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Hydrogenation Processes (hydrogenation + process)

Distribution by Scientific Domains
Polymers and Materials Science40%
Chemistry40%

Selected Abstracts

Graphene Shape Control by Multistage Cutting and Transfer

ADVANCED MATERIALS, Issue 44 2009
Lijie Ci
Cutting graphene by a catalytic hydrogenation process can generate graphene pieces with smooth edges of atomic precision and well-defined shapes. Controlled cutting of graphene by creating graphene step edges by oxidation or plasma etching is demonstrated. A combination of cutting, transfer, and lithography is shown to allow the fabrication of isolated graphene devices with specific edge and shape control. [source]

Integration of methanation into the hydrogenation process of benzoic acid

AICHE JOURNAL, Issue 1 2009
Baoning Zong
Abstract The traditional industrial process for hydrogenation of benzoic acid to cyclohexanecarboxylic acid (CCA) has drawbacks of low-activity and fast deactivation of the Pd/C catalyst due to the poisoning of CO arising from the decarboxylation of CCA. A novel rapidly quenched skeletal NiCrFe promoter (RQ NiCrFe) is developed for the methanation of CO to harmless CH4. Evaluations in bench-scale autoclave and in traditional industrial equipment verified that RQ NiCrFe was very effective in promoting the activity of the Pd/C catalyst in the hydrogenation of benzoic acid. In order to solve the catalyst recycle and separation problem introduced by RQ NiCrFe, the industrial process was modified by incorporating a hydraulic cyclone and a magnetic separator to the separation unit. The modified process showed merits of lower costs of catalyst and operation, higher productivity, and better product purity than the traditional process. © 2008 American Institute of Chemical Engineers AIChE J, 2009 [source]

Numerical investigation of continuous processes for catalytic hydrogenation of nitrile butadiene rubber

POLYMER ENGINEERING & SCIENCE, Issue 5 2002
Qinmin Pan
Dynamic behavior of continuous processes was numerically investigated for the catalytic hydrogenation of nitrile butadiene rubber, based on developed models, which took into account the coupling between kinetics and mass transfer. The evolution of hydrogenation reaction trajectories in both cases were analyzed. It is proposed that the coupling behavior between the catalytic hydrogenation and mass transfer was completely determined by the ability of the catalyst in activating hydrogen, carbon-carbon double bond loading level and the relative capacity of reaction to mass transfer as well as the residence time in the reactor. Four dimensionless parameters were derived to characterize these aspects. The effects of operation conditions on the hydrogenation processes were investigated. The application of the ideal flow models to non-ideal flows was in addition discussed. It is suggested that the optimal reactor for such a hydrogenation system would be a plug flow reactor with an instantaneous well-mixing component in the inlet of it, and a reasonable approach to the proposed optimal reactor should be with the flow behavior of at least three continuous stirred tank reactors in series. Further research directions are suggested. [source]

A Single Catalyst for Sequential Reactions: Dual Homogeneous and Heterogeneous Behavior of Palladium Nanoparticles in Solution

CHEMCATCHEM, Issue 2 2009
Susanna Jansat Dr.
One becomes two: Palladium nanoparticles stabilized by ionic liquids are used as the sole catalytic precursors for sequential Heck and hydrogenation processes. The dual role of these systems, which act as both a heterogeneous catalyst and also as a reservoir of catalytically active molecular species, is investigated. [source]

Hydrogenation for Low Trans and High Conjugated Fatty Acids

COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 1 2005
Eun Seok Jang
ABSTRACT Hydrogenated vegetable oils contain of trans fatty acids. Because of the increased health concern about trans fatty acids, new hydrogenations have been studied to seek ways for substantial reduction of the trans fatty acids in the hydrogenated vegetable oils. This paper reviews new hydrogenation processes such as electrocatalytic hydrogenation, precious catalyst hydrogenation, and supercritical fluid state hydrogen, which have shown promising results for the reduction of trans fatty acids below the level of 8%. This paper also reviews the recently introduced hydeogenation technique for high accumulation of conjugated linoleic acids, beneficiary functional components. The hydrogenated vegetable oils with high quantity conjugated linoleic acid might provide the possibility for the utilization of hydrogenated oils as health-prompting food ingredients. [source]