Kinetic investigations on the modified chitosan catalyzed solvent-free synthesis of jasminaldehyde

Sudheesh, N.; Sharma, Sumeet K.; Khokhar, Munir D.; Shukla, Ram S.

doi:10.1016/j.molcata.2011.02.016

Cited by 21 publications

(9 citation statements)

References 23 publications

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“…It is noteworthy that the W‐W value (ηϕ 2 ) for the reactants on the CuSi/monolith are all significantly lower than 0.1, implying the internal mass transfer is negligible. It agrees with the results reported by Oh et al,54 and Hayes et al52, 69 that the molecular diffusion in the wash‐coat does not affect the reaction rate, when the thickness is lower than 50 μm. In our case, the wash‐coat thickness of the monolith is within this range.…”

Section: Stability Testsupporting

confidence: 92%

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Hydrogenation of dimethyl oxalate to ethylene glycol on a Cu/SiO₂/cordierite monolithic catalyst: Enhanced internal mass transfer and stability

et al. 2011

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in Wiley Online Library (wileyonlinelibrary.com).The design and application of a Cu/SiO 2 -based monolithic catalyst for hydrogenation of dimethyl oxalate (DMO) to ethylene glycol (EG) is presented. The catalyst was dip-coated on cordierite with highly dispersed Cu/SiO 2 slurry prepared by ammonia evaporation method. This structure guarantees high dispersion of copper species within the mesopores of silica matrix in the form of copper phyllosilicate. The catalyst is low cost, stable, and exhibits high activity in the reaction of hydrogenation of DMO, achieving a 100% conversion of DMO and more than 95% selectivity to EG. Notably, STY EG over the monolith is significantly enhanced compared to the packed bed Cu/SiO 2 catalysts in both forms of pellet and cylinder. It is primarily due to the relatively short diffusive pathway of the thin wash-coat layer and high efficiency of the active phase derived from the monolithic catalyst. Theoretical results indicated that the internal mass transfer is dominated on the catalysts of pellet and cylinders. Moreover, the monolithic catalyst possessed excellent thermal stability compared to the pellet catalyst, which is attributed to the regular channel structure, uniform distribution of flow. Catalytic activity testsOur catalytic reactivity system (monolithic fixed-bed MRCS8004B System) (shown in Figure 1) consists of a continuous-flow stainless steel reactor (15 mm i.d. and 350 mm length) inside a horizontal furnace with a temperature controller. The gas distributor has been equipped at the entrance of the reactor to ensure a uniform gas distribution. The monolithic Cu/SiO 2 catalysts were placed in the middle of the (a) scheme of monolith catalyst, (b) SEM images of a monolith channel, and (c) cross-sectional cordierite monolith wash-coated with Cu/SiO2 catalyst, and (d) TEM image of calcined wash-coat layer.

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Section: Stability Testsupporting

confidence: 92%

“…The W‐W group has been reported41, 47, 52–54 to investigate the influence of internal diffusion. When the value of ηϕ 2 is less than 0.1, the effect of the internal mass transfer of the reactant on the reaction rate can be neglected 55, 56.…”

Section: Methodsmentioning

confidence: 99%

Hydrogenation of dimethyl oxalate to ethylene glycol on a Cu/SiO₂/cordierite monolithic catalyst: Enhanced internal mass transfer and stability

et al. 2011

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“…So far, in silico data were presented and, therefore, it is of interest to link the reported results with some literature data. Some excellent references on experimental work can be mentioned [12,14,15,16]. In this report, two examples are addressed where alcohols were also used as solvent.…”

Section: Resultsmentioning

confidence: 99%

“…This work uses the reaction of benzaldehyde and 1-heptanal, which is an important aldol condensation reaction, in the production of α-pentyl cinnamaldehyde, as a test case. This fine chemical compound of jasmine odor is also known as ‘jasmine aldehyde’ and it is widely applied in the perfume industries [10,11,12,13]. Excellent experimental reports can be found in literature [12,14,15,16,17], see also Appendix A.…”

Section: Introductionmentioning

confidence: 99%

Activity Coefficients for Liquid Organic Reactions: Towards a Better Understanding of True Kinetics with the Synthesis of Jasmin Aldehyde as Showcase

Heynderickx

2019

IJMS

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The aldol condensation of benzaldehyde and heptanal is taken as an example of reversible liquid phase organic reactions to show that inclusion of activity coefficients reveal distinct differences in conversion and product distribution when different solvents methanol, ethanol, n-propanol, or n-butanol are used. The purpose of this work is to show a pronounced solvent effect for a given set of identical kinetic parameters, i.e., the same liquid phase kinetics can result in different conversion and yield values, depending on the choice of solvent. It was shown that subsequent parameter estimation without inclusion of the activity coefficients resulted in a pronounced deviation from the ‘true’ kinetics, up to a factor of 30. It is proposed that the usage of average activity coefficients gives already a significant improvement, resulting in acceptable parameter estimates.

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“…The conversion and the selectivity were temperature dependent, increasing, for instance, from 13 % conversion at 100 8C after 2 h to 78 % conversion at 160 8C after 2 h. The amount of catalyst and the benzaldehyde/ heptanal ratio both had an impact on the conversion and selectivity; the optimal heptanal/benzaldehyde ratio was 1:5, which afforded 99 % conversion and 84 % selectivity. [113] The tested catalyst could be recycled five times with a slight decrease in activity. However, considering the high temperature at which the reaction operates, in this special case, the recyclability does not reflect the intactness of the polymeric catalyst skeleton and does not rule out the possible formation of aminated carbonaceous materials.…”

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confidence: 99%

Chitosan as a Sustainable Organocatalyst: A Concise Overview

Kadib

2014

ChemSusChem

205

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Increased demand for more sustainable materials and chemical processes has tremendously advanced the use of polysaccharides, which are natural biopolymers, in domains such as adsorption, catalysis, and as an alternative chemical feedstock. Among these biopolymers, the use of chitosan, which is obtained by deacetylation of natural chitin, is on the increase due to the presence of amino groups on the polymer backbone that makes it a natural cationic polymer. The ability of chitosan-based materials to form open-network, macroporous, high-surface-area hydrogels with accessible basic surface sites has enabled their use not only as macrochelating ligands for active metal catalysts and as a support to disperse nanosized particles, but also as a direct organocatalyst. This review provides a concise overview of the use of native and modified chitosan, possessing different textural properties and chemical properties, as organocatalysts. Organocatalysis with chitosan is primarily focused on carbon-carbon bond-forming reactions, multicomponent heterocycle formation reactions, biodiesel production, and carbon dioxide fixation through [3+2] cycloaddition. Furthermore, the chiral, helical organization of the chitosan skeleton lends itself to use in enantioselective catalysis. Chitosan derivatives generally display reactivity similar to homogeneous bases, ionic liquids, and organic and inorganic salts. However, the introduction of cooperative acid-base interactions at active sites substantially enhances reactivity. These functional biopolymers can also be easily recovered and reused several times under solvent-free conditions. These accomplishments highlight the important role that natural biopolymers play in furthering more sustainable chemistry.

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Kinetic investigations on the modified chitosan catalyzed solvent-free synthesis of jasminaldehyde

Cited by 21 publications

References 23 publications

Hydrogenation of dimethyl oxalate to ethylene glycol on a Cu/SiO₂/cordierite monolithic catalyst: Enhanced internal mass transfer and stability

Hydrogenation of dimethyl oxalate to ethylene glycol on a Cu/SiO₂/cordierite monolithic catalyst: Enhanced internal mass transfer and stability

Activity Coefficients for Liquid Organic Reactions: Towards a Better Understanding of True Kinetics with the Synthesis of Jasmin Aldehyde as Showcase

Chitosan as a Sustainable Organocatalyst: A Concise Overview

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Kinetic investigations on the modified chitosan catalyzed solvent-free synthesis of jasminaldehyde

Cited by 21 publications

References 23 publications

Hydrogenation of dimethyl oxalate to ethylene glycol on a Cu/SiO2/cordierite monolithic catalyst: Enhanced internal mass transfer and stability

Hydrogenation of dimethyl oxalate to ethylene glycol on a Cu/SiO2/cordierite monolithic catalyst: Enhanced internal mass transfer and stability

Activity Coefficients for Liquid Organic Reactions: Towards a Better Understanding of True Kinetics with the Synthesis of Jasmin Aldehyde as Showcase

Chitosan as a Sustainable Organocatalyst: A Concise Overview

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Product

Resources

About

Hydrogenation of dimethyl oxalate to ethylene glycol on a Cu/SiO₂/cordierite monolithic catalyst: Enhanced internal mass transfer and stability

Hydrogenation of dimethyl oxalate to ethylene glycol on a Cu/SiO₂/cordierite monolithic catalyst: Enhanced internal mass transfer and stability