A versatile bench-scale unit for kinetic studies of catalytic reactions

1988 ◽  
Vol 27 (4) ◽  
pp. 576-580 ◽  
Author(s):  
Egbert Lox ◽  
Frank Coenen ◽  
Rene Vermeulen ◽  
Gilbert F. Froment
Keyword(s):  
Kinetic Studies ◽  
Catalytic Reactions ◽  
Bench Scale ◽  
Scale Unit

scholarly journals Revisiting the Role of Mass and Heat Transfer in Gas–Solid Catalytic Reactions

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1599
Author(s):  
Riccardo Tesser ◽  
Elio Santacesaria
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Kinetic Studies ◽  
Packed Bed ◽  
Catalytic Reactions ◽  
Catalytic Reactors ◽  
Tremendous Progress ◽  
Mass And Heat Transfer ◽  
Energy Balances

The tremendous progress in the computing power of modern computers has in the last 20 years favored the use of numerical methods for solving complex problems in the field of chemical kinetics and of reactor simulations considering also the effect of mass and heat transfer. Many classical textbooks dealing with the topic have, therefore, become quite obsolete. The present work is a review of the role that heat and mass transfer have in the kinetic studies of gas–solid catalytic reactions. The scope was to collect in a relatively short document the necessary knowledge for a correct simulation of gas–solid catalytic reactors. The first part of the review deals with the most reliable approach to the description of the heat and mass transfer outside and inside a single catalytic particle. Some different examples of calculations allow for an easier understanding of the described methods. The second part of the review is related to the heat and mass transfer in packed bed reactors, considering the macroscopic gradients that derive from the solution of mass and energy balances on the whole reactor. Moreover, in this second part, some examples of calculations, applied to chemical reactions of industrial interest, are reported for a better understanding of the systems studied.

scholarly journals Removal Effectiveness of Nanoplastics (<400 nm) with Separation Processes Used for Water and Wastewater Treatment

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 635 ◽  
Author(s):  
Audrey Murray ◽  
Banu Örmeci
Keyword(s):  
Wastewater Treatment ◽  
Surface Waters ◽  
Wastewater Treatment Plants ◽  
General Idea ◽  
Stormwater Treatment ◽  
Water And Wastewater Treatment ◽  
Separation Processes ◽  
Bench Scale ◽  
Scale Unit ◽  
Water And Wastewater

Microplastics and nanoplastics are abundant in the environment, and the fate and impact of nanoplastics are of particular interest because of their small size. Wastewater treatment plants are a sink for nanoplastics, and large quantities of nanoplastics are discharged into surface waters through wastewater as well as stormwater effluents. There is a need to understand the fate and removal of nanoplastics during water, wastewater, and stormwater treatment, and this study investigated their removal on a bench-scale using synthesized nanoplastics (<400 nm) to allow controlled experiments. Plastic particles were created in the lab to control their size, and bench-scale dewatering devices were tested for their ability to remove these particles. Filtration with a 0.22 μm filter removed 92 ± 3% of the particles, centrifugation at 10,000 rpm (670,800 g) for 10 min removed 99 ± 1% of the particles, and ballasted flocculation removed 88 ± 3%. These results provide a general idea of the magnitude of the removal of nanoplastics with separation processes, and more work is recommended to determine the degree of removal with full-scale unit processes. Even though the removal was good using all three treatments, smaller particles escaping treatment may increase the nanoplastics concentration of receiving water bodies and impact aquatic ecosystems.

A Bench-scale Unit for Continuous Extraction of Red Colorant from Sunflower Hulls

1993 ◽  
Vol 36 (5) ◽  
pp. 1411-1416 ◽  
Author(s):  
D. Wiesenborn ◽  
A. Glowacki ◽  
N. Hettiarachchy ◽  
L. Zander
Keyword(s):  
Continuous Extraction ◽  
Bench Scale ◽  
Scale Unit

Kinetic studies on cyclopalladation in palladium(II) complexes containing an indole moiety

2014 ◽  
Vol 86 (2) ◽  
pp. 151-161 ◽  
Author(s):  
Satoshi Iwatsuki ◽  
Takuya Suzuki ◽  
Syogo Tanooka ◽  
Tatsuo Yajima ◽  
Yuichi Shimazaki
Keyword(s):  
Bond Formation ◽  
Kinetic Studies ◽  
Catalytic Reactions ◽  
Biological Molecules ◽  
Side Chain ◽  
Formation Mechanisms ◽  
Indole Derivatives ◽  
Reaction Intermediates ◽  
Pd Catalysts ◽  
Amino Acid Tryptophan

Abstract Various Pd–C complexes have been developed to date, affording deep insights into the reaction intermediates in useful catalytic reactions in organic syntheses. Cyclopalladation is one of the most famous Pd–C bond formation reactions to generate the palladacycles. Indole is an electron-rich aromatic ring involved in the side chain of an essential amino acid, tryptophan (Trp), and Trp and its derivatives are important in biological systems, such as electron transfer in protein, cofactors for conversion of biological molecules and so on. Pd catalysts are also useful for syntheses of such indole derivatives, and the mechanisms are considered to be through the Pd–C intermediates. However, the detailed properties and formation mechanisms of Pd–indole species are still unclear. With these points in mind, we focus on Pd(II)–indole-C2 carbon bond formations using various Pd(II) complexes having an indole moiety, especially on the recent studies on the kinetic analyses for these cyclopalladation reactions and their detailed mechanisms.

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