dehydrogenation

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dehydrogenation

[dē¦hī·drə·jə′nā·shən]
(chemistry)
Removal of hydrogen from a compound.

Dehydrogenation

A reaction in which hydrogen is detached from a molecule. The reaction is strongly endothermic, and therefore heat must be supplied to maintain the reaction temperature. When the detached hydrogen is immediately oxidized, two benefits accrue: (1) the conversion of reactants to products is increased because the equilibrium concentration is shifted toward the products (law of mass action); and (2) the added exothermic oxidation reaction supplies the needed heat of reaction. This process is called oxidative dehydrogenation. On the other hand, excess hydrogen is sometimes added to a dehydrogenation reaction in order to diminish the complete breakup of the molecule into many fragments.

The primary types of dehydrogenation reactions are vapor-phase conversion of primary alcohols to aldehydes, vapor-phase conversion of secondary alcohols to ketones, dehydrogenation of a side chain, and catalytic reforming of naphthas and naphthenes in the presence of a platinum catalyst. All four of these types of dehydrogenation reactions are of major industrial importance. They account for the production of billions of pounds of organic compounds that enter into the manufacture of lubricants, explosives, plastics, plasticizers, and elastomers.

References in periodicals archive ?
The clay used was Cloisite 20A, which is a montmorillonite modified by dimethyl, dehydrogenated tallow, quaternary ammonium.
was modified with 2M2HT (dimethyl, dehydrogenated tallow, quaternary ammonium chloride) with a concentration of 125 mEq/100 g clay (22).
The presence of a higher concentration of the organo-modifier (dimethyl, dehydrogenated tallow, and quaternary ammonium) in the 15A clay (125 meq/100 g clay) also increases its reddish rate in comparison to the 20A clay (95 meq/100 g clay).
Cloisite "20A, manufactured by Southern Clay Products, is a natural montmorillonite modified with dimethyl dehydrogenated tallow quaternary ammonium chloride.
The clay (Cloisite 20A, Southern Clay Products) was a montmorillonite modified with dimethyl dehydrogenated tallow quaternary ammonium chloride.
The fillers were three montmorillonites (OMMTs) organically modified with dimethyl dehydrogenated tallow quaternary ammonium (Cloisite [R] 20A, Southern Clay Products), octadecylamine (Nanomer [R] 130 TC, Nanocor), and bis-2-hydroxyethyl methyl tallow quaternary ammonium (Cloisite "1 30B, Southern Clay Products) that have a cation exchange capacity of 90, 145, and 95 meq/100 g.
The surface modified clays are produced commercially by the substitution of interlayer sodium cations by dimethyl, dehydrogenated tallow or methyl, tallow, bis-2-hydroxyethyl quaternary ammonium cations for Cloisite 20A and 30B, respectively.