scholarly journals Product Distribution in Degradation of Polypropylene over Silica-Alumina and CaX Zeolite Catalysts

1983 ◽  
Vol 56 (9) ◽  
pp. 2768-2773 ◽  
Author(s):  
Yoshio Uemichi ◽  
Yasunori Kashiwaya ◽  
Masaya Tsukidate ◽  
Akimi Ayame ◽  
Hisao Kanoh
Keyword(s):  
Product Distribution ◽  
Zeolite Catalysts ◽  
Silica Alumina

Effect of Silica Base Catalyst on Transformation of Methanol to Hydrocarbon

2017 ◽  
Vol 751 ◽  
pp. 512-517 ◽  
Author(s):  
Supranee Lao-Ubol ◽  
Phunthinee Somwongsa ◽  
Pracha Laoauyporn ◽  
Pasinee Panith ◽  
Siriporn Larpkiattaworn ◽  
...  
Keyword(s):  
Pore Diameter ◽  
Fixed Bed ◽  
Methanol Conversion ◽  
Liquid Hydrocarbon ◽  
Product Distribution ◽  
Catalytic Performance ◽  
Zeolite Catalysts ◽  
Fixed Bed Reactor ◽  
Phosphorus Species ◽  
Methanol To Hydrocarbon

Five different types of silica catalyst (SBA-15, SBA-15-PO3H2, and three different Si/Al ratio of commercial zeolites (30, 80 and 280) were used to study the transformation of methanol to hydrocarbon (MTH). The aim of this study was to investigate the effect of pore diameter and acidity in the structure of silica catalysts on the process performances in terms of methanol conversion and hydrocarbon selectivity. The mesoporous silica catalysts were prepared by co-condensation method. The catalysts samples were characterized by GC-MS, XRD, BET, and NH3-TPD techniques. The catalytic performance of synthesized and commercial catalysts for MTH process was evaluated using a homemade fixed bed reactor at temperature (300°C). It was found that the liquid hydrocarbon product provided by zeolite catalysts is aromatic hydrocarbons-rich. High Si/Al zeolites with larger pore size lead to higher selectivity and yield to paraffins (C1-C7). In contrast to commercial zeolite catalyst, SBA-15 and its modification with phosphorus species showed no conversion under studied condition. These results indicate that both pore diameter and acidity influence the product distribution in methanol to hydrocarbon process.

scholarly journals Deactivation of Zeolite Catalysts in the Prins Reaction between Propene and Formaldehyde in the Liquid Phase

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1181
Author(s):  
Stanislav P. Bedenko ◽  
Konstantin I. Dement’ev ◽  
Valentin F. Tret’yakov
Keyword(s):  
Liquid Phase ◽  
Kinetic Model ◽  
Pore Diameter ◽  
Product Distribution ◽  
Acid Sites ◽  
Weak Acid ◽  
Zeolite Catalysts ◽  
Prins Reaction ◽  
Acidic Properties ◽  
Deactivation Process

The Prins reaction between propene and formaldehyde was studied over H-BEA, H-FAU, H-MFI and H-MOR zeolites at 150 °C in liquid phase. It was found that the H-BEA sample is the most active and selective toward buta-1,3-diene; the H-MFI is a potential catalyst for 3-buten-1-ol synthesis, while H-FAU can be used for 4-methyl-1,3-dioxane production. It had been confirmed that zeolite textural and acidic properties influence catalyst behaviour: the acidic properties influence sample activity, while product distribution is controlled by pore volume and effective pore diameter. The sample’s deactivation process had been studied and the kinetic model of deactivation was proposed. It was shown that the deactivation rate for the H-MFI catalyst is four times greater than for the H-BEA catalyst, probably because its strong/weak acid sites ratio is much more high than for the H-BEA.

Mildly Acidic Aluminosilicate Catalysts for Stable Performance in Ethanol Dehydration

2020 ◽  
Author(s):  
Ales Styskalik ◽  
Vit Vykoukal ◽  
Luca Fusaro ◽  
Carmela Aprile ◽  
Damien Debecker
Keyword(s):  
Sol Gel ◽  
Coke Formation ◽  
Strong Acid ◽  
Acid Sites ◽  
High Specific Surface Area ◽  
Ethylene Oligomerization ◽  
Zeolite Catalysts ◽  
Activity Levels ◽  
Ethanol Dehydration ◽  
Silica Alumina

Ethanol dehydration is effectively catalyzed by strongly acidic zeolite catalysts which are known, however, to exhibit poor time on stream stability. Alumina and silica-alumina on the other hand are relatively stable but reach only low activity levels. Here, a series of aluminosilicate catalysts (Si:Al ratio = 16) was prepared by non-hydrolytic sol-gel (NHSG) and are shown to feature an intermediate level of activity, between the HZSM-5 zeolite and a commercial silica-alumina. Importantly, the best samples, were very stable with time on stream. Unlike HZSM-5, which also catalyzes ethylene oligomerization due to its strong acid sites and is therefore prone to coking, NHSG prepared catalysts did not produce any traces of ethylene oligomers and did not show any trace of coke formation. Characterization (ICP-OES, N<sub>2</sub> physisorption, TEM, XPS, IR coupled with pyridine adsorption, Raman spectroscopy, solid state NMR spectroscopy) reveal that the unconventional synthetic method presented here allowed to prepare mesoporous aluminosilicate materials with a remarkable degree of homogeneity. It is this thorough dispersion of Al in the amorphous silicate matrix which is responsible for the formation of acid sites which are intermediate (in terms of strength and nature) between those of commercial silica-alumina and HZSM-5 zeolite. The texture of the best NHSG catalyst – mainly mesoporous with a high specific surface area (800 m² g<sup>−1</sup>) and pore volume (0.5 cm³ g<sup>−1</sup>) – was also unaffected after reaction. To overcome deactivation issues in ethanol dehydration, this study suggests to target amorphous aluminosilicate catalysts with open mesoporosity and with an intimate mixing of Al and Si.

Evaluation of zeolite catalysts on product distribution during sweet sorghum bagasse catalytic pyrolysis

Energy ◽  
2021 ◽  
Vol 214 ◽  
pp. 118799
Author(s):  
Xiajin Ren ◽  
Hongzhen Cai ◽  
Qingfa Zhang ◽  
Donghong Zhang ◽  
Xiaona Lin
Keyword(s):  
Sweet Sorghum ◽  
Catalytic Pyrolysis ◽  
Product Distribution ◽  
Zeolite Catalysts ◽  
Sweet Sorghum Bagasse ◽  
Sorghum Bagasse

Tailoring product distribution during upgrading of palmitic acid over bi-functional metal/zeolite catalysts

2017 ◽  
Vol 166 ◽  
pp. 262-273 ◽  
Author(s):  
Yanchun Shi ◽  
Enhui Xing ◽  
Yaya Cao ◽  
Mingjuan Liu ◽  
Kejing Wu ◽  
...  
Keyword(s):  
Palmitic Acid ◽  
Product Distribution ◽  
Zeolite Catalysts
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