Friedel-crafts acylation of furan using chromium-exchanged dodecatungstophosphoric acid: effect of support, mechanism and kinetic modelling

2021 ◽  
Author(s):  
Deepak S. Desai ◽  
Ganapati D. Yadav
Keyword(s):  
Kinetic Modelling ◽  
Support Mechanism ◽  
Acid Effect ◽  
Effect Of Support

scholarly journals Friedel-Crafts Acylation of Furan: Development of A Green Process Using Chromium-exchanged Dodecatungstophosphoric Acid: Effect of Support, Mechanism and Kinetic Modelling

2021 ◽  
Author(s):  
Deepak S. Desai ◽  
Ganapati D. Yadav
Keyword(s):  
Acetic Anhydride ◽  
Kinetic Modelling ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Support Mechanism ◽  
Full Characterization ◽  
Prior Art ◽  
Acid Effect ◽  
Ft Ir ◽  
Effect Of Support

Abstract The Friedel-Crafts acylation of furan with acetic anhydride to produce 2-acyl furan is industrially important. With an aim of replacing the highly polluting process, it this study, supported but modified heteropoly acids were used. Metal exchanged dodecatungstophosphoric acid (DTP) was loaded on three different supports and its effect on acylation was evaluated. Thus, chromium exchanged DTP was supported on K-10, SiO2, and ZrO2 using the incipient wetness impregnation method. 20% w/w Cr0.66-DTP/K-10 having the best activity for the acylation of furan with acetic anhydride was chosen for full characterization and reaction kinetics. Under optimized condition, the catalyst to furan ratio was 9.6%, significantly less as per prior art, which gave 88% conversion with 100% selectivity. The prepared catalysts were characterized by sophisticated techniques, namely, XRD, FT-IR, SEM, NH3-TPD, TGA, and BET. The Eley-Rideal mechanism was found to fit the kinetic data. The activation energy was found to be 18.03 kcal/mol. The reaction is green and clean as no chlorinated chemicals, reagents, and catalysts were used.

Intrathoracic Platelet Accumulation in the Guinea-Pig Induced by Intravenous Administration of Arachidonic Acid - Effect of Cyclooxygenase and Thromboxane Synthetase Inhibitors

1986 ◽  
Vol 56 (03) ◽  
pp. 311-317 ◽  
Author(s):  
P A Barrett ◽  
K D Butler ◽  
R A Shand ◽  
R B Wallis
Keyword(s):  
Arachidonic Acid ◽  
Blood Volume ◽  
Intravenous Administration ◽  
Guinea Pigs ◽  
Human Albumin ◽  
Thromboxane Synthetase ◽  
Acid Effect ◽  
Rapid Accumulation ◽  
Platelet Accumulation ◽  
High Doses

SummaryIntravenous administration of arachidonic acid to guinea-pigs caused a dose-related, rapid accumulation of 51Cr-labelled platelets in the thorax. Inhibitors of cyclooxygenase inhibited the platelet accumulation, induced by arachidonic acid (30 mg/kg), at doses which did not alter the thoracic blood volume (as measured by 131I-labelled human albumin). Thromboxane synthetase inhibitors had different effects on platelet accumulation depending on the dose. CGS 12970 (3 mg/kg) and N(1-carboxyheptyl) imidazole (100 mg/kg) reduced platelet accumulation. High doses of CGS 12970 and CGS 13080 caused an apparent enhancement of platelet accumulation which was associated with pooling of blood in the thorax, as measured by either 131I-labelled human albumin or 51Cr-labelled erythrocytes. This increase in thoracic blood volume was abolished if the guinea-pigs were also pretreated with diclofenac (1 mg/kg) in addition to the thromboxane synthetase inhibitor. Increases in thoracic blood volume were also obtained following infusions of PGI2 but not PGD2 or PGE2.

Kinetic modelling of degradation of phenolic compounds in leachate

2011 ◽  
Author(s):  
E. Sekman ◽  
G. Varank ◽  
A. Demir ◽  
S. Top ◽  
M. S. Bilgili
Keyword(s):  
Phenolic Compounds ◽  
Kinetic Modelling

Kinetic Modelling and Equilibrium of Amphoteric Collector Adsorption on Silica and Hematite

2009 ◽  
Vol 46 (2) ◽  
pp. 85-91
Author(s):  
K. A. Selim ◽  
F. H. Abd El-Rahiem ◽  
A. A. El-Midany
Keyword(s):  
Kinetic Modelling

Effect of support plates on the micro-drilled hole form quality in CFRP laminates

2019 ◽  
Vol 61 (5) ◽  
pp. 467-476 ◽  
Author(s):  
Ahmet Dogrusadik ◽  
Aykut Kentli
Keyword(s):  
Cfrp Laminates ◽  
Form Quality ◽  
Effect Of Support

Kinetic Modelling of Anionic Polymerization Involving a Dynamic Equilibrium between Two Growth Centres with Different Growth Rates

1993 ◽  
Vol 58 (10) ◽  
pp. 2349-2361 ◽  
Author(s):  
Jaromír Jakeš
Keyword(s):  
Molecular Weight ◽  
Growth Rates ◽  
Anionic Polymerization ◽  
Dynamic Equilibrium ◽  
Kinetic Modelling ◽  
Polymerization Time ◽  
Fast State ◽  
Growth State ◽  
In The Beginning ◽  
Growth Centres

Kinetic modelling of the molecular weight distribution (MWD) of polymer obtained by an anionic polymerization with two types of growth centres in a dynamic equilibrium, having different growth rates and lifetimes comparable to the polymerization time, was made for low monomer conversions. On the basis of distribution of the growth centres according to the total time spent in the fast growth state, it was shown that MWD of the resulting polymer are mostly bimodal at the beginning of the polymerization and change to unimodal MWD at sufficiently high polymerization degrees depending on the equilibrization rate. When all centres are in the fast state in the beginning, MWD are essentially unimodal throughout. A hint of trimodality is observed in some cases, in an extent hardly detectable in real chromatograms. Hence, a polymodal MWD can be explained only when more than two growth centres with different growth rates are assumed.

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