSM-5 and HZ5-xD demonstrate high selectivity to C3 gaseous hydrocarbons, likely due to the obedience of the carbenium ion mechanism. HZ5-2D still demonstrated more excellent catalytic performance than HZSM-5 after five regenerations. Collectively, these finding illustrates the broad application potential of Oswald ripening in special morphologies of zeolite to improve the conversion efficiency of coal tar to BTEX.

An eco-friendly method for the scale-up synthesis of ZSM-5 Zeolite

Scaling-up is the key step of the commercialisation of ZSM-5 zeolite, and the cost-effectiveness and greenness of the synthesis strategy is a decisive factor that cannot be ignored in the scale-up process. Herein, we present a template-free and solid-state-like crystallisation method for the synthesis of ZSM-5 zeolite by mechanical mixing of starting material components, which can be used for the scale-up production of ZSM-5 zeolite. The crystallisation range of ZSM-5 zeolite was obtained by this mechanical mixing of anhydrous starting materials. We have analyzed the kinetics study of three different Na2O/Al2O3/SiO2 systems in the range, and obtained the trends of nucleation and growth activation energy. The results show that mechanical mixing can effectively achieve a high degree of homogenous dispersion of the starting material, which is conducive to obtaining ZSM-5 with high crystallinity and size uniformity. We have synthesised monolithic ZSM-5 with high crystallinity and uniform grain size of about 2 g, 30 g and 120 g in different sizes (2.5 ml/50 ml/200 ml) of Teflon lined high pressure reactors in a single synthesis method. This study affirms the possibility of achieving the scale-up of ZSM-5 zeolite synthesis through the synthetic pathway proposed, presenting a cost-effective, eco-friendly strategy for the industrial preparation of ZSM-5 zeolite.

Study on the effect of inorganic aluminum sources on ZSM-5 zeolite synthesis by solvent-free method from rice husk ash

Study on the effect of inorganic aluminum sources on ZSM-5 zeolite synthesis by solvent-free method from rice husk ash

Synthesis of Dendritic ZSM-5 Zeolite through Micellar Templating Controlled by the Amphiphilic Organosilane Chain Length.

The synthesis of ZSM-5 zeolites by hydrothermal crystallization of protozeolitic nanounits functionalized with amphiphilic organosilanes of different chain length (Cn-N(CH3)2-(CH2)3-Si-(OCH3)3, n = 10, 14, 18 and 22) has been investigated. Well-developed dendritic nanoarchitectures were achieved when using C14 and C18 organosilanes, exhibiting a radial and branched pattern of zeolitic nanounits aggregates. In contrast, although C10 and C22 organosilanes led to materials with hierarchical porosity, they lack of dendritic features. These differences have been linked to the formation of an amorphous mesophase at the gel preparation stage for the C14 and C18 samples, in which the surfactant micelles are covalently connected with the protozeolitic nanounits through siloxane bonds. The presence of the dendritic nanostructure positively impacts both the textural and catalytic properties of ZSM-5 zeolite. Thus, ZSM-5 (C14) and ZSM-5 (C18) samples exhibit the largest contribution of mesoporosity in terms of both surface area and pore volume. On the other hand, when tested as catalysts in the aldol condensation of furfural with cyclopentanone, which is an interesting reaction for the production of sustainable jet fuels, the highest catalytic activity is attained over the dendritic ZSM-5 materials due to their remarkable accessibility and balanced Brønsted/Lewis acidity.

Characterization of Zeolite ZSM-5 Synthesized from Kaolin and TPABr Using X-Ray Diffraction and Infrared Spectroscopy

Kaolin with alumina and silica content is used as the main material in this research to study the synthesis of ZSM-5 zeolite. The hydrothermal process was carried out through different aging times, namely 12, 24 and 36 hours. Tetrapropyl ammonium bromide (TPABr) was used as a template for the Mobile Five-1 (MFI) structure guide. X-ray diffraction (XRD) and infrared spectroscopy (FTIR) instruments were used to characterize the ZSM-5 zeolite formed from the synthesis results. This was done to identify the phase change from kaolin to zeolite ZSM-5. The results of the analysis using XRD for all samples showed a characteristic peak of the ZSM-5 zeolite at 2θ around 7.88°; 8.72° ;23.09°; 23.84° and 24.32°. However, samples with an aging time of 12 hours also showed peaks at 2θ around 15.84° and 26.03° which indicated an analsim phase. The absorption bands from the FTIR characterization for all samples are seen at wave numbers around 453, 542, 793, 1088 and 1221 cm−1 which are the characteristic peak points of ZSM-5 zeolite. The longer the aging time indicates that the crystallinity of the ZSM-5 zeolite is increasing. The highest crystallinity was obtained from ZSM-5 zeolite samples which were aged for 36 hours. This indicates an increasing number of ZSM-5 crystal nuclei with high purity because there is no other phase besides the ZSM-5 phase.

Effects of aging and hydrothermal treatment on the crystallization of ZSM-5 zeolite synthesis from bentonite.

In the present study, Lam Dong bentonite clay was utilized as a novel resource to effectively synthesize microporous ZSM-5 zeolite (Si/Al ∼ 40). The effects of aging and hydrothermal treatment on the crystallization of ZSM-5 were carefully investigated. Herein, the aging temperatures of RT, 60, and 80 °C at time intervals of 12, 36, and 60 h, followed by high temperature hydrothermal treatment (170 °C) for 3-18 h were studied. Techniques such as XRD, SEM-EDX, FTIR, TGA-DSC, and BET-BJH were applied to characterize the synthesized ZSM-5. Bentonite clay showed great benefits as a natural resource for ZSM-5 synthesis and is cost efficient, environment friendly, and has a large reserves. The form, size, and crystallinity of ZSM-5 were greatly influenced by aging and hydrothermal treatment conditions. The optimal ZSM-5 product had high purity, crystallinity (∼90%), and porosity (BET ∼380 m2 g-1) as well as thermal stability, which are beneficial for adsorptive and catalytic applications.

Synthesis of b-axis oriented ZSM-5 zeolite by mechanochemical-assisted quasi-solvent-free method and its MTO catalytic performance

In this paper, b-axis oriented ZSM-5 zeolite was synthesized by solvent-free method with ammonia as growth regulator. Zeolites were characterized by modern detection techniques such as XRD, SEM, BET and NH3-TPD. The results showed that ammonia could not only promote the crystallization of ZSM-5 zeolite, but also direct the synthesis of ZSM-5 zeolite with b-axis oriented morphology, which was beneficial to enhance the selectivity of light olefins. B-axis oriented ZSM-5 zeolite did not need to be mixed and aged in aqueous solution, which could reduce the discharge of sewage, and avoided the generation of autogenic pressure in the crystallization process. Furthermore, it is consistent with the concept of environmental friendliness, which could guide the green preparation of industrial ZSM-5 zeolites.

Crude oil conversion to chemicals over green synthesized ZSM-5 zeolite

The study reports the conversion of crude oil to basic chemicals over a template-free green synthesis of ZSM-5(40) zeolite using halloysite (HAL) and bolus alpha (BA) as silica and alumina precursors. The Z(40)HAL and Z(40)BA exhibited hierarchical pores with high surface area of 248 m2/g and 257 m2/g, respectively. The addition of soft template during the synthesis of Z(40)BA forms a Z(40)BAT zeolite with lower surface area. The synthesized zeolites were impregnated with 2wt%Mn and tested for the steam catalytic cracking of crude oil to light olefins and aromatics catalysts at 675 °C in a fixed-bed reactor. Maximum light olefins (C2=-C4=) yield (47 wt%) and total aromatics (14.7 wt%) were attained over 2Mn/Z(40)HAL catalyst. The conversion of crude oil (68.4%) is attributed to hierarchical pores and the presence of large weak and strong acid sites in the 2Mn/Z(40)HAL zeolite. Moreover, due to the high reaction temperature, some effects of thermal cracking such as protolytic cracking reactions with high ethylene yield (22%) were introduced. The addition of 1% phosphorus and 1%Mn to Z(40)HAL resulted in lower catalytic cracking activity. Similarly, the 2Mn/Z(40)BAT performed slightly lower than the template-free 2Mn/Z(40)BA additive. The experimental results demonstrate the technical feasibility of template-free green synthesis of ZSM-5 zeolite in the conversion of crude oil to basic chemicals.

Synthesis and Characterization ZSM-5 Based on Kaolin as a Catalyst for Catalytic Cracking of Heavy Distillate
 

This article describes the study of synthesis of ZSM-5 Zeolite based on kaolin as catalysts for catalytic cracking of heavy distillate. There are five types of formulas A, B, C, D, and E synthesized with varying the molar ratios of SiO2/Al2O3, SiO

Synthesis and Acidity Study of Na-ZSM-5 Zeolite

Zeolites are a special class of structured aluminosilicates with a developed inner surface and a large number of micropores, which allows them to be used as sorbents, membrane materials, and catalysts. Zeolite ZSM-5 is an aluminosilicate formed by parallel channels with a diameter of 5.3–5.6Å interconnected by sinusoidal channels with a diameter of 5.1–5.5Å. At the same time, the presence of aluminum atoms in the zeolite crystal lattice makes it possible to carry out dehydrogenation, esterification, isomerization, and aromatization reactions, and the presence of microchannels significantly increases the number of collisions of reacting compounds, which leads to a significant increase in the rate of chemical transformations in such systems. The synthesis of ZSM-5 zeolite using structure-directing agents has been known since the late 70s of the last centuries, while the high cost of structure-directing agents used and the long duration of hydrothermal synthesis and the need for subsequent post-synthetic procedures lead to a high cost of the resulting zeolite. One of the possible ways to reduce the cost of the synthesis of ZSM-5 zeolite is the direct use of ZSM-5 zeolite as a structure-forming agent, while the synthesis conditions play a decisive role in the structure of the resulting zeolite. The article presents the results of a study of the synthesis of ZSM-5 zeolite and a study of its acidic properties using locally produced reagents. Zeolite was prepared using pre-milled silica gel, sodium hydroxide, and sodium aluminate. The pre-weighed silica gel sample was filled with sodium hydroxide solution and stirred at 70 ℃ to form a colloidal solution, after which the pre-prepared sodium aluminate solution was added, and hydrothermal synthesis was carried out at 180 ℃ for 24 hours. During the synthesis, the Si/Al ratio was varied in the range from 7.5 to 2000, while the resulting acidity ranged from 0.002 to 0.265 mmol(NH3)/g(ZSM-5). It was found that the synthesis of ZSM-5 using pre-prepared reagent solutions is superior to the method using direct dissolution of solid reagents in an autoclave. An increase in the Si/Al ratio from 7.5 to 100 leads to a corresponding increase in surface acidity from 0.066 mmol(NH3)/g(ZSM-5) to 0.265 mmol(NH3)/g(ZSM-5). A further increase in the Si/Al ratio to 2000 leads to a decrease in surface acidity to 0.002–0.005 mmol(NH3)/g(ZSM-5). A reliable and simple method for the synthesis of ZSM-5 zeolite has been developed, providing a zeolite yield of up to 97%.

Highly efficient synthesis of ZSM-5 zeolite by one-step microwave using desilication solution of coal gasification coarse slag and its application to VOCs adsorption

The increased production of coal gasification coarse slag (CGCS) has placed a significant environmental load on the environment. In this research, one-step microwave synthesis employing coal gasification coarse slag desilication solution as the major source of Si and Na increased the nucleation and crystallization rate of ZSM-5 zeolite. The optimum synthesis conditions were 180 °C, 4 h, Na2O/SiO2 molar ratio of 0.2, and SiO2/Al2O3 molar ratio of 200, which led to a relative crystallinity of ZSM-5 zeolite higher than 100 % and a specific surface area of 344.27 m2•g−1. The resulting high-purity ZSM-5 zeolite not only has high SiO2/Al2O3 molar ratio, good specific surface area, and regular hexagonal prism structure, but also has high crystallinity, smooth crystal surface and great grain homogeneity because of the microwave process. Its static adsorption capacities toward p-xylene and butyl acetate were 106.84 and 115.47 mg•g−1, respectively, and the dynamic adsorption capacities were 81.44 and 176.14 mg•g−1, respectively. The preparation method of ZSM-5 zeolite with high efficiency and low cost proposed in this paper not only contributes to the high-value utilization of CGCS, but also provides an effective method and practical guidance for the removal of volatile organic compounds (VOCs).

Low-Cost Synthesis of Zsm-5 Zeolite Using Organic Silica from Rice Husk Agro Waste

Rice husk is an agricultural waste that has the potential source of silica in low-cost zeolite synthesis. The objectives of this study were 1) silica extraction of rice husks as synthetic zeolite raw materials, 2) synthesis and characterized ZSM-5 zeolite from rice husks silica. Silica extraction was carried out by soaking rice husks using a heated 15% NaOH solution. Furthermore, 10% HNO3 solution was added to pH 7 for 12 hours. The filtrate dried in an oven for 12 hours at 100oC. Analysis of silica composition using XRF, crystallinity using XRD, and SEM for morphology. The results showed that rice husks were successfully extracted with an alkali addition and used as a source of silica in the synthesized of ZSM-5 zeolite. The zeolite synthesis was carried out with a low temperature of 90oC and a structural directing agent decrease. Zeolite ZSM-5 showed that the level of crystallinity and morphology by the standard ZSM-5 zeolite. Decreasing of the structural directing agent was found at the SDA/Si ratio of 0.045.

Green synthesis of ZSM-5 zeolite for selective catalytic reduction of NO via template-free method from tailing residue

The task of circular economy in mining industry is to develop and utilize a large number of tailing residue that has been shelved for a long time. An economical and sustainable utilization strategy of potassium feldspar tailing residue is reported. The ZSM-5 zeolite catalysts using tailing residue as raw materials by a template-free hydrothermal method are synthesized for selective catalytic reduction (SCR), abandoning the high pollution and energy consumption method of zeolite synthesis from fine chemicals. The effects of feed NaOH and Al2(SO4)3·18H2O on tailing residue and zeolite products are systematically studied, which proved that the silicon and aluminum elements in the tailing residue can be efficiently utilized. The results of scaling up experiment and experiment without additional aluminum confirm the feasibility and repeatability of tailing residue utilization. The synthesized ZSM-5 was used to prepare the Ce-Fe-ZSM-5 catalyst for NO reduction to N2 and showed excellent activity, with the NOx conversion remaining above 80% at the range of 300 °C~500 °C. The synergistic effect of Ce and Fe ions promoted the formation of more chemisorbed oxygen and accelerated the reaction rate of NO and NH3 adsorbed on the catalyst surface, resulting in a significant increase in the low-temperature activity of 1%Ce-Fe-ZSM-5. In this study, zeolite catalysts with excellent catalytic effect from tailing residue that can be used in petrochemical fields are successfully synthesized. The route is economic, environmental, and recyclable, which provides an opportunity for comprehensive development and application of tailing residue.

Lignin as a Bio-Sourced Secondary Template for ZSM-5 Zeolite Synthesis

The aim of this study was to investigate the effect of the addition of lignin as a sacrificial agent in ZSM-5 zeolite synthesis. Peculiar growths of ZSM-5 crystals leading to various textural properties were observed. Hence, the behavior in acid-catalyzed conversion of methanol into hydrocarbons (MTH) shifted from high selectivity toward olefins (>55%) to the sole formation of dimethyl ether (DME). Lignin acted as a bio-sourced secondary template (BSST), impacting the zeolite crystals’ shape and, thus, their physicochemical properties.

Size controllable synthesis of ZSM-5 zeolite and its catalytic performance in the reaction of methanol conversion to aromatics.

ZSM-5 zeolites were hydrothermally synthesized with commercial silica sol, and the crystal size was controlled by adding silicalite-1 seed in the synthetic system. The crystal size of ZSM-5 was affected by the crystallization time of seed, seed content and seed size. ZSM-5 zeolites with controllable particle size in the range of 200–2200 nm could be obtained. The prepared samples with different particle sizes were used for the reaction of methanol conversion to aromatics (MTA). The results suggested that the HZSM-5 catalyst with small crystal size showed much longer catalyst lifetime and higher selectivity for C5+ hydrocarbons and aromatics, especially C9+ aromatics in the MTA reaction. Moreover, the introduction of zinc (Zn) into the HZSM-5 zeolites can considerably promote the selectivity to aromatics in the products. Zn modified HZSM-5 zeolites with different Zn loading amounts were prepared by the incipient wetness impregnation method, and the highest aromatics selectivity was obtained when the Zn loading was 1.0%. The improvement of methanol aromatization was ascribed to the synergistic effect of Brønsted acid sites and the newly formed Zn-Lewis acid sites.