Effect of different TEAOH/DEA combinations on SAPO-34’s synthesis and catalytic performance

Ye, Liping; Cao, Fahai; Ying, Weiyong; Fang, Dingye; Sun, Qiwen

doi:10.1007/s10934-010-9374-4

Cited by 75 publications

(51 citation statements)

References 17 publications

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“…6, two distinct NH 3 desorption peaks can be seen in the NH 3 -TPD profiles at 180-220°C and 400-500°C. They are similar to the reported reference data for the acid properties of SAPO-34 [33]. Usually, the desorption temperature is a measure of the strength of the acid sites.…”

Section: Resultssupporting

confidence: 88%

Performance of Methanol-to-Olefins Catalytic Reactions by the Addition of PEG in the Synthesis of SAPO-34

Wang

Sun

et al. 2017

Trans. Tianjin Univ.

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SAPO-34, a silicoaluminophosphate zeolite, has been synthesized by the hydrothermal method with the addition of different molecular weights of polyethylene glycol (PEG), and has been characterized with XRD, SEM, N 2 adsorption-desorption, FT-IR, and NH 3 temperatureprogrammed desorption (NH 3 -TPD). We studied SAPO-34 as a catalyst in the methanol-to-olefins (MTO) reaction, in a fixed-bed reactor. The results show that the chain length of PEG has a great influence on the particle size and morphology of SAPO-34. PEG acts as inhibitor in the crystallization process. With the increase of the chain length of PEG used in the synthesis, from a relative molecular weight of 400-6000, the morphology of SAPO-34 changes gradually from cubic to nanoplate-like and then changes to cubic again. The particle size decreases markedly at first and then increases to some extent. The catalytic stability in the MTO reaction also increases first and then decreases, with all the catalysts having almost the same selectivity to olefins. When the sample is synthesized with PEG800, the particles become nanoplate-like with a thickness of 46 nm on average, and the catalytic stability is appreciably prolonged, which is attributed to the shorter diffusion paths of the reactants in the zeolite.

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Section: Resultssupporting

confidence: 88%

Performance of Methanol-to-Olefins Catalytic Reactions by the Addition of PEG in the Synthesis of SAPO-34

Wang

Sun

et al. 2017

Trans. Tianjin Univ.

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“…Many researchers reported that conversion of methanol to dimethyl ether (DME) occurs mainly on the weak acid sites and there is a marked relationship between strong acid sites, selectivity, and conversion of DME and methanol to light olefins [30,31]. The results showed that there were no significant differences in the total acidity of the selected catalysts.…”

Section: Research Articlementioning

confidence: 99%

Statistical Optimization for Production of Light Olefins in a Fluidized‐Bed Reactor

Pajaie

Taghizadeh

2015

Chem Eng & Technol

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The methanol-to-olefins reaction (MTO) was studied in a small-scale fluidizedbed reactor over synthesized silicoaluminophosphate (SAPO-34) catalysts. Mesoporous nanocrystalline SAPO-34 molecular sieves were synthesized hydrothermally by ultrasonic and microwave-assisted aging processes in the presence of hexadecyltrimethylammonium bromide (CTAB) and tetradecyldimethyl(3-trimethoxysilylpropyl)ammonium chloride (TPOAC) as surfactant agents. The BoxBehnken experimental design method was applied to determine the optimum operating parameters of this process conducted in the fluidized-bed reactor. The optimum conditions in terms of reaction temperature, ratio of inlet gas velocity to minimum fluidizing velocity, and MeOH weight fraction were evaluated.

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“…Two desorption peaks in the TPD spectrum at 100-250°C and 250-525°C are primarily observed. In general, the desorption temperature represents the strength of acid sites, that is, the low temperature desorption peak at 100-250°C is assigned to the weak acid sites, which corresponds to P\OH hydroxyl groups that are not fully coordinated by AlO 4 tetrahedra [6]. And the high temperature desorption peak at 250-525°C is ascribed to the strong acidic sites which are generated by the incorporation of silicon into the framework of SAPO-34 molecular sieve [8].…”

Section: Nh 3 -Tpdmentioning

confidence: 99%

“…Hydrothermal method, as the conventional strategy, has been applied in the preparation of SAPO-34 by numerous researchers [4][5][6][7][8][9][10][11][12][13][14][15]. However, separation between solvents and solid products is required by filtration or centrifugation, and partial organic SDAs are inevitably preserved in the liquid phase, resulting in the wastewater pollutants and downstream purification system installation [16].…”

Section: Introductionmentioning

confidence: 99%

Facile synthesis of SAPO-34 with small crystal size for conversion of methanol to olefins

Han

et al. 2014

Powder Technology

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a b s t r a c t a r t i c l e i n f oSAPO-34 molecular sieves were fabricated by a dry gel liquid-phase transport method using morpholine (Mor) or morpholine-tetraethylammonium hydroxide (Mor-TEAOH) as the structure-directing agent (SDA). The prepared samples were characterized by scanning electron microscope (SEM), nitrogen adsorption-desorption, X-ray diffraction (XRD), ammonia temperature-programmed desorption (NH 3 -TPD), thermo-gravimetric analysis (TG) and Fourier transform infrared spectroscopy (FT-IR). The results indicated that the dry gel liquid-phase transport method is very effective to fabricate SAPO-34 molecular sieves with average crystal size about 0.6 μm using Mor-TEAOH as SDA and 3 μm using Mor as SDA, respectively. Moreover, the addition of TEAOH is beneficial to produce SAPO-34 with small crystal size. Methanol-to-olefins (MTO) reaction was chosen to test the catalytic performance of as-prepared SAPO-34 catalysts. The prepared SAPO-34 catalyst using Mor-TEAOH as SDA exhibited the excellent catalytic performance in MTO process owing to its small crystal size and high crystallinity. The conversion of methanol and selectivity of ethylene and propylene are up to 100% and 87.9%, respectively.

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Effect of different TEAOH/DEA combinations on SAPO-34’s synthesis and catalytic performance

Cited by 75 publications

References 17 publications

Performance of Methanol-to-Olefins Catalytic Reactions by the Addition of PEG in the Synthesis of SAPO-34

Performance of Methanol-to-Olefins Catalytic Reactions by the Addition of PEG in the Synthesis of SAPO-34

Statistical Optimization for Production of Light Olefins in a Fluidized‐Bed Reactor

Facile synthesis of SAPO-34 with small crystal size for conversion of methanol to olefins

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