Understanding the structural properties of zeolites for isobutane alkylation based on adsorption/diffusion behaviors

Li, Bihong; Huang, P. M.; Cao, Piao; Gao, Weiqun; Zheng, Weizhong; Lian, Cheng; Sun, Weizhen; Zhao, Ling

doi:10.1016/j.micromeso.2022.112040

Cited by 7 publications

(5 citation statements)

References 60 publications

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“…This results in stronger van der Waals forces, promoting the accumulation of PH 3 in LTL compared to GME ( R = 0.94). The effect of expansion is also discussed in the previous work 32,70 and it is emphasized that in addition to the structural properties of zeolites, the expansion in the channels, as indicated by the ratio of PLD to LCD, has a significant effect on the PH 3 adsorption performance.…”

Section: Resultsmentioning

confidence: 93%

“…Among the simulation techniques, Grand Canonical Monte Carlo (GCMC) is a powerful tool to study the gas adsorption and separation performance of porous materials. Li 32 investigated the adsorption and diffusion behavior of C 4 reactants on different topological zeolites using GCMC and molecular dynamic simulations. This research provides valuable design strategies for promising zeolites for isobutane alkylation.…”

Section: Introductionmentioning

confidence: 99%

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Large‐scale computational screening of highly effective zeolites for trace PH₃ capture from hydrogen

Yan,

Tong,

Gao

et al. 2024

AIChE Journal

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Developing highly efficient adsorbents to remove trace PH3 from circulating H2 is essential for electronic‐grade silica production. Here, the pure PH3 adsorption and PH3/H2 separation performances of 103 all‐silica zeolites under various operating conditions were simulated using grand canonical Monte Carlo simulation. Based on our well‐validated force field, the optimal ranges of zeolites and the most decisive factors for pure PH3 adsorption and separation were identified by the combination of quantitative structure–activity relationship, Pearson coefficient, and adsorption density profile. Finally, the top 17 zeolites were identified through TSA, PSA, and VSA processes, which typically feature 10‐membered rings as limiting pores. Structures with 1D channels show the best performance. Some 2D and 3D zeolites (i.e., IMF, ITH, ITR, MEL, TUN), which are characterized by interconnected straight channels with cavities at channel intersections, also exhibit high selective adsorption capacities for PH3. This work provides direction for the design of novel zeolites.

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Section: Resultsmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Large‐scale computational screening of highly effective zeolites for trace PH₃ capture from hydrogen

Yan,

Tong,

Gao

et al. 2024

AIChE Journal

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“…Interestingly, iso-C 4 were only identified when the SAPO-18 zeotype was used, and in fact, its production is favored with high SAPO-18 space time (Figure d) and low temperature (Figure h). We ascribe this phenomenon to the potential presence of Brønsted acid sites on the external surface SAPO-18 crystals as the kinetic diameter of isobutane (5.28 Å) is bigger than the eight-membered ring window of the AEI structure, even in the case of the Mg-containing distorted ring …”

Section: Resultsmentioning

confidence: 99%

Transitioning from Methanol to Olefins (MTO) toward a Tandem CO₂ Hydrogenation Process: On the Role and Fate of Heteroatoms (Mg, Si) in MAPO-18 Zeotypes

Cordero-Lanzac,

Capel Berdiell,

Airi

et al. 2024

JACS Au

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The tandem CO 2 hydrogenation to hydrocarbons over mixed metal oxide/zeolite catalysts (OXZEO) is an efficient way of producing value-added hydrocarbons (platform chemicals and fuels) directly from CO 2 via methanol intermediate in a single reactor. In this contribution, two MAPO-18 zeotypes (M = Mg, Si) were tested and their performance was compared under methanolto-olefins (MTO) conditions (350 °C, P CHd 3 OH = 0.04 bar, 6.5 g CHd 3 OH h −1 g −1 ), methanol/CO/H 2 cofeed conditions (350 °C, P CHd 3 OH /P CO /P Hd 2 = 1:7.3:21.7 bar, 2.5 g CHd 3 OH h −1 g −1 ), and tandem CO 2 hydrogenation-to-olefin conditions (350 °C, P COd 2 /P Hd 2 = 7.5:22.5 bar, 1.4−12.0 g MAPO-18 h mol COd 2 −1 ). In the latter case, the zeotypes were mixed with a fixed amount of ZnO:ZrO 2 catalyst, well-known for the conversion of CO 2 /H 2 to methanol. Focus was set on the methanol conversion activity, product selectivity, and performance stability with time-on-stream. In situ and ex situ Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), solid-state nuclear magnetic resonance (NMR), sorption experiments, and ab initio molecular dynamics (AIMD) calculations were performed to correlate material performance with material characteristics. The catalytic tests demonstrated the better performance of MgAPO-18 versus SAPO-18 at MTO conditions, the much superior performance of MgAPO-18 under methanol/CO/H 2 cofeeds, and yet the increasingly similar performance of the two materials under tandem conditions upon increasing the zeotype-to-oxide ratio in the tandem catalyst bed. In situ FT-IR measurements coupled with AIMD calculations revealed differences in the MTO initiation mechanism between the two materials. SAPO-18 promoted initial CO 2 formation, indicative of a formaldehyde-based decarboxylation mechanism, while CO and ketene were the main constituents of the initiation pool in MgAPO-18, suggesting a decarbonylation mechanism. Under tandem CO 2 hydrogenation conditions, the presence of high water concentrations and low methanol partial pressure in the reaction medium led to lower, and increasingly similar, methanol turnover frequencies for the zeotypes. Despite both MAPO-18 zeotypes showing signs of activity loss upon storage due to the interaction of the sites with ambient humidity, they presented a remarkable stability after reaching steady state under tandem reaction conditions and after steaming and regeneration cycles at high temperatures. Water adsorption experiments at room temperature confirmed this observation. The faster activity loss observed in the Mg version is assigned to its harder Mg 2+ -ion character and the higher concentration of CHA defects in the AEI structure, identified by solid-state NMR and XRD. The low stability of a MgAPO-34 zeotype (CHA structure) upon storage corroborated the relationship between CHA defects and instability.

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“…Nevertheless, its drawbacks of easy deactivation by coking and difficult regeneration hinder the widespread industrial use. [8][9][10] Besides, ionic liquids (ILs) have been reported as catalysts for commercial C4 alkylation, while the problems regarding the disposal of spent salt and high-operating cost still need to be solved. 2,11,12 Owing to the advantages of high stability and excellent catalytic performance, the concentrated H 2 SO 4 has been employed predominantly as the preferred commercial alkylation catalyst.…”

Section: Introductionmentioning

confidence: 99%

“…The solid acids are regarded as greener alternative to traditional liquid acid catalysts. Nevertheless, its drawbacks of easy deactivation by coking and difficult regeneration hinder the widespread industrial use 8–10 . Besides, ionic liquids (ILs) have been reported as catalysts for commercial C4 alkylation, while the problems regarding the disposal of spent salt and high‐operating cost still need to be solved 2,11,12 .…”

Section: Introductionmentioning

confidence: 99%

Enhanced catalytic performance of H₂SO₄‐catalyzed C4 alkylation by formyl functional [N₁_,1,1,1][C₁₀SO₄] additive

Zheng

Sun

et al. 2023

AIChE Journal

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It is of fundamental importance to assess the additive for isobutane alkylation catalyzed by the concentrated H2SO4 in actual industrial reactor, which usually contains 6.0–7.0 wt% red oil (ASO) impurity. Herein, the formyl functional [N1,1,1,1][C10SO4] additive was developed to enhance the catalytic performance of the H2SO4 taken from industrial stream with emphasis on process optimization and reaction kinetics. The ASO that existed in the H2SO4 from industrial stream has a promoting effect, and the introduction of [N1,1,1,1][C10SO4] with ratio of 0.3 wt% can further improve research octane number of alkylate even in a shorter reaction time. The kinetic model can well predict the concentration changes of key components, in which [N1,1,1,1][C10SO4] contributes to the larger reaction rate and lower activation energy for the targeted trimethylpentanes generation due to the intensified isobutane solvation. Hopefully, the novel additive has a promising application to optimize the H2SO4‐catalyzed industrial alkylation process.

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Understanding the structural properties of zeolites for isobutane alkylation based on adsorption/diffusion behaviors

Cited by 7 publications

References 60 publications

Large‐scale computational screening of highly effective zeolites for trace PH₃ capture from hydrogen

Large‐scale computational screening of highly effective zeolites for trace PH₃ capture from hydrogen

Transitioning from Methanol to Olefins (MTO) toward a Tandem CO₂ Hydrogenation Process: On the Role and Fate of Heteroatoms (Mg, Si) in MAPO-18 Zeotypes

Enhanced catalytic performance of H₂SO₄‐catalyzed C4 alkylation by formyl functional [N₁_,1,1,1][C₁₀SO₄] additive

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Understanding the structural properties of zeolites for isobutane alkylation based on adsorption/diffusion behaviors

Cited by 7 publications

References 60 publications

Large‐scale computational screening of highly effective zeolites for trace PH3 capture from hydrogen

Large‐scale computational screening of highly effective zeolites for trace PH3 capture from hydrogen

Transitioning from Methanol to Olefins (MTO) toward a Tandem CO2 Hydrogenation Process: On the Role and Fate of Heteroatoms (Mg, Si) in MAPO-18 Zeotypes

Enhanced catalytic performance of H2SO4‐catalyzed C4 alkylation by formyl functional [N1,1,1,1][C10SO4] additive

Contact Info

Product

Resources

About

Large‐scale computational screening of highly effective zeolites for trace PH₃ capture from hydrogen

Large‐scale computational screening of highly effective zeolites for trace PH₃ capture from hydrogen

Transitioning from Methanol to Olefins (MTO) toward a Tandem CO₂ Hydrogenation Process: On the Role and Fate of Heteroatoms (Mg, Si) in MAPO-18 Zeotypes

Enhanced catalytic performance of H₂SO₄‐catalyzed C4 alkylation by formyl functional [N₁_,1,1,1][C₁₀SO₄] additive