Study of the nature of active sites on zeolites by the measurement of heat of immersion. II. Effects of silica/alumina ratio to electrostatic-field strength of calcium-exchanged zeolites

1972 ◽  
Vol 76 (1) ◽  
pp. 110-115 ◽  
Author(s):  
Kazuo Tsutsumi ◽  
Hiroshi Takahashi
Keyword(s):  
Field Strength ◽  
Electrostatic Field ◽  
Active Sites ◽  
Heat Of Immersion ◽  
Silica Alumina ◽  
Silica Alumina Ratio

scholarly journals Ethylene Oligomerization over Nickel Supported Silica-Alumina Catalysts with High Selectivity for C10+ Products

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 180 ◽  
Author(s):  
Lei Chen ◽  
Guangci Li ◽  
Zhong Wang ◽  
Shuangju Li ◽  
Mingjie Zhang ◽  
...  
Keyword(s):  
Reaction Temperature ◽  
Aging Temperature ◽  
Active Sites ◽  
High Selectivity ◽  
Acid Sites ◽  
Ethylene Oligomerization ◽  
Octahedral Coordination ◽  
Activation Temperature ◽  
High Aging Temperature ◽  
Silica Alumina

The nickel (II) loading silica-alumina under various treatments in terms of aging temperature, Si/Al ratio and activation temperature were investigated by XRD, N2 adsorption-desorption, TEM, UV-Vis, NH3-TPD and XRF and then applied to catalyze the ethylene oligomerization. High aging temperature, low Si/Al ratio and high activation temperature were beneficial to high selectivity for C10+ products because of a reasonable match between Ni active sites and acid sites, high Ni loading content and less octahedral coordination Ni2+ species, respectively. Ni loading content was more important than the number of acid sites for high yield of C10+ products, and less octahedral coordination Ni2+ species favored less by-products produced at high reaction temperature. In addition, other experimental conditions, such as reaction temperature, weight hourly space velocity (WHSV) and nickel precursor were discussed in the paper.

Improving electrospinning process by numerical analysis of 3-D computer models

2019 ◽  
Vol 38 (4) ◽  
pp. 1098-1110
Author(s):  
Anna Firych-Nowacka ◽  
Krzysztof Smolka ◽  
Sławomir Wiak
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Field Intensity ◽  
Electrostatic Field ◽  
Electric Field Intensity ◽  
Computer Models ◽  
Electrospinning Process ◽  
Strength Analysis ◽  
Original Solution ◽  
Content Type

Purpose Electrospinning is a method of the polymer super thin fibres formation by the electrostatic field. The distribution of electrostatic field affects the effectiveness of the electrospinning. Design/methodology/approach This paper presents various computer models that can improve the electrospinning process. The possibilities of modelling the electrostatic field in the design of electrospinning equipment are presented. Findings In the research part, the one focussed on finding a cylinder-shaped collector structure to limit the adverse effect of an uneven distribution of the electric field intensity on the collector. Originality/value The paper concerns the improvement of the electrospinning process with the use of electrostatic field modelling. In the first part, several possible applications of electrostatic models have been indicated, thanks to which the efficiency of the process has been improved. The original solution of the collector geometry was presented, which according to the authors, in comparison with previous models, gives the most promising results. In this solution, it was possible to obtain an even distribution of the electric field intensity while removing the unfavourable effect of the field strength increase on the outer edges of the collector. The most important aspect in this paper is electric field strength analysis.

Fast synthesis of submicron aluminosilicate (low silica/alumina ratio) zeolites under solventless microwave radiation

RSC Advances ◽  
2015 ◽  
Vol 5 (116) ◽  
pp. 95463-95466 ◽  
Author(s):  
Shangjing Zeng ◽  
Runwei Wang ◽  
Yongcun Zou ◽  
Jingru Fu ◽  
Zhongtao Zhang ◽  
...  
Keyword(s):  
Microwave Radiation ◽  
Silica Alumina ◽  
Fast Synthesis ◽  
Silica Alumina Ratio

Sub-micron aluminosilicate zeolites with a low silica/alumina ratio are successfully synthesized by microwave solventless method.

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