A Study of Selective Hydrogenation of [alpha], [beta]-unsaturated Aldehyde in Three Phase Reactors

A Study of Selective Hydrogenation of [alpha], [beta]-unsaturated Aldehyde in Three Phase Reactors PDF Author: Wanida Koo-Amornpattana
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Languages : en
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A Study of Selective Hydrogenation of [alpha], [beta]-unsaturated Aldehyde in Three Phase Reactors

A Study of Selective Hydrogenation of [alpha], [beta]-unsaturated Aldehyde in Three Phase Reactors PDF Author: Wanida Koo-Amornpattana
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Category :
Languages : en
Pages :

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A Study of Selective Hydrogenation of Α,β-unsaturated Aldehyde in Three Phase Reactors

A Study of Selective Hydrogenation of Α,β-unsaturated Aldehyde in Three Phase Reactors PDF Author: Wanida Koo-Amornpattana
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Category : Chemical engineering
Languages : en
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Selective Hydrogenation of [alpha], [beta][alpha, Beta]-unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors

Selective Hydrogenation of [alpha], [beta][alpha, Beta]-unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors PDF Author: Laiqi Zhang
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Languages : en
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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 Α,β[alpha,beta]-unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors

Selective Hydrogenation of Α,β[alpha,beta]-unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors PDF Author: Laiqi Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages :

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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

Selective Hydrogenation of [Alpha], [Beta]-unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors PDF Author: Lai Qi Zhang
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ISBN:
Category :
Languages : en
Pages :

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A Study of the Selective Hydrogenation of 2-butyne-1, 4-diol in Various Forms of Three-phase Reactor

A Study of the Selective Hydrogenation of 2-butyne-1, 4-diol in Various Forms of Three-phase Reactor PDF Author: Marwan
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ISBN:
Category :
Languages : en
Pages : 476

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Selective Hydrogenation of Multifunctional Organic Reactants in Three Phase Reactors

Selective Hydrogenation of Multifunctional Organic Reactants in Three Phase Reactors PDF Author: Sanjeev Sharma
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Category :
Languages : en
Pages :

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Selective Hydrogenation of [alpha]-[beta] Unsaturated Aldehydes Over Ir Catalysts

Selective Hydrogenation of [alpha]-[beta] Unsaturated Aldehydes Over Ir Catalysts PDF Author: J. Gomez-Lopez
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ISBN:
Category :
Languages : en
Pages : 0

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Selective Hydrogenation of [alpha],[beta]-unsaturated Aldehydes Over Metal Catalysts

Selective Hydrogenation of [alpha],[beta]-unsaturated Aldehydes Over Metal Catalysts PDF Author: Thomas Balder Ludwig Wolfgang Marinelli
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ISBN: 9789090067216
Category :
Languages : en
Pages : 129

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British National Bibliography for Report Literature

British National Bibliography for Report Literature PDF Author:
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ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 84

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