A Study of Selective Hydrogenation of Α,β-unsaturated Aldehyde in Three Phase Reactors PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download A Study of Selective Hydrogenation of Α,β-unsaturated Aldehyde in Three Phase Reactors PDF full book. Access full book title A Study of Selective Hydrogenation of Α,β-unsaturated Aldehyde in Three Phase Reactors by Wanida Koo-Amornpattana. Download full books in PDF and EPUB format.
Author: Wanida Koo-Amornpattana
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :
Get Book Here
Book Description
Author: Wanida Koo-Amornpattana
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :
Get Book Here
Book Description
![A Study of Selective Hydrogenation of [alpha], [beta]-unsaturated Aldehyde in Three Phase Reactors PDF](https://books.google.com/books/content/images/frontcover/w7n2HAAACAAJ?fife=w80-h100)
Author: Wanida Koo-Amornpattana
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
![Selective Hydrogenation of Α,β[alpha,beta]-unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors PDF](https://books.google.com/books/content/images/frontcover/ukTlvgEACAAJ?fife=w80-h100)
Author: Laiqi Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
The hydrodynamics and mass transfer characteristics of a concurrent downflow contactor (CDC) are studied in this work in order to investigate the viability of this bubble column as a catalytic reactor for the hydrogenation of ?,?-unsaturated aldehydes. Oxygen/water was used as the system throughout. In order to obtain reproducible results, a very effective gas-liquid separation method was conceived and developed after much trial and error work. Shutdown and deadleg gas holdup measuring methods were compared and it was found that the shutdown method is more reliable than the deadleg method. The hydrogenation of cinnamaldehyde using both in-house-prepared and commercial palladium, platinum and ruthenium catalysts was carried out in stirred tank reactors and cocurrent downflow reactors in order to study the kinetics and mass transfer characteristics and the selectivity towards the corresponding desired product, hydrocinnamaldehyde or cinnamyl alcohol. When palladium catalysts were used the desired product was hydrocinnamaldehyde. The effects of homogenous reactions, type of solvent, catalyst loading, temperature, pressure, reactant concentration and the effects of promoter or poison on the selectivity towards hydrocinnamaldehyde were investigated systematically. Aldehyde acetals were produced in polar solvents, but not in non-polar solvents. Two methods can be used to obtain hydrocinnamaldehyde selectivity without reduction of the carbonyl double bond: (1) by using non-polar solvents such as toluene; (2) by incorporating poisons or promoters into the reactant solution or onto the surface of the catalysts. 97% selectivity to hydrocinnamaldehyde was achieved. The effects of the solvent, temperature, pressure, catalyst loading, promoters, and reactants concentration on the kinetics were studied and the following reaction kinetics are proposed for the hydrogenation of cinnamaldehyde over non-modified palladium/charcoal catalysts in propan-2-ol and in toluene: Ra = kC\(-{Cat}\)C\(-{H2}\)C\( 0-{CAL}\) The apparent activation energy varies with themperature range in propan-2-ol and is 65\(\pm\)5 kJ.mol\( {-1}\) in toluene.
![Selective Hydrogenation of [alpha], [beta][alpha, Beta]-unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors PDF](https://books.google.com/books/content/images/frontcover/SkZ4nQAACAAJ?fife=w80-h100)
Author: Laiqi Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
The hydrodynamics and mass transfer characteristics of a concurrent downflow contactor (CDC) are studied in this work in order to investigate the viability of this bubble column as a catalytic reactor for the hydrogenation of?,?-unsaturated aldehydes. Oxygen/water was used as the system throughout. In order to obtain reproducible results, a very effective gas-liquid separation method was conceived and developed after much trial and error work. Shutdown and deadleg gas holdup measuring methods were compared and it was found that the shutdown method is more reliable than the deadleg method. The hydrogenation of cinnamaldehyde using both in-house-prepared and commercial palladium, platinum and ruthenium catalysts was carried out in stirred tank reactors and cocurrent downflow reactors in order to study the kinetics and mass transfer characteristics and the selectivity towards the corresponding desired product, hydrocinnamaldehyde or cinnamyl alcohol. When palladium catalysts were used the desired product was hydrocinnamaldehyde. The effects of homogenous reactions, type of solvent, catalyst loading, temperature, pressure, reactant concentration and the effects of promoter or poison on the selectivity towards hydrocinnamaldehyde were investigated systematically. Aldehyde acetals were produced in polar solvents, but not in non-polar solvents. Two methods can be used to obtain hydrocinnamaldehyde selectivity without reduction of the carbonyl double bond: (1) by using non-polar solvents such as toluene; (2) by incorporating poisons or promoters into the reactant solution or onto the surface of the catalysts. 97% selectivity to hydrocinnamaldehyde was achieved. The effects of the solvent, temperature, pressure, catalyst loading, promoters, and reactants concentration on the kinetics were studied and the following reaction kinetics are proposed for the hydrogenation of cinnamaldehyde over non-modified palladium/charcoal catalysts in propan-2-ol and in toluene: Ra = kC\(_{Cat}\)C\(_{H2}\)C\(0_{CAL}\) The apparent activation energy varies with themperature range in propan-2-ol and is 65\(\pm\)5 kJ.mol\({-1}\) in toluene.
![Selective Hydrogenation of [Alpha], [Beta]-unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors PDF](https://books.google.com/books/content/images/frontcover/UGr-sgEACAAJ?fife=w80-h100)
Author: Lai Qi Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Marwan
Publisher:
ISBN:
Category :
Languages : en
Pages : 476
Get Book Here
Book Description
Author: Sanjeev Sharma
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Yutichai Mueanngern
Publisher:
ISBN:
Category :
Languages : en
Pages : 70
Get Book Here
Book Description
In this thesis we studied the kinetics of crotonaldehyde hydrogenation on a series of Pt-cerium oxide and Pt-titanium dioxide catalysts to elucidate some mechanistic aspects of partial hydrogenation processes, which occurs on bi-functional catalyst systems. Studies in the literature have shown that the C=O bond hydrogenation of unsaturated aldehydes, more specifically of the crotonaldehyde species, only occurs when a platinum/metal-oxide interface exist, and does not occur on pure platinum or metal oxide surfaces. The mechanism of this process and the determination of the active site of crotonaldehyde have never been investigated. Because the presence of Pt/metal-oxide interfaces lead to this selective C=O bond hydrogenation, the active site is hypothesized to occur on the platinum/metal-oxide interface. However, possibilities of the active site being at the platinum sites or scaling with the metal-oxide sites remains. In this study we show that the active site occurs on the platinum within some distance from the interface of the two phases. We also show in this study that within a region of cerium oxide nanocubes which are uniformly packed on a platinum surface there exist no C=O bond activity, however at the interface between rafts of cerium oxide nanoparticles there exhibits significant enhancements to the C=O bond product. These results provide strong evidence that the chemistry for this C=O bond pathway extends beyond the three phase boundary of the platinum/metal-oxide alone. The results from this study provide insight into fundamental design parameters for designing highly selective bi-functional nanocatalysts.
Author: Frank E. Herkes
Publisher: CRC Press
ISBN: 9780824719296
Category : Science
Languages : en
Pages : 676
Get Book Here
Book Description
Documents up-to-date developments in the study of catalysis and its applications to organic synthesis and industrial processes. The text examines the area of homogenous and heterogenous catalysis for industrial and pharmaceutical chemicals, focusing on recent advances in asymmetric synthesis, environmental uses, acid-based synthesis, hydrogenation, oxidation, alkylation, isomerization, amination, hydroformlyation, and more.
Author: L. Cervený
Publisher: Elsevier
ISBN: 0080960618
Category : Technology & Engineering
Languages : en
Pages : 705
Get Book Here
Book Description
The collection of contributions in this volume presents the most up-to-date findings in catalytic hydrogenation. The individual chapters have been written by 36 top specialists each of whom has achieved a remarkable depth of coverage when dealing with his particular topic. In addition to detailed treatment of the most recent problems connected with catalytic hydrogenations, the book also contains a number of previously unpublished results obtained either by the authors themselves or within the organizations to which they are affiliated.Because of its topical and original character, the book provides a wealth of information which will be invaluable not only to researchers and technicians dealing with hydrogenation, but also to all those concerned with homogeneous and heterogeneous catalysis, organic technology, petrochemistry and chemical engineering.
